Imagine a mouse sniffing the air, its tiny nose twitching as it makes a life-or-death decision: which morsel of food will provide the most energy? This seemingly simple act is actually a complex dance of neurons and chemicals, a process scientists are just beginning to unravel. But here's where it gets fascinating: researchers have discovered the brain's secret code that allows mice to judge the nutritional value of their prey simply by smell.
A team led by Professor Zhang Yunfeng from the Chinese Academy of Sciences has cracked the neural puzzle behind how mice use their sense of smell to assess the nutritional status of their prey and make precise foraging decisions. Their findings, published in the Proceedings of the National Academy of Sciences (https://pnas.org/doi/10.1073/pnas.2514847122), shed light on the intricate mechanisms at the molecular, cellular, and neural circuit levels.
In the wild, animals often rely on odors to determine if food is worth eating. For mice, this ability is crucial—a wrong choice could mean wasted energy or even danger. Odor molecules from potential prey carry vital information about nutritional quality and taste. However, the neural mechanisms behind this behavior have long remained a mystery.
To solve this, the researchers designed a clever experiment mimicking natural predation, using cotton bollworm larvae as prey. Interestingly, whether the mice were hungry or full, they consistently preferred well-fed larvae over unfed ones. This preference, the team found, was entirely dependent on the main olfactory system.
Using advanced techniques like gas chromatography and mass spectrometry, the researchers pinpointed two key chemical compounds on the larvae's surface: linoleic acid (LA), abundant in well-fed larvae, and (Z)-9-tricosene [(Z)-9-TE], found on unfed larvae. Further experiments revealed that LA attracted mice, while (Z)-9-TE triggered avoidance behavior—both in a dose-dependent manner.
And this is the part most people miss: the team identified a specific neural pathway—a dopaminergic pathway originating in the ventral tegmental area (VTA) and projecting to the medial olfactory tubercle (mOT)—as the brain's control center for odor-based preferences. Using cutting-edge techniques like in vivo fiber photometry and pharmacological experiments, they discovered that D1- and D2-type medium spiny projection neurons in the mOT responded specifically to LA and (Z)-9-TE, respectively.
Here’s how it works: D1 receptor signaling drives attraction to LA, while D2 receptor signaling promotes avoidance of (Z)-9-TE. Together, these pathways create a delicate “seesaw” mechanism that guides mice’s foraging decisions.
This study not only deepens our understanding of how species interact in ecosystems but also opens doors for innovative pest management strategies by targeting these conserved olfactory pathways.
But here’s the controversial part: Could manipulating these neural mechanisms lead to ethical dilemmas in pest control? For instance, if we can make pests avoid certain crops by altering their olfactory preferences, are we playing God with nature’s balance?
What do you think? Is this a groundbreaking step forward or a slippery slope? Share your thoughts in the comments below!
More information: Wenqiang Wang et al, A midbrain-to-ventral-striatum dopaminergic pathway orchestrates odor-guided insect predation in mice, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2514847122 (https://dx.doi.org/10.1073/pnas.2514847122)
Citation: Scientists discover neural coding mechanism underlying odor-guided foraging decisions in mice (2025, October 22) retrieved 22 October 2025 from https://phys.org/news/2025-10-scientists-neural-coding-mechanism-underlying.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
