Memory Processing Research Articles

Distinct age-related alterations in alpha-beta neural oscillatory activity during verbal working memory encoding in children and adolescents.

Emerging imaging studies of working memory (WM) have identified significant WM-related oscillatory events that are unique to each phase of working memory (e.g. encoding, maintenance). Although many previous imaging studies have shown age-related changes within the frontoparietal network when performing a WM task, understanding of the age-related changes in the oscillatory dynamics underlying each phase of WM during development and their relationships to other cognitive function is still in its infancy. To this end, we enrolled a group of 74 typically-developing youths aged 7-15years to perform a letter-based Sternberg WM task during magnetoencephalography. Trial-wise data were transformed into the time-frequency domain, and significant oscillatory responses during the encoding and maintenance phases of the task were independently imaged using beamforming. Our results revealed widespread age-related power differences in alpha-beta oscillatory activity during encoding throughout left frontal, parietal, temporal, occipital and cerebellar regions. By contrast, age-related differences in maintenance-related activity were limited to a small area in the superior temporal gyrus and parieto-occipital regions. Follow-up exploratory factor analysis of age-related encoding alpha-beta activity revealed two distinct factors, and these factors were each found to significantly mediate age-related improvements in both verbal and non-verbal cognitive ability. Additionally, late maintenance alpha activity was related to reaction time on the task. Taken together, our results indicate that the neural dynamics in the alpha and beta bands are uniquely sensitive to age-related changes throughout this developmental period and are related to both task performance and other aspects of cognitive development. KEY POINTS: Understanding of the age-related changes in neural oscillatory dynamics serving verbal working memory function is in its infancy. This study identified the age-related neural alterations during each phase of working memory processing in youths. Developmental differences during working memory processing were primarily isolated to alpha-beta activity during the encoding phase. Alpha-beta activity during encoding significantly mediated age-related improvements in both verbal and non-verbal ability. This study establishes new brain-behaviour relationships linking working memory function to other aspects of cognitive development.

Self-supervised learning reduces label noise in sharp wave ripple classification.

In the field of electrophysiological signal analysis, the classification of time-series datasets is essential. However, these datasets are often compromised by the prevalent issue of incorrect attribution of labels, known as label noise, which may arise due to insufficient information, inappropriate assumptions, specialists' mistakes, and subjectivity, among others. This critically impairs the accuracy and reliability of data classification, presenting significant barriers to extracting meaningful insights. Addressing this challenge, our study innovatively applies self-supervised learning (SSL) for the classification of sharp wave ripples (SWRs), high-frequency oscillations involved in memory processing that were generated before or after the encoding of spatial information. This novel SSL methodology diverges from traditional label correction techniques. By utilizing SSL, we effectively relabel SWR data, leveraging the inherent structural patterns within time-series data to improve label quality without relying on external labeling. The application of SSL to SWR datasets has yielded a 10% increase in classification accuracy. While this improved classification accuracy does not directly enhance our understanding of SWRs, it opens up new pathways for research. The study's findings suggest the transformative capability of SSL in improving data quality across various domains reliant on precise time-series data classification.

Exploring the Prevalence of Learning Disabilities in a Community Sample of Children Using the Greek Weschler Intelligence Scale for Children (WISC-V GR)

