NO-synthase activity and generation of reactive oxygen species in the brain in old rats: Association with individual behavior

NO synthase activity and the generation of reactive oxygen species (ROS) were measured in different brain regions of old rats separated in an “emotional resonance” test into two groups: passive rats (those preferring a dark space) and active ones (those preferring a lighted space). In both groups, NO synthase activity and ROS generation were at the highest level in the cerebellum. In the tested brain regions of active rats, NO synthase activity was lower and ROS generation more strongly marked than in the respective regions of passive rats. Interregional positive linear correlations were discovered both for NO synthase activity and for ROS generation. When the two groups were considered together, negative correlations were detected between NO synthase activity and ROS generation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 145–147, August, 1995 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Spontaneous activity and evoked potentials in the caudal trigeminal nucleus,ventrobasal thalamus,and cerebral cortex of rats with neuropathic trigeminal neuralgia

Incomplete compression of the infraorbital nerve in rats leads to spontaneous neuronal activity in the form of bursts in the caudal trigeminal nucleus and to epileptiform activity in the ventrobasal thalamus and cerebral cortex. From the latter, afterdischarges are also recorded. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 26–29, January, 1994     

Enkephalinas activity in various brain structures of naloxone-treated and morphine-insensitive rats

Morphine injected subcutaneously in a dose of 2 mg/kg body weight exerted an analgesic effect in some Wistar rats (morphine-sensitive animals), as was indicated by a significantly prolonged latency of the tail-flick response, butfailed to produce analgesia in others (morphine-insensitive animals). In morphine-sensitive rats, the striatum had the highest enkephalinase A activity, followed in decreasing order by the mesencephalon, hippocampus, pons, cortex, medulla oblongata, and hypothalamus. Thirty minutes after intraperitoneal administration of naloxone (0.3 mg/kg body weight) to morphine-sensitive rats, enkephalinase activity fell significantly in the hippocampus, striatum, and cortex, remained unchanged in the pons and medulla oblongata, and rose significantly in the mesencephalon and insignificantly in the hypothalamus; generally similar differences in enkephalinase activity from naloxone-untreated morphine-sensitive rats were recorded in the brain structures of morphine-insensitive rats given saline instead of naloxone. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 11, pp. 492–494, November, 1995 Presented by K. V. Sudakov, Member of the Russian Academy of Medical Sciences     

Relationship between psychological and bioenergetic characteristics in neurotic old rats

Old rats are found to have greatly reduced capacities for learning conditioned responses of various types, particularly when induced to develop a neurosis-like state which impairs autonomic functions and their regulation. The development of hypertensive responses is accompanied at the cellular level by a significant rise of succinate dehydrogenase activity in the sensorimotor cortex of young neurotic rats and by its significant fall in that of their old counterparts, in which the predominant oxidation substrates are NAD-dependent compounds. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 3, pp. 242–245, March, 1995     

Some cytochemical peculiarities of the rat brain motor system after space flight

The results of cytochemical cytometry of rat brain suggest that a 9-day exposure of rats to microgravitation conditions lowers the activity of monoaminoxidase in the fibrous structures of layer V of the somatosensory cortex and in the head ofnucleus caudatus, as well as the activity of acetylcholine esterase in the bodies of neurons forming the head ofn. caudatus. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 3, pp. 288–290, March, 1995 Presented by the late O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

Reactivity of capillaries and pyramidal neurons in rat cortex under conditions of acutely reduced circulation

A study of capillaries and pyramidal neurons of the cortex in white rats subjected to ligation of the common carotid artery reveals that acute reduction of the circulation is characterized by a decreased activity of alkaline phosphatase and Na, K-ATPase as well as a reduced number of capillaries marked with these enzymes, and a lower activity of butyrylcholine esterase. A decreased activity of cytochrome oxidase in neurons suggests the existence of intracellular compensatory-adaptive mechanisms. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 558–560, May, 1994 Presented by O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

Lipid peroxidation and antioxidant enzymes in the brain of rats exposed to acute emotional stress: Effect of interleukin-1β

