LOCAL scientists say they have identified a key protein in the brain responsible for the development of depression, offering a target for new anti-depressant drugs.
Previous studies had found that a central brain region called the lateral habenula (LHb) was hyperactive in depressed people, while the molecular mechanism remained unknown.
But current antidepressant drugs, many developed in 1970s and 1980s, usually affect the entire brain and can sometimes cause serious side effects.
“Our study, which investigated the LHb specifically, showed that one protein plays an important role in the development of depression,” said Hu Hailan from the Shanghai Institute for Biological Sciences, under the Chinese Academy of Sciences.
“It could be a target for new antidepressant drugs. If targeted directly to the LHb area, there could be fewer side effects.”
The discovery was published in journal “Science” yesterday.
Researchers compared the LHb of normal rats and “depressed rats” — the latter group specially developed by US scientists.
Researchers found a form of calcium-dependent protein kinase type II (CaMKII) was much higher in depressed rats than normal rats.
Rats were given sugared water and put in a situation where they had to swim. Those with higher CaMKII levels showed less interest in the sugared water and were less inclined to swim.
Once fed antidepressants, the depressive symptoms relieved and CaMKII levels dropped.
“Our next step is to study why CaMKII levels rise in depressed animal models and how antidepressant drugs can reduce its level,” Hu said.