Columbia University researchers find mosquito "fullness" is controlled by the rectum, not the brain

Columbia University researchers discover the mosquito rectum regulates the urge to bite, offering a new target to stop the spread of mosquito-borne diseases.

By: AXL Media

Published: Mar 21, 2026, 6:56 AM EDT

Source: Information for this report was sourced from Columbia University.

The Mystery of the Post-Feeding Lull It has long been observed that female mosquitoes lose their appetite for human blood for several days after a successful feed. During this period, they focus on digesting the blood and converting it into yolk protein for their eggs. While the behavioral shift was well-documented, the internal "off switch" remained a mystery. Professor Laura Duvall and her team at Columbia University previously traced this loss of desire to a receptor called Neuropeptide Y-like Receptor 7 (NPYLR7). Without this receptor, mosquitoes never feel "full" and continue to seek out hosts regardless of their nutritional state.

Looking in the Wrong Place: From Brain to Gut The research team initially hypothesized that NPYLR7 would be found in the mosquito’s brain, as similar appetite-regulating receptors are located there in many other animals. However, their study, published in Current Biology, revealed that the receptor is primarily active in the mosquito's rectum. This finding contributes to a growing scientific understanding that the gut is far more than a waste-disposal system; it is a sophisticated sensory organ that directly regulates complex behaviors.

Biological Parallels to Human Weight Loss Duvall noted a striking parallel between mosquito biology and human medicine, specifically regarding GLP-1 agonists (popular weight-loss medications). In humans, GLP-1 is a peptide released by the gut to signal satiety to the brain.

“In both cases, we see peptides playing a very important role, in conversation with the nervous system, and driving how and when eating occurs,” Duvall said.

How the Rectum "Talks" to the Brain To visualize this communication, the team used fluorescent proteins that glow when calcium levels rise. Their observations revealed a sophisticated signaling loop:

The Trigger: After a meal, nerve cells release a peptide called RYamide.