Creating animal models, why not use the Chinese tree shrew (Tupaia belangeri chinensis)?
- Yong-Gang Yao
- Zoological research
BACKGROUND Previously, we demonstrated decreased expression of somatostatin mRNA in aged macaque brain, particularly in the prefrontal cortex. To investigate whether or not this age-dependent decrease in mRNA is related to morphological changes, we analyzed somatostatin cells in the cerebra of aged Japanese macaques and compared them with those in rats and tree shrews, the latter of which are closely related to primates. METHODS Brains of aged macaques, tree shrews, and rats were investigated by immunohistochemistry with special emphasis on somatostatin. RESULTS We observed degenerating somatostatin-immunoreactive cells in the cortices of aged macaques and tree shrews. Somatostatin-immunoreactive senile plaque-like structures were found in areas 6 and 8 and in the nucleus accumbens of macaques, as well as in the nucleus accumbens and the cortex of aged tree shrews, where amyloid accumulations were observed. CONCLUSIONS Somatostatin degenerations may be related to amyloid accumulations and may play roles in impairments of cognitive functions during aging.