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Updated: Dec 30, 2025

Generation of Murine Cardiac Pacemaker Cell Aggregates Based on ES-Cell-Programming in Combination with Myh6-Promoter-Selection
Published on: February 17, 2015
Multiple Rhythm-Generating Circuits Act in Tandem with Pacemaker Properties to Control the Start and Speed of
Jianren Song1, Irene Pallucchi2, Jessica Ausborn3
1Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden; Center of Translational Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.
Abstract:
In vertebrates, specific command centers in the brain can selectively drive slow-explorative or fast-speed locomotion. However, it remains unclear how the locomotor central pattern generator (CPG) processes descending drive into coordinated locomotion. Here, we reveal, in adult zebrafish, a logic of the V2a interneuron rhythm-generating circuits involving recurrent and hierarchical connectivity that acts in tandem with pacemaker properties to provide an ignition and gear-shift mechanism to start locomotion and change speed. A comprehensive mapping of synaptic connections reveals three recurrent circuit modules engaged sequentially to increase locomotor speed. The connectivity between V2a interneurons of different modules displayed a clear asymmetry in favor of connections from faster to slower modules. The interplay between V2a interneuron pacemaker properties and their organized connectivity provides a mechanism for locomotor initiation and speed control. Thus, our results provide mechanistic insights into how the spinal CPG transforms descending drive into locomotion and align its speed with the initial intention.
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