This is a little scary. The first artificially implanted memories have been created by neuroscientists at The Massachusetts Institute of Technology (MIT).

When a memory is created of an event, your birthday party for example, the memory of your party is kept in an engram in your brain. An engram is “a constellation of interconnected neurons in our brains”. When you remember the memory of your birthday party the neurons in the engram are active.

How you would implant a memory

MIT neuroscientist Laureate Susumu Tonegawa and a team of researchers recently published their study where they were able to “isolate and activate engrams in a mouse’s memory-rich hippocampus”. The mouse was able to recall experiences that had not actually occurred when the researchers implanted false memories in the mouse’s mind.

This is how the researchers did it.

Step 1:

Writer Robert Gonzalez explains:

Tonewaga and his team genetically engineered mice capable of expressing a protein called Channelrhodopsin-2 (ChR2). Importantly, the protein was expressed exclusively in the hippocampus, and only in neurons involved in memory formation. This allowed Tonewaga and his team to effectively label only the brain cells encoding for a specific engram. Place a mouse in a safe environment (Chamber A, the blue box above), and the brain cells encoding for the memory of this environment express ChR2 (the white dots).

Step 2:

Gonzalez continues:

ChR2 is a light-sensitive protein; shine a light on it with the tip of an optical fiber that’s been securely implanted in the brain, and cells that express it become activated. The technique – known as “optogenetics” – is among the most useful to emerge in the field of neuroscience in recent memory, and Tonewaga and his colleagues use it here to great effect. By placing the animal in a second, entirely different environment (Chamber B, the red box) and delivering light to the hippocampus, the researchers could reactivate the engram established in Chamber A, forcing the mouse to recall its experience while situated in the entirely novel environment of Chamber B.

While the mouse is busy recalling the first environment, the researchers deliver a mild electrical shock to the rodent’s feet. The shock conditions fear into the mouse. Past research has shown that if one shocks a mouse in a specific environment frequently enough, it will freeze in trepidation when reintroduced to the environment at a later date.

Step 3:

The mouse was then put back into Chamber A, the mouse stopped and displayed signs of fear. This shows the mouse had a false memory that it associated with Chamber A while it was standing in Chamber B. “By manipulating the very neural connections involved in the mouse’s true memory” a false memory has been created.

[Source: iO9]