EFFECTS OF INSULIN, LEPTIN, AND GHRELIN ON REWARD BEHAVIORS

Behavior	Insulin	Leptin	Ghrelin
Brain self-stimulation	decrease (ICV)	decrease (ICV)	not determined
Relapse to heroin seeking	not determined	decrease (ICV)	not determined
Acute sucrose licking	decrease (ICV)	not determined	no effect (ICV)*
Food CPP	decrease (ICV)	decrease (ICV, SC)	not determined
Sucrose self-administration	decrease (ICV,ARC)	decrease (ICV)	increase (ICV)*
Chow intake (4–24 hr)	decrease (ICV)	decrease (ICV,VTA)	increase (ICV,VTA)
Acute sucrose intake	decrease (ICV,VTA)	decrease (VTA)	not determined

^*”Ghrelin affects motivational but not hedonic aspects of feeding”, J. Overduin and D.E. Cummings, North American Association for the Study of Obesity annual meeting 2007