Glial Cell Expansion Coincides with Neural Circuit Formation in the Developing Auditory Brainstem.
Neural circuit formation involves maturation of neuronal, glial and vascular cells, as well as cell proliferation and cell death. A fundamental understanding of cellular mechanisms is enhanced by quantification of cell types during key events in synapse formation and pruning and possessing qualified genetic tools for cell type-specific manipulation. Acquiring this information in turn requires validated cell markers and genetic tools. We quantified changing proportions of neurons, astrocytes, oligodendrocytes, and microglia in the medial nucleus of the trapezoid body (MNTB) during neural circuit development. Cell type-specific markers, light microscopy and 3D virtual reality software, the latter developed in our laboratory, were used to count cells within distinct cell populations at postnatal days (P)3 and P6, bracketing the period of nerve terminal growth and pruning in this system. These data revealed a change from roughly equal numbers of neurons and glia at P3 to a 1.5:1 ratio of glia to neurons at P6. PCNA and PH3 labeling revealed that proliferation of oligodendrocytes contributed to the increase in glial cell number during this timeframe. We next evaluated Cre driver lines for selectivity in labeling cell populations. En1-Cre was specific for MNTB neurons. PDGFRα-Cre and Aldh1L1-Cre, thought to be mostly specific for oligodendrocyte lineage cells and astrocytes, respectively, both labeled significant numbers of neurons, oligodendrocytes, and astrocytes and are non-specific genetic tools in this neural system.
['Brandebura|Ashley N|AN|0000-0001-9862-0977', 'Morehead|Michael|M|', 'Heller|Daniel T|DT|', 'Holcomb|Paul|P|', 'Kolson|Douglas R|DR|', 'Jones|Garrett|G|', 'Mathers|Peter H|PH|', 'Spirou|George A|GA|']
D000818:Animals D001253:Astrocytes D001933:Brain Stem D002453:Cell Cycle D049109:Cell Proliferation D051379:Mice D017628:Microglia D009419:Nerve Tissue Proteins D009457:Neuroglia D009474:Neurons D009836:Oligodendroglia
neuron astrocyte oligodendrocyte microglia gliogenesis