Brain cells grown in a dish
A type of cell found deep in the brain has produced all of the three primary brain cells after being grown in a lab, scientists say.
The researchers say related medical therapies, such as the ability to repair or replace brain cells damaged by head trauma or diseases such as Alzheimer's, Parkinson's and Huntington's, can occur within five years.
"The field of regenerative medicine is moving so quickly," says Professor Dennis Steindler, who led the research.
"New discoveries happen every day, so I would like to offer hope to people with such conditions that they could benefit from related breakthroughs even sooner [than the estimated five-year period]."
Steindler, who is executive director of the University of Florida 's McKnight Brain Institute, says, "with the new brain cell technology we have created a method, a protocol and a model that enables us to get stem-like brain cells into a dish, to look at them and to induce them to differentiate."
The findings are published in the Proceedings of the National Academy of Sciences.
Mining the brain
Steindler and his team extracted glial-fibrillary acidic protein (GFAP+) cells from a region called the subventricular zone, which lies deep within the brain. They worked with cells from adult mice, but say humans possess these exact same cells.
The brain cells were frozen with liquid nitrogen for storage. After thawing the cells, they put them on dishes coated with growth-inducing chemicals, such as polyornithine and laminin.
Other chemicals, including retinoic acid and a cytosine compound, were used to control differentiation.
Defined neuroblast generators, or cells that produce young nerve cells in the brain, appeared four days after the cells started to differentiate.
These cells, in turn, were induced into forming the three main types of brain cells: neurons, which relay messages; astrocytes, which form a barrier between the brain and blood; and oligodendrocytes, which help to form insulation around neurons.
The mother of all stem cells?
Steindler stopped short from calling the cells used in the study "stem cells," but says he suspects they can indeed be "the mother of all stem cells," referring both to the brain's importance in the body, and to researchers' desire to identify brain stem cells.
Dr Angelique Bordey, an assistant professor of neurosurgery and cellular and molecular physiology at Yale University School of Medicine, says she believes Steindler has identified neural stem cells, and hopes the growth technique can be applied to other cells.
Associate professor Eric Holland, a neurosurgeon at Memorial Sloan-Kettering Cancer Center in New York, who specialises in the treatment of brain tumours, says the findings are a promising advance.
"As far as regenerating parts of the brain that have degenerated, such as in Parkinson's disease, Huntington's disease and others of that nature, the ability to regenerate the needed cell type and placing it in the correct spot would have major impact," Holland says.
One of the next steps for Steindler and his team is to study how various drugs might help to control cellular replication so that generated brain cells can repair or replace damaged ones without adversely affecting other brain regions.