TY - JOUR T1 - DOPAMINERGIC NEURONS: SIMILAR BIOCHEMICAL AND HISTOCHEMICAL EFFECTS OF γ-HYDROXYBUTYRATE AND ACUTE LESIONS OF THE NIGRONEOSTRIATAL PATHWAY JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 630 LP - 639 VL - 186 IS - 3 AU - JUDITH R. WALTERS AU - ROBERT H. ROTH AU - GEORGE K. AGHAJANIAN Y1 - 1973/09/01 UR - http://jpet.aspetjournals.org/content/186/3/630.abstract N2 - γ-Hydroxybutyrate (GHB) and its precursor, γ-butyrolactone (GBL) administered in anesthetic doses have been shown to cause a rapid increase in neostriatal dopamine (DA) levels without haveing similar effects on other brain monoamines. The time course of this effect on DA has been correlated with the behavioral effects and brain levels of the drug. This study reports that high frequency electrothermic lesions placed in the nigro-neostriatal DA pathway of the rat caused a similar increase in neostriatal DA; an 80% increase was seen within 30 minutes. Histochemical fluorescence observations indicated that the site of increase in DA fluorescence observed on the side of the brain with the lesion was similar to that observed after GBL treatment. Biochemical studies with αmethyl-p-tyrosine indicated that after both GBL administration and axotomy, the increased DA levels seem protected from release and/or metabolism. Extracellular recording experiments indicated that GHB and GBL administered parenterally inhibit the firing of the units localized to the DA-containing cells of the substantia nigra. These results suggest that the increase in DA in the neostriatum caused by both GHB and electrothermic lesioning of the DA pathway results from an inhibition of impulse flow in the nigro-neostriatal pathway. © 1973 by The Williams & Wilkins Co. ER -