title: Interactive effects of cholecystokinin-8S and various serotonin receptor agonists on the firing activity of neostriatal neuronesin rats.
abstract: In rats anaesthetized with urethane single unit activity was extracellularly recorded in the neostriatum, and several drugs were microiontophoretically ejected. Separate administration of the sulfated octapeptide cholecystokinin (CCK-8S), serotonin (5-HT) or 8-OH-DPAT (a 5-HT(1A/7) receptor agonist) predominantly induced increases in the neuronal discharge rates (Wilcoxon test significant P<0.05), whereas the 5-HT(2A/2C) receptor agonist DOI affected only a few neurones and mainly reduced firing. After coadministration of CCK-8S and serotonin, activating effects also predominated (Wt P<0.05), but the neuronal responsiveness was significantly reduced (Chi2P<0.01). Similarly, concomitant application of CCK-8S and 8-OH-DPAT led to significant activation accompanied with a reduction of inhibitory effects. The block of serotonin- or 8-OH-DPAT-effects through specific 5-HT(1A) receptor antagonists implies the involvement of this receptor subtype within the striatum. In conclusion, concomitant action of CCK-8S and serotonin induces a mean level of neuronal activation that might promote normal function.
authors.affiliation: Johannes-Mueller-Institute of Physiology, Charité, Humboldt University, Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Wilms
authors.forename: G
authors.initials: G
authors.lastname: Vierig
authors.forename: H
authors.initials: H
authors.lastname: Davidowa
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000737:chemistry / Q000494:pharmacology; D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002766:Cholecystokinin / Q000378:metabolism / Q000494:pharmacology*; D004594:Electrophysiology; D006801:Humans; D007215:Indophenol / Q000031:analogs & derivatives* / Q000494:pharmacology; D007478:Iontophoresis; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D017072:Neostriatum / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D010446:Peptide Fragments; D010879:Piperazines; D011725:Pyridines; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C410885:cholecystokinin 8; C113896:dimethoxy-4-indophenyl-2-aminopropane; D012701:Serotonin; D007215:Indophenol; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D002766:Cholecystokinin; D007650:Ketanserin