Pócsai Károly, Kálmán Mihály
Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary (KP, MK).
J Histochem Cytochem. 2015 May;63(5):367-83. doi: 10.1369/0022155415575027. Epub 2015 Feb 11.
The subfornical organ (SFO) is a circumventricular organ with a chemosensitive function, and its vessels have no blood-brain barrier. Our study investigated the glial and vascular components in the SFO to determine whether their distributions indicate subdivisions, how to characterize the vessels and how to demarcate the SFO. To this end, we investigated glial markers (GFAP, glutamine synthetase, S100) and other markers, including vimentin and nestin (immature glia), laminin (basal lamina), β-dystroglycan (glio-vascular connections), and aquaporin 4 (glial water channels). We determined that the 'shell' of the SFO was marked by immunoreactivity for S100, GFAP and aquaporin 4. Nestin immunoreactivity was characteristic of the 'core'. Vimentin was almost evenly distributed. Glutamine synthetase immunoreactivity occurred in the shell but its expression was sparse. Vessels in the core were decorated with laminin but showed a discontinuous expression of aquaporin 4. Vimentin and GFAP staining was usually in separate glial elements, which may be related to their functional differences. Similar to other vessels in the brain, β-dystroglycan was detected along the shell vessels but laminin was not. The gradual disappearance of the laminin immunopositivity was attributed to the gradual disappearance of the perivascular space. Thus, our findings suggest that the shell and core glio-vascular structures are adapted to different sensory functions: osmoperception and the perception of circulating peptides, respectively.
穹窿下器官（SFO）是一种具有化学感受功能的室周器官，其血管没有血脑屏障。我们的研究调查了穹窿下器官中的神经胶质和血管成分，以确定它们的分布是否表明存在细分，如何对血管进行特征描述以及如何界定穹窿下器官。为此，我们研究了神经胶质标记物（胶质纤维酸性蛋白、谷氨酰胺合成酶、S100）和其他标记物，包括波形蛋白和巢蛋白（未成熟神经胶质）、层粘连蛋白（基膜）、β-肌营养不良聚糖（神经胶质-血管连接）和水通道蛋白4（神经胶质水通道）。我们确定穹窿下器官的“壳”以S100、胶质纤维酸性蛋白和水通道蛋白4的免疫反应性为特征。巢蛋白免疫反应性是“核心”的特征。波形蛋白几乎均匀分布。谷氨酰胺合成酶免疫反应性出现在“壳”中，但其表达稀疏。“核心”中的血管有层粘连蛋白修饰，但水通道蛋白4的表达不连续。波形蛋白和胶质纤维酸性蛋白染色通常存在于不同的神经胶质成分中，这可能与它们的功能差异有关。与大脑中的其他血管类似，β-肌营养不良聚糖在“壳”血管中被检测到，但层粘连蛋白未被检测到。层粘连蛋白免疫阳性的逐渐消失归因于血管周围间隙的逐渐消失。因此，我们的研究结果表明，“壳”和“核心”的神经胶质-血管结构分别适应不同的感觉功能：渗透压感知和循环肽感知。
