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Studies of the effects of insularity on animal signals are scarce, particularly in lizards. Here, we use Lilford’s wall lizard from Dragonera (Podarcis lilfordi gigliolii) to ask how island conditions have affected its repertoire of social signals, focusing on two visual signals shared by many Podarcis species: ultraviolet (UV)–blue-reflecting ventrolateral colour patches and visual displays. We examined whether the number or spectral characteristics of the UV–blue patches are associated with traits related to individual quality. We also used visual models to assess visual conspicuousness and to measure sexual dichromatism. We did not observe foot shakes or any other visual displays usually found in continental Podarcis. We found that none of the UV–blue patch variables covaried with morphometric variables indicative of fighting ability or body condition in males, suggesting that this coloration does not signal individual quality. We also found very little sexual dichromatism. In particular, the UV–blue patches of females seem over-expressed and more similar to those of males than those of continental Podarcis. Ancestral state reconstruction reveals that the lack of sexual dimorphism in the UV–blue patches is a derived condition for P. lilfordi gigliolii and other Podarcis living on small islands. Our results thus show a pattern of reduced social signalling in P. lilfordi gigliolii relative to mainland Podarcis, with some signals being lost or under-expressed (visual displays) and others losing their signalling function (UV–blue patches). We hypothesize that these changes are attributable to the high population density of P. lilfordi gigliolii, which discourages territorial behaviour and promotes extreme social tolerance, making most social signals unnecessary. More work will be needed to determine whether this is a common pattern in lizards inhabiting small and densely populated islands.

Stroke is one of the main causes of death and disability worldwide. Ischemic stroke results in unfolded/misfolded protein accumulation in endoplasmic reticulum (ER), a condition known as ER stress. We hypothesized that previously reported neuroprotection of celecoxib, a selective inhibitor of cyclooxygenase-2, in transient middle cerebral artery occlusion (tMCAO) model, relies on the ER stress decrease. To probe this hypothesis, Sprague-Dawley rats were subjected to 1 h of tMCAO and treated with celecoxib or vehicle 1 and 24 h after ischemia. Protein and mRNA levels of the main hallmarks of ER stress, unfolded protein response (UPR) activation, UPR-induced cell death, and ubiquitin proteasome system (UPS) and autophagy, the main protein degradation pathways, were measured at 12 and 48 h of reperfusion. Celecoxib treatment decreased polyubiquitinated protein load and ER stress marker expression such as glucose-related protein 78 (GRP78), C/EBP (CCAAT/enhancer-binding protein) homologous protein (CHOP), and caspase 12 after 48 h of reperfusion. Regarding the UPR activation, celecoxib promoted inositol-requiring enzyme 1 (IRE1) pathway instead of double-stranded RNA-activated protein kinase-like ER kinase (PERK) pathway. Furthermore, celecoxib treatment increased proteasome catalytic subunits transcript levels and decreased p62 protein levels, while the microtubule-associated protein 1 light chain 3 (LC3B) II/I ratio remained unchanged. Thus, the ability of celecoxib treatment on reducing the ER stress correlates with the enhancement of IRE1-UPR pathway and UPS degradation. These data support the ability of anti-inflammatory therapy in modulating ER stress and reveal the IRE1 pathway as a promising therapeutic target in stroke therapy. Graphical abstract

Explaining the evolutionary origin and maintenance of color polymorphisms is a major challenge in evolutionary biology. Such polymorphisms are commonly thought to reflect the existence of alternative behavioral or life‐history strategies under negative frequency‐dependent selection. The European common wall lizard Podarcis muralis exhibits a striking ventral color polymorphism that has been intensely studied and is often assumed to reflect alternative reproductive strategies, similar to the iconic “rock–paper–scissors” system described in the North American lizard Uta stansburiana. However, available studies so far have ignored central aspects in the behavioral ecology of this species that are crucial to assess the existence of alternative reproductive strategies. Here, we try to fill this gap by studying the social behavior, space use, and reproductive performance of lizards showing different color morphs, both in a free‐ranging population from the eastern Pyrenees and in ten experimental mesocosm enclosures. In the natural population, we found no differences between morphs in site fidelity, space use, or male–female spatial overlap. Likewise, color morph was irrelevant to sociosexual behavior, space use, and reproductive success within experimental enclosures. Our results contradict the commonly held hypothesis that P. muralis morphs reflect alternative behavioral strategies, and suggest that we should instead turn our attention to alternative functional explanations., Ventral color morphs in wall lizards have often been assumed to reflect alternative reproductive strategies. In this study, we study the social behavior, space use, and reproductive success of Podarcis muralis color morphs both in a free‐ranging population from the eastern Pyrenees and in ten experimental mesocosm enclosures. Overall, our results suggest that color morphs do not reflect alternative strategies concerning sociosexual behavior or space use.

