A cure for phobias is a step closer today after scientists found a way to switch off a ‘fear centre’ in the brain. Researchers say that injecting a common local anaesthetic directly into the brain may cure fears.
Scientists at the University of Hiroshima experimented on goldfish that were taught to become afraid when a light was flashed. By administering a low-voltage electric shock every time a light was switched on in their tank, the fish learned to associate the light with a shock. Lead researcher Professor Masayuki Yoshida said: “The goldfish soon became afraid of the flash of light because, whether or not we actually gave them a shock, they had quickly learned to expect one. Fear was demonstrated by their heartbeats decreasing, in a similar way to how our heart rate increases when someone gives us a fright.”
However, the team discovered that fish which had been injected in the cerebellum with the anaesthetic lidocaine an hour before the experiment began had stable heart rates and showed no signs of fear when the light was shone.
The cerebellum is the part of the brain that handles basic emotions in people such as fear and pleasure. In fish, it was known to be involved in learning and movement. The study, published in the journal Behaviour and Brain Functions, shows that the cerebellum also controls the way fish learn to be afraid – just like in people.
Professor Yoshida said: “It is interesting to note that mammals and fish may share common brain mechanisms for fear-related emotional learning.” That could lead to new treatments for phobia.
A spokesman for the journal said: ‘Since the brains of goldfish show many similarities with those of mammals, including humans, it is hoped that with further study it may soon be possible to understand more about the biological and chemical processes that cause us to become afraid.” Lidocaine is used by dentists before drilling teeth. It is also used as a local anaesthetic for minor surgery. The effect of the anaesthetic, however, is only temporary.
The fearless goldfish returned to being frightened goldfish as soon as the drug wore off.
Daily Mail
Vocabulary
cerebellum – kisagy
anaesthetic lidocaine – érzéstelenítő szer (lidokain)
mammal – emlős(állat)
drilling – fúrás
