PKA also modulates ethanol consumption. Activation of adenosine A2a receptors increases PKA activity.66 Systemic injection of the A2a receptor antagonist 3,7-dimethylpro-pargylxanthine, which is predicted to decrease PKA activation mainly in the striatum where A2a receptors are highly expressed,112 reduces ethanol self-administration in rats.113 Mice that express a dominant negative form of PKA in the forebrain and hippocampus, and therefore have lower brain PKA activity in these areas, show reductions in both ethanol consumption and ethanol preference when compared with wild-type mice.114 However, injection of the PKA inhibitor Rp-cAMPS into the rat central amygdala increases ethanol intake and preference,115 in part by increasing anxiety-like behavior.116 The effects of PKA on behavior thus display regional specificity within the brain.
