A team of Dutch researchers under the leadership of Vici-winner Merel Kindt has successfully reduced the fear response. They weakened fear memories in human volunteers by administering the beta-blocker propranolol. Interestingly, the fear response does not return over the course of time. Top journal Nature Neuroscience published the findings on 15 February 2009.
Until recently, it was assumed that the fear memory could not be deleted. However, Klindt's team has demonstrated that changes can indeed be effected in the emotional memory of human beings.
Before fear memories are stored in the long-term memory, there is a temporary labile phase. During this phase, protein synthesis takes place that 'records' the memories. The traditional idea was that the memory is established after this phase and can, therefore, no longer be altered. However, this protein synthesis also occurs when memories are retrieved from the memory and so there is once again a labile phase at that moment. The researchers managed to successfully intervene in this phase.
During their experiments the researchers showed images of two different spiders to the human volunteers. One of the spider images was accompanied by a pain stimulus and the other was not. Eventually the human volunteers exhibited a startle response (fear) upon seeing the first spider without the pain stimulus being administered. The anxiety for this spider had therefore been acquired.
One day later the fear memory was reactivated, as a result of which the protein synthesis occurred again. Just before the reactivation, the human volunteers were administered the beta-blocker propranolol. On the third day it was found that the volunteers who had been administered propranolol no longer exhibited a fear response on seeing the spider, unlike the control group who had been administered a placebo. The group that had received propranolol but whose memory was not rea
|Contact: Merel Kindt|
Netherlands Organization for Scientific Research