Nishikata M, Endo S, Yamatani K, Hayashi N, Masuda R, Takaku A
Department of Neurosurgery, Toyama Medical and Pharmaceutical University, School of Medicine, Japan.
Neurosurgery. 1998 Aug;43(2):325-9. doi: 10.1097/00006123-199808000-00091.
The characteristics of the early component of the direct cortical response have not been well studied, although direct cortical response recording is a common method of brain function monitoring.
In this experimental study, we sought conditions affording the clearest recording of the early potential, by varying the polarity and low-cutoff filter setting, and we confirmed that the early potential consists of two components, P1 and P2.
When subcortical damage was induced by local cerebral compression or saline injection, transient changes in P1 and permanent disappearance of P2 were observed. P2 also disappeared when the fiber connections between the cortex and the basal ganglia, including the thalamus, were destroyed by wire insertion. With deep recording, both P1 and P2 exhibited potential reversal at a level histologically confirmed to be in Layer V of the cortex.
These findings suggest that P1 is a spike reflecting the activity of pyramidal cells evoked by electrical stimulation of the brain surface and that P2 is a potential arising in Layer V of the cortex and is related to afferent fibers from the thalamus. Recording of P2 may be useful for monitoring for subcortical damage.
尽管直接皮层反应记录是一种常用的脑功能监测方法，但对其早期成分的特征尚未进行充分研究。
在本实验研究中，我们通过改变极性和低截止滤波器设置，寻找能最清晰记录早期电位的条件，并证实早期电位由P1和P2两个成分组成。
当通过局部脑压迫或注射生理盐水诱导皮层下损伤时，观察到P1的短暂变化和P2的永久消失。当通过插入金属丝破坏包括丘脑在内的皮层与基底神经节之间的纤维连接时，P2也消失。在深部记录时，P1和P2在组织学上证实为皮层V层的水平均表现出电位反转。
这些发现表明，P1是反映脑表面电刺激诱发的锥体细胞活动的尖峰，而P2是皮层V层产生的电位，与来自丘脑的传入纤维有关。记录P2可能有助于监测皮层下损伤。
