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.     

Impulse activity in the CA1 field in animals of various typological groups exposed to emotional stimuli

Hippocampal unit activity in the right and left CA1 fields was studied in rats divided in two groups by the method of "emotional resonance": the animals that did (A) and did not stop (E) crying of rat-partner. The rate of neuron firing was studied in the state of hunger, satiation, and under exposure to intracranial electrical stimulation of the emotional positive and negative structures of the brain. It was shown that the intracranial stimulation, especially positive, increased the rate of firing. Under exposure to emotional stimuli, the neural activity was asymmetric only in the A rats. The activity at the left was more intensive than the right-sided activity and did not depend on the sigh of emotion.     

Effect of GABA receptor agonist phenibut on behavior and respiration of rabbits in the negative emotional situation

The influence of systemic injection of GABA-receptor agonist--phenibut (40 mg/kg, s/c) on open field behavior, behavioral reactivity and changes in respiratory parameters after exposure of negative emotional stimuli was studied in three rabbit groups differentiated by locomotor activity in open field (active, passive and medium-active animals). The injection of phenibut results in decrease of rabbits horizontal locomotor activity and some components of research behavior in open field and also decrease of behavioral reactivity on emotional stimuli. At the same time the probability of both an active orienting exploratory or defensive reactions and passive reactions (freezing) were decreased. The influence of phenibut depended on typological features of rabbits: the most potent effect occurred upon behavior of active rabbits, less on passive animals and practically none on medium-active rabbits. The phenibut injection results in increase of duration of inhalation during exposure to emotional stimuli, whereas it decreased in normal.     

Lipid peroxidation in emotional stress in rats: correlation with parameters of open field behavior]

TBA-reactive products were measured in the brain, liver, and heart of Wistar rats in control conditions and after 24 h immobilization. Animals were subjected to the open field test before and after the immobilization. Behavior patterns, gastric mucosa alterations and MDA accumulation in organs suggested that immobilization as well as food and water deprivation were all strong stressor stimuli. Initial open field behavior characteristics were significantly correlated with MDA contents in various tissues under emotional stress.     

Unilateral injury of sensorimotor cortex of the dominant or subdominant hemispheres of rats-mothers and emotional behavior of their offsprings in the "open field"

Neurohumoral disorders in mothers caused by brain injury, infection, hypoxia, and other pathological factors result in motor and psychoemotional disorders in children. Emotional behavior of 30-day-old offsprings of female rats with unilateral sensorimotor brain injury was studied in the "open field". Individual behavior was estimated (the probability of certain acts and significant transfers between them). Behavioral disorders in rat offsprings depended on the side (left of right) of mother's brain injury and "handedness". The right-side mother's injury turned to be more deleterious. Behavioral alterations were stronger in offsprings of ambidextral and left-handed females than in those born by right-handed males with the same sensorimotor injury.     

On the aperiodic locomotor behavior of Halobacterium salinarium under periodic light stimuli

Two long time series of swimming intervals of a bacterium inverting its motion under periodic light pulses are analysed. The associated next-period plots reveal, through their filiform structure, that the underlying dynamics are low-dimensional. Using recently described properties of such dynamics, a simple second-order black-box model for the swimming intervals is derived and validated. The model reinforces the conjecture that this bacterium is endowed with an oscillator controlling the switching of the flagellar motor.     

The effect of newly synthesized psychotropic preparations on the "open field" behavior of rats]

The results of effect of some new synthesized psychotropic drugs of nootropic series on rats' behavior in "open field" are given. The increase of locomotive activity and decrease of emotional tension correlated with the rise of rats' ability to learning during working-out of avoidance reaction in shuttle-box, e.i. conditionally reflectory memory. It has been concluded that the study of dynamics of behavioral reactions in "open field" may be used for testing of new synthesized psychotropic drugs of nootropic series.     

Effect of vasopressin on open field and activity behavior of the vasopressin-deficient (Brattleboro) rat

The effect of 1 and 5 micrograms AVP injections on open field and photoactivity chamber behavior of D.I. and normal Long-Evans animals was studied. Administration of 5 micrograms AVP (SC) resulted in a statistically significant depression of both open field and photochamber activity in the D.I. rat, but had a less pronounced effect on normal animals. However, 1 microgram AVP resulted in only minor alterations of activity in both D.I. and normal animals. In terms of learned behavior, D.I. and normal animals displayed similar within-session habituation when comparisons were made following the same treatment conditions. Thus, this study supports the hypothesis that vasopressin may influence memory tasks by modulation of related states of emotionality, motivation, and/or attention rather than by direct involvement in the retrieval and/or consolidation of information.     

