•CNS equilibrium is determined by a 

balance between excitatory and

inhibitory neurotransmission

–Excitation -> Glutamate is prototypical NT.

–Inhibition -> GABA is prototypical NT.

–

•Inhibition via GABA is primarily mediated 

by the ionotropic GABA-A receptor.

–GABA binding to GABA-A results in an 

increase in neuronal Cl- conductance and 

subsequent neuronal hyperpolarization.