Spinal V2b neurons reveal a role for ipsilateral inhibition in speed control

eLife

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[1] Department of Neuroscience, Washington University School of Medicine, St Louis, United States;National Institute for Basic Biology, Okazaki, Japan;

关键词: spinal cord;    locomotion;    circuitry;    inhibition;    Zebrafish;   

DOI  :  10.7554/eLife.47837

来源: publisher

【 摘 要 】

10.7554/eLife.47837.001The spinal cord contains a diverse array of interneurons that govern motor output. Traditionally, models of spinal circuits have emphasized the role of inhibition in enforcing reciprocal alternation between left and right sides or flexors and extensors. However, recent work has shown that inhibition also increases coincident with excitation during contraction. Here, using larval zebrafish, we investigate the V2b (Gata3+) class of neurons, which contribute to flexor-extensor alternation but are otherwise poorly understood. Using newly generated transgenic lines we define two stable subclasses with distinct neurotransmitter and morphological properties. These V2b subclasses synapse directly onto motor neurons with differential targeting to speed-specific circuits. In vivo, optogenetic manipulation of V2b activity modulates locomotor frequency: suppressing V2b neurons elicits faster locomotion, whereas activating V2b neurons slows locomotion. We conclude that V2b neurons serve as a brake on axial motor circuits. Together, these results indicate a role for ipsilateral inhibition in speed control.

【 授权许可】

CC BY