Effect of previous experience in reacting to a danger signal on "open field" behavior in the rat

Modification of rats behaviour in an "hopen field" test was investigated, induced by an acoustic stimulus, previously subjected to conditioning in a shuttle chamber in experiments with possibility and impossibility of avoidance from electrical shock. It has been established that presentation of a stimulus having the meaning of a danger signal, in a new situation, significantly suppresses investigating behaviour of rats, whereas the stimulus which had not been subjected to conditioning exerts no marked effect on behaviour. The greatest suppression was observed in rats with "learned helplessness". This fact suggests that the degree of suppression of the behaviour in an open field in response to a danger signal, depends on the animal's previous experience in reacting to this signal.     

Rat behavior in the "open field" next day after haloperidol injection: dependence on experimental conditions

Wistar rats were injected with haloperidol (3.5 mg/kg) that resulted in a high level of cataplexy. Next day after haloperidol injection rat behavior was studied in the open field. The animals were divided in two groups. The first group of animals was tested in the daylight without additional illumination of the open-field chamber. The second group was tested in a darkened room with additional intense illumination of the open-field center with a 60W bulb. The testing time was 240 s. The high level of the open-field locomotor activity in the first group was attributed to anxiety. The low level of locomotor activity in the second group was qualified as depressive state.     

BDNF regulates eating behavior and locomotor activity in mice

Brain-derived neurotrophic factor (BDNF) was studied initially for its role in sensory neuron development. Ablation of this gene in mice leads to death shortly after birth, and abnormalities have been found in both the peripheral and central nervous systems. BDNF and its tyrosine kinase receptor, TrkB, are expressed in hypothalamic nuclei associated with satiety and locomotor activity. In heterozygous mice, BDNF gene expression is reduced and we find that all heterozygous mice exhibit abnormalities in eating behavior or locomotor activity. We also observe this phenotype in independently derived inbred and hybrid BDNF mutant strains. Infusion with BDNF or NT4/5 can transiently reverse the eating behavior and obesity. Thus, we identify a novel non-neurotrophic function for neurotrophins and indicate a role in behavior that is remarkably sensitive to alterations in BDNF activity.     

Effect of tween 80 on exploratory behavior and locomotor activity in rats

Exploratory behavior and locomotor activity is enhanced in male rat pups (aged 10 to 20 days) whose dams received a chronic dose (1.25 ml/l) of Tween 80 via their drinking water. This enhancement manifests itself during the diurnal period of the day. These data suggest that Tween 80 has an effect on the CNS which could lead to misinterpretation of results in toxicology studies that use this compound as a dosage vehicle.     

Influence of anxiolytic afobazole on amygdalar neuronal activity and behavior of rabbits in emotionally negative situations

The influence of systemic injection of anxiolytic afobazole (1 mg/kg) on interaction between neurons of the basal and central amygdaloor nuclei and behavior of rabbits in negative emotional situations was studied in order to reveal characteristics of amygdalar neuronal network properties during unconditioned fear. An afobazole injection results in a prolongation of stay in the light compartment of dark-light chamber, in a decrease in freezing probability after exposure of emotional stimuli, in appearance of some aggressive reactions in open field. Behavioral alterations were accompanied by duration increase and latency changes of amygdalar neuronal inhibitory interactions, by increase of probability of neuronal interactions on delta-range frequency, by decrease of interactions on theta-range frequency. Under the influence of afobazole the asymmetry with right dominance in interhemispheric interaction of amygdalar neurons decreased. Changes in network properties ofamygdalar neurons during afobazole injection testify to reduction of activation level of this structure taking place at the expense of enhancement of inhibitory interactions between neurons.     

Somatosensory and visual cortical unit activity in rabbits during receptive field testing and food-getting behavior

Somatosensory and visual cortical unit activity was compared in experiments on unrestrained rabbits during receptive field testing and natural "self-stimulation" of the receptive surfaces of surrounding objects in the course of food-getting behavior. Unit activity evoked by receptive field testing may correspond completely, partially, or not at all to its activity during food-getting behavior, i.e., neurons demonstrating connection during testing with particular receptive fields (parts of the body or retina) may preserve it, modify it, or lose it during food-getting behavior. Differences of activity during food-getting behavior were observed even in the case of neurons with identical receptive fields during testing. The possible nonidentity of the overall firing pattern of the neurons during food-getting behavior with the pattern which can be simulated by receptive field testing is discussed.Institute of Psychology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 16, No. 2, pp. 254–262, March–April, 1984.     

Individual characteristics of spontaneous locomotor activity and adaptive behavior in the rat

Spontaneous locomotor activity (SLA) of the male rats possesses significant individual differences. The daily volume of this activity is sufficiently stable for each separate individual. Animals with high and low SLA also differ in daily dynamics of this parameter. The behaviour of the rats with low SLA was characterized by lesser orienting activity and greater emotional reactivity in comparison to the rats with high SLA. By means of factor analysis it was established that, along with searching activity, emotional reactivity and alimentary motivation, the need in motor activity is one of the main inner factors, determining various manifestations of adaptive behaviour.