I. P. Pavlov and the development of neuroscience

Ivan Petrovitch Pavlov significantly changed and developed our knowledge of the brain functions and of the behaviour by his fundamental experimental and theoretical work on the physiology and pathophysiology of the higher nervous activity. He was one of the scientists who prepared the development of neuroscience in our century. During the Pavlovian Conference, 1950 in Moscow Stalin and the Communist Party tried to dogmatize his and his pupil's fundamental theories. But his pupils continued to develop Pavlovian ideas in open discussions with representatives of other schools in a very creative way, opening the doors for a system approach to understand the integrative functional systems of brain and behavior. Pavlov emphasized the high plasticity of the central nervous system. He investigated the complex functional systems within the brain and between the organism and its environment, and the designed models for pathology of the higher nervous activity. During his last years, Pavlov freed himself from the strong deterministic view and characterized the organism and its environment as a self-organizing system.     

Patterns in the ontogenetic development of certain forms of higher nervous activity in rhesus macaques

Studies have been made on ontogenetic development of simple and complex behavioural forms, realization of certain sequence of motor feeding conditioned reflexes, visual differentiation of signals, short-term memory and probability prediction in rhesus monkeys. Evolutionary features of ontogenetic development of some of the forms of the higher nervous activity were revealed. Both similarities and differences were noted in animals from three age groups. In ontogenesis of lower monkeys, the development of the main nervous processes of the higher nervous activity (learning, memory, etc.) takes place gradually depending on the age of a baby and the level of integrative activity of the brain.     

The experimental development of the concept of O. S. Adrianov on the correlation of functional and neurochemical processes: regulatory peptides in mediator system dysfunction

The article is devoted to commemoration of full member of Russian Academy of Medical Sciences, Oleg Andreevich Adrianov, who would have celebrated his 75-th anniversary in 1998. O. S. Adrianov, author of numerous works on physiology and morphology of central nervous system, in the recent years of his was studying the problem of the processes relationship at macro and micro levels of brain organization. Further to the concept created by O.S. Adrianov, data on action of two peptides: delta-sleep and tafcine, on behavior, neurophysiological and neurochemical processes have been consolidated. Experimental data were obtained for rabbits, cats, and dogs, both intact and in the state of pathology (psychomotoric excitement, bradykinesia, penicillin epilepsy). Impact of peptides on convergation processes is discussed: peptide of delta-sleep depresses reactions of brain structures to photo- and phono-stimulation, and activates the serotoninergic system in general; tafcine enforces the convergation processes and activates the dopaminergic system.     

Brain function and higher nervous activity

Some actual problems of higher nervous activity have been analysed on the peculiarities of brain states in the course of different types of conditioning and reactivity of the nervous structures which depend on the brain state have been considered. A concept of brain state as a specific mechanism of each temporal connection forming during the learning process has been formulated for the first time. The authors suggest that the brain represents the dynamic system with changeable structure which reveals itself in multitude nervous set constellation during various types of activity. This concept is presented to be the theoretical basis for integral evaluation of functional capacities of central nervous system.     

Comparative aspects of a study of the self-regulation of higher nervous activity in experimental neuroses in dogs, cats and rats

The higher nervous activity has been studied by means of motor-alimentary conditioned reflexes and delayed reactions in dogs, cats and albino rats at early stages of development of experimental informational neurosis. It was shown that formation of stable pathological reactions is preceeded by self- regulational activity of the brain directed towards elimination of a pathological situation, as well as to the increase of the stability of the nervous system to pathogenic agents. Comparative studies on rodents and predatory animals indicate that in different species the same pathogenic effects on the brain may elicit different forms of self-regulation of the higher nervous activity.     

I. P. Pavlov's theory on higher nervous activity: the landmarks and trends in its development

The theory of higher nervous activity created in Pavlovian time is compared with the present-day state of the theory developing due to appearance of new methods, techniques, facts, and concepts. Three principles of Pavlovian theory: determinism; analysis and synthesis; structural approach, as well s types of conditioned reflexes and techniques, types of higher nervous activity, and inhibition problems are discussed. The theory of higher nervous activity is schematically depicted as a tree, some branches of which are presented by facts and concepts obtained and introduced by I.P. Pavlov and his followers during his life, the others are formed by new facts and concepts advancing the theory. What is obsolete in the theory, what are the most prominent tendencies of its development and its new branches are discussed.     

