Tonic Activation of NMDA Receptors Causes Spontaneous Burst Discharge of Rat Midbrain Dopamine NeuronsIn Vivo
| Autor: | Guy Chouvet, P. J. Charlety, Hideo Akaoka, Karima Chergui, Michel Buda, Torgny H. Svensson, Claude Saunier, J.-L. Brunet |
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| Přispěvatelé: | Centre de recherche en neurosciences de Lyon (CRNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 1993 |
| Předmět: |
Male
Dopamine [SDV]Life Sciences [q-bio] MESH: Neurons Kainate receptor MESH: Rats Sprague-Dawley Rats Sprague-Dawley chemistry.chemical_compound 0302 clinical medicine Kynurenic acid Mesencephalon MESH: Animals Neurons 0303 health sciences Kainic Acid MESH: Electrophysiology General Neuroscience Glutamate receptor Iontophoresis Electrophysiology MESH: N-Methylaspartate Ventral tegmental area medicine.anatomical_structure CNQX Excitatory postsynaptic potential MESH: Iontophoresis medicine.drug N-Methylaspartate MESH: Rats Neurotoxins Substantia nigra MESH: Dopamine Biology Receptors N-Methyl-D-Aspartate 03 medical and health sciences medicine Animals MESH: Neurotoxins 030304 developmental biology MESH: Receptors N-Methyl-D-Aspartate MESH: Quisqualic Acid Quisqualic Acid MESH: Mesencephalon MESH: Kainic Acid MESH: Male Rats nervous system chemistry Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | European Journal of Neuroscience European Journal of Neuroscience, Wiley, 1993, 5 (2), pp.137-144. ⟨10.1111/j.1460-9568.1993.tb00479.x⟩ |
| ISSN: | 1460-9568 0953-816X |
| DOI: | 10.1111/j.1460-9568.1993.tb00479.x |
| Popis: | International audience; Midbrain dopamine neurons in vivo discharge in a single-spike firing pattern or in a burst-firing pattern. Such activity in vivo strikingly contrasts with the pacemaker activity of the same dopamine neurons recorded in vitro. We have recently shown that burst activity in vivo of midbrain dopamine neurons is due to the local activation of excitatory amino acid receptors, as microapplication of the broad-spectrum antagonist of excitatory amino acids, kynurenic acid, strongly regularized the spontaneous firing pattern of these dopamine neurons. In the present study, we investigated which subtypes of excitatory amino acid receptors are involved in the burst-firing of midbrain dopamine neurons in chloral hydrate-anaesthetized rats, iontophoretic or pressure microejections of 6-cyano, 7-nitroquinoxaline-2,3-dione (CNQX), a non-N-methyl-D-aspartate (NMDA) receptor antagonist, did not alter the spontaneous burst firing of dopamine neurons (n = 36). In contrast, similar ejections of (+-)2-amino,5-phosphonopentanoic acid (AP-5), a specific antagonist at NMDA receptors, markedly regularized the firing pattern by reducing the occurrence of bursts (n = 52). In addition, iontophoretic ejections of NMDA, but not kainate or quisqualate, elicited a discharge of these dopamine neurons in bursts (n = 20, 12 and 14, respectively). These data suggest that burst-firing of midbrain dopamine neurons in vivo results from the tonic activation of NMDA receptors by endogenous excitatory amino acids. In view of the critical dependency of catecholamine release on the discharge pattern of source neurons, excitatory amino acid inputs to midbrain dopamine neurons may constitute a major physiological substrate in the control of the dopamine level in target areas. |
| Databáze: | OpenAIRE |
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