Experience Dependent Modulation of Hippocampal Synaptic Function.

Abstract

Synaptic plasticity, an activity dependent strengthening or weakening of synapses has been postulated to subserve memory (Martin et al., 2000). Changes in synaptic function have been hypothesized to occur at few synapses and these changes should persist so long as the memory does. Indeed, memory formation involves expression of potentiation and depression (Whitlock et al., 2006, Kemp & Manahan Vaughan, 2007). To date, however, changes in synaptic activity that persist with memory have not been demonstrated.

My thesis work investigated how acquisition of a memory modulated the activity of a subset of CA1 hippocampal synapses, and whether or not these changes persist with memory. 1-day after training, synaptic strength increased, and the ability to express potentiation and depression decreased and increased respectively, however potentiation was not saturated. 1-month after training, changes in synaptic activity were only seen in animals that were able to successfully recall what they previously learned. Taken together, my thesis work suggests that acquisition of a memory produces widespread changes in synaptic function that may reflect some aspect of information storage.