If you thought Inception was a flight of fancy, think again. Implanting memories is already a reality, at least in mice.
If you've ever been frustrated by erratic memories, spare a thought for the mice involved in a study published in the journal Science. Researchers have been able to consistently create a "false memory," making a mouse fearful of a place it has no reason to fear. The memory was implanted by shining blue light into the mouse's brain, which triggered a carefully chosen group of neurons. The researchers used optogenetics, a technique that allows precise control of brain circuits. The control is achieved by expressing proteins that act as switches in particular types of brain cells. These switches are channels that, when struck by a particular color of light, allow charged particles into or out of the neurons, which will either activate or silence them. Susumu Tonegawa of the Massachusetts Institute of Technology and his colleagues wanted to find out whether they could create a new, negative association by flipping the switch on an old, neutral memory while giving the mouse a negative experience. Would this lead the mouse to be scared of the old memory? To find out, Tonegawa's group needed to identify the scattered set of neurons storing the first memory and install an optogenetic on-switch. They figured out how to do that last year. The neurons that record new information are located in a particular corner of the hippocampus, the coiled brain structure that we know is crucial for memory formation. That area, the dentate gyrus, can be targeted with a virus, which acts as a courier that delivers genes that encode the protein switch. The difficult part is to deliver the virus only to cells that are storing the memory of choice. Tonegawa and his colleagues found that they could target those neurons that are busier than usual. Armed with this discovery, they installed the optogenetic trigger in the neurons that were especially busy while a mouse got to know a new environment (we'll call that Place A). The next day, in a different environment, they gave the mouse small electric shocks while triggering the memory of Place A using light. After that, even though it never had a negative experience in Place A itself, the mouse froze when it was returned there. Ars Technica | Read the Full Article
If you've ever been frustrated by erratic memories, spare a thought for the mice involved in a study published in the journal Science. Researchers have been able to consistently create a "false memory," making a mouse fearful of a place it has no reason to fear. The memory was implanted by shining blue light into the mouse's brain, which triggered a carefully chosen group of neurons.
The researchers used optogenetics, a technique that allows precise control of brain circuits. The control is achieved by expressing proteins that act as switches in particular types of brain cells. These switches are channels that, when struck by a particular color of light, allow charged particles into or out of the neurons, which will either activate or silence them.
Susumu Tonegawa of the Massachusetts Institute of Technology and his colleagues wanted to find out whether they could create a new, negative association by flipping the switch on an old, neutral memory while giving the mouse a negative experience. Would this lead the mouse to be scared of the old memory?
To find out, Tonegawa's group needed to identify the scattered set of neurons storing the first memory and install an optogenetic on-switch. They figured out how to do that last year.
The neurons that record new information are located in a particular corner of the hippocampus, the coiled brain structure that we know is crucial for memory formation. That area, the dentate gyrus, can be targeted with a virus, which acts as a courier that delivers genes that encode the protein switch. The difficult part is to deliver the virus only to cells that are storing the memory of choice. Tonegawa and his colleagues found that they could target those neurons that are busier than usual.
Armed with this discovery, they installed the optogenetic trigger in the neurons that were especially busy while a mouse got to know a new environment (we'll call that Place A). The next day, in a different environment, they gave the mouse small electric shocks while triggering the memory of Place A using light. After that, even though it never had a negative experience in Place A itself, the mouse froze when it was returned there.
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