Distribution of retinal responses evoked by transscleral electrical stimulation detected by intrinsic signal Imaging in macaque monkeys
Distribution of retinal responses evoked by transscleral electrical stimulation detected by intrinsic signal Imaging in macaque monkeys
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DOI：
10.1167/iovs.07-0727
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发表时间：
2008-05-01
影响因子：
4.4
通讯作者：
Miyake, Yozo
中科院分区：
文献类型：
--
作者：
Inomata, Koichi;Tsunoda, Kazushige;Miyake, Yozo
目的。电脉冲经巩膜传递时，视网膜上的电流分布尚未得到客观定量的明确测定。本研究的目的是利用本征信号成像技术确定猴视网膜电诱发神经活动的模式。用DTL电极经巩膜电刺激后，记录了猴视网膜的内在信号，即视网膜对红外光的反射变化。研究了改变电流刺激参数（如强度、持续时间和频率）的影响。电刺激引起视网膜后极反射率的均匀变化；也就是说，本征信号均匀变化。在中央凹处没有观察到本征信号的峰值。黄斑、黄斑周围和视盘的固有信号阈值无显著差异，暗适应和光适应条件下的阈值无显著差异。信号强度随刺激时间的延长而增加，刺激频率在15 ~ 20 hz时达到最大。经巩膜电刺激引起的猴视网膜的内在信号均匀地穿过眼底后极，很可能是由视网膜内层或中间层的激活引起的。这些功能测量可以作为绘制视网膜内部活动的诊断工具，通过这种工具可以对病变部位进行无创成像。
PURPOSE. The distribution of the electrical current over the retina when electrical pulses are delivered transsclerally has not been clearly determined objectively and quantitatively in humans. The purpose of this study was to determine the pattern of electrically evoked neural activity in the monkey retina by using intrinsic signal imaging.METHODS. The intrinsic signals of monkey retinas were recorded as changes in the reflectance of infrared light from the retina after transscleral electrical stimulation by DTL electrodes. The effects of changing the stimulus parameters ( e. g., intensity, duration, and frequency) of the electrical current, were investigated.RESULTS. Electrical stimulation evoked a uniform change in the reflectivity across the posterior pole of the retina; that is, the intrinsic signals changed uniformly. A peak of the intrinsic signal was not observed at the fovea. The threshold of the intrinsic signal was not significantly different for the macula, perimacula, and optic disc, and the threshold did not differ under dark- and light- adapted conditions. The strength of the signals increased with longer stimulus durations, and the maximum signals were obtained when the stimulus frequency was between 15 and 20 Hz.CONCLUSIONS. Intrinsic signals of the monkey retina evoked by transscleral electrical stimulation are elicited uniformly across the posterior pole of the fundus and most likely arise from activation of the inner or middle layers of the retina. These functional measurements could serve as a diagnostic tool for mapping the inner retinal activity, by which the site of a lesion can be noninvasively imaged.