[Enkephalinergic transmission: functional characteristics and physiologic role].

Enkephalins are small CNS opioid peptides present in the CNS and the physiological importance of which is well accepted. Their effects at a cellular level and recent acquisitions on their physiological significance are reviewed with a particular mention to the interaction with other neurotransmitters, especially GABA. The role of enkephalins in sensory, motor and vegetative processes is reviewed. Some developments of particular interest are proposed, e.g. the role of enkephalins in memory, or their relations with the immune system. The methodological problems concerning the study of these peptides and the limits of a clinical approach are briefly discussed.