DMH glutamatergic and GABAergic neurons differentially regulate post-anesthesia sleep disturbance through CB1R signaling

Abstract

Abstract Purpose Post-operative sleep disturbance affects more than 60% of surgical patients and impedes recovery. Although general anesthesia itself may profoundly remodel brain function and contribute to this pathology, the underlying neural mechanisms remain unclear. We previously identified the dorsomedial hypothalamus (DMH) as a key modulator of emergence and arousal. Here, we investigated the distinct roles of DMH glutamatergic neurons (DMH Glu ) and GABAergic neurons (DMH GABA ) in the pathophysiology of post-anesthesia sleep disturbance (PSD). Methods Using a mouse model of PSD induced by 2 h of 1.4% isoflurane anesthesia, we used chemogenetics to selectively activate or inhibit DMH neurons. Sleep–wake architecture was assessed using wireless electroencephalography (EEG) and electromyography (EMG) biotelemetry, complemented by fiber photometry for neuronal activity monitoring and single-nucleus RNA sequencing for molecular profiling. Results Isoflurane anesthesia induced a delayed-onset sleep disturbance characterized by increased wakefulness and reduced, fragmented sleep during the subsequent rest phase. Notably, DMH Glu neurons showed heightened activity specifically during rest-phase wakefulness, whereas DMH GABA neurons were predominantly active during wakefulness and non-rapid eye movement sleep in the post-anesthesia active phase. Activation of DMH Glu neurons reversed PSD in a circadian phase-dependent manner, while both activation and inhibition of DMH GABA neurons improved PSD without significant phase variation. Single-nucleus RNA sequencing revealed the involvement of retrograde endocannabinoid signaling in both DMH Glu and DMH GABA neurons. Administration of a type 1 cannabinoid receptor (CB1R) antagonist alleviated PSD, potentially by disinhibiting DMH Glu neurons and remodeling the integration of excitatory and inhibitory inputs onto DMH GABA neurons. Conclusions DMH Glu and DMH GABA neurons differentially regulate PSD through distinct, CB1R-mediated presynaptic modulation, providing novel mechanistic insights into PSD and identifying potential therapeutic targets for its treatment.