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Članek obravnava Hölderlinovo in Claudelovo pesništvo ter Bachelardovo poetiko imaginacije v luči ideje otroka, svetosti otroškega spanca ter s tem povezane respiratorne (po)etike miru. V prvem delu se ukvarja z vprašanjem prastarih redov otroškosti, kakor se pojavljajo v izbranih Hölderlinovih himnah, pri čemer se analize osredotočajo na povezavo materinskih genealogij in ideje otroka v izbranih Hölderlinovih verzih nedokončane »Himne Madoni« ter nekaterih drugih njegovih delih. Temu je dodana interpretacija nekaterih Heideggrovih uvidov, kakor se navezujejo tako na Hölderlinovo poetiko, kakor tudi na Heideggrovo lastno mišljenje rojstvenosti in miru. V drugem delu se prek Bachelardove poetike sveta kot kozmične zibke pomaknemo v svet, v katerem je otroški spanec povezan s kozmičnim ritmom dihanja, kar odpira novo atmosfero miru prebivanja. S tem povezane so tudi navezave na Merleau-Pontyja, ki je deloval pod močnim Bachelardovim vplivom. V tretjem in sklepnem delu pa se na sledi Claudelovega pesništva, zlasti njegove slavilne ode »Magnifikat« ter njegove ideje o nesmrtnosti otroka, pomaknemo proti (post-)krščanskemu okviru premišljevanja in idejo otroka navežemo tudi na filozofijo Luce Irigaray, s posebnim poudarkom na vprašanju razmerja med Marijo kot materjo in Jezusom kot otrokom.

Pre-Bötzinger complex (PBC) neurons located in mammalian brain are the necessary conditions to produce respiratory rhythm, which has been widely verified experimentally and numerically. At present, one of the two different types of bursting mechanisms found in PBC mainly depends on the calcium-activated of non-specific cation current (ICaN). In order to study the influence of ICaN and stimulus current Iexc in PBC inspiratory neurons, a single compartment model was simplified, and firing patterns of the model was discussed by using stability theory, bifurcation analysis, fast, and slow decomposition technology combined with numerical simulation. Under the stimulation of different somatic applied currents, the firing behavior of neurons are studied and exhibit multiple mix bursting patterns, which is helpful to further understand the mechanism of respiratory rhythms of PBC neurons.

The behavioral state of animals is essential information for functional recordings of neuronal activity ; practically, the exact timing when animals recover from anesthesia is important information. Recordings of cortical local field potentials and dorsal neck electromyograms (EMGs), a widely used method to identify behavioral states, requires at least two recording electrodes, one of which also requires a craniotomy procedure. In the present study, recordings of whisker EMGs alone are sufficient to detect the state switch from anesthesia to awakening in head-fixed mice. This method uses a single electrode and thus is technically simple and demands a less physical burden to animals. Moreover, whisker EMGs recorded under anesthesia reflect respiratory rhythms.

Recent studies in animals have convincingly demonstrated that respiration cyclically modulates oscillatory neural activity across diverse brain areas. To what extent this generalises to humans in a way that is relevant for behaviour is yet unclear. We used magnetoencephalography (MEG) to assess the potential influence of respiration depth and respiration phase on the human motor system. We obtained simultaneous recordings of brain activity, muscle activity, and respiration while participants performed a steady contraction task. We used corticomuscular coherence as a measure of efficient long-range cortico-peripheral communication. We found coherence within the beta range over sensorimotor cortex to be reduced during voluntary deep compared to involuntary normal breathing. Moreover, beta coherence was found to be cyclically modulated by respiration phase in both conditions. Overall, these results demonstrate how respiratory rhythms influence the synchrony of brain oscillations, conceivably regulating computational efficiency through neural excitability. Intriguing questions remain with regard to the shape of these modulatory processes and how they influence perception, cognition, and behaviour.

The preBötzinger Complex (preBötC) gives rise to two types of breathing behavior: eupnea and sighing. Here, we examine the neural mechanisms that couple their underlying rhythms by recording from the preBötC in neonatal mouse brainstem slice preparations. It has been proposed that chloride-mediated synaptic inhibition couples inspiratory (eupnea-related) bursts and sigh bursts, but we find no evidence to support that notion. First, we characterize a fluctuating temporal relationship between sigh bursts and their preceding inspiratory bursts; their coupling is far weaker than previously described. Surprisingly, selective blockade of inhibitory synapses strengthened (rather than weakened) that phasic inspiratory-sigh burst relationship. Furthermore, pharmacological disinhibition did not alter the duration of the prolonged interval that follows a sigh burst prior to resumption of the inspiratory rhythm. These results demonstrate that coupling between inspiratory and sigh rhythms does not depend on synaptic inhibition.SIGNIFICANCE STATEMENTBreathing consists of eupnea and sigh breaths, which differ in their magnitude and frequency. Both breath types emerge from a brainstem microcircuit that coordinates their timing. Here, we advance understanding of these rhythms by assessing the nature and strength of their coordination, and by showing that synaptic inhibition does not enforce their temporal coupling in contrast to conventional understanding. This study provides insights into the basic neural mechanisms that link oscillations of different amplitude and frequency in a core oscillator.

