optogenetics
neurophilosophy | July 2, 2010WHO could have guessed that a protein isolated from pond scum would transform the way researchers investigate the brain? The protein, called channelrhodopsin (ChR), is found in algae and other microbes, and is related to the molecule in human photoreceptors that captures light particles. Both versions control the electrical currents that constantly flow in and out of cells; one regulates the algae's movements in response to light, the other generates the nervous impulses sent along the optic nerve to the brain. Unlike its human equivalent, the algal ChR controls the currents directly because…
ddobbs | May 26, 2010
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Two or three years ago, Emory neurologist Helen Mayberg, whose experiments using deep-brain stimulation for depression I check in on now and then, told me that Karl Deisseroth's work using light to fiddle with brain circuits had huge potential both as a replacement for DBS and for much else. As Lizzie Buchen ably reports in Nature, that potential is now being realized.
This is a very slick tool that seems almost too far out to actually work. It lets you use light to turn brain circuits on and off at will, and with great precision. It's not simple to construct. But once constructed, it…
neurophilosophy | May 20, 2010OF all the techniques used by neuroscientists, none has captured the imagination of the general public more than functional magnetic resonance imaging (fMRI). The technique, which is also referred to as functional neuroimaging and, more commonly, "brain scanning", enables us to peer into the human brain non-invasively, to observe its workings and correlate specific thought processes or stimuli to activity in particular regions. fMRI data affect the way in which people perceive scientific results: colourful images of the brain have persuasive power, making the accompanying data seem more…
ddobbs | May 12, 2010Traveling. But here's what I'm reading during train, plane, and bus rides -- and over meals:
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Gravity-defying ramps take illusion prize. This contest always produces fascinating stuff. This time, the ball rolls up. Video here.

Vaughan Bell ponders cortisol, dopamine, neuroplasticity, and other things that set off his bullshit detector. Riff launched from a post from Neuroskeptic on cortisol and childcare scare stories, equally read-worthy.
Dan Vorhaus does a wonderful round-up of reactions and implications stemming from the news that genetic testing is coming to Walgreens. Best blog-…
neurophilosophy | March 24, 2009Optogenetics is a newly developed technique based on a group of light-sensitive proteins called channelrhodopsins, which were isolated recently from various species of micro-organism. Although relatively new, this technique has already proven to be extremely powerful, because channelrhodopsins can be targeted to specific cells, so that their activity can be controlled by light, on a millisecond-by-millisecond timescale.
A group of researchers from Stanford University now report a new addition to the optogenetic toolkit, and demonstrate that it can be used to precisely control biochemical…
neurophilosophy | November 18, 2008Optogenetics is a recently developed technique based on microbial proteins called channelrhodopsins (ChRs), which render neurons sensitive to light when inserted into them, thus enabling researchers to manipulate the activity of the cells using laser pulses.
Although still very new - the first ChR protein was isolated from a species of green algae in 2002 - optogenetics has already proven to be extremely powerful - it can be used to switch neurons on or off in an extremely precise manner and so to control simple behaviours in small organisms such as the nematode worm.
Earlier this year…
neurophilosophy | September 24, 2008The September issue of Scientific American contains an excellent and lengthy article about a state-of-the-art technique called optogenetics, by molecular physiologist Gero Miesenböck, who has been instrumental in its development.
As its name suggests, optogenetics is a combination of optics and genetic engineering. It is a powerful new method for investigating the function of neuronal circuits, based a number of light-sensitive proteins which have recently been isolated from various micro-organisms.
By fusing their genes to promoters which control where they will be activated, researchers…
neurophilosophy | May 27, 2008New research shows that a protein found in green algae can partially restore visual function when delivered into the retina of blind mice, taking us one step further towards genetic therapy for various conditions in which the degeneration of retinal cells leads to imapired vision or complete blindness.
Normally, light entering the eye falls upon the rods and cones at the back of the retina. These are the photoreceptors: they are packed with a light-sensitive protein called rhodopsin, which initiates an electrical signal when struck by photons (the particles which carry light).
The signals…
neurophilosophy | August 24, 2007This year, several research groups have used bacterial proteins called channelrhodopsins to develop a technique with which light can be used to control the activity of nerve cells or the behaviour of small organisms.
For example, Ed Boyden's group at the MIT Media Lab used the method to activate or inhibit neurons on a millisecond-by-millsecond timescale, while Karl Deisseroth and his colleagues at Stanford have created an optical on/off switch that can control the movements of the nematode worm.
Devices employing such technologies could in theory be used in advanced neural prostheses for a…