Electroacupuncture alleviates depressive-like behaviors by restoring hippocampal CA1 dendritic arborization and...

Depression is a common emotional and affective disorder in clinical practice. Its core symptoms include significant and persistent low mood, decreased interest, etc. To date, the treatment approaches for depression primarily consist of pharmacotherapy, psychological counseling and treatment, as well as physical therapy. Drug therapy is the main treatment method in clinical practice, but it is limited by slow onset, low response rate, and many adverse reactions. Electroacupuncture (EA) therapy in traditional medicine has significant advantages of multi-pathway, multi-level, and multi-target in the intervention of depression, but its mechanisms are not fully understood.

In this study, we constructed a mouse olfactory bulbectomy depression model (OBx), and electroacupuncture treatment was performed on the Neiguan (PC6) acupoint for 7 days. In vivo multi - channel, chemogenetic, immunofluorescence and other techniques were used to study the neurophysiological mechanism of this treatment.

1. Electroacupuncture at Neiguan acupoint can improve the depression - like behaviors of OBx mice. 2. Electroacupuncture at Neiguan acupoint re - activates the electrophysiological activities of hippocampal CA1 neurons in OBx mice. 3. Chemogenetic verification shows that electroacupuncture treats the depressive state of mice by re - activating CA1 Pyramidal neurons. 4. Electroacupuncture restores the dendritic complexity of neurons in the hippocampal CA1 region of OBx mice.

We speculate that the absence of the olfactory bulb not only inhibits the activity of CA1 neurons through the neural circuit pathway but also is associated with a long - term stress state of anosmia, which may collectively contribute to the observed neuronal atrophy and causing the electrophysiological activities of CA1 pyramidal neurons to be lower than normal levels. This includes a decrease in local field potentials (LFP), a weakening of spike discharges, and a reduction in the coherence between the two. The treatment of EA at the PC6 acupoint, to some extent, restores the dendritic structure and morphology of neurons and restores the discharge activities of CA1 neurons, thereby improving the depressive state of OBx mice.