| New animal research funded in part by the National Center for Complementary and Integrative Health (NCCIH), a component of the National Institutes of Health (NIH), suggests that stress-induced hair graying in mice may be an accessible model to investigate how stress influences tissue regeneration. This research by a multicenter team of scientists was published in a recent issue of the journalNature. In their research, the scientists found that hair graying in black-furred C57BL/6J mice results from activation of the sympathetic nerves that innervate melanocyte stem cells (a melanocyte is a cell in the skin and eyes that produces and contains the pigment called melanin). Under conditions of stress, this activation leads to burst release of the neurotransmitter noradrenaline (norepinephrine), which then leads to the rapid proliferation of melanocyte stem cells. This is followed by their rapid differentiation, migration, and permanentdepletion. | 