Transfer of Melanin Granules from Melanocytes to the Cortical Cells of Human Hair

Abstract

THE manner by which the cortical cells of developing hair fibres acquire melanin pigment has been the subject of much speculation. Some authors have postulated that the pigment granules are actively inoculated into the pre-keratinized cells by way of the dendritic processes of the melanocyte (cytocrine activity)^1,2, whereas others have suggested that pigment granule transfer involves the active ingestion (phagocytosis) of the granules by the cortical cells^3,4. Birbeck and Mercer^3,4, who have found some evidence for this latter process, observed small ‘pseudopods’ enveloping the pigmented processes of black hair melanocytes at a point adjacent to the developing cortical cells of hair.