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Sample records for spontaneous brain rhythms

  1. Brain-wide slowing of spontaneous alpha rhythms in mild cognitive impairment

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    Pilar eGarcés

    2013-12-01

    Full Text Available The neurophysiological changes associated with Alzheimer’s Disease (AD and Mild Cognitive Impairment (MCI include an increase in low frequency activity, as measured with electroencephalography or magnetoencephalography (MEG. A relevant property of spectral measures is the alpha peak, which corresponds to the dominant alpha rhythm. Here we studied the spatial distribution of MEG resting state alpha peak frequency and amplitude values in a sample of 27 MCI patients and 24 age-matched healthy controls. Power spectra were reconstructed in source space with linearly constrained minimum variance beamformer. Then, 88 Regions of Interest (ROIs were defined and an alpha peak per ROI and subject was identified. Statistical analyses were performed at every ROI, accounting for age, sex and educational level. Peak frequency was significantly decreased (p< 0.05 in MCIs in many posterior ROIs. The average peak frequency over all ROIs was 9.68±0.71 Hz for controls and 9.05±0.90 Hz for MCIs and the average normalized amplitude was (2.57±0.59•10-2 for controls and (2.70±0.49•10-2 for MCIs. Age and gender were also found to play a role in the alpha peak, since its frequency was higher in females than in males in posterior ROIs and correlated negatively with age in frontal ROIs. Furthermore, we examined the dependence of peak parameters with hippocampal volume, which is a commonly used marker of early structural AD-related damage. Peak frequency was positively correlated with hippocampal volume in many posterior ROIs. Overall, these findings indicate a pathological alpha slowing in MCI.

  2. Spontaneous Slow Fluctuation of EEG Alpha Rhythm Reflects Activity in Deep-Brain Structures: A Simultaneous EEG-fMRI Study.

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    Kei Omata

    Full Text Available The emergence of the occipital alpha rhythm on brain electroencephalogram (EEG is associated with brain activity in the cerebral neocortex and deep brain structures. To further understand the mechanisms of alpha rhythm power fluctuation, we performed simultaneous EEGs and functional magnetic resonance imaging recordings in human subjects during a resting state and explored the dynamic relationship between alpha power fluctuation and blood oxygenation level-dependent (BOLD signals of the brain. Based on the frequency characteristics of the alpha power time series (APTS during 20-minute EEG recordings, we divided the APTS into two components: fast fluctuation (0.04-0.167 Hz and slow fluctuation (0-0.04 Hz. Analysis of the correlation between the MRI signal and each component revealed that the slow fluctuation component of alpha power was positively correlated with BOLD signal changes in the brain stem and the medial part of the thalamus and anterior cingulate cortex, while the fast fluctuation component was correlated with the lateral part of the thalamus and the anterior cingulate cortex, but not the brain stem. In summary, these data suggest that different subcortical structures contribute to slow and fast modulations of alpha spectra on brain EEG.

  3. Spontaneous synchronized tapping to an auditory rhythm in a chimpanzee.

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    Hattori, Yuko; Tomonaga, Masaki; Matsuzawa, Tetsuro

    2013-01-01

    Humans actively use behavioral synchrony such as dancing and singing when they intend to make affiliative relationships. Such advanced synchronous movement occurs even unconsciously when we hear rhythmically complex music. A foundation for this tendency may be an evolutionary adaptation for group living but evolutionary origins of human synchronous activity is unclear. Here we show the first evidence that a member of our closest living relatives, a chimpanzee, spontaneously synchronizes her movement with an auditory rhythm: After a training to tap illuminated keys on an electric keyboard, one chimpanzee spontaneously aligned her tapping with the sound when she heard an isochronous distractor sound. This result indicates that sensitivity to, and tendency toward synchronous movement with an auditory rhythm exist in chimpanzees, although humans may have expanded it to unique forms of auditory and visual communication during the course of human evolution.

  4. Voluntary breath holding affects spontaneous brain activity measured by magnetoencephalography

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    Schellart, N. A.; Reits, D.

