Article date: 1992/8/1
PubMed ID: 1325030
Journal name: Molecular pharmacology (ISSN: 0026-895X)
Neuronal cell lines provide a source of pure populations of neurons and allow the properties of many neurotransmitter receptors to be studied. However, none of these cells have been reported to express functional gamma-aminobutyric acid (GABA)A receptors. Indeed, there have been no reports of cell lines expressing functional amino acid receptors. Using biochemical and electrophysiological techniques, we have identified a neuronal cell line expressing functional GABAA receptors. Membranes from immortalized hypothalamic (GT1-7) neurons bound [3H]muscimol but not [3H]flunitrazepam. GABA-activated chloride currents, recorded from GT1-7 cells, were blocked by bicuculline and Zn2+ but were insensitive to diazepam. These results suggest that GABAA receptors on GT1-7 cells lack gamma subunits. The neurosteroid 5 alpha-pregnan-3 alpha-ol-20-one and pentobarbital both modulated GABAA receptors in these cells. Polymerase chain reaction analysis of the cells revealed the presence of mRNAs encoding alpha 1, beta 1, and beta 3 polypeptides. GT1-7 cells provide a useful model system for studying the regulation of GABAA receptor polypeptide expression.
Author List: Hales T G, Kim H, Longoni B, Olsen R W, Tobin A J
Publication Types: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.
Substances mentioned in the article: Anesthetics; Barbiturates; Chloride Channels; GABA Antagonists; Membrane Proteins; Peptides; RNA, Messenger; Receptors, GABA-A; Steroids; Tritium; Muscimol; gamma-Aminobutyric Acid; Flunitrazepam; Zinc; Diazepam; Bicuculline;
Mesh terms: Anesthetics/pharmacology; Animals; Barbiturates/pharmacology; Base Sequence; Bicuculline/pharmacology; Cell Line, Transformed; Cell Membrane/metabolism; Chloride Channels; Diazepam/pharmacology; Electrophysiology; Flunitrazepam/pharmacology; GABA Antagonists; Gene Expression Regulation/genetics; Hypothalamus/pathology; Membrane Proteins/physiology; Mice; Molecular Sequence Data; Muscimol/metabolism; Neurons/pathology; Peptides/genetics; Polymerase Chain Reaction; RNA, Messenger/analysis; Receptors, GABA-A/classification; Sensitivity and Specificity; Steroids/pharmacology; Tritium; Tumor Cells, Cultured; Zinc/pharmacology; gamma-Aminobutyric Acid/pharmacology;