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BACKGROUND: We recently reported that the dopamine (DA) analogue CA140 modulates neuroinflammatory responses in lipopolysaccharide-injected wild-type (WT) mice and in 3-month-old 5xFAD mice, a model of Alzheimers disease (AD). However, the effects of CA140 on Aβ/tau pathology and synaptic/cognitive function and its molecular mechanisms of action are unknown. METHODS: To investigate the effects of CA140 on cognitive and synaptic function and AD pathology, 3-month-old WT mice or 8-month-old (aged) 5xFAD mice were injected with vehicle (10% DMSO) or CA140 (30 mg/kg, i.p.) daily for 10, 14, or 17 days. Behavioral tests, ELISA, electrophysiology, RNA sequencing, real-time PCR, Golgi staining, immunofluorescence staining, and western blotting were conducted. RESULTS: In aged 5xFAD mice, a model of AD pathology, CA140 treatment significantly reduced Aβ/tau fibrillation, Aβ plaque number, tau hyperphosphorylation, and neuroinflammation by inhibiting NLRP3 activation. In addition, CA140 treatment downregulated the expression of cxcl10, a marker of AD-associated reactive astrocytes (RAs), and c1qa, a marker of the interaction of RAs with disease-associated microglia (DAMs) in 5xFAD mice. CA140 treatment also suppressed the mRNA levels of s100β and cxcl10, markers of AD-associated RAs, in primary astrocytes from 5xFAD mice. In primary microglial cells from 5xFAD mice, CA140 treatment increased the mRNA levels of markers of homeostatic microglia (cx3cr1 and p2ry12) and decreased the mRNA levels of a marker of proliferative region-associated microglia (gpnmb) and a marker of lipid-droplet-accumulating microglia (cln3). Importantly, CA140 treatment rescued scopolamine (SCO)-mediated deficits in long-term memory, dendritic spine number, and LTP impairment. In aged 5xFAD mice, these effects of CA140 treatment on cognitive/synaptic function and AD pathology were regulated by dopamine D1 receptor (DRD1)/Elk1 signaling. In primary hippocampal neurons and WT mice, CA140 treatment promoted long-term memory and dendritic spine formation via effects on DRD1/CaMKIIα and/or ERK signaling. CONCLUSIONS: Our results indicate that CA140 improves neuronal/synaptic/cognitive function and ameliorates Aβ/tau pathology and neuroinflammation by modulating DRD1 signaling in primary hippocampal neurons, primary astrocytes/microglia, WT mice, and aged 5xFAD mice.

Drugs of abuse can persistently change the reward circuit in ways that contribute to relapse behavior, partly via mechanisms that regulate chromatin structure and function. Nuclear orphan receptor subfamily4 groupA member2 (NR4A2, also known as NURR1) is an important effector of histone deacetylase 3 (HDAC3)-dependent mechanisms in persistent memory processes and is highly expressed in the medial habenula (MHb), a region that regulates nicotine-associated behaviors. Here, expressing the Nr4a2 dominant negative (Nurr2c) in the MHb blocks reinstatement of cocaine seeking in mice. We use single-nucleus transcriptomics to characterize the molecular cascade following Nr4a2 manipulation, revealing changes in transcriptional networks related to addiction, neuroplasticity, and GABAergic and glutamatergic signaling. The network controlled by NR4A2 is characterized using a transcription factor regulatory network inference algorithm. These results identify the MHb as a pivotal regulator of relapse behavior and demonstrate the importance of NR4A2 as a key mechanism driving the MHb component of relapse.

The developed human brain shows remarkable plasticity following perceptual learning, resulting in improved visual sensitivity. However, such improvements commonly require extensive stimuli exposure. Here we show that efficiently enhancing visual perception with minimal stimuli exposure recruits distinct neural mechanisms relative to standard repetition-based learning. Participants (n = 20, 12 women, 8 men) encoded a visual discrimination task, followed by brief memory reactivations of only five trials each performed on separate days, demonstrating improvements comparable with standard repetition-based learning (n = 20, 12 women, 8 men). Reactivation-induced learning engaged increased bilateral intraparietal sulcus (IPS) activity relative to repetition-based learning. Complementary evidence for differential learning processes was further provided by temporal–parietal resting functional connectivity changes, which correlated with behavioral improvements. The results suggest that efficiently enhancing visual perception with minimal stimuli exposure recruits distinct neural processes, engaging higher-order control and attentional resources while leading to similar perceptual gains. These unique brain mechanisms underlying improved perceptual learning efficiency may have important implications for daily life and in clinical conditions requiring relearning following brain damage. [ABSTRACT FROM AUTHOR]

Objective：To explore the possible mechanism of regular aerobic exercise in improving the learning and memory function in rats with middle cerebral artery occlusion reperfusion (MCAO/R). Method：Total of 36 SD rats were randomly divided into 3 groups：sham operation group (IS group), aerobic exercise group (AE group), and model group (IC group). MCAO/R models were established in the IC and AE groups, while the IS group underwent the same arterial dissection without occlusion. After model establishment, the rats in the AE group were trained on a treadmill for 14 days, while the rats in the IS group and IC group were only placed on the treadmill for the same duration without running. The neurological function of the rats in each group was scored, the cerebral infarction focus of the rats was observed by magnetic resonance imaging T2WI scanning before and after the intervention, and the recognition and memory ability of the rats was detected by the new object recognition experiment before and after the intervention. The Western Blot was used to detect the expression of NLRP3, caspase-1, and GSDMD in the hippocampus, and immunohistochemistry was used to detect the activation of microglia in the CA1 region of the ischemic hippocampus. The levels of IL-1β and IL-18 were detected by ELISA. The expression and co-localization of IBA1 with NLRP3, caspase-1, and GSDMD were detected by immunofluorescence co-labeling assay. Result：Before intervention, the neurological function score and the signal intensity of the left cerebral cortex hippocampus of the IC Group were significantly higher than that of the IS group (P<0.05), and the resolution of new objects decreased significantly (P<0.05). There were no significant differences between the AE and IC groups in the proportion of neurological deficit, cerebral infarction volume and novel object recognition rate (P>0.05). After 14 days of treadmill training intervention, compared with IC group, the AE group showed significantly lower neurological function scores (P<0.05), reduced the percentage of cerebral infarction volume (P<0.05), improved object recognition ability (P<0.05), improved pathology in hippocampal CA1 area, reduced microglia activation level (P<0.05), decreased levels of IL-1β and IL-18 (P<0.05), and significantly reduced expression of NLRP3, caspase-1 and GSDMD proteins (P<0.05). In addition, compared with the IC group, the accumulative optical density of NLRP3, GSDMD in CA1 and caspase-1 in CA3 regions of the ischemic hippocampus in the AE group was significantly decreased, and the number of IBA1 and NLRP3, IBA1 and GSDMD double-positive cells was significantly decreased (P<0.05). Conclusion： Regular aerobic exercise can improve the ability of recognition and memory in MCAO/R rats, which may be related to the inhibition of hippocampal microglia pyroptosis and activation. [ABSTRACT FROM AUTHOR]

Sleep is considered closely related to cognitive function, and cognitive impairment is the main clinical manifestation of Alzheimer's disease (AD). Sleep disturbance in AD patients is more severe than that in healthy elderly individuals. Additionally, sleep deprivation reportedly increases the activity of the hypothalamic orexin system and the risk of AD. To investigate whether intervention with the orexin system can improve sleep disturbance in AD and its impact on AD pathology. In this study, six-month-old amyloid precursor protein/presenilin 1 mice were subjected to six weeks of chronic sleep deprivation and injected intraperitoneally with almorexant, a dual orexin receptor antagonist (DORA), to investigate the effects and mechanisms of sleep deprivation and almorexant intervention on learning and memory in mice with AD. We found that sleep deprivation aggravated learning and memory impairment and increased brain β-amyloid (Aβ) deposition in mice with AD. The application of almorexant can increase the total sleep time of sleep-deprived mice and reduce cognitive impairment and Aβ deposition, which is related to the improvement in Aquaporin-4 polarity. Thus, DORA may be an effective strategy for delaying the progression of AD patients by improving the sleep disturbances. • Almorexant intervention can alleviate chronic sleep deprivation-induced AD learning and memory impairment and Aβ deposition. • The mechanism may be related to mitigating the damage to AQP4 polarity caused by sleep deprivation. • Orexin dual receptor antagonists can be an effective strategy for improving sleep in AD, and slowing pathological progression. [ABSTRACT FROM AUTHOR]

