A Common Progenitor for Retinal Astrocytes and Oligodendrocytes

Abstract

Developing neural tissue undergoes a period of neurogenesis followed by a period of gliogenesis. The lineage relationships among glial cell types have not been defined for most areas of the nervous system. Here we use retroviruses to label clones of glial cells in the chick retina. We found that almost every clone had both astrocytes and oligodendrocytes. In addition, we discovered a novel glial cell type, with features intermediate between those of astrocytes and oligodendrocytes, which we have named the diacyte. Diacytes also share a progenitor cell with both astrocytes and oligodendrocytes.

Original article Heterogeneity of local tissue microenvironment influences differentiation of oligodendroglial progenitors

“…with the preserved tissue organization) the paracrine signals proved to be potent to force the as troglial commitment of OPCs. There are also reports describing a similar in vivo effect, found in different CNS regions [33,56]. The observation coming from our study concerning the promotion of astroglial differentiation in cocultures with hippocampal and spinal cord sli ces are in agreement with the reports about the glial scar formation in injuries occurring to the brain and spinal cord.…”

mTor-signaling is required for the formation of proliferating Müller glia-derived progenitor cells in the chick retina

“…3A). In the chick retina, NIRG cells are a distinct type of glial cell that migrates into the IPL and GCL from the optic nerve during development Rompani and Cepko, 2010). At 4 h after VOTH treatment, levels of pS6 appeared further elevated in the Müller glia, whereas levels in amacrine cells appeared reduced (Fig.…”

Reactive Muller Glia as Potential Retinal Progenitors

“…• Throughout the nervous system, including the retina and optic nerve [226] • Found exclusively in the inner nuclear layer of the retina with the process spanning the entire width of the retina [227,228] Origin • Originate from the glial restricted neural stem cells or the bipotent O2A progenitor cell type [229] • Originate from the neural retinal progenitor cells [227,228] Morphology • Have a stellate or star like morphology [226] • Have a radial morphology [227] Functions • Scaffolding for migration of developing neurons [230] • Aid in the formation of synapses [231][232][233] • Aid in the formation of the blood brain barrier [234] • Serve as a source of nourishment and energy reserve for the neurons by providing glucose and storing excess glucose in the form of glycogen [235,236] • Possess various channels and transporter (Na + /K + channels, aquaporins etc.) which aid in the maintenance of homeostasis, pH levels and removal of toxic metabolites [237,238] • Possess transporters for neurotransmitters (such as GABA, glycine, glutamate)which aid in clearance and release of these molecules into the synaptic space which can affect synaptic transmission [232,239] • Serve as a scaffolding for retinal organizations [227] • Help direct light through the retinal layers to the photoreceptor cells [240] • Help in recycling photopigments [241] • Aid in the formation of the blood retinal barrier [242] • Similar to astrocytes serve as a source of nourishment and energy reserve in the form of glucose and lactate respectively [227] • Help in maintenance of homeostasis and removal of toxic metabolites in a manner similar to astrocytes [115] • Neurotransmitter receptors (AMPA, GluR4, NMDA, GABA-A etc.…”