Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Eyes wide shut

29.03.2010
Different cell types in the visual cortex respond differently to changes in visual experience

In the primary visual cortex of the brain, neurons are organized into alternating columns that receive inputs from either the left or right eye. This organization is strongly dependent on early visual experience.

When one eye is deprived of visual inputs during a critical developmental period, the corresponding columns fail to develop properly, whereas those receiving inputs from the unaffected eye grow larger than normal.

The cortex consists primarily of two different types of neuron: excitatory neurons that synthesize and release the neurotransmitter glutamate, and inhibitory interneurons which use the transmitter ã-aminobutyric acid (GABA). How each of these cell types contributes to experience-dependent changes in the visual cortex is, however, unknown.

To investigate this, Tadaharu Tsumoto of the RIKEN Brain Science Institute, Wako, and his colleagues injected a calcium-sensitive dye, Fura-2, into the visual cortex of genetically engineered mice whose inhibitory interneurons express a fluorescent protein called Venus1. The intensity of Fura-2 fluorescence changes in response to the increase in calcium ion concentration that is characteristic of neuronal activity.

This approach enabled the researchers to both identify the interneurons in the visual cortex and monitor their activity. In animals reared normally, they first identified the ‘binocular’ regions of the primary visual cortex by visually stimulating each eye in turn, and using two-photon laser-scanning microscopy to locate the cells that responded to both. This revealed that inhibitory interneurons are more responsive to inputs from both eyes than excitatory neurons.

The responses in mice deprived of visual inputs to one eye for two days during the critical period were then examined. The change in the responses of both cell types was found to be similar—both had become more responsive to inputs from the open eye.

When mice were deprived of visual inputs to one eye after the critical period, however, the effect observed was far stronger on the inhibitory interneurons. They tended to receive inputs from the open eye, and their responses to inputs from the closed eye were also depressed, whereas those of the excitatory neurons remained almost stable. The interneurons normally act to inhibit the excitatory neurons, so their depressed responses may contribute to the stability of excitatory neuron responses to the deprived eye.

“Inhibitory interneurons are divided into several subtypes,” says Tsumoto. So, the next step is to determine which particular subtypes are involved in maintaining plasticity after the critical period.

The corresponding author for this highlight is based at the Laboratory for Cortical Circuit Plasticity, RIKEN Brain Science Institute

Journal information

1. Kameyama, K., Sohya, K., Ebina, T., Fukuda, A., Yanagawa, Y. & Tsumoto, T. Difference in binocularity and ocular dominance plasticity between GABAergic and excitatory cortical neurons. Journal of Neuroscience 30, 1551–1559 (2010)

Saeko Okada | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6224
http://www.researchsea.com

More articles from Life Sciences:

nachricht Immune Defense Without Collateral Damage
23.01.2017 | Universität Basel

nachricht The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>