Optogenetics: Controlling the Brain with Light [Extended Version]

Noninvasive brain control: New light-sensitive protein enables simpler, more powerful optogenetics -- ScienceDaily Optogenetics, a technology that allows scientists to control brain activity by shining light on neurons, relies on light-sensitive proteins that can suppress or stimulate electrical signals within cells. This technique requires a light source to be implanted in the brain, where it can reach the cells to be controlled. MIT engineers have now developed the first light-sensitive molecule that enables neurons to be silenced noninvasively, using a light source outside the skull. This makes it possible to do long-term studies without an implanted light source. The protein, known as Jaws, also allows a larger volume of tissue to be influenced at once. This noninvasive approach could pave the way to using optogenetics in human patients to treat epilepsy and other neurological disorders, the researchers say, although much more testing and development is needed. Mining nature's diversity To find a better alternative, Boyden, graduate student Amy Chuong, and colleagues turned to the natural world.

Retinitis pigmentosa - National Library of Medicine - PubMed Health Optogenetics: controlling brain cells with lasers - life - 07 January 2010 Brain cells can be switched on and off like light bulbs using newly identified microbial proteins that are sensitive to the colour of laser light. The discovery is the latest in the fast-moving field of optogenetics, which has already given researchers unparalleled control over brain circuits in laboratory animals. The technology may lead to treatments for conditions such as epilepsy, Parkinson's disease and blindness. New Scientist explains the science and its promise. How do scientists control brain cells with lasers? Neurons fire when electrically charged atoms – ions – flood in and out of them, creating a tiny electric potential across their membranes. One algal protein, channelrhodopsin-2, turns neurons on when bathed in blue light, while its foil, halorhodopsin, silences neurons under yellow light. If these proteins are already around, what's new? Channelrhodopsin-2 works swimmingly: it recently helped identify a brain circuit that, when activated, may ease symptoms of Parkinson's.

Optogenetics in monkeys | Human Frontier Science Program Rhesus monkeys are a unique model for investigating the neural correlates of highly cognitive functions and fine motor control. Optogenetics is a new technique using optical excitation and inhibition of specific neuron types based on their expression or projection patterns. With the aim to combine both fields, the authors adapted optogenetic tools to the specific requirements of non-human primate research. This opens the door for a multitude of new scientific experiments investigating causal relationships between neural activities, connections between brain areas, and complex behaviors which can only be studied in non-human-primates. HFSP Long-Term Fellow Ilka Diester and colleaguesauthored on Tue, 08 February 2011 Rhesus monkeys are a unique model for investigating the neural correlates of highly cognitive functions and fine motor control. The aim of this study was to help enable safe, reliable, and effective new experiments using tools designed specifically for non-human primates.

Optogenetics: technology for modifying your brain and your behavior « Canadian Liberty Controlling Brains With a Flick of a Light Switch discovermagazine.com | September 25, 2012 “Using the new science of optogenetics, scientists can activate or shut down neural pathways, altering behavior and heralding a true cure for psychiatric disease . …” We’re supposed to believe this technology is going to be used primarily for good (if that was possible). Is altering or damaging the brain going to “cure” psychiatric conditions? I don’t believe it. “…In his lab at Stanford University’s Clark Center, Deisseroth is developing a remarkable way to switch brain cells off and on by exposing them to targeted green, yellow, or blue flashes….“… When sunlight hits the opsin, it instantly sends an electric signal through the microbe’s cell membrane, telling the tiny critter which way to turn in relation to the sun.

Versatility of optogenetics brain-research technique vastly expanded Recently, brain researchers have gained a powerful new way to troubleshoot neural circuits associated with depression, Parkinson's disease and other conditions in small animals such as rats. They use an optogenetics technology, invented at Stanford University, that precisely turns select brain cells on or off with flashes of light. Although useful, the optogenetics tool set has been limited. In a paper to be published in the April 2 edition of Cell, the Stanford researchers describe major advances that will enable a much wider range of experiments in larger animals. The new capabilities include ways to use any visible color of light (instead of just a few) to control cells, and ways to make cells susceptible to the optogenetics technique even if they cannot be genetically engineered directly. One of the most important new "instruments" is the ability to use light bordering on infrared wavelengths to suppress cell activity.

