The entopeduncular nucleus regulates muscle tone in genetically spastic rats: role of substance P and gamma-aminobutyric acid.
Microinjections of the substance P (SP) antagonist (D-pro2,D-phe7,D-trp9)-SP, or the gamma-aminobutyric acid (GABA) agonist, muscimol, into the entopeduncular nucleus reduced muscle tone in genetically spastic rats in a dose- and time-dependent manner. Similar injections into the ventral thalamus, zona incerta or amygdala had no effect on muscle tone. The muscle relaxant effect of (D-pro2,D-phe7,D-trp9)-SP injected into the entopeduncular nucleus was blocked by co-injections of SP, and that of muscimol by the GABAA antagonist, bicuculline methiodide. These results suggest that SP- and GABA-dependent mechanisms in the entopeduncular nucleus mediate regulation of the muscle tone.
Max-Planck-Institute for Experimental Medicine, Göttingen, F.R.G.
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L
Turski
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Klockgether
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Turski
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Schwartz
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Sontag
D000818:Animals; D005260:Female; D005917:Globus Pallidus / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D009128:Muscle Spasticity / Q000503:physiopathology*; D009129:Muscle Tonus / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism / Q000502:physiology*
D009118:Muscimol; D013373:Substance P; D005680:gamma-Aminobutyric Acid; C041817:substance P, Pro(2)-Phe(7)-Trp(9)-