Summary:
Researchers have identified a specialized neural circuit responsible for the intense food cravings common during pregnancy. The study reveals that pregnancy elevates the activity of the SK3 potassium channel in dorsal raphe serotonin neurons, suppressing their firing and altering reward signaling to drive heightened motivation for palatable foods.
Key Facts:
- Suppressed Serotonin Firing: During pregnancy, serotonin-producing neurons in the dorsal raphe nucleus (DRN) exhibit reduced neural activity, directly triggering food-craving-like behaviors in animal models.
- The SK3 Potassium Channel Switch: Pregnancy upregulates the SK3 potassium ion channel; selectively deleting SK3 from DRN serotonin neurons prevented the dampening of neuronal firing and significantly curtailed cravings.
- Reward Circuit Rewiring: The researchers mapped a functional pathway extending from DRN serotonin neurons to the ventral tegmental area (VTA), a core reward hub, showing that artificially stimulating this tract reduces pregnancy cravings.
Source: LSU Pennington Biomedical Research Center
Decoding the Neurobiology of Maternal Food Cravings
Intense food cravings, particularly for calorie-dense, sweet, or savory treats, are a hallmark experience during pregnancy. While cultural references often treat these cravings as quirks of gestation, excessive cravings can lead to gestational diabetes, maternal obesity, and long-term metabolic health complications for both parent and child.
Until now, the exact neurobiological mechanisms orchestrating this motivational shift remained poorly understood.
In a study published in Nature Neuroscience, a collaborative team of scientists led by Dr. Yanlin He at LSU’s Pennington Biomedical Research Center, Dr. Pingwen Xu at the University of Illinois Chicago, and Dr. Chunmei Wang at Baylor College of Medicine, unmasked the brain circuitry and molecular ion channels that govern food-seeking motivation during pregnancy.
The Dorsal Raphe and the SK3 Ion Channel
The researchers focused their investigation on the dorsal raphe nucleus (DRN), a brainstem region rich in serotonin-producing neurons known to modulate mood, appetite, and satiety.
Electrophysiological recordings demonstrated that during pregnancy, serotonin neurons in the DRN undergo a noticeable drop in basal firing rate. This cellular quieting coincided directly with escalated, craving-like consumption of palatable foods.
Digging deeper into the biophysical drivers of this dampened firing, the team identified the SK3 potassium ion channel (small conductance calcium-activated potassium channel 3). SK3 channels act as critical brakes on electrical excitability by permitting potassium efflux, which hyperpolarizes the neuron and limits action potentials. During pregnancy, SK3 channel activity increases within DRN serotonin neurons, muting their normal signaling output.
To confirm whether SK3 was the primary molecular culprit, researchers selectively knocked out the channel from serotonin neurons in female mice. The results were striking: without SK3, serotonin neurons sustained their normal firing rates throughout gestation, and the animals exhibited a substantial reduction in food-craving-like behavior.
Conversely, when researchers artificially ramped up SK3 activity in nonpregnant female mice, the animals mirrored the exact neurophysiological drop and craving behaviors typical of pregnancy.
Connecting Serotonin to the Brain’s Reward Engine
To understand how decreased serotonin firing translates into motivational feeding, the investigators traced axonal projections originating from the DRN. They uncovered an active inhibitory connection running directly to the ventral tegmental area (VTA), a key nucleus within the mesolimbic dopamine reward system responsible for reinforcement and motivation.
Under normal conditions, robust serotonin signaling keeps reward-driven seeking under control. However, when pregnancy activates SK3 channels and suppresses DRN serotonin firing, this inhibitory tone is lifted, allowing the VTA reward circuit to amplify the drive for highly palatable foods.
Using targeted circuit manipulations, the team found that activating this specific DRN-to-VTA pathway curbed food-seeking in pregnant models, whereas silencing it in nonpregnant controls was sufficient to provoke cravings.
Clinical Perspective and Future Directions
While these findings offer a clear biological explanation for maternal food cravings, the authors caution that direct clinical application will require careful development.
“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.”
Dr. He emphasized that future investigations must explore how maternal hormones like progesterone and estrogen interact with SK3 channels, with translational clinical studies planned to explore safe interventions to prevent maternal obesity and associated metabolic disorders.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this Genetics and Neurology Research:
- Media Contact: Ernie Ballard
- Source: Pennington Biomedical Research Center
- Image Credit: Image generated for Neuroscience News
- Original Research is Closed Access: Nature Neuroscience (September 18, 2026). “Serotonin neurons in the dorsal raphe control food-craving-like behavior during pregnancy in mice” Authors: Jane R. Abolafia, Hanna Hameedy, Lakshmi Prakash, Ziqi Wang, Elze Amileviciute, Srikar Dudipala, and Alexander Jaworski.
- DOI: 10.1038/s41593-026-02445-3
Abstract
Serotonin neurons in the dorsal raphe control food-craving-like behavior during pregnancy in mice
During pregnancy, physiological changes can alter food intake behaviors. However, the underlying neural mechanisms remain unclear.
Here we show that female mice exhibit food-craving-like behavior during pregnancy, mirroring many patterns described in humans.
We show that 5-HTDRN neuronal firing activity is reduced during pregnancy through increased small-conductance calcium-activated potassium type 3 (SK3) ion-channel activity. Genetic knockout of SK3 ion channels from 5-HTDRN neurons abolishes the pregnancy-associated suppression in 5-HTDRN neuronal firing activity and reduces food-craving-like behavior in pregnant mice.
Conversely, overexpression of SK3 in 5-HTDRN neurons mimics pregnancy-induced food-craving-like behavior in virgin female mice. Moreover, activation of 5-HTDRN projections to ventral tegmental area inhibits food-craving-like behavior in pregnant mice.
These findings provide novel insights into the role of 5-HT signaling in modulating food cravings during pregnancy and highlight potential targets for managing pregnancy-associated appetite dysregulation and maternal obesity in humans.
