In experiment 2 intradermal Botox will be given in corrugator (one site) and frontalis (two sites) muscles on one side and placebo to the other side. I.d. capsaicin injection will be given to both sides (between the two sites of frontalis injection horizontally). Capsaicin-induced pain intensity and flare together with the area of hypersensitivity to different stimulus modalities will be measured and mapped at specific time points using different cutaneous stimuli (thermal, electrical, tactile, pressure). This will characterize which fibres and receptors are affected by Botox. The effect of intradermal Botox will be compared to the results of experiment 1.