Potentiation of GABA_A Receptors Expressed in Xenopus Oocytes by Perfume and Phytoncid

Abstract

  To study the effects of perfume and phytoncid on GABA_A receptors, ionotropic GABA_A receptors were expressed in Xenopus oocytes by injecting mRNAs that had been prepared from rat whole brain. Essential oil, perfume and such phytoncid as leaf alcohol, hinokitiol, pinene, eugenol, citronellol and citronellal potentiated the response in the presence of GABA at low concentrations (10 and 30 μM), possibly because they bound to the potentiation-site in GABA_A receptors and increased the affinity of GABA to the receptors. Since it is known that the potentiation of GABA_A receptors by benzodiazepine, barbiturate, steroids and anesthetics induces the anxiolytic, anticonvulsant and sedative activity or anesthetic effect, these results suggest the possibility that the intake of perfume or phytoncid through the lungs, the skin or the intestines modulates the neural transmission in the brain through ionotropic GABA_A receptors and changes the frame of the human mind, as alcohol or tobacco does.