Peptide transmitters: a unifying hypothesis for euphoria, respiration, sleep, and the action of lithium.


Actions of morphine include analgesia, sleep, euphoria, and depression of respiration. Transmitter or modulator substances in the brain that have actions similar to morphine may control these functions in man. This hypothesis proposes that enkephalin is a controlling neurotransmitter and its binding to opiate receptors determines mood state as well as… (More)