Although the effects of biogenic amines and endogenous cannabinoids on PFC neuron excitability have been examined using in vitro electrophysiological techniques, there is much less known about the actions of alcohol on these neurons. Recent studies from the authors’ laboratories have investigated the effects of acute ethanol exposure on persistent activity patterns in PFC neurons in organotypic cell culture and on synaptic transmission in slices from rat prefrontal cortex. Tu et al. (2007) used triple-slice organotypic cultures that contained prefrontal cortex, hippocampus, and ventral tegmental area. As described earlier, pyramidal neurons in the prefrontal cortex portion of these cultures develop spontaneous patterns of persistent activity within 2 weeks of culture, and up-states can also be evoked by direct electrical stimulation of these cultures (Fig. 3). Ethanol, applied via the bath solution, had no effect on firing of PFC pyramidal neurons induced by direct current injection but reduced the duration, amplitude, and spike activity of spontaneous up-states. These effects occurred at the beginning at 17mM (~0.08% blood ethanol concentration) and persistent activity of PFC neurons was almost totally suppressed at 50mM
