Horizontal Motor Activity Research Articles

Effect of chronic stress on the degree of acrylamide toxicity in rats

Introduction. Chronic stress plays an important role in the development of a wide range of mental, somatic and behavioural disorders, and therefore is a risk factor for the health in living organisms. A negative effect on the state of the nervous system is also observed when the body is poisoned with acrylamide, which is a substance of the second class of danger and is considered toxic and carcinogenic. Exposure of the body to mental and toxic stressors leads to autonomic and neuroendocrine activation, which, in turn, manifests itself as special behavioural patterns. 
 The purpose of the experiment was to assess the effect of chronic stress on the degree of acrylamide toxicity in rats.
 Materials and methods. The experiment was conducted on white outbred rats with an average weight of 200 g of both sexes (n=60), which were evenly distributed into five groups: negative control, chronic stress, acrylamide, acrylamide + treatment, acrylamide + chronic stress. Throughout the study, the animals were kept under standard conditions with 12 hours of artificial lighting during the day, a relatively constant level of humidity (30–70%) and an air temperature of 20–25 °C. Behavioural tests were conducted once a week for one calendar month using a 40×40 hole board, a multifunctional cage to assess general activity, and an elevated plus maze with an ANY-maze video tracking system. Biochemical parameters were assessed in accordance with the manufacturer’s instructions.
 Results. Analysis of behaviour on a board with holes did not reveal statistically significant results (H=8.987; p=0.061). When comparing vertical and horizontal motor activity between groups, statistically significant differences were found (p<0.05). AST levels were higher in the stress groups, while cholesterol levels in the same groups were lower (p<0.05).
 Limitations. Laboratory animals of only one biological species were used for the experiment. The toxicant was used only in one concentration.
 Conclusion. Chronic stress may influence on acrylamide toxicity in rats to a certain extent.

Study of the effect of alimentary biocorrectors on the physiological and biochemical parameters of laboratory rats of the Wistar line

Physiological and biochemical parameters of blood plasma of laboratory animals were evaluated when using, in addition to the main diet, a food substance with known biocorrecting properties - a probiotic emulsion administered orally, based on wheat germ oil and biomass of a consortium of lacto and bifidobacteria, including Str. thermophiles, B. bifidum, B. longum, B. adolescentis, L. acidophilus, L. plantarum, L. fermentum. The object of experimental studies was male and female growing white rats of the Wistar line in the amount of 60 individuals, comprising 2 experimental and 2 control groups of 15 individuals each. Evaluation of the average values of physiological indicators showed an increase in the horizontal and vertical motor activity of the white rats of the experimental group by an average of 16-18 % and 60-70%, an increase in the number of examined minks by 10-12 %, a significant decrease in the level of grooming and defecation. It was established that the clinical and biochemical parameters of the blood plasma of white rats were within the physiological limits. The concentrations of total protein, glucose, high and low density lipoproteins, alanine aminotransferase, aspartate aminotransferase by group differed slightly. It was found that the concentration of total cholesterol and LDL in the test groups of females and males at the end of the experimental studies decreased by 2.1-2.2 % and 4.1-5.8 %. The bilirubinaikreatinin concentration was slightly reduced in the experimental group of females and males by 1.1-1.3 % and 2.1-4.2 %, respectively. A significant increase in hemoglobin and red blood cells by 2.6-7.1 % and 4.8-5.1 % was recorded.

The effect of cardarine on the behavior of rats in a lithium-pylocarpine model of temporal lobe epilepsy