An autorhythmic population of excitatory neurons in the brainstem pre-Bötzinger complex is a critical component of the mammalian respiratory oscillator. Two intrinsic neuronal biophysical mechanisms-a persistent sodium current ([Formula: see text]) and a calcium-activated non-selective cationic current ([Formula: see text])-were proposed to individually or in combination generate cellular- and circuit-level oscillations, but their roles are debated without resolution. We re-examined these roles in a model of a synaptically connected population of excitatory neurons with [Formula: see text] and [Formula: see text]. This model robustly reproduces experimental data showing that rhythm generation can be independent of [Formula: see text] activation, which determines population activity amplitude. This occurs when [Formula: see text] is primarily activated by neuronal calcium fluxes driven by synaptic mechanisms. Rhythm depends critically on [Formula: see text] in a subpopulation forming the rhythmogenic kernel. The model explains how the rhythm and amplitude of respiratory oscillations involve distinct biophysical mechanisms.

Deep hibernators go through several cycles of profound drops in body temperature during the winter season, with core temperatures sometimes reaching near freezing. Yet unlike non-hibernating mammals, they can sustain breathing rhythms. The physiological processes that make this possible are still not understood. In this study, we focused on the medullary Ventral Respiratory Column of a facultative hibernator, the Syrian hamster. Using shortened day-lengths, we induced a “winter-adapted” physiological state, which is a prerequisite for hibernation. When recording electrophysiological signals from acute slices in the winter-adapted pre-Bötzinger complex (preBötC), spike trains showed higher spike rates, amplitudes, complexity, as well as higher temperature sensitivity, suggesting an increase in connectivity and/or synaptic strength during the winter season. We further examined action potential waveforms and found that the depolarization integral, as measured by the area under the curve, is selectively enhanced in winter-adapted animals. This suggests that a shift in the ion handling kinetics is also being induced by the winter-adaptation program. RNA sequencing of respiratory pre-motor neurons, followed by gene set enrichment analysis, revealed differential regulation and splicing in structural, synaptic, and ion handling genes. Splice junction analysis suggested that differential exon usage is occurring in a select subset of ion handling subunits (ATP1A3, KCNC3, SCN1B), and synaptic structure genes (SNCB, SNCG, RAB3A). Our findings show that the hamster respiratory center undergoes a seasonally-cued alteration in electrophysiological properties, likely protecting against respiratory failure at low temperatures. ISSN:1662-453X ISSN:1662-4548

Key points: Reduced computational models are used to test effects of loss of inhibition to the Kölliker-Fuse nucleus (KFn). Three reduced computational models that simulate eupnoeic and vagotomized respiratory rhythms are considered. All models exhibit the emergence of respiratory perturbations associated with Rett syndrome as inhibition to the KFn is diminished. Simulations suggest that application of 5-HT 1A agonists can mitigate the respiratory pathology. The three models can be distinguished and tested based on their predictions about connections and dynamics within the respiratory circuit and about effects of perturbations on certain respiratory neuron populations. Abstract: Rett syndrome (RTT) is a developmental disorder that can lead to respiratory disturbances featuring prolonged apnoeas of variable durations. Determining the mechanisms underlying these effects at the level of respiratory neural circuits would have significant implications for treatment efforts and would also enhance our understanding of respiratory rhythm generation and control. While experimental studies have suggested possible factors contributing to the respiratory patterns of RTT, we take a novel computational approach to the investigation of RTT, which allows for direct manipulation of selected system parameters and testing of specific hypotheses. Specifically, we present three reduced computational models, developed using an established framework, all of which successfully simulate respiratory outputs across eupnoeic and vagotomized conditions. All three models show that loss of inhibition to the Kölliker-Fuse nucleus reproduces the key respiratory alterations associated with RTT and, as suggested experimentally, that effects of 5-HT 1A agonists on the respiratory neural circuit suffice to alleviate this respiratory pathology. Each of the models makes distinct predictions regarding the neuronal populations and interactions underlying these effects, suggesting natural directions for future experimental testing.

Interaction of slow-wave rhythmic components of cardiac, respiratory and motor activities was investigated in newborn rat pups on the first day after birth under normal conditions and after pharmacological depression of spontaneous periodic motor activity (SPMA) induced by injection of myocuran (myanesin) at low (100 mg/pg, i/p) and maximal (235 mg/pg, i/p) doses. The data obtained indicate that in rat pups after birth the intersystemic interactions are realized mainly via slow-wave oscillations of the near-minute or multiminute ranges, whereas the rhythms of the decasecond range do not play a significant role in integrative processes. Injection of myocuran at a dose causing neither muscle relaxation nor inhibition of motor activity induces changes in the cardiac and respiratory rhythms as well as a transitory decrease in the magnitude of coordinating relations mediated by the rhythms of the near-minute and multiminute ranges. The consequences of myorelaxant injection were found to be more significant for intersystemic interactions with the involvement of the respiratory system. The increase in the myocuran dose and, correspondingly, complete inhibition of SPMA is accompanied by the reduction in the slow-wave components of the pattern of cardiac and respiratory rhythms. The cardiorespiratory interactions, more pronounced in intact rat pups, decrease in the near-minute and multiminute modulation ranges and increase insignificantly in the decasecond modulation range.

