In male mice, specific cells recognize females, while in female mice, different cells are quiescent, indicating distinct neural circuits for sex recognition.

“If we inactivate these cells, if we silence these cells or if we kill the cells, and again, we're talking of, you know, maybe 2,000 cells. If we kill the cells, he cannot recognize females from males. Typically, he prefers the smell of a female. That preference is gone. And because he can't say that's a male or a female, he neither mates with females nor attacks other males.”

“So that recognitive process has induced a state in the male that says it's a female. Although the sensory input that's coming in, the pherommones that are coming in, the size, the way the animal's walking around, all screams male, he thinks it's a female. He tries to mate with him.”

“So there's sex recognition going on in the male mouse brain. If you record from the same cells in the female brain, those cells to be seem to be quent.”