Donders Institute for Brain, Cognition and Behaviour, Donders Centre for Cognition, Radboud University Nijmegen, Nijmegen, The Netherlands.
Neurobiol Dis. 2012 Jul;47(1):49-60. doi: 10.1016/j.nbd.2012.03.023. Epub 2012 Mar 23.
Generalized spike and wave discharges (SWD) are generated within the cortico-thalamo-cortical system. However the exact interactions between cortex and different thalamic nuclei needed for the generation and maintenance of SWD are still to be elucidated. This study aims to shed more light on these interactions via multisite cortical and thalamic local-field-potential recordings.
WAG/Rij rats were equipped with multiple electrodes targeting layers 4 to 6 of the somatosensory-cortex, rostral and caudal RTN, VPM, anterior (ATN)- and posterior (Po) thalamic nucleus. The maximal-association-strength between signals was calculated for pre-ictal→ictal transition periods and in control periods using non-linear-association-analysis. Dynamics of changes in coupling-direction and time-delays between channels were analyzed.
Earliest and strongest increases in coupling-strength were seen between cortical layers 5/6 and Po. Other thalamic nuclei became later involved in SWD activity. During the first 500ms of SWDs the cortex guided most thalamic nuclei while cortex and Po kept a bidirectional crosstalk. Most thalamic nuclei started to guide the Po until the end of the SWD. While the rostral RTN showed increased coupling with Po, the caudal RTN decoupled. Instead, it directed its activity to the rostral RTN.
Next to the focal cortical instigator zone of SWDs, the Po seems crucial for their occurrence. This nucleus shows early increases in coupling and is the only nucleus which keeps a bidirectional crosstalk to the cortex within the first 500ms of SWDs. Other thalamic nuclei seem to have only a function in SWD maintenance. Rostral and caudal-RTN have opposite roles in SWD occurrence.
广泛的棘波和尖波放电（SWD）在皮质-丘脑-皮质系统中产生。然而，对于 SWD 的产生和维持所需的皮质与不同丘脑核之间的确切相互作用仍有待阐明。本研究旨在通过多部位皮质和丘脑局部场电位记录来进一步阐明这些相互作用。
WAG/Rij 大鼠配备了多个电极，针对感觉皮层的 4 到 6 层、丘脑前核（RTN）的前、后、丘脑膝状体核（VPM）、前（ATN）和后（Po）丘脑核。使用非线性关联分析，在发作前→发作过渡期间和对照期间，计算信号之间的最大关联强度。分析通道之间耦合方向和时间延迟变化的动态。
最早和最强的耦合强度增加发生在皮质层 5/6 和 Po 之间。其他丘脑核随后参与 SWD 活动。在 SWD 的前 500ms 期间，大脑皮层指导大多数丘脑核，而皮层和 Po 保持双向串扰。大多数丘脑核开始指导 Po，直到 SWD 结束。虽然前 RTN 显示与 Po 的耦合增加，但后 RTN 解耦。相反，它将其活动引导到前 RTN。
除了 SWD 的局灶性皮质触发区外，Po 似乎对其发生至关重要。该核显示出早期增加的耦合，并且是唯一在 SWD 的前 500ms 内保持与皮层双向串扰的核。其他丘脑核似乎在 SWD 维持中仅具有功能。前 RTN 和后 RTN 在 SWD 发生中具有相反的作用。
