• Gaolin Qiu, Peng Wang, Jin Rao, Xin Qing, Chenchen Cao, Dijia Wang, Bin Mei, Jiqian Zhang, Hu Liu, Zhilai Yang, and Xuesheng Liu.
• Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesia and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China.
• Anesthesiology. 2024 Mar 18.

BackgroundDexmedetomidine has repeatedly shown to improve anxiety but the precise neural mechanisms underlying this effect remain incompletely understood. Here, we aim to explore the role of corticotropin-releasing hormone-producing hypothalamic paraventricular (CRHPVN) neurons in mediating the anxiolytic effects of dexmedetomidine.MethodsA social defeat stress mouse model was employed to evaluate the anxiolytic effects induced by dexmedetomidine through the elevated plus-maze, open-field test, and measurement of serum stress hormone levels. In vivo Ca2+ signal fibre photometry and ex vivo patch-clamp recordings were utilized to determine the excitability of CRHPVN neurons and investigate the specific mechanism involved. CRHPVN neuron modulation was achieved through chemogenetic activation or inhibition.ResultsCompared with saline, dexmedetomidine (40 µg/kg) alleviated anxiety-like behaviors. Additionally, dexmedetomidine reduced CRHPVN neuronal excitability. Chemogenetic activation of CRHPVN neurons decreased the time spent in the open arms of the elevated plus-maze and in the central area of the open-field test. Conversely, chemogenetic inhibition of CRHPVN neurons had the opposite effect. Moreover, the suppressive impact of dexmedetomidine on CRHPVN neurons was attenuated by the α2 receptor antagonist yohimbine.ConclusionsOur results indicate that the anxiety-like effects of dexmedetomidine are mediated via α2 adrenergic receptor-triggered inhibition of CRHPVN neuronal excitability in the hypothalamus.Copyright © 2024 American Society of Anesthesiologists. All Rights Reserved.

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