Group I metabotropic glutamate receptor antagonists impair discriminability of reinforcer magnitude, but not risky choice, in a probability-discounting task.

Group I metabotropic glutamate receptor antagonists impair discriminability of reinforcer magnitude, but not risky choice, in a probability-discounting task. Behav Brain Res. 2019 Mar 01;: Authors: Yates JR, Chitwood MR, Evans KE, Kappesser JL, Murray CP, Paradella-Bradley TA, Torline BT Abstract The glutamatergic system has been identified as an important mediator of risky choice. However, previous studies have focused primarily on ionotropic glutamate receptors (e.g., NMDA receptors). Little research has examined the contribution of metabotropic glutamate receptors (mGluRs) on risky choice. The goal of the current experiment was to determine the effects of mGluR1 and mGluR5 antagonism on risky choice as assessed in probability discounting (PD). Male Sprague Dawley rats (n = 24) were trained in PD, in which consistently choosing a large, probabilistic reward (LR) reflects risky choice. For half of the rats, the odds against (OA) receiving the LR increased across blocks of trials, whereas the OA decreased across the session for half of the rats. Following training, rats received injections of the mGluR1 antagonist JNJ 16259685 (JNJ; 0, 0.1, 0.3, or 1.0 mg/kg; i.p) and the mGluR5 antagonist MTEP (0, 1.0, 3.0, or 10.0 mg/kg; i.p.). Regardless of which schedule was used, JNJ and MTEP decreased preference for the LR when its delivery was guaranteed. In contrast to delay discounting, in which blocking the mGluR1 has been shown to ...
Source: Behavioural Brain Research - Category: Neurology Authors: Tags: Behav Brain Res Source Type: research