Table 2.

Summary of findings targeting the melanocortin system on ethanol-related phenotypes.

MCR examined	Notable findings
Non-selective MCR	MTII (i.c.v.) ↓ voluntary consumption in AA rats11
	MTII (i.c.v.) ↓ voluntary consumption in C57 mice6
	Intra-amygdala MTII ↓ voluntary consumption in P rats12
	α-MSH (i.c.v.) ↓ ethanol-induced anxiolysis2
	γ-MSH (i.c.v.) ↓ ethanol-induced anxiolysis1
	γ-MSH (i.c.v.) ↑ withdrawal-induced anxiogenesis1
	α-MSH (i.c.v.) ↓ ethanol-induced antidepressive-like effects3
MC3R	MTII (i.c.v.) ↓ voluntary consumption in MC3R−/− mice7
	MTII (i.c.v.) ↓ binge-like ethanol drinking in both MC3R+/+ and MC3R−/− mice, but was more effective in MC3R−/− mice10
MC4R	Selective MC4R agonist (i.c.v.) ↓ voluntary consumption in C57 mice7
	MTII (i.c.v) did not alter voluntary consumption in MC4R−/− mice9
	Selective MC4R agonist directly infused into the NAc ↓ voluntary consumption in rats4
	Selective MC4R agonist directly infused into the NAc ↓ ethanol palatability in rats5
	Selective MC4R agonist (i.c.v.) ↑ ethanol-induced anxiolysis2
	Selective MC4R agonist (i.c.v.) ↓ withdrawal-induced anxiogenesis2
	Selective MC4R agonist (i.c.v.) ↑ ethanol-induced antidepressive-like effects3
	Selective MC4R agonist (i.c.v.) ↓ withdrawal-induced depressive-like symptoms3
AgRP	AgRP (i.c.v.) blocked MTII-induced ↓ voluntary consumption in C57 mice6
	AgRP (i.c.v.) ↑ voluntary consumption in C57 mice7
	AgRP−/− display ↓ voluntary ethanol consumption, ↓ operant ethanol seeking, ↓ binge-like ethanol drinking8

↑, increase; ↓, decrease. AA, Alko Alcohol; AgRP, agouti-related protein; C57, C57BL/6J; LH, lateral hypothalamus; MSH, melanocyte stimulating hormone; MTII, melanotan-II; NAc, nucleus accumbens; P, alcohol-preferring; i.c., intracisternal; i.c.v., intracerebroventricular. References are as follows:

¹Jansone et al. (2009);

²Kokare et al. (2006);

³Kokare et al. (2008);

⁴Lerma-Cabrera et al. (2012);

⁵Lerma-Cabrera et al. (2013);

⁶Navarro et al. (2003);

⁷Navarro et al. (2005);

⁸Navarro et al. (2009);

⁹Navarro et al. (2011);

¹⁰Olney et al. (2014);

¹¹Ploj et al. (2002);

¹²York et al. (2011).