Neostriatal neurons of rats can be influenced by cholecystokinin-A receptor agonists.
The present study investigated the effects of agonists of the neuropeptide cholecystokinin (CCK) on neostriatal neurons in order to confirm the existence of CCK-A receptors in the rat caudate-putamen. Single unit activity was recorded in rats anaesthetized with urethane. The CCK-A receptor agonists A-71378 (desamino-Tyr(SO3H)-Nle-Gly-Trp-Nle-(N-methyl)Asp-Phe-NH2), and A-71623 (Boc-Trp-Lys(epsilon-N-2-methylphenylamino-carbonyl)-Asp-(N-methyl )Phe-NH2, as well as the CCK-B receptor agonist Suc-CCK-4 (Suc-Trp-(N-methyl)Nle-Asp-Phe-NH2) were iontophoretically administered with multibarrel capillaries. About one-third of the neurons responded to the CCK-A receptor agonists. Excitatory effects predominated. The CCK-B receptor agonist also induced mainly increases in the neuronal firing. Several neurons were affected by both types of agonists. The results suggest that in the rat neostriatum not only CCK-B receptors, but also CCK-A receptors seem to mediate the effects of cholecystokinin.
Davidowa
H
H
Institute of Physiology, Faculty of Medicine (Charité), Humboldt University Berlin, Germany. davidowa@charite.hu-berlin.de
Wetzel
K
K
Henklein
P
P
D000818:Animals; D004594:Electrophysiology; D008297:Male; D017072:Neostriatum / Q000166:cytology*; D009474:Neurons / Q000737:chemistry* / Q000187:drug effects; D009842:Oligopeptides / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin / Q000819:agonists*; D013758:Tetragastrin / Q000031:analogs & derivatives / Q000494:pharmacology
D009842:Oligopeptides; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin; D013758:Tetragastrin; C063897:A 71378; C066278:A 71623