Control of cortical interneuron migration by neurotrophins and PI3-kinase signaling.

During telencephalic development, cells from the medial ganglionic eminence (MGE) are thought to migrate to the neocortex to give rise to a majority of cortical GABAergic interneurons. By combining time-lapse video-microscopy, immunofluorescence and pharmacological perturbations in a new in vitro migration assay, we find that MGE-derived cells migrate through the entire extent of the cortex and into the CA fields of the hippocampus, but avoid the dentate gyrus. Migrating neurons initially travel within the marginal zone and intermediate zone, and can enter the cortical plate from either location.

Molecular control of cortical dendrite development.

Dendritic morphology has a profound impact on neuronal information processing. The overall extent and orientation of dendrites determines the kinds of input a neuron receives. Fine dendritic appendages called spines act as subcellular compartments devoted to processing synaptic information, and the dendritic branching pattern determines the efficacy with which synaptic information is transmitted to the soma.

Regulation of cortical dendrite development by Slit-Robo interactions.

Slit proteins have previously been shown to regulate axon guidance, branching, and neural migration. Here we report that, in addition to acting as a chemorepellant for cortical axons, Slit1 regulates dendritic development. Slit1 is expressed in the developing cortex, and exposure to Slit1 leads to increased dendritic growth and branching.