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".
Glutamate carboxypeptidase II
Glutamate is the “primary excitatory neurotransmitter in the human nervous system”, participating in a multitude of brain functions. Over-stimulation and -activation of glutamate receptors as well as “disturbances in the cellular mechanisms that protect against the adverse consequences of physiological glutamate receptor activation” have been known to cause neuron damage and death, which have been associated with multiple neurological diseases.