Harvard Medical School, Boston, Massachusetts, USA.
J Clin Neurophysiol. 2010 Dec;27(6):418-24. doi: 10.1097/WNP.0b013e3181fe0709.
In organotypic hippocampal slice cultures, principal neurons form aberrant excitatory connections with other principal cells in response to slicing induced deafferentation, similar to mechanisms underlying epileptogenesis in posttraumatic epilepsy. To investigate the consequences of this synaptogenesis, the authors recorded field-potential activity from area CA3 during perfusion with the complete growth medium used during incubation. At 7 days in vitro, slice cultures only displayed multiunit activity. At 14 days in vitro, the majority displayed population bursts reminiscent of interictal-like spikes, but sustained synchronous activity was rare. Band-pass filtering of interictal discharges revealed fast ripple-like complexes, similar to in vivo recordings. Spontaneous ictal-like activity became progressively more prevalent with age: at 21 days in vitro, 50% of organotypic hippocampal slice cultures displayed long-lasting, ictal-like discharges that could be suppressed by phenytoin, whereas interictal activity was not suppressed. The fraction of cultures displaying ictal events continually increased with incubation time. Quantification of population spike activity throughout epileptogenesis using automatic detection and clustering algorithms confirmed the appearance of interictal-like activity before ictal-like discharges and also revealed high-frequency pathologic multiunit activity in slice cultures at 14 to 17 days in vitro. These experiments indicate that interictal-like spikes precede the appearance of ictal-like activity in a reduced in vitro preparation. Epileptiform activity in cultures resembled in vivo epilepsy, including sensitivity to anticonvulsants and steadily increasing seizure incidence over time, although seizure frequency and rate of epileptogenesis were higher in vitro. Organotypic hippocampal slice cultures comprise a useful model system for investigating mechanisms of epileptogenesis as well as developing antiepileptic and antiepileptogenic drugs.
在器官型海马脑片培养物中，由于切割引起的去传入，主要神经元与其他主要细胞形成异常兴奋性连接，类似于创伤后癫痫发作中癫痫发生的机制。为了研究这种突触发生的后果，作者在孵育期间使用的完整生长培养基灌流期间从 CA3 区记录场电位活动。在体外 7 天时，切片培养物仅显示多单位活动。在体外 14 天时，大多数显示出类似于发作间样尖峰的群体爆发，但持续同步活动很少见。发作间放电的带通滤波显示出快速涟漪样复合物，类似于体内记录。随着年龄的增长，发作样活动变得越来越普遍：在体外 21 天时，50%的器官型海马脑片培养物显示出持久的、发作样的放电，可被苯妥英钠抑制，而发作间活动不受抑制。显示发作事件的培养物分数随着孵育时间的延长而不断增加。使用自动检测和聚类算法在整个癫痫发生过程中对群体锋电位活动进行量化，证实了在发作样放电之前出现发作间样活动，并且还在体外 14 至 17 天的脑片培养物中显示出高频病理性多单位活动。这些实验表明，在体外简化制备中，发作间样尖峰先于发作样活动出现。培养物中的癫痫样活动类似于体内癫痫，包括对抗惊厥药的敏感性以及随着时间的推移发作发生率的稳步增加，尽管体外的发作频率和癫痫发生速度更高。器官型海马脑片培养物是研究癫痫发生机制以及开发抗癫痫和抗癫痫发生药物的有用模型系统。
