First the animal was placed into a transparent Perspex cylinder (height 18 cm, Ø 15 cm) and observed regarding general activity, respiration and occurrence of tremor. Then the animal was transferred into a Makrolon IV cage (42630627 cm, Allentown) and deviations from normal palpebral closure, piloerection, gait, pelvic elevation, tail elevation, and positional passivity were recorded. Touch escape response was assessed by slowly approaching the mouse with a finger sideways and attempting to stroke it.