An internal thermal sensor controlling temperature preference in Drosophila.
Animals from flies to humans are able to distinguish subtle gradations in temperature and show strong temperature preferences. Animals move to environments of optimal temperature and some manipulate the temperature of their surroundings, as humans do using clothing and shelter. Despite the ubiquitous influence of environmental temperature on animal behaviour, the neural circuits and strategies through which animals select a preferred temperature remain largely unknown. Here we identify a small set of warmth-activated anterior cell (AC) neurons located in the Drosophila brain, the function of which is critical for preferred temperature selection. AC neuron activation occurs just above the fly''s preferred temperature and depends on dTrpA1, an ion channel that functions as a molecular sensor of warmth. Flies that selectively express dTrpA1 in the AC neurons select normal temperatures, whereas flies in which dTrpA1 function is reduced or eliminated choose warmer temperatures. This internal warmth-sensing pathway promotes avoidance of slightly elevated temperatures and acts together with a distinct pathway for cold avoidance to set the fly''s preferred temperature. Thus, flies select a preferred temperature by using a thermal sensing pathway tuned to trigger avoidance of temperatures that deviate even slightly from the preferred temperature. This provides a potentially general strategy for robustly selecting a narrow temperature range optimal for survival.
PubMed ID: 18548007
PMC ID: PMC2730888
Article link: Nature.
Grant support: P01 NS044232 NINDS NIH HHS , P01 NS044232-060002 NINDS NIH HHS , P01 NS044232-070002 NINDS NIH HHS , P30 NS045713-069006 NINDS NIH HHS , P30 NS045713S10 NINDS NIH HHS , R01 EY013874-06 NEI NIH HHS , R01 EY13874 NEI NIH HHS , R01 MH067284 NIMH NIH HHS, R01 MH067284-05 NIMH NIH HHS, RR16780 NCRR NIH HHS , P30 NS045713 NINDS NIH HHS , R01 EY013874 NEI NIH HHS