Scientists at Karolinska Institutet in Stockholm have now shown that most melanocytes actually appear later on in foetal development from an immature cell type that exists in the skin's nerve fibres (as against reported earlier, i.e., melanocytes bud off from the spinal cord at an early foetal stage and then migrate to the skin where they remain for the rest of their lives). These cells, called Schwann cell precursors (SCPs), can also be found in adults. In addition to this, the scientists have demonstrated how neuronal damage in adults can excite the maturation of melanocytes to form hyperpigmentation around the affected nerves.
Their results also shed new light on SCP cells, which were previously seen as an immature form of supportive cells the nervous system. The researchers describe how a change in cell signalling can make the SCP cells in the skin develop into pigment cells instead, and argue that SCP cells are really a kind of stem cell. Congrats for this achievement...
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