Psychological Manifestations of the Basic Properties of the Nervous System in Work

There can be no doubt that the individual psychological distinctions among human beings and, in particular, one area of these differences — the psychological manifestations of the intensity, lability, and equilibrium of nervous processes — are manifested in one form or another in work, that activity which most completely expresses the nature of man. Therefore, study of these peculiarities is a matter of pressing importance in labor psychology. "Investigation of the individual differences among men," writes B.M. Teplov, "is one of the most important tasks of psychology. The importance of this undertaking has become particularly obvious since psychology undertook to become a science of practical value (educational and child psychology, labor psychology, pathopsychology)." (19; p. 108)     

The Nervous System of Procerodes littoralis (Maricola,Tricladida). An Ultrastructural and Immunoelectron Microscopical Study

The ultrastructure of the nervous system of a planarian, Procerodes littoralis, belonging to the taxon Maricola is described for the first time. The study has revealed the presence of two neuronal cell types and a glia-like cell. Immunogold labelling with antibodies to two native flatworm neuropeptides—neuropeptide F and GNFFRFamide—has been localised to one neuronal cell type and associated processes and synapses, thus indicating its peptidergic nature. The ultrastructural features are compared to those of other investigated turbellarian species. The number of features shared by species from the Proseriata, Lecitoepitheliata and Tridadida show that in respect of the nervous system these taxa form a closely related group.     

The development of the nervous system in Laevicaudata (Crustacea, Branchiopoda): insights into the evolution and homologies of branchiopod limbs and ‘frontal organs’

We investigated the development of the external morphology and of the nervous system in Lynceus biformis and Lynceus brachyurus (Laevicaudata, Branchiopoda), by using immunohistochemical methods in combination with a confocal laser scanning analysis. In both Lynceus species, a free-swimming nauplius larva, equipped with three appendages, hatches from resting eggs. Despite their close phylogenetic relationship to each other, considerable differences are present in their external morphology. Hatching L. brachyurus larvae are equipped with a large and flattened labrum, where in contrast, the L. biformis larvae possess a smaller labrum with four conspicuous posteriorly directed spines at its margin. Despite these differences, the development of the nervous system is quite similar in both species. The hatching larvae are equipped with a naupliar nervous system, and only in the more advanced stages, the development of the ventral nerve cord starts. Furthermore, our investigation into the nervous system provided insights into architecture and evolution of protocerebral sensory organs, the dorsal setae field and the dorsal frontal organ, only present in Laevicaudata. The identification of frontal filaments with an associated frontal filament organ in Lynceus revealed—after a comprehensive comparison with other branchiopods—that these organs exist throughout Branchiopoda and are comparable to those in other crustaceans. Additionally, our results of the peripheral nervous system analysis showed that the innervation pattern of the naupliar appendages (antenna and mandible) and the trunk appendages could be serially homologized, despite much difference in gross morphology of these. Based on the innervation pattern of limbs, we suggest that the larval uniramous mandibular palp, found in the larvae of all ‘large’ branchiopods, is largely exopodal of nature (contrary to most earlier statements) and that the endopodite of the trunk limbs consists of only one distal endite-like segment (confirming some earlier statements) and not of three as proposed by others.     

The identification of an invertebrate acetylcholine receptor

The results of a series of experimental studies have culminated in the identification of an acetylcholine receptor from the invertebrate $\text{Limulus polyphemus}$. The binding ligand α-bungarotoxin was used to identify a specific protein in the central nervous system tissue of this organism. The specific interaction of α-bungarotoxin with an acetylcholine receptor has been confirmed by physiological, competitive binding, subcellular fractionation and autoradiographic techniques. The toxin binding protein was solubilized and exhibited properties consistent with the nature of a nicotinic cholinergic receptor. Therefore, the identified protein is proposed as an acetylcholine receptor protein from the central nervous system of this invertebrate species.     

Problems in the Integrated Study of Individual Differences

The properties of all the stages of evolution of matter, from the chemical to the sociohistorical, are part of man as well. In each of these properties, in addition to what is common and typical for groups of people, there is something that is unique to the individual and irreproducible. One characteristic noted in theoretical conceptions of individual differences is that they tend to study properties relating to different stages in the development of matter in isolation from one another. In most studies of differential psychophysiology, the biochemical and endocrine properties of the organism and the bioelectric properties of the nervous system are examined as if they had nothing to do with individual characteristics in the formation of classical Pavlovian conditioned reflexes. The psychological properties of the personality are examined in the Vygotsky and Leont'ev school independently of their relationship to somatic, neurophysiological, and psychodynamic properties (the properties of temperament).     

