SENSITIVITY OF BRAIN SITES TO THE INHIBITORY EFFECT ON ALCOHOL INTAKEOF THE TACHYKININ AMINOSENKTIDE

The present study evaluated the sensitivity of several brain sites to the inhibitory effect of the tachykinin (TK) NK-3 receptor agonist ami nosenktide (NH2-SENK) on 10% ethanol intake in genetically selected Ma rchigian Sardinian alcohol-preferring rats. Attention was focused on l imbic structures involved in alcohol-seeking behavior and endowed with TK NK-3 receptors. NH2-SENK was bilaterally injected into the shell o f the nucleus accumbens (NACC), the medial amygdala (AMY), the dorsal hippocampus (HIPP), the ventral tegmental area (VTA), the bed nucleus of the stria terminalis (BNST), the lateral hypothalamus (LH), and the nucleus basalis magnocellularis (NBM). NH2-SENK (injected up to 25-75 ng/site) into the NACC, AMY, HIPP, and VTA did not significantly modi fy ethanol intake. Injection of NH2-SENK into the BNST reduced ethanol intake at doses of 25 ng/site or higher, but the same doses also redu ced water intake in water-deprived rats and food intake in food-depriv ed rats. Injection of NH2-SENK into the LH or the NBM at doses of 0.5, 5, or 25 ng/site inhibited 10% ethanol intake even at the lowest dose tested without affecting either food or water consumption in deprived animals. Present results indicate that the LH and the NBM are highly sensitive to the inhibitory effect of the TK NK-3 receptor agonist NH2 -SENK on ethanol intake. TK peptides have been shown to evoke conditio ned place preference following injection in the LH or the NBM. suggest ing that in these brain sites the effect of TK agonists on ethanol int ake might be due to interference with reward processes. (C) 1998 Elsev ier Science Inc.