CRUSTACEAN MOTOR NEURON CONNECTIONS TRACED BY BACKFILLING FOR ELECTRON MICROSCOPY
H. L. Atwood, Bruce H. Pomeranz · The Journal of Cell Biology · 1974
Individual neurons can be marked by injection through a microelectrode of the fluorescent dye Procion yellow (17) or of cobalt chloride (13). These materials can also be used to study neurons which have peripheral connections by allowing the markers to move up the cut axons into the cell bodies and central processes (5, 11). This "backfilling" method is facilitated by application of electrical current through the cut ends of the axons (5). So far, both Procion yellow and cobalt chloride have been more useful for studies carried out by light microscopy than for those requiring electron microscopy, although attempts have been made to trace Procion yellow-injected cells with the electron microscope (14). The microinjection of Pro-