Effect of Orexin A antagonist (SB-334867) infusion into the nucleus accumbens on consummatory behavior and alcohol preference in Wistar rats.

OBJECTIVE: Nucleus accumbens (NAcc) has a role in addiction and ingestive behavior. In order to assess orexinergic system involved in this, we infused Orexin A antagonist and assessed the effect on food intake fluid intake and alcohol preference in Wistar rats.

MATERIALS AND METHODS: Inbred Wistar rats (n = 54) were divided into control and experimental groups (low dose and high dose). Using stereotaxic method, guide cannula was set in place bilaterally to reach NAcc. Low dose (3 ng) and high dose (6 ng) of Orexin A antagonist (SB-334867) was infused, and the food consumption, water intake and alcohol intake, and two bottle free choice preference test for alcohol were carried out in the experimental group. The control group received saline infusion and rest of the methods followed were same. The measurements were carried out immediately after the infusion, at 1 h, 2 h, 4 h, and for the whole day and represented in the figure and tables.

RESULTS: A decrease in water intake observed immediately after the infusion in 1(st) h (P < 0.05) and 2(nd) h (P < 0.01), which was more in high dose group compared to low dose and controls. Alcohol intake was also following the same pattern. In two bottle free choice, rats did not show any specific preference to alcohol.

CONCLUSION: There was dose dependent reduction in intake of food and fluids in treated rats. This suggested a possible role for orexinergic system in ingestive behavior. However, Orexin A may not have a role in modulation of alcohol addiction by the rewarding center NAcc.