Muscarinic cholinergic receptors build up on the proximal side of a ligature placed on the rat sciatic and vagus nerves. These receptors appear to be flowing down the axons of at least a portion of the nerve fibers present in sciatic and vagus nerves. Most of the anterograde flowing muscarinic binding sites are displaceable with 10(-4) M carbachol indicating that many are high affinity agonist binding sites. These receptors can also be localized in the ganglionic nerve cell bodies in the dorsal root ganglia which contribute fibers to the sciatic nerve. We hypothesize that muscarinic cholinergic receptors are synthesized in the ganglion cell bodies and transported distally in sensory nerve axons in the sciatic nerve.