Colour signals are ubiquitous in nature but only recently have researchers recognised the potential of ultraviolet (UV)-reflecting colour patches to function as signals of quality. Lacertid lizards often display UV-blue patches on their flanks and black spots over their entire body, both of which are under sexual selection. They also have a cryptic dorsum and some species have a conspicuous, polymorphic ventral coloration. In this study, we use the Tyrrhenian wall lizard Podarcis tiliguerta to investigate the information content of the lateral UV-blue patches and black melanin spots of males by assessing the relationship between colour features and individual quality traits. In addition, we use a visual modelling procedure to examine whether the coloration of the different body parts and different colour morphs can be distinguished by a wall lizard visual system. We found that larger males had more numerous and larger UV-blue patches, with a higher UV chroma, UV-shifted hue, but a lower spectral intensity than smaller males. The extent of black on the throat, dorsum, and flanks also correlated with male body size and size-corrected head length but not with colour features of the UV-blue patches. These results suggest that the UV-blue and melanic colour patches may provide different, non-redundant information about male resource holding potential, and thus act as condition-dependent indicators of male quality. Finally, we found that the different body parts can be chromatically distinguished from each other, and that the UV-blue patches are the most conspicuous while the dorsum is the least conspicuous. Many animals use their coloration to convey information about their quality as rivals or mates. Yet, until recently researchers have not recognised the potential of ultraviolet colour patches to function as signals of quality. In this study, we first show that male Tyrrhenian wall lizards display ultraviolet-blue and black colour patches that correlate positively with some aspect of their quality such as body or head size. Furthermore, our visual modelling procedure suggests that these lizards are able to distinguish the colours of their body parts from each other, with dorsal colours being the least conspicuous and ultraviolet-blue coloration being the most conspicuous.

Directly linked to promote strong intramolecular interactions, donor-acceptor dyads and a donor-acceptor-donor triad featuring zinc phthalocyanine (ZnPc) as electron donor and perylenediimide (PDI) as electron acceptor have been synthesized and characterized. Owing to complementary absorption features of the entities, improved light absorption was witnessed in these conjugates. The optimized geometry and electronic structures showed the majority of the highest occupied molecular orbital (HOMO) on the ZnPc entity, whereas the lowest unoccupied molecular orbital (LUMO) was on the PDI entity, suggesting that the charge-separated states would be ZnPc+ -PDI.- . The electrochemical and free-energy calculations suggested exothermic energy and/or electron transfer processes via the singlet states of PDI or ZnPc entities depending on the excitation wavelength of the laser used. The measured rates using femtosecond pump-probe spectroscopy coupled with global analysis of transient data revealed ultrafast energy transfer from 1 PDI* to ZnPc followed by charge separation. However, when ZnPc was selectively excited, only electron transfer was witnessed wherein the time constants for forward and reverse electron transfer processes followed Marcus predictions. The absorption in a wide section of the solar spectrum and the ultrafast charge separation suggest the usefulness of these systems as good photosynthetic models.

A one-step reaction for the fusion of aromatic rings to one or both bay areas of perylenediimides using benzynes is presented. Yields as high as 70% for naphthoperylenendiimide 2 and 80% for dibenzocoronenediimide 3 are obtained. The reaction is also carried out using substituted benzynes, heteroaromatic benzynes and substituted perylenediimides. A combined experimental/theoretical approach, based on measuring redox and absorption/emission properties and performing density functional theory calculations, indicates that increasing the π-skeleton of PDIs transversally leads to significant and unexpected changes in the electronic, redox and optical properties. The observed trends are rationalized in terms of molecular orbital topology and overlap according to three different levels of core expansion, and can be used as design principles for obtaining PDIs with improved functionalities.

Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature. Two of the mechanisms of balancing selection currently thought to explain the long-term persistence of polymorphisms are the evolution of alternative phenotypic optima through correlational selection on suites of traits including color and heterosis. Both of these mechanisms can generate differences in offspring viability and fitness arising from different morph combinations. Here, we examined the effect of parental morph combination on fertilization success, embryonic viability, newborn quality, antipredator, and foraging behavior, as well as inter-annual survival by conducting controlled matings in a polymorphic lacertid Podarcis muralis, where color morphs are frequently assumed to reflect alternative phenotypic optima (e.g., alternative reproductive strategies). Juveniles were kept in outdoor tubs for a year in order to study inter-annual growth, survival, and morph inheritance. In agreement with a previous genome-wide association analysis, morph frequencies in the year-old juveniles matched the frequencies expected if orange and yellow expressions depended on recessive homozygosity at 2 separate loci. Our findings also agree with previous literature reporting higher reproductive output of heavy females and the higher overall viability of heavy newborn lizards, but we found no evidence for the existence of alternative breeding investment strategies in female morphs, or morph-combination effects on offspring viability and behavior. We conclude that inter-morph breeding remains entirely viable and genetic incompatibilities are of little significance for the maintenance of discrete color morphs in P. muralis from the Pyrenees.

The inflammatory response plays an important role in neuroprotection and regeneration after ischemic insult. The use of non-steroidal anti-inflammatory drugs has been a matter of debate as to whether they have beneficial or detrimental effects. In this context, the effects of the anti-inflammatory agent meloxicam have been scarcely documented after stroke, but its ability to inhibit both cyclooxygenase isoforms (1 and 2) could be a promising strategy to modulate post-ischemic inflammation. This study analyzed the effect of the anti-inflammatory agent meloxicam in a transient focal ischemia model in rats, measuring its neuroprotective effect after 48 hours and 7 days of reperfusion and the effects of the treatment on the glial scar and regenerative events such as the generation of new progenitors in the subventricular zone and axonal sprouting at the edge of the damaged area. We show that meloxicam’s neuroprotective effects remained after 7 days of reperfusion even if its administration was restricted to the two first days after ischemia. Moreover, meloxicam treatment modulated glial scar reactivity, which matched with an increase in axonal sprouting. However, this treatment decreased the formation of neuronal progenitor cells. This study discusses the dual role of anti-inflammatory treatments after stroke and encourages the careful analysis of both the neuroprotective and the regenerative effects in preclinical studies.Abstract Figure

Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature. Two of the mechanisms of balancing selection currently thought to explain the long-term persistence of polymorphisms are the evolution of alternative phenotypic optima through correlational selection on suites of traits including color and heterosis. Both of these mechanisms can generate differences in offspring viability and fitness arising from different morph combinations. Here, we examined the effect of parental morph combination on fertilization success, embryonic viability, newborn quality, antipredator, and foraging behavior, as well as inter-annual survival by conducting controlled matings in a polymorphic lacertid

Stroke is one of the main causes of death and disability worldwide. Ischemic stroke results in unfolded/misfolded protein accumulation in endoplasmic reticulum (ER), a condition known as ER stress. We hypothesized that previously reported neuroprotection of celecoxib, a selective inhibitor of cyclooxygenase-2, in transient middle cerebral artery occlusion (tMCAO) model, relies on the ER stress decrease. To probe this hypothesis, Sprague-Dawley rats were subjected to 1 h of tMCAO and treated with celecoxib or vehicle 1 and 24 h after ischemia. Protein and mRNA levels of the main hallmarks of ER stress, unfolded protein response (UPR) activation, UPR-induced cell death, and ubiquitin proteasome system (UPS) and autophagy, the main protein degradation pathways, were measured at 12 and 48 h of reperfusion. Celecoxib treatment decreased polyubiquitinated protein load and ER stress marker expression such as glucose-related protein 78 (GRP78), C/EBP (CCAAT/enhancer-binding protein) homologous protein (CHOP), and caspase 12 after 48 h of reperfusion. Regarding the UPR activation, celecoxib promoted inositol-requiring enzyme 1 (IRE1) pathway instead of double-stranded RNA-activated protein kinase-like ER kinase (PERK) pathway. Furthermore, celecoxib treatment increased proteasome catalytic subunits transcript levels and decreased p62 protein levels, while the microtubule-associated protein 1 light chain 3 (LC3B) II/I ratio remained unchanged. Thus, the ability of celecoxib treatment on reducing the ER stress correlates with the enhancement of IRE1-UPR pathway and UPS degradation. These data support the ability of anti-inflammatory therapy in modulating ER stress and reveal the IRE1 pathway as a promising therapeutic target in stroke therapy.Graphical abstract.

Recent reviews have highlighted the use of perylenediimides (PDIs) as non-fullerene acceptors in bulk-heterojunction organic photovoltaic devices. This review is focused on the advances in the incorporation of PDIs as photoactive components in different solar cell devices. An impressive number of perylenediimides have been incorporated into p-n organic solar cells, as non-fullerene acceptors in bulk heterojunction solar cells, as photosensitisers in dye-sensitised solar cells, in perovskite solar cells, and also as interlayers acting as either electron- or hole-transporting materials. All of this has led to devices with outstanding photovoltaic performance and these are described in this review.

Despite decades of study, mimicry continues to inspire and challenge evolutionary biologists. This essay aims to assess recent conceptual frameworks for the study of mimicry and to examine the links between mimicry and related phenomena. Mimicry is defined here as similarity in appearance and/or behavior between a mimic and a model that provides a selective advantage to the mimic because it affects the behavior of a receiver causing it to misidentify the mimic, and that evolved (or is maintained by selection) because of those effects. Mimics copy cues or signals that are already in use as part of a stable communication system, but offer misleading information to receivers. Mimicry overlaps, both conceptually and evolutionarily, with camouflage and perceptual exploitation but the overlap is only partial, which may create some confusion. Certain types of camouflage (e.g. masquerade) conform to the definition of mimicry, while others (e.g. background matching) are not considered mimicry because they prevent detection rather than recognition of the camouflaged animal. Mimicry, on the other hand, works by exploiting peculiarities of the receiver at higher stages of sensory processing involving recognition and classification of stimuli. Perceptual exploitation models of trait evolution are also closely related to mimicry, and sensory traps in particular may act as a precursor for true mimicry to evolve. The common thread through these diverse phenomena is deception of a receiver by a mimic. Thus receiver deception (i.e. perceptual error) emerges as a key characteristic of mimicry shared with some types of camouflage and perceptual exploitation.

Areas of selective neuronal loss (SNL) represent the first morphologic signs of damage in the penumbra region and are considered putative targets for ischemic stroke therapy. We performed a novel assessment of measuring the effects of the anti-inflammatory agent celecoxib by analyzing simultaneously the different neural populations (neurons, astrocytes, and microglia cells) in SNL and non-SNL areas. Rats were subjected to 1 hour of middle cerebral artery occlusion (MCAO) and treated with celecoxib 1 and 24 hours after ischemia. Infarct volume measurements and triple immunostaining of neurons (neuronal nuclear antigen), microglia (ionized calcium-binding adaptor molecule 1), and astroglia were performed after 12 and 48 hours of reperfusion. Motor response was tested by standard behavioral assays at 3, 12, 24, and 48 hours. Confocal analysis revealed that the percentage of SNL areas, microglia densities, and glial activation increased at 48 hours of reperfusion. Celecoxib treatment improved the neurologic deficit, reduced the infarct volume by 50% after 48 hours of reperfusion, and resulted in a reduced percentage of SNL areas and microglia and astroglia reactivity after 48 hours of reperfusion. This study proves, for the first time, that celecoxib presents postischemic neuroprotective effects in a transient MCAO model, prevents or delays the presence of SNL areas, and reduces glial activation.

