Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MIT researcher finds neuron growth in adult brain

27.12.2005


Despite the prevailing belief that adult brain cells don’t grow, a researcher at MIT’s Picower Institute for Learning and Memory reports in the Dec. 27 issue of Public Library of Science (PLoS) Biology that structural remodeling of neurons does in fact occur in mature brains.



This finding means that it may one day be possible to grow new cells to replace ones damaged by disease or spinal cord injury, such as the one that paralyzed the late actor Christopher Reeve.

"Knowing that neurons are able to grow in the adult brain gives us a chance to enhance the process and explore under what conditions - genetic, sensory or other - we can make that happen," said study co-author Elly Nedivi, the Fred and Carole Middleton Assistant Professor of Neurobiology.


While scientists have focused mostly on trying to regenerate the long axons damaged in spinal cord injuries, the new finding suggests targeting a different part of the cell: the dendrite. A dendrite, from the Greek word for tree, is a branched projection of a nerve cell that conducts electrical stimulation to the cell body.

"We do see relatively large-scale growth" in the dendrites, Nedivi said. "Maybe we would get some level of improvement (in spinal cord patients) by embracing dendritic growth." The growth is affected by use, meaning the more the neurons are used, the more likely they are to grow, she said.

The study’s co-authors - Nedivi; Peter T. So, an MIT professor of mechanical and biological engineering; Wei-Chung Allen Lee, an MIT brain and cognitive sciences graduate student; and Hayden Huang, a mechanical engineering research affiliate - used a method called two-photon imaging to track specific neurons over several weeks in the surface layers of the visual cortex in living mice. While many studies have focused on the pyramidal neurons that promote firing, this work looked at all types of neurons, including interneurons, which inhibit the activity of cortical neurons.

With the help of technology similar to magnetic resonance imaging (MRI), but at a much finer, cellular resolution, the researchers were able to stitch together two-dimensional slices to create the first 3-D reconstruction of entire neurons in the adult cortex. Dendritic branch tips were measured over weeks to evaluate physical changes.

What the researchers saw amazed them.

In 3-D time-lapse images, the brain cells look like plants sprouting together. Some push out tentative tendrils that grow around or retract from contact with neighboring cells. Dendrite tips that look like the thinnest twigs grow longer. Of several dozen branch tips, sometimes only a handful changed; in all, 14 percent showed structural modifications. Sometimes no change for weeks was followed by a growth spurt. There were incremental changes, some as small as seven microns, the largest a dramatic 90 microns.

"The scale of change is much smaller than what goes on during the critical period of development, but the fact that it goes on at all is earth-shattering," Nedivi said. She believes the results will force a change in the way researchers think about how the adult brain is hard-wired.

Nedivi had previously identified 360 genes regulated by activity in the adult brain that she termed candidate plasticity genes or CPGs. Her group found that a surprisingly large number of CPGs encode proteins in charge of structural change. Why are so many of these genes "turned on" in the adult well after the early developmental period of dramatic structural change?

The neuroscience community has long thought that whatever limited plasticity existed in the adult brain did not involve any structural remodeling, mostly because no such remodeling was ever detected in excitatory cells. Yet evidence points to the fact that adult brains can be functionally plastic. In response to the CPG data, Nedivi and Lee revisited this question with the help of So and Huang.

By applying an innovative new imaging technology that allows monitoring of neuronal structural dynamics in the living brain, they found evidence for adult neuronal restructuring in the less-known, less-accessible inhibitory interneurons.

"Maybe the inhibitory network is where the capacity is for large-scale changes," Nedivi said. "What’s more, this growth is tied to use, so even as adults, the more we use our minds, the more robust they can be."

This work is supported by the National Eye Institute.

Elizabeth A. Thomson | MIT News Office
Further information:
http://www.mit.edu

More articles from Life Sciences:

nachricht New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

New drug reduces transplant and mortality rates significantly in patients with hepatitis C

29.05.2017 | Statistics

VideoLinks
B2B-VideoLinks
More VideoLinks >>>