Inhibition of LPS-activated neurons in the cNST greatly increases the inflammatory response. AAVs carrying an mCherry construct, or the hM4Di inhibitory DREADD, were targeted to the cNST of LPS-TRAP2 mice for chemogenetic silencing. Control mCherry animals injected with LPS (grey bars) exhibit the expected induction of cytokines. By contrast, animals with silenced cNST neurons displayed increases in the levels of pro-inflammatory cytokines and a large reduction in the levels of an anti-inflammatory cytokine (IL-10; compare red or green and grey bars). Mice in all groups were given CNO 1 h before either the saline or the LPS injection; n = 6 for each group. Values are mean s.e.m.; MannWhitney U -tests: P = 0.24 (saline, IL-6), P = 0.97 (saline, IL-1), P = 0.78 (saline, IL-10), P = 0.004 (LPS, IL-6), P = 0.004 (LPS, IL-1) and P = 0.002 (LPS, IL-10).
