1,041 results on '"Spines"'
Search Results
2. Cerebrolysin treatment improved short-term memory deficits while simultaneously increasing hippocampal spine density in hypertensive female rats
- Author
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Espinoza, Ivette, Gómez-Villalobos, Ma de Jesús, Aguilar-Hernández, Leonardo, Flores, Gonzalo, and Morales-Medina, Julio César
- Published
- 2025
- Full Text
- View/download PDF
3. Comprehensive software suite for functional analysis and synaptic input mapping of dendritic spines imaged in vivo.
- Author
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Yu, Yiyi, Adsit, Liam, and Smith, Ikuko
- Subjects
cross-session alignment ,dendrites ,input mapping ,point-cloud registration ,spine turnover ,spines - Abstract
SIGNIFICANCE: Advances in genetically encoded sensors and two-photon imaging have unlocked functional imaging at the level of single dendritic spines. Synaptic activity can be measured in real time in awake animals. However, tools are needed to facilitate the analysis of the large datasets acquired by the approach. Commonly available software suites for imaging calcium transients in cell bodies are ill-suited for spine imaging as dendritic spines have structural characteristics distinct from those of the cell bodies. We present an automated tuning analysis tool (AUTOTUNE), which provides analysis routines specifically developed for the extraction and analysis of signals from subcellular compartments, including dendritic subregions and spines. AIM: Although the acquisition of in vivo functional synaptic imaging data is increasingly accessible, a hurdle remains in the computation-heavy analyses of the acquired data. The aim of this study is to overcome this barrier by offering a comprehensive software suite with a user-friendly interface for easy access to nonprogrammers. APPROACH: We demonstrate the utility and effectiveness of our software with demo analyses of dendritic imaging data acquired from layer 2/3 pyramidal neurons in mouse V1 in vivo. A user manual and demo datasets are also provided. RESULTS: AUTOTUNE provides a robust workflow for analyzing functional imaging data from neuronal dendrites. Features include source image registration, segmentation of regions-of-interest and detection of structural turnover, fluorescence transient extraction and smoothing, subtraction of signals from putative backpropagating action potentials, and stimulus and behavioral parameter response tuning analyses. CONCLUSIONS: AUTOTUNE is open-source and extendable for diverse functional synaptic imaging experiments. The ease of functional characterization of dendritic spine activity provided by our software can accelerate new functional studies that complement decades of morphological studies of dendrites, and further expand our understanding of neural circuits in health and in disease.
- Published
- 2024
4. Abdominal Spines on an Amazonian Spiny Spider (Micrathena schreibersi): A Defense Against Mud‐Dauber Wasps (Sceliphron spp.) Attack?
- Author
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Almeida, João Gabriel Lacerda, Oliveira, Larissa Lotti, and Cola, Carine Mariá
- Subjects
- *
SPIDER behavior , *FORAGING behavior , *WASPS , *SPIDERS , *SPINE - Abstract
ABSTRACT The conspicuous abdominal spines in females of Micrathena spiders have evolved independently in several species within the genus. Like other orb‐web spiders, Micrathena species can serve as prey to parasitoid mud‐dauber wasps, which paralyzes the spiders and inserts them into their nests to serve as food to their larvae. Based on this fact, some studies suggest that Micrathena spines evolved as an antipredator defense against the wasp. However, there is no direct evidence of how the spines could act to avoid the wasp behavior. Here, we present two distinct records involving an Amazonian species of spiny spider, Micrathena schreibersi, where the abdominal spines act as a mechanical barrier against mud‐dauber wasps (Sceliphron spp.). These spines prevented the wasps from completely inserting the paralyzed spiders into their tubular nests, forcing the wasps to alter the opening shape to close it. In our second record, the wasp was not able to completely close the nest, leading to predation of her offspring by ants. We discuss the ecological implications of this potential defense trait for both species and propose future hypotheses to further elucidate how these spines may have evolved based on the foraging behavior of mud‐dauber wasps. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Are Cactus Spines Modified Leaves? Morphological and Anatomical Characterization of Saguaro Seedlings (Carnegiea gigantea) with Special Focus on Aerial Organ Primordia.
- Author
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Miravel-Gabriel, Cristina Betzabeth, Koeth, Ryan, Marsch-Martínez, Nayelli, and Hernández-Hernández, Tania
- Subjects
MORPHOGENESIS ,GENETIC models ,ENDANGERED species ,SPINE ,MERISTEMS ,CACTUS - Abstract
The reduction of leaves was a key event in the evolution of the succulent syndrome in Cactaceae, evolving from large, photosynthetic leaves in Pereskia to nearly suppressed microscopic foliar buds in succulent Cactoideae. This leaf reduction was accompanied by the development of spines. Early histological studies, dating back a century, of the shoot apical meristem (SAM) in several species concluded that, in succulent cacti, axillary buds became areoles and leaves transformed into spines. However, these conclusions were based on limited observations, given the challenges of obtaining SAM samples from long-lived, often endangered species. Here, we present a complete study of early aerial organ development in seedlings of the iconic Carnegiea gigantea (saguaro), characterizing the different stages of seedling development. We focus on the SAM to track the emergence and development of primordia and aerial organs, closely following the spine development from undifferentiated structures. We demonstrate that young, few-days-old saguaro seedlings provide a valuable model for morpho-anatomical and molecular studies in Cactaceae. We also outline optimal laboratory practices for germinating saguaro seeds and conducting histological studies. Our observations confirm the absence of clear foliar structures and the presence of a distinct type of primordia, hypothesized to be foliar but lacking definitive foliar features. Based on our observations and a review of the literature, we revive the discussion on the ontogenetic origin of spines and propose saguaro seedlings as a promising model for studying the genetic identity of SAM primordia. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. MCU expression in hippocampal CA2 neurons modulates dendritic mitochondrial morphology and synaptic plasticity
- Author
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Katy E. Pannoni, Quentin S. Fischer, Renesa Tarannum, Mikel L. Cawley, Mayd M. Alsalman, Nicole Acosta, Chisom Ezigbo, Daniela V. Gil, Logan A. Campbell, and Shannon Farris
- Subjects
Mitochondrial calcium uniporter ,Hippocampal CA2 ,Synaptic plasticity ,Mitochondria ,Dendrites ,Spines ,Medicine ,Science - Abstract
Abstract Neuronal mitochondria are diverse across cell types and subcellular compartments in order to meet unique energy demands. While mitochondria are essential for synaptic transmission and synaptic plasticity, the mechanisms regulating mitochondria to support normal synapse function are incompletely understood. The mitochondrial calcium uniporter (MCU) is proposed to couple neuronal activity to mitochondrial ATP production, which would allow neurons to rapidly adapt to changing energy demands. MCU is uniquely enriched in hippocampal CA2 distal dendrites compared to proximal dendrites, however, the functional significance of this layer-specific enrichment is not clear. Synapses onto CA2 distal dendrites readily express plasticity, unlike the plasticity-resistant synapses onto CA2 proximal dendrites, but the mechanisms underlying these different plasticity profiles are unknown. Using a CA2-specific MCU knockout (cKO) mouse, we found that MCU deletion impairs plasticity at distal dendrite synapses. However, mitochondria were more fragmented and spine head area was diminished throughout the dendritic layers of MCU cKO mice versus control mice. Fragmented mitochondria might have functional changes, such as altered ATP production, that could explain the structural and functional deficits at cKO synapses. Differences in MCU expression across cell types and circuits might be a general mechanism to tune mitochondrial function to meet distinct synaptic demands.
- Published
- 2025
- Full Text
- View/download PDF
7. Integrated Morphological, Comparative Transcriptomic, and Metabolomic Analyses Reveal Mechanisms Underlying Seasonal Patterns of Variation in Spines of the Giant Spiny Frog (Quasipaa spinosa).
- Author
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Wan, Gang, Jiang, Ze-Yuan, Shi, Nuo, Xiong, Yi-Ge, and Zheng, Rong-Quan
- Subjects
- *
SEXUAL cycle , *MELANOGENESIS , *WILDLIFE conservation , *WNT signal transduction , *SEXUAL dimorphism - Abstract
Quasipaa spinosa, commonly known as the spiny frog, is an economically valued amphibian in China prized for its tender meat and nutritional value. This species exhibits marked sexual dimorphism, most notably the prominent spiny structures on males that are pivotal for mating success and species identification. The spines of Q. spinosa exhibit strong seasonal variation, changing significantly with the reproductive cycle, which typically spans from April to October. Sexually mature males develop densely packed, irregularly arranged round papillae with black spines on their chests during the breeding season, which may then reduce or disappear afterward, while females have smooth chest skin. Despite their ecological importance, the developmental mechanisms and biological functions of these spines have been inadequately explored. This study integrates morphological, transcriptomic, and metabolomic analyses to elucidate the mechanisms underlying the seasonal variation in spine characteristics of Q. spinosa. Our results demonstrate that spine density inversely correlates with body size and that spine development is accompanied by significant changes in epidermal thickness and keratinization during the breeding season. Comparative transcriptomic analysis across different breeding stages revealed significant gene expression alterations in pathways related to extracellular matrix interactions, tyrosine metabolism, Wnt signaling, and melanogenesis. Metabolomic analysis further identified significant seasonal shifts in metabolites essential for energy metabolism and melanin synthesis, including notable increases in citric acid and β-alanine. These molecular changes are consistent with the observed morphological adaptations, suggesting a complex regulatory mechanism supporting spine development and functionality. This study provides novel insights into the molecular basis of spine morphogenesis and its seasonal dynamics in Q. spinosa, contributing valuable information for the species' conservation and aquaculture. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. The plasticity of pyramidal neurons in the behaving brain.
