Touching Findings: Elkin1 is Key to Sensory Perception

Summary: Researchers discovered a new ion channel, Elkin1, appears to be crucial for touch perception. This finding marks a significant advancement in understanding the molecular basis of touch.

This discovery complements the known role of Piezo2, suggesting a complex system where both ion channels work together to convert mechanical stimuli into electrical signals for the brain.

Experiments with genetically modified mice lacking Elkin1 showed a marked decrease in touch sensitivity, while studies on human sensory neurons imply Elkin1’s importance in human touch perception too. This breakthrough not only deepens our grasp of sensory science but also opens new avenues for treating chronic pain by targeting Elkin1.

Key Facts:

  1. Discovery of Elkin1: A new ion channel critical for touch perception, highlighting a sophisticated mechanism alongside Piezo2 for sensing mechanical stimuli.
  2. Reduced Touch Sensitivity in Mice: Genetically modified mice without Elkin1 showed significant insensitivity to light touch, underscoring the protein’s role in touch sensation.
  3. Potential Human Impact: Preliminary findings suggest Elkin1’s role in human touch perception, pointing to its universal significance across species.

Source: Helmholtz

Every hug, every handshake, every dexterous act engages and requires touch perception. Therefore, it is essential to understand the molecular basis of touch.

“Until now, we had known that the ion channel – Piezo2 – is required for touch perception, but it was clear that this protein alone cannot explain the entirety of touch sensation,” says Professor Gary Lewin, head of the Molecular Physiology of Somatic Sensation Lab at the Max Delbrück Center.

This shows hands touching.
The researchers assume that during normal signal transmission, Elkin1 and Piezo2 share roles in touch perception. Credit: Neuroscience News

For over 20 years Lewin has been studying the molecular basis of the sensation of touch. He and his team have now discovered a new ion channel, named Elkin1, that plays a vital role in touch perception.

This is only the second ion channel implicated in the touch perception. It is likely that the protein is directly involved in converting a mechanical stimulus, such as light touch, into an electrical signal. When Elkin1 is present, the receptors in the skin can transmit the touch signals via nerve fibers, to the central nervous system and brain.

The researchers have published their findings in the journal Science.

Lewin’s team came across Elkin1 a few years ago while investigating a malignant melanoma cell line. The researchers had found that the protein is required for sensing mechanical forces by these highly motile cancer cells.

“Now we wanted to determine whether the same protein also plays a role in touch sensation” says Lewin.

Lack of Elkin1 reduces touch sensitivity

The researchers bred genetically modified mice that lacked the Elkin1 gene. They then conducted simple behavioral experiments that involved lightly brushing a cotton swab against the rodents’ hind paws.

“Usually, normal mice react to the cotton swab 90% of the time,” says Lewin. “In contrast, mice lacking Elkin1 only reacted half of the time, indicating touch insensitivity”. Importantly, the rodents’ reaction to non-mechanical stimuli like temperature was not affected.

At the neuronal level, Dr. Sampurna Chakrabarti, a scientist in Lewin’s team, used the patch clamp method to record the electrical activity of sensory neurons in response to poking of the neuronal membrane.  

“Around half of the neurons in genetically modified mice lacking Elkin1 didn’t respond to mechanical stimuli, and no signal transmission occurred,” says Chakrabarti.

Further experiments confirmed that there were no signals relayed from the neuron’s receptor ending in the skin, on the first leg of the signals journey from skin to the spinal cord and brain.

Furthermore, their Australian collaborators in the lab of Professor Mirella Dottori in the University of Wollongong tested whether Elkin1 in necessary for touch transduction in human sensory neurons grown in a petri dish from stem cells. Their findings also strongly suggest that Elkin1 could play a major role in human touch perception.

The researchers assume that during normal signal transmission, Elkin1 and Piezo2 share roles in touch perception. They have also found evidence that Elkin1 may play a part in the transmission of painful mechanical stimuli.

“If this is confirmed to be the case, we will have not only identified a second ion channel with an indispensable role in normal touch perception, but also a new potential target for treating chronic pain,” says Lewin.

About this genetics and sensory perception research news

Author: Christina Anders
Source: Helmholtz
Contact: Christina Anders – Helmholtz
Image: The image is credited to Neuroscience News

Original Research: Closed access.
Touch sensation requires the mechanically-gated ion channel Elkin1” by Gary Lewin et al. Science


Touch sensation requires the mechanically-gated ion channel Elkin1

Touch perception is enabled by mechanically activated ion channels, the opening of which excites cutaneous sensory endings to initiate sensation.

In this study, we identify ELKIN1 as an ion channel likely gated by mechanical force, necessary for normal touch sensitivity in mice.

Touch insensitivity in Elkin1−/− mice was caused by a loss of mechanically activated currents (MA currents) in around half of all sensory neurons activated by light touch (low-threshold mechanoreceptors). Reintroduction of Elkin1 into sensory neurons from Elkin1−/− mice restored MA currents.

Additionally, small interfering RNA–mediated knockdown of ELKIN1 from induced human sensory neurons substantially reduced indentation-induced MA currents, supporting a conserved role for ELKIN1 in human touch.

Our data identify ELKIN1 as a core component of touch transduction in mice and potentially in humans.

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