2004). Therefore, a methodical analysis of differences between B6 inbred lines and their B6 × 129 hybrid counterparts would be useful for planning new ethanol studies and for interpreting prior studies that used different strains. Here, we examined

five strains of mice: B6NT and B6J inbreds, and B6129S6, B6129X1, and B6129S4 hybrids in five ethanol studies: continuous access two-bottle choice drinking, intermittent limited-access binge drinking, ethanol-induced loss of the righting reflex (LORR), ethanol clearance, and conditioned place preference (CPP) for ethanol. Our findings may inform decisions on whether or not to backcross newly generated hybrid lines of gene-targeted Inhibitors,research,lifescience,medical mice to study ethanol-related behaviors. Inhibitors,research,lifescience,medical Materials and Methods Rodent care and breeding Mice were housed under a 12:12 h light–dark cycle (lights off from 7 PM to 7 AM), except for mice used in the limited-access drinking procedure (see below). A naïve group of mice was used for each experiment, with the exception of the ethanol clearance tests, which were performed on mice that underwent the loss of righting procedure at least one week prior. All mice had ad libitum access to food and water. All experiments were conducted using eight- to

13-week-old male mice. For experiments involving B6129S6 mice, C57BL/6NTac mice obtained from Taconic were compared with C57BL/6NTac × 129S6/mTOR inhibitor SvEvTac (B6129S6) F1 hybrids obtained from Taconic or bred in house Inhibitors,research,lifescience,medical by mating C57BL/6NTac females with 129S6/SvEvTac males. No differences in ethanol-related behaviors were observed between Inhibitors,research,lifescience,medical mice generated at Taconic versus mice bred in house. For experiments involving B6129X1 and B6129S4 mice, C57BL/6J mice were obtained from The Jackson Laboratory and compared with C57BL/6J × 129X1/SvJ (B6129X1) and C57BL/6J × 129S4/SvJae (B6129S4) F1 hybrids. Both of these hybrid lines were bred in house Inhibitors,research,lifescience,medical by mating C57BL/6J females with

129X1/SvJ or 129S4/SvJae males. All procedures were approved and conducted in accordance with Gallo Center Institutional Animal Care and Use Committee policies and NIH guidelines for the care and use of animals in research. Continuous access two-bottle Bumetanide choice ethanol drinking Naïve mice were singly housed for one week and then were given 24-h access to two bottles, one containing ethanol and the other water. The ethanol concentration was increased every four to five days as follows: 3%, 6%, 10%, 14%, and 20% (v/v) ethanol in water. Bottles were weighed on Monday, Wednesday, and Friday, and the positions of the bottles were alternated every day to control for any side preferences. Baseline water consumption was measured prior to the start of the ethanol series, and mice were weighed weekly throughout the study. Ethanol consumption was measured as the difference between bottle weights between weighing sessions and calculated as g ethanol/kg mouse/24 h. Ethanol preference was calculated as g ethanol/g total fluid consumed/24 h.