[Experimental study of the influence of phenozanic acid and its combination with valproic acid on the development of the epileptic system]. / Izuchenie vliyaniya fenozanovoi kisloty i ee kombinatsii s val'proevoi kislotoi na razvitie epilepticheskoi sistemy v eksperimente.

OBJECTIVE: To study the effect of phenosanic acid (PA) and its combination with valproic acid (VA) on the development of the Epi system. MATERIAL AND METHODS: A model of focal chronic epilepsy in rats was created by applying metallic cobalt to the surface of the sensorimotor area of the cortex. Long-term electrodes were implanted in the sensorimotor cortex of the left and right hemispheres, the hippocampus, and the hypothalamus. The effect of PA (80 mg/kg) and its combination with VA (200 mg/kg) on discharge activity was carried out on the 2nd day and at the stage of generalization of the Epi system - on the 6th day. The stability of the Epi system on day 10 was assessed by provoking the development of epileptic status (Epi status) in response to the administration of thiolactone homocysteine (HMC) at a dose of 5.5 mmol/kg. RESULTS: In rats treated with PA, low discharge activity is observed, which is confirmed by the absence of EEG and motor manifestations of status epilepticus caused by HMC. PA does not suppress paroxysmal activity at the stages of development of the Epi system. VA significantly suppresses paroxysmal activity, but does not affect the formation of new foci of Epi activity in subcortical structures and the contralateral cortex. The epi system of rats treated with VA is characterized by high discharge activity by the 10th day of the experiment and lability to provocation of epi status. The combination of drugs is more pronounced than PA, but less than VA, reduces the numerical characteristics of paroxysmal activity in the brain structures of rats. CONCLUSION: PA when administered alone, in combination with VA, causes a slowdown in the generalization of convulsive foci of Epi activity and prevents the formation of a stable Epi system. VA, having a pronounced anticonvulsant effect, does not weaken the development of the Epi system in the model of focal cobalt-induced epilepsy.

Levetiracetam effect on behavioral and electrophysiological parameters in rat model of global brain ischemia.

Post-stroke paroxysmal activity is a neurophysiological indicator of epileptogenesis and increase of seizure susceptibility, so treatments with neuroprotective activity and anti-paroxysmal activity can be more beneficial during post-ischemic period. The goal of this study was evaluation of levetiracetam (100 mg/kg, 7 days of administration) effect on behavior and brain bioelectric activity changes in the post-ischemic period. Global ischemia model was carried out with bilateral ligation of carotid arteries in rats. Neurological deficit and electrophysiological changes of brain structures (striatum, cortex, hypothalamus, hippocampus) were analyzed during 28 days. Paroxysmal activity was not observed on the 1st day after ischemia and had early (2nd day) and late (28th day) onsets. Spectral analysis showed that rats, that died by the 10th day, had delta wave increase and theta decrease on the 1st day and delta activity reduction on the 2-7th days. LEV did not affect survival rate, however, it contributed to neurological disorder regression towards lighter forms on the 1st day after ischemia. It suppressed paroxysmal activity with an early onset and affected delta and theta waves on the 1st day in all structures except hippocampus. On the 7th and 28th days LEV increased delta activity due to 1-3 Hz frequency. Thus, LEV eliminates early onset post-ischemic paroxysmal activity and contributes to normalization of delta waves activity on the 1st day after ischemia, that positively affects neurological status of animals in post-ischemic period. It allows one to make a conclusion about possible LEV application in the post-ischemic period.

[Pharmacological effects and clinical application of pantogam and pantogam active]. / Farmakologicheskie éffekty i klinicheskoe primenenie preparatov pantogam i pantogam aktiv.

Clinical studies and experience in the use of pantogam (hopanthenic acid) and pantogam active (rac-gopantenic/D-, L-gopantenic acid) showed their efficacy and safety in patients with various pathologies. Pantogam has a unique spectrum of pharmacological effects (nootropic, anticonvulsant, mild activating) in the absence of addiction, hyperstimulation or withdrawal syndrome. Pantogam active, having also an additional anxiolytic effect, is characterized by bimodal activity, improves not only cognitive functions, but also emotional state in patients in psychiatric, neurological and cardiological practice with such diseases and conditions as anxiety/anxiety-depressive disorders, chronic brain ischemia, ischemic heart disease, chronic heart failure, arterial hypertension, epilepsy, craniocerebral trauma, schizophrenia as well as cognitive impairment in the structure of neurological and psychogenic deficiencies.

