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Shifted encoding strategy in retinal luminance adaptation: from firing rate to neural correlation

JOURNAL OF NEUROPHYSIOLOGY 2013年第8期110卷 1793-1803页

作者： Xiao, Lei Zhang, Mingsha Xing, Dajun Liang, Pei-Ji Wu, Si Shanghai Jiao Tong Univ Sch Biomed Engn Shanghai 200030 Peoples R China Chinese Acad Sci Inst Neurosci Shanghai Peoples R China NYU Ctr Neural Sci New York NY 10003 USA Beijing Normal Univ State Key Lab Cognit Neurosci & Learning Beijing 100875 Peoples R China Beijing Normal Univ IDG McGovern Inst Brain Res Beijing 100875 Peoples R China

Neuronal responses to prolonged stimulation attenuate over time. Here, we ask a fundamental question: is adaptation a simple process for the neural system during which sustained input is ignored, or is it actually part of a strategy for the neural system to adjust its encoding properties dynamically? After simultaneously recording the activities of a group of bullfrog's retinal ganglion cells (dimming detectors) in response to sustained dimming stimulation, we applied a combination of information analysis approaches to explore the time-dependent nature of information encoding during the adaptation. We found that at the early stage of the adaptation, the stimulus information was mainly encoded in firing rates, whereas at the late stage of the adaptation, it was more encoded in neural correlations. Such a transition in encoding properties is not a simple consequence of the attenuation of neuronal firing rates, but rather involves an active change in the neural correlation strengths, suggesting that it is a strategy adopted by the neural system for functional purposes. Our results reveal that in encoding a prolonged stimulation, the neural system may utilize concerted, but less active, firings of neurons to encode information.

关键词： retinal ganglion cell luminance adaptation information coding neural correlation discrimination

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Response dynamics of bullfrog ON-OFF RGCs to different stimulus durations

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JOURNAL OF COMPUTATIONAL NEUROSCIENCE 2014年第1期37卷 149-160页

作者： Xiao, Lei Zhang, Pu-Ming Wu, Si Liang, Pei-Ji Shanghai Jiao Tong Univ Sch Biomed Engn Shanghai 200240 Peoples R China Beijing Normal Univ State Key Lab Cognit Neurosci & Learning Beijing 100875 Peoples R China Beijing Normal Univ IDG McGovern Inst Brain Res Beijing 100875 Peoples R China

Stimulus duration is an important feature of visual stimulation. In the present study, response properties of bullfrog ON-OFF retinal ganglion cells (RGCs) in exposure to different visual stimulus durations were studied. By using a multi-electrode recording system, spike discharges from ON-OFF RGCs were simultaneously recorded, and the cells' ON and OFF responses were analyzed. It was found that the ON response characteristics, including response latency, spike count, as well as correlated activity and relative latency between pair-wise cells, were modulated by different light OFF intervals, while the OFF response characteristics were modulated by different light ON durations. Stimulus information carried by the ON and OFF responses was then analyzed, and it was found that information about different light ON durations was more carried by transient OFF response, whereas information about different light OFF intervals were more carried by transient ON response. Meanwhile, more than 80 % information about stimulus durations was carried by firing rate. These results suggest that ON-OFF RGCs are sensitive to different stimulus durations, and they can efficiently encode the information about visual stimulus duration by firing rate.

关键词： Retinal ganglion cells Stimulus duration Response latency Firing rate Correlation strength information coding

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Preface: A Physical Sciences Perspective of the Evolution of Drug Resistance in Cancer

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MOLECULAR PHARMACEUTICS 2011年第6期8卷 1994-1995页

作者： Kuhn, Nastaran Zahir Nagahara, Larry NCI Off Phys Sci Oncol Ctr Strateg Sci Initiat Off DirectorNIH Bethesda MD 20892 USA

