Common Quantitative Trait Loci for Alcohol-Related Behaviors and CNS Neurotensin Measures: Voluntary Ethanol Consumption

The C57BL/6, DBA/2, and recombinant inbred (RI) strains derived from them (B × D RIs) are the most frequently studied mouse strains with regard to genetic regulation of voluntary ethanol consumption (VEC). We have studied VEC in an alternate genetic model provided by the LS × SS RIs. These RI strains exhibit phenotypic extremes in VEC comparable to the C57BL/6 and DBA/2 mice and genotype-dependent sex differences in drinking behavior. A correlational analysis between various ethanol-related behaviors suggests genetic independence of VEC from high-dose neurosensitivity (sleep time), acute ethanol tolerance, hypothermia, and low-dose locomotor activity. A search for quantitative trait loci identified a number of putative quantitative trait loci (QTL), three of which are identical to those previously reported for 10% ethanol drinking in the B × D RIs. We also find a significant correlation between low-affinity neurotensin receptor densities (NTRJ in the frontal cortex and VEC, and more common QTL between these two phenotypes than expected by chance. This suggests a role for frontal cortex NTR_L in regulating voluntary ethanol intake