Fig. 5. Catecholaminergic and cholinergic co-phenotypes in primate intrinsic cardiac innervation.
Confocal images of double immunofluorescence illustrate that TH (B, C) and VMAT2 (E, F) are present in a major subpopulation of the VAChT-positive neuronal cell bodies of an intracardiac parasympathetic ganglion. Note adjacent TH-positive, VAChT-negative extrinsic catecholaminergic nerve fibers (asterisks in A and B). A subpopulation of TH-positive catecholaminergic nerves in the left ventricle also stains for VAChT (arrows in G, H, I). Note discrepancies between varicose fiber space staining for VAChT and TH in G-I which are due to the pan-cytoplasmic varicose and non-varicose localization of the enzyme TH in contrast to the concentration of VAChT to areas of the nerve fiber with local enrichment of cholinergic small clear vesicles. Arrow heads in G-I mark TH+ but VAChT negative fiber. Size bars 50 μm (A-C; D-I).