A recent study revealed that periadolescent binge-ethanol consumption, using our drinking-in-the-dark—multiple-scheduled-access model,27,29 resulted in a general elevation of mGlu1 and mGlu4 (twice or three times that of controls, respectively) in the dorsal raphe nucleus (DRN) and mGlu7 (~1.4-fold increase) in the CeA.213 However, there was a significant decrease (~1.7-fold decrease) in mGlu6 expression within the DRN as well. Given that mGlu1, for the most part, is excitatory and the others inhibitory, this suggests a balance between ethanol-induced up- and downregulation of gene expression for these metabotropic receptors.
