Exercise may stimulate new brain cells

STOCKHOLM, Sweden, June 29 (UPI) -- Exercise may stimulate the production of new brain cells, according to a study by Swedish researchers.

The study conducted by Dr. Astrid Bjornebekk, of the Karolinska Institute, in Stockhom, Sweden, indicates both exercise and antidepressants increase the formation of new cells in an area of the brain that is important to memory and learning.

Bjornebekk said that exercise is a good complement to medicines.

"What is interesting is that the effect of antidepressant therapy can be greatly strengthened by external

environmental factors," Bjornebekk said in a statement.

Previous studies have shown that drug abusers have lowered levels of the dopamine D2 receptor, which may be linked to the depressive symptoms drug abusers often suffer from. Studies also show that genetic factors may influence how external environmental factors can regulate levels of the dopamine D2 receptor in the brain.

Different individuals may have differing sensitivity to how stress lowers dopamine D2 receptor levels, and this might be significant in explaining why certain individuals develop depression more readily than others, according Bjornebekk.