RRC ID 33630
Author Ampatzis K, Song J, Ausborn J, El Manira A.
Title Separate microcircuit modules of distinct v2a interneurons and motoneurons control the speed of locomotion.
Journal Neuron
Abstract Spinal circuits generate locomotion with variable speed as circumstances demand. These circuits have been assumed to convey equal and uniform excitation to all motoneurons whose input resistance dictates their activation sequence. However, the precise connectivity pattern between excitatory premotor circuits and the different motoneuron types has remained unclear. Here, we generate a connectivity map in adult zebrafish between the V2a excitatory interneurons and slow, intermediate, and fast motoneurons. We show that the locomotor network does not consist of a uniform circuit as previously assumed. Instead, it can be deconstructed into three separate microcircuit modules with distinct V2a interneuron subclasses driving slow, intermediate, or fast motoneurons. This modular design enables the increase of locomotor speed by sequentially adding microcircuit layers from slow to intermediate and fast. Thus, this principle of organization of vertebrate spinal circuits represents an intrinsic mechanism to increase the locomotor speed by incrementally engaging different motor units.
Volume 83(4)
Pages 934-43
Published 2014-8-20
DOI 10.1016/j.neuron.2014.07.018
PII S0896-6273(14)00629-1
PMID 25123308
MeSH Acceleration Action Potentials / physiology Animals Interneurons / physiology* Locomotion / physiology* Motor Neurons / physiology* Nerve Net / cytology* Nerve Net / physiology Spinal Cord / cytology* Spinal Cord / physiology Zebrafish
IF 14.403
Times Cited 27
Zebrafish Tg(chx10:GFP) Tg(vsx2:EGFP)