Defects in the brain’s ability to process psychological stress or excess stress may increase the likelihood of developing depression, according to a new study from the Okinawa Institute of Science and Technology in Japan, published in the journal Nature.
According to the study, approximately 50% of adults experience a traumatic event in their lifetime and “it is imperative to study the mechanisms that underlie stress responses, and identify potential therapeutic targets that coordinate resilience to stress.”
Researchers have identified a “jumping gene”, dubbed TOB, which has been proposed to regulate learning and memory. It is also one of the early response genes in times of stress; reduced TOB gene expression has been associated with depression.
The gene name is derived from the Japanese word tobu which means to fly or jump. This is because when the cell is exposed to stimuli, its protein levels jump dramatically in activity.
“The TOB gene is linked to many different phenomena, but working on the brain system is particularly difficult,” Professor Yamamoto said. “Although previously suspected, this research is the first work that clarifies that TOB has a function in the brain against stress.”
The study was carried out on mice, some of which had their TOB protein inhibited by selective breeding. The mice were exposed to various stressful situations, in order to examine their hippocampi to determine the protein level.
“We concluded that the TOB gene in the hippocampus suppresses fear and depression,” says Dr. Youssef. “But the suppression of anxiety must be regulated by another part of the brain.”