- Author
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Regele-Blasco, Elena and Palmer, Lucy M.
- Subjects
- *
PYRAMIDAL neurons , *LONG-term potentiation , *NEUROPLASTICITY , *DENDRITES , *COMPUTER performance - Abstract
Neurons are plastic. That is, they change their activity according to different behavioural conditions. This endows pyramidal neurons with an incredible computational power for the integration and processing of synaptic inputs. Plasticity can be investigated at different levels of investigation within a single neuron, from spines to dendrites, to synaptic input. Although most of our knowledge stems from the in vitro brain slice preparation, plasticity plays a vital role during behaviour by providing a flexible substrate for the execution of appropriate actions in our ever-changing environment. Owing to advances in recording techniques, the plasticity of neurons and the neural networks in which they are embedded is now beginning to be realized in the in vivo intact brain. This review focuses on the structural and functional synaptic plasticity of pyramidal neurons, with a specific focus on the latest developments from in vivo studies. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Ancestral reproductive bias in continuous-time branching trees under various sampling schemes.
- Author
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Igelbrink, Jan Lukas and Ischebeck, Jasper
- Abstract
Cheek and Johnston (JMB 86:70, 2023) consider a continuous-time Bienaymé-Galton-Watson tree conditioned on being alive at time T. They study the reproduction events along the ancestral lineage of an individual randomly sampled from all those alive at time T. We give a short proof of an extension of their main results (Cheek and Johnston in JMB 86:70, 2023, Theorems 2.3 and 2.4) to the more general case of Bellman-Harris processes. Our proof also sheds light onto the probabilistic structure of the rate of the reproduction events. A similar method will be applied to explain (i) the different ancestral reproduction bias appearing in work by Geiger (JAP 36:301–309, 1999) and (ii) the fact that the sampling rule considered by Chauvin et al. (SPA 39:117–130, 1991), (Theorem 1) leads to a time homogeneous process along the ancestral lineage. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Morphological Characterization of Opuntia Accessions from Tenerife (Canary Islands, Spain) Using UPOV Descriptors.
- Author
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Díaz-Delgado, Goretti L., Rodríguez-Rodríguez, Elena M., Ríos, Domingo, Cano, María Pilar, and Lobo, María Gloria
- Subjects
CULTIVARS ,DISCRIMINANT analysis ,CLUSTER analysis (Statistics) ,OPUNTIA ,PEARS ,OPUNTIA ficus-indica - Abstract
Twenty Opuntia accessions from Tenerife (Canary Islands, Spain) were classified according to 52 quantitative and qualitative descriptors, including the traits of the cladodes, flowers, fruits, and spines, as described by the International Union for the Protection of New Varieties of Plants (UPOV) guidelines. A database composed of 20 accessions and 52 traits was used to perform a cluster analysis based on the Euclidian distance and Ward's method and a canonical discriminant analysis. In terms of the analyzed characteristics, cactus pears with orange flesh showed less variability than cactus pears with white or purple flesh. Good classifications according to fruit flesh color were obtained using discriminant analysis. As a result of the cluster analysis, Opuntia plant accessions with white, orange, or purple-fleshed fruits were classified into four homogeneous groups according to the cubic clustering criteria. This study proves that it was possible to make a preliminary classification of Opuntia varieties from the Canary Islands based on a few main morphological characteristics. To improve the classification, a molecular analysis of the different Opuntia plants is necessary. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Are Cactus Spines Modified Leaves? Morphological and Anatomical Characterization of Saguaro Seedlings (Carnegiea gigantea) with Special Focus on Aerial Organ Primordia
- Author
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Cristina Betzabeth Miravel-Gabriel, Ryan Koeth, Nayelli Marsch-Martínez, and Tania Hernández-Hernández
- Subjects
Cactaceae ,saguaro ,cactus development ,aerial organ primordia ,spines ,areole ,Botany ,QK1-989 - Abstract
The reduction of leaves was a key event in the evolution of the succulent syndrome in Cactaceae, evolving from large, photosynthetic leaves in Pereskia to nearly suppressed microscopic foliar buds in succulent Cactoideae. This leaf reduction was accompanied by the development of spines. Early histological studies, dating back a century, of the shoot apical meristem (SAM) in several species concluded that, in succulent cacti, axillary buds became areoles and leaves transformed into spines. However, these conclusions were based on limited observations, given the challenges of obtaining SAM samples from long-lived, often endangered species. Here, we present a complete study of early aerial organ development in seedlings of the iconic Carnegiea gigantea (saguaro), characterizing the different stages of seedling development. We focus on the SAM to track the emergence and development of primordia and aerial organs, closely following the spine development from undifferentiated structures. We demonstrate that young, few-days-old saguaro seedlings provide a valuable model for morpho-anatomical and molecular studies in Cactaceae. We also outline optimal laboratory practices for germinating saguaro seeds and conducting histological studies. Our observations confirm the absence of clear foliar structures and the presence of a distinct type of primordia, hypothesized to be foliar but lacking definitive foliar features. Based on our observations and a review of the literature, we revive the discussion on the ontogenetic origin of spines and propose saguaro seedlings as a promising model for studying the genetic identity of SAM primordia.
- Published
- 2024
- Full Text
- View/download PDF
12. Rise and fall of a continental mesic radiation in Australia: spine evolution, biogeography, and diversification of Cryptandra (Rhamnaceae: Pomaderreae).
- Author
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Nge, Francis J, Kellermann, Jürgen, Biffin, Ed, Thiele, Kevin R, and Waycott, Michelle
- Subjects
- *
BIOGEOGRAPHY , *SPINE , *NUCLEOTIDE sequencing , *RADIATION , *VICARIANCE , *PHYLOGEOGRAPHY - Abstract
The Australian continent has experienced progressive aridification since the Miocene, spurring recent radiations of arid-adapted lineages and the likely decline of mesic biotic groups. While examples of the former have been relatively well-documented, post-Miocene declines of non-arid sclerophyllous floras are less well understood. Here, we present a well-sampled time-calibrated nuclear phylogeny (140 accessions representing 60/65 species) of an Australian plant genus (Cryptandra Sm.: Rhamnaceae) and using ancestral range reconstructions and diversification analyses, elucidate its evolutionary history through space and time. We used high-throughput sequencing to recover 30 orthologous nuclear loci and BioGeoBEARS to infer ancestral areas. We show that the present-day distribution of Cryptandra can be explained by multiple vicariance events followed by in situ diversification with little exchange between regions. All diversification models show a speciation rate decline in Cryptandra after its radiation in the Miocene (c. 23 Mya). This coincides with aridification episodes across Australia and indicates that diversification of this genus has been negatively affected by the expansion of aridity. We also show that there were no significant differences in diversification rates between spinescent and non-spinescent Cryptandra lineages, suggesting that spinescent lineages may be the legacies of selection from extinct megaherbivores. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Comprehensive software suite for functional analysis and synaptic input mapping of dendritic spines imaged in vivo.
- Author
-
Yiyi Yu, Adsit, Liam M., and Smith, Ikuko T.
- Subjects
DENDRITES ,FUNCTIONAL imaging sensors ,DENDRITIC spines ,SYNAPSES ,NEURAL circuitry - Abstract
Significance: Advances in genetically encoded sensors and two-photon imaging have unlocked functional imaging at the level of single dendritic spines. Synaptic activity can be measured in real time in awake animals. However, tools are needed to facilitate the analysis of the large datasets acquired by the approach. Commonly available software suites for imaging calcium transients in cell bodies are ill-suited for spine imaging as dendritic spines have structural characteristics distinct from those of the cell bodies. We present an automated tuning analysis tool (AUTOTUNE), which provides analysis routines specifically developed for the extraction and analysis of signals from subcellular compartments, including dendritic subregions and spines. Aim: Although the acquisition of in vivo functional synaptic imaging data is increasingly accessible, a hurdle remains in the computation-heavy analyses of the acquired data. The aim of this study is to overcome this barrier by offering a comprehensive software suite with a user-friendly interface for easy access to nonprogrammers. Approach: We demonstrate the utility and effectiveness of our software with demo analyses of dendritic imaging data acquired from layer 2/3 pyramidal neurons in mouse V1 in vivo. A user manual and demo datasets are also provided. Results: AUTOTUNE provides a robust workflow for analyzing functional imaging data from neuronal dendrites. Features include source image registration, segmentation of regions-of-interest and detection of structural turnover, fluorescence transient extraction and smoothing, subtraction of signals from putative backpropagating action potentials, and stimulus and behavioral parameter response tuning analyses. Conclusions: AUTOTUNE is open-source and extendable for diverse functional synaptic imaging experiments. The ease of functional characterization of dendritic spine activity provided by our software can accelerate new functional studies that complement decades of morphological studies of dendrites, and further expand our understanding of neural circuits in health and in disease. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Clustered synapses develop in distinct dendritic domains in visual cortex before eye opening
- Author
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Alexandra H Leighton, Juliette E Cheyne, and Christian Lohmann
- Subjects
calcium imaging ,in vivo ,spines ,patch-clamp methodology ,in utero electroporation ,two-photon microscopy ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Synaptic inputs to cortical neurons are highly structured in adult sensory systems, such that neighboring synapses along dendrites are activated by similar stimuli. This organization of synaptic inputs, called synaptic clustering, is required for high-fidelity signal processing, and clustered synapses can already be observed before eye opening. However, how clustered inputs emerge during development is unknown. Here, we employed concurrent in vivo whole-cell patch-clamp and dendritic calcium imaging to map spontaneous synaptic inputs to dendrites of layer 2/3 neurons in the mouse primary visual cortex during the second postnatal week until eye opening. We found that the number of functional synapses and the frequency of transmission events increase several fold during this developmental period. At the beginning of the second postnatal week, synapses assemble specifically in confined dendritic segments, whereas other segments are devoid of synapses. By the end of the second postnatal week, just before eye opening, dendrites are almost entirely covered by domains of co-active synapses. Finally, co-activity with their neighbor synapses correlates with synaptic stabilization and potentiation. Thus, clustered synapses form in distinct functional domains presumably to equip dendrites with computational modules for high-capacity sensory processing when the eyes open.