This study aimed to explore the prevalence of learning disabilities (LDs) and the emotional–behavioral difficulties in 208 children from the Crete region in Greece, and who voluntarily presented themselves for study and were evaluated by a university-based interdisciplinary team of mental health professionals. The Greek version of the Wechsler Intelligence Scale for Children–Fifth Edition (WISC-V GR) was used, with its five Primary Index scores and full-scale IQ (Verbal Comprehension Index, VCI; Visual Spatial Index, VSI; Fluid Reasoning Index, FRI; Working Memory Index, WMI; and Processing Speed, PCI). Five diagnostic categories were established for the purpose of analysis: (a) no LDs (TD group), (b) Attention Deficit Hyperactivity Disorder (ADHD), (c) Specific Learning Disabilities (SLDs), (d) Extremely Low FSIQ (below 79), and (e) Emotional/Behavioral difficulties. The results revealed a 25.5% prevalence of SLDs, 18.75% ADHD, 8.65% Extremely Low FSIQ, and 5.29% emotional/behavioral problems, suggesting that 58% of the study population struggled with some kind of learning difficulty. Statistically significant differences were observed between the “Extremely Low FSIQ” group, the “SLD”, the “ADHD”, and the “TD” diagnostic groups in terms of the “VCI”, “FRI”, and the “FSIQ” scales (p < 0.001). Likewise, the “Extremely Low FSIQ” group differed significantly from the “SLD” and “TD” groups in terms of the “VSI”, the WMI, and the “PSI” (p < 0.001). The “Behavioural/emotional” and “SLD” groups differed in terms of “VCI” and “Full scale IQ” (p < 0.001). The analysis indicated that the children with severe learning difficulties differed from the other groups in terms of their cognitive profiles and that they needed tailor-made educational programs and interventions in a typical classroom. This study offers comparative data from a community sample of children, as well as generated initial evidence from non-clinical settings on the usability and the diagnostic accuracy of the Wechsler Intelligence Scale for Children–Fifth Edition (WISC-V). Further research is suggested. The present study was funded by the Crete Region (MIS 5162111).

Distinct neural responses of ventromedial prefrontal cortex-projecting nucleus reuniens neurons during aversive memory extinction

Animals adaptively regulate aversive memories in safe environments through extinction, a process central to exposure therapy for anxiety disorders. The limbic thalamus controls cognitive function in concert with interconnected cortical and limbic structures. Though medial prefrontal (mPFC) afferents to the limbic thalamus regulate aversive memory, the functional role of limbic thalamus efferents to mPFC is unclear. Here, we investigated the roles of thalamic nuclei, the reuniens (RE) and mediodorsal (MD) thalamus, projecting to the medial prefrontal cortex (mPFC) in aversive memory conditioning and extinction in male mice. Using retrograde tracing, we demonstrated that ventromedial PFC (vmPFC)- and dorsomedial PFC (dmPFC)-projecting neurons are topologically segregated within the RE and MD. Fiber photometry revealed that both RE→vmPFC and MD→vmPFC neurons respond to aversive stimuli. Notably, RE→vmPFC neurons develop shock-associated cue (CS+) response during aversive conditioning. During extinction, RE→vmPFC neurons exhibited a biphasic response to CS+, while MD→vmPFC neurons showed no cue-evoked activity. Neither optogenetic activation nor inactivation of these populations altered freezing behavior during extinction compared to controls. Collectively, these findings indicate that RE→vmPFC neurons encode aversive cue information during extinction but are dispensable for behavioral modulation. This study highlights the distinct contributions of limbic thalamus-PFC circuits to aversive memory processing.

The moderating effect of the psychosocial working conditions (effort/reward/overcommitment) on the association between noise annoyance and cognitive performance among adolescents

ObjectivesThe primary objective of the current study was to evaluate the correlation between noise-induced annoyance and the cognitive performance within the Lebanese adolescent population and the moderating effect of psychosocial work aspects-namely effort, reward, and overcommitment- in this association.MethodsAn anonymous online survey was conducted in Lebanon between April and May 2023, using a snowball sampling technique and distributed across various social media platforms, to gather data from Lebanese adolescents. The sample was composed of 1269 adolescents. Participants voluntarily completed a self-administered Arabic questionnaire that consisted of a sociodemographic section and implemented three scales: Noise Annoyance scale, Effort-Reward in school scale, as well as LEAF scale.ResultsThe moderation analysis findings revealed that at low levels of effort, higher noise annoyance was significantly associated with worse memory function (Beta = 0.94; p =.002) and mathematics skills (Beta = 0.40; p =.002), whereas at low (Beta = 0.49; p <.001) and moderate (Beta = 0.29; p =.001) levels of effort, it was significantly associated with worse sustained sequential processing. At low and moderate levels of reward, higher noise annoyance was significantly associated with worse attention (Beta = 0.48; p <.001 and Beta = 0.20; p <.031 respectively), sustained sequential processing (Beta = 0.43; p <.001 and Beta = 0.22; p =.013 respectively) and working memory (Beta = 0.47; p <.001 and Beta = 0.28; p =.002 respectively). At low levels of reward, higher annoyance was significantly associated with worse memory function (Beta = 0.82; p =.007), processing speed (Beta = 0.38; p =.001) and mathematic skills (Beta = 0.28; p =.026). Finally, at low and moderate levels of overcommitment, higher noise annoyance was significantly associated with worse factual memory (Beta = 0.49; p <.001 and Beta = 0.25; p =.005 respectively), worse attention (Beta = 0.45; p <.001 and Beta = 0.26; p =.005 respectively) and worse processing speed (Beta = 0.43; p <.001 and Beta = 0.23; p =.012 respectively).ConclusionThis study could encourage the integration of targeted interventions and strategic measures that address both noise annoyance and psychosocial working conditions, defined as the academic work students perform both at school and at home, to proactively prevent the emergence of cognitive impairment among the adolescent population.

