Immortalized hypothalamic GT1-7 neurons express functional gamma-aminobutyric acid type A receptors.
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.
Hales
T G
TG
Department of Anesthesiology, School of Medicine, University of California, Los Angeles 90024.
Kim
H
H
Longoni
B
B
Olsen
R W
RW
Tobin
A J
AJ
D000777:Anesthetics / Q000494:pharmacology; D000818:Animals; D001463:Barbiturates / Q000494:pharmacology; D001483:Base Sequence; D001640:Bicuculline / Q000494:pharmacology; D002461:Cell Line, Transformed; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology; D018118:Chloride Channels; D003975:Diazepam / Q000494:pharmacology; D004594:Electrophysiology; D005445:Flunitrazepam / Q000494:pharmacology; D018756:GABA Antagonists; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D007031:Hypothalamus / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure*; D008565:Membrane Proteins / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D009118:Muscimol / Q000378:metabolism; D009474:Neurons / Q000473:pathology / Q000648:ultrastructure*; D010455:Peptides / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011963:Receptors, GABA-A / Q000145:classification / Q000235:genetics / Q000502:physiology*; D012680:Sensitivity and Specificity; D013256:Steroids / Q000494:pharmacology; D014316:Tritium; D014407:Tumor Cells, Cultured; D015032:Zinc / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D000777:Anesthetics; D001463:Barbiturates; D018118:Chloride Channels; D018756:GABA Antagonists; D008565:Membrane Proteins; D010455:Peptides; D012333:RNA, Messenger; D011963:Receptors, GABA-A; D013256:Steroids; D014316:Tritium; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D005445:Flunitrazepam; D015032:Zinc; D003975:Diazepam; D001640:Bicuculline