Molecular blueprints for spinal circuit modules controlling locomotor speed in zebrafish

• Published in: Nature neuroscience Vol. 27; no. 1; pp. 78 - 89
• Main Authors: Pallucchi, Irene, Bertuzzi, Maria, Madrid, David, Fontanel, Pierre, Higashijima, Shin-ichi, El Manira, Abdeljabbar
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01-01-2024; Nature Publishing Group
• Subjects: 13/51; 14/19; 14/32; 38/39; 38/91; 631/378/2632/1664; 631/378/2632/2633; 64/116; 9/74; Animal Genetics and Genomics; Behavioral Sciences; Biological Techniques; Biomedical and Life Sciences; Biomedicine; Circuits; Cluster analysis; Danio rerio; Flexibility; Genes; Interneurons; Medicin och hälsovetenskap; Modularity; Modules; Molecular modelling; Motor neurons; Neural networks; Neurobiology; Neurosciences; Spinal cord; Transcriptomics; Zebrafish
• ISSN: 1097-6256; 1546-1726; 1546-1726
• DOI: 10.1038/s41593-023-01479-1

The flexibility of motor actions is ingrained in the diversity of neurons and how they are organized into functional circuit modules, yet our knowledge of the molecular underpinning of motor circuit modularity remains limited. Here we use adult zebrafish to link the molecular diversity of motoneurons (MNs) and the rhythm-generating V2a interneurons (INs) with the modular circuit organization that is responsible for changes in locomotor speed. We show that the molecular diversity of MNs and V2a INs reflects their functional segregation into slow, intermediate or fast subtypes. Furthermore, we reveal shared molecular signatures between V2a INs and MNs of the three speed circuit modules. Overall, by characterizing how the molecular diversity of MNs and V2a INs relates to their function, connectivity and behavior, our study provides important insights not only into the molecular mechanisms for neuronal and circuit diversity for locomotor flexibility but also for charting circuits for motor actions in general.
The study by Pallucchi et al. links the molecular identity of motoneuron and V2a interneuron subtypes to their function and uncovers orthogonal transcriptomic rules for their assembly into separate circuit modules controlling locomotor speed.