Ultrastructure of sensorimotor cortex neurons in the progeny of rats receiving alcohol during pregnancy

Dynamics of ultrastructural changes in the sensomotor cortex neurons has been studied on the 21st, 30th and 60th days of life in offspring born by the rats given 20% alcohol (2 g/kg) during pregnancy. Moderate antenatal alcoholization produces certain disturbances in the ultrastructure of the cortical neurons and their dendrites. This is manifested as presence of retardation signs in maturation of nervous cell populations, as dystrophic changes in the neurons and their dendrites and display of reparative character with their own dynamics in the postnatal period of ontogenesis. The first two categories of the ultrastructural changes in the cortical neurons are more manifested at early stages of the postnatal development of the offspring, and the reparative processes--at the age of two months. Despite the presence of the reparative shifts, the dystrophic changes of the neurons of hypoxic character are present up to the period of sexual maturation. This demonstrates that the antenatal alcoholic intoxication in the offspring is manifested in the postnatal ontogenesis for a long time.     

Effect of gamma-radiation of an extremely high dose on the cerebral cortex of the rat (ultrastructural aspects)

For 24 h after total gamma-radiation of mature Wistar male rats (180-210 g) in the dose of 150 Gy, ultrastructural rearrangements of the cerebral sensomotor cortex are presented as small destructive changes in neurons, neuroglia and vascular endothelium. Total combination of the changes in ultrastructure of the blood capillaries and perivascular astrocytes makes it possible to suppose that permeability of the microvascular bed wall is increased. At this period, together with the destructive changes there are evidently certain compensatory-restorative processes, developing in the cerebral tissue. It is possible to suppose that already during the first hours after the radiation the ultrastructural changes of neurons are resulted not only from the direct effect of radiation, but from certain influences of the radiation damage of neuroglia and microvessels.     

l-Dopa methyl ester attenuates amblyopia-induced neuronal injury in visual cortex of amblyopic cat

In the present study, we aimed to assess the potential anti-amblyopic effects of l-dopa methyl ester (LDME) on visual cortex area 17 in an amblyopic feline model induced by monocular vision deprivation. After LDME administration, pathophysiologic and ultrastructural observations were utilized to examine the morphological changes of nerve cells in visual cortex area 17. Dopamine (DA) and its metabolite contents in visual cortex area 17 were investigated through HPLC analysis. Apoptotic cells in visual cortex area 17 were evaluated by TUNEL assay. Additionally, the c-fos expression both at gene and protein levels was assessed using RT-PCR and immunohistochemistry analyses, respectively. The contents of DA and its metabolites were elevated in visual cortex area 17. Neuronal rejuvenation which occurred in visual cortex area 17 was observed through anatomical and physiological assessments. Similarly, TUNEL results showed that neuronal apoptosis was inhibited in the visual cortex of amblyopic cats by both l-dopa and LDME therapies. Meanwhile, the c-fos expression was notably up-regulated at both the mRNA and protein levels by the treatments. These findings suggested that LDME treatment could effectively increase DA and its metabolite contents, and restrain the apoptotic process, as well as elevate the c-fos expression in nerve cells of visual cortex area 17. Taken together, LDME might ameliorate the functional cytoarchitecture in visual cortex area 17 through mechanisms that elevate DA content and increase endogenous c-fos expression, as well as inhibit neuronal lesion in visual cortex tissue.     

Morphofunctional features of the secretory cells of the adenohypophysis and adrenal glands of the rat during aging

Karyometric and electron microscopic investigation has been performed in the adenohypophyseal secretory cells, in the cortex and medulla of the adrenal glands in mature (6 months) and ageing (25-26 months) white male rats. The diameter of the corticotropic cell nuclei of the adenohypophysis significantly increases with age. In the secretory cells of the adrenal cortex and medulla no important changes in their parameters are revealed. With age destructive changes of the ultrastructures are manifested variously in different types of the secretory cells in the endocrinic glands studied. In the corticotropic, somatotropic, thyreotropic cells of the adenohypophysis, in spongiocytes of the adrenal cortex, compensatory ultrastructural rearrangements develop; they are aimed to preserve functional activity of the cells mentioned. No age changes are revealed in ultrastructure of chromaffin cells of the adrenal medulla.     

Relation between the dynamics of early ultrastructural changes in the cerebral cortex of the rat and radiation dose

The electron microscopic investigation of the sensomotor zone in the cerebral cortex of mature male rats after total neutron and gamma radiation of high doses has demonstrated, that during first three hours after the influence the dynamics of ultrastructural changes in neurons, glial elements and microcirculatory bed depends on the radiation dose. After gamma radiation of 150 Gy, destructive changes in neurons, increased permiability of blood capillaries and development of perivascular edema are noted at earlier time than after radiation dose of 10 Gy. When the greater dose of radiation is used, also earlier reaction of the barrier structures in the brain is observed.     