Background: The impact of acrylamide (ACR) on learning and memory has garnered considerable attention. However, the targets and mechanisms are still unclear. Results: Elongation factor 2 (eEF2) was significantly upregulated in the results of serum proteomics. Results from in vitro and in vivo experiments indicated a notable upregulation of Eukaryotic elongation factor 2 kinase (eEF2K), the sole kinase responsible for eEF2 phosphorylation, following exposure to ACR (P < 0.05). Subsequent in vitro experiments using eEF2K siRNA and in vivo experiments with eEF2K-knockout mice demonstrated significant improvements in abnormal indicators related to ACR-induced learning and memory deficits (P < 0.05). Proteomic analysis of the hippocampus revealed Lpcat1 as a crucial downstream protein regulated by eEF2K. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses indicated that eEF2K may play a role in the process of ACR-induced learning and memory impairment by affecting ether lipid metabolism. Conclusions: In summary, eEF2K as a pivotal treatment target in the mechanisms underlying ACR-induced learning and memory impairment, and studies have shown that it provides robust evidence for potential clinical interventions targeting ACR-induced impairments. [ABSTRACT FROM AUTHOR]

A topic of recent debate is the hypothesis that deficits associated with developmental disorders of language, such as reading disability, can be explained by a selective weakness in procedural memory. Adults with (n = 29; RD) and without (n = 29; TD) reading disability completed a weather prediction task under immediate and delayed feedback conditions, that rely on the striatal (procedural) and hippocampal (declarative) circuits, respectively. We examined trial‐by‐trial accuracy by feedback condition (immediate vs. delayed) and group (RD vs. TD). In the immediate feedback condition, we found the TD group to have a higher learning rate than the RD group. In the delayed feedback condition, we found the TD group reach a high level of accuracy early, and outperform the RD group for the duration of the task. The TD group also made gains in reaction time under both conditions, while the RD group slowed in their responses. Taken together, it appears that while procedural memory is indeed impaired in adults with reading disability, to a lesser extent, declarative memory is also affected. This lends partial support to the PDH, and more broadly to the position that reading disability is associated with general (non‐linguistic) difficulties in learning. [ABSTRACT FROM AUTHOR]

Phenylacetaldehyde (PAH), an aromatic compound, is present in a diverse range of fruits including overripe bananas and prickly pear cactus, the two major host fruits for Drosophila melanogaster. PAH acts as a potent ligand for the ionotropic receptor 84a (IR84a) in the adult fruit fly and it is detected by the IR84a/IR8a heterotetrameric complex. Its role in the male courtship behavior through IR84a as an environmental aphrodisiac is of additional importance. In D. melanogaster, two distinct kinds of olfactory receptors, that is, odorant receptors (ORs) and ionotropic receptors (IRs), perceive the odorant stimuli. They display unique structural, molecular, and functional characteristics in addition to having different evolutionary origins. Traditionally, olfactory cues detected by the ORs such as ethyl acetate, 1‐butanol, isoamyl acetate, 1‐octanol, 4‐methylcyclohexanol, etc. classified as aliphatic esters and alcohols have been employed in olfactory classical conditioning using fruit flies. This underlines the participation of OR‐activated olfactory pathways in learning and memory formation. Our study elucidates that likewise ethyl acetate (EA) (an OR‐responsive odorant), PAH (an IR‐responsive aromatic compound) too can form learning and memory when associated with an appetitive gustatory reinforcer. The association of PAH with sucrose (PAH/SUC) led to learning and formation of the long‐term memory (LTM). Additionally, the Orco1, Ir84aMI00501, and Ir8a1 mutant flies were used to confirm the exclusive participation of the IR84a/IR8a complex in PAH/SUC olfactory associative conditioning. These results highlight the involvement of IRs via an IR‐activated pathway in facilitating robust olfactory behavior. [ABSTRACT FROM AUTHOR]

Objective：To observe the effects of repetitive transcranial magnetic stimulation (rTMS) at different frequencies on learning and memory abilities in rats during the early recovery phase of middle cerebral artery occlusion (MCAO) and to explore the underlying mechanisms. Method： Successfully modelled MCAO rats were randomly divided into the model group, low- frequency group, high- frequency group, and sham- operated group was set up at the same time, with 12 rats in each group. The low-frequency group and high-frequency group were stimulated with a CCY-I transcranial magnetic stimulator 2 times/day for 14d; the low-frequency group was treated with 1Hz at the left prefrontal lobe of the rat's skull, and the high-frequency group was treated with 10Hz at the right prefrontal lobe. The model group and the sham-operated group were not treated but were subjected to the same conditions of handling and restraint before returning to their cages. Neurobehavioral scores were recorded on the 1st and 14th day after the operation; the Morris water maze test was conducted on day 3—7 after the operation; TTC staining, PCR and Western blot to detect the mRNA and protein expression of key genes (Notch1, Hes1, Hes5) were performed at the end of the intervention on the 14th postoperative day. Result：①Neurological deficit scores: After 14 days of intervention, both the high-frequency and low-frequency groups showed a reduction in neurofunctional compared to the model group (P<0.05), with no significant difference between the model group and high-frequency group (P>0.05). ②Morris water maze experiment: The average escape latency during the directional navigation experiment was significantly reduced day by day in the low frequency group, high frequency group and sham operation group (P<0.05). The escape latency was shorter in the high- frequency group compared to the model group, and shorter in the low- frequency group compared to the high-frequency group (P<0.05). The number of platform crossings in the spatial exploration experiment showed no significant difference between low frequency group and sham operation group, high frequency group and model group (P>0.05). The high-frequency group and the model group had fewer crossing than the sham operation group, and the low-frequency group had more than the model group and high-frequency group (P<0.05). ③TTC staining: The infarct size in the low-frequency group and high-frequency group was significantly smaller than in the model group. ④PCR and Western blot: Compared to the model group, the high frequency group and the low frequency group had significantly increased mRNA and protein expression of Notch1, Hes1 and Hes5 (P<0.05). There was no significant difference in the mRNA and protein expression of Notch1, Hes1 and Hes5 between the low frequency group and high frequency group (P>0.05). Conclusion： Both high and low frequency rTMS can improve the learning and memory abilities in MCAO rats, potentially by activating and increasing the expression of the Notch1 pathway in hippocampal tissues, which improves the synaptic plasticity of hippocampus. [ABSTRACT FROM AUTHOR]

Objective: Ethanol (Eth) intake is known to cause numerous detrimental effects on the structure and function of the brain, and it is commonly used as a psychostimulant drug by adolescents. Conversely, omega‐3 (O3) can reduce the risk of cognitive decline and promote the maintenance of neurophysiological functions. In this study, we investigated the protective effects of O3 on behavioral alterations, oxidative stress, and interleukin‐6 (IL‐6) levels induced by chronic Eth intake during adolescence in rats. Materials and methods: Adolescent male rats (21 days old) were divided as follows: (1) Vehicle, (2) Eth (Eth in drinking water [20%]), (3–5) Eth + O3 (50/100/150 mg/kg), and (6) O3 (150 mg/kg). After 5 weeks, Morris water maze (MWM) and passive avoidance (PA) tests were performed, and the hippocampal and cortical levels of oxidative stress markers and inflammatory indices were measured. Results: Adolescent Eth intake impairs learning and memory function in MWM and PA tests (groups × day, p < 0.05 and p < 0.001, respectively). It was shown that Eth induced oxidative stress and neuroinflammation. O3 improved learning and impairment induced by Eth by reducing the adverse effects of Eth on the oxidant/antioxidant balance in the hippocampi (for malondialdehyde [MDA]/thiol: p < 0.01, p < 0.001, respectively) and for superoxide dismutase (SOD)/catalase (CAT): p < 0.01 and p < 0.05, respectively). Furthermore, we found that O3 prevented the Eth‐induced increase of hippocampal IL‐6 (p < 0.001). Conclusion: O3 supplementation acts as an effective approach to prevent learning and memory impairments induced by chronic Eth consumption during adolescence. In this respect, the antioxidant and anti‐inflammatory properties of O3 seem to be the main underlying mechanisms of neuroprotection. [ABSTRACT FROM AUTHOR]

Simple Summary: This perspective article examines the differences between memory, information, and knowledge. It is proposed that the creation of knowledge is not simply the extraction of information or sequencing and storage of memories, but its contextualization that offers a point of advantage for survival within a decision-making framework; outside these contexts there are no useful memories and therefore no relevant knowledge. A constellation of neural networks spread across multiple brain regions must work together to grow knowledge over time. Knowledge must be stored in such a way that it can be accessed by multiple tokens, or handles, at any time. The emergence of knowledge networks underlies the evolution of complex brains that can predict outcomes, induce imagination and expand knowledge. Attention and sleep play important roles in creating and protecting knowledge. The brain receives information via sensory inputs through the peripheral nervous system and stores a small subset as memories within the central nervous system. Short-term, working memory is present in the hippocampus whereas long-term memories are distributed within neural networks throughout the brain. Elegant studies on the mechanisms for memory storage and the neuroeconomic formulation of human decision making have been recognized with Nobel Prizes in Physiology or Medicine and in Economics, respectively. There is a wide gap, however, in our understanding of how memories of disparate bits of information translate into "knowledge", and the neural mechanisms by which knowledge is used to make decisions. I propose that the conceptualization of a "knowledge network" for the creation, storage and recall of knowledge is critical to start bridging this gap. Knowledge creation involves value-driven contextualization of memories through cross-validation via certainty-seeking behaviors, including rumination or reflection. Knowledge recall, like memory, may occur via oscillatory activity that dynamically links multiple networks. These networks may show correlated activity and interactivity despite their presence within widely separated regions of the nervous system, including the brainstem, spinal cord and gut. The hippocampal–amygdala complex together with the entorhinal and prefrontal cortices are likely components of multiple knowledge networks since they participate in the contextual recall of memories and action selection. Sleep and reflection processes and attentional mechanisms mediated by the habenula are expected to play a key role in knowledge creation and consolidation. Unlike a straightforward test of memory, determining the loci and mechanisms for the storage and recall of knowledge requires the implementation of a naturalistic decision-making paradigm. By formalizing a neuroscientific concept of knowledge networks, we can experimentally test their functionality by recording large-scale neural activity during decision making in awake, naturally behaving animals. These types of studies are difficult but important also for advancing knowledge-driven as opposed to big data-driven models of artificial intelligence. A knowledge network-driven understanding of brain function may have practical implications in other spheres, such as education and the treatment of mental disorders. [ABSTRACT FROM AUTHOR]

