皮质脊髓运动神经元突触的早期易化

Early facilitation at corticomotoneuronal synapses.

作者信息

Porter R

出版信息

J Physiol. 1970 May;207(3):733-45. doi: 10.1113/jphysiol.1970.sp009091.

DOI:10.1113/jphysiol.1970.sp009091

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1348738/

Abstract

Corticomotoneuronal EPSPs have been generated in lumbar motoneurones of the monkey by single and paired corticospinal volleys. The facilitation of the second of a pair of EPSPs with respect to the size of the first has been measured.2. The relationship between the degree of facilitation of the second response and the interval between the two volleys has been studied. Average facilitation of minimal EPSPs was found to be maximal about 2 msec after the arrival of the corticospinal volley and to decay roughly exponentially thereafter with a time constant of about 10 msec.3. The degree of facilitation varied from one minimal corticomotoneuronal EPSP to another but this facilitation was not statistically correlated with the time course of the individual EPSPs.4. Significant facilitation (0.4) was still present 10 msec after a corticospinal volley so that this phenomenon could play a part in the initiation of motoneuronal discharge by corticospinal activity at natural frequencies of the order of 100 impulses/sec.

摘要

通过单脉冲和双脉冲皮质脊髓冲动，在猴子的腰段运动神经元中产生了皮质运动神经元兴奋性突触后电位（EPSPs）。已测量了一对EPSPs中第二个相对于第一个大小的易化作用。
研究了第二个反应的易化程度与两个脉冲之间间隔的关系。发现最小EPSPs的平均易化作用在皮质脊髓冲动到达后约2毫秒时最大，此后大致呈指数衰减，时间常数约为10毫秒。
易化程度在不同的最小皮质运动神经元EPSP之间有所不同，但这种易化作用与单个EPSP的时间进程在统计学上没有相关性。
在皮质脊髓冲动后10毫秒时仍存在显著的易化作用（0.4），因此这种现象可能在皮质脊髓活动以约100次冲动/秒的自然频率引发运动神经元放电中发挥作用。