Activation of ganglion cells in wild-type and rd1 mouse retinas with monophasic and biphasic current pulses
Activation of ganglion cells in wild-type and rd1 mouse retinas with monophasic and biphasic current pulses
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DOI：
10.1088/1741-2560/6/3/035004
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发表时间：
2009-06-01
影响因子：
4
通讯作者：
Rizzo, Joseph F., III
中科院分区：
文献类型：
--
作者：
Jensen, Ralph J.;Rizzo, Joseph F., III
我们和其他研究小组正在设计全电子视网膜假体，为因感光细胞变性而失明的患者提供视力。在这项研究中，我们研究了刺激波形对刺激视网膜神经网络时激活视网膜神经节细胞（RGC）所需的电流量的影响。用持续时间为1 ms的阴极和阳极双相电流脉冲刺激野生型和rd 1小鼠的离体视网膜，并通过位于视网膜下的所有电极传递对称双相电流脉冲（每相1 ms）。对于野生型和rd 1小鼠视网膜，阴极电流脉冲在激活大多数RGC方面效果最差。阴极电流脉冲的中值阈值电流比全阳极或双相电流脉冲的中值阈值电流高2.0-4.4倍。在野生型小鼠视网膜中，用阳极电流脉冲激活RGCs的中值阈值电流比用双相电流脉冲激活RGCs的中值阈值电流低23%。在rd 1小鼠视网膜中，阳极和双相电流脉冲的中值阈值电流大致相同。然而，双相脉冲刺激的rd 1 RGCs阈值的变化远小于阳极脉冲刺激。因此。对称的双相电流脉冲可能是用于在缺乏光感受器的视网膜中激活最大数量的RGC的最佳刺激。
We and other research groups are designing all electronic retinal prosthesis to provide vision for patients who are blind due to photoreceptor degeneration. In this Study, we examined the effect Of stimulus waveform Oil the amount Of Current needed to activate retinal ganglion cells (RGCs) when the retinal neural network is stimulated. Isolated retinas of wild-type and rd1 mice were stimulated with cathodal and anodal monophasic Current Pulses of 1 ms duration and symmetric biphasic current pulses (1 ms per phase) delivered through all electrode that was located subretinally. For both wild-type and rd1 Mouse retinas, cathodal current pulses were least effective in activating most RGCs. The median threshold Current for a cathodal current pulse was 2.0-4.4 fold higher than the median threshold current for either all anodal or a biphasic current pulse. In wild-type mouse retinas, the median threshold Current for activating RGCs with anodal Current pulses was 23% lower than that with biphasic Current pulses. In rd1 mouse retinas, the median threshold currents for anodal and biphasic Current pulses were about the same. However, the variance in thresholds of rd1 RGCs for biphasic pulse stimulation was Much smaller than for anodal pulse stimulation. Thus. a symmetric biphasic current pulse may be the best Stimulus for activating the greatest number of RGCs in retinas devoid of photoreceptors.