Investigation of the Higher Nervous Activity and of Certain Vegetative Features in Twins

The study of the higher nervous activity of cortical-subcortical relationships in man is most pressing and of indubitable significance to the further deepening of our knowledge in the field of medicine and physiology. Here a major role may be played by the "twin" technique, based on study of the similarities and differences of various characteristics and properties in uniovular and biovular twins. Employment of this method in the study of intra-pair differences in signs and characteristics of uniovular twins is of significance for discovery of the influence of various environmental factors in the normal and the pathological states (1-5 and elsewhere).     

The migration of olfactory ensheathing cells during development and regeneration

The primary olfactory nervous system is unique in that it continuously renews itself and regenerates after injury. These properties are attributed to the presence of olfactory glia, termed olfactory ensheathing cells (OECs). Evidence is now emerging that individual OEC populations exist with distinct anatomical localisations and physiological properties, but their differential roles have not been determined. Unlike other glia, OECs can migrate from the periphery into the central nervous system, and organised OEC migration can enhance axonal extension after injury. Despite this, the mechanisms regulating OEC migration are largely unknown. Here, we provide an overview of the roles of OECs in development and adulthood. We review the latest research describing the differences between individual OEC subpopulations and discuss potential regulatory mechanisms for OEC guidance and migration. Using advanced time lapse techniques, we have obtained novel insights into how OECs behave in a complex multicellular environment which we discuss here with particular focus on cell-cell interactions. Significantly, transplantation of OECs constitutes a promising novel therapy for nerve injuries, but results are highly variable and the method needs improvement. We here review the roles of transplanted OECs in neural repair of damaged neuronal tracts distinct from the primary olfactory nervous system.     

Memory and Learning

The main principles of information processing in the nervous system of animals and man may be defined as follows:

1. A stimulus acting upon the input of a system is transformed in receptors, where it forms a combination of receptor excitations—the EM-dimensional receptor vector of excitation.     

The role of interspecies differences in the ratio of choline-containing phospholipid fractions of rodent erythrocytes in response of these cells to the effect of membranotropic compounds

In in vitro experiments, interspecies differences were revealed in the erythrocyte responses in varied rodent species—laboratory mice (Mus musculus L.), tundra voles (Microtus oeconomus Pall.) and bank voles (Myodes glareolus Pall.)—to the effect of chemical agents able to interact with membrane lipids and disrupt the membrane structure (detergent Triton X-100, oxidative stress inductor AAPH, antioxidant ionol or BHT, uranyl ion). It was hypothesized that these differences are due to physicochemical peculiarities of the erythrocyte membrane structure, specifically, the ratio of choline-containing fractions of phospholipids (phosphatidylcholine and sphingomyelin). The use of blood erythrocytes as an in vitro experimental model to study the mechanisms of toxicity as well as antioxidant and membrane-protective properties of compounds of different nature was shown to imply the choice of an adequate source of erythrocytes in view of considerable speciesdependent structural specificity of the lipid component of mammalian erythrocyte membranes.     

Polysialic acid and activity-dependent synapse remodeling

Polysialic acid (PSA) is a large carbohydrate added post-translationally to the extracellular domain of the Neural Cell Adhesion Molecule (NCAM) that influences its adhesive and other functional properties. PSA-NCAM is widely distributed in the developing nervous system where it promotes dynamic cell interactions, like those responsible for axonal growth, terminal sprouting and target innervation. Its expression becomes restricted in the adult nervous system where it is thought to contribute to various forms of neuronal and glial plasticity. We here review evidence, obtained mainly from hypothalamic neuroendocrine centers and the olfactory system, that it intervenes in structural synaptic plasticity and accompanying neuronal-glial transformations, making possible the formation and elimination of synapses that occur under particular physiological conditions. While the mechanism of action of this complex sugar is unknown, it is now clear that it is a necessary molecular component of various cell transformations, including those responsible for activity-dependent synaptic remodeling.Key words: adhesion, synaptic plasticity, astrocytes, central nervous system, hypothalamus, olfactory system     

The impact of manganese on neurotransmitter systems

BackgroundManganese (Mn) is a metal ubiquitously present in nature and essential for many living organisms. As a trace element, it is required in small amounts for the proper functioning of several important enzymes, and reports of Mn deficiency are indeed rare.MethodsThis mini-review will cover aspects of Mn toxicokinetics and its impact on brain neurotransmission, as well as its Janus-faced effects on humans and other animal’s health.ResultsThe estimated safe upper limit of intracellular Mn for physiological function is in anarrow range of 20–53 μM.Therefore, intake of higher levels of Mn and the outcomes, especially to the nervous system, have been well documented.ConclusionThe metal affects mostly the brain by accumulating in specific areas, altering cognitive functions and locomotion, thus severely impacting the health of the exposed organisms.     