1 - Over the past twenty years, portable and relatively affordable spectrophotometers have greatly advanced the study of animal coloration. However, the small size of many colour patches poses methodological challenges that have not, to date, been assessed in the literature. Here, we tackle this issue for a reflectance spectrophotometry set-up widely used in ecology and evolution (the beam method). 2 - We reviewed the literature on animal coloration reporting the use of reflectance spectrophotometry to explore how the minimum measurable size of a colour patch is determined. We then used coloured plastic sheets to create artificial colour patches, and quantify the relationship between colour patch size and distortions induced by resulting chimeric spectra (spectra contaminated by an adjacent colour patch). Finally, we assessed the generality of our findings using natural colour spots in the lizard Podarcis muralis, as a biologically realistic model. 3 We found a lack of consensus in the literature, frequently resulting in the rejection of valid data or the potential inclusion of unreliable data. As expected, we show that decreasing colour patch size reduces the reliability of reflectance measurements, but also that spectral distortions resulting from chimeric spectra depend on patch/background colour combinations. We found similar results using natural colour spots in P. muralis. 4 - We propose a series of steps to avoid the pitfalls described above. First, we provide guidelines on how to identify chimeric spectra and estimate the minimum size of a measurable colour patch in order to avoid them. Second, we show that reducing the probe-to-surface distance allows for more accurate measurements and therefore improves the spectrophotometric assessment of small colour patches. Third, we suggest that, as a general rule of thumb, very small (< 2 mm) colour patches should be avoided when using traditional spectrophotometry methods. This article is protected by copyright. All rights reserved.

Polymer waveguides doped with luminescent materials serve as a suitable flexible platform for active elements (lasers and amplifiers) in on-chip optical circuits. However, at present, the best parameters (lowest thresholds) achieved with these devices are obtained with the use of the stripe excitation technique in the framework of which external illumination of an active material along the whole length of the waveguide is realized that is not convenient for the waveguide on-chip integration and requires high peak energies due to the large excitation area. In the present work, an elegant method is proposed to overcome this obstacle and provide efficient active material pumping along the whole waveguide length with use of on-chip integration compatible edge-type excitation light injection. This novel type of planar active-passive polymer waveguides includes a thin (50–100 nm) active layer of poly(methyl methacrylate) (PMMA), which is heavily doped with highly luminescent perylenediimide (PDI) molecules, san...

The reaction of ortho- and bay-substituted chloro- or bromoperylenediimides with alcohols and thiols in the presence of fluoride ions affords the corresponding alkoxy- or alkylthioPDIs in good to excellent yields under mild conditions.

Body size correlates with most structural and functional components of an organism’s phenotype – brain size being a prime example of allometric scaling with animal size. Therefore, comparative studies of brain evolution in vertebrates rely on controlling for the scaling effects of body size variation on brain size variation by calculating brain weight/body weight ratios. Differences in the brain size-body size relationship between taxa are usually interpreted as differences in selection acting on the brain or its components, while selection pressures acting on body size, which are among the most prevalent in nature, are rarely acknowledged, leading to conflicting and confusing conclusions. We address these problems by comparing brain-body relationships from across >1,000 species of birds and non-avian reptiles. Relative brain size in birds is often assumed to be 10 times larger than in reptiles of similar body size. We examine how differences in the specific gravity of body tissues and in body design (e.g., presence/absence of a tail or a dense shell) between these two groups can affect estimates of relative brain size. Using phylogenetic comparative analyses, we show that the gap in relative brain size between birds and reptiles has been grossly exaggerated. Our results highlight the need to take into account differences between taxa arising from selection pressures affecting body size and design, and call into question the widespread misconception that reptile brains are small and incapable of supporting sophisticated behavior and cognition.

Animal body coloration is a complex trait resulting from the interplay of multiple mechanisms. While many studies address the functions of animal coloration, the mechanisms of colour production still remain unknown in most taxa. Here we compare reflectance spectra, cellular, ultra- and nano-structure of colour-producing elements, and pigment types in two freshwater turtles with contrasting courtship behaviour,Trachemys scriptaandPseudemys concinna. The two species differ in the distribution of pigment cell-types and in pigment diversity. We found xanthophores, melanocytes, abundant iridophores and dermal collagen fibres in stripes of both species. The yellow chin and forelimb stripes of bothP. concinnaandT. scriptacontain xanthophores and iridophores, but the post-orbital regions of the two species differ in cell-type distribution. The yellow post-orbital region ofP. concinnacontains both xanthophores and iridophores, whileT. scriptahas only xanthophores in the yellow-red postorbital/zygomatic regions. Moreover, in both species, the xanthophores colouring the yellow-red skin contain carotenoids, pterins and riboflavin, butT. scriptahas a higher diversity of pigments thanP. concinna.Trachemys s. elegansis sexually dichromatic. Differences in the distribution of pigment cell types across body regions in the two species may be related to visual signalling but do not match predictions based on courtship position. Our results demonstrate that archelosaurs share some colour production mechanisms with amphibians and lepidosaurs (i.e. vertical layering/stacking of different pigment cell types and interplay of carotenoids and pterins), but also employ novel mechanisms (i.e. nano-organization of dermal collagen) shared with mammals.

