Figure 1.

Expression of Na channel α subunits mRNAs in cerebellum. (a) PCR amplification of sodium channels sequences in genomic DNA and cerebellar rtRNA. Two percent agarose gel. Genomic DNA (100 ng) or rtRNA (40 ng) was subjected to 40 cycles of PCR amplification under standard PCR conditions. Lanes: A, no rtRNA or DNA (negative control); B, cerebellar rtRNA; C, φ174 HaeIII Std.; D, rat genomic DNA with the primers directed to sodium channels; E, rat genomic DNA with primers that amplify a 740-bp product in genomic DNA (positive control); F and G, similar to D and E but with genomic DNA from mice. (b) Expression of sodium channels in rat cerebellar mRNA. Northern blots of rat cerebellar poly(A) RNA (4 μg per lane) were hybridized with probes specific to RbI (A), RbII (B), or CerIII (C). The blots were exposed to Kodak XAR-5 film at −70°C with no intensifying screens. The RNA sizes are from GIBCO/BRL RNA markers. (c) Single-cell RT-PCR. Samples obtained throughout the recording electrodes from a single cell were amplified by PCR with Na⁺ channel-specific degenerate oligonucleotides. Seven microliters of the amplification reaction were run in 2% agarose gel. Lanes: A, 50 ng of reverse-transcribed cerebellar RNA; B, chamber solution in presence of reverse transcriptase (control 1); C, φ174-HaeIII molecular weight Std.; D, non-reverse-transcribed RNA from a single PC (control 2); E, reverse-transcribed RNA from a single Purkinje cell.