Increased dynamin-1 and -2 protein expression in the aged gerbil hippocampus.

Dynamin (DNM) plays roles in membrane dynamics, vesicle formation, and transport. In the present study, we compared DNM-1 and DNM-2 protein expressions between the adult (postnatal month 6) and aged (postnatal month 24) gerbil hippocampus using immunohistochemistry and western blot analysis. DNM-1 and DNM-2 immunoreactivities were primarily observed in hippocampal principal neurons: pyramidal cells in the hippocampus proper (CA1-CA3) and granule cells in the dentate gyrus. DNM-1 and DNM-2 immunoreactivities in principal neurons were significantly increased in the aged group compared with the adult group. In addition, DNM-1 and DNM-2 protein levels as well as phospho-DNM-1 level were significantly increased in the aged group. These results indicate that the increases of DNM-1 and DNM-2 protein expressions may reflect the age-related changes in hippocampal function.