Preparation of whisker hair follicles for the in situ patch-clamp recordings from Merkel cells. A) Image shows a whisker hair follicle with its capsule cut open using an eye scissors. The arrow indicates the core of the whisker hair follicle (Follicle core). B) The follicle core (arrow indicated) is separated from the capsule (arrowhead indicated). C) The follicle core is affixed in a recording chamber by a tissue anchor. The arrow indicates the enlargement part of the follicle core. D) Image shows the surface of the enlargement part of the follicle core viewed under a 40X objective. Some whisker afferent nerve fibers can be observed in this region (arrow indicated). E) A glass electrode (arrow indicated) is used to break through the tissue layers and its tip reaches the glassy membranes in the follicle core. F-G) The electrode (star indicated) is moved forward, backward, left and right (indicated by dashed lines) to push off the tissue barrier (F) and to expose the underneath Merkel cell layer (G). H-I) Image shows Merkel cell layer in the whisker hair follicle preparation after vital staining with quinacrine. The image in H is under a bright field and in I under a fluorescent microscope (40X objective). The arrow in H and I indicates a Merkel cell, and in I the cell shows green fluorescence.