Exercise has been recognized as a beneficial factor for cognitive health, particularly in relation to the hippocampus, a vital brain region responsible for learning and memory. Previous research has demonstrated that exercise-mediated improvement of learning and memory in humans and rodents correlates with increased adult neurogenesis and processes related to enhanced synaptic plasticity. Nevertheless, the underlying molecular mechanisms are not fully understood. With the aim to further elucidate these mechanisms, we provide a comprehensive dataset of the mouse hippocampal transcriptome at the single-cell level after 4 weeks of voluntary wheel-running. Our analysis provides a number of interesting observations. For example, the results suggest that exercise affects adult neurogenesis by accelerating the maturation of a subpopulation of Prdm16-expressing neurons. Moreover, we uncover the existence of an intricate crosstalk among multiple vital signaling pathways such as NF-κB, Wnt/β-catenin, Notch, and retinoic acid (RA) pathways altered upon exercise in a specific cluster of excitatory neurons within the Cornu Ammonis (CA) region of the hippocampus. In conclusion, our study provides an important resource dataset and sheds further light on the molecular changes induced by exercise in the hippocampus. These findings have implications for developing targeted interventions aimed at optimizing cognitive health and preventing age-related cognitive decline. [ABSTRACT FROM AUTHOR]

Short- and long-term forms of N-methyl-d-aspartate receptor (NMDAR)-dependent potentiation (most commonly termed short-term potentiation (STP) and long-term potentiation (LTP)) are co-induced in hippocampal slices by theta-burst stimulation, which mimics naturally occurring patterns of neuronal activity. While NMDAR-dependent LTP (NMDAR-LTP) is said to be the cellular correlate of long-term memory storage, NMDAR-dependent STP (NMDAR-STP) is thought to underlie the encoding of shorter-lasting memories. The mechanisms of NMDAR-LTP have been researched much more extensively than those of NMDAR-STP, which is characterized by its extreme stimulation dependence. Thus, in the absence of low-frequency test stimulation, which is used to test the magnitude of potentiation, NMDAR-STP does not decline until the stimulation is resumed. NMDAR-STP represents, therefore, an inverse variant of Hebbian synaptic plasticity, illustrating that inactive synapses can retain their strength unchanged until they become active again. The mechanisms, by which NMDAR-STP is stored in synapses without a decrement, are unknown and we report here that activation of metabotropic glutamate receptors may be critical in maintaining the potentiated state of synaptic transmission. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'. [ABSTRACT FROM AUTHOR]

Hippocampal long-term potentiation (LTP) and long-term depression (LTD) are Hebbian forms of synaptic plasticity that are widely believed to comprise the physiological correlates of associative learning. They comprise a persistent, input-specific increase or decrease, respectively, in synaptic efficacy that, in rodents, can be followed for days and weeks in vivo. Persistent (>24 h) LTP and LTD exhibit distinct frequency-dependencies and molecular profiles in the hippocampal subfields. Moreover, causal and genetic studies in behaving rodents indicate that both LTP and LTD fulfil specific and complementary roles in the acquisition and retention of spatial memory. LTP is likely to be responsible for the generation of a record of spatial experience, which may serve as an associative schema that can be re-used to expedite or facilitate subsequent learning. In contrast, LTD may enable modification and dynamic updating of this representation, such that detailed spatial content information is included and the schema is rendered unique and distinguishable from other similar representations. Together, LTP and LTD engage in a dynamic interplay that supports the generation of complex associative memories that are resistant to generalization. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'. [ABSTRACT FROM AUTHOR]

The integrated stress response (ISR), a pivotal protein homeostasis network, plays a critical role in the formation of long-term memory (LTM). The precise mechanism by which the ISR controls LTM is not well understood. Here, we report insights into how the ISR modulates the mnemonic process by using targeted deletion of the activating transcription factor 4 (ATF4), a key downstream effector of the ISR, in various neuronal and non-neuronal cell types. We found that the removal of ATF4 from forebrain excitatory neurons (but not from inhibitory neurons, cholinergic neurons, or astrocytes) enhances LTM formation. Furthermore, the deletion of ATF4 in excitatory neurons lowers the threshold for the induction of long-term potentiation, a cellular model for LTM. Transcriptomic and proteomic analyses revealed that ATF4 deletion in excitatory neurons leads to upregulation of components of oxidative phosphorylation pathways, which are critical for ATP production. Thus, we conclude that ATF4 functions as a memory repressor selectively within excitatory neurons. [ABSTRACT FROM AUTHOR]

• PI3K/Akt signaling pathway is related to anti-apoptosis and pro-axonal regeneration. • The PI3K/Akt pathway is a potential key pathway for the treatment of PSCI in TCM. • Moxibustion can activate the PI3K/Akt signaling pathway to function. • Moxibustion can promote axonal regeneration and improve learning and memory of PSCI. This study aimed to investigate whether moxibustion could affect PI3K/Akt pathway to regulate Transforming acidic coiled-coil containing protein 3 (TACC3) and promote axonal regeneration to improve learning and memory function in middle cerebral artery occlusion (MCAO) rats. Sixty SD rats were randomly divided into 4 groups: sham-operated control group (SC), model control group (MC), model + moxibustion group (MM), and model + inhibitor + moxibustion group (MIM). The rats in MC, MM, and MIM groups were made into MCAO models, and PI3K inhibitor LY294002 was injected into the rats in MIM group before modeling; while the rats in SC group were only treated with artery separation without monofilament inserting. After that, the rats in MM and MIM groups were intervented with moxibustion. We used the Zea-Longa scale, micro-Magnetic Resonance Imaging (micro-MRI), Morris water maze (MWM), TUNEL, western blot (WB), immunofluorescence and immunohistochemistry to evaluate the neurological deficits, cerebral infarct volume, learning and memory, apoptotic cell percentage in the hippocampal, the expression level of axonal regeneration and PI3K/AKt related proteins, the expression level of TACC3. The detection of 2 h after surgery showed the result before moxibustion and 7 days after the intervention showed the results after moxibustion. After 7 d of intervention, the scores of Zea-Longa and the cerebral infarct volume, the escape latency, the percentage of apoptosis cells of MM group were lower than that of MC and MIM groups; the frequency of rats crossed the previous platform location, PI3K, p-Akt/t-Akt and TACC3, the level of GAP-43 in MM group was more than MC and MIM groups (P < 0.05). While no statistical difference existed between MIM group and MC group (P > 0.05). Moxibustion can promote axonal regeneration and improve learning and memory of Post-stroke cognitive impairment via activating the PI3K/AKT signaling pathway and TACC3. [ABSTRACT FROM AUTHOR]

As an evolutionarily ancient sense, olfaction is key to learning where to find food, shelter, mates, and important landmarks in an animal's environment. Brain circuitry linking odor and navigation appears to be a well conserved multiregion system among mammals; the anterior olfactory nucleus, piriform cortex, entorhinal cortex, and hippocampus each represent different aspects of olfactory and spatial information. We review recent advances in our understanding of the neural circuits underlying odor-place associations, highlighting key choices of behavioral task design and neural circuit manipulations for investigating learning and memory. [ABSTRACT FROM AUTHOR]

