Methodology: Using virtual reality to study complex behaviour in zebrafish

A virtual reality system based on gaming software allows the study of brain activity in adult zebrafish while they interact with their environment, reports a paper published in Nature Methods.

Many researchers study brain functions of young zebrafish because the neuronal activity across much of the brain can be recorded, but young zebrafish exhibit a limited range of behaviour. Adult zebrafish have a broader behavioural repertoire that includes social interactions, complex innate behaviours and various forms of learning and decision making. However, methods for capturing high-resolution activity measurements in adult zebrafish are lacking.

Virtual reality systems (VRs) are useful tools to analyse and manipulate interactions between animals and their environment and to measure neuronal activity during behaviour. Rainer Friedrich and colleagues developed a VR system that allows two-photon calcium imaging of the adult zebrafish brain as it processes its environment. The authors found that the zebrafish in the VR showed regular spontaneous swimming and affiliative behaviour when viewing video of members of the same species. They also examined how the zebrafish brain deals with sensory input that does not conform to expectations.

The authors conclude that this combination of virtual reality with large-scale imaging of neural activity in the adult zebrafish provides a new opportunity to study the mechanisms underlying higher brain functions.