Remarkable detective work by Lindsey Salay at Caltech. She discovered a thalamic nucleus, SPFp, with neurons that selectively respond to touch *when an animal is sexually aroused*, triggering release of mounting behavior. Inhibition of this tiny group of neurons causes complete elimination of consummatory mating actions! (In case you're wondering how I got involved in a paper on mouse mating: David Anderson told me about a phenomenon of 'object craving' that could be triggered by stimulation of a specific mouse hypothalamic pathway...I thought this could be a powerful entrypoint to study object vision in mice...I was wrong, the behavior turned out to be purely driven by touch, but it was amazing to watch Lindsey figure out all the pieces of the actual circuit that enables a sensory stimulus to trigger a powerful behavior.)