    1999-01-01

    Spontaneous brain activity was measured by multichannel magnetoencephalography (MEG) during voluntary breath holds. Significant changes in the activity are limited to the alpha rhythm: 0.25 Hz frequency increase and narrowing of the peak. The area of alpha activity shifts slightly toward (fronto-)

  5. Brain networks for integrative rhythm formation.

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    Michael H Thaut

    2008-05-01

    Full Text Available Performance of externally paced rhythmic movements requires brain and behavioral integration of sensory stimuli with motor commands. The underlying brain mechanisms to elaborate beat-synchronized rhythm and polyrhythms that musicians readily perform may differ. Given known roles in perceiving time and repetitive movements, we hypothesized that basal ganglia and cerebellar structures would have greater activation for polyrhythms than for on-the-beat rhythms.Using functional MRI methods, we investigated brain networks for performing rhythmic movements paced by auditory cues. Musically trained participants performed rhythmic movements at 2 and 3 Hz either at a 1:1 on-the-beat or with a 3:2 or a 2:3 stimulus-movement structure. Due to their prior musical experience, participants performed the 3:2 or 2:3 rhythmic movements automatically. Both the isorhythmic 1:1 and the polyrhythmic 3:2 or 2:3 movements yielded the expected activation in contralateral primary motor cortex and related motor areas and ipsilateral cerebellum. Direct comparison of functional MRI signals obtained during 3:2 or 2:3 and on-the-beat rhythms indicated activation differences bilaterally in the supplementary motor area, ipsilaterally in the supramarginal gyrus and caudate-putamen and contralaterally in the cerebellum.The activated brain areas suggest the existence of an interconnected brain network specific for complex sensory-motor rhythmic integration that might have specificity for elaboration of musical abilities.

  6. Brain rhythms reveal a hierarchical network organization.

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    G Karl Steinke

    2011-10-01

    Full Text Available Recordings of ongoing neural activity with EEG and MEG exhibit oscillations of specific frequencies over a non-oscillatory background. The oscillations appear in the power spectrum as a collection of frequency bands that are evenly spaced on a logarithmic scale, thereby preventing mutual entrainment and cross-talk. Over the last few years, experimental, computational and theoretical studies have made substantial progress on our understanding of the biophysical mechanisms underlying the generation of network oscillations and their interactions, with emphasis on the role of neuronal synchronization. In this paper we ask a very different question. Rather than investigating how brain rhythms emerge, or whether they are necessary for neural function, we focus on what they tell us about functional brain connectivity. We hypothesized that if we were able to construct abstract networks, or "virtual brains", whose dynamics were similar to EEG/MEG recordings, those networks would share structural features among themselves, and also with real brains. Applying mathematical techniques for inverse problems, we have reverse-engineered network architectures that generate characteristic dynamics of actual brains, including spindles and sharp waves, which appear in the power spectrum as frequency bands superimposed on a non-oscillatory background dominated by low frequencies. We show that all reconstructed networks display similar topological features (e.g. structural motifs and dynamics. We have also reverse-engineered putative diseased brains (epileptic and schizophrenic, in which the oscillatory activity is altered in different ways, as reported in clinical studies. These reconstructed networks show consistent alterations of functional connectivity and dynamics. In particular, we show that the complexity of the network, quantified as proposed by Tononi, Sporns and Edelman, is a good indicator of brain fitness, since virtual brains modeling diseased states

  7. How does the brain create rhythms?

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    Szirmai, Imre

    2010-01-30

    Connection was found between rhythmic cortical activity and motor control. The 10 Hz micro-rhythm and the 20-30 Hz bursts represent two functional states of the somatomotor system. A correspondence of the central micro-rhythm of the motor cortex and the physiological hand tremor (8-12 Hz) is presumed. The precise tuning of the motor system can be estimated by the frequency of repetitive finger movements. In complex tapping exercise, the index finger is the most skillful, the 3rd, 4th and 5th fingers keep rhythm with less precision. It was found that the organization of mirror movements depends on the cortical representation of fingers. Mirror finger movements are more regular if the subject begins the motor action with the 5th (small) finger. Concerning cortical regulation of finger movements, it was suggested that there are two time-keeping systems in the brain; one with a sensitivity above and another with a sensitivity below the critical frequency of 3 Hz. The preferred meter which helps to maintain synchronous finger movements is the cadence of 4/4 and 8/8. We observed that the unlearned inward-outward sequential finger movement was equally impaired in nonmusician controls and patients with Parkinson-disease. In movement disorders, the ability of movement and the "clock-mechanism" are equally involved. The polyrhythmic finger movement is not our inborn ability, it has to be learned. The "timer" function, which regulates the rhythmic movement, is presumably localised in the basal ganglia or in the cerebellum. The meter of the music is built on the reciprocal values of 2 raised to the second to fifth power (1/1(2), 1/2(2), 1/2(3), 1/2(4), 1/2(5)). The EEG frequencies that we consider important in the regulation of conscious motor actions are approximately in the same domain (4, 8, 16, 32, 64 Hz). During music performance, an important neural process is the coupling of distant brain areas. Concerning melody, the musical taste of Europeans is octave-based. Musical

  8. High-Tc superconducting quantum interference device recordings of spontaneous brain activity: Towards high-Tc magnetoencephalography

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    Öisjöen, F.; Schneiderman, J. F.; Figueras, G. A.; Chukharkin, M. L.; Kalabukhov, A.; Hedström, A.; Elam, M.; Winkler, D.

