Krause corpuscles of the genitalia are vibrotactile sensors required for normal sexual behavior

Abstract

Krause corpuscles, first discovered in the 1850s, are enigmatic sensory structures with unknown physiological properties and functions found within the genitalia and other mucocutaneous tissues. Here, we identified two distinct somatosensory neuron subtypes that innervate Krause corpuscles of the mouse penis and clitoris and project to a unique sensory terminal region of the spinal cord. Using in vivo electrophysiology and calcium imaging, we found that both Krause corpuscle afferent types are A-fiber rapid-adapting low-threshold mechanoreceptors, optimally tuned to dynamic, light touch and mechanical vibrations (40-80 Hz) applied to the clitoris or penis. Optogenetic activation of male Krause corpuscle afferent terminals evoked penile erection, while genetic ablation of Krause corpuscles impaired intromission and ejaculation of males as well as reduced sexual receptivity of females. Thus, Krause corpuscles, which are particularly dense in the clitoris, are vibrotactile sensors crucial for normal sexual behavior.

A novel Nav1.8-FLPo driver mouse for intersectional genetics to uncover the functional significance of primary sensory neuron diversity

“…This strategy was recently used in an elegant study by the Ginty laboratory for selective visualization of the projection pattern and manipulation of the activity of two different somatosensory neuron subtypes innervating the Krause corpuscles of the mouse penis and clitoris. 36 …”

“… 23 , 24 , 25 , 26 , 27 , 28 , 29 The use of such systems has led to the generation of a large number of mouse lines in which the Cre-recombinase drives gene inactivation or the targeted expression of effector molecules, such as fluorescent markers, calcium reporters, optogenetic actuators, or exogenous ligand-responsive receptors (designer receptors exclusively activated by designer drugs [DREADDs]) in particular subsets of somatosensory and dorsal horn spinal neurons. 4 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 Despite these advances in genome-editing techniques, it is becoming increasingly clear that the recombinase-mediated expression of a single gene cannot provide the necessary resolution for studies of the functional specialization of a single cell type. The need to overcome this obstacle led to the development of intersectional genetic tools, pioneered by Qiufu Ma and Martyn Goulding, to restrict the effect of Cre lines specifically to spinal cord neurons.…”

Neurophysiology of male sexual arousal—Behavioral perspective

“…They are rapid-adapting low-threshold mechanoreceptors, sensitive to light touch and vibration (optimum 40–80 Hz). Activation of these receptors induced penile erection, and genetic ablation of Krause corpuscles impaired intromission and ejaculation in mice ( Qi et al, 2023 ). In men, the glans penis stimulation induced contraction of the cavernous muscle, the smooth muscle of the seminal vesicle, and the vassal ampullary.…”