Imagination can have a powerful effect on memory, and neuroscientists are starting to unravel the physical connections between the two. In this study, researchers at the Scripps Research Institute genetically engineered some mice to contain neuron triggers which the researchers could control. The mice were given a special memory receptor inserted into neurons that would normally be activated by sensory experiences. The technique is appropriately called a DREADD receptor (designer receptor exclusively activated by designer drug) - the team was working with the animals' fear response.

They conditioned the mice to fear a particular cage by giving them a shock whenever they were in it, and this fear activated the special neuron receptor. Then, when the mice were in a different cage, the researchers gave their mice a drug that reactivates this same receptor, triggering the same neurons that fired when the mice were actually scared. The mice behaved as if they were forming a hybrid memory, sharing experiences from the shock box and the non-shock box. This suggests the researchers can recreate the memory of fear even when there was no shock, and the mice were in a different location.

Next, the Scripps team wants to refine its neuronal manipulation to turn off parts of memory entirely - so a mouse would think it's in the shock box when it's really not.

There are implications for human health here, too, the researchers say. Mental health disorders like schizophrenia are associated with false memories or crippling fears - a drug that turns off this response in the right neurons could help patients live healthier lives. The study was published Friday in Science.

[via Science Daily]