Early intervention with electroacupuncture prevents PTSD-like behaviors in rats through enhancing hippocampal endocannabinoid signaling

Electroacupuncture (EA) is a clinically useful physiological therapy that has been recently adopted to treat several brain disorders. However, the potential role of early EA intervention in the prevention of posttraumatic stress disorder (PTSD) as well as its potential cellular and molecular mechanism has never been investigated previously. In the present study, we used an enhanced single prolonged stress (ESPS) model to access the effects of early EA intervention on the prevention of anxiety-like and fear learning behaviors, as well as the influence of the expression of post-synaptic density protein 95 (PSD95), synaptophysin (Syn), brain derived neurotrophic factor (BDNF), diacylglycerol lipase alpha (DAGL alpha) and cannabinoid type 1 receptor (CB1R) in the hippocampus with or without DAGL alpha or CB1R knockdown by a short hairpin RNA (shRNA) in the hippocampus. Moreover, the effects of electrical stimulation with different parameters on the expression of DAGL alpha and CB1R in the hippocampal astrocytes were also observed. The results showed that Early EA intervention improved hippocampal synaptic plasticity and ameliorated PTSD-like behaviors and also increased expression of BDNF, DAGL alpha and CB1R. However, either DAGL alpha or CB1R knockdown by a short hairpin RNA (shRNA) eliminated the neuroprotective effects of early EA intervention. Furthermore, electrical stimulation with 2/15 Hz 1 mA elevated the expression of DAGL alpha and CB1R. Altogether, our findings provide new insights regarding the possibility of using early EA intervention in the prevention of PTSD, and the protective effects of EA is involving the activation of DAGL alpha and CB1R.