- Published
- 2024
- Full Text
- View/download PDF
15. Cortex-restricted deletion of Foxp1 impairs barrel formation and induces aberrant tactile responses in a mouse model of autism
- Author
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Xue Li, Shishuai Hao, Shimin Zou, Xiaomeng Tu, Weixi Kong, Tian Jiang, and Jie-Guang Chen
- Subjects
Autism ,Tactile ,Barrel cortex ,Thalamocortical ,c-Fos ,Spines ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Many children and young people with autism spectrum disorder (ASD) display touch defensiveness or avoidance (hypersensitivity), or engage in sensory seeking by touching people or objects (hyposensitivity). Abnormal sensory responses have also been noticed in mice lacking ASD-associated genes. Tactile sensory information is normally processed by the somatosensory system that travels along the thalamus to the primary somatosensory cortex. The neurobiology behind tactile sensory abnormalities, however, is not fully understood. Methods We employed cortex-specific Foxp1 knockout (Foxp1-cKO) mice as a model of autism in this study. Tactile sensory deficits were measured by the adhesive removal test. The mice’s behavior and neural activity were further evaluated by the whisker nuisance test and c-Fos immunofluorescence, respectively. We also studied the dendritic spines and barrel formation in the primary somatosensory cortex by Golgi staining and immunofluorescence. Results Foxp1-cKO mice had a deferred response to the tactile environment. However, the mice exhibited avoidance behavior and hyper-reaction following repeated whisker stimulation, similar to a fight-or-flight response. In contrast to the wild-type, c-Fos was activated in the basolateral amygdala but not in layer IV of the primary somatosensory cortex of the cKO mice. Moreover, Foxp1 deficiency in cortical neurons altered the dendrite development, reduced the number of dendritic spines, and disrupted barrel formation in the somatosensory cortex, suggesting impaired somatosensory processing may underlie the aberrant tactile responses. Limitations It is still unclear how the defective thalamocortical connection gives rise to the hyper-reactive response. Future experiments with electrophysiological recording are needed to analyze the role of thalamo-cortical-amygdala circuits in the disinhibiting amygdala and enhanced fearful responses in the mouse model of autism. Conclusions Foxp1-cKO mice have tactile sensory deficits while exhibit hyper-reactivity, which may represent fearful and emotional responses controlled by the amygdala. This study presents anatomical evidence for reduced thalamocortical connectivity in a genetic mouse model of ASD and demonstrates that the cerebral cortex can be the origin of atypical sensory behaviors.
- Published
- 2023
- Full Text
- View/download PDF
16. Exploring Dendritic and Spine Structural Profiles in Epilepsy: Insights From Human Studies and Experimental Animal Models.
- Author
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Kumari, Shikha and Brewster, Amy L.
- Subjects
- *
DENDRITIC spines , *EPILEPSY in animals , *EPILEPSY , *NEURAL transmission , *ANIMAL models in research , *EIGENFUNCTIONS - Abstract
Dendrites are tree-like structures with tiny spines specialized to receive excitatory synaptic transmission. Spino-dendritic plasticity, driven by neural activity, underlies the maintenance of neuronal connections crucial for proper circuit function. Abnormalities in dendritic morphology are frequently seen in epilepsy. However, the exact etiology or functional implications are not yet known. Therefore, to better comprehend the structure-function significance of this dendritic pathology in epilepsy, it is necessary to identify the common spino-dendritic disturbances present in both human and experimental models. Here, we describe the dendritic and spine structural profiles found across human refractory epilepsy as well as in animal models of developmental, acquired, and genetic epilepsies. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Extracellular enzymatic activity of endophytic fungi isolated from spines of rattan palm (Calamus castaneus Griff.).
- Author
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Azuddin, Nurul Farizah, Mohd, Masratul Hawa, Rosely, Nik Fadzly Nik, Mansor, Asyraf, and Zakaria, Latiffah
- Subjects
ENDOPHYTIC fungi ,RATTAN palms ,SPINE physiology ,EXTRACELLULAR enzymes ,CELLULASE - Abstract
Aims: Calamus castaneus is a non-climbing rattan plant widely distributed in tropical rainforests. The sharp spines of rattan palm harbour endophytic fungi, which may produce extracellular enzymes that contribute to various functions without harming the host plant. This study was aimed to evaluate the ability of fungal endophytes isolated from the C. castaneus spines to produce extracellular enzymes, including protease, pectinase, amylase, lipase and cellulase. Methodology and results: Thirty-four (34) endophytic fungal isolates were tested for their ability to produce extracellular enzymes using the agar plate method. Enzyme activity was measured using the enzyme index (EI) by measuring the halo (clear zone) on the agar medium. The EI value indicates the strength of the enzyme produced by the endophytes. Results demonstrated that all thirty-four fungal endophytes could produce at least one extracellular enzyme. Xylaria cubensis BR90 showed the highest protease activity of 5.73 EI. Muyocopron laterale (SM60) showed the highest pectinase activity of 2.74 EI. For lipase and cellulase activities, Cyphellophora guyanensis (BR71) produced 2.26 EI while Acremonium hennebertii (BR70) produced 1.97 EI, respectively. Conclusion, significance and impact of study: Endophytic fungi from spines of C. castaneus were able to produce cellulase, pectinase, lipase, protease and amylase. The extracellular enzymes degraded different substrates, suggesting different types of interaction of the fungal endophytes with the host plant. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Postnatal persistence of hippocampal Cajal-Retzius cells has a crucial role in the establishment of the hippocampal circuit.
- Author
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Glærum, Ingvild Lynneberg, Dunville, Keagan, Moan, Kristian, Krause, Maike, Montaldo, Nicola Pietro, Kirikae, Hinako, Nigro, Maximiliano Jose, Sætrom, Pål, van Loon, Barbara, and Quattrocolo, Giulia
- Subjects
- *
ENTORHINAL cortex , *PYRAMIDAL neurons , *HIPPOCAMPUS (Brain) , *THETA rhythm , *DENDRITIC spines , *GENETIC vectors , *TRANSGENIC mice , *PROTEOMICS - Abstract
Cajal-Retzius (CR) cells are a transient neuron type that populate the postnatal hippocampus. To understand how the persistence of CR cells influences the maturation of hippocampal circuits, we combined a specific transgenic mouse line with viral vector injection to selectively ablate CR cells from the postnatal hippocampus. We observed layerspecific changes in the dendritic complexity and spine density of CA1 pyramidal cells. In addition, transcriptomic analysis highlighted significant changes in the expression of synapse-related genes across development. Finally, we were able to identify significant changes in the expression levels of latrophilin 2, a postsynaptic guidance molecule known for its role in the entorhinal-hippocampal connectivity. These findingswere supported by changes in the synaptic proteomic content in CA1 stratum lacunosum-moleculare. Our results reveal a crucial role for CR cells in the establishment of the hippocampal network. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Differential regulation of hippocampal transcriptome by circulating estrogen.
