Neurodegeneration, Neuroprotection, and Disease-Oriented NeuroscienceResearch PaperPilocarpine-induced status epilepticus and subsequent spontaneous seizures: lack of effect on the number of gonadotropin-releasing hormone-positive neurons in a mouse model

Women with temporal lobe epilepsy have a higher incidence of reproductive disorders, which have been linked to alterations in the pulsatile release of gonadotropin-releasing hormone (GnRH). These experiments tested the hypothesis that the number of GnRH neurons is reduced in an animal model of temporal lobe epilepsy. The effects of pilocarpine-induced status epilepticus (SE) and the subsequent spontaneous recurrent eizures on the number of GnRH-positive neurons were studied in adult female mice. Systemic injections of pilocarpine were used to induce SE, and diazepam was administered 90 min after the first seizure. Control mice received all drugs except pilocarpine. The mice were euthanized either 1 week or 3 months after SE (i.e. after spontaneous recurrent seizures were observed). Even though the estrous cycle was disrupted after SE, and hippocampal damage was detected in both the CA1 and CA3 regions, pilocarpine-treated mice did not show a significant decrease in total or regional numbers of GnRH-immunopositive neurons. Therefore, these data do not support the hypothesis that a reduction in the number of GnRH neurons is responsible for the disruption of the estrous cycle after pilocarpine-induced epilepsy, which suggests that other mechanisms contribute to female reproductive disorders associated with chronic epilepsy.

▶Pilocarpine-induced status epilepticus served as a model of temporal lobe epilepsy. ▶Key result: the number of GnRH-immunopositive neurons was not significantly reduced. ▶Positive control: Neuronal loss was confirmed in the hippocampal CA1 and CA3 areas. ▶Positive control: All mice had spontaneous, recurrent, convulsive seizures by 3 months. ▶Positive control: the disruption of the estrous cycle was confirmed for up to 3 months.