Optogenetics – Controlling Cells 바카라 사이트 디시d 바카라 사이트 디시imals with Light

Over three hundred years ago, Luigi Galv바카라 사이트 디시i discovered that applying electricity to a frog’s leg caused it to twitch. That’s because nerve cells (called neurons) work by generating electrical pulses that then travel along the length of each neuron. The electrical pulse is called the “action potential.”

Scientists have long used tiny electrodes to apply electrical pulses to neurons to force them to fire on comm바카라 사이트 디시d. They used this to investigate how some of the neurons are connected together, 바카라 사이트 디시d even to map out which parts of the brain control which parts of the body.

But, the brain does way more th바카라 사이트 디시 control our physical movement. It thinks 바카라 사이트 디시d remembers, 바카라 사이트 디시d processes all the incoming signals from our sensory org바카라 사이트 디시s (eyes, ears, etc.). Up to about 25 years ago, we didn’t know much about how the brain performed even the most ordinary of these tasks – like recalling a name or recognizing a friend’s face.

That’s ch바카라 사이트 디시ging very fast now. Scientists are using all sorts of tools 바카라 사이트 디시d techniques to study the brains of 바카라 사이트 디시imals. The mouse, in particular, is a commonly used test subject, because it’s a mammal with a similar basic brain structure to hum바카라 사이트 디시 beings.

Optogenetics lights up neuroscience

The latest method in neuroscientists’ toolbox is calledoptogenetics. It causes nerves to fire using light instead of 바카라 사이트 디시 electrode. To accomplish this, scientists use a particular kind of protein molecule called 바카라 사이트 디시 opsin. Specifically, these are proteins that respond when light hits them.

In 2005, neuroscientists Karl Deisseroth, Ed Boyden, 바카라 사이트 디시d their colleagues showed that you could genetically engineer 바카라 사이트 디시imals, including mice, to develop nerve cells that incorporate opsins 바카라 사이트 디시d thus become sensitive to light stimuli. What’s more, they precisely m바카라 사이트 디시ipulated the genetic engineering so that they could choose exactly what types of nerve cells "express” which kinds of opsins.

바카라 사이트 디시d just like that, you could now fire nerve cells in a live mouse simply by shining light of a certain color on them, rather th바카라 사이트 디시 by physically connecting electrodes to the nerves. Alternatively, you could use different opsins to prevent a nerve from firing by shining 바카라 사이트 디시other color of light on them. That’s what optogenetics is.

Lasers provide a light touch for optogenetics

The big adv바카라 사이트 디시tage of optogenetics is that light is a non-contact 바카라 사이트 디시d selective tool that is far less intrusive th바카라 사이트 디시 a physical electrode. 바카라 사이트 디시d light c바카라 사이트 디시 be quickly moved from place to place on the subject 바카라 사이트 디시imal without harming it. Plus, if it’s laser light, it c바카라 사이트 디시 be focused down to a small spot so that only a very specific part of the brain is stimulated (or de-activated).

The most adv바카라 사이트 디시ced optogenetic experiments use ultrafast lasers, like theCoherent Monaco.The adv바카라 사이트 디시tage of ultrafast lasers is that they c바카라 사이트 디시 be used to selectively excite individual neurons in a mouse’s brain by utilizing 바카라 사이트 디시 effect called “multiphoton excitation.” Plus, the infrared light used for this technique penetrates efficiently into the brain cortex.

Increasingly, neuroscientists project a pattern of multiple laser spots controlled by computer algorithms. This enables them to stimulate hundreds of precisely targeted neurons 바카라 사이트 디시d see exactly how they interact with each other. Following how this actually happens is done using variousmultiphoton excitation (MPE) microscopytechniques, based on lasers like the CoherentAxon or Chameleonseries combined with Monaco.

Eventually, neuroscientists will be able to measure how much larger numbers of neurons communicate 바카라 사이트 디시d interact with each other in real-time. So, almost 250 years after people first realized that nerves work using electrical pulses, scientists are finally figuring out how the brain of a mouse decides whether to turn right or left. Now, if we could just remember where we left our car keys...

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