Phagocytosis of myelin sheath fragments by dendrites

In serial ultrathin sections of the frog spinal cord, profiles of dendritic appearance were identified that contained myelin fragment inclusions and received synaptic contacts. In a number of cases it could be established that the inclusions were derived from adjacent myelin sheaths. It is suggested that the phenomenon may refer to a turnover of the myelin sheath in which the detached myelin fragments are eliminated by dendrites.