Behavioural effects of serotonin agonists and antagonists in the rat and marmoset.

Abstract

The present study was conducted to investigate the effects of various 5-hydroxytryptamine (5-HT) agonists and antagonists on motor behaviour in rats and marmosets. Various motor-based responses were assessed after central or peripheral administration of 5-HT agents to rats and marmosets. Drugs acting as agonists at the 5-HT1A receptor (8-OHDPAT, gepirone, BMY-7378, NAN-190, PAPP (LY165163) and flesinoxan) and 5-HT2/1C receptors (DOI) were found to reverse neuroleptic-induced catalepsy in the rat whereas 5-HT2/1C antagonists (mianserin, ritanserin and ICI-170,809) and the 5-HT1 antagonist ((+/-)pindolol) increased catalepsy. Agonists acting at 5-HT3 receptors (phenylbiguanide and 2-methyl-5-HT) had no effect on catalepsy. The putative 5-HT1A antagonist, (+/-) pindolol, attenuated the reversal of catalepsy by 8-OHDPAT. Although both 8-OHDPAT and BMY-7378 were tested, only the latter was found to reduce apomorphine-induced stereotypy. Bilateral or unilateral infusions of 8-OHDPAT, BMY-7378 or pindolol into the substantia nigra of non-lesioned rats had no effect on spontaneous locomotor or rotational activity, respectively. However, 8-OHDPAT and BMY-7378 were found to increase or decrease motor activity, after injection into the median or dorsal raphe nuclei, respectively. Finally, 8-OHDPAT and BMY-7378 were found to be inactive against MPTP-induced bradykinesia in the marmoset. It is concluded that both 5-HT1A and 5-HT2/1C receptors are involved in the anti-cataleptic effects of 5-HT agents. The 5-HT1A receptors are probably situated within the raphe, whereas the location of the 5-HT2/1C receptors remains undetermined.

• Authors: P J Elliott, D M Walsh, S P Close, G A Higgins, A G Hayes
• Journal: Neuropharmacology (Neuropharmacology) Vol. 29 Issue 10 Pg. 949-56 (Oct 1990) ISSN: 0028-3908 [Print] England
• PMID: 2123971 (Publication Type: Journal Article)

Chemical References

• Psychotropic Drugs
• Receptors, Serotonin
• Serotonin Antagonists

Topics

• Animals
• Brain (drug effects, physiology)
• Callitrichinae
• Catalepsy
• Female
• Male
• Motor Activity (drug effects)
• Organ Specificity
• Psychotropic Drugs (pharmacology)
• Rats
• Receptors, Serotonin (drug effects, physiology)
• Rotation
• Serotonin Antagonists (pharmacology)
• Species Specificity
• Stereotyped Behavior (drug effects)