Median raphe, but not dorsal raphe, application of the 5-HT1A agonist 8-OH-DPAT stimulates rat motor activity.
Local application of the selective 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) in the median raphe of rats caused locomotor stimulation. In contrast, dorsal raphe application of the compound induced flat body posture, which was discontinuous and not dose-dependent, and therefore distinct from that characteristic for postsynaptic 5-HT receptor-mediated behaviour. Injection of 8-OH-DPAT into the dorsal raphe or median raphe caused neither forepaw treading nor head-weaving; stiff tail and sniffing occurred inconsistently. By activating somatodendritic 5-HT1A autoreceptors in the median raphe, 8-OH-DPAT may disinhibit locomotor-enforcing neural pathways that receive 5-HT afferents from this nucleus. The data suggest that median raphe and dorsal raphe 5-HT neurons have different roles in motor control.
Hillegaart
V
V
Department of Psychology, University of Göteborg, Sweden.
Hjorth
S
S
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009281:Naphthalenes / Q000494:pharmacology*; D011903:Raphe Nuclei / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects*; D013268:Stimulation, Chemical; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*
D009281:Naphthalenes; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin