Navigation Links
Scientists discover a molecular scaffold that guides connections between brain cells
Date:5/20/2008

Brain cells known as neurons process information by joining into complex networks, transmitting signals to each other across junctions called synapses. But neurons dont 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 report in PLoS Biology that 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 Cerebellums 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. Huangs 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. Huangs 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.


'/>"/>

Contact: Jim Bono
bono@cshl.edu
516-367-8455
Cold Spring Harbor Laboratory
Source:Eurekalert

Related biology news :

1. UK scientists working to help cut ID theft
2. Scientists show that mitochondrial DNA variants are linked to risk factors for type 2 diabetes
3. Comet probes reveal evidence of origin of life, scientists claim
4. Scientists link fragile X tremor/ataxia syndrome to binding protein in RNA
5. Male elephants get photo IDs from scientists
6. Scientists retrace evolution with first atomic structure of an ancient protein
7. Muscle mass: Scientists identify novel mode of transcriptional regulation during myogenesis
8. Carnegie Mellon scientists develop nanogels that enable controlled delivery of carbohydrate drugs
9. Clemson scientists shed light on molecules in living cells
10. Scientists tackle mystery mountain illness
11. T. rex quicker than Becks, say scientists
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/16/2017)... , Feb. 16, 2017  Genos, a community ... that it has received Laboratory Accreditation from the ... is presented to laboratories that meet stringent requirements ... scientifically rigorous processes. "Genos is committed ... laboratory practices. We,re honored to be receiving CAP ...
(Date:2/9/2017)... , Feb. 9, 2017 The biomass boiler ... of the biomass boiler market globally in terms of ... biomass boilers. The market for biomass boilers has been ... end-user, application, and country/region. The market based on feedstock ... forest residues, biogas & energy crops, urban residues, and ...
(Date:2/8/2017)... Feb. 7, 2017 Report Highlights ... 2021 from $8.3 billion in 2016 at a compound ... 2021. Report Includes - An overview of the ... trends, with data from 2015 and 2016, and projections ... Segmentation of the market on the basis of product ...
Breaking Biology News(10 mins):
(Date:2/24/2017)... SAN DIEGO , Feb. 24, 2017  OncoSec ... intratumoral cancer immunotherapies, will host a Key Opinion Leader ... featured as an oral and poster presentation at the ... development plan. The KOL event will be held in-person ... 12:00 PM EST / 9:00 AM PST at the ...
(Date:2/23/2017)... Madison, Wisconsin (PRWEB) , ... February 23, 2017 ... ... their Drug Discovery Services portfolio to include an array of biochemical ... clients with reliable data to drive their hit-to-lead and SAR programs, including inhibitor ...
(Date:2/23/2017)... Atlanta, it seems everyone has a chance to express their ... expressive and dynamic community unlike any other. The businesses that ... With their newest salon in ... on that tradition with a unique, fresh approach to head ... the newest of 13 nationwide locations, each of them well-situated ...
(Date:2/23/2017)... ... February 23, 2017 , ... Brain Sentinel, Inc. has received ... SPEAC® System, the Brain Sentinel® Seizure Monitoring and Alerting System. The adjunctive seizure ... periods of rest. A lightweight, non-invasive monitor is placed on the belly of ...
Breaking Biology Technology: