As the brain develops, each neuron must find its way to precisely the right spot to weave the intricate network of links the brain needs to function. Like the wiring in a computer, a few misplaced connections can throw off functioning for an entire segment of the brain.
A new study by researchers at the University of North Carolina School of Medicine reveals how some nerve cells, called interneurons, navigate during the development of the cerebral cortex. Mutations in a key gene behind this navigation system underlie a rare neurological disorder called Joubert syndrome; a condition linked with autism spectrum disorders and brain structure malformations.
The study was published online on Nov. 12, 2012 by the journal Developmental Cell.
"We were trying to understand how neurons get to the right place at the right time during brain development," said senior study author Eva Anton, PhD, a professor in the UNC Neuroscience Center and the Department of Cell Biology and Physiology at the UNC School of Medicine.
To do that, the UNC researchers and their collaborator, Dr. Tamara Caspary, at Emory University tracked brain development in mice with and without a gene called Arl13b. They found that the gene, when functioning normally, allows interneurons to use an appendage called the primary cilium as a sensor.
These appendages are found on many types of cells, but scientists did not previously know what they were doing on developing neurons.
"We found that primary cilia play an important role in guiding neurons to their appropriate places during development so that the neurons can wire up appropriately later on," said Anton. "It's like an antenna that allows the neuron to read the signals that are out there and navigate to the right target location."
Neurons in mice without the Arl13b gene or expressing mutant Arl13b found in Joubert syndrome patients essentially had a broken antenna, causing the cells to get lost on the way to their destinations.
Variants of the Arl13b gene are known to cause Joubert syndrome, which is characterized by brain malformations, abnormal eye and tongue movements, low muscle tone and mental retardation. This is one of the first studies to uncover how mutations of this gene actually disrupt brain development.
"Ultimately, if you're going to come up with therapeutic solutions, it's important to understand the biology of the disease," said Anton. "This contributes to our understanding of the biological processes that are disrupted in Joubert syndrome patients."
University of North Carolina Health Care: http://www.med.unc.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Results of largest ever genetics study of a single population could also help refine dates for major events during human evolution Humans are evolving more rapidly than previously thought, according to the largest ever genetics study of a single population.
Latest genetic tests reveal another break in the male line, potentially undermining the legitimacy of the entire House of Plantagenet When scientists revealed last year that an adulterous affair had apparently broken the male line in Richard III’s family tree, they vowed to investigate further.
By 2016, Icelandic genetics company deCODE will have data on half the country's population. Releasing the data will be controversial, but could save lives
A clinical trial has shown that the drug aducanumab slows cognitive decline in people with Alzheimer's and reduces the amount of amyloid plaque in their brain
A leading researcher issues a call for pills that deliver a full course of treatment in one swallow.One of the world’s preëminent biomedical researchers is calling for a concerted effort by scientists to develop pills that would stay in the stomach or gut for weeks or months once swallowed, delivering one or more drugs continuously or over set intervals.
Two genes responsible for building up drug-resistance can easily be shared between a family of bacteria
When malaria parasites infect blood, they manufacture odor molecules that smell sweet to mosquitoes, scientists report. So how do these odors get from the bloodstream to the insects?
Researchers are developing new method of wireless deep brain stimulation.
Zoos belonging to World Association of Zoos and Aquariums filmed allowing shocking mistreatment of elephants, dolphins, lions, bears, penguins and whales
Owners of Highland Wildlife Park hope Victoria, 18, will get chummy with male Arktos during her stay in the Cairngorms