痒感多由蚊虫叮咬、过敏等引发的局部炎症产生，通过细直径慢神经元经脊髓丘脑束传导至大脑。而皮肤中的机械感受器能感知触摸和震动，其信号通过粗直径快神经元经背柱传导。脊髓内两类神经元通过中间神经元交联，触摸信号会激活抑制痒感传导的神经元，这就是 “闸门理论”—— 触摸能 “关闭” 痒感通道。此外，触摸刺激大脑深层结构会反向抑制痒感传递，功能性磁共振成像研究还显示，挠痒能激活大脑奖励中枢，带来愉悦感。

Despite the saying “happiness is having a scratch for every itch,” itching often makes the itchy skin condition worse. So why is the instinct so strong? In a study with mice, researchers from the ...

What’s common between a scratchy sweater, a mosquito bite, and poison ivy? A brush with any of them guarantees an itchy spot on the skin. Scratching that itch is extremely tempting because of how ...

Medical science has deciphered many of the body’s workings, down to the level of the gene, and isn’t too far from using stem cells to repair its hobbled organs. But in many ways, the human body ...

Scratching an itch can bring a contradictory wave of pleasure and misery. A mouse study on scratching, reported in the Jan. 31 Science, fleshes out this head-scratching paradox and could point out ...

When you’ve got an itch, you probably want to scratch it. But whether it’s from a mosquito bite, chickenpox, or chronic skin issue like eczema, any relief from scratching will be short-lived. And too ...

Researchers might have finally scratched below the surface of this medical mystery. Itchiness is a common symptom of various skin conditions, but why that is has long been unclear — until now. A new ...

One of the greatest pleasures in life is to scratch an itch — in both the real and figurative sense. Although scratching an itch provides immediate (albeit temporary) relief, it may actually trigger ...

Journalist Annie Lowrey has a rare disease that causes a near-constant itch that doesn't respond to most treatments. She likens the itchiness to a... Chronic itch is miserable. Scientists are just ...

Russell has a PhD in the history of medicine, violence, and colonialism. His research has explored topics including ethics, science governance, and medical involvement in violent contexts. Russell has ...

I remember it well: our dark winter of itch when the kids were small. It started with a note sent home—years before the pandemic—that my child had been exposed, not to a deadly virus but to lice.