GABA receptors are channel
receptors. This means that when GABA binds to them, they
change shape slightly to allow ions to pass through their
central channel. This channel mainly allows negatively charged
chloride ions to enter the neuron, thus reducing its excitability.
Because of this property of the GABA channel receptor,
GABA is classified as an inhibitory neurotransmitter,
as opposed to excitatory neurotransmitters, such as glutamate,
which augment the nerve impulses in the neuron.