[The organization of the neuronal activity of the cortical cingulate gyrus in the waking-sleep cycle]. / Organizatsiia neironnoi aktivnosti poiasnoi izviliny kory golovnogo mozga v tsikle bodrstvovanie--son.

Dynamics of the neuronal activity of the cingulate gyrus (CG) in the sleep-wakefulness cycle (SWC) was studied in free-moving cats. Most of neurons (65.4) discharged with high frequency during active wakefulness (AW) and emotional stage of paradoxical sleep (PS); the frequency of discharges decreased during the passive wakefulness (PW) and slow-wave sleep (SWS). 15% of neurons showed opposite dynamics of the activity. They fired more intensively during the SWS. 19.6% of neurons showed no statistically significant difference in the discharge frequency of different phases of the SWC. Most of neurons (75.2%) regularly changed the pattern of discharges at a chang of the phases of the SWC. In particular, those neurons discharged by single spikes, more or less uniformly distributed in time, against the background of AW and PS. With the development of the SWS neurons began to discharge according to the cluster-pause principle. During the development of the short fragments of the EEG arousal, most of neurons either decrease (42.6%) or did not change (50.4%) the activity. The involvement of the CG in the regulation of the SWC is discussed.

The influence of electrocoagulation of the septum and section of the entorhinal cortex on general behaviour and memory in cats.

In chronic experiments on cats it was shown that the lesion of the medial part of the septum does not result in the "septal syndrome"; the ratio of the different sleep-wakefulness cycle phases remains within the baseline values; the acquisition, retrieval and extinction of instrumental alimentary conditioned reflexes proceed normally; the delayed conditioned reflexes are impaired. Massive septal lesion, including its lateral part, leads to the development of the "septal syndrome"; there are changes in the structure and percentage of the different sleep-wakefulness cycle phases; the acquisition and extinction of instrumental alimentary reflexes with the sound discrimination are markedly retarded; the performance of delayed conditioned reflexes is completely destroyed. The section of the entorhinal cortex produces an increase in the number of repeated errors and perseverative movements during performance of instrumental alimentary reflexes, the deceleration of the acquisition and extinction of instrumental alimentary reflexes, complete disturbance of the delayed conditioned reflexes and does not affect the sleep-wakefulness cycle. The problems of the role of the hippocampus and its main inputs in the regulation of the short-term operative memory in the "pure form" as well as the significance of the descending influence of the hippocampus on the regulation of general animal behavior were also discussed.

Influence of some monoamine oxidase inhibitors on the sleep-wakefulness cycle of the cat.

The influence of some monoamine oxidase inhibitors (phenelzine, transamin [tranylcypromine], nialamide) on the structure of the sleep-wakefulness cycle of the cat was studied. It was shown that these monoamine oxidase inhibitors elicit and increase in slow-wave sleep in the sleep-wakefulness cycle due to complete suppression of paradoxical sleep and significant decrease in wakefulness. After the cessation of the action of the monoamine oxidase inhibitors, a selective rebound of wakefulness is observed against the background of complete or partial absence of paradoxical sleep. The gives grounds for the hypothesis that during partial deprivation of wakefulness under the influence of monoamine oxidase inhibitors an intensification occurs on the accumulation of specific need for this physiological state, the satisfaction of which is accomplished as the result of its rebound in the post-deprivational cycle, i.e., after the termination of the EEG of the synchronizing effect of the monoamine oxidase inhibitors.

[Self-deprivation of paradoxical sleep in cats]. / Samodeprivatsiia paradoksal'nogo sna u koshek.

The phenomenon of paradoxical sleep (PS) self-deprivation has been detected and described. The self-deprivation is acquired just as a classical conditioned reflex during enforced PS deprivation both by water tank procedure and by the animal's awakenings in response to sensory stimuli or direct electric stimulation of activating structures of the midbrain and diencephalon, following the transition of slow-wave sleep to PS. In this situation the transition of the brain from one physiological state to another is a conditioned signal, and sensory stimulation or brain stimulation, resulting in arousal reaction, serves as an unconditioned stimulus. It is suggested that the detection and analysis of PS self-deprivation are of a great importance, on the one hand, for correct understanding of the functional significance of this physiological brain state, and, on the other hand, for accurate analysis and assessment of the dissociative processes, observed during PS deprivation and postdeprivation period.

[Effect of monoamine oxidase inhibitors with a broad range of action on the structure and phase ratio of the wakefulness-sleep cycle in the cat]. / Vliianie ingibitorov monoaminoksidazy shirokogo diapazona deistviia na strukturu i sootnosheniia faz tsikla bodrstvovanie--son u koshki.

The monoamine oxidase (MAO) inhibitors disturb the structure of the sleep-wakefulness cycle and its ultradian rhythms by prolongation of the slow-wave sleep, complete suppression of the paradoxical sleep (PS) and considerable shortage of the wakefulness phase. When synchronizing action of MAO inhibitors has stopped prolongation of wakefulness is observed both before and during partial recovery of the PS. This fact is considered as an indication of the accumulation of a need of wakefulness in the course of its partial deprivation by MAO inhibitors. MAO inhibitors exert a particularly strong effect on the PS producing long-term suppression of its tonic and phasic components. Complete inhibition of the PS is apparently due to selective deterioration of the functional state of its trigger mechanisms.

