Guiding light: how the brain gets wired for stereo vision

June 15, 2011
Guiding light: how the brain gets wired for stereo vision
Expression of the VEGF receptor NRP1 (red) on the axons of retinal ganglion cell neurons. The lens is green, blood vessels are yellow and nuclei containing DNA are blue. Credit: Laura Denti.

(Medical Xpress) -- Nerve cells that transmit light signals from the eye into the brain use a molecule best known for its role in blood vessel growth as a ‘stepping stone’ to help them reach the opposite brain hemisphere, according to research published in Neuron.

When light enters our , it passes through to the retina in the back of the eye, where it is converted to electrical signals that pass along nerve cells known as retinal . These ganglion cells follow a path into the brain, where they reach an area known as the optic chiasm. At this point, the path forks and the signal passes to both hemispheres of the brain - this is essential in order to create stereo vision, which allows us to see perspective.

However, until now, it has not been clear what guides the nerves to cross to the opposite side of the brain at the chiasm - why, for example, doesn't light from the right eye just pass to the right side of the brain rather than reaching to the left hemisphere?

The answer, according to Dr. Lynda Erskine from the University of Aberdeen and Dr. Christiana Ruhrberg, a Wellcome Trust New Investigator at UCL (University College London), is that a molecule known as VEGF164, which ordinarily plays a part in the growth of blood vessels, acts as a stepping stone, allowing nerve cells carrying images from each eye to cross the chiasm and reach the opposite hemisphere.

The researchers developed a mouse model that allowed them to track how the ganglion cells are wired during fetal development. In mice lacking VEGF164, the axons of many retinal ganglion cell neurons do not cross to the opposite hemisphere.

"We found that the nerves from the eye grow along a path strewn with a small molecule that plays an important role in the growth and development of blood vessels," says Dr. Ruhrberg. "This provides an interesting insight into the development of stereo vision, which relies on the balanced growth of axons from each eye into both hemispheres. We did not expect to find that in the eye co-opt essential for to guide them to their destination."

Explore further: Better treatment sought for blinding traumatic optic nerve damage

More information: Erskine L et al. VEGF signalling through neuropilin 1 guides commissural axon crossing at the optic chiasm. Neuron 2011;70(5):951-65

Related Stories

Recommended for you

Deep brain stimulation may not boost memory

December 7, 2016

Deep brain stimulation (DBS) of areas in the brain known to be involved in making memories does not improve memory performance, according to a study by Columbia University researchers published December 7 in Neuron. The study ...

Knowing one's place in a social hierarchy

December 7, 2016

When you start a new job, it's normal to spend the first day working out who's who in the pecking order, information that will come in handy for making useful connections in the future. In an fMRI study published December ...

When neurons are 'born' impacts olfactory behavior in mice

December 7, 2016

New research from North Carolina State University shows that neurons generated at different life stages in mice can impact aspects of their olfactory sense and behavior. The work could have implications for our understanding ...

Rhythm of breathing affects memory and fear

December 6, 2016

Northwestern Medicine scientists have discovered for the first time that the rhythm of breathing creates electrical activity in the human brain that enhances emotional judgments and memory recall.

Rare infant seizure disorder often missed

December 6, 2016

(HealthDay)—Many infants with a rare form of epilepsy known as infantile spasms aren't promptly diagnosed, and that delay can lead to devastating health consequences, new research indicates.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.