Modulation Of Neurotransmission By The Gaba(B) Receptor

Most inhibitory signals are mediated via gamma-aminobutyric acid (GABA) receptors whereas glutamate receptors mediate most excitatory signals (Trends Neurosci 14:515-519, 1991; Annu Rev Neurosci 17:31-108, 1994). Many factors influence the regulation of excitatory and inhibitory synaptic inputs on a given neuron. One important factor is the subtype of neurotransmitter receptor present not only at the correct location to receive the appropriate signals but also their abundance at synapses (Pharmacol Rev 51:7-61, 1999; Cold Spring Harb Perspect Biol 3, 2011). GABA(B) receptors are G-protein-coupled receptors and different subunits dimerise to form a functional receptor. GABA(B) receptor subunits are widely expressed in the brain and by assembling different isoform combinations and accessory proteins they produce variety of physiological and pharmacological profiles in mediating both inhibitory and excitatory neurotransmission. This chapter will describe the understanding of the molecular mechanisms underlying GABA(B) receptor regulation of glutamate and GABA(A) receptors and how they modulate excitatory and inhibitory neurotransmission.