Two-stage adaptation of inhibition mediates predictive sensitization in the retina

Abstract

AbstractA critical function of the nervous system is the prediction of future sensory input. One such predictive computation is retinal sensitization, a form of short-term plasticity seen in multiple species that elevates local sensitivity following strong local stimulation. Here we perform a causal circuit analysis of retinal sensitization using simultaneous intracellular and multielectrode recording in the salamander. We show, using direct current injection into inhibitory sustained amacrine cells that a decrease in amacrine transmission is necessary, sufficient and occurs at the right time and manner to cause sensitization in ganglion cells. Because of neural dynamics and nonlinear pathways, a computational model is essential to explain how a change in steady inhibitory transmission causes sensitization. Whereas adaptation of excitation removes an expected result in order to transmit novelty, adaptation of inhibition provides a general mechanism to enhance the sensitivity to the sensory feature conveyed by an inhibitory pathway, creating a prediction of future input.