Limits...
Molecules and mechanisms that regulate multipolar migration in the intermediate zone.

Cooper JA - Front Cell Neurosci (2014)

Bottom Line: This reorientation implies the existence of directional signals in the IZ that are ignored during the multipolar stage but sensed after axonogenesis.Other signals are implicated in starting multipolar migration and triggering axon outgrowth.Here we review the molecules and mechanisms that regulate multipolar migration, and also discuss how multipolar migration affects the orderly arrangement of neurons in layers and columns in the developing neocortex.

View Article: PubMed Central - PubMed

Affiliation: Fred Hutchinson Cancer Research Center, Division of Basic Sciences Seattle, Washington, USA.

ABSTRACT
Most neurons migrate with an elongated, "bipolar" morphology, extending a long leading process that explores the environment. However, when immature projection neurons enter the intermediate zone (IZ) of the neocortex they become "multipolar". Multipolar cells extend and retract cytoplasmic processes in different directions and move erratically-sideways, up and down. Multipolar cells extend axons while they are in the lower half of the IZ. Remarkably, the cells then resume radial migration: they reorient their centrosome and Golgi apparatus towards the pia, transform back to bipolar morphology, and commence locomotion along radial glia (RG) fibers. This reorientation implies the existence of directional signals in the IZ that are ignored during the multipolar stage but sensed after axonogenesis. In vivo genetic manipulation has implicated a variety of candidate directional signals, cell surface receptors, and signaling pathways, that may be involved in polarizing multipolar cells and stabilizing a pia-directed leading process for radial migration. Other signals are implicated in starting multipolar migration and triggering axon outgrowth. Here we review the molecules and mechanisms that regulate multipolar migration, and also discuss how multipolar migration affects the orderly arrangement of neurons in layers and columns in the developing neocortex.

No MeSH data available.


Regulation of lateral movement by Ephs and Ephrins (Efns) during multipolar migration. Newborn neurons starting from one radial glia progenitor (RG) can follow the blue path, and position radially above their starting point, or follow the red path, and disperse laterally, depending on the strengths of signaling from EphA-EfnA and EphB-EfnB signals. See text for details and references.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4231986&req=5

Figure 3: Regulation of lateral movement by Ephs and Ephrins (Efns) during multipolar migration. Newborn neurons starting from one radial glia progenitor (RG) can follow the blue path, and position radially above their starting point, or follow the red path, and disperse laterally, depending on the strengths of signaling from EphA-EfnA and EphB-EfnB signals. See text for details and references.

Mentions: An alternative hypothesis is that the direction of MP migration is not random, but is controlled by signaling molecules. Indeed, there is now excellent evidence that horizontal movement of MP cells is regulated by Ephrin (Efn) and Eph family proteins (Figure 3).


Molecules and mechanisms that regulate multipolar migration in the intermediate zone.

Cooper JA - Front Cell Neurosci (2014)

Regulation of lateral movement by Ephs and Ephrins (Efns) during multipolar migration. Newborn neurons starting from one radial glia progenitor (RG) can follow the blue path, and position radially above their starting point, or follow the red path, and disperse laterally, depending on the strengths of signaling from EphA-EfnA and EphB-EfnB signals. See text for details and references.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231986&req=5

Figure 3: Regulation of lateral movement by Ephs and Ephrins (Efns) during multipolar migration. Newborn neurons starting from one radial glia progenitor (RG) can follow the blue path, and position radially above their starting point, or follow the red path, and disperse laterally, depending on the strengths of signaling from EphA-EfnA and EphB-EfnB signals. See text for details and references.
Mentions: An alternative hypothesis is that the direction of MP migration is not random, but is controlled by signaling molecules. Indeed, there is now excellent evidence that horizontal movement of MP cells is regulated by Ephrin (Efn) and Eph family proteins (Figure 3).

Bottom Line: This reorientation implies the existence of directional signals in the IZ that are ignored during the multipolar stage but sensed after axonogenesis.Other signals are implicated in starting multipolar migration and triggering axon outgrowth.Here we review the molecules and mechanisms that regulate multipolar migration, and also discuss how multipolar migration affects the orderly arrangement of neurons in layers and columns in the developing neocortex.

View Article: PubMed Central - PubMed

Affiliation: Fred Hutchinson Cancer Research Center, Division of Basic Sciences Seattle, Washington, USA.

ABSTRACT
Most neurons migrate with an elongated, "bipolar" morphology, extending a long leading process that explores the environment. However, when immature projection neurons enter the intermediate zone (IZ) of the neocortex they become "multipolar". Multipolar cells extend and retract cytoplasmic processes in different directions and move erratically-sideways, up and down. Multipolar cells extend axons while they are in the lower half of the IZ. Remarkably, the cells then resume radial migration: they reorient their centrosome and Golgi apparatus towards the pia, transform back to bipolar morphology, and commence locomotion along radial glia (RG) fibers. This reorientation implies the existence of directional signals in the IZ that are ignored during the multipolar stage but sensed after axonogenesis. In vivo genetic manipulation has implicated a variety of candidate directional signals, cell surface receptors, and signaling pathways, that may be involved in polarizing multipolar cells and stabilizing a pia-directed leading process for radial migration. Other signals are implicated in starting multipolar migration and triggering axon outgrowth. Here we review the molecules and mechanisms that regulate multipolar migration, and also discuss how multipolar migration affects the orderly arrangement of neurons in layers and columns in the developing neocortex.

No MeSH data available.