A great deal of progress has been made in defining GABA (gamma-aminobutyric acid) transmission in the brain. Volume 54 of the "Advances in Pharmacology" series has also provided new insights into fundamental features of neurotransmission in general, such as the importance of allosterism and coincident signaling in regulating receptor function and overall cellular activity. These studies have led to the design and development of new drugs and potential therapeutic agents. Given the successes achieved over the first 50 years of GABA research, it is certain the 6th decade will yield its share of surprising discoveries and new insights. Published in this volume are articles providing thoughts and perspectives on this topic, some with the benefit of hindsight, others in the context of recent findings, but all with a hint, or prediction, of what the future holds as the secrets of GABA neurotransmission continue to unfold. "Advances in Pharmacology" is available online on ScienceDirect full-text online of volumes 48 onwards. GABA is an amino acid found in mammalian brain. This work contains articles written by leading investigators in the field. It also provides new insights into fundamental features of neurotransmission.