Neural circuits underlying the optokinetic response in larval zebrafish

How neural circuits integrate sensory information to produce appropriate actions is a fundamental question in neuroscience. We aim to address this question using optokinetic behavior, reflexive eye movements in response to whole field motion. Even these simple responses can involve coordinated activity in hundreds of neurons distributed in areas throughout the brain. We image the pattern of neural activity in the brains of transgenic fish, which express a genetically encoded calcium indicator in all of their neurons, while they track visual stimuli with their eyes. Since this behavior is very repeatable, we can systematically record responses from the whole brain with single cell resolution. Presentation of different stimuli, such as monocular, or binocularly conflicting gratings allows us to determine what sensory or motor signals are represented at each point. These experiments represent the first comprehensive analysis of the neural circuit underlying a sensorimotor behavior in a vertebrate brain.