Quantitative study of the somatosensory sensitization underlying cross-modal plasticity
Quantitative study of the somatosensory sensitization underlying cross-modal plasticity
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DOI：
10.1371/journal.pone.0208089
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发表时间：
2018-12-05
期刊：
影响因子：
3.7
通讯作者：
Yawo, Hiromu
中科院分区：
文献类型：
--
作者：
Abe, Kenta;Yawo, Hiromu
一种感觉模态的丧失会导致其他类型变得更具感知力（跨模态可塑性）。为了验证这一假设，即视力的丧失改变了体感系统的感知阈值，我们应用光遗传学直接操纵传入输入参与的须桶系统使用转基因大鼠（W-TChR 2 V4），表达通道视紫红质-2（ChR 2）选择性的大机械感受神经元在三叉神经节（TG）和周围神经末梢。W-TChR 2 V4大鼠的舔行为被条件化为在胡须区域上的蓝色LED光提示，同时改变光脉冲的幅度和持续时间。结果发现，在出生后26-30天，视觉剥夺大鼠的知觉阈值比对照组明显降低，视觉剥夺大鼠的知觉阈值比对照组明显降低（P26- 30，早期VD组），而P58-66（晚期VD组）则无。然而，晚期VD动物的感觉阈值与对照组相似。我们的研究结果表明，存在跨模态可塑性，在青少年时期的视力丧失增加了触觉的胡须参与的躯体感觉系统的敏感性。
Loss of one sensory modality can cause other types to become more perceptive (cross-modal plasticity). To test the hypothesis that the loss of vision changes the perceptual threshold in the somatosensory system, we applied optogenetics to directly manipulate the afferent inputs involved in the whisker-barrel system using a transgenic rat (W-TChR2V4) that expresses channelrhodopsin-2 (ChR2) selectively in the large mechanoreceptive neurons in the trigeminal ganglion (TG) and their peripheral nerve terminals. The licking behavior of W-TChR2V4 rat was conditioned to a blue LED light cue on the whisker area while the magnitude and duration of light pulses were varied. The perceptual threshold was thus quantitatively determined for each rat according to the relationship between the magnitude/duration of light and the reaction time between the LED light cue and the first licking event after it. We found that the perceptual threshold was more significantly reduced than the control non-deprived rats when the rats were visually deprived at postnatal 26-30 days (P26- 30, early VD group), but not at P58-66 (late VD group). However, the sensory threshold of a late VD animal was similar to that of a control. Our results suggest the presence of cross-modal plasticity by which the loss of vision at the juvenile period increased the sensitivity of the somatosensory system involved in the touch of whiskers.