Fetal mesencephalic grafts influence the dopamine release in the non-lesioned striatum of 6-OHDA-lesioned rats: a behavioral and in vivo voltammetric study.
This study was performed to investigate the effect of intraventricular fetal mesencephalic grafts on the non-lesioned nigro-striatal system of rats with unilateral lesions of dopaminergic neurones in the medial forebrain bundle and to analyze the involvement of the non-lesioned side in functional recovery due to grafts in this model. Grafts placed to the lesioned striatum produced a continuous decrease of apomorphine (APO, 0.25 mg/kg intraperitoneally (i.p.)) and amphetamine (AMPH, 5 mg/kg, i.p.) induced rotations over 7 months after grafting. Using differential pulse voltammetry (DPV) in anaesthetized and pargyline (75 mg/kg, i.p.) pretreated rats we found that 8 months after grafting in the lesioned striatum AMPH (5 mg/kg, i.p.) produced a higher increase of the dopamine (DA) signal (i.e., it became measurable), whereas in the non-lesioned striatum the same treatment produced a smaller increase of the DA signal, both compared to that in sham-grafted controls. After grafting onto the non-lesioned striatum, only a slight decrease of APO-induced rotations was observed, whereas AMPH-induced rotations were increased. In these animals AMPH did not produce a measurable DA signal in the lesioned striatum. The DA signal in the non-lesioned striatum was slightly higher than that of non-grafted controls. These results show clearly that unilateral fetal mesencephalic grafts producing behavioural recovery in the unilateral 6-OHDA model of the rat produce changes at dopaminergic mechanisms in the non-lesioned striatum.
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Institute of Pharmacology and Toxicology, Medical Faculty (Charité), Humboldt-University at Berlin, FRG.
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D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D016380:Brain Tissue Transplantation / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism*; D004594:Electrophysiology; D005260:Female; D016332:Fetal Tissue Transplantation / Q000502:physiology*; D008297:Male; D008636:Mesencephalon / Q000637:transplantation*; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D016627:Oxidopamine / Q000494:pharmacology*; D010293:Pargyline / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar
D016627:Oxidopamine; D010293:Pargyline; D000661:Amphetamine; D001058:Apomorphine; D004298:Dopamine