The uptake of horseradish peroxidase by neuronal elements within the guinea-pig distal colon and its subsequent retrograde transport to the inferior mesenteric ganglion: an in vitro study using an intact neuronal system.

An in vitro guinea-pig preparation comprising the inferior mesenteric ganglion (IMG), the colonic nerves, and a segment of the distal colon was used to study the uptake and retrograde transport of horseradish peroxidase by intact neurons. Peroxidase rapidly penetrated the colonic wall from the lumen and was taken into autonomic nerves by pinocytotic vesicles, usually of the coated variety. The peroxidase subsequently appeared in long vesicles within the axons, and, 24 hours later, could be detected in many neuronal perikarya throughout the IMG. The similarities between the modes of uptake of peroxidase by damaged and intact axons are discussed.