Breathing is vital for survival but also interesting from the perspective of rhythm generation. This rhythmic behavior is generated within the brainstem and is thought to emerge through the interaction between independent oscillatory neuronal networks. In mammals, breathing is composed of three phases – inspiration, post-inspiration, and active expiration – and this article discusses the concept that each phase is generated by anatomically distinct rhythm-generating networks: the preBötzinger complex (preBötC), the post-inspiratory complex (PiCo), and the lateral parafacial nucleus (pFL), respectively. The preBötC was first discovered 25 years ago and was shown to be both necessary and sufficient for the generation of inspiration. More recently, networks have been described that are responsible for post-inspiration and active expiration. Here, we attempt to collate the current knowledge and hypotheses regarding how respiratory rhythms are generated, the role that inhibition plays, and the interactions between the medullary networks. Our considerations may have implications for rhythm generation in general.

Pre-Botzinger complex is considered to have a closely relationship with the respiratory rhythms. In this paper, we investigate the bursting phenomena of the pre-Botzinger complex respiratory neuron with periodic slow stimulation. Since the external forcing visit the spiking and rest areas in different ways, thus the system could generate various complex bursting patterns. With the external forcing is taken as a slow variable that modulates the dynamics of the system, different types of bursting are distinguished and the generation mechanism is explored by using the combination of two parameter bifurcation analysis and fast slow decomposition. Our results show that both the external forcing and the neural intrinsic property play an important role in neural activities.

A novel 3D breath-held Dixon fat–water separated balanced steady state free precession (b-SSFP) sequence for MR cholangiopancreatography (MRCP) is described and its potential clinical utility assessed in a series of patients. The main motivation is to develop a robust breath-held alternative to the respiratory gated 3D Fast Spin Echo (FSE) sequence, the current clinical sequence of choice for MRCP. Respiratory gated acquisitions are susceptible to motion artifacts and blurring in patients with significant diaphragmatic drift, erratic respiratory rhythms or sleep apnea. A two point Dixon fat–water separation scheme was developed which eliminates signal loss arising from B0 inhomogeneity effects and minimizes artifacts from perturbation of the b-SSFP steady state. Preliminary results from qualitative analysis of 49 patients demonstrate robust performance of the 3D Dixon b-SSFP sequence with diagnostic image quality acquired in a 20–24 s breath-hold.

Activity of neurons in the pre-Botzinger complex within the mammalian brain stem has an important role in the generation of respiratory rhythms. Previous experimental results have shown that the dynamics of sodium and calcium within each cell may be responsible for various bursting mechanisms. In this paper, we study the bursting dynamics of the two-coupled pre-Botzinger complex neurons. Using a combination of fast-slow decomposition and two-parameter bifurcation analysis, we explore the possible forms of dynamics that the model network can produce as well the transitions of in-phase and anti-phase bursting respectively.

The pre-Botzinger complex of the mammalian brain stem has been discovered to play a crucial role in the generation of the respiratory rhythms. Neurons within the pre-Botzinger complex have been found experimentally and numerically exhibit spiking and bursting activities. By using the first recurrence map based on fast-slow decomposition, we explore the dynamics of a mathematical model for a single pre-Botzinger complex cell. We explore the possible transitions between bursting and spiking mathematically.

In many tissues, PO2 fluctuates spontaneously with amplitudes of a few mmHg. Here we further characterized these oscillations. PO2 recordings were made from the whisker barrel cortex of six rabbits with acutely or chronically placed polarographic electrodes. Measurements were made while rabbits were awake and while anesthetized with isoflurane, during air breathing, and during 100 % oxygen inspiration. In awake rabbits, 90 % of the power was between 0 and 20 cycles per minute (cpm), not uniformly distributed over this range, but with a peak frequently near 10 cpm. This was much slower than heart or respiratory rhythms and is similar to the frequency content observed in other tissues. During hyperoxia, total power was higher than during air-breathing, and the dominant frequencies tended to shift toward lower values (0–10 cpm). These observations suggest that at least the lower frequency fluctuations represent efforts by the circulation to regulate local PO2. There were no consistent changes in total power during 0.5 or 1.5 % isoflurane anesthesia, but the power shifted to lower frequencies. Thus, both hyperoxia and anesthesia cause characteristic, but distinct, changes in spontaneous fluctuations. These PO2 fluctuations may be caused by vasomotion, but other factors cannot be ruled out.

