Optogenetics: Your Brain Controlled by Light

 

optogenetics

Follow the light! http://www.extremetech.com Optogenetics rules

A relatively new field of study called optogenetics is affording scientists the ability to activate and deactivate individual neurons of the brain using only light. This light-switch method is paving the way to an exponentially brighter future in neuroscience.

In April 2013 President Obama announced that he would ask congress for $100 million in 2014 in what he called The Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. The initiative seeks a more thorough understanding of the human brain. According to Obama, the goal is to “better understand how we think and how we learn and how we remember.” Optogenetics will undoubtedly play a vital role in attaining this goal.

Related Article: Electronic Brain Implants Increase Intelligence

While Obama’s goal seems straightforward, the brain is one of the most complex structures humans have ever come across. According to Francis Collins, director of the National Institutes of Health,

It’s an amazingly ambitious idea. To understand how the human brain works is about the most audacious scientific project you can imagine. It’s the most complicated structure in the known universe.

Until a few years ago, before the method of optogenetics had been created, scientists depended on fMRI technology to scan areas of the brain and observe which areas are most active. If an area of the brain was found to be inactive, the only way to activate it was by using a wire probe.  While the probe was invasive, it still gave scientists a powerful and effective tool, and allowed them to activate individual brain cells. But, what if we want to investigate and understand a single neuron, or a group of neurons, or different groups all at once?

There are approximately 84 billion neurons in the human brain. This number has always seemed daunting, especially with the relatively limited tools of the past. Optogenetics, however, throws this hurdle aside in a blaze of innovation.

Related Article: Doctors Communicate with Vegetable Through Brain Scans

The method of optogenetics involves using only light to activate neurons based on their genetic type. Optogenetics is non-invasive and can even be performed on freely moving animals while still retaining exceptional precision.

Elizabeth Hillman, a biomedical engineer at Columbia University, is very excited about the optogenetic breakthrough, explaining that,

[Through optogenetics] you can select that very specific genetic cell type, and you can tell that specific cell type to react when you shine light on it.

For example, in the video below, scientists selected a specific motor neuron in a mouse to be affected by light. Just by shining a blue light on its head, they tell the mouse to start running. When the blue light disappears, so does the mouse’s movement.

While the methodology is opening doors left and right, optogenetics does not come without faults. Because neurons don’t naturally respond to light, it is necessary to alter the gene with additional genetic material so that it reacts to the optogenetic process. Genetic engineering in humans isn’t exactly mainstream right now. We know that using viruses to alter genes in humans works very well, but there are obvious risks associated with that process.

Related Article: Controlling Dreams and Implanting Memories

Another issue is that the light cannot reach the deepest cells in the brain. Additionally, optogenetic precision still has much room for improvement. Despite these concerns, optogenetics is still heralded as one of the top ten scientific breakthroughs of the decade. One of the most recent breakthroughs in optogenetics was the ability to influence cell types in the pre-frontal cortex.

So, how will optogenetics personally influence your life when it is commercialized? Depression, epilepsy, Parkinson’s disease, Alzheimer’s disease, addiction, and even fear may one day be flipped off with a simple flash of light. Consequently, these illnesses could be activated with a flash of light as well.

The future is clear: multicolored laser pointers will become the new standard tool for doctors and soldiers alike.

 

Sources:

http://www.npr.org/blogs/health/2013/12/26/256881128/experimental-tool-uses-light-to-tweak-the-living-brain

http://www.npr.org/blogs/health/2013/04/02/176060875/obama-s-brain-map-plan-a-most-audacious-project

http://www.ncbi.nlm.nih.gov/pubmed/23340416

http://www.ncbi.nlm.nih.gov/pubmed/19226510

http://www.npr.org/blogs/health/2013/12/26/256881128/experimental-tool-uses-light-to-tweak-the-living-brain

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820367/

http://www.sciencemag.org/content/330/6011/1612

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3597095/

http://www.neuro-cloud.net/nature-precedings/baratta

 

Of Cyborg Monkeys and New Hope for Amputees

 

The innovative breeze of 2013 carries a particularly interesting development in the field of Neuroscience.

