But new research in mice and rats suggests that the spinal cord plays a more important role in sex and arousal than ever realised. In previous research, the team had identified that spinal cord neurons expressing a molecule called galanin (Gal) were key to ejaculation. Under the microscope, they found that the axons of these neurons overlapped with the BSM motor neurons. “When we activated the far ends of Gal⁺ neurons – where they pass on signals – we recorded a burst of activity in the BSM motor neurons,” says Lenschow. Experiments showed that, in mice, Gal⁺ neurons received sensory input from the penis.