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The International Space Station (ISS) has the possibility to perform experiments regarding rodent reproduction in microgravity. The musculoskeletal system at birth in precocial rodent species more resembles the human than that of altricial rodent species. For precocial rodent species with body weight ≤ 500 g (limit of ISS) determined were: adult body mass, newborn body mass, head-body length, tail length, existing variants (wild, domesticated, laboratory), single/group housing, dry food consumption/24 h, water intake/24 h, basal metabolic rate mlO2/g/h, environmental temperature, sand baths, urine output ml/24 h, fecal output g/24 h, size of fecal droplet, hair length, life span, length of oestrus cycle, duration of pregnancy, building nest, litter size, stage of musculoskeletal maturity at birth, and the duration of weaning. Characteristics were obtained by searching SCOPUS as well as the World Wide Web with key words for each of the species in English, Latin and, local language name. These characteristics were compared in order to find most appropriate species. Twelve precocial rodent species were identified. There is not enough data for Common yellow-toothed cavy, and Eastern spiny mouse. Inappropriate species were: Gundis, Dassie rat are a more demanding species for appropriate tending, litter size is small; Octodon degus requires sand baths as well as a nest during the first two weeks after delivery; muscle maturity of Spiny mouse at birth (myotubular stage), does not correspond to the human (late histochemical stage); Chinchilla requires separately housing, daily sand baths, has upper limit of weight. Possibility of keeping Southern mountain cavy as pet animal, short estrus, large litter size, absence of the need for nest and sand baths, makes this species the most promising candidates for experiments on ISS. If an experiment is planned with exposing gravid animals before term of the birth, then they might be kept together in the existing Rodent Habitat (USA). If an experiment with birth in microgravity is planned on ISS, the existing habitats do not provide conditions for such an experiment. It is necessary to develop habitats for separate keeping of pregnant animals to enable the following: 1. undisturbed delivery 2. prevent the possibility of hurting the newborns 3. ensure adequate post-partum maternal care and nursing.
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Roedores , Ingravidez , Animales , Femenino , Cobayas , Modelos Teóricos , Embarazo , Ratas , ReproducciónRESUMEN
Some contemporary theorists such as Mazzocchi, Theise and Kafatos are convinced that the reformed complementarity may redefine how we might exploit the complexity theory in 21st-century life sciences research. However, the motives behind the profound re-invention of "biological complementarity" need to be substantiated with concrete shreds of evidence about this principle's applicability in real-life science experimentation, which we found missing in the literature. This paper discusses such pieces of evidence by confronting Bohr's complementarity and ion channel modeling practice. We examine whether and to what extent this principle might assist in developing ion channel models incorporating both deterministic and stochastic solutions. According to the "mutual exclusiveness of experimental setups" version of Bohr's complementarity, this principle is needed when two mutually exclusive perspectives or approaches are right, necessary in a particular context, and are not contradictory as they arise in mutually exclusive conditions (mutually exclusive experimental or modeling setups). A detailed examination of the modeling practice reveals that both solutions are often used simultaneously in a single ion channel model, suggesting that the opposite conceptual frameworks can coexist in the same modeling setup. We concluded that Bohr's complementarity might find applications in these complex modeling setups but only through its realistic phenomenological interpretation that allows applying different modes of description regardless of the nature of the underlying ion channel opening process. Also, we propose the combined use of complementarity and Complex thinking in building the multifaceted ion channel models. Overall, this paper's results support the efforts to establish a more general form of complementarity to meet today's complexity theory-inspired life sciences modeling demands.
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Canales IónicosRESUMEN
Polyhydramnios is a condition related to an excessive accumulation of amniotic fluid in the third trimester of pregnancy and it can be acute and chronic depending on the duration. Published data suggest that during muscle development, in the stage of late histochemical differentiation decreased mechanical loading cause decreased expression of myosin heavy chain (MHC) type 1 leading to slow-to-fast transition. In the case of chronic polyhydramnios, histochemical muscle differentiation could be affected as a consequence of permanent decreased physical loading. Most affected would be muscles which are the most active i.e., spine extensor muscles and muscles of legs. Long-lasting decreased mechanical loading on muscle should cause decreased expression of MHC type 1 leading to slow-to-fast transition, decreased number of muscle fiber type I especially in extensor muscles of spine and legs. Additionally, because MHC type 1 is present in all skeletal muscles it could lead to various degrees of hypotrophy depending on constituting a percentage of MHC type 1 in affected muscles. These changes in the case of preexisting muscle disorders have the potential to deteriorate the muscle condition additionally. Given these facts, idiopathic chronic polyhydramnios is a rare opportunity to study the influence of reduced physical loading on muscle development in the human fetus. Also, it could be a medical entity to examine the influence of micro- and hypogravity conditions on the development of the fetal muscular system during the last trimester of gestation.
