Relação entre os efeitos da meta-clorofenilpiperazina (mCPP) na aversão condicionada ao lugar e na autolimpeza em ratos machos e fêmeas

Abstract

Obsessive-Compulsive Disorder (OCD) is characterized by unwanted thoughts, images, or impulses and repetitive behaviors performed according to rigid rules, resulting in a significant reduction in patients' quality of life. In this context, animal models are practical and theoretical tools of great importance for studying OCD and other mental disorders. Among the pharmacological models for studying OCD, the administration of meta-chlorophenylpiperazine (mCPP), a non-selective serotonin receptor agonist, can exacerbate obsessive-compulsive and anxiety-related symptoms in humans and induce compulsive-like and pro-aversive behaviors in rodents. Thus, the present study aimed to evaluate the effects of mCPP (0; 0.5; 1.0 and 3.0 mg/kg) in the conditioned place aversion test in male and female rats, as well as the correlation of these effects with self-grooming behavior. Additionally, the influence of the estrous cycle in females was investigated. The experimental protocol consisted of three sessions for each animal: baseline (day 1), confinement (day 2), and test (day 3). During baseline and test, animals freely explored the open field for 15 minutes, with the number of entries and time spent in each quadrant being evaluated. On day 2, animals received mCPP or saline administration and were confined in one of the apparatus quadrants for 30 minutes, with grooming behavior assessed during confinement. mCPP was able to induce a pro-aversive effect in males at the 0.5 dose, reducing the time in the target quadrant on test day. In metaestrous/diestrous females, self-grooming exacerbation was observed at the 1.0 dose. Also in females, regardless of the cycle, a reduction of this behavior was observed at the 3.0 dose compared to the other doses. Finally, there was no significant correlation between conditioned place aversion and grooming. The results of the present study contribute to the mCPP literature, especially regarding the use of females in neuroscience research.