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".
Choline transporter
Choline is a necessary reagent for the synthesis of acetylcholine in the central nervous system. Neurons get their choline by specific protein transporters known as choline transporters. In the human brain microvascular endothelial cells, two systems initiate the choline absorption. The first system is known as the Choline transporter-like protein 1, or CTL1. The second system is the Choline transporter-like protein 2, or CTL2. Those two systems are found on the plasma membrane of the brain microvascular endothelial cells. They are also found on the mitochondrial membrane. CTL2 was found to be highly expressed on the mitochondria. Meanwhile, CTL1 was mostly found on the plasma membrane of those microvascular cells.