Sullivan Robert K P, Woldemussie Elizabeth, Pow David V
School of Biomedical Sciences, University of Newcastle, Newcastle, NSW, Australia.
Invest Ophthalmol Vis Sci. 2007 Jun;48(6):2782-91. doi: 10.1167/iovs.06-1283.
To determine whether structural plasticity is evident in human retinal tissues in response to age-related macular degeneration (AMD). Remodeling events such as sprouting of neuronal processes and the reconnection of synapses are essential elements in repairing any damage to adult nervous tissues such as might occur in response to insults such as strokes or in AMD.
The anatomic architecture of normal and AMD-affected human retinas was examined in the central, midperipheral, and far-peripheral regions. The retina, by virtue of its well-organized laminar structure, allows the identification and analysis of abnormal projections or connections of neuronal elements.
In AMD-afflicted retinas, but not in normal aged human retinas, a large number of photoreceptor synapses across the entire retina retract into the outer nuclear layer. This event evokes the subsequent outgrowth of dendrites from the postsynaptic bipolar cells, again across the entire retina, and the subsequent reformation of synaptic contacts between photoreceptor and bipolar cells.
These findings illustrate that there are anatomic changes in the AMD retina at all eccentricities, not just in the macular region. Aged human retinal neurons have the capacity to form new synapses, and this finding may be important when investigating possible means of repairing the damaged human retina.
确定在年龄相关性黄斑变性（AMD）患者的视网膜组织中是否存在明显的结构可塑性。诸如神经元突起的萌发和突触重新连接等重塑事件是修复成年神经组织损伤（如中风或AMD中可能发生的损伤）的关键要素。
在中央、中周边和远周边区域检查正常和受AMD影响的人类视网膜的解剖结构。视网膜因其组织良好的层状结构，便于识别和分析神经元成分的异常投射或连接。
在受AMD影响的视网膜中，而非正常老年人类视网膜中，整个视网膜的大量光感受器突触回缩至外核层。这一事件引发了突触后双极细胞树突随后在整个视网膜的再次生长，以及光感受器与双极细胞之间突触联系的随后重新形成。
这些发现表明，AMD视网膜在所有偏心度处均存在解剖学变化，而非仅在黄斑区域。老年人类视网膜神经元具有形成新突触的能力，这一发现对于研究修复受损人类视网膜的可能方法或许具有重要意义。