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This paper examines some methodological and epistemological issues underlying the ongoing "artificial" divide between pragmatic-systems biology and systems-theoretical biology. The pragmatic systems view of biology has encountered problems and constraints on its explanatory power because pragmatic systems biologists still tend to view systems as mere collections of parts, not as "emergent realities" produced by adaptive interactions between the constituting components. As such, they are incapable of characterizing the higher-level biological phenomena adequately. The attempts of systems-theoretical biologists to explain these "emergent realities" using mathematics also fail to produce satisfactory results. Given the increasing strategic importance of systems biology, both from theoretical and research perspectives, we suggest that additional epistemological and methodological insights into the possibility of further integration between traditional experimental studies and complex modeling are required. This integration will help to improve the currently underdeveloped pragmatic-systems biology and system-theoretical biology. The "epistemology of complexity," I contend, acts as a glue that connects and integrates different and sometimes opposing viewpoints, perspectives, streams, and practices, thus maintaining intellectual and research coherence of systems research of life. It allows scientists to shift the focus from traditional experimental research to integrated, modeling-based holistic practices capable of providing a comprehensive knowledge of organizing principles of living systems. It also opens the possibility of the development of new practical and theoretical foundations of systems biology to build a better understanding of complex organismic functions.
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Conocimiento , Análisis de Sistemas , Biología de Sistemas/clasificación , Simulación por Computador , Cibernética , Predicción , Humanos , Modelos Teóricos , Filosofía , Biología de Sistemas/métodosRESUMEN
This study explores the conceptual history of systems biology and its impact on philosophical and scientific conceptions of reductionism, antireductionism and emergence. Development of systems biology at the beginning of 21st century transformed biological science. Systems biology is a new holistic approach or strategy how to research biological organisms, developed through three phases. The first phase was completed when molecular biology transformed into systems molecular biology. Prior to the second phase, convergence between applied general systems theory and nonlinear dynamics took place, hence allowing the formation of systems mathematical biology. The second phase happened when systems molecular biology and systems mathematical biology, together, were applied for analysis of biological data. Finally, after successful application in science, medicine and biotechnology, the process of the formation of modern systems biology was completed. Systems and molecular reductionist views on organisms were completely opposed to each other. Implications of systems and molecular biology on reductionist-antireductionist debate were quite different. The analysis of reductionism, antireductionism and emergence issues, in the era of systems biology, revealed the hierarchy between methodological, epistemological and ontological antireductionism. Primarily, methodological antireductionism followed from the systems biology. Only after, epistemological and ontological antireductionism could be supported.
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BACKGROUND AND OBJECTIVE: For more than 20 years, Higuchi's fractal dimension (HFD), as a nonlinear method, has occupied an important place in the analysis of biological signals. The use of HFD has evolved from EEG and single neuron activity analysis to the most recent application in automated assessments of different clinical conditions. Our objective is to provide an updated review of the HFD method applied in basic and clinical neurophysiological research. METHODS: This article summarizes and critically reviews a broad literature and major findings concerning the applications of HFD for measuring the complexity of neuronal activity during different neurophysiological conditions. The source of information used in this review comes from the PubMed, Scopus, Google Scholar and IEEE Xplore Digital Library databases. RESULTS: The review process substantiated the significance, advantages and shortcomings of HFD application within all key areas of basic and clinical neurophysiology. Therefore, the paper discusses HFD application alone, combined with other linear or nonlinear measures, or as a part of automated methods for analyzing neurophysiological signals. CONCLUSIONS: The speed, accuracy and cost of applying the HFD method for research and medical diagnosis make it stand out from the widely used linear methods. However, only a combination of HFD with other nonlinear methods ensures reliable and accurate analysis of a wide range of neurophysiological signals.
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Fractales , Modelos Teóricos , Fenómenos Fisiológicos del Sistema Nervioso , HumanosRESUMEN
To study the influence of a static magnetic field (SMF, 2 mT) and extremely low frequency magnetic field (ELF MF, 50 Hz, 2 mT) on the neuronal population activity, the experiments were performed on adult longhorn beetles Morimus funereus (Coleoptera, Cerambycidae). Based on a wavelet analysis of the local field potentials (LFPs), our study showed for the first time that the effects of prolonged and repeated exposure to the ELF MF on the LFPs were irreversible within investigated time frame. The relative wavelet energy (RWE) of 4-8 Hz frequency band was significantly increased after sine ELF MF (SnMF)/square ELF MF (SqMF) in comparison to the control value. The RWE of slower oscillations (1-2Hz) was significantly decreased after the repeated exposures to either SnMF or SqMF. The SqMF induced decreasing of the faster waves in the range of 64-128 Hz. However, we did not prove with presented methods that exposure to the SMF for 5 min produces any effects on the neuronal population activity. This study has proved the wavelet transform as a valuable tool for measuring the effects of SMF and ELF MF on the neuronal population activity in M. funereus antennal lobe.
