Gutnick M J, Heinemann U, Lux H D
Electroencephalogr Clin Neurophysiol. 1979 Sep;47(3):329-44. doi: 10.1016/0013-4694(79)90284-0.
Extracellular potassium activity (ak) and field potentials (fp) were measured in the nucleus ventro-postero-lateralis (VPL) thalami in order to assess the extent of thalamic participation in cortical seizure activity. Small increases (up to 0.7 mmole/l) or decreases (up to 0.2 mmole/l) in ak were induced by electrical stimulation of the contralateral forepaw. These changes in ak were spatially more limited than the simultaneously recorded fp. Similar observations were made during weak electrical stimulation of the somatosensory cortex and during interictal spikes in a cortical penicillin focus. Large and widespread increases in ak to levels of 11.6 mmoles/l and slow negative fps of 8 mV accompanied seizure generation either in a cortical penicillin focus or during intense repetitive electrical stimulation of the cortical surface. Subsequent to such increases ak fell to subnormal levels. The amplitudes and durations of such undershoots were correlated with the amplitudes of the preceding increases in ak. Sometimes thalamic seizures ceases before cortical epileptic episodes. This resulted in a decrease of cortical EEG amplitudes. After ablation of the sensorimotor cortex seizures in forepaw-VPL could be induced by stimulation of the somatosensory cortex. These results further support the conclusion that specific thalamic nuclei participate in seizure generation and may serve as a subcortical route of seizure spread.
为了评估丘脑在皮层癫痫活动中的参与程度，在丘脑腹后外侧核（VPL）测量了细胞外钾活性（ak）和场电位（fp）。通过对侧前爪的电刺激可引起ak的小幅升高（高达0.7毫摩尔/升）或降低（高达0.2毫摩尔/升）。ak的这些变化在空间上比同时记录的fp更局限。在体感皮层的弱电刺激期间以及皮层青霉素病灶的发作间期棘波期间也有类似的观察结果。在皮层青霉素病灶中或在皮层表面的强烈重复电刺激期间，ak大幅广泛升高至11.6毫摩尔/升水平，同时伴有8毫伏的缓慢负向场电位，这与癫痫发作的产生相伴。在这种升高之后，ak降至正常以下水平。这种下冲的幅度和持续时间与先前ak升高的幅度相关。有时丘脑癫痫在皮层癫痫发作之前停止。这导致皮层脑电图幅度降低。在切除感觉运动皮层后，刺激体感皮层可诱发前爪-VPL的癫痫发作。这些结果进一步支持了以下结论：特定的丘脑核参与癫痫发作的产生，并且可能作为癫痫传播的皮层下途径。
