Anxiety is being increasingly diagnosed in the elderly population. In this sense, epidemiologic data have linked late-life anxiety disorders to increased cognitive decline, morbidity, and even mortality. In addition, studies have already reported the influence of the environment on the association between aging and anxiety. Therefore, the present study aimed to conduct a comparative analysis between Elevated Plus Maze (EPM) and Open Field (OF) tests as methods for evaluating mice's anxiety-like behavior, considering environmental and age variables. For this, eighty Female albino Swiss mice aged 6, 12, and 18 months were housed in an impoverished environment (IE) and enriched environment (EE). Following this, the animals were tested in EPM and OF tests. The environment and age affect the anxiety-like behavior of the mice in the OF, with a difference between the animals of 6 and 18 months, only in the EE (p < 0.021). However, in the EPM, it does not occur. Despite that, the environment affected the distance traveled by the mice in the EPM, where the IE animals showed greater exploratory activity than the EE, only in the 18-month group (p < 0.001). No environmental influences were detected in the OF. Concerning age, in the EPM, animals in the 18-month-old group traveled shorter distances compared to the 6-month group (p < 0.001) and the 12-month group (p < 0.001), only in EE. In turn, in the OF there was a decrease in the distance traveled in the 18-month group compared to the 6-month group (p = 0.012), only in the IE. Thus, the divergences between the results of EPM and OF instigate a better evaluation of the parameters analyzed in each test.

The Clibadium spp. is a shrub of occurrence in the Amazon, popularly known as Cunambi. The compounds in the leaves demonstrate ichthyotoxic properties, and its major substance, cunaniol, is a powerful central nervous system stimulant with proconvulsant activity. Few current studies relate behavioral changes to the electrophysiological profile of fish poisoning. This study aimed to describe the behavioral, electromyographic, electroencephalographic, electrocardiographic, and seizure control characteristics of anticonvulsant drugs in Colossoma macropomum submitted to cunaniol intoxication during bathing containing 0.3 μg/L cunaniol. The behavioral test showed rapid evolution presenting excitability and spasms, which were confirmed by the analysis of Electroencephalogram (EEG), Electromyogram (EMG), and changes in cardiac function detected in the ECG. Cunaniol-induced excitability control was evaluated using three anticonvulsant agents: Phenytoin, Phenobarbital, and Diazepam. While phenytoin was not effective in seizure control, diazepam proved to be the most efficient. These results demonstrate the susceptibility of Colossoma macropomum to cunaniol poisoning, given that the central nervous system and electrocardiographic changes were considered severe.

As aging and cognitive decline progresses, the impact of a sedentary lifestyle on the appearance of environment-dependent cellular morphologies in the brain becomes more apparent. Sedentary living is also associated with poor oral health, which is known to correlate with the rate of cognitive decline. Here, we will review the evidence for the interplay between mastication and environmental enrichment and assess the impact of each on the structure of the brain. In previous studies, we explored the relationship between behavior and the morphological features of dentate gyrus glial fibrillary acidic protein (GFAP)-positive astrocytes during aging in contrasting environments and in the context of induced masticatory dysfunction. Hierarchical cluster and discriminant analysis of GFAP-positive astrocytes from the dentate gyrus molecular layer revealed that the proportion of AST1 (astrocyte arbors with greater complexity phenotype) and AST2 (lower complexity) are differentially affected by environment, aging and masticatory dysfunction, but the relationship is not straightforward. Here we re-evaluated our previous reconstructions by comparing dorsal and ventral astrocyte morphologies in the dentate gyrus, and we found that morphological complexity was the variable that contributed most to cluster formation across the experimental groups. In general, reducing masticatory activity increases astrocyte morphological complexity, and the effect is most marked in the ventral dentate gyrus, whereas the effect of environment was more marked in the dorsal dentate gyrus. All morphotypes retained their basic structural organization in intact tissue, suggesting that they are subtypes with a non-proliferative astrocyte profile. In summary, the increased complexity of astrocytes in situations where neuronal loss and behavioral deficits are present is counterintuitive, but highlights the need to better understand the role of the astrocyte in these conditions.

Studies indicating the influence of masticatory dysfunction, due to a soft diet or lack of molars, on impairing spatial memory and learning have led to research about neuronal connections between areas and cell populations possibly affected. In this sense, with scarce detailed data on the subfields of hippocampus in dementia neurodegeneration, there is no information about astrocytic responses in its different layers. Thus, considering this context, the present study evaluated the effects of deprivation and rehabilitation of masticatory activity, aging, and environmental enrichment on the stereological quantification of hippocampal astrocytes from layers CA1, CA3, and DG. For this purpose, we examined mature (6-month-old; 6M), and aged (18-month-old; 18M) mice, subjected to distinct masticatory regimens and environments. Three different regimens of masticatory activity were applied: continuous normal mastication with hard pellets (HD); normal mastication followed by deprived mastication with equal periods of pellets followed by soft powder (HD/SD); or rehabilitated masticatory activity with equal periods of HD, followed by powder, followed by pellets (HD/SD/HD). Under each specific regimen, half of the animals were raised in standard cages (impoverished environment (IE)) and the other half in enriched cages (enriched environment (EE)), mimicking sedentary or active lifestyles. Microscopic stereological, systematic, and random sampling approaches with an optical dissector of GFAP-immunolabeled astrocytes were done, allowing for an astrocyte numerical estimate. Stratum moleculare and hilus, from the dentate gyrus (DG) and Strata Lacunosum-Moleculare, Oriens, and Radiatum, similarly to the dentate gyrus, showed no significant change in any of the investigated variables (age, diet, or environment) in these layers. However, in Stratum radiatum, it was possible to observe significant differences associated with diet regimens and age. Therefore, diet-related differences were found when the HD 18M IE group was compared to the HD/SD/HD 18-month-old group in the same environment (IE) (p = 0.007). In the present study, we present modulatory factors (masticatory function, environmental enrichment, and aging) for the differentiated quantitative laminar response in the hippocampal regions, suggesting other studies to read the plasticity and responsiveness of astrocytes, including the molecular background.

