Differential expression of glycine receptor subunit messenger RNA in the rat following spinal cord injury

Study design: Spinal cord injury (SCI) results in alterations in the regulation of many genes that may influence neuronal death and the subsequent loss of motor function and neuropathic pain. The subtype expression mRNA levels of glycine receptors (GlyRs) after SCI are unknown. Methods: Using real-time reverse transcription PCR, this study analyzed changes in the mRNA abundance of the four major GlyR subunits (alpha 13 and beta) at 6, 24 h and 3, 7 and 10 days after SCI in adult male rats. SCI was induced at the T9 level by transection. Results: Our results show a complicated temporal and spatial pattern of alteration in GlyR mRNA expression levels after SCI. Temporal and spatial variations with different degrees and direction (up or downregulation) of expression alteration were observed. The greatest variation was seen in GlyR alpha 1, whereas GlyR alpha 2 was downregulated in all regions following SCI. Conclusion: This study shows that alteration in GlyR expression starts as early as 6 h after SCI. The most significant points of this research are temporal elevation of GlyR alpha 1 and continuous reduction of GlyR alpha 2. Alterations in GlyR expression within the spinal cord may have a key role in the development of pathological pain. Therefore, control of GlyR expression could represent a novel therapeutic avenue for the development of new painkiller agents in SCI. Spinal Cord (2011) 49, 280-284; doi: 10.1038/sc.2010.109; published online 24 August 2010