[Dynamics of the neuronal activity of the posterior hypothalamus during a phase shift of the wakefulness-sleep cycle]. / Dinamika aktivnosti neironov zadnego gipotalamusa pri smene faz tsikla bodrstvovanie--son.

Dynamics of neuronal activity of the posterior hypothalamus in the sleep-wakefulness cycle was studied in free moving cats using mobile metal microelectrodes. Computer analysis and statistical treatment of the data have shown that the majority of neurons (89.3%) in the above-mentioned area discharge with high frequency during active wakefulness and emotional stage of paradoxical sleep; the frequency of discharges decreases during passive wakefulness and nonemotional stage of paradoxical sleep and is the lowest in the slow wave sleep though it has been higher than at the other states. Comparatively small number of neurons (3.6%) show opposite dynamics of the activity. They fire more intensely during slow wave sleep and the frequency of discharges decreases during active wakefulness and paradoxical sleep. In posterior hypothalamus some neurons (7.1%) are found which fire intensely during active wakefulness as compared with slow wave sleep and paradoxical sleep. The neurophysiological mechanisms for regulation of the sleep-wakefulness cycle and the involvement of posterior hypothalamus in this process are discussed.

[Neurophysiological analysis of the effects of selective deprivation of paradoxical sleep]. / Neirofiziologicheskii analiz éffektov selektivnoi deprivatsii paradoksal'nogo sna.

Neurophysiological analysis of the effects of selective and total paradoxical sleep deprivation (PSD) involving the replacement of paradoxical sleep (PS) phases by equivalent (as to duration) episodes of wakefulness is carried out. In contrast to the "classical" method of momentary awakening of the animal, a new method does not lead to: (1) the accumulation of PS need associated with more frequent PS onsets during deprivation; (2) PS rebound in a postdeprivation period; (3) dissociation of PS components, i.e. their occasional occurrence in other phases of the sleep-wakefulness cycle due to the phenomenon of self-deprivation; (4) increase in the rate of pontogeniculo-occipital (PGO) spikes, eye movements and heart rate during PS phases in the postdeprivation period. The application of selective and total PSD techniques caused no noticeable changes in the functional state and integrative activity of the brain, the latter warranting its successful use for treatment of some psychoneurological disturbances in clinics. The assumption has been advanced about the similarity of the neurochemical changes forming the need both for wakefulness and PS.

[Dynamics of unit activity of the gigantocellular tegmental field in the sleep-wakefulness cycle of rats]. / Dinamika neuronnoi aktivnosti gigantokletochnogo polia pokryshki v tsikle bodrstvovanie--son u krys.

Computer analysis and statistical processing of the unit activity showed that the majority of neurons (65.2%) in the gigantocellular tegmental field were discharging with high frequency during active wakefulness and paradoxical sleep as compared to slow-wave sleep in unrestrained rats. 11.6% of the neurons revealed an inverse pattern of activity: they discharged more intensively during slow-wave sleep, their firing rate decreasing during active wakefulness and paradoxical sleep. Some neurons (23.2%) were found which fired intensively during active wakefulness, their firing rate decreasing both in slow-wave and paradoxical sleep. Involvement of the gigantocellular tegmental field in the neurophysiological mechanisms of phases and stages of the sleep-wakefulness cycle is discussed.

[Effect of various monoamine oxidase inhibitors on the structure of the sleep-wakefulness cycle of the cat]. / Vliianiie nekotorykh ingibitorov monoaminoksidazy na strukturu tsikla bodrstvovanie--son koshki.

The effect of some monoamine oxidase inhibitors (phenelzine, transamine, nialamide) on the structure of the cat sleep--wakefulness cycle involved an increase of slow-wave sleep at the expense of totally inhibited REM sleep and substantial reduction of wakefulness. Following this effect, selective rebound of wakefulness occurred against the background of total or partial absence of REM sleep. The partial deprivation of wakefulness induced with monoamine oxidase inhibitors seem to entail an accumulation of a specific need in the given physiological state, the gratification of which is effected through its rebound in the post-deprivation cycle.

[Interdependence of learning and paradoxical sleep in the cat]. / Vzaimovliianie obucheniia i paradoksal'nogo sna u koshek.

The effect of learning sessions on the structure of the sleep-wakefulness cycle, as well as the effect of paradoxical sleep (PS) deprivation (PSD) following learning sessions, on the acquisition and extinction of instrumental alimentary reflexes to two feeders with sound discrimination, were studied on cats. The analysis of the data obtained led to following conclusions: The above learning sessions have no marked effect on the structure of the sleep-wakefulness cycle in the post-learning period, i.e. the percentage ratio of its phases is not altered by the increase of one of them. When PSD by non-emotional awakening is used, the number of PS onsets is not affected by learning sessions. This indicates that learning does not produce any considerable effect on the formation of PS need. PSD by non-emotional awakening following learning sessions does not retard the acquisition and extinction of the instrumental alimentary reflexes. The above data are interpreted as indicating that PS has no specific significance in memory trace consolidation during formation of long-term memory.

