Scientists find a way to switch off fear centre in the brain

London: 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."

The findings "should shed light on the evolution of fear and underlying neural mechanisms", he added.

That could lead to new treatments for phobia.

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.