    2012-03-01

    We have performed single- and two-channel high transition temperature (high-Tc) superconducting quantum interference device (SQUID) magnetoencephalography (MEG) recordings of spontaneous brain activity in two healthy human subjects. We demonstrate modulation of two well-known brain rhythms: the occipital alpha rhythm and the mu rhythm found in the motor cortex. We further show that despite higher noise-levels compared to their low-Tc counterparts, high-Tc SQUIDs can be used to detect and record physiologically relevant brain rhythms with comparable signal-to-noise ratios. These results indicate the utility of high-Tc technology in MEG recordings of a broader range of brain activity.

  9. Meanfield modeling of propofol-induced changes in spontaneous EEG rhythms

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    Hindriks, Rikkert; van Putten, Michel Johannes Antonius Maria

    2012-01-01

    During the maintenance period of propofol-induced general anesthesia, specific changes in spontaneous EEG rhythms can be observed. These comprise increased delta and theta power and the emergence of alpha oscillations over frontal regions. In this study we use a meanfield model of the

  10. Predicting sex from brain rhythms with deep learning.

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    van Putten, Michel J A M; Olbrich, Sebastian; Arns, Martijn

    2018-02-15

    We have excellent skills to extract sex from visual assessment of human faces, but assessing sex from human brain rhythms seems impossible. Using deep convolutional neural networks, with unique potential to find subtle differences in apparent similar patterns, we explore if brain rhythms from either sex contain sex specific information. Here we show, in a ground truth scenario, that a deep neural net can predict sex from scalp electroencephalograms with an accuracy of >80% (p deep net filter layers, showing that fast beta activity (20-25 Hz) and its spatial distribution is a main distinctive attribute. This demonstrates the ability of deep nets to detect features in spatiotemporal data unnoticed by visual assessment, and to assist in knowledge discovery. We anticipate that this approach may also be successfully applied to other specialties where spatiotemporal data is abundant, including neurology, cardiology and neuropsychology.

  11. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging.

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    Nozaradan, Sylvie

    2014-12-19

    The ability to perceive a regular beat in music and synchronize to this beat is a widespread human skill. Fundamental to musical behaviour, beat and meter refer to the perception of periodicities while listening to musical rhythms and often involve spontaneous entrainment to move on these periodicities. Here, we present a novel experimental approach inspired by the frequency-tagging approach to understand the perception and production of rhythmic inputs. This approach is illustrated here by recording the human electroencephalogram responses at beat and meter frequencies elicited in various contexts: mental imagery of meter, spontaneous induction of a beat from rhythmic patterns, multisensory integration and sensorimotor synchronization. Collectively, our observations support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. More generally, they highlight the potential of this approach to help us understand the link between the phenomenology of musical beat and meter and the bias towards periodicities arising under certain circumstances in the nervous system. Entrainment to music provides a highly valuable framework to explore general entrainment mechanisms as embodied in the human brain. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. Brain Rhythms Connect Impaired Inhibition to Altered Cognition in Schizophrenia

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    Pittman-Polletta, Benjamin R.; Kocsis, Bernat; Vijayan, Sujith; Whittington, Miles A.; Kopell, Nancy J.

    2015-01-01

    In recent years, schizophrenia research has focused on inhibitory interneuron dysfunction at the level of neurobiology, and on cognitive impairments at the psychological level. Reviewing both experimental and computational findings, we show how the temporal structure of the activity of neuronal populations, exemplified by brain rhythms, can begin to bridge these levels of complexity. Oscillations in neuronal activity tie the pathophysiology of schizophrenia to alterations in local processing and large-scale coordination, and these alterations in turn can lead to the cognitive and perceptual disturbances observed in schizophrenia. PMID:25850619

  13. Brain MRI findings of spontaneous intracranial hypotension

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    Park, Won Kyu; Byun, Woo Mok; Cho, Jae Ho; Cho Kil Ho; Hwang, Mi Soo; Park, Bok Hwan [Yeungnam Univ. College of Medicine, Taegu (Korea, Republic of); Joo, Yang Gu [Keimyoung Univ. College of Medicine, Taegu (Korea, Republic of); Lee, Sang Jin [Soonchunhyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-09-01

