Rash J E, Yasumura T, Dudek F E
Department of Anatomy and Neurobiology, Colorado State University, Fort Collins, CO 80523, USA.
Cell Biol Int. 1998 Nov;22(11-12):731-49. doi: 10.1006/cbir.1998.0392.
The historical development of concepts of gap junctions as sites for electrical, ionic, and metabolic coupling is reviewed, from the initial discovery of gap junctions linking heart cells, to the current concepts that gap junctions represent 'electrotonic synapses' between neurons. The ultrastructure and immunocytochemistry of gap junctions in heart, brain, and spinal cord of adult rats is examined using conventional thin sections, negative staining, grid-mapped freeze-fracture replicas, and immunogold-labeled freeze-fracture replicas. We review evidence for neuronal gap junctions at 'mixed' (combined electrical and chemical) synapses throughout adult rat spinal cord. We also show immunogold labeling of connexin43 in astrocyte and ependymocyte gap junctions and of connexin32 in oligodendrocyte gap junctions. Ultrastructural and freeze-fracture immunocytochemical methods have provided for definitive determination of the number, size, histological distribution, and connexin composition of gap junctions between neurons in all regions of the central nervous systems of vertebrate species.
本文回顾了间隙连接作为电、离子和代谢偶联位点的概念的历史发展，从最初发现连接心脏细胞的间隙连接，到目前认为间隙连接代表神经元之间“电紧张性突触”的概念。使用传统薄切片、负染色、网格映射冷冻断裂复制品和免疫金标记冷冻断裂复制品，研究了成年大鼠心脏、大脑和脊髓中间隙连接的超微结构和免疫细胞化学。我们回顾了成年大鼠脊髓中“混合”（电和化学结合）突触处神经元间隙连接的证据。我们还展示了星形胶质细胞和室管膜细胞间隙连接中连接蛋白43的免疫金标记，以及少突胶质细胞间隙连接中连接蛋白32的免疫金标记。超微结构和冷冻断裂免疫细胞化学方法已用于明确确定脊椎动物物种中枢神经系统所有区域神经元之间间隙连接的数量、大小、组织学分布和连接蛋白组成。