O principal componente psicoativo do tabaco é a nicotina, um estimulante que exerce seus efeitos por meio da liberação de neurotransmissores no sistema nervoso central e periférico. Poucos estudos relatam a toxicidade da nicotina na forma de convulsões. O objetivo deste estudo foi descrever os efeitos comportamentais e eletrocorticais causados ​​pela aplicação de nicotina (5 mg/kg i.p.) em ratos Wistar e comparar os resultados produzidos pela pilocarpina (300 mg/kg i.p.). Além disso, o controle das crises foi avaliado com diferentes anticonvulsivantes. O teste de comportamento mostrou seis padrões que iniciaram com acinesia e evoluíram para crises tônico-clônicas e foram comparados ao modelo convulsivo da pilocarpina que apresentou diferença nas latências de aparecimento dos comportamentos. Os registros eletrocorticográficos mostraram aumento da amplitude do traçado compatível com convulsões. Embora o ritmo Beta fosse o mais potente e consistente com outros modelos convulsivos como a pilocarpina, o ritmo Theta era a característica predominante da convulsão induzida pela nicotina. O controle das crises foi avaliado usando três agentes: diazepam, fenobarbital e escopolamina (10 mg / kg i.p.). Enquanto a escopolamina não foi eficaz no controle das crises, o diazepam foi a droga mais eficaz para atenuar a crise. Este modelo quimio-convulsivo deve ser mais estudado. Palavras-chave: Estimulante. Nicotina. Pilocarpina. Eletrocorticográficos. Modelos Convulsivos. Abstract The major psychoactive component in tobacco is nicotine, a stimulant that exerts its effects through the release of neurotransmitters in the central and peripheral nervous system. Few studies report nicotine toxicity as seizures. This study aimed at providing a description of behavioral and electrocortical effects caused by nicotine application (5 mg/kg i.p.) in Wistar rats and comparing the results produced by pilocarpine (300 mg/kg i.p.). Further, seizure control was assessed using different anticonvulsants. The behavior test showed six patterns that started with akinesia and evolved into tonic-clonic seizures and were compared to the convulsive model of pilocarpine that showed a difference in the latencies of the appearance of behaviors. Electrocorticographic records showed an increase in the amplitude of the tracing compatible with seizures. Although the Beta rhythm was the most powerful and consistent with other convulsive models like pilocarpine, the Theta rhythm was the predominant characteristic of the nicotine-induced seizure. The seizure control was evaluated using three agents: diazepam, phenobarbital, and scopolamine (10 mg/kg i.p.). While scopolamine was not effective in seizure control, diazepam was the most efficient drug for the attenuation of the crisis. This chemo-convulsive model should be further studied. Keywords: Stimulant. Nicotine. Pilocarpine. Electrocorticographic. Convulsive Models.

Visual cortical plasticity during early postnatal life is profoundly shaped by species‐specific ocular anatomy and ecological demands. This review synthesizes comparative evidence on how monocular deprivation (MD)—a classical model of amblyopia—affects visual system development in frontal‐ versus lateral‐eyed mammals. Frontal‐eyed species, including cats and primates, exhibit extensive binocular field overlaps and columnar architecture in the primary visual cortex (V1), making them highly susceptible to MD‐induced shifts in ocular dominance and synaptic remodeling. In contrast, lateral‐eyed species such as rodents and ungulates possess limited binocular overlaps and lack well‐defined ocular dominance columns yet still demonstrate significant MD‐induced plasticity involving callosal reorganization, glial activation, and extracellular matrix remodeling. We examine shared and divergent cellular mechanisms underpinning these responses, including the role of parvalbumin‐expressing interneurons, perineuronal nets, and neuromodulators like BDNF and NRG1. Rodent models support the notion that even in the absence of classical columnar organization, lateral‐eyed species can undergo region‐specific structural remodeling in V1 following MD. These distinctions underscore how binocular integration circuits are fine‐tuned through extended critical periods in frontal‐eyed species, whereas plasticity in lateral‐eyed species is more diffusely distributed. The integration of cross‐species data revealed conserved principles of visual cortical plasticity and identified mechanisms potentially targetable for amblyopia therapy. Understanding the ecological and anatomical context of plasticity allows for a more accurate interpretation of animal models and supports the development of precision strategies for visual rehabilitation. This comparative framework expands the scope of amblyopia research and offers new avenues for translational interventions.