Neuronal Clock: Scientists have discovered neurons that could act as a "metronome" of our brain. These clocks seem to reconcile neuronal processes, allowing the coordinated processing of sensory stimuli. In mice, the even activity of metronome cells improves the perception of touch stimuli, the team reports. Further studies must now show whether there are similar clocks in the human brain.
Our brain is exposed to numerous different stimuli every second. How does the mind manage to process all these signals in a coordinated way? Neuroscientists have long suspected that this is achieved by a kind of metronome – a clock or synchronizer that brings neuronal signals from different areas of the brain in line and so among other things, the processing of sensory stimuli coordinated.
"The activity of the different brain cells involved results only then a coherent perception, a unity, "said Hyeyoung Shin from Brown University in Providence and her colleague Christopher Moore. One question is still open, however: What does this neural metronome actually look like?
Gamma waves in focus
Some researchers believe that they have found the clock of the brain in the form of so-called gamma waves ̵
To find out more about the influence of sensory stimuli on gamma-wave neuronal activity, Shin and Moore have now carried out research on mice. In the experiment, they easily moved the rodent's probes and observed what was happening in the brain region responsible for registering such touches and movements. What changed in the brain depending on whether the rodents were still able to perceive the touch or not?
A New Type of Neuron
Unlike previous studies, the two scientists not only derived the average activity of all neurons in this brain region. They also looked at individual brain cells using implanted electrodes and were thus able to detect abnormalities that are otherwise easily overlooked.
The evaluations revealed that some of the neurons observed by the researchers changed their activity as expected in response to the tactile stimuli , But Shin and Moore also discovered a subtype of brain cells that did not seem to respond to these sensory signals.
Even and Synchronous
Instead, this subspecies of so-called "almost spiking interneurons" (FSs) fired continuously and evenly in the Gamma waves typical interval – no matter what stimuli just got from the proboscis to the brain. Interestingly, the activity of all neurons of this subtype was also remarkably synchronous. Could these be the long-sought metronome neurons?
Further investigation revealed that this newly discovered cell type actually plays an important role in the perception of mice. The smoother the neurons ticked, the better the rodents could perceive even subtle touches. By setting the pace in the brain, the metronome neurons seem to improve the sensory perception of animals, as the scientists report.
Role for optimal communication
Further studies are now to show whether such clocks occur in other areas of the brain – and whether people own this particular neuron subtype. If the hypothesis that the newly discovered brain cells are of importance for optimal communication within the brain confirms this, new insights into a number of diseases may also emerge.
According to the researchers, brain cells from the group of "almost spiking interneurons "Already associated with disorders such as autism, schizophrenia and ADHD. In their view, it is therefore quite conceivable that changes in the metronome neurons could also play a role in this context. First of all, more research is needed to better understand how this new brain cell subtype works. (Neuron, 2019; doi: 10.1016 / j.neuron.2019.06.014)
Source: Brown University