ABSTRACT
The results of studying an effect of microwaves on the different regions of visual analyzer are investigated. The morphofunctional changes at the light-optic and electron-microscopic levels are revealed. The changes involve not only peripheric area of visual analyzer but also its central regions. Some epidemiologic observations are indicative of: altered sizes of blind spot; decreased magnitudes of optic rheobase and chronaxy; color vision disorder; increased diastolic pressure in central artery of the retina. Study of bioelectrical activity of the retina enabled some investigators to make a conclusion about a reaction disorders occurring in the subcortical visual centers. It is noted that the animal studies not always explain unequivocally the microwave effects on the visual analyzer.
Subject(s)
Eye/radiation effects , Microwaves , Neural Analyzers/radiation effects , Animals , Cataract/etiology , Dose-Response Relationship, Radiation , Eye/physiopathology , Humans , Microwaves/adverse effects , Neural Analyzers/physiopathology , Occupational Exposure/adverse effects , Time FactorsABSTRACT
A single total radiation of guinea pigs by means of microwaves of thermogenic intensity (energy density stream 60 mVt/sm2) and exposition for 10 min produces ultrastructural reactions in various parts of the visual analyser, differing in their manifestation degree. The most essential alterative changes have been revealed in the retina, appearing in 6 h after radiation, as degeneration of the membrane disks of the photoreceptors and as enhancement of phagocytic activity of pigmentocytes, and immediately after the radiation--as destructive disturbances of mitochondria in radial glyocytes and as reaction of the synaptic apparatus. In the cerebral visual centers a higher reactivity of neurons of the external geniculate bodies than in the visual cortex is noted, but ultrastructural disturbances of the hematoencephalic barrier and synapses of the visual cortex are more manifested. Early ultrastructural changes in the optic nerve are least manifested.
Subject(s)
Disease Models, Animal , Models, Neurological , Neural Analyzers/radiation effects , Optic Nerve/radiation effects , Radiation Injuries, Experimental/pathology , Radio Waves/adverse effects , Retina/radiation effects , Visual Cortex/radiation effects , Whole-Body Irradiation/adverse effects , Animals , Female , Guinea Pigs , Male , Microscopy, Electron , Neural Analyzers/injuries , Neural Analyzers/ultrastructure , Optic Nerve/ultrastructure , Optic Nerve Injuries , Radiation Injuries, Experimental/etiology , Retina/injuries , Retina/ultrastructure , Time Factors , Visual Cortex/injuries , Visual Cortex/ultrastructureABSTRACT
Studies were performed on rabbits to investigate single stimulation of the rabbit's eye with low-intensive dissipated laser radiation at 0.53 micron and their influence on the bioelectric activity of the retina which was evaluated at the amplitude b-ERG wave. Established was the dependence of the stimulus' disadapting effect on the laser radiation density within the range of 1 x 10(-11)-3.5 x 10(-4) J.cm-2. The radiation beams with at frequency of 50 Hz and density of 1 x 10-11 J.cm-2 or less did not exhibit any disadapting effect on the retina. Radiation density at 1 x 10(-9)-1 x 10(-7) J.cm-2 decreased the b-ERG wave amplitude only at the time of stimulating the retina. This biological effect can be regarded as an adequate physiological reaction to the stimuli. Radiation exposition at 1 x 10(-6)-4 x 10(-4) J x cm-2 caused a decrease in b-ERG wave after the retina had been stimulated.
Subject(s)
Lasers , Models, Neurological , Neural Analyzers/radiation effects , Retina/radiation effects , Animals , Electroretinography , Neural Analyzers/physiology , Rabbits , Radiation Dosage , Retina/physiologyABSTRACT
Morpho-quantitative estimation of changes in IV and V layers of visual cortex and outer geniculate bodies of the brain of guinea pigs subjected to whole-body X-irradiation with a median lethal doses shows that neurons from the visual analyzer sections under study are differently damaged. The morphogenesis of changes is connected with the original variations in the quantitative structure of a neuron-glial complex and a selective alterative and productive reaction of the perivascular glia.
Subject(s)
Geniculate Bodies/radiation effects , Neural Analyzers/radiation effects , Radiation Injuries, Experimental/pathology , Visual Cortex/radiation effects , Animals , Female , Geniculate Bodies/pathology , Guinea Pigs , Male , Neural Analyzers/pathology , Visual Cortex/pathology , Whole-Body IrradiationABSTRACT
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.
Subject(s)
Geniculate Bodies/radiation effects , Microwaves/adverse effects , Neural Analyzers/radiation effects , Neuroglia/radiation effects , Neurons/radiation effects , Visual Cortex/radiation effects , Animals , Cell Count/radiation effects , Female , Geniculate Bodies/pathology , Guinea Pigs , Male , Neural Analyzers/pathology , Neuroglia/pathology , Neurons/pathology , Time Factors , Visual Cortex/pathology , Whole-Body IrradiationABSTRACT
For the purpose of studying the influence of extreme conditions of a long-term voyage on the functional state of the visual analyser, light sensitivity was studied in 21 seamen. It is shown that adaptation mechanisms regulating light sensitivity have a phase tendency: phase is characterized by a rise of the level of light sensitivity within first 90-120 days of the voyage; phase II--by a gradual fall of the level of light sensitivity beginning from 120-140 days of the long-term voyage. The investigations performed allow to create an informative diagnostic test for a well-grounded therapy intended to widen adaptive possibilities of the system responsible for regulation of light sensitivity.
Subject(s)
Light , Naval Medicine , Neural Analyzers/radiation effects , Vision, Ocular/radiation effects , Dark Adaptation/radiation effects , Humans , Male , Neural Analyzers/physiology , Time Factors , USSR , Vision, Ocular/physiologySubject(s)
Eye/radiation effects , Lasers , Light , Visual Cortex/radiation effects , Animals , Female , Humans , Male , Neural Analyzers/radiation effects , RabbitsSubject(s)
Otorhinolaryngologic Diseases/radiotherapy , Pharyngeal Neoplasms/radiotherapy , Radiation Effects , Vestibule, Labyrinth/radiation effects , Audiometry , Hearing Disorders/etiology , Humans , Methods , Neural Analyzers/radiation effects , Radiotherapy Dosage , Tinnitus/etiology , Vertigo/etiology , Vestibular Function TestsABSTRACT
During space flights the vestibular analyzer functions under conditions which are not usual for Earth environments. The vestibular analyzer periodically or constantly experiences the action of angular, linear or Coriolis acceleration combined with ionizing radiation. The quantitative evaluation of the functional state of the vestibular analyzer made it possible to obtain material on semicircular canal activity disturbances at different periods of radiation sickness and responses of the irradiated body, given various doses of gamma radiation, to angular and Coriolis acceleration. Experiments were performed on 250 rabbits and 22 dogs. Rabbits were exposed to the total gamma radiation at doses of 50, 100, 500, 800, 5000, 10000 rad; dogs experienced single and fractional radiation exposures at doses of 200 rad (gamma-rays) and at doses of 500 and 350 rad (protons of 510 MeV). Specific conditions under which the astronaut's vestibular analyzer is functioning during space missions and our own experimental results make it possible to state that the vestibular analyzer serves as the critical organ in evaluation of radiation hazards during space flights.
