[ { "id": "authors:p1hbf-tgc20", "collection": "authors", "collection_id": "p1hbf-tgc20", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:MALjcs67", "type": "article", "title": "A study of mitochondrial membranes in relation to elementary particles", "author": [ { "family_name": "Malhotra", "given_name": "S. K.", "clpid": "Malhotra-S-K" }, { "family_name": "Eakin", "given_name": "R. T.", "clpid": "Eakin-R-T" } ], "abstract": "Elementary particles that commonly have been seen by electron microscopy to be attached by stalks to mitochondrial cristae in negatively stained preparations, were not apparent in similarly stained mitochondria from exponentially growing wild-type Neurospora crassa when these were isolated in sucrose solution containing 1 x 10^-3 M EDTA. However, elementary particles were easily demonstrable in electron micrographs if the mitochondria were isolated without EDTA in the sucrose solution. A biochemical study indicated that both kinds of mitochondrial preparations, isolated in the presence or absence of EDTA, had about the same capacity for oxidative phosphorylation. Observations on rat-liver mitochondria also suggested that the stalked elementary particles were more easily demonstrated if the preparation was made in the absence of EDTA. It was difficult to demonstrate elementary particles in wild-type Neurospora mitochondria isolated with or without EDTA and subsequently prepared for electron microscopy by spreading on the surface of an aqueous solution of potassium phosphotungstate. Elementary particles could be demonstrated in poky Neurospora mitochondria isolated with EDTA if the mitochondria were spread on the surface of an aqueous solution of phosphotungstate. It was concluded that biochemical functions associated with elementary particles are independent of structural configuration as seen by electron microscopy.", "issn": "0021-9533", "publisher": "Company of Biologists", "publication": "Journal of Cell Science", "publication_date": "1967-06", "series_number": "2", "volume": "2", "issue": "2", "pages": "205-212" }, { "id": "authors:tpy4m-01r89", "collection": "authors", "collection_id": "tpy4m-01r89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:HARjcb66", "type": "article", "title": "Demonstration of Extracellular Space by Freeze-Drying in the Cerebellar Molecular Layer", "author": [ { "family_name": "van Harreveld", "given_name": "A.", "clpid": "van-Harreveld-A" }, { "family_name": "Malhotra", "given_name": "S. K.", "clpid": "Malhotra-S-K" } ], "abstract": "In electron micrographs of the molecular layer of the mouse cerebellum frozen within 30 sec of circulatory arrest and subsequently dried at -79 \u00b0C an appreciable extracellular space was found between the axons of the granular cells. Tight junctions were regularly observed between pre- and postsynaptic structures and the enveloping glia cells. In micrographs of cerebellum frozen 8 min after decapitation the space between the axons was absent and tight junctions between the nerve fibres were almost exclusively encountered. The extracellular space of asphyxiated and non-asphyxiated tissue in electron micrographs of frozen-dried material is similar to the space in comparable tissues treated by freeze-substitution. These observations suggest that there is an appreciable amount of extracellular material in oxygenated, living tissue which is taken up by cellular elements during asphyxiation.", "issn": "0021-9533", "publisher": "Company of Biologists", "publication": "Journal of Cell Science", "publication_date": "1966-06", "series_number": "2", "volume": "1", "issue": "2", "pages": "223-228" }, { "id": "authors:1s9mp-68a66", "collection": "authors", "collection_id": "1s9mp-68a66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:HARjcb65", "type": "article", "title": "A study of extracellular space in central nervous tissue by freeze-substitution", "author": [ { "family_name": "van Harreveld", "given_name": "A.", "clpid": "van-Harreveld-A" }, { "family_name": "Crowell", "given_name": "Jane", "clpid": "Crowell-J" }, { "family_name": "Malhotra", "given_name": "S. K.", "clpid": "Malhotra-S-K" } ], "abstract": "It was attempted to preserve the water distribution in central nervous tissue by rapid freezing followed by substitution fixation at low temperature. The vermis of the cerebellum of white mice was frozen by bringing it into contact with a polished silver mirror maintained at a temperature of about -207\u00b0C. The tissue was subjected to substitution fixation in acetone containing 2 per cent OsO4 at -85\u00b0C for 2 days, and then prepared for electron microscopy by embedding in Maraglas, sectioning, and staining with lead citrate or uranyl acetate and lead. Cerebellum frozen within 30 seconds of circulatory arrest was compared with cerebellum frozen after 8 minutes' asphyxiation. From impedance measurements under these conditions, it could be expected that in the former tissue the electrolyte and water distribution is similar to that in the normal, oxygenated cerebellum, whereas in the asphyxiated tissue a transport of water and electrolytes into the intracellular compartment has taken place. Electron micrographs of tissue frozen shortly after circulatory arrest revealed the presence of an appreciable extracellular space between the axons of granular layer cells. Between glia, dendrites, and presynaptic endings the usual narrow clefts and even tight junctions were found. Also the synaptic cleft was of the usual width (250 to 300 A). In asphyxiated tissue, the extracellular space between the axons is either completely obliterated (tight junctions) or reduced to narrow clefts between apposing cell surfaces.", "doi": "10.1083/jcb.25.1.117", "pmcid": "PMC2106613", "issn": "0021-9525", "publisher": "Rockefeller University Press", "publication": "Journal of Cell Biology", "publication_date": "1965-04", "series_number": "1", "volume": "25", "issue": "1", "pages": "117-137" } ]