Ischemic stroke is one of the most important causes of death and disability worldwide. Subroutines underlying cell death after stroke are largely unknown despite their importance in the design of novel therapies for this pathology. Necroptosis, a recently described form of regulated cell death, has been related with inflammation and, in some models, with endoplasmic reticulum (ER) stress. We hypothesize that alleviation of ER stress following a salubrinal treatment will reduce the ischemic-dependent necroptosis. To probe the hypothesis, we measured, at 48 and 72 h after transient global cerebral ischemia in rat, in cerebral cortex and cornu ammonis 1, the main hallmarks of necroptosis: mRNA levels and phosphorylation of mixed lineage kinase domain like pseudokinase as well as receptor interacting serine/threonine protein kinase 3, along the years 2017-2018. Selective neuronal loss after 7 days of the ischemic insult, and other markers related with the inflammatory response were also measured. This study shows that necroptosis in cerebral cortex can be detected after 72 h of the insult and seems to be elicited before 48 h of reperfusion. The type of necroptosis here observed seems to be tumor necrosis factor receptor 1 independent. Necroptotic response is less evident in the cornu ammonis 1 hippocampal area than in cerebral cortex. The treatment with salubrinal administered 1 and 24 h after the ischemia, decreased the necroptotic marker levels and reduced the areas of selective neuronal loss, supporting the presence of ischemic-dependent necroptosis, and the notion that ER stress is involved in the necroptotic response. Open Science: This manuscript was awarded with the Open Materials Badge For more information see: https://cos.io/our-services/open-science-badges/.

176 p. El ictus o accidente cerebrovascular (ACV) es una de las principales causas de muerte e incapacidad y conlleva grandes gastos tanto sociales como económicos. Los supervivientes de un ictus normalmente presentan incapacidades motoras o cognitivas que reducen gravemente su nivel de vida. Entre los factores de riesgo del ictus la edad es el más importante, dado que la mayor parte de los casos de ACV se dan a partir de los 65 años, y su incidencia aumenta exponencialmente con la edad. El progresivo envejecimiento de la población ha supuesto un aumento en la incidencia de esta patología, lo que incrementa la urgencia en la búsqueda de nuevas terapias para paliar el daño isquémico. A pesar de que el proceso de envejecimiento provoca una serie de alteraciones que pueden llevar a una respuesta diferente frente al ACV, la mayor parte de los estudios entorno a la patología del ictus y la búsqueda de nuevas terapias se realiza en animales jóvenes. Éste trabajo se centra en el proceso neuroinflamatorio, que es en parte responsable de los procesos de muerte celular retrasada asociada a esta patología, en animales jóvenes y viejos. En concreto éste estudio analiza el proceso de necroptosis, una modalidad de muerte celular regulada (MCR) descrita recientemente y estrechamente relacionada con la respuesta inflamatoria. Para la realización de este trabajo se ha utilizado un modelo de isquemia cerebral global inducida mediante la oclusión de las carótidas en un estado hipotenso. Este modelo permite la comparación entre la corteza cerebral (cx) y el área hipocampal CA1, regiones que presentan diferente vulnerabilidad al daño isquémico. En el primer capítulo se analizan, mediante Western blot (WB) y PCR cuantitativa en tiempo real (qPCR), los principales marcadores de la señalización inducida por el receptor 1 del factor de necrosis tumoral (TNFR1) 48 y 72 horas después del ictus. Además, se analiza la pérdida neuronal 7 días después del ACV mediante inmunomarcado del antígeno neuronal NeuN. Nuestros datos indican que el ictus provoca necroptosis en la Cx, que esta respuesta comienza antes de las 48 horas y se mantiene al menos hasta las 72 horas de reperfusión. Algunos datos obtenidos en CA1, sugieren una respuesta necroptótica en esta región, sin embargo, los resultados obtenidos no permiten asegurarlo. La isquemia causa además estrés de retículo endoplasmático en la Cx, que ocurre simultáneamente a la inducción de la necorptosis, y cuya ejecución es paralela a una respuesta transcripcional mediada por NF-κB. La falta de activación de NF-κB en CA1 sugiere que la activación de NF-κB depende de la ejecución de la necroptosis. Además, dado que el alivio del estrés de retículo mediante la potenciación de la respuesta a las proteínas mal plegadas (UPR) inhibe la necroptosis y reduce la pérdida neuronal en la Cx, sugerimos que la necroptosis observada en esta área es dependiente del estrés de retículo. En el segundo capítulo se analiza el efecto del envejecimiento en la inflamación inducida por el ictus y se compara la respuesta entre la Cx y el CA1. La activación glial por el ictus se caracterizó a las 48 horas de reperfusión mediante análisis morfométricos y densitométricos de la microglía y la astroglía. Además, se caracterizó el fenotipo y la activación de la microglía mediante ensayos de qPCR. Los datos obtenidos en animales jóvenes muestran que, en la Cx, el ACV induce una polarización hacia ambos fenotipos microgliales, M1 y M2, mientras que en el CA1 solo se observa una polarización hacia el fenotipo M1. El envejecimiento altera la polarización de la microglía en el CA1, donde se puede observar cierta polarización hacia el fenotipo M2 asociado a la edad, pero no en la Cx, donde el envejecimiento, aunque altera la respuesta en algunos marcadores fenotípicos, no modifica sustancialmente la polarización. Estos datos sugieren una respuesta dependiente de la estructura asociada al envejecimiento, en la que la microglía del CA1 se ve más afectada que la microglía cortical. El ACV provoca una fuerte activación astroglial en la Cx que no se detecta en el CA1. Estos datos sugieren que la astrogliosis puede tener un papel en la diferente vulnerabilidad al daño isquémico observado entre estas regiones. Esta respuesta astroglial no se observa en los animales viejos, lo cual concuerda con el aumento en el daño isquémico asociado a la edad. Por último, el tercer capítulo se centra en los efectos del envejecimiento en la necroptosis inducida por el ACV. Para analizar el efecto de la edad en este tipo de MCR se midieron los principales marcadores de la ruta de señalización de TNFR1, mediante ensayos de WB y qPCR, tanto en animales jóvenes como en viejos, 48 horas después del ACV. Los resultados obtenidos en este estudio confirman que el ACV provoca necroptosis en la Cx, mientras que en CA1 podrían predominar otros tipos de MCR, como la apoptosis. Además, el envejecimiento acelera al menos 24 horas la progresión de la necroptosis en la Cx. El aceleramiento de la necroptosis parece depender de una menor expresión de las proteínas pro-supervivencia que regulan la señalización por TNFR1. Finalmente, los aumentos de algunos marcadores apoptóticos asociados a la edad en CA1, sugieren que la apoptosis es más relevante que la necroptosis en la muerte celular provocada por el ACV en esta área cerebral.

