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T B Golubeva

Publications and source records attributed to T B Golubeva.

At least 19 recordsLinked to original sources
PubMed2000

[The 3-dimensional organization of the sensory epithelium of the cochlea in birds].

Using authors' original approach to studying histoarchitecture of cellular layers three-dimensional structure of bird helix sensory epithelium was studied theoretically and experimentally. The composition of its elementary morphofunctional unit, AB3 (one sensory cell per three supporting cells) was established. Three dimensional model of this unit was worked out that described shape and arrangement of cells at apical, basal and intermediate levels of the layer. The presence of its translation symmetry was demonstrated. Comparison of theoretical model and results of morphological research of sensory epithelium allowed to conclude that the model corresponds with the real tissue. The model assists in three-dimensional reconstruction of sensory epithelium. And allows to deal with minimum number of sections and also gives an opportunity to forecast its developmental changes.

Animals↗
PubMed1991

Amino acid sequence determination of vaccinia virus immunodominant protein p35 and identification of the gene.

A major immunodominant envelope protein of vaccinia virus (protein p35) was purified by extraction from virions with the nonionic detergent Nonidet P-40. The protein was cleaved with cyanogen bromide. Four homogeneous peptides were isolated and their N-terminal amino acid sequences determined. A computer search of a protein-sequence data bank revealed complete identity of the determined sequences with sequences 44-63, 144-149, 154-165, and 224-238 of ORF H3 of the HindIII-H fragment of the vaccinia virus genome (Rosel et al 1986). It has therefore been established that the immunodominant protein p35 of vaccinia virus is encoded by the gene in the HindIII-H fragment of the vaccinia virus genome.

Amino Acid Sequence↗
PubMed1991

Studies on the N-terminal sequences of lectins isolated from the seeds of Butea frondosa.

Two lectin fractions (FI and FII) were obtained from seeds of Butea frondosa by affinity chromatography on a sorbent of macroporous glass coupled to the disaccharide alpha-D-GalNAc-(1----3)-beta-D-Gal. Both of these fractions, although different in their sugar specificity, were found on SDS-PAGE to consist of two polypeptide chains of 33 kDa and 35 kDa. In the native state the subunits associated to form a 250 kDa complex, possibly comprising four molecules of the 33 kDa polypeptide and four molecules of the 35 kDa polypeptide. The presence of a faint 70 kDa band when the 250 kDa complex was subjected to SDS-PAGE may indicate the existence of a sequential mechanism of aggregation. N-terminal amino acid sequence analysis revealed extensive homology between these lectins and those of other Leguminosae.

Amino Acid Sequence↗
PubMedDate not supplied

Sensory information--the major factor of ontogeny.

On the basis of their own data authors postulate that the increase in sensory input during early ontogeny results in a delay in the development of the sensory systems formed earlier. In connection with this, the sensory basis of behavioral patterns becomes ineffective, causing their reorganization and the appearance of new forms of behavior. Limitation of sensory input during during the critical periods of development stimulates the accelerated manifestation of behavioral patterns. However, this acceleration also has long-lasting negative effects - alterations in the process of learning and memory in adult animals.

Aging↗
PubMedDate not supplied

The minimal provision principle of functional systems. Neuronal mechanisms.

An important characteristic of the developing nerve cell is its ability to function long before maturity. At this time, the neuron has the basic properties of an excitable membrane, an incompletely developed dendritic tree, and a low level of afferent input. All of these factors hinder the initiation of synaptic and spike potentials. It is proposed that the functional potential of neurons at the early stages of development are provided by an adaptive system, which may include: 1) the excess phenomenon, i.e., increases in the numbers of nerve cells, their processes, spines, and synapses; 2) factors increasing the chances of meeting the expected afferentation, i.e., the orientation and growth of dendrites towards the afferent input and the structure and localization of branch points; 3) factors facilitating the initiation of nerve spikes i.e., juvenile channels for ion current generation, electrical interactions between cells. and additional trigger zones. These groups of properties solve a single common problem: that of facilitating cells to respond to single or weak signals. This is the basic condition supporting the operation of interneuron interactions at the early stages of brain development.

Animals↗
PubMedDate not supplied

[Visual afferentation deficit during diffuse photosensitivity period in nestlings affects morphogenesis in Wulst neurons].

Golgi-stained preparations were processed with computerized morphometry to study the effect of the deprivation (eyes covered with nontransparent caps) on the development of neurons in the Wulst (the structure analogous to mammalian visual cortex) of pied flycatcher nestlings. Six-day-old nestlings that have only one form of the visual perception--diffuse photosensitivity--were studied. In the previous paper [Korneeva et al., 1994] in was shown that the Wulst of 6-day-old nestlings consisted of non-differentiated neurons and stellate-like cells at different stages of maturation; the latter group was subdivided into more- and less-mature cells. This work proved that even a 1.5-day-long deprivation (actual duration being counted off from the moment of appearance of the first retinal photoreceptors at the age of 4.5 days) resulted in significant changes in the geometry of stellate-like neurons. The changes in less-mature cells were predominantly destructive (decline of all quantitative indices of a cell, including the significant decrease in the total length of dendrites, maximal radius of the dendritic field and cell branching index), while the changes in more-mature cells were constructive (increase in all quantitative cell indices, including statistically significant increase in the soma section area, total length of dendrites, maximal radius of dendritic field and the number of foci of maximal branching). Different reactions of these cell types to the limitation of visual afferentation may be connected with differences in the afferent inflow to less- and more-mature cells or/and with different maturational stages of these neurons at the onset of deprivation.

