Department of Neurology, University of California, Los Angeles, CA, USA.
Brain Research Institute, University of California, Los Angeles, CA, USA.
Epilepsia. 2018 Apr;59(4):e51-e55. doi: 10.1111/epi.14041. Epub 2018 Mar 6.
The current study aimed to investigate the spatial and temporal patterns of high-frequency oscillations (HFOs) in the intra-/extrahippocampal areas during epileptogenesis. Local field potentials were bilaterally recorded from hippocampus (CA1), thalamus, motor cortex, and prefrontal cortex in 13 rats before and after intrahippocampal kainic acid (KA) lesions. HFOs in the ripple (100-200 Hz) and fast ripple (250-500 Hz) ranges were detected and their rates were computed during different time periods (1-5 weeks) after KA-induced status epilepticus (SE). Recurrent spontaneous seizures were observed in 7 rats after SE, and the other 6 rats did not develop epilepsy. During the latent period, the rate of hippocampal HFOs increased at the ipsilateral site of the KA lesion in both groups, and the HFO rate was significantly higher in the animals that later developed epilepsy. Animals that later developed epilepsy also demonstrated widespread appearance of HFOs, in both the ripple and the fast ripple range, whereas animals that did not develop epilepsy only exhibited changes in the ipsilateral intrahippocampal HFO rate. This study demonstrates an association between an increased rate of widespread HFOs and the later development of epilepsy, suggesting the formation of large-scale distributed pathological networks during epileptogenesis.
本研究旨在探讨癫痫发生过程中 intra-/extrahippocampal 区域高频振荡（HFOs）的时空模式。在 13 只大鼠海马（CA1）、丘脑、运动皮层和前额叶皮层双侧记录局部场电位，在海马内 KA 损伤前后。在 KA 诱导的癫痫持续状态（SE）后不同时间（1-5 周）检测到 ripples（100-200 Hz）和 fast ripples（250-500 Hz）范围内的 HFOs，并计算其速率。7 只大鼠在 SE 后出现复发性自发性癫痫发作，其余 6 只大鼠未发生癫痫。在潜伏期，两组 KA 损伤同侧海马的 HFO 率均增加，而后来发生癫痫的动物的 HFO 率明显更高。后来发生癫痫的动物还表现出广泛的 HFO 出现，包括 ripples 和 fast ripples 范围，而未发生癫痫的动物仅表现出同侧海马内 HFO 率的变化。本研究表明，广泛 HFO 率的增加与后来癫痫的发生之间存在关联，提示在癫痫发生过程中形成了大规模的分布式病理网络。
