Hunger-dependent modulation of neural circuits for social visuomotor processing in schooling fish - PROJECT SUMMARY The continuous influx and prioritization of particular aspects of sensory information into the nervous system is fundamental for interaction with the environment. The brain must dynamically modulate neural representations of and behavioral responses to relevant sensory stimuli depending on an organism’s internal state. This flexibility can drive important changes in behavior, subsequently conferring evolutionary advantages and balances to homeostatic needs (e.g., a small fish might benefit from heightened sensitivity to food-relevant sensory cues when hungry, enhancing its ability to detect small prey-like organisms). Collective behavior, such as the coordinated movement of a school of fish, is thought to confer a selective advantage, helping the group perform behaviors such as food-seeking more effectively. How does an animal group synchronize its behavior based on the internal states of individual members? Relatively little is known about the neural circuits processing the social motion of conspecifics and how they may be modulated by an internal state, such as hunger. To better understand how internal states influence complex natural sensorimotor behaviors, this project will investigate the neural circuits involved in hunger-dependent perception of social motion in schooling fish. To accomplish this, the small and transparent micro glassfish (Danionella cerebrum) will be used, a new model system in neuroscience with genetic amenability, lifelong optical transparency, and innate engagement in coordinated schooling behavior. Previous work in the Lovett-Barron lab has indicated that adult D. cerebrum engage in schooling using vision alone, providing a unique opportunity to investigate the brain-wide networks that underlie hunger-dependent social motion perception using a visual virtual reality system and simultaneous brain-wide, cellular-resolution two-photon calcium imaging in behaving adult fish. In addition, multi-animal posture tracking and pharmacological perturbation will be used to quantify complex group behavior and probe the involvement of specific brain areas to state-dependent behavior. This project will identify the neural populations involved with the perception of and response to group social motion across the brain and investigate how those circuits are modulated by hunger. Then, targeted pharmacological perturbation of hunger-producing neurons will be used to reveal how this population influences the sensory representation of social motion. Understanding how the brain responds to hunger cues and regulates sensory processing is critical for comprehending the complex interplay between appetite regulation and sensory perception. By leveraging insights from evolutionary conserved neural circuits, this research has the potential to uncover fundamental principles applicable to diverse vertebrate species, including humans, paving the way for novel strategies to address obesity and malnutrition on a broader scale.
