Navigation Links
Finding turns neuroanatomy on its head
Date:4/18/2014

Harvard neuroscientists have made a discovery that turns 160 years of neuroanatomy on its head.

Myelin, the electrical insulating material 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 a new work lead 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 of a number of devastating diseases, including multiple sclerosis and schizophrenia.

But the new research shows that despite myelin 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" Arlotta, co-director of the HSCI neuroscience program, says.

What this means, Arlotta says, is that the higher in the cerebral cortex one looks the closer to the top of the brain, which is its most evolved region - the less myelin one finds. 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. They have 'intermittent myelin' with long axon tracts that lack myelin interspersed among myelin-rich segments.

Arlotta continues: "contrary to the common assumptions that neurons use a universal profile of myelin distribution on their axons, the work indicate that different neurons choose to myelinate their axons differently. In classic neurobiology textbooks myelin is represented on axons as a sequence of myelinated segments separated by very short nodes that lack myelin. This distribution of myelin was tacitly assumed to be always the same, on every neuron, from the beginning to the end of the axon. This new work finds this not to be the case."

The results of the research by Arlotta and post doctoral fellow Giulio Srubek Tomassy, the first author on the report, are published in the latest edition of Science, the journal of the American Association for the Advancement of Science.

The paper is accompanied by a "Perspective" by R. Douglas Fields, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, at the National Institutes of Health, who says that Arlotta and Tomassy's findings raise important questions about the purpose of myelin, "are likely to spark new concepts about how information is transmitted and integrated in the brain."

Arlotta and Tomassy collaborated closely on the new work with postdoctoral fellow Daniel Berger of the Lichtman group, which generated one of the two massive electron microscopy data bases that made the work possible.

"The fact that it is the most evolved neurons, the ones that have expanded dramatically in humans, suggests that what we're seeing might be the "future". As neuronal diversity increases and the brain needs to process more and more complex information, neurons change the way they use myelin to "achieve" more", says Arlotta.

It is possible, said Tomassy, that these profiles of myelination "may be giving neurons an opportunity to branch out and 'talk' to neighboring neurons". For example, because axons cannot make synaptic contacts when they are myelinated, a possibility is that these long myelin gaps may be needed to increase neuronal communication and synchronize responses across different neurons. Perhaps, he and Arlotta postulate, the intermittent myelin is intended to fine-tune the electrical impulses traveling along the axons, in order to allow the emergence of highly complex neuronal behaviors.


'/>"/>

Contact: B. D. Colen
617-495-7821
Harvard University
Source:Eurekalert  

Related medicine news :

1. Gene implicated in progression and relapse of deadly breast cancer finding points to potential Achilles heel in triple negative breast cancer
2. Stem cell findings may offer answers for some bladder defects and disease
3. New findings show link between diabetes and pancreatic cancer
4. Finding a target for tumor suppression
5. The Secret Society of Happy People Provides Activities for Finding Happiness in the New Year
6. Female Veterans Leaving the Military Can Get Help Finding Civilian Careers with Career Confidential’s Mission: Transition Job Kit
7. As Tylenol Lawsuits Mount, Bernstein Liebhard LLP Notes New Study Finding that Acetaminophen Combined With Alcohol May Increase Risk for Kidney Damage
8. Tylenol Lawsuit News: Bernstein Liebhard LLP Notes Release of Study Finding Tylenol Use in Pregnancy May Affect Child Development
9. Finding Holiday Gifts for People with Alzheimer’s Just Got a Whole Lot Easier
10. Finding antitumor T cells in a patients own cancer
11. Da Vinci Robot Lawsuit News: Bernstein Liebhard LLP Notes FDA Finding that Robotic Surgery Complications Linked to da Vinci Robot Doubled in Past Year
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Finding turns neuroanatomy on its head
(Date:4/29/2016)... ... April 29, 2016 , ... New York City based oral and maxillofacial surgeon Dr. ... very effective way to treat obstructive sleep apnea. Dr. Jamali is proud to offer this ... procedure that involves one or both jaw bones. This surgery is performed to correct the ...
(Date:4/29/2016)... ... 29, 2016 , ... For those who skip meals occasionally (which is pretty ... among the many new lifestyle diet tips offered by nutritionists Pam Bonney and Priya ... Water® radio show. Bonny and Lawrence noted that because proper nutrition, including water, provides ...
(Date:4/29/2016)... ... April 29, 2016 , ... Innovations with Ed Begley Jr., ... episode, airing third quarter 2016 via Discovery Channel. Dates and show times TBA. ... Products, located in Greenwood, Wisconsin applies product research and development and continuous technological ...
(Date:4/29/2016)... ... April 29, 2016 , ... CURE Media Group ... patients with cancer, today announced that Lynne Malestic, RN, of Eisenhower Lucy Curci ... Extraordinary Healer® for Oncology Nursing , which honors nurses who have dedicated their ...
(Date:4/29/2016)... Rafael, CA (PRWEB) , ... April 29, 2016 , ... ... week long softball camp from July 24th – 27th for girls aged 10-18. All ... camp is held at the beautiful Clark V. Whited Complex, one of the finest ...
Breaking Medicine News(10 mins):
(Date:4/28/2016)... , April 28, 2016 ... George Phillips und Stephen ...    ArisGlobal®, ein führender Anbieter ... gab heute bekannt, dass neue Führungskräfte zum ... gestoßen sind, die vielfältige Erfahrungen mitbringen.  Dies ...
(Date:4/28/2016)... Oramed Pharmaceuticals Inc. (NASDAQ: ORMP ) ( ... of oral drug delivery systems, announced today that the Company ... Joseph Gunnar & Co. LLC, taking place on ... Nadav Kidron , CEO of Oramed, will present a ...   PIONEERS 2016, presented by Joseph Gunnar ...
(Date:4/27/2016)... Inc. (Nasdaq: HOLX ) announced today ... quarter ended March 26, 2016.  GAAP diluted earnings ... non-GAAP diluted EPS of $0.47 increased 14.6%.  Revenue ... basis, and 6.3% on a constant currency basis.  ... highlighted by 14.6% growth in non-GAAP EPS," said ...
Breaking Medicine Technology: