NEWS
19 June 2024

Sensory secrets of penis and clitoris unlocked after more than 150 years

Low-frequency vibrations arouse genital nerve cells in mice — a finding that might lead to treatments for erectile dysfunction and more.

By Sara Reardon



Researchers have learnt that sensory nerve cells called Krause corpuscles are denser on the clitoris of female mice (left) than on the penis of male mice (right). Credit: Lijun Qi, Michael Iskols, and David Ginty

Specific nerve cells on the penis and clitoris detect vibrations and then become activated, causing sexual behaviours such as erections, a study in mice has revealed1. The findings could lead to new treatments for conditions such as erectile dysfunction, or for restoring sexual function in people with lower-body paralysis.

Krause corpuscles — nerve endings in tightly wrapped balls located just under the skin — were first discovered in human genitals more than 150 years ago. The structures are similar to touch-activated corpuscles found on people’s fingers and hands, which respond to vibrations as the skin moves across a textured surface.

But there is little research into how the genital corpuscles work and how they are involved in sex, probably because the topic is sometimes considered taboo. “It’s been hard to get people to work on this because some people have a hard time talking about it,” says David Ginty, a sensory neurobiologist at Harvard Medical School in Boston, Massachusetts, who led the team that conducted the latest research. “But I don’t, because the biology is so interesting.”

Good vibrations
Ginty and other sensory biologists have long wanted to study these mysterious neuron balls. But activating and tracking specific neurons was nearly impossible until advanced molecular techniques emerged in the past 20 years.

Article
Open access
Published: 19 June 2024

Krause corpuscles are genital vibrotactile sensors for sexual behaviours

Lijun Qi, Michael Iskols, Rachel S. Greenberg, Jia Yin Xiao, Annie Handler, Stephen D. Liberles & David D. Ginty

Nature (2024) Cite this article

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Abstract
Krause corpuscles, which were discovered in the 1850s, are specialized sensory structures found within the genitalia and other mucocutaneous tissues1,2,3,4. The physiological properties and functions of Krause corpuscles have remained unclear since their discovery. Here we report the anatomical and physiological properties of Krause corpuscles of the mouse clitoris and penis and their roles in sexual behaviour. We observed a high density of Krause corpuscles in the clitoris compared with the penis. Using mouse genetic tools, we identified two distinct somatosensory neuron subtypes that innervate Krause corpuscles of both the clitoris and penis and project to a unique sensory terminal region of the spinal cord. In vivo electrophysiology and calcium imaging experiments showed that both Krause corpuscle afferent types are A-fibre rapid-adapting low-threshold mechanoreceptors, optimally tuned to dynamic, light-touch and mechanical vibrations (40–80 Hz) applied to the clitoris or penis. Functionally, selective optogenetic activation of Krause corpuscle afferent terminals evoked penile erection in male mice and vaginal contraction in female mice, while genetic ablation of Krause corpuscles impaired intromission and ejaculation of males and reduced sexual receptivity of females. Thus, Krause corpuscles of the clitoris and penis are highly sensitive mechanical vibration detectors that mediate sexually dimorphic mating behaviours.

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