    To evaluate brain MRI findings of spontaneous intracranial hypotension. A retrospective review of MRI findings was conducted on six patients with clinically proven spontaneous intracranial hypotension; no patient had a history of previous spinal puncture. Follow-up MRI was available in two patients, and to detect CSF leakage, radio-nuclide cisternography(n=3D5), myelography(n=3D1), and MR myelography(n=3D1) were performed. On contrast-enhanced T1WI, diffuse dural enhancement was seen in all cases, subdural hematoma or hygroma was seen in four cases, pituitary gland prominence in four, dural sinus dilatation in four, downward displacement of the cerebellar tonsil in two, downward displacement of the iter in one, and suprasellar and prepontine cistern effacement in two. In no patient was abnormal CSF leakage found. Although dural enhancement, as seen on MRI, is not specific, diffuse enhancement of the dura mater accompanied by subdural hematoma, hygroma, pituitary gland prominence, dural sinus dilatation, downward displacement of the cerebellar tonsil, or suprasellar and prepontine cistern effacement can strongly suggest intracranial hypotension.=20.

  14. Dynamic correlations between heart and brain rhythm during Autogenic meditation

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    Daekeun eKim

    2013-07-01

    Full Text Available This study is aimed to determine significant physiological parameters of brain and heart under meditative state, both in each activities and their dynamic correlations. Electrophysiological changes in response to meditation were explored in 12 healthy volunteers who completed 8 weeks of a basic training course in autogenic meditation. Heart coherence, representing the degree of ordering in oscillation of heart rhythm intervals, increased significantly during meditation. Relative EEG alpha power and alpha lagged coherence also increased. A significant slowing of parietal peak alpha frequency was observed. Parietal peak alpha power increased with increasing heart coherence during meditation, but no such relationship was observed during baseline. Average alpha lagged coherence also increased with increasing heart coherence during meditation, but, again, no significant relationship was observed at baseline. Relative alpha power increased with increasing heart coherence during both meditation and baseline periods. Heart coherence can be a cardiac marker for the meditative state and also may be a general marker for the meditative state since heart coherence is strongly correlated with EEG alpha activities. It is expected that increasing heart coherence and the accompanying EEG alpha activations, heart brain synchronicity, would help recover physiological synchrony following a period of homeostatic depletion.

  15. Theta Brain Rhythms Index Perceptual Narrowing in Infant Speech Perception

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    Alexis eBosseler

    2013-10-01

    Full Text Available The development of speech perception shows a dramatic transition between infancy and adulthood. Between 6 and 12 months, infants’ initial ability to discriminate all phonetic units across the worlds’ languages narrows—native discrimination increases while nonnative discrimination shows a steep decline. We used magnetoencephalography (MEG to examine whether brain oscillations in the theta band (4-8Hz, reflecting increases in attention and cognitive effort, would provide a neural measure of the perceptual narrowing phenomenon in speech. Using an oddball paradigm, we varied speech stimuli in two dimensions, stimulus frequency (frequent vs. infrequent and language (native vs. nonnative speech syllables and tested 6-month-old infants, 12-month-old infants, and adults. We hypothesized that 6-month-old infants would show increased relative theta power (RTP for frequent syllables, regardless of their status as native or nonnative syllables, reflecting young infants’ attention and cognitive effort in response to highly frequent stimuli (statistical learning. In adults, we hypothesized increased RTP for nonnative stimuli, regardless of their presentation frequency, reflecting increased cognitive effort for nonnative phonetic categories. The 12-month-old infants were expected to show a pattern in transition, but one more similar to adults than to 6-month-old infants. The MEG brain rhythm results supported these hypotheses. We suggest that perceptual narrowing in speech perception is governed by an implicit learning process. This learning process involves an implicit shift in attention from frequent events (infants to learned categories (adults. Theta brain oscillatory activity may provide an index of perceptual narrowing beyond speech, and would offer a test of whether the early speech learning process is governed by domain-general or domain-specific processes.

  16. Spontaneous theta rhythm and working memory co-variation during child development.

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    Rodriguez-Martinez, Elena I; Barriga-Paulino, Catarina I; Rojas-Benjumea, Maria A; Gómez, Carlos M

    2013-08-29

    The present study examines possible relationships between changes in electroencephalogram (EEG) power and in working memory (WM) due to brain maturation. Scores on the phonological loop, visuospatial sketchpad and executive components of WM, measured by the Working Memory Test Battery for Children (WMTB-C), were correlated with the power spectral density (PSD) values on the spontaneous EEG from 1 to 46 Hz. In order to control for non-specific processes of visuomotor abilities, the reaction time (RT) variable was measured with an Oddball task. One hundred and sixty seven subjects (82 males and 85 females) between 6 and 26 years old participated in the study. Three minutes of spontaneous EEG were recorded. The WMTB-C and the Oddball task were also administered. The scores on each WM component increased and the RT in the Oddball decreased with age, while PSD values in the different frequencies decreased with age. Significant negative correlations between each of the components and the PSD were obtained. The maximal negative correlations were obtained in the theta (4-7 Hz) range. A bivariate linear model including theta PSD and RT explained most of the WM variance due to age. The results suggest that spontaneous EEG maturation is closely related to WM maturation, particularly in the theta range. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Circadian rhythm disturbance after radiotherapy for brain tumor in infantile period

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    Kubota, Masaya; Shinozaki, Masako; Sasaki, Hideo.