The effect of interferon preparations on the ultrastructural organization of Legionella pneumophila]

The influence of the preparations of interferon on morphological changes in L. pneumophila on the ultrastructural level has been studied. Disturbances in the ultrastructure of L. pneumophila result from the direct bactericidal action of interferons without any interference of immune mechanisms. These disturbances are manifested by damages in the cell wall, plasma membrane, nuclear and ribosomal apparatuses of microbial cells. Leukinferon exhibits pronounced anti-Legionella activity, both in vitro in a liquid culture medium and in ovo, than reaferon.     

Ultrastructure of the zone fascicularis of the adrenal cortex of the rat after a single physical loading to fatigue and in the recovery period

Ultrastructure of the fascicular zone in the cortex of the adrenals has been studied in untrained rats after a single physical loading (swimming with an additional load up to fatigue) and during restorative period (24, 48, 72 and 96 h of rest after the loading). The massive release of hormones during the prolonged physical work, as well as during the 1st and the 3d days of rest are estimated by ultrastructural changes in adrenocorticocytes. Signs of an increased permiability of the histohematic barrier in the gland are mostly manifested in 48 h after the loading: in the wall of the smallest vessels ruptures and discharge of formed elements of blood into the pericapillary space; numerous macrophages in the intercellular space phagocytaze the products of degeneration; residual bodies, fragments of decaying cells are seen in the blood capillary lumen. In 96 h of rest, in the fascicular zone of the adrenal cortex changes directed to restoration of the cholesterin depot are observed.     

Total activation change of visual and motor area due to various disturbances

Brain activation is affected by gradient acoustic noise and various disturbances as well as by other primary tasks. Therefore, we have studied the effects of various disturbances of two different levels of difficulty, that is, weak and strong difficulty levels for primary visual and motor tasks. In the case of visual task with motor and mental disturbances, we found it decreased as motor and mental disturbance difficulty-level increased, compared with the case of without motor and mental disturbances. To the contrary, in the case of motor activity, the total activation of motor cortex with weak and with strong mental disturbance increased as mental disturbance difficulty-levels increased. Therefore, one can conclude that when mental disturbance is added, the visual cortex and motor cortex have an opposite result and when the difficulty-level of the disturbance is increased, the primary tasks are affected more significantly. Although the current observation is preliminary and requires more careful experimental study, it appears that various disturbance effects on brain functions (such as motor and visual cortical responses) produce significant differences in data observations.     

Quantitative histologic changes of the glioneuronal complex in the central and intermediate parts of the visual analyzer exposed to microwaves of thermogenic intensity

Whole-body exposure of guinea pigs to microwaves of 60 mW/cm2 for 10 min causes quantitative changes in glial population of outer geniculate bodies and visual cortex that are manifested by the enlarged perineuronal glia, an increased glioneuronal index, and a relatively stable perivascular glia. The dynamics of the changes observed indicates higher reactivity and repair capacity of the glioneuronal complex of outer geniculate bodies.     

Ultrastructural characteristics of myocardial capillaries during physical exertion

In the model experiments with physical overloading of "trained" rabbits, that repeatedly terminated in death, it has been stated that ultrastructural changes of the myocardial blood capillaries can be manifested as a considerable increase of the endotheliocytic nuclei volume, swelling of the cytoplasmic matrix, an essential accumulation of pinocytic vesicles, or a rather significant decrease of their number in cytoplasm and as various combinations of the changes mentioned; this negatively influences hemodynamic and trophic functions of the capillaries. The changes of endotheliocytes can be characterized as submicroscopical bases of the transcapillary insufficiency. More manifested ultrastructural changes of the capillaries are noted in the left cardiac parts.     

Ultrastructure of cells of the lateral field of the hypothalamus of the cat after exposure to electromagnetic radiation

Under the effect of electromagnetic radiation not any specific changes are revealed in the neural system unequivocally characterizing disturbances in its structure as a result of an excess absorption of electromagnetic energy. The ultrastructural changes revealed in the lateral fields of the cat hypothalamus are suitable for a well known scheme demonstrating the course of the pathological process, where three phases are distinguished: reactive, destructive and restorative. The pathological process develops gradually. The reactive changes in neurons and synapses, observed immediately after withdrawal of the electromagnetic action. increase during the following three months and result in coarse destructive disorders and in death of some neurons and synapses. In 6 months certain signs of restoration of the structures are observed. Under the effect of electromagnetic radiation water redistribution between the structures takes place, the sympathetic terminals loosing their fluid. Thus, certain conditions are produced for sticking together the synaptic vesicles. Possibly that deficiency of Ca++ ions contributes to it.     

