H2S improves hippocampal synaptic plasticity in SPS rats via PI3K/AKT signaling pathway

Post-traumatic stress disorder (PTSD) is a severe mental illness that could impose heavy burdens on individuals and society, but effective and precise treatment modalities are unknown. The level of hydrogen sulfide (H₂S) in the brain plays an important role in psychiatric diseases. However, it is still unclear whether PTSD exposure could affect the level of H₂S and whether there is a correlation between H₂S levels and the pathogenesis of PTSD. In this study, we selected single prolonged stress (SPS) as a PTSD model and found that SPS exposure decreased the endogenous H₂S content accompanied by abnormal behavioral changes and dysregulation of the hippocampal synaptic plasticity in SPS rats. We further found that the exogenous administration of H₂S could alleviate PTSD-like behaviors and improve hippocampal synaptic plasticity in SPS rats. In addition, we further used the phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002 to interfere with the PI3K/AKT/BDNF signaling pathway. It was found that LY294002 significantly blocked the anti-anxiety effect and the improvement in synaptic plasticity derived from the exogenous administration of H₂S in SPS rats. These results suggested that the endogenous H₂S content was decreased in SPS rats, and that the exogenous administration of H₂S could ameliorate abnormal disorders and improve hippocampal synaptic plasticity by mediating the PI3K/AKT pathway.