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I A Keder-Stepanova

Publications and source records attributed to I A Keder-Stepanova.

13 recordsLinked to original sources

[The role of the bulbospinal respiratory neurons in generating the breathing rhythm].

The role of the medullary respiratory bulbospinal neurones in respiratory timing was studied. The respiratory neurones and phrenic activity were recorded in conditions of various types of stimulation of the descending axons in the spinal cord. The activation of the bulbospinal neurones by repetitive antidromic stimulation caused the increase of the breathing rhythm and changes of the structure of the respiratory cycle. The antidromic activation of these neurones by the brief train of stimuli evoked the phase reset of the respiratory cycle. The breathing system reproduced an artificial rhythmic regime of antidromic stimulation by brief trains of stimuli. The obtained data show that the activation of the respiratory bulbospinal neurons results in the change of the respiratory timing. Consequently the bulbospinal neurons take part in the generation of respiratory rhythm.

Animals↗

[The structural characteristics of the phrenic nucleus in the cat and their functional significance].

The structural elements of phrenic nucleus have been compared under the horseradish peroxidase introduction into the phrenic muscle and using a silver staining method. All the neurons of nucleus have been proposed to be motoneurons. The characteristic features of phrenic nucleus organisation are created by the groups of motoneurons and their dendritic bundles. Each nucleus contains about 800 motoneurons. Their sizes have been determined in three planes. Some functional characteristics of phrenic nucleus on the basis of its structural architecture are under discussion.

Animals↗

[Distribution of the fibers of the descending respiratory pathway in the phrenic nucleus of the cat].

A distribution of degenerated fibers in contralateral phrenic nucleus of cats with chronic hemisection of the spinal cord under medulla oblongata has been studied. These fibers approach the nucleus after the partial secondary crossing of the descending respiratory pathway on the level of cervical segments. Degenerated fibers follow the dendrites of phrenic motoneurons and approach the basal segments of dendrites but do not reach the cell bodies. Possible mode of control over phrenic nucleus activity is under discussion.

Animals↗

[Contacts between dendrites in motor neurons of the cat diaphragm].

Three radial and one longitudinal bundles of phrenic motoneuron dendrites have been detected. The dendrites were found to have spines and appendages which formed touching contacts with each other. If, as believed, some descending respiratory pathways terminate on the bundles, the touching contacts seem to be a substrate of phrenic motoneuron synchronous activation.

Animals↗