Using a combination of advanced genetic and optical techniques, scientists have confirmed that the neurotransmitter serotonin plays a key role in pain management.

This neurotransmitter is popularly known to contribute to feelings of happiness and well being, as some anti—depression medications work through increasing serotonin in the brain. Serotonin’s great importance led researchers to seek ways of understanding its function, but studying it has been a long—standing challenge.
Using genetic techniques, the researchers expressed a light—sensitive protein specifically in the serotonin—producing cells of rats, so that when the researchers shone light on these cells, the cells released serotonin.
For the study, rats were stimulated with serotonin and the effect of the liberation of serotonin was clear. Xinhua stated Guillaume Dugue, one of the researchers said, "The results showed a significant decrease in sensibility to pain, when we compared them to the rats in the control group."
The study was published in the journal PLoS One.
Source-Medindia