The answer that best completes the statement above is GABA. GABA stands for gamma-Aminobutyric acid. This is one of the neurotransmitters in our nervous system. Its chief function is inhibition, specifically in the reduction of neuronal excitability. In epileptic patients, their neuronal functions are abnormally over excited, that is why they are given medications that would increase GABA in order to inhibit this excitability.