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Biomedical subjects

I P Levshina

Publications and source records attributed to I P Levshina.

At least 19 recordsLinked to original sources
PubMed2007

Behavior and measures of respiration in rabbits differing in terms of movement activity in an open field.

Analysis of the behavior of 19 Chinchilla rabbits the first time they were placed in an open field allowed them to be divided into three groups differing in terms of investigative movement activity (passive rabbits accounted for 37%, active for 21%, and intermediate for 42%). On repeat placing in the open field, passive rabbits increased and active rabbits decreased their levels of activity. Correlations were found between the rabbits' behavior in the open field and the nature of their external respiration in the absence of movements in the comfort situation. Passive rabbits, as compared with intermediate and active animals, showed longer respiratory cycles, expirations, and breath holds in expiration. Animals with a predominance of right-hand turns in the open field showed shorter respiratory cycles and expirations than animals with a predominance of left-hand turns. These studies led to the conclusion that the characteristics of external respiration can serve as a predictive factor for the passive-defensive strategy of behavior in rabbits in emotionally negative situations.

Analysis of Variance↗
PubMed2006

Acquisition of a conditioned avoidance reflex and morphometric characteristics of the sensorimotor cortex in rats subjected to social deprivation in early ontogenesis.

Male Wistar rats were subjected to social deprivation from day 22 to day 70 of postnatal development to form a group of isolants. Measures of learning of a passive avoidance and the results of training to active avoidance of painful electrical stimulation in these rats were significantly lower at age 110-120 days than in control rats. The characteristics of movement activity in isolants during training and testing, as well as in the open field test, probably resulted from their high levels of anxiety. Morphometric measurements of the numbers of neurons, satellite glial cells, and free glial cells in the sensorimotor area of the neocortex showed that isolants had a significantly lower density of neural elements per unit area, which resulted from a decrease in the afferent flow due to social isolation.

Age Factors↗
PubMed2005

[The behaviour and respiration features in rabbits with different pattern of their open field locomotor activity].

Behavior of 19 Chinchilla rabbits was tested in the open field. By the results of the first trial, animals were divided into three groups by the type of the exploratory locomotor activity (passive--37%; active--21; and medium--42%). During the repeated open field trials, the passive rabbits increased their activity and the active ones decreased it. Correlations were found between the open field behavior and patterns of the external respiration in the absence of movements. The longest respiratory cycles, expirations and respiratory breath holdings were observed in passive rabbits. Animals with prevailing right turnings in the open field displayed longer respiratory cycles and expirations than those with prevailing left turnings. It seems that the pattern of external respiration can predict the passive defensive strategy of rabbits in negative emotional situations.

Animals↗
PubMed2004

Characteristics of behavior associated with alternative choice in a Y maze in rats and their interpretation in terms of complex probability amplitudes.

This report demonstrates the possibility of interpreting rat behavior in situations associated with the choice between "safe" locations in a Y maze using pain reinforcement on the basis of summation rules for complex amplitude probabilities characterizing the prognostic assessment by the rat that it will achieve relative safety. Functionally incomplete actions in rat behavior were analyzed in the experimental situation. When the rat needed to avoid pain reinforcement and both pathways to avoid painful stimulation were equally suitable, interference could appear in the animal's assessment of the suitability of the two paths, this preventing decision-making. When this occurred, there was a delay in the executive action. After rats left one of the "safe" arms, they could move into the other "safe" arm, and vice versa. These transfers were completed in a quasi-periodic fashion, as predicted by a formal description of transfers between coincident (or sufficiently similar) states.

Animals↗
PubMed1993

[Change in cerebral beta-adrenoreceptors in experimental neurosis].

Pathological and adaptive-compensatory alterations of rat cerebral cortical beta-adrenergic receptors have been demonstrated using the model of experimental neurosis developing as a result of chronic emotional painful stress. After the first week of stress increases of both Kd and Bmax occur; both indexes reach control levels after 3 weeks of neurotization. The changes of cortical beta-adrenoreceptors accompany transient fall of cholesterol-to-phospholipid ratio and decrease of free radical lipid oxidation in brain cortex. The normalization of all cerebral parameters after 3 weeks of stress coincides with the activation of lipid peroxidation in blood serum.

Adaptation, Physiological↗
PubMed1991

[Protection of beta-adrenoreceptors of the rat brain during emotional-pain stress by oxidants of the steric hindrance class of phenols].

Adaptogenic properties of a new antioxidant-isoquinoline derivative of hindered phenol class under pain-emotional stress have been investigated. This new antioxidant was shown to have stress-protective effects, i.e. it stabilizes cerebral beta-adrenoreceptors, inhibits lipid peroxidation and stimulates anti-radical defense systems in the brain and serum, as well as normalizes vegetative functions in rats.

Animals↗
PubMed1991

[Effects of acute stress on lateralization of lipid peroxidation in the brain depend on the behavioral typology of rats].

Using the "emotional resonance test" albino mongrel male rats were separated for their preference to light or dark space during the cry of a "victim" rat receiving footshock. Rats avoiding the cry of a "victim" by moving to the light space were characterized by higher levels of lipid peroxidation (LPO) products. A short footshock resulted in a dramatic LPO decrease in both hemispheres in the brain of all rats under study, but in rats not avoiding the cry of a "victim" (preferring dark space) "left" asymmetry of LPO increased.

