To maintain homeostasis, the immune system must orchestrate complex, multi-organ responses to protect against pathogens. The coordination of such responses happens not only through the immune system itself, via the mobilization of immune cells and the release of cytokines, but also through the nervous system. Indeed, the largest secondary lymphoid organ in the body, the spleen, is densely innervated, and this innervation has been conserved throughout evolution. Previous studies revealed evidence for an interoceptive interplay between the spleen and the brain that regulates immune function. Together, these findings suggest that the nervous system can modulate immunity, not only through peripheral circuits, but also by broader neuronal networks involving the brain. Leonor is interested in understanding the central-to-peripheral neuronal circuits that regulate immune function.