Cortico-cortical connectivity of the somatosensory cortex of the agouti: Topographical organization and evolutionary implications.

Understanding patterns of cortico-cortical connections in both frequently and infrequently studied species advances our knowledge of cortical organization and evolution. The agouti (Dasyprocta aguti, a medium-size South American rodent) offers a unique opportunity, because of its large lissencephalic brain and its natural behaviors, such as gnawing and hiding seeds, that require bimanual interaction while sitting on its hindlimbs and aligning its head to receive images of the horizon on the retinal visual streak. There have been no previous studies of the intrinsic and extrinsic ipsilateral projections of the agouti's primary somatosensory cortical area (S1).

The Hidden Dangers of Sedentary Living: Insights into Molecular, Cellular, and Systemic Mechanisms.

With the aging of the global population, neurodegenerative diseases are emerging as a major public health issue. The adoption of a less sedentary lifestyle has been shown to have a beneficial effect on cognitive decline, but the molecular mechanisms responsible are less clear. Here we provide a detailed analysis of the complex molecular, cellular, and systemic mechanisms underlying age-related cognitive decline and how lifestyle choices influence these processes.

Unraveling the Influence of Litter Size, Maternal Care, Exercise, and Aging on Neurobehavioral Plasticity and Dentate Gyrus Microglia Dynamics in Male Rats.

This study explores the multifaceted influence of litter size, maternal care, exercise, and aging on rats' neurobehavioral plasticity and dentate gyrus microglia dynamics. Body weight evolution revealed a progressive increase until maturity, followed by a decline during aging, with larger litters exhibiting lower weights initially. Notably, exercised rats from smaller litters displayed higher body weights during the mature and aged stages.

Organization of Somatosensory Cortex in the South American Rodent Paca (Cuniculus paca).

Introduction: The study of non-laboratory species has been part of a broader effort to establish the basic organization of the mammalian neocortex, as these species may provide unique insights relevant to cortical organization, function, and evolution.

Methods: In the present study, the organization of three somatosensory cortical areas of the medium-sized (5-11 kg body mass) Amazonian rodent, the paca (Cuniculus paca), was determined using a combination of electrophysiological microelectrode mapping and histochemical techniques (cytochrome oxidase and NADPH diaphorase) in tangential sections.

Results: Electrophysiological mapping revealed a somatotopically organized primary somatosensory cortical area (S1) located in the rostral parietal cortex with a characteristic foot-medial/head-lateral contralateral body surface representation similar to that found in other species.

Unexpected cognitive similarities between older adults and young people: Scores variability and cognitive performances.

Background: Increased interindividual variability in cognitive performance during aging has been proposed as an indicator of cognitive reserve.

Objective: To determine if interindividual variability performance in episodic memory (PAL), working memory (SWM), reaction time (RTI), and sustained attention (RVP) could differentiate clusters of differential cognitive performance in healthy young and older adults and search for cognitive tests that most contribute to these differential performances.

Methods: We employed hierarchical cluster and canonical discriminant function analyses of cognitive scores using the Cambridge Neuropsychological Test Automated Battery (CANTAB) to identify cognitive variability in older and young adults using the coefficient of variability of cognitive performances between and within groups.

Pilates and Cognitive Stimulation in Dual Task an Intervention Protocol to Improve Functional Abilities and Minimize the Rate of Age-Related Cognitive Decline in Postmenopausal Women.

Unlabelled: It is already known the effectiveness of Pilates training on cognitive and functional abilities. It is also known that dual-task exercise and cognitive stimuli improve cognition and functional capacity. However, no previous report combined cognitive stimuli and Pilates in dual task and measured its effects on the cognitive and physical performances of postmenopausal women.

Unwanted Exacerbation of the Immune Response in Neurodegenerative Disease: A Time to Review the Impact.

The COVID-19 pandemic imposed a series of behavioral changes that resulted in increased social isolation and a more sedentary life for many across all age groups, but, above all, for the elderly population who are the most vulnerable to infections and chronic neurodegenerative diseases. Systemic inflammatory responses are known to accelerate neurodegenerative disease progression, which leads to permanent damage, loss of brain function, and the loss of autonomy for many aged people. During the COVID-19 pandemic, a spectrum of inflammatory responses was generated in affected individuals, and it is expected that the elderly patients with chronic neurodegenerative diseases who survived SARSCoV-2 infection, it will be found, sooner or later, that there is a worsening of their neurodegenerative conditions.

Microglial Morphology Across Distantly Related Species: Phylogenetic, Environmental and Age Influences on Microglia Reactivity and Surveillance States.

