J Kapur1. 1. Department of Neurology, University of Virginia Health Sciences Center, Charlottesville 22908, USA. jk8t@virginia.edu
Abstract
PURPOSE: To define the properties of gamma-aminobutyric acid-type A (GABAA) receptors expressed on dentate granule cells in neonatal rats and to define the impact of prolonged seizures on GABAA receptors in 28- to 35-day-old rats. METHODS: Whole GABAA receptor currents were recorded from acutely isolated dentate granule cells. Cells were isolated from 7- to 14-day-old rats for the first experiment. For the second experiment, cells were isolated from 28- to 35-day-old naive rats and rats that had undergone 45 minutes of status epilepticus. Modulation of GABAA receptor currents by diazepam (DZP), zinc, and zolpidem was studied. RESULTS: In 7- to 14-day-old rats, dentate granule cells express DZP- and zolpidem-insensitive, zinc-sensitive GABAA receptors. In 28- to 35-day-old rats, dentate granule cells express DZP-sensitive GABAA receptors. At the latter age, prolonged seizures render GABAA receptors DZP-insensitive. CONCLUSION: Hippocampal dentate granule cells express DZP-insensitive receptors in hyperexcitable states. These receptors are likely to contain alpha4 subunit.
PURPOSE: To define the properties of gamma-aminobutyric acid-type A (GABAA) receptors expressed on dentate granule cells in neonatal rats and to define the impact of prolonged seizures on GABAA receptors in 28- to 35-day-old rats. METHODS: Whole GABAA receptor currents were recorded from acutely isolated dentate granule cells. Cells were isolated from 7- to 14-day-old rats for the first experiment. For the second experiment, cells were isolated from 28- to 35-day-old naive rats and rats that had undergone 45 minutes of status epilepticus. Modulation of GABAA receptor currents by diazepam (DZP), zinc, and zolpidem was studied. RESULTS: In 7- to 14-day-old rats, dentate granule cells express DZP- and zolpidem-insensitive, zinc-sensitive GABAA receptors. In 28- to 35-day-old rats, dentate granule cells express DZP-sensitive GABAA receptors. At the latter age, prolonged seizures render GABAA receptors DZP-insensitive. CONCLUSION: Hippocampal dentate granule cells express DZP-insensitive receptors in hyperexcitable states. These receptors are likely to contain alpha4 subunit.
Authors: D S Roberts; Y H Raol; S Bandyopadhyay; I V Lund; E C Budreck; M A Passini; M J Passini; J H Wolfe; A R Brooks-Kayal; S J Russek Journal: Proc Natl Acad Sci U S A Date: 2005-08-09 Impact factor: 11.205
Authors: Ingrid V Lund; Yinghui Hu; YogendraSinh H Raol; Rebecca S Benham; Ramona Faris; Shelley J Russek; Amy R Brooks-Kayal Journal: Sci Signal Date: 2008-10-14 Impact factor: 8.192