The Problem of Allergy in Psychiatry

In recent years many authors have directed attention to allergic reactivity in mental disease. This problem has been studied with particular depth by O. V. Kerbikov (1) and his associates. (2) Clinical data, as well as, to some degree, laboratory research data demonstrate beyond all question that an allergic component often plays a substantial role in the genesis and shaping of various psychotic conditions. Also providing a basis for study of the problem of allergy in psychiatry are our data of pathophysiological studies in the field of allergy conducted in recent years (3-6), which demonstrate that the major role in the shaping of allergic reactions belongs to the central nervous system and that "nervous tissue may be the object in which the allergic reaction of antigen with antibody occurs" (A. D. Ado). Any pathological process modifies the immunological properties of the organism and causes adaptive defense reactions. Sometimes, under particular conditions, these defensive developments begin to play a pathogenic role. Under the influence of endogenic toxicosis, particularly in schizophrenia, autoantigens may be formed which acquire the nature of auto-or endo-allergens (A. D. Ado), which exercise a very pronounced effect upon the organism, including the central nervous system. In certain circumstances they facilitate the allergic genesis of psychopathological syndromes. The development of antibodies and auto-allergens in mental diseases may also be a consequence of the modification, under the influence of the pathological process and of various drugs, of the "normal flora" relationship characteristic of the given organism, and sometimes the result of this may be auto-infection.     

The Influence of Ablation of the Dorsal Section of the Hippocampus on Alimentary Conditioned Reflexes in Cats

At present a great deal of attention is given to questions of the physiological role of the hippocampal formation in the higher nervous activity of animals and man. A sizable number of both experimental and clinical-neurological investigations indicate that the hippocampus plays a definite part in conditioned reflex activity. Both ablation and stimulation produce noticeable alterations (Grastyan [13, 14], Brady [1], Bures et al. [11], Zager et al. [3], Urmancheyeva [9, 10] etc). (1)     

Synaptic function in the nervous system: A theory and its application

The objective of this paper is to present a new theory of synaptic function in the nervous system. The basis for this theory is the experimental demonstration that a nerve impulse assumes five different forms as it advances through the synaptic region, and that five basic mathematical operations have been identified as being involved in the transformation of one form into another form. As a result of these data, the synaptic region is regarded as a functional unit where information coming to it is unpacked, processed, stored, and retrieved for transit to another synaptic region or effector site. The data also suggests that a nerve impulse is a bolus of energy, therefore, without substance; that it contains information coded in its shape or form; that it is precisely described mathematically. Furthermore, the data suggests synaptic regions process these nerve impulses by applying mathematical operations to them; that function in the synaptic region is highly stereotyped (programmed); that chemical substances are associated with the mathematical operations. The basic approach of this theory is to regard a significant portion of the nervous system as an interface between the external universe and man himself. As an interface, the nervous system receives and processes information from both the external universe and man himself in a programmed manner. The interface functions by converting the information it receives into a bolus of energy, the nerve impulse, then processes the bolus by converting it into numbers or functions and applying mathematical operation to it.     

The blood-brain barrier in vitro: Ten years of research on microvessels isolated from the brain

The cerebral microvessels represent a distinctive compartment in the brain with unique physiological, biochemical and morphological properties. The barrier which separates the general circulation from the central nervous system is a complex mechanism that has a relative impermeability to a number of blood-borne substances, but—at the same time—operates with several specific carriers for the various compounds needed in the brain. Morphologically, the presence of tight interendothelial junctions, the paucity of pinocytotic vesicles in the endothelium and the absence of fenestrations are the hallmarks of this barrier.     

Importance of tree height and social position for drought-related stress on tree growth and mortality

Key message

A higher mortality of dominant trees under drought stress is explained by impacts of tree size, canopy- and root structure and the hydraulic transport system.

Abstract

Drought stress can trigger tree mortality but the impact depends on stress intensity (water demand and availability) and on the vulnerability of the individual. Therefore, most research focusses on the species-specific properties such as water use efficiency or hydraulic conductivity that determine vulnerability. At the ecosystem scale, however, tree properties that have been found important for drought sensitivity or resistance vary with individual size and resource availability within a forest—also within the same species. This is caused by different environmental conditions for each tree and hence different growth histories of individuals generating specific anatomical and physiological features. Individual drought stress sensitivity might thus be considerably different from stand scale sensitivity. Indeed, empirical evidence shows that drought stress impact depends on tree social position which can be defined in degrees of suppression but correlated to resource availability, stress sensitivity and stress exposure. In this review, we collect such evidence and discuss the role of microclimate and soil water distribution as well as anatomical and physiological adjustments, which might serve as foundation for better-adapted management strategies to mitigate drought stress impacts. Finally, we define model requirements aiming to capture stand-scale drought responses or management impacts related to drought stress mitigation.

