Featured Research

from universities, journals, and other organizations

Molecular Scaffold That Guides Connections Between Brain Cells Discovered

Date:
May 22, 2008
Source:
Cold Spring Harbor Laboratory
Summary:
Brain cells known as neurons process information by joining into complex networks, transmitting signals to each other across junctions called synapses. But "neurons don't just connect to other neurons," emphasizes the lead researcher, "in a lot of cases, they connect to very specific partners, at particular spots." As they learn through research like this how the brain develops its complex wiring, the scientists hope they can clarify what goes wrong in disorders like autism.

Brain cells known as neurons process information by joining into complex networks, transmitting signals to each other across junctions called synapses. But “neurons don’t just connect to other neurons,” emphasizes Z. Josh Huang, Ph.D., “in a lot of cases, they connect to very specific partners, at particular spots.”

Dr. Huang, a professor at Cold Spring Harbor Laboratory (CSHL), leads a team that has identified molecules guiding this highly specific neuronal targeting in the developing brains of mice. The researchers reportthat in some cases, these molecular guides -- non-signaling brain cells known as glia -- form a kind of scaffold. This scaffold, in turn, directs the growth of nerve fibers and their connections between specific types of neurons.

As they learn through research like this how the brain develops its complex wiring, the scientists hope they can clarify what goes wrong in disorders like autism.

The Cerebellum’s ‘Organized Architecture’

Distinctive wiring patterns are unmistakable in the cerebellum, a brain region best known for controlling movement, in both mice and people. Compared to regions involved in more sophisticated functions like vision and thought, “the cerebellum is an easier place to start, because of its very organized architecture,” Dr. Huang says, although he notes that other parts of the brain have their own specific wiring patterns.

Central to the wiring architecture of the cerebellum are so-called Purkinje cells, a type of neuron that deploys a bushy array of fibers called dendrites that extend through layers of cerebellar territory. The dendrites gather signals from many other neurons in the cerebellum and send signals to other parts of the body.

The complex wiring pattern emerges during the early growth of the brain, when individual neurons migrate from their places of origin in other brain regions and emit filaments called axons that connect to particular parts of other neurons, such as the dendrites. Dr. Huang likens this process to the address on a letter that brings it from another country directly to your door by specifying the country, state, city, street, and house number. He and other brain researchers have learned much about the higher levels of this addressing scheme, identifying, for instance, chemical signals that guide axons to the right section of the brain, and different signals that lead them to the appropriate layer within that section.

How Neurons Form Synapses

Only recently, however, have Dr. Huang and his colleagues traced the chemical signals leading neurons to form synapses with specific parts of other neurons. Such sub-cellular specificity is critical to ensure the precision and reliability of communication among neurons. Synapses are the tiny gaps across which nerve cells exchange signals, conveyed by chemicals called neurotransmitters.

A few years ago, Dr. Huang’s team established that a protein from the immunoglobulin family directs one group of cerebellar neurons to connect with a specific part of Purkinje cells. Immunoglobulin proteins are best known for acting as antibodies in the immune system, where they take on myriad forms to attack new invaders. Here, however, they are observed to be involved in the wiring of the brain.

“The striking feature is that there is a lot of capacity for variety” in immunoglobulin molecules, Dr. Huang explains. In the nervous system, their versatility may help them guide cells to form synapses with specific partners. Intriguingly, Dr. Huang adds, immunoglobulins have been implicated in neural developmental disorders, such as autism. “There is good evidence that these disorders involve miswiring of the nervous system,” Dr. Huang says, which may reflect a problem with immunoglobulin-guided synapse formation.

A Guiding Scaffold Made of Glial Cells

In the work reported in their newly published paper, Dr. Huang’s team traced the sub-cellular targeting of a different set of cerebellar neurons called stellate cells, which make numerous connections to the dendritic “bush” emanating from clumps of Purkinje cells. Unlike the cells they had studied previously, however, these neurons need help to form synapses. The researchers developed sophisticated techniques to label different cell types with chemical markers, and found that non-signaling cells called glia act as a scaffold, guiding the growing axons of the stellate cells and determining where they form synapses to the Purkinje cells.

In this role, the glia act something like “matchmakers” to bring the stellate and Purkinje cells together. But Dr. Huang notes that the scaffold of glia interspersed among the neurons allows each stellate cell to make contact to many different Purkinje cells. A direct attraction between stellate and Purkinje cells, he suggests, might lead two cells two pair up exclusively.


Story Source:

The above story is based on materials provided by Cold Spring Harbor Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Fabrice Ango, Caizhi Wu, Johannes J. Van der Want, Priscilla Wu, Melitta Schachner, Z. Josh Huang. Bergmann Glia and the Recognition Molecule CHL1 Organize GABAergic Axons and Direct Innervation of Purkinje Cell Dendrites. PLoS Biology. April 2008. doi: 10.1371/journal.pbio.0060103. [link]

Cite This Page:

Cold Spring Harbor Laboratory. "Molecular Scaffold That Guides Connections Between Brain Cells Discovered." ScienceDaily. ScienceDaily, 22 May 2008. <www.sciencedaily.com/releases/2008/05/080520175334.htm>.
Cold Spring Harbor Laboratory. (2008, May 22). Molecular Scaffold That Guides Connections Between Brain Cells Discovered. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2008/05/080520175334.htm
Cold Spring Harbor Laboratory. "Molecular Scaffold That Guides Connections Between Brain Cells Discovered." ScienceDaily. www.sciencedaily.com/releases/2008/05/080520175334.htm (accessed April 18, 2014).

Share This



More Mind & Brain News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Study On Artists' Brain Shows They're 'Structurally Unique'

Study On Artists' Brain Shows They're 'Structurally Unique'

Newsy (Apr. 17, 2014) The brains of artists aren't really left-brain or right-brain, but rather have extra neural matter in visual and motor control areas. Video provided by Newsy
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Are School Dress Codes Too Strict?

Are School Dress Codes Too Strict?

AP (Apr. 16, 2014) Pushing the limits on style and self-expression is a rite of passage for teens and even younger kids. How far should schools go with their dress codes? The courts have sided with schools in an era when school safety is paramount. (April 16) Video provided by AP
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins