Needle from a haystack. Optimal signaling by a nonlinear synapse

Abstract

Commonly, a neuron must separate a small, rare event carried by one of its inputs from the noise carried by many others. In this issue of Neuron, demonstrate that to solve this problem, the rod bipolar neuron in mouse retina selectively amplifies a rod's single-photon signal only when it is larger than average. This nonlinearity rejects nearly three-fourths of the single-photon signals. Yet, by also rejecting noise, it provides nearly optimal filtering near absolute visual threshold.