Animal models of chronic pain: Advances and challenges for clinical translation

Abstract

Chronic pain is a global problem that has reached epidemic proportions. An estimated 20% of adults suffer from pain, and another 10% are diagnosed with chronic pain each year (Goldberg and McGee, ). Despite the high prevalence of chronic pain (an estimated 1.5 billion people are afflicted worldwide), much remains to be understood about the underlying causes of this condition, and there is an urgent requirement for better pain therapies. The discovery of novel targets and the development of better analgesics rely on an assortment of preclinical animal models; however, there are major challenges to translating discoveries made in animal models to realized pain therapies in humans. This review discusses common animal models used to recapitulate clinical chronic pain conditions (such as neuropathic, inflammatory, and visceral pain) and the methods for assessing the sensory and affective components of pain in animals. We also discuss the advantages and limitations of modeling chronic pain in animals as well as highlighting strategies for improving the predictive validity of preclinical pain studies. © 2016 Wiley Periodicals, Inc.

Neuropathic pain

“…Nonetheless, a substantial part of our knowledge of neuropathic pain mechanisms is derived from animal studies. Animal models of neuropathic pain use surgical lesions of the spinal cord, cranial and peripheral sensory nerves, such as ligation, constriction or transection of parts or branches of nerves 198 . These animal models exhibit hypersensitivity to external stimuli, commonly to mechanical stimuli as assessed with von Frey hairs (for measuring the tactile sensitivity), but may also include hypersensitivity to thermal stimuli (especially cold).…”

Antinociceptive Effects of a Novel α2/α3-Subtype Selective GABAA Receptor Positive Allosteric Modulator

“…Some argue that the low success rate in the discovery of new analgesics could be partially due to the poor translation of existing animal models of pain 8, 9 . For example, most studies of pain only use pain-stimulated behaviors such as tail flick or paw withdrawal.…”

Nitroxidative Signaling Mechanisms in Pathological Pain

“…intraplantar complete Freund’s adjuvant (CFA), formalin) and neuropathic pain (e.g. peripheral nerve injury (PNI), chemotherapy-induced peripheral neuropathy (CIPN), diabetic neuropathy (DN), spinal cord injury (SCI), experimental autoimmune encephalomyelitis (EAE)), which have recently been reviewed elsewhere [12]. There are numerous endogenous sources of ROS and nitric oxide (NO) that are engaged during pain processing [13].…”