Histamine and its receptors modulate temperature preference behavior in Drosophila

Abstract

Temperature is an essential factor for living organism and profoundly influences various life phenomena such as behavioral pattern, external morphology, cellular metabolism and integrity, and developmental and physiological process. Most animals have abilities to track suitable temperature for surviving and maintaining body temperature (thermotaxis or temperature preference). Thus, it is no wonder that organisms from bacteria to vertebrates have evolved to have a mechanism to sense around temperature and response properly. In a genetic screen for mutants, we found that the histaminergic genes (hdc, hisCl1, and ort) showed abnormal temperature preferences and confirmed using genetic and pharmacological approaches. The histaminergic genes were expressed in the various brain regions including circadian clockworks. The histaminergic mutants showed normal starvation resistance and decrease in mean life span. Interestingly, the histaminergic mutants showed high cold tolerance by low chloride conductance. Also, histamine-administered $w_{1118}$ showed low cold tolerance in a concentrate dependent manner. This suggests that histamine and histamine gated chloride channels could have roles in regulating physiological responses caused by cold stress as well as modulating temperature preferences