Afferent Pathways↗
PubMedDate not supplied

[Increasing selectivity of defense behavior during development of pied flycatcher nestlings].

The development of defense reaction was studied in the wildlife and experimentally in 7 broods of altricial pied flycatcher (Ficedula hypoleuca) nestlings. Field studies demonstrated that passive-defense response first appeared on the 4th day of the nest life. It developed from the cessation of begging in young relatively satiated nestlings to characteristic freezing response independent of the level of feeding motivation in older nestlings. Older nestlings also acquire the defense reaction in response to novel visual stimuli. The efficiency of the natural stimulus for defense behavior (species-specific alarm call) nongradually changes during the nest life attaining the 100% level only on the 11th posthatching day. During the initial phase of defense behavior development, the reaction can be induced by different rhythmically organized stimuli. Later it becomes considerably more selective and other rhythmic and acoustic signals become much less effective than the alarm call.

Acoustic Stimulation↗
PubMedDate not supplied

[Identification of the gene for the immunodominant p35 protein from vaccinia virus].

A major immunodominant envelope protein p35 of vaccina virus was purified by means of extraction from virions with detergent NP-40. The protein was cleaved with CNBr, four homogenous peptides were isolated and their N-terminal amino acid sequences were determined. Computer search in a protein sequences data bank revealed that the immunodominant protein p35 of vaccinia virus is encoded by H3 gene in HindIII-H fragment of vaccinia virus genome.

Amino Acid Sequence↗
PubMedDate not supplied

[The role of visual afferentation in the development of early defense behavior of pied flycatcher nestlings].

The development of defense behavior in normal and visually deprived pied flycatcher nestlings was studied in the wild. It was demonstrated that the young deprived of the visual afferentation did not develop the freezing posture. In the majority of cases, specific alarm call suppressed begging in visually deprived nestlings less effectively than in the control ones. Visually deprived nestlings could not discriminate between the alarm call and other rhythmically organized acoustic signals even though the latter effectively suppressed begging.

Acoustic Stimulation↗
PubMedDate not supplied

[Heterochronicity in the development of hearing in birds during ontogenesis].

Studies have been made on the development of hearing in the jackdaw Coloeus monedula and sea-gulls Larus canus and L. argenatus, by means of recording microphonic component of the cochlear potential under chronic experimental conditions. Special attention was paid to changes in the regions of maximum sensitivity of the microphonic component during avian growth. It was shown that the range of the perceived frequencies at the beginning of functioning of the auditory analyser coincides completely with the spectrum of parental feeding signals. Threshold parameters of the microphonic component in jackdaw nestlings differ from those of sea-gull embryos by more evident flatness. Narrow bands of the increased sensitivity which are typical of the threshold curves in sea-gull embryos essentially correlated with the chirps of embryos. These data suggest the influence of afferent stimulation on the development of the organ of hearing in birds.

Age Factors↗
PubMedDate not supplied

[A delay in the development of hearing and a shift in the leading afferentation in the early behavioral ontogeny of birds].

Development of auditory sensitivity was studied by recording microphonic component of cochlear potentials during the period of opening the eyes in 6 species of birds with different types of ontogeny (Anas plathyrynchos, Larus canus and L. argentatus, Sterna paradisaea, Coloeus monedula and Corvus frugeleus). The onset of opening the eyes is accompanied by a delay in development of auditory sensitivity and temporary decrease of upper frequency limit of the audible range. Before such a delay acoustic afferentation is leading in feeding behaviour or in response of following in nestlings or chicks. After the period of delay pure tones lose the efficacy in eliciting feeding and following reactions, and the correlation between the low-frequency range of increased sensitivity and the efficacy of pure tone signals disappears, while the new peak of sensitivity appears which fits the maximal energetic component of the parental acoustic signals. It seems possible that the delay may be the result of brain temperature decrease while eyes open the thermoregulation being unstable. Such a delay may facilitate also the substitution of acoustic afferentation for visual in the main behavioural responses in early ontogeny.

Acoustic Stimulation↗
PubMedDate not supplied

[Acoustically guided behavior in the early ontogeny of the long-eared owl: the characteristics of its feeding behavior and the parameters of the acoustic signal important for its stimulation].

Feeding behaviour of nestlings of long-eared owls (Asio otus) is manifested as a complex of two components, i. e., the vocal reaction (uttering of begging calls) and specific motor response. Exposure to the appropriate acoustic signals resulted in an increase in the number of begging calls and approaching reaction to the source of acoustic signals. The range of monotonal signals effective for eliciting feeding behaviour was 0.2--1.5 kHz, the most effective were the tones of 0.3--0.7 kHz. The approaching reaction to acoustic signals was rather weak up to the 5th day after hatching, clearly pronounced in the 6--11th days, and later on was abruptly substituted for the response of following the visual stimulus provoked by the acoustic stimulation. Specific acoustic afferentation is the sole stimulus for begging in nestlings up to 11 days of age, and it remains a triggering stimulus for feeding behaviour in owl nestlings throughout the period of artificial feeding under laboratory conditions (up to the 40th day after hatching.

Acoustic Stimulation↗