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1.
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.  相似文献   

2.
A new frame of reference, which in its fundamental structuring differs radically from the structuring of the familiar western Indo-European viewpoints (logical, mathematical, scientific, philosophical, etc.), already exists. Recently, by the strategem of systematically disallowing a previously unnoticed untenable assumption encoded in the traditional Western symbolic logics, set theories, etc., in particular and in the Western World-View in general, this frame of reference has generated its own, entirely non-traditional, formalized language. The Notre Dame Journal of Formal Logic has accepted for publication a first paper presenting this non-standard formalized language (Hilgartner, 1975).As one of its accomplishments, this new frame of reference delivers a general theory of living. This theory purports to span the entire domain of what we call living systems, human or non-human.The author did not originally devise this new frame of reference to account for the observable doings of one-celled organisms. Consequently, any effort to illustrate the generalizations of this already-existing abstract theory in terms of humanly observable bacterial behavior has the effect of experimentally testing these generalizations.In the second portion of this paper, the author shows that the new viewpoint neatly accounts, with no loose ends, for the published observations concerning the sensing of chemicals by bacteria; and also proposes two new experiments.Meanwhile, there exists a special dilemma which arises whenever its adepts attempt to discuss this non-standard frame of reference with persons versed in the standard Western one. By delineating the structuring of this dilemma, in the context of a human studying the sensing of chemicals by bacteria, the author demonstrates that the untenable assumption mentioned above does underlie the traditional Western viewpoints; and this demonstration suffices to show the traditional Western World-View as fundamentally flawed.The author presented an earlier version of this paper at the, Annual Meetings of the Society for Mathematical Biology, University of Pennsylvania Medical School, Philadelphia, August 1976.  相似文献   

3.
There might be an undetermined order in the interaction of the substrates with the ribosomes in the reaction of CACCA-Leu-Ac with puromycin to form Ac-Leu-puromycin and CACCA (fragment reaction). Km 0°=6×10-4 M for the puromycin · ribosome interaction. Chloramphenicol totally blocks the fragment reaction as a consequence of a single interaction with the ribosome of Kd 0°=2.2×10-6 M. The inhibition by chloramphenicol of the fragment reaction is mixed competitive for puromycin.  相似文献   

4.
Ubiquitin — protein conjugates   总被引:18,自引:0,他引:18  
Summary The data available at present indicates there are three distinct functions of ubiquitin, two of which are related to protein conjugation. The first of these has been extensively studied by our laboratory and others interested in nucleosomes and changes in chromatin states. The ubiquitin-histone (Ub-2A, Ub-2B) conjugation reaction now appears to be a very dynamic process. In the deconjugation (lyase) reaction, both the histone 2A and the ubiquitin are left intact and in a form which makes possible ready reconjugation. Accordingly, this may be a mechanism for moment-to-moment control of the genome.The second function in which ubiquitin is conjugated involves proteolytic activity. This activity is correlated with protein turnover. In this process, the ubiquitin-protein conjugate apparently serves as a signal for the protease cleavage of the protein. The released ubiquitin is also intact and is probably available for reconjugation.In the third function, ubiquitin was suggested to serve as hormone. The studies thus far have been carried out primarily on induction of T- and B-lymphocytes, reduction or delay of Coombs' positivity and reduction of spleen weight. The precise physiological role of this reported function is still unclear, particularly because the ubiquitin used was probably not the physiologically active form.  相似文献   

5.
The effects were investigated of purified subsynaptic fractions on the efflux of radioactivity from a plain synaptic vesicle fraction which had incorporated [3H]dopamine. About 50% of the radioactivity incorporated into the plain vesicles (120 g protein) was liberated on exposure to purified synaptic membranes (30 g protein). The synaptic membrane-dependent efflux appeared to depend on both adenosine triphosphate and divalent cations, especially Ca2+. Of the subcellular fractions used, the heavy microsomal fraction showed the same effects as the synaptic membrane fraction. Purified synaptic junctions exhibited the strongest stimulating effects: the efflux was 2 times greater than that observed with synaptic membranes. The stimulating effects of myelin were less than oneseventh of those of synaptic junctional fraction. These observations may indicate that the transmitters are liberated by interaction of vesicle membrane with synaptic membrane in the presence of ATP and divalent cations.Abbreviations EDTA ethylenediamine tetraacetic acid - EGTA ethyleneglycol bis-(-aminoethylether)-N,N-tetraacetic acid - AMP-PNP adenyl imidodiphosphate  相似文献   

