With nothing more than a very well-aimed beam of light, a team of researchers have discovered that they can effectively eliminate the feeling of anxiety—at least in mice. The research could eventually spell relief for the millions of Americans suffering with anxiety disorders. It also adds to the growing body of evidence that alternative treatments and emerging technologies have the potential to mitigate the symptoms associated with anxiety and other mood disorders. The team’s findings were first published in Neuron.
How this all came to pass is something of a medical marvel that was accomplished by a medical research team that asked if there was a neural location within the brain that causes a subject to feel anxious. They assumed there was, and that it was located in the hypothalamus because this is the area of the brain that regulates how we respond to stress.
To aid them in their search, the team used a technique known as calcium imaging, which involves the insertion of extremely small microscopes into the brain. This allowed them to see how the neural frameworks of the test mice responded in real time to different levels of stress. They then placed the mice in a labyrinth that included open spaces and elevated platforms. These types of settings generate anxious feelings in mice because, in the wild, such spaces would have left the mice vulnerable to predators.
When the mice were in these locations, a region of the hypothalamus called ventral CA1 (vCA1) became flooded with activity. The more anxious the mice behaved, the more active vCA1 became. Furthermore, the researchers found that this area of the hypothalamus was not responding to another endogenous antecedent. Their study revealed that the increased activity in vCA1 was the cognitive source of anxiety.
The team then targeted this area using optogenetics, which can increase or decrease neural activity in specific parts of the brain using only light. When activity within vCA1 was enhanced, the mice became frozen with anxiety. When it was muted, the mice became more confident and exploratory.
Because humans and mice share very similar brain structures, the researchers are confident that they have a way to significantly reduce anxious feelings in people, too. If studies can confirm this hypothesis, this could lead to the creation of drugs that can target vCA1, thereby providing relief to those who suffer from anxiety disorders.