Stimulating certain parts of the brain with pulses of light could prevent feelings of anxiety, US researchers claimed.

Scientists from Stanford University pinpointed the neural circuit that controls anxious behavior in mice and were able to manipulate it using light, according to research published Wednesday.

During tests, the amygdala region of the mice's brains was exposed to specially-structured fiber-optic cables, and depending on which cells were exposed to the light, the mice became less fearful of their surroundings or more inhibited.

Rodents usually try to avoid wide-open spaces that could expose them to predators, but during simulations, the mice were much more willing to explore open areas when light was pulsed into the brain circuit.

The scientists were also able to make the mice more anxious by deactivating the cells with a different light frequency.

The human brain is structured in a similar way to those of mice, and researchers now hope the study will improve the treatment of anxiety disorders, which affect more than 40 million adults in the US alone.

"Now that we know that these cell projections exist, we can first use this knowledge to understand anxiety more than we do now," said lead researcher Professor Karl Deisseroth, writing in the journal Nature.