Source: George Washington University Medical Center
Date: March 11, 2011
Summary:
Proteins in fluids bathing the brain are essential for building the brain, discover scientists in a report published March 10 in the journal Neuron. The finding promises to advance research related to neurological disease, cancer and stem cells. Before now, the fluid surrounding the brain was generally considered to be a sort of salt-solution that simply maintained the brain's ionic balance. Recent reports of fluctuating proteins in the fluid suggested otherwise, however. And thus, a multi-institutional research teams at the Children's Hospital in Boston, led by Maria Lehtinen, Mauro Zappaterra and Christopher Walsh and researchers from the George Washington University School of Medicine and Health Sciences in Washington, D.C., decided to take a closer look at what proteins in the fluid do. What they found shocked them: As embryos and their brains are growing, a type of protein that tells brain cells to multiply increases in the so-called cerebrospinal fluid.
The current team extracted cerebrospinal fluid from mouse embryos around two weeks after conception, when their brains develop most quickly. The fluid contained high levels of a protein, insulin-like growth factor or Igf2, which is known to help stem cells multiply and differentiate. Notably, the protein isn’t elevated after birth. When the authors blocked Igf2, stem cells in the brain stopped making brain cells, which resulted in abnormally tiny mice brains. And when the team placed brain stem cells in a dish filled with Igf2-rich, embryonic cerebrospinal fluid, the cells proliferated rapidly.
