PubMed Health⌕ Search

Biomedical subjects

L B Kalimullina

Publications and source records attributed to L B Kalimullina.

At least 19 recordsLinked to original sources
PubMed2006

Characteristics of small neurons of the reticular thalamic nucleus in WAG/Rij rats.

The aim of the present work was to study the ultrastructure of small neurons in the reticular thalamic nucleus (RTN) in WAG/Rij rats, which are used as a model of absence epilepsy. A total of 24 rats were studied. The brains of 10 rats were used for studies of the cytoarchitectonics and cytological characteristics of neurons, for which paraffin sections were stained with cresyl violet by the Nissl method. Electron microscopic studies were performed by microscope-controlled harvesting of the RTN with fixation in 2.5% glutaraldehyde in phosphate buffer pH 7.4. Small neurons were found to account for 5-8% of all neurons in the RTN. These had oval bodies, sparse and pale-staining cytoplasm, and were frequently located in pairs. The ultrastructure of these neurons was characterized by poor development of cell membranes, branching of the axon close to the cell body, and multiple axon contacts with the body and dendrites. It is suggested that these neurons are short-axon neurons.

Animals↗
PubMed2005

Neurosecretory cells of the amygdaloid complex during estrous cycle.

Ultrastructure of neurosecretory cells of the dorsomedial nucleus of the cerebral amygdaloid complex (one of the main zones of sexual dimorphism) was studied in different phases of the estrous cycle. The characteristics of the "light" and "dark" cells change depending on the concentrations of sex steroids during estrus and metestrus.

Amygdala↗
PubMed2005

Dendroarchitectonics of neurons in the posterior cortical nucleus of the amygdaloid body of the rat brain as influenced by gender and neonatal androgenization.

The aim of the present work was to identify gender-related differences in the dendroarchitectonics of neurons in the posterior cortical nucleus of the amygdaloid body and the role of androgens in forming the dendroarchitectonics during the period of sexual differentiation of the rat brain. Golgi staining showed that long-axon, sparsely branched neurons in males had large numbers of primary dendrites, while long-axon densely branched neurons had a greater total dendrite length in females. Administration of testosterone propionate (1250 microg) to females on postnatal day 5 increased the number of primary dendrites in long-axon, sparsely branched neurons in adults as compared with the number in control females; treatment also produced a significant increase in dendrite length in long-axon, densely branched neurons, leading to an increase in the area of the dendritic field.

Amygdala↗
PubMed2005

Neuronal organization of structures in the central part of the amygdaloid body of the brain.

The features of neurons in the central part of a amygdaloid body (AB) were studied and compared with published data on similar measures of cells in the anterior and posterior parts of the amygdaloid complex. Neurons were impregnated with silver nitrate using the Golgi method. Neurons were classified and measured as described by Leontovich (1978). Long-axon and short-axon neurons were identified and their quantitative characteristics were described.

Amygdala↗
PubMed2005

The paleoamygdala: cytoarchitectonics, organization, and the cytological characteristics of its neurons.

The aim of the present work was to compare the cytoarchitectonics, neuronal organization, and cytological characteristics of the dorsomedial, posterior medial, and posterior cortical nuclei of the amygdaloid body (AB) of the rat brain. Series of frontal brain sections stained with cresyl violet and silver nitrate impregnation by the Golgi method were studied. The results showed that rearrangements of the nuclear principle of organization of the gray matter of the nervous system into the screened organization occur within the territory of this complex of nuclei; it consists of a sparsely branched neuron system and contains neuroendocrine cells. It is concluded that this complex of nuclei is unique in terms of its structural organization and the mechanism of development of this part of the AB, which forms in the earliest stages of AB development; it is termed the "paleoamygdala."

Amygdala↗
PubMed2005

[Characteristics of small neurons in the reticular thalamic nucleus of WAG/Rij rat].

The aim of this investigation was to study the ultrastructure of small neurons in the reticular thalamic nucleus (RTN) in rats of the WAG/Rij strain, which is a recognized model for human absence epilepsy. 24 rats were used in these studies. The paraffin sections of the brain taken from 10 rats were stained with Nissl's cresyl violet and were used for the study of neuronal cytoarchitecture and cytological characteristics. For electron microscopic study, RTN was dissected under microscopic control and fixed in cooled 2.5% glutaraldehyde solution in 0.1 M sodium phosphate buffer (pH 7.4). Small neurons were found to constitute 5-8% of the total number of RTN neurons. They had ovoid cell body, scanty pale-staining cytoplasm, often were seen in pairs. The ultrastructure of these neurons was characterized by poor development of membranes, axonal branching close to the cell body, multiple contacts of axon with cell body and dendrites. It is suggested that the neurons described are short-axonal.

Animals↗
PubMed2005

[Ultrastructural characteristics of the reticular thalamic nucleus neurons in WAG/Rij rats].

The aim of this study was to investigate the ultrastructure of the reticular thalamic nucleus (RTN) in rats of WAG/Rij strain, an established model for human absence epilepsy. Most RTN neurons are medium-to large-sized and have either dark or light appearance, depending on their functional state. Moreover, small-sized neurons with short axons are present, their characteristics being described for the first time.

