A group of neurobiologists and neuroscientists from the Woods Hole Marine Biological Laboratory have made an intriguing discovery about rats and their whiskers. In a study published in the open-access journal PLOS Biology, the team reveals that sub-orbital whiskers, located above the eyes, play a crucial role in helping rats detect the direction of air movement and respond accordingly.
The researchers embarked on this study due to the lack of research on wind sensing in mammals, particularly focusing on rats and their whiskers. Previous studies have demonstrated that rats utilize their whiskers for various purposes, including sensing air movement. However, the sub-orbital whiskers had not been thoroughly investigated. These whiskers are relatively few in number but notably long in rats. Thus, the scientists decided to delve into their function through a series of experiments.
In the initial test, several rats were anesthetized and exposed to different levels of airflow, enabling the team to observe and measure the whiskers’ movements under varying conditions. They observed that the sub-orbital whiskers displayed distinct behavior compared to the whiskers on the nose. Due to their length, the sub-orbital whiskers showed greater displacement in low wind conditions. Moreover, these whiskers exhibited a tendency to bend upward more than the other whiskers on the rat’s face.
The researchers then conducted micro-CT scans on the rats, focusing specifically on the follicles of their sub-orbital whiskers. They discovered slight differences in the follicles compared to those of other whiskers. The nerve arrangements in the sub-orbital whiskers allowed for more precise detection of changes in direction, enabling the rats to accurately perceive the movement of air around them.
To further investigate how rats might utilize their whiskers to determine wind direction and intensity, the team developed simulations. These simulations revealed that the response to wind was much more sensitive in the sub-orbital whiskers compared to other whiskers.
Based on their findings, the researchers concluded that rats likely employ their sub-orbital whiskers to sense air movement. Previous research has demonstrated that rats instinctively turn their faces toward a source of wind, even in complete darkness. The team suggests that the sub-orbital whiskers are instrumental in this air movement sensing ability of rats.