scholarly journals Correlating Synaptic Ultrastructure and Function at the Nanoscale

2019 ◽  
Author(s):  
Lydia Maus ◽  
Bekir Altas ◽  
JeongSeop Rhee ◽  
Nils Brose ◽  
Cordelia Imig ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Mossy Fiber ◽  
Electron Tomography ◽  
Freeze Substitution ◽  
Ultrastructural Organization ◽  
Vesicle Pools ◽  
Synaptic Ultrastructure ◽  
Organotypic Slice Cultures ◽  
Ultrastructure And Function ◽  
And Function

SUMMARYDespite similarities in the composition of the molecular release machinery, synapses can exhibit strikingly different functional transmitter release properties and short- and long-term plasticity characteristics. To address the question whether ultrastructural differences could contribute to this functional synaptic heterogeneity, we employed a combination of hippocampal organotypic slice cultures, high-pressure freezing, freeze substitution, and 3D-electron tomography to resolve the spatial organization of vesicle pools at individual active zones (AZ) in two functionally distinct synapses, namely Schaffer collateral (SC) and mossy fiber (MF) synapses. We found that mature MF and SC synapses harbor equal numbers of docked vesicles at their AZs, MF synapses at rest exhibit a second pool of possibly ‘tethered’ vesicles in the AZ vicinity, and MF synapses contain at least three morphological types of docked vesicles, indicating that differences in the ultrastructural organization of MF and SC synapses may contribute to their respective functional properties and corresponding plasticity characteristics.

Novel Molecular Specializations of the Pinceau in Rat Cerebellum as Revealed by Correlated Confocal Microscopy and Electron Tomography

2001 ◽  
Vol 7 (S2) ◽  
pp. 96-97
Author(s):  
Marketta Bobik ◽  
F. Capani ◽  
M. E. Martone ◽  
M. Ellisman
Keyword(s):  
Electron Microscopy ◽  
Electron Tomography ◽  
Basket Cell ◽  
Ultrastructural Organization ◽  
Inhibitory Influence ◽  
Cellular Element ◽  
Novel Proteins ◽  
Gaba Transporters ◽  
And Function ◽  
Oxide Synthase

The pinceau is a cerebellar structure formed by GABA-ergic descending basket cell axonal terminals converging on the initial axonal segment of Purkinje cell. Although it exerts a powerful inhibitory influence on the output of the cerebellar cortex, the exact ultrastructural organization and function of this structure are not understood. The unique morphology of the pinceau lies in several elements: lack of synaptic contacts between basket cell terminals and the initial axonal segment, the absence of postsynaptic densities, and heavy ensheathment of the initial segment with glial processes, making astrocytes the only intervening cellular element between the two types of axonal structures. Several plasticity related proteins in this area have been previously characterized by immunocytochemistry. Those include nitric oxide synthase, PSD95, GABA transporters, and several voltage gated potassium channel subunits. We are using a combination of confocal and electron microscopy, correlated photooxidation, EM and tomography to reveal the ultrastructural distribution of novel proteins and their relationships to morphological compartments in the pinceau.We describe here Kv3.2, a recently discovered member of the Shaw-like subfamily of potassium channels, and the correlated distribution of other proteins described below. Pre-embedding immunolabeling, electron microscopy and tomography showed that Kv3.2 was selectively localized to basket cell axons.

scholarly journals Linking Ultrastructure and Function in Four Genera of Anaerobic Ammonium-Oxidizing Bacteria: Cell Plan, Glycogen Storage, and Localization of Cytochrome c Proteins

2007 ◽  
Vol 190 (2) ◽  
pp. 708-717 ◽  
Author(s):  
Laura van Niftrik ◽  
Willie J. C. Geerts ◽  
Elly G. van Donselaar ◽  
Bruno M. Humbel ◽  
Richard I. Webb ◽  
...  
Keyword(s):  
Electron Tomography ◽  
Glycogen Storage ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Intracytoplasmic Membrane ◽  
Transmission Electron ◽  
Cell Plan ◽  
Ultrastructure And Function ◽  
And Function ◽  
Common Cell

ABSTRACT Anaerobic ammonium oxidation (anammox) is an ecologically and industrially important process and is performed by a clade of deeply branching Planctomycetes. Anammox bacteria possess an intracytoplasmic membrane-bounded organelle, the anammoxosome. In the present study, the ultrastructures of four different genera of anammox bacteria were compared with transmission electron microscopy and electron tomography. The four anammox genera shared a common cell plan and contained glycogen granules. Differences between the four genera included cell size (from 800 to 1,100 nm in diameter), presence or absence of cytoplasmic particles, and presence or absence of pilus-like appendages. Furthermore, cytochrome c proteins were detected exclusively inside the anammoxosome. This detection provides further support for the hypothesis that this organelle is the locus of anammox catabolism.

