Expressão dos receptores de glutamato do tipo NMDA em aves durante o desenvolvimento e envelhecimento / Expression of NMDA type glutamate receptors in the cerebellum of birds during aging

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Aging is a physiologic process that takes place in a non-synchronic way in different areas of the brain and which can be defined as a dynamic and progressive process. There are morphological, functional and biochemical alterations which can lead to cognitive, affective, learning, memory and motor deficiencies. Since the cerebellum and the glutamatergic neurotransmission are involved in the processing of several of those functions, the present paper aimed at studying the presence of the NR1 subunit in the NMDA type glutamate receptors in the Purkinje cells of the cerebellum of chicks during aging. Young (30 days old), adult (1 year and 6 months old) and ol (approximately 4 years old) chicks (Gallus gallus) were utilized in order to evaluate the presence of the NR1 subunit. The brains of those animals were subjected to immunohistochemical and immunoblotting techniques. Average density of positive NR1 cells and optical density of the immunoblotting results were analyzed and submitted to statistical analysis by utilizing the ANOVA test and the Bonferroni test when appropriate. A 5% significance level was adopted. The NR1 presence in the Purkinje cells showed an intense immunoreactivity in the cellular bodies and from moderate to intense in the dendritic arborization of the young animals. In the old animals, however, this presence showed a substantial decrease, going from slight to moderate in the bodies of the Purkinje cells and slight in the dendritic arborization. Moreover, the average density of the Purkinje cells in the cerebellar leaves II, VI and IX which present NR1 showed a statistically significant decrease (p=0,028) in the old animals when compared to the young animals. Nevertheless, when compared to the young animals, a subtle increase in the percentage of Purkinje cells which present NR1 in relation to the Purkinje cells in the old animals was observed. The presence of NR1 in the chickens cerebellum revealed by the immunoblotting technique did not present any significant change during aging. Our data suggest that aging can lead to changes in the presence pattern of the NR1 subunit showing a decrease in the average density of the positive NR1 Purkinje cells and respective dendritic arborization in the cerebellum of hens, phenomenon which can cause the cognitive and motor disorders found in old animals

ASSUNTO(S)

physical therapy fisioterapia e terapia ocupacional envelhecimento receptores de glutamato receptors, glutamate aging fisioterapia

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