Validation and additional support for an experimental animal model of fibromyalgia

Abstract Objectives. In the current study, we have evaluated the intermittent cold stress (ICS) induction in mice, in order to validate and optimize its utility as a fibromyalgia-like model. Methods. Twenty-four mice of 5-week old, female Swiss, weighing 18-22 g were used for the experiments. These mice were divided into three groups of eight animals per group [health control group (control), ICS group (ICS), and Gabapentin group (GBP)]. When in-vivo tests were completed, we proceeded to isolation and culture of peritoneal macrophages in order to determine the effects of the ICS on the release of proinflammatory mediators. Results. The results showed that this model is suitable to induce mechanical allodynia, thermal allodynia, and hyperalgesia. It is also able to reproduce behavioral changes related to cognitive disturbances, anxiety, and depression. Besides, ICS model might increase the inflammatory response in LPS-macrophages stimulated from stressed mice. Conclusions. Our results show that ICS is a useful animal model to assess hypothesis about underlying mechanisms involved in the development of fibromyalgia as well as to evaluate possible future therapies.