Neuron
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Professor Yoon-Key Nam Received the 2013 Emerging Scholars Award
Professor Yoon-Key Nam, the Department of Bio and Brain Engineering at KAIST, received the 2013 Emerging Scholars Award from the Korean BioChip Society (KBCS), an organization consisted of professionals and researchers in the biochip field such as proteomics, functional genomics, Bio-MEMS, nanotechnology, biosensors, and bioinformatics, at the fall annual conference of KBCS held on November 13th, 2013 at Kangwon National University in Korea.
Professor Nam was recognized for his development of neuron-on-a-chip technology through the convergence research of neuroscience and biochip.
Since 2008, the KBCS has been giving an award to one or two scholars under 40 years of age who have made a great stride in biochip research.
2014.01.27 View 9721 -
Two Dimensions of Value: Dopamine Neurons Represent Reward but not Aversiveness
Professor Christopher D. Fiorillo of the Bio & Brain Engineering (http://ineuron.kaist.ac.kr/web/home.html) at KAIST published a research paper in the August 2 issue of Science. The title of the paper is “Two Dimensions of Value: Dopamine Neurons Represent Reward but not Aversiveness.” The following is an introduction of his research work:
To make decisions, we need to estimate the value of sensory stimuli and motor actions, their “goodness” and “badness.” We can imagine that good and bad are two ends of a single continuum, or dimension, of value. This would be analogous to the single dimension of light intensity, which ranges from dark on one end to bright light on the other, with many shades of gray in between. Past models of behavior and learning have been based on a single continuum of value, and it has been proposed that a particular group of neurons (brain cells) that use dopamine as a neurotransmitter (chemical messenger) represent the single dimension of value, signaling both good and bad.
The experiments reported here show that dopamine neurons are sensitive to the value of reward but not punishment (like the aversiveness of a bitter taste). This demonstrates that reward and aversiveness are represented as two discrete dimensions (or categories) in the brain. “Reward” refers to the category of good things (food, water, sex, money, etc.), and “punishment” to the category of bad things (stimuli associated with harm to the body and that cause pain or other unpleasant sensations or emotions).
Rather than having one neurotransmitter (dopamine) to represent a single dimension of value, the present results imply the existence of four neurotransmitters to represent two dimensions of value. Dopamine signals evidence for reward (“gains”) and some other neurotransmitter presumably signals evidence against reward (“losses”). Likewise, there should be a neurotransmitter for evidence of danger and another for evidence of safety. It is interesting that there are three other neurotransmitters that are analogous to dopamine in many respects (serotonin, norepinephrine, and acetylcholine), and it is possible that they could represent the other three value signals.
For the research article, please visit: http://www.sciencemag.org/content/341/6145/546.abstract
For the Science 2nd issue, please visit: http://www.sciencemag.org/content/current#ResearchArticles
Illustration of Value Dimension
2013.08.08 View 9456 -
Professor Eunjoon Kim's team finds synapse-forming protein
Professor Eunjoon Kim’s team finds synapse-forming protein
- discover a new protein ‘NGL’ that promotes the formation of neuronal synapses
- can presume the cause of various brain disorders including schizophrenia
- will be published at Nature Neuroscience Vol. 9 in September
A new protein that promotes the formation of synapses in human brains was discovered by a Korean research team.
The team led by Eunjoon Kim, Professor of Department of Biological Sciences and Head of Creative Research Group of Synapse Formation), announced that it had discovered a new fact that NGL protein promotes the formation of neuronal synapses and this fact would be published in Nature Neuroscience Vol. 9 on September 18.
Professor Kim’s team discovered that a membrane protein named ‘NGL’ located at post synapse links with other membrane protein named netrin-G in pre synapse, acting as crosslink, and promotes the formation of a new synapse.
‘NGL’ is the second protein found to crosslink synapse, following neuoroligin. With the discovery of this new protein, the principle of synapse formation and the causes of various brain disorders can be presumed.
In the human brain, about more than 100 billion neuron cells and about 10,000 synapses compose neural circuit. A synapse is the place where innervation occurs between neuron cells. The formation of synapse induces the formation of neural circuit, and neural circuit is deeply related with various brain disorders as well as normal development of brains or brain functions.
“As netrin-G linked with NGL is related with schizonphrenia and neuoroligin and synapse crosslinking protein having a similar function with NGL is deeply related with mental retardation and autism, I think NGL is related with various brain disorders including schizophrenia.”
<Explanation of attached photos>
■ Photo1: Experiment for confirming NGL’s ability to form synapse No. 1
Mix ordinary cell (green) revealing NGL at its surface and neuron cell. Axon grows toward NGL (ordinary cell) located in the middle of ten o’clock direction and meets NGL, where NGL induces the formation of pre synapse (red) in the contacting axon.
Whether pre synapse has been formed can be told by the fluorescent dying (red) of pre synapse protein named Synapsin.
- Figure a-b: formation of synapse by NGL
- Figure c-d: transformed NGL losing synapse forming ability cannot form synapse
■ Photo 2: Experiment for confirming NGL’s ability to form synapse No. 2
When beads coated with NGL are scattered on neuron cell, the beads contact with the axon of the neuron cell (the beads are clearly visible at the phase differentiation image in the middle panel). At this time, NGL induces the formation of pre synapse (red) in the axon. Whether pre synapse has been formed can be told by the fluorescent dying (red) of pre synapse protein named SynPhy (panel a) or VGlut1 (panel b).
2006.09.21 View 18605
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Nerve-protecting gene discovered
Korean scientists for the first time have identified a gene that blocks nerve damage from fevers and the use of narcotics, a state-run research institute said yesterday.
The finding may open the way for new medicine that can prevent the loss of brain function which is frequently caused by excessive stimulation of nerves and abnormally high body temperature.
"The research is in an early stage. But this approach has the potential to develop genetics-based preventatives against brain-attacking diseases," said Kim Jae-seob, a bioscience professor of the Korea Advanced Institute of Science and Technology, who led the study.
The researchers named the gene Pyrexia, which means fever. Kim"s team extracted it from genetically engineered fruit flies using a genome-screening system. In laboratory tests, they found that the gene is activated to 39 degrees Celsius or higher.
The researchers enhanced Pyrexia"s functionality in some fruit flies while removing the gene from others to observe their different reactions when exposed to high temperature.
"The fruit flies without the gene showed severe nerve disorder and suffered paralysis of brain function, while Pyrexia-enhanced flies maintained their normal brain conditions," the professor said.
The researchers got the same result from experiments with human cells, he said.
There are a lot of channel proteins, which enable ions to enter and exit the cell, that react to the level of temperature, but Pyrexia is the first of its kind that actually protects the neurons from external stimulus, he said.
The finding will appear on the March edition of the London-based science magazine Nature Genetics.
THE KOREA HERALD 2005.1.31 (thkim@heraldm.com) By Kim Tong-hyung
2005.02.02 View 18544