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 ...

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 ...

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 ...

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 ...

Do you feel an itch, right now, working its way down the back of your neck? Scratching temporarily relieves that itch, but can also make it worse. Now researchers at the Center for the Study of Itch ...

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 ...

The itch from bug bites, rashes, and other skin conditions can sometimes be so overpowering that it feels impossible to avoid scratching them. But new research explains why you might want to hold off ...

This is Explainer, a column that answers questions we all have (or should have). Anyone with skin knows the feeling of having a bad itch that won’t go away. Whether it’s a mosquito bite, hives, or ...

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 ...

Your parents were right: Scratching an itchy rash really does make it worse. Now we know why, thanks to new research that uncovers how scratching aggravates inflammation and swelling in a mouse model ...