Fig. 7

Strength duration relationships-comparison of thresholds in TRPV1 transfected HEK cells and DRG neurons. a 50% responder thresholds of DRG neurons (open) and transfected HEK cells (filled symbols) measured as laser power (mW) as a function of stimulus duration (ms). The hyperbolic fit suggests that thresholds may be expressed as a constant stimulus energy. The rheobase of the fitted function was calculated as 23.7 mW (dashed line). b 50% responder thresholds calculated as applied laser energy (mJ) plotted as a function of stimulus duration (ms). The rising linear function indicates loss of energy at the stimulation spot due to lateral thermal diffusion