Old fruit flies’ swagger restored with brain chemical dopamine

The chemical messenger dopamine can bring back that loving feeling for old fruit flies. By carefully boosting dopamine levels in a handful of specific brain cells, scientists coaxed male flies past their prime into wooing females more vigorously.

Tsai-Feng Fu of National Chi Nan University in Nantou, Taiwan, and colleagues engineered male fruit flies, Drosophila melanogaster, so that dopamine levels would be higher in a particular group of nerve cells called PPL2ab neurons. When dopamine levels were boosted in 40-day-old males, they spent more time courting females by performing an elaborate dance that involves tapping, licking, and also playing a love song with wing vibrations. The results appear June 30 in Nature Communications.

Naturally waning dopamine levels in these fly neurons are behind the declines in sexual behavior that come with age, the study suggests. Although dopamine may have a role in human sexual behavior, it’s not known whether these fruit fly results relate to people.