Afobazole protects rats exposed to peat smoke in utero.

Female outbred albino rats were daily subjected to forced inhalations of peat smoke (4 cores packed with a mixture of peat (70%) and wood pulp (30%); 0.46 g, pH at least 5.5, core burning time 6 min,; total exposure 44 min) per se and in combination with oral afobazole (anxiolytic) in doses of 1 and 10 mg/kg on days 1-20 of pregnancy. Some groups of females received oral afobazole (200 mg/kg) after delivery, due to which their newborn rats received the drug in doses of 1-10 mg/kg with maternal milk on days 1-20 of life. Exposure to peat smoke inhibited body weight gain in the progeny on days 5-60 of life. Afobazole treatment during the pre- and postnatal periods prevented this effect. Open field testing showed that exposure to peat smoke prolonged the motor activity in the progeny and impaired the loss of orientation and exploratory behavior during repeated testing. Oral afobazole (1 and 10 mg/kg) during the prenatal and/or postnatal period (with maternal milk) prevented the effects of peat smoke.

Involvement of BDNF and NGF in the mechanism of neuroprotective effect of human recombinant erythropoietin nanoforms.

Human recombinant erythropoietin adsorbed on poly(butyl)cyanoacrylate nanoparticles and administered intraperitoneally in a dose of 0.05 mg/kg exhibited a neuroprotective effect in experimental intracerebral posttraumatic hematomas (hemorrhagic stroke) and reduced animal mortality. Human recombinant erythropoietin, native and adsorbed on lactic and glycolic acid copolymer-based nanoparticles, exhibited no antistroke effect on this model. Analysis of reverse transcription PCR products showed that human recombinant erythropoietin adsorbed on poly(butyl)cyanoacrylate nanoparticles more than 2-fold increased the expression of BDNF and NGF neurotrophins in the rat brain frontal cortex and hippocampus.

Antidepressant Effect of Dimeric Dipeptide GSB-106, an Original Low-Molecular-Weight Mimetic of BDNF.

A large amount of clinical and experimental data suggest the involvement of neurotrophins, in particular the brain-derived neurotrophic factor (BDNF), in depression pathogenesis. However, the therapeutic use of BDNF is limited because of its instability in biological fluids, poor blood-brain barrier (BBB) permeability, and the presence of side effects. A low-molecular-weight mimetic GSB-106, which is a substituted dimeric dipeptide bis(N-monosuccinyl-L-seryl-L-lysine)hexamethylenediamide, was designed and synthesized based on the BDNF fourth loop structure at the V.V. Zakusov Institute of Pharmacology (RAMS). GSB-106 was found to exhibit an antidepressant activity in various models of depressive-like state when administered intraperitoneally to outbred mice and rats. An effect for the substance, when administered daily for 4-5 days, was detected in the Porsolt forced swimming test (0.1 and 1.0 mg/kg) and in the tail suspension test in mice (1.0 and 1.5 mg/ kg). An effect for GSB-106 at doses of 0.1 and 0.5 mg/kg was observed after a single application in experiments on rats in the Nomura water wheel test. The obtained evidence supports the hypothesis on the involvement of BDNF in the pathogenesis of various depression conditions, thus opening prospects for searching for new original antidepressants.

[Neuroprotective effect of recombinant human erythropoietin-loaded poly(lactic-co-glycolic) acid nanoparticles in rats with intracerebral posttraumatic hematoma].

The neuroprotective activity of recombinant human erythropoietin (rhEPO) loaded poly(lactic-co-glycolic) acid (PLGA) nanoparticles has been observed in rats with model intracerebral post-traumatic hematoma (hemorrhagic stroke). It is established that rhEPO-loaded PLGA nanoparticles produce a neuroprotective effect in rats with hemorrhagic stroke, which is manifested by reduced number of lethal outcomes and animals with neurological disorders. Treatment with rhEPO-loaded PLGA prevented amnesia of passive avoidance reflex (PAR), which was produced by the hemorrhagic stroke, and reduced the area of brain damage caused by the intracerebral hematoma. These effects were recorded during one-week observation period. Native rhEPO exhibited a similar, but much less pronounced effect on the major disorders caused by the model hemorrhagic stroke in rats.

[The absence of tolerance and withdrawal syndrome after the treatment with the new L-tryptophane-containing dipeptide anxiolytic GB-115].

