Construction of a simple suction electrode for extracellular recording and stimulation

Principles of signal transmission in nervous systems are commonly demonstrated in the undergraduate neuroscience laboratory through extracellular recording of nerve and muscle action potentials. Here we describe the construction of a simple suction electrode that we use routinely in our laboratory classes for nerve recording and stimulation. The electrode parts are relatively inexpensive, easily available from established scientific and electronic distributors and local hardware stores, and the electrode is resilient to student handling. Our undergraduate students use this electrode design for high resolution, extracellular recordings of action potentials from crayfish motor and sensory nerves and insect muscle, and for stimulation of crustacean and insect motor nerves.