This study was designed to investigate the progressive effect of tactile stimulation in the cytoarchitecture of the optic nerve of normal rats during early postnatal development. We used 36 male pups which were randomly assigned to either the tactile-stimulated group (TS-stimulation for 3 min, once a day, from postnatal day (P) 1 to 32) or the non-tactile-stimulated (NTS) group. Morphological analysis were performed to evaluate the alterations caused by tactile stimulation, and morphometric analysis were carried out to determine whether the observed changes in optic nerve cytoarchitecture were significantly different between groups and at three different ages (P18, P22, and P32), thereby covering the entire progression of development of the optic nerve from its start to its completion. The rats of both groups presented similar increase in body weight. The morphometric analysis revealed no difference in the astrocyte density between age-matched groups; however, the oligodendrocyte density of TS group was higher compared to the NTS at P22, and P32, but not at P18. The optic nerve of TS group showed an increase of blood vessels and a reduction of damage fiber density when compared to the age-matched pups of NTS. Taken together, these findings support the view that tactile stimulation, an enriching experience, can positively affects the neuroanatomy of the brain, modifying its cellular components by progressive morphological and morphometric changes.

This study was designed to verify whether different lactation conditions influenced nervous system development. The authors used motor tasks to verify changes in exploratory activity and muscle strength of weaned rats from different litter sizes and evaluated the applicability of the grid-walking test for assessing motor abnormalities caused by undernutrition. Alterations in litter size during the suckling period perturbed the nutritional status of pups, which exhibited body weight differences between the groups. Large-litter (L) pups showed significant delays in achieving developmental milestones and neurological reflexes compared to the small-litter (S) and medium-litter (M) pups. The S, M, and L group pups exhibited similar exploratory responses and muscle strength. In the grid-walking and foot-fault tests, the L group pups traveled shorter distances and, consequently, had less footsteps. However, the percentages of foot faults in the L group were higher than S and M groups. These results reflect delayed maturation of structures responsible for sensorimotor responses, such as the cerebellum, because much cerebellar maturation takes place postnatally. This is the first study to report that early undernutrition in pups resulted in suboptimal performances on the grid-walking and foot-fault tests and that the former test was sensitive to alterations caused by nutritional deficiency.

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Our data indicate that protein malnutrition imposed during the critical period of brain development alters the cytoarchitecture of the optic nerve. In addition, we affirm that a 1-hour exposure to an enriched environment everyday was sufficient for tissue preservation in rats maintained on a low-protein diet. This protective effect might be related to angiogenesis, as confirmed by the increased vascular density observed in morphometric analyses.

Introdução. O indivíduo é considerado idoso a partir dos 60 anos e o processo de envelhecimento é caracterizado por alterações morfológicas, fisiológicas, bioquímicas e psicológicas que dependem do modo de vida. O envelhecimento resulta do acúmulo de danos moleculares e celulares ao longo da vida, levando a uma diminuição gradual da capacidade física e mental, e maiores chances do desenvolvimento de patologias a exemplo do declínio da função cognitiva. Estudos apontam que o consumo adequado de alimentos que contém selênio atua na inibição da produção de radicais livres, reduzindo os danos causados pelo estresse oxidativo. Objetivo. Deste modo, objetivo deste estudo foi investigar a relação entre selênio e a manutenção da função cognitiva. Método. Este estudo se trata de uma revisão sistemática da literatura, realizada nas bases eletrônicas de dados PubMed, MedLine e Lilacs, utilizando a combinação de palavras-chave específicas. Resultados. A busca resultou em 270 estudos, contudo, aplicado os critérios de inclusão e exclusão, selecionou-se oito artigos. Conclusão. Segundo os artigos selecionados, o consumo de selênio pode melhorar o sistema antioxidante e assim, apresentar efeitos positivos sobre a função cognitiva em idosos humanos. Os estudos com animais mostraram que a suplementação por selênio foi capaz de diminuir o estresse oxidativo e melhorar o aprendizado e o funcionamento da memória em testes comportamentais específicos. Conclusão. Em síntese, os estudos discutidos neste trabalho mostram uma alta relação do consumo de selênio e a melhora do desempenho cognitivo, tanto em humanos, quanto em animais.

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ObjectiveTo investigate the effect of kinesiotherapy on the functionality of the pelvic limb of rats after ischemic and reperfusion injury.Methods10 rats were divided into two groups, GI (control) and GII (kinesiotherapy). All the animals underwent ischemia for a period of three hours, followed by tissue reperfusion. In Group GII, non-resistive systemic kinesiotherapy was performed (swimming) in three weekly sessions of 50 minutes, over a period of four weeks, while the GI animals remained at rest. Functional analysis of motor behavior was evaluated weekly. The animals were then sacrificed, and the soleus and gastrocnemius muscles and the sciatic nerve removed for histopathological analysis.ResultsThere was a significant recovery of motor behavior with kinesiotherapeutic treatment during the four weeks of treatment. However, the histological examination of the tissues showed no morphological changes of cell injury and repair.ConclusionIt was not possible to affirm that the exercise was effective in cell repair, because neither of the groups (control and experimental) showed any histological difference. On the other hand, systemic kinesiotherapy showed a beneficial effect on functional rehabilitation after ischemia and reperfusion. Level of evidence III, Case-Control Study.