Effects of neurotoxic chemicals on central synaptic function can be assessed using electrophysiological recording techniques in freshly isolated brain slices. The three most commonly used electrophysiological recording methods in brain slices are extracellular microelectrode recording, intracellular microelectrode recording, and whole-cell patch clamp recording. This unit presents the basic procedures and applications of extra- and intracellular recordings in hippocampal slices and whole-cell recording in cerebellar slices.