Spinal ganglion cells innervating the stomach of the rat as demonstrated by somatopetal transport of horseradish peroxidase (HRP).

Spinal ganglion cells innervating the stomach of the rat were demonstrated using the somatopetal horseradish peroxidase (HRP) transport technique. After injection of the tracer into the anterior wall of the stomach, labelled neurons were observed bilaterally within spinal ganglia T4--L1. They were most numerous in ganglia T8--T10. No clear evidence of somatotopic organization of the labelled cells was found. Most of the cells measured 35--40 micrometer in diameter. There was a striking paucity of cells smaller than 30 micrometer. The predominance of medium-sized spinal ganglion cells may indicate that the stomach is innervated mainly by small myelinated rather than unmyelinated splanchnic afferent fibers.