Practicing retrieval is a potent learning enhancer. Theoretical accounts of the testing effect generally suggest that the magnitude of the testing effect is dependent on retrieval practice performance, such that conditions that promote better retrieval practice performance should result in a greater testing effect. Empirical evidence, however, has been mixed. Although some studies showed a positive association between retrieval practice performance and the testing effect, others have shown either no relation or the reverse. In the present study, we experimentally manipulated retrieval practice performance using a retrieval-based response deadline manipulation and an encoding-based study trial manipulation. Across six experiments, the magnitude of the testing effect was independent of retrieval practice performance. However, when we aggregated the data across the experiments, participants with superior retrieval practice performance showed a greater testing effect—an individual difference. This dissociation between experimental and correlational outcomes suggests that the positive relation between retrieval practice performance and the testing effect is not causal, and indeed, simulation data showed that the correlation between retrieval practice performance and testing effect was an artifact. We discuss the challenges these findings present to existing accounts of the testing effect. Public Significance Statement: Practicing retrieval from memory can enhance learning and retention—the testing effect. However, research has produced mixed evidence about whether the benefits of retrieval depend on practice performance, with some suggesting that conditions that elicit better practice performance produce a greater testing effect, whereas others demonstrating either no effect or the opposite. In the present experiments, we showed that conditions that favored better retrieval practice performance did not produce a greater testing effect. These results challenge existing theories, and they demonstrate that students can reap similar benefits from retrieval practice regardless of whether or not learning conditions are optimized for successful retrieval practice. [ABSTRACT FROM AUTHOR]

One of the best ways to improve new learning and increase memory strength is by reprocessing the recently acquired information, for example, by thinking of it again. Synaptic plasticity, the process by which neurons change the strength of their connections with each other, is fundamental for learning and memory formation. Yet, at present, it is unclear how reprocessing information drives synaptic plasticity to support memory improvement. A new study suggests that reprocessing enhances memory formation by recruiting more synapses to represent the new memory, thus increasing its strength. [ABSTRACT FROM AUTHOR]

The neuroprotective potential of blueberry (BB) extracts against Alzheimer's disease (AD) has been previously hinted at, while its exact mechanism has remained largely enigmatic. Our study endeavored to unravel the impacts and mechanisms by which BB extracts ameliorated the learning and memory prowess of AD-afflicted mice, with a specific focus on the MEK-ERK pathway. We employed 3-month-old APP/PS1 transgenic mice and stratified them into three distinct groups: AD+BB, AD, and control (CT). The Morris Water Maze Test (MWMT) was then administered to gauge their learning and memory faculties. In vitro experiments were executed on Aβ25-35-afflicted rat hippocampal neurons, which were subsequently treated with varying concentrations of BB extracts. We then assessed the expression levels of genes and proteins integral to the MEK-ERKBDNF/UCH-L1 pathway. The data showed that the AD mice demonstrated compromised learning and memory faculties in MWMT. However, the AD+BB cohort showcased marked improvements in performance. Furthermore, in the AD subset, significant elevations in the expressions of MEK2 and ERK1/2 were observed, both at the mRNA and protein levels. Conversely, UCH-L1 mRNA expressions exhibited a decline, while BDNF expressions surged significantly. However, post BB extract treatment, the expressions of MEK2 and ERK1/2 were subdued, with UCH-L1 and BDNF mRNA expressions reverting to control levels. Our findings propounded that BB extracts could offer therapeutic promise for AD by bolstering learning and memory capacities. The unwarranted activation of the MEK-ERK pathway, coupled with the aberrant expressions of BDNF and UCH-L1, might underpin AD's pathogenesis. [ABSTRACT FROM AUTHOR]

Introduction: Pregnant women may need to undergo non‐obstetric surgery under general anesthesia owing to medical needs, and pregnant women frequently experience sleep disturbances during late gestation. Preclinical studies demonstrated that maternal isoflurane exposure (MISO) or maternal sleep deprivation (MSD) contributed to cognitive impairments in offspring. Research studies in mice have revealed that SD can aggravate isoflurane‐induced cognitive deficits. However, it remains unclear whether MSD aggravates MISO‐induced cognitive deficits in offspring. The purpose of this research was to explore the combined effects of MSD and MISO on offspring cognitive function and the role of neuroinflammation and synaptic function in the process of MSD + MISO. Methods: Pregnant mice were exposed to 1.4% isoflurane by inhalation for 4 h on gestational day (GD) 14. Dams were then subjected to SD for 6 h (12:00–18:00 h) during GD15–21. At 3 months of age, the offspring mice were subjected to the Morris water maze test to assess cognitive function. Then the levels of inflammatory and anti‐inflammatory markers and synaptic function‐related proteins were assessed using molecular biology methods. Results: The results of this study demonstrated that MISO led to cognitive dysfunction, an effect that was aggravated by MSD. In addition, MSD exacerbated the maternal isoflurane inhalation, leading to an enhancement in the expression levels of interleukin (IL)‐1β, IL‐6, and tumor necrosis factor‐alpha and a reduction in the hippocampal levels of IL‐10, synaptophysin, post‐synaptic density‐95, growth‐associated protein‐43, and brain‐derived neurotrophic factor. Conclusion: Our findings revealed that MSD aggravated the cognitive deficits induced by MISO in male offspring mice, and these results were associated with neuroinflammation and alternations in synaptic function. [ABSTRACT FROM AUTHOR]

Background and purpose: Stress, especially immobility stress, is quite common and one of the most important and influential risk factors in neurological disorders. This study aimed to investigate the effect of acute and chronic immobility stress on the level of cortical and hippocampal oxidative stress indicators and memory impairment following global cerebral ischemia. Experimental approach: In this study, 48 male Wistar rats were randomly divided into 6 groups: 1, sham (S); 2, sham-acute stress (SSA); 3, sham-chronic stress (SSC); 4, ischemia (IS); 5, ischemia-acute stress (ISA); 6, ischemia-chronic stress (ISC). The Morris water maze (MWM) test was performed 14 days after surgery, and cortisol levels and oxidative stress factors such as malondialdehyde MDA and total thiol were measured. Findings/Results: In the MWM test, the time to find the platform (latency time) in the ISC and IS groups significantly increased compared to the S group. The time spent in the target quarter in these two groups was significantly reduced compared to the S group on the day of the probe. The results showed a significant increase in cortisol levels and malondialdehyde concentration in the ISA, ISC, and IS groups compared to the S group, but there was no significant difference in total thiol concentration. No significant difference was observed in the level of oxidative stress factors in the cortex. Conclusion and implication: Chronic immobility stress could reduce antioxidant factors in the hippocampus and exacerbate memory impairment caused by global ischemia.

Abstract Background The impact of acrylamide (ACR) on learning and memory has garnered considerable attention. However, the targets and mechanisms are still unclear. Results Elongation factor 2 (eEF2) was significantly upregulated in the results of serum proteomics. Results from in vitro and in vivo experiments indicated a notable upregulation of Eukaryotic elongation factor 2 kinase (eEF2K), the sole kinase responsible for eEF2 phosphorylation, following exposure to ACR (P

Abstract Background We recently reported that the dopamine (DA) analogue CA140 modulates neuroinflammatory responses in lipopolysaccharide-injected wild-type (WT) mice and in 3-month-old 5xFAD mice, a model of Alzheimer’s disease (AD). However, the effects of CA140 on Aβ/tau pathology and synaptic/cognitive function and its molecular mechanisms of action are unknown. Methods To investigate the effects of CA140 on cognitive and synaptic function and AD pathology, 3-month-old WT mice or 8-month-old (aged) 5xFAD mice were injected with vehicle (10% DMSO) or CA140 (30 mg/kg, i.p.) daily for 10, 14, or 17 days. Behavioral tests, ELISA, electrophysiology, RNA sequencing, real-time PCR, Golgi staining, immunofluorescence staining, and western blotting were conducted. Results In aged 5xFAD mice, a model of AD pathology, CA140 treatment significantly reduced Aβ/tau fibrillation, Aβ plaque number, tau hyperphosphorylation, and neuroinflammation by inhibiting NLRP3 activation. In addition, CA140 treatment downregulated the expression of cxcl10, a marker of AD-associated reactive astrocytes (RAs), and c1qa, a marker of the interaction of RAs with disease-associated microglia (DAMs) in 5xFAD mice. CA140 treatment also suppressed the mRNA levels of s100β and cxcl10, markers of AD-associated RAs, in primary astrocytes from 5xFAD mice. In primary microglial cells from 5xFAD mice, CA140 treatment increased the mRNA levels of markers of homeostatic microglia (cx3cr1 and p2ry12) and decreased the mRNA levels of a marker of proliferative region-associated microglia (gpnmb) and a marker of lipid-droplet-accumulating microglia (cln3). Importantly, CA140 treatment rescued scopolamine (SCO)-mediated deficits in long-term memory, dendritic spine number, and LTP impairment. In aged 5xFAD mice, these effects of CA140 treatment on cognitive/synaptic function and AD pathology were regulated by dopamine D1 receptor (DRD1)/Elk1 signaling. In primary hippocampal neurons and WT mice, CA140 treatment promoted long-term memory and dendritic spine formation via effects on DRD1/CaMKIIα and/or ERK signaling. Conclusions Our results indicate that CA140 improves neuronal/synaptic/cognitive function and ameliorates Aβ/tau pathology and neuroinflammation by modulating DRD1 signaling in primary hippocampal neurons, primary astrocytes/microglia, WT mice, and aged 5xFAD mice.

