SHORT-TERM BRAIN PLASTICITY IN HUMANS - TRANSIENT FINGER REPRESENTATION CHANGES IN SENSORY CORTEX SOMATOTOPY FOLLOWING ISCHEMIC ANESTHESIA
SHORT-TERM BRAIN PLASTICITY IN HUMANS - TRANSIENT FINGER REPRESENTATION CHANGES IN SENSORY CORTEX SOMATOTOPY FOLLOWING ISCHEMIC ANESTHESIA
复制标题
DOI：
10.1016/0006-8993(94)90919-9
复制
发表时间：
1994-04-11
期刊：
影响因子：
2.9
通讯作者：
ROMANI, GL
中科院分区：
文献类型：
--
作者：
ROSSINI, PM;MARTINO, G;ROMANI, GL
在动物实验中，麻醉剂阻断相邻手指的感觉信息，可引起初级躯体感觉皮层中手指表征的短暂重排。这种现象现在已经在7名健康的人类志愿者身上得到了复制。在第1、第3或第5手指的单独电刺激期间记录了体感诱发场（SEF）。在对照条件下（A阶段）、4个未刺激手指完全缺血麻醉后（B阶段）和恢复感觉后（C阶段）获得记录。使用28通道DC-SQUID磁强计记录SEF;传感器的单个位置足以使用等效电流偶极子（ECD）模型识别N20 m、P30 m和以下分量的来源。在阶段A至C期间的传入输入的量用放置在腕部和肘部的神经上的表面电极监测。在A至C阶段，未观察到神经复合电位的变化。在阶段A中，本地化算法能够根据感觉侏儒的躯体位置组织来区分个体手指表示。据观察，负责从未麻醉的手指皮层反应的ECD显着改变后，从相邻的手指感觉剥夺相对较短的时间。相对于控制条件的ECDs的这种变化的特征在于增加的强度和加深的中指，并通过冠状面上的拇指和小指（内侧为前者，外侧为后者）的移位。这种变化在B期逐渐明显，但在C期持续存在。
Transient rearrangements of finger representation in primary somatosensory cortex induced by an anesthetic block of the sensory information from adjacent fingers have been shown invasively in animals. Such a phenomenon has been now replicated in seven healthy human volunteers. Somatosensory Evoked Fields (SEFs) have been recorded during separate electrical stimulation of the 1st, 3rd, or 5th finger. Recordings were obtained in control conditions (stage A), following complete ischemic anesthesia of the 4 non-stimulated fingers (stage B), and after regaining sensation (stage C). SEFs were recorded using a 28-channel DC-SQUID magnetometer; a single position of the sensor was enough to identify the source of N20m, P30m and following components using the Equivalent Current Dipole (ECD) model. The amount of afferent input during stages A through C was monitored with surface electrodes placed on the nerve at wrist and elbow. No variation of the nerve compound potential was observed during stages A through C. In stage A, the localizing algorithm was able to discriminate the individual finger representation in accordance with the somatotopic organisation of the sensory homunculus. It was observed that the ECDs responsible for the cortical responses from the unanesthetized finger were significantly changing following a relatively brief period of sensory deprivation from the adjacent fingers. Such changes of the ECDs with respect to the control conditions were characterized by an increase in strength and deepening for the middle finger, and by a shift on the coronal plane for the thumb and the little finger (medial for the former, lateral for the latter). Such changes became progressively evident in stage B, but were persisting in stage C.