A LIGHT-SENSITIVE pigment derived from vitamin B2 may help to set
the body’s clock.
ÒÁÈ˾þÃs reported earlier this year that bright light on the back of the
knees can reset the body’s daily rhythms
(This Week, 24 January, p 11). Now
Yasuhide Miyamoto and Aziz Sancar at the University of North Carolina in Chapel
Hill have shown that cryptochrome, a derivative of vitamin B2, may be
the light-sensitive molecule involved in this response.
The researchers found the pigment in neurons which connect to the
suprachiasmatic nucleus, a brain region containing the “master clock” (
Proceedings of the National Academy of Sciences, vol 95, p 6097). It is a
different pigment from that involved in vision, which may explain why blind
people who lack vision proteins are able to maintain a normal daily rhythm.
