9618935 Bronzino This research is designed to test the hypothesis that there are significant changes, during early postnatal development, in synaptic plasticity in a specific neuronal circuit, the perforant path/dentate granule synapse, in the hippocampal formation, a structure intimately involved in learning and memory. Recently, it has been shown that hippocampal circuit responses to afferent input vary depending upon the frequency and pattern of the input. Specifically, the response to certain patterns of hippocampal afferent inputs may result in either enhancement (long-term potentiation), or a diminishment (long-term depression) of the hippocampal synaptic response. The major goal of this research is to apply recently developed surgical and recording techniques to quantify the development of frequency-dependent responses of the perforant path/dentate granule cell synapse in preweaning, freely moving male and female rats. In this research, evoked field potential analyses will be used to evaluate changes in both synaptic activation and cellular discharge. This work will attempt to quantify changes in frequency-dependent synaptic function during an early period of development. This research could provide information on the functional development of a neural network known to be involved in cognitive processes including spatial learning, memory and mapping. ***
