Voltage-sensitive pores in the cell membrane known as ion channels play an important role in generating the electrical spikes in brain cells (neurons). Dysfunction of ion channels has emerged as one of the most common causes of inherited epilepsy as well as autism, ataxia and migraines. Despite the clear association between ion channel dysfunction and disease of neural excitability, we do not know where processing electrical activity is deficient within a neuron due to their small physical size. This is a critical gap in order to discover effective molecular targets for therapeutic intervention to prevent suffering in young children. To identify how molecules disturb sodium channels and the delicate patterns of electrical activity in the brain we have developed sensitive optical approaches that can visualize neural activity. The specialized imaging systems we designed and built at Dartmouth allows us to measure neural function at the millisecond and micron scale. We combine these optical approaches with electrophysiology, genetic and biochemical approaches to identify novel molecular mechanisms that control the spread of electrical activity in the brain.