Positive emotional learning is regulated in the medial prefrontal cortex by GluN2B-containing NMDA receptors

摘要

In rats, hedonic ultrasonic vocalizations (USVs) is a validated model of positive affect and is best elicited by rough-and-tumble play. Here we report that moduiation of GluN2B-containing NIVfDA receptors (NWSDAR) in the medial prefrontal cortex (MPFC) is involved in positive emotional learning. Rough and tumble play increased both GluN1 and GIuN2B NMDAR subunit rnRNA and protein levels in the frontal cortex. GLYX-13, a GluN2B-preferring, NMDAR glycine-site partial agonist (1 mg/kg, i.v.) significantly increased positive emotional learning whereas the GIuN2B receptor-specific antagonist, ifenprodil (10 mg/kg, i.p.), inhibited positive emotional learning. Animals selectively bred for low rates of hedonic USVs were returned to wild-type levels of positive emotional learning following GLYX-13 treatment. MPFC microinjections of GLYX-13 (0.1-10 mug/side) significantly increased rates of positive emotional learning. Thus GiuN2B-containing NMDARs may be involved in positive emotional learning in the MPFC by similar mechanisms as spatial/temporal learning in the hippocampus.