”Reflexes of purpose and freedom” in the comparative physiology of higher nervous activity

The most complex unconditioned reflexes of aim and freedom, discovered by I. P. Pavlov, are compared with the competence drive and the motivation of the resistance to coercion, respectively, described by contemporary ethologists. On the basis of the unconditioned reflex of purpose, conditioned reflexes were developed in which positive emotions arising in connection with the perfection of a skill, irrespective of its pragmatic significance at a given moment, serve as the reinforcement. The unconditioned reflex of freedom is regarded as a phylogenetic precursor of the will, and its acute extinction as the physiological mechanism of hypnosis. It was demonstrated experimentally that the appearance of the state of animal hypnosis (immobilization catatonia) in rabbits is accompanied by the predominance of electrical activity and heat production in the right hemisphere, i. e., by symptoms which are found in hypnosis in man.Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 39, No. 3, pp. 415–420, May–June, 1989.     

Disturbance of delayed match-to-sample in macaques by tetanization of anterior commissure versus limbic system or basal ganglia

Summary Three pig-tailed macaques were trained to select (match) from a pair of colored images that which they had seen (sample) and responded to 5–15 s previously. The anterior commissure (AC) and/or its radiation, various loci in basal ganglia, hippocampal formation and control areas, (splenium of corpus callosum, precentral gyrus, insular cortex), totalling 40 loci, were each tetanized for 4 s during presentation of the sample image, during the delay period, or when the monkey was required to select the matching image. For several loci in the hippocampal formation tetanization at any phase of the task reduced matching to chance levels and gave evidence of electrical after-discharge; but other comparable hippocampal loci had little or no effect. Response to sample or match stimuli were absent during tetanization of basal ganglia or anterior commissure. When finally made, upon cessation of tetanization, responses were equally correct for basal ganglia and control sites, but for AC were at chance levels.     

Distribution of degenerated fibers in the cortex of the medial and lateral surfaces of the dog's brain after destruction of the anterior limbic and motor areas

Summary Damage to the anterior limbic and motor regions of the brain cortex results in two types of distribution of degenerated fibers over the brain cortex in dogs. The first lateral type is characterized by a predominant fragmentation of a large number of thick horizontal or diagonal fibers of the lower cortical layers on the lateral surface; the second type, known as medial, by the fragmentation of single slender radial fibers and horizontal fibers of the first cortical layer on the medial surface.The lateral-type degenerated fibers are distributed over the cortex of the sigmoid, presplenial, suprasplenial and ectolateral convolutions (motor, parietal and occipital fields). They are most numerous in the motor (4) and optic (19, 18) areas. The medial-type degeneration is characteristic of the cingulum (gyrus cinguli) (limbic fields).An injury to the anterior and posterior portions of the sigmoid convolution causes a less extensive lateral-type degeneration than an injury to the genual convolution.Presented by Academician V. N. Chernigovskii Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 59, No. 3, pp. 18–22, March, 1965     

Convergent inputs from articular,cutaneous and muscle receptors onto ascending tract cells in the cat spinal cord