Microglial immunosurveillance of the brain parenchyma to detect local perturbations in homeostasis, in all species, results in the adoption of a spectrum of morphological changes that reflect functional adaptations. Here, we review the contribution of these changes in microglia morphology in distantly related species, in homeostatic and non-homeostatic conditions, with three principal goals (1): to review the phylogenetic influences on the morphological diversity of microglia during homeostasis (2); to explore the impact of homeostatic perturbations (Dengue virus challenge) in distantly related species ( and ) as a proxy for the differential immune response in small and large brains; and (3) to examine the influences of environmental enrichment and aging on the plasticity of the microglial morphological response following an immunological challenge (neurotropic arbovirus infection). Our findings reveal that the differences in microglia morphology across distantly related species under homeostatic condition cannot be attributed to the phylogenetic origin of the species.

Limbic Encephalitis Brain Damage Induced by Cocal Virus in Adult Mice Is Reduced by Environmental Enrichment: Neuropathological and Behavioral Studies.

We previously demonstrated, using the Piry virus model, that environmental enrichment promotes higher T-cell infiltration, fewer microglial changes, and faster central nervous system (CNS) virus clearance in adult mice. However, little is known about disease progression, behavioral changes, CNS cytokine concentration, and neuropathology in limbic encephalitis in experimental models. Using Cocal virus, we infected C57Bl6 adult mice and studied the neuroanatomical distribution of viral antigens in correlation with the microglial morphological response, measured the CNS cytokine concentration, and assessed behavioral changes.

BALB/c female subjected to valproic acid during gestational period exhibited greater microglial and behavioral changes than male mice: A significant contra intuitive result.

Most animal model studies of autism spectrum disorders (ASD) were performed in males. Thus, little is known about the mechanisms underlying disease progression in females. Here, we searched for potential influences of sex and environment on gestational valproic acid-induced behavioral abnormalities using hippocampal-dependent tasks, and on number and morphometry of microglia of the molecular layer of the dentate gyrus (Mol-DG).

Long-term environmental enrichment reduces microglia morphological diversity of the molecular layer of dentate gyrus.

We investigated long-term environmental influences on morphology of microglia from the outer and middle thirds of molecular layer of the dentate gyrus (MolDG), and on microglia from dorsal and ventral dentate gyrus molecular layer. We also estimated the total number of MolDG microglia using stereology. For this purpose, microglia of the molecular layer of the dentate gyrus of 20-month-old female Swiss albino mice, housed from 21st postnatal day onwards, in the impoverished environment of the standard laboratory cages (SEA), or in a cage with an enriched environment (EEA), were reconstructed microscopically in three dimensions and compared with each other and with microglia of 6-month-old female Swiss albino mice, also housed from weaning onwards in an enriched cage (EEY).

Contrasting migratory journeys and changes in hippocampal astrocyte morphology in shorebirds.

Semipalmated sandpiper (Calidris pusilla) migration to the Southern Hemisphere includes a 5-day non-stop flight over the Atlantic Ocean, whereas semipalmated plover (Charadrius semipalmatus) migration, to the same area, is largely over land, with stopovers for feeding and rest. We compared the number and 3D morphology of hippocampal astrocytes of Ch. semipalmatus before and after autumnal migration with those of C.

The Organization and Connections of Second Somatosensory Cortex in the Agouti.

In order to understand how the mammalian sensory cortex has been structured during evolution, it is necessary to compare data from different species across distinct mammalian lineages. Here, we investigated the organization of the secondary somatosensory area (S2) in the agouti (), a medium-sized Amazonian rodent, using microelectrode mapping techniques and neurotracer injections. The topographic map obtained from multiunit electrophysiological recordings were correlated with both cytochrome oxidase (CO) histochemistry and with patterns of corticocortical connections in tangential sections.

Age and Environment Influences on Mouse Prion Disease Progression: Behavioral Changes and Morphometry and Stereology of Hippocampal Astrocytes.

Because enriched environment (EE) and exercise increase and aging decreases immune response, we hypothesized that environmental enrichment and aging will, respectively, delay and increase prion disease progression. Mice dorsal striatum received bilateral stereotaxic intracerebral injections of normal or ME7 prion infected mouse brain homogenates. After behavior analysis, animals were euthanized and their brains processed for astrocyte GFAP immunolabeling.

Virus Infections on Prion Diseased Mice Exacerbate Inflammatory Microglial Response.

We investigated possible interaction between an arbovirus infection and the ME7 induced mice prion disease. C57BL/6, females, 6-week-old, were submitted to a bilateral intrahippocampal injection of ME7 prion strain (ME7) or normal brain homogenate (NBH). After injections, animals were organized into two groups: NBH ( = 26) and ME7 ( = 29).

Hierarchical Cluster Analysis of Three-Dimensional Reconstructions of Unbiased Sampled Microglia Shows not Continuous Morphological Changes from Stage 1 to 2 after Multiple Dengue Infections in Callithrix penicillata.

