Mechanisms and Regulation of Neuronal GABA Receptor-Dependent Signaling.

γ-Aminobutyric acid B receptors (GABARs) are broadly expressed throughout the central nervous system where they play an important role in regulating neuronal excitability and synaptic transmission. GABARs are G protein-coupled receptors that mediate slow and sustained inhibitory actions via modulation of several downstream effector enzymes and ion channels. GABARs are obligate heterodimers that associate with diverse arrays of proteins to form modular complexes that carry out distinct physiological functions. GABAR-dependent signaling is fine-tuned and regulated through a multitude of mechanisms that are relevant to physiological and pathophysiological states. This review summarizes the current knowledge on GABAR signal transduction and discusses key factors that influence the strength and sensitivity of GABAR-dependent signaling in neurons.