| Activity-dependent synaptic plasticity is a fundamental organizing principle for neural systems. Two important forms of long-term synaptic plasticity, long-term potentiation and long-term depression, have attracted widespread attention over the last few decades. Recent reports have shown that the precise timing of pre- and postsynaptic action potentials is a critical parameter in determining the sign and magnitude of long-term synaptic modification, and is known as spike-timing-dependent plasticity. The discovery of spike-timing-dependent plasticity provides a mechanism for associative learning closely related to the predictions of Donald Hebb. In this thesis, I describe several electrophysiological experiments in brain slices of the rat visual cortex. These experiments are designed to show how complex spike trains and spatially distributed spike trains induce spike-timing-dependent plasticity. Both the underlying mechanisms and functional ramifications are investigated, and a predictive model is developed that accounts well for the degree of long-term synaptic modification induced by several classes of complex spike trains. |