Barriers to Deprescribing Benzodiazepines in Older Adults in a Survey of European Physicians.

The use of benzodiazepine receptor agonists (BZRA) poses serious health risks to older adults. Although several guidelines recommend deprescribing, implementation in clinical practice remains limited. To identify physicians' barriers to and enablers of deprescribing BZRA in adults aged 65 years and older taking a BZRA for sleep problems; to determine factors associated with hospital physicians' intention to deprescribe BZRA and their self-reported routine BZRA deprescribing. This survey study included hospital physicians and general practitioners (GPs) working across 6 European Countries (Belgium, Greece, Norway, Poland, Spain, and Switzerland) between December 2022 and March 2023. Barriers identification via a 35-item questionnaire based upon the Theoretical Domains Framework (TDF). Responses were categorized as major barriers, moderate barriers, and enablers based on their mean scores. Multivariable logistic regressions were used to identify background characteristics and TDF-based domains associated with hospital physicians' intention to deprescribe and self-reported routine deprescribing. Questionnaires from 240 hospital physicians and 96 GPs were analyzed. Most participants were women: 144 (61.0%) hospital physicians and 52 (54.2%) GPs. In terms of experience, the most common reported time in practice was less than 5 years for hospital physicians (76 [31.7%]) and between 10 and 14 years for GPs (35 [36.5%]). Most reported deprescribing BZRA routinely (135 hospital physicians [57.2%] and 66 GPs [72.5%]). Major barriers (and TDF domains) were similar for hospital physicians and GPs across the 6 countries. These barriers included: lack of training (skills), low self-efficacy (beliefs about capabilities), prioritization of other health issues (goals), frustration with the challenges of deprescribing (emotions), insufficient staff and time, absence of local policies (environmental context and resources), and reluctance from patients (social influence). Intention to deprescribe was significantly associated with country, occupation type, and 5 TDF domains: memory, attention, and decision process (odds ratio [OR], 1.70; 95% Ci, 1.22-2.40); social and/or professional role and identity (OR, 5.92; 95% CI, 3.28-11.07); beliefs about capabilities (OR, 2.35; 95% CI, 1.55-3.63); beliefs about consequences (OR, 3.00; 95% CI, 1.61-5.71); and reinforcement (OR, 1.49; 95% CI, 1.05-2.15). Routine deprescribing was significantly associated with 3 TDF domains: memory, attention, and decision processes; intentions; and emotions. In this theory-based survey study of physicians, physicians and general practitioners described numerous barriers to deprescribing BZRA in older adults. Our findings indicate that effective deprescribing efforts require approaches that address both reflective processes (eg, enhancing capability) and impulsive processes (eg, managing emotions).

Neurobiological Mechanisms of Ketamine Use, its Addiction, and Withdrawal: A Mini Review.