- Author
-
Iqbal, Javed, Bibi, Maryam, Huang, Geng-Di, Xue, Yan-Xue, Khatttak, Jabbar Zaman Khan, Yang, Mei, and Jia, Xiao-Jian
- Abstract
Estrogen (E2) modulates the synaptic structure and plasticity in the hippocampus. Previous studies showed that E2 fluctuations during various phases of the menstrual cycle produce subtle neurosynaptic changes that impact women's behavior, emotion, and cognitive functions. In this study, we explored the transcriptome of the hippocampus via RNA-seq (RNA-sequencing) between proestrus (PE) and diestrus (DE) stages in young female rats to determine the effect of E2 of PE and DE stages on hippocampal gene expression. We identified 238 genes (at 1.5-fold-change selection criteria, FDR adjusted p-value < 0.05) as differentially expressed genes (DEGs) that responded to E2 between PE and DE stages. Functional analysis based on Gene Ontology (GO) revealed that a higher E2 level corresponded to an increase in gene transcription among most of the DEGs, suggesting biological mechanisms operating differentially in the hippocampus of female rats between PE and DE stages in the estrus cycle; while analysis with Kyoto Encyclopedia of Genes and Genomes database (KEGG) found that the DEGs involving neuroactive ligand-receptor interaction, antigen processing, cell adhesion molecules, and presentation were upregulated in PE stage, whereas DEGs in pathways relating to bile secretion, coagulation cascades, osteoclast differentiation, cysteine and methionine metabolism were upregulated in DE stage of the estrus cycle. The high-fold expression of DEGs was confirmed by a follow-up quantitative real-time PCR. Our findings in this current study have provided fundamental information for further dissection of neuro-molecular mechanisms in the hippocampus in response to E2 fluctuation and its relationship with disorders. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Morphological Characterization of Opuntia Accessions from Tenerife (Canary Islands, Spain) Using UPOV Descriptors
- Author
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Goretti L. Díaz-Delgado, Elena M. Rodríguez-Rodríguez, Domingo Ríos, María Pilar Cano, and María Gloria Lobo
- Subjects
cactus pear ,cladodes ,flower ,fruit ,spines ,multivariate analysis ,Plant culture ,SB1-1110 - Abstract
Twenty Opuntia accessions from Tenerife (Canary Islands, Spain) were classified according to 52 quantitative and qualitative descriptors, including the traits of the cladodes, flowers, fruits, and spines, as described by the International Union for the Protection of New Varieties of Plants (UPOV) guidelines. A database composed of 20 accessions and 52 traits was used to perform a cluster analysis based on the Euclidian distance and Ward’s method and a canonical discriminant analysis. In terms of the analyzed characteristics, cactus pears with orange flesh showed less variability than cactus pears with white or purple flesh. Good classifications according to fruit flesh color were obtained using discriminant analysis. As a result of the cluster analysis, Opuntia plant accessions with white, orange, or purple-fleshed fruits were classified into four homogeneous groups according to the cubic clustering criteria. This study proves that it was possible to make a preliminary classification of Opuntia varieties from the Canary Islands based on a few main morphological characteristics. To improve the classification, a molecular analysis of the different Opuntia plants is necessary.
- Published
- 2024
- Full Text
- View/download PDF
21. Cortex-restricted deletion of Foxp1 impairs barrel formation and induces aberrant tactile responses in a mouse model of autism.
- Author
-
Li, Xue, Hao, Shishuai, Zou, Shimin, Tu, Xiaomeng, Kong, Weixi, Jiang, Tian, and Chen, Jie-Guang
- Subjects
DENDRITIC spines ,WHISKERS ,LABORATORY mice ,YOUNG adults ,SOMATOSENSORY cortex ,ANIMAL disease models ,AUTISM spectrum disorders ,NEUROBIOLOGY ,AFFECTIVE neuroscience - Abstract
Background: Many children and young people with autism spectrum disorder (ASD) display touch defensiveness or avoidance (hypersensitivity), or engage in sensory seeking by touching people or objects (hyposensitivity). Abnormal sensory responses have also been noticed in mice lacking ASD-associated genes. Tactile sensory information is normally processed by the somatosensory system that travels along the thalamus to the primary somatosensory cortex. The neurobiology behind tactile sensory abnormalities, however, is not fully understood. Methods: We employed cortex-specific Foxp1 knockout (Foxp1-cKO) mice as a model of autism in this study. Tactile sensory deficits were measured by the adhesive removal test. The mice's behavior and neural activity were further evaluated by the whisker nuisance test and c-Fos immunofluorescence, respectively. We also studied the dendritic spines and barrel formation in the primary somatosensory cortex by Golgi staining and immunofluorescence. Results: Foxp1-cKO mice had a deferred response to the tactile environment. However, the mice exhibited avoidance behavior and hyper-reaction following repeated whisker stimulation, similar to a fight-or-flight response. In contrast to the wild-type, c-Fos was activated in the basolateral amygdala but not in layer IV of the primary somatosensory cortex of the cKO mice. Moreover, Foxp1 deficiency in cortical neurons altered the dendrite development, reduced the number of dendritic spines, and disrupted barrel formation in the somatosensory cortex, suggesting impaired somatosensory processing may underlie the aberrant tactile responses. Limitations: It is still unclear how the defective thalamocortical connection gives rise to the hyper-reactive response. Future experiments with electrophysiological recording are needed to analyze the role of thalamo-cortical-amygdala circuits in the disinhibiting amygdala and enhanced fearful responses in the mouse model of autism. Conclusions: Foxp1-cKO mice have tactile sensory deficits while exhibit hyper-reactivity, which may represent fearful and emotional responses controlled by the amygdala. This study presents anatomical evidence for reduced thalamocortical connectivity in a genetic mouse model of ASD and demonstrates that the cerebral cortex can be the origin of atypical sensory behaviors. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Allometry of Defense: Predator Shift Alters Ontogenetic Growth Patterns in an Antipredator Trait.
- Author
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Jiang, Bin, Yao, Yu, Mauersberger, Rüdiger, and Mikolajewski, Dirk J.
- Subjects
- *
PREDATION , *ALLOMETRY , *BODY size , *PREDATORY animals , *SPINE , *DRAGONFLIES - Abstract
Simple Summary: Predators drive prey trait diversification and promote ecological speciation. The impacts of predation are not only on the final state of antipredation traits, but also on the development of antipredation traits. Species of the dragonfly genus Leucorrhinia are distributed in both habitats dominated by predatory fish (fish lakes) and habitats dominated by predatory invertebrates (invertebrate lakes). In larval dragonflies, the spine is one of the most efficient traits deterring gape-limited fish predators. However, the spine is not useful in invertebrate lakes. In this study, we compared the developmental patterns of spines in both habitats. We constructed the scaling relationship between spine length and body size and compared the inflexion point on those curves in five species of Leucorrhinia dragonfly larvae. Here, we found that fish-lake Leucorrhinia species kept a higher spine growth rate than species from invertebrate lakes, and Leucorrhinia species from fish lakes displayed accelerated spine growth rate at larger body size compared to invertebrate-lake species. Our results highlight that development patterns, as well as the final states of antipredator traits, are essential to understanding predator–prey interactions. Predation is a major factor driving prey trait diversification and promoting ecological speciation. Consequently, antipredator traits are widely studied among prey species. However, comparative studies that examine how different predators shape the ontogenetic growth of antipredator traits are scarce. In larval dragonflies, abdominal spines are effective traits against predatory fish in fish lakes, which prefer larger prey. However, defensive spines increase mortality in habitats dominated by invertebrate predators (invertebrate lakes), which prefer smaller prey. Thus, species from fish lakes may accelerate spine growth at a later body size compared to species from invertebrate lakes when growing into the preferred prey size range of predatory fish. In this study, we constructed the allometric relationship between spine length and body size and compared the inflexion point of those growth curves in five species of Leucorrhinia dragonfly larvae. We found that fish-lake Leucorrhinia species accelerated spine growth at a larger body size than congenerics from invertebrate lakes. Further, rather than extending spine length constantly through development, fish-lake species rapidly accelerated spine growth at a larger body size. This is likely to be adaptive for avoiding invertebrate predation at an early life stage, which are also present in fish lakes, though in smaller numbers. Our results highlight that comparative studies of ontogenetic patterns in antipredator traits might be essential to develop an integrated understanding of predator–prey interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
23. Repurposing drugs against Alzheimer's disease: can the anti-multiple sclerosis drug fingolimod (FTY720) effectively tackle inflammation processes in AD?
- Author
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Leßmann, Volkmar, Kartalou, Georgia-Ioanna, Endres, Thomas, Pawlitzki, Marc, and Gottmann, Kurt
- Subjects
- *
ALZHEIMER'S disease , *DRUG repositioning , *FINGOLIMOD , *ORGANS (Anatomy) , *APOLIPOPROTEIN E4 , *ANIMAL young - Abstract
Therapeutic approaches providing effective medication for Alzheimer's disease (AD) patients after disease onset are urgently needed. Previous studies in AD mouse models and in humans suggested that physical exercise or changed lifestyle can delay AD-related synaptic and memory dysfunctions when treatment started in juvenile animals or in elderly humans before onset of disease symptoms. However, a pharmacological treatment that can reverse memory deficits in AD patients was thus far not identified. Importantly, AD disease-related dysfunctions have increasingly been associated with neuro-inflammatory mechanisms and searching for anti-inflammatory medication to treat AD seems promising. Like for other diseases, repurposing of FDA-approved drugs for treatment of AD is an ideally suited strategy to reduce the time to bring such medication into clinical practice. Of note, the sphingosine-1-phosphate analogue fingolimod (FTY720) was FDA-approved in 2010 for treatment of multiple sclerosis patients. It binds to the five different isoforms of Sphingosine-1-phosphate receptors (S1PRs) that are widely distributed across human organs. Interestingly, recent studies in five different mouse models of AD suggest that FTY720 treatment, even when starting after onset of AD symptoms, can reverse synaptic deficits and memory dysfunction in these AD mouse models. Furthermore, a very recent multi-omics study identified mutations in the sphingosine/ceramide pathway as a risk factor for sporadic AD, suggesting S1PRs as promising drug target in AD patients. Therefore, progressing with FDA-approved S1PR modulators into human clinical trials might pave the way for these potential disease modifying anti-AD drugs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Extracellular matrix composition affects outgrowth of dendrites and dendritic spines on cortical neurons.
- Author
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Sharma, Archana, Hill, Katherine E., and Schwarzbauer, Jean E.
