Terahertz wave stimulation improves visual recognition memory via the activation of excitatory neurons in the...

Terahertz (THz) waves, with frequencies between those of microwaves and infrared light, can excite nonlinear resonance and affect cellular function. However, the effects and underlying mechanism of terahertz radiation on neurons and rodent behaviour are still unclear. Here, we constructed THz radiation exposure models in the perirhinal cortex (PRH) of male mice. First, we measured the power and depth of penetration of the 0.152 THz photons cranially above the PRH. We demonstrated that the visual recognition memory of mice was improved after THz wave irradiation, which was similar to the effect of light activation of glutamatergic neurons in the PRH. In addition, THz wave exposure increased the number of c-Fos⁺ neurons, synchronous electrical activity, synaptic plasticity and glutamatergic neuronal excitability in the PRH. Moreover, the expression of molecules involved in glutamate transmission, such as VAMP2, EAAT, CaMKII and PSD95, increased along with enhanced NMDAR and AMPAR activity. Our findings revealed that THz waves could improve recognition memory via the activation of excitatory neurons and accelerated glutamate metabolism in the PRH, suggesting that THz photon stimulation might be developed as a noninvasive neuromodulation technique to promote cognitive function.