Abstract
The stomatogastric ganglion (STG) of lobsters and crabs has been a favorite experimental preparation for the study of the neural basis of rhythmic motor outputs. The STG itself has only about 30 neurons, all of which are large (50–120 μm in diameter), easy to record from with intracellular microelectrodes, and individually identifiable from preparation to preparation. Equally important, when the nerve connecting the STG to the rest of the animal is severed, the STG can continue to produce rhythmic motor patterns that are similar to those it produces in the intact animal. Therefore, it is possible to use this preparation to study in detail how rhythmic patterns are produced by groups of neurons. Most frequently the STG is dissected free from the animal and placed in a clear recording chamber filled with a saline solution. This allows the experimenter to place several recording and stimulating electrodes under visual control (Fig. 1) and permits easy and rapid changes of the composition of the saline bathing the preparation.