Neurotransmitter activity in the brain: Focus on the opiate receptor

Understanding the molecular basis of synaptic transmission requires a biochemical approach to the receptors upon which neurotransmitters act. Binding studies with radioactive neurotransmitters or related drugs have afforded considerable advances with the opiate receptor being one of the best characterized. The opiate receptor interacts with normally occurring morphine-like pentapeptides in the brain, enkephalins. The detailed localization of opiate receptor and enkephalins throughout the brain helps to clarify mechanisms of pain perception and emotional regulation.