Lateral giant fibers of crayfish: Location of somata by dye injection

Using a new technique for injecting fluorescent dye, we have analyzed the intraganglionic architecture of the lateral giant interneutron in crayfish. Each lateral giant interneuron comprises a giant axon, an ipsilateral dendritic arborization of fairly constant form, and a contralateral soma. Antidromic axon spikes produce only, small, electronic potentials in the soma; direct depolarization there fails to produce electrically excitable membrane responses and cannot discharge the main axon.