Guest blog time! My fellow Imperial alumni Mia Kukathasan tells us how mice show some people may have depressive tendencies in our genes. Look out for more from Mia soon…
Scientists have genetically engineered mice with a predisposition for depression. The study aims to find out why, when faced with stressful situations, some people’s are genetically more prone to fall to depression. The mice were altered to carry a genetic change that affects serotonin transport in the brain, mimicking a change that occurs in people with the condition.
“There is a clear relationship between a short form of the serotonin transporter and a very high vulnerability to develop clinical depression when people are exposed to increasing levels of stressful life events.” says Dr. Allesandro Bartolomucci of Parma university, Italy.
Brain imaging of people with depression shows that they have greater activity in some brain areas, but the link with genetics is not as well understood. Chemical changes could be seen in these ‘knock’out’ mice in areas of the brain that regulate memory formation, emotional responses to stimuli and social interactions, such as meeting new mice. They showed physical signs of stress with changes in body temperature, body weight gain, higher levels of the ‘stress’ hormone corticosterone and lower levels of the ‘feel good’ hormone serotonin.
Depression is the number one cause of ‘disability’ worldwide, according to the World Health Organisation with 120 million people affected globally. The increased risk of hormone imbalances, heart disease, digestive problems and reduced immune response faced by depressed people makes it a formidable foe for the health services. The work from this study will help to find out how this genetic change in people affects serotonin turnover in the brain. The results published in the journal Disease Models and Mechanisms suggest that the genetic mutation causes an exaggerated response to stress.