TRESK; Despite the high levels of TRESK mRNA detected by qPCR analysis, the levels of TRESK immunoreactivity detected in the adult mouse retina were low with the antibody used in this study (Fig. 6A–C). TRESK immunoreactivity was limited to a small number of cells in the GCL, typically only 4–6 cells per section. However, positive staining with this antibody was inconsistent between different retina samples.