The aim of this study was to compare the actions of CCK neuropeptides within the nucleus accumbens (N.Acc) of alcohol preferring (Fawn-Hooded, FH) and alcohol nonpreferring (Wistar-Kyoto, WKY) rats. CCK-8S (30-300 nM) facilitated the K + stimulated release of [ 3 H]dopamine (DA) from N.Acc prisms in both rat strains, whereas CCK-4 (30 nM-1 μM) caused a significant decrease of evoked [ 3 H]DA in the FH rat only. A scattered distribution of CCK-A and -B receptor immunopositive varicose fibers were visualized throughout the N.Acc of both rat strains along with a topographic distribution of CCK receptor positive cells throughout the ventral mesencephalon.