- Subjects
DENDRITIC spines ,EXTRACELLULAR matrix ,DENDRITES ,NEURONS ,NERVE tissue ,GENOME editing - Abstract
The composition of the extracellular matrix (ECM) in nervous tissue plays an important role in controlling neuronal outgrowth and synapse development. Changes in both protein and glycosaminoglycan components of the ECM occur with tissue injury and may affect neuron growth. To investigate neuron responses to alterations in fibronectin (FN), a major component of the wound ECM, we grew cortical neurons on cell-derived decellularized matrices composed of wild type FN (FN+/+) or of a mutant form of FN (FN1/+) from which the III13 heparin-binding site had been deleted by CRISPR-Cas 9 gene editing. The most significant effect of the mutant FN was a reduction in dendrite outgrowth. Not only were dendrites shorter on mutant FN1/+-collagen (COL) matrix than on wild type (FNC/+-COL) matrix, but the number of dendrites and dendritic spines per neuron and the spine densities were also dramatically reduced on FN1/+-COL matrices. Mass spectrometry and immunostaining identified a reduction in tenascin-C (TN-C) levels in the mutant matrix. TN-C is an ECM protein that binds to the III13 site of FN and modulates cell-matrix interactions and has been linked to dendrite development. We propose that TN-C binding to FN in the wound matrix supports dendrite and spine development during repair of damaged neural tissue. Overall, these results show that changes in ECM composition can dramatically affect elaboration of neurites and support the idea that the ECM microenvironment controls neuron morphology and connectivity. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. Fear
- Author
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Quirk, Gregory J., Pfaff, Donald W., editor, Volkow, Nora D., editor, and Rubenstein, John L., editor
- Published
- 2022
- Full Text
- View/download PDF
26. Maternal influence on the larval morphometry of the brush-clawed shore crab Hemigrapsus takanoi (Decapoda: Brachyura)
- Author
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José M. Landeira, Effrosyni Fatira, Kana Banno, and Yuji Tanaka
- Subjects
brood ,life history ,phenotype ,size ,spines ,zoea ,Aquaculture. Fisheries. Angling ,SH1-691 - Abstract
The morphology of larvae is a key factor influencing their behaviour, performance and ultimately their survival. There is evidence indicating a significant morphological variability among broods, and that this may be related to the size or conditions of the mother. However, this maternal influence is not consistent across decapod crustaceans. Using 35 broods from different mothers of the crab Hemigrapsus takanoi collected in the same locality of inner Tokyo Bay and at the same time, we tested the hypothesis that there is a positive relationship between the size of the mother and the progeny’s morphology. Our results indicate that different patterns in the length of the lateral, rostral and dorsal spines differentiated two distinct morphogroups of larvae. These morphogroups were linked to the size of the mother, showing that larger mothers produced bigger larvae with longer carapace spines. It is possible that larger size and longer spines can influence swimming performance and predator avoidance, respectively. These relationships should be tested in future experimental studies.
- Published
- 2023
- Full Text
- View/download PDF
27. Extracellular matrix composition affects outgrowth of dendrites and dendritic spines on cortical neurons
- Author
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Archana Sharma, Katherine E. Hill, and Jean E. Schwarzbauer
- Subjects
decellularized ECM ,fibronectin ,tenascin-C ,cortical neurons ,dendrites ,spines ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
The composition of the extracellular matrix (ECM) in nervous tissue plays an important role in controlling neuronal outgrowth and synapse development. Changes in both protein and glycosaminoglycan components of the ECM occur with tissue injury and may affect neuron growth. To investigate neuron responses to alterations in fibronectin (FN), a major component of the wound ECM, we grew cortical neurons on cell-derived decellularized matrices composed of wild type FN (FN+/+) or of a mutant form of FN (FNΔ/+) from which the III13 heparin-binding site had been deleted by CRISPR-Cas 9 gene editing. The most significant effect of the mutant FN was a reduction in dendrite outgrowth. Not only were dendrites shorter on mutant FNΔ/+-collagen (COL) matrix than on wild type (FN+/+-COL) matrix, but the number of dendrites and dendritic spines per neuron and the spine densities were also dramatically reduced on FNΔ/+-COL matrices. Mass spectrometry and immunostaining identified a reduction in tenascin-C (TN-C) levels in the mutant matrix. TN-C is an ECM protein that binds to the III13 site of FN and modulates cell-matrix interactions and has been linked to dendrite development. We propose that TN-C binding to FN in the wound matrix supports dendrite and spine development during repair of damaged neural tissue. Overall, these results show that changes in ECM composition can dramatically affect elaboration of neurites and support the idea that the ECM microenvironment controls neuron morphology and connectivity.
- Published
- 2023
- Full Text
- View/download PDF
28. Ancestral reproductive bias in branching processes.
- Author
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Cheek, David and Johnston, Samuel G. G.
- Abstract
Consider a branching process whose reproduction law is homogeneous. Sampling a single cell uniformly from the population at a time T > 0 and looking along the sampled cell’s ancestral lineage, we find that the reproduction law is heterogeneous—the expected reproductive output of ancestral cells on the lineage from time 0 to time T continuously increases with time. This ‘inspection paradox’ is due to sampling bias, that cells with a larger number of offspring are more likely to have one of their descendants sampled by virtue of their prolificity. The bias’s strength changes with the random population size and/or the sampling time T. Our main result explicitly characterises the evolution of reproduction rates and sizes along the sampled ancestral lineage as a mixture of Poisson processes, which simplifies in special cases. The ancestral bias helps to explain recently observed variation in mutation rates along lineages of the developing human embryo. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Ecology shapes the evolutionary trade-off between predator avoidance and defence in coral reef butterflyfishes.
- Author
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Hodge, Jennifer R, Alim, Chidera, Bertrand, Nick G, Lee, Wesley, Price, Samantha A, Tran, Binh, and Wainwright, Peter C
- Subjects
Animals ,Fishes ,Perciformes ,Anthozoa ,Predatory Behavior ,Ecology ,Coral Reefs ,Chaetodontidae ,constraint ,coral reef ecology ,evolutionary trade-off ,foraging strategy ,functional morphology ,phylogenetic comparative method ,predation risk ,social behaviour ,spines ,Ecological Applications ,Evolutionary Biology - Abstract
Antipredator defensive traits are thought to trade-off evolutionarily with traits that facilitate predator avoidance. However, complexity and scale have precluded tests of this prediction in many groups, including fishes. Using a macroevolutionary approach, we test this prediction in butterflyfishes, an iconic group of coral reef inhabitants with diverse social behaviours, foraging strategies and antipredator adaptations. We find that several antipredator traits have evolved adaptively, dependent primarily on foraging strategy. We identify a previously unrecognised axis of diversity in butterflyfishes where species with robust morphological defences have riskier foraging strategies and lack sociality, while species with reduced morphological defences feed in familiar territories, have adaptations for quick escapes and benefit from the vigilance provided by sociality. Furthermore, we find evidence for the constrained evolution of fin spines among species that graze solely on corals, highlighting the importance of corals, as both prey and structural refuge, in shaping fish morphology.
- Published
- 2018
30. APPsα rescues CDK5 and GSK3β dysregulation and restores normal spine density in Tau transgenic mice.
- Author
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Baltissen, Danny, Bold, Charlotte S., Rehra, Lena, Banićević, Marija, Fricke, Justus, Just, Jennifer, Ludewig, Susann, Buchholz, Christian J., Korte, Martin, and Müller, Ulrike C.
- Abstract
The Tau protein can be phosphorylated by numerous kinases. In Alzheimer’s disease (AD) hyperphosphorylated Tau species accumulate as neurofibrillary tangles that constitute a major hallmark of AD. AD is further characterized by extracellular Aβ plaques, derived from the β-amyloid precursor protein APP. Whereas Aβ is produced by amyloidogenic APP processing, APP processing along the competing nonamyloidogenic pathway results in the secretion of neurotrophic and synaptotrophic APPsα. Recently, we demonstrated that APPsα has therapeutic effects in transgenic AD model mice and rescues Aβ-dependent impairments. Here, we examined the potential of APPsα to regulate two major Tau kinases, GSK3β and CDK5 in THYTau22 mice, a widely used mouse model of tauopathy. Immunohistochemistry revealed a dramatic increase in pathologically phosphorylated (AT8 and AT180) or misfolded Tau species (MC1) in the hippocampus of THY-Tau22 mice between 3 and 12 months of age. Using a highly sensitive radioactive kinase assay with recombinant human Tau as a substrate and immunoblotting, we demonstrate an increase in GSK3β and CDK5 activity in the hippocampus of THY-Tau22 mice. Interestingly, AAVmediated intracranial expression of APPsα in THY-Tau22 mice efficiently restored normal GSK3β and CDK5 activity. Western blot analysis revealed upregulation of the CDK5 regulatory proteins p35 and p25, indicating CDK5 hyperactivation in THYTau22 mice. Strikingly, AAV-APPsα rescued p25 upregulation to wild-type levels even at stages of advanced Tau pathology. Sarkosyl fractionation used to study the abundance of soluble and insoluble phospho-Tau species revealed increased soluble AT8-Tau and decreased insoluble AT100-Tau species upon AAV-APPsα injection. Moreover, AAV-APPsα reduced misfolded (MC1) Tau species, particularly in somatodendritic compartments of CA1 pyramidal neurons. Finally, we show that AAV-APPsα upregulated PSD95 expression and rescued deficits in spine density of THY-Tau22 mice. Together our findings suggest that APPsα holds therapeutic potential to mitigate Tau-induced pathology. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Morphological and Genetic Diversity of Cucumber (Cucumis sativus L.) Fruit Development.
