Maldonado P E, Gerstein G L
Department of Neuroscience, School of Medicine, University of Pennsylvania, Philadelphia 19104, USA.
Exp Brain Res. 1996 Dec;112(3):420-30. doi: 10.1007/BF00227948.
Many manipulations are able to change or perturb various aspects of single neuron properties and interneuronal relationships. Changes of cerebral cortex organization have been observed in different cortical areas and at different time scales in relation to peripheral stimulation, peripheral damage, associative learning, and electrical stimulation. Here we describe studies on separable multineuron recordings in the rat's auditory cortex under two different anesthetics. Acoustic stimuli were used as a normal, physiological input, and weak electrical intracortical microstimulation (ICMS) as a perturbation that forces a rapid cortical reorganization. ICMS induced fast changes in the cortical map and in the receptive field properties of cells at the electrically stimulated and adjacent electrodes. In effect there was an enlargement of the cortical domain tuned to the acoustic frequency that had been represented at the stimulating electrode. ICMS also incremented afterdischarge responses; these consisted of an initial response to the auditory stimulus followed by less intense repetitive activity that was stimulus-time locked and had a period of 8-12 Hz, similar to that of the spontaneous synchronous activity. Cortical activity under ketamine differed from that under pentobarbital sodium, although in both situations we observed that cortical neurons were highly synchronous.
许多操作能够改变或扰乱单个神经元特性和神经元间关系的各个方面。在不同的皮质区域以及与外周刺激、外周损伤、联合学习和电刺激相关的不同时间尺度上，已观察到大脑皮质组织的变化。在此，我们描述了在两种不同麻醉剂作用下对大鼠听觉皮质进行可分离多神经元记录的研究。声刺激被用作正常的生理输入，而弱的皮质内微刺激（ICMS）则作为一种扰动，促使皮质快速重组。ICMS在电刺激电极和相邻电极处引起皮质图谱和细胞感受野特性的快速变化。实际上，调谐到在刺激电极处曾被表征的声频的皮质区域有所扩大。ICMS还增加了后放电反应；这些反应包括对听觉刺激的初始反应，随后是强度较低的重复活动，该活动与刺激时间锁定，频率为8 - 12 Hz，类似于自发同步活动。尽管在两种情况下我们都观察到皮质神经元高度同步，但氯胺酮作用下的皮质活动与戊巴比妥钠作用下的不同。