In this day and age with advanced technologies for the detection JLand diagnosis of cancer, the treatment to cure or even to control cancer remains a challenge greatly due to the evolution of resistance to available treatments. It is estimated that in the United States 1,530,000 people were diagnosed with and 570,000 people died of cancer of all sites in 2010 [http://***/csr/ 1975_2007/results_single/sect_01_***]. Most cancer-related deaths are not due to cancer in the primary site; rather, the deaths are due to disseminated disease when metastasis occurs in vital organs such as the liver, lungs, or pancreas. Relapse in cancer patients undergoing therapy is by and large due to the evolution of drug resistance in the cancer cell population. Evolutionary- theory predicts that, given time, heredity, and variation, any living organisms will evolve when a selective pressure is introduced. Albeit much more complex, the evolution of drug resistance in cancer is akin to the evolution of antibiotic drug resistance in bacteria, where evolutionary theory has been applied to suggest specific strategies to delay the onset of drug *** October 2009 the Physical Sciences-Oncology Centers (PS-OCs) Program was launched by the Office of Physical Sciences-Oncology (OPSO) of the National Cancer Institute (NCI) to taclde longstanding problems in cancer biology and oncology with a physical sciences perspective. Across the country, twelve PS-OCs were established to form a PS-OC Network bringing together for the first time teams of experts from the physical and biological sciences to study cancer at a fundamental level. Thematic areas around which the PS-OCs formed are (l) the physical laws and principals of cancer; (2) information coding, decoding, transfer and translation in cancer; (3) deconvolving cancer\'s complexity; and (4) evolution and evolutionary theory in cancer. A subtheme of the lattermost is the topic for this special issue of Molecular Pharma..

关键词： Theory of Evolution Cancer Biology Antibiotic Resistance, Microbial Physical science advanced technologies Biological Science Disciplines information coding Drug Resistance Antimicrobial Drug Resistance

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information encoding and computation with spikes and bursts

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NETWORK-COMPUTATION IN NEURAL SYSTEMS 2003年第1期14卷 103-118页

作者： Kepecs, A Lisman, J Brandeis Univ Volen Ctr Complex Syst Waltham MA 02454 USA

Neurons compute and communicate by transforming synaptic input patterns into output spike trains. The nature of this transformation depends crucially on the properties of voltage-gated conductances in neuronal membranes. These intrinsic membrane conductances can enable neurons to generate different spike patterns including brief, high-frequency bursts that are commonly observed in a variety of brain regions. Here we examine how the membrane conductances that generate bursts affect neural computation and encoding. We simulated a bursting neuron model driven by random current input signal and superposed noise. We consider two issues: the timing reliability of different spike patterns and the computation performed by the neuron. Statistical analysis of the simulated spike trains shows that the timing of bursts is much more precise than the timing of single spikes. Furthermore, the number of spikes per burst is highly robust to noise. Next we considered the computation performed by the neuron: how different features of the input current are mapped into specific, output spike patterns. Dimensional reduction and statistical classification techniques were used to determine the stimulus features triggering different firing patterns. Our main result is that spikes, and bursts of different durations, code for different stimulus features, which can be quantified without a priori assumptions about those features. These findings lead us to propose that the biophysical mechanisms of spike generation enables individual neurons to encode different stimulus features into distinct spike patterns.

关键词： Hippocampal pyramidal cells Visual information Auditory-cortex Dendritic trees In-vivo Neurons Precision Model Oscillations Variability Membrane conductance brain region Precision BURSTS Pyramidal Cells input current timing sequence Neurons information coding visual information Primary Auditory Cortex

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Recording the brain at work: The visible, the readable, and the invisible in electroencephalography

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JOURNAL OF THE HISTORY OF THE NEUROSCIENCES 2008年第3期17卷 367-379页

作者： Borck, Cornelius Med Univ Lubeck Inst Hist Sci & Med D-23552 Lubeck Germany

The electroencephalogram (EEG), the graphic recording of the electric activity of the human brain, kindled far-reaching speculations about the imminent deciphering of mind and brain in the 1930s. Regardless of the thousands of neurons in the human cortex, recording from a person at rest produced a surprisingly regular line oscillating at 10 per second that disappeared at the moment of mental activity. With ever more groups specializing in electroencephalography, however, the deciphering of mind and brain did not materialize but moved further away in the information produced. In the various approaches employed in EEG research, such as the analysis of the graphic code, the search for pathognomic patterns or the imaging of cognitive processing, visualization guided research as well as theorizing, its productivity continued to keep the epistemological question open.