Summary 1.Responses were recorded from 160 ascending tract cells in segments L4 to L6 of the spinal cord in chloralose anaesthetized, spinalized cats. The tract cells were identified by antidromic activation following stimulation of pathways in the lateral and ventral funiculi at the level of the spinal cord transection at the thoracolumbar junction. Axonal conduction velocities ranged from 9 to 114 m/s. 2. A sample of 152 of the neurones examined could be subdivided according to the distribution of their receptive fields into 49 cells activated just from receptors located in skin (s cells), 17 neurones excited by receptors in deep tissues (d cells), 15 units with a convergent input from receptors in skin and deep tissues (sd cells), and 25 neurones with a convergent input from the knee joint and either skin (sj cells), deep tissues (dj cells) or both (sdj cells). No receptive fields could be demonstrated for the remaining 46 neurones. 3. S and sj cells were found almost exclusively in the dorsal horn, whereas many d, sd, sdj and dj units were in the ventral horn. Almost all of the cells that lacked receptive fields were in the ventral horn or intermediate grey. 4. Ninety-one of 158 cells (56%) demonstrated no background activity. Of these, 43 cells (27%) lacked receptive fields. Many of the silent neurones were in the ventral horn, but some were in the dorsal horn. Of 25 cells having knee joint input, 18 (72%) had background activity. 5. All of the neurones that had a receptive field in the knee joint also had a convergent input from receptors in other tissues. In 3 cases, there was a receptive field in the skin over the foot (sj cells). For 16 cells, receptive fields included not only the knee joint but also skin and deep tissue (sdj cells). Usually, the cutaneous receptive field was near the knee joint, but sometimes it was remote, such as on the foot. The deep receptive fields were chiefly in the muscles of the thigh and/or leg. For 6 dj cells, the receptive fields included not only the knee joint but also deep fields like those of sdj cells. 6. Cutaneous receptive fields were classified as low threshold (cells excited best by innocuous intensities of mechanical stimulation), wide dynamic range (cells activated by weak mechanical stimuli, but the best responses were to noxious stimuli) or high threshold (innocuous stimuli had little effect, but noxious mechanical stimuli produced a vigorous discharge). Similarly, stimulation of the knee joint with weak mechanical stimuli could excite some neurones, while others could be activated by weak or strong articular stimuli but were excited best by noxious stimuli, and still other neurones were activated by knee joint stimuli only if the intensity was noxious. 7. In several instances, contralateral receptive fields were noted. These were generally in deep tissue or in the knee joint. 8. It was concluded that many of the responses to articular stimulation of the spinal cord ascending tract cells examined in this study could have been mediated by the fine afferent fibres that supply the knee joint. Although further work will be required to determine which particular ascending tracts transmit nociceptive information concerning the knee joint, it can be proposed that many of the responses demonstrated here were likely to play a role in either joint pain of in triggering responses associated with joint pain.     

Time constants of facilitation and depression in Renshaw cell responses to random stimulation of motor axons

Summary In 9 adult anaesthetized cats, 22 lumbosacral Renshaw cells recorded with NaCl-filled micropipettes were activated by random stimulation of ventral roots or peripheral nerves. The stimulus patterns had mean rates of 9.5–13 or 20–23 or 45 pulses per second and were pseudo-Poisson; short intervals below ca. 5 ms (except in two cases) were excluded. The Renshaw cell responses were evaluated by two kinds of peristimulus-time histograms (PSTHs). Conventional PSTHs were calculated by averaging the Renshaw cell discharge with respect to all the stimuli in a train. These PSTHs showed an early excitatory response which was often followed by a longer-lasting slight reduction of the discharge probability. These two response components were positively correlated. Conditional PSTHs were determined by averaging the Renshaw cell discharge with respect to the second (test) stimulus in pairs of stimuli which were separated by varied intervals, . The direct effect of the first conditional response was subtracted from the excitation following the second (test) stimulus so as to isolate the effect caused by the second stimulus per se. After such a correction, the effect of the first conditioning stimulus showed pure depression, pure facilitation or mixed facilitation/depression. Analysis of such conditioning curves yielded two time constants of facilitation (ranges: ca. 4–35 ms and 93–102 ms) and two of depression (ranges: ca. 7–25 ms and 50–161 ms). It is concluded that these time constants are compatible with processes of short-term synaptic plasticity known from other synapses. Other processes such as afterhyperpolarization and mutual inhibition probably are of less importance.     

