Coincidence detection in neurons with in vivo-like synaptic activity

Cyrille Rossant (1) , Romain Brette (1)

1 APMN - Equipe Audition

Neuronal synchronization is ubiquitous in the nervous system, yet its functional role for information processing is still unclear. Because of the leak current, two input spikes are more likely to make a postsynaptic neuron fire when they are synchronous. This coincidence detection property has been demonstrated in vivo for thalamocortical processing, but the theory of coincidence detection in neurons with in vivo-like synaptic activity is still sparse. We estimated the extra probability for a noisy neuron to fire a spike in response to two synchronous input spikes compared to two distant spikes. Using a simple probabilistic approach, we were able to quantify this extra probability for spiking models as a function of the background noise and the shape of postsynaptic potentials. Our predictions agreed well with numerical simulations. We found that neurons act as coincidence detectors when excitation and inhibition are balanced, as in cortical neurons in vivo, but not in the mean-driven regime. In the balanced regime, coincident spikes can be several times more efficient than distant spikes in realistic situations. We conclude that in cortical neurons, the relative timing of presynaptic spikes has a major impact on postsynaptic firing.

Mots clés: Oscillation and synchronization; Neuron models; Action selection

Domaines: Neurosciences [q-bio.NC]; Neurosciences

Cyrille Rossant, Romain Brette. Coincidence detection in neurons with in vivo-like synaptic activity. Cinquième conférence plénière française de Neurosciences Computationnelles, "Neurocomp'10", Aug 2010, Lyon, France. ⟨hal-00553404⟩