Selection for signal efficacy (detectability) is an important factor driving the evolution of chromatic signals. Communication theory predicts that colour signals should evolve to show those properties that maximize their conspicuousness to receivers in their own visual environment. In the ventrally polymorphic lizard Podarcis muralis, visual modelling has shown morph-specific differences in chromatic conspicuousness (orange > yellow > white). Although this suggests that morphs may incur different detectability costs, the differences in conspicuousness could be compensated behaviourally if individuals of the more conspicuous morphs adopted postures that made their colour patches less visible. We quantified the degree of exposure of the lizard ventral and ventrolateral coloration in the field to investigate the relationship between body posture and colour morph. We used a classification based on four lizard postures, from ventral surface completely hidden to full exposure of the ventral and ventrolateral colour patches (when lizards extend their forelegs and raise the head). As these postures may have consequences for thermoregulation, we also recorded substrate and lizard body temperatures using a thermographic camera. Results did not reveal differences among morphs in the frequency with which they adopt postures that expose their colour patches. In contrast, we found a strong relationship between body temperature and lizard posture. Overall, our results support the view that, regardless of colour morph, perching wall lizards adopt the elevated postures that maximize exposure of their ventral colour patches only when their body temperature is high enough to allow for an efficient predator avoidance response. Selection for effective communication favours flashy, highly conspicuous coloration, but conspicuousness also makes colour signals more detectable to unintended receivers (e.g. predators). Some animals offset the costs associated with conspicuous coloration by evolving compensatory traits. In the lizard P. muralis, ventral colour morphs differ in conspicuousness and we hypothesized that the most conspicuous morphs might compensate for their increased conspicuousness by adopting postures that minimize exposure of their conspicuous colour patches. Results show that the morph-specific differences in conspicuousness are not compensated behaviourally. In contrast, we found a strong relationship between body temperature and lizard posture, suggesting that lizards, regardless of colour morph, adopt postures exposing their conspicuous colour patches only when their body temperature allows for an efficient predator avoidance response.

The reaction of perylenediimides with alcohols in the presence of fluoride anions yields 1-alkoxy- or 1,6(7)-dialkoxyperylenediimides under very mild metal-free conditions. The reaction can also be applied to bay- and ortho-brominated perylenediimides.

Colour signals play a key role in regulating the intensity and outcome of animal contests. Males of the common wall lizard (Podarcis muralis) show conspicuous ventrolateral ultraviolet (UV)-blue and black patches. In addition, some populations express a striking ventral colour polymorphism (i.e., discrete orange, white and yellow morphs). In this study, we set out to evaluate the potential signalling function of these colour patches by staging pairwise combats between 60 size-matched adult lizards (20 per morph). Combats were held in a neutral arena, with each lizard facing rivals from the three morphs in a tournament with a balanced design. We then calculated a fighting ability ranking using the Bradley–Terry model, and used it to explore whether ventral colour morph, the size of UV-blue and black patches or the spectral characteristics of UV-blue patches (i.e., brightness, hue, chroma) are good predictors of fighting ability. We did not find an effect of the UV-blue patches on contest outcome, but the size of black patches emerged as a good predictor of fighting ability. We also found that winners were more aggressive when facing rivals with black patches of similar size, suggesting that black patches play a role in rival assessment and fighting rules. Finally, we found that orange males lost fights against heteromorphic males more often than yellow or white males. In light of these results, we discuss the potential signalling function of ventrolateral and ventral colour patches in mediating agonistic encounters in this species.

Iridescence is a visual property of those surfaces that change in colour with viewing angle. Iridescence has been rarely reported in reptiles, but some snakes and lizards show this type of coloration. Here we study the effect of different angles of light incidence and observation on the spectrophotometrically assessed reflectance of dorsal coloration in the lizard Podarcis muralis. The results demonstrate clear angle dependence of several colour parameters. In particular, different angles of light incidence and observation result in changes in hue of more than 30 nm. This suggests that lizard dorsal coloration may be perceived, depending on viewing geometry, as being of different colours by a wide range of potential observers. Functional implications of iridescence in dorsal coloration are discussed.

