Improvement of spike coincidence detection with facilitating synapses

A realistic model of activity dependent dynamical synapses is used to study the conditions in which a postsynaptic neuron detects temporal coincidences of spikes arriving from NN different afferents. We analyse the interaction between synaptic depression and facilitation, which are known to be important short-term mechanisms for synaptic transmission. Compared with the case of only depressing synapses, our results show that facilitation improves the detection of correlated signals arriving from a subset of presynaptic excitatory neurons, as well as presynaptic firing-rate changes. In addition, facilitation determines the existence of an input-frequency value which allows the best performance for a wide (maximum) range of the neuron firing threshold. This fact could be important for the detection of relevant information in neural systems constituted by neurons which show a high variability in the firing thresholds, as occurs in some cortical areas.