Auditory modulation of the inferior temporal cortex neurons in rhesus monkey

We performed a systematic study to check whether neurons in the area TE (the anterior part of inferotemporal cortex) in rhesus monkey, regarded as the last stage of the ventral visual pathway, could be modulated by auditory stimuli. Two fixating rhesus monkeys were presented with visual, auditory or combined audiovisual stimuli while neuronal responses were recorded. We have found that the visually sensitive neurons are also modulated by audiovisual stimuli. This modulation is manifested as the change of response rate. Our results have shown also that the visual neurons were responsive to the sole auditory stimuli. Therefore, the concept of inferotemporal cortex unimodality in information processing should be re-evaluated.     

低剂量伽玛刀照射癫痫大鼠颞叶神经元超微结构的改变及线粒体形态计量分析

目的观察低剂量伽玛刀照射癫痫大鼠颞叶神经元超微结构的变化,探讨线粒体形态改变程度及性质。方法建立大鼠青霉素局灶性癫痫动物模型,将48只SD大鼠分为对照组（A组）、实验组（癫痫模型组,简称B组）和癫痫后伽玛刀照射组（C组）。照射周边剂量12Gy,等剂量曲线为50％。分别于0．5h～60d后取靶区颞叶皮质区制备电镜样本,透射电镜观察,通过计算机图像分析系统对线粒体形态计量分析。结果A组细胞结构基本正常;B组可见神经元细胞质细胞器明显减少空化,线粒体体密度、数密度、比表面和嵴膜密度较对照组明显减少（P〈0．05）,线粒体平均体积和平均截面积较对照组明显增大（P〈0．05）。C组早期与B组基本一致,细胞质内有少量脂褐素,中期和晚期线粒体的各项参数与A组相差不显著,低剂量伽玛刀照射后早期线粒体的平均体积、平均截面积数密度、比表面与A组相差显著（P〈0．05）,圆球度各组间无明显差异。结论大鼠癫痫发作后其线粒体的形态结构发生明显变化,低剂量伽玛刀照射对神经元的修复有重要作用,本研究认为线粒体参与了癫痫的病理过程。     

Effect of visual deprivation on evoked potentials in the visual cortex and superior colliculus in rabbits

Evoked potentials arising in the visual cortex and superior colliculus to stimulation of the collateral eye by single, paired, and repetitive flashes were recorded in rabbits reared in darkness or in normal illumination. The absence of significant change in the latent period and amplitudes of the first two components of the collicular responses and of the recovery cycle and response to repetitive stimulation in the light-deprived animals suggest that photic stimulation does not affect the normal functional development of the rabbit retinotectal system. However, functional deafferentation in the early postnatal period gives rise to serious disturbances of visual cortical function, as reflected in a marked decrease in amplitude of the primary response, lengthening of the recovery cycle, and narrowing of the range of rhythm-binding frequencies of flashes. These disturbances were reversible. The period of maximal sensitivity of the rabbit retinocortical system to visual deprivation begins at the end of the first month of postnatal life. The possible mechanisms lying at the basis of these functional disturbances in light-deprived animals are discussed.     

An X-Ray Scattering Study into the Structural Basis of Corneal Refractive Function in an Avian Model

Avian vision diseases in which eye growth is compromised are helping to define what governs corneal shape and ultrastructural organization. The highly specific collagen architecture of the main corneal layer, the stroma, is believed to be important for the maintenance of corneal curvature and hence visual quality. Blindness enlarged globe (beg) is a recessively inherited condition of chickens characterized by retinal dystrophy and blindness at hatch, with secondary globe enlargement and loss of corneal curvature by 3–4 months. Here we define corneal ultrastructural changes as the beg eye develops posthatch, using wide-angle x-ray scattering to map collagen fibril orientation across affected corneas at three posthatch time points. The results disclosed alterations in the bulk alignment of corneal collagen in beg chicks compared with age-matched controls. These changes accompanied the eye globe enlargement and corneal flattening observed in affected birds, and were manifested as a progressive loss of circumferential collagen alignment in the peripheral cornea and limbus in birds older than 1 month. Progressive remodeling of peripheral stromal collagen in beg birds posthatch may relate to the morphometric changes exhibited by the disease, likely as an extension of myopia-like scleral remodeling triggered by deprivation of a retinal image.     

