A novel paradigm for investigating compulsive-like behavior in rats: excessive precautionary behavior

Compulsions, conceptualized as time-consuming and exaggerated behaviors aimed at preventing anticipated adverse outcomes, have not been adequately considered within existing animal models. This study aims to address this gap.

Twenty Wistar albino rats entered the training phase; 12 animals (6 female and 6 male) met the predefined task-acquisition criteria and were included in the final analysis. In the experiment phase no unpleasant stimulus was given. The number and duration of lever presses and sucrose bottle contacts, the number of grooming, defecations, and zone changes were measured. Behavioral data were analyzed using the k-means clustering algorithm (k = 2; 10,000 iterations) to derive a Compulsion_Probability (CP). Group differences were assessed using Mann-Whitney U tests, and associations were assessed via Spearman correlation test.

Rats were divided into two groups of six: CLB (-) and CLB (+). In group comparisons, differences were observed in number of lever presses (p=0.03), time spent on the lever (p=0.026) and grooming duration (p=0.026).

This exploratory study presents preliminary evidence that excessive precautionary behavior is associated with reduced engagement in alternative appetitive activities. However, this relationship remains tentative and requires replication and validation against alternative explanations, such as anxiety-related responding, perseveration, and impaired extinction. Instead of directly modeling obsessive-compulsive disorder, the proposed model may provide a complementary behavioral framework. Further multimodal studies are necessary to clarify its neurobiological basis and translational relevance.