Extracellular space in mouse cerebellar cortex revealed by in vivo cryotechnique

Ohno, Nobuhiko; Terada, Nobuo; Saitoh, Shu‐ichi; Ohno, Shinichi

doi:10.1002/cne.21498

Cited by 36 publications

(18 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Likewise, the presence of dendritic spines results in wider ECS surrounding the perisynaptic regions (Fig. 7A), as confirmed in recent findings using a cryogenically cooled knife that demonstrated large voids in the ECS, especially around synapses (Ohno et al,2007). In contrast, large‐diameter dendrites are preferentially surrounded by narrow ECS regions (Van Harreveld et al,1965), as were the vellate wings of the astrocytes (Fig.…”

Section: Discussionsupporting

confidence: 83%

Extracellular sheets and tunnels modulate glutamate diffusion in hippocampal neuropil

Kinney

Spaček

Bartol

et al. 2012

J of Comparative Neurology

124

133

View full text Add to dashboard Cite

Although the extracellular space in the neuropil of the brain is an important channel for volume communication between cells and has other important functions, its morphology on the micron scale has not been analyzed quantitatively owing to experimental limitations. We used manual and computational techniques to reconstruct the 3D geometry of 180 μm3 of rat CA1 hippocampal neuropil from serial electron microscopy and corrected for tissue shrinkage to reflect the in vivo state. The reconstruction revealed an interconnected network of 40–80 nm diameter tunnels, formed at the junction of three or more cellular processes, spanned by sheets between pairs of cell surfaces with 10–40 nm width. The tunnels tended to occur around synapses and axons, and the sheets were enriched around astrocytes. Monte Carlo simulations of diffusion within the reconstructed neuropil demonstrate that the rate of diffusion of neurotransmitter and other small molecules was slower in sheets than in tunnels. Thus, the non-uniformity found in the extracellular space may have specialized functions for signaling (sheets) and volume transmission (tunnels).

show abstract

Section: Discussionsupporting

confidence: 83%

Extracellular sheets and tunnels modulate glutamate diffusion in hippocampal neuropil

Kinney

Spaček

Bartol

et al. 2012

J of Comparative Neurology

124

133

View full text Add to dashboard Cite

show abstract

“…The IVCT-FS has some benefits for preserving biological molecules, including soluble proteins of animal tissues, as well as stopping dynamic morphology reflecting their living state, as reported before (Liao et al 2006, Ohno et al 2007b. Briefly, three wild-type mice or the 4.1G-deficient mice were anesthetized with pentobarbital, and IVCT was performed on their left testis by directly pouring 50 ml liquid isopentanepropane cryogen (K193 8C), which was cooled in liquid nitrogen, as reported before (Liao et al 2006, Zhou et al 2008.…”

Section: Ivct and Fs For Living Mouse Testesmentioning

confidence: 61%

Involvement of a membrane skeletal protein, 4.1G, for Sertoli/germ cell interaction

Terada¹,

Ohno²,

Saitoh³

et al. 2010

Reproduction

Self Cite

View full text Add to dashboard Cite

We previously reported that a membrane skeletal protein, 4.1G (also known as EPB41L2), is immunolocalized in mouse seminiferous tubules. In this study, the 4.1G immunolocalizaiton was precisely evaluated at various stages of the mouse seminiferous epithelial cycle with 'in vivo cryotechnique' and also with pre-embedding immunoelectron microscopy in testicular tissues whose ultrastructures were well preserved with glycerol treatment before cryosectioning. In addition, 4.1G-deficient mice were produced, and the morphology of their seminiferous tubules was also evaluated. The 4.1G immunolocalization was different among stages, indicating that it was not only along cell membranes of Sertoli cells, but also those of spermatogonia and early spermatocytes. To confirm the 4.1G immunolocalization in germ cells, in vitro culture of spermatogonial stem cells (SSCs) was used for immunocytochemistry and immunoblotting analysis. In the cultured SSCs, 4.1G was clearly expressed and immunolocalized along cell membranes, especially at mutual attaching regions. In testicular tissues, cell adhesion molecule-1 (CADM1), an intramembranous adhesion molecule, was colocalized on basal parts of the seminiferous tubules and immunoprecipitated with 4.1G in the tissue lysate. Interestingly, in the 4.1G-deficient mice, histological manifestation of the seminiferous tubules was not different from that in wild-type mice, and the CADM1 was also immunolocalized in the same pattern as that in the wild-type. Moreover, the 4.1G-deficient male mice were fertile. These results were probably due to functional redundancy of unknown membrane skeletal molecules in germ cells. Thus, a novel membrane skeletal protein, 4.1G, was found in germ cells, and considering its interaction with CADM family, it probably has roles in attachment of both Sertoli-germ and germ-germ cells.

show abstract

“…Post processing and embedding of brain tissue also likely caused water movement. A study of synaptic clefts with cryo-electromicroscopy (432) and work by Ohno et al (278) using an in vivo cryotechnique substantiate the idea that the ECS is wider than seen in conventional electron microscopy but it is still difficult to accurately gauge the width from electron micrographs.…”

Section: Extracellular Space and Applicable Concepts Of Diffusionmentioning

confidence: 96%

Diffusion in Brain Extracellular Space

Syková

Nicholson²

2008

Physiological Reviews

1,260

1,452

View full text Add to dashboard Cite

Diffusion in the extracellular space (ECS) of the brain is constrained by the volume fraction and the tortuosity and a modified diffusion equation represents the transport behavior of many molecules in the brain. Deviations from the equation reveal loss of molecules across the blood-brain barrier, through cellular uptake, binding, or other mechanisms. Early diffusion measurements used radiolabeled sucrose and other tracers. Presently, the real-time iontophoresis (RTI) method is employed for small ions and the integrative optical imaging (IOI) method for fluorescent macromolecules, including dextrans or proteins. Theoretical models and simulations of the ECS have explored the influence of ECS geometry, effects of dead-space microdomains, extracellular matrix, and interaction of macromolecules with ECS channels. Extensive experimental studies with the RTI method employing the cation tetramethylammonium (TMA) in normal brain tissue show that the volume fraction of the ECS typically is ∼20% and the tortuosity is ∼1.6 (i.e., free diffusion coefficient of TMA is reduced by 2.6), although there are regional variations. These parameters change during development and aging. Diffusion properties have been characterized in several interventions, including brain stimulation, osmotic challenge, and knockout of extracellular matrix components. Measurements have also been made during ischemia, in models of Alzheimer's and Parkinson's diseases, and in human gliomas. Overall, these studies improve our conception of ECS structure and the roles of glia and extracellular matrix in modulating the ECS microenvironment. Knowledge of ECS diffusion properties is valuable in contexts ranging from understanding extrasynaptic volume transmission to the development of paradigms for drug delivery to the brain.

show abstract

Extracellular space in mouse cerebellar cortex revealed by in vivo cryotechnique

Cited by 36 publications

References 48 publications

Extracellular sheets and tunnels modulate glutamate diffusion in hippocampal neuropil

Extracellular sheets and tunnels modulate glutamate diffusion in hippocampal neuropil

Involvement of a membrane skeletal protein, 4.1G, for Sertoli/germ cell interaction

Diffusion in Brain Extracellular Space

Contact Info

Product

Resources

About