Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado.
Department of Biology, The University of Akron, Akron, Ohio.
J Comp Neurol. 2018 Aug 1;526(11):1749-1759. doi: 10.1002/cne.24446. Epub 2018 Apr 29.
Functionally distinct retinal ganglion cells have density and size gradients across the mouse retina, and some degenerative eye diseases follow topographic-specific gradients of cell death. Hence, the anatomical orientation of the retina with respect to the orbit and head is important for understanding the functional anatomy of the retina in both health and disease. However, different research groups use different anatomical landmarks to determine retinal orientation (dorsal, ventral, temporal, nasal poles). Variations in the accuracy and reliability in marking these landmarks during dissection may lead to discrepancies in the identification and reporting of retinal topography. The goal of this study was to compare the accuracy and reliability of the canthus, rectus muscle, and choroid fissure landmarks in reporting retinal orientation. The retinal relieving cut angle made from each landmark during dissection was calculated based on its relationship to the opsin transition zone (OTZ), determined via a custom MATLAB script that aligns retinas from immunostained s-opsin. The choroid fissure and rectus muscle landmarks were the most accurate and reliable, while burn marks using the canthus as a reference were the least. These values were used to build an anatomical map that plots various ocular landmarks in relationship to one another, to the horizontal semicircular canals, to lambda-bregma, and to the earth's horizon. Surprisingly, during normal locomotion, the mouse's opsin gradient and the horizontal semicircular canals make equivalent 6° angles aligning the OTZ near the earth's horizon, a feature which may enhance the mouse's ability to visually navigate through its environment.
功能不同的视网膜神经节细胞在小鼠视网膜上呈现出密度和大小的梯度分布，而一些退行性眼病则遵循特定的细胞死亡拓扑学梯度。因此，视网膜相对于眼眶和头部的解剖方位对于理解健康和疾病状态下视网膜的功能解剖学非常重要。然而，不同的研究小组使用不同的解剖学标志来确定视网膜的方位（背侧、腹侧、颞侧、鼻侧极）。在解剖过程中，这些标志的标记准确性和可靠性存在差异，可能导致视网膜拓扑结构的识别和报告存在差异。本研究的目的是比较眼角、直肌和脉络膜裂标志在报告视网膜方位时的准确性和可靠性。根据它们与视蛋白转换区（OTZ）的关系，通过一个定制的 MATLAB 脚本计算每个标志在解剖过程中所做的视网膜松解切口角度，该脚本通过对免疫染色 s-视蛋白的视网膜进行对齐来确定 OTZ。脉络膜裂和直肌标志是最准确和可靠的，而以眼角为参照的烧伤标记则是最不准确和不可靠的。这些值被用来构建一个解剖图谱，该图谱将各种眼球标志彼此之间、与水平半规管、lambda-矢状缝和地球地平线联系起来。令人惊讶的是，在正常运动过程中，老鼠的视蛋白梯度和水平半规管形成了等效的 6°角，使 OTZ 接近地球地平线，这一特征可能增强了老鼠在环境中进行视觉导航的能力。
