title: Increased subthalamic neuronal activity after nigral dopaminergic lesion independent of disinhibition via the globus pallidus.
abstract: Electrophysiological records of unit activity were used to compare the effects of excitotoxic pallidal lesions and 6-hydroxydopamine-induced damage to the midbrain dopaminergic neurons on the discharge rates and patterns of the subthalamic neurons. Removal of the pallidal input induced a slight, but statistically significant, increase (19.5%) in the discharge rate and no change in the firing pattern when compared to control animals. The rats with a dopaminergic lesion showed greater increase (105.7%) while the firing pattern activity of the subthalamic neurons became more irregular, with burst. These results indicate that the increased activity of the subthalamic neurons following a midbrain dopaminergic lesion cannot be due solely to inhibition-disinhibition involving the striato-pallido-subthalamic pathway and induced by the striatal dopaminergic depletion.
authors.affiliation: Laboratoire de Pharmacologie, Faculté des Sciences Pharmaceutiques et Biologiques, Université R. Descartes, Paris, France.
authors.forename: O K
authors.initials: OK
authors.lastname: Hassani
authors.forename: M
authors.initials: M
authors.lastname: Mouroux
authors.forename: J
authors.initials: J
authors.lastname: Féger
mesh_terms: D000818:Animals; D004298:Dopamine / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage / Q000633:toxicity; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005917:Globus Pallidus / Q000502:physiology*; D007051:Ibotenic Acid / Q000008:administration & dosage / Q000633:toxicity; D008297:Male; D008845:Microinjections; D009474:Neurons / Q000502:physiology*; D016627:Oxidopamine / Q000008:administration & dosage / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000502:physiology*; D013565:Sympatholytics / Q000008:administration & dosage / Q000633:toxicity; D013787:Thalamic Nuclei / Q000166:cytology / Q000502:physiology*
chemical_list: D018690:Excitatory Amino Acid Agonists; D013565:Sympatholytics; D007051:Ibotenic Acid; D016627:Oxidopamine; D004298:Dopamine