Complex wiring of the nervous system may rely on a just a handful of genes and proteins

February 10, 2012 in Medical research

Complex wiring of the nervous system may rely on a just a handful of genes and proteins

Enlarge

This image shows nerves (labeled in green) that control body movements emerging from the spinal cord of a mouse (upper left, in cross section) and connecting to muscles in the base of the leg. The Salk researchers discovered that a combination of genes direct nerves to split in the leg (lower right) to make the proper connections with their target muscles during early development. Credit: Image: Courtesy Dario Bonanomi, Salk Institute for Biological Studies

Researchers at the Salk Institute have discovered a startling feature of early brain development that helps to explain how complex neuron wiring patterns are programmed using just a handful of critical genes. The findings, published February 3 in Cell, may help scientists develop new therapies for neurological disorders, such as amyotrophic lateral sclerosis (ALS), and provide insight into certain cancers.

The Salk researchers discovered that only a few proteins on the leading edge of a motor neuron's axon - its outgoing electrical "wire" - and within the extracellular soup it travels through guide the nerve as it emerges from the spinal cord. These molecules can attract or repel the axon, depending on the long and winding path it must take to finally connect with its target muscle.

"The budding neuron has to detect the local environment it is growing through and decide where it is, and whether to grow straight, move to the left or right, or stop," says the study's senior investigator, Sam Pfaff, a professor in Salk's Gene Expression Laboratory and a Howard Hughes Medical Institute investigator.

"It does this by mixing and matching just a handful of protein products to create complexes that tell a growing neuron which way to go, in the same way that a car uses the GPS signals it receives to guide it through an unfamiliar city," he says.

The brain contains millions of times the number of neuron connections than the number of genes found in the DNA of . This is one of the first studies to try and understand how a growing neuron integrates many different pieces of information in order to navigate to its eventual target and make a functional connection.

Complex wiring of the nervous system may rely on a just a handful of genes and proteins
Enlarge

This is Samuel Pfaff. Credit: Image: Courtesy of Salk Institute for Biological Studies

"We focused on that control muscle movements, but the same kind of thing is going on throughout embryonic development of the entire nervous system, during which millions of axons make trillions of decisions as they move to their targets," he says. "It is the exquisite specificity with which they grow that underlies the basic architecture and proper function of the nervous system."

These findings might eventually shed new light on a number of clinical disorders related to faulty nerve cell functioning, such as ALS, which is also known as Lou Gehrig's disease, says the first author on the paper, Dario Bonanomi, a post-doctoral researcher in Pfaff's laboratory.

"These are the motor neurons that die in diseases like Lou Gehrig's disease and that are linked to a genetic disorder in children known as spinal muscle atrophy," Bonanomi says.

"It is also a jumping off point to try and understand the basis for defects that might arise during fetal development of the nervous system," he added. "A better understanding of those signals might help to be able to regenerate and rewire circuits following diseases or injuries of the ."

The researchers say the study also offers insights into cancer development, because a protein the researchers found to be crucial to the "push and pull" signaling system - Ret- is also linked to cancer. Mutations that activate Ret are linked to a number of different kinds of tumors.

The other protein receptors described in the study, known as Ephs, have also been implicated in cancer, Pfaff says.

"This study suggests that the way cells detect signals in their environment is likely a universal strategy," he says, "and we know that genes and proteins known to function primarily during have been linked to cancer."

"Controlling neuronal growth requires very potent signaling molecules, and it makes sense they would be linked to disease," Pfaff says. "We hope our findings help further unravel these connections."

Provided by Salk Institute search and more info website

4.9 /5 (11 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

Tausch
Feb 11, 2012

Rank: not rated yet
Embryonically you are looking for a 'never-before-seen bioelectric pattern':

http://www.physor...een.html

GPS as a universal strategy has never looked better.
Rank 4.9 /5 (11 votes)
Relevant PhysicsForums posts

More news stories

Study suggests new source of kidneys for transplant

Nearly 20 percent of kidneys that are recovered from deceased donors in the U.S. are refused for transplant due to factors ranging from scarring in small blood vessels of the kidney's filtering units to the organ going too ...

Medical research created 13 hours ago | popularity 5 / 5 (2) | comments 0 | with audio podcast

Discovery of circadian clock in mice hair reveals period of time when damage from radiotherapy can be quickly repaired

Discovering that mouse hair has a circadian clock - a 24-hour cycle of growth followed by restorative repair - researchers suspect that hair loss in humans from toxic cancer radiotherapy and chemotherapy ...

Medical research created 14 hours ago | popularity 5 / 5 (2) | comments 1 | with audio podcast

Do salamanders hold the solution to regeneration?

Salamanders' immune systems are key to their remarkable ability to regrow limbs, and could also underpin their ability to regenerate spinal cords, brain tissue and even parts of their hearts, scientists have ...

Medical research created 15 hours ago | popularity 4.9 / 5 (7) | comments 2 | with audio podcast

New study finds blind people have the potential to use their 'inner bat' to locate objects

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 created 17 hours ago | popularity not rated yet | comments 1 | with audio podcast

Germ-fighting vaccine system makes great strides in delivery

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 created 18 hours ago | popularity not rated yet | comments 0


Holding drivers' attention

Each day, an average of nine people are killed in the United States and more than 1,000 injured by drivers doing something other than driving.

Genetic predictors of postpartum depression uncovered

Johns Hopkins researchers say they have discovered specific chemical alterations in two genes that, when present during pregnancy, reliably predict whether a woman will develop postpartum depression.

Nobel laureate plays down flu pandemic scaremongering

A Nobel prize-winning scientist Tuesday played down "shock-horror scenarios" that a new virus strain will emerge with the potential to kill millions of people.

Study puts Huntington's disease trials on TRACK

(Medical Xpress)—A three-year multinational study has tracked and detailed the progression of Huntington's disease (HD), predicting clinical decline in people carrying the HD gene more than 10 years before ...

Child maltreatment increases risk of adult obesity

Children who have suffered maltreatment are 36% more likely to be obese in adulthood compared to non-maltreated children, according to a new study by King's College London. The authors estimate that the prevention or effective ...

New immune system discovered

(Medical Xpress)—A research team, led by Jeremy Barr, a biology post-doctoral fellow, unveils a new immune system that protects humans and animals from infection.