Número total de neurônios no gânglio mesentérico caudal de cães domésticos nas diferentes fases do desenvolvimento. Qual o papel da idade na população total e no tamanho dos neurônios? / Total number of neurons in the dog´s caudal mesenteric ganglion in different phases of aging. What is the role of aging in the total number and size of neurons?

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The aging is characterized by a progressive decline of neuronal function that involves both the central and the peripheral nervous system. Aging process is accompanied by changes in the number and size of neurons. However, these data are controversial and poorly known in the peripheral ganglia. In this way, the present investigation aimed to study the dogs caudal mesenteric ganglion (CMG) in different phases of aging, looking for qualitative, quantitative and morphometric alterations in these neurons. The importance of the CMG is associated with the innervation of the lower large intestine, internal anal sphincter and partially the urogenital system. To the study, was used nine males, mongrel, domestic dogs from the Veterinary Hospital of the Veterinary and Zoöthecny College of the São Paulo University. They were divided into three different well defined aged groups (1-2 months old; 1-3 years old; 5-10 years old). The ganglia were processed for the light microscopy study. The morphometric and stereological analyses were, respectively, done using morphometric analyses software KS 400 Zeiss® and the stereological physical disector method. The increase of age was caractherized by a major amount of the non-neuronal tissue between the neurons and a increase of ganglion volume. The size of the neurons, represented by their sectional area, also increased with the age, being frequent, the presence of lipofucsin granules in old animals. The nucleus-citoplasmic relation of neurons of the CMG tend to decrease with the age. Referring to the quantitative changes, the total number of neurons in the CMG increased by aging in adults and elder dogs, differently of the neuronal density (neurons/mm3) which decreased with the aging. Through the body weight of the dog, it was possible to predict the values of the different stereological variables represented in this paper, where, the obtained values were close to the normal rates.

ASSUNTO(S)

morfometria dogs envelhecimento morphometric cães neurons gânglios ganglio aging neurônios

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