关键词： electroencephalography visualization of brain waves graphic method information coding brain theory machine thinking visual thinking epistemology of neuroscience

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Putative chemical signals about sex, individuality, and genetic background in the preputial gland and urine of the house mouse (Mus musculus)

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CHEMICAL SENSES 2007年第3期32卷 293-303页

作者： Zhang, Jian-Xu Rao, Xiao-Ping Sun, Lixing Zhao, Cheng-Hua Qin, Xiao-Wei Chinese Acad Sci Inst Zool State Key Lab Integrated Management Pest Insects Beijing 100080 Peoples R China Beijing Normal Univ Dept Biol Beijing 100875 Peoples R China Cent Washington Univ Dept Sci Biol Ellensburg WA 98926 USA

To explore whether preputial gland secretions and/or urine from the house mouse (Mus musculus) can be used for coding information about sex, individuality, and/or the genetic background of strain [ICR/albino, Kunming (KM), and C57BL/6], we compared the volatile compositions of mouse preputial glands and urine using a combination of dichloromethane extraction and gas chromatography coupled with mass spectrometry (GC-MS). Of the 40 identified compounds in preputial gland secretions, 31 were esters, 2 sesquiterpens, and 7 alcohols. We failed to find any compound unique to a specific sex, individual, or strain. However, many low molecular weight compounds between the sexes, most compounds among individuals, and several compounds among the 3 strains varied significantly in relative ratios. These quantitative differences in preputial gland volatiles (analog coding) are likely to convey information about sex, individual, and the genetic background of mouse strain. We identified 2 new main and male-elevated compounds, 1-hexadecanol (Z= 3.676, P = 0.000, N = 19 in ICR;Z= 3.576, P= 0.000, N= 18) and 1-hexadecanol acetate (Z = 3.429, P = 0.000, N = 19 in ICR;Z = 3.225, P = 0.001, N = 18), which were eluted in GC chromatogram after the 2 sesquiterpens. They might also be potential male pheromones, in addition to the well-known E-beta-farnesene and E,E-alpha-farnesene. Additionally, a few compounds including 1-hexadecanol also varied with strains and might also code for genetic information. Of the 9 identified volatile compounds in male urine, (s)-2-sec-butyl-4,5-dihydrothiazole and R,R-3,4-dehydroexo-brevicomin are known urine-originated male pheromones from previous studies. We also detected 6-hydroxy-6-methyl-3-heptanone, a male urinary pheromonal compound, which had not been directly detected by GC-MS previously. Chemical analysis shows that the genetically more closely related ICR and KM strains had a higher similarity in the volatile compositions of preputial glands and ur

关键词： house mouse individual information coding Mus musculus pheromone preputial gland sex strain urine

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Strong individual distinctiveness across the vocal repertoire of a colonial seabird, the little auk, Alle alle

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ANIMAL BEHAVIOUR 2024年 210卷 199-211页

作者： Osiecka, Anna N. Briefer, Elodie F. Kidawa, Dorota Wojczulanis-Jakubas, Katarzyna Univ Gdansk Fac Biol Dept Vertebrate Ecol & Zool Gdansk Poland Univ Copenhagen Dept Biol Sect Ecol & Evolut Behav Ecol Grp Copenhagen Denmark

For species maintaining long-term social bonds, particularly in complex networks such as dense colonies, vocal cues to identity can be crucial. Here, we investigated the vocal individuality within and across five call types of the little auk: a monogamous, colonial bird with a strong nest fidelity. Calls produced inside the nest over the incubation period were recorded in 2019 and 2020 and assigned to a call type and individual. We extracted a set of 16 acoustic parameters for each vocalization, and seven additional temporal patterns for a complex, multisyllable call. Calls could be reliably assigned to an individual both within and across call types, although classification performance differed between linear and machine learning methods. All call types showed information content theoretically allowing us to distinguish at least 11 individuals, and up to at least 41 for the classic call. The raw acoustic parameters that contributed most information across the five call types (i.e. the five highest potential of individuality coding scores) were peak fundamental frequency, frequency value at the upper limit of the second and first quartiles of energy, sound duration and amplitude modulation rate. We suggest that this strong individuality across call types and parameters is selected for in the species to help maintain monogamous partnerships, and perhaps social bonds with neighbours, over the years. (c) 2024 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

