The galanin-3 receptor antagonist, SNAP 37889, reduces operant responding for ethanol in alcohol-preferring rats

Background/objectiveThe galanin-3 receptor (GALR3) subtype has been identified as having a role in both feeding behaviour and the regulation of emotional states including anxiety. Despite the evidence for an association between galanin and alcohol, the current study is the first to explore the direct role of GALR3 in this context. The present study investigated the potential of the novel selective GALR3 antagonist, SNAP 37889, to reduce anxiety-like behaviour and voluntary ethanol consumption in the iP (alcohol-preferring) rat. This was achieved through a number of behavioural paradigms testing for anxiety, along with the operant self-administration model.ResultsOverall, male iP rats treated with SNAP 37889 at a dose of 30 mg/kg (i.p.) did not show altered locomotor activity or changes in anxiety-like behaviour in the elevated plus maze or light–dark paradigms. Treatment with SNAP 37889 (30 mg/kg, i.p.) reduced operant responding for solutions containing ethanol, sucrose and saccharin. Collectively, results from the current study showed that SNAP 37889 (30 mg/kg, i.p.) is effective in reducing operant responding for ethanol, independent of a sedative effect.ConclusionsThese findings provide evidence that GALR3 antagonism reduces alcohol consumption and further suggest that GALR3 may be implicated in the rewarding effects of natural and drug reinforcers.

Research highlights
► The GALR3 antagonist, SNAP 37889, reduces operant responding for ethanol, sucrose and saccharin.
► The effects seen with the dose employed are independent of any sedative effect of the drug.
► Results obtained highlight a role of GALR3 to influence consummatory behaviour of positive reinforcers which may have implications for not only drug-seeking, but also feeding disorders.
► Lack of any anxiolytic effect at the dose employed further suggests dissociation between ethanol-seeking behaviour and anxiety in this strain of rat.