Walden J, Speckmann E J, Witte O W
Electroencephalogr Clin Neurophysiol. 1985 Oct;61(4):299-309. doi: 10.1016/0013-4694(85)91096-x.
Calcium currents were found to participate in the generation of epileptic discharges of single cortical neurones. The present experiments tested whether a systemic administration of a calcium antagonist is able to influence epileptic activity in neuronal populations. Focal interictal epileptiform discharges (FIEDs) were elicited by application of penicillin to the motor cortex of the rat. The calcium antagonist verapamil dissolved in artificial cerebrospinal fluid was applied by intraventricular push-pull perfusion to achieve high concentrations of the drug in cerebral tissue and to avoid alterations of the systemic circulatory system. The application of the calcium antagonist reduced FIEDs in amplitude and in frequency of occurrence. In some experiments the suppression of seizure activity was preceded by a transient enhancement. After termination of the drug perfusion FIEDs were often re-established. Control experiments revealed that perfusion with drug-free cerebrospinal fluid did not change FIEDs. In experiments without epileptic activity, cortical evoked potentials elicited by stimulation of the sciatic nerve tended to increase with perfusion of the calcium antagonist. As a whole, the systemic administration of the calcium antagonist verapamil depressed FIED and exerted an inverse effect on synchronized non-epileptic neuronal activity.
研究发现钙电流参与单个皮层神经元癫痫放电的产生。本实验旨在测试全身给予钙拮抗剂是否能够影响神经元群体中的癫痫活动。通过向大鼠运动皮层施加青霉素来诱发局灶性发作间期癫痫样放电（FIEDs）。将溶解于人工脑脊液中的钙拮抗剂维拉帕米通过脑室内推挽灌注给药，以在脑组织中达到高浓度的药物，并避免影响全身循环系统。钙拮抗剂的应用降低了FIEDs的幅度和发生频率。在一些实验中，癫痫活动的抑制之前会有短暂的增强。药物灌注终止后，FIEDs常常会重新出现。对照实验表明，用无药脑脊液灌注不会改变FIEDs。在无癫痫活动的实验中，刺激坐骨神经诱发的皮层诱发电位倾向于随着钙拮抗剂的灌注而增加。总体而言，全身给予钙拮抗剂维拉帕米可抑制FIEDs，并对同步的非癫痫性神经元活动产生相反的影响。
