Researchers Identify Brain Circuit Linked to Food Cravings During Pregnancy

September 18 2026 · Baton Rouge, LA

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Study in Nature Neuroscience provides new insight into how pregnancy alters brain circuits that influence food motivation

Why do food cravings become so strong during pregnancy? Researchers at LSU’s Pennington Biomedical Research Center, in collaboration with colleagues, have identified a brain mechanism that may help explain how pregnancy changes the motivation to seek certain highly palatable foods. This collaborative study was led by Dr. Yanlin He of Pennington Biomedical Research Center, together with Dr. Pingwen Xu of the University of Illinois Chicago and Dr. Chunmei Wang of Baylor College of Medicine.

The study, “Serotonin neurons in the dorsal raphe control food-craving-like behavior during pregnancy in mice,” published in Nature Neuroscience, provides new insight into the basic neuroscience of how physiological changes during pregnancy can influence the brain circuits that regulate food motivation.

Researchers examined how pregnancy affects serotonin-producing neurons in a brain region called the dorsal raphe nucleus. They found that these neurons become less active during pregnancy, increasing food-craving-like behavior in animal models.

The researchers found that activity of the SK3 potassium ion channel increases in serotonin neurons during pregnancy. SK3 helps regulate whether neurons fire, and increased SK3 activity reduced the firing of serotonin neurons in the dorsal raphe nucleus. Tests were conducted then to determine whether SK3 was responsible for the change.

Removing SK3 specifically from these serotonin neurons prevented the pregnancy-associated reduction in neuronal activity and substantially reduced food-craving-like behavior. Conversely, increasing SK3 activity in nonpregnant females produced changes in neuronal activity and food-seeking behavior that resembled those observed during pregnancy.

The team also identified a neural pathway connecting the serotonin neurons in the dorsal raphe nucleus to the ventral tegmental area, a brain region involved in reward and motivation. Activating this pathway reduced food-craving-like behavior in pregnant animals, while inhibiting the pathway increased the behavior in nonpregnant animals.

Together, the findings suggest a model in which pregnancy increases SK3 activity, reducing the activity of serotonin neurons and altering signaling through a reward-related brain circuit. The work builds on previous research showing that pregnancy-related food cravings involve changes in the brain’s reward system.

“The discovery could ultimately improve understanding of why some women experience strong food cravings and excessive weight gain during pregnancy,” said Dr. He, director of the Brain Glycemic and Metabolism Control Laboratory at Pennington Biomedical. “However, the findings are currently based in animal model studies, so we caution that directly manipulating serotonin during pregnancy could carry risks. Further research is needed to determine how pregnancy-related hormonal and other physiological 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.”

This work was supported by institutional grants from Pennington Biomedical Research Center, the Department of Defense (Innovative grant no. W81XWH-20-1-0075), American Diabetes Association postdoctoral fellowship award (grant no. 1-17-PDF-138) and the U.S. Department of Agriculture’s Current Research Information System (grant no. 58-3092-5-008).