Epilepsy is a serious neuropsychiatric disorder characterized by the occurrence of spontaneous recurrent seizures and linked cognitive, psychoemotional, and social impairments. Objective research showed that up to 30% of epilepsy patients do not respond to current therapeutic interventions, necessitating the development of novel treatment options. In recent years, researchers actively studied the neuroprotective properties of peroxisome proliferator-activated receptor agonists (PPAR α, β/δ, γ). As nuclear transcription factors involved in inflammatory signaling pathways, PPARs play a role in the pathogenesis of neuropsychiatric disorders, such as epilepsy. Various nervous pathology models were used for the investigations. The neuroprotective properties of PPAR γ agonists were reported in epilepsy models, whereas sufficient investigation into PPAR β/δ agonists’ effects is lacking. The aim of this study was to evaluate the effectiveness of the PPAR β/δ receptor agonist cardarine in alleviating behavioral disruptions observed in rats exhibiting temporal lobe epilepsy in response to the lithium-pilocarpine model. The lithium-pilocarpine model is considered one of the most effective experimental models for studying temporal lobe epilepsy in humans. Administration of pilocarpine in animals results in acute seizures, followed by a latent period devoid of seizures. Subsequently, spontaneous recurrent seizures appear, marking the chronic phase of the model. Epilepsy was induced in male Wistar rats that were 7 weeks old, through the administration of pilocarpine, 24 hours after being injected with LiCl (127 mg/kg). The peripheral effects of pilocarpine were negated through the use of methyl bromide-scopolamine (1 mg/kg, administered intraperitoneally 1 hour before pilocarpine). Pilocarpine was administered in fractional doses of 10 mg/kg, every half hour, until the seizures reached at least stage 4 on the Racine scale, with a dose range of 20–40 mg/kg. Following pilocarpine administration, Cardarine was administered intraperitoneally at a dose of 2.5 mg/kg daily for a period of 7 days, with the initial injection taking place 24 hours post-administration. Behavioral tests were conducted during the chronic phase of the model, 2-2.5 months after pilocarpine injection, using several tests, including the Open Field (to measure exploratory behavior, motor activity, and anxiety levels), the Intruder-Resident test (to measure communicative behavior), the Y-maze test (to measure working memory), and the Morris Water Maze (to measure spatial memory in the short and long term). Untreated experimental animals with temporal lobe epilepsy exhibited heightened vertical and horizontal motor activity, increased anxiety in the Open Field test, reduced communicative activity in the Intruder-Resident test, and impaired memory in the Y-maze test and the Morris Water Maze. Cardarine reduced alterations in vertical movement (time of climbing) and anxiety levels (number of grooming behaviors) in the Open Field, hindered short-term memory in the Y-maze, and restrained communicative conduct in the Intruder-Resident test. However, the medication did not impact the rats’ survival rate, body weight changes, overall activity (distance traveled in the Open Field), and damage to learning and long-term memory in the Morris Water Maze. Thus, administration of cardarine partially neutralized behavioral disorders developing in rats in the lithium-pylocarpine model of temporal lobe epilepsy.

DISORDERS OF MOTOR ACTIVITY ON THE MODEL OF AUTISM SPECTRUM DISORDERS

Autism, or autism spectrum disorder (ASD), is a multifactorial disease that is characterized not only by disorders of the psycho-emotional state and social interaction, but also by somatic dysfunctions. A number of studies have also reported changes in the musculoskeletal system in patients with ASD. In this work, by the method of video analysis of movements, we demonstrated a decrease in horizontal and vertical motor activity, in addition, deviant movements were recorded, which indicates a violation in locomotor activity and increased anxiety in rats with a valproate model of autism. However, a mechano-myographic study did not reveal significant changes in the contractility parameters of isolated skeletal muscles of rats with the ASD model. Thus, it can be concluded that general differences in movement may be an independent factor in the diagnosis of autism. A more thorough study using a larger sample and detailed kinematic analysis can help in further assessing the variability of motor functions as a potential diagnostic and prognostic marker of ASD.

The Effect of the Microbiota Metabolite – Butyric Acid on Motor Coordination, Muscle Strength and the Level of Oxidative Stress in Skeletal Muscles in Mice with Dysbiosis

According to modern concepts, the composition and diversity of the intestinal microbiota play an essential role in maintaining immunity, homeostasis, and, in general, the physiological functions of the host organism. Recently the positive role of the microbiota and its metabolites especially short-chain fatty acids, in the metabolism and functional activity of skeletal muscles was reported. The aim of our work was to analyze muscle strength and motor coordination in mice after injection of broad–spectrum antibiotics with simultaneous administration of a microbiota metabolite – one of the representatives of short-chain fatty acids – butyric acid. In addition, we determined the level of malondialdehyde, the concentration of total glutathione and the activity of glutathione peroxidases in the muscles of the hind limbs in mice with administration of antibiotics and butyric acid. The administration of antibiotics to adolescent mice for two weeks induced higher mortality and decrease of weight, and also caused significant changes in motor behavior, including an increase in horizontal motor activity, decrease in vertical motor activity, muscle strength, and motor coordination. A higher level of oxidative stress was found in the muscle tissues of the hind limbs of mice treated with antibiotics. At the same time, oral administration of butyric acid prevented the observed changes and improved not only behavioral disorders, but also partially reduced the level of oxidative stress. In conclusion, metabolite of normal microbiota has a positive effect on the functional and biochemical parameters of skeletal muscles in dysbiosis, which can be used to prevent loss of muscle function in various pathological conditions.

Specific Manifestations of Neurotoxicity of Some Drug Combinations for Treatment of Drug Resistant Tuberculosis from the Perspective of Experimental Studies

The objective: to evaluate comparative neurotoxicity of combinations of anti-tuberculosis and antimicrobial drugs with different and similar toxic potentials assessing behavioral changes in rats.Subjects and Methods: non-linear female rats divided in 3 groups were used in this study. For 14 days, the rats received a daily combinations of drugs: Group 1 – Mxf + Lzd + Cs + Pto, Group 2 – Mxf + Bdq + Cs + Z , and Group 3 – Bdq + Lzd + Cfz + Z. Neurotoxicity was assessed by changes in behavioral responses using Open Field Test. The number of crossed squares and racks was recorded which characterized horizontal and vertical activity, also peeping into burrows (exploratory activity), the number of groomings (washing and scratching) and physiological functions were registered.Results. In rats of Group 1 versus baseline parameters, we observed a significant limitation of horizontal motor activity and a sharp decrease (by 5 times) in exploratory activity, a 2.8-fold decrease in the number of groomings which indicated emotional suppression. In rats of Groups 2 and 3, the decrease in motor and exploratory activity was insignificant but there was a more pronounced emotional depression. The use of the Mxf + Lzd + Cs + Pto combination in which all drugs possessed a neurotoxic potential, led to diverse and profound changes in behavioral responses which indicated a pronounced neurotoxic effect.

