Crone C, Olesen S P
Brain Res. 1982 Jun 3;241(1):49-55. doi: 10.1016/0006-8993(82)91227-6.
A newly developed technique for determination of the electrical resistance of the capillary wall was applied to microvessels at the surface of the frog brain. Current was injected into a capillary or venule via a microelectrode and the ensuing intravascular potential profile away from the current source was determined with a second microelectrode placed at various positions along the capillary. The membrane resistance was calculated according to the theory for leaky cables used in determinations of axon membrane resistance. The average resistance was 1870 omega . cm2. Since the surface vessels of the frog brain are devoid of glial investment but otherwise similar to brain parenchymal vessels, the results prove that the endothelium is the site of the blood-brain barrier. The electrical resistance is similar to that of a 'tight' epithelium.
一种新开发的用于测定毛细血管壁电阻的技术被应用于青蛙脑表面的微血管。电流通过微电极注入毛细血管或小静脉，然后用第二个微电极在沿毛细血管的不同位置测定远离电流源的血管内电位分布。根据用于测定轴突膜电阻的漏电电缆理论计算膜电阻。平均电阻为1870Ω·cm²。由于青蛙脑的表面血管没有神经胶质覆盖，但在其他方面与脑实质血管相似，结果证明内皮是血脑屏障的部位。其电阻与“紧密”上皮的电阻相似。
