Data are presented throughout as the mean±SEM. Statistical analyses were performed using GraphPad Prism (GraphPad Software; La Jolla, CA). Quantal events were analyzed using Minianalysis software (Synaptosoft, Decatur, GA). The impact of genotype on VTA DA neuron characteristics, baclofen-induced current amplitude, EPSC and IPSC frequency and amplitude, synaptic level of AMPA subunits, synapse density, and cocaine-induced motor activity were assessed using one-way ANOVA, followed by Tukey’s Multiple Comparison post hoc test when appropriate. For all statistical comparisons, P values of less than 0.05 were considered to reflect significant differences between groups.
