Effect of local intracerebral corticosterone implants on alcohol intake in the rat

Corticosterone acts within the brain to stimulate alcohol consumption in the rat. The experiments reported here were aimed at identifying where in the brain corticosterone acts to facilitate ethanol drinking. The daily fluid intake of male Wistar rats with simultaneous access to 6% ethanol and water was determined during a 1-week pre-operative baseline period and following implantation of corticosterone in various brain areas. Animals bearing unilateral or bilateral implants of corticosterone in the ventral striatum showed increased ethanol consumption compared to cholesterol-treated controls. Ethanol intake was not affected when corticosterone was implanted into septum, hippocampus, or thalamus. Neither were changes in fluid intake detected in animals bearing ventral striatal implants of two related steroid hormones, aldosterone and testosterone. These results indicate that corticosterone partly acts within the ventral striatopallidal system to facilitate alcohol consumption in the rat.