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".
Neuromedin U
Neuromedin U (or NmU) is a neuropeptide found in the brain of humans and other mammals, which has a number of diverse functions including contraction of smooth muscle, regulation of blood pressure, pain perception, appetite, bone growth, and hormone release. It was first isolated from the spinal cord in 1985, and named after its ability to cause smooth muscle contraction in the uterus.