Rate and pattern of migration of lineally-related olfactory bulb interneurons generated postnatally in the subventricular zone of the rat
MB Luskin, MS Boone - Chemical Senses, 1994 - academic.oup.com
MB Luskin, MS Boone
Chemical Senses, 1994•academic.oup.comA spatially discrete region of the anterior part of the postnatal telescephalic subventricular
zone, referred to as the SVZa generates vast numbers of lineally-related neurons destined
for the olfactory bulb (Luskin, 1993). The cells originating in the SVZa migrate to the olfactory
bulb along a highly restricted pathway which is in a direction orthogonal to the orientation of
radial glial fibers. In this study we analysed the number, distribution, orientation and rate of
migration of SVZa-derived cells as they approach the olfactory bulb. In order to track the …
zone, referred to as the SVZa generates vast numbers of lineally-related neurons destined
for the olfactory bulb (Luskin, 1993). The cells originating in the SVZa migrate to the olfactory
bulb along a highly restricted pathway which is in a direction orthogonal to the orientation of
radial glial fibers. In this study we analysed the number, distribution, orientation and rate of
migration of SVZa-derived cells as they approach the olfactory bulb. In order to track the …
Abstract
A spatially discrete region of the anterior part of the postnatal telescephalic subventricular zone, referred to as the SVZa generates vast numbers of lineally-related neurons destined for the olfactory bulb (Luskin, 1993). The cells originating in the SVZa migrate to the olfactory bulb along a highly restricted pathway which is in a direction orthogonal to the orientation of radial glial fibers. In this study we analysed the number, distribution, orientation and rate of migration of SVZa-derived cells as they approach the olfactory bulb. In order to track the SVZa-derived cells, a retroviral lineage tracer, encoding the reporter gene E.coli β-galactosidase (lacZ) was injected precisely into the rat SVZa at postnatal day 1 (Pl). The lacZ-positive cells were visualized 1, 2 and 3 days later by X-Gal histochemistry in cryostat sections. As the number of SVZa-derived cells in the pathway increased with survival time, their distribution changed systematically. The distribution pattern of lacZ-positive cells by 2 and 3 days postinjection suggested that some of the progeny of infected progenitor cells were undergoing neurogenesis as they proceeded to the olfactory bulb; a large percentage of the lacZ-positive cells were substantially displaced from the SVZa injection site. To investigate whether lacZ-positive cells migrate in a directed fashion, their orientation preference was scored. For the majority of lacZ-positive cells (>94%), their leading process was directed toward the olfactory bulb, possibly reflecting a response to migratory cues present along the pathway. The estimated average rate of cell migration to the olfactory bulb was 23 μm/h, which is approximately twice the speed of radially directed neuronal migration from the telencephalic ventricular zone to the cortical plate (O'Rourke et al, 1992). Collectively, these results suggest that SVZa-derived intemeurons en route to the olfactory bulb may employ a novel mode of tangential migration.
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