Abstract Recent years, the rapid advancement of technology has raised concerns. We studied the effects of prenatal exposure to 900 MHz radiofrequency (RF) from mobile phones and the protective effects of linalool on learning and memory, and anxiety in adolescent male and female offspring rats. Pregnant rats were divided into four groups: control, wave, wave + linalool, and linalool. Rats received linalool (25mg/kg) by gavage for 21 days. Irradiation was conducted from day 0 to day 21 of pregnancy. Offsprings underwent behavioral and electrophysiological tests on days 50 and 60 after birth. Exposure to RF during pregnancy caused anxiety-like behavior in the EPM test and impairment of learning and memory in the Morris water maze and shuttle box tests. Electrophysiological properties and synaptic plasticity of the dorsal hippocampal CA3-CA1 synapse showed a decrease in fEPSP amplitude and slope. The trace element levels in both male and female offspring were consistent across all groups compared to their respective controls. In the hippocampus tissue, the levels of Fe, Cu, and Mn, as well as the Cu/Zn ratio, were significantly higher in the exposed groups (wave groups) compared to their controls. Moreover, Zn levels were significantly lower in the hippocampus tissue of the exposed groups. Linalool administration mitigated the excessive increase in Fe, Cu, Mn, and Cu/Zn ratio and normalized the disrupted levels of trace elements, except for Zn levels in both male and female offspring. Sex differences were observed in the EPM and shuttle box tests, females were more sensitive than males. In summary, our study demonstrates that prenatal exposure to mobile phone radiation induces stress-like behaviors, disrupts learning and memory, alters hippocampal electrophysiological properties and trace element balance in offspring. Treatment with linalool mitigates these deleterious effects, highlighting its potential as a therapeutic intervention. These findings contribute to our understanding of the impact of prenatal environmental exposures on neurodevelopment and offer insights into potential strategies for neuroprotection.

BACKGROUND: Gamma sensory stimulation may reduce AD-specific pathology. Yet, the efficacy of alternating electrical current stimulation in animal models of AD is unknown, and prior research has not addressed intensity-dependent effects. METHODS: The intensity-dependent effect of gamma electrical stimulation (GES) with a sinusoidal alternating current at 40 Hz on Aβ clearance and microglia modulation were assessed in 5xFAD mouse hippocampus and cortex, as well as the behavioral performance of the animals with the Morris Water Maze. RESULTS: One hour of epidural GES delivered over a month significantly (1) reduced Aβ load in the AD brain, (2) increased microglia cell counts, decreased cell body size, increased length of cellular processes of the Iba1 + cells, and (3) improved behavioral performance (learning & memory). All these effects were most pronounced when a higher stimulation current was applied. CONCLUSION: The efficacy of GES on the reduction of AD pathology and the intensity-dependent feature provide guidance for the development of this promising therapeutic approach.

Emotions, in general, have no scientific definition. Emotions can be denoted as the mental state because of the neurophysiological changes. Emotions are related to mood, personality, temperament, and consciousness. People exhibit different emotions in different situations causing changes in cognitive functions. One of the major cognitive functions is the ability to learn, to store the acquired information in the parts of the brain such as the hippocampus, amygdala, cortex, and cerebellum. Learning and memory are affected by different types of emotions. Emotional responses such as fear, depression, and stress have impaired effects on cognitive functions such as learning and memory, whereas optimistic and happy emotions have positive effects on long-term memory. Certain disorders have greater effects on the regions of the brain which are also associated with synaptic plasticity and Learning and Memory(LM). Neuroimaging techniques are involved in studying the changing regions of the brain due to varied emotions and treatment strategies based on the changes observed. There are many drugs, and in advancements, nanotechnology is also utilized in the treatment of such psychiatric disorders. To improve mental health and physical health, emotional balance is most important, and effective care should be provided for people with less emotional quotient and different types of disorders to inhibit cognitive dysfunctions. In this review, emotions and their varied effects on a cognitive function named learning and memory, disorders associated with the defects of learning due to emotional instability, the areas of the brain that are in control of emotions, diagnosis, and treatment strategies for psychiatric disorders dependent on emotions are discussed.

BackgroundThe compound 6:2 chlorinated polyfluorinated ether sulfonic acids (6:2 Cl-PFESA) has been demonstrated abilities of strong bioaccumulation and placental barrier penetration, and it can also cross the blood-brain barrier. However, the mechanism of its neurodevelopmental toxicity in offspring induced by early-life exposure is still unknown.ObjectiveTo explore effects of 6:2 Cl-PFESA on the growth and the α-amino-3-hydroxy-5-methylisoxazole-4-propionic (AMPA) receptor gene expression in the hippocampus of offspring mice by establishing a 6:2 Cl-PFESA exposure animal model.MethodsThirty Kunming pregnant mice were randomly divided into five groups: control group, and 2, 10, 50, and 250 μg·L−1 6:2 Cl-PFESA exposure groups. The treatment groups were exposed to designed doses of 6:2 Cl-PFESA through drinking water from the first day of gestation until the end of lactation. The pups were weaned on postnatal day (PND) 21, and continued to be exposed to 6:2 Cl-PFESA through drinking water. Birth weight and body length of the offspring were recorded. Offspring mice were anesthetized and sacrificed respectively on PND7, PND21, and PND35, then their hippocampus was peeled from harvested brain tissue. The ultrastructure of hippocampus was observed via transmission electron microscopy; and the expression of AMPA receptors GluR1, GluR2, and GluR3 in the hippocampus was evaluated by real-time reverse transcription polymerase chain reaction. The learning and memory ability of the PND35 mice was measured by Morris water maze test before they were sacrificed.ResultsThe birth weights and the lengths of the pups in the 10, 50, and 250 μg·L−1 6:2 Cl-PFESA exposure groups were (2.23±0.36), (1.92±0.20), (1.88±0.31) g, and (33.73±0.98), (32.91±1.30), (32.52±2.07) mm, respectively, which were lower than those in the control group, (2.78±0.35) g and (36.46±2.34) mm (P

Abstract Dexmedetomidine (Dex) has been used in surgery to improve patients' postoperative cognitive function. However, the role of Dex in stress-induced anxiety-like behaviors and cognitive impairment is still unclear. In this study, we tested the role of Dex in anxiety-like behavior and cognitive impairment induced by acute restrictive stress and analyzed the alterations of the intestinal flora to explore the possible mechanism. Behavioral and cognitive tests, including open field test, elevated plus-maze test, novel object recognition test, and Barnes maze test, were performed. Intestinal gut Microbe 16S rRNA sequencing was analyzed. We found that intraperitoneal injection of Dex significantly improved acute restrictive stress-induced anxiety-like behavior, recognition, and memory impairment. After habituation in the environment, mice (male, 8 weeks, 18–23 g) were randomly divided into a control group (control, N = 10), dexmedetomidine group (Dex, N = 10), AS with normal saline group (AS + NS, N = 10) and AS with dexmedetomidine group (AS + Dex, N = 10). By the analysis of intestinal flora, we found that acute stress caused intestinal flora disorder in mice. Dex intervention changed the composition of the intestinal flora of acute stress mice, stabilized the ecology of the intestinal flora, and significantly increased the levels of Blautia (A genus of anaerobic bacteria) and Coprobacillus. These findings suggest that Dex attenuates acute stress-impaired learning and memory in mice by maintaining the homeostasis of intestinal flora.

Resumen: Objetivo: El presente estudio tiene como objetivo proporcionar normas y ajustes para edad, educación y género para el Wisconsin Card Sorting Test (WCST), la Figura Compleja Modificada de Taylor (FCMT) y el Ruff-Light Trail Learning Test (RULIT) como parte del proyecto NEURONORMA-Plus. Método: La muestra consiste en 308 individuos cognitivamente sanos de entre 18 y 92 años. Se proporcionan tablas para convertir las puntuaciones brutas en puntuaciones escalares ajustadas por edad y ajustes por educación y género tras aplicar modelos de regresión independientes en 2 grupos de edad (

Objective: To explore the mechanism of A kinase anchor-protein 150 AKAP150) in alleviating learning and memory impairment induced by propofol in rats at developmental stage. Methods 80 SD rats aged 7 days were randomly divided into a control group (Con group), propofol group (Pro group), dexmedetomidine pre-administration group (DP group), and AKAP150 adenovirus plus DP group (ADP group) (n = 20). The Con group was injected with equal volume normal saline. The Pro group was injected with propofol of 50 mg/kg twice, and the DP group was injected with dexmedetomidine of 25 μg/kg plus propofol of 50 mg/kg. The ADP group was treated with adenovirus to construct an AKAP150 knockout model. Expression levels of AKAP150, PKA, NLRP3, GSDMD, IL-1β and IL-18 in hippocampus were detected by Western blot. The ultrastructure of hippocampus was observed by transmission electron microscopy. ResultsAfter propofol treatment, hippocampal cell membrane split and pores formed, expressions of AKAP150 and PKA were down-regulated (P < 0.05), while expressions of NLRP3, GSDMD, IL-1β and IL-18 were up-regulated (P < 0.05), and the frequency of crossing the platform was decreased (P < 0.05). After pre-administration of dexmedetomidine, the cell membrane structure of hippocampus was basically normal, expressions of AKAP150 and PKA were up-regulated (P < 0.05), expressions of NLRP3, GSDMD, IL-1β and IL-18 were down-regulated (P < 0.05), and the frequency of crossing the platform was increased (P < 0.05). ConclusionsDexmedetomidine may enhance the activity of PKA and inhibit expressions of NLRP3, GSDMD, IL-1β and IL-18 by activating expression of AKAP150, thereby alleviating propofol-induced pyroptosis in hippocampal tissues and improving learning and memory impairment in rats at developmental stage. K [ABSTRACT FROM AUTHOR]

