Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Critical viewing

19.07.2010
The maturation of inhibitory synapses in the visual cortex is modulated by visual experience

Sensory experience changes the way humans see the world during early postnatal development. Now, an international team of researchers, including Tadaharu Tsumoto from the RIKEN Brain Science Institute in Wako, may have an explanation.

They report in the journal Neuron that visual experience drives the maturation of inhibitory synapses in the visual cortex during a critical period of early postnatal development by activating endocannabinoid receptors1. “This maturation makes synaptic transmission more reliable,” explains Tsumoto. These findings may be crucial to understanding the changes in the way the brain processes visual information from early postnatal life to puberty.

The researchers electrically stimulated the visual cortex and measured the resulting inhibitory currents in the superficial layer of visual cortex slices from 3-week-old rats, a time during development soon after the initial opening of the eyes. High-frequency stimulation of the slices—similar to input that visual cortex neurons may receive during visual experience—led to a long-lasting drop in the amount of inhibitory current that the stimulation could elicit. This is called long-term depression of inhibitory currents (iLTD). Tsumoto and colleagues could not induce iLTD in the visual cortex of 5-week-old rats, a stage in development akin to puberty. The researchers therefore realized that there was a ‘critical period’ for the induction of visual cortex iLTD that occurred after eye opening.

Interestingly, Tsumoto and colleagues were able to delay the onset of the critical period by raising the rats in darkness, and even brief exposure of dark-reared rats to light induced the loss of iLTD in the visual cortex. The research team realized that visual experience therefore plays an important role in regulating the timing of the critical period.

Endocannabinoids are signaling molecules that regulate neuronal activity throughout the nervous system. The researchers showed that a drug that activates endocannabinoid receptors can induce the loss of iLTD in the visual cortex in dark-reared animals that would normally still exhibit iLTD, while a drug that blocks endocannabinoid signaling could inhibit the loss of iLTD that is normally induced by light. This suggested to Tsumoto and colleagues that visual experience drives endocannabinoid signaling to induce iLTD during visual cortex development.

The researchers argue that endocannabinoid-mediated iLTD seems to be important for the maturation of inhibitory synapses that occurs during development of the visual cortex. Tsumoto suggests that this maturation could help to “make responses of neurons in the visual cortex selective to a particular feature of visual stimuli,” such as orientation of contours or direction of movement.

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

Journal information

Jiang, B., Huang, S., de Pasquale, R., Millman, D., Lee, H.-K., Tsumoto, T. & Kirkwood, A. The maturation of GABAergic transmission in visual cortex requires endocannabinoid-mediated LTD of inhibitory inputs during a critical period. Neuron 66, 248–259 (2010).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Life Sciences:

nachricht Rochester scientists discover gene controlling genetic recombination rates
23.04.2018 | University of Rochester

nachricht One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>