Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa.
Center for Neuroscience, University of California, Davis, California.
J Comp Neurol. 2019 Jul 1;527(10):1675-1688. doi: 10.1002/cne.24582. Epub 2018 Dec 9.
Early loss of vision produces dramatic changes in the functional organization and connectivity of the neocortex in cortical areas that normally process visual inputs, such as the primary and second visual area. This loss also results in alterations in the size, functional organization, and neural response properties of the primary somatosensory area, S1. However, the anatomical substrate for these functional changes in S1 has never been described. In the present investigation, we quantified the cortical and subcortical connections of S1 in animals that were bilaterally enucleated very early in development, prior to the formation of retino-geniculate and thalamocortical pathways. We found that S1 receives dense inputs from novel cortical fields, and that the density of existing cortical and thalamocortical connections was altered. Our results demonstrate that sensory systems develop in tandem and that alterations in sensory input in one system can affect the connections and organization of other sensory systems. Thus, therapeutic intervention following early loss of vision should focus not only on restoring vision, but also on augmenting the natural plasticity of the spared systems.
早期视力丧失会导致初级视皮层和第二视觉区等正常处理视觉输入的皮质区域的功能组织和连接发生显著变化。这种丧失还会导致初级躯体感觉皮层（S1）的大小、功能组织和神经反应特性发生改变。然而，S1 中这些功能变化的解剖学基础从未被描述过。在本研究中，我们在动物发育早期双侧眼球摘除后（在视网膜-节细胞和丘脑皮质通路形成之前），定量分析了 S1 的皮质和皮质下连接。我们发现 S1 接收来自新皮层区域的密集输入，并且现有的皮质和丘脑皮质连接的密度发生了改变。我们的结果表明，感觉系统是协同发育的，一个系统中的感觉输入的改变会影响其他感觉系统的连接和组织。因此，早期视力丧失后的治疗干预不仅应集中于恢复视力，还应增强未受损系统的自然可塑性。
