Source : Webster's Revised Unabridged Dictionary (1913)

Medullated \Me*dul"la*ted\, a. (Anat.)
   Furnished with a medulla or marrow, or with a medullary
   sheath; as, a medullated nerve fiber.

Source : WordNet®

medullated
     adj : (of neurons) covered with a layer of myelin [syn: {myelinated}]
           [ant: {unmyelinated}]