Intratypic antigenic heterogeneity of Coxsackie B viruses

Summary Neutralization tests, employing the cytopathogenic effect in tissue culture tubes, with a variety of homotypic antisera and strains of Coxsackie B viruses often yielded high titers in early readings and low titers in late readings — the break-through phenomenon — and occasionally also low, early-reading titers with heterologous, homotypic sera, which gave high titers with the homologous strains. Of 27 strains of Goxsackie B 1 to B 5, that were tested, 10 showed no break-through tendency while others showed varying degrees of break-through, without reference to any evidence of intratypic antigenic variation. There was a positive correlation between a small number of tissue culture passages away from man or mouse brain and the break-through tendency. Moreover, strains without break-through tendency yielded viral populations with marked break-through properties after a single intracerebral passage in newborn mice, and even after two subsequent tissue culture passages. Plaque-purified progeny exhibited the break-through phenomenon to the same extent as the original, unpurified cultures.The early readings yielded reproducible titers, which could be used for analysis of antigenic variation. Prime antigenic variants, of broader antigenic constitution than their non-prime relatives, were found among the Coxsackie B 2, B 3, and B 4 strains that were tested. These prime strains (e. g., B. V. A. 96- B2; Stevens - B 3, and Burrier or J. V. B. - B 4) were found to be antigenically broader than the prototype strains (Ohio 1 - B 2, Nancy - B 3, Powers or Texas 13 - B 4) generally used for the preparation of diagnostic antisera. The broader antigenicity of the prime variant was also present in plaque-purified progeny.Aided by grants from The National Foundation, Inc.The work reported here was carried out in 1957–1958 during Dr.Wigand's tenure of a fellowship in the Cincinnati Laboratory.     

The Involvement of Dopamine in Strengthening Cortical Signals Activating NMDA Receptors in the Striatum (a hypothetical mechanism)

A possible mechanism is proposed for the enhancement/weakening of those cortical signals in the cortex-basal ganglia-thalamus-cortex neural network which induce/do not induce opening of NMDA channels in the spiny neurons of the striatum and which can be regarded as strong/weak in terms of this measure. The mechanism is based on the modulatory influences of dopamine on changes in the efficiency of corticostriatal inputs. In the absence of dopamine, relative increases in the intensity of strong (weak) cortical signals can lead to the induction of long-term potentiation (depression) of corticostriatal synapses. In this case, because of the differently directed influences on thalamic cells of signals passing via strionigral and striopallidal cells, strong signals at the output of the thalamus are weakened, while weak signals are strengthened. Activation of dopamine D₁ (D₂) receptors on strionigral (striopallidal) neurons may facilitate increases in the extent of long-term potentiation/depression (decreases in the extent of long-term potentiation/depression or induction of long-term potentiation/depression). The consequence of this is that strong signals at the output of the thalamus can be strengthened synergistically, while weak signals cab be weakened synergistically. Background cortical signals evoking tonic release of dopamine in the striatum can decrease strengthening because of weakening of the modulatory influence of dopamine on the modification of corticostriatal synapses.     

A cyclin protein modulates mitosis in the budding yeast Saccharomyces cerevisiae

Summary For the budding yeast Saccharomyces cerevisiae the mitotic cell cycle is coordinated with cell mass at the regulatory step start. The threshold amount of cell mass (reflected as a critical size) necessary for start is proportional to nutrient quality. This relationship leads to a transient accumulation of cells at start, termed nutrient modulation, upon enrichment of nutrient conditions. Nutrient enrichment abruptly increases the critical size needed for start, causing the smaller cells, produced in the previous cell cycle, to be delayed at start while growing larger. Here we show that, in S. cerevisiae, a second cell-cycle step, at mitosis, also exhibits nutrient modulation, and is, therefore, another point of cell-cycle regulation. At both mitosis and start, nutrient modulation was found through mutation to be regulated by the activity of the cyclin-related WHI1 (CLN3) gene product.     

