Pregnant women experience a variety of food cravings and there has long been speculation why, but a recent paper says they have identified a brain mechanism that may help explain it.
But it is only in mice, and mice are not tiny people, no matter what activist groups try to claim about chemicals, so this paper is only EXPLORATORY.
The authors looked at serotonin-producing neurons in the dorsal raphe nucleus and found they become less active during pregnancy, increasing food-craving-like behavior in animal models. And that is linked to SK3 potassium ion channel, which helps determine whether neurons fire.
Increased SK3 activity reduced the firing of serotonin neurons in the dorsal raphe nucleus so they removed SK3 from the serotonin neurons and it prevented the pregnancy-associated reduction in neuronal activity and substantially reduced food-craving-like behavior. Increasing SK3 activity in non-pregnant females produced changes in neuronal activity and food-seeking behavior that resembled those observed during pregnancy.
They have identified a neural pathway connecting those serotonin neurons in the dorsal raphe nucleus to the ventral tegmental area, which is linked to reward and motivation. Activating it also reduced food-craving-like behavior in pregnant animals, while inhibiting the pathway increased the behavior in non-pregnant animals.
They believe pregnancy increases SK3 activity, reducing the activity of serotonin neurons and altering signaling through a reward-related brain circuit.
This has no implication for human women yet. Take out a life insurance policy on the scholar who tries to take cheese quesadillas with maple syrup away from their pregnant test subject.
Citation: Qianru Zhao, Bing Feng, Vicky Dong, Lee How Lau, Hailan Liu, Meng Yu, Keqin Liang, Cindy Tran, Heidi Feng, Taylor Smiley, Peiyu Gao, Amy Yan, Hui Ye, Yuwei Jiang, Chunmei Wang, Pingwen Xu & Yanlin He, Serotonin neurons in the dorsal raphe control food-craving-like behavior during pregnancy in mice. Nat Neurosci (2026). DOI:10.1038/s41593-026-02445-3
