Atherosclerosis induced in rabbits by prolonged electrical stimulation of the hypothalamus

The effect of prolonged electrical stimulation of emotiogenic zones of the hypothalamus in rabbits on their blood lipid level and the development of atherosclerosis was studied with the aid of a specially designed autonomous system. A negative emotional state observed during stimulation was accompanied by hyperlipemia and by the development of atherosclerosis in one third of uncastrated and two thirds of castrated animals.Department of Pathological Physiology and Central Scientific-Research Laboratory, Leningrad Sanitary Hygiene Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR P. N. Beselkin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1294–1296, November, 1976.     

Effect of thymoptin on the behavior of experimental animals

A study is made of the effect of thymoptin, a preparation containing a complex of acid peptides from the thymus, on the behavior of experimental animals. It is found that in a dose of 400 μg/kg the preparation enhances motor activity, raises the body temperature, augments pain sensitivity, stimulates behavior in the open field test, and facilitates learning and memory processes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121 N ^o 3, pp. 285–287, March, 1996 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Variation in antiinfectious nonspecific resistance of the organism caused by cholinergic stimulation

Cholinergic stimulation (acetylcholine, aceclidine, armin) is found to improve antiinfectious nonspecific resistance in mice. The effect depends on the dose of cholinomimetic (armin), is maximal during the first 18 hours of the infectious process, and is determined by serum antibacterial activity, lysozyme activity, and the function of neutrophils and natural killers. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o . 8, pp. 164–166, August, 1995 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Mechanism of heart-rate acceleration caused by stimulation of vagal centers in the frog

The mechanism by which heart rate is increased upon stimulation of vagal centers is studied using frog heart preparations perfused with Ringer—Locke solution containing atropine and/or benzohexonium. Atropine stimulates vagus-induced heart-rate acceleration in dilutions of 10⁻⁶ and 10⁻⁵ g/ml. In a dilution of 10⁻⁴ g/ml both atropine and benzohexonium abolish vagal tachycardia. Rausedyl (3–4 injections, 5 mg/kg, at 18–20-h interval) prevents tachycardia. Stimulation of both halves of the medulla oblongata increases heart rate to a greater extent than stimulation of one half. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 16–20, July, 1997     

Effect of met-enkephalin on sinus arrhythmia caused by burst stimulation of the vagus nerve

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 7, pp. 4–6, July, 1993     

Effect of neurotensin and epinephrine on sinus arrhythmia caused by burst stimulation of the vagus nerve

Administration of neurotensin against the background of sinus arrhythmia caused by burst stimulation of the vagus nerve in cats restores synchronization of the cardiac and vagal rhythms or modulates the proportion between them. This either stops the arrhythmia or changes its parameters. The effects of the peptide are similar to those of epinephrine and are abolished by β-adrenoreceptor blockage. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 494–497, May, 1997     

Disturbances in the integrative activity of the rat brain after bilateral focal compression ischemia of the frontal cortex

Pathomorphological changes and disturbances in the integrative activity of the central nervous system of rats are studied after bilateral compression ischemia of the frontal cortex. Bilateral compression of the frontal cortex is shown to result in the formation of limited foci of ischemic necroses in the cortex, which are surrounded by the perifocal zone. This is attended by reduced horizontal motor activity in the “open field” test, as well as by a reduced latency of the conditioned passive avoidance response. The motor activity of operated animals is restored on day 14 postoperation, correlating with regeneration of some damaged neurons in the perifocal zone, whereas the latency of the conditioned passive avoidance response remains markedly reduced. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 568–571, December, 1994 Presented by O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

Myoclonic hyperkinesia induced in rats by repeated injections of picrotoxin into the neostriatum

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 114, No. 1, pp. 7–9, January, 1993.     

Effect of seleptine on retrieval of active avoidance task in rats

We have examined seleptine, a new derivative of the atypical neuroleptic clozapinum, on the retrieval of the active avoidance task in rats placed in a shuttlebox. Retention of the conditioned response was assessed in the test of repeated training for the same task to the score achieved in the first session. After oral seleptine (100 mg/kg), the retention of the active avoidance task was deteriorated to a greater extent than the ability for a new learning. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 7, pp. 28–30, July, 1998     

Quantitative analysis of stimulation frequency transformation in the neuromuscular apparatus

The dependence of the parameters of neuromuscular transmission on the frequency of stimulation was determined. This dependence was analyzed in relation to fatigue of the synapse arising during prolonged repetitive stimulation of muscle. The proposed mathematical model and the method of statistical analysis of the records of evoked responses of the muscle derived from it permit approximate estimates to be made from the experimental data of parameters quantitatively reflecting frequency (transmission) properties of the neuromuscular apparatus.Laboratory of Mathematical Modeling and Processing of Experimental Data, Institute of General Pathology and Pathophysiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byullten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 1016–1018, August, 1976.     