Ketamine, a substance used for anesthesia and known for inducing dissociation, can lead to addiction and the development of severe withdrawal symptoms. Ketamine alters brain networks before affecting somesthetic sensation. Ketamine abuse was especially prevalent in East and Southeast Asia, and its popularity has continued to expand globally in recent decades. Ketamine is gaining popularity in the public and private sectors as a cheaper off-label depression treatment. Unfortunately, ketamine may cause side effects, such as heart and blood vessel instability, respiratory depression, liver injury, hallucinations, etc. The pain-relieving and mental effects of ketamine might induce reliance; thus, it should be used cautiously. This review highlights the neurobiological processes underpinnings of ketamine's addictive potential, withdrawal, and its effects on brain networks like the prefrontal cortex, hippocampus, and mesolimbic pathway, which play vital roles in decision-making, memory, and reward processing. In addition, the involvement of neurotransmitter systems, specifically glutamate and dopamine, in mediating the addictive properties of ketamine and the neuroadaptive changes that occurred during withdrawal are also discussed. It also explains that low-dose ketamine can alter the secretion of stress hormone cortisol and hypothalamic-pituitary-adrenal (HPA) axis dysregulation, possibly attributed to the current repurposing study of ketamine as a fast-acting antidepressant. Understanding these pathways is essential for developing effective ketamine addiction treatments, managing withdrawal symptoms, and possibly reversing brain changes for the betterment of human health and psychological well- being.

3D Integrated Process and Hybrid Bonding of High Bandwidth Memory (HBM)

3D Integrated Process and Hybrid Bonding of High Bandwidth Memory (HBM)

Neural evidence of implicit emotion regulation deficits: An explorative study of comparing PTSD with and without alcohol dependence.

Neural evidence of implicit emotion regulation deficits: An explorative study of comparing PTSD with and without alcohol dependence.

A hybrid approach for hotspot problem using load balancing and advanced ant colony algorithm

Wireless sensor networks (WSNs) are crucial in various applications such as environmental surveillance, military operations, transportation monitoring, and healthcare. However, due to a finite set of sensor nodes' resources concerning energy, memory, disk, and CPU processing, nodes in WSNs often face hotspot issues. The sensor nodes that are located near the base station, are responsible for relaying data not only from themselves but also from neighboring nodes. This leads to hotspot issues, where nodes near the base station experience higher traffic loads and faster energy depletion. This paper mainly focuses on mitigating hotspot issues in heterogeneous WSNs using unequal clustering, load balancing, and an advanced ant colony algorithm. This approach involves devising strategies for selecting cluster heads, determining clusters optimal number and formation, and optimizing data transmission processes. Central to the methodology is utilizing load balancing mechanisms and an advanced ant colony algorithm to distribute the workload among sensor nodes more evenly and find the optimum routing path. The proposed algorithm shows promise in alleviating traffic congestion and energy depletion and provides an innovative approach to enhance network performance and prolong the lifespan of sensor nodes.

MEMORY AS BELONGING: EXISTENTIAL CONCRETIZATION IN THE WORK “THE TRUTH ABOUT ME: A HIJRA LIFE STORY” BY A. REVATHI

This work seeks to discuss the concepts of memory, resistance and belonging, through reflections on some authors such as Alfredo Bosi (1996), Augusto Sarmento-Pantoja (2022), Tânia Sarmento-Pantoja (2022) with regard to resistance; Maurice Halbwachs (1990), Michael Pollak (1992) on the concepts of memory; Sandra Regina Lestinge (2004) and Lucimara Valdambrini Moriconi (2014) on belonging, among others who corroborate the development of this work. The aim of this research is to understand relations of resistance as a way of existing and to understand the process of memory for existential realization. The corpus of this research is chapters 1, 2 and 3 of the autobiographical work “The Truth About Me: A Hijra Life Story by A. Revathi”. To develop this research, we used the method of qualitative bibliographical research based on a theoretical-critical analysis of the selected work. As a result, we witness through Revathi's narrative a resistance based on the need for survival, where we are introduced to her trajectory as a Hijra and how these memories were/are essential for existential fulfillment, in order to be who you have always been.

