Impoverished rearing impairs working memory and metabotropic glutamate receptor 5 expression.

Impoverished rearing conditions deregulate metabotropic glutamate receptor (mGluR) function and expression within the prefrontal cortex, which contributes to poor performance in positively reinforced spatial working memory tasks. This study extended earlier data by demonstrating that impoverished rearing conditions impair spatial working memory even under conditions of negative reinforcement, indicating a generalized deficit in working memory processing. This protracted behavioral effect was associated with reduced total prefrontal cortex levels of the active, dimerized form of mGluR 5, but there was no change in mGluR 1 or mGluR 2/3 dimer expression in any brain region examined. Thus, impoverished rearing conditions produce protracted deficits in spatial working memory, in association with reduced prefrontal mGluR 5 function that may be relevant to the etiology of several neuropsychiatric disorders.