The Rabies virus is a neurotropic virus that manipulates the natural cell death processes of its host to ensure its own survival and replication. Studies have shown that the anti-apoptotic effect of the virus is mediated by one of its protein named, rabies glycoprotein (RVG). Alzheimer's disease (AD) is characterized by the loss of neural cells and memory impairment. We aim to examine whether expression of RVG in the hippocampal cells can shield the detrimental effects induced by Aβ. Oligomeric form of Aβ (oAβ) or vehicle was bilaterally microinjected into the dorsal hippocampus of male Wistar rats. One week later, two μl (108 T.U. /ml) of the lentiviral vector carrying RVG gene was injected into their dorsal hippocampus (post-treatment). In another experiment, the lentiviral vector was microinjected one week before Aβ injection (pre-treatment). One week later, the rat's brain was sliced into cross-sections, and the presence of RVG-expressing neuronal cells was confirmed using fluorescent microscopy. Rats were subjected to assessments of spatial learning and memory as well as passive avoidance using the Morris water maze (MWM) and the Shuttle box apparatuses, respectively. Protein expression of AMPA receptor subunit (GluA1) was determined using western blotting technique. In MWM, Aβ treated rats showed decelerated acquisition of the task and impairment of reference memory. RVG expression in the hippocampus prevented and restored the deficits in both pre- and post- treatment conditions, respectively. It also improved inhibitory memory in the oAβ treated rats. RVG increased the expression level of GluA1 level in the hippocampus. Based on our findings, the expression of RVG in the hippocampus has the potential to enhance both inhibitory and spatial learning abilities, ultimately improving memory performance in an AD rat model. This beneficial effect is likely attributed, at least in part, to the increased expression of GluA1-containing AMPA receptors. [ABSTRACT FROM AUTHOR]

Dexmedetomidine (Dex) has been used in surgery to improve patients' postoperative cognitive function. However, the role of Dex in stress-induced anxiety-like behaviors and cognitive impairment is still unclear. In this study, we tested the role of Dex in anxiety-like behavior and cognitive impairment induced by acute restrictive stress and analyzed the alterations of the intestinal flora to explore the possible mechanism. Behavioral and cognitive tests, including open field test, elevated plus-maze test, novel object recognition test, and Barnes maze test, were performed. Intestinal gut Microbe 16S rRNA sequencing was analyzed. We found that intraperitoneal injection of Dex significantly improved acute restrictive stress-induced anxiety-like behavior, recognition, and memory impairment. After habituation in the environment, mice (male, 8 weeks, 18–23 g) were randomly divided into a control group (control, N = 10), dexmedetomidine group (Dex, N = 10), AS with normal saline group (AS + NS, N = 10) and AS with dexmedetomidine group (AS + Dex, N = 10). By the analysis of intestinal flora, we found that acute stress caused intestinal flora disorder in mice. Dex intervention changed the composition of the intestinal flora of acute stress mice, stabilized the ecology of the intestinal flora, and significantly increased the levels of Blautia (A genus of anaerobic bacteria) and Coprobacillus. These findings suggest that Dex attenuates acute stress-impaired learning and memory in mice by maintaining the homeostasis of intestinal flora. [ABSTRACT FROM AUTHOR]

Obesity has been linked with the impairment of spatial memory and synaptic plasticity but the molecular mechanisms remained unidentified. Since glutamatergic transmission and NMDA receptor neural pathways in hippocampal dentate gyrus (DG) are essential in the learning and memory, we aimed to investigate glutamate (Glu) and NMDA receptor signaling of DG in spatial learning and memory in diet-induced obesity (DIO) rats. Spatial learning and memory were assessed via Morris water maze (MWM) test on control (Ctr) and DIO rats. Extracellular concentration of Glu in the DG was determined using in vivo microdialysis and HPLC. The protein expressions of NMDA receptor subunit 2B (NR2B), brain-derived neurotrophic factor (BDNF), the activation of calcium/calmodulin-dependent kinase II (CaMKII) and cAMP-response-element-binding protein (CREB) in the DG were observed by western blot. Spatial learning and memory were impaired in DIO rats compared to those of Ctr. NR2B expression was increased, while BDNF expression and CaMKII and CREB activation were decreased in DG of DIO rats. Extracellular concentration of Glu was increased in Ctr on the 3rd and 4th days of the MWM test, but significant further increment was observed in DIO rats. Microinjection of an NMDA antagonist (MK-801) into the DG reversed spatial learning and memory impairment. Such effects were accompanied by greater BDNF expression and CaMKII/CREB activation in the DG of DIO rats. In conclusion, the enhancement of Glu-NMDA receptor transmission in the hippocampal DG contributes to the impairment of spatial learning and memory in DIO rats, maybe via the modulation of CaMKII-CREB-BDNF signaling pathway. [ABSTRACT FROM AUTHOR]

The brain is complex and metabolically active, and the detection of metabolites plays an important role in brain development and diseases. Currently, there is a lack of research on the metabolic spectrum changes in learning and memory impairment, and hippocampal damage induced by microwave radiation from the metabolic perspective. Aiming to provide sensitive indicators for microwave radiation-induced brain damage and establish a foundation for understanding its injury mechanisms, this study employed non-targeted metabolomics to investigate metabolic fluctuations and key metabolic pathway alterations in rats' hippocampal tissue after microwave radiation. The memory and spatial exploration abilities of rats decreased after radiation. The postsynaptic densities were thickened in the MW group. The cholesterol sulfate, SM(d16:1/24:1(15Z)), and linoelaidylcarnitine were significantly increased after radiation, whereas etrahydrocorticosterone, L-phenylalanine, and histamine were significantly decreased after radiation. These metabolites were enriched in signaling pathways related to the inflammatory mediator regulation of transient receptor potential (TRP) channels, neuroactive ligand–receptor interaction, steroid hormone biosynthesis, and phenylalanine, tyrosine, and tryptophan biosynthesis. These findings indicate that microwave radiation causes spatial learning and memory dysfunction in rats and structural damage to hippocampal tissue. [ABSTRACT FROM AUTHOR]

Octopamine (OA), analogous to norepinephrine in vertebrates, is an essential monoamine neurotransmitter in invertebrates that plays a significant role in various biological functions, including olfactory associative learning. However, the spatial and temporal dynamics of OA in vivo remain poorly understood due to limitations associated with the currently available methods used to detect it. To overcome these limitations, we developed a genetically encoded G PC R   a ctivation- b ased (GRAB) OA sensor called GRABOA1.0. This sensor is highly selective for OA and exhibits a robust and rapid increase in fluorescence in response to extracellular OA. Using GRABOA1.0, we monitored OA release in the Drosophila mushroom body (MB), the fly's learning center, and found that OA is released in response to both odor and shock stimuli in an aversive learning model. This OA release requires acetylcholine (ACh) released from Kenyon cells, signaling via nicotinic ACh receptors. Finally, we discovered that OA amplifies aversive learning behavior by augmenting dopamine-mediated punishment signals via Octβ1R in dopaminergic neurons, leading to alterations in synaptic plasticity within the MB. Thus, our new GRABOA1.0 sensor can be used to monitor OA release in real time under physiological conditions, providing valuable insights into the cellular and circuit mechanisms that underlie OA signaling. [ABSTRACT FROM AUTHOR]

Neuronal ensembles in the medial prefrontal cortex mediate cocaine self‐administration via projections to the nucleus accumbens. We have recently shown that neuronal ensembles in the prelimbic cortex form rapidly to mediate cocaine self‐administration. However, the role of neuronal ensembles within the nucleus accumbens in initial cocaine‐seeking behaviour remains unknown. Here, we sought to expand the current literature by testing the necessity of the cocaine self‐administration ensemble in the nucleus accumbens core (NAcCore) 1 day after male and female rats acquire cocaine self‐administration by using the Daun02 inactivation procedure. We found that disrupting the NAcCore ensembles after a no‐cocaine reward‐seeking test increased subsequent cocaine seeking, while disrupting NAcCore ensembles following a cocaine self‐administration session decreased subsequent cocaine seeking. We then characterized neuronal cell type in the NAcCore using RNAscope in situ hybridization. In the no‐cocaine session, we saw reduced dopamine D1 type neuronal activation, while in the cocaine self‐administration session, we found preferential dopamine D1 type neuronal activity in the NAcCore. [ABSTRACT FROM AUTHOR]

