Sitnikova Evgenia, van Luijtelaar Gilles
NICI, Biological Psychology, Radboud University Nijmegen, The Netherlands.
Epilepsy Res. 2006 Oct;71(2-3):159-80. doi: 10.1016/j.eplepsyres.2006.06.008. Epub 2006 Jul 31.
The study examines cortico-cortical and cortico-thalamic network synchronization at the onset of spike-wave discharges (SWD) in a genetic model of absence epilepsy, WAG/Rij rats. Coherence was measured between multiple cortical areas (intracortical), reticular and rely thalamic nuclei (intrathalamic) and between the cortex and the thalamus. SWD-related increase of coherence (5-60 Hz) was found in all investigated pairs. The highest increase of coherence was around the mean frequency of SWD (8-11.5 Hz) and in the harmonic band 16-21.5 Hz with two central maxima around 10 and 20 Hz. The frequency profile of coherence was different in different intracortical networks, therefore latter were divided into local, global and transhemispheric networks. The presumable source of SWD in the somatosensory cortex and its closest surroundings formed a minimal (local) circuit, in which occurrence of SWD was facilitated by a consistent shift of network synchrony from delta to alpha/beta frequencies. Transhemispheric coherence revealed the largest increase with an additional 16 Hz peak, suggesting a crucial involvement of the corpus callosum in the pathophysiology of absence seizures. The increase in interhemispheric coherence was largest between relatively remote somatosensory or frontal areas, supporting the assumption that SWD originate from the lateral fronto-parietal cortical area.
该研究在失神癫痫的遗传模型WAG/Rij大鼠中，检测了棘慢波放电（SWD）起始时的皮质-皮质和皮质-丘脑网络同步性。测量了多个皮质区域（皮质内）、网状核和丘脑中继核（丘脑内）之间以及皮质与丘脑之间的相干性。在所有研究的配对中均发现与SWD相关的相干性增加（5 - 60赫兹）。相干性增加最高的频率在SWD的平均频率（8 - 11.5赫兹）附近以及谐波频段16 - 21.5赫兹，在10赫兹和20赫兹左右有两个中心最大值。不同皮质内网络的相干性频率分布不同，因此将后者分为局部、全局和跨半球网络。体感皮层及其最邻近区域中SWD的可能来源形成了一个最小（局部）回路，其中网络同步性从δ频率一致转变为α/β频率促进了SWD的发生。跨半球相干性显示增加最大，还有一个额外的16赫兹峰值，表明胼胝体在失神发作的病理生理学中起关键作用。半球间相干性增加在相对较远的体感或额叶区域之间最大，支持了SWD起源于外侧额顶叶皮质区域的假设。
