[Effects of acupuncture on anxiety-like behavior and PKC/ERK/CREB pathway in the bed nucleus of the stria terminalis in rats with post-traumatic stress disorder].

OBJECTIVE

To observe the effect of acupuncture (acupuncture for soothing the liver and regulating the spirit) on the protein kinase C/extracellular signal-regulated kinase/cAMP response element-binding protein (PKC/ERK/CREB) signaling pathway in the bed nucleus of the stria terminalis (BNST) of rats with post-traumatic stress disorder (PTSD), and to explore the mechanism of acupuncture on alleviating anxiety and fear in PTSD.

METHODS

Fifty SPF-grade male SD rats were randomly divided into a blank group (10 rats) and a PTSD model group (40 rats). The PTSD model was induced by using a combination of closed electric shock and forced exhaustive swimming. Thirty successfully modeled rats were randomly assigned to a model group, a medication group, and an acupuncture group, with 10 rats in each group. The rats in the medication group were treated with paroxetine hydrochloride solution by gavage, once daily for 12 consecutive days. The rats in the acupuncture group were treated with acupuncture at "Baihui" (GV 20) and bilateral "Neiguan" (PC 6), "Shenmen" (HT 7), "Taichong" (LR 3). "Baihui" (GV 20) was needled daily, while the other acupoints were alternately needled on the left side on odd days and the right side on even days, once daily for 12 consecutive days. Anxiety and fear behaviors changes were assessed by using the open field test and elevated plus maze test. Histological changes in the BNST were observed by using HE staining and Nissl staining. The expression of PKC, phosphorylated PKC (p-PKC), ERK1/2, phosphorylated ERK1/2 (p-ERK1/2), and p-CREB proteins in the BNST were detected by using Western blot.

RESULTS

Compared with the blank group, the model group showed decreased time and total distance spent in the center of the open field and on the open arms of the elevated plus maze (<0.05); the BNST tissues in the model group exhibited a reduced number of neurons, disorganized cell arrangement, cell shrinkage, nuclear condensation, abnormal neuronal structure, uneven Nissl staining, and reduced Nissl bodies. The model group showed increased protein expression of p-PKC and p-PKC/PKC ratio (<0.05) and decreased protein expression of p-ERK1/2, p-CREB, and p-ERK1/2/ERK1/2 ratio (<0.05). Compared with the model group, the medication group and the acupuncture group showed increased time and total distance spent in the center of the open field and on the open arms of the elevated plus maze (<0.05); the BNST tissues showed increased number of neurons, more organized cell arrangement, improved neuronal structure, and increased Nissl bodies; the medication group and the acupuncture group also showed decreased p-PKC protein expression and p-PKC/PKC ratio (<0.05) and increased p-ERK1/2, p-CREB protein expression, and p-ERK1/2/ERK1/2 ratio (<0.05).

CONCLUSION

acupuncture could alleviate anxiety and fear behaviors in PTSD rats, and improve neuronal damage in the BNST. The mechanism may be related to the regulation of the PKC/ERK/CREB signaling pathway in the BNST.