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Journal Article 2013; 34(7): 615-617 PubMed PMID: 24463997 Citation  Keywords:  Decision Making, Entropy, Humans, Models, Psychological, Psychophysics, Uncertainty,.   

: Connections between information theory and decision under uncertainty have been attracting attention in econophysics, neuroeconomics and quantum decision theory. This paper proposes a psychophysical theory of Shannon entropy based on a mathematical equivalence of delay and uncertainty in decision-making, and psychophysics of the perception of waiting time in probabilistic choices. Furthermore, it is shown that the well-known Shannon entropy is a special case of the general psychophysical entropy. Future directions in the application of the present theory to studies in econophysics and neuroeconomics are discussed....

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Journal Article 2012; 33(5): 471-476 PubMed PMID: 23090262 Citation  Keywords:  Algorithms, Brain:physiology, Entropy, Humans, Magnetic Resonance Imaging:methods, Models, Neurological, Signal-To-Noise Ratio,.   

: Entropy is a measure of information content or complexity. Information-theoretic modeling has been successfully used in various biological data analyses including functional magnetic resonance (fMRI). Several studies have tested and evaluated entropy measures on simulated datasets and real fMRI data. The efficiency of entropy algorithms has been compared to classical methods based on the linear model. Here we explain and summarize entropy algorithms that have been used in fMRI analysis, their advantages over classical methods and their potential use in event-related and block design fMRI....

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Journal Article 2005; 26(3): 237-241 PubMed PMID: 15990728 Citation  Keywords:  Animals, DNA:chemistry, Entropy, Evolution, Molecular, Humans, Models, Chemical, Nucleic Acid Conformation, Peptides:chemistry, Promoter Regions, Genetic, Protein Binding, Protein Conformation, Transcription Factors:chemistry,.   

PROBLEM: Gerontology observations show that ageing of organism is accompanied by the decrease of the chromatin activity and slowing down of the protein synthesis. Natural regulatory oligopeptides and their synthetic analogues take part in the activation of chromatin and normalise rate of the protein synthesis in cultured tissues. Regulatory peptides significantly enhance longevity.

OBJECTIVES: The objective of this work is to find a possible molecular mechanism by which the regulatory peptides influence the part of genetic system is responsible for initiation of protein synthesis in higher organisms.

METHODS: An interdisciplinary approach was used to address the problem. The work involved not only medical scientists and biologists, but also specialists in biopolymer chemistry, and mathematicians for statistical analysis of information interaction of amino acid and nucleotide sequences.

CONCLUSIONS: The structures and metrics of peptides and the DNA double-helix cause the recognition and complementary binding of a regulatory peptide with DNA functional groups at the interface of the major groove. We have used complementary binding model to find a possible base pair sequence ATTTTC for specific binding of synthetic tetrapeptide epitalon. This base pair block and its reverse complement were found repeatedly in the promoter region of telomerase. A comparison of statistical information content of peptides and oligonucleotide sequences shows that these two classes of biopolymers are information carriers and. exchange the information to initiate the gene transcription....

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Journal Article 2005; 26(1): 25-28 PubMed PMID: 15726015 Citation  Keywords:  Aging:physiology, Animals, Animals, Newborn, Brachial Plexus:physiology, Electrophysiology, Entropy, Male, Neurons, Afferent:physiology, Pain:etiology, Rats, Rats, Wistar, Rhizotomy, Self Mutilation:etiology,.   

OBJECTIVES: The aim of the study was to describe the development of self-mutilation after extensive dorsal rhizotomy of the brachial plexus performed during early ontogeny in rats.

SETTINGS AND DESIGN: The rhizotomy was performed in three groups of rats according to the central nervous system maturation: infant, young, and adult. After the surgery the occurrence of self-mutilation behavior was compared. Rats from the infant group and non-mutilating deafferentated rats from the adult group underwent extracellular recordings from intralaminar thalamic neurons. Interspikes intervals of the records were compared by means of chaodynamic methods.

RESULTS: In the infant group self-mutilation did not develop at all. Among the young group self-mutilation developed in 40% of rats and consisted of superficial wounds in all cases. In adult self-mutilation appeared in 80% rats and consisted of both superficial wounds (75%) and amputation (25%). In the newborn group and the deafferentated adult group without any signs of self-mutilation means of the parameters were not significantly different and were significantly lower than those of intact adult rats.

MAIN FINDINGS: 1. Self-mutilation does not develop after the rhizotomy in the infant rats. 2. Neurons behave in chaotic way in adult as well as in young animals. 3. Chaodynamic parameters do not differ between infant and adult rats without any signs of self-mutilation.

CONCLUSIONS: The results suggest that development of self-mutilation behavior in rats strongly depends on the ontogenetical period of nervous system injury, and that mature nervous system is required for the development of described pathological behavior....

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Journal Article 2004; 25(6): 407-410 PubMed PMID: 15665800 Citation  Keywords:  Action Potentials, Animals, Entropy, Intralaminar Thalamic Nuclei:physiology, Male, Models, Neurological, Neuralgia:physiopathology, Nonlinear Dynamics, Rats, Rats, Wistar, Rhizotomy,.   

OBJECTIVES: A novel evaluative approach was used to determine single unit activities of non-bursting intralaminar thalamic nuclei under neuropathic pain state following dorsal rhizotomy.

SETTINGS AND DESIGN: Extensive dorsal rhizotomy at cervicothoracic level in rats was used as a model of central pain. After rhizotomy, rats were divided into two groups: rats without any signs of self-mutilation, and those presenting self-mutilation. Spontaneous single unit activities of neurons of intralaminar thalamic nuclei were recorded and interspike intervals (ISIs) of non-bursting cells were counted for both groups and compared with that of non-rhizotomized control rats. Chaodynamic methods were applied for the evaluation of the ISIs.

RESULTS: In control rats Lyapunov exponents, Shannon entropy and mutual information average values were significantly higher than those of rhizotomized rats without any signs of self-mutilation. Paradoxically, in animals presenting self-mutilation following rhizotomy the evaluated parameters were similar to those of controls. Further, Lyapunov exponents were positive values in all animals indicating chaotic pattern of the neuronal firing.

MAIN FINDINGS: 1. Neurons behave in chaotic way in all animals, 2. The most regular firing was found in non-mutilating rhizotomized animals, 3. Patterns of the firing in selfmutilating rats were similar to those in controls.

CONCLUSIONS: It is concluded that pain feeling is not executed neither by changes of chaotic dynamics of non-bursting intralaminar thalamic neurons. On the other hand, the paradoxical firing of the neurons under pathological brain matrix might participate in modification pain feeling....

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