Role of the interaction between different types of serotonin and α2-adrenergic receptors in the regulation of audiogenic seizures in DBA/2 micereceptors in the regulation of audiogenic seizures in DBA/2 mice

It is shown that the serotonin receptors 5-HT_1c, 5-HT₃, and 5-HT₄ and α₂-adrenergic receptors are involved in the regulation of audiogenic seizures in DBA/2 mice, and that the effects of these serotonin receptors on the duration and magnitude of convulsive activity are the opoosite of those produced by α₂-adrenergic receptors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 381–383, April, 1995     

Adaptation to periodic hypoxia restricts subdural hemorrhage during audiogenic epileptic seizures in rats

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 12, pp. 572–574, December, 1993     

Relation of cerebral blood flow to neuronal activity in rats with different susceptibilities to emotional stress as a predictor of cerebral ischemia severity

According to the results of 5-minute testing of free behavior in an open field carried out in different seasons, white laboratory rats were separated into three groups with high, medium, and low resistance to emotional stress, respectively (HR, MR, and LR rats), and it was found that the proportions of HR and MR rats, but not that of LR animals, varied with the season. Laser fluorimetry showed that local cerebral blood flow rates were highest in the HR group and lowest in the LR group. Conversely, wave amplitudes on the electroencephalogram (EEG) were lowest in the former group and highest in the latter. More significant differences among the three groups in levels of blood supply to the brain were revealed with a new method proposed to estimate blood flow per unit of EEG activity by calculating the ratio between the cerebral blood flow rate (expressed in ml/min/100 g brain tissue) and EEG activity (expressed in μV). HR rats proved to be more susceptible than their MR and LR counterparts to cerebral ischemia produced by occlusion of the common carotid arteries. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N^no 10, pp. 360–363, October, 1994     

Rat model of blood hyperviscosity syndrome: Informativity of blood rheological parameters in cerebral ischemia

Blood rheological status is studied in Wistar rats with cerebral ischemia induced by ligation of the left coronary artery and reduced blood flow via the right coronary artery. Substantial changes in blood rheology and manifestations of the sludge syndrome are noted. The results obtained are compared with clinical observations, and the informativeness of each parameter is evaluated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 274–275 September, 1996     

Dynamics of the recovery period in rats exposed to global cerebral ischemia

Global cerebral ischemia-reperfusion was modeled by thermocoagulation of the vertebrobasilar arteries followed by occlusion of both carotid arteries. Behavioral parameters, neurological status, and mnesic functions in rats were studied during the recovery period. It is concluded that this model of ischemia is reproducible and can be used for studying ischemiareperfusion damages to the brain. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 10, pp. 475–477, October, 2000     

Protective effect of intracerebroventricular injection of adenosine agonists during total cerebral ischemia

Adenosine and its analogs N⁶-cyclohexyladenosine (CHA) and N-ethylcarboxamideadenosine (NECA) are highly effective when injected into the lateral ventricle in very low doses (by 1–2 orders lower than subcutaneously). The protective effect of A-agonists is considered to be mediated by a central mechanism and realized via A-receptors of the brain: the effects of low doses of A-agonists are mediated by A₁-receptors, whereas higher doses exert an extra A₂-effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 622–624, June, 1994 Presented by P. V. Sergeev, Member of the Russian Academy of Medical Sciences     

Effect of cerebral ischemia on acute convulsions and chronic epileptogenesis

The pharmacological kindling with corazol was used as a model of chronic cerebral epileptization. In contrast to sham-operated rats or rats with unilateral occlusion of the common carotid arteries, bilateral occlusion of these vessels moderated acute seizures provoked by a single administration of the convulsant corazol and abated the enhanced cerebral seizure readiness induced by its repeated administration. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 7, pp. 30–33, July, 1998     

Effect of cerebrocrast on local cerebral bloodflow and EEG of alert rats with brain ischemia

Cerebrocrast, a, 1,4-dihydropyridine derivative, accelerated blood delivery to the brain and normalized the spectrum and total power of the electroencephalogram during brain ischemia; manifestations of interhemispheric asymmetry of the electroencephalogram and cerebral bloodflow were leveled. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o . 3, pp. 296–298, March, 1995 Presented by E. D. Gol'dberg, Member of the Russian Academy of Medical Sciences     

Neuroprotective activity of angiotensin-converting enzyme inhibitors in cerebral ischemia

Captopril and enalapril improved rat survival after ischemia caused by bilateral occlusion of the common carotid arteries. The neuroprotective effect of the angiotensin-converting enzyme inhibitors was confirmed by histological examination. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 11, pp. 535–537, November, 1999     

Effects of leu-enkephalin analog on cerebral circulation in cerebral ischemia of different severity

Leu-enkephalin analog reduces cerebral circulation in mild and has no effect in moderate ischemia, while in severe cerebral ischemia it causes periodic compensatory enhancement of cerebral circulation in experimental animals, instead of its monotonous reduction, thus ensuring 100% survival during a 6-h period, whereas in the control group 60% animals die within 3 h. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 11, pp. 516–519, November, 1998     

