Pallidal border cells: an anatomical and electrophysiological study in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated monkey.
A dopamine transporter-radioligand binding study demonstrated a dopaminergic innervation around the pallidal complex in the normal monkey (n=5), i.e. where a subpopulation of pallidal neurons known as "border cells" is classically identified. Surprisingly, this peripallidal binding persists in monkeys rendered parkinsonian (n=5) with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment. The border cell electrophysiological activity was then analysed in normal and parkinsonian monkeys (n=2), either in the untreated state or following administration of levodopa. Pallidal border cell firing frequency was significantly decreased after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment (8.9+/-0.7 vs 31.4+/-1.6Hz, P<0.05). This decrease was partly corrected by levodopa administration (19.2+/-1.0Hz, P<0.05 vs both normal and parkinsonian situations). The peripallidal dopaminergic innervation suggests that pallidal border cells are under a direct dopaminergic control, arising from the ventral tegmental area and/or the basal forebrain magnocellular complex, the role of which remains unknown. Moreover, the relative sparing of these dopaminergic fibers in parkinsonian monkeys suggests that they would exhibit specific adaptive properties totally different from those described in the nigrostriatal pathway.
Bezard
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Manchester Movement Disorder Laboratory, Division of Neuroscience, School of Biological Sciences, University of Manchester, 1.124 Stopford Building, Manchester M13 9PT, UK. erwan.bezard@umr5543.u-bordeaux2.fr
Boraud
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T
Chalon
S
S
Brotchie
J M
JM
Guilloteau
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D
Gross
C E
CE
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D000818:Animals; D000978:Antiparkinson Agents / Q000627:therapeutic use; D002352:Carrier Proteins / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D015259:Dopamine Agents; D050483:Dopamine Plasma Membrane Transport Proteins; D004594:Electrophysiology; D005260:Female; D005917:Globus Pallidus / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D007980:Levodopa / Q000627:therapeutic use; D008251:Macaca; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D010302:Parkinson Disease, Secondary / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D011869:Radioligand Assay
D000978:Antiparkinson Agents; D002352:Carrier Proteins; D015259:Dopamine Agents; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D007980:Levodopa; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D004298:Dopamine