Quantitative analysis of the role of cholinergic, gastrin, and histamine regulatory mechanisms of pepsinogen production in the stomach of narcotized rats

Pepsinogen secretion in the intraluminally perfused stomach of narcotized rats was induced by electrical stimulation of the vagus nerve or intravenous injection of pentagastrin. Blockade of histamine H₂ receptors inhibited pepsinogen production induced by vagal stimulation by 35%, but caused only a 13% decrease in pentagastrin-stimulated pepsinogen secretion. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 12–15, January, 2000     

Effect of amiridin and piracetam on memory disturbances induced by experimental stress

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 115, N ^o 2, pp. 155–157, February, 1993.     

Alterations of phrenic nerve activity caused by stimulation of neuronal structures in rostral area of ventral surface of the medulla oblongata

Electrical stimulation of neuronal structures in a rostral area of the ventral bulbar surface alters central inspiratory activity in anesthetized rats, augmenting the amplitude and velocity of this activity during the periods of its increase and plateau. The reactions are more pronounced in rats with transected vagal nerves. Blockade of pulmonary mechanoreceptors eliminates the influence of rostral neuronal structures only on the temporal parameters of the plateau. Bilateral cooling of neuronal structures to 20°C results in complete block of central inspiratory activity. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 6, pp. 617–619, June, 1997     

Morphometric analysis of liver acini in endotoxicoses caused by peritonitis and gangrene of the leg

Morphometric and information analysis is used to quantify the structural changes occurring in the liver and to reveal the specific features of damage to different zones of acini in peritonitis and gangrene of the leg. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 547–549, May, 1994 Presented by V. V. Kupriyanov, Member of the Russian Academy of Medical Sciences     

Comparative effects of tranquilizers and nootropes on the elaboration and functional impairment of the avoidance response

Experiments with rats show that pyracetam, phenazepam, and gidazepam accelerate the development of an avoidance response and diminish its functional impairment through unexpected exposure to electric current applied notwithstanding the relations established between stimuli, the response, and its sequelae. The drugs under study increase the reproducibility of avoidance responses in the rats after the indicated procedure, by preventing or diminishing the increase in intersignal reactions, i.e., exerted equivalent effects despite differences in the pharmacological spectra of the drugs. The results of this study show that the substances used affect emotional tension but do so by different mechanisms. Thus, the tranquilizers decrease emotional tension by acting on the emotional sphere directly, whereas pyracetam decreases it in an indirect way, by activating cognitive and mnestic processes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 8, pp. 152–155, August, 1996     

Electrophysiological and neuropharmacological analysis of interaction between the systems of excitation and inhibition in the cerebral cortex

GABA- and cholinergic substances selectively affect different phases of the restoration cycle of primary somatosensory response in albino rats. The GABA antagonist bicuculline reduced and the deactivation inhibitor valproic acid enhanced depression of the test response when stimulated at pulse intervals of 60–125 msec. The cholinomimetic arecoline enhanced and the cholinolytic amizylum diminished facilitation of test response at intervals of 150–200 msec. The data suggest a dynamic interaction as well as a competition between GABA- and cholimergic systems in processing the sensory input. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 9, pp. 315–318, September, 1997     

Secretion of suppressor factors by mouse lymphocytes on contact with syngeneic and xenogeneic red cells

During incubation of spleen cells of immune micein vitro with syngeneic and xenogeneic red cells a factor (or factors) with immunosuppressive activity is secreted into the medium. Secretion of the suppressor factor by spleen cells of nonimmune mice takes place only on contact with xenogenic red cells.Department of Immunology, Scientific-Research Center Attached to the N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. M. Lopukhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 308–310, March, 1977.     

Pharmacological analysis of the activity of phenazepam and flunitrazepam administered in superlow doses

Benzodiazepine tranquilizers, phenazepam and flunitrazepam, administered to random-bred albino male rats in superlow doses (10⁻⁹–10⁻¹⁵ mol/kg), are shown to exert an anxiolytic effect in the conflict test. In contrast to the case with the usual doses, the above effect is not accompanied by marked myorelaxant or sedative effects. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, № 2, pp. 164–166, February, 1996