I stumbled upon a pretty cool paper recently published in Science: “Creating a False Memory in the Hippocampus”. A group of scientists at the Massachusetts Institute of Technology were able to plant false memory directly into mice brains, making them afraid of places they had no reason to fear.
They used a nifty technique called optogenetics to implant the false fear memory. Using viruses as carrier, the scientists were able to inserted a light sensitive protein switch (microbial opsin) directly into neurones which are known to play a key role during memory formation and are particularly active during the exploration of new territories.
The researcher allowed the mice to explore an area, lets call it place 1, without any experimental manipulation. On the following day they reactivated the neurones which were active during the exploration of place 1 and applied a small electric shock at the same time. When placing the mice back into place 1 mice showed a place specific and characteristic fear response without ever experiencing harm in place 1.
We will never know what exactly the mice “remembered”, but I think this is one further step in understanding the complex process of memory formation demonstrating the power of optogenetic tools in neuroscience. However, thinking about the potential consequences if this method is further developed feels scary! An interesting paper if you have access to it!
The paper can be found here
And further information on optogenetics can be downloaded here