Differential expression of neuregulins and their receptors in the olfactory bulb layers of the developing mouse

Abstract

Neuregulins (NRGs), and their cognate receptors (ErbBs), play essential roles in numerous aspects of neural development and adult synaptic plasticity. The goal of this study was to investigate the developmental expression profiles of these molecules during the olfactory bulb (OB) maturation. The OB is a highly organized structure with cell types and synaptic connections segregated into discrete anatomical layers. We employed a novel approach by combining single-layer microdissection at different development ages,with isoform-specific semi-quantitative RT-PCR and Western blotting to monitor layer-specific developmental profiles of these molecules and alternate splice variants. Layer and age specific regulation was observed for the ErbB4 splice variants JMa/JMb and NRG-1-β1/β2 forms. With the exception of the outermost (nerve) layer, ErbB4-JMb and NRG-1-β1 are expressed throughout the OB and their expressions decrease in the adult age in most layers. In contrast both ErbB4-JMa and NRG-1-β2 are highly expressed in the granule cell layer in the early postnatal OB. This early postnatal expression correlates with the dramatic change from radial glia to astrocytes and appearance of the bulk of granule cells occurring at this developmental stage.

Denervation and reinnervation of adult skeletal muscle modulate mRNA expression of neuregulin‐1 and ErbB receptors

“…30 Yet, the presence of colocalization between NRG1 and myogenin in differentiating satellite cells 6 and 10 days after muscle damage was also shown supporting the view that NRG1 regulates myogenin expression at fusing myotubes. 29 Our results add an original piece of information by revealing that NRG1a, the predominant isoform detectable in cells of mesenchymal origin, [31][32][33] is the only isoform that is regulated during denervation and reinnervation of the skeletal muscle. Recent studies on NRG/ ErbB loss-and gain-of function in mice 11,[34][35][36] support the critical role for NRG-signaling in maintenance of muscle trophism and Schwann cell survival, whereas they no longer support the notion that NRG-signaling to muscle fibres has an essential role in controlling synapse-specific AchR transcription.…”

Phenotypic characterization of spatial cognition and social behavior in mice with ‘knockout’ of the schizophrenia risk gene neuregulin 1

“…Indeed, in the developing rodent brain the expression profiles of ErbB receptors and their ligands in the olfactory bulb suggest a putative role for neuregulin in olfactory bulb maturation (Anton et al, 2004;Bovetti et al, 2006), while in the adult rodent brain NRG1 is expressed in distinct layers of the olfactory bulb (Corfas et al, 1995;Longart et al, 2004). However, using the buried pellet localization test, we found no difference between NRG1 mutants and WT in latency to locate a buried food pellet or in subsequent consumption of that pellet.…”

Specific Regulation of NRG1 Isoform Expression by Neuronal Activity

“…Type I, II and III are known to express in rodent brains (Pinkas-Kramarski et al, 1994; Corfas et al, 1995; Lu et al, 1995; Chuah et al, 2000; Bovetti et al, 2006; Edwards and Bottenstein, 2006). However, whether the other, novel types exist in rodent brains remains unknown.…”