Sun G, Lin L P, Chen S L, Yoshida S, Kato K, Suzuki J, Momota Y, Shiosaka S, Tohyama M
Department of Anatomy and Neuroscience, Osaka University Medical School, Suita, Japan.
Med J Osaka Univ. 1994 Sep;43(1-4):1-8.
Light and electron microscopic observation showed two types of neuronal immunostaining for basic fibroblast growth factor in the hippocampal CA2 subfield, where the densest immunoreactive neurons were localized in the brain. One neuronal type showed intense nuclear (eu- and heterochromatin) immunostaining but weak cytoplasmic immunostaining (N-type), and the other showed intense cytoplasmic but no or only faint nuclear immunoreactivity (C-type). The N-type also showed weak immunoreactivity in the perinuclear rough endoplasmic reticulum and contained bFGF mRNA as observed by in situ hybridization histochemistry, showed that this type can produces the bFGF protein. The N-type localized exclusively in the CA2 subfield. The C-type showed strong immunoreactivity on the rER, free ribosomes, and Golgi apparatus, although no clear evidence for bFGF production was observed. The multivesicular bodies, a pathway of endocytosis in hippocampal neurons showed apparent immunoreactivity under EM observation of both of types neurons (Parton et al. J. Cell Biol. 119: 123-137, 1992) suggesting a receptor-mediated type of incorporation of the bFGF.
光镜和电镜观察显示，在脑内免疫反应性神经元最密集的海马CA2亚区，存在两种碱性成纤维细胞生长因子神经元免疫染色类型。一种神经元类型显示强烈的核（常染色质和异染色质）免疫染色，但胞质免疫染色较弱（N型），另一种显示强烈的胞质免疫反应，但无核免疫反应或仅有微弱的核免疫反应（C型）。N型在核周粗面内质网也显示弱免疫反应性，原位杂交组织化学观察显示其含有bFGF mRNA，表明该类型可产生bFGF蛋白。N型仅定位于CA2亚区。C型在粗面内质网、游离核糖体和高尔基体上显示强免疫反应性，尽管未观察到bFGF产生的确切证据。多泡体是海马神经元内吞作用的一条途径，在两种类型神经元的电镜观察下均显示明显的免疫反应性（Parton等人，《细胞生物学杂志》119: 123 - 137, 1992），提示存在受体介导的bFGF摄取类型。
