Immunohistochemical Study on the Distribution of Neuropeptide Yand NADPH-Diaphorase Positive Neurons in the Cerebral Cortex of Mice

Kim, Young Soo; Huh, Young Buhm; Ahn, Hee Kyung

Abstract

This study was aimed to clarify the change of neuropeptide Y -immunoreactive (NPY -IR) and NADPH -diaphorase (NADPH -d)-positive neurons associated with aging of ICR and C57Bl/6 mice. To verify the effect of aging on NPY and NADPH -d neurons in the cerebral cortex, the tissues were stained by the immunohistochemical and histochemical method. The coexistence of NADPH -d and NPY was found in the cerebral cortex of the ICR and C57Bl/6 mice. The 30 -week -old ICR mice showed a significant increase in the number of NPY - IR neurons in comparison with the 5 -week -old mice in primary motor, secondary somatosensory, ectorhinal, auditory and visual cortex. In the 30 -week -old C57Bl/6 mice, the number of NPY -IR neurons was significantly increased in primary and secondary somatosensory cortex, decreased in retrosplenial and visual cortex compared to the 5 -week -old group. However, the number of NPY -IR/NADPH -d positive neurons of ICR mice was no significant changes in most cerebral cortical areas except insular and perirhinal cortex in the 30 week -old group in comparison with 5 -week -old group of both mice group. The number of coexisted neurons of 30 -week -old C57Bl/6 mice was significantly decreased in primary motor and auditory cortex compared to the 5 -week - old group. These results provides the morphological evidence for the change of NPY -IR neurons that do not contain NADPH -d may be more susceptible to age -related change than NADPH -d -containing neurons in the cerebral cortex of mice.