Heat hyperalgesia following partial sciatic ligation in rats: interacting nature and nurture.

As in humans, levels of neuropathic pain produced by nerve injury are highly variable among animals. This variability was attributed to genetic and environmental factors. For example, we reported that chronic neuropathic sensory disorders developing following total (autotomy) or partial nerve injury (allodynia and hyperalgesia) depended on the diet rats consumed. Here we investigated the interaction between genetic and dietary factors in the development of heat hyperalgesia in rats following partial sciatic ligation (the PSL model). We show that heat sensitivity of intact rats and levels of heat hyperalgesia of PSL-injured rats were highly variable across eight different rat strains and seven different diets. Thus, genetic and environmental variables interact in determination of levels of chronic neuropathic sensory disorders in rats.