Brain electrical activity spurs insulation of brain's wiring
(Medical Xpress) -- Researchers at the National Institutes of Health have discovered in mice a molecular trigger that initiates myelination, the process by which brain cell networks are reinforced with an insulating material called myelin that speeds their ability to transmit messages.
The researchers showed that an electrical signal passing through a brain cell (neuron) results in the brain cell releasing the molecule glutamate. Glutamate, in turn, triggers another type of brain cell, called an oligodendrocyte, to form a point of contact with the neuron. Signals transmitted through this contact point stimulate the oligodendrocyte to make myelin protein and begin the process of myelination. In this process, the oligodendrocyte wraps myelin around axons the long, cable-like projections that extend from each neuron. The myelination process is analogous to wrapping electrical tape around bare wires.
Electrical signals transmitted from one neuron to the next are a basic form of communication in the brain. The myelin layers that oligodendrocytes wrap around neurons boost these signals so that they travel 50 times faster than before.
The study was conducted by Hiroaki Wake, Philip R. Lee, and R. Douglas Fields of the Nervous System Development and Plasticity Section of the NIHs Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Their findings appear online in Science Express.
Insulation begins to form on axons in the late stages of fetal development, but the process continues through childhood, adolescence, and into early adulthood, said Dr. Fields, the studys senior author. For example, infants cannot hold up their heads or walk until the appropriate motor axons become myelinated, and the frontal lobes of the brain, responsible for judgment and higher-level complex reasoning, are not fully myelinated until the early twenties.
Understanding how oligodendrocytes generate and help repair myelin could provide insight into how only the appropriate axons in the brain become insulated during development as people acquire skills, with the eventual goal of helping them do so more efficiently, Dr. Fields explained. Similarly, understanding the myelination process could lead to insights into disorders like multiple sclerosis, in which myelin is either damaged or destroyed. Moreover, understanding myelination may allow researchers to speed myelination and repair of axons recovering from injury.
Throughout the brain, oligodendrocytes and neurons exist side by side. The researchers placed mouse nerve cells and myelin-making oligodendrocytes together in a dish and stimulated the nerve cells with electrical pulses. After three weeks, they found that the nerve cells were wrapped in a myelin covering.
In a separate culture of neurons and oligodendrocytes, the researchers blocked the release of the molecule glutamate, a neurotransmitter. Neurotransmitters make it possible for signals to pass between cells. When glutamate release was blocked, very little myelin coating formed. Further experiments showed that after the electrical pulses and the release of glutamate, nerve cells and the neighboring oligodendrocytes began sending chemical signals back and forth. Then the oligodendrocytes started to make the protein used to form the myelin sheath. Specifically, receptors on the cell membrane of oligodendrocytes detect glutamate released by the axon, and this triggers the formation of what the researchers termed specialized adhesive signaling junctionspoints of contact between oligodendrocytes and axons that enable signals to be passed between the cells. Then the oligodentrocytes began depositing myelin on electrically active axons, but not on axons that were not electrically active.
In a previous study, Dr. Fields and his coauthors found that electrical activity in neurons stimulates other cells, called astrocytes, that also are involved in the myelination process.
Provided by National Institutes of Health
- New research reveals critical knowledge about the nervous system Nov 06, 2007 | not rated yet | 0
- Scientists discover a new line of communication between nervous system cells Jun 26, 2007 | not rated yet | 0
- MS research: Myelin influences how brain cells send signals Jul 21, 2011 | not rated yet | 0
- Claudin 11 stops the leaks in neuronal myelin sheaths Dec 01, 2008 | not rated yet | 0
- Turning back the clock for Schwann cells May 19, 2008 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
Marie Curie's leukemia
May 13, 2013 Does anyone know what might be the cause of Marie Curie's cancer
- More from Physics Forums - Medical Sciences
More news stories
New research from the University of Southampton has shown that blind and visually impaired people have the potential to use echolocation, similar to that used by bats and dolphins, to determine the location of an object.
Medical research 46 minutes ago | not rated yet | 0 |
A novel vaccine study from South Dakota State University (SDSU) will headline the groundbreaking research that will be unveiled at the American Association of Pharmaceutical Scientists' (AAPS) National Biotechnology Conference ...
Medical research 1 hour ago | not rated yet | 0
Every 20 seconds, a limb is lost as a consequence of diabetic foot ulcer that does not heal. To date, medical solutions that can change this situation are very limited. In his doctoral thesis Yue Shen from the Industrial ...
Medical research 5 hours ago | not rated yet | 0
When tumours metastasise, they can block lymphatic vessels, as researchers from ETH Zurich have discovered using a new method. The lymphatic fluid subsequently has to find a new path through the tissue. Such ...
Medical research 5 hours ago | not rated yet | 0 |
In their quest to learn more about the variability of cells between and within tissues, biomedical scientists have devised tools capable of simultaneously measuring dozens of characteristics of individual ...
Medical research 23 hours ago | 5 / 5 (3) | 0 |
While the effects of acute stroke have been widely studied, brain damage during the subacute phase of stroke has been a neglected area of research. Now, a new study by the University of South Florida reports that within a ...
29 minutes ago | not rated yet | 0 |
A new report suggests that improved health care and significant reductions in drug costs might be attained by breaking up the age-old relationship between physicians and drug company representatives who promote the newest, ...
31 minutes ago | not rated yet | 0
Food microbiology laboratories continue to submit false negative results and false positive results on a routine basis. A retrospective study of nearly 40,000 proficiency test results over the past 14 years, presented today ...
17 minutes ago | not rated yet | 0
Posterior fossa subdural hematoma (PFSDH) is a serious and rare condition in newborns, generally occurring after difficult deliveries. But with appropriate treatment, there's an excellent chance of good long-term outcomes ...
21 minutes ago | not rated yet | 0
National guidelines recommend that at-risk women be screened for elevated cholesterol levels to reduce their chances of developing cardiovascular disease. But who is 'at risk?' The results of a study by investigators ...
30 minutes ago | not rated yet | 0
A new study conducted by researchers at the Child Study Center at NYU Langone Medical Center found men diagnosed as children with attention-deficit/hyperactivity disorder (ADHD) were twice as likely to be obese in a 33-year ...
1 hour ago | not rated yet | 0 |