Effects of scratching and other counterstimuli on responses of trigeminothalamic tract neurons to itch-inducing stimuli in rats.
Counterstimuli such as scratching, pinching, noxious heat and cold, and innocuous cooling and warming have been shown to inhibit itch in humans. In the present study, the effects of each of these counterstimuli were determined on baseline firing rates and on sustained pruriceptive responses of rat trigeminothalamic tract neurons. We found that scratching had little, if any, effect on baseline firing levels but greatly reduced mean pruriceptive firing following scratching for nearly 1 min. None of the other noxious or innocuous counterstimuli significantly inhibited pruriceptive responses. Our results indicate that scratching, but not other counterstimuli, significantly reduces itch-induced responses of trigeminothalamic tract neurons.
['Lipshetz|Brett|B|', 'Giesler|Glenn J|GJ|']
D000818:Animals D002610:Cheek D003080:Cold Temperature D006358:Hot Temperature D008297:Male D009434:Neural Pathways D010812:Physical Stimulation D011537:Pruritus D051381:Rats D017207:Rats, Sprague-Dawley D012701:Serotonin D014110:Touch D014279:Trigeminal Nucleus, Spinal D020651:Ventral Thalamic Nuclei
scratching itch pruriception pain