Regulation of temperature preference behavior by dopamine signaling to mushroom bodies in drosophila

Abstract

Sensing and interpreting the temperature of surrounding and body are essential for animal to find more favorable environment, to control body temperature and to survive. Drosophila maintain their body temperature through heat exchange with the surrounding environment due to the large surface area-to-volume ratio of their bodies (Bear et al 2001 ; Zars 2001). Thus, Temperature preference behavior is a genetic process whereby Drosophila instinctively track to an environmental temperature as close as possible to their genetically determined desired body temperature. Drosophila shows temperature preference behavior standing on 24-25℃ region on the temperature gradient plate (Hong et al 2008). It was reported that dTrpA1 in warmth-activated anterior cell neuron and the level of cAMP in mushroom bodies are critical for the temperature preference behavior in Drosophila (Hong et al 2008 ; Hamada et al 2008). To understand the temperature sensing, interpretation and regulation system, it is need to find new components and mechanism involved in temperature preference behavior. Dopamine is a key neurotransmitter playing various critical roles in the animal brain (Chinta and Andersen 2005). One of its known roles is modulation of learning and memory in Drosophila mushroom bodies (Riemensperger et al 2005 ; Kim et al 2007). Here we show that dopamine controls TPB in mushroom bodies in Drosophila brain. Inhibition of dopamine biosynthesis by genetic mutations or treatment with chemical inhibitors, targeted inactivation of dopaminergic neurons with over expression of a potassium channel (Kir2.1), and mutations in a dopamine receptor gene DopR, all caused the animal to prefer colder temperatures than normal. Moreover, localized artificial expression of wild-type DopR gene only in mushroom bodies rescued the abnormal TPB phenotype of DopR mutants. In addition to the importance of dopamine in information acquisition and processing in the animal brain, our results show that dop...