    1993-01-01

    We report a 19-year-old man suffering from circadian sleep-wake (S-W) rhythm disturbance after total tumor resection and whole brain irradiation. The patient was diagnosed as having astrocytoma in the right temporal lobe by CT scan and angiography at the age of 6 months. After total tumor resection and whole brain irradiation ( 60 Co 60 Gy), he showed profound psychomotor retardation, endoclinologic dysfunction including hypothyroidism and growth hormone deficiency, and S-W rhythm disturbance. At the age of 19, brain MRI revealed asymmetrical low intensity in the hypothalamic region. On endoclinological examination panhypopituitarism due to primary hypothalamic lesion was evident. His S-W rhythm was disturbed; i.e., sleep periods were dispersedly distributed throughout 24 hours. So he showed a lethargic tendency in the daytime. All-day polysomnography revealed abnormal sleep structure such as the absence of sleep spindle and hump, peripheral apnea, snoring and low oxygen saturation. After L-thyroxine supplementation his daily activity improved gradually. The decrease in short time sleep and tendency of a free-running rhythm were observed and oxygen saturation improved remarkably. Peripheral apnea and snoring disappeared. This wakening effect of L-thyroxine administration may be due to improvement of hypothyroidism symptom such as myxoedematous pharynx. It also seems related to the alteration of the central S-W rhythm regulation, because free-running rhythm appeared after L-thyroxine administration. Vitamin B 12 (VB 12 ), which has been reported to be effective for S-W rhythm disorders, was not effective for our patient's free-running rhythm. Compared with the patients responding to VB 12 , our patient's organic brain damage was more evident radiologically and endoclinologically. Following the hypothesis that VB 12 has a potential to reinforce the entrainment of circadian rhythm, our patient's organic brain damage may include entrainment system. (author)

  18. Uncovering intrinsic modular organization of spontaneous brain activity in humans.

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    Yong He

    Full Text Available The characterization of topological architecture of complex brain networks is one of the most challenging issues in neuroscience. Slow (<0.1 Hz, spontaneous fluctuations of the blood oxygen level dependent (BOLD signal in functional magnetic resonance imaging are thought to be potentially important for the reflection of spontaneous neuronal activity. Many studies have shown that these fluctuations are highly coherent within anatomically or functionally linked areas of the brain. However, the underlying topological mechanisms responsible for these coherent intrinsic or spontaneous fluctuations are still poorly understood. Here, we apply modern network analysis techniques to investigate how spontaneous neuronal activities in the human brain derived from the resting-state BOLD signals are topologically organized at both the temporal and spatial scales. We first show that the spontaneous brain functional networks have an intrinsically cohesive modular structure in which the connections between regions are much denser within modules than between them. These identified modules are found to be closely associated with several well known functionally interconnected subsystems such as the somatosensory/motor, auditory, attention, visual, subcortical, and the "default" system. Specifically, we demonstrate that the module-specific topological features can not be captured by means of computing the corresponding global network parameters, suggesting a unique organization within each module. Finally, we identify several pivotal network connectors and paths (predominantly associated with the association and limbic/paralimbic cortex regions that are vital for the global coordination of information flow over the whole network, and we find that their lesions (deletions critically affect the stability and robustness of the brain functional system. Together, our results demonstrate the highly organized modular architecture and associated topological properties in

  19. Modulating spontaneous brain activity using repetitive transcranial magnetic stimulation

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    van der Werf, Y.D.; Sanz-Arigita, E.J.; Menning, S.; van den Heuvel, O.A.

    2010-01-01

    Background: When no specific stimulus or task is presented, spontaneous fluctuations in brain activity occur. Brain regions showing such coherent fluctuations are thought to form organized networks known as 'resting-state' networks, a main representation of which is the default mode network.

