Rats' Whiskers May Shed Light on Sensor-Brain Connection

Newborn rats twitching their whiskers during sleep may shed light on the connection between the sensors in our body and the brain, suggests a new study.

A team of researchers from The University of Iowa has revealed that the twitches (convulsive movements) of rats' whiskers during active sleep are linked to bursts of brain activity. They suggest that such spontaneous movements may play a significant role in the development of sensorimotor systems.

"We found that even whiskers twitch during sleep -- and they do so in infant rats long before they move their whiskers in the coordinated fashion known as whisking," Mark Blumberg of The University of Iowa, said in a statement.

"This discovery opens up new avenues for investigating how we develop critical connections between the sensors in our body and the parts of the brain that interpret and organize sensory information," he said.

The whiskers of baby rats not just twitch, but they also move rapidly in a complex manner. Other parts of the body such as eyes and the limbs also twitch during sleep. Such involuntary movements can play vital roles in early development and even throughout life. However, twitches occur infrequently when the rats are awake.

"It can be a source of brain activity in general as well as a source of highly specific, patterned activity that can help shape specific neural circuits," Blumberg said.

Researchers suggest that whiskers are as important as eyes to humans.  Each whisker maps distinct regions of the brain, which processes the information from individual whiskers. The region of the brain that is specific to each individual whisker forms an arrangement that maps to the physical arrangements of whiskers on the nose, they said.

This specific arrangement has led researchers to show interest in understanding the link between the sensors and the brain. This may also throw new insights into understanding what infants do when they are in slumber.

"One of the jobs of the infant is to learn how all the parts of the body function even as those parts are growing in size and proportion," said Blumberg. "It is a difficult job."

The findings of the study,"Rapid Whisker Movements in Sleeping Newborn Rats," are published in the journal Current Biology.