TIME the brain

Noninvasive Brain Control Is Real — and That’s Good

Give in, give in, give in to the light...
Give in, give in, give in to the light... tunart; Getty Images

A diabolical-sounding breakthrough may actually be able to treat a range of disabling diseases

You might think you don’t want anyone controlling your brain. You might think that anyone who did want to control your brain was behaving, you know, invasively. But you’d be wrong — and that’s actually very good news.

Most of the reactions in your brain are mediated either electrically or neurochemically — or, really, a combination of the two. But given the right manipulation, light can do it too.

Nature is awash in light-sensitive proteins known as opsins, which microbes and other simple organisms use to detect different levels and wavelengths of light in their environment and react to them. For more than a decade, scientists have been experimenting with a technique known as optogenetics, which involves introducing opsins into the brain and then using light to switch certain neurons on and off, effectively controlling the behavior of a local region of the brain. (In one dramatic study last year, researchers found they could use the technique to implant false memories in mice, leading them to think they had experienced an electrical shock in a particular part of their cage, which they then avoided.)

The problem was that stimulating the opsins so that they would switch the neurons on and off as desired required threading a fiber-optic cable into the brain and sending pulses of light through it — something even a mouse would rather not sit still for. If there was ever going to be a way to use optogenetics in humans, a more benign method had to be developed.

Enter Ed Boyden, associate professor of biological engineering and brain and cognitive sciences at MIT. Boyden knew that one of the limitations of most opsins is that they respond only to green or blue wavelengths, which are pretty much stopped cold by solid objects like the bone and soft tissue that makes up the head. But red light can penetrate scalp and skull — at least a little bit. Boyden’s team thus went scouring through light-sensitive bacteria and found two that produce red-sensitive opsins. Those proteins, however, produce only a very weak photocurrent — not nearly enough to affect brain function.

So Boyden’s team — especially grad student Amy Chuong — began tinkering with the proteins, genetically engineering mutants that produced a bigger kick when hit with red light. When these engineered opsins were introduced into the brains of laboratory mice, they were able to shut down or turn on local neural activity with nothing more than a well-aimed beam of red light on the skull.

Fantastic — but why exactly would a human being want to go within 10 feet of the technology? A lot of reasons. Epilepsy, for example, is little more than an out-of-control electrical storm in the brain, and optogenetics might offer a quick and painless way to regulate it. Other neurological disorders could similarly be treated in much the way researchers are using transcranial magnetic stimulation as a means to control Parkinson’s disease, depression, migraine headaches and other conditions. The MIT team is also working with investigators at the Friedrich Miescher Institute for Biomedical Research in Switzerland to use the same protein to resensitize cone cells in the retina. If the technique proves successful in mice, in could be used to treat retinitis pigmentosa, which causes blindness by destroying the cones.

So, as with so many other scary-sounding advances in medical history, brain control is very bad — but only until it’s very good.

TIME Research

Researchers Hope ‘Super Bananas’ Will Combat Vitamin A Deficiency

If approved for cultivation, the genetically engineered fruit could revolutionize child health in much of the developing world

Genetically engineered bananas, packed with micronutrients, are to undergo their first human trial in the United States to test their ability to battle rampant vitamin A deficiency — a large cause of infant death and blindness throughout low-income communities around the world.

“The consequences of vitamin A deficiency are dire with 650,000 to 700,000 children worldwide dying … each year and at least another 300,000 going blind,” the project leader, Professor James Dale from Australia’s Queensland University of Technology, told AFP.

The six-week trial backed by the Bill and Melinda Gates Foundation expects to have results by the end of the year and plans to have the bananas growing in Uganda by 2020.

Standard Ugandan bananas provide sustenance to East Africa but have low levels of nutrients such as iron and vitamin A. “Good science can make a massive difference here by enriching staple crops such as Ugandan bananas with pro-vitamin A and providing poor and subsistence-farming populations with nutritionally rewarding food,” said Dale.

Researchers infused the staple crop in Uganda with alpha- and beta-carotene — which the body turns into vitamin A — as an easy solution to the problem that plagues the country, but the same modification could be used on different crops as well. If the bananas are approved for growth in Uganda, other staple crops in Rwanda, Tanzania and Kenya could also be engineered with micronutrients.

“In West Africa farmers grow plantain bananas and the same technology could easily be transferred to that variety as well,” Dale said.

[AFP]

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