Adult brain neurons can remodel connections

Nov 24, 2008 By Deborah Halber

Overturning a century of prevailing thought, scientists are finding that neurons in the adult brain can remodel their connections. In work reported in the Nov. 24 online edition of the Proceedings of the National Academy of Sciences (PNAS), Elly Nedivi, associate professor of neurobiology at the Picower Institute for Learning and Memory, and colleagues found that a type of neuron implicated in autism spectrum disorders remodels itself in a strip of brain tissue only as thick as four sheets of tissue paper at the upper border of cortical layer 2.

"This work is particularly exciting because it sheds new light on the potential flexibility of cerebral cortex circuitry and architecture in higher-level brain regions that contribute to perception and cognition," said Nedivi, who is also affiliated with MIT's departments of brain and cognitive sciences and biology. "Our goal is to extract clues regarding the contribution of structural remodeling to long-term adult brain plasticity — the brain's ability to change in response to input from the environment — and what allows or limits this plasticity."

In a previous study, Nedivi and Peter T. So, professor of mechanical engineering and biological engineering at MIT, saw relatively large-scale changes in the length of dendrites — branched projections of nerve cells that conduct electrical stimulation to the cell body. Even more surprising was their finding that this growth was limited to specific type of cell. The majority of cortical neurons were stable, while the small fraction of locally connecting cells called interneurons underwent dynamic rearrangement.

In the current study, they show that the capacity of interneurons to remodel is not predetermined by genetic lineage, but imposed by the circuitry within the layers of the cortex itself. "Our findings suggest that the location of cells within the circuit and not pre-programming by genes determines their ability to remodel in the adult brain," Nedivi said. "If we can identify what aspect of this location allows growth in an otherwise stable brain, we can perhaps use it to coax growth in cells and regions that are normally unable to repair or adjust to a changing environment.

"Knowing that neurons are able to grow in the adult brain gives us a chance to enhance the process and explore under what conditions we can make it happen," Nedivi said. "In particular, we need to pay more attention to the unique interneuron population that retains special growth features into adulthood."

Source: Massachusetts Institute of Technology

Explore further: Serotonin neuron subtypes: New insights could inform SIDS understanding, depression treatment

add to favorites email to friend print save as pdf

Related Stories

Researcher finds neuron growth in adult brain

Dec 27, 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 ...

Researchers identify gene involved in building brains

Mar 29, 2005

A tiny molecule is key to determining the size and shape of the developing brain, researchers from the Picower Institute for Learning and Memory at MIT reported in the March issue of Nature Neuroscience. This molecule may on ...

Recommended for you

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Star_Gazer
not rated yet Nov 24, 2008
FINALLY! A scientific proof that you CAN teach the old dogs new tricks!!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.