Motor neurons control locomotor circuit function retrogradely via gap junctions
Jianren Song, Konstantinos Ampatzis, E. Rebecka Björnfors & Abdeljabbar El Manira
Nature (2016) doi:10.1038/nature16497
Received 01 June 2015 Accepted 27 November 2015 Published online 13 January 2016
Abstract
Motor neurons are the final stage of neural processing for the execution of motor behaviours. Traditionally, motor neurons have been viewed as the ‘final common pathway’, serving as passive recipients merely conveying to the muscles the final motor program generated by upstream interneuron circuits1, 2. Here we reveal an unforeseen role of motor neurons in controlling the locomotor circuit function via gap junctions in zebrafish. These gap junctions mediate a retrograde analogue propagation of voltage fluctuations from motor neurons to control the synaptic release and recruitment of the upstream V2a interneurons that drive locomotion. Selective inhibition of motor neurons during ongoing locomotion de-recruits V2a interneurons and strongly influences locomotor circuit function. Rather than acting as separate units, gap junctions unite motor neurons and V2a interneurons into functional ensembles endowed with a retrograde analogue computation essential for locomotor rhythm generation. These results show that motor neurons are not a passive recipient of motor commands but an integral component of the neural circuits responsible for motor behaviour.
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Professores, pesquisadores e alunos de universidades públicas ou privadas com acesso ao Portal de Periódicos CAPES/MEC podem acessar gratuitamente este artigo da Nature e de mais 30.000 publicações científicas.
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NOTA DESTE BLOGGER:
Diante de tanta complexidade biológica, os pesquisadores não puderam dizer outra coisa - mais uma mudança paradigmática em biologia:
“This study represents a paradigm shift that will lead to a major revision of the long held view of the role of motor neurons,” says Professor El Manira. “Motor neurons can no longer be considered as merely passive recipients of motor commands – they are an integral component of the circuits generating motor behaviour.”
“This study represents a paradigm shift that will lead to a major revision of the long held view of the role of motor neurons,” says Professor El Manira. “Motor neurons can no longer be considered as merely passive recipients of motor commands – they are an integral component of the circuits generating motor behaviour.”
Pergunta científica: Mero acaso, fortuita necessidade ou design inteligente?