• A high-fat diet impairs learning and memory in male mice and increases anxiety-like behavior across sexes and ages. • A high-fat diet exacerbates systemic inflammation across age and sex in mice and induces microglia in aged male mice. • Hypothalamic proteome reveals metabolic stress induced by a high-fat diet in aged male mice. Aging and age-related diseases are associated with cellular stress, metabolic imbalance, oxidative stress, and neuroinflammation, accompanied by cognitive impairment. Lifestyle factors such as diet, sleep fragmentation, and stress can potentiate damaging cellular cascades and lead to an acceleration of brain aging and cognitive impairment. High-fat diet (HFD) has been associated with obesity, metabolic disorders like diabetes, and cardiovascular disease. HFD also induces neuroinflammation, impairs learning and memory, and may increase anxiety-like behavior. Effects of a HFD may also vary between sexes. The interaction between Age- and Sex- and Diet-related changes in neuroinflammation and cognitive function is an important and poorly understood area of research. This study was designed to examine the effects of HFD on neuroinflammation, behavior, and neurodegeneration in mice in the context of aging or sex differences. In a series of studies, young (2–3 months) or old (12–13 months) C57BL/6J male mice or young male and female C57Bl/6J mice were fed either a standard diet (SD) or a HFD for 5–6 months. Behavior was assessed in Activity Chamber, Y-maze, Novel Place Recognition, Novel Object Recognition, Elevated Plus Maze, Open Field, Morris Water Maze, and Fear Conditioning. Post-mortem analyses assessed a panel of inflammatory markers in the plasma and hippocampus. Additionally, proteomic analysis of the hypothalamus, neurodegeneration, neuroinflammation in the locus coeruleus, and neuroinflammation in the hippocampus were assessed in a subset of young and aged male mice. We show that HFD increased body weight and decreased locomotor activity across groups compared to control mice fed a SD. HFD altered anxiety-related exploratory behavior. HFD impaired spatial learning and recall in young male mice and impaired recall in cued fear conditioning in young and aged male mice, with no effects on spatial learning or fear conditioning in young female mice. Effects of Age and Sex were observed on neuroinflammatory cytokines, with only limited effects of HFD. HFD had a more significant impact on systemic inflammation in plasma across age and sex. Aged male mice had induction of microglial immunoreactivity in both the locus coeruleus (LC) and hippocampus an effect that HFD exacerbated in the hippocampal CA1 region. Proteomic analysis of the hypothalamus revealed changes in pathways related to metabolism and neurodegeneration with both aging and HFD in male mice. Our findings suggest that HFD induces widespread systemic inflammation and limited neuroinflammation. In addition, HFD alters exploratory behavior in male and female mice, and impairs learning and memory in male mice. These results provide valuable insight into the impact of diet on cognition and aging pathophysiology. [ABSTRACT FROM AUTHOR]

The methylazoxymethanol acetate (MAM) rodent model is used to study aspects of schizophrenia. However, numerous studies that have employed this model have used only males, resulting in a dearth of knowledge on sex differences in brain function and behaviour. The purpose of this study was to determine whether differences exist between male and female MAM rats in neuronal oscillatory function within and between the prefrontal cortex (PFC), ventral hippocampus (vHIP) and thalamus, behaviour, and in proteins linked to schizophrenia neuropathology. We showed that female MAM animals exhibited region-specific alterations in theta power, elevated low and high gamma power in all regions, and elevated PFC-thalamus high gamma coherence. Male MAM rats had elevated beta and low gamma power in PFC, and elevated vHIP-thalamus coherence. MAM females displayed impaired reversal learning whereas MAM males showed impairments in spatial memory. Glycogen synthase kinase-3 (GSK-3) was altered in the thalamus, with female MAM rats displaying elevated GSK-3α phosphorylation. Male MAM rats showed higher expression and phosphorylation GSK-3α, and higher expression of GSK-β. Sex-specific changes in phosphorylated Tau levels were observed in a region-specific manner. These findings demonstrate there are notable sex differences in behaviour, oscillatory network function, and GSK-3 signaling in MAM rats, thus highlighting the importance of inclusion of both sexes when using this model to study schizophrenia. [ABSTRACT FROM AUTHOR]

Rich in unsaturated fatty acids, walnut oil provides a number of physiological benefits, including a reduction in the risk of cardiovascular disease and a delay in the aging process. In this work, walnut oil was prepared using the aqueous enzyme process and cold pressing method, and it was then analyzed using HPLC and FTIR. The characterization results show that the walnut oil extracted by the aqueous enzyme method outperformed the pressing oil in content of LLL by 11.64%, LLLn by 9.16% and OLL by 4.08%. But this oil had significantly less OLnLn (‐) than the pressing oil (7.90%). The Morris water maze and shuttle box tests of ICR mice revealed a notable improvement in the memory of the animals administered walnut oil. Among them, mice fed the walnut oil extracted by aqueous enzyme method showed a much shorter escape latency and a significantly higher rate of active avoidance reaction (p < 0.05, p < 0.01) than mice fed cold pressing method. With the prolongation of time, the mice even performed better than the positive control PIR group in all aspects. In summary, the quality of walnut oil extracted by aqueous enzyme method is better than that by cold pressing method. Practical Applications: Walnut oil prepared by aqueous enzymatic extraction can improve learning ability, is healthy and pollution‐free, and can be utilized as a dietary supplement in ordinary life. [ABSTRACT FROM AUTHOR]

Prediction error plays a pivotal role in theories of learning, including theories of language acquisition and use. Researchers have investigated whether and under which conditions children, like adults, use prediction to facilitate language comprehension at different levels of linguistic representation. However, many aspects of the reciprocal relation between prediction error and the development of language learning remain unclear. In this article, we review studies in language development that can inform us about the role of prediction error in updating, learning, and retrieving linguistic information. We argue that the study of individual differences in linguistic and cognitive skills will help the field understand more thoroughly whether, when, and why prediction aids language learning, and whether prediction error necessarily results in language learning and retrieval from memory. We close with a discussion of the needs and challenges for researchers to answer these questions. [ABSTRACT FROM AUTHOR]

Introduction: Noninvasive brain stimulation (NIBS) has shown benefits for cognitive function in older adults. However, the effects of transcranial direct current stimulation (tDCS) on cognitive function in older adults are inconsistent across studies, and the evidence for tDCS has limitations. We aim to explore whether tDCS can improve cognitive function and different cognitive domains (i.e., learning and memory and executive function) in adults aged 65 years and older with and without mild cognitive impairment and to further analyze the influencing factors of tDCS. Methods: Five English databases (PubMed, Cochrane Library, EMBASE, Web of Science, the cumulative Index to Nursing and Allied Health Literature [CINAHL]) and four Chinese databases were searched from inception to October 14, 2023. Literature screening, data extraction, and quality assessment were completed independently by two reviewers. All statistical analyses were conducted using RevMan software (version 5.3). Standardized mean difference (SMD) along with a 95% confidence interval (CI) was used to express the effect size of the outcomes, and a random-effect model was also used. Results: A total of 10 RCTs and 1,761 participants were included in the meta-analysis, and the risk of bias in those studies was relatively low. A significant effect favoring tDCS on immediate postintervention cognitive function (SMD = 0.16, Z = 2.36, p = 0.02) was found. However, the effects on immediate postintervention learning and memory (SMD = 0.20, Z = 2.00, p = 0.05) and executive function (SMD = 0.10, Z = 1.22, p = 0.22), and 1-month postintervention cognitive function (SMD = 0.12, Z = 1.50, p = 0.13), learning and memory (SMD = 0.17, Z = 1.39, p = 0.16), and executive function (SMD = 0.08, Z = 0.67, p = 0.51) were not statistically significant. Conclusion: tDCS can significantly improve the immediate postintervention cognitive function of healthy older adults and MCI elderly individuals. Additional longitudinal extensive sample studies are required to clarify the specific effects of tDCS on different cognitive domains, and the optimal tDCS parameters need to be explored to guide clinical practice. [ABSTRACT FROM AUTHOR]

