RUI: Ontogeny of Frequency-dependent Hippocampal Synaptic Plasticity in Freely Moving Rat

Trinity College, Hartford CT

Investigators

Abstract

0074530 Bronzino The objective of this research is to test a major hypothesis that there are significant changes, during early postnatal development, in synaptic plasticity in a specific neuronal circuit, the first limb of the hippocampal trisynaptic circuit, in a brain structure intimately involved in learning and memory. It has been shown that hippocampal circuit responses to afferent input vary depending upon the frequency and pattern of the input. The response to certain patterns of activation of hippocampal afferent inputs may result in either enhancement (long-term potentiation (LTP)), or a diminishment (long-term depression (LTD)) of the hippocampal synaptic response. The phenomena of long-term potentiation and long-term depression have been extensively studied in adult animals, but the few studies which have examined the developmental onset and maturation of such neuroplastic responses have generally been carried out in vitro slice or anesthetized preparations. No such developmental study has been carried out in behaving animals; hence, the studies to be conducted are unique in this regard. The major goal for the project is to apply recently developed surgical and recording techniques to quantify the ontogeny of frequency-dependent responses of the perforant path/dentate granule cell synapse in pre-weaning, freely moving male rats.