Changes in the Neurochemical Composition of Motor Neurons of the Spinal Cord in Mice under Conditions of Space Flight.

Expression of choline acetyltransferase, 200-kDa neurofilament protein, 28-kDa calbindin, neuronal NO synthase, caspase 3, and Ki-67 in the motor neurons of spinal cord segments T3-T5 in male C57Bl/6 mice after 30-day space flight in the Bion-M1 biosatellite was studied by immunohistochemical methods. Under conditions space flight, the size of motoneurons increased, the number of neurons containing choline acetyltransferase and neurofilaments, decreased, and the number of calbindin-positive neurons increased; motoneurons, expressing neuronal NO synthase and caspase 3 appeared, while Ki-67 was not detected. Fragmentation of neurons with the formation structures similar to apoptotic (residual) bodies was observed in individual caspase 3-positive motoneurons.

[CHANGES OF SPINAL MOTOR NEURONS IN MICE AFTER А SPACE FLIGHT].

The expression of choline acetyltransferase (ChAT), neurofilament (NF) protein 200 kDa, calbindin (CAB) 28 kDa, neuronal NO-synthase (nNOS), caspase 3, Ki-67 was studied in motor neurons from TIII­TV segments of the spinal cord in C57/ BL6 male mice by immunohistochemical methods 12 h after a 30 days-long space flight on the Bion-M1 biosatellite. Mice living under standard vivarium conditions served as a control. The motoneurons of experimental animals demonstrated the reactive changes that were manifested by the increase of their size, decrease in the number of subpopulations expressing ChAT and NF, increase of subpopulations containing CAB, appearance of motor neurons expressing nNOS, caspase-3, and the absence of Ki-67. The lack of proliferating gliocytes, the preservation of nucleolar component indicate the absence of necrobiotic changes characteristic of necrosis. The cytoplasmic vacuolization was observed in thionine-stained CAB-immunoreactive neurons. The disintegration of motor neurons into fragments resembling the apoptotic bodies was observed in single cells that contained caspase-3.

[Subpopulation of calbindin-immunoreactive interneurons in the dorsal horn of the mice spinal cord].

In the dorsal horn of the spinal cord in the plates I-IV on the thoracic and lumbar levels different subpopulations of interneurons immunoreactive for calbindin 28 kDa (CAB IR), which are specific to each plate. In the area of the medial edge of the dorsal horn, we have found a special subpopulation of CAB IR interneurons whose morphometric characteristics differ from CAB IR interneurons subpopulations of said plates. The number of CAB IR interneurons was maximal in the plate II at all levels of the spinal cord. Leveled differences are more CAB IR interneurons and larger area of the cross sections at the lumbar level.

[Calbindin-containing neurons of the ventral horn of murine spinal cord gray matter].

The study was performed in 4 C57black/6 mice to examine the neurons located in T(II), L(IV), L(V) and L(VI) segments of the spinal cord (SC) ventral horn, containing 28 kD calbindin (CAB) and 200 kD neurofilament (NF) proteins. To demonstrate immunoreactive neurons, the cells were labeled with antibodies against CAB and double labeled with antibodies against CAB and NF. The total cell population was demonstrated using NeuroTrace Red Fluorescent Nissl Stain. Results have shown that CAB-immunopositive neurons were identified in ventromedial area of the ventral horn at all SC levels and were represented by Renshaw cells. CAB-positive interneurons located in the medial area of the ventral horn were present only in SC lumbar segments. CAB-positive motorneurons that were identified in the medial area of the ventral horn, were present in one SC segment (L(IV)) and were also found to contain a NF protein.

[Peculiarities of age changes of NF200(+)-neurons in the sensory ganglia of different segmental levels after chemical deafferentation].

