Nonlinear photobiostimulation: The mechanism of visible and infrared laser-induced stimulation and reduction of neural excitability and growth

Non-linearity in photobiostimulation is described as a process where linear optical absorption produces activc chemicals such as cytoplasmic H^* and Ca² which participate in chemical reactions whose reaction rates depend non-linearly on the concentration of these photoproduccd active chemicals, thus allowing very sensitive light control of non-linear biological reactions. Important contributions to neural excitability and growth include photostimulation of ATP production which fuels the action potential and (ills the synaptic ATP vesicles. As was recently shown, the synaptic ATP plays the important role of an extracellular neurotransmitter. The importance of this effect on the possibility of systemic laser therapy of nervous disoders by photostimulation of ATP release by migrating macrophages is mentioned. The connection between light-enhanced electrical activity of the nerve and ncurite growth is also analysed.