Cognitive and Spiritual Approaches To Qur’anic Memorization: A Study of The Yadain Method in Yogyakarta

This paper examines the contemporary process of Qur'anic memorization in Indonesia using the Yadain Method, which integrates traditional memorization practices with modern cognitive strategies. The background of this study highlights the need for innovative approaches to enhance both the intellectual retention and spiritual understanding of the Qur’an in diverse age groups. The objective is to analyze how the Yadain Method, emphasizing visualization and tadabbur (reflective contemplation of meanings), contributes to effective and holistic Qur’anic memorization. Employing a case study qualitative method, the research explores the implementation and impact of the method on participants at the Executive Tahfidz Center Yogyakarta. Key components of the method include cognitive aids such as color-coded visualizations and structured exercises, which facilitate rapid memorization and long-term retention. The findings reveal that this approach not only improves memorization efficiency but also fosters mental tranquility and spiritual growth, benefiting learners across various educational levels. The study introduces a novel framework for Qur’anic memorization in Indonesia, combining cognitive techniques with psychological and spiritual support, thus demonstrating its flexibility and effectiveness as a modern pedagogical tool.

COGNITIVE LOAD CHANGE IN CHEMICAL CONCEPT LEARNING: INSIGHTS FROM EVENT-RELATED POTENTIALS

This study explored the impact of oxidation-reduction reaction problem difficulty on university students' cognitive load using event-related potentials (ERPs). Forty-eight balanced low and high difficulty problems were designed. Fifteen undergraduate students majoring in chemistry (8 females and 7 males) participated in the study. Results demonstrated significantly increased reaction time, significantly decreased accuracy, and highly significantly elevated subjective effort as task difficulty intensified. ERP analysis revealed significant differences in N200, P300, and N400 amplitudes between easy and difficult problems, indicating increased demands on control, working memory, and in-depth processing under high load. The study provided physiological evidence supporting cognitive load theory and offered implications for optimizing oxidation-reduction reaction teaching. The findings bridged the gap between cognition and education, suggesting potential avenues for improving chemistry education through cognitive load management. Keywords: oxidation-reduction reactions, chemistry learning, cognitive load, event-related potentials

EEG slow oscillations and overnight spatial navigational memory performance in CPAP-treated obstructive sleep apnea.

Obstructive sleep apnea (OSA) exerts pathogenic effects through a combination of sleep fragmentation (SF) and intermittent hypoxia (IH). The mechanisms through which sleep disruption impacts memory might arise by investigating disruption of specific sleep stages and, when such disruption occurs through OSA, by evaluating the individual contributions of SF and IH. Given region-specific EEG slow activity during non-REM sleep has been associated with overnight declarative, motor and spatial memory formation, we investigated the effects of disrupting slow wave sleep (SWS) on a virtual maze navigation task. Thirty three participants (24 male, 56 years old [range 28-68 years] with OSA (baseline AHI4%>20/hour) who were habitually well-treated and adherent to CPAP completed 3 timed trials on a 3D spatial maze before and after polysomnographically (PSG) recorded sleep. We restricted CPAP withdrawal to SWS through real-time monitoring of the PSG under three conditions: 1) stable-SWS on therapeutic CPAP, 2) SWS-CPAP withdrawal containing SF and IH, and 3) SWS-CPAP withdrawal with supplemental oxygen containing SF with reduced IH. SWS-specific CPAP withdrawal (with or without supplemental oxygen) did not significantly impact EEG slow oscillation or spatial navigational memory, despite effectively reducing %SWS and SWS bout length. Greater regional EEG slow oscillation (0.6-1Hz), but not delta (1-4Hz) activity, was associated with improvements in overnight memory during stable SWS in the CPAP condition. These observations suggest that slow oscillations may be important for overnight memory processing, and sleep disruptions of sufficient magnitude to reduce slow oscillations may be required to capture demonstrable change in spatial navigation performance.

Regulation of peripheral glucose levels during human sleep.

