Impact of paired-housing on a preclinical model of alcohol use disorder

The succession of intermittent access of alcohol with a two-bottle choice followed by operant self-administration is a well-established model for research on alcohol use disorder in rodents. In most studies using this type of model, animals are isolated during the entire protocol to facilitate individual measures. Isolation may also be a crucial element to promote alcohol intake escalation, but its impact on adult animals remains unclear. Determining whether single housing is a central parameter or not is essential to better understand the underlying motivational mechanisms driving high level of alcohol intake in these models, and may have some important ethical as well as economic considerations if it appears unnecessary.

For this reason, we assessed here whether paired-housing would affect induction of alcohol consumption during a classical, widely used intermittent access procedure followed by operant self-administration in female and male Long-Evans rats.

Pair-housed rats reached similar levels of alcohol consumption as isolated animals during the intermittent access but exhibited, however, lower operant self-administration performances irrespective of the sex.

These results indicate that the transposition of these models of alcohol consumption to group-housing may be complex and, importantly, is likely to involve different psychobiological mechanisms than those underlying alcohol drinking behaviors in isolated rodents, that should be carefully taken into consideration.