An adaptive spike-timing-dependent plasticity rule

We examine the conditions under which spike-timing-dependent plasticity (STDP) normalizes post-synaptic 0ring rates. Our simulations show that the rate normalization property of STDP is fragile and small changes in the LTD=LTP ratio or pre-synaptic input rates can lead to high 0ring rates. We propose an adaptive scheme to dynamically control the LTP=LTD ratio. The biophysics of synapses lead us to suggest a control mechanism using action potential-induced calcium in4ux, a known mediator of synaptic plasticity. This adaptive STDP rule is shown to stabilize the post-synaptic 0ring rates under a variety of perturbations. c © 2002 Published by Elsevier Science B.V.