In vitro electrophysiology has also been used to study the effects of medium doses of ethanol on VTA DA neurons. 40 mM ethanol has been found to decrease the amplitude of the M-type K+ channel current by 7% in dissociated rat neurons [22]. In addition, this concentration of ethanol has been shown to decrease the peak amplitude of GABAA receptor-mediated evoked IPSCs in VTA DA neurons by 23% while increasing the paired-pulse ratio of evoked IPSCs by 24% [21]. The amplitude of the depolarizing current Ih, which is carried by HCN channels, has been found to increase by 12% after the administration of 50 mM ethanol.
