A natural glutamate antagonist is the structurally similar amino acid L-theanine. The similarity enables L-theanine (L-Glutamic acid-?-monoethylamide) to physically block glutamate, thus preventing calcium ion induced hyperexcitability. Although researchers aren’t positive how theanine works yet, they theorize that theanine blocks the NMDA receptor which is the doorway that glutamate uses to enter cells. Theanine is known to increase GABA (Gamma-Amino-Butyric Acid), an important inhibitory neurotransmitter. Continue reading L-theanine