Neurons with a Sixth Sense

Conspecific or rat trap? To answer this question, rats use their whiskers, or vibrissae. With their help, they can perceive different objects and textures even in the dark. In this process, each whisker sends information to nerve cells in the primary sensory brain area: the so-called barrel cortex. Scientists at the Bernstein Center Berlin and the Humboldt-Universität in Berlin now show that neurons in the barrel cortex recognize touch even before actual physical contact.

“In our study, we measured the electrical potential that exists across the cell membrane of brain cells. It is the basis for the transmission of signals and virtually establishes the “language” of nerve cells,” explains first author Constanze Lenschow. “When we examined the membrane potential while striking the vibrissae, we discovered: the potential starts to fluctuate prior to the actual touch. This basically means: the nerve cells begin to talk before they know the topic of the conversation.” This finding stands in contrast to the idea that the barrel cortex simply represents touch information. The neurobiologists suggest that the brain area processes other sensory stimuli as well.

“Socially induced sniffing of the rat might be responsible for the pre-touch activity in the barrel cortex,” says lead author Michael Brecht. It is also conceivable that odors in the form of pheromones or acoustic sounds emitted by the rodents in the ultrasonic range play a role. This hypothesis is supported by the fact that contact with conspecifics and non-conspecific causes different effects.

“When the vibrissae are touched by another rat, there are much larger membrane potential fluctuations than when they are struck by a stuffed rat or the hand of the experimenter,” Lenschow reports. Until now, little was known about how the whisker-to-barrel system processes biologically meaningful information, such as social contact. The result of the scientists indicates a difference between simple and complex social stimuli. An important finding for the research field: so far, many studies have examined the role of the barrel cortex using artificial stimuli to stimulate the whiskers. The result of the current study is published in the journal Neuron.

The Bernstein Center Berlin is part of the National Bernstein Network Computational Neuroscience in Germany. With this funding initiative, the German Federal Ministry of Education and Research (BMBF) has supported the new discipline of Computational Neuroscience since 2004 with over 180 million Euros. The network is named after the German physiologist Julius Bernstein (1835-1917).

Contact:

Constanze Lenschow
Bernstein Center Berlin
Humboldt-Universität zu Berlin
Philippstr. 13, House 6
Tel: +49 (0)30 2093 6727
Email: constanze.lenschow@bccn-berlin.de

Prof. Dr. Michael Brecht
Bernstein Center Berlin
Humboldt-Universität zu Berlin
Philippstr. 13, House 6
Tel: +49 (0)30 2093 6718
Email: michael.brecht@bccn-berlin.de

Original publication:

C. Lenschow & M. Brecht (2015): Barrel cortex membrane potential dynamics in social touch. Neuron, 85(4), 718 – 725.
doi: 10.1016/j.neuron.2014.12.059

Scroll to Top