A unified model of mitochondrial morphology

Korman, Ephraim F.; Addink, Albert D.F.; Wakabayashi, Takashi; Green, David E.

doi:10.1007/bf01516086

Cited by 34 publications

(8 citation statements)

References 21 publications

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“…Such mitochondria are much larger than the typical mitochondria within taste cells, and their cristae differ from the lamellar cristae characteristic of most taste cell mitochondria. As illustrated in Figure 10B and lOC, the cristae of atypical mitochondria appear as electron-dense sacs or tubules, in a configuration that has been termed twisted-energized or swollen twisted-energized (Green and Baum, 1970;Korman et al, 1970;Williams et al, 1970). Such a configuration of the cristae suggests that these mitochondria may be providing large quantities of energy for a n unidentified metabolic activity a t sites of contact between taste cells and nerve fibers.…”

Section: Figmentioning

confidence: 97%

Application of serial sectioning and three‐dimensional reconstruction to the study of taste bud ultrastructure and organization

Royer

Kinnamon

1994

Microscopy Res & Technique

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The lingual taste buds of mammals are complex organs containing dozens of cells of varying morphology and numerous nerve fibers that are intermingled among the cellular processes. Some of the taste bud cells form synaptic contacts with these nerve fibers. Important questions remain to be answered regarding the structure and function of the cells of various types within taste buds and the means by which responses to gustatory stimuli are transmitted to the nerve fibers that communicate with the brain. Using both conventional and high voltage electron microscopy, we have examined serially sectioned taste buds from the tongues of mice and rabbits in order to address these issues and to obtain more complete information than that available from sampling of sections. The technique of computer-assisted 3-D reconstruction was used to generate models of whole taste buds and individual cellular and neural elements within taste buds from the serial sections. Analysis of serially sectioned taste buds from mice and rabbits has revealed that in both of these species relatively few (30% or less) of the cells within the taste buds form synaptic contacts with nerve fibers. In the foliate taste buds of rabbits, all of the cells that are presynaptic to nerve fibers are of a single morphological type (type III). The cells that are presynaptic to nerve fibers within the taste buds of mice are morphologically diverse. A pattern of synaptic connectivity exists within murine taste buds such that a given nerve fiber receives synaptic input only from taste cells that are ultrastructurally similar. In the taste buds of both mice and rabbits, we have observed both divergence and convergence of synaptic input from the putative taste receptor cells onto nerve fibers, suggesting that at the level of the taste bud there is some integration of the information generated by individual receptor cells. In addition to typical chemical synapses, other cytoplasmic specializations (such as subsurface cisternae and atypical mitochondria) may be involved in interactions between taste bud cells and nerve fibers.

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Section: Figmentioning

confidence: 97%

Application of serial sectioning and three‐dimensional reconstruction to the study of taste bud ultrastructure and organization

Royer

Kinnamon

1994

Microscopy Res & Technique

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“…This edema and organelle swelling probably are due to the severe osmotic imbalance after the shock which is produced by the prolonged shock-induced depolarization. The mitochondria in the areas showing edema not only exhibit largeamplitude swelling, a common characteristic of cell injury, but are in a "non-energized" configuration similar to that observed in the presence of uncouplers (Korman et al, 1970). Thus, these mitochondria are not able to produce energy to aid cellular recovery from the shock, an observation consistent with the decreased oxygen consumption by guinea pig hearts after high-energy shocks (Dalli and Chiesa, 1966).…”

Section: Ultrastructural Changes Following 200 V/cm Shocksmentioning

confidence: 73%

“…When oxidative activity is depressed because of lack of oxygen or substrate or under the influence of uncouplers, the cristae are collapsed, with very narrow intracristal spaces and an expanded matrix translucent to electrons; this configuration is called "orthodox" or "nonenergized." When oxygen, substrate, and ADP are added, the intracristal spaces expand, with concomitant condensation of the matrix space, until the cristal walls of adjoining cristae touch each other and develop an internal structure at the points of contact (energized zigzag in Korman et al, 1970). Configurational changes take place very rapidly (within 35 seconds after the addition of ADP to the preparation), and the mitochondria revert to the orthodox form when all of the ADP is phosphorylated (Green, 1974).…”

Section: Ultrastructural Changes Following 80 V/cm Shocksmentioning

confidence: 99%

“…Therefore, this configuration can be considered as a precursor of mitochondrial injury, an interpretation consistent with the fact that, whereas the "condensed" configuration was found in 24% of the control cultures, the whorled configuration was found in less than 1% of these ( Table 2). The tubular configuration (called "energized" by Korman et al, 1970) of the cristae (Fig. ID) appeared most often in conjunction with the whorled configuration; it may represent a section through a peripheral portion of mitochondria in the whorled configuration since in these areas the cristae are dilated and tubular in appearance.…”

Section: Ultrastructural Changes Following 80 V/cm Shocksmentioning

confidence: 99%

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Ultrastructural injury to chick myocardial cells in vitro following "electric countershock".

