Effect of polychromatic polarized light on afferent traffic in skin branches of somatic nerves

Short-term irradiation of rat hind limb with polychromatic polarized light at 400-2000 nm produces a long-term inhibition of baseline afferent traffic in n. saphenus, while nonpolarized light produces biphasic changes in baseline activity: transient activation is followed by long-term inhibition of discharges in the nerve. Subcutaneous injection of sodium nitroprusside (10 mug/ml) with subsequent irradiation of the hind limb with polarized light significantly increased afferent activity in the sciatic nerve and n. saphenus, which attests to involvement of nitric oxide in activation of cutaneous nerve terminals during irradiation with polarized light.