Sublethal effects of pesticides in insects can be observed through physiological changes, which are commonly estimated by metabolic rate and respiratory patterns, more precisely by the patterns of discontinuous gas-exchange (DGE) cycles. The aim of the present research was to study the effect of some low concentrations of Fastac 50 EC on the cycles of CO2 release and respiratory water loss rates (WLR) in bumble bee Bombus terrestris L. foragers. Bumble bees were dipped into 0.004% and 0.002% Fastac 50 EC solution. Flow-through respirometry was used to record the respiration and WLR 3 h before and after the treatment. The respirometry was combined with infrared actography to enable simultaneous recording of abdominal movements. Our results show that Fastac 50 EC has an after-effect on bumble bee respiratory rhythms and muscle activity but does not affect WLR. Treatment with 0.004% Fastac 50 EC solution resulted in disappearance of the respiration cycles; also the lifespan of treated bumble bees was significantly shorter. Treatment with 0.002% Fastac 50 EC solution had no significant effect on respiration patterns or longevity. We found no evidence for the DGE cycles functioning as a water saving mechanism. 2012 Elsevier Ltd. All rights reserved.

Neurons in the pre-Botzinger complex within the mammalian brain stem play important roles in the generation of respiratory rhythms. Experimental observations show that some neurons can exhibit novel mixed bursting activities. In this paper, based on a mathematical model proposed by Butera, we show how the mixed bursting activities depend on the potassium current in the coupled pre-Botzinger complex. Using fast-slow decomposition and bifurcation analysis, we investigate the dynamics of mixed bursting, as well as the mechanisms of transition between different mixed bursting patterns. We find that mixed bursting involves different bistability, and it is the transition state of two types of regular burstings.

Recently, the technique of fish bioassay has attracted attention as a method for constant monitoring of aquatic contamination. The respiratory rhythms of fish are considered to be an efficient indicator for the monitoring of water quality, since they are sensitive to chemicals and can be measured indirectly from the bioelectric signals generated by their breathing. However, no method has yet been established to measure signals in small free-swimming fish. In this article, we propose a system to measure bioelectric signals in small fish and monitor the frequency component in real time. To cover the large measurement range required in a free-swimming environment, the signals are measured using multiple electrodes. Further, the system focuses on the frequency component of the signal to assess the condition of the fish using frequency analysis and a band-pass filter. Experiments were conducted with the purpose of enabling remote sensing and environment estimation. First, it was verified that the measured signals were synchronized with the breathing of the fish. Then, a remote sensing experiment was performed using medaka (Oryzias latipes) that were allowed to swim freely in a measurement aquarium. The results confirmed that bioelectric signals which were synchronized with breathing could be measured in unconstrained and noninvasive conditions.

High-frequency oscillations may be signatures of the basic mechanisms underlying the neurogenesis of various patterns of automatic ventilatory activity. These high-frequency oscillations in phrenic activity differ greatly in eupnoea and gasping, implying different mechanisms of neurogenesis. In a decerebrate, in situ preparation of the rat, the peak frequency of high-frequency oscillations fell in apneusis following removal of the rostral pons. Following removal of all pons, phrenic discharge had a mixed pattern of gasps and multiple bursts; some of the latter were incrementing, as in eupnoea. Regardless of pattern, peak frequencies were significantly below those which were found during eupnoea, apneusis or gasping of the decerebrate preparation. Results do not support the concept that ‘non-gasping’ rhythmic patterns that can be recorded following a removal of pons are generated by the same mechanisms as those generating eupnoea. Indeed, both pons and medulla appear essential for all aspects of eupnoea to be expressed.

Fast respiratory rhythms include medium- (MFO) and high-frequency oscillations (HFO), which are much faster than the fundamental breathing rhythm. According to previous studies, HFO is characterized by high coherence (Coh) in phrenic (Ph) nerve activity, thereby providing a means of distinguishing between these two types of oscillations. Changes in Coh between the Ph and hypoglossal (XII) nerves during the transition from normal eupnic breathing to gasping have not been characterized. Experiments were performed on nine unanesthetized, chemo- and barodenervated, decerebrate adult rats, in which sustained asphyxia elicited hyperpnea and gasping. A gated time-frequency Coh analysis was developed and applied to whole Ph and medial XII nerve recordings. The results showed dynamic Ph-Ph Coh during eupnea, including MFO and HFO. XII-XII Coh during eupnea was broadband and included four distinct peaks, with low-frequency Coh dominating the epochs preceding the onset of Ph activity. During gasping, only MFO-peaks were present in Ph-Ph Coh. Bilateral XII activity showed a significant reduction in Coh and a shift toward lower frequencies during gasping. In contrast, contralateral Ph-XII Coh progressively increased during state changes from eupnea to gasping, a tendency mirrored in the startup part of the Ph activity. These data suggest significant hypoxia/hypercapnia-induced alterations in synchronization between respiratory outputs during the transition from eupnea to gasping, reflecting a reconfiguration of the respiratory network and/or alterations in the circuitry associated with the motor pools, including dynamic coupling between outputs.

