ISSN:
1432-1912
Schlagwort(e):
Dopamine
;
Noradrenaline
;
Nerve Impulses
;
Hemisection
;
Gammaydroxybutyric Acid
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary Both a unilateral, frontal section of the brain at the level of the caudal hypothalamus (hemisection) and systemic treatment with gammahydroxybutyric acid (GHBA, sodium form, 1.5 g/kg i.p.) increased the dopamine (DA) in the rat forebrain by about 70% in 1 h. Both procedures also markedly decelerated the α-methyltyrosine-induced DA disappearance. The brain noradrenaline was significantly lowered after the hemisection, but was not influenced by the treatment with GHBA given either alone or in combination with α-methyltyrosine. Intrastriatal injections of 25% KCl did not change the normal DA content significantly but prevented the increase in DA observed after hemisection or treatment with GHBA, probably due to a depolarization of the DA nerve terminals. Such a treatment with KCl also rapidly released the DA accumulated after hemisection. These effects were not seen after 20% NaCl. The same increase in forebrain DA, as produced by hemisection or treatment with GHBA, was also seen after injections of 25% KCl into the substantia nigra or injections of tetrodotoxin into the neostriatum. To judge from the turning of rats, unilateral injections of 25% KCl into the neostriatum depolarized the cells in this area, whereas stimulation of the DA receptors hyperpolarized them. The increases in brain DA described may be due to an inhibition of the nerve impulse flow to the DA nerve terminals.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00501479
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