The Expression of Glycine Receptor α3 Subunit is Differentially Regulated in Different Types of Pain

Abstract

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.

Spinal Glycine Receptor Alpha 3 Cells Communicate Sensations of Chemical Itch in Hairy Skin

“…In addition to the expression in the spinal cord, Glra3 is detected in the amygdala, hypothalamus, nucleus accumbens, tegmentum, and brainstem, but not in the dorsal root ganglia (DRG; Lein et al, 2007 ; Usoskin et al, 2015 ; McCracken et al, 2017 ; Häring et al, 2018 ; Tudeau et al, 2020 ; San Martin et al, 2021 ; Groemer et al, 2022 ). Expression analyses have shown that spinal cord injury decreases levels of GLRA3 in the dorsal spinal cord, whereas zymosan A-induced inflammation increases GLRA3 levels ( Berrocal et al, 2014 ; Mariqueo, 2020 ). Additionally, in an endometriosis mouse model, Glra3 expression was found to be upregulated in the insula ( Li et al, 2018 ), emphasizing this receptor subunit's role in pain and its potential as a novel pain treatment.…”