N-cadherin sustains motility and polarity of future cortical interneurons during tangential migration.

In the developing brain, cortical GABAergic interneurons migrate long distances from the medial ganglionic eminence (MGE) in which they are generated, to the cortex in which they settle. MGE cells express the cell adhesion molecule N-cadherin, a homophilic cell-cell adhesion molecule that regulates numerous steps of brain development, from neuroepithelium morphogenesis to synapse formation. N-cadherin is also expressed in embryonic territories crossed by MGE cells during their migration.

Dynamics of the leading process, nucleus, and Golgi apparatus of migrating cortical interneurons in living mouse embryos.

Precisely arranged cytoarchitectures such as layers and nuclei depend on neuronal migration, of which many in vitro studies have revealed the mode and underlying mechanisms. However, how neuronal migration is achieved in vivo remains unknown. Here we established an imaging system that allows direct visualization of cortical interneuron migration in living mouse embryos.

Intrinsic and extrinsic mechanisms control the termination of cortical interneuron migration.

During development, neurons migrate from their site of origin to their final destinations. Upon reaching this destination, the termination of their migration is crucial for building functional architectures such as laminated structures and nuclei. How this termination is regulated, however, is not clear.

Random walk behavior of migrating cortical interneurons in the marginal zone: time-lapse analysis in flat-mount cortex.

Migrating neurons are thought to travel from their origin near the ventricle to distant territories along stereotypical pathways by detecting environmental cues in the extracellular milieu. Here, we report a novel mode of neuronal migration that challenges this view. We performed long-term, time-lapse imaging of medial ganglionic eminence (MGE)-derived cortical interneurons tangentially migrating in the marginal zone (MZ) in flat-mount cortices.

Intracortical multidirectional migration of cortical interneurons.

It is well documented that most cortical interneurons originate from the basal forebrain and migrate tangentially to the cortex. However, relatively little is known about their migration after their arrival at the cortex. To elucidate the route and mode of intracortical migration of the interneurons, we performed real-time analysis by utilizing glutamate decarboxylase (GAD)67/green fluorescence protein (GFP) knock-in mice and an electroporation-based gene transfer of DsRed into the ganglionic eminence (GE) of a mouse embryo.