The TRPC (Transient Receptor Potential Canonical) cation channel family consists of seven members; TRPC1-7. TRPC subunits are expressed in many brain areas but little is known about their cellular function in neurons. Recently, it has been reported that the TRPC1 cation channel is involved in the mGluR1-dependent slow excitatory postsynaptic current (ImGluR) in Purkinje cells. However, we found that ImGluR can be evoked when TRPC1 is absent (s. poster by Hartmann et al.). This suggests a role for other TRPC family members in the activation of ImGluR. Here, we investigated the cell type-specific gene expression patterns of TRPC encoding transcripts in single Purkinje cells of the cerebellum by quantitative single-cell RT-PCR. Single Purkinje cells were harvested by means of whole cell recording pipettes from acute cerebellar slices. After reverse transcription of single cell RNA material and specific purification steps, quantitative PCR was performed using a real time PCR device (LightCycler). We found that the subunit TRPC3 (443 copies/cell) and not TRPC1 (42 copies/cell) is the predominant TRP-family member in Purkinje cells. TRPC4 (10 copies/cell), TRPC6 (4 copies/cell), and TRPC7 (7 copies/cell) have been detected in few copies, while TRPC5 was not detected at all.