6.
We use a mathematical model to investigate how climbing fiber-dependent plasticity at granule cell to Purkinje cell (grPkj) synapses in the cerebellar cortex is influenced by the synaptic organization of the cerebellar-olivary system. Based on empirical studies, grPkj synapses are assumed to decrease in strength when active during a climbing fiber input (LTD) and increase in strength when active without a climbing fiber input (LTP). Results suggest that the inhibition of climbing fibers by cerebellar output combines with LTD/P to self-regulate spontaneous climbing fiber activity to an equilibrium level at which LTP and LTD balance and the expected net change in grPkj synaptic weights is zero. The synaptic weight vector is asymptotically confined to an equilibrium hyperplane defining the set of all possible combinations of synaptic weights consistent with climbing fiber equilibrium. Results also suggest restrictions on LTP/D at grPkj synapses required to produce synaptic weights that do not drift spontaneously.  相似文献   

7.
The existence of hot or cold nutrient broth or primeval soup is challenged on the basis of the recent geochemistry of soluble organic carbon in the oceans. Most of the dissolved organic carbon is recycled quickly by organisms, but the residual, biologically refractive, organic matter is efficiently scavenged from the oceans (residence time of 1000 to 3500 years) by nonbiologically mediated chemical and physical processes, such as adsorption on sinking minerals, polymerization and aggregation to humic type polymers or by aggregation to particulate matter through bubbling ans sinking of this material to the ocean bottom. Since there is no reason to believe that such nonbiological scavenging was not operative in the prebiotic oceans as well, then the prolonged existence of organic soup is very doubtful. The question of the orgin of life is thus assumed to be related to solid-liquid interfacial activity, and the answer may be associated with sediment-water interaction rather than with solution chemistry.  相似文献   

8.
Koval'  O. M.  Skok  M. V.  Skok  V. I. 《Neurophysiology》2003,35(1):17-23
We studied the subunit composition of nicotinic cholinoreceptors (nChR) of neurons of the inferior mesenteric ganglion (IMG) of the guinea pig using antibodies against the 3, 4, 5, and 7 nChR subunits and a standard technique of intracellular recording. Application of the 3 subunit-specific antibodies resulted in a decrease in the EPSP amplitude by 29.7 ± 1.8%, on average, in 17 of 20 studied neurons. The 4 subunit-specific antibodies evoked no changes in the amplitude of EPSP recorded from IMG neurons (n = 10). Effects of the 5 subunit-specific antibodies were studied in 20 neurons, where the EPSP amplitude dropped after application of these antibodies by 40.0 ± 1.8%, on average. Superfusion of the neurons with a solution containing the 3 and 5 subunit-specific antibodies completely suppressed synaptic responses (n = 3). The 7 subunit-specific antibodies provided an increase in the EPSP amplitude in 13 of 15 studied IMG neurons (by 37 ± 6%, on average); this fact allows us to suppose that 7-containing nChR are present in the IMG neurons and are indirectly involved in the processes of synaptic transmission. Application of the antibodies evoked no significant shifts in the membrane potential in IMG neurons. Our findings demonstrate that synaptic transmission through the guinea pig IMG is realized mostly with the involvement of the 3- and 5-containing nChR; the 4-containing receptors are not engaged in this process.  相似文献   

