GHSR 1a receptors are also highly expressed in the Arc (Zigman et al., 2006). However, D-Lys3-GHRP-6 did not affect c-Fos immunoreactivity following alcohol drinking in this nucleus arguing against actions of ghrelin on alcohol drinking though this nucleus. An unexpected finding in this study was the induction of c-Fos after D-Lys3-GHRP-6 in the Arc in Experiment 3. The direction of the effect on c-Fos levels is surprising because this drug is an antagonist of the receptors. Since, this increase in c-Fos positive cells was not observed in the DID study (Experiment 2), it is important to note that one of the differences of Experiment 3 versus Experiment 2, is that in Experiment 3 the mice underwent two systemic injections. Although mice were subjected to similar procedures prior to the experiment, it is presumed that it is more difficult to habituate to two injections versus one, and systemic injections are also accompanied by the stress of unexpected alcohol intoxication, which could in itself induce c-Fos in many areas. To extrapolate, it would appear that endogenous ghrelin may have anxiolytic effects which