THE USE OF VARIOUS BEHAVIORAL MODELS IN STUDYING THE RESPONSE OF RATS UNDER THE IMPACT OF NEGATIVE AEROIONS

The aim of the work was to evaluate the behavior of laboratory rats under the influence of negative air ions using various behavioral models. To create an excess of negative air ions, a Hippocrates ionizer (Enterprise Energia, Naberezhnye Chelny, Russia) was used. The exposure was carried out daily for 2 hours for 18-20 days. Wistar rats were used in the work. It was found that according to the open field test, under the influence of negative air ions, the level of indicators reflecting vertical and horizontal motor activity increased; decreased grooming rates and the number of bowel movements; the frequency of examination of holes increased. According to the elevated plus maze test, the number of visits to open and closed arms, hanging from open arms significantly increased with a simultaneous decrease in the frequency and duration of grooming, a decrease in the duration and number of freezes. The index of anxiety in the studies changed insignificantly. On the model of a black-and-white chamber, the time spent by rats in the dark and light compartments varied. The rats of the experimental group spent more time in the open space of the test, there was a significant increase in the exits and the duration of the time of looking out from the dark into the light compartments. In general, according to the behavioral models used, keeping animals in an environment enriched with air ions led to significant changes in the behavior of animals, increasing activity, emotional reactivity and stress resistance.

Effect of Clozapine and 5-NT2A-Antagonist RU-31 on electroencephalography and Motor Activity of Rats in a Model of Schizophrenia with Neonatal Destruction of the Ventral Hippocampus

Background. Schizophrenia is a socially signifi cant disease that takes a variety of forms. The form of the course determines prescribing antipsychotic drugs with a different range of clinical effects. The study of the pharmacological activity of neuroleptics involves an experimental model using animals which makes it possible to reproduce some aspects of schizophrenia.Objectives. The study is aimed at evaluating the antipsychotic activity of 5-HT2A— RU-31 antagonist and atypical neuroleptic clozapine in behavioral tests and electroencephalography (EEG).Methods. The research methodology involved a dysontogenetic model of schizophrenia, implemented via aspiration destruction of the ventral hippocampus of rats on day 7 of postnatal development. The study was carried out on white outbred male rats selected from the offspring of females, represented by a simple random sample, provided by Rappolovo animal breeding facility of the National Research Center “Kurchatov Institute”. Injection of the studied substances was initiated on day 35 of postnatal development. Motor activity was assessed on day 54 of postnatal development in the Open Field unit and included assessing vertical motor activity, measured as the number of acts of verticalization in 5 minutes, and horizontal motor activity of rats, recorded as the number of crossed squares in 5 minutes. EEG signals were recorded on day 55 of postnatal development; thereafter the spectral density was calculated in the delta- (д) (0.4–4 Hz), theta- (и) (4.8–8 Hz), alpha- (б) (8–12 Hz) and beta- (в) (12–30 Hz) frequency ranges and the effect of the “operation” and “substance” factors on spectral density was evaluated in comparison with control groups. Statistical data processing was performed using GraphPad Prism 9 (Insight Partners, USA).Results. The antipsychotic activity of 1-(2-diethylaminoethyl)-2-(4-methoxyphenyl)-imidazo[1,2-a] benzimidazole — RU-31 compound with 5-HT2A-antagonistic mechanism of action was evaluated. RU-31 compound (10 mg/kg, intraperitoneally (i.p.)) statistically signifi cantly reduced vertical and horizontal spontaneous locomotor activity in rats with psychotic disorder by 18.8% and 20.9%, while the atypical neuroleptic clozapine (2 mg/kg, i.p.) signifi cantly reduced these values by 41.15% and 27.67%, respectively. The 5-HT2A-receptor antagonist RU-31 increased EEG signal power in the delta range by 123.33% and decreased it in the alpha range by 41.86% in surgically operated animals (p < 0.05). Clozapine increased the EEG signal power in all studied frequency ranges: in delta — by 107.99%, theta — by 97.16%, alpha — by 41.86% and in beta — by 49.16% in animals with neonatal destruction of the ventral hippocampus (p < 0.05).Conclusion. The studied substances contributed to the correction of behavioural disturbances associated with hypermobility as well as electrophysiological changes induced by a surgical operation, while similar activity was not observed (or was observed to a lesser extent) in healthy animals.

