Homeostasis of Mitochondrial Ca2+ Stores Is Critical for Signal Amplification in Drosophila melanogaster Olfactory Sensory Neurons
2022
Wiesel, Eric | Kaltofen, Sabine | Hansson, Bill S. | Wicher, Dieter
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 Ca²⁺. OSNs expressing different groups of ORs show varying optimal odor concentration ranges according to environmental needs. Certain types of OSNs, usually attuned to high odor concentrations, allow for the detection of even low signals through the process of sensitization. By increasing the sensitivity of OSNs upon repetitive subthreshold odor stimulation, Drosophila melanogaster can detect even faint and turbulent odor traces during flight. While the influx of extracellular Ca²⁺ has been previously shown to be a cue for sensitization, our study investigates the importance of intracellular Ca²⁺ management. Using an open antenna preparation that allows observation and pharmacological manipulation of OSNs, we performed Ca²⁺ imaging to determine the role of Ca²⁺ storage in mitochondria. By disturbing the mitochondrial resting potential and induction of the mitochondrial permeability transition pore (mPTP), we show that effective storage of Ca²⁺ in the mitochondria is vital for sensitization to occur, and release of Ca²⁺ from the mitochondria to the cytoplasm promptly abolishes sensitization. Our study shows the importance of cellular Ca²⁺ management for sensitization in an effort to better understand the underlying mechanics of OSN modulation.
显示更多 [+] 显示较少 [-]