Studies in rats indicate that oscillatory signatures of memory processing during sleep, and specifically hippocampal sharp wave-ripples, also regulate peripheral glucose concentration. Here, we examined whether there is a similar link between such signatures of memory processing and glucose regulation during sleep in healthy humans. We obtained polysomnographic recordings and continuous recordings of peripheral interstitial glucose levels (1 sample/min) from 10 participants (5 females) during two consecutive nights. Temporal relationships between EEG events of interest and glucose levels were examined using cross-correlation functions and time-event histograms. Confirming the findings in rats, we find that sleep spindles, a core signature of sleep-dependent memory processing, are followed within 1-6min by a robust decrease in glucose concentrations. By contrast, slow oscillation events hallmarking slow wave sleep (SWS) were followed, with a lag of 5-11min, by an increase in glucose levels. Transitions into rapid eye movement (REM) sleep were followed by a glucose decrease after 10-14min, whereas awakenings and microarousals were linked to immediate glucose increases. These temporal relationships indicate a sleep-specific regulation of peripheral glucose concentrations that is linked to both signatures of sleep-dependent memory processing as well as the macro-architecture of sleep. They possibly reflect noradrenergic regulation of sympathetic activity via the brainstem locus coeruleus, and may be of relevance in clinical conditions with concurrent disturbances of sleep and glucose regulation.

ChatGPT-estimated occupational complexity predicts cognitive outcomes and cortical thickness above and beyond socioeconomic status among older adults.

Many aging cohort studies have collected data on participants' job titles, yet these job titles were seldom analyzed within the cognitive aging context despite their relevance to neurocognition, due to difficulties in analyzing these job titles quantitatively. While it is possible to rate these jobs' occupational complexity (OC)using job classification systems, this can be somewhat labor-intensive and prone to human errors. To this end, we demonstrate a novel and simple method to extract OC ratings from job titles using ChatGPT. Then, we showcased the utility of these ratings in predicting cognitive and structural brain outcomes, especially compared to other socioeconomic status (SES) indicators. Community-dwelling older adults (N = 238, agemean = 70) completed cognitive assessments and underwent MRI scans. Regression models were fitted to predict 14 different cognitive outcomes, vertex-wise cortical thickness (CT), and subcortical gray matter volumes, using OC scores and/or SES predictors (e.g., education, housing type, and income levels), controlling for demographical covariates. OC scores outperformed SES indicators in predicting clusters of CT increases and most cognitive outcomes, including diagnoses of mild cognitive impairment. Furthermore, OC scores significantly predicted clusters of CT increases and various cognitive outcomes, even after controlling for SES. Meta-analytic decoding suggests these clusters of CT increases occurred in regions typically associated with sensorimotor and memory processing. These results highlight the significant and unique contribution ofChatGPT-derived OC scores in predicting cognitive and brain aging outcomes. These scores are easy to derive and can be helpful in fine-tuning predictions of cognitive and brain aging outcomes.

Specific contribution of cognitive and motor impairments with functional capacity and dependence in Huntington’s disease

BackgroundHuntington’s disease (HD) leads to increasing dependence. Unlike psychiatric disorders, motor and cognitive deficits evolve progressively over time. Understanding their specific impact on daily activities is crucial for preserving autonomy. However, because cognitive tasks in HD rely on motor functions, and motor tasks demand cognitive processing, disentangling their specific impact remains a challenge.ObjectiveTo identify the specific contribution of cognitive and motor impairments on global functional capacity, basic and instrumental activities of daily living (ADL/IADL), and work-related activities (WRA) in HD.Methods158 HD mutation carriers, enrolled in the BioHD (NCT01412125) and RepairHD (NCT03119246) studies, were evaluated with the Unified Huntington’s Disease Rating Scale and the SelfCog. The SelfCog assesses motor processing separately from memory, language, executive functions and visuospatial processing. Linear regressions were fitted to assess how functional capacity declined with motor and cognition impairments. Odds of dependence in ADLs, IADLs and WRAs were estimated using logistic regressions.ResultsCognitive and motor performance were independently associated with functional capacities, though motor performance showed a stronger association than cognitive performance. Decline of all SelfCog cognitive domains contributed to functional decline, with stronger association with global and executive scores compared to language, visuospatial, and memory domains. Higher global and executive deficits were associated with an increased risk of dependence in ADLs, IADLs, and WRAs.ConclusionThe independent contributions of motor, followed by cognitive—mainly executive—functions to functional decline suggest targeted interventions to preserve autonomy and quality of life in HD.