Background: The inflammation and synaptic dysfunction induced by mitochondrial dysfunction play essential roles in the learning and memory impairment associated with sleep dysfunction. Elamipretide (SS‐31), a novel mitochondrion‐targeted antioxidant, was proven to improve mitochondrial dysfunction, the inflammatory response, synaptic dysfunction, and cognitive impairment in models of cerebral ischemia, sepsis, and type 2 diabetes. However, the potential for SS‐31 to improve the cognitive impairment induced by chronic sleep deprivation (CSD) and its underlying mechanisms is unknown. Methods: Adult c57BL/6J mice were subjected to CSD for 21 days using an activity wheel accompanied by daily intraperitoneal injection of SS‐31 (5 mg/kg). The novel object recognition and Morris water maze test were used to evaluate hippocampus‐dependent cognitive function. Western blotting and reverse transcription‐quantitative polymerase chain reaction assays were used to determine the effects of CSD and SS‐31 on markers of mitochondria, inflammation response, and synaptic function. Enzyme‐linked immunosorbent assays were used to examine the levels of proinflammatory cytokines. Results: SS‐31 could improve the cognitive impairment induced by CSD. In particular, SS‐31 treatment restored the CSD‐induced decrease in sirtuin 1 (SIRT1) and peroxisome proliferator‐activated receptor γ coactivator alpha levels and the increase in levels nuclear factor kappa‐B and inflammatory cytokines, including interleukin (IL)‐1β, IL‐6, and tumor necrosis factor‐alpha. Furthermore, SS‐31 significantly increased the levels of brain‐derived neurotrophic factor, postsynaptic density protein‐95, and synaptophysin in CSD mice. Conclusion: Taken together, these results suggest that SS‐31 could improve CSD‐induced mitochondrial biogenesis dysfunction, inflammatory response, synaptic dysfunction, and cognitive impairment by increasing SIRT1 expression levels. [ABSTRACT FROM AUTHOR]

Aims: Nerve growth factor (NGF) loss is a potential factor for the degeneration of basal forebrain cholinergic neurons (BFCNs) in Alzheimer's disease (AD), and Rab5a is a key regulatory molecule of NGF signaling transduction. Here, we investigated the changes of Rab5a in 5 × FAD mice and further explored the mechanism of Electroacupuncture (EA) treatment in improving cognition in the early stage of AD. Methods: The total Rab5a and Rab5a‐GTP in 5‐month‐old 5 × FAD mice and wild‐type mice were detected using WB and IP technologies. 5 × FAD mice were treated with EA at the Bai hui (DU20) and Shen ting (DU24) acupoints for 4 weeks and CRE/LOXP technology was used to confirm the role of Rab5a in AD mediated by EA stimulation. The Novel Object Recognition and Morris water maze tests were used to evaluate the cognitive function of 5 × FAD mice. The Nissl, immunohistochemistry, and Thioflavin S staining were used to observe pathological morphological changes in the basal forebrain circuit. The Golgi staining was used to investigate the synaptic plasticity of the basal forebrain circuit and WB technology was used to detect the expression levels of cholinergic‐related and NGF signal‐related proteins. Results: The total Rab5a was unaltered, but Rab5a‐GTP increased and the rab5a‐positive early endosomes appeared enlarged in the hippocampus of 5 × FAD mice. Notably, EA reduced Rab5a‐GTP in the hippocampus in the early stage of 5 × FAD mice. EA could improve object recognition memory and spatial learning memory by reducing Rab5a activity in the early stage of 5 × FAD mice. Moreover, EA could reduce Rab5a activity to increase NGF transduction and increase the levels of phosphorylated TrkA, AKT, and ERK in the basal forebrain and hippocampus, and increase the expression of cholinergic‐related proteins, such as ChAT, vAchT, ChT1, m1AchR, and m2AchR in the basal forebrain and ChAT, m1AchR, and m2AchR in the hippocampus, improving synaptic plasticity in the basal forebrain hippocampal circuit in the early stage of 5 × FAD mice. Conclusions: Rab5a hyperactivation is an early pathological manifestation of 5 × FAD mice. EA could suppress Rab5a‐GTP to promote the transduction of NGF signaling, and enhance the synaptic plasticity of the basal forebrain hippocampal circuit improving cognitive impairment in the early stage of 5 × FAD mice. [ABSTRACT FROM AUTHOR]

Three experiments explored how retrieval practice and corrective feedback affect a third language (L3) vocabulary learning. In the first two experiments, Chinese–English bilinguals without prior French language experience studied English (Second Language, L2)–French (L3) word pairs in repeated studying or retrieval practice without (Experiment 1)/with (Experiment 2) corrective feedback. A final recognition test was administered after a 30-min retention interval. Experiment 3 was identical to Experiment 2 in all respects, except that Chinese (First Language, L1)–French (L3) word pairs were used as study materials. Experiment 1 found that repeated studying led to greater accuracy and faster response time on the final test than retrieval practice without feedback. However, the opposite results were found in Experiment 2: retrieval practice with feedback yielded superior performance compared with repeated studying. The benefit of retrieval practice plus feedback was also found in Experiment 3, while it produced larger gains than Experiment 2. These results demonstrate that retrieval practice plus feedback is a powerful learning strategy, and L1–L3 learning is more effective than L2–L3 learning for L3 vocabulary learning. Our findings support the bifurcation model of the retrieval practice effect. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that simply reducing β‐amyloid (Aβ) plaques may not significantly affect the progression of Alzheimer's disease (AD). There is also increasing evidence indicating that AD progression is driven by a vicious cycle of soluble Aβ‐induced neuronal hyperactivity. In support of this, it has recently been shown that genetically and pharmacologically limiting ryanodine receptor 2 (RyR2) open time prevents neuronal hyperactivity, memory impairment, dendritic spine loss and neuronal cell death in AD mouse models. By contrast, increased RyR2 open probability (Po) exacerbates the onset of familial AD‐associated neuronal dysfunction and induces AD‐like defects in the absence of AD‐causing gene mutations. Thus, RyR2‐dependent modulation of neuronal hyperactivity represents a promising new target for combating AD. [ABSTRACT FROM AUTHOR]

Fibroblast growth factor 21 (FGF21) plays a crucial role in metabolism and brain function. Glucosamine (GLN) has been recognized for its diverse beneficial effects. This study aimed to elucidate the modulation of FGF21 production by GLN and its impact on learning and memory functions. Using both in vivo and in vitro models, we investigated the effects of GLN on mice fed with a normal diet or high-fat diet and on mouse HT22 hippocampal cells, STHdhQ7/Q7 striatal cells, and rat primary cortical neurons challenged with GLN. Our results indicated that GLN promotes learning and memory functions in mice and upregulates FGF21 expression in the hippocampus, cortex, and striatum, as well as in HT22 cells, STHdhQ7/Q7 cells, and cortical neurons. In animals receiving GLN together with an FGF21 receptor FGFR1 inhibitor (PD173074), the GLN-enhanced learning and memory functions and induction of FGF21 production in the hippocampus were significantly attenuated. While exploring the underlying molecular mechanisms, the potential involvement of NF-κB, Akt, p38, JNK, PKA, and PPARα in HT22 and NF-κB, Akt, p38, and PPARα in STHdhQ7/Q7 were noted; GLN was able to mediate the activation of p65, Akt, p38, and CREB in HT22 and p65, Akt, and p38 in STHdhQ7/Q7 cells. Our accumulated findings suggest that GLN may increase learning and memory functions by inducing FGF21 production in the brain. This induction appears to be mediated, at least in part, through GLN's activation of the NF-κB, Akt, p38, and PKA/CREB pathways. [ABSTRACT FROM AUTHOR]

Background: Our previous research has demonstrated that hypoxic preconditioning (HPC) can improve spatial learning and memory abilities in adult mice. Adult hippocampal neurogenesis has been associated with learning and memory. The Neurogenic locus notch homolog protein (Notch) was involved in adult hippocampal neurogenesis, as well as in learning and memory. It is currently unclear whether the Notch pathway regulates hippocampal neuroregeneration by modifying the DNA methylation status of the Notch gene following HPC. Method: The HPC animal model and cell model were established through repeated hypoxia exposure using mice and the mouse hippocampal neuronal cell line HT22. Step-down test was conducted on HPC mice. Real-time PCR and Western blot analysis were used to assess the mRNA and protein expression levels of Notch1 and hairy and enhancer of split1 (HES1). The presence of BrdU-positive cells and Notch1 expression in the hippocampal dental gyrus (DG) were examined with confocal microscopy. The methylation status of the Notch1 was analyzed using methylation-specific PCR (MS-PCR). HT22 cells were employed to elucidate the impact of HPC on Notch1 in vitro. Results: HPC significantly improved the step-down test performance of mice with elevated levels of mRNA and protein expression of Notch1 and HES1 (P < 0.05). The intensities of the Notch1 signal in the control group, the H group and the HPC group were 2.62 ± 0.57 × 107, 2.87 ± 0.84 × 107, and 3.32 ± 0.14 × 107, respectively, and the number of BrdU (+) cells in the hippocampal DG were 1.83 ± 0.54, 3.71 ± 0.64, and 7.29 ± 0.68 respectively. Compared with that in C and H group, the intensity of the Notch1 signal and the number of BrdU (+) cells increased significantly in HPC group (P < 0.05). The methylation levels of the Notch1 promoter 0.82 ± 0.03, 0.65 ± 0.03, and 0.60 ± 0.02 in the C, H, and HPC groups, respectively. The methylation levels of Notch1 decreased significantly (P < 0.05). The effect of HPC on HT22 cells exhibited similarities to that observed in the hippocampus. Conclusion: HPC may confer neuroprotection by activating the Notch1 signaling pathway and regulating its methylation level, resulting in the regeneration of hippocampal neurons. [ABSTRACT FROM AUTHOR]

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