Effects of the action of microwave-frequency electromagnetic radiation on the spike activity of neurons in the supraoptic nucleus of the hypothalamus in rats.

Acute experiments on white rats anesthetized with Nembutal (40 mg/kg, i.p.) were performed with extracellular recording and analysis of background spike activity from neurons in the supraoptic nucleus of the hypothalamus after exposure to electromagnetic radiation in the millimeter range.

The effects of vibration on the baseline spike activity of neurons in the superior vestibular nucleus.

The characteristics of the baseline spike activity of neurons in the superior vestibular nucleus of rats were studied after exposure to vibration for five, 10, and 15 days using a computerized method for recording and analyzing interspike intervals. The distributions of neurons in terms of their regularity, their dynamic types, and the modalities of their interspike interval histograms were assessed. In intact animals, the mean spike frequency was 14.

Comparative analysis of the baseline spike activity of neurons in the fastigial nucleus of the cerebellum at different durations of exposure to vibration.

Acute experiments on Nembutal-anesthetized (40 mg/kg, i.p.) white rats with extracellular recording and analysis of baseline spine activity of neurons in the fastigial nucleus of the cerebellum were performed in normal conditions and after exposure to vibration for 5, 10, and 15 days.

Effect of licorice root on peripheral blood indexes upon vibration exposure.

We studied the effect of continuous vibration and treatment with licorice root (Glycyrrhiza glabra L.) on peripheral blood red cells in rabbits. Active substances of licorice root accelerated metabolism in cells of the bone marrow erythroid stem, enhanced compensatory reserve of the organism, and increased animal's resistance to stress.

Changes in succinate dehydrogenase activity in various parts of the brain during combined exposure to vibration and licorice root.

Data obtained in the studies reported here provide evidence that during exposure to vibration for 30 days, feeding with licorice root significantly increases the activity of the anaerobic respiration enzyme succinate dehydrogenase (SDH) in the cerebral cortex, while activity in the subcortex, conversely, decreases. Combined treatment for 30 days with licorice root and vibration after a preliminary 30-day period of feeding with licorice root resulted in high SDH activity in all the structures studied, improving brain energy supply and metabolism and ameliorating the effect of vibration.

Postvibration changes in the spike activity of neurons in the medial vestibular nucleus.

Changes in the baseline spike activity in the medial vestibular nucleus were studied after exposure to vibration for 5, 10, and 15 days. Studies addressed the distributions of neurons within this structure in terms of the regularity of their spike activity, the dynamics of neural flows, and the modalities of interspike histogram modalities. Mean values were calculated for the major statistical measures of baseline spike activity.

[The influence of examination stress on psychophysiological characteristics and heart rate in students].

With the aim to assess the influence of pre-examination psychoemotional stress on the level of centralization of the heart rate control, mathematical analysis of ECG of students was performed in normal condition (a common day of academic semester), before, and after an examination. The ECG was recorded and processed with the help of IBM-486 PC. R-R cardiointevalograms were processed by the method of variational pulsometry after Baevsky.

Antioxidant effect of licorice root on blood catalase activity in vibration stress.

Rabbits were treated (orally) with a preparation of Glycyrrhiza glabra L. for 30 days and in parallel were exposed to vibration stress (30 days). The licorice preparation reduced catalase activity in the peripheral blood and increased animal resistance to vibration stress.

Imbalance between rat blood metalloproteins in the early stage of hypokinesia.

Changes in the contents of blood metalloproteins with prooxidant (plasma cytochromes b558 I and b558 II, erythrocyte membrane cytochromes b558 III and b558 IV, superoxide-producing plasma lipoprotein suprol, and cytochrome b5 from soluble erythrocyte fractions) and antioxidant activities (Cu,Zn-superoxide dismutase, catalase, ceruloplasmin, and transferrin) depended on the duration of hypokinesia (5, 10, and 15 days). The content of metalloproteins, particularly cytochrome b5 and ceruloplasmin, increased at the initial stage, but decreased at later stages of hypokinesia (except for cytochrome b5 concentration, which continued to increase).

[Dependence of the activity of L-amino acid oxidase in the fungus Aspergillus niger R-3 on the source of nitrogen in growth media].

Various populations of peroxisomes in cells of Aspergillus niger R-3 were formed under the growth in media containing 0.5% glucose and various sources of nitrogen (1/4 of optimal concentrations of (NH4)2SO4, L-alanine, and L-methionine). Different levels of of L-amino acid oxidase activity were found in these populations of peroxisomes.

The effects of the mediodorsal nucleus of the thalamus on respiratory neurons of the medulla oblongata and respiration in rats in conditions of hypoxia.

The effects of the associated mediodorsal nucleus of the thalamus on spike activity of respiratory neurons in the medulla oblongata and on respiration were studied in normal conditions and in oxygen insufficiency. At normal atmospheric pressure, before animals were elevated to low pressures, electrical stimulation of the mediodorsal nucleus of the thalamus had predominantly inhibitory effects. At the initial phase of hypoxia, at a "height" of 4,000-5,000 m, hypoxic activation of neuron discharge frequency occurred.

Responses of hypothalamic neurons to stimulation of the vestibular nerve and lateral vestibular nucleus in the rabbit.

Acute experiments were performed on rabbits to study the responses of neurons in the anterior, ventromedial, and posterior nuclei of the hypothalamus to single, paired, and rhythmic stimulation of the vestibular nerve and lateral vestibular nucleus of Deiters. The data obtained showed that neurons of the posterior nucleus of the hypothalamus were the most sensitive. Three types of response were seen from hypothalamic neurons, with short, long, and intermediate latent periods.

[Effect of temperature on H+-K+ exchange in Escherichia coli bacteria during their anaerobic growth].

The H(+)-K(+)-exchange in E.coli grown under anaerobic conditions at temperatures from 17 to 37 degrees C was studied. The Arrhenius plots for both the N,N'-dicyclohexylcarbodiimide-sensitive release of H+ and K+ uptake by cells transferred into a fresh medium containing a carbon source (glucose) are nonlinear.

[Correlation of changes in the electrical activity and indices of tissue respiration of brain structures in rabbits exposed systematically to vibration].

The electrical activity and tissue respiration of the cortex and subcortex (posterior hypothalamic nucleus, Deiters' vestibular nucleus) have been studied in the rabbits during 3-month exposure to vibration (60H2, for 3h daily). On days 15-30 of exposure to vibration the electrocorticogram demonstrated the prevalence of alfa-waves whereas in the subcortex the teta-waves were dominated. On long-term vibration exposure (2-3 months), the synchronized slow waves were recorded on the EEG.

[Cortical and thalamic regulating mechanisms of the pulse neuron activity of oblongata medulla respiration center of the rats in normal condition and during hypoxia].

In normoxia, the orbitofrontal cortex and thalamic mediodorsal nucleus (MDN) basically inhibit the pulse activity of bulbar respiratory neurons and respiration in general. During initial hypoxia (4,000-5,000 m) a slight reduction of PO2 in the inspired air increases excitability of all the brain structures including those under study. However, strengthening of the orbitofrontal cortex and MDN inhibitory effect was leveled down by activizing brain structures, and the direct exciting effect of reduced PO2 on peripheral and central chemoreceptors.