Are Males Wired to Choose Sex Over Food?

We all know that men are from Mars and women are from Venus, and a new study supporting this way of thinking shows that male brains - at least in nematodes - are wired to choose sex over food, whereas the same doesn't ring true for females.

Choosing between two good things can be tough, and for animals, choosing between feeding and mating, both necessary for survival, can be even tougher. But a new study published in the journal Current Biology indicates that subtle changes in the brain's circuitry can make this choice easier.

"While we know that human behavior is influenced by numerous factors, including cultural and social norms, these findings point to basic biological mechanisms that may not only help explain some differences in behavior between males and females, but why different sexes may be more susceptible to certain neurological disorders," lead author Douglas Portman said in a press release.

Portman and his team at the University of Rochester looked at Caenorhabditis elegans, a type of microscopic roundworm. Specifically, they focused on the species' sense of smell, which, along with taste and touch, are critical for how male and female roundworms search for food and find a potential mate.

Though, when describing C. elegans, it's not males versus females but rather males versus hermaphrodites. Though the hermaphrodites are able to self-fertilize, they are also mating partners for males, and are considered to be modified females.

In order to confirm their suspicions, that both sexes of C. elegans were wired differently, the Rochester researchers placed hermaphrodites in the center of a petri dish with some food, with an additional ring of tempting food surrounding them - an obstacle for the males placed at the edge of the dish. The males either had a normal genetic profile - the control group - or overexpressed the chemoreceptor ODR-10, related to the worms' sense of smell and found to control their decision between food and sex.

As predicted, the normal worms made a B-line for the hermaphrodites at the center of the dish looking for a mate - given that fewer ODR-10 receptors are active. And since hermaphrodites produce ODR-10 receptors, they are more sensitive - and therefore attracted - to food, explaining why they didn't stray from their food, unlike the males.

What's more, when given the choice to overexpress ODR-10 or maintain normal levels, males opted for the latter 10 to one, researchers say. Clearly, male nematodes prefer to choose sex over food.

The results were published in the journal Current Biology.