Basal forebrain cholinergic signaling regulates peripheral cytokine responses (INC1P.349)

Abstract

Abstract Brain cholinergic signaling regulates peripheral cytokine release and inflammation (Nat Rev Endocrinol, 2012, 8:743). We have previously shown that the centrally-acting acetylcholinesterase inhibitor galantamine suppresses peripheral pro-inflammatory cytokine release through a brain muscarinic receptor-mediated and vagus nerve-dependent mechanism. Here, we provide insight into the brain mechanisms of this regulation. VAChTNkx21-Cre-flox/flox mice with selective, basal forebrain cholinergic neuron genetic ablation of the vesicular acetylcholine transporter (an important determinant of acetylcholine release), and control VAChTflox/flox mice, were treated with galantamine or saline and subjected to endotoxemia. Galantamine (3mg/kg) i.p. administration suppressed serum TNF levels in control mice only. In addition, serum TNF and IL-10 in VAChTNkx2 1-Cre-flox/flox mice were significantly higher (2.9-fold, P<0.05) and lower (57%, P<0.05) respectively, as compared to control mice. Furthermore, electrical stimulation of the medial septum, an important basal forebrain cholinergic region, significantly lowered serum TNF (79%, P<0.01) and other pro-inflammatory cytokine levels in endotoxemic mice, as compared to sham-stimulation. These results demonstrate a previously unrecognized role of basal forebrain cholinergic signaling in the regulation of peripheral inflammation.