Animals↗
PubMed2004

Structural organization of the amygdaloid complex of the rat brain.

The amygdaloid complex, traditionally regarded as part of the system of basal endbrain nuclei, has a unique structure in that it combines the two major principles of organization of the gray matter--the nuclear and the screening. Working from the studies of Zavarzin on the nuclear and screening centers, the authors suggest a classification of its structures into nuclei, paleocortex, and intermediate formations.

Amygdala↗
PubMed2004

The central nucleus of the amygdaloid body of the brain: cytoarchitectonics, neuronal organization, connections.

This review considers the questions of the structural-functional organization of the central nucleus (CN) of the amygdaloid body (AB) of the brain in relation to new data on its involvement in the formation of stress reactions and adaptive behavior in animals. Data are presented on the distribution of neuropeptides, neurotransmitters, and modulators in the CN. It is noted that the CN, appearing at the earliest stages of establishment of the AB, is reorganized with it and reflects the evolution of the whole AB. Detailed data are presented on the cytoarchitectonics of the CN of the AB, its heteromorphousness, and subdivision into zones (subnuclei) based on the use of different study methods and assessment criteria. The neuronal organization of the CN and its subnuclei is considered; detailed descriptions of different types of neurons are provided, with consideration of their topographies, sizes, and shapes and of their perikarya, the orientation and type of branching of their dendrites, the organization of the spine apparatus, and axon structure. The characteristics of the development of the CN of the AB in the ontogenesis of mammals and man are discussed. Analysis of published data and our own results supports the role of the CN not only as an intra-amygdalar integrative center, but also as one of the major channels for the afferent and efferent connections of the AB with the rest of the brain.

Amygdala↗
PubMed2004

Structural and quantitative characteristics of the dendrites of neurons in the posterior zone of the amygdaloid body in the rat brain.

The aim of the present work was to study the structure of the dendritic tree of the main groups of neurons in the posterior zone of the amygdaloid body and to analyze their quantitative characteristics. Frontal sections of rat brain impregnated with Golgi silver nitrate were used to study the characteristics of neuronal organization. Classification of neurons was based on criteria developed by Leontovich (1978) and Polyakov (1973). The main groups of neurons were long-axon, rarely branched cells, long-axon, densely branched subcortical cells, and long-axon, densely branched cortical cells. Quantitative studies of seven measures of the dendrite tree showed that the most informative parameters for differences between the main groups of neurons were the number of branching points and the number of free dendrite tips. The contents of rarely and densely branched neuron systems in the nuclei, paleocortex, and intermediate formations are described.

Amygdala↗
PubMed2004

[Rostro-caudal gradient in the amygdala structural and functional organisation].

New data supporting the assumptions of the hypothesis stating the rostro-caudal gradient in the amygdala structural and functional organization are presented. First formulated on the basis of particular location of amygdala zones possessing sexual dimorphism, the above hypothesis is corroborated by the works which characterize its structural organization, participation of amygdala rostral and caudal parts in ensuring various functions including behavior. The authors believe that the amygdala rostro-caudal gradient is predetermined by the phase character of its formation in phylogenesis.

Amygdala↗
PubMed2004

[Gender-associated and androgen dependent neonatal dendrite morphology in neurons of the posterior cortical nucleus of the amygdala].

The aim of this study was to establish gender-associated differences in dendroarchitectonics of neurons in posterior cortical nucleus of amygdala and the role of androgens in their formation during the period of sexual differentiation of rat brain. Using Golgi method, it was demonstrated that long-axon sparsely branched neurons had more primary dendrites in males, while long-axon densely branched neurons had greater total dendrite length in females. In mature female rats that received 1250 mg of testosterone propionate on their postnatal day 5, the number of primary dendrites in long-axon sparsely branched neurons was increased, while the dendrites in long-axon densely branched neurons were elongated as compared to those in control females.

Amygdala↗
PubMed2004

["Dark" and "pale" cells of the amygdala complex in dynamics of the estrous cycle].

Data on cytological peculiarities of dorsomedial nucleus neurones of the amygdala complex, one of the main zones of sexual dimorphism, in dynamics of estrous cycle are reported. We show that structural and functional characteristics of "dark" and "pale" cells may change depending on the concentrations of gonadal steroids in estrous and metaestrous stages. This specifies the previous hypothesis about mutual reorganization of these cells.

Amygdala↗
PubMed2004

[Paleoamygdala: cytoarchitectonics, organization and cytological characteristics of neurons].

This investigation was aimed at the comparative analysis of cytoarchitectonics, neuronal organization and cytological peculiarities of dorsomedial, posterior medial and posterior cortical nuclei of rat amygdala. The series of brain frontal sections stained with cresyl violet and impregnated with silver nitrate using Golgi method were studied. It was shown that within the territory of the nuclear complex studied, the organization of the centers of the nervous system gray matter evolved from the nuclear-type into the screen-type. This formation belongs to a sparcely-dendritic neuronal system and it contains the neuroendocrine cells. As a result, it is suggested that on the basis of its structural organization and developmental mechanisms, the nuclear complex studied comprises a unified area of amygdala, which was formed at the earliest stages of its evolution, therefore it should be named a "paleoamygdala".

Amygdala↗