Inhibitory effects of cholecystokinin on rat's geniculate activity can be blocked by GABA-antagonists.
Cholecystokinin applied iontophoretically as the sulfated octapeptide (CCK-8S) or as highly selective CCKA- and CCKB-agonists induced excitatory as well as inhibitory effects on dorsal lateral geniculate unit activity. Inhibitory effects of CCK could be abolished by administration of GABAergic antagonists, especially bicuculline. Therefore, interneurons seem to be largely excited by CCK, and in this way, they appear to mediate the inhibition of the discharge rate in geniculate relay cells induced by CCK.
Department of Neurophysiology, Faculty of Medicine (Charité), Humboldt University Berlin, Germany.
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Albrecht
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Zippel
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Henklein
D000818:Animals; D001418:Baclofen / Q000031:analogs & derivatives / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D002766:Cholecystokinin / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D005110:Extracellular Space / Q000187:drug effects; D018756:GABA Antagonists / Q000494:pharmacology*; D005829:Geniculate Bodies / Q000187:drug effects*; D007395:Interneurons / Q000187:drug effects; D007478:Iontophoresis; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014343:Trypan Blue
D018756:GABA Antagonists; C052329:phaclofen; D002766:Cholecystokinin; D001418:Baclofen; D014343:Trypan Blue; D001640:Bicuculline