Effects of GB-115, an anxiolytic L-triptophan-containing dipeptide, based on the endogenous tetrapeptide cholecystokinin, were evaluated during and after withdrawal of its long-term administration to rats in comparison with diazepam. It was shown using the "elevated plus-maze" test (EPM) that GB-115 retained its anxiolytic properties after i/p injections at a daily dose of 0.1 mg/kg fo r 30-days. Discontinuation of dipeptide administration 24h and 48 hours after the onset of the experiment did not lead to behavioral (increased anxiety, aggression) and convulsive (decreased corazol sensitivity) manifestations of withdrawal syndrome. In contrast, the withdrawal ofdiazepam (4.0 mg/kg/day, ip, 30 days) induced the anxiogenic response in EPM, reduction of the aggression threshold, and enhancement of convulsive readiness. Significant differences between GB-115 and diazepam effects on the levels of dopamine, norepinephrine, and their metabolites after chronic administration and withdrawal were restricted to striatum.

[Neuroprotector effect of human recombinant erythropoietin sorbed on polymer nanoparticles studied on model of intracerebral post-traumatic hematoma (hemorrhagic stroke)].

The neuroprotective activity of recombinant human erythropoietin (r-HuEpo) sorbed on poly(butyl)cyanoacrilate nanoparticles (EPO-PBCA) and on polylactic-co-glycolic acid nanoparticles (EPO-PLGA) has been studied on Wistar rats with intracerebral post-traumatic hematoma (model of hemorrhagic stroke) (IPH-HS) in comparison to native r-HuEpo. It is established that EPO-PBCA produced a protective effect in rats after IPH-HS that was manifested by a decrease in the number of animals with neurological disorders such as circus movement, paresis, and paralysis of hind limbs; the drug also improved coordination (rotating rod test), reduced the number of lost animals, and decreased the loss weight among survived rats. In addition, EPO-PBCA optimized the research behavior of rats with IPH-HS in the open field test and prevented amnesia of passive avoidance reflex (PAR), which was caused by the IPH-HS. These effects were manifested during a two-week observation period. EPO-PLGA has a similar but much less pronounced effect on the major disorders caused by IPH-HS. The efficiency of native r-HuEpo as a neuropotective agent was insignificant and only manifested by decrease in the number of lost animals with IPH-HS.

[Effects of chronic administration of dimebon on behavior and memory of SAMP 10 mice].

SAMP 10 mice with genetically determined senescence (senescence-accelerated mouse prone 10) aged 16 months demonstrated (in comparison to 3-months old animals of the same strain) the following traits typical of old animal: behavior and memory deficiency, exploratory behavior impairment, and elevated level of anxiety. Dimebon administered for a long period of time with drinking water (1.5 mg/kg over 5 months) produced a positive action upon behavior and memory of 16-months-old SAMP 10 mice, optimized exploratory behavior in the open field test, diminished anxiety in elevated plus maze test, and improved retrieval of passive avoidance reaction.

[Features of memantine action profile in cholinergic deficit and intracerebral posttraumatic hematoma (hemorrhagic stroke) models in rats].

Memantine, a low-affinity non-competitive antagonist of glutamatergic NMDA-subtype receptors, was used at a daily dose of 1 mg/kg over 10 days for the treatment of rats with cholinergic deficit induced by the chronic administration of scopolamine (1 mg/kg, 20 days). The drug prevented violation of the learning of conditioned active and passive avoidance reflexes and produced no significant effect on the emotional state of animals in elevated plus maze (EPM) test. In animals with intracerebral posttraumatic hematoma (hemorrhagic stroke), memantine (2 mg/kg, for 3 days after operation) completely prevented the loss of animals, reduced the neurological deficit, improved conditioned passive avoidance reflex performance, and decreased emotional stress in the EPM test.

[Effect of nooglutyl on the behavior and memory of SAMP10 mice with genetically determined accelerated aging].

It is established that SAMP10 mice (senescence-accelerated mice prone 10) with genetically determined accelerated senescence at an age of 9-month exhibit (in comparison to 3-month animals of the same strain) the behavior and memory deficits typical of aged animals, namely, reduced locomotor activity elevated anxiety, and disturbances of memory trace retrieval. Nooglutyl in a dose of 20 mg/kg produces a positive effect on the behavior and memory of 9-month old SAMP10 mice. The observed improvements include optimization of the locomotor activity in the open field test, diminished anxiety in elevated plus maze test, and improved retrieval of passive avoidance reflex.