Layer positioning of late-born cortical interneurons is dependent on Reelin but not p35 signaling.

We tested the response of interneurons to the absence of Reelin signaling or p35 in the mouse neocortex. We provide three independent strands of evidence to demonstrate that layering of late-born (but not early-born) interneurons is regulated by Reelin signaling. First, early-born and late-born interneurons behaved differently in mice lacking Reelin or disabled 1 (Dab1).

Layer specification of transplanted interneurons in developing mouse neocortex.

The six-layered neocortex is composed of excitatory projection neurons and inhibitory interneurons. Recent studies have established separate embryological origins for these two cellular populations. However, it remains uncertain how interneurons arising from the subcortical ganglionic eminences are able to participate in the orderly stratification of the cortical layers.

Cellular dispersion patterns and phenotypes in the developing mouse superior colliculus.

The mammalian superior colliculus is structurally and functionally divided into two entities: superficial visual and deep multimodal motor. To discover the role, if any, of developmental processes in establishing separate tectal compartments, we have used highly unbalanced mouse chimaeras to mark cell dispersion pathways and trace cell lineages. Two forms of cell dispersion were detected: radial and tangential.