Unilateral neostriatal kainate, but not 6-OHDA, lesions block dopamine agonist-induced ascorbate release in the neostriatum of freely moving rats.
Unilateral kainate lesions of the neostriatum and 6-hydroxydopamine (6-OHDA) lesions of the medial forebrain bundle were used to assess the role of neostriatal and ascending dopaminergic neurons, respectively, on dopamine-agonist induced release of neostriatal ascorbate as measured voltammetrically in freely moving rats. Electrochemically modified, carbon-fiber electrodes recorded the effects of direct (a combination of 10 mg/kg SKF-38393 and 1.0 mg/kg quinpirole) as well as indirect (2.5 mg/kg D-amphetamine or 20.0 mg/kg GBR-12909) dopamine agonists. Relative to controls, kainate, but not 6-OHDA, lesions abolished the ability of both direct and indirect dopamine agonists to induce neostriatal ascorbate release. These results suggest that unlike dopaminergic afferents, neostriatal output pathways play a critical role in the modulation of neostriatal ascorbate levels.
Pierce
R C
RC
Department of Psychology, Indiana University, Bloomington 47405.
Miller
D W
DW
Reising
D B
DB
Rebec
G V
GV
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D001933:Brain Stem / Q000502:physiology*; D004566:Electrodes; D007608:Kainic Acid; D008297:Male; D009068:Movement / Q000502:physiology; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009434:Neural Pathways / Q000187:drug effects; D016627:Oxidopamine; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000187:drug effects*
D011954:Receptors, Dopamine; D016627:Oxidopamine; D001205:Ascorbic Acid; D007608:Kainic Acid