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Analysis of shape and spatial interaction of synaptic vesicles using data from focused ion beam scanning electron microscopy (FIB-SEM).

Khanmohammadi M, Waagepetersen RP, Sporring J - Front Neuroanat (2015)

Bottom Line: Statistics for marked point processes were employed to study spatial interactions between vesicles.We found that the synaptic vesicles in excitatory synapses appeared to be of oblate ellipsoid shape and in inhibitory synapses appeared to be of cigar ellipsoid shape, and followed a systematic pattern regarding their orientation toward the active zone.Moreover, there was strong evidence of spatial alignment in the orientations of pairs of synaptic vesicles, and of repulsion between them only in excitatory synapses, beyond that caused by their physical extent.

View Article: PubMed Central - PubMed

Affiliation: Computer Science Department, University of Copenhagen Copenhagen, Denmark.

ABSTRACT
The spatial interactions of synaptic vesicles in synapses were assessed after a detailed characterization of size, shape, and orientation of the synaptic vesicles. We hypothesized that shape and orientation of the synaptic vesicles are influenced by their movement toward the active zone causing deviations from spherical shape and systematic trends in their orientation. We studied three-dimensional representations of synapses obtained by manual annotation of focused ion beam scanning electron microscopy (FIB-SEM) images of male mouse brain. The configurations of synaptic vesicles were regarded as marked point patterns, where the points are the centers of the vesicles, and the mark of a vesicle is given by its size, shape, and orientation characteristics. Statistics for marked point processes were employed to study spatial interactions between vesicles. We found that the synaptic vesicles in excitatory synapses appeared to be of oblate ellipsoid shape and in inhibitory synapses appeared to be of cigar ellipsoid shape, and followed a systematic pattern regarding their orientation toward the active zone. Moreover, there was strong evidence of spatial alignment in the orientations of pairs of synaptic vesicles, and of repulsion between them only in excitatory synapses, beyond that caused by their physical extent.

No MeSH data available.


Related in: MedlinePlus

A 3D view of the pre-synaptic compartments of one of the synapses including the active zone (red), the mitochondria (blue), the centers of the synaptic vesicles (black dots), and the slices (cyan) parallel to the active zone surface. For better visualization one of the bands is shown in green.
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Figure 2: A 3D view of the pre-synaptic compartments of one of the synapses including the active zone (red), the mitochondria (blue), the centers of the synaptic vesicles (black dots), and the slices (cyan) parallel to the active zone surface. For better visualization one of the bands is shown in green.

Mentions: To assess a possible dependence of vesicle density on distance to the active zone, we estimate the density of the synaptic vesicles in 50 nm thick contiguous slices parallel to the active zone. Figure 2 shows these slices for one of the synapses used in this study as well as the pre-synaptic compartment, the mitochondria, and the centers of the synaptic vesicles.


Analysis of shape and spatial interaction of synaptic vesicles using data from focused ion beam scanning electron microscopy (FIB-SEM).

Khanmohammadi M, Waagepetersen RP, Sporring J - Front Neuroanat (2015)

A 3D view of the pre-synaptic compartments of one of the synapses including the active zone (red), the mitochondria (blue), the centers of the synaptic vesicles (black dots), and the slices (cyan) parallel to the active zone surface. For better visualization one of the bands is shown in green.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555025&req=5

Figure 2: A 3D view of the pre-synaptic compartments of one of the synapses including the active zone (red), the mitochondria (blue), the centers of the synaptic vesicles (black dots), and the slices (cyan) parallel to the active zone surface. For better visualization one of the bands is shown in green.
Mentions: To assess a possible dependence of vesicle density on distance to the active zone, we estimate the density of the synaptic vesicles in 50 nm thick contiguous slices parallel to the active zone. Figure 2 shows these slices for one of the synapses used in this study as well as the pre-synaptic compartment, the mitochondria, and the centers of the synaptic vesicles.

Bottom Line: Statistics for marked point processes were employed to study spatial interactions between vesicles.We found that the synaptic vesicles in excitatory synapses appeared to be of oblate ellipsoid shape and in inhibitory synapses appeared to be of cigar ellipsoid shape, and followed a systematic pattern regarding their orientation toward the active zone.Moreover, there was strong evidence of spatial alignment in the orientations of pairs of synaptic vesicles, and of repulsion between them only in excitatory synapses, beyond that caused by their physical extent.

View Article: PubMed Central - PubMed

Affiliation: Computer Science Department, University of Copenhagen Copenhagen, Denmark.

ABSTRACT
The spatial interactions of synaptic vesicles in synapses were assessed after a detailed characterization of size, shape, and orientation of the synaptic vesicles. We hypothesized that shape and orientation of the synaptic vesicles are influenced by their movement toward the active zone causing deviations from spherical shape and systematic trends in their orientation. We studied three-dimensional representations of synapses obtained by manual annotation of focused ion beam scanning electron microscopy (FIB-SEM) images of male mouse brain. The configurations of synaptic vesicles were regarded as marked point patterns, where the points are the centers of the vesicles, and the mark of a vesicle is given by its size, shape, and orientation characteristics. Statistics for marked point processes were employed to study spatial interactions between vesicles. We found that the synaptic vesicles in excitatory synapses appeared to be of oblate ellipsoid shape and in inhibitory synapses appeared to be of cigar ellipsoid shape, and followed a systematic pattern regarding their orientation toward the active zone. Moreover, there was strong evidence of spatial alignment in the orientations of pairs of synaptic vesicles, and of repulsion between them only in excitatory synapses, beyond that caused by their physical extent.

No MeSH data available.


Related in: MedlinePlus