Participation of GABAA, GABAB Receptors and Neurosteroids in Toluene-Induced Hypothermia: Evidence of Concentration-Dependent Differences in the Mechanism of Action

This study investigated the effects of acute toluene inhalation on core body temperature in mice, focusing on the involvement of GABAA and GABAB receptors and neurosteroids. Toluene exposure at concentrations of 4000 and 6000 ppm resulted in a concentration-dependent decrease in core temperature. The hypothermic effect at 4000 ppm was mitigated by GABAA receptor blockers (picrotoxin, bicuculline), a GABAB receptor antagonist (phaclofen), and a neurosteroid synthesis inhibitor (finasteride), but not by the benzodiazepine receptor antagonist flumazenil. However, none of these treatments prevented the hypothermic effect at 6000 ppm, suggesting different mechanisms of action at higher concentrations.