The influence of sex and estrous cycle on QTL for emotionality and ethanol consumption.

The inbred rat strains Lewis (LEW) and Spontaneously Hypertensive Rats (SHR) differ with respect to several emotionality- and ethanol intake-related behaviors, one of which (inner locomotion in the open field; OF) is strongly influenced by a locus (Anxrr16) on chromosome (Chr) 4. We aimed to further investigate the influence of Chr 4 on these behaviors and to evaluate the role of the estrous cycle in QTL expression. LEW females and SHR males were intercrossed to produce F1 and F2 rats (96-97/sex), which were then tested in the OF, light-dark box (LDB), forced swimming test (FST), and an ethanol consumption procedure (ECP).