Jones¹,

Proskauer²,

Paull³

et al. 1980

Circulation Research

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We studied the structural alterations that follow the application of currents similar to those used in clinical electric countershock procedures in cultured chick myocardial cells. Myocardial cells 48 hours in culture were subjected to electric field stimulation. The cells then were fixed for electron-microscope examination 30 seconds postshock. The ultrastructural alterations that appeared after an 80 V/cm shock included the appearance of >25% of the mitochondria per cell in the "condensed" configuration and mitochondria with swirled or tubular cristae. Large-amplitude swelling of the mitochondria and swollen endoplasmic reticulum also were observed in a few cells. The alterations that appeared after a 200 V/cm shock included contracture and disorganization of the myofibrils, large-amplitude swelling and loss of cristae in the mitochondria, swollen endoplasmic reticulum and nuclear envelope, and intracellular edema. The degree of ultrastructural change was dependent on the intensity of the shock. These structural alterations are consistent with an osmotic imbalance which occurs during a shock-induced prolonged depolarization of the cell membrane (Jones et al., 1978a), possibly due to a transient dielectric breakdown during the shock, and may underlie the arrhythmias and necrosis which often occur after high-intensity clinical and experimental eountershock procedures in vivo.

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“…The atypical mitochondria that we have observed have diameters two to three times larger than conventional mitochondria. Typically the cristae of the atypical mitochondria exhibit a “twisted-energized” or “swollen twisted-energized configuration” [50,51,53], resembling electron-dense sacs or tubules within the mitochondrion. The outer membranes of these atypical mitochondria are closely apposed to the cytoplasmic leaflet of the Type II taste cell’s membrane (Figure 5).…”

Section: Discussionmentioning

confidence: 99%

Immunocytochemical analysis of P2X2 in rat circumvallate taste buds

et al. 2012

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BackgroundOur laboratory has shown that classical synapses and synaptic proteins are associated with Type III cells. Yet it is generally accepted that Type II cells transduce bitter, sweet and umami stimuli. No classical synapses, however, have been found associated with Type II cells. Recent studies indicate that the ionotropic purinergic receptors P2X2/P2X3 are present in rodent taste buds. Taste nerve processes express the ionotropic purinergic receptors (P2X2/P2X3). P2X2/P2X3Dbl−/− mice are not responsive to sweet, umami and bitter stimuli, and it has been proposed that ATP acts as a neurotransmitter in taste buds. The goal of the present study is to learn more about the nature of purinergic contacts in rat circumvallate taste buds by examining immunoreactivity to antisera directed against the purinergic receptor P2X2.ResultsP2X2-like immunoreactivity is present in intragemmal nerve processes in rat circumvallate taste buds. Intense immunoreactivity can also be seen in the subgemmal nerve plexuses located below the basal lamina. The P2X2 immunoreactive nerve processes also display syntaxin-1-LIR. The immunoreactive nerves are in close contact with the IP3R3-LIR Type II cells and syntaxin-1-LIR and/or 5-HT-LIR Type III cells. Taste cell synapses are observed only from Type III taste cells onto P2X2-LIR nerve processes. Unusually large, “atypical” mitochondria in the Type II taste cells are found only at close appositions with P2X2-LIR nerve processes. P2X2 immunogold particles are concentrated at the membranes of nerve processes at close appositions with taste cells.ConclusionsBased on our immunofluorescence and immunoelectron microscopical studies we believe that both perigemmal and most all intragemmal nerve processes display P2X2-LIR. Moreover, colloidal gold immunoelectron microscopy indicates that P2X2-LIR in nerve processes is concentrated at sites of close apposition with Type II cells. This supports the hypothesis that ATP may be a key neurotransmitter in taste transduction and that Type II cells release ATP, activating P2X2 receptors in nerve processes.

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A unified model of mitochondrial morphology

Cited by 34 publications

References 21 publications

Application of serial sectioning and three‐dimensional reconstruction to the study of taste bud ultrastructure and organization

Application of serial sectioning and three‐dimensional reconstruction to the study of taste bud ultrastructure and organization

Ultrastructural injury to chick myocardial cells in vitro following "electric countershock".

Immunocytochemical analysis of P2X2 in rat circumvallate taste buds

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