BEIJING — We itch, we scratch, we scratch, we itch, what is the science behind this annoying cycle?<br />A recent study published in the journal Neuron reveals that a small category of neurons located in an area of the brain called the periaqueductal gray tracks itch-evoked scratching behavior in mice. <br />Researchers from the Chinese Academy of Sciences studied periaqueductal gray neurons of freely moving mice that were induced to scratch through injections containing histamine, or chloroquine. <br />Histamine is an organic compound involved in itch perception and chloroquine is a medication used to treat malaria.<br />The team then studied the itch-induced scratching behavior by observing the activity of a set of neurons that produce a neurotransmitter called tachykinin 1 or Tac1 which produces glutamate and neuropeptides.<br />Scientists observed that when Tac-1 neurons were eliminated itch-induced scratching also decreased.<br />Stimulating these neurons, on the other hand, resulted in spontaneous scratching behavior even without using histamine and chloroquine injections.<br />Scientists participating in the study will continue to investigate which molecules in the Tac1 can be targeted by drugs. This would allow for the development of a drug that could be used to treat patients with chronic itch.