- Author
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Grumet, Rebecca, Lin, Ying-Chen, Rett-Cadman, Stephanie, and Malik, Ajaz
- Subjects
CUCUMBERS ,GENETIC variation ,CELL cycle regulation ,FRUIT development ,CELL division ,TRANSCRIPTION factors - Abstract
Cucumber (Cucumis sativus L.) fruits, which are eaten at an immature stage of development, can vary extensively in morphological features such as size, shape, waxiness, spines, warts, and flesh thickness. Different types of cucumbers that vary in these morphological traits are preferred throughout the world. Numerous studies in recent years have added greatly to our understanding of cucumber fruit development and have identified a variety of genetic factors leading to extensive diversity. Candidate genes influencing floral organ establishment, cell division and cell cycle regulation, hormone biosynthesis and response, sugar transport, trichome development, and cutin, wax, and pigment biosynthesis have all been identified as factors influencing cucumber fruit morphology. The identified genes demonstrate complex interplay between structural genes, transcription factors, and hormone signaling. Identification of genetic factors controlling these traits will facilitate breeding for desired characteristics to increase productivity, improve shipping, handling, and storage traits, and enhance consumer-desired qualities. The following review examines our current understanding of developmental and genetic factors driving diversity of cucumber fruit morphology. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Latest Oligocene sea urchin fragments (Cidaroida, Echinodermata) from Hokianga, Northland, New Zealand.
- Author
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Rust, Seabourne and Grant-Mackie, Jack
- Subjects
- *
OLIGOCENE Epoch , *ECHINODERMATA , *SEA urchins , *SPINE , *MIOCENE Epoch , *SANDSTONE - Abstract
Cidaroid sea urchin remains (isolated radioles and rare plates) are described from marine strata of the Harnetts Formation (New Zealand Waitakian Stage (=Late Chattian – Early Aquitarian)), part of the Otaua Group (Late Oligocene – Early Miocene) outcropping in the Waimamaku Valley, in the South Hokianga district, Northland, New Zealand. Abundant large and robust spines (radioles), assigned here to two previously known Indo-Pacific genera Stereocidaris and Phyllacanthus, form part of a distinctive, transported shallow shelf component of a macrofossil assemblage occurring in grit horizons within the deep marine (bathyal) sandstone sequence. Cidaroid spine morphology allows for tentative identification of fossil taxa to species level. Several test fragments, namely large but worn interambulacral plates, have also been collected from the type locality and a possible nearby outlier of Harnetts Formation. These outcrops are locally significant as the only known exposures of the geographically restricted unit, incorporated into the Northland Allochthon during its emplacement. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
33. Classification, Distribution and Morphological Characterization of Opuntia Species
- Author
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Ahmed, Sidra Nisar, Ahmad, Mushtaq, Zafar, Mohammad, Rashid, Sofia, Sultana, Shazia, Ramadan, Mohamed Fawzy, editor, Ayoub, Tamer E. Moussa, editor, and Rohn, Sascha, editor
- Published
- 2021
- Full Text
- View/download PDF
34. No evidence for the simultaneous induction of structural and chemical defences in spiny southern African savanna trees.
- Author
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Wigley, Benjamin J., Coetsee, Corli, Mawoyo, Kuzivakwashe A., and Fritz, Hervé
- Subjects
- *
SAVANNAS , *TREES , *PHYTOCHEMICALS , *CHEMICAL plants , *TANNINS , *WOODY plants - Abstract
It is still not well established whether plant chemical and physical defence traits can be simultaneously induced in savanna trees and how this would affect plant nutritional quality. Here, we use a long‐term mammalian herbivore exclosure experiment in a dystrophic semi‐arid African savanna to test how chemical (condensed tannins [CTs] and total polyphenols [TPs]) and structural (spines and thorns) defences are affected by herbivore exclusion in five common savanna woody species. We also tested whether nutritional quality interacted with either physical or chemical defences after protected trees were reintroduced to herbivores. Trees that remained available to herbivores did not increase CTs and TPs, rather these were found to be higher without mammalian herbivory in some species. In contrast, herbivory resulted in a significant induction of structural defences (i.e. longer and thicker spines) and at the same time, improved nutritional quality (i.e. higher available crude protein and lower C:N ratios) for some species. We found that the plant defence traits of the treatment which previously excluded herbivores were mostly similar to the control, which both differed from the exclosure, suggesting that legacies of herbivore exclusion on plant defence traits are mostly short‐lived. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. The Role of the Dentate Gyrus in Mediating Hippocampal Functions: The Healthy Brain.
- Author
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Kitchigina, V. F., Shubina, L. V., and Popova, I. Yu.
- Subjects
DENTATE gyrus ,GRANULE cells ,PYRAMIDAL neurons ,HIPPOCAMPUS (Brain) ,GABAERGIC neurons ,LONG-term potentiation - Abstract
The dentate gyrus (DG), which is part of the hippocampal formation, is the main target of neocortical and subcortical afferents received by the hippocampus, and this forms the anatomical basis for its role in cognitive processes such as attention and memory. The DG is involved in organizing many of the cognitive functions of the hippocampus and the brain as a whole, including novelty detection, pattern separation, pattern completion, spatial working memory, information encoding, and memory consolidation. Long-term potentiation – plastic changes in synapses similar to those occurring when information is memorized – was first discovered in the DG. The DG is a unique region of the brain, one of the few where neurogenesis occurs in adult mammals, including humans. Another feature of the DG distinguishing it from the hippocampus is that it contains two types of glutamatergic neurons – granule cells and mossy cells. Granule cells, which normally have low activity, limit the excitability of hippocampal pyramidal neurons in adverse conditions. The functions of mossy neurons in the DG are the least well understood; these cells, innervating both glutamatergic and GABAergic neurons, are likely to be involved in the organization of complex network activity both in the DG itself and in the hippocampus. Despite intensive research on the DG, its role in the hippocampal activity is still largely unclear. This review discusses the anatomical, histochemical, and functional features of the DG, the activity of its individual cellular elements, and its role in the hippocampal functions of the normal brain. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. Morphological investigations on the wing scales of four species of common Indian butterflies.
- Author
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Sijina, K. P. and Evans, D. A.
- Subjects
BUTTERFLIES ,SPECIES ,SPINE - Abstract
Wing scales of butterflies exhibit extreme diversity in shape, size, colour, and number of spines. They are sub microscopic with a length of 300 to 600 µm and a breadth of 150 to 400 µm. A typical scale possessed a flat body with basal pedicel and apical crown which is provided with a varying number of pointed edges called spines. Investigations were carried out on the morphology of wing scales in four species of common butterflies viz., Pachilopta hector (Linnaeus 1758), Troides minos (Cramer 1779), Jamides celeno (Cramer 1775) and Eurema andersonii (Linnaeus 1758). Wings of P. hector possessed nine types of scales, the crown of all are with pointed spines of varying numbers, ranging from one to five. The southern birdwing T. minos, possessed nine types of scales. A major portion of wings with black colour is due to black coloured scales but white bands of the forewings are due to transparent and colourless scales. The prominent yellow colour on the hind wings of this butterfly is due to the presence of a single type of scale with a round crown that is devoid of spines and is fully packed with yellow pigment. Jamides celeno possessed twenty different types of scales, most of them are devoid of spines and the ridges within the scales are not clear. Scales on the upper surface of the wing with ashy blue colour and scales of white bands on the lower surface of the wings are identical and are transparent and colourless. The common grass yellow E. andersonii possessed twenty five different types of scales, of which thirteen are on the black margins of wings and twelve are in the yellow portions of wings. Almost half of the total number of scales in the yellow portions of the wing is transparent and colourless and in coloured scales distribution of pigment is not uniform. This is the first report on the different types of wings scales in the selected butterflies. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. Standardization of harvest maturity of jackfruit (Artocarpus heterophyllus lam.) by morpho-physical investigation.
- Author
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Budnimath, Suma H., Babu, A. G., Jagadeesh, S. L., and Prakash, B. G.
- Subjects
JACKFRUIT ,HARVESTING ,STANDARDIZATION ,LAMINATED composite beams ,ONE-way analysis of variance ,DESIGN software - Abstract
An experiment was carried out to investigate the standardization of harvest maturity indicators in Jackfruit (Artocarpus heterophyllus Lam.)The mean number of spines/cm2 was lowest in tree 1 (8.0), the mean metallic sound (hedonic scale) was highest in tree 1 (2.8), the mean fruit length was significantly increasing and reaching its maximum in tree 1 (39.00 cm), and the mean fruit circumference was significantly increasing and reaching its maximum in tree 1 (39.00 cm) (41.48 cm). The experiment's data were considered non-replicated, and the recorded data were statistically analyzed using a one-way ANOVA design in the computer software MS Excel. Considering morphological analysis the characters viz., fruit circumference(39.00 cm), low spine density(8.0), moderate to high spreading of spines, presence of sensible hollow metallic sound could be used as the maturity indices of jackfruit. It is also noted that jackfruit could be harvested after 100 days of fruit set. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
38. DArTseq molecular markers associated with the piping leaf margin phenotype in pineapple (Ananas comosus L.).
- Author
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Sanewski, Garth M.
