Neurons hard wired to tell left from right

Mar 31, 2008

It's well known that the left and right sides of the brain differ in many animal species and this is thought to influence cognitive performance and social behaviour. For instance, in humans, the left half of the brain is concerned with language processing whereas the right side is better at comprehending musical melody.

Now researchers from UCL publishing their work in the open access journal Neural Development have pinpointed for the first time the left/right differences in how brains are wired at the level of individual cells. To do this, a research team led by Stephen Wilson looked at left and right-sided neurons (nerve cells) in a part of the brain called the habenula.

By causing habenular neurons to produce a bright green fluorescent protein they saw that they form remarkable "spiral-shaped" axons, the long nerve fibres that act as the nervous system's transmission lines.

"It's clear that the left and right halves of the brain process different types of information but almost nothing is known about the differences in the brain's circuitry which achieve this" says Wilson. "One possibility is that totally different types of neuron might be found on the left and right. Alternatively, both sides could contain the same building blocks but put them together in different ways".

The researchers saw that there are two types of habenular neuron and both types can be found on both left and right sides. However, whilst most left-sided cells have spiral axons shaped into a domed crown, such neurons are not very common on the right. Instead, most right-sided cells form flat, shallow spirals, and these are formed only occasionally on the left.

"In the same way that an engineer can make different electronic circuits from the same set of electronic components, so the left and right halves of the brain use the same types of neuron but in different combinations" explains Isaac Bianco, the student who did this work as part of his PhD studies.

The left and right habenular circuits both connect to the same part of the brain and the researchers found that this target can either combine signals from the left and right or handle them independently.

"Even though language is processed largely on the left side of the human brain, people don't speak with only one half of their mouth. The brain must contain circuits which take information from the left or right and then send it on to targets on both sides of the body" says Wilson.

Source: BioMed Central

Explore further: US scientists make embryonic stem cells from adult skin

add to favorites email to friend print save as pdf

Related Stories

Quantifying sensory data

Apr 02, 2014

Bite into a juicy pear or a spicy hot pepper, and thousands of electrical impulses race to your brain. Taste buds pick up signals for basic taste qualities like sweet and sour, and your tongue also senses ...

New technique for identifying gene-enhancers

Mar 24, 2014

An international team led by researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) has developed a new technique for identifying gene enhancers - sequences of DNA that act to amplify the ...

Recommended for you

Leeches help save woman's ear after pit bull mauling

Apr 18, 2014

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

New pain relief targets discovered

Apr 17, 2014

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

User comments : 0

More news stories

UAE reports 12 new cases of MERS

Health authorities in the United Arab Emirates have announced 12 new cases of infection by the MERS coronavirus, but insisted the patients would be cured within two weeks.

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...