RT Journal Article SR Electronic T1 A descending pathway facilitates undulatory wave propagation in Caenorhabditis elegans through gap junctions JF bioRxiv FD Cold Spring Harbor Laboratory SP 131490 DO 10.1101/131490 A1 Tianqi Xu A1 Jing Huo A1 Shuai Shao A1 Michelle Po A1 Taizo Kawano A1 Yangning Lu A1 Min Wu A1 Mei Zhen A1 Quan Wen YR 2017 UL http://biorxiv.org/content/early/2017/07/23/131490.abstract AB Descending signals from the brain play critical roles in controlling and modulating locomotion kinematics. In the Caenorhabditis elegans nervous system, descending AVB premotor interneurons exclusively form gap junctions with B-type motor neurons that drive forward locomotion. We combined genetic analysis, optogenetic manipulation, and computational modeling to elucidate the function of AVB-B gap junctions during forward locomotion. First, we found that some B-type motor neurons generated intrinsic rhythmic activity, constituting distributed central pattern generators. Second, AVB premotor interneurons drove bifurcation of B-type motor neuron dynamics, triggering their transition from stationary to oscillatory activity. Third, proprioceptive couplings between neighboring B-type motor neurons entrained the frequency of body oscillators, forcing coherent propagation of bending waves. Despite substantial anatomical differences between the worm motor circuit and those in higher model organisms, we uncovered converging computational principles that govern coordinated locomotion.