Shades of gray: The delineation of marker expression within the adult rodent subventricular zone.

The research field of adult neurogenesis is rapidly expanding with more and more information becoming available on the identity of the cells located within the subventricular zone (SVZ). Much of our understanding is based on rodent studies. The SVZ is comprised of several different cell types including B1 astrocytes, transit amplifying progenitor cells (C cells), and neuroblasts (A cells).

Reactive glia show increased immunoproteasome activity in Alzheimer's disease.

The proteasome is the major protein degradation system within the cell, comprised of different proteolytic subunits; amyloid-β is thought to impair its activity in Alzheimer's disease. Neuroinflammation is a prominent hallmark of Alzheimer's disease, which may implicate an activation of the immunoproteasome, a specific proteasome variant induced by immune signalling that holds slightly different proteolytic properties than the constitutive proteasome. Using a novel cell-permeable proteasome activity probe, we found that amyloid-β enhances proteasome activity in glial and neuronal cultures.

GFAPδ expression in glia of the developmental and adolescent mouse brain.

Glial fibrillary acidic protein (GFAP) is the major intermediate filament (IF) protein in astrocytes. In the human brain, GFAP isoforms have unique expression patterns, which indicate that they play distinct functional roles. One isoform, GFAPδ, is expressed by proliferative radial glia in the developing human brain.

GFAP isoforms in adult mouse brain with a focus on neurogenic astrocytes and reactive astrogliosis in mouse models of Alzheimer disease.

Glial fibrillary acidic protein (GFAP) is the main astrocytic intermediate filament (IF). GFAP splice isoforms show differential expression patterns in the human brain. GFAPδ is preferentially expressed by neurogenic astrocytes in the subventricular zone (SVZ), whereas GFAP(+1) is found in a subset of astrocytes throughout the brain.

In vivo targeting of subventricular zone astrocytes.

The subventricular zone (SVZ) is a dynamic cellular niche with unique neurogenic properties that are, as of yet, not fully understood. Astrocytes residing in the SVZ have been shown to spawn migratory neuroblasts via transitory amplifying progenitor cells. These migratory neuroblasts play a role in maintaining the olfactory circuitry in healthy brains and potentially have restorative properties after brain injury.