Department of Neurology, University of Alabama at Birmingham, Birmingham, USA
Copyright © 2011 The Korean Movement Disorder Society
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Since 1979, induction of parkinsonism in non-human primates using dopamine antagonists and electrolytic lesions of the nigro-striatal pathway had not been associated with increased neuronal activity in the globus pallidus interna.5
In 1979, it was reported that globus pallidus interna neuronal activities initially were increased in non-human primates following induction of parkinsonism using n-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP), but the neuronal activities tended towards normal rates following MPTP while the animals were, presumably, still parkinsonian.6
Since 1986, careful induction of parkinsonism in non-human primates with MPTP did not produce changes in neuronal activities of the striatum, globus pallidus externa or ventrolateral thalamus as predicted by the Globus Pallidus Interna Rate theory.7 These observations were extended to the globus pallidus interna and reported in 2009.8
Since 1989, recordings of neuronal activity in the motor cortex and supplementary motor area demonstrate no changes in baseline or resting neuronal activities following induction of parkinsonism using MPTP.9–11
Recordings of neuronal activity in the subthalamic nucleus of patients with Parkinson’s disease and patients with epilepsy in 2006 demonstrate no change in mean discharge frequencies or in the variability (coefficient of variation) in the discharge rate. Further, the neuronal spike trains of both patients demonstrated the same random Poison process.12
DBS of the globus pallidus interna in non-human primates, of the type found therapeutic in humans, drives the output of the globus pallidus interna.1
DBS of the subthalamic nucleus in non-human primates and humans with Parkinson’s disease, of the type found therapeutic in humans, drives the output of the globus pallidus interna.2–4
DBS of the globus pallidus interna in humans drives the output of the globus pallidus interna as evidenced by recordings of ventrolateral thalamic neuronal recordings during globus pallidus interna DBS and yet the patient was not made parkinsonian.5
DBS of the subthalamic nucleus on one side of the brain causes increased neuronal activities in the contralateral subthalamic nucleus and yet, the parkinsonian symptoms ipsilateral to the stimulation in patients are improved and not worsened as would be expected from the Globus Pallidus Interna Rate theory.6
Preliminary studies of DBS of the globus pallidus interna on one side of the brain causes increased neuronal activities in the contralateral globus pallidus interna and yet, the parkinsonian symptoms ipsilateral to the stimulation in patients are improved and not worsened as would be expected from the Globus Pallidus Interna Rate (Montgomery Jr. EB, Walker HC and Watts RL, 2009 unpublished observations).
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