We examine the conditions under which spike-timing-dependent plasticity (STDP) normalizes post-synaptic firing 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 firing 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 influx, a known mediator of synaptic plasticity. This adaptive STDP rule is shown to stabilize the post-synaptic firing rates under a variety of perturbations.
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King Abdullah bin Abdulaziz Al Saud, 1924 – 2015
Thuwal 23955-6900, Kingdom of Saudi Arabia