Formation of alimentary conditioned reflexes with probable reinforcement in rats with frontal cortex injuries

Alimentary conditioned response to the sound of turning of the feeding-rack reinforced in 33 and 25 per cent of cases was formed faster in rats with frontal cortical lesion than in intact animals. The results obtained permit to suppose that during integrative brain activity the frontal areas of the cerebral cortex participate in organization of behavior with a high probability of reinforcement.     

Characteristics of memory and the functional organization of the hippocampo-reticulo-neocortical complex of the brain in the acute postoperative period

In tests on dogs, rabbits and rats, it has been established that in acute postoperative period, the time of memorizing of conditioned signals (light, tone and metronome) is reduced, the time of realization of conditioned reactions increases, the excitability and the bloodflow of the midbrain reticular formation and Mg-AtPhase activity of pons Varolii raise. In the hippocampus the excitability and local bloodflow lower and the activity of Ca-Mg-ATPhase is enhanced. In the frontal cortex these processes do not change. Functional interrelations of the brain structures in the acute postoperative period are characterized by the weakening of the activating influence of the reticular formation on the frontal cortex and an increase of its suppressive action on the dorsal hippocampus. It is suggested, that the discovered damages in the higher nervous activity are stipulated by the changes in neurochemical organization of the brain.     

The age of 40]

Formation of scientific researches program of the Institute of Higher Nervous Activity and Neurophysiology of the USSR Academy of Sciences from the moment of its foundation in 1951 till the present time is considered as a result of creative interaction and inter-enrichment of three scientific schools connected with the names of E. A. Asratian, M. N. Livanov and V. S. Rusinov. The systemic principle in the integrative brain activity, the dominant phenomenon and the idea on spatial synchronization of the electrical processes in various cerebral micro- and macrostructures at the elaboration of conditioned reflex became a basis of long-term strategy of studies of the human and animals higher nervous activity. At the present time these studies embrace two main trends: mechanisms of learning and memory and neurophysiological bases of consciousness.     

Organizational and activational effects of hormones on insect behavior

The concepts of hormone organization and activation provide a framework for thinking about the influence of hormones on development, brain, and behavior in vertebrates. There is good evidence for activational effects of hormones on the nervous system and behavior in insects, but organizational effects are almost never discussed in the insect literature. This paper explores the utility of the concepts of hormonal organization and activation of behavior in insects. We describe the two concepts as developed from studies of vertebrates, review some insect examples that appear to fit this classification scheme, and consider how explicit use of the concept of organization might benefit studies of the insect brain and behavior.     

Peculiarities of modifying influence of the factors forming the functional status of the central nervous system on dynamics of the rat higher nervous activity disturbances totally exposed to electron and gamma-radiation at a dose of 100 Gy

The dynamics of using a stabilized motor defensive conditioned reflex of active avoidance in "shuttle-box" in rats after the total influence of high energy electrons and gamma-rays at a dose of 100 Gy and a modifying influence of the two most important factors forming the functional status of the central nervous system: the stage of the conditioned reflex consolidation and typological peculiarities of the higher nervous activity have been investigated. The influence of both types of ionizing radiation has been shown to cause far more profound disturbances of non consolidated conditioned reflexes in comparison with the automatized conditioned reflexes and provoke an inverted picture of disturbances in the animals with opposed peculiarities of the higher nervous activity. The qualitative picture of the dynamics of disturbances that are caused by these types of radiation is identical. In summary, the studied conditions that form the functional status of the central nervous system determine the nature of neuroradiation syndrome to a greater extent than differences in the effectiveness of these types of radiation.     

