COMPUTATIONAL NEUROSCIENCE COLLOQUIUM Modeling Neocortical Networks with Short-term Synaptic Plasticity Misha Tsodyks Weizmann Institute Wednesday, February 14, 2.30pm Maxwell Dworkin 115 ABSTRACT Recurrent connections in neocortical circuits exhibit pronounced activity-dependent short-term plasticity--synaptic depression/facilitation--but the role it plays in information processing is still not clear. Recent experiments indicate that synaptic properties may systematically change when moving along the information stream from the sensory areas towards the prefrontal cortex. In particular, it was found that connections between pyramidal neurons in the prefrontal cortex are more diverse, with substantial fraction of them exhibiting strong facilitation, as opposed to corresponding connections in the sensory areas that are predominantly depressing. To uncover the potential functional implications of these diverse properties, we analyzed two different recurrent networks. In the first study, we describe the information processing via temporal neuronal synchronization (which we call 'Population Spikes') in network with synaptic depression. In particular, we constructed a neural network model of primary auditory cortex that responds to complex sounds with specific spatio-temporal pattern of population spikes at different iso-frequency columns. In the second study, we analyzed the attractor neural network model of persistent activity with synaptic facilitation. Depending on the strength of synaptic facilitation, the network exhibits qualitatively different regimes of convergence to persistent activity sate, from fast irreversible transition with population spike, to slow reversible transition. We then considered the attractor neural network of interacting sub-populations with different synaptic properties, and observed an emerging new selectivity of the resulting persistent state to the temporal profile of the triggering input. Host: Leslie Valiant _______________________________________________ Colloquium mailing list Colloquium(a)deas.harvard.edu https://lists.deas.harvard.edu/mailman/listinfo/colloquium _______________________________________________ iic-seminars mailing list iic-seminars(a)calists.harvard.edu http://calists.harvard.edu/mailman/listinfo/iic-seminars