A joint venture funded by DARPA, composed of a group of researchers from the University of Pittsburgh and Carnegie Mellon University, revealed promising results in a recent study when monkeys were successful in moving a robotic arm using solely the power of their mind.

The practical application and climax of this study, as if it weren’t exciting enough already, finally arrived this January, when a woman was able to operate an artificial arm in a wide range of angles using her brain alone.

Related Article: Robotic Legs Controlled by Your Brain

For the past 11 years researchers have been conducting a series of experiments involving the motor-cortex, a part of the brain which facilitates movement. A tiny electrode array was implanted in the motor cortices of monkeys, enabling the scientists to read neural activity in the form of electrical spikes. Using a model based approach, the scientists were able to calculate the desired instantaneous hand and arm direction based on the activity of a few hundred neurons.

Reading brain-activity enabled the scientists to accurately move the artificial limb in the correct direction and angle, exactly the way the brain normally signals a healthy flesh and blood arm. In this way they trained the monkeys to move the arms through biofeedback.

Related Article: Robotic Sense and Feel

The monkeys were chosen as test subjects due to their similar brain structure to humans. However, it can’t be helped but to wonder: What is the secret for convincing a monkey to operate a robotic arm? The answer is simple: Marshmallows.

By hanging the treat just out of the monkey’s reach, far enough so that they would need to use the robotic arm to reach it, scientists were able to “train” the monkeys in moving the robotic arm in a space and they were able to teach the monkeys to grip their treat.

The next question that comes to mind is how many monkey-arms were removed due to the experiment? Animal rights fighters – rest assured; No monkeys were hurt in the process.

Related Article: Bionic Hand That Can Feel

After a decade of data-mining, the scientists are ready to implant a brain computer interface (BCI), an electrode array, in 53 year old Jan Scheuermann who suffers from quadriplegia; completely paralyzed from the neck down. The outcome of a not-so-simple surgery was optimistic news to all.

For many amputees, lacking an arm does not necessarily mean the brain is damaged as well. The successful experiment described above makes it very easy for a person to control a prosthetic arm, as all that needs to be done is  to ‘think’ which way the arm should move, much in the same way you are operating the arm you are using to scroll down and read this article.

Jan’s reports of headaches quickly disappeared, and no sooner did she prove to be able to feed herself, and even high-five Professor Andrew B. Schwartz, a senior figure in the research. According to Jan, feeding herself was:

One small nibble for a woman, one giant bite for BCI.

While the results of the research are certainly a breakthrough, leaving neuroscientists to fantasize about a world of possibilities opening up, major flaws cannot be ignored.

Implanting the electrode array requires invasive surgery, involving a temporary removal of part of the skull. The degree of control created by the invasive BCI (Brain Computer Interface) is limited by the number of neurons recorded, currently at a few hundred. Non-invasive methods of reading brain signals, such as EEG, offer a much lower information rate and require much more training.

Another flaw that is evident by observing Ms. Scheuermann’s arm movement is a poor eye-arm coordination. Neuroscientists are still looking for a reasonable explanation for Ms. Scheuermann inability to catch a falling object while observing it. Curiously enough, she is able to do so when not looking directly at the object.

Regardless of those facts, the sweet taste of success should not be bittered: this is still the first time a human has been able to operate a robotic arm in so many degrees of freedom, using only the power of the mind.

So what’s next? Killer-coding-ninja monkeys using telepathy? Anyone?

Sources:

NYTimes: Monkeys Think, Moving Artificial Arm as Own

Lancet: Nueroprosthetic Control by Individual with Tetraplegia 

Invasive BCI UPMC: Woman with Quadraplegia Feeds Herself

Nature: Cortical Control of a Prosthetic Arm for Self-Feeding

Killer Coding Ninja Monkeys

 

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