wheat gluten (Latin gluten = glue), from which it received its name.
Its neurotransmitter function did not come to light until nearly a
century later, in the 1950s and 1960s. In its neutral or nonionized
form, this molecule is most correctly called glutamic acid. As a soluble
molecule inside the brain, the acid portions of the molecule will give
up a positive charge to the solution and become negative, and the
amine portion of the molecule will take on a positive charge. This ion-
ized form is properly referred to as glutamate. In many descriptions of
neurochemistry, including my own, the terms are used interchange-
ably, and it is understood that in physiological solution the ionized
form prevails.
oO oONH»
Glutamic acidoO Oo8 &
NH
GlutamateGlutamate is the primary excitatory neurotransmitter in the
human brain. How does glutamate communicate an excitatory signal
between neurons? Large numbers of glutamate receptors in the brain
are ionotropic receptors that are Ca* and Na channels. Thus, the
binding of glutamate to ionotropic glutamate receptors initiates a
flow of Ca* or Na from outside the cell (where these ions are higher