  20. Biological rhythms, higher brain function, and behavior: Gaps, opportunities, and challenges.

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    Benca, Ruth; Duncan, Marilyn J; Frank, Ellen; McClung, Colleen; Nelson, Randy J; Vicentic, Aleksandra

    2009-12-11

    Increasing evidence suggests that disrupted temporal organization impairs behavior, cognition, and affect; further, disruption of circadian clock genes impairs sleep-wake cycle and social rhythms which may be implicated in mental disorders. Despite this strong evidence, a gap in understanding the neural mechanisms of this interaction obscures whether biological rhythms disturbances are the underlying causes or merely symptoms of mental disorder. Here, we review current understanding, emerging concepts, gaps, and opportunities pertinent to (1) the neurobiology of the interactions between circadian oscillators and the neural circuits subserving higher brain function and behaviors of relevance to mental health, (2) the most promising approaches to determine how biological rhythms regulate brain function and behavior under normal and pathological conditions, (3) the gaps and challenges to advancing knowledge on the link between disrupted circadian rhythms/sleep and psychiatric disorders, and (4) the novel strategies for translation of basic science discoveries in circadian biology to clinical settings to define risk, prevent or delay onset of mental illnesses, design diagnostic tools, and propose new therapeutic strategies. The review is organized around five themes pertinent to (1) the impact of molecular clocks on physiology and behavior, (2) the interactions between circadian signals and cognitive functions, (3) the interface of circadian rhythms with sleep, (4) a clinical perspective on the relationship between circadian rhythm abnormalities and affective disorders, and (5) the pre-clinical models of circadian rhythm abnormalities and mood disorders.

  1. Learning sculpts the spontaneous activity of the resting human brain

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    Lewis, Christopher M.; Baldassarre, Antonello; Committeri, Giorgia; Romani, Gian Luca; Corbetta, Maurizio

    2009-01-01

    The brain is not a passive sensory-motor analyzer driven by environmental stimuli, but actively maintains ongoing representations that may be involved in the coding of expected sensory stimuli, prospective motor responses, and prior experience. Spontaneous cortical activity has been proposed to play an important part in maintaining these ongoing, internal representations, although its functional role is not well understood. One spontaneous signal being intensely investigated in the human brai...

  2. Circadian rhythms in the pineal organ persist in zebrafish larvae that lack ventral brain

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    Goldstein-Kral Lauren

    2011-01-01

    Full Text Available Abstract Background The mammalian suprachiasmatic nucleus (SCN, located in the ventral hypothalamus, is a major regulator of circadian rhythms in mammals and birds. However, the role of the SCN in lower vertebrates remains poorly understood. Zebrafish cyclops (cyc mutants lack ventral brain, including the region that gives rise to the SCN. We have used cyc embryos to define the function of the zebrafish SCN in regulating circadian rhythms in the developing pineal organ. The pineal organ is the major source of the circadian hormone melatonin, which regulates rhythms such as daily rest/activity cycles. Mammalian pineal rhythms are controlled almost exclusively by the SCN. In zebrafish and many other lower vertebrates, the pineal has an endogenous clock that is responsible in part for cyclic melatonin biosynthesis and gene expression. Results We find that pineal rhythms are present in cyc mutants despite the absence of an SCN. The arginine vasopressin-like protein (Avpl, formerly called Vasotocin is a peptide hormone expressed in and around the SCN. We find avpl mRNA is absent in cyc mutants, supporting previous work suggesting the SCN is missing. In contrast, expression of the putative circadian clock genes, cryptochrome 1b (cry1b and cryptochrome 3 (cry3, in the brain of the developing fish is unaltered. Expression of two pineal rhythmic genes, exo-rhodopsin (exorh and serotonin-N-acetyltransferase (aanat2, involved in photoreception and melatonin synthesis, respectively, is also similar between cyc embryos and their wildtype (WT siblings. The timing of the peaks and troughs of expression are the same, although the amplitude of expression is slightly decreased in the mutants. Cyclic gene expression persists for two days in cyc embryos transferred to constant light or constant dark, suggesting a circadian clock is driving the rhythms. However, the amplitude of rhythms in cyc mutants kept in constant conditions decreased more quickly than in their

  3. Environmental stimuli modulate the circadian rhythm of [3H-methyl]thymidine incorporation into brain DNA of male rats.

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    Zucconi, G G; Crognale, M C; Bassetti, M A; Giuditta, A

    1990-12-14

    A circadian rhythm of DNA synthesis is present in most organs of adult mammals, with peak levels (acrophase) generally in the rest period. We have recently reported that in the rat brain the acrophase of the rhythm of thymidine incorporation into DNA occurs on the contrary during the active period. To determine whether the brain waking activity was exerting a modulatory action we measured the circadian rhythm of incorporation in the brain and kidney of young adult male rats housed in conditions of sensory and social enrichment or impoverishment for four days. Biochemical and autoradiographic data show that the brain rhythm persists in the enriched condition, but is abolished in the impoverished condition. On the other hand, the rhythm of incorporation in the kidney is maintained in both conditions. These results suggest that the permanence of the brain oscillation is selectively dependent on the complexity of the sensory and social stimulation.

