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Sotocinal SG, Sorge RE, Zaloum A et al. (2011). The Rat Grimace Scale: a partially automated method for quantifying pain in the laboratory rat via facial expressions. Molecular Pain 7: 55. doi:10.1186/1744-8069-7-55

Read the original training manual

Rat Grimace Scale (RGS): The Manual

Read papers that validate or use this technique

Chi H, Kawano T, Tamura T et al. (2013). Postoperative pain impairs subsequent performance on a spatial memory task via effects on N-methyl-D-aspartate receptor in aged rats. Life Sciences 93(25-26): 986-993. doi:10.1016/j.lfs.2013.10.028

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Miller AL, Golledge HDR and Leach MC (2016). The influence of isoflurane anaesthesia on the Rat Grimace Scale. PLOS ONE 11(11): e0166652. doi.org/10.1371/journal.pone.0166652

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Saine L, Hélie P and Vachon P (2016). Effects of fentanyl on pain and motor behaviors following a collagenase-induced intracerebral hemorrhage in rats. Journal of Pain Research 9: 1039-1048. doi:10.2147/JPR.S121415

Schneider LE, Henley KY, Turner OA et al. (2016). Application of the rat grimace scale as a marker of supraspinal pain sensation after cervical spinal cord injury. Journal of Neurotrauma 34(21): 2982-2993. doi:10.1089/neu.2016.4665

Long H, Liao L, Zhou Y et al. (2017). A novel technique of delivering viral vectors to trigeminal ganglia in rats. European Journal of Oral Sciences 125(1): 1-7. doi:10.1111/eos.12326

Philips BH, Weisshaar CI and Winkelstein BA (2017). Use of the rat grimace scale to evaluate neuropathic pain in a model of cervical radiculopathy. Comparative medicine 67(1): 34-42. doi:1484259021557

Jeger V, Arrigo M, Hildenbrand FF et al. (2017). Improving animal welfare using continuous nalbuphine infusion in a long-term rat model of sepsis. Intensive Care Medicine Experimental 5(1): 23. doi:10.1186/s40635-017-0137-2

Yamanaka D, Kawano T, Nishigaki A et al. (2017). The preventive effects of dexmedetomidine on endotoxin-induced exacerbated post-incisional pain in rats. Journal of Anesthesia 31(5): 664-671. doi:10.1007/s00540-017-2374-7

Gao Z, Cui F, Cao X et al. (2017). Local infiltration of the surgical wounds with levobupivacaine, dexibuprofen, and norepinephrine to reduce postoperative pain: A randomized, vehicle–controlled, and preclinical study. Biomedicine & Pharmacotherapy 92: 459-467. doi:10.1016/j.biopha.2017.05.038

Senko T, Olexova L, Mokosakova M et al. (2017). Angiotensin II enhancement during pregnancy influences the emotionality of rat offspring (Rattus norvegicus) in adulthood. Potential use of the Rat Grimace Scale. Neuro Endocrinology Letters 38(2): 117-123. PMID: 28650605

Akintola T, Raver C, Studlack P et al. (2017). The grimace scale reliably assesses chronic pain in a rodent model of trigeminal neuropathic pain. Neurobiology of Pain 2: 13-17. doi:10.1016/j.ynpai.2017.10.001

Guo P and Hu SP (2017). Thalidomide alleviates postoperative pain and spatial memory deficit in aged rats. Biomedicine & Pharmacotherapy 95: 583-588. doi:10.1016/j.biopha.2017.08.114

Khoo SY, Lay BP, Joya J et al. (2018). Local anaesthetic refinement of pentobarbital euthanasia reduces abdominal writhing without affecting immunohistochemical endpoints in rats. Laboratory animals 52(2): 152-162. doi:10.1177/0023677217721260

Fujita M, Fukuda T, Sato Y et al. (2018). Allopregnanolone suppresses mechanical allodynia and internalization of neurokinin-1 receptors at the spinal dorsal horn in a rat postoperative pain model. Korean Journal of Pain 31(1): 10-15. doi:10.3344/kjp.2018.31.1.10

