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Pericellular innervation of neurons expressing abnormally hyperphosphorylated tau in the hippocampal formation of Alzheimer's disease patients.

Blazquez-Llorca L, Garcia-Marin V, Defelipe J - Front Neuroanat (2010)

Bottom Line: This neurofibrillary lesion involves the accumulation of abnormally hyperphosphorylated or abnormally phosphorylated microtubule-associated protein tau into paired helical filaments (PHF-tau) within neurons.Furthermore, the distribution of both GABAergic and glutamatergic terminals around the soma and proximal processes of PHF-tau-ir neurons does not seem to be altered as it is indistinguishable from both control cases and from adjacent neurons that did not contain PHF-tau.These observations suggest that the synaptic connectivity around the perisomatic region of these PHF-tau-ir neurons was apparently unaltered.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Circuitos Corticales (Centro de Tecnología Biomédica), Universidad Politécnica de Madrid Madrid, Spain.

ABSTRACT
Neurofibrillary tangles (NFT) represent one of the main neuropathological features in the cerebral cortex associated with Alzheimer's disease (AD). This neurofibrillary lesion involves the accumulation of abnormally hyperphosphorylated or abnormally phosphorylated microtubule-associated protein tau into paired helical filaments (PHF-tau) within neurons. We have used immunocytochemical techniques and confocal microscopy reconstructions to examine the distribution of PHF-tau-immunoreactive (ir) cells, and their perisomatic GABAergic and glutamatergic innervations in the hippocampal formation and adjacent cortex of AD patients. Furthermore, correlative light and electron microscopy was employed to examine these neurons and the perisomatic synapses. We observed two patterns of staining in PHF-tau-ir neurons, pattern I (without NFT) and pattern II (with NFT), the distribution of which varies according to the cortical layer and area. Furthermore, the distribution of both GABAergic and glutamatergic terminals around the soma and proximal processes of PHF-tau-ir neurons does not seem to be altered as it is indistinguishable from both control cases and from adjacent neurons that did not contain PHF-tau. At the electron microscope level, a normal looking neuropil with typical symmetric and asymmetric synapses was observed around PHF-tau-ir neurons. These observations suggest that the synaptic connectivity around the perisomatic region of these PHF-tau-ir neurons was apparently unaltered.

No MeSH data available.


Related in: MedlinePlus

Drawings based on Neurolucida plots made with a 40× objective showing the distribution of diffuse, cored neuritic and non-cored neuritic plaques (red, green, and blue circles, respectively; see Garcia-Marin et al., 2009) in the hippocampal formation and adjacent cortex from AD cases. Borders between the different cortical cytoarchitectonic regions are indicated by arrowheads. Abbreviations as in Figure 5. Scale bar: 1,000 μm.
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Figure 9: Drawings based on Neurolucida plots made with a 40× objective showing the distribution of diffuse, cored neuritic and non-cored neuritic plaques (red, green, and blue circles, respectively; see Garcia-Marin et al., 2009) in the hippocampal formation and adjacent cortex from AD cases. Borders between the different cortical cytoarchitectonic regions are indicated by arrowheads. Abbreviations as in Figure 5. Scale bar: 1,000 μm.

Mentions: Finally, adjacent sections stained for PHF-tau were processed to visualize Aβ plaques to find out whether the density and distribution of PHF-tau-ir neurons was related to the density of Aβ plaques in tissue from both control (Figure 8) and AD patients (Figure 9). Comparing the distribution of PHF-tau-ir neurons and Aβ plaques revealed no such correlation since there were regions where the density of both PHF-tau-ir neurons and Aβ plaques was very high whereas in other regions a high density of PHF-tau-ir neurons coincided with a region with few Aβ plaques and vice versa.


Pericellular innervation of neurons expressing abnormally hyperphosphorylated tau in the hippocampal formation of Alzheimer's disease patients.

Blazquez-Llorca L, Garcia-Marin V, Defelipe J - Front Neuroanat (2010)

Drawings based on Neurolucida plots made with a 40× objective showing the distribution of diffuse, cored neuritic and non-cored neuritic plaques (red, green, and blue circles, respectively; see Garcia-Marin et al., 2009) in the hippocampal formation and adjacent cortex from AD cases. Borders between the different cortical cytoarchitectonic regions are indicated by arrowheads. Abbreviations as in Figure 5. Scale bar: 1,000 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2903190&req=5

Figure 9: Drawings based on Neurolucida plots made with a 40× objective showing the distribution of diffuse, cored neuritic and non-cored neuritic plaques (red, green, and blue circles, respectively; see Garcia-Marin et al., 2009) in the hippocampal formation and adjacent cortex from AD cases. Borders between the different cortical cytoarchitectonic regions are indicated by arrowheads. Abbreviations as in Figure 5. Scale bar: 1,000 μm.
Mentions: Finally, adjacent sections stained for PHF-tau were processed to visualize Aβ plaques to find out whether the density and distribution of PHF-tau-ir neurons was related to the density of Aβ plaques in tissue from both control (Figure 8) and AD patients (Figure 9). Comparing the distribution of PHF-tau-ir neurons and Aβ plaques revealed no such correlation since there were regions where the density of both PHF-tau-ir neurons and Aβ plaques was very high whereas in other regions a high density of PHF-tau-ir neurons coincided with a region with few Aβ plaques and vice versa.

Bottom Line: This neurofibrillary lesion involves the accumulation of abnormally hyperphosphorylated or abnormally phosphorylated microtubule-associated protein tau into paired helical filaments (PHF-tau) within neurons.Furthermore, the distribution of both GABAergic and glutamatergic terminals around the soma and proximal processes of PHF-tau-ir neurons does not seem to be altered as it is indistinguishable from both control cases and from adjacent neurons that did not contain PHF-tau.These observations suggest that the synaptic connectivity around the perisomatic region of these PHF-tau-ir neurons was apparently unaltered.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Circuitos Corticales (Centro de Tecnología Biomédica), Universidad Politécnica de Madrid Madrid, Spain.

ABSTRACT
Neurofibrillary tangles (NFT) represent one of the main neuropathological features in the cerebral cortex associated with Alzheimer's disease (AD). This neurofibrillary lesion involves the accumulation of abnormally hyperphosphorylated or abnormally phosphorylated microtubule-associated protein tau into paired helical filaments (PHF-tau) within neurons. We have used immunocytochemical techniques and confocal microscopy reconstructions to examine the distribution of PHF-tau-immunoreactive (ir) cells, and their perisomatic GABAergic and glutamatergic innervations in the hippocampal formation and adjacent cortex of AD patients. Furthermore, correlative light and electron microscopy was employed to examine these neurons and the perisomatic synapses. We observed two patterns of staining in PHF-tau-ir neurons, pattern I (without NFT) and pattern II (with NFT), the distribution of which varies according to the cortical layer and area. Furthermore, the distribution of both GABAergic and glutamatergic terminals around the soma and proximal processes of PHF-tau-ir neurons does not seem to be altered as it is indistinguishable from both control cases and from adjacent neurons that did not contain PHF-tau. At the electron microscope level, a normal looking neuropil with typical symmetric and asymmetric synapses was observed around PHF-tau-ir neurons. These observations suggest that the synaptic connectivity around the perisomatic region of these PHF-tau-ir neurons was apparently unaltered.

No MeSH data available.


Related in: MedlinePlus