Risk of developing drug abuse in administration of a new hexaazaisowurtzitane derivative-based analgesic (experimental study)

The aim of the study was to assess the probability of developing withdrawal syndrome caused by discontinuation of 5-day administration of thiowurtzine with naloxone challenge test in the experiment.Materials and methods. The test sample of the analgesic “Thiowurtzine, capsule 120 mg” served as the study object. The active pharmaceutical ingredient is an organic, low molecular weight compound 4-(3,4-dibromothiophene carbonyl)-2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazatetracyclo [5,5,0,03,11,05,9]dodecane that was first synthesized according to computer modeling results at the IPCET SB RAS (Biysk).The likelihood of developing physical dependence was explored by per os administration of thiowurtzine and the reference drug tramadol twice a day for 5 days as follows: 1) at 9 a.m. – thiowurtzine 50 mg / kg and tramadol 10 mg / kg, at 3 p.m. – thiowurtzine 50 mg / kg and tramadol 10 mg / kg; 2) at 9 a.m. – thiowurtzine 50 mg / kg and tramadol 10 mg / kg, at 3 p.m. – thiowurtzine 75 mg / kg and tramadol 15 mg / kg; 3) at 9 a.m. – thiowurtzine 75 mg / kg and tramadol 15 mg / kg, at 3 p.m. – thiowurtzine 75 mg / kg and tramadol 15 mg / kg; 4) at 9 a.m. – thiowurtzine 100 mg / kg and tramadol 20 mg / kg, at 3 p.m. – thiowurtzine 100 mg / kg and tramadol 20 mg / kg; 5) at 9 a.m. – thiowurtzine 100 mg / kg and tramadol 20 mg / kg, at 3 p.m. – naloxone 10 mg / kg subcutaneously.In all the groups, the intensity of the withdrawal syndrome was studied by specific features in outbred male CD1 mice. During one hour following the naloxone injection, health of mice was assessed according to dominant abstinence components and recessive traits of mild withdrawal syndrome. Two hours after the naloxone injection, the number of mice with negative body weight gain was determined. 24 hours after discontinuation of test compound administration, the open-field test was used to determine the impact on animal behavioral patterns (horizontal and vertical motor and exploratory activity, emotionality and its vegetative manifestations). The hot plate test was carried out to measure the analgesic activity (55˚). The criterion of the withdrawal syndrome severity was a decrease in the number of jumping reactions, changes in the general condition of the animals, stimulation of motor activity, manifestations of hyperalgesia, and a decrease in body weight.Results. No dominant abstinence components and recessive signs of withdrawal syndrome were detected in animals from the thiowurtzine groups. The data obtained in the study (orientation and exploratory behavior, motor activity, emotionality and its vegetative manifestations, grooming, etc.) allow to conclude that thiowurtzine causes no physical dependence in animals after discontinuation of its 5-day administration with naloxone challenge test, as opposed to the reference drug naloxone. A positive disinhibition effect of this analgesic was revealed due to the activated orientation and exploratory behavior (stress caused by the new environment) in the conditions of the open-field test. The animals showed no manifestations of hyperalgesia in the hot plate test. The animals treated with thiowurtzine did not demonstrate any changes in the body weight.Conclusion. The obtained results prove that thiowurtzine is a non-narcotic analgesic. It evokes no side effects typical of opioid analgesics (tramadol), including development of physical dependence and withdrawal syndrome following naloxone challenge test. Previous in vivo and in silico studies (docking, molecular modeling, molecular dynamics simulation) on the multi-target mechanism of thiowurtzine explain the absence of its morphine-like effect by the fact that the major targets of the analgesic are TRPA1 receptors and voltage-gated Ca 2+ channels. With a high degree of probability, the conclusions made herein predict no drug abuse development when thiowurtzine is used in the clinical setting. Absence of ulcerotoxicity found earlier will enable to administer thiowurtzine in long-term cycles for chronic pain syndrome.

Study of the sedative effect of extract from tissue culture biomass of Rauwolfia serpentina

