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E M Zamoskovskiĭ

Publications and source records attributed to E M Zamoskovskiĭ.

9 recordsLinked to original sources
PubMed1982

[Postactivation changes in the ultrastructure of motor neurons].

The prolonged high-frequency synaptic activation of the frog spinal motoneurons suppressing their firing, leads to an increase in the size of synapses and to a considerable shift in their ultrastructure. Restoration of the functional and morphological alterations in the cells after cessation of their rhythmical activation proceeds with different speed: the restoration of neurons' ability to generate synaptic and spike potentials in response to testing stimulation of afferents occurs much earlier than the restoration of the cells' ultrastructure and size. Neurons with obviously changed ultrastructure of soma and synaptic apparatus are capable of generating synaptic and spike potentials in response to stimulation. At the same time, the size of the neurons returns to normal either than the normalizing of cell ultrastructures whose speed of restoration varies as well.

Action Potentials↗
PubMed1981

[Effect of a ginseng tissue culture preparation on morphofunctional changes in motor neurons upon activation].

Irritation for 10 min of the posterior spinal root in the frog Rana temporaria (electrical stimulation 50 imp/sec, threshold power 4) results in decreasing size of the motoneurons and their nuclei and in appearing pycnomorphous type of neurons. Simultaneously, peculiar changes in cellular ultrastructure connected with inhibition of protein synthesis are observed. When the ginseng preparation is administered to intact animals, an increased excitability of the spinal centers, as well as increasing volume of the motoneuronal nuclei and certain ultrastructural shifts demonstrating activation of protein synthesis and cellular energy are observed. When the ginseng preparation is preliminary administered to the frogs, before a high-frequency synaptic activation of the motoneurons, it protects the cells from pathological changes and pycnotic shrinkage.

Animals↗
PubMed1976

[Changes in the dimensions of motor neurons and their components with different forms of nerve center activation].

Experiments in frogs have shown that a prolonged orthodromic rhythmical activation of motoneurons induce changes in their size and staining. Under these conditions the size of all components of motoneurons (cytoplasm, nucleus, nucleolus) is changed. The cytoplasm size changes are more pronounced than those of the nucleus. Under prolongation of the low frequency stimulation (1 per sec.) of the dorsal roots the changes are of phasic character: an initial enlargement (10 minute-long stimulation) and a subsequent decrease of all the above spinal cord motoneuron components (25 minute stimulation). After the 10 minute high frequency stimulation (50 impulses per second) of nerve centers there occur a sharp decrease of the size of the cytoplasm and the nucleus.

Animals↗
PubMed1976

[The influence of synaptic processes on changes in neuronal structure].

Reactions of the spinal motoneurons to the afferent inflow were different in frogs: some neurons generated spike potentials during 10-min rhythmic stimulation (1/sec) of afferents, other neurons were switched on and off. The motoneurons and their synapses increased in size, their cytoplasmic matrix became lighter and ribosoms deteriorated. Antidromic activation did not entail modofocation of size or color of the cells. RNP granules were safe and local organellas degenerated. The role of synaptic processes in regulation of RNP metabolism and in intracellular reparation, was revealed.

Animals↗
PubMed1975

[Changes in the ultrastructure of frog spinal cord motor neurons following low frequency stimulation of afferent fibers].

Effect of 10 min stimulation on the motoneurones ultrastructure depended on the amplitude of the ventral root biopotentials. In case of low amplitudes dilated endoplasmic spaces, Golgi complex cisterns were seen. Mitochondria were swollen and the number of free ribosomes increased. In the cytoplasm many "whorl--like" structures appeared. In case of high amplitude ventral root biopotentials, alterations were particularly evident in decrease in the ribosomes number, fragmentation of the endoplasmic reticulum. Electron density of the motoneurons was very low. After 25 min stimulation, the number of ribosomes increased in the motoneurons, the Golgi complex proliferated, very large mitochondria appeared. In the dendrites, swollen mitochondria often were adjacent to postsynaptic membranes. Electron density of the motoneurons was very high. The ultrastructural alterations of the motoneurons are supposed to be due to a change of cellular metabolism in the conditions of increased functional activity.

Animals↗
PubMed1975

[A change in the ultrastructure of frog spinal cord and motor neuron synapses during prolonged activation].

Motoneuron axosomatic synapses (AS) were shown to be larger than axodendritic (AD) synapses under anaesthesia. A 10 minute-long electrical stimulation both by low and high frequency caused enlargement of AS and AD synapses, it being the more pronounced the higher was the activation frequency. In all cases changes the AS synapses were more marked than those of AD synapses. On the bases of morphological and physiological data it was concluded that the changes of the synapse dimentions did not affect the synaptic transmission.

Animals↗