Elger C E, Speckmann E J, Prohaska O, Caspers H
Electroencephalogr Clin Neurophysiol. 1981 Apr;51(4):393-402. doi: 10.1016/0013-4694(81)90103-6.
The pattern of intracortical potential distribution during focal interictal epileptiform discharges (FIED) was analysed with respect to the occurrence of descending neuronal activity to the spinal cord recorded as spinal field potentials (SFPs). The experiments were performed in rats. Epileptiform activity was elicited by application of penicillin to the motor cortex. The spread of active penicillin was limited by penicillinase in part of the experiments. (1) When penicillinase was applied 10--20 sec before penicillin to the cortical surface typical FIED appeared in the epicortical lead. During well-established focal activity they were accompanied by negative field potentials at a depth of 300 micrometers and 600 micrometers and by positive field potentials in deeper records. This pattern of intracortical potential distribution was not associated with characteristic SFPs. (2) When penicillinase was applied simultaneously with penicillin, the fully developed epicortical FIED were accompanied by negative intracortical field potentials which in this case reached a depth of 900 micrometers. In the layers below predominantly positive potential fluctuations occurred. This pattern of intracortical potential distribution was associated with characteristic SFPs. (3) Intracortical application of penicillin at a depth of 800--900 micrometers led to negative field potentials of large amplitude in all intracortical records, with the concomitant epicortical potentials being positive in polarity. In this case SFPs occurred throughout the interictal activity. Since seizure activity can be restricted to only a few cortical laminae, descending neuronal activity to the spinal cord need not be correlated with definite epicortical potentials. A prerequisite for cortical output is intracortical activity reflected negative potentials at a depth of approx. 900 micrometers.
针对记录为脊髓场电位（SFP）的向脊髓下行的神经元活动的发生情况，分析了局灶性发作间期癫痫样放电（FIED）期间皮质内电位分布模式。实验在大鼠身上进行。通过向运动皮质施加青霉素诱发癫痫样活动。在部分实验中，青霉素酶限制了活性青霉素的扩散。（1）在向皮质表面施加青霉素前10 - 20秒应用青霉素酶时，典型的FIED出现在皮质表面导联。在确立良好的局灶性活动期间，它们伴随着300微米和600微米深度处的负性场电位以及更深记录中的正性场电位。这种皮质内电位分布模式与特征性SFP无关。（2）当青霉素酶与青霉素同时应用时，完全发展的皮质表面FIED伴随着皮质内负性场电位，这种情况下其深度可达900微米。在其下方各层主要出现正性电位波动。这种皮质内电位分布模式与特征性SFP有关。（3）在800 - 900微米深度皮质内应用青霉素导致所有皮质内记录中出现大幅度负性场电位，同时皮质表面电位极性为正。在这种情况下，发作间期活动全程均出现SFP。由于癫痫发作活动可能仅限于少数皮质层，向脊髓下行的神经元活动不一定与明确的皮质表面电位相关。皮质输出的一个先决条件是皮质内活动在约900微米深度处表现为负性电位。
