Evaluation of Spontaneous Pain in a Monosodium Iodoacetate-Induced Mouse Model of Osteoarthritis Using the Mouse Grimace Scale

Authors

• Mohammed Alnoud, The University of Texas Rio Grande Valley School of MedicineFollow
• Jose A. Rivera, The University of Texas Rio Grande Valley School of MedicineFollow
• Megan W. Szobody, The University of Texas Rio Grande Valley School of MedicineFollow
• Ayesha Usman, The University of Texas Rio Grande Valley School of MedicineFollow
• Alma Rodriguez, The University of Texas Rio Grande Valley School of Medicine
• Thao-April Nguyen
• Seryna Ayala
• Massimo Salinas
• Khalid Benamar, The University of Texas Rio Grande Valley School of MedicineFollow

Document Type

Article

Publication Date

9-18-2026

Abstract

Animal models are critical for elucidating disease mechanisms and pathological outcomes, and for evaluating therapeutic interventions. Osteoarthritis (OA) is a leading cause of chronic pain and disability globally. Clinically, individuals with OA experience both sensory and ongoing pain. However, ongoing pain, as assessed by the Mouse Grimace Scale (MGS), has not yet been evaluated in animal models of OA. This study aims to address this significant knowledge gap. We induced OA by intra-articular injection of monosodium iodoacetate (MIA), while control mice received saline injections. We assessed pain behaviors using the MGS on days 1, 3, 7, and 14 after MIA administration. MIA-treated mice exhibited significantly higher MGS scores than saline-treated controls throughout the study period, indicating ongoing pain-related behavior in the MIA OA model. Furthermore, longitudinal studies showed that this pain is chronic, as seen in people with OA. These findings support the usefulness of the MGS test in the MIA model for studying ongoing pain.

Comments

© 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.

Recommended Citation

Alnoud, Mohammed, Jose Rios, Megan W. Szobody, Ayesha A. Usman, Alma Rodriguez, Thao-April Nguyen, Seryna Ayala, Ayaan S. Quraishi, Massimo Salinas, and Khalid Benamar. 2026. "Evaluation of Spontaneous Pain in a Monosodium Iodoacetate-Induced Mouse Model of Osteoarthritis Using the Mouse Grimace Scale" Biomedicines 14, no. 9: 2114. https://doi.org/10.3390/biomedicines14092114

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Biomedicines

DOI

10.3390/biomedicines14092114

Academic Level

faculty

Mentor/PI Department

Neuroscience