Figure 5.

Schematic representation of SVZ and GnRH neuroblast migration within the olfactory system. (A) During development, neuroblasts originated in the lateral ganglionic eminences migrate toward the OB (red cells). GnRH-1 neuroblasts (green cells) generated in the OE follow the olfactory and vomeronasal axons on their way to the hypothalamus. (B) In the adult, the contingent of migrating SVZ neuroblasts (in red) forms the RMS toward the OB, whereas GnRH neurons (in green) are located in several areas comprising the preoptic area and the hypothalamus. The inset on the right illustrates the aspect of mature RMS, with the chains of migrating neuroblasts (in red) advancing among astrocytic channels (in yellow). Once they reach the OB, SVZ neuroblasts migrate radially to their final targets within the OB (left panel). Abbreviations: EP, external plexiform layer; GL, glomerular layer; GCL, granule layer; LOT, lateral olfactory tract; M, mitral cells; OB, olfactory bulb; OE, olfactory epithelium; OSN, olfactory sensory neuron; RMS, rostral migratory stream; SVZ, subventricular zone; VNO, vomeronasal organ.