Is the postganglionic sympathetic neuron zinc-enriched? A stop-flow nerve crush study on rat sciatic nerve

Axonal transport of endogenous zinc ions in the rat sciatic nerve was studi ed by a stop-flow/nerve crush technique combined with zinc selenide automet allography (ZnSeAMG) at light and electron microscopic levels. Distinct acc umulations of ZnSeAMG grains were detected. in particular proximal but also distal to the crushes, 1.5h after the operation, and the amounts of zinc i ons increased further in the following 3-8 h. Ultrastructurally, ZnSeAMG gr ains were located predominantly in unmyelinated axons. The data suggest tha t a subpopulation of sciatic nerve axons contains and transports zinc ions both antero- and retrogradely, indicating that the second neuron in the sym pathetic nervous system is zinc enriched (ZEN). NeuroReport 12:2247-2250 (C ) 2001 Lippincott Williams & Wilkins.