Interictal spike frequency varies with ovarian cycle stage in a rat model of epilepsy
| Autor: | James D'Amour, Alejandra Magagna-Poveda, André A. Fenton, Daniel Friedman, John LaFrancois, Neil J. MacLusky, Helen E. Scharfman, Jillian N Moretto, Patrice Pearce |
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| Rok vydání: | 2014 |
| Předmět: |
Male
Kainic acid medicine.medical_specialty endocrine system media_common.quotation_subject Status epilepticus Biology Hippocampus Article Rats Sprague-Dawley chemistry.chemical_compound Epilepsy Sex Factors Status Epilepticus Developmental Neuroscience Internal medicine Catamenial epilepsy medicine Animals Ictal reproductive and urinary physiology Menstrual cycle Menstrual Cycle media_common Estrous cycle Kainic Acid urogenital system Pilocarpine Electroencephalography medicine.disease Disease Models Animal Endocrinology Neurology chemistry nervous system medicine.symptom hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Experimental neurology. 269 |
| ISSN: | 1090-2430 |
| Popis: | In catamenial epilepsy, seizures exhibit a cyclic pattern that parallels the menstrual cycle. Many studies suggest that catamenial seizures are caused by fluctuations in gonadal hormones during the menstrual cycle, but this has been difficult to study in rodent models of epilepsy because the ovarian cycle in rodents, called the estrous cycle, is disrupted by severe seizures. Thus, when epilepsy is severe, estrous cycles become irregular or stop. Therefore, we modified kainic acid (KA)- and pilocarpine-induced status epilepticus (SE) models of epilepsy so that seizures were rare for the first months after SE, and conducted video-EEG during this time. The results showed that interictal spikes (IIS) occurred intermittently. All rats with regular 4-day estrous cycles had IIS that waxed and waned with the estrous cycle. The association between the estrous cycle and IIS was strong: if the estrous cycles became irregular transiently, IIS frequency also became irregular, and when the estrous cycle resumed its 4-day pattern, IIS frequency did also. Furthermore, when rats were ovariectomized, or males were recorded, IIS frequency did not show a 4-day pattern. Systemic administration of an estrogen receptor antagonist stopped the estrous cycle transiently, accompanied by transient irregularity of the IIS pattern. Eventually all animals developed severe, frequent seizures and at that time both the estrous cycle and the IIS became irregular. We conclude that the estrous cycle entrains IIS in the modified KA and pilocarpine SE models of epilepsy. The data suggest that the ovarian cycle influences more aspects of epilepsy than seizure susceptibility. |
| Databáze: | OpenAIRE |
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