Temporal structure in spiking patterns of ganglion cells defines perceptual thresholds in rodents with subretinal prosthesis.
Temporal structure in spiking patterns of ganglion cells defines perceptual thresholds in rodents with subretinal prosthesis.
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DOI：
10.1038/s41598-018-21447-1
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发表时间：
2018-02-16
影响因子：
4.6
通讯作者：
Palanker D
中科院分区：
文献类型：
--
作者：
Ho E;Lorach H;Goetz G;Laszlo F;Lei X;Kamins T;Mariani JC;Sher A;Palanker D
视网膜下假体的设计是为了通过电刺激视网膜内部神经元来恢复因视网膜变性而失明的患者的视力。为了将视网膜输出与感知联系起来，我们研究了接受20 Hz全场脉冲照射的光伏视网膜下假体的盲鼠的行为阈值，并在体外测量了视网膜神经节细胞对类似刺激的反应。在行为上，大鼠对亮度的变化表现出惊人的反应，平均对比度阈值为12%，这不能用平均RGC峰化率的变化来解释。然而，RGC在棘波计时上表现出毫秒级的变化，即使平均速率没有显著变化。在12%的时间对比度下，假体反应的激发模式的变化与在健康视网膜的可见光刺激中2.3%的对比度步骤一样显著。这表明，尖峰模式的毫秒级变化定义了假体视觉的感知阈值。在突发刺激中，对最后一个脉冲的反应持续时间比突发期间的稳态反应更长。这可能被解释为对假肢刺激的兴奋性关闭反应，并可以解释对光照减少的行为反应。在交付给视网膜下假体之前对图像进行对比度增强可以部分补偿假体视觉对比度敏感性的降低。
Subretinal prostheses are designed to restore sight in patients blinded by retinal degeneration using electrical stimulation of the inner retinal neurons. To relate retinal output to perception, we studied behavioral thresholds in blind rats with photovoltaic subretinal prostheses stimulated by full-field pulsed illumination at 20 Hz, and measured retinal ganglion cell (RGC) responses to similar stimuli ex-vivo. Behaviorally, rats exhibited startling response to changes in brightness, with an average contrast threshold of 12%, which could not be explained by changes in the average RGC spiking rate. However, RGCs exhibited millisecond-scale variations in spike timing, even when the average rate did not change significantly. At 12% temporal contrast, changes in firing patterns of prosthetic response were as significant as with 2.3% contrast steps in visible light stimulation of healthy retinas. This suggests that millisecond-scale changes in spiking patterns define perceptual thresholds of prosthetic vision. Response to the last pulse in the stimulation burst lasted longer than the steady-state response during the burst. This may be interpreted as an excitatory OFF response to prosthetic stimulation, and can explain behavioral response to decrease in illumination. Contrast enhancement of images prior to delivery to subretinal prosthesis can partially compensate for reduced contrast sensitivity of prosthetic vision.
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影响因子：
4.4
作者：
Lorach, Henri;Lei, Xin;Palanker, Daniel
通讯作者：
Palanker, Daniel
影响因子：
--
作者：
Davis, M
通讯作者：
Davis, M
影响因子：
1.8
作者：
Lorach, Henri;Goetz, Georges;Mandel, Yossi;Lei, Xin;Kamins, Theodore I.;Mathieson, Keith;Huie, Philip;Dalal, Roopa;Harris, James S.;Palanker, Daniel
通讯作者：
Palanker, Daniel
影响因子：
4
作者：
Goetz GA;Mandel Y;Manivanh R;Palanker DV;Čižmár T
通讯作者：
Čižmár T
影响因子：
1.9
作者：
Leaton, RN;Brucato, FH
通讯作者：
Brucato, FH