Morphological features of the neurons containing neurofilaments with molecular mass of 200 kD (NF200+), were studied in the sensory ganglia of thoracic and lumbar spinal nerves in rats (n = 80) during the first year of their life. Capsaicin treatment (150 mg/kg) of the newborn animals resulted in the change of age dynamics of NF200+ neurons. This was reflected by a reduction of NF200+ neuron numbers and their cross-sectional areas in both ganglia. Segmental differences included greater reduction of NF200+ neuron number in the sensory ganglion of lumbar spinal nerve in both early and late developmental periods.

[Substance P-immunopositive neurons in rat sensory ganglion of the spinal nerve in postnatal development].

Afferent neurons containing substance P (SP) were studied immunohistochemically in the sensory ganglion of the spinal nerve in 30 rats aged 10-90 days. The results obtained indicated that SP-immunoreactive neurons are present in thesel ganglia from the moment of birth. During the development, the percentage of SP-containing neurons decreased till day 10. SP-immunoreactive neurons were represented by the cells of very small or small size.

[Age-related changes in sensory neurons containing calcitonin gene-related peptide under conditions of afferentation deficit in rats].

Morphological features of calcitonin gene-related peptide (CGRP)-immunoreactive neurons were studied in the sensory ganglia of the vagus and thoracic nerves in 3-, 10-, 20-, 30-, 60-, 90-, and 120-day-old rats under conditions of chemically-induced deafferentation. We found that, in rats, CGRP-containing neurons appeared in both ganglia immediately after they were born and their number decreased with aging. Most of CGRP-immunoreactive neurons were small in size, i.e., up to 600 microm2. Administration of capsaicin modified age-related changes in the number of CGRP-immunopositive neurons. In the thoracic nerve ganglion, the mean square of these cells and their number substantially decreased, whereas, in the vagus nerve ganglion, positive cells were not observed.

[Changes the TRPV1-immunoreactive neurons of the rat spinal nerve sensory ganglia induced by capsaicin].

Morphological features of the TRPV1-immunoreactive neurons were studied in thoracic spinal nerve sensory ganglion in 10-, 20-, 30-, 60- and 90-day-old rats under normal conditions and after chemical deafferentation caused by capsaicin (100 mg/kg) subcutaneous injection at postnatal day 2. TRPV1-immunoreactive neurons differed in their morphometric characteristics: positive neurons had very small and small sizes, negative cells had the small, medium and large sizes. Capsaicin treatment of newborn rats was shown to change age dynamics of TRPV1-positive neurons resulting in the reduction of the average cell cross-sectional area and cell numbers during the whole period of observation.

[Morphometric and histochemical characteristic of cluster organization of the neurons of rat spinal nerve sensory ganglion and of sympathetic trunk cervicothoracic ganglion].

The topographic pattern of neurons in spinal nerve sensory ganglion and of sympathetic trunk cervicothoracic ganglion was investigated at adult rats (n = 12). Results of the work have shown, that these organs are characterized by a heterogeneity of the neurons according to their morphometric (Nissl's stain) and histochemical (acetylcholinestherase and NADPH-diaphorase activity) parameters. The common feature of ganglia organization was demonstrated by the clustered pattern of neuron topography. Clusters were formed on a principle of heterogeneity, uniting from 3-4 to 9-10 neurons. The application of a combined histochemical method has allowed to identify the histo-functional charactristics of neurons within the clusters of the ganglia studied, which were also detected by standard histological methods.

[NADPH-diaphorase-positive structures in the spinal cord and spinal ganglia].

Using the histochemical reaction with the various incubation medium pH, the localization of NADPH-diaphorase was studied in the spinal cord and spinal ganglia of the adult rat. The data obtained indicate, that the application of the incubation medium with pH 7.4 allows to demonstrate the neurons with various NADPH-diaphorase activity, to define not only the density of enzyme distribution, but also to calculate the numbers of NADPH-diaphorase-positive neurons. It was established, that both in the spinal cord and spinal ganglia, NADPH-diaphorase activity was found not in all the neurons: high activity was found in small and medium neurons of the spinal ganglia, while low activity was detected in motoneurons. Other cellular structures of the spinal cord also possessed NADPH-diaphorase activity and were found to be the interneurons.

