GABA

GABA, also know as gamma-Aminobutyric acid, is the main inhibitory neurotransmmitter found in the central nervous system of vertebrates. The main function of GABA is to reduce neuronal activity in the nervous system. It is refferred to as 4-aminobutanoic acid via the IUPAC nomenclature. The neurotransmitter binds to transmembrane receptors on the plasma membrane on postsynaptic neurones. This either results in the flow of negatively charges chloride ions into the neurone or the flow of postively charged potassium ions outside of the neurone. Either of these actions results in hyperpolarisation of the postsynaptic neurone, so no further action potentials can be fired. However, in insects the effects of GABA have the additional effects of being excitatory as well and inhibitory, resulting in the stimulation of muscle and glands.