New concepts on the structure of the neuronal networks: The miniaturization and hierarchical organization of the central nervous system

The hypothesis is introduced that miniaturization of neuronal circuits in the central nervous system and the hierarchical organization of the various levels, where information handling can take place, may be the key to understand the enormous capability of the human brain to store engrams as well as its astonishing capacity to reconstruct and organize engrams and thus to perform highly sophisticated integrations. The concept is also proposed that in order to understand the relationship between the structural and functional plasticity of the central nervous system it is necessary to postulate the existence of memory storage at the network level, at the local circuit level, at the synaptic level, at the membrane level, and finally at the moIecular level. Thus, memory organization is similar to the hierarchical organization of the various levels, where information handling takes place in the nervous system. In addition, each higher level plays a role in the reconstruction and organization of the engrams stored at lower levels. Thus, the trace of the functionally stored memory (i.e. its reconstruction and organization at various levels of storage) will depend not only on the chemicophysical changes in the membranes of the local circuits but also on the organization of the local circuits themselves and their associated neuronal networks.Dedicated to Prof. R. Luft for his outstanding achievements in endocrinology and his provocative and inspiring discussions in biology.     

I.S. Beritashvili (Beritov) is one of the founders of the modern biobehavioral science (to the 120th anniversary)

Ivan Solomonovich Beritashvili (Beritov) is one of the great Russian physiologists who have created the Russian route of the modern science of behavior. He has proposed and experimentally substantiated a concept of psychoneural activity according to which the behavior controlled by images is the main and higher form of the behavior of vertebrates. Behaviors on the basis of conditioned reflexes and images are qualitatively different activities underlain by different neural substrates. Recently, the Beritashvili's principle ideas have been confirmed by multiple experimental studies of the animal and human cognitive behavior. At present, the concept of the procedural memory formed by training and acquisition and episodic memory formed on the basis of images is commonly accepted. The episodic memory stores the environmental events and phenomena perceived by an animal or a human. Each time when the image is reproduced during perception of environment or its part, an animal performs the same behavioral act as during the actual perception. Beritashvili's viewpoint that the procedural and declarative memories are controlled by different brain structures has been confirmed by experiments.     

In search for neurophysiological criteria of altered consciousness

Neurophysiological approaches to brain mechanisms of consciousness are discussed. The concept of spatial synchronization of nervous processes developed by M.N. Livanov is applied to neurophysiological analysis of higher brain functions. However, the spatial synchronization of brain potentials is only a condition for information processing and does not represent it as such. This imposes restrictions on conclusions about the neural mechanisms of consciousness. It is more adequate to use the concept of spatial synchronization in views of consciousness as a psychophysiological level along with sub- and superconsciousness in three-level structure of mind according to P.V. Simonov. Forms of consciousness interaction with other levels concern the problem of altered consciousness and may be reflected in various patterns of spatial organization of brain potentials.     

Individual typologic characteristics of the open-field behavior of rats

By means of ethograms record and analysis, connection has been studied between the properties of rats behaviour organization in the open field, determining the level of behaviour entropy in this test, and the speed of conditioned reflexes formation in the Skinner chamber. According to behaviour entropy level the rats are significantly divided into four groups; the lowest speed of conditioned reflexes formation in the Skinner's chamber is observed in the animals of the first (low entropy) group, the highest--in the fourth (high entropy) group. The obtained data are discussed according to Pavlov's concepts on the characteristics of the basic nervous processes, determining individual-typological characteristics of the higher nervous activity of the animal. Conclusion is made that division according to the level of behaviour entropy in the open field test may serve as a safe method of express-estimation of the animals abilities to conditioned habits formation.     

Deconstructing memory in Drosophila

Unlike most organ systems, which have evolved to maintain homeostasis, the brain has been selected to sense and adapt to environmental stimuli by constantly altering interactions in a gene network that functions within a larger neural network. This unique feature of the central nervous system provides a remarkable plasticity of behavior, but also makes experimental investigations challenging. Each experimental intervention ramifies through both gene and neural networks, resulting in unpredicted and sometimes confusing phenotypic adaptations. Experimental dissection of mechanisms underlying behavioral plasticity ultimately must accomplish an integration across many levels of biological organization, including genetic pathways acting within individual neurons, neural network interactions which feed back to gene function, and phenotypic observations at the behavioral level. This dissection will be more easily accomplished for model systems such as Drosophila, which, compared with mammals, have relatively simple and manipulable nervous systems and genomes. The evolutionary conservation of behavioral phenotype and the underlying gene function ensures that much of what we learn in such model systems will be relevant to human cognition. In this essay, we have not attempted to review the entire Drosophila memory field. Instead, we have tried to discuss particular findings that provide some level of intellectual synthesis across three levels of biological organization: behavior, neural circuitry and biochemical pathways. We have attempted to use this integrative approach to evaluate distinct mechanistic hypotheses, and to propose critical experiments that will advance this field.     

