Temporarily Epigenetic Repression in Bergmann Glia Regulates the Migration of Granule Cells

THE FINE STRUCTURE OF THE RAT CEREBELLUM

The Journal of Cell Biology ◽

10.1083/jcb.23.2.277 ◽

1964 ◽

Vol 23 (2) ◽

pp. 277-293 ◽

Cited By ~ 76

Author(s):

Robert M. Herndon

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Light Microscope ◽

Osmium Tetroxide ◽

Granule Cells ◽

Cell Types ◽

Bergmann Glia ◽

Rat Cerebellum

This paper describes the fine structure of the granule cells, stellate neurons, astrocytes, Bergmann glia, oligodendrocytes, and microglia of the rat cerebellum after fixation by perfusion with buffered 1 per cent osmium tetroxide. Criteria are given for differentiating the various cell types, and the findings are correlated with previous light microscope and electron microscope studies of the cerebellum.

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Ttc21b is required in Bergmann glia for proper granule cell radial migration

10.1101/181230 ◽

2017 ◽

Cited By ~ 1

Author(s):

Ashley M. Driver ◽

Christopher Shumrick ◽

Rolf W. Stottmann

Keyword(s):

Primary Cilia ◽

Granule Cells ◽

Tumor Formation ◽

Bergmann Glia ◽

Cerebellar Development ◽

Cerebellar Tumor ◽

Form And Function ◽

Similar Phenotype ◽

Tetratricopeptide Repeat Domain ◽

And Function

AbstractProper cerebellar development is dependent on tightly regulated proliferation, migration, and differentiation events. Disruptions in any of these leads to a range of cerebellar phenotypes from ataxia to childhood tumors. Animal models have shown proper regulation of sonic hedgehog (Shh) signaling is crucial for normal cerebellar architecture and increased signaling leads to cerebellar tumor formation. Primary cilia are known to be required for the proper regulation of multiple developmental signaling pathways, including Shh. Tetratricopeptide Repeat Domain 21B (Ttc21b) is required for proper primary cilia form and function and is primarily thought to restrict Shh signaling. Here we investigated a role for Ttc21b in cerebellar development. Surprisingly, Ttc21b ablation in Bergmann glia resulted in accumulation of ectopic granule cells in the lower/ posterior lobes of the cerebellum and a reduction in Shh signaling. Ttc21b ablation in just Purkinje cells resulted in a similar, phenotype seen in fewer cells, but across the entire extent of the cerebellum. These results suggest that Ttc21b expression is required for Bergmann glia structure and signaling in the developing cerebellum, and in some contexts, augments, rather than attenuates, Shh signaling.

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Ultrasturcture of cerebellar cells and neuropil in rats subjected to partial global cerebral ischemia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014227x ◽

1986 ◽

Vol 44 ◽

pp. 126-127

Author(s):

R.V.W. Dimlich ◽

M.H. Biros

Keyword(s):

Purkinje Cells ◽

Glial Cells ◽

Granule Cells ◽

Molecular Layer ◽

Cell Types ◽

Primary Objective ◽

Global Cerebral Ischemia ◽

Forebrain Ischemia ◽

Substantial Evidence ◽

Cerebellar Cells

Although a previous study in this laboratory determined that Purkinje cells of the rat cerebellum did not appear to be damaged following 30 min of forebrain ischemia followed by 30 min of reperfusion, it was suggested that an increase in rough endoplasmic reticulum (RER) and/or polysomes had occurred in these cells. The primary objective of the present study was to morphometrically determine whether or not this increase had occurred. In addition, since there is substantial evidence that glial cells may be affected by ischemia earlier than other cell types, glial cells also were examined. To ascertain possible effects on other cerebellar components, granule cells and neuropil near Purkinje cells as well as neuropil in the molecular layer also were evaluated in this investigation.

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Effects of aging on axon terminals in the dentate molecular layer

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128924 ◽

1987 ◽

Vol 45 ◽

pp. 928-929

Author(s):

K. Cullen-Dockstader ◽

E. Fifkova

Keyword(s):

Granule Cells ◽

Molecular Layer ◽

Age Groups ◽

Long Term Potentiation ◽

Male Rats ◽

Perforant Path ◽

Axon Terminals ◽

Fischer 344 ◽

Spatial Memory Deficit ◽

Effects Of Aging

Normal aging results in a pronounced spatial memory deficit associated with a rapid decay of long-term potentiation at the synapses between the perforant path and spines in the medial and distal thirds of the dentate molecular layer (DML), suggesting the alteration of synaptic transmission in the dentate fascia. While the number of dentate granule cells remains unchanged, and there are no obvious pathological changes in these cells associated with increasing age, the density of their axospinous contacts has been shown to decrease. There are indications that the presynaptic element is affected by senescence before the postsynaptic element, yet little attention has been given to the fine structure of the remaining axon terminals. Therefore, we studied the axon terminals of the perforant path in the DML across three age groups.5 Male rats (Fischer 344) of each age group (3, 24 and 30 months), were perfused through the aorta.

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