The Sideshow

Mystery of why we itch revealed by scientists

View photo

.

A squirrel scratches itself (Wikicommons)

Scientists had an itch they just needed to scratch: solving the ages-old mystery as to why, exactly, we scratch ourselves.

The National Institute of Dental and Craniofacial Research says the answer is a mixture of commonly held beliefs along with some interesting new research.

While it’s true that irritants on the skin, such as a rash or a insect landing on us, can trigger an itch through nerve cells, the process of how we are made aware of the sensation, clinically known as “pruritus,” takes part in different parts of the body.

Testing on mice, the scientists found that a molecule released in the dorsal horn of the spine begins the biological process. The molecule, neuropeptide natriuretic polypeptide b (Nppb), then travels to the brain, creating the feeling of the itch.

In their study, the scientists were able to isolate mice without Nppb. “When we exposed the Nppb-deficient mice to several itch-inducing substances, it was amazing to watch,” said Santosh Mishra, lead author on the study. “Nothing happened. The mice wouldn’t scratch.”

“The receptors were exactly in the right place in the dorsal horn,” added study co-author Mark Hoon. “We went further and removed the Npra neurons from the spinal cord. We wanted to see if their removal would short-circuit the itch, and it did.”

Through their research, the scientists learned some other fascinating facts about Nppb as well.

“It’s released by the heart,” Hoon told Time, “to control blood sodium and blood pressure. It’s a cornerstone of biology that a lot of these neurotransmitters are used in different parts of the body for different purposes.”

So, does that mean it’s time to take a celebratory dive into poison ivy? Do humans no longer have to worry about annoying itches?

Not exactly. Hoon says doctors would currently be faced with two undesirable options: Affecting blood pressure control or injecting Nppb directly into the spinal cord, which, he dryly notes, “is not a trivial thing to do.”

In the meantime, the study’s authors are hoping to solve the other end of the equation, finding out why itching stops.

“Now the challenge is to find similar biocircuitry in people, evaluate what’s there, and identify unique molecules that can be targeted to turn off chronic itch without causing unwanted side effects,” Hoon said in a release accompanying the study. “So, this is a start, not a finish.”

View Comments (518)

Recommended for You

  • Man with 'Islamic extremist leanings' attacks NY police

    The man who attacked New York City police officers with a hatchet before being shot dead was reported to have Islamic "extremist leanings" police and a monitoring group said. The man, identified in the US media as Zale Thompson, had posted an array of statements on YouTube and Facebook that…

    AFP
  • Six bodies identified after decades in Oklahoma lake

    By Heide Brandes OKLAHOMA CITY (Reuters) - Oklahoma authorities have formally identified six people whose bodies were found in a western Oklahoma lake in 2013, bringing a resolution to missing persons mysteries that spanned decades, a spokeswoman for the state medical examiner said Thursday. The…

    Reuters
  • World War II airmen fly again in storied B-29

    BATON ROUGE, La. (AP) — The bomber best known for dropping the atomic bombs on Japan also flew countless other raids. Karnig Thomasian's final mission on a B-29 Superfortress ended in flames when bombs collided and exploded in the air over Burma in 1945.

    Associated Press
  • Pistorius shoves race, crime and punishment in South Africa's face

    By Ed Cropley PRETORIA (Reuters) - As Oscar Pistorius spent his first day behind bars this week, a suspected child rapist and murderer went on trial at the same Pretoria court in a case that has also provoked fierce debate about crime and punishment in post-apartheid South Africa. Although the two…

    Reuters
  • After 1st Ebola case in NYC, 3 others quarantined

    NEW YORK (AP) — A doctor who became New York City's first Ebola patient was praised for getting treatment immediately upon showing symptoms, and health officials stressed that the nation's most populous city need not fear his wide-ranging travel in the days before his illness began.

    Associated Press
  • Play

    Woman Stabbed to Death in Front Of Children in Dispute Over Parking Space: Family

    A South Los Angeles man and woman were charged with murder Tuesday in the stabbing death of a Whittier woman during a dispute over a parking space, authorities announced on Thursday. Nerissa Knight reports for the KTLA 5 News at 10 on Thursday, Oct. 23, 2014.

    KTLA - Los Angeles
  • Driver attacked after ice cream truck kills boy

    LOS ANGELES (AP) — Neighborhood residents attacked the driver of an ice cream truck after it struck and killed a 7-year-old boy riding a motorized bike in South Los Angeles, authorities said.

    Associated Press
  • Heads roll in Russia as more details emerge of Total crash

    Top Russian airport officials quit on Thursday as more employees were detained over the Moscow plane crash that killed the CEO of French oil giant Total. The driver of the snowplough that collided with Total boss Christophe de Margerie's plane as it was taking off from Moscow's Vnukovo airport late…

    AFP
  • Ebola cases could spur lawsuits _ with big hurdles

    DALLAS (AP) — In a land of lawsuits, this case seems made for litigation: A doctor appears to miss a red flag, an Ebola diagnosis is delayed, and a patient dies. But this is Texas.

    Associated Press
  • Japan warns of increased activity at volcano near nuclear plant

    TOKYO (Reuters) - Japan warned on Friday that a volcano in southern Japan located roughly 64 km (40 miles) from a nuclear plant was showing signs of increased activity that could possibly lead to a small-scale eruption and warned people to stay away from the summit. The warning comes nearly a month…

    Reuters
  • Two dead in murder-suicide at Houston hospital: police say

    HOUSTON (Reuters) - Two health workers died on Wednesday in an apparent murder-suicide at the out-patient pharmacy of a major Houston hospital, police said. A woman who worked at Ben Taub Hospital was shot dead by a male co-worker, who then killed himself. The names of the two have not been…

    Reuters
  • Dancing priests become Internet sensation

    ROME (AP) — A video of a pair of dueling, dancing American priests studying in Rome has gone viral, following in the footsteps of a now-famous Italian nun whose Alicia Keys-esque voice won her a singing contest and a record contract.

    Associated Press
  • Lebanon army nabs beheading suspect in 'terror cell' raid

    Lebanese troops arrested a recruiter for the Islamic State group wanted for the beheading of a captured soldier, in a raid Thursday that netted more suspects and killed three gunmen, the army said. "A military intelligence unit carried out a security operation at dawn in the Dinniyeh area" of…

    AFP
  • View

    Ebola in New York City (18 photos)

    Craig Spencer, a 33-year-old Doctors Without Borders physician who recently returned from Guinea, became the fourth person ever diagnosed with Ebola on U.S. soil on Thursday night. He was rushed to Bellevue Hospital Center by paramedics in hazmat suits and placed in the site’s isolation ward. But…

    Yahoo News
  • Mexico mayor accused of ordering attack on missing students

    Mexico on Wednesday ordered the arrest of the mayor of the city of Iguala, his wife and an aide, charging they masterminded last month's attack that left six students dead and 43 missing. Carrying torches and candles, tens of thousands of people marched through Mexico City and other cities to…

    AFP
  • Paintings in national parks spark probe, furor

    SALT LAKE CITY (AP) — A series of colorful, eerie faces painted on rocks in some of the West's most famously picturesque landscapes has sparked an investigation by the National Park Service and a furor online.

    Associated Press
  • Six in quarantine in Connecticut as U.S. steps up Ebola checks

    By Richard Weizel WEST HAVEN, Conn. (Reuters) - Connecticut placed six West Africans who recently arrived in the United States under quarantine for possible Ebola exposure, a move that comes as the United States starts new restrictions on those coming from the countries hardest hit by the deadly…

    Reuters