Study On The Molecular Mechanism And Anti-anxiety Function Of Chinese Medicine Monomers Regulating Type A γ-aminobutyric Acid Recepto

Objective1.The present study was to investigate the molecular mechanis of curcumol on inhibitory y-aminobutyric acid(GABA)receptors.2.Another study was to investigate the mechanism and the effect of methyleugenol on inhibitory GABAARs and identify it’s effects on anxiety.Methods1.The effects of the single or combined application of curcumol,diazepam or menthol on GABA-activated current(IGABA)were recorded in cultured neurons or HEK293T cells using conventional whole-cell configuration under voltage clamp conditions,exploring the synergistic effect on GABAARs.2.Studying the effects of curcumol,menthol or diazepam on GABA-activatedcurrent(IGABA)in HEK-293T cells expressing mutant GABAARs.3.Exploring the effects of methyleugenol on tonic and miniature inhibitory postsynaptic GABAergic currents in central amygdala slices.4.Studying the synaptic and cellular mechanisms of methyleugenol in regulating anxiety liked-behaviors.Results1.When co-applied with the classical benzodiazepine,curcumol further potentiated GABA-induced currents.2.In the presence of a saturating concentration of menthol,curcumol failed to futher enhance GABA-induced currents,suggesting shared mechanisms underlying these two agents on GABAARs.3.Benzodiazepine antagonist flumazenil did not alter the enhancement of GABAresponse by curcumol and menthol,but abolished that by diazepam.4.Curcumol shares site of action with menthol,but not DZP,on the α1-β2-γ2 subtype of GABAAR.5.Variant mechanisms underlying actions of curcumol over menthol or DZP on theα5-β2-γ2 subtype of GABAAR.6.Methyleugenol enhanced the two forms of inhibitory effect of miniature and tonic inhibitory postsynaptic GABAergic currents in central amygdala neurons in brain slices.7.In the conditioned fear anxiety model,intracranial injection of methyleugenol in central amygdala attenuated anxiety in mice.Conclusion1.Curcumol allosterically modulates GABA(A)receptors in a manner distinct from benzodiazepines.2.Methyleugenol reduces anxietyand fear generalization by potentiation of GABAergic inhibition in central amygdale.