Fig. 2

Schematic diagram of changes in rat behavior in response to graded CRD based on abdominal withdrawn reflex (AWR) scores (revised according to Al-Chaer et al. [22]). 0 No behavior response to CRD; 1 brief head or body movement at the onset of stimulus; 2 contraction of the abdominal muscles, but no lifting off the platform; 3 a strong contraction of the abdominal muscles and lifting off the platform, but no lifting the pelvic structure off the platform; 4 a severe contraction of the abdominal muscles based on body arching and lifting of the pelvic and scrotum. Arrows in panels indicate lifting of the abdomen