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Astrocyte morphology, heterogeneity, and density in the developing African giant rat (Cricetomys gambianus).

Olude MA, Mustapha OA, Aderounmu OA, Olopade JO, Ihunwo AO - Front Neuroanat (2015)

Bottom Line: Astrocyte heterogeneity in juvenile and adult groups revealed eight subtypes to include fibrous astrocytes chiefly in the corpus callosum and brain stem, protoplasmic astrocytes in the cortex and dentate gyrus (DG); radial glia were found along the olfactory bulb (OB) and subventricular zone (SVZ); velate astrocytes were mainly found in the cerebellum and hippocampus; marginal astrocytes close to the pia mater; Bergmann glia in the molecular layer of the cerebellum; perivascular and periventricular astrocytes in the cortex and third ventricle, respectively.Cell counts from twelve anatomical regions of the brain were significantly higher in juveniles than in adults (p ≤ 0.01) using unpaired student t-test in the cerebral cortex, pia, corpus callosum, rostral migratory stream, DG, and cerebellum.Highest astrocyte count was found in the DG, while the least count was in the brain stem and sub cortex.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Unit, Department of Veterinary Anatomy, Federal University of Agriculture Abeokuta, Nigeria ; Neuroscience Unit, Department of Veterinary Anatomy, University of Ibadan Ibadan, Nigeria ; School of Anatomical Sciences, Neuroscience Unit, University of the Witwatersrand Johannesburg, South Africa.

ABSTRACT
Astrocyte morphologies and heterogeneity were described in male African giant rats (AGR; Cricetomys gambianus, Waterhouse) across three age groups (five neonates, five juveniles, and five adults) using Silver impregnation method and immunohistochemistry against glial fibrillary acidic protein. Immunopositive cell signaling, cell size and population were least in neonates, followed by adults and juveniles, respectively. In neonates, astrocyte processes were mostly detected within the glia limitans of the mid and hind brain; their cell bodies measuring 32 ± 4.8 μm in diameter against 91 ± 5.4 μm and 75 ± 1.9 μm in juveniles and adults, respectively. Astrocyte heterogeneity in juvenile and adult groups revealed eight subtypes to include fibrous astrocytes chiefly in the corpus callosum and brain stem, protoplasmic astrocytes in the cortex and dentate gyrus (DG); radial glia were found along the olfactory bulb (OB) and subventricular zone (SVZ); velate astrocytes were mainly found in the cerebellum and hippocampus; marginal astrocytes close to the pia mater; Bergmann glia in the molecular layer of the cerebellum; perivascular and periventricular astrocytes in the cortex and third ventricle, respectively. Cell counts from twelve anatomical regions of the brain were significantly higher in juveniles than in adults (p ≤ 0.01) using unpaired student t-test in the cerebral cortex, pia, corpus callosum, rostral migratory stream, DG, and cerebellum. Highest astrocyte count was found in the DG, while the least count was in the brain stem and sub cortex. Astrocytes along the periventricular layer of the OB are believed to be part of the radial glia system that transport newly formed cells towards the hippocampus and play roles in neurogenesis migration and homeostasis in the AGR. Therefore, astrocyte heterogeneity was examined across age groups in the AGR to determine whether age influences astrocytes population in different regions of the AGR brain and discuss possible functional roles.

No MeSH data available.


Glial fibrillary acidic protein positive immunostaining for astrocytes (black arrows) in neonate (A) mesencephalon showing more processes than cell bodies (B) at the pial surface of the mesencephalic region.
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Figure 3: Glial fibrillary acidic protein positive immunostaining for astrocytes (black arrows) in neonate (A) mesencephalon showing more processes than cell bodies (B) at the pial surface of the mesencephalic region.

Mentions: Visualization and image J quantification of GFAP astrocytes revealed greatest signaling intensity in juveniles followed by adults and lastly neonates despite using the same dilution factors for staining all sections (Figure 2). The pattern of GFAP signaling intensity was caudo-rostral in all the groups. In neonates, processes were more apparent than cell bodies (Figure 3). Their cell bodies measured approximately 32 ± 4.8 μm in diameter against 91 ± 5.4 μm and 75 ± 1.9 μm in juveniles and adults, respectively (Figure 4). Over 90% of astrocytic cells detected in neonates were within the glia limitans of the germinal zone of the ventriclular region, dorsal, and ventral regions of the mid and hind brain, mesencephalon, and a thin line extending along the hippocampal fissure. The expression of GFAP in the forebrain was confined to a thin line of signal extending along the hippocampal fissure and surrounding the ventricular region. Generally, low levels of signal were observed in the forebrain glia limitans and within the corpus callosum.


