There are many methods that people may use to control their reactions to anxiety, from the use of herbal supplements to meditation.

A new study gives insight into the way animals – and potentially humans – can train their minds to avoid anxiety, fear and depression.

Dr. Eric Kandel of the Howard Hughes Medical Institute and colleagues conditioned a group of mice to feel calm and safe when a certain tone was played.

They found that when the animals were forced to swim continually until they lost the will to go on and just floated, playing this particular tone reinstated their determination to continue swimming.

The researchers also measured the brain activity of the mice and discovered that the tone activated the neurotransmitter dopamine. Standard antidepressants such as Prozac affect serotonin, a different neurotransmitter.

In addition, the calming tone affected a compound that encourages the growth of new brain cells

“The ability to identify, develop and exploit conditions of safety and security is central to survival and mental health,” commented Kandel.

Previous research, published in the Journal of Neuroscience, revealed that dopamine plays a part in production both fear and desire.