From the article:
We knew that blood cells produced BDNF,“[…] "We didn’t know why it was produced in blood cells.”
Dr. Hiroshi Urabe and Dr. Hideto Kojima, current and former postdoctoral fellows in Chan’s laboratory respectively, looked for BDNF in the brains of mice who had not been fed for about 24 hours. The bone marrow-derived cells had been marked with a fluorescent protein that showed up on microscopy. To their surprise, they found cells producing BDNF in a part of the brain’s hypothalamus called the paraventricular nucleus.
“We knew that in embryonic development, some blood cells do go to the brain and become microglial cells,” said Chan. […]“This is the first time we have shown that this happens in adulthood. Blood cells can go to one part of the brain and become physically changed to become microglial-like cells.”
A new way to affect appetite and obesity?
When normal bone marrow cells that produce BDNF are injected into the third ventricle (a fluid-filled cavity in the brain) of mice that lack BDNF, they no longer have the urge to overeat, said Chan.
All in all, the studies represent a new mechanism by which these bone-marrow derived cells control feeding through BDNF and could provide a new avenue to attack obesity, said Chan.
He and his colleagues hypothesize that the bone marrow cells that produce BDNF fine tune the appetite response, although a host of different appetite-controlling hormones produced by the regular nerve cells in the hypothalamus do the lion’s share of the work.