Dopamine Signalling in Mushroom Bodies Regulates Temperature-Preference Behaviour in Drosophila

Abstract

The ability to respond to environmental temperature variation is essential for survival in animals. Flies show robust temperature-preference behaviour (TPB) to find optimal temperatures. Recently, we have shown that Drosophila mushroom body (MB) functions as a center controlling TPB. However, neuromodulators that control the TPB in MB remain unknown. To identify the functions of dopamine in TPB, we have conducted various genetic studies in Drosophila. Inhibition of dopamine biosynthesis by genetic mutations or treatment with chemical inhibitors caused flies to prefer temperatures colder than normal. We also found that dopaminergic neurons are involved in TPB regulation, as the targeted inactivation of dopaminergic neurons by expression of a potassium channel (Kir2.1) induced flies with the loss of cold avoidance. Consistently, the mutant flies for dopamine receptor gene (DopR) also showed a cold temperature preference, which was rescued by MB–specific expression of DopR. Based on these results, we concluded that dopamine in MB is a key component in the homeostatic temperature control of Drosophila. The current findings will provide important bases to understand the logic of thermosensation and temperature preference decision in Drosophila.

Dopaminergic Modulation of cAMP Drives Nonlinear Plasticity across the Drosophila Mushroom Body Lobes

“…Dopaminergic neurons innervate multiple spatial regions of the MB and modulate multiple learned and motivated behaviors, ranging from temperature preference to aversive and appetitive olfactory learning (Figure S1) [14, 17, 18, 22, 24, 25, 29–31]. This diversity in behavioral functions led us to question whether distinct sets of dopaminergic neurons exert different effects on postsynaptic cAMP levels across different postsynaptic terminal zones (e.g., via bidirectionally regulation of cAMP through actions on distinct pools of postsynaptic D1- and D2-like receptors).…”

“…In Drosophila , dopaminergic neurons innervate multiple brain regions, including the mushroom body (MB), where they modulate aversive learning [3–5, 13–19], forgetting [20, 21], state-dependent modulation of appetitive memory retrieval [22], expression of ethanol-induced reward memory [23], and temperature preference behavior [24, 25]. …”

The Influence of Light on Temperature Preference in Drosophila

“…Not only do flies avoid noxious temperatures [11, 12, 14–17], they also exhibit a temperature preference rhythm (TPR) in which preferred temperature is lower in the morning and higher in the evening [18]. We previously observed that flies entrained with light and dark (LD) cycles prefer a higher temperature than flies in free-run (constant darkness (DD)) during the daytime [18], suggesting that acute light may affect the temperature preference in flies.…”

A Higher Brain Circuit for Immediate Integration of Conflicting Sensory Information in Drosophila

“…While temperature preference behavior is innate, finding the preferred temperature requires the MB [35]. Different temperatures could activate distinct sets of dopaminergic neurons, which in turn lead to preference or avoidance of a particular temperature in a gradient [36,37]. Such a setup could allow the animal to adapt its temperature preference to its context such as higher or lower outside temperatures.…”