Excitability Changes in Hippocampal Granule Cells of Senescent Rat

Research on senescent nervous systems has tended to emphasize processes of deterioration, which may be among the most obvious and important kinds of alterations to occur over the lifespan. A number of recent findings, however, suggest that preservation of function, in spite of deteriorative change, occurs at many levels of the nervous system. One example of a seemingly compensatory change in senescent rat brain function is an increased electrical excitability of hippocampal granule cells in the face of a considerable reduction in the afferent fiber population. This chapter examines one possible mechanism of this change.