  4. An Evolutionary Game Theory Model of Spontaneous Brain Functioning.

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    Madeo, Dario; Talarico, Agostino; Pascual-Leone, Alvaro; Mocenni, Chiara; Santarnecchi, Emiliano

    2017-11-22

    Our brain is a complex system of interconnected regions spontaneously organized into distinct networks. The integration of information between and within these networks is a continuous process that can be observed even when the brain is at rest, i.e. not engaged in any particular task. Moreover, such spontaneous dynamics show predictive value over individual cognitive profile and constitute a potential marker in neurological and psychiatric conditions, making its understanding of fundamental importance in modern neuroscience. Here we present a theoretical and mathematical model based on an extension of evolutionary game theory on networks (EGN), able to capture brain's interregional dynamics by balancing emulative and non-emulative attitudes among brain regions. This results in the net behavior of nodes composing resting-state networks identified using functional magnetic resonance imaging (fMRI), determining their moment-to-moment level of activation and inhibition as expressed by positive and negative shifts in BOLD fMRI signal. By spontaneously generating low-frequency oscillatory behaviors, the EGN model is able to mimic functional connectivity dynamics, approximate fMRI time series on the basis of initial subset of available data, as well as simulate the impact of network lesions and provide evidence of compensation mechanisms across networks. Results suggest evolutionary game theory on networks as a new potential framework for the understanding of human brain network dynamics.

  5. Identification of circadian brain photoreceptors mediating photic entrainment of behavioural rhythms in lizards.

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    Pasqualetti, Massimo; Bertolucci, Cristiano; Ori, Michela; Innocenti, Augusto; Magnone, Maria C; De Grip, Willem J; Nardi, Irma; Foà, Augusto

    2003-07-01

    We have shown previously that in ruin lizards (Podarcis sicula) the ablation of all known photoreceptive structures (lateral eyes, pineal and parietal eye) in the same individual animal does not prevent entrainment of their circadian locomotor rhythms to light. The present study was aimed at identifying the circadian brain photoreceptors mediating entrainment. For this purpose, we looked for opsin expression in the brain by means of immunocytochemistry. Using anti-cone-opsin antiserum CERN 874 we have localized photoreceptors in the periventricular area of hypothalamus, near the third cerebral ventricle. We also cloned a brain opsin cDNA that, on the basis of the deduced amino acid sequence, appears to belong to the RH2 class of cone-opsins. We named the cloned cone-opsin Ps-RH2. To examine whether brain cone-opsins mediate photic entrainment of circadian locomotor rhythms, we performed post-transcriptional inactivation experiments by injecting an expression eukaryotic vector transcribing the antisense cone-opsin Ps-RH2 mRNA in the third cerebral ventricle of pinealectomized-retinectomized lizards previously entrained to a light-dark (LD) cycle. Injections of the antisense construct abolished photic entrainment of circadian locomotor rhythms of pinealectomized-retinectomized lizards to the LD cycle for 6-9 days. CERN 874 completely failed to label cells within the periventricular area of hypothalamus of brains injected with antisense construct. Thus, abolishment of photic entrainment is due to inactivation of endogenous brain cone-opsins mRNA. The present results demonstrate for the first time in a vertebrate that brain cone-opsins are part of a true circadian brain photoreceptor participating in photic entrainment of behavioural rhythms.

  6. Analysis of a phase synchronized functional network based on the rhythm of brain activities

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    Li Ling; Jin Zhen-Lan; Li Bin

    2011-01-01

    Rhythm of brain activities represents oscillations of postsynaptic potentials in neocortex, therefore it can serve as an indicator of the brain activity state. In order to check the connectivity of brain rhythm, this paper develops a new method of constructing functional network based on phase synchronization. Electroencephalogram (EEG) data were collected while subjects looking at a green cross in two states, performing an attention task and relaxing with eyes-open. The EEG from these two states was filtered by three band-pass filters to obtain signals of theta (4–7 Hz), alpha (8–13 Hz) and beta (14–30 Hz) bands. Mean resultant length was used to estimate strength of phase synchronization in three bands to construct networks of both states, and mean degree K and cluster coefficient C of networks were calculated as a function of threshold. The result shows higher cluster coefficient in the attention state than in the eyes-open state in all three bands, suggesting that cluster coefficient reflects brain state. In addition, an obvious fronto-parietal network is found in the attention state, which is a well-known attention network. These results indicate that attention modulates the fronto-parietal connectivity in different modes as compared with the eyes-open state. Taken together this method is an objective and important tool to study the properties of neural networks of brain rhythm. (interdisciplinary physics and related areas of science and technology)

  7. Measurement of the occipital alpha rhythm and temporal tau rhythm by using magnetoencephalography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. E.; Gohel, Bakul; Kim, K.; Kwon, H.; An, Kyung Min [Center for Biosignals, Korea Research Institute of Standards and Science(KRISS), Daejeon (Korea, Republic of)

    2015-12-15

    Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8–13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively.

