A James Burke Special. James demonstrates the biochemistry of communication between neurons and how neurotransmission is an electrical message. His props include man-sized models and he likens the various operations of a hotel to the functioning of a brain. James demonstrates learning and habituation. He relates the statement "Today's brains are yesterday's mashed potatoes" to GABA neurons. He likens hyperactivity by a hotel's staff to an epileptic fit. One scene shows James Burke playing his classical guitar while narrating to show how the complexity of finger movements is programmed and is carried out while he is also involved in speaking, at the same time, his attention is also on the script and the filming situation. The role of dopamine in understanding Parkinson's Disease or schizophrenia is discussed, among other topics on the brain.