The nervous system uses electrical signals to encode and process information. These signals take the form of action potentials within neurons and synaptic potentials between neurons. The molecules responsible for these signals include voltage-gated channels, which generate and shape action potentials; neurotransmitter receptors, which generate and shape synaptic potentials; and membrane trafficking proteins, which catalyze the fusion of neurotransmitter-containing vesicles with the plasma membrane. Research into membrane excitability and synaptic transmission provides insight into the cellular and molecular basis for learning and memory, and illuminates the molecular mechanisms of neurological disease and drug action. Faculty in the Neuroscience Training Program investigate these questions in a wide variety of models from yeast and Drosophila to humans, using a broad range of techniques including patch clamping, electrophysiology, and cellular imaging.