This means that scientists have found a particular neural cell type that blocks the relay of pain and itch sensations from the spinal cord to the brain in mice. The existence of such cells was proposed 50 years ago as part of a “Gate Control Theory” of pain, however n physiological evidence was available at the time to support this theory.
In a research brief, the lead researcher Hanns Ulrich Zeilhofer, a pain researcher at the University of Zürich, notes: “Evidently, the neurons don’t just control pain, but also various forms of itch.”
Zeilhofer explains that he and his team found that blocking the activity of certain inhibitory neurons in the dorsal horn of the spinal cord caused pain and itching in mice, whereas inducing their activity alleviated the symptoms. These findings suggests that glycine-producing interneurons are a key component of a spinal gate that controls the relay of pain and itch signals. It could also be that excitatory cells in the spinal cord may also be part of the body’s pain and itch signaling apparatus, and the inhibitory neurons studied may have additional roles in gait and posture.
Whether the finding can be used to help reduce the effects of pain and itching remains to be seen.
The findings have been published in the journal Neuron. The research paper is “Targeted Ablation, Silencing, and Activation Establish Glycinergic Dorsal Horn Neurons as Key Components of a Spinal Gate for Pain and Itch.”
