From the annual meeting of the American Academy of Neurology in Toronto:
If you suspect that the mice living in your home are too smart for their own good, you haven’t seen anything yet. Make way for mice with humanized brains that have been proven to learn faster than do their normal counterparts.
In his Presidential Lecture at the meeting, Dr. Steven Goldman of the University of Rochester, N.Y., engrossed listeners with a story of his research team’s use of human glial progenitor cells that had been isolated from the brains of second trimester human fetuses that had been aborted because of premature rupture of the membranes. These glial progenitor cells have the abilityto transform into astrocytes and oligodendrocytes, that latter of which produce the myelin sheath that wraps around the axons of neurons to speed electrical signals from neuron to neuron. Mice that are born with oligodendrocytes that cannot produce myelin—called shiverer mice—experience uncontrollable body and limb convulsions that cause progressive neuronal degeneration and the development of continual, uncontrollable seizures (status epilepticus) that kill them.
Dr. Goldman and his colleagues found that infusions of human glial progenitor cells into newborn shiverer mice could rescue them to a nearly normal state and a normal life span. The transplanted glial cells in these mice differentiated into oligodendrocytes that produce myelin and astrocytes that wrap themselves around the synapses of the murine neurons. These human astrocytes almost completely replace the mice’s own astrocytes after 13 months. Such a treatment could potentially be used to treat myelin disorders in children.
These results are amazing in themselves, but Dr. Goldman’s research gets even more interesting.
One of the striking differences in the brains of mice and humans is the larger size and greater complexity of human astrocytes in comparison to their murine counterparts. Dr. Goldman’s research team demonstrated that human glial progenitor cells infused into the brain of newborn normal mice also led to a gradual replacement of murine glial cells with human glial cells. These mice need only one trial to establish a fear response to a noise associated with a subsequent electrical shock, compared with many repeated trials in normal mice.
Dr. Goldman pointed out that his findings aren’t entirely new. Go and watch The Secret of NIMH.
–Jeff Evans (@jeffaevans on Twitter)