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Biomedical subjects

A V Bursian

Publications and source records attributed to A V Bursian.

7 recordsLinked to original sources
PubMedDate not supplied

[The temporal organization of human fetal motor function].

Fetal motor bursts were recorded in pregnant women at 11-18, 20-24 and 30-32 weeks of pregnancy. It was stated that spontaneous motor activity in human fetus is similar to autogenic periodic motor excitation observed in other species of vertebrates, i.e. presence of the main rest-activity circles with a period near 1 minute, the existence of rhythmic components with 6-8-second intervals during active phases and decreasing of quantity of excitation bursts with age.

Female↗
PubMedDate not supplied

[Primary excitatory rhythms in locomotor activity of scyphomedusae].

Periodic organization of autorhythmic motor activity which is typical of ontogenetically earlier stages of development of the nervous functions in vertebrates has been found in larval scyphomedusae. In hydromedusae which exhibit less complex nervous system, periodic organization of excitation persists also in adult individuals. It is suggested that already at the level of scyphomedusae, periodic form of organization of autorhythmic excitation in the nervous system was transformed in a category of recapitulating characters and in this quality passed along all phylogenetic pathways.

Animals↗
PubMedDate not supplied

[Effect of stimulation of the sensomotor cortex on the activity of the lumbar motor center in rats during ontogenesis].

In rats ageing up to 3 weeks, studies have been made on the reactions of the spinal motor center to long-lasting rhythmic stimulation of sensorimotor cortex. It was found that in 5-day old rats specific periodic pattern of the activity may be recorded similar to the autorhythmic spontaneous activity described in our earlier papers. In older animals periodic pattern of reaction can also be observed, but it may be modulated by stimulation. Beginning from the 12th day, periodic pattern of reaction is transformed into aperiodic one typical for adult animals. From the 3rd week of life, the inhibitory effect of motor cortex stimulation on locomotor activity could be observed.

Age Factors↗
PubMedDate not supplied

[The characteristics of the potential of the dorsal surface of the spinal cord in week-old rat pups].

In 7-day albino rats, the negative component of the potential of the dorsal surface of the spinal cord during stimulation of the nervous trunk exhibits long latent period, low amplitude and significant duration. Slow positive potential has a low amplitude, whereas its duration is approximately the same as that in adult rats. The presence of a slow positive wave in 7-day rats indicates a possibility of presynaptic inhibition already at the beginning of postnatal life of these animals.

Aging↗
PubMedDate not supplied

[Reflex reactions of the spinal motor center of rats in the early periods following birth].

Reactions of the spinal motor center to tetanic stimulation of afferent nerve fibers in the peripheral nerve or dorsal roots L4--L6, have been investigated in rat pups ageing from 1 to 30 days. EMG was recorded in m. gastrocnemius. Within the first 12 days, in response to a constant stimulation periodic motor activity was observed which in its pattern was similar to the spontaneous cycles in newborn animals. On further development of rats, periodic form of the reaction is abolished, although it may be elicited after decerebration or during fatigue caused by a prolondged tetanization. Within the first week, tetanization of the afferents by the increasing stimuli either does not affect the periodic pattern of the activity, or results in a stepwise increase of the amplitude and duration of separate periods. On further development, gradual dependence of the intensity of the response from the stimulus strength is established, which is associated with functional differentiation of various motor units. The data obtained are discussed in relation to the role of afferent systems in evolution of functions of the central nervous system.

Animals↗