Activation of subthalamic neurons produces NMDA receptor-mediated dendritic dopamine release in substantia nigra pars reticulata: a microdialysis study in the rat

• Published in: Brain research Vol. 645; no. 1; pp. 335 - 337
• Main Authors: Rosales, Manuel G., Flores, Gonzalo, Hernández, Salvador, Martínez-Fong, Daniel, Aceves, Jorge
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 09.05.1994; Amsterdam Elsevier; New York, NY
• Subjects: Animals; Biological and medical sciences; Brain microdialysis; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Dendrites - metabolism; Dopamine; Dopamine - metabolism; Dopamine release; Fundamental and applied biological sciences. Psychology; Glutamate; Glutamate receptor; Male; Microdialysis; NMDA receptor; Rats; Rats, Wistar; Receptors, N-Methyl-D-Aspartate - physiology; Substantia nigra; Substantia Nigra - metabolism; Subthalamic nucleus; Thalamic Nuclei - cytology; Thalamic Nuclei - physiology; Vertebrates: nervous system and sense organs; Dopamine; Dopamine release; Substantia nigra; Glutamate receptor; Subthalamic nucleus; Brain microdialysis; Glutamate; NMDA receptor; Rat; Rodentia; Central nervous system; Catecholamine; Vertebrata; Mammalia; Locus niger; Microdialysis; Neurotransmitter; Release; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/0006-8993(94)91669-1

Here we have studied whether the activation of the subthalamic neurons induces the release of dopamine (DA) from dopaminergic dendrites in the pars reticulata of the substantia nigra. Subthalamic neurons were activated by carbachol microinjected into the subthalamic nucleus. A microdialysis probe was implanted in the medial aspect of the pars reticulata to collect samples of the perfusate. Carbachol (1 μg/0.25 μl saline) enhanced (58 ± 8% over basal values) nigral DA release. The enhancement was fully blocked by the NMDA antagonist AP5 added to the microdialysis medium perfusing the pars reticulata. Perfusion of the pars reticulata with NMDA also increased (125 ± 25% over basal) nigral DA release. Again, AP5 reversed the effect. These results suggest that activation of the glutamatergic subthalamonigral pathway enhances dendritic DA release by activating NMDA receptors present on dopaminergic dendrites.