All BXD RI strains and the B6 and D2 progenitors were purchased from Jackson Laboratory (Bar Harbor, ME). All animals were male and between 10–12 weeks of age. Mice were housed 4 per cage with ad libitum access to standard rodent chow (catalog #7912, Harlan Teklad, Madison, WI) and water. Following a two week acclimation period mice were injected intraperitoneally (IP) with saline or 1.8 g/kg of ethanol. This ethanol dose was originally chosen from pilot experiment data to maximize anxiolytic activity and minimize sedative responses (decreased locomotor activity) as part of a parallel study of ethanol induced anxiolysis. In that study, all mice underwent behavioral testing that included 15 minutes of restraint in a 50 mL conical tube followed by 10 minutes in a light-dark chamber. The results of these behavioral genetics experiments will be published elsewhere (Putman et al, submitted) and are not discussed in this manuscript. Mice were killed by cervical dislocation four hours following IP injection. Immediately thereafter, brains were extracted and chilled for one minute in iced phosphate buffer before being microdissected into 8 constituent
