An experiment carried out at the University of Puerto Rico (Quirk et al.) on rats has shown that administering a drug directly into their brains can induce in them a sense of safety in a situation in which they were previously fearful.
Brief Summary If Experiment :
Rats can be conditioned to fear the sound of a particular tone (the fearful response takes the form of the rats ‘freezing’ )if, each time the tone is sounded, the experimenter administers to them an electric shock (this works through technique known as classical conditioning).
However, this conditioned, fearful response to the same tone can be extinguished / eliminated if it is then sounded a sufficient number of times during which, now, when the rats hear it, they are NOT administered with an electric shock (this is known as ‘extinguishing training’).
It was also found that the extinguishing of the rats’ fear response to the sound of the tone is NOT due to their fear memory / memory of the electric shocks being wiped out, but, instead, due to a NEW MEMORY OF THE SOUND’S (NOW) SIGNALLING OF SAFETY (i.e. NO ELECTRIC SHOCK ADMINISTERED WHEN TONE IS HEARD) BEING CREATED.
DRUG MIMICS EXTINGUISHING EFFECT :
Crucially, the researchers involved in the study found that, instead of the rats needing to go through this extinguishing process / training to stop them feeling fearful (freezing) in response to the tone being sounded, but, instead, feeling safe in response to it, the same effect can be obtained by administering a drug (the drug used was a protein, brain-derived neurotrophic that helps the brain’s neurons to grow) directly into the rats’ brains.
In other words, it seems that the researchers involved in the experiment have found a way to pharmacologically (i.e. through the use of a drug), CREATE IN THE RATS’ BRAINS A MEMORY OF SAFETY.
IMPLICATIONS OF THE ABOVE FINDINGS :
The hope is that research like the above will help with the development of drugs which can be given to humans in order to help create feelings and memories of safety in individuals who are suffering from PTSD, a condition which, in the absence of effective treatment, can completely incapacitate and ‘paralyze’ sufferers with unremitting, intense feelings of fear and terror.
David Hosier BSc Hons; MSc; PGDE(FAHE).