Graphical Abstract Highlights d Brain IL-1R1 is found in endothelial and ventricular cells, astrocytes, and DG neurons d Ventricular IL-1R1 regulates monocyte recruitment d Endothelial and ventricular IL-1R1 regulates IL-1-induced microglial activation d Endothelial IL-1R1 mediates sickness behavior, leukocyte recruitment, and neurogenesis In BriefLiu et al. employ a genetic knockin reporter system in mice to track and reciprocally delete and/or express IL-1 receptor 1 (IL-1R1) in specific CNS cell types. They define cell-type-specific roles for IL-1 signaling, including an essential role for endothelial IL-1R1 in mediating sickness behavior, and provide a foundation for the dissection of IL-1R1 signaling pathways in the pathogenesis of CNS disease.

In the original version of the published manuscript, the insets of Figure 3F (middle and right panels) were identical to the insets of Figure 3E. This error was generated inadvertently during the revision process of the manuscript. The insets of Figure 3F (middle and right panels) have now been replaced and are consistent with their corresponding images, and the revised version is provided below and has been corrected online. The authors apologize for the error.

Interleukin-1 (IL-1) mediates diverse neurophysiological and neuropathological effects in the CNS through type I IL-1 receptor (IL-1R1