Chemosensory detection of aversive concentrations of ammonia and basic volatile amines in insects

Jonathan Trevorrow Clark; Anindya Ganguly; Jadrian Ejercito; Matthew Luy; Anupama Dahanukar; Anandasankar Ray

doi:10.1016/j.isci.2022.105777

Chemosensory detection of aversive concentrations of ammonia and basic volatile amines in insects

iScience. 2022 Dec 8;26(1):105777. doi: 10.1016/j.isci.2022.105777. eCollection 2023 Jan 20.

Authors

Jonathan Trevorrow Clark¹, Anindya Ganguly¹, Jadrian Ejercito², Matthew Luy², Anupama Dahanukar^{1

2}, Anandasankar Ray^{1

2}

Affiliations

¹ Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA.
² Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA.

Abstract

Basic volatiles like ammonia are found in insect environments, and at high concentrations cause an atypical action potential burst, followed by inhibition in multiple classes of olfactory receptor neurons (ORNs) in Drosophila melanogaster. During the period of inhibition, ORNs are unable to fire action potentials to their ligands but continue to display receptor potentials. An increase in calcium is also observed in antennal cells of Drosophila and Aedes aegypti. In the gustatory system, ammonia inhibits sugar and salt responses in a dose-dependent manner. Other amines show similar effects in both gustatory and olfactory neurons, correlated with basicity. The concentrations that inhibit neurons reduce proboscis extension to sucrose in Drosophila. In Aedes, a brief exposure to volatile ammonia abolishes attraction to human skin odor for several minutes. These findings reveal an effect that prevents detection of attractive ligands in the olfactory and gustatory systems and has potential in insect control.

Keywords: Biological sciences; Neuroscience; Sensory neuroscience.