Sperry MM, Yu YH, Welch RL et al. (2018). Grading facial expression is a sensitive means to detect grimace differences in orofacial pain in a rat model. Scientific Reports 8(1): 13894. doi:10.1038/s41598-018-32297-2

Chaves RHF, Souza CC, Furlaneto IP et al. (2018). Influence of tramadol on functional recovery of acute spinal cord injury in rats. Acta Cirúrgica Brasileira 33(12): 1087-1094. doi:10.1590/s0102-865020180120000006

Cheng Y, Huang P, Meng B et al. (2018). Antinociceptive effects of the adenylyl cyclase inhibitor ST034307 on tooth-movement-induced nociception in rats. Archives of Oral Biology 98: 81-86. doi:10.1016/j.archoralbio.2018.11.012

de Barros Silva PG, de Lima Martins JO, de Lima Praxedes Neto RA et al. (2019). Tumor necrosis factor alpha mediates orofacial discomfort in an occlusal dental interference model in rats: the role of trigeminal ganglion inflammation. Journal of Oral Pathology and Medicine 49(2): 169-176. doi:10.1111/jop.12984

Wilkinson CM, Kalisvaart ACJ, Kung TFC et al. (2019). The collagenase model of intracerebral hemorrhage in awake, freely moving animals: the effects of isoflurane. Brain Research 6: 146593. doi:10.1016/j.brainres.2019.146593

Nagakura Y, Miwa M, Yoshida M et al. (2019). Spontaneous pain-associated facial expression and efficacy of clinically used drugs in the reserpine-induced rat model of fibromyalgia. European Journal of Pharmacology 864: 172716. doi:10.1016/j.ejphar.2019.172716

George RP, Howarth GS and Whittaker AL (2019). Use of the Rat Grimace Scale to evaluate visceral pain in a model of chemotherapy-induced mucositis. Animals (Basel) 9(9). doi:10.3390/ani9090678

Shinozuka K, Tajiri N, Ishikawa H et al. (2019). Empathy in stroke rats is modulated by social settings. Journal of Cerebral Blood Flow and Metabolism 271678X19867908. 0.1177/0271678X19867908

Harikrishnan VS, Krishnan LK and Abelson KSP (2019). A novel technique to develop thoracic spinal laminectomy and a methodology to assess the functionality and welfare of the contusion spinal cord injury (SCI) rat model. PLOS One 14(7): e0219001. doi:10.1371/journal.pone.0219001

Klune CB, Larkin AE, Leung VSY et al. (2019). Comparing the Rat Grimace Scale and a composite behaviour score in rats. PLOS One 14(5): e0209467. doi:10.1371/journal.pone.0209467

Leung VSY, Benoit-Biancamano MO and Pang DSJ (2019). Performance of behavioral assays: the Rat Grimace Scale, burrowing activity and a composite behavior score to identify visceral pain in an acute and chronic colitis model. Pain Reports 4(2): e718. doi:10.1097/PR9.0000000000000712

Uddin O, Studlack PE, Parihar S et al. (2019). Chronic pain after blast-induced traumatic brain injury in awake rats. Neurobiology of Pain 6: 100030. doi:10.1016/j.ynpai.2019.100030

Akintola T, Tricou C, Raver C et al. (2019). In search of a rodent model of placebo analgesia in chronic orofacial neuropathic pain. Neurobiology of Pain 6: 100033. doi:10.1016/j.ynpai.2019.100033

Koyama T, Kawano T, Iwata H et al. (2019). Acute postoperative pain exacerbates neuroinflammation and related delirium-like cognitive dysfunction in rats. Journal of Anesthesia 33(3): 482-486. doi:10.1007/s00540-019-02635-3

Guo R, Zhou Y, Long H et al. (2019). Transient receptor potential Vanilloid 1-based gene therapy alleviates orthodontic pain in rats. International Journal of Oral Science 11(1): 11. doi:10.1038/s41368-019-0044-3

Zhang EQ, Leung VS and Pang DS (2019). Influence of rater training on inter- and intrarater reliability when using the rat grimace scale. Journal of the American Association for Laboratory Animal Science 58(2): 178-183. doi:10.30802/AALAS-JAALAS-18-000044