Nys Julie, Scheyltjens Isabelle, Arckens Lutgarde
Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven Leuven, Belgium.
Front Syst Neurosci. 2015 Apr 28;9:60. doi: 10.3389/fnsys.2015.00060. eCollection 2015.
The groundbreaking work of Hubel and Wiesel in the 1960's on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research.
20世纪60年代，休伯尔和威塞尔关于眼优势可塑性的开创性工作引发了许多对哺乳动物视觉系统的研究，丰富了我们对其结构和功能的发育如何依赖于通过双眼的高质量视觉输入的理解。这些研究主要采用对不同物种进行眼睑缝合、黑暗饲养和眼罩遮盖等方法来减少或损害视觉输入，并产生了关于双眼视觉的广泛知识。然而，视觉皮层可塑性的所有方面和类型并未得到详尽阐述。在这方面，像眼球摘除这样更极端的剥夺方法，导致完全失明，似乎很有用，因为它对传入视觉通路甚至非视觉脑区有更广泛的影响。由于单眼摘除（ME）导致的单眼视觉会深刻影响对侧视网膜接受的皮层下和皮层结构，从而创造了一种强大的手段来研究双眼竞争不起作用的皮层可塑性现象。在本综述中，我们将介绍关于ME作为研究视觉和跨模态脑可塑性的实验工具的具体应用的现有知识，并比较从出生后早期到成年期的情况。将讨论在几种动物物种和人类患者中记录和研究的这种广泛感觉丧失的结构和生理后果。我们将总结ME研究如何有助于我们目前对感觉系统分化的理解，以及哺乳动物皮层回路的结构和功能如何因这种广泛的经验改变而形成。总之，我们将强调在视觉系统研究中，将ME添加到更长期的剥夺模型列表中的未来前景和临床相关性。
