Feeling unafraid

By • Published: January 21st, 2009
Category: Health in a Heartbeat

Construction workers can do their jobs hundreds of feet above the ground. Fighter pilots have no qualms about maneuvering at nearly the speed of sound. And police officers routinely encounter situations that would send us running for cover.

But what actually goes on within the heads of people who have the ability to stay calm, even while in a proverbial pickle?

For answers, scientists at Howard Hughes Medical Institute looked to mice, not men.

They wanted to find out whether biological brain changes occur when animals learn to feel safe and secure in situations that would normally make them feel anxious.

Investigators taught mice to feel safe when given an unexpected dip in a swim tank, a situation the animals naturally find stressful.

Over time, the mice learned to take advantage of sources of safety and security in their environments.

The researchers discovered that the safety-conditioned mice had a greater number of newborn cells deep within the hippocampus, as well as ramped up production of a brain growth factor that promotes new neurons and their connections.

In other words, the learning experience actually caused biological changes that squelched anxiety about as effectively as antidepressant drugs such as Prozac.

Apparently, learned behavior influences production of neurotransmitters such as dopamine.

Knowing how the behavioral process works at the molecular and cellular levels is not intended to endow everyone with nerves of steel. But it could lead to new ways to treat depression and anxiety disorders.