Meningeal natural killer cells and innate lymphoid cells 1 tune anxiety and memory via interferon-? and acetylcholine

The mechanisms of communication between the brain and the neighboring meningeal immune cells are still unclear. Here we characterized the resident group 1 innate lymphoid cells in the meninges of adult mice, and identified ILC1/NK cell-derived interferon-? and acetylcholine as mediators involved in the modulation of brain circuitries underlying anxiety-like behavior and memory. This discloses a new meningeal-to-brain communication mechanism that modulates brain functions under physiological conditions. Overall design: To expand our understanding of functions of individual meningeal cell populations, we investigated group 1 innate lymphoid cells (ILCs), which comprise conventional NK1.1+ NK cells and type 1 ILCs in adult male mice by single-cell RNA-sequencing.