Terahertz Photons Improve Cognitive Functions in Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is a serious psychosis leading to cognitive impairment. To restore cognitive functions for patients, the main treatments are based on medication or rehabilitation training but with limited effectiveness and strong side effects. Here, we demonstrate a new treatment approach for PTSD by using terahertz (THz) photons stimulating the hippocampal CA3 subregion. We verified that this method can nonthermally restore cognitive function in PTSD rats in vivo. After THz photon irradiation, the PTSD rats' recognitive index improved by about 10% in a novel object recognition test, the PTSD rats' accuracy improved by about 100% in a shuttler box test, the PTSD rats' numbers to identify target box was about 5 times lower in a Barnes maze test, and the rate of staying in new arm increased by approximately 40% in a Y-maze test. Further experimental studies found that THz photon (34.5 THz) irradiation could improve the expression of NR2B (increased by nearly 40%) and phosphorylated NR2B (increased by about 50%). In addition, molecular dynamics simulations showed that THz photons at a frequency of 34.5 THz are mainly absorbed by the pocket of glutamate receptors rather than by glutamate molecules. Moreover, the binding between glutamate receptors and glutamate molecules was increased by THz photons. This study offers a nondrug, nonthermal approach to regulate the binding between the excitatory neurotransmitter (glutamate) and NR2B. By increasing synaptic plasticity, it effectively improves the cognitive function of animals with PTSD, providing a promising treatment strategy for NR2Brelated cognitive disorders.