Conclusion
Consistent AUD-like behavior was detected in a small proportion of alcohol drinking rats. Alcohol consumption, habit formation, motivation for alcohol and punishment resistance contribute in varying degrees to the AUD-like phenotype across the population. These findings emphasise the importance of considering the heterogeneity of AUD-like behavior.
Methods
Lister Hooded rats (n = 47) were characterised for alcohol consumption, habit formation, motivation for alcohol and quinine-adulterated alcohol consumption. The interrelation between these measures was evaluated through correlation and cluster analyses. In addition, addiction severity scores were computed using different combinations of the behavioral measures, to assess the consistency of the AUD-like subpopulation.
Objective
The aim of this study was therefore to explore the relation between these AUD-associated behavioral constructs in rats. We hypothesised that a subpopulation of animals could be identified that, based on these measures, display consistent AUD-like behavior.
Results
We found that the data was uniformly distributed, as there was no significant tendency of the behavioral measures to cluster in the dataset. On the basis of multiple ranked addiction severity scores, five animals (~ 11%) were classified as displaying AUD-like behavior. The composition of the remaining subpopulation of animals with the highest addiction severity score (9 rats; ~ 19%) varied, depending on the combination of measures included.