Acute emotional stress is shown to raise the level of malonic dialdehyde in the hypothalamus of August rats. After intraventricular administration of interleukin-1β, the malonic dialdehyde level and the activity of antioxidant enzymes tended to rise selectively in the hypothalamus (but not in the sensorimotor cortex) of August, Wistar, and WAG rats. In the presence of this interleukin, acute emotional stress did not cause increases in lipid peroxidation products in the hypothalamus of August rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 244–247, September, 1995     

Binding of3H-diazepam in rat brain eleven months after termination of corazole kindling

Binding of³H-diazepam in rat cerebellum decreases by 14% (p<0.05) 11 months after termination of kindling and one day after injection of a test dose of corazole (30 mg/kg), while it increases by 19.5% after a single injection of a convulsive dose of corazole (50–75 mg/kg). No changes are found in the cortex. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 135–137, February, 1994 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Lipid peroxidation level in the focus of compression ischemia in the cerebral cortex of rats

Pathomorphological changes in a focus of ischemia, the level of lipid peroxidation (as indicated by the content of products reacting with thiobarbituric acid), and the postischemic levels of adenyl nucleotides and tissue lipids were studied in rats with focal compression ischemia of the cerebral cortex. An increased level of the TBA-reactive products paralleled by a reduction of the concentrations of adenyl nucleotides and tissue lipids was found to be in clear-cut correlation with the processes of neuronal injury and death and with subsequent repair phenomena in the focus of cortical ischemia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 589–590, December, 1994 Presented by O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

Impact of 8-isoestrone analogs on estradiol binding in uterine tissue from ovariectomized rats

8-Isoanalogs of estrone were studied for their ability to influence estradiol binding in the cytosolic fraction of uterine tissue from ovariectomized rats and for their uterotropic activity 24 h after injection into such rats. Two groups of estrone 8-isoanalogs with opposite biological effects were identified: those increasing estradiol binding in the cytosolic fraction of uterine tissue and those decreasing this binding. Uterogenic activity was exhibited by all of the compounds tested, with the exception of compound I. No correlation was found between the uterogenic activity of the isoanalogs and hormone-receptor interactions. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 165–167, February, 1995     

The effect of morphine on RNA synthesis in some brain structures of rats with various narcological resistance

Different incorporation of³H-uridine in RNA and increased RNA synthesis after the addition of morphine are demonstrated in all brain structures of resistant rats, as well as in the cortex, nucleus accumbens, griseum centrale, and nucleus ventriculus hypothalami of prone rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 100–102, January, 1994     

Age-related alterations in brain α1-adrenoceptors of hypertensive rats: Their possible role in the development of arterial hypertensionof hypertensive rats: Their possible role in the development of arterial hypertension

The binding of labeled agonist (³H-prazosin) to α₁-receptors in the frontal cortex, hypothalamus, and medulla oblongata of hypertensive (NISAG) and normotensive (Wistar) rats of different age is studied to elucidate the role of these receptors in the development of hereditary stress-induced arterial hypertension. It is found that the density of α₁-adrenoceptors in the hypothalamus of 30-day-old and adult NISAG rats is decreased, while in the medulla oblongata the number of these receptors, starting from the first week of life, is greater than in Wistar rats of the same age. From a comparison of these findings with the development of hypertension in NISAG rats it is concluded that α₁-adrenoceptors of the medulla oblongata are involved in this process. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 78–80, July, 1995 Presented by V. P. Kaznacheev, Member of the Russian Academy of Medical Sciences     

Informational capacity of the rat sensorimotor cortex in the postresuscitation period (morphometric analysis of a neuronal population)

The number of neurons was counted in different functional neuronal complexes of the sensorimotor cortex in albino rats in the control and at different times after clinical death caused by asphyxia. A decrease of the number of neurons from 2.5×10⁶ in the control to 1.56×10⁶ toward the 30th day of the postresuscitation period was found in the sensorimotor cortex. The complexes of small neurons in the upper floor (layers II–IV) suffer badly, while the neurons of layer VI are damaged to a somewhat lesser degree and the cells of layer V are minimally altered. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 3, pp. 331–333, March, 1995 Presented by L. V. Poluektov, Member of the Russian Academy of Medical Sciences     

