Robinson I M, Finnegan J M, Monck J R, Wightman R M, Fernandez J M
Department of Physiology and Biophysics, Mayo Clinic, Rochester, MN 55905, USA.
Proc Natl Acad Sci U S A. 1995 Mar 28;92(7):2474-8. doi: 10.1073/pnas.92.7.2474.
"Snapshot" images of localized Ca2+ influx into patch-clamped chromaffin cells were captured by using a recently developed pulsed-laser imaging system. Transient opening of voltage-sensitive Ca2+ channels gave rise to localized elevations of Ca2+ that had the appearance of either "hotspots" or partial rings found immediately beneath the plasma membrane. When the Ca2+ imaging technique was employed in conjunction with flame-etched carbon-fiber electrodes to spatially map the release sites of catecholamines, it was observed that the sites of Ca2+ entry and catecholamine release were colocalized. These results provide functional support for the idea that secretion occurs from "active zone"-like structures in neuroendocrine cells.
利用最近开发的脉冲激光成像系统，捕捉到了局部Ca2+流入膜片钳嗜铬细胞的“快照”图像。电压敏感Ca2+通道的瞬时开放导致Ca2+局部升高，其表现为质膜正下方立即出现的“热点”或部分环。当将Ca2+成像技术与火焰蚀刻碳纤维电极结合使用，以在空间上绘制儿茶酚胺释放位点时，观察到Ca2+进入位点和儿茶酚胺释放位点共定位。这些结果为神经内分泌细胞中从“活性区”样结构发生分泌这一观点提供了功能支持。
