I wrote here about how taurine affects overexcitable membranes in general, and it essentially boils down to two interrelated things: the NMDA receptor (which is stimulated by the excitatory neurotransmitter glutamate, and inhibited by calming neurotransmitters glycine and GABA), and calcium conduction (the flow of which occurs when the NMDA receptor gets stimulated.)
A hyperreactive NMDA receptor means excitotoxicity, a hallmark of chemical toxicity as well as several neurological conditions.
Taurine calms the NMDA receptor down. But it turns out that this has far-reaching consequences, at least in terms of neurochemistry.
Taurine’s Effect on GABA (and therefore NMDA Receptors)
Taurine has a direct effect on quieting the NMDA receptors because it is a GABA (gamma-aminobutyric acid) agonist (stimulant), affecting both GABA receptors, and increasing the production of GABA directly. It does the latter by increasing activity of glutamic acid decarboxylase (GAD), the enzyme responsible for producing GABA from glutamate with the help of Vitamin B6. (So, taurine is therefore supportive for anyone who has a slow-down mutation in the gene for the GAD enzyme.)
More GABA means less calcium flow through the neurons guarded by NMDA receptors, which means calmer neurons. It’s also been found that taurine directly affects calcium balance in the neurons as well.
Taurine’s Effect on Adrenaline
Taurine’s ability to regulate calcium transport has also been shown to inhibit adrenaline (norepinephrine and epinephrine) release from the adrenal cortex.
This is a bit of a daisy chain effect: taurine stimulates GABA receptors and upregulates GABA production, which in turn quiets calcium flow via NMDA receptors, which in turn suppresses the fight-or-flight signal to the adrenals to pump out adrenaline.
I’ve found taurine to be particularly helpful for people who wake at night with a pounding heart, indicating a pre-dawn spike of adrenaline.
Taurine has far-reaching effects on several neurotransmitters that have been associated with anxiety, including low levels of GABA, and high adrenaline output. It can therefore be helpful for several different types of anxiety, as well as sleep disturbances.