Several social, psychological and biological factors could be cause for central nervous system disorders, especially anxiety; the latter could lead to more serious neurological and psychosomatical disorders. Sedative medications of plant origin are widely used practically as an alternative and/or additive to traditional pharmacological treatments of anxiety, hyperexcitation and other neuroses. Thus, the search of new effective sedatives based on plant extracts is an actual and perspective task.
 Aim of the present work is to investigate the sedative effect of biomass extract from cell culture of Rauwolfia serpentina K-27 strain.
 Sedative action of biomass extract from cell culture of Rauwolfia serpentina high-productive strain was determined by open field method on 24 white mice males (no line). Mice weight was in 18–25 g interval. The behavior was assessed by usual behavioristic acts: motor activity, psychoemotional activity and tentative research reaction. Animals were randomized into 3 groups of 8 individuals each. Rauwolfia serpentina biomass extract at doses of 7.5 mg/kg (group 1) or 15 mg/kg (group 2) was administered orally as an aqueous solution. Animals of the control group (group 3) received a solvent (distilled water).
 The sedative effect of extract was discovered in doses of 7.5 and 15 mg/kg, that showed a decrease in horizontal motor activity to 63.31 and 79.76% respectively, vertical activity to 82.05 and 71.79%, grooming duration to 57.28 and 60.78% at experimental days 20 to 28. Tentative research reaction demonstrated the direct dependence of sedation intensity on duration of extract administration. As a result of the conducted researches significant differences in the number of fecal bolus of both experimental and control groups of mice were not revealed. No significant difference between the sedative effect and the dose (7.5 and 15 mg/kg) was observed.
 The sedative effect of biomass extract from cell culture of Rauwolfia serpentina K-27 strain was proven. This leads to perspective inclusion of the extract to traditional medicine in prophylaxis and treatment of insomnia and of physical and psychological overexcitation.

Safety assessment of β-lactoglobulin hydrolysate with reduced allergenicity

The increase in production of milk whey and the large-scale introduction of membrane technologies for fractionation of its various components has led to a significant interest in the use of whey proteins. Their application in food technologies is constrained by their potential antigenicity. The authors developed a technology for reducing the allergenicity of the β-lactoglobulin in the ultrafiltration concentrate of cheese whey by means of biocatalytic conversion using enzyme preparations Flavorpro 750MDP and Promod 439L. The purpose of the research was to justify the required modes of proteolytic enzymes inactivation in the obtained β-lactoglobulin hydrolysate that can ensure safety for a living organism. The mode of enzymes inactivation which is necessary and sufficient for reducing their activity in the hydrolysate when consumed was determined with a certain safety margin (t = (80 ± 2) °C, τ = 5 min). Preclinical studies of the obtained food composition were carried out by pharmacoetological method on adult BALB/c mice. Significant differences were found in horizontal and vertical motor activity, as well as the frequency of “looking into burrows” and the level of defecation. Under new conditions the animals of the experimental group demonstrated more exploratory behaviour rather than defensive one. This indicates a positive effect of β-lactoglobulin hydrolysate on the physical and psycho-emotional state of the tested animals and its safety for a living organism. The developed technology allows to obtain functional foods based on β-lactoglobulin hydrolysate with target physiological and biochemical properties, reduced allergenicity, increased food and biological value.

Comparative analysis of rats’ behavior in the «elevated plus maze» after the intranasal administration of single-walled carbon nanotubes in a small dose in subacute experiments of different duration

The unique properties of carbon nanotubes (CNT) (increased strength, flexibility, electrical and thermal conductivity) make them very promising for use in various fields of human activity. But the question of their toxic effects on the body is actively discussed in the literature. There is a lot of body toxicity data of large doses of CNT, but the question of the potential danger of small doses of CNT is a practically unexplored issue. Earlier, we showed that a single intranasal injection of single-walled CNT (SWCNT) in a small dose (4 μg / kg) to rats inhibited the mRNA production of most cytokines in both spleen and brain. At the same time, the expression of the early c-fos gene in the olfactory bulb and the pyriform cortex was increased [Loseva E.V. et al., 2016]. It is known very little about the effect of low doses of SWCNT on animal behavior. The aim of this study was to investigate the effect of a small doses of SWCNT with subacute intranasal administration of different duration on the behavior of rats in the elevated plus-maze (EPM) test, which is used to estimate the anxiety. Male Wistar rats were daily intranasal administrated 100 μl of SWCNT suspensions in physiological saline (PS) in small (5.2 μg / kg, n = 9) dose for 4 (n = 9) or 13 (n = 9) days. Control rats were administrated analogically 100 μl of PS (n = 19). A statistical analysis of indicators of rats' behavior in EPM (5 minutes each) was performed using Kruskal-Wallis one-way analysis of variance, and then using the comparison on the non-parametric criterion of Mann-Whitney for independent features by the program STATISTICA 7.0. It was shown that in the EPM test in rats after 4-fold injection of a small dose of SWCNT, as compared with the control group, there was observed the behavior activation in the center and open arm, what was expressed in frequent and lengthy visits, but with a reduction of the average time of such visits. These animals also had increased the vertical exploratory activity (rears), horizontal exploratory activity (head dips) and motor activity, but the grooming indicators were decreased. After chronic administration of SWCNT in a small dose for 13 days, the direction of some of these changes was maintained, but was expressed to a much lesser degree (only at the level of the tendency in comparison to the control group). So, these rats, compared with the control, more often and longer visited the central site, more often visited open arms and less time were in closed arms. At the same time, the average time of the dark visits was smaller, and the average time of grooming, on the contrary, was longer than in the control. Thus, the intranasal administration of SWCNT in a small dose for 4 days in rats had provoked atypical symptoms of anxiety, which were expressed in an agitated behavior in the EPM, as evidenced by the strong activation of most behavioral reactions. The intranasal administration of SWCNT in a small dose for 13 days also has led to some activation of behavior or atypical anxiety, but it was expressed to a much lesser extent than with the acute injection of SWCNT. There wasn't observed an increasing of agitated behavior or a cumulative negative effect of SWCNT during chronic intranasal injection. We can suggest that nanotubes when administered in a small dose for 4 days can penetrate cells and their organelles, causing damage and death of tissue structures, in particular, when they penetrate into the brain, which leads to agitated behavior. At the same time, with subacute administration of SWCNT in a small dose during 13 days, protective reactions can gradually develop, leading to accelerated utilization of nanotubes, for example, by macrophages and astrocytes, which can absorb them, that leads to a diminution of the activation of behavior. To test this assumption, special morpho-functional studies are required.