Reptiles use pterin and carotenoid pigments to produce yellow, orange, and red colors. These conspicuous colors serve a diversity of signaling functions, but their molecular basis remains unresolved. Here, we show that the genomes of sympatric color morphs of the European common wall lizard, which differ in orange and yellow pigmentation and in their ecology and behavior, are virtually undifferentiated. Genetic differences are restricted to two small regulatory regions, near genes associated with pterin (SPR) and carotenoid metabolism (BCO2), demonstrating that a core gene in the housekeeping pathway of pterin biosynthesis has been co-opted for bright coloration in reptiles and indicating that these loci exert pleiotropic effects on other aspects of physiology. Pigmentation differences are explained by extremely divergent alleles and haplotype analysis revealed abundant trans-specific allele sharing with other lacertids exhibiting color polymorphisms. The evolution of these conspicuous color ornaments is the result of ancient genetic variation and cross-species hybridization.

Mammals and birds are capable of navigating to a goal using learned map-like representations of space (i.e. place learning), but research assessing this navigational strategy in reptiles has produced inconclusive results, in part due to the use of procedures that do not take account of the peculiarities of reptilian behavior and physiology. Here I present a procedure suitable for testing spatial cognition that exploits a naturally evolved, ethologically relevant ability common to many lizards (i.e. refuge seeking behavior). The procedure requires lizards to learn the location of an open refuge inside a rectangular arena containing artificial refuges in every corner, using distal extramaze visual cues and with no local cues marking the location of the open refuge. The procedure probes the lizards’ place learning ability and effectively rules out the use of egocentric and response-based strategies. The described procedure was successfully used to demonstrate place learning in a lacertid lizard (Podarcis liolepis). Over the course of two weeks of training both the latency to entering the open refuge and the number of corners visited in each trial decreased gradually, indicating that learning had taken place in over 60% of the lizards tested. These results confirm that, under certain circumstances, lizards are capable of navigating to a goal using a place learning strategy.

In many species, male coloration signals aggressiveness and/or fighting ability. Males of the Tenerife lizard (Gallotia galloti) have conspicuous ultraviolet (UV)-blue cheek and lateral color patches that are brighter in the breeding season and larger than those of females. We analyzed experimentally the effect of morphological and behavioral traits, including spectral variables from UV-reflecting color patches, on the outcome of staged dyadic contests between males of two subspecies of G. galloti. We performed two experiments: (1) using pairs of unmanipulated males and (2) reducing the UV reflectance of the UV-blue patches of one of the contestants with sunscreen lotion. Results from experiment 1 showed no significant difference between subspecies in the effect of any variable on contest outcome. Overall, winners had larger body mass, head width, and fore-limb length and showed a higher rate of aggressive behavior patterns than losers, whereas losers showed a higher rate of “tail shake,” which is considered a submissive behavior. Winners also had lateral UV-blue patches with higher (more blue-biased) hue than losers, but no other spectral trait had a significant effect on contest outcome. Results from experiment 2 showed that reducing patch reflectance in the UV range had no effect in one subspecies but significantly increased fighting success in the other. The probability of winning was positively associated with the frequency of bites (irrespective of whether individuals had manipulated patches or not). Results from both experiments suggest that while multiple traits (morphometric, coloration, and behavioral) may influence the outcome of male contests in G. galloti, behavioral traits take prevalence over morphological, including coloration, traits. The effect of several traits on the outcome of contests has been previously analyzed in males of several lizard species. These analyses have commonly considered the effect of a single trait on contest outcome. However, as even males of the same age and experience often vary across multiple morphological (including coloration), performance, and behavioral traits, it has been suggested that contest outcome could be influenced by several interacting traits. We tested this hypothesis by staging dyadic contests between males of two subspecies of the Tenerife lizard. Results from a first experiment showed that larger body mass, head width, fore-limb lengths, higher frequency of bites, throat extension, and higher peak reflectance (hue) of UV-blue patches significantly affected the probability of winning, while a large frequency of tail shakes was associated with losing. Results from a second experiment, in which we experimentally manipulated patch UV reflectance in one of the contestant lizards, showed that bite frequency and reduction of UV reflectance affected the probability of winning; we discuss the complex effect of this latter trait on contest outcome.

Brain-derived neurotrophic factor (BDNF) is considered as a putative therapeutic agent against stroke. Since BDNF role on oxidative stress is uncertain, we have studied this role in a rat brain slice ischemia model, which allows BDNF reaching the neural parenchyma. Hippocampal and cerebral cortex slices were subjected to oxygen and glucose deprivation (OGD) and then returned to normoxic conditions (reperfusion-like, RL). OGD/RL increased a number of parameters mirroring oxidative stress in the hippocampus that were reduced by the BDNF presence. BDNF also reduced the OGD/RL-increased activity in a number of antioxidant enzymes in the hippocampus but no effects were observed in the cerebral cortex. In general, we conclude that alleviation of oxidative stress by BDNF in OGD/RL-exposed slices relies on decreasing cPLA2 activity, rather than modifying antioxidant enzyme activities. Moreover, a role for the oxidative stress in the differential ischemic vulnerability of cerebral cortex and hippocampus is also supported.

