Single-Photon Absorptions Evoke Synaptic Depression in the Retina to Extend the Operational Range of Rod Vision

SummaryAdaptation or gain control allows sensory neurons to encode diverse stimuli using a limited range of output signals. Rod vision exemplifies a general challenge facing adaptational mechanisms—balancing the benefits of averaging to create a reliable signal for adaptation with the need to adapt rapidly and locally. The synapse between rod bipolar and AII amacrine cells dominates adaptation at low light levels. We find that adaptation occurs independently at each synapse and completes in