Protagon
Pronunciation : Pro"ta*gon
Part of Speech : n.
Etymology : [Proto- + Gr. Protagonist. So called because it was the first definitely ascertained principle of the brain.] (Physiol. Chem.)
Definition : Defn: A nitrogenous phosphorized principle found in brain tissue. By decomposition it yields neurine, fatty acids, and other bodies.
Source : Webster's Unabridged Dictionary, 1913