Search for frequency-specific effects of millimeter-wave radiation on isolated nerve function
- Army Medical Research Detachment of the Walter Reed Army Inst. of Research, Brooks AFB, TX (United States). Microwave Bioeffects Branch
- McKesson BioServices, Brooks AFB, TX (United States)
Effects of a short-term exposure to millimeter waves on the compound action potential (CAP) conduction were studied in an isolated frog sciatic nerve preparation. CAPs were evoked by either a low-rate or a high-rate electrical stimulation of the nerve. The low-rate stimulation did not alter the functional state of the nerve, and the amplitude, latency, and peak latency of CAPs could stay virtually stable for hours. Microwave irradiation for 10--60 min at 0.24--1.5 mW/cm{sup 2}, either at various constant frequencies or with a stepwise frequency change, did not cause any detectable changes in CAP conduction or nerve refractoriness. The effect observed under irradiation at a higher field intensity of 2--3 mW/cm{sup 2} was a subtle and transient reduction of CAP latency and peak latency along with a rise of the test CAP amplitude. These changes could be evoked by any tested frequency of the radiation; they reversed shortly after cessation of exposure and were both qualitatively and quantitatively similar to the effect of conventional heating of 0.3--0.4 C. The high-rate electrical stimulation caused gradual and reversible decrease of the amplitude of conditioning and test CAPs and increased their latencies and peak latencies. These changes were essentially the same with and without irradiation, except for attenuation of the decrease of the test CAP amplitude. This effect was observed at both field intensities, but was statistically significant only for certain frequencies of the radiation. Within the studied limits, this effect appeared to be dependent on the frequency rather than on the intensity of the radiation, but this observation requires additional experimental confirmation.
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States); Department of the Army, Washington, DC (United States)
- OSTI ID:
- 479387
- Journal Information:
- Bioelectromagnetics, Vol. 18, Issue 4; Other Information: PBD: 1997
- Country of Publication:
- United States
- Language:
- English
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