Neurite growth acceleration of adult Dorsal Root Ganglion neurons illuminated by low-level Light Emitting Diode light at 645 nm

The effect of a 645 nm Light Emitting Diode (LED) lightirradiation on the neurite growth velocity of adult DorsalRoot Ganglion (DRG) neurons with peripheral axon in-jury 4–10 days before plating and without previous injurywas investigated. The real amount of light reaching theneurons was calculated by taking into account the opticalcharacteristics of the light source and of media in the lightpath. The knowledge of these parameters is essential tobe able to compare results of the literature and a way toreduce inconsistencies. We found that 4 min irradiation ofa mean irradiance of 11.3 mW/cm