To drink or not to drink: open field behavior in alcohol-preferring and-nonpreferring rat strains

High open field activity has been associated with high alcohol intake in inbred mouse strains. The present study sought to determine if a similar relationship might exist in rats. Strains which voluntarily drink large amounts of alcohol (alcohol-preferring [P], alcohol-accepting [AA], Fawn-Hooded [FH]) or little or no alcohol (alcohol-nonpreferring [NP], alcohol-nonaccepting [ANA], Flinders Resistant Line [FRL]) were compared with the Maudsley strains of rats selectively bred for differences in open field defecation and activity. There were highly significant strain differences in open field activity, with the alcohol-preferring P rats exhibiting the highest activity and the alcohol-nonpreferring Maudsley Reactive rats exhibiting the lowest. However, the NP rats were almost as active as the P rats and the AA and ANA rats exhibited intermediate levels of activity which did not differ from each other. Thus, there was no consistent relationship between open field activity and high voluntary alcohol intake. Defecation was highest in the Maudsley Reactive rats, and there was a consistent negative relationship with alcohol intake (r = -0.455 across all strains). In a population of 57 FHxFRL F2 hybrids, there were no significant correlations between alcohol intake and open field activity (r = -0.01) or defecation (r = +0.12). We conclude, therefore, that there was no consistent relationship between voluntary alcohol intake and open field behavior across strains of rats.