These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Absence seizures decrease steroid modulation of t-[35S]butylbicyclophosphorothionate binding in thalamic relay nuclei. Author: Banerjee PK, Olsen RW, Tillakaratne NJ, Brailowsky S, Tobin AJ, Snead OC. Journal: J Pharmacol Exp Ther; 1998 Nov; 287(2):766-72. PubMed ID: 9808708. Abstract: Interaction of gamma-aminobutyric acid (GABA), pentobarbital and two neuroactive steroids on t-butylbicyclophosphorothionate ([35S]TBPS) binding to GABAA receptors in thalamus was studied during absence seizures. In control brain sections, the steroids alphaxalone and tetrahydrodeoxycorticosterone (at low 0.1-1 microM concentrations) increased [35S]TBPS binding in thalamic relay nuclei. Both GABA and pentobarbital dose-dependently decreased [35S]TBPS binding in these nuclei. A significant decrease in the ability of steroids to increase [35S]TBPS binding in thalamic relay nuclei was observed during absence seizures induced by gamma-hydroxybutyric acid (GHB). This loss of steroid effect on binding was 1) selective to steroids only as GABA and pentobarbital modulation of [35S]TBPS binding in these nuclei did not change significantly and 2) not causally related to the generation of GHB-induced absence seizures as it was not observed at the onset of GHB-seizures but developed 30 min after the seizure-onset. We tested whether absence seizures were critical for the development of this loss of steroid effect on [35S]TBPS binding in thalamic relay nuclei. The ability of the steroids to increase [35S]TBPS binding in relay nuclei was preserved when GHB-seizures were blocked. When the duration of GHB-seizures was prolonged, the loss of steroid effect on [35S]TBPS binding in thalamus persisted throughout the seizure-duration. These findings suggest that absence seizures cause a rapid loss of steroid effect on [35S]TBPS binding to GABAA receptors in thalamic relay nuclei.[Abstract] [Full Text] [Related] [New Search]