%0 Journal Article
%T Prenatal Cocaine Exposure Uncouples mGluR1 from Homer1 and Gq Proteins
%A Kalindi Bakshi
%A Raminder Parihar
%A Satindra K. Goswami
%A Melissa Walsh
%A Eitan Friedman
%A Hoau-Yan Wang
%J PLOS ONE
%D 2014
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0091671
%X Cocaine exposure during gestation causes protracted neurobehavioral changes consistent with a compromised glutamatergic system. Although cocaine profoundly disrupts glutamatergic neurotransmission and in utero cocaine exposure negatively affects metabotropic glutamate receptor-type 1 (mGluR1) activity, the effect of prenatal cocaine exposure on mGluR1 signaling and the underlying mechanism responsible for the prenatal cocaine effect remain elusive. Using brains of the 21-day-old (P21) prenatal cocaine-exposed rats, we show that prenatal cocaine exposure uncouples mGluR1s from their associated synaptic anchoring protein, Homer1 and signal transducer, Gq/11 proteins leading to markedly reduced mGluR1-mediated phosphoinositide hydrolysis in frontal cortex (FCX) and hippocampus. This prenatal cocaine-induced effect is the result of a sustained protein kinase C (PKC)-mediated phosphorylation of mGluR1 on the serine residues. In support, phosphatase treatment of prenatal cocaine-exposed tissues restores whereas PKC-mediated phosphorylation of saline-treated synaptic membrane attenuates mGluR1 coupling to both Gq/11 and Homer1. Expression of mGluR1, Homer1 or G¦Á proteins was not altered by prenatal cocaine exposure. Collectively, these data indicate that prenatal cocaine exposure triggers PKC-mediated hyper-phosphorylation of the mGluR1 leading to uncoupling of mGluR1 from its signaling components. Hence, blockade of excessive PKC activation may alleviate abnormalities in mGluR1 signaling and restores mGluR1-regulated brain functions in prenatal cocaine-exposed brains.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0091671