Effects of temperature and level of illumination on cardiac and respiratory rhythms have been analyzed in the juvenile Atlantic salmon Salmo salar L. at different stages of ontogenesis. The study was carried out under field conditions, which allowed avoiding to a considerable degree the effect of artifacts due to chemical and physical properties of water and to fish transposition. The “handlinglp”-reaction of the fry cardiac and respiratory activities was examined. A statistically significant decrease of the respiration rate (RR) by the 30th min and of the heart rate (HR) by the 15th min of experiment was revealed. A more expressed reaction of the decrease of cardiac and respiratory activities after transfer to the working chamber was found in juvenile salmons at early stages of their development. A linear dependence of frequency characteristics of electrocardiograms and electropneumograms (ECG and EPG) was shown in parrs and smolts on temperature in the range from 4 to 24°C. According to reaction of the respiratory system of smolts there was identified a signaling significance of the illumination level in the range of 10–20 kLx, which is confirmed by data on fish behavior in nature. Study of the changes in EEG and EPG allowed suggesting the presence of correlation of frequency characteristics of cardiac and respiratory activities of juvenile salmons with the metabolic level. However, moments of fundamental organism rearrangement in smolts are to be identified, which complicates the use of RR and HR as the measure of the metabolic level at this stage of the Atlantic salmon development.

Recent research from a dynamical and complex systems perspective has shown that loss of complexity and variability may characterize changes in biological function due to aging and disease. We provide an overview of the empirical evidence for the functional role of variability in the stability and adaptability of human gait. This evidence is derived from research on coordination within the motor system as well as between different physiological systems, such as in the coupling between locomotor and respiratory rhythms. Coordinative analyses of relative phase between segments of the lower extremities and between pelvis, trunk, and head are shown to be instrumental in pinpointing age and disease related changes in gait. These analyses also provide powerful tools in uncovering the different compensatory strategies available to older individuals and those suffering from neurological and orthopedic disorders.

In the pond snail Lymnaea stagnalis, a firm phase-locked coupling of pneumostome movements to the locomotor cycle was observed during terrestrial locomotion, thus demonstrating that the coordination between locomotor and respiratory rhythms is a natural behavioral event in this animal. The results of computational modelling suggest a possible scheme of coordination between these motor rhythms which is based on inhibitory projection from the central pattern generator for locomotion to that for respiration. These findings allow the neuronal mechanisms underlying coordination of two rhythmic behaviors to be investigated.

Although the terms burrowing and burying are often used interchangeably in the literature, there are clear distinctions between these two types of behaviour in terms of their ecological, mechanical and physiological implications. Both types of behaviour are widely observed in the Brachyura. In comparison to the well researched area of burrowing in crabs, information on burying is relatively dispersed. This review will examine the extent of burying behaviour in brachyurans, and the physiological and ecological consequences of the behaviour within the group. At least nine of the 50 families of brachyuran crabs have either been observed to bury in soft substrata or are suspected, on morphological grounds, of burying. There appears to be no specific morphological adaptations for burying in brachyurans, apart from those features associated with respiration whilst buried in the sediment. Buried individuals must ensure constant access to oxygenated water in the face of mechanical problems resulting from direct contact with the sediment, i.e., the threat of clogging. Burying taxa deal with this challenge through accessory respiratory channels and altered respiratory rhythms. The evolutionary implication of the burying habit is equivocal. Burying taxa are amongst the most speciose and numerically dominant brachyuran groups in marine systems, all reaching their greatest diversity and abundance in soft substrata. Burying may be an ancestral condition, with many of these groups evolving in habitats characterized by soft sediment.

Cardiac and respiratory rhythms are known to exhibit a modest degree of phase synchronization, which is affected by age, diseases, and other factors. We study the fine temporal structure of this synchrony in healthy young, healthy elderly, and elderly subjects with coronary artery disease. We employ novel time-series analysis to explore how phases of oscillations go in and out of the phase-locked state at each cycle of oscillations. For the first time we show that cardiorespiratory system is engaged in weakly synchronized dynamics with a very specific temporal patterning of synchrony: the oscillations go out of synchrony frequently, but return to the synchronous state very quickly (usually within just one cycle of oscillations). Properties of synchrony depended on the age and disease status. Healthy subjects exhibited more synchrony at the higher (1:4) frequency-locking ratio between respiratory and cardiac rhythms, while subjects with coronary artery disease exhibited relatively more 1:2 synchrony. However, multiple short desynchronization episodes prevailed regardless of age and disease status. The same average synchrony level could alternatively be achieved with few long desynchronizations, but this was not observed in the data. This implies functional importance of short desynchronizations dynamics. These dynamics suggest that a synchronous state is easy to create if needed, but is also easy to break. Short desynchronizations dynamics may facilitate the mutual coordination of cardiac and respiratory rhythms by creating intermittent synchronous episodes. It may be an efficient background dynamics to promote adaptation of cardiorespiratory coordination to various external and internal factors., 33 pages, 5 figures. In press at Am J Physiol-Heart C

