Nature paper: Discovery of a region of the brain that allows the mouse to coordinate breathing and whisking
Mice explore their environment by sniffing and whisking more than 700 times per minute. These motor commands must be perfectly synchronized in the brain.
Anyone who has ever seen a mouse or hamster soon realized that these little creatures explore the world and interact with their peers through their snout and their whiskers. What is less obvious is how to harmonize these frantic sniffles and beating whiskers. How do they manage not to interfere with normal breathing or chewing of the animals?
The answer lies in a well-defined region of the brain that acts as central breathing clock. This area also coordinates the commands sent to the muscles involved in orofacial behaviors (movements of the face and ears). This is what an international team of researchers, which are associated with Martin Deschênes and Maxime Demers of the Faculty of Medicine from Université Laval, propose in the April 28 edition of the journal Nature.
“Rodents explore their environment by sniffing and shaking their whiskers, hairs that are actually tactile organs, says Dr. Deschênes. The frequency of sniffles and whisker beats may exceed 700 per minute, and several muscles involved in orofacial behaviors are also active during breathing, which raises the problem of coordination. “
Their work, done in collaboration with American and Japanese researchers, suggests that these behaviors are coordinated with breathing and governed by a central clock located in the medulla. This oscillator would synchronize rhythmic activity of neurons that activate the whiskers and send neuronal projections to the motor centers which control most of the facial muscles.
This work opens a door to a better understanding how the human brain works. “Many areas of the central nervous system generate rhythmic activities that control motor activity, sleep-wake states and cognition, says Martin Deschênes. It is a question of understanding how neural oscillators coordinate their activities to ensure the normal functioning of the brain. A disruption of these rhythms or of their control can lead to neurological problems such as tremor in Parkinson’s disease and epilepsy. “
Source of text and image: Université Laval
Translation: CAN-ACN
Original research article: Hierarchy of orofacial rhythms revealed through whisking and breathing. Jeffrey D. Moore, Martin Deschênes, Takahiro Furuta, Daniel Huber, Matthew C. Smear, Maxime Demers & David Kleinfeld Nature 497, 205–210 (09 May 2013) doi:10.1038/nature12076
