Disappointment can come from small setbacks in life as well as great misfortunes; Either way, everything originates inside the brain. Now, new research led by the University of California, San Diego (USA) has identified the exact part of the brain that controls the processing of both emotional and sensory information that causes our mood to change .
For their research, the scientists conducted an experiment with mice, discovering that neurons connecting to the area of the brain called the lateral habenula produced both glutamate (an excitatory neurotransmitter) and GABA (an inhibitory neurotransmitter) . Neurons are responsible for producing these chemical messengers, but it is common to see that they release one or the other, not both. However, this area of the brain does.
“Our study is one of the first to rigorously document that inhibition can coexist with excitation in a brain pathway . In our case, it seems that this path points to disappointment, ”says Steven Shabel, co-author of the study in the journal Science .
The researchers then administered an antidepressant to the rodents to raise their brain’s serotonin levels, so their relative GABA levels increased, finally confirming that the lateral habenula region is part of the so-called “path of deception .” The experiments with primates gave the same result.
“The idea that some people see the world as a glass half empty has a chemical basis in the brain . What we have found is a process that can dampen the brain’s sensitivity to negative life events, ”says Roberto Malinow, co-author of the study.
This discovery could be very useful in future treatment to treat mood disorders as serious as depression, as well as another step to unravel how the human body registers negative events in life.
“Our study suggests that one of the ways serotonin alleviates depression is by rebalancing the brain’s processing of negative life events with the balance of glutamate and GABA in the habenula. Now we can have a precise neurochemical explanation for why antidepressants make some people more resistant to negative experiences , ”concludes Shabel.
