The nervous system maintains its function through a dynamic balance between excitation and inhibition. Gamma-aminobutyric acid, known as GABA, plays a central role in this balance, but it does not act in isolation. Its effects depend on the receptors involved, the brain region, the cell type, the metabolic state, and its interaction with glutamate, acetylcholine, dopamine, galanin, and other systems.

This book presents a progressive introduction to these systems. It first explains the cellular and molecular foundations. Then it examines the relationship between inhibition, plasticity, neuroinflammation, aging, and neurodegeneration. Finally, it analyzes therapeutic applications and includes a chapter on open pharmacology that deliberately remains in the realm of hypothesis.