Sensory and motor encoding in one interneuron during C. elegans navigation

Summary

Date: 
October 29, 2014 - 1:00pm
Location: 
NW 243
About the Speaker
Name: 
Ni Ji (Samuel Lab)

To generate precise and coordinated movements, the nervous system must integrate sensory input with feedback about motor state. Corollary discharge, where signals from the motor system are relayed to upstream interneurons, has been shown to be a feedback mechanism in C. elegans. However, how motor feedback is integrated into neural circuits to accomplish complex navigational tasks like thermotaxis is not yet understood. I have been interested in finding and elucidating loci for sensorimotor integration in the compact thermotaxis circuitry in C. elegans . Using calcium imaging in behaving animals, I found that the AIY interneurons, that has long been known to play a key role in thermosensory signaling, also exhibits activity patterns that are tightly coupled to motor state. AIY activity patterns are strongly correlated with both thermosensory signals from its presynaptic partner, the AFD sensory neuron, and motor state. Blocking synaptic release from AIY does not disrupt AIY’s motor-correlated signal, suggesting that AIY is receiving corollary discharge from the motor system. I will discuss ongoing experiments to delineate the circuitry for motor signaling to the AIY interneuron, and the relevance of AIY sensorimotor integration for thermotactic navigation.