July 28 (UPI) -- The drive the reproduce is one the strongest of natural instincts. But how do species -- particularly those with relatively small and simple brains -- balance the needs of survival, like sleep, with the drive to have sex?
In a new study of fruit flies, scientists identified neural centers tasked with mediating between competing impulses -- centers responsible for deciding between sleep and sex.
Scientists published their analysis this week in the journal Nature Communications.
"An organism can only do one thing at a time," Michael Nitabach, professor of cellular and molecular physiology at Yale University, said in a news release. "What we have discovered is a neuronal connection that regulates the interplay between courtship and sleep."
When researchers tracked neural activity of male and female fruit flies, they found tired fruit flies had little interest in sex, while aroused fruit flies rarely slept. For female fruit flies, arousal had no effect on sleep patterns -- and vice versa.
Sleep-deprived females were more likely to mate than tired males, while aroused females slept significantly more than aroused males.
Researchers hypothesized that females must take any chance they get to mate, regardless of how little sleep they've gotten.
"It appears that whichever behavior has the highest biological drive suppresses the other behavior," Nitabach said.
Researchers suggests similar neural centers may help the human brain decide between sleep and sex.