protagon Meaning, Definition & Usage

Pro"ta*gon noun
Etymology
Proto- + Gr. a contest. See. Protagonist. So called because it was the first definitely ascertained principle of the brain.
Definitions
  1. (Physiol. Chem.) A nitrogenous phosphorized principle found in brain tissue. By decomposition it yields neurine, fatty acids, and other bodies.

Webster 1913