Glutamate is the most abundant neurotransmitter in your brain and central nervous system, which means that it's involved in virtually every major excitatory brain function. It increases the likelihood that a neuron will have an action potential - or nerve impulse - when it acts upon it. While this definition of "excitatory" has a very specific meaning to neuroscientists, we can think about these terms more generally as being something that makes things happen.
Glutamate is also a metabolic precursor for another neurotransmitter called GABA (gamma-aminobutyric acid). GABA is the main inhibitory neurotransmitter in the central nervous system. Inhibitory neurotransmitters are essentially the flip-side of the coin—they decrease the likelihood that neurons will fire, which stabilizes neuronal activity and keeps your brain on point.
What does glutamate do?
Glutamate is an amino acid that plays a major role in the transmission of nerve impulses. It is one of the most abundant neurotransmitters in the brain and can be found on neuroreceptors, which are specialized structures on neurons that allow for them to communicate with other cells. These receptors detect when glutamate binds to them, signaling it has arrived at its destination neuron and allowing for communication between these two cells to take place. Glutamate also controls neuronal excitability, or how excited a cell becomes by stimuli so it can receive messages from neighboring cells.
Chemicals like glutamate play a key role in neural circuits related to synaptic plasticity, the process of how signals from neurons strengthen or weaken over time to shape their connections.
Glutamate is not capable of crossing the blood-brain barrier but can be synthesized in neurons from building block molecules. The most prevalent biosynthetic pathway involves glutaminase converting glutamine into glutamate.
Glutamine is the most abundant amino acid that we use to build proteins. It can be produced in your body (so it’s non-essential). Most glutamine is stored in our muscles. Under certain circumstances, such as severe stress, the body may require more than it can produce. This has led many scientists to consider glutamine as being a conditionally essential amino acid.