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A Csillag

Publications and source records attributed to A Csillag.

66 records · Page 4Linked to original sources
PubMed1979

The morphology of microtubules in incubated synaptosomes. Effect of low temperature and vinblastine.

A time-dependent rise in the percentage of microtubule-containing synaptosomes was observed reaching a 41--47% peak after 30 min incubation at room temperature (22--25 degrees C) in a saline medium. Fixation at low temperature or incubation with vinblastine decreased markedly the number of synpatosomes containing microtubules. It was concluded that incubation with cations and processing at room temperature were prerequisites of optimal preservation of synaptosomal microtubules. Their spatial orientation relative to the synaptic cleft was deduced from statistical examination of profiles in different orientations.

Animals↗
PubMed1979

The effect of ethanol on the distribution of synaptic vesicles in cortical synaptosomes of the rat.

Ethanol was shown to cause a redistribution of synaptic vesicles in incubated synaptosomes. While the number of synaptosomes containing synaptic vesicles attached to the presynaptic membrane decreased markedly, an increase in the number of synaptosomes lacking membrane-vesicle associations was observed. The findings support the possibility of a presynaptic action of ethanol and point to the role of membrane-attached vesicles in synaptic transmission.

Animals↗
PubMed1978

The effect of pentobarbital, chloralhydrate, ether and protoveratrine on the distribution of synaptic vesicles in rat cortical synaptosomes.

Rat cortical synaptosomes were incubated in a saline medium. On the addition of pentobarbital, chloralhydrate, ether and protoveratrine a redistribution of synaptic vesicles was revealed by electron microscopy. The anaesthetics decreased the number of synaptic vesicles attached to the presynaptic membrane while protoveratrine increased them. It is assumed that these agents affect the mechanism of vesicle reformation from the synaptosomal membrane and/or vesicle migration towards the synaptic cleft.

Animals↗
PubMed1978

Variations of matrix electrondensity in brain mitochondria.

The configuration of brain mitochondria was compared in situ, after aldehyde perfusion and/or osmium immersion fixation and in isolated fractions of different functional performance. After combined aldehyde perfusion osmium immersion fixation in situ, mitochondria were condensed having a dark matrix. Fractions capable of controlled respiration also consisted of condensed mitochondria. On the contrary, expanded mitochondria with light matrix were brought about by immersion fixation. Fractions consisting predominantly of light mitochondria displayed no controlled respiration. Light matrix and expanded form are therefore regarded as a functionally impaired state of brain mitochondria. The condensed form is thought to be a landmark of good fixation.

Aldehydes↗
PubMed1977

Ultrastructural, optical and volume changes in brain mitochondria during gramicidin-induced ion uptake.

Gramicidin-induced swelling of rat brain mitochondria was followed spectrophotometrically with a parallel analysis of changes in the ultrastructure, volume and eccentricity ratio of the mitochondria. Under the effect of gramicidin the expansion of the inner compartment occurs with an overall increase in volume. Mitochondria tend to be rounded although not entirely spherical in shape. The reversal of swelling with respiratory inhibitor (KCN, rotenone) results in a shrinkage of the inner compartment and is not accompanied by a proportional reduction of the outer compartment. Mitochondria fail to regain their original shape. It can be concluded that in the course of energy-dependent swelling the ability to contract might be retained, whereas other factors controlling the shape of the mitochondrion are irreversibly affected.

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