Optogenetics: A wireless, optical router for your brain Ready for the Bleeding Edge Science Word of the Day? Optogenetics. It’s even weirder than it sounds, too: optogenetics is the manipulation of a cell’s functions with light (usually lasers). Today, American startup Kendall Research has announced that it has made a wireless optogenetics device that the company’s founder calls “a wireless router for the brain.” To understand the importance of optogenetics, and to marvel at the magic of hooking your brain up to a network with a wireless router, we have to first look at how researchers currently investigate cell function, and thus just how groundbreakingly different the optogenetic approach is. At the moment, the only real way to investigate animal cells is to knock out a function, usually by breeding a genetically engineered mutant. Now, back to the “wireless router” claim. As far as humans are concerned, optogenetics are probably the key to Matrix-like “I want to learn Kung Fu!” Read more at Technology Review

Controlling Brains With a Flick of a Light Switch Stopped at a red light on his drive home from work, Karl Deisseroth contemplates one of his patients, a woman with depression so entrenched that she had been unresponsive to drugs and electroshock therapy for years. The red turns to green and Deisseroth accelerates, navigating roads and intersections with one part of his mind while another part considers a very different set of pathways that also can be regulated by a system of lights. In his lab at Stanford University’s Clark Center, Deisseroth is developing a remarkable way to switch brain cells off and on by exposing them to targeted green, yellow, or blue flashes. With that ability, he is learning how to regulate the flow of information in the brain. Deisseroth’s technique, known broadly as optogenetics, could bring new hope to his most desperate patients. Today, those breakthroughs have been demonstrated in only a small number of test animals. For all its complexity, the brain in some ways is a surprisingly simple device.

Light switches on the brain | Moheb Costandi | Science Leading lights in optogenetics presented the latest developments in their field during a mini-symposium at the 40th annual meeting of the Society for Neuroscience in San Diego at the weekend. Optogenetics has emerged in the past decade as a high-precision tool for monitoring and controlling the activity of nerve cells. It is based on light-sensitive proteins called rhodopsins, which are isolated from algae and bacteria and are related to the proteins found in the human retina. When rhodopsins in the human eye's photoreceptors are struck by light, they initiate a cascade of biochemical reactions, causing the cells to send signals to the brain via the optic nerve. But the microbial rhodopsins behave differently – they alter the electrical properties of neurons directly, and it is these properties that make them so useful. When introduced into neurons, they insert themselves into the membrane, making the cells sensitive to light. Mo Costandi writes the Neurophilosophy blog

Optogenetics and genomic tools make it possible to pinpoint the source of memory, consciousness, and emotions. What might be called the “make love, not war” branch of behavioral neuroscience began to take shape in (where else?) California several years ago, when researchers in David J. Anderson’s laboratory at Caltech decided to tackle the biology of aggression. They initiated the line of research by orchestrating the murine version of Fight Night: they goaded male mice into tangling with rival males and then, with painstaking molecular detective work, zeroed in on a smattering of cells in the hypothalamus that became active when the mice started to fight. The hypothalamus is a small structure deep in the brain that, among other functions, coördinates sensory inputs—the appearance of a rival, for example—with instinctual behavioral responses. By 2010, Anderson’s Caltech lab had begun to tease apart the underlying mechanisms and neural circuitry of aggression in their pugnacious mice. That was a provocative discovery, but it was also a relic of old-style neuroscience. Connections Eavesdropping

Optogenetic/PET-scan technique for mapping brain activity in moving rats Immunolabeling of gene expression in the brain following optogenetic stimulation in rats (credit: P. K. Thanos et al./JNEUROSCI) A technique that uses light-activated proteins to stimulate particular brain cells and positron emission tomography (PET) scans to trace their effects throughout the entire brain of fully-awake, moving animals has been developed by U.S. Department of Energy’s Brookhaven National Laboratory The method will allow researchers to map exactly which downstream neurological pathways are activated or deactivated by stimulation of targeted brain regions, and how that brain activity correlates with particular behaviors and/or disease conditions. “Because the animals are awake and able to move during stimulation, we can also directly study how their behavior correlates with brain activity,” he said. Optogenetics combined with PET scans The scientists used a modified virus to deliver a light-sensitive protein to particular brain cells in rats.

Neuronal light switches : Neurophilosophy The 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 can target the proteins to specified cells and thus render those cells sensitive to light. The activity of cells expressing these proteins can therefore be controlled by laser pulses. In his article, Miesenböck describes how he and others developed optogenetics from existing techniques which use fluorecsent proteins as cellular dyes. Related: