Scientists may have gotten a sense of what the sadness in the brain looks like.
A 21-person study found that feelings of emotion were associated with greater communication between brain areas involved in emotions and memory for most. The University of California, San Francisco, said on Thursday the Journal Cell .
"There was a network that would keep telling us whether they felt happy or sad," says Vikaas Sohal, an associate professor of psychiatry at UCSF.
The finding may lead to a better understanding of mood disorders and possibly new treatments.
Previous research has found that the amygdala, an almond-shaped mass, is associated with sadness and other emotions found in each side of the brain. There was also evidence that the memory-associated hippocampus could play a role in emotion.
But Sohal and the other researchers were curious what exactly these and other brain areas do when mood changes.  "We really wanted to achieve something when you feel bad or feel happy, what exactly happens in those moments in the brain," says Sohal.
You can not get this information from brain scans that do not detect changes that occur in fractions of a second. Therefore, the team examined 21 people who were in the hospital waiting for brain surgery for severe epilepsy.
Before surgery, doctors insert tiny wires into the brain and monitor their electrical activity for up to a week.
Sohal says the team hoped these shots would help answer a basic question: "When patients sit there watching TV or talking to their family or waiting or being anxious, which brain regions talk to each other?"
The patients agreed to keep a record of their mood. The team investigated whether certain moods coincided with communication within certain networks in the brain.
The researchers thought they could find networks that are similar in some people. They were "really surprised" when they learned that 13 of the 21 patients had the same network, says Sohal.
However, it makes sense that communication between areas involved in memory and emotion is associated with sadness. "Maybe you feel bad and you start to remember times in your life where bad things happened, or you start to remember those experiences, and that's what makes you do that feeling bad, "he says.
The study could not confirm that. Nor was it possible to show whether the increase in communication was the result of or was the cause of a mood change.
Sohal says the finding can bring comfort to people with depression.
"As a psychiatrist, it's incredibly powerful to simply be able to tell the patient," Hey, I know something in your brain happens when you feel bad. "
In a sense, the new study merely confirms the results of previous animal studies, Dr. Joshua Gordon, who heads the National Institute of Mental Health.
"It's a circuit to find, a part of the brain that we already knew was mood-it's the less than wow part," he says. "The wow part is that it's people."
The study also provides a detailed map of what's going on in the human brain. This is what doctors and scientists need to find better treatments for patients with mood disorders. 19659008] "It's really important that we find the circuits that underlie the mood so that we can learn more about them and treat them with tools that we develop, and that aim at circuits." These tools include transcranial magnetic stimulation, which uses energy pulses delivered by the skull to alter the activity of brain circuits.
The study also demonstrates the value of the BRAIN initiative launched in 2013 by President Obama, Gordon says.
"The goals of the BRAIN initiative are to develop tools that can provide unprecedented access to the brain and an understanding of the brain," says Gordon. "This study does both."
The research team was partly funded by the Defense Advanced Research Projects Agency, a major supporter of the BRAIN initiative.