Scientists Map Brain Area That May Aid for Human Brain Stem Cells

Brain Stem Cells

Discovery of "displaced" cells also suggestive of stem cell activity

A study led by a Johns Hopkins neurosurgeon has provided the first comprehensive map of a part of the adult human brain containing astrocytes, cells known to produce growth factors critical to the regeneration of damaged neural tissue and that potentially serve as brain stem cells. The mapping study - using special microscopes and chemical analysis of 42 samples of brain tissue taken at autopsy from seven people, and 43 samples of tissue removed with permission from living patients as part of unrelated neurosurgical procedures - also revealed evidence of the move of cells lining the ventricles, or ependymal cells, to the same area of the brain, a discovery expected to provide further insight into the critical relationship among ependymal cell, astrocytes and potential brain stem cells.

"Although we have not confirmed the existence of human brain stem cells in vivo or their ability to migrate to parts of the brain that need repair, what we have learned from this complete map of the lateral wall of the subventricle zone or SVZ, including the unexpected existence of ependymal cells there, suggests that additional research is warranted," says Alfredo Quinones-Hinojosa, M.D., lead author of the study and an assistant professor in the Department of Neurosurgery at the Johns Hopkins University School of Medicine. "If there is stem-cell-like activity in the SVZ, this discovery could help pave the way for a number of therapeutic treatments for treating brain cancer, neurodegenerative diseases and brain damage."

The subventricle zone refers to tissue and cells that lie next to the ventricles or tubes located in the center of the brain that act as conduits for the cerebral spinal fluid that bathes the entire brain. The ependymal layer is a layer of cells that make up the outer wall of these tubes. Behind that layer lies the SVZ.

Previous studies have shown that astrocytes located in rodent SVZs travel to the olfactory bulb, where they develop into new brain cells, according to Quinones. However, the human SVZ