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Low-power (non-thermal) infrared (IR) radiation with the wavelength of 10.6 μm activates the Na,K-ATPase transducer function in sensory neurons, which is manifested in decrease of NaV1.8 channel voltage sensitivity at the cellular membrane level and in inhibition of growth of chick embryo dorsal root ganglia neurites at the tissue level. It is shown that the effect of low-power IR radiation is totally blocked by a specific Src kinase inhibitor, PP2. Upon irradiation on the background of PP2, the effective charge of NaV1.8 channel activation gating system does not differ from its control value in patch-clamp experiments, and the area index of sensory ganglia neurites growth remains unchanged as compared with the control in organotypic tissue culture. The data obtained demonstrate that Src kinase is involved in intracellular signaling pathways triggered by CO2 laser low-power IR radiation by the transducer-activated mechanism. This is the first indication that in primary sensory neuron the signals of low-power IR radiation are sensed, amplified, and transduced by the Na,K-ATPase/Src complex and not by G proteins.

The role of the temperature factor in the mechanism of reception of the CO2 laser low-power infrared (IR) radiation (λ = 10.6 μm) by a sensory neuron membrane has been studied. Organotypic embryonic tissue culture has been used to measure and estimate the temperature of a sensory ganglia monolayer exposed to radiation at different energy densities. The effects of tissue exposure to low-power IR radiation have been investigated. It has been found that inhibition of tissue growth by radiation of low energy density (10–14–10–10 J/cm2) is replaced by tissue growth (10–7–10–4 J/cm2), and again followed by inhibition in the range of 0.1–6 J/cm2. A statistically significant specific reaction to nonthermal radiation has been detected at the radiation power density of 3 × 10–10 J/cm2, which is due to activation of the Na+,K+-ATPase transducer function. The mechanisms of interaction of IR radiation with embryonic nerve tissue have been considered. Low-power IR radiation with the wavelength of 10.6 μm has been demonstrated to specifically activate a novel signal transducer function of the sodium pump, which controls the reception of nonthermal IR radiation in the energy density range of 10–14 to 10–10 J/cm2.

The patch-clamp technique has been used to demonstrate that low-intensity IR irradiation affects the effective charge of the activation gating system of slow sodium channels in the nociceptive neuron membrane. IR photons are absorbed by ATP molecules bound to Na+,K+-ATPase at their hydrolysis site. Na+,K+-ATPase is a transducer of signal that is further delivered to slow sodium channels and cell genome. It is demonstrated that the irradiation does not modulate the response of a sensory neuron in the presence of PP2, an inhibitor of Src-kinase. The results show that Src-kinase is a series unit involved in the intracellular cascade processes triggered by low-intensity radiation of CO2 laser.

Effects of infrared (IR) radiation generated by a low-power Co2-laser on sensory neurons of chick embryos were investigated by organotypic culture method. Low-power IR radiation firstly results in marked neurite suppressing action, probably induced by activation of Na+,K+-ATPase signal-transducing function. A further increase in energy of radiation leads to stimulation of neurite growth. We suggest that this effect is triggered by activation of Na+,K+-ATPase pumping function. Involvement of Na+,K+-ATPase in the control of the transduction process was proved by results obtained after application of ouabain at very low concentrations. Physiological significance of low-power IR radiation and effects of ouabain at nanomolar level was investigated in behavioral experiments (formalin test). It is shown that inflammatory pain induced by injection of formalin is relieved both due to ouabain action and after IR irradiation.

Effects of infrared (IR) radiation generated by a low-power CO2-laser on the membrane of cultured dissociated nociceptive neurons of newborn rat spinal ganglia were investigated using the whole-cell patch-clamp method. Low-power IR radiation diminished the voltage sensitivity of activation gating machinery of slow sodium channels (Na(v)1.8). Ouabain known to block both transducer and pumping functions of Na+,K+-ATPase eliminated IR irradiation effects. The molecular mechanism of interaction of CO2-laser radiation with sensory membrane was proposed. The primary event of this interaction is the process of energy absorption by ATP molecules. The transfer of vibrational energy from Na+,K+- ATPase-bound and vibrationally excited ATP molecules to Na+,K+-ATPase activates this enzyme and converts it into a signal transducer. This effect leads to a decrease in the voltage sensitivity of Na(v)1.8 channels. The effect of IR-radiation was elucidated by the combined application of a very sensitive patch-clamp method and an optical facility with a controlled CO2-laser. As a result, the mechanism of interaction of non-thermal low-power IR radiation with the nociceptive neuron membrane is suggested.

We have built a wavelength-tunable CO2 laser meeting the requirements for low-intensity laser therapy. At λ = 10.57 μm and 9.24 μm, we observe a physiological effect detectable from the change in the extent of neurite outgrowth from sensory neurons. This makes it possible to study molecular mechanisms for interaction of low-intensity radiation with tissues in a living body. The ATP molecule is considered as the specific molecular target for the action of the radiation.

The results of an experimental research of action of the intensive mid IR-range pulse-periodic laser radiation on VO2-mirrors are represented. The damage thresholds of VO2-mirrors are defined for pulse-periodic and continuous radiation and the analysis of the mechanism of their destruction is carried out. The results of numerical simulation of dynamics of switching of VO2-mirrors under the action of pulse-periodic radiation are presented.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The present work is the further evolution of our studies on wide-angle intracavity beaming in 3-10.6-micron gas lasers by space-time light modulators.

The possibility of the effective induction of human platelet aggregation by CO 2 -laser radiation has been experimentally stated. Radiation parameters required for the aggregation induction have been estimated. A mechanism of platelet activation influenced by radiation has been under discussion.

It has been found, that the main process, responsible for the frequency shift of hybrid C02-electron beamlaser (EBL) generation with a pulse duration of more than 10 1us is the thermal self-action of radiation. The possibilities of frequency shift decreasing at the expense of sell-action decay by active medium optimization are demonstrated.1. Introduction. The thermal self-action (TSA) of radiation is one of the processes, that produces the optical unhomogemties in the active medium (AM) of high-powered C02 lasers and causes the frequency shift of generation. Amongmany factors which dictate the character of AM disturbance, the laser pulse duration r plays a significant role. If r thechange of the sign of the thermal gradient in AM at the boundaries of laser beam takes