Electromagnetic millimeter wave induced hypoalgesia: Frequency dependence and involvement of endogenous opioids

Abstract

Millimeter wave treatment (MMWT) is based on the systemic biological effects that develop following local skin exposure to low power electromagnetic waves in the millimeter range. In the present set of experiments, the hypoalgesic effect of this treatment was analyzed in mice. The murine nose area was exposed to MMW of "therapeutic" frequencies: 42.25, 53.57, and 61.22 GHz. MMWT-induced hypoalgesia was shown to be frequency dependent in two experimental models: (1) the cold water tail-flick test (chronic non-neuropathic pain), and (2) the wire surface test (chronic neuropathic pain following unilateral constriction injury to the sciatic nerve). Maximum hypoalgesic effect was obtained when the frequency was 61.22 GHz. Other exposure parameters were: incident power density = 13.3 mW/cm(2), duration of each exposure = 15 min. Involvement of delta and kappa endogenous opioids in the MMWT-induced hypoalgesia was demonstrated using selective blockers of delta- and kappa-opioid receptors and the direct ELISA measurement of endogenous opioids in CNS tissue. Possible mechanisms of the effect and the perspectives of the clinical application of MMWT are discussed.

Effects of 60-GHz millimeter waves on neurite outgrowth in PC12 cells using high-content screening

“…Hypoalgesia is the most reported and the only reproducible effect of MMW exposure on animal models or on human volunteers using wellcontrolled blind experimental conditions [9][10][11]. The involvement of the opioid system, triggered by the peripheral nervous system was previously shown [12]. As MMW penetration in the skin is very limited (i.e.…”

“…As MMW penetration in the skin is very limited (i.e. between a few tenth to 1 mm in the therapeutic range (42 -62 GHz) [13,14]), the hypothesis of the activation of free nerve endings from the epidermis and upper dermis by MMW has been proposed [12]. The physiology of the nervous system involves a large panel of cellular processes such as proliferation, migration, differentiation, synaptogenesis and programmed cell death.…”

Millimeter wave radiation induces apoptosis via affecting the ratio of Bax/Bcl-2 in SW1353 human chondrosarcoma cells

“…The power density of this therapy used in medicine varies from 1 to 10 mw/cm 2 , and is applied in experimental and clinical oncology (3,4). While it is well established that at high power densities, millimeter wave radiation induces thermal increase on the exposed biosystems whose mechanisms could be non-thermal and of resonant nature or at least frequency-specific (5).…”

THz in biology and medicine: toward quantifying and understanding the interaction of millimeter- and submillimeter-waves with cells and cell processes

“…Radiant heating of the cells failed to reproduce the effect. Finally, in a set of experiments on mouse skin receptors, the tail flick response was observed to decrease with millimeter wave exposure [15,16] in contrast to simple heating.…”

“…Civilian Federal Agencies, very few research groups are willing to undertake these studies. Several investigations [4][5][6][7][8][9][10][11][12][13][14][15][16], mainly outside the U.S., have noted significant impact on neuronal activity from modest level millimeter wave exposures (40-130 GHz, 1-100 mW/cm 2 , seconds to minutes) that are not much higher than the Federal Communications Commission-established maximum permissible exposure (MPE) limits of 1 mW/cm 2 for 6 minutes in the 30-300 GHz frequency regime [17]. Synchronization of the firing rate of neurons in the hypothalamus of both rabbit and rat was observed at and below 10 mW/cm 2 [4,5].…”