Conductance of GABA A Channels Activated by Pentobarbitone in Hippocampal Neurons from Newborn Rats
| Autor: | Bryndis Birnir, Peter W. Gage, Mansoureh Eghbali |
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| Rok vydání: | 2003 |
| Předmět: |
Agonist
Pentobarbital Patch-Clamp Techniques Physiology medicine.drug_class Hippocampal formation Bicuculline Hippocampus GABA Antagonists medicine Animals GABA Modulators Cells Cultured gamma-Aminobutyric Acid Neurons Diazepam GABAA receptor Chemistry Electric Conductivity Conductance Original Articles Receptors GABA-A Rats Animals Newborn Biochemistry Chloride channel Biophysics Ion Channel Gating medicine.drug |
| Zdroj: | The Journal of Physiology. 552:13-22 |
| ISSN: | 1469-7793 0022-3751 |
| DOI: | 10.1113/jphysiol.2003.047415 |
| Popis: | Neurons were obtained from the CA1 region of the hippocampus of newborn rats and maintained in culture. Channels were activated by pentobarbitone in cell-attached, inside-out or outside-out patches, normally by applying pentobarbitone in flowing bath solution. Currents were outwardly rectifying and blocked by bicuculline, properties of GABAA channels in these cells. Maximum channel conductance increased as pentobarbitone concentration was increased to 500 microM but conductance then decreased as pentobarbitone concentration was raised further. The best fit of a Hill-type equation to the relationship between maximum channel conductance and pentobarbitone concentration (up to 500 microM) gave an EC50 of 41 microM, a maximum conductance of 36 pS and a Hill coefficient of 1.6. Bicuculline decreased the maximum conductance of the channels activated by pentobarbitone, with an IC50 of 224 microM. Diazepam increased channel conductance, with a maximum effect being obtained with 1 microM diazepam. Diazepam (1 microM) decreased the EC50 of the pentobarbitone effect on channel conductance from 41 microM to 7.2 microM and increased maximum conductance to 72 pS. We conclude that GABAA channel conductance is related to the concentration of the allosteric agonist pentobarbitone. |
| Databáze: | OpenAIRE |
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