Berlin 2008 – scientific programme

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BP: Fachverband Biologische Physik

BP 3: Neuronal Systems

BP 3.4: Talk

Monday, February 25, 2008, 15:15–15:30, C 243

Broadband coding with dynamic synapses — •Benjamin Lindner¹, John Lewis², and Andre Longtin³ — ¹Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany — ²Department of Biology, University of Ottawa, Ottawa, Canada — ³Department of Physics, University of Ottawa, Ottawa, Canada

Short-term synaptic plasticity (STP) is commonly thought to provide a basis for low-pass or high-pass filtering of information transmission across the synapse depending on whether depression or facilitation, respectively, is dominant. To evaluate this assumption, we consider a general case of information transmission from a population of independent synaptic inputs to a model neuron. We show using standard information theoretic approaches that the changes in synaptic response amplitude produced by STP interact with associated membrane fluctuations, such that information transmission is frequency-independent (no high-pass or low-pass filtering), regardless of whether synaptic depression or facilitation dominates. Interestingly, the baseline firing rate of the post-synaptic neuron is a critical factor in determining whether or not this frequency-independence is reflected in the output spike train: high-firing rates maintain broadband transmission, whereas low-firing rates recover the expected filtering. This suggests that neurons in a rate-coding regime will not be influenced by STP.