The new finding proves the evidence that "socially contagious itchiness" exists in rodents. The researchers' neural analysis suggests that social and contagious itchiness is linked with the mouse's brain.
The study was conducted by study senior researcher Zhoufeng Chen, director at the Center for the Study of Itch at the Washington University School of Medicine in St. Louis. According to, Live Science, itchiness attacks mice when they see their compatriots scratch themselves. The findings are also true to human and monkey.
A previous 2013 research have proven that Rhesus macaque monkeys also tend to start scratching themselves when they witness other monkeys or even videos of monkeys scratching in front of them. This discovery has initiated Chen and his team putting mice within the view of other mice having a condition that made them scratch. They were also able to attach a silent video of mice suffering from itchiness. In both situations, the observing mice also start to scratch.
In humans, as reported by Scientific American, has termed itchiness as pruritus. Pruritus is a general sensation manifested by the irritation of skin cells and nerve cells within the skin. The condition might be a nuisance however; it could serve as an important sensory and self-protective mechanism. Furthermore, itch is a primary symptom of many skin diseases and is stimulated by pruriceptors mediated mechanically, thermally, and chemically.
The recent study has also proven that itchiness in mice is associated with the brain. When the mice suffers itch, the brain scans of the mice showed an increased activity in suprachiasmatic nucleus (SCN). SCN is a structure that controls the sleeping rhythm of animals.
As the mice witnesses their fellows scratch, the SCN cells releases a chemical known as gastrin-releasing peptide (GRP). A 2007 study has found that GRP acts as a key transmitter of itch signaling between the skin and spinal cord. When the researchers tried to block GRP, the mice did not scratch themselves. Thus, GRP is the main cause of itchiness and may trigger social and contagious itching.