It is known that microglial morphology and function are related, but few studies have explored the subtleties of microglial morphological changes in response to specific pathogens. In the present report we quantitated microglia morphological changes in a monkey model of dengue disease with virus CNS invasion. To mimic multiple infections that usually occur in endemic areas, where higher dengue infection incidence and abundant mosquito vectors carrying different serotypes coexist, subjects received once a week subcutaneous injections of DENV3 (genotype III)-infected culture supernatant followed 24 h later by an injection of anti-DENV2 antibody.

Beneficial effects of multisensory and cognitive stimulation in institutionalized elderly: 12-months follow-up.

We previously demonstrated the beneficial effects of a multisensory and cognitive stimulation program, consisting of 48 sessions, twice a week, to improve the cognition of elderly subjects living either in long-term care institutions (institutionalized - I) or in communities with their families (noninstitutionalized - NI). In the present study, we evaluated these subjects after the end of the intervention and compared the rate of age-related cognitive decline of those living in an enriched community environment (NI group, n=15, 74.1±3.

CANTAB object recognition and language tests to detect aging cognitive decline: an exploratory comparative study.

Objective: The recognition of the limits between normal and pathological aging is essential to start preventive actions. The aim of this paper is to compare the Cambridge Neuropsychological Test Automated Battery (CANTAB) and language tests to distinguish subtle differences in cognitive performances in two different age groups, namely young adults and elderly cognitively normal subjects.

Method: We selected 29 young adults (29.

In vitro cytokines profile and ultrastructural changes of microglia and macrophages following interaction with Leishmania.

In the present study, we assessed morphological changes and cytokine production after in vitro interaction with causative agents of American cutaneous leishmaniasis and compared the microglia and macrophage immune responses. Cultures of microglia and macrophages infected with stationary-phase promastigotes of Leishmania (Viannia) shawi, Leishmania (Viannia) braziliensis or Leishmania (Leishmania) amazonensis were evaluated 24, 48 and 72 h after interaction. Macrophages only presented the classical phagocytic process while microglia also displayed large cytoplasmic projections similar to the ruffles described in macropinocytosis.

Beneficial effects of multisensory and cognitive stimulation on age-related cognitive decline in long-term-care institutions.

The aim of the present report was to evaluate the effectiveness and impact of multisensory and cognitive stimulation on improving cognition in elderly persons living in long-term-care institutions (institutionalized [I]) or in communities with their families (noninstitutionalized [NI]). We compared neuropsychological performance using language and Mini-Mental State Examination (MMSE) test scores before and after 24 and 48 stimulation sessions. The two groups were matched by age and years of schooling.

Enriched environment and masticatory activity rehabilitation recover spatial memory decline in aged mice.

Background: To measure the impact of masticatory reduction on learning and memory, previous studies have produced experimental masticatory reduction by modified diet or molar removal. Here we induced spatial learning impairment in mice by reducing masticatory activity and then tested the effect of a combination of environmental enrichment and masticatory rehabilitation in recovering spatial learning at adulthood and in later life. For 6 months (6M) or 18 months (18M), we fed three groups of mice from postnatal day 21 respectively with a hard diet (HD) of pellets; pellets followed by a powdered, soft diet (HD/SD, divided into equal periods); or pellets followed by powder, followed by pellets again (HD/SD/HD, divided into equal periods).

Environmental influences on antibody-enhanced dengue disease outcomes.

Because an enriched environment (EE) enhances T-cell activity and T-lymphocytes contribute to immunopathogenesis during heterologous dengue virus (DENV) infections, we hypothesised that an EE increases dengue severity. To compare single serotype (SS) and antibody-enhanced disease (AED) infections regimens, serial intraperitoneal were performed with DENV3 (genotype III) infected brain homogenate or anti-DENV2 hyperimmune serum followed 24 h later by DENV3 (genotype III) infected brain homogenate. Compared AED for which significant differences were detected between the EE and impoverished environmental (IE) groups (Kaplan-Meyer log-rank test, p = 0.

Differential vulnerability of substantia nigra and corpus striatum to oxidative insult induced by reduced dietary levels of essential fatty acids.

Oxidative stress (OS) has been implicated in the etiology of certain neurodegenerative disorders. Some of these disorders have been associated with unbalanced levels of essential fatty acids (EFA). The response of certain brain regions to OS, however, is not uniform and a selective vulnerability or resilience can occur.

Dopaminergic cell populations of the rat substantia nigra are differentially affected by essential fatty acid dietary restriction over two generations.

Essential fatty acids play a crucial role in the activity of several neurotransmission systems, especially in the monoaminergic systems involved in cognitive and motor aspects of behavior. The present study investigated whether essential fatty acid dietary restriction over two generations could differentially affect dopaminergic cell populations located in the substantia nigra rostro-dorso-medial (SNrm) or caudo-ventro-lateral (SNcv) regions which display distinct neurochemical profile and vulnerability to lesions under selected pathological conditions. Wistar rats were raised from conception on control or experimental diets containing adequate or reduced levels of linoleic and α-linolenic fatty acids, respectively.