Figure 5.

Catecholaminergic or tyrosine hydroxylase-positive fibers course in conjunction with vagal IMA neurites as they travel through bundles and fascicles in the gastric wall and as they form the terminal arrays of the IMAs. Panel A illustrates a bundle of fibers located proximally in the wall of the stomach that contains several IMA fibers (DAB, brown) and several TH+ axons (Vector VIP, violet). Panels B, C, D and F illustrate single TH+ (Vector VIP, violet) axons co-mingling with the parallel neurites and bridging fibers of individual IMAs. Panels E¹ through E⁶ illustrate individual TH+ fibers (Vector VIP, violet) running in tandem with long parallel neurites of IMAs (DAB, brown) within the arrays. Both the (presumptively sympathetic efferent) TH+ fibers and the vagal afferent IMA fibers contain varicosities that could be en passage appositions. Scale bars: Panel A: 10 μm; Panel D: 10 μm, applies to panels B, C, and D; Panel E⁶: 10 μm, applies to panels E¹ through E⁶; Panel F: 10 μm.