If something itches you, the only thing you can do is scratch yourself . A new study from the University of Minnesota has just deciphered the physiological mechanisms that make this action provide us so much relief.
As Glenn J. Giesler explains in the latest issue of the journal Nature Neuroscience , experiments in humans and primates suggest that scratching our skin inhibits the activity of a type of neurons in the spinal cord (the neurons of the spinothalamic tract ) that convey the sensation of itching. However, there has to be itchiness for the simple friction of the skin to take effect. In other words, if there is no prior itching stimulus, scratching has no effect on neurons.
Giesler hopes his results will help find new ways to alleviate chronic itching that some sufferers suffer, for example by mimicking the pleasant sensation of scratching using mechanical stimuli or drugs.
