Chronic exposure to 2.45 GHz microwave radiation improves cognition and synaptic plasticity impairment in vascular dementia model

Abstract

<b>Purpose:</b> In this study, we evaluated the effects of 2.45 GHz microwave radiation on cognitive dysfunction induced by vascular dementia (VaD).<b>Methods:</b> The VaD was induced by bilateral-common carotid occlusion (2-VO). The rats were divided into 4 groups including: control (<i>n</i> = 6), sham (<i>n</i> = 6), 2-VO (<i>n</i> = 8), and 2-VO + Wi-Fi (<i>n</i> = 10) groups. Wi-Fi modem centrally located at the distance of 25 cm from the animal's cages and the animals were continuously exposed to Wi-Fi signal while they freely moved in the cage (2 h/day for forty-five days). Therefore, the power density (PD) and specific absorption rate value (SAR) decreased at a distance of 25 to 60 cm (PD = 0.018 to 0.0032 mW/cm², SAR = 0.0346 to 0.0060 W/Kg). The learning, memory, and hippocampal synaptic-plasticity were evaluated by radial arm maze (RAM), passive avoidance (PA), and field-potential recording respectively. The number of hippocampal CA1 cells was also assessed by giemsa staining.<b>Results:</b> Our results showed that VaD model led to impairment in the spatial learning and memory performance in RAM and PA that were associated with long-term potentiation (LTP) impairment, decrease of basal-synaptic transmission (BST), increase of GABA transmission, and decline of neurotransmitter release-probability as well as hippocampal cell loss. Notably, chronic Wi-Fi exposure significantly recovered the learning-memory performance, LTP induction, and cell loss without any effect on BST.<b>Conclusions:</b> The LTP recovery by Wi-Fi in the 2-VO rats was probably related to significant increases in the hippocampal CA1 neuronal density, partial recovery of neurotransmitter release probability, and reduction of GABA transmissiSon as evident by rescue of paired-pulse ratio 10 ms.