Reduction of Neuroinflammation as a Common Mechanism of Action of Anorexigenic and Orexigenic Peptide Analogues in the Triple Transgenic Mouse Model of Alzheimer´s Disease

Alzheimer’s disease (AD) is the most common form of dementia. Characterized by progressive neurodegeneration, AD typically begins with mild cognitive decline escalating to severe impairment in communication and responsiveness. It primarily affects cerebral regions responsible for cognition, memory, and language processing, significantly impeding the functional independence of patients. With nearly 50 million dementia cases worldwide, a number expected to triple by 2050, the need for effective treatments is more urgent than ever. Recent insights into the association between obesity, type 2 diabetes mellitus, and neurodegenerative disorders have led to the development of promising treatments involving antidiabetic and anti-obesity agents. One such novel promising candidate for addressing AD pathology is a lipidized analogue of anorexigenic peptide called prolactin-releasing peptide (palm11-PrRP31). Interestingly, anorexigenic and orexigenic peptides have opposite effects on food intake regulation, however, both types exhibit neuroprotective properties. Recent studies have also identified ghrelin, an orexigenic peptide, as a potential neuroprotective agent. Hence, we employed both anorexigenic and orexigenic compounds to investigate the common mechanisms underpinning their neuroprotective effects in a triple transgenic mouse model of AD (3xTg-AD mouse model) combining amyloid-beta (Aβ) pathology and Tau pathology, two hallmarks of AD. We treated 3xTg-AD mice for 4 months with two stable lipidized anorexigenic peptide analogues – palm11-PrRP31, and liraglutide, a glucagon-like peptide 1 (GLP-1) analogue – as well as Dpr3-ghrelin, a stable analogue of the orexigenic peptide ghrelin, and using the method of immunohistochemistry and western blot demonstrate the effects of these compounds on the development of AD-like pathology in the brain. Palm11-PrRP31, Dpr3-ghrelin, and liraglutide reduced intraneuronal deposits of Aβ plaque load in the hippocampi and amygdalae of 3xTg-AD mice. Palm11-PrRP31 and Dpr3-ghrelin reduced microgliosis in the hippocampi, amygdalae, and cortices of 3xTg-AD mice. Palm11-PrRP31 and liraglutide reduced astrocytosis in the amygdalae of 3xTg-AD mice. We propose that these peptides are involved in reducing inflammation, a common mechanism underlying their therapeutic effects. This is the first study to demonstrate improvements in AD pathology following the administration of both orexigenic and anorexigenic compounds, highlighting the therapeutic potential of food intake-regulating peptides in neurodegenerative disorders.Graphical

Functional segregation of rostral and caudal hippocampus in associative memory.

The hippocampus plays a crucial role in episodic memory. Given its complexity, the hippocampus participates in multiple aspects of higher cognitive functions, among which are semantics-based encoding and retrieval. However, the "where," "when" and "how" of distinct aspects of memory processing in the hippocampus are still under debate. Here, we employed a visual associative memory task that involved encoding three levels of subjective congruence to delineate the differential involvement of the rostral and caudal portions (also referred as anterior/posterior portions) of the human hippocampus during memory encoding, recognition and associative recall. Through stereo-EEG recordings in epilepsy patients we show that associative memory is reflected by rostral hippocampal activity during encoding, and caudal hippocampal activity during retrieval. In contrast, recognition memory encoding selectively activates the rostral hippocampus. The temporal dynamics of memory processing are manifested by gamma power increase, which partially overlaps with low-frequency power decrease during encoding and retrieval. Congruence levels modulate low-frequency activity prominently in the caudal hippocampus. These findings highlight an anatomical segregation in the hippocampus in accordance with the contributions of its partitions to associative and recognition memory.

Muscimol injection in the thalamic reticular nucleus reverts the effect of dopaminergic lesion on short-term memory in the rat globus pallidus externus.

Muscimol injection in the thalamic reticular nucleus reverts the effect of dopaminergic lesion on short-term memory in the rat globus pallidus externus.