From neuron to behavior: Sensory-motor coordination of zebrafish turning behavior.

Recent development of optogenetics brought non-invasive neural activation in living organisms. Transparent zebrafish larva is one of the suitable animal models for this technique, which enables us to investigate neural circuits for behaviors based on a whole individual nervous system. In this article we review our recent finding that suggests sensory-motor coordination in larval zebrafish escape behavior. When water vibration stimulates mechanosensory Rohon-Beard (RB) neurons, intra-spinal reflex circuit launches contralateral trunk muscle contraction that makes rapid body curvature for turning. In addition, positional information of the stimulus is conveyed to supra-spinal circuits, and then regulates the curvature strength for appropriate escape pathway from the threat. Sensory-motor coordination is a fundamental feature to adapt behaviors to environment, and zebrafish larvae would be an excellent model for elucidating its neural backbones.