© Daniel Berger and Giulio Tomassy
The higher you look in the cerebral cortex, the less myelin you'll find, according to Professor Paola Arlotta. Not only that, but “neurons in this part of the brain display a brand-new way of positioning myelin along their axons that has not been previously seen," Arlotta added. Pictured is an image of three neurons.
Harvard neuroscientists have made a discovery that turns 160 years of neuroanatomy on its head.
, the electrical insulating material in the body long known to be essential for the fast transmission of impulses along the axons of nerve cells, is not as ubiquitous as thought, according to new work led by Professor Paola Arlotta
of the Harvard Stem Cell Institute
(HSCI) and the University's Department of Stem Cell and Regenerative Biology
, in collaboration with Professor Jeff Lichtman
of Harvard's Department of Molecular and Cellular Biology
"Myelin is a relatively recent invention during evolution," says Arlotta. "It's thought that myelin allowed the brain to communicate really fast to the far reaches of the body, and that it has endowed the brain with the capacity to compute higher-level functions."
In fact, loss of myelin is a feature in a number of devastating diseases, including multiple sclerosis
But the new research shows that despite myelin's essential roles in the brain, "some of the most evolved, most complex neurons of the nervous system have less myelin than older, more ancestral ones
," said Arlotta, co-director of the HSCI neuroscience program.