Training on a visual task improves the outcome of optic nerve regeneration
Training on a visual task improves the outcome of optic nerve regeneration
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DOI：
10.1089/089771503770802925
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发表时间：
2003-11-01
影响因子：
4.2
通讯作者：
Dunlop, SA
中科院分区：
文献类型：
--
作者：
Beazley, LD;Rodger, J;Dunlop, SA
尽管大多数视网膜神经节细胞存活，轴突再生到视顶盖，但蜥蜴Ctenophorus ornatus的视神经再生功能障碍。6个月时再生的视网膜顶盖投射具有粗糙的地形，但到1岁时是无序的;通过实验眼，视觉诱发的行为是不存在的。在这里，我们评估训练对视神经再生结果的影响。蜥蜴被训练捕捉在单眼视野内的猎物。然后切断一条视神经，并在整个再生过程中恢复视觉刺激。在训练组中，演示仅限于正在进行视神经再生的眼睛;对于未训练组，刺激未手术的眼睛。在训练的动物中，瞳孔反应恢复，但在未经训练的动物中没有。在1岁时，训练的动物定向并捕获猎物;未经训练的动物表现出最小的定向，未能捕获猎物。通过体外电生理记录和碳菁染料追踪评估，训练组中再生的视网膜顶盖投射是局部的，但未训练组中则不然。在体外电生理记录应用神经递质拮抗剂的顶盖显示，GABA能抑制的水平是温和的训练动物，但在未经训练的组升高，反应主要是AMPA介导的两组。我们的结论是，培训提高了再生的行为结果，大概是通过稳定和完善的瞬态视网膜顶盖地图，防止建立顶盖抑制。研究结果表明，对于哺乳动物成功的中枢神经再生，可能有必要引入训练来补充刺激轴突再生的程序。
Optic nerve regeneration in a lizard, Ctenophorus ornatus, is dysfunctional despite survival of most retinal ganglion cells and axon regeneration to the optic tectum. The regenerated retino-tectal projection at 6 months has crude topography but by I year is disordered; visually-elicited behavior is absent via the experimental ye. Here, we assess the influence of training on the outcome of optic nerve regeneration. Lizards were trained to catch prey presented within the monocular field of either eye. One optic nerve was then severed and visual stimulation resumed throughout regeneration. In the trained group, presentation was restricted to the eye undergoing optic nerve regeneration; for the untrained group, the unoperated eye was stimulated. Pupil responses returned in trained but not in untrained animals. At 1 year, trained animals oriented to and captured prey; untrained animals demonstrated minimal orienting and failed to capture prey. Regenerated retino-tectal projections were topographic in the trained but not in the untrained group as assessed by in vitro electrophysiological recording and by carbocyanine dye tracing. In vitro electrophysiological recording during application of neurotransmitter antagonists to the tectum revealed that the level of GABAergic inhibition was modest in trained animals but elevated in the untrained group; responses were mainly AMPA-mediated in both groups. We conclude that training improves the behavioral outcome of regeneration, presumably by stabilizing and refining the transient retino-tectal map and preventing a build-up of tectal inhibition. The results suggest that for successful central nerve regeneration to occur in mammals, it may be necessary to introduce training to complement procedures stimulating axon regeneration.