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Antenas de Artrópodos/fisiología , Escarabajos/fisiología , Neuronas/fisiología , Potenciales de Acción , Algoritmos , Animales , Antenas de Artrópodos/inervación , Encéfalo/fisiología , Escarabajos/citología , Campos Magnéticos , Modelos Biológicos , Transmisión Sináptica , Análisis de OndículasRESUMEN
Aim of this study was to investigate the application of normalized mean of the empirical Higuchi fractal dimension (FD) distributions, as a new approach to analyze the spontaneous bioelectrical activity of garden snail (Helix pomatia) Br neuron. The effect of ouabain on modulation of Br neuron bursting activity before and after the exposure to 10 mT static magnetic field (SMF) was observed by analyzing the following parameters: action potential (AP), interspike interval (ISI) and interbursting interval (IBI) components. Normalized mean of the empirical FD distributions were formed for the following experimental conditions: Control 1, Ouabain 1, Control 2, SMF 2, ASMF 2, Control 3, SMF 3 and Ouabain ASMF 3. Our main results have shown that ouabain without SMF induced increase in participation of AP and a decrease in participation of IBI components compared to the first control condition. However, in the presence of 10 mT SMF, ouabain-induced changes of measured parameters of Br neuron activity were less pronounced compared to the third control condition. We have shown that normalized mean of the empirical FD distributions is a useful method for detecting the changes in AP, ISI, and IBI components of complex bursting activity in altered physiological states.
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Fenómenos Electrofisiológicos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Ouabaína/química , Potenciales de Acción , Animales , Fractales , Glucósidos/química , Campos Magnéticos , Distribución Normal , Transducción de Señal , CaracolesRESUMEN
We used spectral analysis and Higuchi fractal dimension (FD) to correlate the EEG spectral characteristics of the sensorimotor cortex, hippocampus, and pons with their corresponding EEG signal complexities in anesthetized rats. We have explored the quantitative relationship between the mean FDs and EEG wide range high frequency (8-50 Hz) activity during ketamine/xylazine versus nembutal anesthesia at surgical plane. Using FD we detected distinct inter-structure complexity pattern and uncovered for the first time that the polygraphically and behaviorally defined anesthetized state at surgical plane as equal during experiment in two anesthetic regimens, is not the same with respect to the degree of neuronal activity (degree of generalized neuronal inhibition achieved) at different brain levels. Using the correlation of certain brain structure EEG spectral characteristics with their corresponding FDs, and the surrogate data modeling, we determined what particular frequency band contributes to EEG complexities in ketamine/xylazine versus nembutal anesthesia. In this study we have shown that the quantitative relationship between higher frequency EEG amplitude and EEG complexity is the best-modeled by surrogate data as a 3rd order polynomial. On the base of our EEG amplitude/EEG complexity relationship model, and the evidenced spectral differences in ketamine versus nembutal anesthesia we have proved that higher amplitudes of sigma, beta, and gamma frequency in ketamine anesthesia yields to higher FDs.
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Anestésicos Generales/farmacología , Electroencefalografía/efectos de los fármacos , Monitoreo Intraoperatorio/métodos , Procesamiento de Señales Asistido por Computador , Animales , Encéfalo/efectos de los fármacos , Encéfalo/fisiología , Electroencefalografía/métodos , Fractales , Hipnóticos y Sedantes/farmacología , Ketamina/farmacología , Masculino , Pentobarbital/farmacología , Ratas , Ratas Sprague-Dawley , Xilazina/farmacologíaRESUMEN
PURPOSE: Sigma and theta frequency electroencephalogram (EEG) oscillations exhibit substantial and well-recognized shifts with transitions across sleep and wake states. We aimed in this study to test the changes in coupling between these characteristic oscillations of non-rapid-eye-movement (NREM)/rapid-eye-movement (REM) sleep within and between cortical and pontine EEGs following monoaminergic lesion, by using the Pearson's product-moment correlation coefficients. METHODS: Experiments were performed in 14 adult, male Sprague Dawley rats chronically instrumented for sleep recording. We lesioned the dorsal raphe nucleus axon terminals in four rats using PCA neurotoxin (p-chloroamphetamine; Sigma-Aldrich, MO) administered as two intraperitoneal (IP) injections (6 mg/kg) 24 h apart. Lesioning of locus coeruleus axon terminals was performed in five rats using DSP-4 neurotoxin (N-2-chloroethyl-N-ethyl-2-bromobenzilamine; Sigma-Aldrich, MO) in a single IP dose of 50 mg/kg. RESULTS & CONCLUSIONS: Our previous study [Saponjic et al., Physiol Behav 90:1-10, 2007] demonstrated that these systemically induced monoaminergic lesions failed to produce significant changes in sleep/wake distribution from control conditions. The present study, by using spectral analysis and by examining the Pearson's correlation coefficients and their approximate probability density (APD) distribution profiles in control and lesion condition, demonstrates significant augmentation of the sigma/theta coupling strength, an inversion of cortical sigma/theta coupling direction and emergence of an additional sigma/theta coupling "mode" specific to the post-lesion state only within the cortex. By using the Pearson's correlation coefficients and their APD profiles, instead of classical sleep/wake distribution analysis, as a measure of direction and strength of sigma/theta coupling within and between cortex and pons, we were able to uncover the impact of a tonically decreased level of brain monoamines as altered strength and mode of coupling between sigma and theta oscillations. Specifically, a new mode of sigma/theta coupling emerged following lesion, which was specific to NREM sleep, suggests that loss of monoaminergic signaling interferes with NREM sleep consolidation. Our results also indicate an importance of monoamines in control of the sleep spindle and theta rhythm generators.