Neurotransmitter composition of neurons in the cranial cervical and celiac sympathetic ganglia in postnatal ontogenesis.

The neurotransmitter composition of neurons in the cranial cervical ganglion (CCG) and celiac ganglia (CG) in rats of different ages (neonatal, 10, 12, 30, and 60 days) was studied by immunohistochemical methods. The results showed that most neurons in these sympathetic ganglia contain tyrosine hydroxylase (TH). Most TH-positive neurons were also neuropeptide Y (NPY)-positive. In all ganglia, the proportions of neurons containing NPY increased from the moment of birth to the end of the first month of life. In the CG, NPY was present in a significantly greater proportion of neurons than in the CCG. Substance P, vasoactive intestinal peptide, and choline acetyltransferase were present in occasional neurons in the CCG and CG from birth. There was no change in the proportion of this type of neuron with age. Definitive establishment of the neurotransmitter composition in the sympathetic ganglia studied here occurred by the end of the first month of life.

NADPH-diaphorase-positive neurons in sympathetic ganglia during postnatal ontogenesis.

The locations and morphometric characteristics of NADPH-diaphorase (NADPH-d)-positive neurons were identified in the cranial cervical (CCG), stellate (SG), and celiac (CG) ganglia in neonatal rats, mice, and cats and animals aged 10, 20, 30, 60, and 180 days. No NADPH-d-positive neurons were found in rats and mice in any of the age groups studied. In kittens, the majority of NADPH-d-positive neurons were located in the SG, with fewer in the CCG and only occasional neurons in the CG, regardless of age. The proportion of NADPH-d-positive neurons in the SG increased during the first 20 days of life and decreased after 30 days, to the end of the second month of life. The proportion of NADPH-d-reactive neurons in the CCG and CG did not change during ontogenesis. The mean sizes of NADPH-d-positive neurons in different ganglia in animals of the same age were not significantly different. These data lead to the conclusion that the development of NADPH-d-positive neurons with age occurs heterochronously and is complete by the end of the second month of life.

[NADPH-diaphorase-positive neurons in the sympathetic ganglia during postnatal ontogenesis].

Localization and the morphometric characteristics of NADPH-diaphorase--(NADPH-d)-positive neurons were studied in the superior cervical ganglion (SCG), stellate ganglion (SG) and the celiac ganglia (CG) in newborn, 10-, 20-, 30-, 60 and 180-day-old rats, mice and cats. No NADPH-d-positive neurons were found in rats and mice of all the age groups studied. In cats, the largest proportion of NADPH-d-positive neurons was found in the SG, the smaller one--in the SCG, while only the individual neurons we detected in the CG, irrespective of the animal age. In the SG, the proportion of NADPH-d-positive neurons increased during the first 20 days of life and then decreased after 30 days till the end of the second month. The content of NADPH-d-positive neurons in the CG and SCG d-remained unchanged during the development. There were no significant differences in the cross-sectional area between the neurons located in the different ganglia of animals from the same age group. It is concluded that the age development of NADPH-d-positive neurons in different sympathetic ganglia occured heterochronously was finished by the end of the second month of life.

Efferent innervation of the cervical segment of the trachea in early postnatal ontogenesis.

A method based on retrograde axonal transport of horseradish peroxidase was used to study the efferent innervation of the cervical segment of the trachea in neonatal kittens and kittens aged 10, 20, and 30 days and two months. Labeled neurons in all animals were located in the cranial cervical, middle cervical, and cervicothoracic sympathetic ganglia on the right and left sides, at the level of the medulla oblongata, and in the dorsal and ambiguus nuclei of the vagus nerves. Up to age 30 days, neurons were also seen in the ventral horns of the spinal cord in segments C1 to C5. The number of sympathetic neurons innervating the trachea increased from the moment of birth, reaching a maximum by 10-20 days and then decreasing to age two months. The number of parasympathetic neurons gradually decreased during ontogenesis.

