Lack of MeCP2 leads to region-specific increase of doublecortin in the olfactory system

AbstractThe protein doublecortin is mainly expressed in migrating neuroblasts and immature neurons. The X-linked geneMECP2, associated to several neurodevelopmental disorders such as Rett syndrome, encodes the protein methyl-CpG-binding protein 2 (MeCP2), a regulatory protein that has been implicated in neuronal maturation and refinement of olfactory circuits. Here, we explored doublecortin immunoreactivity in the brain of young adult femaleMecp2-heterozygous and maleMecp2-null mice and their wild-type littermates. The distribution of doublecortin-immunoreactive somata in neurogenic brain regions was consistent with previous reports in rodents, and no qualitative differences were found between genotypes or sexes. Quantitatively, we found a significant increase in doublecortin cell density in the piriform cortex ofMecp2-null males as compared to WT littermates. A similar increase was seen in a newly identified population of doublecortin cells in the olfactory tubercle. In these olfactory structures, however, the percentage of doublecortin immature neurons that also expressed NeuN was not different between genotypes. By contrast, we found no significant differences between genotypes in doublecortin immunoreactivity in the olfactory bulbs. Nonetheless, in the periglomerular layer ofMecp2-null males, we observed a specific decrease of immature neurons co-expressing doublecortin and NeuN. Overall, no differences were evident betweenMecp2-heterozygous and WT females. In addition, n...

Source: Anatomy and Embryology - March 27, 2019 Category: Anatomy Source Type: research