Glutamate excitotoxicity triggered by overstimulation of glutamate receptors also contributes to intracellular oxidative stress. Alcohol also decreases the excitatory neurotransmitter glutamate. It inhibits receptor activity in the NMDA glutamate receptor subtypes. These chemical neurotransmitters include dopamine, serotonin, GABA, glutamate, and acetylcholine. Monosodium glutamate (MSG), also known as sodium glutamate, is the sodium salt of glutamic acid. A major cause of neuronal injury is the release of the excitatory neurotransmitter glutamate. Glutamine is synthesized by the enzyme glutamine synthetase from glutamate and ammonia. It may work by decreasing release of the excitatory neurotransmitter glutamate from pre-synaptic neurons. Certain dysfunctions of the neurotransmitters glutamate, serotonin and acetylcholine have also been implicated. Calcineurin is linked to receptors for several brain chemicals including glutamate, dopamine and GABA. The NMDA receptor is one of three types of ionotropic glutamate receptors. Many synapses use multiple types of glutamate receptors. Umami is the taste of glutamates, especially monosodium glutamate (MSG). Candidate include aspartate, glutamate, histidine, cysteine. GHB is a precursor to GABA, glutamate, and glycine in certain brain areas.