title: Subthalamic nucleus modulates burst firing of nigral dopamine neurones via NMDA receptors.
abstract: The role of the subthalamic nucleus in the burst firing of dopamine neurones of the substantia nigra was investigated using extracellular single unit recordings combined with pressure or iontophoretic micro-injections in anaesthetized rats. Inhibition of subthalamic neurones by pressure injection of gamma-aminobutyric acid (GABA) regularized the burst firing pattern in eight out of 17 dopamine neurones. Bicuculline injection near subthalamic neurones increased their firing rate and increased burst discharge in a subpopulation of dopamine neurones tested (34 out of 102). The increase was depressed by iontophoresis of the N-methyl-D-aspartate (NMDA) antagonist (+-)2-amino,5-phosphonopentanoic acid (AP-5), but not of the non-NMDA antagonist, 6-cyano,7-nitroquinoxaline-2,3-dione (CNQX). These data suggest that the subthalamic nucleus promotes burst discharge in a subpopulation of substantia nigra dopamine neurones via NMDA receptors.
authors.affiliation: INSERM U 171 and CNRS URA 1195, Centre Hospitalier Lyon Sud, Pierre-Bénite, France.
authors.forename: K
authors.initials: K
authors.lastname: Chergui
authors.forename: H
authors.initials: H
authors.lastname: Akaoka
authors.forename: P J
authors.initials: PJ
authors.lastname: Charléty
authors.forename: C F
authors.initials: CF
authors.lastname: Saunier
authors.forename: M
authors.initials: M
authors.lastname: Buda
authors.forename: G
authors.initials: G
authors.lastname: Chouvet
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D001640:Bicuculline / Q000008:administration & dosage / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004594:Electrophysiology; D007478:Iontophoresis; D008297:Male; D008845:Microinjections; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017459:Receptors, Amino Acid / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology*; D013378:Substantia Nigra / Q000166:cytology / Q000502:physiology*; D013787:Thalamic Nuclei / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D017459:Receptors, Amino Acid; D016194:Receptors, N-Methyl-D-Aspartate; D005680:gamma-Aminobutyric Acid; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; D004298:Dopamine; D001640:Bicuculline