The Effects of Ethanol on GABA-Gated Currents (2008)
Undergraduate: Ryan Hawkins
Faculty Advisor: Hugh Criswell
Department: Psychology & Neuroscience
Extrasynaptic receptors in the thalamic neurons exhibit large tonic currents that may be responsible for producing the sedative properties of ethanol (EtOH). The purpose of this study was to observe the effects of THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) on GABA-gated currents. THIP is a GABA agonist that selectively acts on extrasynaptic receptors, especially in thalamic neurons. Rats 12 to 14 days old were anesthetized, decapitated, and their brains were removed. Parasagittal slices (350µm thick) were prepared for electrical recording. Tonic currents from mechanically dissociated neurons were recorded using whole-cell voltage-clamp recording. The effects produced by the extrasynaptic receptors were observed after substituting THIP for GABA, and recorded on a computer. A change in RMS (root mean squared) noise and current (in picoamps, pA) levels after application of THIP and EtOH showed a trend towards suggesting that EtOH may alter the effects of THIP. However, the trends of these results were not statistically reliable. While EtOH increased the magnitude of the tonic currents produced by THIP, its enhancement of THIP may be very minimal.