Further evidence for a functional dorsal-ventral division of the rat striatum: GABAergic involvement in oral movements.
Interactions between the gamma-aminobutyric acid (GABA)ergic system and the dopaminergic and cholinergic systems in the control of jaw movements, measured with a phototransducer system, were investigated in both dorsal and ventral regions of the rat striatum. Muscimol (25 and 50 ng/0.2 microliters) injected into the dorsal striatum did not affect jaw movements induced by apomorphine (0.2 mg/kg i.v.) or pilocarpine (4 mg/kg i.v.), but when injected into the ventral striatum it inhibited these jaw movements and those induced by carbachol (1 micrograms/0.2 microliters) injected into the ventral striatum. Picrotoxin (250 and 500 ng/0.2 microliters) injected into the dorsal striatum enhanced the effects of apomorphine (0.2 mg/kg) but not those of pilocarpine. When injected into the ventral striatum, picrotoxin did not affect apomorphine-induced oral movements but enhanced the effects of pilocarpine and carbachol. The benzodiazepine, flunitrazepam (100 ng/0.2 microliters), had no effect when injected in the dorsal striatum, and showed some inhibitory effects on dopaminergic and cholinergic oral movements when injected in the ventral striatum. The results suggest that the striatal GABAergic inhibitory effect on dopaminergic and cholinergic function is regionally specific, supporting a dorsal/ventral functional division of the rat striatum. The results also suggest that oral movements induced by dopaminergic and cholinergic drugs are distinct forms of repetitive oral behaviour.
Kikuchi de Beltrán
K
K
Department of Pharmacology, Nihon University School of Dentistry, Tokyo, Japan.
Koshikawa
N
N
Miwa
Y
Y
Kobayashi
M
M
Stephenson
J D
JD
D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D001549:Benzamides / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D002217:Carbachol / Q000008:administration & dosage / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D005445:Flunitrazepam / Q000494:pharmacology; D007568:Jaw / Q000502:physiology*; D008297:Male; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology*; D019832:N-Methylscopolamine; D010852:Picrotoxin / Q000008:administration & dosage / Q000494:pharmacology*; D010862:Pilocarpine / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012602:Scopolamine Derivatives / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D001058:Apomorphine; D001549:Benzamides; D001552:Benzazepines; D002217:Carbachol; D004298:Dopamine; D005445:Flunitrazepam; D009118:Muscimol; D019832:N-Methylscopolamine; D010852:Picrotoxin; D010862:Pilocarpine; D012602:Scopolamine Derivatives; D005680:gamma-Aminobutyric Acid; C030265:nemonapride