ANALYSIS OF HORIZONTAL MOTOR ACTIVITY OF RATS IN THE TEST “OPEN FIELD” USING THE VIDEO TRACKING TECHNIQUE

Using an original computer program (Delphi, Windows OS) and a Genius web camera, video recording and quan-titative analysis of horizontal motor activity of 12 nonlinear rats in the test “open field” were carried out. According to the results of the statistical analysis of the horizontal motor activity of rats in the “open field” test, three groups of the examined animals were identified: of low-, medium- and high-activity. To assess the influence of individual-typological characteristics of animals on their behavior, a one-way analysis of variance (ANOVA) was carried out.

Ozone-induced changes in oxidative stress parameters in brain regions of adult, middle-age, and senescent Brown Norway rats

A critical part of community based human health risk assessment following chemical exposure is identifying sources of susceptibility. Life stage is one such susceptibility. A prototypic air pollutant, ozone (O3) induces dysfunction of the pulmonary, cardiac, and nervous systems. Long-term exposure may cause oxidative stress (OS). The current study explored age-related and subchronic O3-induced changes in OS in brain regions of rats. To build a comprehensive assessment of OS-related effects of O3, a tripartite approach was implemented focusing on 1) the production of reactive oxygen species (ROS) [NADPH Quinone oxidoreductase 1, NADH Ubiquinone reductase] 2) antioxidant homeostasis [total antioxidant substances, superoxide dismutase, γ-glutamylcysteine synthetase] and 3) an assessment of oxidative damage [total aconitase and protein carbonyls]. Additionally, a neurobehavioral evaluation of motor activity was compared to these OS measures. Male Brown Norway rats (4, 12, and 24 months of age) were exposed to air or O3 (0.25 or 1 ppm) via inhalation for 6 h/day, 2 days per week for 13 weeks. A significant decrease in horizontal motor activity was noted only in 4-month old rats. Results on OS measures in frontal cortex (FC), cerebellum (CB), striatum (STR), and hippocampus (HIP) indicated life stage-related increases in ROS production, small decreases in antioxidant homeostatic mechanisms, a decrease in aconitase activity, and an increase in protein carbonyls. The effects of O3 exposure were brain area-specific, with the STR being more sensitive. Regarding life stage, the effects of O3 were greater in 4-month-old rats, which correlated with horizontal motor activity. These results indicate that OS may be increased in specific brain regions after subchronic O3 exposure, but the interactions between age and exposure along with their consequences on the brain require further investigation.

Peculiarities of influence of NO-synthase inhibitors on behavioral parameters of rats

Aim. A comparative study of the influence of nitric oxide synthase (NO-synthase) inhibitors on the parameters of anxiety, motor activity and pain sensitivity of rats.
 Materials and Methods. The work was conducted on male rats of Wistar line. The anxiety level and locomotor activity of rats were studied in the elevated plus maze (EPM) test. Pain sensitivity of the animals was tested on the hotplate apparatus. In the work, selective inhibitor of inducible isoform of NO-synthase aminoguanidine at a dose of 50 mg/kg, and non-selective inhibitor of this enzyme N-nitro-L-arginine at a dose of 50 mg/kg, were used. Rats of the control group were introduced the equivalent quantity of normal saline. 
 NO-synthase inducible inhibitor aminoguadinine did not produce any influence on the anxiety level, but led to reduction of the horizontal motor activity of rats. Introduction of non-selective NO-synthase inhibitor N-nitro-L-arginine was accompanied by reduction of the anxiety and of the locomotor activity of animals in the EPM test. Both investigated NO-synthase inhibitors induced alteration of pain sensitivity of rats in the form of hypoalgesia. Here, the most pronounced nociceptive effect was observed with introduction of non-selective NO-synthase inhibitor.
 Conclusion. In the work the evidence of participation of inducible isoform of NO-synthase in realization of the motor activity and pain sensitivity processes in rats is shown. In result of the conducted experiments it was found that introduction of non-selective NO-synthase inhibitor N-nitro-L-arginine was accompanied by evident alterations of anxious behavior, locomotor activity and nociceptive sensitivity of rats. The results obtained confirm the important role of the system of regulation of nitric oxide synthesis in neurochemical mechanisms of behavioral reactions in rats.

