论文部分内容阅读
BACKGROUND:Gamma-aminobutyric acid A(GABAA)and N-methyl-D-aspartate(NMDA)receptors are significant receptors in the central nervous system.An understanding of GABAA and NMDA receptor expression in spiral ganglion neurons(SGN)provides information for the functional role of these receptors in the auditory system.OBJECTIVE:To investigate mRNA expression of GABAA receptor(GABAAR)and NMDA receptor(NMDAR)subunits in the rat SGN.DESIGN,TIME AND SETTING:This in vitro,molecular biological study was performed at the Laboratory of Otolaryngology-Head and Neck Surgery,Guangxi Medical University,China from July 2007 to May 2008.MATERIALS:Reverse Transcriptase Kit and Taq DNA polymerase were purchased from Fermentas,Burlington,ON,Canada; GABAAR and NMDAR primers were purchased from Shanghai Sangon,Shanghai,China.METHODS:SGN from 3-5 day postnatal Wistar rats was collected for primary cultures,mRNA expression of GABAAR and NMDAR subunits in the SGN was determined by reverse transcription polymerase chain reaction.MAIN OUTCOME MEASURES:Expression levels of GABAAR and NMDAR subunits were determined by quantitative analysis.RESULTS:GABAAR subunits(α16,β13,and γ13)and NMDAR subunits(NR1,NR2A,NR2B,NR2C,NR2D,NR3A,and NR3B)were detected in the SGN.In α subunit genes of GABAAR,α1 andα3 expression was similar(P > 0.05)and greater than the other subunits.Of the β subunit genes,β1subunit mRNA levels were greater than β2 and β3.Of the γ subunit genes,γ2 subunit mRNA levels were greater than γ1 and γ3.NR1 mRNA expression was the greatest of NMDAR subunits.CONCLUSION:GABAAR subunits(α1-6,β1-3,and γ1-3)and NMDAR subunits(NR1,NR2A,NR2B,NR2C,NR2D,NR3A,and NR3B)were expressed in the rat SGN.Through comparison of GABAAR and NMDAR subunit expression,possible GABAAR combinations,as well as highly expressed subunit combinations,were estimated,which provided information for pharmacological and electrophysiological characteristics of GABAAR in the auditory system.