The perception of temperature in the Drosophila brain

Abstract

All motile organisms possess means of sensing and responding to changes of the external temperature. Given a choice, an animal moves towards a cooler area when overheating, and towards a source of warmth when faced with a cold environment. This simple behaviour demonstrates the main task of the thermosensory system: to define the thermal quality of a stimulus (hot versus cold), and to trigger appropriate behavioral and physiological responses. In addition, extreme temperatures are sensed as noxious stimuli, and as such evoke unique, very rapid reactions. Despite the essential nature of thermosensation, little is known about the central mechanism of temperature discrimination and the circuits involved in behavioral choices and output. The study of temperature coding is further complicated in mammals by the existence of multiple layers of autonomic, endocrine and skeletomotor responses that are interconnected to the sensory pathways to regulate the production of endogenous heat. I propose to employ an integrated genetic, molecular and behavioural approach to elucidate the logic of temperature perception in Drosophila, a system ideally suited for a comprehensive dissection of complex circuits and behaviors.