Scientists Erase Frightening Memories in Mice
The Los Angeles Times reported that scientists have successfully erased traumatizing memories in mice, a breakthrough in the process towards aiding humans in forgetting their own haunting memories.
A study published in the journal Neuron this week revealed that researchers have genetically manipulated the brains of mice to produce an excess of an enzyme that appeared to permanently wipe select memories.
Scientists said that the Calcium/calmodulin protein kinase II (CaMKII) enzyme is also present in humans, making it a possible target for a drug that would treat post-traumatic stress disorder and other psychological problems.
The report said that researchers from the Medical College of Georgia and East China Normal University in Shanghai trained the mice to associate certain environmental cues - a specific tone or cage, for example - with an electric shock. Researchers then studied what the animals could remember.
When confronted with such cues, regular mice freeze in fear. The trained animals did not, a sign they did not remember that the cage they saw or the tone they heard meant a shock was coming.
By giving the mice a drug that reduced the amount of enzyme produced to normal levels, the scientists were able to determine whether the memory loss was permanent. The animals still did not freeze when they were placed in the cage or heard the tone.
In a following series of experiments scientists found they could choose to erase fearful memories related to the electric shocks while still leaving other memories - such as the fear of cat odor - intact.
Joe Z. Tsiena, study author and neuroscientist at the Medical College of Georgia, warned that many obstacles must be overcome before translating the findings into a human drug. The same engineering techniques used on the mice cannot be used on humans, he said.
Tsiena also said there is not currently a practical method of overproducing the enzyme within the human brain.