?? ???? ????? ?? ??? ?? ???? ??? ???? ????? ?????? ?? ??????? ?? ???? ?????? ??? ???? ?? ???? ????? ?? ?????? ???? ?????The two neurotransmitters which are most generally located in the vertebrate brain are glutamate, which nearly always exerts excitatory effects on target neurons, and gamma-aminobutyric acid (GABA), which can be almost always inhi