Why evolutionarily ancient brain areas are important: RUB researchers study eye reflex

Structures in the midbrain that developed early in evolution can be responsible for functions in newborns which in adults are taken over by the cerebral cortex. New evidence for this theory has been found in the visual system of monkeys by a team of researchers from the RUB.

The scientists studied a reflex that stabilizes the image of a moving scene on the retina to prevent blur, the so-termed optokinetic nystagmus. They found that nuclei in the midbrain initially control this reflex and that signals from the cerebral cortex (neocortex) are only added later on. PD Dr. Claudia Distler-Hoffmann from the Department of General Zoology and Neurobiology and Prof. Dr. Klaus-Peter Hoffmann from the Department of Animal Physiology report in the Journal of Neuroscience.

Why the neocortex needs help

To control sensorimotor functions (e.g. eye movements), the adult brain is equipped with different areas in the neocortex, the evolutionarily youngest part of the cerebrum. “This raises the question, why older subcortical structures in the brain have not lost the functions that can also be controlled by the neocortex” says Hoffmann. The neocortex of primates is, however, not fully functional shortly after birth and therefore cannot control the optokinetic nystagmus. “This is most probably also the case with people” says Distler-Hoffmann. Nevertheless, this reflex works directly after birth.

First the brain stem, then the cerebral cortex

The researchers examined what information controls the optokinetic nystagmus in the first weeks after birth. During the first two weeks, the reflex is controlled by signals from the retina, which are transmitted to two nuclei in the midbrain. The neocortex then adds its information and takes over during the first months of life. The optokinetic reflex, which was studied by the researchers also at the behavioural level, is almost identical under the control of the midbrain and the neocortex. It occurs, for example, when watching a moving scene. First the eyes follow the passing scene, then they move quickly in the opposite direction back to their original position. On this reflex, monkeys and humans build their slow eye tracking movements with which they keep “an eye” on moving objects.

Detecting maldevelopments in the visual system at an early stage

The optokinetic nystagmus changes if the visual system does not develop normally. Lens aberrations, corneal opacity and strabismus affect the reflex. “These findings from research with primates are important for recognizing and treating maldevelopments in the visual system of infants and young children at an early stage” explains Distler-Hoffmann.

Bibliographic record

C. Distler, K.-P. Hoffmann (2011): Visual pathway for the optokinetic reflex in infant macaque monkeys, Journal of Neuroscience, doi: 10.1523/JNEUROSCI.4302-11.2011

Further information

PD. Dr. Claudia Distler-Hoffmann, Department of Biology and Biotechnology at the Ruhr-Universität, 44780 Bochum, Tel.: 0234/32-24365

claudia.distler@rub.de

Editor
Dr. Julia Weiler

Media Contact

Dr. Josef König idw

More Information:

http://www.ruhr-uni-bochum.de

All latest news from the category: Life Sciences and Chemistry

Articles and reports from the Life Sciences and chemistry area deal with applied and basic research into modern biology, chemistry and human medicine.

Valuable information can be found on a range of life sciences fields including bacteriology, biochemistry, bionics, bioinformatics, biophysics, biotechnology, genetics, geobotany, human biology, marine biology, microbiology, molecular biology, cellular biology, zoology, bioinorganic chemistry, microchemistry and environmental chemistry.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors