Neuroscience Blog

Channelrhodopsin-2 is a cation channel from algae that depolarizes neurons in the presence of blue light. ChR2 will allow the study of neuronal circuits function by switching from on to off (and reverse) neurons from a neuronal network. So, in a network, the firing responess will be..."this" ...with all the neurons working, and in the same network the response will be..."that".. with the selected neurons switched off by ChR2 in the presence of the blue light, and then the network will be reversed to the original state!!. Smells like clinical neuroscience here!? Also ChR2 could be used in electrophysiological experiments to evoke neurotransmitter release, and it could be used in combination with neuroimaging techniques. Although the technique is new and several factors (see the links below) will have to be well managed in the experiments, combined techniques, including the use of ChR2 will give us a more precise perspective on how neuronal networks work.
ChR2, alone or combined with the other photostimulation techniques will be a minimally invasive technique, genetically targeted, and it will have temporally precise control of electrical activity of neurons. In oocytes of Xenopus laevis and mammalian cells, ChR2 is a
directly light-switched cation-selective ion channel and Petreanu et al. mapped the projections of pyramidal neurons in the barrel cortex using this method. Also, Arenkiel et al used this on mitral cells with the Thy1 promoter.
It is possible that the "classic" experiments to be reevaluated (where is possible) with this new method? Is this a new road in mental disorders research or a new way for the study of degenerative diseases of the brain? It is possible to evaluate in the future witch neuronal population is relevant to a behavior, witch population has a modulatory role in a behavior and witch population of neurons is dispensable? Hmm....

articles on this subject here
another article here
more about the subject here
and here
and you can find more from here
and more links here
and here too.

neuroscience bucharest blog team
parteners www.thalamus.ro

Mircea Steriade spent his life challenging the conventional thought of the past about the thalamus and unlocked multiple mysteries about the human brain with his groundbreaking research. Edward G. Jones, MD, DPhil, of the University of California at Davis - "He reactivated a field that had long lain dormant and made it into one of the most active in modern neuroscience." Startig with the third year fo faculty, in Bucharest, Romania, at Carol Davila uNiversity of Medicine he was interested in neuroanatomy. His research work began with studies about cerebelo-cortical connectios, and the results were published (when he was 34 years old) as a monography - "Physiologie et Pathophysiologie du Cervelet", Ed. Masson & Co., Paris. In 1958 he left Bucharest for becoming a postdoctoral fellow at Bruxelles in Frédéric Bremer's neurophysiology lab. Once he was advised by a researcher and proffessor to "be more patient" but Steriade said that "I respectfully disobeyed then as well as now". From December 1, 1968, to his last day, Dr. Steriade was professor at the Department of Physiology, later renamed to the Department of Anatomy and Physiology, of Université Laval, Québec, Canada. In 1969 he was promoted as full professor.
"Dr. Mircea Steriade was the founder of modern studies on the cellular basis of electroencephalography. He pioneered research that identified the network operations and neuronal properties in thalamocortical system, which are implicated in the generation of normal brain rhythms during different states of vigilance and different types of electrical seizures."Neuroscience 142 (2006) 917–920
Studies about responses of intracellular recorded neurons during different states of vigilance (Steriade et al., 2001) and a series of monographs (Steriade, 2001; Steriade et al., 1990) made from Dr. M.Steriade a pioneer in thalamic neurons research. A favorite structure for research was the thalamus. In parallel with works in Llinas’ laboratory (Jahnsen and Llinás, 1984; Llinás and Jahnsen, 1982) Dr. Steriade and colleagues have described low-threshold spikes generated by thalamocortical neurons (Deschénes et al., 1982, 1984; Steriade and Deschénes, 1984). Steriade’s laboratory greatest discovery during this period of time was the disclosure of the pacemaker role played by the thalamic reticular GABAergic nucleus in the generation of sleep spindles (Steriade et al., 1985, 1987). Later related studies showed the leading role of intrathalamic network in the generation of augmenting responses (Steriade et al., 1998). He was interested in neuronal networks and the most comprehensive description of differences found between the behavior of individual neurons and neurons involved in network functions was described in ‘The intact and sliced brain’ (Steriade, 2001).
In the last period of his life he was very interested in investigation of plasticity in thalamocortical system. "Gating in Neuronal Networks" will appear in 2007 , written with D. Pare, a former Steriade Ph.D. student. He was an active member of the Society for Neuroscience and he found, Thalamus and Related Systems, a new and interesting journal.

"I have known Dr. Steriade personally since May 1994. Every day he came to his office at 6:00 a.m. All morning he was usually writing papers, books, review chapters, discussing with trainees the results of their recent experiments and planning further research activities. From
11:00–11:45 he was in swimming pool. He used to say that he swims not because he likes to swim, but to survive. After lunch, he was usually reviewing bunches of articles, assisting experiments or continuing to write papers, books, and reviews. Some time between 3 p.m. and 4 p.m. he usually received a call form his younger daughter, Claude, describing her day in school. She was (and I wish she always will be) the best student of her class and Mircea
was very pleased with her success both in high school and in piano classes. He was also very proud of the remarkable success of his older daughter Donca, who is a well-known
professor of phonology at MIT".I. Timofeev / Neuroscience 142 (2006) 917–920

He was Honor Member of Société de Neurologie de Paris (1957), and received Claude Bernard de l’Université de Paris Medal (1965), Distinguished Scientist Award, Sleep Research
Society (1989), Marie-Victorin Prize du Québec (1991), Member of the Academy of Science, Royal Society of Canada (1994), Pierre Gloor Award of the American Society for Clinical Neurophysiology for Outstanding Achievements in Research (1998), Presidential Lecture at
the Society for Neuroscience Meeting (1999), Editor-inchief, Thalamus and Related Systems (2001), Honor Member of the Romanian Academy of Medical Sciences (2003).

"I used to look through the microscope all day long, at the expense of some medical disciplines that I regarded as marginal and for which I remained a layman. I already knew that all my life would be spent with the brain and its operations." said Dr. Steriade, and we think that this must be a very interesting and useful point of view for many other scientists, because he knew what he was doing - becoming a great and revolutionary scientist.

He was the first to demonstrate the role of GABAergic thalamic reticular neurons in the production of sleep spindles. He also discovered a new type of sleep rhythm, the slow oscillation.

Steriade authored or co-authored more than 400 original articles, review chapters and 12 books. He presented a Presidential Special Lecture at SfN's 1999 annual meeting. In an interview with Mircea Steriade, made by Carmen Rasanu , he was asked what was his greatest moment of joy as a researcher. Steriade answered that is hard to select just one, but the first one was in 1960, in a tram in Bucharest, while reading an article, by Bremer, article that came with a confirmation of the results of his work at that moment. Other moments of joy are regarding "technical stuff" he said. Also, he was happy when, after 55 years, he was invited to speak at the 'Carol Davila" University, where he was a student. A very long time, we consider.

His work was outstanding and interesting, with a great impact on the scientific world, being a mentor for a part of the new generation of researchers.

O premiera pentru lumea stiintifica romaneasca si fara nici o exagerare, un unicat din foarte multe puncte de vedere (expuse sus :) ) pe intreg www-ul.

Speram ca site-ul va fi primit si in spatiul romanesc asa cum se cuvine, la adevarata sa valoare, proportional cu noutatea pe care o aduce si proportional cu efortul investit in acest site. Exista astfel bazele, fie ele si in pixeli :) , ale unui spatiu in care cei pasionati de cercetarea talamusului si a conexiunilor talamocorticale - sa se intalneasca. Poate si prin faptul ca asupra cercetarii structurilor subcorticale, cel putin in Romania, se oglindeste un look modern acum, mecanismele criticismului si ale orgoliilor emfatice vor fi supuse actiunii unui mecanism GABAergic ( in fond, talamusul (.ro) n-ar functiona corect fara inhibitia data de gaba).