ABSTRACT
When recording the nervous activity from any nerve in the cockroach, a great deal can often be learned from a recording using simple wire electrodes. The wire used varies according to the particular situation. The method of recording extracellular nerve activity using wire electrodes is well illustrated in the preparation where output from the tibial mechanoreceptive hairs on the cockroach leg can be recorded and their responses to mechanical distortion monitored. For electrophysiological experiments, the amplifiers can be divided into those required for intracellular recording and those needed for extracellular recording. Those for extracellular recording are much less demanding in their specifications. The cercal nerve/giant intemeuron synapse in the sixth abdominal ganglion of the American cockroach has been used by zoologists as a model cholinergic synapse. The “giant” axons produce enough electrical activity that they may be used in situ in the ventral nerve cord with an appropriately miniaturized nerve chamber to study the propagation of the nerve impulse.
