Environmental temperature modulates olfactory reception in Drosophila melanogaster

Sensory systems, including the olfactory system, are able to adapt to changing environmental conditions. In nature, changes in temperature modify the volatility and concentration of odorants in the air. If the olfactory system does not adapt to these changes, it could relay wrong information about the distance to or direction of odor sources. Recent behavioral studies in Drosophila melanogaster showed olfactory acclimation to temperature. In this report, we investigated if temperature affects olfaction at the level of the receptors themselves. With this aim, we performed electroantennograms (EAGs) and single sensillum recordings (SSRs) to measure the response to several odorants in flies that had been submitted to temperature treatments. In response to all tested odorants, the amplitude of the EAGs increased in flies that had been exposed to a higher temperature and decreased after cold treatment, revealing that at least part of the reported change in olfactory perception happens at reception level. SSRs of odorant stimulated basiconic sensilla ab2 and ab3 showed some changes in the number of spikes after heat or cold treatment. However, the number and shape of spontaneous action potentials were unaffected, suggesting that the observed changes related specifically to the olfactory function of the neurons.

Figure optionsDownload as PowerPoint slideHighlights
► Drosophila melanogaster adults modify their response to odors depending on temperature.
► Changes were observed at the antennal level and in olfactory receptor neurons.
► However, temperature treatments do not affect neuron excitability mechanisms.
► These signaling changes could initiate previous reported adjusts in perception.