The aim of the study was to investigate characteristics of low-frequency components in respiration. Sixteen healthy term infants were examined from the first day up to the 6th month of life. The respirogram, instantaneous respiratory frequency and respiratory amplitude of undisturbed segments of quiet sleep phases and periodic breathing (PB) were analysed via fast Fourier transformation. The peak frequency (PF) in the low-frequency range (0.04-0.2 Hz) was determined. PF for PB ranged from 0.056 to 0.1 Hz. Further, low-frequency rhythms (LFR) of the respirogram, which were stable during the recordings as well as during development, were found ranging from 0.045 to 0.067 Hz. The LFR of the respirogram is correlated with rhythmic changes in the relationship between inspiratory and expiratory amplitudes. The frequency of the LFR was significantly lower than that of the PB. The data indicate that LFR and PB are low-frequency respiratory rhythms which are separately controlled and perform independently.

Multimedia quality evaluation recently started to take into account also analysis of emotional response to audiovisual stimuli. This is especially true for quality of experience evaluation. Self-assessed affective reports are commonly used for this purpose. Nevertheless, measuring emotions via physiological measurement might be also considered as it could limit the effects of cognitive bias due to self-report following the rule that your body cannot lie. In this paper we first review in the context of emotion assessment, common physiological measurements such as cardiac and respiratory rhythms, Electroencephalography (EEG) and Galvanic Skin Resistance (GSR); more advanced techniques as infrared thermography or blood perfusion with laser Doppler flowmetry. Then we present some results of electrophysiological measures related to the evaluation of emotions triggered by sounds. H.6 — Speech, Image and Video Processing: Models for Signal and Image Processing.

The pre-Bötzinger complex of the mammalian brain stem plays a crucial role in the respiratory rhythms generation. Neurons within the pre-Bötzinger complex have been found experimentally to yield different firing activities. In this paper, we study the spiking and bursting activities related to the respiratory rhythms in the pre-Bötzinger complex based on a mathematical model proposed by Butera. Using the one-dimensional first recurrence map induced by dynamics, we investigate the different bursting patterns and their transition of the pre-Bötzinger complex neurons based on the Butera model, after we derived a one-dimensional map from the dynamical characters of the differential equations, and we obtained conditions for the transition of different bursting patterns. These analytical results were verified through numerical simulations. We conclude that the one-dimensional map contains similar rhythmic patterns as the Butera model and can be used as a simpler modeling tool to study fast–slow models like pre-Bötzinger complex neural circuit.

In conscious adult rabbits, "classical" respiratory sinus arrhythmia does not occur because the respiratory frequency (RF) always exceeds half the heart rate (HR). However, slow HR fluctuations, not synchronous with the respiratory rhythm but affected by it, occur systematically. We have shown that these can be calculated by using aliasing rules. During general anaesthesia, when the RF decreases so that respiratory frequency is less than half the heart rate, classical respiratory sinus arrhythmia occurs and can be greatly reduced by vagal blockade. The slow HR fluctuations which are not synchronous with the respiratory rhythms, but are affected by it are mainly vagally mediated, because vagal blockade virtually eliminates them.

The mechanisms by which telencephalic areas affect motor activities are largely unknown. They could either take over motor control from downstream motor circuits or interact with the intrinsic dynamics of these circuits. Both models have been proposed for telencephalic control of respiration during learned vocal behavior in birds. The interactive model postulates that simple signals from the telencephalic song control areas are sufficient to drive the nonlinear respiratory network into producing complex temporal sequences. We tested this basic assumption by electrically stimulating telencephalic song control areas and analyzing the resulting respiratory patterns in zebra finches and in canaries. We found strong evidence for interaction between the rhythm of stimulation and the intrinsic respiratory rhythm, including naturally emerging subharmonic behavior and integration of lateralized telencephalic input. The evidence for clear interaction in our experimental paradigm suggests that telencephalic vocal control also uses a similar mechanism. Furthermore, species differences in the response of the respiratory system to stimulation show parallels to differences in the respiratory patterns of song, suggesting that the interactive production of respiratory rhythms is manifested in species-specific specialization of the involved circuitry. © 2012 the American Physiological Society. Fil: Méndez, Jorge M.. University of Utah; Estados Unidos Fil: Mindlin, Bernardo Gabriel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Goller, Franz. University of Utah; Estados Unidos

