Lab-created human brain cells grow in mice

In a finding that may pave way for treatments for Parkinson's disease, epilepsy and Alzheimer's, researchers have found that a key type of lab-grown human brain cell developed seamlessly when transplanted into mice.
The findings by University of California, San Francisco researchers may also help find treatments for complications of spinal cord injury such as chronic pain and spasticity.
"We think this one type of cell may be useful in treating several types of neurodevelopmental and neurodegenerative disorders in a targeted way," said Arnold Kriegstein, co-lead author of the paper.
Researchers generated and transplanted a type of human nerve-cell progenitor called the medial ganglionic eminence (MGE) cell, in experiments published in the journal Cell.

Development of these human MGE cells within the mouse brain mimics what occurs in human development, they said.
Kriegstein sees MGE cells as a potential treatment to better control nerve circuits that become overactive in certain neurological disorders.

To generate MGE cells in the lab, the researchers reliably directed the differentiation of human pluripotent stem cells - either human embryonic stem cells or induced pluripotent stem cells derived from human skin.
These two kinds of stem cells have virtually unlimited potential to become any human cell type.
When transplanted into a strain of mice that does not reject human tissue, the human MGE-like cells survived within the rodent forebrain, integrated into the brain by forming connections with rodent nerve cells, and matured into specialised subtypes of interneurons.

"The hope is that we can deliver these cells to various places within the nervous system that have been overactive and that they will functionally integrate and provide regulated inhibition," said researcher Cory Nicholas.
These findings may serve as a model to study human diseases in which mature interneurons malfunction, according to researchers.
Researchers said their methods may also be used to generate vast numbers of human MGE cells in quantities sufficient to launch potential future clinical trials.