Brain Circuit for Pregnancy Food Cravings Identified in Mice
Researchers have pinpointed a brain mechanism involving serotonin neurons that drives food-craving-like behavior in pregnant mice, offering a potential
Scientists have identified a specific brain circuit that appears to drive food cravings during pregnancy. The research, led by Dr. Yanlin He of LSU's Pennington Biomedical Research Center, was published in the journal Nature Neuroscience on September 18, 2026.
A collaborative team from Pennington Biomedical, the University of Illinois Chicago, and Baylor College of Medicine found that pregnancy quiets a group of serotonin-producing neurons in a brain area called the dorsal raphe nucleus. This reduction in neuronal activity increases food-craving-like behavior in animal models.
How Pregnancy Alters Brain Activity
The study reveals that pregnancy increases the activity of a potassium ion channel known as SK3 within these serotonin neurons. Increased SK3 activity makes the neurons fire less. Researchers tested the channel's role by removing SK3 from the serotonin neurons in pregnant mice. This prevented the usual drop in neuronal activity and substantially reduced the animals' food-craving-like behavior.
Conversely, when scientists increased SK3 activity in nonpregnant female mice, it produced changes in both brain activity and food-seeking behavior that mimicked the state of pregnancy. "The discovery could ultimately improve understanding of why some women experience strong food cravings and excessive weight gain during pregnancy," said Dr. He, according to the Pennington Biomedical Research Center report.
A Pathway to the Brain's Reward Center
The researchers also mapped a neural pathway connecting the inhibited serotonin neurons to the ventral tegmental area, a key region for processing reward and motivation. Activating this pathway reduced food-craving-like behavior in pregnant animals. Inhibiting the same pathway increased the behavior in nonpregnant animals.
Together, the findings suggest a model where pregnancy increases SK3 activity, which reduces serotonin neuron firing and alters signaling through this reward-related brain circuit. The work builds on prior research linking pregnancy-related food cravings to changes in the brain's reward system.
From Mice to Maternal Health
The authors caution that their findings are currently based on animal studies. Directly manipulating serotonin during human pregnancy could carry unknown risks. Dr. He noted that further research is needed to understand how pregnancy-related hormonal changes influence SK3 activity and serotonin signaling.
More importantly, we hope to gather additional evidence from human clinical studies at PBRC to determine whether these findings can be translated to the prevention of maternal obesity, He stated. The research provides a foundational neuroscience insight into how physiological changes in pregnancy can rewire the brain circuits governing food motivation.
