LOCATIONS OF POSTGANGLIONIC NERVE-CELLS WHOSE AXONS ENTER NERVES ORIGINATING FROM PREVERTEBRAL GANGLIA

Major nerve trunks that supply abdominal viscera contain axons of post ganglionic neurons that originate in the coeliac ganglion, superior me senteric ganglion, inferior mesenteric ganglia, hypogastric nerve gang lia and the sympathetic chain ganglia. Using the retrogradely transpor ted neuronal marker Fast Blue, we mapped the distribution of labelled nerve cells after application of the dye to either the superior coelia c nerves, inferior coeliac nerves, superior mesenteric nerve, colonic nerves or hypogastric nerves. Distinctive patterns of nerve cell locat ions were associated with each nerve trunk. Within the coeliac ganglio n, nerve cells that projected into the superior coeliac nerves were al most exclusively lateral, whilst neurons in the medial part of the coe liac ganglion and in the rostral pole of the superior mesenteric gangl ion tended to project into the inferior coeliac nerves. Nerve cells lo cated around the emerging superior mesenteric nerve in the superior me senteric ganglion contributed the majority of axons to that nerve. Cel ls in both poles of the inferior mesenteric ganglia contributed the ma jority of postganglionic axons to the colonic nerves, but some cells i n the caudal pole of the superior mesenteric ganglion also projected i nto the colonic nerves. Postganglionic axons in the hypogastric nerves originated from cells predominantly located in the caudal pole of the inferior mesenteric ganglion; however, cells in the rostral pole of t he inferior mesenteric ganglia, the superior mesenteric, coeliac and h ypogastric nerve ganglia also contributed some axons. Nerve cells of s ympathetic chain ganglia projected into each of the nerve trunks; they were distributed rostro-caudally according to the nerve injected. The more rostrally located coeliac nerves contained axons mainly from the lower thoracic and upper lumbar ganglia, whilst the more caudal colon ic and hypogastric nerves contained axons from the mid-lumbar ganglia. Thus a widespread distribution of sympathetic neurons projects into e ach of the major abdominal nerve trunks, with the ganglion from which the nerve emerges being the greatest contributor, and the region aroun d the emerging nerve comprising the preferred location within the gang lion.