Figure 1.

Graphical overview of the experimental procedure.

Notes: Included pain models (upper) and flowchart (lower) are illustrated. Included pain models were: 1) skin heat; 2) bone pressure; 3) muscle pressure; 4) visceral stimulations, and 5) the cold pressor test. Stimulations were applied in the indicated order (1 → 2 → 3 → 4 → 5) at baseline and 60 minutes after drug administration. Skin 1) and muscle 3) stimulations were performed at several time points (0, 15, 30, 60, and 150 minutes after drug administration). Blue bars on flowchart indicate duration of test battery. The full battery (1–5) lasted approximately 30 minutes. Skin and muscle stimulation lasted approximately 7 minutes in total.