IMMUNOLOGICAL CELULLAR-MOLECULAR MARKERS OF THE PERIPHERAL BLOOD OF А53Т MICE WITH GENETIC PREDISPOSITION TO PARKINSON’S DISEASE

The present experimental study aimed to find the most informative peripheral cellular-molecular immune markers, which can determine a risk of the development of Parkinson’s disease. The experiments were performed in transgenic mice of the A53T strain (2 months) characterized by an increased expression of alpha synuclein and genetically predisposed to Parkinson’s disease during aging. In comparison with the WT strain mice (control), A53T mice were found to have a reduced emotionality (increased horizontal motor activity and a significant decrease in defecation acts in the open field test) along with unchanged coordination and balance, tested using the Rotarod + hardware-software complex. These mice were also characterized by significant changes in the content of immune cell subpopulations in the peripheral blood - an increase in the percentage of CD3+T cells and CD3+4+T helper cells, a decrease in the content of CD19+B cells, with unaltered numbers of CD3+4+25+ 27-regulatory, CD19+25+B-regulatory cells and CD11b+115+monocytes. The percentage of T-regulatory cells expressing Toll-like receptors of the 2nd and 4th types (TLR2 and TLR4) was higher in A53T mice than in controls, while the number of cells expressing only TLR4 was reduced. The TLR2 expression did not differ between A53T and control mice. Analysis of the TLR2 and TLR4 expression on CD11b+115+monocytes has shown that the percentage of these cells with TLR4 was reduced in A53T mice compared to the control, while the content of cells with both TLR types did not depend on genotype. Proinflammatory cytokines (IL-6) prevailed over antiinflammatory (IL-10) in the supernatant of mononuclear blood cells of A53T mice suggesting the development of neuroinflammation.The study was supported by Russian Foundation of Basic Research (grant N18-015-00226 А).

Влияние витаминов группы В на раннее развитие крысят с пренатальной гипергомоцистеинемией

High plasma homocysteine levels - hyperhomocysteinemia (hHCy), are considered as an independent risk factor for early abortion of pregnancy, placental abruption, preeclampsia, and other complications. One of the factors of hHCy development is a deficiency of vitamins B. At the same time, both deficiency and excess of B vitamins can induce neurotoxic effects and oxidative stress. The aim of our work was to analyze the treatment of rats with hHCy with vitamins B during pregnancy on the early development and glutathione level in plasma of the offspring. In the offspring of rats with hHCy we observed high mortality, reduced body weight, increased concentrations of homocysteine and reduced glutathione level in plasma, and a delay in the development of sensory-motor reflexes and different types of behavior analyzed in the Open Field and Rotarod tests. Administration of vitamins B (B6,9,12) to pregnant rats with hHCy led to lower mortality and higher body weight of the offspring, increased level of glutathione, and partial prevention of sensory-motor deficit of the offspring. At the same time, we observed decreased plasma homocysteine levels, which, however, did not reach the control values. Positive effects of vitamins B on the level of anxiety and muscle strength of animals with prenatal hHCy were observed. However, the horizontal motor activity, rearing, motor balance were not restored. Thus, despite positive effects of vitamins B therapy on the physical development and the formation of sensory-motor reflexes, the impairments of motor coordination in complex behavior acts were not prevented, which may be explained by the fact that plasma homocysteine levels were not restored to the control values and/or the inability of the B vitamins completely neutralize the consequences of chronic hHCy.

Improving the organism's resistance to the stress “time deficiency” by iodine-containing thyroid hormones

The high prevalence of diseases of stressful etiology and insufficient knowledge of the mechanisms of their pathogenesis, as well as factors limiting the intensity of the stress reaction, among which iodine-containing thyroid hormones have recently been studied, determine the relevance of the study. The purpose of the work is to study the effect of thyroid status on the organism's resistance to emotional stress. The experiment was performed on 180 white male rats weighing 220–240 g. Stress was modeled according to the “time deficiency” method, when the animal, trying to avoid contact with water quickly filling the spiral tunnel, was forced to move up. Statistical processing of the obtained results was carried out using generally accepted medical statistics methods using program “Statistica 10.0”. The introduction of mercazolyl (25 mg / kg for 20 days), which determines a lower concentration of iodine-containing thyroid hormones in the blood under stress, prevents an increase in the relative weight of the adrenal glands and the corticosteroids level in the blood, an increase in physical endurance and horizontal motor activity of animals, inhibits their research behavior, and aggravates damage gastric mucosa in these conditions. The introduction of L-thyroxine in small doses (1.5-3 μg / kg 28 days) provides a higher level of iodine-containing thyroid hormones and increases the body's resistance to stress (limits the changes in the relative weight of the adrenal glands, spleen and thymus, corticosteroids and insulin levels in the blood , behavior and physical endurance of animals, damage to the gastric mucosa). Iodine-containing thyroid hormones increase the body's resistance to stress of the “time deficiency”, which proves their important role in the body's anti-stress system.