     

The status and future of the Lake Naivasha fishery,Kenya

I describe a laboratory system for investigating the role of light as a proximate cue for diel changes in locomotor activity and vertical location on the substrate of stream macro-invertebrates. The system consisted of computer-controlled halogen lamps positioned over a laboratory stream in which video-recordings were made of Stenonema modestum mayfly nymphs located on the undersides of unglazed tile substrates. Locomotor activity of study organisms in response to light changes were quantified during computer-programmed and reproducible light/dark (LD) cycles. The system provided the flexibility to simulate a variety of light environments so that the separate influences of light intensity and light change on diel activities of individuals and populations could be examined, which is difficult under natural light conditions. As a group, nymphs responded similarly to simulated twilight (light decrease from 7.9 × 10² to 6.9 × 10^–2 W cm^–2 at a constant –1.9 × 10^–3 s^–1 rate of relative light change) and to natural twilight, suggesting that proposed mechanisms of light control of diel activities in nature can be adequately tested in the simulated environment. However, locomotor activity and vertical movements among individual mayflies were highly variable under controlled conditions, suggesting that physiological differences influence their responses to environmental conditions.     

Evolutionary origin of autonomic regulation of physiological activities in vertebrate phyla

Proper regulation of physiological activities is crucial for homeostasis in animals. Autonomic regulation of these activities is most developed in mammals, in which a part of peripheral nervous system, termed the autonomic nervous system plays the dominant role. Circulatory activity and digestive activity in vertebrates change in opposite phases to each other. The stage where circulatory activity is high and digestive activity is low is termed the "fight or flight stage" while the stage where circulatory activity is low and digestive activity is high is termed the "rest and digest stage". It has been thought that the autonomic nervous system originated in early vertebrate phyla and developed to its greatest extent in mammals. In this study, we compared the pattern of change of circulatory and digestive activities in several invertebrates and found that the two stages seen in mammals are also present in a wide variety of animals, including evolutionarily early-diverging invertebrate taxa. From this and other arguments we propose a novel possibility that the basic properties of the autonomic nervous system were established very early in metazoan evolution.     

The Influence of Simulated Fasted Gastrointestinal pH Profiles on Diclofenac Sodium Dissolution in a Glass-Bead Flow-Through System

High inter- and intra-individual variability in the pH of fluids in the human gastrointestinal (GI) tract has been described in the literature. The aim of this study was to assess the influence of physiological variability in fasted pH profiles of media along the GI tract on diclofenac sodium (DF-Na) dissolution from matrix tablets. Four individual in vivo fasted pH profiles were selected from the literature that differed in pH values and transit times from the stomach to the proximal colon. Using a glass-bead device flow-through dissolution system, these pH profiles were simulated in vitro using a specific media sequence and considering simulated intestinal buffer capacities corresponding to in vivo literature data. Dissolution experiments were then performed in the same system with media sequence following individual pH profiles. In dissolution experiments, where influences of simulated gastric emptying time (GET), gastric pH value, small intestinal transit time, and colonic pH were studied; high influence of gastric pH value and GET on DF-Na dissolution was observed. The effect of variability in pH profiles in the range of individual in vivo data on DF-Na dissolution was also clearly observed in experiments, where dissolution studies were performed following three simulated in vivo individual pH profiles. The differences in DF-Na release between three individual pH profiles were substantial; they also reflected in simulated plasma concentration profiles and can be attributed to pH dependent diclofenac solubility.     

Clinical Application of a Novel Automatic Algorithm for Actigraphy-Based Activity and Rest Period Identification to Accurately Determine Awake and Asleep Ambulatory Blood Pressure Parameters and Cardiovascular Risk

This paper reports the results of a study designed to determine whether there are statistically significant differences between the values of ambulatory blood pressure monitoring (ABPM) parameters obtained using different methods—fixed schedule, diary, and automatic algorithm based on actigraphy—of defining the main activity and rest periods, and to determine the clinical relevance of such differences. We studied 233 patients (98 men/135 women), 61.29?±?.83 yrs of age (mean?±?SD). Statistical methods were used to measure agreement in the diagnosis and classification of subjects within the context of ABPM and cardiovascular disease risk assessment. The results show that there are statistically significant differences both at the group and individual levels. Those at the individual level have clinically significant implications, as they can result in a different classification, and, therefore, different diagnosis and treatment for individual subjects. The use of an automatic algorithm based on actigraphy can lead to better individual treatment by correcting the accuracy problems associated with the fixed schedule on patients whose actual activity/rest routine differs from the fixed schedule assumed, and it also overcomes the limitations and reliability issues associated with the use of diaries. (Author correspondence: cristina.crespo@oit.edu)