The research group led by Susan Dymecki, a professor of genetics at Harvard Medical School, observed how mice behave in a normal environment when suddenly their serotonin neurons are turned down.
"By selectively and abruptly switching off the serotonin-producing cells, we can get a definite idea of what bodily functions the serotonin cells specifically control," Dymecki said.
"These findings and the new tools in neuroscience that it brings to the table will help us understand the role of serotonergic neurons in many human disorders," he said.
Serotonin is a major brain neurotransmitter produced solely by cells in the lower brain, or brainstem. Cells that make serotonin can convey information to large numbers of neurons distributed throughout the brain and can affect behaviour as complex as mood.
When serotonergic neuron activity was diminished, the mice lost their capacity to maintain body temperature, and their temperatures plummeted to that of their surrounding environment.
These findings will appear in the July 29 edition of the journal Science.