Limits...
Mapping Synaptic Pathology within Cerebral Cortical Circuits in Subjects with Schizophrenia.

Sweet RA, Fish KN, Lewis DA - Front Hum Neurosci (2010)

Bottom Line: Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g., dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin), or to quantification of proteins using methods unable to resolve relevant cellular compartments.An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions.In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex.

View Article: PubMed Central - PubMed

Affiliation: Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh Pittsburgh, PA, USA.

ABSTRACT
Converging lines of evidence indicate that schizophrenia is characterized by impairments of synaptic machinery within cerebral cortical circuits. Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g., dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin), or to quantification of proteins using methods unable to resolve relevant cellular compartments. Multiple label fluorescence confocal microscopy represents a means to circumvent many of these limitations, by concurrently extracting information regarding the number, morphology, and relative protein content of synaptic structures. An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions. In this review article we consider the application of multiple label fluorescence confocal microscopy to the mapping of synaptic alterations in subjects with schizophrenia and describe the application of a novel, readily automated, iterative intensity/morphological segmentation algorithm for the extraction of information regarding synaptic structure number, size, and relative protein level from tissue sections obtained using unbiased stereological principles of sampling. In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex.

No MeSH data available.


Related in: MedlinePlus

Parvalbumin-positive inhibitory boutons. (A) Projection images of deconvolved confocal image stacks (13 z-planes taken 0.22 μm apart) labeled for PV in Cryostat sections (40 μm). Arrowheads indicate a chandelier cell cartridge. An unlabeled pyramidal cell (P) is surrounded by PV+ presumptive basket cell boutons. (B,C) The entire PV cartridge was masked (B) followed by the masking of puncta that make up the cartridge using a modification of our iterative segmentation methodology (C). (D) Shows the mask objects remaining after using our masking method followed by the subtraction of mask objects that colocalized with the mask in (B). The objects thus represent the PV+ boutons not located within cartridges. Bar = 10 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2903233&req=5

Figure 5: Parvalbumin-positive inhibitory boutons. (A) Projection images of deconvolved confocal image stacks (13 z-planes taken 0.22 μm apart) labeled for PV in Cryostat sections (40 μm). Arrowheads indicate a chandelier cell cartridge. An unlabeled pyramidal cell (P) is surrounded by PV+ presumptive basket cell boutons. (B,C) The entire PV cartridge was masked (B) followed by the masking of puncta that make up the cartridge using a modification of our iterative segmentation methodology (C). (D) Shows the mask objects remaining after using our masking method followed by the subtraction of mask objects that colocalized with the mask in (B). The objects thus represent the PV+ boutons not located within cartridges. Bar = 10 μm.

Mentions: Iterative segmentation process for automated quantification of fluorescent structures (Fish et al., 2008). (A–C) Show the intensity histograms with the lower bounds for segmentation progressively migrating towards higher values, which results in fewer and fewer objects being masked (A′–C′). At each step, only mask objects within the selected size range are kept (A′′–C′′). After each iterative step the resulting masks (A′′–C′′) are combined. Even after only these 3 iterative steps, the combined mask shown in (D′′) already has excellent object representation [compare with the unmasked data in (D’)]. In practice any number of iterations can be chosen so as to ensure comprehensive masking of objects (see e.g., Figures 2–5).


Mapping Synaptic Pathology within Cerebral Cortical Circuits in Subjects with Schizophrenia.

Sweet RA, Fish KN, Lewis DA - Front Hum Neurosci (2010)

Parvalbumin-positive inhibitory boutons. (A) Projection images of deconvolved confocal image stacks (13 z-planes taken 0.22 μm apart) labeled for PV in Cryostat sections (40 μm). Arrowheads indicate a chandelier cell cartridge. An unlabeled pyramidal cell (P) is surrounded by PV+ presumptive basket cell boutons. (B,C) The entire PV cartridge was masked (B) followed by the masking of puncta that make up the cartridge using a modification of our iterative segmentation methodology (C). (D) Shows the mask objects remaining after using our masking method followed by the subtraction of mask objects that colocalized with the mask in (B). The objects thus represent the PV+ boutons not located within cartridges. Bar = 10 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2903233&req=5

Figure 5: Parvalbumin-positive inhibitory boutons. (A) Projection images of deconvolved confocal image stacks (13 z-planes taken 0.22 μm apart) labeled for PV in Cryostat sections (40 μm). Arrowheads indicate a chandelier cell cartridge. An unlabeled pyramidal cell (P) is surrounded by PV+ presumptive basket cell boutons. (B,C) The entire PV cartridge was masked (B) followed by the masking of puncta that make up the cartridge using a modification of our iterative segmentation methodology (C). (D) Shows the mask objects remaining after using our masking method followed by the subtraction of mask objects that colocalized with the mask in (B). The objects thus represent the PV+ boutons not located within cartridges. Bar = 10 μm.
Mentions: Iterative segmentation process for automated quantification of fluorescent structures (Fish et al., 2008). (A–C) Show the intensity histograms with the lower bounds for segmentation progressively migrating towards higher values, which results in fewer and fewer objects being masked (A′–C′). At each step, only mask objects within the selected size range are kept (A′′–C′′). After each iterative step the resulting masks (A′′–C′′) are combined. Even after only these 3 iterative steps, the combined mask shown in (D′′) already has excellent object representation [compare with the unmasked data in (D’)]. In practice any number of iterations can be chosen so as to ensure comprehensive masking of objects (see e.g., Figures 2–5).

Bottom Line: Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g., dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin), or to quantification of proteins using methods unable to resolve relevant cellular compartments.An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions.In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex.

View Article: PubMed Central - PubMed

Affiliation: Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh Pittsburgh, PA, USA.

ABSTRACT
Converging lines of evidence indicate that schizophrenia is characterized by impairments of synaptic machinery within cerebral cortical circuits. Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g., dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin), or to quantification of proteins using methods unable to resolve relevant cellular compartments. Multiple label fluorescence confocal microscopy represents a means to circumvent many of these limitations, by concurrently extracting information regarding the number, morphology, and relative protein content of synaptic structures. An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions. In this review article we consider the application of multiple label fluorescence confocal microscopy to the mapping of synaptic alterations in subjects with schizophrenia and describe the application of a novel, readily automated, iterative intensity/morphological segmentation algorithm for the extraction of information regarding synaptic structure number, size, and relative protein level from tissue sections obtained using unbiased stereological principles of sampling. In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex.

No MeSH data available.


Related in: MedlinePlus