The role of mitochondria in shaping odor responses in Drosophila melanogaster olfactory sensory neurons.

Insects detect volatile chemosignals with olfactory sensory neurons (OSNs) that express olfactory receptors. Among them, the most sensitive receptors are the odorant receptors (ORs), which form cation channels passing also Ca. Here, we investigate if and how odor-induced Ca signals in Drosophila melanogaster OSNs are controlled by intracellular Ca stores, especially by mitochondria. Using an open antenna preparation that allows observation and pharmacological manipulation of OSNs we performed Ca imaging to determine the role of Ca influx and efflux pathways in OSN mitochondria. The results indicate that mitochondria participate in shaping the OR responses. The major players of this modulation are the mitochondrial Ca uniporter and the mitochondrial permeability transition pore. Intriguingly, OR-induced Ca signals were only mildly affected by modulating the Ca management of the endoplasmic reticulum.