Manipulation of the nuclear envelope-associated protein SLAP during mammalian brain development affects cortical lamination and exploratory behavior.

Here, we report the first characterization of the effects resulting from the manipulation of Soluble-Lamin Associated Protein (SLAP) expression during mammalian brain development. We found that SLAP localizes to the nuclear envelope and when overexpressed causes changes in nuclear morphology and lengthening of mitosis. SLAP overexpression in apical progenitors of the developing mouse brain altered asymmetric cell division, neurogenic commitment and neuronal migration ultimately resulting in unbalance in the proportion of upper, relative to deeper, neuronal layers. Several of these effects were also recapitulated upon Cas9-mediated knockdown. Ultimately, SLAP overexpression during development resulted in a reduction in subcortical projections of young mice and, notably, reduced their exploratory behavior. Our study shows the potential relevance of the previously uncharacterized nuclear envelope protein SLAP in neurodevelopmental disorders.

Isolation of neural stem and oligodendrocyte progenitor cells from the brain of live rats.

Postnatal brain neural stem and progenitor cells (NSPCs) cluster in anatomically inaccessible stem cell niches, such as the subependymal zone (SEZ). Here, we describe a method for the isolation of NSPCs from live animals, which we term "milking." The intracerebroventricular injection of a release cocktail, containing neuraminidase, integrin-ß1-blocking antibody, and fibroblast growth factor 2, induces the controlled flow of NSPCs in the cerebrospinal fluid, where they are collected via liquid biopsies. Isolated cells retain key in vivo self-renewal properties and their cell-type profile reflects the cell composition of their source area, while the function of the niche is sustained even 8 months post-milking. By changing the target area more caudally, we also isolate oligodendrocyte progenitor cells (OPCs) from the corpus callosum. This novel approach for sampling NSPCs and OPCs paves the way for performing longitudinal studies in experimental animals, for more in vivo relevant cell culture assays, and for future clinical neuro-regenerative applications.