5-HT2A and 5-HT2C/5-HT1B receptors are differentially involved in alcohol preference and consummatory behavior in cAA rats.
The present study aimed to investigate the role of serotonin 5-HT2A and 5-HT2C receptors in the control of alcohol preference and consummatory behavior in alcohol-preferring cAA rats. Effects of the 5-HT(2A/2C) receptor agonist, DOI, the 5-HT(2C/1B) receptor agonist, mCPP, the 5-HT(2A/2C) receptor antagonist, ritanserin, and the 5-HT2A receptor antagonist, MDL 100,907, on ethanol (EtOH, 10% v/v) preference and intake, as well as total fluid and food intake were evaluated in a 12-h limited-access two-bottle paradigm. DOI (0.3-3 mg/kg, i.p.) reduced EtOH intake and preference, but not total fluid or food intake; whereas mCPP (1-10 mg/kg, s.c.) reduced EtOH, total fluid, and food intake. Therefore, it is concluded that DOI induces a specific and selective antialcohol effect, whereas mCPP rather induces a general suppressive effect on consummatory behavior. Ritanserin (1-10 mg/kg, i.p.) did not affect EtOH intake and preference, nor total fluid and food consumption. MDL 100,907 (0.1-1 mg/kg, i.p.) induced only a small reduction of food intake at the highest dose tested. Pretreatment with ritanserin (3 mg/kg, i.p.) and MDL 100,907 (0.3 mg/kg, i.p.) blocked the effects of DOI (3 mg/kg, i.p.), but not those of mCPP (10 mg/kg, i.p.). It is suggested that activation of 5-HT2C and/or 5-HT1B receptors results in a general decrease of consummatory behavior, whereas activation of 5-HT2A receptors selectively decreases EtOH intake and preference, as assessed in the cAA rat model of alcoholism.
Maurel
S
S
CNS Research, Bayer AG, Cologne, Germany.
De Vry
J
J
De Beun
R
R
Schreiber
R
R
D000428:Alcohol Drinking / Q000503:physiopathology*; D000704:Analysis of Variance; D000818:Animals; D005260:Female; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D044302:Receptor, Serotonin, 5-HT1B; D044402:Receptor, Serotonin, 5-HT2A; D044405:Receptor, Serotonin, 5-HT2C; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*