|
Fig. 9
Catecholaminergic innervation of the intestine. (A) Schematic of 6dpf zebrafish larva with scanned sections as depicted in (B,C). (B) Sagittal section from XZ-orthoslice at 243 ?m of z-stack (dorsal scan, step size: 1 ?m, total depth: 507 ?m, total width: 509 ?m) of larval region including the gut. Dotted gray lines outline anatomical landmark structures rhombencephalon (RhE), swim bladder (SB) and intestine (Int). Dashed white vertical line indicates region of transverse section shown in C. Solid white horizontal lines indicate borders of regions used for Z-MIPs shown in (D?G). White arrowheads point to catecholaminergic structures in the RhE (region D), and in and around the SB, cell bodies anteriorly of the SB represent sympathetic ganglia (SG) and their projections (region F). (C) Transverse section from YZ-orthoslice at 246 ?m of same z-stack. Outlined structures: spinal cord (SC), notochord (NC), dorsal Aorta (dAo), SB and Int. Arrowheads point to catecholaminergic projection tracts in SC (region D), and projections on lateral line nerve (regions (D,E)), around dAo (region E), and SB (region F). (D) Z-MIP from dorsal subregion as indicated in (B,C) (slice 1?140). Arrowheads point to catecholaminergic commissures of descending central projections in the SC. Asterisks mark neuromasts of the lateral line. Cell bodies are visible in the sympathetic ganglia (SG), of which only a subset is marked with GFP. (E) Z-MIP from middle substack (slice 140?225) containing catecholaminergic cell bodies in anterior SG (SGa) and in the more posteriorly located SG of the superior cervical ganglion complex, as well as dispersed caudal trunk sympathetic neurons, which project between NC and dAo. (F) Z-MIP of ventral substack (225?265) including cell bodies of SGa and SG, arrowheads point to ring-shaped innervation around SB and projections peripheral to SB. (G) Z-MIP of ventral-most substack (225?400) containing a ventral part of the gut. Arrowheads point to sparse catecholaminergic projections above and around the intestine. All scale bars (B?G): 50 ?m; GFP-expression driven by th:Gal4: green and panels 2; anti-TH: magenta and panels 3; TOTO-3: blue.