Introduction: Increasing evidence suggests that changes in the balance of excitatory/inhibitory neurotransmission are involved in the development of the majority of chronic pain forms. In this context, impairment in glycine mediated inhibitory neurotransmission is thought to play a critical role in the disinhibition that accounts for the development and maintenance of central pain hypersensitivity. Aims:The goal of this study was to evaluate the glycine receptor α3 subunit (α3GlyR) expression in neuropathic (Chronic Constriction Injury, CCI) and inflammatory (Zymosan A injected) animal models of chronic pain. Results and Conclusion:RT-qPCR analysis of spinal cord samples showed that glra3 gene expression does not change after 3 days of CCI and 4 hours of Zymosan. A injection. However, we found that protein levels evaluated by Western blot increased after inflammatory pain. These data suggest that central sensitization is differentially regulated depending on the type of pain.