Extracellular taurine in the substantia nigra: Taurine-glutamate interaction

• Published in: Journal of neuroscience research 2004-05, Vol.76 (4), p.528-538
• Main Authors: García Dopico, José, Perdomo Díaz, Juan, Alonso, Teofilo Jorge, González Hernández, Tomás, Castro Fuentes, Rafael, Rodríguez Díaz, Manuel
• Format: Article
• Language: English
• Subjects: Adrenergic Agents - toxicity; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid - analysis; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid - pharmacology; Animals; Aspartic Acid - analysis; Brain Chemistry; Calcium - metabolism; Chelating Agents - pharmacology; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Drug Interactions; Egtazic Acid - pharmacology; Excitatory Amino Acid Antagonists - toxicity; Extracellular Space - metabolism; GABA; gamma-Aminobutyric Acid - metabolism; glutamate; Glutamic Acid - metabolism; Kainic Acid - analysis; Ketamine - toxicity; Male; Membrane Potentials - drug effects; Microdialysis - methods; N-Methylaspartate - analysis; N-Methylaspartate - pharmacology; Oxidopamine - toxicity; Parkinson's disease; Potassium - pharmacology; Rats; Rats, Sprague-Dawley; substantia nigra; Substantia Nigra - drug effects; Substantia Nigra - metabolism; taurine; Taurine - metabolism; Time Factors; zinc; Zinc - pharmacology
• ISSN: 0360-4012; 1097-4547
• DOI: 10.1002/jnr.20108

Taurine has been proposed as an inhibitory transmitter in the substantia nigra (SN), but the mechanisms involved in its release and uptake remain practically unexplored. We studied the extracellular pool of taurine in the rat's SN by using microdialysis methods, paying particular attention to the taurine–glutamate (GLU) interaction. Extracellular taurine increased after cell depolarization with high‐K+ in a Ca2+‐dependent manner, being modified by the local perfusion of GLU, GLU receptor agonists, and zinc. Nigral administration of taurine increased the extracellular concentration of γ‐aminobutyric acid (GABA) and GLU, the transmitters of the two main inputs of the SN. The modification of the glial metabolism with fluocitrate and L‐methionine sulfoximine also changed the extracellular concentration of taurine. The complex regulation of the extracellular pool of taurine, its interaction with GABA and GLU, and the involvement of glial cells in its regulation suggest a volume transmission role for taurine in the SN. © 2004 Wiley‐Liss, Inc.