Subunits of voltage-gated calcium channels in murine spiral ganglion cells

Abstract

Conclusion. The results show that α1D, α1E, α2/δ, β1, and β3 subunits are expressed in spiral ganglion cells (SGCs), and the coexpression of α1D and α1E suggests the presence of L-type and R-type calcium channels in mammalian SGCs. Objective. To investigate the types of subunits of voltage-gated calcium channels in SGCs of the mouse. Materials and methods. SGCs were isolated from cochleae of neonatal mice and cultured for 24 h. Total RNA was extracted from cultured cells. After reverse transcription, the resulting cDNA was amplified by PCR with primers targeted to nucleotide sequences corresponding to seven different calcium channel subunits. The types of calcium channel subunits were identified by PCR analysis and nucleotide sequencing. Results. RT-PCR showed the strong and consistent amplification of α1D, α1E, α2/δ, β1, and β3 subunits from the mRNA of SGCs, and nucleotide sequencing confirmed the identity of mouse cochlear subunit cDNAs.