Molecular Mechanisms of Itch Sensations
نویسندگان
چکیده
OF THE DISSERTATION Molecular mechanisms of itch sensations By Seungil Kim Doctor of Philosophy in Biology and Biomedical Sciences (Developmental Biology) Washington University in St. Louis, 2011 Associate Professor James Skeath, Chairperson Itch is a sensation which causes scratching response to protect skin against external harmful reagents. Acute itch arises in short time period after insect bites or allergen contact. Chronic itch happens in various skin diseases such as atopic dermatitis (AD) and psoriasis. Chronic itch usually continues for over six weeks and is resistant to commonly used anti-histamine drugs. While pain has caught an early attention due to its severity, the molecular mechanism of itch has not been studied in detail. Itch and pain share common features because they are transmitted by similar neuronal circuits. However, itch is a distinct somatosensation and has opposite characteristics to pain. Itch elicits scratching but pain causes withdrawal reflex. Interestingly, minor pain induced by scratching reduces itch and suppression of pain by opioid analgesics such as morphine
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