mGlu5 Receptors and Relapse to Cocaine-Seeking: The Role of Receptor Trafficking in Postrelapse Extinction Learning Deficits

Figure 3

Surface expression of mGlu5 receptors in the dlSTR is reduced exclusively in animals with history of cocaine self-administration and context-primed relapse that also received intra-dlSTR infusion of MTEP. (a) Left panel: an outline of the coronal rat brain section according to Paxinos and Watson [13] demonstrating the site of drug microinjection relative to dSTR tissue dissection. Right panel: representative immunoblot analysis of fractions (T: total lysate, I: intracellular fraction, and S: surface fraction) prepared by surface biotinylation of the dlSTR slices. In addition to mGlu5, distribution of plasma membrane protein (syntaxin-1a), endoplasmic reticular protein (calnexin), and intracellular enzyme (tyrosine hydroxylase, TH) was used to monitor the cross-contamination of the prepared fractions. (b) The total protein expression of mGlu5 is not altered by cocaine or MTEP. (c) Surface protein expression of mGlu5 is reduced in animals that self-administered cocaine and received intra-dlSTR MTEP prior to the relapse test. compared to Sal-Veh.

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