- Abstract
This study sought to understand the genetic basis of the piping leaf margin phenotype in pineapple. To achieve this aim, a genome-wide association study (GWAS) using mixed linear regression and logistic regression analysis was conducted on three pineapple diversity panels including seedling populations segregating for spiny, spiny-tip and piping leaf margins. This study identified single nucleotide polymorphism (SNP) markers associated with the piping and spiny-tip leaf margin phenotypes. A broad quantitative trait locus (QTL) positioned on chromosome 23 between positions 240,475 and 2,369,197 bp was the most highly associated with piping leaf margin in all analyses. Major candidate genes proposed are a Zinc finger protein 2, a Zinc finger protein 3, a WUSCHEL-related homeobox 2, a WUSCHEL-related homeobox 1 and a Zinc finger protein CONSTANS-like. Some other genes of a lower association, linked or nearby genes of interest, are also considered potentially involved to varying degrees. All candidate genes are known to be involved in aspects of stem cell maintenance, cell proliferation, epidermal cell differentiation, organogenesis, leaf polarity, cell wall modification or hormone signalling. It is possible each plays a role in either differentiation or morphological aspects of the spiny-tip and piping leaf margin phenotypes. It is expected the relative role of each associated gene might vary with genetic background. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
39. Protracted dendritic growth in the typically developing human amygdala and increased spine density in young ASD brains
- Author
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Weir, RK, Bauman, MD, Jacobs, B, and Schumann, CM
- Subjects
Zoology ,Biomedical and Clinical Sciences ,Neurosciences ,Biological Sciences ,Intellectual and Developmental Disabilities (IDD) ,Brain Disorders ,Mental Health ,Autism ,Behavioral and Social Science ,Basic Behavioral and Social Science ,Pediatric ,Mental health ,Adolescent ,Adult ,Age Factors ,Amygdala ,Autism Spectrum Disorder ,Child ,Dendritic Spines ,Female ,Humans ,Male ,Middle Aged ,Neurons ,Silver Staining ,Young Adult ,amygdala ,autism spectrum disorder ,golgi-kopsch ,neuromorphology ,spines ,RRID:SCR_003131 ,Medical Physiology ,Neurology & Neurosurgery - Abstract
The amygdala is a medial temporal lobe structure implicated in social and emotional regulation. In typical development (TD), the amygdala continues to increase volumetrically throughout childhood and into adulthood, while other brain structures are stable or decreasing in volume. In autism spectrum disorder (ASD), the amygdala undergoes rapid early growth, making it volumetrically larger in children with ASD compared to TD children. Here we explore: (a) if dendritic arborization in the amygdala follows the pattern of protracted growth in TD and early overgrowth in ASD and (b), if spine density in the amygdala in ASD cases differs from TD from youth to adulthood. The amygdala from 32 postmortem human brains (7-46 years of age) were stained using a Golgi-Kopsch impregnation. Ten principal neurons per case were selected in the lateral nucleus and traced using Neurolucida software in their entirety. We found that both ASD and TD individuals show a similar pattern of increasing dendritic length with age well into adulthood. However, spine density is (a) greater in young ASD cases compared to age-matched TD controls (
- Published
- 2018
40. Study of triclabendazole effects on Fasciola hepatica’s life-supporting organs, spines and suckers responsible for stable position of the parasite in the host
- Author
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O. I. Bibik and I. A. Arkhipov
- Subjects
trematodes ,fasciola hepatica ,anthelmintics ,triclabendazole ,spines ,oral and abdominal suckers ,Biology (General) ,QH301-705.5 - Abstract
The purpose of the research is to study triclabendazole effects on the Fasciola’s life-supporting organs, spines and suckers which are responsible for stable position of the parasite in the host.Materials and methods. The study material was trematodes Fasciola hepatica (Linneus 1758, family Fasciolidae Railliet 1895), which were collected after the action of triclabendazole (fasinex) (chemically 5-chloro-6-(2,3-dichlorophenoxy)-2-methylthiobenzimidazole)on the 7th day after the drug administered at a single dose of 10 mg/kg for the Active Substance in the treatment of ovine fasciolosis. F. hepatica from untreated animals served as control. Mature F. hepatica collected after treatment with triclabendazole, and marita from the control groups were dehydrated in ascending alcohol series for 1–2 days after fixation; then passed through a mixture of chloroform and absolute alcohol (in a ratio of 1:1), and through pure chloroform in two portions for 10–15 minutes. The material was then soaked in a mushy mixture of chloroform and paraffin in a thermostat at 37 °C for 12–18 hours, and in paraffin in a thermostat at 56 °C for 30–45 minutes; and then embedded in paraffin with added wax. The resulting paraffin blocks were broken down into serial sections of 5–7 μm thick, then stained and examined under a light microscope.Results and discussion. Pathomicromorphological analysis of F. hepatica’s spines and suckers, organs that come into adhesive contact with the host organism revealed destructive changes in them after the action of triclabendazole. After the action of triclabendazole on fascioles, the spines look enlarged and swollen, and have a more rounded shape and some changes in color, absorbing eosin in greater concentration. The muscle fibers of the fascioles’ oral and abdominal suckers also look swollen after the action of triclabendazole. Although the musculature of the F. hepatica’s pharynx retained its structure, it has changes. It thickened sharply, which is clearly visible on the transverse and longitudinal sections of the helminths; neurosecretory cells are destroyed, and voids are observed in their place.
- Published
- 2021
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41. Somatic and neuritic spines on tyrosine hydroxylase–immunopositive cells of rat retina
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Fasoli, Anna, Dang, James, Johnson, Jeffrey S, Gouw, Aaron H, Iseppe, Alex Fogli, and Ishida, Andrew T
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Biomedical and Clinical Sciences ,Neurosciences ,Eye Disease and Disorders of Vision ,Animals ,Dendritic Spines ,Female ,Immunohistochemistry ,Interneurons ,Male ,Microscopy ,Confocal ,Rats ,Rats ,Inbred Lew ,Rats ,Long-Evans ,Retina ,Tyrosine 3-Monooxygenase ,retina ,interplexiform cells ,dopamine ,dendrites ,axons ,spines ,RRID: RGD_60991 ,RRID: RGD_1566443 ,RRID: AB_2201528 ,RRID: AB_90755 ,RRID: AB_11001825 ,RRID: AB_2307331 ,RRID: AB_399431 ,RRID: AB_2213602 ,RRID: AB_90711 ,RRID: AB_2314955 ,RRID: AB_310272 ,RRID: AB_2340863 ,RRID: AB_2315778 ,RRID: AB_2338694 ,RRID: AB_2338917 ,RRID: AB_2576217 ,RRID: AB_2338854 ,RRID: SCR_002285 ,RRID: SCR_014237 ,RRID: SCR_007370 ,RRID: SCR_001622 ,RRID: SCR_001905 ,RRID: NLX_143660 ,Zoology ,Medical Physiology ,Neurology & Neurosurgery - Abstract
Dopamine- and tyrosine hydroxylase-immunopositive cells (TH cells) modulate visually driven signals as they flow through retinal photoreceptor, bipolar, and ganglion cells. Previous studies suggested that TH cells release dopamine from varicose axons arborizing in the inner and outer plexiform layers after glutamatergic synapses depolarize TH cell dendrites in the inner plexiform layer and these depolarizations propagate to the varicosities. Although it has been proposed that these excitatory synapses are formed onto appendages resembling dendritic spines, spines have not been found on TH cells of most species examined to date or on TH cell somata that release dopamine when exposed to glutamate receptor agonists. By use of protocols that preserve proximal retinal neuron morphology, we have examined the shape, distribution, and synapse-related immunoreactivity of adult rat TH cells. We report here that TH cell somata, tapering and varicose inner plexiform layer neurites, and varicose outer plexiform layer neurites all bear spines, that some of these spines are immunopositive for glutamate receptor and postsynaptic density proteins (viz., GluR1, GluR4, NR1, PSD-95, and PSD-93), that TH cell somata and tapering neurites are also immunopositive for a γ-aminobutyric acid (GABA) receptor subunit (GABAA Rα1 ), and that a synaptic ribbon-specific protein (RIBEYE) is found adjacent to some colocalizations of GluR1 and TH in the inner plexiform layer. These results identify previously undescribed sites at which glutamatergic and GABAergic inputs may stimulate and inhibit dopamine release, especially at somata and along varicose neurites that emerge from these somata and arborize in various levels of the retina. J. Comp. Neurol. 525:1707-1730, 2017. © 2016 Wiley Periodicals, Inc.
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- 2017
42. Inflammation in Alzheimer’s disease: Lessons learned from microglia-depletion models
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Spangenberg, Elizabeth E and Green, Kim N
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Biomedical and Clinical Sciences ,Neurosciences ,Alzheimer's Disease ,Acquired Cognitive Impairment ,Neurodegenerative ,Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD) ,Aging ,Dementia ,Brain Disorders ,2.1 Biological and endogenous factors ,1.1 Normal biological development and functioning ,Neurological ,Alzheimer Disease ,Animals ,Brain ,Disease Models ,Animal ,Inflammation ,Microglia ,Neurons ,Phagocytosis ,tau Proteins ,Colony-stimulating factor 1 receptor ,Alzheimer's disease ,Amyloid ,Tau ,Spines ,Alzheimer’s disease ,Immunology ,Psychology ,Neurology & Neurosurgery ,Biological psychology - Abstract
Microglia are the primary immune cell of the brain and function to protect the central nervous system (CNS) from injury and invading pathogens. In the homeostatic brain, microglia serve to support neuronal health through synaptic pruning, promoting normal brain connectivity and development, and through release of neurotrophic factors, providing support for CNS integrity. However, recent evidence indicates that the homeostatic functioning of these cells is lost in neurodegenerative disease, including Alzheimer's disease (AD), ultimately contributing to a chronic neuroinflammatory environment in the brain. Importantly, the development of compounds and genetic models to ablate the microglial compartment has emerged as effective tools to further our understanding of microglial function in AD. Use of these models has identified roles of microglia in several pathological facets of AD, including tau propagation, synaptic stripping, neuronal loss, and cognitive decline. Although culminating evidence utilizing these microglial ablation models reports an absence of CNS-endogenous and peripheral myeloid cell involvement in Aβ phagocytosis, recent data indicates that targeting microglia-evoked neuroinflammation in AD may be essential for potential therapeutics. Therefore, identifying altered signaling pathways in the microglia-devoid brain may assist with the development of effective inflammation-based therapies in AD.
