Featured Research

from universities, journals, and other organizations

The evolution of brain wiring: Navigating to the neocortex

Date:
March 24, 2011
Source:
Cell Press
Summary:
A new study is providing fascinating insight into how projections conveying sensory information in the brain are guided to their appropriate targets in different species. The research reveals a surprising new evolutionary scenario that may help to explain how subtle changes in the migration of "guidepost" neurons underlie major differences in brain connectivity between mammals and non-mammalian vertebrates.

A new study is providing fascinating insight into how projections conveying sensory information in the brain are guided to their appropriate targets in different species. The research, published in the March 24 issue of the journal Neuron, reveals a surprising new evolutionary scenario that may help to explain how subtle changes in the migration of "guidepost" neurons underlie major differences in brain connectivity between mammals and nonmammalian vertebrates.

The neocortex (the "new" cortex) is a brain area that is unique to mammals and plays a central role in cognition, motor behavior, and sensory perception. A deeper brain region, called the thalamus, sends sensory information to the neocortex via a major highway called the internal capsule. As might be expected given the differences in brain anatomy, thalamic projections vary tremendously among vertebrates, with paths in reptiles and birds taking a completely different route than that seen in mammals.

"What controls the differential path-finding of thalamic axons in mammals versus nonmammalian vertebrates and how these essential projections have evolved remains unknown," explains senior study author, Dr. Sonia Garel from Ecole Normale Supιrieure in Paris. "We examined how thalamic axons, which constitute the main input to the neocortex, are directed internally to their evolutionarily novel target in mammals, while they follow an external path to other targets in reptiles and birds."

Using a series of comparative and functional studies, Dr. Garel and colleagues observed species-specific differences in the migration and positioning of well-characterized "corridor guidepost" neurons. The researchers went on to show that a protein called Slit2, previously implicated in cell migration and axon guidance, was critical for local positioning of mammalian guidepost cells and functioned as a kind of switch to reroute thalamic axons from the default external route to an internal path to the neocortex.

"Taken together, our results show that minor differences in the positioning of conserved guidepost neurons, which is controlled by Slit2, plays an essential role in the species-specific pathfinding of thalamic axons, thereby providing a novel framework to understand the shaping and evolution of a novel and major brain projection," concludes Dr. Garel. "Furthermore, our study opens the possibility that changes in cell migration may more generally control the evolution of brain connectivity, particularly the formation of other mammalian-specific tracts. Since an increase in cell migration has participated in the morphogenesis of the neocortex itself, these novel findings reveal that cell migration can be considered as a general player in the evolutionary changes that led to the emergence of the mammalian brain."


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Franck Bielle, Paula Marcos-Mondejar, Maryama Keita, Caroline Mailhes, Catherine Verney, Kiml Nguyen Ba-Charvet, Marc Tessier-Lavigne, Guillermina Lopez-Bendito, Sonia Garel. Slit2 Activity in the Migration of Guidepost Neurons Shapes Thalamic Projections during Development and Evolution. Neuron, Volume 69, Issue 6, 1085-1098, 24 March 2011 DOI: 10.1016/j.neuron.2011.02.026

Cite This Page:

Cell Press. "The evolution of brain wiring: Navigating to the neocortex." ScienceDaily. ScienceDaily, 24 March 2011. <www.sciencedaily.com/releases/2011/03/110323135629.htm>.
Cell Press. (2011, March 24). The evolution of brain wiring: Navigating to the neocortex. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2011/03/110323135629.htm
Cell Press. "The evolution of brain wiring: Navigating to the neocortex." ScienceDaily. www.sciencedaily.com/releases/2011/03/110323135629.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) — The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) — Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) — New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) — Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. 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