Animals↗
PubMed1989

[The effect of carnosine on indicators of free radical lipid oxidation during acute stress in rats].

The effect of carnosine intraperitoneal injection in rats (in doses 0.2, 2.0 or 20 mg/kg) on the vegetative parameters (arterial blood pressure, Hildebrandt index), the content of free radical oxidation (FRO) products and superoxide dismutase activity in serum and brain homogenates and brain lipid composition under normal condition and after different stress forms have been investigated. The carnosine injection in dose 20 mg/kg preserves and increase in arterial pressure and Hildebrandt index at all steps of stress development. The phase non-unidirectional changes in studied biochemical parameters have been revealed depending on the level of stress development in animals under control. The unidirectional and dose-dependent changes of phospholipid content and the level of brain lipids, decrease of FRO products in tissue and brain cholesterol, the increase of the superoxide dismutase activity of serum and brain homogenates have been found in intact and stressed animals after carnosine injection. A comparison of carnosine pharmacokinetics with concentration dependences of the antioxidative effect under in vitro and in vivo experiments comes to conclusion concerning the carnosine indirect adaptogenic action.

Acute Disease↗
PubMed1989

[Carnosine prevents the activation of free-radical lipid oxidation during stress].

Carnosine (beta-alanyl-L-histidine) injected to intact albino rats (20 mg/kg body weight) induces depletion of lipid peroxidation (LPO) products in brain and blood serum, an increase of superoxide scavenging activity in brain and serum, decrease of cholesterol: phospholipid ratio and increase of easy oxidizable phospholipid portion in brain lipid extracts. After painful stress (footshock during 2 hours) LPO products are accumulated in brain and serum, cholesterol: phospholipid ratio increases and the portion of easy oxidizable phospholipids decreases. Carnosine given before stress prevents LPO activation. Effects of carnosine and stress are not additive: LPO inhibition induced by carnosine is much more in rats subjected to stress.

Animals↗
PubMed1988

[Superoxide elimination activity and the transferrin-ceruloplasmin antioxidant system in the blood serum in chronic emotional-pain stress and the administration of dimethyl sulfoxide in rats].

The influence of emotional painful stress (EPS) and dimethyl sulfoxide (DMSO) treatment on ceruloplasmin-transferrin (Cp-Tr) antioxidant system and superoxide dismutase-like activity (SODLA) of the rat serum was studied. No changes in Cp-Tr and SODLA were observed in EPS. On the contrary, DMSO treatment was followed by a decrease in Cp-Tr activity and an increase in SODLA. It is suggested that Cp-Tr and SODLA systems are two interacting antioxidant systems of the serum.

Animals↗
PubMed1988

[Antistress effects of vitamin E and dimethylsulfoxide during their combined administration in low doses].

Low doses of vitamin E (5 mg/kg body weight) and dimethyl sulfoxide (50 mg/kg) given simultaneously orally to albino rats prevented the disturbances of the behaviour and vegetative functions induced by chronic emotional painful stress. The adaptive effect of vitamin E or dimethyl sulfoxide given alone was much lower or altogether absent. The antioxidant combination used decreased the intensity of lipid peroxidation in the brain and blood serum as well as cholesterol content in brain lipids and activated brain superoxide dismutase and nonenzymatic superoxide scavenging activity of the serum. The results obtained suggest that the combination of vitamin E with dimethyl sulfoxide may be used for the treatment of pathological conditions accompanied by lipid peroxidation syndrome.

Animals↗
PubMed1988

[The inhibition stage of lipid peroxidation during stress].

Stress is shown to induce at first the generalized inhibition of lipid peroxidation (LPO), and then the activation of LPO. In brain and blood serum of rats subjected to continuous footshock as well as to restraint stress LPO products decreased and superoxide scavenging activity increased during the initial period of stress, after 1 hour of footshock LPO indices nearly reached normal values, and after 2 hours of footshock the accumulation of LPO products and decrease of superoxide scavenging activity were seen. LPO inhibition was accompanied by accumulation of easy oxidizable brain phospholipids and by depletion of brain cholesterol, during LPO activation brain cholesterol content and cholesterol-phospholipid ratio increased. The content of LPO products--fluorescent Schiff bases in blood plasma of women suffering from algomenorrhea at first decreased (O-12 h) and then dramatically increased (12-24 h) after a onset of pain at the beginning of menstruation. The data suggest that the stage of LPO inhibition precedes its activation during stress.

Acute Disease↗
PubMed1988

[Characteristics of free-radical oxidation and antiradical protection of the brain in adaptation to chronic stress].

During the phase of long-lasting adaptation to chronic emotional painful stress three stages have been distinguished on the basis of physiological and neurobiochemical data. The first stage (1 week of stress)--transition from urgent to long-lasting adaptation--corresponds to labilization of vegetative indices, predominance of fear reactions and suppression of research behaviour in rats, inhibition of lipid peroxidation, activation of superoxide scavenging activity, decrease in cholesterol content in brain lipids. The second stage (2 weeks of stress)--long-lasting adaptation--is characterized by normalization of the behaviour, stabilization of high blood pressure, maximum brain antiradical activity and low level of lipid peroxidation. The third stage (3 weeks of stress)--transition from long-lasting adaptation to exhaustion--is characterized by blood pressure lowering, disturbed regulation of vegetative functions, behavioural hyperactivity in the open field, increased lipid peroxidation and decreased phospholipid content.

Adaptation, Physiological↗