published in Photodiagnosis and Photodynamic Therapy, 8(2):149, 2011; International audience; Bladder PDT, the first FDA indication, has been abandoned in favour of photodiagnosis with ALA or derivatives. Major drawback of this treatment modality is prolonged and severe irritative bladder symptoms, due to lack of selectivity of the drug and generalized urothelial necrosis. Low fluence rates are known to potentiate therapeutic efficacy due to an oxygen sparing regime. We have evaluated the effect of low fluence rate PDT on therapeutic outcome and side effects in rat tumor bearing bladders. Bladders were instilled with 8 mM hexylaminolevulinate and illuminated with 635 nm light to a total light dose of 20 or 15 J/cm2 at 100 or 15 mW/cm2, 5 rats per group. Fluence rates of 15 mW/cm2 did not provoke enhancement of cardiac and respiratory rhythms as opposed to 100 mW/cm2, neither was hematuria observed post treatment. Macroscopic aspects of bladders at 100 mW/cm2 show thickened bladders with hemorrhagic areas whereas 15 J/cm2 does not alter macroscopic features. Pathology revealed the absence of viable superficial tumors, irrespective of irradiation conditions. Inflammatory volume was calculated to be 96 a.u. for high fluence high light dose, reduced to 18 a.u. when reducing the light dose and 12 a.u. for the low fluence rates, irrespective of the light dose. Normal urothelial is preserved over the total bladder in case of 15 mW/cm2, whereas major portions of the bladder show absence of reduction of cell layers at 100 mW/cm2. Low fluence rate PDT does not hamper therapeutic efficacy and minimizes local side effects in rats.

The workers of the stingless bee, Melipona quadrifasciata, assume different tasks during their adult life. Newly emerged individuals remain inside the nest, without contact with the external environment. Maturing workers go to more peripheral regions and only the oldest, the foragers, leave the nest. As this diversity of activities implies different metabolic patterns, oxygen consumption has been measured in workers of three different ages: 24–48 h (nurses), 10–15 days (builders), and older than 25 days (foragers). Oxygen consumption of individually isolated workers was determined by intermittent respirometry, under constant darkness and temperature of 25 ± 1°C. Sets of 24-h measurements were obtained from individuals belonging to each of the three worker groups. Rhythmicity has been assessed in the daily (24 h) and ultradian (5–14 h) domains. This experimental design allowed detection of endogenous rhythms without the influence of the social group and without inflicting stress on the individuals, as would be caused by their longer isolation from the colony. Significant 24-h rhythms in oxygen consumption were present in nurses, builders and foragers; therefore, workers are rhythmic from the age of 24–48 h. However, the amplitude of the circadian rhythm changed according to age: nurses showed the lowest values, while foragers consistently presented the largest ones, about ten times larger than the amplitude of nurses’ respiratory rhythm. Ultradian frequencies were detected for all worker groups, the power and frequencies of which varied little with age. This means that the ultradian strength was relatively larger in nurses and apparently maintains some relationship with the queen’s oviposition episodes.

The pre-Botzinger complex (preBotc) in the mammalian brainstem has an important role in generating respiratory rhythms. An influential differential equation model for the activity of individual neurons in the preBotc yields transitions from quiescence to bursting to tonic spiking as a parameter is varied. Further, past work has established that bursting dynamics can arise from a pair of tonic model cells coupled with synaptic excitation. In this paper, we analytically derive one- and two-dimensional maps from the differential equations for a self-coupled neuron and a two-neuron network, respectively. Using a combination of analysis and simulations of these maps, we explore the possible forms of dynamics that the model networks can produce as well as which transitions between dynamic regimes are mathematically possible.

This study focused on the neurogenic mechanisms of coordination between locomotor and respiratory rhythms. The aim of the present study was to investigate the influence of peripheral neurogenic drive from moving limbs, and the level of consciousness, on locomotor-respiratory coordination. Subjects performed movement for 20 min in a supine position using a bicycle ergometer. The movement comprised three types of leg movements: active (loadless) movement, passive movement while awake and passive movement during sleep. We found no difference between active and passive movement in the degree of coordination. However, the degree of coordination during sleep was significantly lower than that while awake (p

Dynamic changes in physiologic systems have become an increasingly important topic in biomedical signal processing. To demonstrate a novel approach to this type of analysis, we recorded the cardiac and respiratory rhythms of six normal subjects over 5 minutes. We used cross-wavelet transforms to identify any correlations between these signals and then a unique approach to surrogate data generation in the frequency domain to confirm the statistical significance of the correlations that were found. The cross-wavelet transform provides a means of statistically quantifying weak correlations between systems that might otherwise not show significant interactions, while the method of surrogate data generation is a robust way of confirming a true physiological relationship.

Protein concentration in a cell increases during stimulation of ultradian rhythms by multifrequency irritation corresponding to the hierarchy of cell biorhythms. Physiotherapy synchronous with patient's pulse and respiratory rhythms accelerates regeneration of postoperative wounds and trophic ulcers. Rhythms of physiological regeneration stimulate the repair regeneration.

