Adenosine deaminase-dependent RNA editing is a widespread universal mechanism of posttranscriptional gene function modulation. Changes in RNA editing level may contribute to various physiological and pathological processes. In the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) glutamate receptor GluA2 subunit, A-I editing in the Q607R site leads to dramatic changes in function, making the receptor channel calcium-impermeable. A standard approach for quantifying (un)edited RNAs is based on endpoint PCR (Sanger sequencing or restriction analysis), a time-consuming and semiquantitative method. We aimed to develop RT-qPCR assays to quantify rat Q607R (A-I) edited/unedited mRNA in samples in the present work. Based on self-probing PCR detection chemistry, described initially for detecting short DNA fragments, we designed and optimised RT-qPCR assays to quantify Q607R (un)edited mRNA. We used self-probing primer PCR technology for mRNA quantification for the first time. Using a novel assay, we confirmed that Q607R GluA2 mRNA editing was increased in 14-day- (P14) or 21-day-old (P21) postnatal brain tissue (hippocampus) compared to the embryonic brain (whole brains at E20) in Wistar rats. Q607R unedited GluA2 mRNA was detectable by our assay in the cDNA of mature brain tissue compared to that derived through classical methods. Thus, self-probing primer PCR detection chemistry is an easy-to-use approach for RT-qPCR analysis of RNA editing.