Modulation of striatal aspartate and dynorphin B release by cholecystokinin (CCK-8) studied in vivo with microdialysis.
Sulphated cholecystokinin-8 (CCK-8) given into the neostriatum of the rat by in vivo microdialysis produced a concentration-dependent (1-100 microM) increase in extracellular aspartate (Asp) and dynorphin B (Dyn B), but not in glutamate, GABA or dopamine levels. The increase in Asp levels produced by 10 microM CCK-8 was approximately 10 fold and was inhibited (approximately 50%) by the CCKB antagonist L-365,260 (20 mg kg-1, i.p.), while the increase in Dyn B (approximately 2 fold) was totally abolished. Both increases were inhibited (approximately 50%) by local infusion of 10 microM of tetrodotoxin (TTX). Thus, CCK exerts modulatory effects in the basal ganglia, possibly by interacting with local neostriatal neurones releasing Asp, and with Dyn B-containing neurones projecting to the pars reticulata of the substantia nigra.
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Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Pettersson
E
E
Herrera-Marschitz
M
M
Hökfelt
T
T
Terenius
L
L
Nylander
I
I
Goiny
M
M
Hughes
J
J
O'Connor
W T
WT
Ungerstedt
U
U
D000818:Animals; D001224:Aspartic Acid / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001570:Benzodiazepinones / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D004399:Dynorphins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004723:Endorphins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D010671:Phenylurea Compounds; D051381:Rats; D017207:Rats, Sprague-Dawley; D011949:Receptors, Cholecystokinin / Q000037:antagonists & inhibitors; D012844:Sincalide / Q000494:pharmacology*; D013779:Tetrodotoxin / Q000494:pharmacology
D001570:Benzodiazepinones; D004723:Endorphins; D010671:Phenylurea Compounds; D011949:Receptors, Cholecystokinin; D001224:Aspartic Acid; C058121:L 365260; D013779:Tetrodotoxin; D004399:Dynorphins; C036200:rimorphin; D012844:Sincalide