Effect of serotonergic drugs on negative contrast in consummatory behavior.
The effect of acute and chronic administration of the 5-HT1A agonist buspirone on successive negative contrast was investigated in Experiments 1-6. Contrast in consummatory behavior was induced by shifting rats from a 32% to a 4% sucrose solution. Experiments 1-5 showed that buspirone (0.125, 0.25, 0.5, 1.0, 2.0, 15.0 mg/kg) was ineffective in alleviating contrast or in facilitating recovery from contrast. The 15 mg/kg dose substantially decreased consummatory responding. Experiment 6 showed that the chronic (24 days) administration of buspirone (0.5, 2.0 mg/kg) also did not alleviate contrast. The chronic, but not the acute administration of the 2.0 mg/kg dose decreased consummatory behavior. In Experiment 7 the 5-HT1A agonist gepirone (2.5, 5.0 and 10.0 mg/kg) was also found to be ineffective in reducing contrast but, at the higher doses, decreased overall sucrose intake. Experiments 8 and 9 found that the 5-HT2 antagonists ketanserin (2.0 and 8.0 mg/kg) and ritanserin (0.63 and 2.5 mg/kg) also did not alleviate contrast. Midazolam (1.0 mg/kg), included as a positive control, eliminated contrast. These data suggest that serotonergic mechanisms are not involved in negative contrast.
Flaherty
C F
CF
Psychology Department, Rutgers University, New Brunswick, NJ 08903.
Grigson
P S
PS
Demetrikopoulos
M K
MK
Weaver
M S
MS
Krauss
K L
KL
Rowan
G A
GA
D000818:Animals; D002065:Buspirone / Q000494:pharmacology; D002707:Chlordiazepoxide / Q000494:pharmacology; D003533:Cyproheptadine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects*; D010134:Fenclonine / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008874:Midazolam / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D016713:Ritanserin; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology
D010880:Piperidines; D011743:Pyrimidines; D012702:Serotonin Antagonists; D016713:Ritanserin; D003533:Cyproheptadine; D012701:Serotonin; D000431:Ethanol; D002707:Chlordiazepoxide; D007650:Ketanserin; C039979:gepirone; D010134:Fenclonine; D008874:Midazolam; D002065:Buspirone