Morphology of the turtle accessory optic system.
Morphology of the turtle accessory optic system.
复制标题
乌龟辅助光学系统的形态。
DOI：
10.1017/s0952523803206064
复制
发表时间：
2003
影响因子：
1.9
通讯作者：
Ariel,Michael
中科院分区：
文献类型：
--
作者：
Martin,John;Kogo,Naoki;Fan,TianXing;Ariel,Michael
运动视觉世界的神经信号是由投射到脊椎动物脑干副视觉系统的视网膜神经节细胞亚类检测到的。我们研究了这些脑干神经元的树突形态和方向调节，以了解它们在视觉加工中的作用。在对侧视网膜上漂移全场棋盘图案，同时在体外完整脑干制备的基底视核上进行全细胞记录。神经生物素在记录过程中扩散到神经元中，随后在脑切片中定位。使用适当的计算机软件跟踪神经元形态，分析它们在脑干中的位置。大多数标记的神经元在形状上是梭状的，并且在它们的过程中有许多变异。大多数树突树在垂直于核的背尾轴的横向平面上展开。脑干表面附近的神经元常向脑干表面切向定向，而核背侧更多的细胞向脑干表面径向定向。对nissl染色神经元的进一步分析显示，最大的神经元位于细胞核的吻侧和内侧部分，尽管神经元最密集地聚集在细胞核的中部。在这个样本中，神经元的视觉反应的首选方向与它们在细胞核中的形态和位置无关。因此，海龟副视系统细胞的形态似乎取决于其在细胞核内的位置，而其视觉反应可能取决于与每个细胞接触的突触输入。
Neural signals of the moving visual world are detected by a subclass of retinal ganglion cells that project to the accessory optic system in the vertebrate brainstem. We studied the dendritic morphologies and direction tuning of these brainstem neurons in turtle (Pseudemys scripta elegans) to understand their role in visual processing. Full-field checkerboard patterns were drifted on the contralateral retina while whole-cell recordings were made in the basal optic nucleus in an intact brainstem preparation in vitro. Neurobiotin diffused into the neurons during the recording and was subsequently localized in brain sections. Neuronal morphologies were traced using appropriate computer software to analyze their position in the brainstem. Most labeled neurons were fusiform in shape and had numerous varicosities along their processes. The majority of dendritic trees spread out in a transverse plane perpendicular to the rostrocaudal axis of the nucleus. Neurons near the brainstem surface were often oriented tangential to that surface, whereas more cells at the dorsal side of the nucleus were oriented radial to the brainstem surface. Further analysis of Nissl-stained neurons revealed the largest neurons are located in the rostral and medial portions of the nucleus although neurons are most densely packed in the middle of the nucleus. The preferred directions of the visual responses of the neurons in this sample did not correlate with their morphology and position in the nucleus. Therefore, the morphology of the cells in the turtle accessory optic system appears dependent on its position within the nucleus while its visual responses may depend on the synaptic inputs that contact each cell.