Resveratrol noncompetitively inhibits glycine receptor-mediated currents in neurons of rat central auditory neurons.

Resveratrol, a naturally occurring stilbene found in red wine, is known to modulate the activity of several types of ion channels and membrane receptors, including Ca2+, K+, and Na+ ion channels. However, little is known about the effects of resveratrol on some important receptors, such as glycine receptors and GABAA receptors, in the central nervous system (CNS). In the present study, the effects of resveratrol on glycine receptor or GABAA receptor-mediated currents in cultured rat inferior colliculus (IC) and auditory cortex (AC) neurons were studied using whole-cell voltage-clamp recordings. Resveratrol itself did not evoke any currents in IC neurons but it reversibly decreased the amplitude of glycine-induced current (IGly) in a concentration-dependent manner. Resveratrol did not change the reversal potential of IGly but it shifted the concentration-response relationship to the right without changing the Hill coefficient and with decreasing the maximum response of IGly. Interestingly, resveratrol inhibited the amplitude of IGly but not that of GABA-induced current (IGABA) in AC neurons. More importantly, resveratrol inhibited GlyR-mediated but not GABAAR-mediated inhibitory postsynaptic currents in IC neurons using brain slice recordings. Together, these results demonstrate that resveratrol noncompetitively inhibits IGly in auditory neurons by decreasing the affinity of glycine to its receptor. These findings suggest that the native glycine receptors but not GABAA receptors in central neurons are targets of resveratrol during clinical administrations.