Entries in optogenetics (1)


Manipulating Memory: From Inception to Neuroscience 

In Christopher Nolan's 2010 movie, Inception, Leonardo DiCaprio plants an idea or a specific memory in another person’s subconscious through a dream. Is this possible? Might be. MIT neuroscientists Liu and Ramire et al. have shown that they were able to create false memories in mice via optogenetics. Optogenetics is a technique that utilizes light stimuli to control specific genetically modified cells in living tissue via light-gated ion channel.

In their study, the mice were firstly subjected to a safe environment, Box A. Memories of this new environment were recorded in certain cells, which were programmed to respond to pulses of light. By applying light pulses, the mice will recall the memory of Box A. Then the mice were placed in a completely different environment, Box B, where the mice were subjected to foot shocks, with simultaneous delivery of light pulses into their brains to reactivate the memory of Box A. This resulted in a negative association between the light-reactivated memory of Box A and the foot shocks that the mice obtained in Box B. When the researchers put the mice back into Box A, it was observed that the mice displayed heightened fear responses. A false fear memory was implanted into the mice brain via artificial means.

This work has shown that memories can be altered during the recall process. The researchers pointed out that recall could make memories more labile and external information might be incorporated into existing memories occasionally over time. As Ramirez explained in their TEDx Boston talk, “The mind, with its seemingly mysterious properties, is actually made of physical stuff that we can tinker with.” Their work illustrates the increasing ability of neuroscientists to control, manipulate, and engineer memory in the brain.



(1) Liu, X., Ramirez, S., Pang, P. T., Puryear, C. B., Govindarajan, A., Deisseroth, K., Tonegawa, S. Nature, 2012, 484 (7394), 381-385.

(2) Ramirez, S., Liu, X., Lin, P. A., Suh, J., Pignatelli, M., Redondo, R. L., Tonegawa, S. Science, 2013, 341(6144), 387-391.

(3) https://www.youtube.com/watch?v=kDXJhxLzmBQ