Effects of Melatonin on the Behavioral Indices and Structural Characteristics of Cerebral and Spinal Neurons of Rats with Experimental Hemiparkinsonism

In adult Wistar rats, a model of experimental hemiparkinsonism (EHP) was induced by stereotaxic microinjection of 8.0 μg 6-hydroxydopamine (6-HODA) into the left forebrain lateral ascending bundle. In such animals, we studied behavioral indices in the open field and elevated plus maze tests and also structural changes in the cerebral substantia nigra and spinal L5 ventral horn neurons. Six groups of animals were formed (in each group, n = 8): intact rats (I), animals that obtained microinjections of saline into the above lateral bundle (sham-injected, ShI), two groups with weak and intense motor EHP manifestations (frequency of circulatory movements in the apomorphine test less than one and six and more per 1 min, groups HP<1 and HP≥6, respectively), and two groups of rats with weak and intense EHP manifestations, which obtained daily i.p. injections of 10 mg/kg melatonin during 18 days (groups HP<1+M and HP≥6+M). In the open-field test, we observed in groups HP<1 and HP≥6 significant suppression of horizontal motor activity (very intense in the latter of the above-mentioned groups) and also significant weakening of vertical activity (number of rearings). Changes in the number of defecation acts were less expressed. In the elevated plus maze, manifestations of a significantly increased anxiety level were observed in rats of the above two groups. In the substantia nigra of animals with EHP, a considerable part of the neurons demonstrated clear signs of negative structural modifications; the number of neurons with the normal structure was considerably smaller than in the control. Analogous negative morphological changes were found in the lumbar segment of the spinal cord. Course injections of melatonin into rats with EHP noticeable weakened negative shifts in both open-field behavioral indices and level of anxiety (according to estimates in the elevated plus maze). Under the action of melatonin, morphological characteristics of neurons and gliocytes in the substantia nigra and spinal cord of rats with EHP demonstrated appreciable normalization. The mechanisms underlying functionaland structural disorders in the CNS of animals after central microinjections of the 6-HODA neurotoxin and also neuroprotective effects of melatonin, which provide weakening of such disorders, are discussed.

Effect of exogenous leukemia inhibitory factor on reparative regeneration of the peripheral nerve in mice

The role of trophic and growth factors in the regeneration of the damaged peripheral nerve is known. The leukemia inhibitory factor (LIF) exhibits properties not only of the polyfunctional cytokine, but also the neurotrophic factor. Regeneration of the peripheral nerve is impaired during oxidative stress in the area of injury.The purpose of the work was to investigate the effect of recombinant human LIF (rhLIF) on the efficacy of reparative regeneration of the sciatic nerve.Materials and methods. Adult male FVB/N mice were divided into the following groups: sham-operated; trauma (neurotomy) of the right sciatic nerve; nerve injury and subcutaneous injection of rhLIF at a dose of 1 μg per animal daily from the third day after the nerve injury. The study was conducted 4 weeks after the injury. At morphometry, the density of nerve fibers in distal nerve segments after impregnation with nitric oxide silver was evaluated. The motor function was evaluated in the “open field” test by the number of crossed squares, and in footprint test by the distance between the extreme toes of the right foot. In the area of muscle injury, the content of malondialdehyde, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase was estimated.Results. The total number of nerve fibers in the distal segment of the nerve of mice with trauma and injection of rhLIF is greater (p &lt; 0.05) than in mice with only nerve injury and does not differ from sham-operated animals. Horizontal motor activity in mice with nerve injury is lower (p &lt;0.05) than in sham-operated and cytokine injected mice. The distance between the extreme toes of the sham-operated mice is greater (p &lt; 0.05) than in mice with nerve injury, as well as injuries and injections of rhLIF, but after the injection of cytokine, the rates are higher (p &lt; 0.05) than in the group of mice without it. After the injury, the content of malondialdehyde and catalase activity increases in muscle tissue, while the activity of glutathione reductase decreases (p &lt; 0.05). Under the influence of rhLIF, the parameters change to the values of sham-operated mice, and, in addition, the activity of the glutathione peroxidase is significantly increased.Conclusions. Injection of rhLIF to mice with a sciatic nerve injury promotes a more complete restoration of the structural organization of the damaged nerve and improves the motor function of the injured limb. At the same time, the balance between the factors of oxidative stress and antioxidant system is improved in the muscle tissue in the area of the nerve injury.