Immature Neuron Marker Antibody Sampler Kit

Background

The antibodies in this kit serve to characterize and identify immature neurons. During development, radial glia (RG) cells located in the ventricular zone (VZ) of the brain divide asymmetrically, each producing a neuronal and RG daughter cell. The daughter RG cell is also known as a neural progenitor cell (NPC) or an intermediate progenitor cell (IPC). Newly formed IPCs migrate to the subventricular zone (SVZ) where they divide symmetrically, each giving rise to two post-mitotic neurons that can then migrate to their final destination. In adulthood, NPCs reside within the subgranular zone (SGZ) of the dentate gyrus, and the adult SVZ, which surrounds the lateral ventricles of the cerebral cortex. NPCs within the SGZ and SVZ divide and give rise to immature neurons (1). The cytoskeleton of these cells plays an important role in generating neuronal processes. The cytoskeleton consists of three types of cytosolic fibers: actin microfilaments, intermediate filaments, and microtubules. β3-tubulin is one of six β-tubulin isoforms that make up the building blocks of microtubules (2). Stathmin is a tubulin binding protein that regulates microtubule dynamics in a phosphorylation dependent manner. Stathmin is heavily expressed during neuronal development, mediating differentiation and synaptic plasticity (3,4). Doublecortin is a microtubule-associated protein that facilitates neurite outgrowth and cell migration (5). The dual expression of doublecortin and NCAM (neural cell adhesion molecule, CD56), combined with the lack of expression of mature neuronal markers, is evidence of an immature neuronal phenotype (6). NCAM mediates neuronal attachment, neurite extension, and cell to cell interactions through homo and heterophilic interactions. Polysialic acid (PSA) post-translational modification of NCAM disrupts cell to cell adhesion, promoting axonal growth, cell migration, and synaptic plasticity during neurogenesis (7-9).

Transcription factors also play a key role in immature neuron growth and differentiation. NeuroD1 is a member of the basic helix-loop-helix (bHLH) family of transcription factors. These proteins function by forming heterodimers with E-proteins and binding to the canonical E-box sequence CANNTG (10,11). Neuronal activity results in CaMKII-mediated phosphorylation of NeuroD1 at Ser336, which is necessary for the formation and growth of dendrites (12,13). T-box, brain, 1 (TBR1) is a transcription factor important in vertebrate embryo development. As a member of the T-Box family of transcription factors, TBR1 is expressed in postmitotic glutamatergic projection neurons (14). During cortical neurogenesis, sequential expression of transcription factors Pax6, TBR2, and TBR1 regulates discrete steps in projection neuron differentiation (15).