Is that what this study is saying? http://www.ncbi.nlm.nih.gov/pubmed/7566370 "Focusing on the tyrosine-noradrenalin axis in cerebellum we showed 5-methyltetrahydrofolate causes a significant reduction in the apparent K+ evoked secretion of noradrenalin to only 12.9% of control release." But here's the part that's especially confusing: "Evidence supports the idea that this could actually be due to increased synthesis leading to; depletion of reserves, possibly through leakage, exocytotic inhibition via activation of presynaptic receptors or end product inhibition by noradrenalin at the pteridine cofactor level of tyrosine hydroxylase…" Increased synthesis of what? Depletion of what? I'm just wondering if this study might explain why methylfolate (after years of on and off experimentation), clearly helps me sleep a lot better -- by lowering noradrenalin (a.k.a. norepinephrine) levels... ???