硬骨鱼表现出最明显和最广泛的成年神经发生。最近,据报道,鱼类视神经顶盖(OT)的功能发育和新生神经元的命运。为了确定神经发生在OT中的作用,这项研究使用组织学,免疫组织化学,和18个成年莫莉鱼标本(Poeciliasphenops)的电子显微镜研究。Molly鱼的OT是位于中脑背侧的双侧叶状结构。它表现出由交替的纤维层和细胞层组成的层压结构,分为六个主要层次。视神经层(SO)由视神经纤维提供,其中神经纤维是主要成分。在纤维层和皮肤表层(SFGS)中观察到具有微管束的放射状双极神经元。此外,可以观察到少突胶质细胞的过程包裹在神经纤维周围。地层专辑centrale(SAC)主要由地层中心(SGC)的轴突和大构造组成,梨形,和水平神经元。SO的神经元细胞和SAC的大顶盖细胞表达自噬相关蛋白5(APG5)。白细胞介素-1β(IL-1β)在SGC的神经元和神经胶质细胞中均表达。此外,诱导型一氧化氮合酶(iNOS)在SAC突触层的神经纤维和脑室周围层(SPV)的颗粒细胞中表达。此外,转化生长因子β(TGF-β),SRY盒转录因子9(SOX9),肌肉生长抑制素在增殖神经元中明显表达。在所有地层中,小胶质细胞表达S100蛋白和少突胶质细胞谱系转录因子2(Olig2),少突胶质细胞,和星形胶质细胞。总之,可以识别视神经顶盖中不同种类的神经元,每个人都有不同的角色。星形胶质细胞的存在,增殖神经元,干细胞突出了OT的再生能力。研究重点:Molly鱼的OT表现出由交替的纤维层和细胞层组成的层状结构,分为六个主要层次。在纤维层和皮肤表层(SFGS)中观察到具有微管束的放射状双极神经元。中央地层(SAC)主要由中央地层(SGC)的轴突和大构造组成,梨形,和水平神经元。诱导型一氧化氮合酶(iNOS)在SAC突触层的神经纤维和脑室周围(SPV)的颗粒细胞中表达。此外,转化生长因子β(TGF-β),SRY盒转录因子9(SOX9),肌肉生长抑制素在增殖神经元中明显表达。星形胶质细胞的存在,增殖神经元,干细胞突出了OT的再生能力。
Teleost fish exhibit the most pronounced and widespread adult neurogenesis. Recently, functional development and the fate of newborn neurons have been reported in the optic tectum (OT) of fish. To determine the role of neurogenesis in the OT, this study used histological, immunohistochemical, and electron microscopic investigations on 18 adult Molly fish specimens (Poecilia sphenops). The OT of the Molly fish was a bilateral lobed structure located in the dorsal part of the mesencephalon. It exhibited a laminated structure made up of alternating fiber and cellular layers, which were organized into six main layers. The stratum opticum (SO) was supplied by optic nerve fibers, in which the neuropil was the main component. Radial bipolar neurons that possessed bundles of microtubules were observed in the stratum fibrosum et griseum superficiale (SFGS). Furthermore, oligodendrocytes with their processes wrapped around the nerve fibers could be observed. The stratum album centrale (SAC) consisted mainly of the axons of the stratum griseum centrale (SGC) and the large tectal, pyriform, and horizontal neurons. The neuronal cells of the SO and large tectal cells of the SAC expressed autophagy-related protein-5 (APG5). Interleukin-1β (IL-1β) was expressed in both neurons and glia cells of SGC. Additionally, inducible nitric oxide synthase (iNOS) was expressed in the neuropil of the SAC synaptic layer and granule cells of the stratum periventriculare (SPV). Also, transforming growth factor beta (TGF-β), SRY-box transcription factor 9 (SOX9), and myostatin were clearly expressed in the proliferative neurons. In all strata, S100 protein and Oligodendrocyte Lineage Transcription Factor 2 (Olig2) were expressed by microglia, oligodendrocytes, and astrocytes. In conclusion, it was possible to identify different varieties of neurons in the optic tectum, each with a distinct role. The existence of astrocytes, proliferative neurons, and stem cells highlights the regenerative capacity of OT. RESEARCH HIGHLIGHTS: The OT of the Molly fish exhibited a laminated structure made up of alternating fiber and cellular layers, which were organized into six main layers. Radial bipolar neurons that possessed bundles of microtubules were observed in the stratum fibrosum et griseum superficiale (SFGS). The stratum album central (SAC) consisted mainly of the axons of the stratum griseum centrale (SGC) and the large tectal, pyriform, and horizontal neurons. Inducible nitric oxide synthase (iNOS) was expressed in the neuropil of the SAC synaptic layer and granule cells of the stratum periventricular (SPV). Also, transforming growth factor beta (TGF-β), SRY-box transcription factor 9 (SOX9), and myostatin were clearly expressed in the proliferative neurons. The existence of astrocytes, proliferative neurons, and stem cells highlights the regenerative capacity of OT.