LETTER Communicated by Misha Tsodyks Short-Term Synaptic Plasticity and Network Behavior

We develop a minimal time-continuous model for use-dependent synap-tic short-term plasticity that can account for both short-term depression and short-term facilitation. It is analyzed in the context of the spike re-sponse neuron model. Explicit expressions are derived for the synaptic strength as a function of previous spike arrival times. These results are then used to investigate the behavior of large networks of highly inter-connected neurons in the presence of short-term synaptic plasticity. We extend previous results so as to elucidate the existence and stability of limit cycles with coherently ring neurons. After the onset of an external stimulus, we have found complex transient network behavior that man-ifests itself as a sequence of different modes of coherent ring until a stable limit cycle is reached.