关键词： alcid Beecher's information statistic dovekie individuality information coding information content potential for identity coding vocal communication

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Chiral encoding may provide a simple solution to the origin of life

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NATURE CHEMISTRY 2014年第7期6卷 569-574页

作者： Brewer, Ashley Davis, Anthony P. Univ Bristol Sch Chem Bristol BS8 1TS Avon England

The route by which the complex and specific molecules of life arose from the 'prebiotic soup' remains an unsolved problem. Evolution provides a large part of the answer, but this requires molecules that can carry information ( that is, exist in many variants) and can replicate themselves. The process is commonplace in living organisms, but not so easy to achieve with simple chemical systems. It is especially difficult to contemplate in the chemical chaos of the prebiotic world. Although popular in many quarters, the notion that RNA was the first self-replicator carries many difficulties. Here, we present an alternative view, suggesting that there may be undiscovered self-replication mechanisms possible in much simpler systems. In particular, we highlight the possibility of information coding through stereochemical configurations of substituents in organic polymers. We also show that this coding system leads naturally to enantiopurity, solving the apparent problem of biological homochirality.

关键词： Organic polymers coding Prebiotics Answer SOUP life biogenesis molecules information coding Organism

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Specialized Computer System Controlling the Technological Parameters of the Drilling Rig 15

Specialized Computer System Controlling the Technological Pa...

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15th IEEE International Conference on the Experience of Designing and Application of CAD Systems (CADSM)

作者： Shyrmovska, Nadiia Voronych, Artur Zaiachuk, Yaroslav Karpash, Maksym Lazoriv, Olha Ivano Frankivsk Natl Tech Univ Oil & Gas Dept Comp Syst & Networks Ivano Frankivsk Ukraine Ivano Frankivsk Natl Tech Univ Oil & Gas Dept Energy Management & Tech Diagnost Ivano Frankivsk Ukraine

ISBN: (纸本)9781728100531

Systematized and researched characteristics of quasi-stationary oil and gas objects complex on the example of industrial drilling plants. As a result, requirements for the implementation of algorithms and special processors for performing diagnostic functions of quasi-stationary objects are formed. The algorithm of identification of states of quasi-stationary objects on the basis of special codes is developed. The technique is proposed besides the compact coding of a set of technological parameters of drilling states in the form of structured codes that carry information about the number, time and planned economic data on the example of drilling processes.

关键词： Control of technological parameters drilling rig information coding bar code

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PYROELECTRICALLY GENERATED HIGH VOLTAGE TO DIGITALLY CODE INVISIBLE ELECTROSTATIC information ON FLEXIBLE POLYMER FOR APPLICATION IN SECURITY AND ANTI-COUNTERFEIT 35

PYROELECTRICALLY GENERATED HIGH VOLTAGE TO DIGITALLY CODE IN...

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35th IEEE International Conference on Micro Electro Mechanical Systems Conference (IEEE MEMS)

作者： Gonzalez-Losada, Pedro Martins, Marco Vinayakumar, K. B. Int Iberian Nanotechnol Lab Braga Portugal

ISBN: (纸本)9781665409117

In this manuscript, we explore the idea of an environmentally sustainable solution to store information in dielectric materials using a less energy-intensive approach. The reported pyroelectric method can code information electrostatically on flexible dielectric polymers (Parafilm). A thermally cycled pyroelectric crystal (1 degrees C/s) generates a high electric field required to polarize the flexible polymer sample. Depending on the orientation of the crystal and temperature polarity (heating or cooling), induced surface charges on the dielectric surface are either positive (1 ' s) or negative (0 ' s) hence depicting as bits in digital format. This approach opens new application avenues related to security, counterfeit, and smart logistics in supply chain management.

关键词： Invisible coding Pyroelectric Anti-counterfeit information coding

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