The deficit in GAD67 expression in the GAD67+/− mice was only about three-quarters of the 50% predicted reduction for a heterozygote, perhaps reflecting a compensatory increase in transcription from the remaining allele. On the other hand, the deficits in CB1R mRNA expression in the CB1R+/− mice (49.6%) and CB1R−/− mice (94.6%) were nearly exactly those predicted for heterozygotes and knockout animals, respectively. These comparisons suggest that the methods employed were sensitive to detect real differences in gene expression, and the absence of any differences in DAGLα mRNA expression also indicates that the CB1R mRNA deficit observed in the GAD67+/− mice is unlikely to be a false positive finding.
