By John Salak –
Everyone has heard the expression: The way to a man’s heart is through his stomach. A product of 19th Century American novelist, humorist and newspaper columnist Fanny Fern. The notion is cute, dated and probably demeaning to both men and women. California scientists, however, now report that it may also be true as they’ve identified a direct physiological link between food consumption and reproduction behaviors.
There has always been a fair amount of speculation and empirical evidence that supports a link between nutrition and mating—and not just for humans but across all species. Researchers at the University of California San Diego have gone further by nailing down a biological link in fruit flies that showed they release a molecule in the gut after eating that switched their focus from mealtime to romance. They noted that protein-rich foods, in particular, triggered the release of diuretic hormone 31 (DH31), which served as a chemical messenger.
“We found the transition from feeding to mating and were very surprised that a single molecule would have such a profound influence on behavior decisions,” reported Professor Jing Wang, the study’s senior author. “Our study provides a mechanistic explanation of how the Dh31 neuropeptide acts on the brain to change the motivational drive of two evolutionarily critical behaviors.”
The California researchers used various methods to double-check their findings, including performing genetic experiments, which eliminated Dh31 from fruit flies and other procedures where it was introduced. Without it, the flies simply kept eating, when DH31 was included, they rapidly flipped from mealtime to fruit-fly courting. “These results indicate that Dh31 is a signaling molecule that reorders the priority of these two contending behaviors: feeding over courtship in the absence of Dh31 and courtship overfeeding when Dh31 is released from the gut,” Wang concluded.
The study readily acknowledged that fruit flies, humans and other mammals are different in many ways, including mating behaviors and that its findings only scratched the surface on the impact of gut hormones on inciting reproductive actions. Yet it stressed the physiological link identified by the research provides critical insights into how and why animals, including humans, switch from one behavior that promotes survival, like eating, to a mode that triggers courtship.
“This work embodies a multidisciplinary approach to understand behavioral prioritization at multiple levels, from molecules to neurons and circuit function,” Wang noted. “This line of work provides us with an empirical paradigm to study the hierarchical organization of different need-based behaviors, a framework established by Abraham Maslow 80 years ago to explain the orderly transition of human behaviors.”