Glial cells are cells in the central nervous system that protect and maintain the brain’s neurons. They supply nutrients and oxygen to neurons, clean up brain debris, and help hold neurons in place. Now, researchers at the University of Basel report the discovery of two new types of glial cells that may play a role in brain repair and neuroplasticity.
Their findings are published in the journal Science in a paper titled, “Release of stem cells from quiescence reveals gliogenic domains in the adult mouse brain.”
“Quiescent neural stem cells (NSCs) in the adult mouse ventricular-subventricular zone (V-SVZ) undergo activation to generate neurons and some glia,” wrote the researchers. “Here we show that platelet-derived growth factor receptor beta (PDGFRβ) is expressed by adult V-SVZ NSCs that generate olfactory bulb interneurons and glia. Selective deletion of PDGFRβ in adult V-SVZ NSCs leads to their release from quiescence, uncovering gliogenic domains for different glial cell types.”
The research group led by Fiona Doetsch, PhD, professor at the Biozentrum of the University of Basel is investigating stem cells in the ventricular-subventricular zone in the adult mouse brain. The team identified a molecular signal that awakened the stem cells from their quiescent state.
“We found an activation switch for quiescent stem cells,” Doetsch explained. “It is a receptor that maintains the stem cells in their resting state. We were able to turn off this switch and thus activate the stem cells,” Doetsch added.
The researchers were also able to observe the development of the stem cells into different glial cells in specific areas of the stem cell niche.
“Some of the stem cells did not develop into neurons, but into two different novel types of glial cells,” Doetsch said.
To their surprise, they found that one glial cell type was found attached to the surface of the wall of the brain ventricle instead of in the brain tissue. They also discovered that both glial cell types were activated in a model of demyelination.
Demyelination is loss of myelin, a type of fatty tissue that surrounds and protects nerves throughout the body. This condition causes neurological deficits, such as vision changes, weakness, altered sensation, and behavioral or cognitive issues. Their findings suggest that these new glial cell types may play a role for repair in neurodegenerative diseases or after injury.
Looking toward the future, Doetsch and the team would would like to trace these new glial cell types and to further investigate their roles in normal brain function and how they respond in different physiological contexts.