Olfactory perception in Drosophila melanogaster changes according to environmental temperature

Olfaction provides chemical information from his environment to the animal. When environmental conditions change individuals should be able to adapt preserving adequate function. Temperature may influence olfaction in a double manner, first, modifying the odorant concentration present in the gaseous phase and, second, affecting biological processes. One can ask if environmental temperature variation is followed by the olfactory system adaptation and, in that case, if changes in olfactory perception try to compensate for the odor concentration alteration in the air. With this aim olfactory sensitivity after heat and cold treatments was analyzed in Drosophila melanogaster. Since the consequences extend some time after the treatment’s end, direct comparison of the olfactory behavior in treated flies and not treated controls at the same temperature was possible. Although at low odorant concentrations heat treatments induce a heterogeneous pattern, at higher concentrations always generate a reduction of olfactory sensitivity, as it would be expected to compensate for the increase of volatiles in the air. Cold produces the opposite effect at all range of concentrations. Short applications suffice to cause detectable olfactory perception changes but even prolonged temperature treatments have a transitory effect. All these results show that environmental temperature affects olfactory perception in Drosophila with a fine-tuning at intermediate odorant concentrations, where sensitivity changes compensate for the odor concentration oscillations. However, time-course of acclimation to new temperature conditions may depend on the animal thermal history, with short time periods of imperfect adjustment for olfactory function.

Funded by the Spanish Ministry of Education and Science, FEDER and the PCTI Program of the Principado de Asturias.