A chronic restraint stress (CRS) model produced clear depressive-like phenotypes in mice. The model group spent more time immobile in both the forced swim and tail suspension tests; they also traveled farther in the peripheral zone of the open-field test, consistent with anxiety-like locomotor patterns, investigators reported. Daily bilateral electroacupuncture at LI4 and LR3 for seven days shortened immobility time in both despair assays and reduced peripheral-zone distance in the open-field test when compared with the CRS model cohort. The study team thus attributed a behavioral benefit to the EA protocol described, while noting the serum CRH response showed only a non-significant downward trend after EA.
CRS increased circulating hypothalamic-pituitary-adrenal (HPA axis) hormones relative to blank controls. Serum CRH, ACTH and corticosterone (CORT) were all higher in the stressed mice according to ELISA measurements reported by the authors. After the EA intervention, serum ACTH and CORT fell versus the CRS model group; the reductions reached statistical significance for both hormones. Serum CRH decreased numerically but did not show a statistically significant change in the authors' analysis. These endocrine data were presented alongside behavioral improvements and used by the authors to support an HPA-axis–related mechanism for EA’s effect on stress-induced behavior.
The study evaluated neuronal activation in the paraventricular nucleus (PVN) using c-Fos immunofluorescence and mCherry labeling of CRH neurons in CRH-Cre mice. CRS increased the number of c-Fos–positive cells in the PVN and raised the percentage of c-Fos/mCherry double-positive cells among mCherry-labeled PVN CRH neurons. EA reduced both the total PVN c-Fos–positive cell count and the proportion of c-Fos–positive cells within the mCherry-labeled CRH population. The authors interpreted these changes as evidence that EA attenuates stress-induced activation of PVN neurons, including the subset expressing CRH, linking circuit-level activity to the observed hormonal and behavioral effects.
Event-related calcium signals from PVN CRH neurons were recorded by fiber photometry. The investigators quantified ΔF/F area under the curve and peak ΔF/F within a 0–5 second window. Both AUC and peak ΔF/F were lower during and after EA compared with pre-EA baselines in the same animals. Those acute suppressions of PVN CRH neuron calcium activity occurred in temporal association with the EA sessions, and the data provided a real-time correlate to the reduced c-Fos labeling and endocrine changes reported elsewhere in the study.
Authors used chemogenetic activation (clozapine‑N‑oxide, CNO) to selectively stimulate PVN CRH neurons in mice exposed to subthreshold stress. Activation prolonged immobility in forced swim and tail suspension tests and reduced peripheral-zone locomotion in the open-field test. When EA was applied after chemogenetic activation, those behavioral changes were reversed by the investigators' readouts. The authors used this set of experiments to argue that modulation of PVN CRH neuron activity is both sufficient to induce depressive-like behaviors under low-level stress and modifiable by EA intervention.
The authors did not report several procedural details in the abstract: group sizes for each experiment, randomization and blinding procedures, and longer-term durability of the EA effect beyond the reported 7-day regimen were not provided in the English abstract. The study presents correlative endocrine, histologic and calcium-imaging data alongside chemogenetic manipulation; causal chain elements remain to be fully mapped. It was not specified whether EA effects are mediated by direct somatosensory pathways to the PVN, by upstream modulatory nuclei, or by peripheral autonomic changes. Additional work — including replication, dose-response of EA parameters, and pathway-specific interventions — would be required to define precise mechanistic steps and to evaluate translational relevance.
The article's data indicate that in this mouse CRS model, electroacupuncture at LI4 and LR3 is associated with reduced depressive-like behavior, reduced HPA axis hormone responses, lowered PVN neuronal activation, and suppressed PVN CRH neuron calcium transients. The source did not provide sample sizes, randomization or blinding details in the abstract, nor long-term follow-up data beyond the intervention window.