title: Origin of excitation underlying locomotion in the spinal circuit of zebrafish.
abstract: Neural circuits in the spinal cord transform instructive signals from the brain into well-coordinated locomotor movements by virtue of rhythm-generating components. Although evidence suggests that excitatory interneurons are the essence of locomotor rhythm generation, their molecular identity and the assessment of their necessity have remained unclear. Here we show, using larval zebrafish, that V2a interneurons represent an intrinsic source of excitation necessary for the normal expression of the locomotor rhythm. Acute and selective ablation of these interneurons increases the threshold of induction of swimming activity, decreases the burst frequency, and alters the coordination of the rostro-caudal propagation of activity. Thus, our results argue that V2a interneurons represent a source of excitation that endows the spinal circuit with the capacity to generate locomotion.
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden.
authors.forename: Emma
authors.initials: E
authors.lastname: Eklöf-Ljunggren
authors.forename: Sabine
authors.initials: S
authors.lastname: Haupt
authors.forename: Jessica
authors.initials: J
authors.lastname: Ausborn
authors.forename: Ivar
authors.initials: I
authors.lastname: Dehnisch
authors.forename: Per
authors.initials: P
authors.lastname: Uhlén
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Higashijima
authors.forename: Abdeljabbar
authors.initials: A
authors.lastname: El Manira
mesh_terms: D000818:Animals; D007395:Interneurons / Q000166:cytology*; D008124:Locomotion; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*; D013550:Swimming; D015027:Zebrafish / Q000502:physiology*