Electroacupuncture alleviates chronic stress-induced anxiety via excitatory neuron CB1 receptor-dependent suppression of GR/SGK1 signaling in the mPFC.

Abstract

Emerging evidence highlights the critical role of cannabinoid receptor 1 (CB1) in anxiety regulation, yet its neuron subtype-specific mechanisms remain poorly defined. This study investigated how CB1 receptors on medial prefrontal cortex (mPFC) excitatory versus inhibitory neurons mediate electroacupuncture (EA)-induced anxiolysis in chronic restraint stress (CRS) model mice. We demonstrated that EA significantly upregulated endocannabinoid levels and selectively enhanced CB1 receptor expression on mPFC excitatory neurons (neurogranin+, a commonly used marker for excitatory neurons), but not inhibitory neurons (GABA), in CRS mice. Genetic ablation of CB1 receptors on excitatory neurons (GLU-CB1R KO) induced anxiety-like behaviors in naïve mice and abolished EA's therapeutic effects in CRS models. In contrast, CB1 knockout on inhibitory neurons (GABA-CB1R KO) neither elicited baseline anxiety nor interfered with EA efficacy. Mechanistically, excitatory neuron-specific CB1 knockout upregulated glucocorticoid receptor (GR) and serum/glucocorticoid-regulated kinase 1 (SGK1) expression in the mPFC, suggesting CB1 activation suppresses GR-SGK1 signaling-a pathway previously linked to EA's attenuating anxiety-like behaviors effects. Fiber photometry confirmed CRS-induced mPFC endocannabinoid deficits, which were reversed by EA. These findings reveal a cell type-specific mechanism whereby EA alleviates stress-induced anxiety by restoring excitatory neuron CB1 signaling to inhibit maladaptive GR/SGK1 activation. Our work identifies glutamatergic CB1 receptors in the mPFC as pivotal targets for neuro-modulatory therapies against anxiety disorders.