Brief presentation of the story and present status of studies of the vertebrate cholinergic system.

This year marks the seventieth anniversary of Otto Loewi's demonstration of chemical transmission generally and autonomic cholinergic transmission specifically and the fortieth anniversary of John Eccles's proof of the existence of central cholinergic transmission. Following these epochal findings, the subsequent studies of the cholinergic system led to discoveries of similarly important phenomena. This review concerns these phenomena, including chemical structure and molecular biology of cholinergic receptors; electrophysiologic and ionic aspects of pre- and postsynaptic cholinergic events; the quantal expression of cholinergic postsynaptic events and activities of their subunits, the elementary events; second messengers and G proteins; synthesis, storage and release of acetylcholine; cholinesterases, anticholinesterases, and war gases; central cholinergic pathways; central cholinergic functions, behaviors, cholinergic EEG and REM sleep; cholinergic ontogeny and teratology; trophic phenomena; and the clinical aspects of the cholinergic system. This review refers to the history as well as the present status of each of these phenomena; furthermore, it describes briefly the nineteenth-century work with calabar bean, pilocarpine, muscarine, and nicotine, that is, the work performed before the promulgation of the cholinergic era.