Temporally asymmetric Hebbian learning and neuronal response variability

Recent experimental data have characterized a form of long-term synaptic mo dification that depends on the relative timing of pre- and post-synaptic ac tion potentials. Modeling studies indicate that this rule can automatically adjust excitatory synaptic strengths so that the post-synaptic neuron rece ives roughly equal amount of excitation and inhibition and as a consequence fires irregular spike trains as observed in vivo. This rule also induces c ompetition between different inputs and strengthens groups of synapes that are correlated over short time periods. (C) 2000 Elsevier Science B.V. All rights reserved.