Ultrastructural changes in Shigella flexneri cells during interaction with bacteriocinogenic Lactobacillus acidophilus

Results of electron-microscopic examination of Shigella flexneri cells, subjected to influence the bacteriocin-producing Lactobacillus acidophilus bacteria are presented. The response of shigellae to bacteriocinogenic lactobacilli was shown both on cellular and population levels. On population level the correlation of various morphological types of shigella cells with increase of involution, lysing and resting forms is revealed. At a cellular level the specific ultrastructural changes of shigella evidencing the significant destructive processes of the cells were revealed. In one case destabilization of shigella cellular wall was observed, that was manifested in expansion of periplasmic spaces and appearence of specific involution forms of the cells. In other cases, changes in the ultrastructural organization of shigella nucleoid were found out, manifested in disappearance of thin-fibrillar DNA and formation of electronic-dense globular structures of the cells.     

An X-Ray Scattering Study into the Structural Basis of Corneal Refractive Function in an Avian Model

Avian vision diseases in which eye growth is compromised are helping to define what governs corneal shape and ultrastructural organization. The highly specific collagen architecture of the main corneal layer, the stroma, is believed to be important for the maintenance of corneal curvature and hence visual quality. Blindness enlarged globe (beg) is a recessively inherited condition of chickens characterized by retinal dystrophy and blindness at hatch, with secondary globe enlargement and loss of corneal curvature by 3–4 months. Here we define corneal ultrastructural changes as the beg eye develops posthatch, using wide-angle x-ray scattering to map collagen fibril orientation across affected corneas at three posthatch time points. The results disclosed alterations in the bulk alignment of corneal collagen in beg chicks compared with age-matched controls. These changes accompanied the eye globe enlargement and corneal flattening observed in affected birds, and were manifested as a progressive loss of circumferential collagen alignment in the peripheral cornea and limbus in birds older than 1 month. Progressive remodeling of peripheral stromal collagen in beg birds posthatch may relate to the morphometric changes exhibited by the disease, likely as an extension of myopia-like scleral remodeling triggered by deprivation of a retinal image.     

Ultrastructure of epithelial cells in rat's epididymal caput in experimental hyperprolactinemia induced by metoclopramide

The aim of the performed studies has been to find out wether or not the ultrastructural alterations of the epithelial cells in the rat's epididymal caput occur in hyperprolactinemia induced by metoclopramide and to see if the observed changes are of reversible character. It has been revealed that prolactin concentration was twice as high as in control animals due to peritoneal administration of metoclopramide in a dose of 2.2 mg/kg body mass, given for 14 days. The ultrastructural alterations in the principal cells of epididymal caput affected cellular organelles being involved in proteins synthesis, glycosylation, secretion as well as energetic processes. They were manifested by decreased amount of rough endoplasmic reticulum, widening of its cisternae combined with degranulation, distension of Golgi apparatus cisternae, elevated number of vesicles in apical part of the cells, and changes in mitochondria. The termination of metoclopramide administration made prolactin concentration exhibit values being almost similar to those determined in control rats, whereas the ultrastructural changes in the principal cells were found to be reversible.     

Changes in visual evoked potentials after injection of tetanus toxin into the lateral geniculate body

Changes in visual evoked potentials were studied in rats at different stages of formation of experimental photogenic epilepsy induced by injection of tetanus toxin into the lateral geniculate body. The greatest change in evoked potentials in the lateral geniculate body consisted of the appearance of an aditional component in the series of waves of the primary response. Meanwhile in the ipsilateral visual cortex the amplitude of the first negative component of the evoked potential was considerably increased. Correlation was found between the changes in the amplitude of this component in the visual cortex and the change in steepness of the additional component of the evoked potential in the geniculate body, reflecting functional reorganization of that nucleus. The results are evidence of significant disturbances of the relay function of the lateral geniculate body when a generator of pathologically enhanced excitation is formed in it.Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 10, No. 2, pp. 142–149, March–April, 1978.     

Lipofuscin granule dynamics during development of age-related macular degeneration

The pigment epithelium cell structure and therapeutic effect of antioxidant SkQ1, selectively penetrating into mitochondria from eye drops, were studied upon development in OXYS rats of age-related retinopathy as a model of macular degeneration. The characteristic dynamics and ultrastructural peculiarities of the layer of electron-dense cytoplasmic structures of the pigment epithelium apex part and incorporated lipofuscin granules were revealed. The therapy of OXYS animals for 68 days using 250 nM SkQ1 drops decreased the extent of development of age-related macular degeneration. Electron-microscopic investigation showed that SkQ1 prevented development of ultrastructural changes in the pigment epithelium characteristic of macular degeneration, the condition of which after therapy with SkQ1 drops corresponded to ultrastructure of pigment epithelium in Wistar rats of the same age having no symptoms of retinal damage. It is supposed that ultrastructural changes in the electron-dense layer upon development of age-related macular degeneration are indicative of disturbances in the optical cycle functioning, especially of disturbances in functioning of photoreceptor membranes.