Effect of the degree of myocardial hypertrophy associated with an experimental heart defect on the resistance to altitude hypoxia

Summary Experimental coarctation of the abdominal aorta with constriction of its lumen to one-third of the original diameter was created in 18 albino rats. Four months later various degrees of myocardial hypertrophy developed in the animals with a relative weight of the heart ranging from 0.0033 to 0.0069. In elevation in the barochamber, the altitude ceiling of the animals with a relative cardiac weight below 0.0040, did not differ from the normal one. The altitude ceiling proved to be considerably decreased in animals with a relative cardiac weight of over 0.0040. Analysis of ECG recorded during the elevation demonstrated that in the animals with a considerable myocardial hypertrophy reduced resistance to the acute high altitude hypoxia depended on the reduction of the functional resistance of the heart.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 55, No. 5, pp. 37–40, May, 1963     

Oncogenic activity of the BK type of human papova virus in inbred rat strains

Summary The oncogenicity of the human polyomavirus BK (BKV) was tested in newborn inbred rats.It was found that the tumor rate was negatively correlated with the levels of T antibody 3 months after inoculation and the frequency of animals with detectable T antibodies 1.5 months after inoculation.By contrast, no influence of viral HI titers on the tumor rates was found. Thymectomy of animals resulted in most experiments in increased tumor rates. Inoculation with BKV of animals later than 24 hours after birth yielded a decrease of tumor rates.The results obtained suggest that T antibody titers present at a critical time after inoculation are associated with low oncogenicity of BKV.The oncogenicity of BKV was comparatively tested in rat strains possessing the allele l or the allele a, respectively. The oncogenicity was significantly higher in rats with the allele l than in rats with the allele a. Rats with the allele l showed lower T antibody response than rats with the allele a.These differences could be explained by the finding that cells of a origin showedin vitro a higher percentage of T antigen bearing cells than did cells of a strain possessing the allele l. In comparison to previous results obtained with BKV inoculated outbred WISTAR rats, the oncogenicity of comparable BKV doses in inbred rats was generally higher and the latency period of tumor manifestation shortened.     

Vascular lesions in testes associated with male infertility in Cameroon

Summary Testicular biopsies in 40 of 41 infertile males with severe oligospermia in Cameroon presented massive subendothelial fibrinoid deposits in the small and medium sized vessels. Fibrinogen, complement and IgM were demonstrated in these deposits by immunofluorescence. Evidence strongly suggestive of parasitic testicular involvement was also observed in 2 cases.It is postulated that the fibrinoid deposits are the result of repeated formation and deposition of circulating immune complexes by reaction of antibodies with antigens. These antigens could be of various origins and in the cases described here they could be derived from living or dying parasites in the region. The accumulation and incorporation of the fibrinoid deposits may lead to vascular stenosis resulting in chronic ischaemia, tubular atrophy and fibrosis, and finally oligospermia.     

Evidence for a direct relationship between mitochondrial genome organization and regeneration ability in hexaploid wheat somatic tissue cultures

Summary Embryogenic and non-embryogenic long-term callus cultures of hexaploid wheat exhibit differences in the organization of their mitochondrial genome. Embryogenic and non-embryogenic fractions of callus cultures initiated from immature embryos of the wheat cultivar Chinese Spring have been isolated and subsequently subcultured. DNA-DNA hybridization experiments using labelled cloned wheat mitochondrial DNA fragments have shown that the mitochondrial DNA organization of embryogenic subcultures derived from embryogenic parts of Chinese Spring calli is closely related to that of the initial Chinese Spring calli, while non-embryogenic subcultures derived from non-embryogenic fragments of Chinese Spring calli exhibit a mitochondrial DNA organization similar to that found in non-embryogenic calli derived from cultivar Aquila. In addition, somatic tissue cultures initiated from three other non-embryogenic wheat cultivars (Talent, Thésée and Capitole) display mitochondrial DNA arrangements similar to those found in cultivar Aquila. These results strongly suggest that, in wheat callus cultures, a particular mitochondrial genome organization is correlated with the ability of cultured cells to regenerate whole plants.Abbreviations mtDNA mitochondrial DNA - ctDNA chloroplast DNA - rRNA ribosomal RNA - kb kilobase pair - cv cultivar - 2,4-D 2,4-dichlorophenoxyacetic acid     

The distribution of lanthanum in tight junctions of the kidney tubule

Summary The penetration of either ionic or colloidal lanthanum into the tight junctions of different tubular segments of the rat kidney was studied with the electron microscope. After perfusing the tracer through the aorta it was found that ionic and colloidal lanthanum penetrated the tight junctions of both the proximal and distal convoluted tubules, while the junctions of the collecting tubules were free of tracer. An attempt to correlate junctional tightness and electrical resistance in these epithelia is presented.     

