Neuronal growth and development promoted by low-intensity roadband terahertz radiation

Abstract

Terahertz waves are located in the energy level range of hydrogen bonding and van der Waals forces, and can directly couple with proteins to excite the nonlinear resonance effect of proteins. Therefore, terahertz can affect the conformation of proteins, the structure and function of neurons. Primary cerebral cortex neurons of SD rats were cultured in vitro. Neurons were radiated 3 days by THz with frequency of 0.3-3THz and a power of 100μW; record the growth and development indicators of neurons (Cell body area, total length of process). At the end of a radiation programme, Western blotting was used to detect the protein expressions of GluA1, GluN1, postsynaptic density protein-95(PSD-95) and synaptophysin 38(SYP-38). After the first day of terahertz radiation, the increase in cell area increased by 144.9% (P<0.05); On the second and third days of terahertz radiation, the growth value of the total length of neuronal neurites increased by 65.1% (P<0.05) and 109.4% (P<0.05), respectively; Three days after terahertz irradiation, the protein expressions of GluA1 and SY-38 were increased by 38.1% (P<0.05) and 19.2% (P<0.05), respectively. The results show that (1)The use of Low intensity of broadband terahertz in this study will not cause the death of cortical neurons, and will not affect their growth regularity;(2)Low intensity of broadband terahertz radiation. can promote the growth of cortical neuron cell bodies and processes, but the effects on cortical neuron cell bodies and processes are different. This may be related to the developmental cycle of cultured cortical neurons in vitro, and there is a cumulative effect on the promotion of neuronal processes by low intensity of broadband terahertz;(3) The promotion of neuronal growth and development by low intensity of broadband terahertz radiation may be related to the proportion of AMPA receptor subtypes and the expression of presynaptic specific protein SY-38. These results herald specific frequencies and energies of terahertz radiation as a novel neuromodulation technology for the treatment or intervention of diseases such as neurodevelopmental disorders.

High Frequency Electromagnetic Radiation Stimulates Neuronal Growth and Hippocampal Synaptic Transmission

“…In addition, there was a strong correlation between the effect of terahertz radiation on neuronal growth and the developmental cycle in which the neuron was located. However, the terahertz waves’ effect on neuronal growth and development was not significant when neurons were in a slow developmental state [ 38 ]. It has been shown that in vitro cultured neurons grow slowly at 6–24 h after inoculation, and during the latency period neurons undergo apposition and adaptation to their environment.…”

“…No existing studies have clarified the mechanism by which terahertz waves regulate dynamic neuronal growth, but some studies have reported that terahertz radiation can alter gene expression associated with neuronal growth at the molecular level [ 23 ]. Other studies have reported that terahertz radiation can alter the proportional size of AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) receptor isoforms at the protein level [ 38 ], thus affecting the permeability of AMPA receptor channels to Ca 2+ [ 49 ]. Neuronal growth is correlated with intracellular Ca 2+ concentration, where higher or lower concentrations prevent neuronal protrusions from growing while appropriate Ca 2+ concentrations promote continuous protrusion growth [ 50 ].…”

“…This hypothesis is supported by several studies in which terahertz radiation decreased the inhibitory neurotransmitter GABA content in the neurons and increased the excitatory neurotransmitter Glu’s concentration [ 23 ]. In terms of changes in the number of receptors, it has been found that the number of AMPA receptors increased after terahertz radiation [ 38 ]. We also found that the slope of postsynaptic potentials in the CA1 region was correlated with the terahertz radiation time.…”

“…Thus, the increase in the PSP slope after terahertz radiation may be caused by an increase in the proportion of AMPA receptor-mediated PSP. Moreover, it has been found that the number of AMPA receptors increased significantly after terahertz radiation, but the number of NMDA receptors did not change significantly [ 38 ]. This finding corroborates our hypothesis about the slope of PSP after terahertz radiation.…”

“…Firstly, to ensure that the neurons recorded were terahertz-radiated each time, and to find the same neuron quickly and efficiently, we drew two marker lines on the Petri dishes which intersected at the center of the dishes. Images were taken of neuronal growth and development in four quadrants, with the center of the Petri dishes as a right-angle coordinate system [ 38 ]. Next, we selected images with a clear background and low neuronal density (where the cell and protrusions of individual neurons were visible and not connected to other neurons).…”