Studying the isolated central nervous system; a report on 35 years: more inquisitive than acquisitive

1. The CNS from invertebrate animals such as slugs, snails, leeches, and cockroaches, can be isolated and kept alive for many hours. 2. The electrical and pharmacological properties of invertebrate CNS neurons have many similarities and it is probable that the basic rules governing the CNS evolved more than 600 million years ago. 3. The nerve cells can show sodium action potentials, calcium action potentials, EPSP, IPSP, biphasic potentials, electrogenic sodium pump potentials, and a variety of potassium, sodium, calcium and chloride currents. 4. Invertebrate CNS ganglia contain identifiable individual nerve cells whose properties and responses to neurotransmitters and drugs are constant and repeatable from preparation to preparation. 5. It was possible to set up an isolated CNS-nerve trunk-muscle preparation and study the transport of radioactive material from the CNS to the muscle and from muscle to CNS. This has provided information about axoplasmic transport in both invertebrate and vertebrate preparations. 6. The methods developed from studies of invertebrate isolated CNS preparations have been applied to vertebrate isolated CNS preparations. 7. In addition to thin slices of the mammalian brain, it is possible to keep 5 cm lengths of the whole mammalian spinal cord and brain stem alive for many hours. 8. The isolated mammalian spinal cord has functional ipsilateral and contralateral reflexes, ascending and descending pathways, extensive sensory integrative local area networks, and inhibitory interneuron circuits. Much of the in vivo circuitry is functional in vitro. 9. The isolated mammalian spinal cord and brain stem can be developed to include functional higher brain circuits that will provide increased understanding of the control and integrative action of the mammalian central nervous system.     

Nonsomatotopic Organization of the Higher Motor Centers in Octopus

Hyperredundant limbs with a virtually unlimited number of degrees of freedom (DOFs) pose a challenge for both biological and computational systems of motor control. In the flexible arms of the octopus, simplification strategies have evolved to reduce the number of controlled DOFs [1], [2] and [3]. Motor control in the octopus nervous system is hierarchically organized [4] and [5]. A relatively small central brain integrates a huge amount of visual and tactile information from the large optic lobes and the peripheral nervous system of the arms [6], [7], [8] and [9] and issues commands to lower motor centers controlling the elaborated neuromuscular system of the arms. This unique organization raises new questions on the organization of the octopus brain and whether and how it represents the rich movement repertoire. We developed a method of brain microstimulation in freely behaving animals and stimulated the higher motor centers—the basal lobes—thus inducing discrete and complex sets of movements. As stimulation strength increased, complex movements were recruited from basic components shared by different types of movement. We found no stimulation site where movements of a single arm or body part could be elicited. Discrete and complex components have no central topographical organization but are distributed over wide regions.     

Integration of conditioned reflex systems in intact and callosotomized dogs

Characteristics of integrative activity were studied by Kupalov's method of situational conditioned reflexes in 2 groups of dogs with complete section of the callosal body and in group of intact animals. The dogs of the first group were callosotomized before the formation of the conditioned reflex systems, the dogs of the second group--after their stabilization. The level of the reflex systems integration in the first group was considerably lower than in the second one. This testifies to a special role of the callosal body in the initial period of formation of complex conditioned systems. The callosotomized dogs developed inertia of nervous processes which was manifested in slowing down of formation and of adaptive realization of reactions during integration of various reflex systems. It was shown that the integrative activity is provided for by the interaction of cerebral hemispheres at different structural levels.     

Integrative properties of parietal cortex neurons of rabbits during the switching of heterogeneous classical conditioned reflexes

The impulsive activity of parietal cortex neurons of rabbits during the elaboration and specialisation of switching-over of alimentary and defensive conditioned reflexes has been studied. There are changes of parietal cortex neurons activity correlated with the stages of switching-over elaboration. The significant differences of the background neurons activity and neurons response to the conditional signal during alimentary and defensive conditioned reflexes have been established. The dominant motivation influences the neurons activity by modulation of background and conditioned activity of neurons. The integrative properties of neurons investigated in switching-over situation are revealed in their ability to summarize the excitation coming to the same sensory input with excitation from different motivational and reinforcement systems.