Schooling in Xenopus laevis Tadpoles as a Way to Assess Their Neural Development

Escape behaviors, orienting reflexes, and social behaviors in Xenopus laevis tadpoles have been well-documented in the literature. Schooling behavior experiments allow for the observation of tadpole social interactions and in the past have been used to characterize behavioral deficits in models of neurodevelopmental disorders. Unlike other species of frogs, Xenopus tadpoles show polarized schooling. Not only do tadpoles aggregate, they also swim in the same direction. Quantifying both aggregation and relative swim angle can give us an important measure of social behavior and sensory integration. Past iterations of these experiments have required the continued presence of an experimenter throughout the duration of each trial and relied on expensive software for subsequent data analysis. The instrument configuration and analysis protocol outlined here provide an automated method to assess schooling by delivering a series of timed vibratory stimuli to a group of tadpoles to induce swimming behavior and then controlling a camera to document their positions via still images. Both stimulus delivery and image acquisition are automated using the Python programming language. Analysis is done using ImageJ and custom Python scripts, which are provided in this protocol. The specific equipment configuration and scripts shown here provide one solution, but other equipment and custom scripts can be substituted.