9.
The Classical Theory of function in the nervous system postulates that the nerve impulse is the result of a sequential reversal of the membrane potential due to an increased permeability of the membrane, first to sodium ions, then to potassium ions. The new theory presents a bio-physical model which depicts the nerve impulse as an event involving the motions of electrons and waves, and their interactions with sodium and potassium atoms and ions. The velocity of the nerve impulse (the most important parameter of nerve function) is determined by the product of two constants: c = the speed of light, which is a constant for all nerves; k =a constant for each nerve and is believed to be a specific property of nerve matter related in some way to the atomic process. The theory proposes that the nerve impulse in the axon is dualistic in nature (particles and waves play equally significant roles). The dualistic nature accounts for the three most fundamental characteristics of conduction of the nerve impulse: periodicity (conduction of a nerve impulse over long distances with constant velocity and form); non-summing (two nerve impulses cannot be in the same place at the same time); quantum nature of each nerve impulse — i.e., the unit message of the nerve impulse is an indivisible unit.  相似文献   

10.
The founders of the Marburger Schule of Neo-Kantianism, Hermann Cohen and Paul Natorp, laid an emphasis upon a Platonic understanding of mathematics and logic as the paradigmatic epistemological basis of philosophy. Their successors, namely Ernst Cassirer and Nicolai Hartmann, made obvious, however, that new biological thinking can have a strong influence on ontology as well as on the theory of knowledge. They could show that biology was no longer to be treated as a metaphysical system in that pejorative meaning of metaphysics which Kant had so severely been opposing. Against the anti-realistic approach of the older neo-Kantians who wanted to eliminate Kant's thing-in-itself (Ding an sich), both Cassirer and Hartmann returned to a form of realism by way of Hegel's philosophical results and reflections on his method. This makes clear that their realism is still to be taken as a more of less monistic idealism. However, considering that modern biology as an antimetaphysical force became influential in their system for the first time and that it did so in two different but - on second thoughts - complementary ways, it becomes clear that it was necessary to change the paradigms of any neo-Kantian philosophy. Cassirer proved this by his development as a philosopher with a strong historical impetus while Hartmann as a more systematical philosopher only pointed in that direction.

Überarbeitete Fassung eines Vortrages, der am 26.6.1977 im Rahmen eines Symposiums Medizin und Naturwissenschaften in Marburg anlä\lich der 450-Jahr-Feier der Philipps-Universität Marburg gehalten wurde.  相似文献   

11.
Bacillus polymyxa grown in a recycling fermentor shows the same behavior previously observed with Escherichia coli: 3 successive growth phases. In the last 2 phases the growth rate is linear and the apparent maintenance energy demand rate and the molar growth yield are both independent of the specific growth rate, , and of the cells mass. The final phase of very slow growth is an indefinitely prolonged state of strong, stringent control, the regulatory system based on guanosine 3-diphosphate 5-diphosphate, and guanosine 3-diphosphate 5-triphosphate. The maximum cost of this stringent response is calculated to be 9% of the energy available to these energy-limited cells. There is a further energy cost contained in substantial amounts of DNA, RNA, and protein released from the cells during the latter 2 growth phases. The cost of production of these extra cellular anabolites ranges from 8–11% of the available energy.After a carbon-energy upshift in phase 3, the population growth rate immediately returned to that of early phase 2 growth, 50 h or more earlier.If maintenance energy is considered as energy expended by cells to maintain homeostasis, catabolic capacity, or anabolic potential, then the cost of stringent control — which preserves the fidelity of protein synthesis in slowly growing cells — must be considered a maintenance energy cost.Abbreviations GPR glucose provision rate - FR medium flow rate - SR substrate concentration - VF fermentor volume - FS filtrate removal rate - ppGpp guanosine 3-diphosphate 5-diphosphate - pppGpp guanosine 3-diphosphate 5-triphosphate  相似文献   

12.
Purified myelin from fresh calf brain white matter was subfractionated in a discontinuous sucrose gradient; significant recovery of protein and 2,3-cyclic nucleotide 3-phosphohydrolase (CNP) and 5-nucleotidase (5N) activities occurred in all three obtained subfractions, the highest recovery being in the light subfraction; highest 5N and CNP specific activities were in medium myelin. Purified myelin was also subfractionated in a continuous sucrose gradient, with a similar localization of protein; CNP activity and 5N activity maxima suggest that myelin may be a predominant locus of 5N in bovine brain white matter. Freezing of brain white matter caused an increase in protein and in CNP and 5N total activity recoveries in denser myelin subfractions. Cytochemistry showed the reaction product of 5N in the whole myelin fraction to be associated with the innermost, outermost and medial compact myelin layers. Effects of non-ionic detergent (Lubrol WX) on 5N activity were studied, and the results also suggest the intrinsic nature of 5N as an ectoenzyme in myelin membranes. Lubrol WX was viewed as an advisable detergent for the stimulation of myelin 5N activity, but not for the solubilization of this enzyme.  相似文献   

