The Raspberry Pi Virtual Reality (PiVR) system is a versatile tool for presenting virtual reality environments to small, freely moving animals (such as flies and fish larvae). Using PiVR along with techniques such as optogenetics will facilitate the mapping and characterization of neural circuits involved in behavior. The results of the study are published by the journal PLOS Biology.
The PiVR consists of a behavioral arena, a camera, a Raspberry Pi microcomputer, an LED controller, and a touch screen. This system can implement a feedback loop between real-time behavioral tracking and stimulus delivery. PiVR is a versatile, customizable system that costs less than $500, and takes less than six hours to assemble (using a 3D printer). The purpose of the development is to be accessible to a wide circle of researchers in the field of neurology.
In a new study, scientists used their PiVR system to present virtual realities to small, freely moving animals during optogenetic experiments. Optogenetics is a method that allows researchers to use light to control the activity of neurons in live animals. In turn, this allows them to investigate the causal relationship between the activity of genetically labeled neurons and specific behavior.
To confirm the concept, the researchers used PiVR to study sensory navigation in response to the gradients of chemicals and light in a number of animals. They showed how fruit fly larvae change their movements in response to real and virtual odor gradients. They then demonstrated how adult flies change their speed to avoid places associated with bitter tastes. They were triggered by optogenetic activation of the bitter-sensitive neurons of flies.
In addition, scientists have shown that zebrafish larvae change their rotation maneuvers in response to changes in light intensity that mimic spatial gradients. According to the authors, PiVR is a technology that should enable many laboratories to characterize the behavior of animals and study the functions of nerve chains.
More than ever, neurobiology is technology-based. Yes, integrating the new interdisciplinary methodology into the laboratory can be intimidating. With PiVR, our goal was to make virtual reality paradigms accessible to everyone, from professional scientists to schoolchildren. PiVR should help democratize advanced technology to study brain behavior and function.
David Tadres, Mathieu Louis, study authors