Background Blood reperfusion of the ischemic tissue after stroke promotes increases in the inflammatory response as well as accumulation of unfolded/misfolded proteins in the cell, leading to endoplasmic reticulum (ER) stress. Both Inflammation and ER stress are critical processes in the delayed death of the cells damaged after ischemia. The aim of this study is to check the putative synergic neuroprotective effect by combining anti-inflammatory and anti-ER stress agents after ischemia. Methods The study was performed on a two-vessel occlusion global cerebral ischemia model. Animals were treated with salubrinal one hour after ischemia and with robenacoxib at 8 h and 32 h after ischemia. Parameters related to the integrity of the blood–brain barrier (BBB), such as matrix metalloproteinase 9 and different cell adhesion molecules (CAMs), were analyzed by qPCR at 24 h and 48 h after ischemia. Microglia and cell components of the neurovascular unit, including neurons, endothelial cells and astrocytes, were analyzed by immunofluorescence after 48 h and seven days of reperfusion. Results Pharmacologic control of ER stress by salubrinal treatment after ischemia, revealed a neuroprotective effect over neurons that reduces the transcription of molecules involved in the impairment of the BBB. Robenacoxib treatment stepped neuronal demise forward, revealing a detrimental effect of this anti-inflammatory agent. Combined treatment with robenacoxib and salubrinal after ischemia prevented neuronal loss and changes in components of the neurovascular unit and microglia observed when animals were treated only with robenacoxib. Conclusion Combined treatment with anti-ER stress and anti-inflammatory agents is able to provide enhanced neuroprotective effects reducing glial activation, which opens new avenues in therapies against stroke.

Reducing the number of animal subjects used in biomedical experiments is desirable for ethical and practical reasons. Previous reviews of the benefits of reducing sample sizes have focused on improving experimental designs and methods of statistical analysis, but reducing the size of control groups has been considered rarely. We discuss how the number of current control animals can be reduced, without loss of statistical power, by incorporating information from historical controls, i.e. subjects used as controls in similar previous experiments. Using example data from published reports, we describe how to incorporate information from historical controls under a range of assumptions that might be made in biomedical experiments. Assuming more similarities between historical and current controls yields higher savings and allows the use of smaller current control groups. We conducted simulations, based on typical designs and sample sizes, to quantify how different assumptions about historical controls affect the power of statistical tests. We show that, under our simulation conditions, the number of current control subjects can be reduced by more than half by including historical controls in the analyses. In other experimental scenarios, control groups may be unnecessary. Paying attention to both the function and to the statistical requirements of control groups would result in reducing the total number of animals used in experiments, saving time, effort and money, and bringing research with animals within ethically acceptable bounds.

Two phthalocyanines possessing carboxylate groups ((TBA)4H2Pc·1 and (TBA)4H2Pc·2) form 1:2 supramolecular complexes with lithium cation-encapsulated C60 (Li(+)@C60) [H2Pc·1(4-)/(Li(+)@C60)2 and H2Pc·2(4-)/(Li(+)@C60)2] in a polar mixed solvent. From the UV-vis spectral changes, the binding constants (K) were estimated as ca. 10(12) M(-2). Upon the photoexcitation of constructed supramolecular complexes, photoinduced electron transfer occurred to form the charge-separated (CS) state. The lifetime of the CS state was determined to be 1.2 ms for H2Pc·2(4-)/(Li(+)@C60)2, which is the longest CS lifetime among the porphyrinoid/fullerene supramolecular complexes. H2Pc·1(4-)/(Li(+)@C60)2 also afforded the long-lived CS state of 1.0 ms. The spin state of the long-lived CS states was determined to be a triplet, as indicated by the EPR signal at g = 4. The reorganization energy (λ) and the electronic coupling term were determined to be λ = 1.70 eV, V = 0.15 cm(-1) from the temperature dependence of the rate constant for the charge recombination of the CS state of H2Pc·1(4-)/(Li(+)@C60)2. The energy of the CS state (0.49 eV) is much smaller than the reorganization energy, indicating that the back-electron-transfer process is located in the Marcus normal region. The small electronic coupling term results from the spin-forbidden back electron transfer due to the triplet CS state. Supramolecular complexes of anionic zinc phthalocyanines with Li(+)@C60 were also prepared and investigated. The ZnPc·4(4-)/Li(+)@C60 supramolecular nanoclusters were assembled on the optically transparent electrode (OTE) of nanostructured SnO2 (OTE/SnO2) to construct the dye-sensitized solar cell. The IPCE (incident photon-to-photocurrent efficiency) values of OTE/SnO2/(ZnPc·4(4-)/Li(+)@C60)n were much higher than the sum of the two IPCE values of the individual systems OTE/SnO2/(Li(+)@C60)n and OTE/SnO2/(ZnPc·4(4-))n, covering the near-infrared region.

Colour polymorphisms are thought to be maintained by complex evolutionary processes some of which require that the colours of the alternative morphs function as chromatic signals to conspecifics. Unfortunately, a key aspect of this hypothesis has rarely been studied: whether the study species perceives its own colour variation as discrete rather than continuous. The European common wall lizard (Podarcis muralis) presents a striking colour polymorphism: the ventral surface of adults of both sexes may be coloured orange, white, yellow, or with a mosaic of scales combining two colours (orange-white, orange-yellow). Here we use a discrimination learning paradigm to test if P. muralis is capable of discriminating colour stimuli designed to match the ventral colours of conspecifics. We trained 20 lizards to eat from colour-coded wells bored in wooden blocks. Blocks had four colour-coded wells (orange, white, yellow, and an achromatic control), but only one contained food (mealworm larvae). After six trials, the lizards performed significantly better than expected by chance, showing a decrease in both the number of wells explored and the latency to finding the food. Using visual modelling techniques we found that, based on their spectral properties and the lizards’ cone sensitivities, the ventral colours of P. muralis correspond to discrete rather than continuous colour categories, and that colour discriminability (i.e. distance in perceptual space) varies depending on the morphs compared, which may have implications for signal detection and discrimination. These results suggest that P. muralis can discriminate hue differences matching their own ventral colour variation.