Relative changes in cerebral blood flow and neuronal activity in local microdornains during generalized seizures
Relative changes in cerebral blood flow and neuronal activity in local microdornains during generalized seizures
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DOI：
10.1097/01.wcb.0000131669.02027.3e
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发表时间：
2004-09-01
影响因子：
6.3
通讯作者：
Blumenfeld, H
中科院分区：
文献类型：
--
作者：
Nersesyan, H;Herman, P;Blumenfeld, H
普遍认为全身强直阵挛性发作（GTCS）和正常的躯体感觉刺激与局部CBF增加有关。然而，有关失神发作期间CBF变化的数据存在争议。在WAG/Rij大鼠（一种已建立的失神发作动物模型）中进行的电生理学研究表明，口周体感皮层中的棘波放电（SWD）最大，而视觉皮层则除外。最近的功能磁共振成像（fMRI）在同一模型的研究也表明，在口周躯体感觉皮层在SWD功能磁共振信号的局部增加。由于fMRI信号仅与神经元活动间接相关，因此作者在芬太尼/氟哌啶醇麻醉下使用专门设计的探针结合激光多普勒血流仪和细胞外微电极记录直接测量了WAG/Rij皮质特定微区的CBF和神经元活动。使用这种方法，平行增加神经元活动和CBF观察SWD期间在晶须体感（桶）皮层，而视觉皮层没有显着变化。为了进行比较，在相同的动物中，在体感（胡须）刺激和荷包牡丹碱诱导的GTCS期间重复这些测量。有趣的是，胡须刺激增加神经元的活动和CBF在桶皮质比在SWD。在GTCS期间，观察到包括躯体感觉和视觉皮层在内的更大幅度的增加。因此，SWD在这个模型中产生平行的局部神经元活动和CBF增加，与躯体感觉刺激的分布相似，而GTCS产生更大和更广泛的变化。对躯体感觉刺激的正常反应似乎处于由两种生理上不同类型的癫痫发作产生的两种异常反应之间。
There is broad agreement that generalized tonic-clonic seizures (GTCS) and normal somatosensory stimulation are associated with increases in regional CBF. However, the data regarding CBF changes during absence seizures are controversial. Electrophysiologic studies in WAG/Rij rats, an established animal model of absence seizures, have shown spike-wave discharges (SWD) that are largest in the perioral somatosensory cortex while sparing the visual cortex. Recent functional magnetic resonance imaging (fMRI) studies in the same model have also shown localized increases in fMRI signals in the perioral somatosensory cortex during SWD. Because fMRI signals are only indirectly related to neuronal activity, the authors directly measured CBF and neuronal activity from specific microdomains of the WAG/Rij cortex using a specially designed probe combining laser-Doppler flowmetry and extracellular microelectrode recordings under fentanyl/haloperidol anesthesia. Using this approach, parallel increases in neuronal activity and CBF were observed during SWD in the whisker somatosensory (barrel) cortex, whereas the visual cortex showed no significant changes. For comparison, these measurements were repeated during somatosensory (whisker) stimulation, and bicuculline-induced GTCS in the same animals. Interestingly, whisker stimulation increased neuronal activity and CBF in the barrel cortex more than during SWD. During GTCS, much larger increases that included both the somatosensory and visual cortex were observed. Thus, SWD in this model produce parallel localized increases in neuronal activity and CBF with similar distribution to somatosensory stimulation, whereas GTCS produce larger and more widespread changes. The normal response to somatosensory stimulation appears to be poised between two abnormal responses produced by two physiologically different types of seizures.