RESUMO
We assessed changes of olfactory bulbs in rata with 6-hydroxydopamine destruction of the substantia nigra. The expression of marker proteins of immature and differentiated neurons and glia (vimentin, PSA-NCAM, tyrosine hydroxylase, and S100) was analyzed by immunohistochemical and morphometric methods. The number of periglomerular dopamine neurons and astroglia in the olfactory bulbs increased on the side of toxin injection and expression of PSA-NCAM and vimentin increased in the rostral migratory stream. Destruction of the substantia nigra shifted differentiation of neuronal progenitors towards the dopaminergic phenotype and increased their survival in the olfactory bulbs, which can be explained by increased expression of PSA-NCAM.
Assuntos
Neuroglia/patologia , Neurônios/patologia , Bulbo Olfatório/patologia , Doença de Parkinson Secundária/patologia , Substância Negra/patologia , Adaptação Fisiológica , Animais , Biomarcadores/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Humanos , Imuno-Histoquímica , Injeções Intraventriculares , Masculino , Atividade Motora/fisiologia , Molécula L1 de Adesão de Célula Nervosa/genética , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Bulbo Olfatório/metabolismo , Oxidopamina/administração & dosagem , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/genética , Doença de Parkinson Secundária/metabolismo , Ratos , Ratos Wistar , Proteínas S100/genética , Proteínas S100/metabolismo , Ácidos Siálicos/genética , Ácidos Siálicos/metabolismo , Técnicas Estereotáxicas , Substância Negra/metabolismo , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismo , Vimentina/genética , Vimentina/metabolismoRESUMO
Computerized morphometry was used to examine the sizes of neuronal bodies and the compactness of arrangement of neurons and neuroglial cells in layers III and V of the sensorimotor cortex in senescence-accelerated prone 1 (SAMP1) mice (an experimental group) and senescence-accelerated-resistant strain 1 (SAMR1) ones (a control group). In the SAMP1 mice as compared to the SAMR1 ones, the neuronal body sizes were significantly unchanged; the compactness of their arrangement decreased by 17 and 20% in layers III and V, respectively; that of neuroglial cells significantly increased by 14% in layer III only. In the SAMP1 mice versus the SAMR1 ones, the glial index rose by 36% in layer III and by 24% in layer V. During simulation of physiological aging, the sizes of neuronal bodies were shown to be virtually unchanged in the cerebral cortex; the compactness of their arrangement (cell counts) moderately reduced and that of neuroglial cells increased, which caused a rise in the glioneuronal index that was indicative of the enhanced supporting function of neuroglial cells during the physiological aging of brain structures.