Biophysical studies of teschen disease virus (Talfan strain)

Summary Studies have been made of the heterogeneity of infectivity and CFA in Teschen virus (Talfan strain) suspensions. Most of the infectivity was contained in two components of densities 1.46 gm./ml. and 1.35 gm./ml. The physical, chemical and immunological properties of these components have been compared. It was possible, however, to convert a large proportion of 1.46 component to 1.35 component by treating the 1.46 component with sodium dodecyl sulphate. This would indicate that the 1.46 component was a complex formed between the infective particles and cellular debris.Further studies on the growth characteristics and electron microscopy of the virus have been made.     

Recognition by peptide mapping of three different structural groups of outer membrane protein YOP-1 of Yersinia enterocolitica and Yersinia pseudotuberculosis

The structural relation of YOP-1 of european and american Yersinia enterocolitica serotypes O3, O9, O5, 27, and O8 and O20, respectively, and Y. pseudotuberculosis serotypes I, II, and III was compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis and peptide mapping using Staphylococcus aureus protease V8. Apparent molecular weights of YOP-1 ranged from 206,000 (O3) to approx. 180,000 (O8). According to their respective peptide maps YOP-1 of the european and american Y. enterocolitica serotypes and Y. pseudotuberculosis serotypes could be assigned to three different groups. Evaluation of several isolates of Y. enterocolitica serotypes O3, O9, and O8 by peptide mapping indicated that YOP-1 is conserved within a serotype. However, one serotype O8 isolate differed from the consensus peptide pattern of the other serotype O8 and O20 isolates. The similarity of the peptide patterns of Yersinia serotypes which predominate in certain geographical locations, i. e., european and american Y. enterocolitica serotypes, suggest common evolution of YOP-1 of these serotypes independent of the evolution of the other serotypes.     

Summation and adaptation in stimulation of the motor cortex in adult and newborn animals

Summary In rabbits and their progeny an investigation was made of summation and adaptation of the neurones of the motor cortex; unipolar stimulation was used, and the muscular response recorded. Two types of summation curves were found: exponential and Y-shaped,, and were related to the direct and indirect summation of stimulation. In adults, Y-shaped summation curves were more frequent, whereas in rabbits aged 24 h exponential curves preponderted. We found very little capacity for adaptation at any age.(Presented by Active Member AMN SSSR A. F. Turom) Translated from Byulleten Éksperimental'noi Biologii i Medisiny, Vol. 55, No. 6, pp. 3–7, June, 1963     

A Proposed Heuristic for Communicating Heritability Estimates to the General Public, with Obesity as an Example

It is well established that many continuously distributed traits have a heritable component. However, it is often difficult to communicate to the general public the meaning of quantitative estimates of heritability. To address this problem, the present paper introduces a heuristic for communicating heritability to nonscientific audiences. This heuristic involves adopting an extremely simplified model of inheritance and artificially (and somewhat arbitrarily) defining a cutoffs of low environmental risk and affectation status. Using body weight and obesity as an example, we present a table which gives estimates of the proportion of obese persons who are genetically obese assuming varying levels of environmental risk for obesity and relative body weight scores for defining obesity. The resulting statistic may prove useful for lay audiences in understanding a heritability estimate.     

