Neurons born in the postnatal SVZ (subventricular zone) must migrate a great distance before becoming mature interneurons of the OB (olfactory bulb). During migration immature OB neurons maintain an immature morphology until they reach their destination. While the morphological development of these cells must be tightly regulated, the cellular pathways responsible are still largely unknown. Our results show that the non-canonical Wnt pathway induced by Wnt5a is important for the morphological development of OB interneurons both in vitro and in vivo. Additionally, we demonstrate that non-canonical Wnt signalling works in opposition to canonical Wnt signalling in neural precursors from the SVZ in vitro. This represents a novel role for Wnt5a in the development of OB interneurons and suggests that canonical and non-canonical Wnt pathways dynamically oppose each other in the regulation of dendrite maturation.
Keywords: dendrites, dkk1, non-canonical, sfrp1, subventricular zone (SVZ), wnt signalling
Abbreviations: BMP, bone morphogenic protein; CB, calbindin; CSF, cerebrospinal fluid; DAPI, 4′,6-diamidino-2-phenylindole; DKK-1, Dickkopf-related protein 1; JNK, c-Jun N-terminal kinase; LEF, lymphoid enhancer factor; LRP5/6, LDL (low-density lipoprotein)-receptor-related protein 5/6; NPC, neural progenitor cell; OB, olfactory bulb; OSN, olfactory sensory axon; PFA, paraformaldehyde; RMS, rostral migratory stream; sFRP-1, secreted frizzled-related protein 1; SVZ, subventricular zone; TDBTN, total dendritic branch tip number; TH, tyrosine hydroxylase; VGAT, vesicular γ-aminobutyric acid transporter