CSC counteracts l-DOPA-induced overactivity of the corticostriatal synaptic ultrastructure and function in 6-OHDA-lesioned rats

2011 ◽  
Vol 1376 ◽  
pp. 113-121 ◽  
Author(s):  
Yi-xian Huang ◽  
Wei-feng Luo ◽  
Dan Li ◽  
Wei-dong Hu ◽  
Chun-feng Liu
Keyword(s):  
Synaptic Ultrastructure ◽  
Ultrastructure And Function ◽  
And Function

scholarly journals Alterations in flight muscle ultrastructure and function in Drosophila tropomyosin mutants.

1996 ◽  
Vol 135 (3) ◽  
pp. 673-687 ◽  
Author(s):  
A J Kreuz ◽  
A Simcox ◽  
D Maughan
Keyword(s):  
Amino Acid ◽  
Power Output ◽  
Flight Muscle ◽  
Structure And Function ◽  
Wild Type ◽  
Muscle Tropomyosin ◽  
Ultrastructure And Function ◽  
And Function ◽  
Net Power Output ◽  
Current Report

Drosophila indirect flight muscle (IFM) contains two different types of tropomyosin: a standard 284-amino acid muscle tropomyosin, Ifm-TmI, encoded by the TmI gene, and two > 400 amino acid tropomyosins, TnH-33 and TnH-34, encoded by TmII. The two IFM-specific TnH isoforms are unique tropomyosins with a COOH-terminal extension of approximately 200 residues which is hydrophobic and rich in prolines. Previous analysis of a hypomorphic TmI mutant, Ifm(3)3, demonstrated that Ifm-TmI is necessary for proper myofibrillar assembly, but no null TmI mutant or TmII mutant which affects the TnH isoforms have been reported. In the current report, we show that four flightless mutants (Warmke et al., 1989) are alleles of TmI, and characterize a deficiency which deletes both TmI and TmII. We find that haploidy of TmI causes myofibrillar disruptions and flightless behavior, but that haploidy of TmII causes neither. Single fiber mechanics demonstrates that power output is much lower in the TmI haploid line (32% of wild-type) than in the TmII haploid line (73% of wild-type). In myofibers nearly depleted of Ifm-TmI, net power output is virtually abolished (< 1% of wild-type) despite the presence of an organized fibrillar core (approximately 20% of wild-type). The results suggest Ifm-TmI (the standard tropomyosin) plays a key role in fiber structure, power production, and flight, with reduced Ifm-TmI expression producing corresponding changes of IFM structure and function. In contrast, reduced expression of the TnH isoforms has an unexpectedly mild effect on IFM structure and function.

scholarly journals Cryo-electron tomography of cells: connecting structure and function

2008 ◽  
Vol 130 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Vladan Lučić ◽  
Andrew Leis ◽  
Wolfgang Baumeister
Keyword(s):  
Electron Tomography ◽  
Structure And Function ◽  
Cryo Electron Tomography ◽  
And Function

Essential thrombocythemia in a child: Platelet ultrastructure and function

1980 ◽  
Vol 8 (1) ◽  
pp. 87-107 ◽  
Author(s):  
Marion I. Barnhart ◽  
Tae H. Kim ◽  
Bruce L. Evatt ◽  
Abdelsalam H. Ragab ◽  
Victor K. Lui ◽  
...  
Keyword(s):  
Essential Thrombocythemia ◽  
Ultrastructure And Function ◽  
And Function

scholarly journals Ultrastructure and function of mitochondria in gametocytic stage ofPlasmodium falciparum

Parasite ◽  
2000 ◽  
Vol 7 (1) ◽  
pp. 19-26 ◽  
Author(s):  
J. Krungkrai ◽  
P. Prapunwattana ◽  
S.R. Krungkrai
Keyword(s):  
Ofplasmodium Falciparum ◽  
Ultrastructure And Function ◽  
And Function
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