13.
This paper seeks a deeper understanding of the congener as a factor in animal and human behaviour. It does so, not by concentrating on analyses of stimulus exchanges - largely specific to the species - by which a congener is recognized, but on the more general questions of why a notion of congener exists at all and why it plays such an extraordinary important role in animal and human behaviour.Three separate approaches, by way of anthropomorphic psychology, a paraphysical energy model and the physical theory of the implicate order, lead to the recognition of a certain inseparability of self and congener; and to an interpretation of the content of the notion of congener and of the behaviour in relation to it, in terms of the fundamental concept of energy and the even more fundamental one of order.Dedicated to Professor Gerard P. Baerends, one of my valued guides in ethology.  相似文献   

14.
The biochemical composition and spatial distribution of particulate organic matter (POM) were studied in the Ross Sea (Antarctica) in summer 1989 to assess the quantitative role of organic carbon fractions in the cycling of organic matter in the water column. Large differences in chemical composition were observed between surface and deep layers. The results indicated that, despite large geographical differences, POM was quite homogeneous, of phytoplankton origin and mostly detrital. Different ratios were used to investigate the changes in biochemical composition of particulate organic matter in relation to the ice-melting: CN (organic carbonorganic nitrogen ratio) and C-POMPOC (sum of carbohydrate, protein and lipid carbontotal organic carbon ratio) were used to analyse the percentage of refractory organic material. PPRTPCHO (proteincarbohydrate ratio) were used to establish POM age and RNADNA ratios as a relative measure of particulate activity; POCChl a and N-PPRTChl a ratios were used to estimate the autotrophic contribution to the suspended particulate organic matter. Despite its low caloric value (5.3 Kcal g POM–1), an high caloric content in the photic layer (1.6 Kcal m–3 of POM and 2.5 Kcal m–3 of POC) was found thus indicating that a large amount of food was available to higher trophic levels.  相似文献   

15.
Below-ground biomass in healthy and impaired salt marshes   总被引:1,自引:0,他引:1  
Twelve salt marshes in south Louisiana (USA) were classified as either impaired or healthy before a summer sample collection of above- and below-ground biomass and determination of sediment accretion rates. The above-ground biomass of plant tissues was the same at both impaired and healthy salt marshes and was not a good predictor of marsh health. However, below-ground root biomass in the upper 30cm was much lower in the impaired marshes compared to the healthy marshes. Compromises to root production apparently occur before there is an obvious consequence to the above-ground biomass, which may quickly collapse before remedial action can be taken. The subsequent change in vertical position of the marsh surface may be equivalent to many years of accretion, and be irreversible within decades without considerable effort. These results are consistent with the hypothesis that it is the plants below-ground accumulation of organic matter, not inorganic matter that governs the maintenance of salt marsh ecosystem in the vertical plane. Reversing the precursor conditions leading to marsh stress before the collapse of the above-ground biomass occurs is therefore a prudent management objective and could be easier than restoration.  相似文献   

16.
Muranaka  S.  Shimizu  K.  Kato  M. 《Photosynthetica》2002,40(4):505-515
The effects of NaCl treatment on the photosynthetic machinery in wheat (Triticum aestivum L.) cultivars differing in salt tolerance were investigated by comparison with iso-osmotic PEG treatment. Both cultivars similarly reduced the photosystem 2 (PS2) energy conversion efficiency (PS2) rapidly when plants were exposed to a 100 mM NaCl solution, though no decline was detected under the iso-osmotic PEG treatment. There was no correlation between the reduction of the leaf relative water content (RWC) and the PS2 in the two iso-osmotic stress treatments. In contrast, a decline of PS2 along with the increase of the leaf sodium content above 4 % dry matter was detected under the NaCl treatment, while no such correlation was detected with other cations. The recovery of PS2 after photoinhibitory irradiation was repressed by the NaCl treatment as the increase of the duration of the treatment. Norin 61 subjected to the 100 mM NaCl treatment for 10 d showed a decline of the PS2 after 1 h moderate irradiation of 400 mol m–2 s–1 PPFD. Thus the concentrated Na+ within a leaf under salinity treatments may decrease the stability of PS2 functions and lead to photochemical inactivation.  相似文献   

