Sleep deprivation induces anxiety-like behaviors through IL-6 driven astrocyte-GABAergic neuron crosstalk in the PAG-ACC circuit.

Sleep deprivation (SD) is associated with anxiety-like behaviors, yet the underlying molecular and neural circuit mechanisms remain unclear. Using a 24-hour SD paradigm in mice, we found that SD induced anxiety-like behaviors and increased interleukin-6 (IL-6) in blood and the periaqueductal gray (PAG), and PAG-targeted administration of IL-6 receptor antagonist rescued the anxiety-like behaviors. This increased IL-6 activated PAG astrocytes, as evidenced by morphological remodeling, increased calcium activity, and enhanced glutamate release. Astrocytic activation upregulated several genes associated with endoplasmic reticulum (ER) protein synthesis and processing, including neuronal mesencephalic astrocyte-derived neurotrophic factor (Manf). Knockdown of Manf in PAG neurons upregulated the GABAA receptor α1 subunit (Gabra1), reduced the activity of GABAergic neurons projecting to the anterior cingulate cortex (ACC), and rescued anxiety-like behaviors. Chemogenetic inhibition of this PAG-ACC circuit prevented SD-induced anxiety-like behaviors, whereas its activation recapitulated the anxiety-like behaviors. Our study identifies an IL-6-astrocyte-Manf signaling axis in the PAG that drives anxiety-like behaviors via enhanced GABAergic neuronal output to the ACC. This PAG-ACC circuit may serve as a neuroimmune hub for SD-mediated anxiety-like behaviors and represents a potential therapeutic target.