Table 1.
Effects of different microwave frequencies on brain.
| Ref. No. | Frequency | Study Type | Main Findings | Effects |
|---|---|---|---|---|
| [123] | 2.45 GHz | in vivo | Irradiated rats showed a significant decrease in spatial learning and memory performance. | Negative |
| [111] | 2.45 GHz | in vivo | Microwave exposure led to oxidative/nitrosative stress that induced p53 activation of hippocampal neuronal and nonneuronal apoptosis related to memory loss. | Negative |
| [124] | 0.9, 1.8, and 2.45 GHz | in vivo | Microwaves decreased cognitive functions while increasing HSP70 levels and DNA damage in the brain. | Negative |
| [105] | 2.45 and 16.5 GHz | in vivo | Microwave exposure caused DNA single-strand breaks. | Negative |
| [125] | 0.9 GHz | in vitro | No obvious changes were observed in promyelocytic leukemia (HL-60) and neuroblastoma (SK-N-SH) cell lines following microwave exposure. | Neutral |
| [98] | 0.935 GHz | in vitro | No effects in murine microglial (N9) and human neuroblastoma (SH-SY5Y) cells following microwave exposure. | Neutral |
| [126] | 0.9 GHz | in vitro | Increased apoptotic sub-G1 DNA content in human neuroblastoma (SH-SY5Y) cells. Short-term exposures induced a transient rise in Egr-1 mRNA levels, along with activating MAPK subtypes ERK1/2 and SAPK/JNK. | Negative |
| [127] | 0.8–0.9 GHz | in vivo | Microwave exposure led to significant epigenetic modulations in the hippocampus. | Negative |
| [128] | 2.856 GHz | in vivo | Rats exposed to 10 and 50 mW·cm-2 microwaves showed a significant decrease in spatial learning and memory, whereas 5 mW·cm-2 showed no change. | Negative |
| [93] | 2.856 GHz | in vivo | Phospholipid and triglyceride (TG) metabolisms were significantly modified in exposed rats. | Positive |
| [129] | 2.856 GHz | in vivo, in vitro |
Microwave exposure at 30 mW·cm-2 altered synaptic structure, amino acid release, and calcium influx. | Negative |
| [130] | 1.7 GHz | in vitro | No effects on human-adipose-tissue-derived stem cells (ASCs) or liver cancer stem cells (Huh7) following microwave exposure. | Neutral |
| [131] | 1.8 GHz | in vitro | Microwave exposure may have decreased the excitatory synaptic activity and the number of excitatory synapses in rat hippocampal neurons. | Negative |
| [132] | 1.8 GHz | in vivo | Hippocampi were injured by long-term microwave exposure, leading to the impairment of cognitive function owing to neurotransmitter disruption. | Negative |
| [133] | 1.8 GHz | in vitro | Microwave exposure at indicated frequencies during the early developmental stage may have influenced dendritic development and excitatory synapse formation in hippocampal neurons. | Negative |
| [94] | 1.8 GHz | in vitro | Microwave exposure significantly increased permeability for 14C-sucrose. | Positive |
| [134] | 1.9 GHz | in vitro | No significant changes were observed across three human-derived immune cell lines (HL-60, Mono-Mac-6, TK6) following microwave exposure. | Neutral |
| [95] | 0.8–1 GHz | in vitro | Microwave radiation exposure across a given frequency range may have induced a considerable survival adaptive response. | Positive |
| [135] | 1 GHz | in vitro | Microwave radiation did not influence efflux in rat brain tissue. | Neutral |
| [136] | 9.3 GHz | in vivo | Irradiation did not affect neuron ability, as no lasting or delayed effects were observed at the analyzed frequency. | Neutral |
| [69] | 50 GHz | in vivo | Microwave exposure caused DNA double-stranded breaks, and changed antioxidant enzymes in the neurological system due to free radical formation. | Negative |
| [96] | 5.8 GHz | in vivo | Microwave exposure did not show any obvious effects on the hippocampal synaptic plasticity of the selected rats at the indicated frequencies. | Neutral |
| [97] | 5.8 GHz | in vitro | Microwave exposure had little to no effect on DNA strand breaks, micronucleus formation, and Hsp expression in eye cells at the assessed frequencies. | Neutral |