Fig. 4: Dynamic contraction of the secretory duct occurs at the concertina-like region surrounded by coiled nerve fibers.

a Eccrine gland costained with CMDR and for αSMA. b, c Magnified views of the secretory duct (b; red solid box in a) and the excretory duct (c; red dashed box in a). The white dashed lines indicate the outline of the excretory duct. d Time-lapse images of a CMDR-stained eccrine gland before (left) and after (right) the addition of 10 mM pilocarpine. The red arrowheads indicate the position of duct deformation. The white arrows indicate the blood vessels. The white arrowheads indicate concertina-like signals in the secretory duct. e Magnified image of the white dotted box in d. f The secretory duct costained to visualize PGP9.5 (green), αSMA (magenta) and nuclei (blue). White arrowheads indicate PGP9.5-positive signals.