Capek R, Esplin B
J Pharmacol Exp Ther. 1977 May;201(2):320-5.
The effects of ethosuximide on spinal monosynaptic transmission were studied in cats. The drug in doses of 200 or 400 mg/kg deepened the decline of monosynaptic response amplitude evoked by trains of 10 stimuli to a motor nerve at 2, 5 or 10 Hz, without affecting the transmission of single isolated impulses. The patterns of decline were analyzed under the assumption that they reflect a partial depletion of the apparent transmitter stores in the presynaptic terminals, each incoming volley releasing a constant fraction of the store while a constant fraction of the instant size of the depleted part is being replenished per second. Ethosuximide increased the fractional release without a consistent effect on the fractional rate of replenishment. It is suggested that the resulting more rapid and more profound depletion of the apparent transmitter store could account for the observed preferential depression of repetitive transmission in the spinal monosynaptic pathway by this drug.
在猫身上研究了乙琥胺对脊髓单突触传递的影响。剂量为200或400mg/kg的该药物加深了以2、5或10Hz频率对运动神经施加10次刺激串所诱发的单突触反应幅度的下降，而不影响单个孤立冲动的传递。在这样的假设下分析下降模式，即它们反映了突触前终末中表观递质储备的部分耗竭，每次传入冲动释放储备的恒定比例，而每秒有恒定比例的已耗竭部分的即时大小得到补充。乙琥胺增加了释放比例，但对补充比例没有一致的影响。有人提出，由此导致的表观递质储备更快、更深刻的耗竭可以解释该药物在脊髓单突触通路中观察到的对重复传递的优先抑制作用。
