Book excerpt: during the past few years increasing interest has been focused on the role of gamma-aminobutyric acid (GABA) outside the central nervous systems (CNS).Biochemical, pharmacological, histochemical, physiological approaches have all been employed to investigate the role of GABA in themammalian periphery. The International Symposium on Peripheral GABAergic Mechanism held in Rome, July 1990, was devoted to gather scientists from allover the world in order to summarize and sythesize their most recent results and conceptions on the significance of GABA outside the CNS. Written in a thought-provoking style, this proceedings volume is an overviewof the timely knowledge about GABA in the peripheral nervous system and in non-neuronal tissues. Chapters of the book provide many examples for the diverse functions of this amino acid in the periphery as neurotransmitter, hormone, humoral or even trophic factor from the autonomic ganglia to the endocrine stomach and pancreas, from the tubular epithelium of the kidney to the spermatozoa.