Fig. 6. Cholinergic markers are not colocalized with noradrenergic markers in cardiac nerve fibers.

(A–C) Immunostaining for TH (A) and VAChT (B), while located in very close proximity, were not in the same physical space, as evident by the lack of yellow in the overlay image (C). (D–F) Likewise, immunostaining for VMAT2 (D) and VAChT (E) were not colocalized in atrial nerve fibers or nerve fibers within ICG (F). Arrows indicate two examples of nerve fibers in which the labels were obviously not colocalized (F), even at a low magnification. Inserts at lower left show boxed regions at higher magnification. Panels (D–F) show maximum projection images complied from confocal scans spanning 8 µm, while panels (A–C) and all inserts show single optical sections. Scale bars indicate 150 µm in (A–C) and 50 µm in (D–F).