[Reading Science] Which Is Stronger: Sexual Desire, Appetite, or Thirst?

Among animals including humans, which desire is stronger: sexual desire, appetite, or thirst? Scientists conducted experiments using mice as models and found that under moderate, non-extreme conditions, sexual desire is stronger than appetite, and thirst can suppress all other desires. When mice with moderately suppressed appetite were starved, they preferred interacting with the opposite sex over eating to a certain extent. In contrast, thirsty mice ignored both appetite and social interaction.

A research team from the University of Cologne in Germany published a paper on this topic on the 23rd (local time) in the international journal Cell Metabolism. The team suppressed the appetite of male mice using a technique that mimics the effect of the appetite-suppressing hormone leptin. Despite not eating for a day and being moderately hungry, the male mice preferred approaching female mice rather than the bowl containing food.

Laboratory mouse. Stock photo.

The research team designed this experiment to study how leptin, a hormone that promotes satiety by activating certain brain cells, influences animal decision-making. As expected, male mice injected with leptin showed reduced appetite and increased interaction with females. To understand the specific mechanism, the team examined brain cells in the lateral hypothalamus, known as the 'hunger center,' which are activated by leptin. They confirmed that brain cells capable of detecting leptin were activated when the mice interacted with the opposite sex. Conversely, artificially activating these leptin-sensitive brain cells using light led to increased activity in approaching female mice for mating.

These experimental results suggest that leptin plays a certain role not only in regulating appetite but also in promoting social behavior in mice. Notably, even mice that had not eaten for a day showed a greater tendency to seek the opposite sex rather than food when leptin-activated brain cells were stimulated with light. However, mice starved for five days chose appetite over sexual interaction.

The research team also conducted experiments stimulating brain cells that produce the neurotensin hormone, which induces thirst in mice. As a result, the mice chose to drink water, ignoring both appetite and social behavior.

Scientists explained that leptin, previously thought to be simply related to appetite, is actually closely linked to social activities. Of course, it is impossible to directly equate the behaviors of humans and mice. However, leptin is a hormone that functions commonly across the animal kingdom, including humans, mice, and even flies. This research may help understand behaviors such as some people with autism spectrum disorder having eating disorders or some individuals with binge eating disorder suffering from social phobia. Professor Gina Leininger of the University of Michigan stated in the international journal Nature, "Whether we eat and drink more or less plays a decisive role in countless human diseases," adding, "If we can figure out how to regulate these circuits, it could have a significant impact on human health."

This content was produced with the assistance of AI translation services.