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- 2017
43. Pharmacological rescue of cognitive function in a mouse model of chemobrain
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Lien D. Nguyen, Tom T. Fischer, and Barbara E. Ehrlich
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Calcium ,Paclitaxel ,Protein kinase C ,Dendrites ,Spines ,Neurology. Diseases of the nervous system ,RC346-429 ,Geriatrics ,RC952-954.6 - Abstract
Abstract Background After chemotherapy, many cancer survivors suffer from long-lasting cognitive impairment, colloquially known as “chemobrain.” However, the trajectories of cognitive changes and the underlying mechanisms remain unclear. We previously established paclitaxel-induced inositol trisphosphate receptor (InsP3R)-dependent calcium oscillations as a mechanism for peripheral neuropathy, which was prevented by lithium pretreatment. Here, we investigated if a similar mechanism also underlay paclitaxel-induced chemobrain. Method Mice were injected with 4 doses of 20 mg/kg paclitaxel every other day to induced cognitive impairment. Memory acquisition was assessed with the displaced object recognition test. The morphology of neurons in the prefrontal cortex and the hippocampus was analyzed using Golgi-Cox staining, followed by Sholl analyses. Changes in protein expression were measured by Western blot. Results Mice receiving paclitaxel showed impaired short-term spatial memory acquisition both acutely 5 days post injection and chronically 23 days post injection. Dendritic length and complexity were reduced in the hippocampus and the prefrontal cortex after paclitaxel injection. Concurrently, the expression of protein kinase C α (PKCα), an effector in the InsP3R pathway, was increased. Treatment with lithium before or shortly after paclitaxel injection rescued the behavioral, cellular, and molecular deficits observed. Similarly, memory and morphological deficits could be rescued by pretreatment with chelerythrine, a PKC inhibitor. Conclusion We establish the InsP3R calcium pathway and impaired neuronal morphology as mechanisms for paclitaxel-induced cognitive impairment. Our findings suggest lithium and PKC inhibitors as candidate agents for preventing chemotherapy-induced cognitive impairment.
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- 2021
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44. Skill, Competence and Assessment Revisited
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Burke, Derek and Burke, Derek
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- 2020
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45. Brain Plasticity, Learning and Memory
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Burke, Derek and Burke, Derek
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- 2020
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46. Plant-Induced Irritant Contact Dermatitis
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Waldman, Reid A., Grant-Kels, Jane M., Trevino, Julian, editor, and Chen, Amy Y-Y, editor
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- 2020
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47. Taxonomic significance of palynological studies for identification of two morphologically similar Malva species.
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Ahmad, Farooq, Hameed, Mansoor, and Ahmad, Muhammad Sajid Aqeel
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Pollen studies can assist in distinguishing different plant taxa on the basis of pollen diameter, exine thickness, spines length, spine shape, number of rows of spines between colpi, shape of pollen, P/E ratio, pollen class and aperture type. Light microscopy (LM) and scanning electron microscopy (SEM) was used to compare and differentiate two Malva species on the basis of different pollen characteristics. Pollen in Malva neglecta and Malva parviflora had punctate and subpsilate, and, granulate and verrucate sculpturing between spines respectively. Both species pollen had bulbous spine base, but were more swollen in M. parviflora. M. neglecta had more pollen size, spine length and distance between spine base and spine apex, except spine base and pore diameter. The scatterplot matrix showed a wide variation among sculpturing types and other pollen attributes of both species. In PCA biplot, pore diameter and spine length were linked to M. parviflora while other pollen attributes were clearly linked to M. neglecta, indicating the taxonomic significance of the observed characters. It was concluded that the palynological studies can act as an identification tool and are of great significance in delimiting Malva and different plant taxa. Research Highlights: Taxonomic identifications is a big problem in morphologically identical Malva neglecta and Malva parviflora.The usefulness of pollen morphology (pollen diameter and exine thickness) and wall ornamentation in identification through light microscopy (LM) and scanning electron microscopy (SEM) was confirmed.Pollen of M. neglecta can be differentiated from M. parviflora by its sculpturing patterns.Spine base and pore diameter of M. parviflora is a taxonomically important feature. [ABSTRACT FROM AUTHOR]
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- 2022
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48. The FKB invariant is the 3d index.
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Garoufalidis, Stavros and van der Veen, Roland
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SPINE - Abstract
We identify the q-series associated to an 1-efficient ideal triangulation of a cusped hyperbolic 3-manifold by Frohman and Kania-Bartoszynska with the 3D-index of Dimofte– Gaiotto–Gukov. This implies the topological invariance of the q-series of Frohman and Kania- Bartoszynska for cusped hyperbolic 3-manifolds. Conversely, we identify the tetrahedron index of Dimofte–Gaiotto–Gukov as a limit of quantum 6j -symbols. [ABSTRACT FROM AUTHOR]
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- 2022
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49. Herbivory, intraspecific trait variability and back to herbivory.
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Gorné, Lucas D. and Díaz, Sandra
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PLANT cuttings , *LEAF area , *PLANT species , *PLANT populations , *PLANT evolution , *LEGUMES , *PLANT defenses - Abstract
Ungulate herbivory is a key driver of leaf trait syndromes and defense strategies at the ecological and macroevolutionary levels. Herbivory should also cause short‐term evolution within plant populations, but few studies have experimentally tested this prediction. We set out to experimentally assess the plastic and heritable effects of contemporary history of ungulate herbivory on 1) leaf trait syndromes at the intraspecific level, and on the defense traits, 2) leaf size and 3) size of spines. We measured leaf traits (specific leaf area, leaf dry matter content, leaf nitrogen concentration and leaf mechanical resistance) in populations of six grass and four woody legume species that had grown under contrasting pressures of domestic ungulate herbivory for at least 40 years. We then performed a common garden experiment, measuring the same traits. Next, we performed cutting experiments on the plants grown in the common garden to measure leaf trait plasticity. In the woody species, we also measured the length of spines and the leaf size (average area per leaf), in the field and in the common garden experiment. We found that in grasses field herbivory over decades produced a displacement toward more acquisitive leaf trait syndromes. Most of these changes appeared largely due to plasticity. In woody legume species, in contrast, herbivory produced a displacement towards more conservative leaves, longer spines and smaller leaves, with the trait differences between histories of herbivory being mostly hereditary. These results point out that vertebrate herbivory can lead to evolutionary processes at contemporary time scales even in long‐lived perennial plant species, but the direction of such change depends on the life form of the species. These divergent effects could depend on the predominant anti‐herbivore strategies in the different life forms (tolerance versus resistance). [ABSTRACT FROM AUTHOR]
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- 2022
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50. Chapter 4 Corticostriatal plasticity, neuronal ensembles, and regulation of drug-seeking behavior
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Bobadilla, Ana-Clara, Heinsbroek, Jasper A, Gipson, Cassandra D, Griffin, William C, Fowler, Christie D, Kenny, Paul J, and Kalivas, Peter W
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Biological Psychology ,Pharmacology and Pharmaceutical Sciences ,Biomedical and Clinical Sciences ,Psychology ,Basic Behavioral and Social Science ,Substance Misuse ,Behavioral and Social Science ,Brain Disorders ,Neurosciences ,Drug Abuse (NIDA only) ,Good Health and Well Being ,Anesthetics ,Local ,Animals ,Cerebral Cortex ,Cocaine ,Corpus Striatum ,Drug-Seeking Behavior ,Humans ,Neuronal Plasticity ,Neurons ,Neuronal ensembles ,Cocaine self-administration ,Cued reinstatement ,Nucleus accumbens ,Glutamate ,Synaptic plasticity ,Synaptic potentiation ,Spines ,Neurology & Neurosurgery - Abstract
The idea that interconnected neuronal ensembles code for specific behaviors has been around for decades; however, recent technical improvements allow studying these networks and their causal role in initiating and maintaining behavior. In particular, the role of ensembles in drug-seeking behaviors in the context of addiction is being actively investigated. Concurrent with breakthroughs in quantifying ensembles, research has identified a role for synaptic glutamate spillover during relapse. In particular, the transient relapse-associated changes in glutamatergic synapses on accumbens neurons, as well as in adjacent astroglia and extracellular matrix, are key elements of the synaptic plasticity encoded by drug use and the metaplasticity induced by drug-associated cues that precipitate drug-seeking behaviors. Here, we briefly review the recent discoveries related to ensembles in the addiction field and then endeavor to link these discoveries with drug-induced striatal plasticity and cue-induced metaplasticity toward deeper neurobiological understandings of drug seeking.
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- 2017
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