L-Theanine is an amino acid that can be found in Camellia and Boletus; it is a glutamic acid analog. L-theanine exhibits neuroprotective, cognition enhancing, anxiolytic, and antipsychotic activities. L-Theanine is a weak agonist at AMPA and NMDA receptors, increasing brain DA, 5-HT, and GABA levels. This compound improves memory, cognition, mood, and attention in clinical settings. In animal models of cerebral ischemia, L-theanine inhibits apoptosis of hippocampal neurons, improving spatial memory.