Multiple mechanisms of transmitter release evoked by ‘pathologically’ elevated extracellular [K+]: involvement of transporter reversal and mitochondrial calcium

• Published in: Journal of neurochemistry Vol. 80; no. 4; pp. 706 - 714
• Main Authors: Raiteri, Luca, Stigliani, Sara, Zedda, Luca, Raiteri, Maurizio, Bonanno, Giambattista
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science, Ltd 01.02.2002; Blackwell
• Subjects: Animals; Anticonvulsants - pharmacology; Biochemistry and metabolism; Biological and medical sciences; Brain Chemistry; Ca2+ exchanger; Ca2+ pools; Calcium - metabolism; Carrier Proteins - antagonists & inhibitors; carrier‐mediated release; Central nervous system; Cerebral Cortex - chemistry; Chelating Agents - pharmacology; Clonazepam - analogs & derivatives; Clonazepam - pharmacology; Dose-Response Relationship, Drug; Enzyme Inhibitors - pharmacology; exocytosis; Exocytosis - drug effects; Extracellular Space - chemistry; Fluorescent Dyes; Fundamental and applied biological sciences. Psychology; GABA Plasma Membrane Transport Proteins; GABA release; gamma-Aminobutyric Acid - chemistry; gamma-Aminobutyric Acid - metabolism; K+ depolarization; Male; Membrane Proteins - antagonists & inhibitors; Membrane Transport Proteins; mitochondrial Na+; Nicotinic Acids - pharmacology; Organic Anion Transporters; Potassium Chloride - chemistry; Potassium Chloride - pharmacology; Rats; Rats, Sprague-Dawley; Sodium-Calcium Exchanger - antagonists & inhibitors; Synaptosomes - chemistry; Synaptosomes - drug effects; Synaptosomes - metabolism; Thiazepines - pharmacology; Tritium; Vertebrates: nervous system and sense organs; Calcium; Rat; Rodentia; Central nervous system; Exocytosis; Extracellular; In vitro; Depolarization; Vertebrata; Mitochondria; Synaptosome; Mammalia; Na; exchanger; Neurotransmitter; GABA; Membrane potential; Potassium; Release; Carrier protein; Ca; Brain (vertebrata)

The release of [3H]GABA evoked by depolarization with various concentrations of KCl was studied using superfused rat cerebrocortex synaptosomes. Elevating [K+] produced release of [3H]GABA over basal which was increasingly less dependent on external Ca2+ but more sensitive to the GABA transporter bl...