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".
Nucleus basalis
The nucleus basalis, also known as the nucleus basalis of Meynert or nucleus basalis magnocellularis, is a group of neurons located mainly in the substantia innominata of the basal forebrain. Most neurons of the nucleus basalis are rich in the neurotransmitter acetylcholine, and they have widespread projections to the neocortex and other brain structures.