Granule cell disinhibition in dentate gyrus of genetically seizure susceptible El mice
| Autor: | Koki Ohno, Yoshiyuki Murai, Takao Ono, Takashi Mita, Yukiko Fueta, Osamu Ohmori, Najma A. Janjua |
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| Rok vydání: | 1997 |
| Předmět: |
Male
Aging medicine.medical_specialty Glutamic Acid Mice Inbred Strains Flunitrazepam In Vitro Techniques Biology Hippocampal formation Bicuculline Hippocampus Epileptogenesis GABA Antagonists Mice Seizures Internal medicine medicine Animals GABA Modulators Molecular Biology Chromatography High Pressure Liquid gamma-Aminobutyric Acid GABAA receptor General Neuroscience Dentate gyrus Granule cell Electrophysiology Endocrinology medicine.anatomical_structure nervous system Disinhibition Phenobarbital Dentate Gyrus GABAergic Anticonvulsants Neurology (clinical) medicine.symptom Neuroscience Developmental Biology medicine.drug |
| Zdroj: | Brain Research. 745:165-172 |
| ISSN: | 0006-8993 |
| DOI: | 10.1016/s0006-8993(96)01145-6 |
| Popis: | Paired-pulse inhibition was investigated electrophysiologically in the dentate gyrus using hippocampal slices from epileptic El mice. At short interpulse intervals (IPIs), the inhibition was 30% in the El, and 90% in the control ddY mice at the ages of 10 and 15 weeks. No difference in inhibition was observed at the age of 5 weeks. Bicuculline, a GABAA receptor antagonist, attenuated the inhibition during short IPIs in the ddY mice, while in the El mice, phenobarbital and flunitrazepam, which enhance GABAA receptor function, restored the inhibitory activity comparable to that of the ddY. The disinhibition progressed with growth, closely correlating with seizure development in El mice. These results suggest that decrease in the GABAergic inhibition occurs in the dentate gyrus of the El mice with growth. GABA concentration in the hippocampus was also quantified using HPLC. In El mice, GABA level was significantly lower than that in ddY mice at the ages of 5 and 15 weeks. Thus, the disinhibition observed in the El dentate gyrus at 15 weeks of age does not appear to be directly related to the content of GABA. GABAergic disinhibition suggests possible loss of unknown inhibition control factor(s) in the El dentate gyrus as growth progresses. The growth-dependent disinhibition in the granule cells may be a prerequisite for epileptogenesis in El mice. |
| Databáze: | OpenAIRE |
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