[Effects of 40 Hz multisensory stimulation on trauma-induced anxiety-like behavior in rats].

OBJECTIVE

To investigate the effects of 40 Hz acousto-optical stimulation on anxiety like symptoms of post-traumatic stress disorder (PTSD), with emphasis on the possible molecular mechanism stimulation.

METHODS

Thirty SD rats were randomly divided into three groups: Control group, PTSD group and PTSD+40 Hz group,ten rats in each group. The SPS&S model was established in the rats of the PTSD group and PTSD+40 Hz group and, then PTSD+40 Hz group rats were stimulated with 40 Hz acousto-optical stimulation for 7 days. The behavior of anxiety was tested by elevated plus maze (EPM) and open field test (OFT). The expressions of brain-derived neurotrophic factor (BDNF), tyrosine kinase receptor B (TrkB), synapsinⅠand postsynaptic density protein 95 (PSD95) in the rat prefrontal cortex (PFC) and hippocampus (HIP) were detected by Western blot. The mRNA transcription level of BDNF genes in the PFC and HIP was verified by real-time quantitative PCR (RT-PCR) and the distribution of BDNF in the PFC and HIP was determined by immunofluorescence.

RESULTS

Compared with the Control group, in the OFT the total distance and the time spending in the center, and in the EPM the total distance were decreased significantly (＜0.05), the number of entering into the open arm as a percentage of the total number of entering in two arms was decreased,and the expression levels of BDNF, TrkB, PSD95, Synapsin I protein in HIP and PFC, and the mRNA expression level of BDNF were reduced significantly (＜0.01), the immunofluorescence expression of BDNF was reduced in CA1, DG and PFC in the PTSD group rats; Compared with the PTSD group, the total distance and the time spending in the center in OFT (＜0.05), the total distance and the number of entering into the open arm as a percentage of the total number were increased significantly (＜0.05), the protein expression levels of BDNF, TrkB, PSD95, SynapsinⅠin the PFC and HIP, the mRNA expression level of BDNF were increased significantly (＜0.05), and the immunofluorescence expression of BDNF was increased significantly in CA1, DG and PFC in the PTSD+40 Hz group rats.

CONCLUSION

40 Hz acousto-optical stimulation improves the formation of anxiety-like symptoms in rats with PTSD, which may be related to the synaptic plasticity influenced by BDNF-TrkB signaling pathway.