Functional diversity of excitatory commissural interneurons in adult zebrafish
Abstract
Flexibility in the bilateral coordination of muscle contraction underpins variable locomotor movements or gaits. While the locomotor rhythm is generated by ipsilateral excitatory interneurons, less is known about the commissural excitatory interneurons. Here we examined how the activity of the V0v interneurons - an important commissural neuronal class - varies with the locomotor speed in adult zebrafish. Although V0v interneurons are molecularly homogenous, their activity pattern during locomotion is not uniform. They consist of two distinct types dependent on whether they display rhythmicity or not during locomotion. The rhythmic V0v interneurons were further subdivided into three sub-classes engaged sequentially, first at slow then intermediate and finally fast locomotor speeds. Their order of recruitment is defined by scaling their synaptic current with their input resistance. Thus we uncover, in an adult vertebrate, a novel organizational principle for a key class of commissural interneurons and their recruitment pattern as a function of locomotor speed.
Article and author information
Author details
Funding
Karolinska Institutet
- Abdel El Manira
Hjärnfonden
- Abdel El Manira
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Ronald L Calabrese, Emory University, United States
Ethics
Animal experimentation: All experimental protocols were approved by the local Animal Research Ethical Committee, Stockholm (Stockholms Norra Djurförsöksetiska Nämnd). Protocol number N122/13.
Version history
- Received: June 7, 2016
- Accepted: August 24, 2016
- Accepted Manuscript published: August 25, 2016 (version 1)
- Accepted Manuscript updated: August 27, 2016 (version 2)
- Version of Record published: September 27, 2016 (version 3)
Copyright
© 2016, Björnfors & El Manira
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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