Scientists think they have identified the long-hypothesized neurons based on studies using rats. By applying a new method to assess the fast electrical spikes of individual neurons the findings suggest that a newly discovered nerve cell can help rodents to detect subtle sensations. Furthermore, the cell that keeps time with a high-degree of regularly.
The researchers, from Brown University, found that the neuron spikes rhythmically, and it does so in a synchronized manner, independent of any external sensations. In the experiments this included testing the rodents’ ability to detect when their whiskers are lightly tapped.
This led to the discovery of the new cells, which the researchers describe as gamma regular nonsensory fast-spiking interneurons. Instead the researchers were looking into gamma rhythms, which could be the unifying clock that align signals across brain areas. Not all neuroscientists are convinced of the gamma wave argument.
Delving deeper, the researchers used a precise electrical signaling machine to move the whiskers slightly, this was just to the edge of a rodent’s ability to detect movement. From this point, they recorded neuron activity in the whisker-sensation part of the brain. The scientists wished to see what was different in the brain when the rodent was able detect the faint tapping of its whiskers compared to when it was not able to detect any sensation.
This led to the discovery that some of the fast-spiking interneurons were ‘ticking’ very regularly, and this ensured that rodent was more equipped to perceive subtle sensations. This was the subgroup of regularly spiking metronome neurons. To explore further, the team used computer modeling to better understand the logic of fast-spiking neurons.
The next phase of the research is to assess whether these newly identified metronome neurons are found in primates and humans. If so, this could provide new insights into conditions such as the neurological disorders autism, schizophrenia and attention deficit hyperactivity disorder.
The research has been published in the journal Neuron, with the research paper titled “Persistent Gamma Spiking in SI Nonsensory Fast Spiking Cells Predicts Perceptual Success.”
