Cholinergic Sensorimotor Integration Regulates Rapid Behavioral Decisions - Yun Zhang
From Kathryn Gentilello on May 10th, 2018
During active exploration, the spatial and temporal pattern of the sensory cue perceived by an animal is shaped by the animal’s own movement. Thus, to move towards a sensory target, the nervous system needs to make rapid locomotory decisions by integrating the sensory information with the ongoing motor state. One of our studies addresses the signaling mechanisms underlying sensorimotor integration in C. elegans during olfactory steering, when the sinusoidal movements of the worm generate an in-phase oscillation in the concentration of the sampled odorant. We find that cholinergic neurotransmission encodes the oscillatory sensory response and the motor state of head undulations by acting through an acetylcholine-gated channel and a muscarinic acetylcholine receptor, respectively. These signals converge on two axonal domains of an interneuron RIA, where the sensory-evoked signal suppresses the motor-encoding signal to transform the spatial information of the odorant into the asymmetry between the axonal activities. The asymmetric synaptic outputs of the RIA axonal domains generate a directional bias in the locomotory trajectory. We also find that this type of sensorimotor integration can be modulated by experience to alter chemotactic movement. Together, our study reveals how cholinergic neurotransmission regulates sensorimotor integration during goal-directed locomotions. In the mammalian central nervous system, cholinergic neurotransmission integrates sensory processing with the internal state, including the information of motor generation. It also mediates the hippocampal theta wave that is proposed to subserve the sensorimotor integration underlying rapid behavioral decisions. Our work characterizes a simple form of cholinergic integration that regulates rapid neural processing during active exploration of the environment.