Distribution of MAP2 in hippocampus and cerebellum of young and old rats by quantitative immunohistochemistry

The microtubule-associated protein MAP2 is a cytoskeletal protein that play s a regulatory role in neuronal plasticity and in maintaining the morpholog y of differentiated neurons. MAP2 distribution was assessed in hippocampus and cerebellum of young and old rats by quantitative immunohistochemistry. In old vs young rats, densitometric analysis showed a significant decrease of MAP2 immunoreactivity in the hippocampus CA1 field (-93%), whereas no di fference was found in cerebellar MAP2 distribution. These preliminary data suggest that in areas of the brain involved in memory acquisition and conso lidation, MAP2-dependent neuroplasticity and structural integrity are signi ficantly decreased in aging.