FIG. 5.

Nuclear patch-clamp electrophysiology. A: schematic of cell nucleus, illustrating that the outer membrane of the double-membrane nuclear envelope is continuous with the endoplasmic reticulum (ER), with the lumen between the two membranes continuous with the ER lumen. Patch-clamping isolated Xenopus oocyte nucleus (B) and insect Sf9 cell nucleus (C) visualized on the stage of a patch-clamp microscope, with patch pipettes forming giga-ohm seals on the outer nuclear membrane. Horizontal shadow over the Xenopus nucleus is the edge of a stabilizing piece of coverslip. Intact Sf9 cell is also present in C. [B modified from Mak et al. (287).]