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     

Contribution of 5-HT1A serotonin receptors of the brain to the regulation of hereditary catalepsy

Selective agonists 5-HT_1A of serotonin receptors (8-OH-DPAT and flezinoxan) had an inhibitory effect on the manifestation of hereditary catalepsy in mice and rats. No differences were revealed in specific binding of³H-8-OH-DPAT to 5-HT_1A receptors in the striatum of either cataleptic or noncataleptic mice and rats. Nonetheless, an increase of the density of these receptors was observed in the frontal cortex of CBA mice predisposed to catalepsy in comparison with mice of the noncataleptic C57Bl strain. The data indicate a contribution of 5-HT_1A receptors to the regulation of hereditary catalepsy. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 633–635, December, 1994 Presented by V. P. Kaznacheev, Member of the Russian Academy of Medical Sciences     

Changes in the coronary vessel tone resulting from immobilization stressA

Coronary perfusion pressure at increasing flow of Krebs-Henseleit buffer in the hearts of animals exposed to stress is decreased 23%, a decrease which is eliminated by administering the NO-synthase blocker N^G-monomethyl-L-arginine. Stimulated vasodilation of coronary vessels (administration of sodium nitroprusside and acetylcholine) decreases markedly in stressed animals; the concentrations of sodium nitroprusside and acetylcholine inducing a half-maximum coronary response increase. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 246–249, September, 1994 Presented by K. V. Sudakov, Member of the Russian Academy of Medical Sciences     

Structural and functional changes in the brain of rats with different behavioral types at later stages of circulatory hypoxia

Structural changes in the brain were studied at later (one and three months) stages of cerebral hypoxia caused by occlusion of the common carotid arteries, which were indicative of the development of recovery and destructive processes. Brain ultrastructure was found to be better preserved in rats with an active type of behavior one month after the onset of ischemia than in rats of the other groups; motor activity was restored to the baseline level, thus demonstrating a higher rate of recovery processes. Significant ultrastructural damage to the brain at the same stage of ischemia was observed in rats with a passive type of behavior (especially in rats of the middle group), while motor activity was increased. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 11, pp. 529–534, November, 1994 Presented by P. V. Simonov, Member of the Russian Academy of Sciences     

Variation in plasma morphine level and pain sensitivity in prenatally morphinized rats

It is established that mature random-bred and Wistar rats exhibit the same level of pain sensitivity in the tail-flick test, but the analgetic effect of morphine (5 mg/kg) is variously expressed: marked hypalgesia is observed in mongrel but not in Wistar rats. Prenatal morphinization enhances the analgetic effect of morphine in both mongrel and Wistar rats. There is a direct correlation between the plasma morphine content in prenatally morphinized rats and their sensitivity to the analgetic action of morphine. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 273–275, September, 1995 Presented by D. A. Kharkevich, Member of the Russian Academy of Medical Sciences     

Analysis of changes in the electroencephalogram power spectrum on a new model of brain ischemia in rats

The bioelectrical activity is studied in the left and right parietal cortex by recording the power spectrum of the electroencephalogram in brain ischemia caused by complete ligation of the left common carotid artery and 50% reduction of the blood flow in the right common carotid artery in experiments carried out on nonnarcotized Wistar rats. Ischemia results in marked and stable disorders in the bioelectrical activity manifested in a decrease of the total EEG power, depression of the dominating frequency in the Θ-range, increase of the δ-range power, and interhemispheric asymmetry of some spectrogram parameters. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny Vol. 118, N ^o 12, pp. 565–567, December, 1994 Presented by E. D. Gol'dberg, Member of the Russian Academy of Medical Sciences     

Effect of insulin and adrenocorticotropic hormone on rat brain cortex in the early postnatal period

Administration of insulin and adrenocorticotropic hormone to 1-, 2-, and 3-day-old rats leads to an increase in the RNA and total protein contents of cortical neurons, while administration of adrenocorticotropic hormone alone increases the number of dying neurons in layer V of the cortex. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 305–307, September, 1995 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences