their first behavioral test while intoxicated may have been adapting nonspecifically to handling and novelty. One reason we suspect this may be true is that the control group tested first on the rotarod also showed substantially lower performance than the water-drinking control mice tested second (Figure 8). Also, we have observed that BECs in the range we obtained here cause improvements in performance on the ARR in some genotypes (21), so it is possible that we were assessing a mixture of performance decrements and improvements in the HDID-1 mice. In a study that employed a different ethanol drinking schedule and C57BL/6J mice, mice were impaired in a different variant of the rotarod task (fixed speed) after extensive pretraining on the accelerating rotarod. In that study, average BECs were 1.3–1.4 g/kg (22). We also note that levels of intake and BECs were lower in the second litters of HDID-1 mice that were tested for intoxication than those seen across the first litters of S9 HDID-1 mice tested for selection. We usually do not see such a difference between first and second litters; one potential explanation for the lower intakes (and BECs) is that concurrent testing for intoxication and intake in the
