In vivo recording from identifiable neurons of the locomotor network in the developing zebrafish

The zebrafish is a popular model for developmental studies due to its acces sibility by cellular, molecular and genetic approaches. As a complement to these other methods, we have devised an exposed hindbrain/spinal cord prepa ration in the curarized zebrafish embryo and larva that permits intracellul ar labeling and patch clamp recording from individually identified sensory neurons, motoneurons and interneurons in vivo. Regular bursts of synaptic p otentials and action potentials were observed under whole-cell current clam p in embryonic motoneurons and in some identified interneurons. Larval neur ons showed prolonged depolarizations with synaptically driven bursts of act ion potentials. Frequent spontaneous synaptic potentials were observed and synaptic currents were effectively space clamped. It is thus feasible to st udy in vivo the properties of identifiable neurons of the developing locomo tor network in the zebrafish, including their synaptic activity, firing pat terns and interconnections. (C) 1999 Elsevier Science B.V. All rights reser ved.