Station Holding During Rheotaxis: A Sensitive Assay of Lateral Line Function in Larval Zebrafish.

Hair cells are the sensory receptors of the auditory and vestibular systems in the inner ears of all vertebrates. Hair cells also serve to detect water flow in the lateral line system in amphibians and fish. The zebrafish lateral line serves as a well-established model for investigating hair cell development and function, including research on genetic mutations associated with deafness and environmental factors that cause hair cell damage. Rheotaxis, the ability to orient and swim in response to water flow, is a behavior mediated by multiple sensory modalities, including the lateral line organ. In this protocol, we describe a rheotaxis assay in which station holding behavior, which employs positive rheotaxis to maintain position in oncoming water flow, serves as a sensitive measure of lateral line function in larval zebrafish. This assay provides a valuable tool for researchers assessing the functional consequences of genetic or environmental disruptions of the lateral line system. Key features • Describes the method developed by Newton et al. [1] to assess lateral line function in larval zebrafish. • Provides instructions on building the micro flume apparatus with updated information from the WashU Neurotech Hub. • Uses DeepLabCut to track fish and SimBA to classify rheotaxis to compare lateral line-mediated behaviors in large cohorts of larval zebrafish.