Preoperative open field behavior predicts levels of neuropathic pain-related behavior in mice

Exploratory open field (OF) activity was assessed in seven different mouse strains and selection lines. We counted the number of beam interruptions made by three cagemate mice at a time. This assay tests reactivity to aversive stimuli, anxiety and emotionality. One hindlimb was then totally denervated by transecting the sciatic and saphenous nerves on one side, and autotomy, a behavior thought to be related to neuropathic pain, was quantified over 35 days. We report that OF activity and autotomy are highly variable across different strains/lines. These results reaffirm the genetic control of these behaviors. We also found that these behaviors are inversely and significantly correlated. We suggest that common genetically-determined neural mechanisms may underlie anxiety, emotionality and neuropathic pain in mice.