Transport of latex microspheres by peripheral nerves of the rat

The usefulness of rhodamine-labelled latex microspheres (RLM) as a marker for studying intracellular transport in peripheral nerves has been investigated in the intercostal and sciatic nerves of the rat. Suspensions of microspheres were injected into peripheral nerves, and after periods of survival ranging from 24 to 240 h, the nerves and dorsal root ganglia were fixed, frozen sections cut, and sections examined by fluorescence microscopy. It was found that RLM were transported in both anterograde and retrograde directions, but that dorsal root ganglion cells were poorly labelled. Horseradish peroxidase histochemistry did not affect the fluorescence of RLM. Features of the uptake and transport of RLM are discussed and possible applications suggested.