Spatiotemporal effects of microstimulation in rat neocortex: A parametric study using multielectrode recordings
Spatiotemporal effects of microstimulation in rat neocortex: A parametric study using multielectrode recordings
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DOI：
10.1152/jn.00245.2003
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发表时间：
2003-11-01
影响因子：
2.5
通讯作者：
Schwarz, C
中科院分区：
文献类型：
--
作者：
Butovas, S;Schwarz, C
使用微刺激将有意义的活动模式压印到本质上高度互连的神经元基质中受到通道纤维激活的阻碍，导致活动的时空“模糊”。本研究的重点是表征新皮层中这种模糊的形状，以估计信号可以通过多电极刺激传输的分辨率。在氯胺酮麻醉大鼠的初级躯体感觉皮层的面部表征中，由近阈值局灶性电刺激（电荷转移0.8-4.8 nC）和多电极记录诱发的显著单位活动的水平扩展被确定为约1，350 μ m。在此范围内的诱发活动包括一个序列的快速兴奋反应，然后抑制持续时间>100 ms。这两个反应不能分开，通过改变刺激强度，而缓慢的兴奋反弹后，抑制反应被限制在较高的刺激强度（>2.4 nC）。20和40 Hz的刺激频率引起的重复兴奋性反应站出来对连续的背景抑制。在5-和10-Hz的刺激，抑制反应表现出复杂的相互作用模式归因于高度次线性叠加的个人抑制反应。目前的数据有助于阐明微刺激的行为效应的神经基础。此外，他们提供了必要的信息，以确定时空限制有目的的多电极刺激在新皮层。
Using microstimulation to imprint meaningful activity patterns into intrinsically highly interconnected neuronal substrates is hampered by activation of fibers of passage leading to a spatiotemporal "blur" of activity. The focus of the present study was to characterize the shape of this blur in the neocortex to arrive at an estimate of the resolution with which signals can be transmitted by multielectrode stimulation. The horizontal spread of significant unit activity evoked by near-threshold focal electrical stimulation (charge transfer 0.8-4.8 nC) and multielectrode recording in the face representation of the primary somatosensory cortex of ketamine anesthetized rats was determined to be about 1,350 mum. The evoked activity inside this range consisted in a sequence of fast excitatory response followed by an inhibition lasting >100 ms. These 2 responses could not be separated by varying the intensity of stimulation while a slow excitatory rebound after the inhibitory response was restricted to higher stimulus intensities (>2.4 nC). Stimulation frequencies of 20 and 40 Hz evoked repetitive excitatory response standing out against a continuous background of inhibition. At 5- and 10-Hz stimulation, the inhibitory response showed a complex interaction pattern attributed to highly sublinear superposition of individual inhibitory responses. The present data help to elucidate the neuronal underpinnings of behavioral effects of microstimulation. Furthermore, they provide essential information to determine spatiotemporal constraints for purposeful multielectrode stimulation in the neocortex.