Additivity and independence of neuroprotective effects of GABAA and GABAB receptor agonists in complete global cerebral ischemia

Neuroprotective effects of GABA_B agonist baclofen and GABA_A agonists THIP and muscimol are completely additive. GABA_A and GABA_B receptor antagonists block the neuroprotective effects of the corresponding agonists without cross-blocking. In fact, the blockade of combined effect of two agonists with selective GABA_A and GABA_B antagonists separately and in combination is not below the estimated value. Therefore, GABA_A and GABA_B receptor mechanisms of the neuroprotective effects independently and separately contribute to the improvement of brain resistance to global ischemia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 8, pp. 187–189, August, 2000     

Protective effect of adaptation to hypoxia and its prolongation by pharmacological agents in rats prone to audiogenic epilepsy

Cytophotometric determination of RNA in various brain structures of hypoxia-adapted and unadapted epilepsy-prone rats at different times after an epileptic seizure shows much smaller decreases in RNA levels and their much more rapid return to normal in the adapted than in the unadapted rats. The adaptation to hypoxia produces a marked anticonvulsive effect, and this effect is enhanced and prolonged considerably by pharmacotherapy. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 120–123, February, 1994     

Antiedematous activity of cerebrocrastin cerebral ischemia

The effect of a course of cerebrocrast, a 1,4-dihydropyridine derivative, on brain edema (as shown by impedometry) and cerebral tissue microvascularization in ischemia caused by ligation of the left common carotid artery and 50% restriction of the bloodflow in the right common carotid artery is studied in Wistar rats. Cerebrocrast is found to appreciably limit the development of brain tissue edema and to improve the status of microvessels by reducing the number of sharply constricted nonfunctioning capillaries and increasing the number of capillaries of 4 μ and more in diameter. Pronounced antioxidative effects of cerebrocrast in transitory cerebral ischemia are demonstrated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, No. 3, pp. 291–293, March, 1995 Presented by E. D. Gol'dberg, Member of the Russian Academy of Medical Sciences.     

Adaptation to multiple electrostimulation limits hemorrhages in the brain of rats with audiogenic epilepsy

Exposure of Krushinsky-Molodkina rats (a strain genetically predisposed to audiogenic epilepsy) to multiple electrostimulation (a course consisting of 10 sessions) prolongs the latency of epileptic seizures, lowers blood levels of stress hormones, lessens the severity of seizures, and reduces by half the area occupied by subdural hemorrhages. It is concluded that the major role in the mechanism of these protective effects is played by adaptation to stress, accompanied by the accumulation in the brain of heat-shock proteins that stabilize cellular structures. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 127–129, February, 1994     

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     

Alterations of cortical neurons and their dendrites after chronic alcohol intoxication

Alterations occurring in the neurons of rat sensorimotor cortex 1, 2, and 4 months after a 4-month alcohol intoxication and 1 and 4 months after a 1-year alcoholization are studied by the methods of Nissl and Golgi. Pronounced dystrophic changes in cortical neurons and dendrites as well as reparative processes in the cell body are revealed 1 month after a 4-month intoxication. The recovery period for the upper cortical layer neurons (phylogenetically younger) is faster than that of neurons from the lower layers (phylogenetically older), as well as that of hypochromatousvs. hyperchromatous cells. Normalization of dendrite structure is slower than that of the cell body. Four months after a 1-year alcohol intoxication the structure of cortical neurons and dendrites is not restored. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 10, pp. 467–470, October, 1996     

Different antiarrhythmic effects of dalargin and β-endorphin in severe myocardial ischemia during stimulation of the sensorimotor cortex

The effects of the opiate receptor agonists dalargin and β-endorphin on the occurrence of idioventricular arrhythmias, including ventricular tachycardia and fibrillation, are studied in acute experiments on Nembutal-anesthetized cats. Dalargin administered in the dose crossing the blood-brain barrier produces a pronounced antiarrhythmic effect, while β-endorphin is effective only against ventricular fibrillation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 28–31, July, 1997     

Dynamics of dendritic and transcallosal cortical potentials during hyperthermia

Dendritic and transcallosal potentials in the course of hyperthermia and after restoration of temperature homeostasis were investigated in experiments of waking rabbits exposed in a heat chamber to an air temperature of 45°C. The effect of the high temperature was accompanied by marked depression of the amplitude of the dendritic potential, although by a lesser degree than the transcallosal response. The results are evidence of the direct inhibitory effect of heat on neurons in the various layers of the cortex. Restoration of the function of the cortical neurons after a high degree of hyperthermia is observed 24 h after normothermia is reached.Central Research Laboratory, Rostov Medical Institute. (Presented by Academician V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 931–933, August, 1976.     

Changes in cortical astrocytes in offspring of moderately alcoholized female rats

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 9, pp. 318–321, September, 1993     

Effect of lozartan on postischemic cerebral blood flow in normotensive rats

Transient cerebral ischemia considerably impaired autoregulation of cerebral blood flow in rats. Lozartan reliably reduced blood pressure and restored the autoregulatory vascular response to hypotension. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 10, pp. 417–418, October, 1999