Glutamic acid
Glutamate is also a neurotransmitter (see below), which makes it one of the most abundant molecules in the brain. Malignant brain tumors known as glioma or glioblastoma exploit this phenomenon by using glutamate as an energy source, especially when these tumors become more dependent on glutamate due to mutations in the gene "IDH1".
Behavioral epigenetics
Epigenetic changes including hypomethylation of glutamatergic genes (i.e., NMDA-receptor-subunit gene NR3B and the promoter of the AMPA-receptor-subunit gene GRIA2) in the post-mortem human brains of schizophrenics are associated with increased levels of the neurotransmitter glutamate. Since glutamate is the most prevalent, fast, excitatory neurotransmitter, increased levels may result in the psychotic episodes related to schizophrenia. Epigenetic changes affecting a greater number of genes have been detected in men with schizophrenia as compared to women with the illness.