Modelling of electrolyte transport in renal and intestinal epithelia

Summary Epithelia can be classified as leaky and tight epithelia due to their conductive properties and their modes of solute transport. Both the proximal segment of the nephron and the intestinal tract are leaky whereas the distal nephron and the colon are tight. Consequently, inborn errors and exogenous disorders of solute transport often involve both the proximal tubule and the small intestine. In addition, effects on ion and water transport in the distal nephron closely resemble those in the large intestine. Models of solute transport in leaky and tight epithelia are presented employing porter systems known in mammalian tissues. These porter systems are discussed as possible sites of transport defects and as targets for pharmacological agents.     

Further observations on the morphogenesis of human rotavirus in MA 104 cells

Summary Human rotavirus KUN strain was cultivated in a fetal rhesus monkey kidney cell line, MA 104 cells. Four types of virus particles in cells infected with KUN strain were clearly identified: nucleoid cores, single-shelled particles, double-shelled particles, and membrane band, enveloped particles. Enveloped particles were found only in the thin sections of infected cells. When first visible, the virus precursors appeared at the ribosome free membrane of rough endoplasmic reticulum (RER), increasing in size while simultaneously being coated with nucleocapsid, inner shell. Single-shelled particles were also synthesized within bundles of filaments of viroplasm in the cytoplasma. During subsequent virus maturation two types of budding processes were observed. Double-shelled particles arising at the RER membrane entered the cisternae of the RER through an exocytosis-like process. In contrast, the enveloped particles developed in the cisternae by being completely enclosed with RER membrane, and later during cytolysis released the single-shelled particles. These enveloped virus particles appeared to be the result of inefficient virus maturation at the last stage of outer capsid formation.With 11 Figures     

Eine neue Bestimmung der Neutralfette im Blutserum und Gewebe

Zusammenfassung Die Neutralfette im Blutserum und Gewebe lassen sich über Glycerin exakt ermitteln. Freies und nach alkoholischer Verseifung nachweisbares Gesamt-Glycerin werden mit Glycerokinase in einer dreistufigen enzymatischen Nachweisreaktion im Mikroverfahren bestimmt. Die Differenz wird als Glycerid-Glycerin angesprochen. Reaktionsprinzip, Durchführung der Methode und Berechungsweise werden ausführlich besprochen.Für freies Glycerin werden 0,2 ml Serum, für Gesamtglycerin etwa 0,007–0,015 ml Serum äquivalente Hydrolysatmengen in den Test eingesetzt. Bei einer Empfindlichkeit von 0,0008 µMol (wenn bei 340 nm, bzw. 0,0015 µMol Glycerin, wenn bei 366 nm gemessen wird), können noch 1/20 bis 1/10 des im Normalserum vorhandenen freien bzw. Gesamtglycerins mit den Standardansätzen erfaßt werden. Die obere Nachweisgrenze reicht dann bis 0,15 bzw. 0,3 µMol Glycerin, das entspricht der 8- bzw. 15fachen Normalmenge für freies und Gesamtglycerin. In den angegebenen Grenzen liegen die über Glyceridglycerin nachweisbaren Triglyceridkonzentrationen. Empfindlichkeit und obere Nachweisgrenze können durch andere Serum- bzw. Hydrolysatmengen in weiten Grenzen variiert und der jeweiligen Fragestellung angepaßt werden.

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Summary Triglycerides in blood serum and tissue can be identified exactly by means of glyceride-glycerol. Free and total glycerol, measurable after alcoholic saponification, are determined by glycerolkinase in a three-step enzymatic proof-reaction by means of micro-methods. The difference between total and free glycerol is called glycerideglycerol. Reaction principles, working instructions and the calculation will be discussed in detail.The sensitivity of the standard test runs to 0,0008 respeccively 0,0015 µMol glycerol or 1/20 resp. 1/10 of the normal contentrations. The upper proof limit is at 0,15 respectively 0,3 µMol glycerol per test. This is equal to 8–15 times more than the normal of free and total glycerol. Sensitivity and upper proof limit can easily by varied and adapted to the formulation of the question.