Epidermal Laser Stimulation of Action Potentials in the Frog Sciatic Nerve

Measurements of laser stimulated action potentials in the sciatic nerve of leopard frogs Rana pipiens were made using two infrared lasers. The dorsal sides of the frogs hind limbs were exposed to short-pulsed 1540 nm and 1064 nm wavelengths at three separate spot sizes 2 mm, 3 mm, and 4 mm. Energy density thresholds were determined for eliciting an action potential at each experimental condition. Results from these exposures showed similar evoked potential thresholds for both wavelengths. The 2-mm diameter spot sizes yielded action potentials at irradiance levels almost double that seen with the larger beam sizes.