Gap junctions on hippocampal mossy fiber axons demonstrated by thin-section electron microscopy and freeze–fracture replica immunogold labeling
Autor: | John E. Rash, Susan L. Wearne, Farid Hamzei-Sichani, Patrick R. Hof, Mark G. Stewart, Steven R. Young, Thomas Yasumura, Naomi Kamasawa, Miles A. Whittington, Roger D. Traub, Kimberly G. V. Davidson, William G.M. Janssen |
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Rok vydání: | 2007 |
Předmět: |
Materials science
Connexon law.invention Rats Sprague-Dawley Microscopy Electron Transmission Basic Science law medicine Microtome Animals Freeze Fracturing Axon Microscopy Immunoelectron Hippocampal mossy fiber Multidisciplinary Gap junction Gap Junctions Microtomy Immunogold labelling Anatomy Biological Sciences Rats medicine.anatomical_structure Mossy Fibers Hippocampal Biophysics Gold Electron microscope Stratum lucidum |
Zdroj: | Proceedings of the National Academy of Sciences. 104:12548-12553 |
ISSN: | 1091-6490 0027-8424 |
DOI: | 10.1073/pnas.0705281104 |
Popis: | Gap junctions have been postulated to exist between the axons of excitatory cortical neurons based on electrophysiological, modeling, and dye-coupling data. Here, we provide ultrastructural evidence for axoaxonic gap junctions in dentate granule cells. Using combined confocal laser scanning microscopy, thin-section transmission electron microscopy, and grid-mapped freeze–fracture replica immunogold labeling, 10 close appositions revealing axoaxonic gap junctions (≈30–70 nm in diameter) were found between pairs of mossy fiber axons (≈100–200 nm in diameter) in the stratum lucidum of the CA3b field of the rat ventral hippocampus, and one axonal gap junction (≈100 connexons) was found on a mossy fiber axon in the CA3c field of the rat dorsal hippocampus. Immunogold labeling with two sizes of gold beads revealed that connexin36 was present in that axonal gap junction. These ultrastructural data support computer modeling and in vitro electrophysiological data suggesting that axoaxonic gap junctions play an important role in the generation of very fast (>70 Hz) network oscillations and in the hypersynchronous electrical activity of epilepsy. |
Databáze: | OpenAIRE |
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