OBSERVATIONS ON THE PASSAGE OF WEED'S PRUSSIAN BLUE MIXTURE ALONG THE AXIS CYLINDERS AND INTER-FIBRE FLUID OF NERVES

Abstract

Expts. were carried out in situ on the sciatic nerves of 4 living rabbits. The cut end of the nerve was continuously bathed in a 10% mixture of sodium ferrocyanide and iron ammonium citrate in Ringer''s soln. A non-polarizable (Ag-AgCl) electrode was kept in moist contact with the lumbar cord and another was placed in the capillary tube at the cut end of the nerve. A current of 0.3-0.5 milliamp. flowed in the circuit for the 6-8 hrs.apos duration of the expt. Similar cataphoresis was employed with excised nerves 1.5 cm. long in 7 cases. The tissues were afterward paraffin embedded, sectioned at 7-10 [mu] and stained with carmalum. Diffusion of the prussian blue mixture took place in the axis cylinder, interfiber spaces and connective tissue sheaths, without revealing any special conducting ability of the axis cylinder. The nodes of Ranvier became intensely stained even when the internodal axons showed no blue. Some anterior horn cell nuclei and dorsal root ganglion nuclei showed a high affinity for prussian blue.