TY - JOUR T1 - Excitatory Motor Neurons are Local Central Pattern Generators in an Anatomically Compressed Motor Circuit for Reverse Locomotion JF - bioRxiv DO - 10.1101/135418 SP - 135418 AU - Shangbang Gao AU - Sihui Asuka Guan AU - Anthony D. Fouad AU - Jun Meng AU - Taizo Kawano AU - Yung-Chi Huang AU - Yi Li AU - Salvador Alcaire AU - Wesley Hung AU - Yangning Lu AU - Yingchuan Billy Qi AU - Yishi Jin AU - Mark Alkema AU - Christopher Fang-Yen AU - Mei Zhen Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/07/17/135418.abstract N2 - Central pattern generators are cell‐ or network-driven oscillators that underlie motor rhythmicity. The existence and identity of C. elegans CPGs remain unknown. Through cell ablation, electrophysiology, and calcium imaging, we identified oscillators for reverse locomotion. We show that the cholinergic and excitatory class A motor neurons exhibit intrinsic and oscillatory activity, and such an activity can drive reverse locomotion without premotor interneurons. Regulation of their oscillatory activity, either through effecting an endogenous constituent of oscillation, the P/Q/N high voltage-activated calcium channel UNC-2, or, via dual regulation – inhibition and activation ‐ by the descending premotor interneurons AVA, determines the propensity, velocity, and sustention of reverse locomotion. Thus, the reversal motor executors themselves serve as oscillators; regulation of their intrinsic activity controls the reversal motor state. These findings exemplify anatomic and functional compression: motor executors integrate the role of rhythm generation in a locomotor network that is constrained by small cell numbers. ER -