PDE10A mRNA and protein levels decline in the striatum of R6/1 and R6/2 HD mice before onset of motor symptomsThe rate of reduction in PDE10A mRNA and protein is more rapid in R6/2 compared with R6/1 miceStriatal PDE1B mRNA levels decline in R6/1 and R6/2 HD mice, but to a lesser extent than PDE10APDE4A mRNA levels are relatively low in the striatum and do not differ between age‐matched WT and transgenic HD mice. Here, PDE10A is linked to ring chromosome 6.