Behavioral and biochemical studies in monkeys made hemiparkinsonian by MPTP.
Monkeys were required to press a lever rapidly for food, using either the right or the left hand. After stable baseline performance was established, MPTP (N-methyl-4-phenyl-2,3,5,6-tetrahydropyridine) was injected into the internal carotid of one side via a transfemoral catheter. The onset and time course of clinically severe, Parkinson-like symptoms were paralleled by a significant decrease of bar-pressing activity in the side contralateral to injection, while the forelimb in the unaffected side continued normal pressing. The unilaterality of effects was confirmed biochemically after sacrifice by a 95% drop in striatal dopamine (DA) levels of the injected compared to the uninjected hemisphere. The results show that hemiparkinsonism achieved by carotid injection is very stable; that normal motor behavior is maintained on the unaffected side and that goal-achieving strategies remain active, but that the affected side is unable to execute the task unless extrinsic levodopa is provided.
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D000818:Animals; D002339:Carotid Arteries; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D007269:Injections, Intra-Arterial; D008252:Macaca fascicularis; D009048:Motor Skills / Q000187:drug effects*; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology*; D011725:Pyridines / Q000008:administration & dosage*
D011725:Pyridines; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D004298:Dopamine