I am a
Home I AM A Search Login

Papers of the Week

Papers: 23 Sep 2023 - 29 Sep 2023

Basic Science, Sex/Gender/Race

Animal Studies, Molecular/Cellular, Neurobiology, Sex Differences

Abdominal/Pelvic Pain, Inflammation/Inflammatory, Orofacial/Head Pain, Psychological/Comorbidities

2023 Sep 27



Editor's Pick

Sex differences in visceral sensitivity and brain activity in a rat model of comorbid pain: a longitudinal study.


Da Silva JT, Hernandez-Rojas LG, Mekonen HK, Hanson S, Melemedjian O, Scott AJ, Ernst RK, Seminowicz DA, Traub RJ


Temporomandibular disorder (TMD) and irritable bowel syndrome (IBS) are 2 chronic overlapping pain conditions (COPCs) that present with significant comorbidity. Both conditions are more prevalent in women and are exacerbated by stress. While peripheral mechanisms might contribute to pain hypersensitivity for each individual condition, mechanisms underlying the comorbidity are poorly understood, complicating pain management when multiple conditions are involved. In this study, longitudinal behavioral and functional MRI-based brain changes have been identified in an animal model of TMD-like pain (masseter muscle inflammation followed by stress) that induces de novo IBS-like comorbid visceral pain hypersensitivity in rats. In particular, data indicate that increased activity in the insula and regions of the reward and limbic systems are associated with more pronounced and longer-lasting visceral pain behaviors in female rats, while the faster pain resolution in male rats may be due to increased activity in descending pain inhibitory pathways. These findings suggest the critical role of brain mechanisms in chronic pain conditions and that sex may be a risk factor of developing COPCs.