Neurons with pacemaker properties have been described in several neural networks. Nonlinearity of their bursting activity might enable them to facilitate onset of excitatory states or to synchronize neuronal ensembles. However, whether such neurons are essential for generating a network activity pattern remains mostly unknown. For the mammalian respiratory network, located in the preBotzinger complex (PBC), two types of pacemaker neurons have been described. Bursting properties of one type of pacemakers rely on the riluzole-sensitive persistent sodium current, whereas bursting mechanisms of a second type are sensitive to Cd 2+ and flufenamic acid, a calcium-dependent nonspecific cationic current blocker. The role of pacemakers in the generation of respiratory rhythms in vitro is state dependent. Under control conditions, the respiratory network generates fictive eupneic activity; this activity depends on both riluzole-sensitive and flufenamic acid-sensitive pacemakers. During hypoxia, fictive eupneic activity is supplanted by the neural correlate of gasping and only riluzole-sensitive pacemaker neurons appear to be necessary for this rhythm. Thus, at least two types of pacemaker bursting mechanisms are present in the PBC and underlie fictive eupnea, whereas only one burst mechanism seems to be critical for gasping generation in vitro.

We tested whether pre-assigned arm movements performed in a group setting spontaneously synchronized and whether synchronization extended to heart and respiratory rhythms. We monitored arm movements, respiration and electrocardiogram at rest and during spontaneous, music and metronome-associated arm-swinging. No directions were given on whether or how the arm swinging were to be synchronized between participants or with the external cues. Synchronization within 3 groups of 10 participants studied collectively was compared with pseudo-synchronization of 3 groups of 10 participants that underwent an identical protocol but in an individual setting. Motor synchronization was found to be higher in the collective groups than in the individuals for the metronome-associated condition. On a repetition of the protocol on the following day, motor synchronization in the collective groups extended to the spontaneous, un-cued condition. Breathing was also more synchronized in the collective groups than in the individuals, particularly at rest and in the music-associated condition. Group synchronization occurs without explicit instructions, and involves both movements and respiratory control rhythms.

Entrainment between two rhythms is a very well-known phenomenon in the theory of nonlinear dynamics. Although heart and respiration influence each other by several mechanisms, and though modulation of heart rate by respiration is a very well-known and investigated phenomenon, there are surprisingly few indications of true entrainment between the two rhythms. This absence might be due to an insufficient coupling strength or to disturbances by other physiological rhythms. Nonetheless, we sometimes observe intermittent phases where cardiac and respiratory rhythms run in parallel; i.e., where both rhythms seem to be entrained. However, it is not obvious how to decide whether this effect is true entrainment or whether it is just quasi-entrainment that occurs when two rhythms have an approximate frequency ratio of for example, 4:1. Therefore, we use a surrogate-data technique to determine the probability of quasi-entrainment as a function of its duration. This probability can be used to obtain a significance level for true entrainment.

In rats, respiratory neurons in the medulla oblongata are arranged in longitudinally distributed groups that are duplicated on each side of the neuraxis. Our aim was to determine whether respiratory rhythm is generated independently by each side. We made a complete mid-saggital section of the medulla oblongata, 3.5 mm rostral and 3.5 mm caudal to the obex, in decerebrate, vagotomized, and paralysed adult rats. Respiratory rhythm, monitored by recording the activity of both left and right phrenic nerves, was maintained and became asynchronous between the left and right sides. We concluded that in the adult rat each half of the medulla oblongata is capable of generating respiratory rhythm independently.

In this investigation an attempt is made to find the effects of controlled breathing on brain with the help of optical sensors mounted on the left and right temples of a subject. It has already been established that the brain activity can be monitored in terms of arterial blood volumetric changes to the left and right hemispheres of the brain recorded with the help of optical sensors. To investigate the influence of controlled breathing, an expert in controlled breathing (pranayama) is chosen as the subject. Pranayama is believed to be the controlled intake and outflow of breath in a firmly established posture. Some types of pranayama are believed to relive mental stress. While the subject is practicing one such type of breath control, arterial blood volume changes in the brain are recorded using optical sensors mounted on the left and right temples of the subject. From these measurements at the beginning and end of the pranayama exercise, it could be noticed that the subject could induce changes in the cardiac and respiratory rhythms by controlled breathing. Rhythmic phenomena in the skin perfusion in the vicinity of the brian are also studied when the subject is holding his breath. The arterial blood volume changes to the left and right hemispheres of the brain, as monitored by the optical sensors during this period, exhibit asymmetric reaction when the subject is holding his breath. An attempt is made to understand whether these changes induced by stoppage of breathing are 'chaotic' or 'adaptive' in nature.

The coordination of ventilatory and locomotor rhythms has been documented in many birds and mammals. It has been suggested that the physiological significance of such coordination is a reduction in the cost of ventilation which confers an energetic advantage to the animal. We tested this hypothesis by measuring the external work required to ventilate birds mechanically during simulated flight. Patterns of wing motion and breathing were produced in which the relationship between wing motion and breathing was in phase and out of phase with the relationship seen during normal flight. Differences between the energetic costs of in-phase versus out-of-phase synchronization were particularly large (26 %) in instances where locomotion and respiration frequency were synchronized at one breath per wingbeat. The saving (9 %) obtained from in-phase versus out-of-phase coordination at the 3:1 coordination ratio seen normally in free-flying Canada geese was smaller but still supported the hypothesis that there is a significant net saving obtained from reducing the mechanical interference between locomotion and ventilation by locomotor–respiratory coupling.