Castro Antonio, Becerra Manuela, Manso María Jesús, Sherwood Nancy M, Anadón Ramón
Department of Cell and Molecular Biology, Faculty of Sciences, University of A Coruña, Spain.
J Comp Neurol. 2006 Jan 1;494(1):54-62. doi: 10.1002/cne.20783.
The present study reports the organization of the Hesse cell axonal system in the central nervous system of the amphioxus, with the use of a polyclonal antiserum raised against lamprey gonadotropin-releasing hormone-I (GnRH-I). In the spinal cord, the rhabdomeric photoreceptor cells of the bicellular organs were well labeled with this antibody. These cells sent smooth, straight, lateral processes that bent and became beaded as they passed ventrally and crossed to the contralateral side of the cord. There, the processes of several cells aggregated to give rise to a longitudinal fiber bundle. Beaded collaterals of these processes were directed to ventral neuropil and did not appear to contact giant Rohde cell axons. The crossed projections of the Hesse photoreceptors are compared with those of vertebrate retinal ganglion cells. Other antisera raised against GnRH weakly labeled rhabdomeric photoreceptors located dorsally in the brain, the Joseph cells. The finding that GnRH antibodies label amphioxus photoreceptor cells and axons is not definitive proof that the photoreceptors contain GnRH. Regardless of whether the antibody recognizes amphioxus GnRH, which has not yet been identified by structure, the antibody has revealed the processes of the Hesse photoreceptor cells.
本研究利用针对七鳃鳗促性腺激素释放激素 -I（GnRH -I）产生的多克隆抗血清，报告了文昌鱼中枢神经系统中黑塞细胞轴突系统的组织结构。在脊髓中，双细胞器官的视杆感光细胞被这种抗体很好地标记。这些细胞发出光滑、笔直的侧突，这些侧突在腹侧通过并交叉到脊髓对侧时会弯曲并形成串珠状。在那里，几个细胞的突起聚集形成一个纵向纤维束。这些突起的串珠状侧支指向腹侧神经毡，似乎不与巨大的罗德细胞轴突接触。将黑塞感光细胞的交叉投射与脊椎动物视网膜神经节细胞的交叉投射进行了比较。其他针对GnRH产生的抗血清对位于脑背侧的视杆感光细胞——约瑟夫细胞进行了弱标记。GnRH抗体标记文昌鱼感光细胞和轴突这一发现并非感光细胞含有GnRH的确凿证据。无论该抗体是否识别尚未通过结构鉴定的文昌鱼GnRH，该抗体都揭示了黑塞感光细胞的突起。