[Effect of electrocoagulation of the septum on the behavior and memory of the cat]. / Vliianie élektrokoaguliatsii septum na povedenie i pamiat' u koshki.

Lesion effects of various areas of the septum on general behaviour, learning and memory were studied in cats. It appeared that electrocoagulation of the medial septum alone leading to the disappearance of the hippocampal theta rhythm does not result in the development of the septal syndrome signs; does not disturb the normal structure of the sleep-wakefulness cycle; does not delay the elaboration of instrumental alimentary reflexes (to approach two feeders) or their extinction, but does entirely disturb the delayed responses to conditioned stimuli. In cases when lesion involves also the lateral septum, it produces the development of all signs of the septal syndrome (hyperemotionality, hyperactivity, rage, hyperphagia, etc.), disturbance of the normal structure of the sleep-wakefulness cycle, delay of both the elaboration and extinction of instrumental alimentary reflexes, disturbance of pre-elaborated conditioned reactions with sound discrimination, entire disturbance of conditioned delayed responses. On the basis of these data, the specific significance of hippocampal theta-rhythm in the organization of learning and memory is rejected, and a more important role is attributed to the descending regulatory influence exerted by the hippocampus and other archipaleocortical structures on the activating and motivatiogenic structures of mesodiencephalon.

Does paradoxical sleep deprivation disturb memory trace consolidation?

The effect of water tank PSD on memory in the passive avoidance test as well as on open field behavior was studied in rats. The effect of combining water tank PSD with a period of normal sleep-wakefulness cycle or with PSD by non-emotional awakening was investigated in a special series of experiments. It is concluded that PSD, even by the water tank procedure, does not disturb trace consolidation and formation of long-term memory in the passive avoidance test. However, a change in the correlation of motor-exploratory activity and fear reaction, due to the stressful situation intrinsic in the water tank PSD procedure, does not allow the animals to reach comparatively long temporal criteria in the passive avoidance test.

[Does deprivation of paradoxical sleep interfere with consolidation of memory traces?]. / Narushaet li deprivatsiia paradoksal'nogo sna konsolidatsiiu sledov pamiati?

The effect of paradoxical sleep deprivation (PSD) with water tank method on memory in the passive avoidance test as well as on open field behaviour was studied in rats. The effect of combining water tank PSD with a period of normal sleep-wakefulness cycle or with PSD non-emotional awakening was investigated in a special series of experiments. It is concluded that PSD, even by the water tank procedure, does not disturb trace consolidation and formation of long-term memory in the passive avoidance test. However, change in the correlation of motor-exploratory activity and fear reaction due to stress situation intrinsic in the water tank PSD procedure, does not allow the animals to reach comparatively long temporal criteria in the passive avoidance test.

[Effect of partial deprivation of slow-wave sleep on the structure of the sleep-wakefulness cycle]. / Vliianie chastichnoi deprivatsii medlennovolnovogo sna na strukturu tsikla bodrstvovanie--son.

In cats, partial (35% and 55%) deprivation of slow-wave sleep by way of inducing fragments of isolated EEG wakefulness in response to electrical stimulation of brain-stem activating structures, was shown to lead to an enhancement of behavioral sleep and reduction of paradoxical sleep. The reduction of paradoxical sleep is particularly obvious if the deprivation of slow-wave sleep is induced by fragments of behavioral wakefulness. In these situations no rebound of paradoxical sleep is observed in post-deprivation period. The causal interrelationships and interdependence of different phases of the sleepwakefulness cycle as well as interaction of EEG and behavioral mechanisms of sleep and wakefulness, are discussed.

Some aspects of conditioned reflex activity during sleep.

Acquisition, retrieval and extinction of instrumental alimentary reflexes during various types of sleep was studied in cats with metallic electrodes chronically implanted in different brain structures. The possible acquisition and extinction of a defensive conditioned reflex with the onset of paradoxical sleep (PS) serving as a conditioned signal and painful electrical stimulation of the skin as unconditioned was investigated. Results suggest that: (i) in the presence of a high food motivation the conditioned signals delivered during sleep cause the retrieval of previously acquired instrumental alimentary reflexes, and in PS the brain is capable of discriminating conditioned signals more accurately than during slow wave sleep, (ii) after a conditioned reaction to one of two conditioned signals is extinguished through non- reinforcement, the second signal remains effective, causing an instrumental alimentary reflex, (iii) the extinction of instrumental alimentary reflexes effected during sleep is not retained after the animal's awakening, whereas the extinction of a defensive conditioned reflex is retained, (iv) PS may serve as an endogenous conditioned signal during the acquisition of a defensive conditioned reflex. Thus motivational processes developing during PS are effective endogenous stimuli eliciting past experience dreams.