Evidence for specific involvement of 5-HT1A and 5-HT2A/C receptors in the expression of patterns of spontaneous motor activity of the rat.
The 5-HT1A and the 5-HT2A/C receptor agonists 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (0.006-0.4 mg kg-1 s.c.) and (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) (0.05-4.0 mg kg-1 s.c.), respectively, produced a similar stereotyped forward locomotion in rats, although the intensity of the behavioral change was considerably less with DOI. The stereotyped forward locomotion was accompanied by a slight decrease in total activity, suppression of rearing behavior and an increased activity in the periphery of the open-field arena. In support of receptor specificity, the effects of 8-OH-DPAT and DOI could be antagonised by pretreatment with the 5-HT1A/B and the 5-HT2A/C receptor antagonists (-)-pindolol (2 mg kg-1 s.c.) and ritanserin (2 mg kg-1 s.c.), respectively. In addition, (-)-pindolol, but not the selective beta-adrenoceptor antagonist betaxolol, markedly enhanced the behavioral effects produced by DOI. The nature of these specific actions and interactions in terms of pre- and post-synaptic serotonergic mechanisms remains an important question.
Hillegaart
V
V
Department of Biochemical and Behavioral Pharmacology, Södertälje, Sweden.
Estival
A
A
Ahlenius
S
S
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015784:Betaxolol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000145:classification / Q000187:drug effects*
D011985:Receptors, Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D015784:Betaxolol