Astrocyte morphology, heterogeneity, and density in the developing African giant rat (Cricetomys gambianus).

Olude MA, Mustapha OA, Aderounmu OA, Olopade JO, Ihunwo AO - Front Neuroanat (2015)

Glial fibrillary acidic protein positive immunostaining for astrocytes (black arrows) in neonate (A) mesencephalon showing more processes than cell bodies (B) at the pial surface of the mesencephalic region.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4443027&req=5

Figure 3: Glial fibrillary acidic protein positive immunostaining for astrocytes (black arrows) in neonate (A) mesencephalon showing more processes than cell bodies (B) at the pial surface of the mesencephalic region.
Mentions: Visualization and image J quantification of GFAP astrocytes revealed greatest signaling intensity in juveniles followed by adults and lastly neonates despite using the same dilution factors for staining all sections (Figure 2). The pattern of GFAP signaling intensity was caudo-rostral in all the groups. In neonates, processes were more apparent than cell bodies (Figure 3). Their cell bodies measured approximately 32 ± 4.8 μm in diameter against 91 ± 5.4 μm and 75 ± 1.9 μm in juveniles and adults, respectively (Figure 4). Over 90% of astrocytic cells detected in neonates were within the glia limitans of the germinal zone of the ventriclular region, dorsal, and ventral regions of the mid and hind brain, mesencephalon, and a thin line extending along the hippocampal fissure. The expression of GFAP in the forebrain was confined to a thin line of signal extending along the hippocampal fissure and surrounding the ventricular region. Generally, low levels of signal were observed in the forebrain glia limitans and within the corpus callosum.

Bottom Line: Astrocyte heterogeneity in juvenile and adult groups revealed eight subtypes to include fibrous astrocytes chiefly in the corpus callosum and brain stem, protoplasmic astrocytes in the cortex and dentate gyrus (DG); radial glia were found along the olfactory bulb (OB) and subventricular zone (SVZ); velate astrocytes were mainly found in the cerebellum and hippocampus; marginal astrocytes close to the pia mater; Bergmann glia in the molecular layer of the cerebellum; perivascular and periventricular astrocytes in the cortex and third ventricle, respectively.Cell counts from twelve anatomical regions of the brain were significantly higher in juveniles than in adults (p ≤ 0.01) using unpaired student t-test in the cerebral cortex, pia, corpus callosum, rostral migratory stream, DG, and cerebellum.Highest astrocyte count was found in the DG, while the least count was in the brain stem and sub cortex.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Unit, Department of Veterinary Anatomy, Federal University of Agriculture Abeokuta, Nigeria ; Neuroscience Unit, Department of Veterinary Anatomy, University of Ibadan Ibadan, Nigeria ; School of Anatomical Sciences, Neuroscience Unit, University of the Witwatersrand Johannesburg, South Africa.

ABSTRACT
Astrocyte morphologies and heterogeneity were described in male African giant rats (AGR; Cricetomys gambianus, Waterhouse) across three age groups (five neonates, five juveniles, and five adults) using Silver impregnation method and immunohistochemistry against glial fibrillary acidic protein. Immunopositive cell signaling, cell size and population were least in neonates, followed by adults and juveniles, respectively. In neonates, astrocyte processes were mostly detected within the glia limitans of the mid and hind brain; their cell bodies measuring 32 ± 4.8 μm in diameter against 91 ± 5.4 μm and 75 ± 1.9 μm in juveniles and adults, respectively. Astrocyte heterogeneity in juvenile and adult groups revealed eight subtypes to include fibrous astrocytes chiefly in the corpus callosum and brain stem, protoplasmic astrocytes in the cortex and dentate gyrus (DG); radial glia were found along the olfactory bulb (OB) and subventricular zone (SVZ); velate astrocytes were mainly found in the cerebellum and hippocampus; marginal astrocytes close to the pia mater; Bergmann glia in the molecular layer of the cerebellum; perivascular and periventricular astrocytes in the cortex and third ventricle, respectively. Cell counts from twelve anatomical regions of the brain were significantly higher in juveniles than in adults (p ≤ 0.01) using unpaired student t-test in the cerebral cortex, pia, corpus callosum, rostral migratory stream, DG, and cerebellum. Highest astrocyte count was found in the DG, while the least count was in the brain stem and sub cortex. Astrocytes along the periventricular layer of the OB are believed to be part of the radial glia system that transport newly formed cells towards the hippocampus and play roles in neurogenesis migration and homeostasis in the AGR. Therefore, astrocyte heterogeneity was examined across age groups in the AGR to determine whether age influences astrocytes population in different regions of the AGR brain and discuss possible functional roles.

No MeSH data available.