Abstract
Drugs with different intrinsic activity at 5-HT1A receptors and antagonists at 5-HT 2A 2C and 5-HT3 receptors were studied for their ability to increase the rates of punished operant responding in rats. Like chlordiazepoxide (5 and 10 mg/kg) and diazepam (1.25 and 2.5 mg/kg), 0.125 mg/kg 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A receptor agonist, and 5 and 10 mg/kg ipsapirone, a partial agonist at these receptors, increased the rates of punished responding, whereas (S)-WAY 100135, a 5-HT1A receptor antagonist, had no effect at doses from 1 to 10 mg/kg. 8-OH-DPAT and ipsapirone, like benzodiazepines, significantly reduced unpunished responding. The 5-HT 2A 2C receptor antagonists ritanserin (2 mg/kg), mianserin (8 mg/kg), and mesulergine (0.1 mg/kg) significantly increased the rates of punished responding, whereas 0.5-2 mg/kg ketanserin, that has higher affinity for 5-HT2A than 5-HT2C receptors, had no effect. Antagonists, at 5-HT3 receptors such as ondansetron (0.001-0.1 mg/kg) and tropisetron (0.001-0.1 mg/kg), had no effect on punished or unpunished responding. The results show that agents acting as full or partial agonists at 5-HT1A receptors and blockers of postsynaptic 5-HT2C receptors have anxiolytic-like effects in a model of punished operant responding, whereas antagonists at 5-HT1A and 5-HT3 receptors have no such effect.
Original language | English |
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Pages (from-to) | 671-676 |
Number of pages | 6 |
Journal | Pharmacology, Biochemistry and Behavior |
Volume | 52 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1995 |
Keywords
- 5-HT receptors
- 5-HT receptors
- 5-HT receptors
- Anxiolytic activity
- Benzodiazepines
- Operant conflict
- Punishment
ASJC Scopus subject areas
- Biochemistry
- Clinical Biochemistry
- Behavioral Neuroscience
- Biological Psychiatry
- Pharmacology
- Toxicology