BDNF Gene Structure in Rodents 529 Fig. 2. Expression analysis of mouse and rat BDNF mRNAs. Semiquantitive RT-PCR analysis of tis- sue-speciﬁc expression of mouse (A) and rat (B) BDNF transcripts and control HPRT mRNA was performed in developing and adult brain and in peripheral organs. E, embryonic day; P, postnatal day. development as well as in adulthood. In mouse adult brain, exon IXA-containing transcripts were expressed at similar levels in all brain regions (Fig. 2A), whereas, in rat adult brain, exon IXA expression was detected at high levels in hippocampus, olfactory bulb, colliculus, and cerebellum and at lower levels in cortex and pons Journal of Neuroscience Research DOI 10.1002/jnr