[Efferent innervation of the cervical region of the trachea during the early postnatal ontogenesis].

Method based on retrograde axonal transport of horseradish peroxidase was used to study the efferent innervation of the cervical trachea in neonatal, 10-, 20-, 30-day-old and two-month-old kittens. In all the animals, labeled neurons were localized in the cranial cervical, middle cervical and cervicothoracic (stellate) sympathetic ganglia both on the right and on the left sides. Neurons were also localized at the level of medulla oblongata, in the dorsal and ambiguus nuclei of the vagus nerve. Labeled neurons were also found in the ventral horns of C(I-)C(V) spinal segments in the animals before 30 days of life. The number of sympathetic neurons, innervating the trachea, cells increased from the moment of birth, reaching a maximum by the age of 10 and 20 days and then declined up to the second month of life. The total number of parasympathetic neurons decreased gradually in the early development.

Immunocytochemical characteristics of neurons in the stellate ganglion of the sympathetic trunk in mice during postnatal ontogenesis.

The neurotransmitter composition of neurons in the stellate ganglion of mice of different ages (neonatal and aged 10, 20, 30, and 60 days) was studied using an immunocytochemical method. Most of the neurons in the mice of these age groups contained tyrosine hydroxylase (TH). Most choline acetyltransferase (CAT)-positive neurons in neonatal and 10-day mice were also TH-positive. From birth and at all subsequent ages, there were increases in the proportion of cells contained TH and neuropeptide Y. The proportion of neurons containing vasoactive intestinal peptide and CAT increased to 10 days of life and then decreased. Somatostatin-and galanin-positive neurons were absent from all animals. Maturation of the set of neurotransmitters in stellate ganglia was complete by age two months.

[Immunocytochemical characteristic of neurons of the mouse truncus sympaticus stellate ganglion in postnatal ontogenesis].

Neurotransmitter content in stellate ganglion neurons was studied immunocytochemically in mice of different ages (newborns, 10-, 20-, 30- and 60-days-old). Majority of the stellate ganglion neurons in mice of all the groups studied were tyrosine hydroxylase (TH)-positive. Most of neurons with the immunore-activity to choline acetyltransferase (ChAT) were shown to be also TH-positive in the newborn and 10-day-old animals. The percentage of neurons containing TH and neuropeptide Y increased from birth throughout all the age periods studied. The proportion of vasoactive intestinal peptide (VIP)- and ChAT-positive neurons was maximal in 10-day-old animals and then decreased up to 60 days of age. The somatostatin- and galanin-reactive cells were absent in all the mice. Thus, the maturation of neurotransmitter composition is complete in the mouse stellate ganglion by the end of the second month of life.

[Histoenzymochemical characteristic of neuromuscular synapse in skeletal muscles]. / Gistoénzimokhimicheskaia kharakteristika neiromyshechnogo sinapsa skeletnykh myshts.

The paper summarizes the results of longstanding research on the construction of AChE-positive zone in neuromuscular synapse (NMS) in relation to the metabolic profile, muscle fibre diameter and function of the muscles of the head, neck, anterior and posterior extremities of mature albino rat. Comparison of cross-sectional areas and forms of NMS region indicates that the values of these parameters are significantly associated with the muscle fibre diameter. Other muscle characteristics are less important for the construction of AChE-positive zone of NMS in mature rat.

[Innervation centers in the cervical and thoracic trachea]. / Innervatsionnye tsentry sheinogo i grudnogo otdela trakhei.

Using HRP axonal transport links between trachea and ganglia of cervical thoracic regions of right and left sympathetic trunks, spinal ganglia and vagal posterior ganglia were established. Quantitative and morphometric characteristics of neurocytes of contralateral ganglia involved into trachea innervation were given. Peculiarities of localization of innervation centres of cervical and thoracic trachea regions were established.