Effects of the serotonergic agonist mCPP on male rats in the quinpirole sensitization model of obsessive–compulsive disorder (OCD)

Abstract

mCPP did not exacerbate or induce compulsive checking behavior. Instead, it ameliorated compulsive checking by reducing vigor of checking and increasing post-checking satiety, without affecting focus on checking. Ameliorative effects of mCPP may involve 5HT2A/2C receptors in substantia nigra pars reticulata that inhibit expression of motor vigor.

5-HT2A/C receptors do not mediate the attenuation of compulsive checking by mCPP in the quinpirole sensitization rat model of obsessive–compulsive disorder (OCD)

“…Generally, salinetreated rats have 1-2 bouts of checking behavior in a session while quinpirole-treated rats usually perform 2 or more bouts [6,18]. As in Tucci et al [5], if more than one bout of checking was performed, only the first 'time to next checking bout' was used for statistical analysis.…”

“…Quinpirole hydrochloride was administered at a dose of 0.125 mg/kg. This dose was chosen because it was shown in a previous study [5] to induce compulsive checking behavior in rats. mCPP was administered at a dose of 1.25 mg/kg.…”

“…mCPP was administered at a dose of 1.25 mg/kg. This dose was chosen because Tucci et al [5] found that 1.25 mg/kg of mCPP attenuated quinpirole effects on vigor of checking and on satiety. Both quinpirole and mCPP were administered in a 0.9% physiological saline vehicle at a volume of 1 ml/kg.…”

“…In a recent study employing the quinpirole sensitization rat model of OCD, it was reported that acute treatment with the 5-HT agonist drug mCPP reduced the motor vigor of checking and prolonged the post-checking satiety, but did not affect the focus on the task of checking [5]. Vigor, focus, and satiety, had been identified as three separate functional components underlying compulsive checking behavior in the animal model [6,7].…”

“…11.017 0166-4328/© 2014 Elsevier B.V. All rights reserved. no longer meeting criteria for 'compulsive' checking behavior [5]. Given the induction of compulsive checking by the DA agonist drug quinpirole and its reduction by the 5-HT agonist drug mCPP, the authors suggested the presence of a putative DA-5-HT interaction underlying the model compulsive behavior.…”