17.
Phospho- and galacto- lipids and lipidhydrolyzing enzymes have been determined in the white matter of a young patient with a subacute course of multiple sclerosis (MS). Significant changes were observed for the concentration of glycerophosphatides and the fatty acid pattern of the normal appearing with matter surrounding MS-plaques. Among the individual glycerophosphatides a significant decrease of phosphatidylserine and phosphatidylinositol was found, whereas the ethanolamine containing phosphatides showed lower figures (non significant).The fatty acid pattern of the ethanolamine-phosphatide-fraction of the diseased tissue showed a decrease of the 181 and the sum of 201 and 183 fatty acids as compared to the normal control, whereas the highly unsaturated, long-chained fatty acids 204 (arachidonic acid) and 226 (docosahexaenic acid) were elevated. The measurement of lipidhydrolyzing enzymes resulted in an increased phospholipase A1 activity in the diseased tissue. The experimental data point to a decreased activity of the fatty acid elongation system in the course of MS. The decrease of the acidic glycerophosphatides might be due to the increased phospholipase A1 activity.The impaired interaction of the lipids with the basic myelin protein, as described in the present paper, might be involved in the pathogenesis of the demyelinating process.  相似文献   

18.
Summary A novel deletion derivative, kal, of the kalilo senescence plasmid from Neurospora intermedia, was recovered from a culture treated with chloramphenicol. The deletion derivative exists in mitochondria as two different, equally abundant forms: a 2.8 kb duplex DNA molecule kal-2.8) and a 1.4 kb hairpin form kal-1.4). The kal-2.8 plasmid contains the 1366 by terminal inverted repeats and a partially duplicated 102 by segment of the unique sequence of the 8.6 kb kalilo plasmid. In contrast, the kal-1.4 hairpin plasmid appears to result from the folding of single strands that are generated during the replication of kal-2.8. Both forms of kal have covalently linked terminal proteins. Sequence analysis suggests that kal was generated either by slippage of the tip of a growing strand during the replication of kalilo, or by illegitimate recombination between two copies of the plasmid at non-homologous palindromic sequences that might form cruciform structures. In either case, the deletion process was mediated at least in part by an inverted repeat of 5 by in the unique region of kalilo. Since the terminal segments of kalilo DNA that are implicated in plasmid integration might also form cruciform structures, it is possible, but improbable, that the process that generated the first kal molecule is related to that which mediates integration of the plasmid into mitochondrial DNA.  相似文献   

19.
Mouse class I antigens are the major targets of cytolytic T lymphocytes in both major histocompatibility complex (MHC)-restricted and allogeneic responses. Considerable evidence has recently accumulated demonstrating that MHC class I molecules encoded by genes whose 1 and 2 coding exons were interchanged are not recognized by T lymphocytes specific for parental class I products. Along with the loss of T -cell reactivity, there is a loss of recognition by some, but not all monoclonal antibodies. In this communication we report that the loss of reactivity by monoclonal antibodies is accompanied by the gain of new epitopes caused by the interaction of 1 and 2 domains. These epitopes are immunodominant. They are the major determinant recognized by polyclonal antisera raised by immunization with L cells transfected with exon-shuffled class I genes. Four new monoclonal antibodies have been produced which recognize at least two separate epitopes caused by the interaction of the 1P and 2d domains.  相似文献   

20.
Summary A fibrous lamina that lines the inner surface of the nuclear envelope and has openings opposite the nuclear pores is described in the central nervous system of the leech.  相似文献   

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