Fig. 2

Intracerebroventricular (ICV) administration of IL-1β induces NF-κB nuclear localization in a time- and region-dependent manner. The effect of ICV IL-1β is both rapid and transient as demonstrated by NF-κB immunoreactivity (IR) in representative confocal images of the paraventricular nucleus (PVN). IR in vehicle (aCSF, n = 6)-treated animals showed cytoplasmic labeling of blood vessels (a). IL-1β treatment caused NF-κB nuclear localization that peaked by 30 min (b, n = 8), persisted for at least 2 h (c, n = 4) and returned to near baseline, with cytoplasmic vascular patterns reappearing, by 4 h after treatment (d, n = 4). This effect was most prominent in and around the PVN, organum vasculosum lamina terminalis (OVLT; e, f), subfornical organ (SFO; g, h), arcuate nucleus/median eminence (ARC/ME; i, j), and choroid plexus (ChP; k, l). High-magnification confocal images of co-labeling with cell-specific markers shows that vascular endothelial cells (m), microglia (n), astrocytes (o), and tanycytes (p) directly respond to IL-1β. Scale bars: a–l = 50 μm, m–p = 10 μm