Principles governing recruitment of motoneurons during swimming in zebrafish

Jens Peter Gabriel (1) , Jessica Ausborn (1) , Konstantinos Ampatzis (1) , Riyadh Mahmood (1) , Emma Eklof-Ljunggren (1) , Abdel El Manira (1)

1 Department of Neuroscience

Locomotor movements are coordinated by a network of neurons that produces sequential muscle activation. Different motoneurons need to be recruited in an orderly manner to generate movement with appropriate speed and force. However, the mechanisms governing the recruitment order have not been fully clarified. Here we show, using an in vitro juvenile/adult zebrafish brainstem-spinal cord preparation, that motoneurons are organized in four pools with specific topographic locations and are incrementally recruited to produce swimming at different frequencies. The threshold of recruitment is not dictated by the input resistance of motoneurons but is rather set by a combination of specific biophysical properties and the strength of the synaptic currents. Thus, our results provide insights into the cellular and synaptic computations governing recruitment of motoneurons during locomotion.

Mots clés: Motor System

Jens Peter Gabriel, Jessica Ausborn, Konstantinos Ampatzis, Riyadh Mahmood, Emma Eklof-Ljunggren, et al.. Principles governing recruitment of motoneurons during swimming in zebrafish. Nature Neuroscience, 2010, ⟨10.1038/nn.2704⟩. ⟨hal-00596593⟩