Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Epilepsy Behav. 2011 Feb;20(2):257-66. doi: 10.1016/j.yebeh.2010.11.024. Epub 2011 Jan 14.
Epileptic seizures are clinical manifestations of neuronal discharges characterized by hyperexcitability and/or hypersynchrony in the cortex and other subcortical regions. The pilocarpine (PILO) model of epilepsy mimics temporal lobe epilepsy (TLE) in humans. In the present study, we used a more selective approach: microinjection of PILO into the hilus of the dentate gyrus (H-PILO). Our main goal was to evaluate the behavioral and morphological alterations present in this model of TLE. Seventy-six percent of all animals receiving H-PILO injections had continuous seizures called status epilepticus (SE). A typical pattern of evolution of limbic seizures during the SE with a latency of 29.3 ± 16.3 minutes was observed using an analysis of behavioral sequences. During the subsequent 30 days, 71% of all animals exhibited spontaneous recurrent seizures (SRSs) during a daily 8-hour videotaping session. These SRSs had a very conspicuous and characteristic pattern detected by behavioral sequences or neuroethiological analysis. Only the animals that had SE showed positive Neo-Timm staining in the inner molecular layer of the dentate gyrus (sprouting) and reduced cell density in Ammon's horn pyramidal cell subfield CA1. However, no correlation between the intensity of sprouting and the mean number and total number of SRSs was found. Additionally, using Fluoro-Jade staining, we observed neurodegeneration in the hilus and pyramidal cell subfields CA3 and CA1 24 hours after SE. These data indicate that H-PILO is a reliable, selective, efficient, low-mortality model that mimics the acute and chronic behavioral and morphological aspects of TLE.
癫痫发作是神经元放电的临床表现，其特征是皮质和其他皮质下区域的过度兴奋和/或过度同步。匹罗卡品（PILO）癫痫模型模拟人类颞叶癫痫（TLE）。在本研究中，我们采用了更具选择性的方法：将 PILO 微注射到齿状回的门区（H-PILO）。我们的主要目标是评估这种 TLE 模型中存在的行为和形态改变。所有接受 H-PILO 注射的动物中有 76%出现持续癫痫发作，称为癫痫持续状态（SE）。通过对行为序列的分析，观察到 SE 期间边缘性癫痫发作的典型演变模式，潜伏期为 29.3±16.3 分钟。在随后的 30 天中，所有动物中有 71%在每天 8 小时的录像会议期间出现自发性复发性癫痫发作（SRS）。这些 SRS 通过行为序列或神经电生理分析检测到具有非常明显和特征性的模式。只有发生 SE 的动物在齿状回内分子层（发芽）出现阳性 Neo-Timm 染色和 Ammon 角锥体细胞亚区 CA1 细胞密度降低。然而，发芽的强度与 SRS 的平均数量和总数之间没有相关性。此外，使用 Fluoro-Jade 染色，我们在 SE 后 24 小时观察到门区和锥体细胞亚区 CA3 和 CA1 的神经退行性变。这些数据表明，H-PILO 是一种可靠、选择性、高效、低死亡率的模型，可模拟 TLE 的急性和慢性行为和形态方面。
