**6. Conclusion**

Certain limitations exist in the development of animal models that simulate human pathological conditions of pain. For instance, the most common clinical indication for SCS has become the treatment of intractable neuropathic pain of the lower back and legs, largely associated with failed surgical spine interventions (failed back surgery syndrome, FBSS), which causes axial back pain that radiates to the limbs in a unilateral or bilateral manner. The existing rat models of neuropathic pain, which are described in this chapter, are mostly peripherally induced (nerve injury) and test the manifestation of mechanical hypersensitivity in the paws, not necessarily in the leg of the animals. An animal model that resembles FBSS has yet to be developed. Such peripheral nerve injury models, however, resemble symptoms found in other pain-related syndromes such as complex regional pain syndrome (CRPS), which are also indicated for SCS treatment in humans. Despite these limitations, the existing models have proven extremely useful to understand the effects of various modalities of SCS on pain-like behavior of the animals, and more importantly, on the mechanistic understanding of SCS via the molecular analysis of samples obtained from neural tissues (spinal cord, DRG) that cannot be obtained in clinical assessments. Such molecular evaluations have made use of pharmacological approaches that use the coadministration of neurotransmitters agonists and antagonists, opioids, receptor blockers, etc., as well as immunohistochemical analysis

*Animal Pain Models for Spinal Cord Stimulation DOI: http://dx.doi.org/10.5772/intechopen.96403*

that target cellular markers of glial activation. Recent approaches are most robust and utilize high throughput transcriptomic and proteomic analysis in combination with many bioinformatic tools that provide an understanding of the effects of SCS on complex biological processes that involve a multitude of proteins and their encoding genes. These advancements should provide the field with tools to enhance current therapies and improvements on pain diagnostics that could ultimately lead to an integral and personalized treatment of painful conditions in humans. Animal models will continue to play a crucial role in the development of the science and technology of electrical neuromodulation for treating pain.