  8. Measurement of the occipital alpha rhythm and temporal tau rhythm by using magnetoencephalography

    International Nuclear Information System (INIS)

    Kim, J. E.; Gohel, Bakul; Kim, K.; Kwon, H.; An, Kyung Min

    2015-01-01

    Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8–13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively

  9. Hyperbaric oxygen therapy in spontaneous brain abscess patients

    DEFF Research Database (Denmark)

    Bartek, Jiri; Jakola, Asgeir S; Skyrman, Simon

    2016-01-01

    study included 40 consecutive adult patients with spontaneous brain abscess treated surgically between January 2003 and May 2014 at our institution. Twenty patients received standard therapy with surgery and antibiotics (non-HBOT group), while the remaining 20 patients also received adjuvant HBOT (HBOT......BACKGROUND: There is a need to improve outcome in patients with brain abscesses and hyperbaric oxygen therapy (HBOT) is a promising treatment modality. The objective of this study was to evaluate HBOT in the treatment of intracranial abscesses. METHOD: This population-based, comparative cohort...

  10. Daily exposure to a running wheel entrains circadian rhythms in mice in parallel with development of an increase in spontaneous movement prior to running-wheel access.

    Science.gov (United States)

    Yamanaka, Yujiro; Honma, Sato; Honma, Ken-ichi

    2013-12-01

    Entrainment of circadian behavior rhythms by daily exposure to a running wheel was examined in mice under constant darkness. Spontaneous movement was individually monitored for more than 6 mo by a thermal sensor. After establishment of steady-state free running, mice were placed in a different cage equipped with a running-wheel for 3 h once per day at 6 AM. The daily exchange was continued for 80 days. The number of wheel revolutions during exposure to the running wheel was also measured simultaneously with spontaneous movement. In 13 out of 17 mice, circadian behavior rhythm was entrained by daily wheel exposure, showing a period indistinguishable from 24 h. The entrainment occurred in parallel with an increase in spontaneous movement immediately prior to the daily wheel exposure. A similar preexposure increase was observed in only one of four nonentrained mice. The preexposure increase appeared in 19.5 days on average after the start of daily wheel exposure and persisted for 36 days on average after the termination of the exposure schedule. The preexposure increase was detected only when daily wheel exposure came into the activity phase of the circadian behavior rhythm, which was accompanied by an increase in the number of wheel revolutions. These findings indicate that a novel oscillation with a circadian period is induced in mice by daily exposure to a running wheel at a fixed time of day and suggest that the oscillation is involved in the nonphotic entrainment of circadian rhythms in spontaneous movement.

  11. Learning to modulate one's own brain activity: The effect of spontaneous mental strategies

    Directory of Open Access Journals (Sweden)

    Silvia Erika Kober

    2013-10-01

    Full Text Available Using neurofeedback (NF, individuals can learn to modulate their own brain activity, in most cases electroencephalographic (EEG rhythms. Although a large body of literature reports positive effects of NF training on behavior and cognitive functions, there are hardly any reports on how participants can successfully learn to gain control over their own brain activity. About one third of people fail to gain significant control over their brain signals even after repeated training sessions. The reasons for this failure are still largely unknown. In this context, we investigated the effects of spontaneous mental strategies on NF performance. Twenty healthy participants performed either a SMR (sensorimotor rhythm, 12-15 Hz based or a Gamma (40-43 Hz based NF training over ten sessions. After the first and the last training session, they were asked to write down which mental strategy they have used for self-regulating their EEG. After the first session, all participants reported the use of various types of mental strategies such as visual strategies, concentration, or relaxation. After the last NF training session, four participants of the SMR group reported to employ no specific strategy. These four participants showed linear improvements in NF performance over the ten training sessions. In contrast, participants still reporting the use of specific mental strategies in the last NF session showed no changes in SMR based NF performance over the ten sessions. This effect could not be observed in the Gamma group. The Gamma group showed no prominent changes in Gamma power over the NF training sessions, regardless of the mental strategies used. These results indicate that successful SMR based NF performance is associated with implicit learning mechanisms. Participants stating vivid reports on strategies to control their SMR probably overload cognitive resources, which might be counterproductive in terms of increasing SMR power.

  12. Brain perihematoma genomic profile following spontaneous human intracerebral hemorrhage.

    Directory of Open Access Journals (Sweden)

    Anna Rosell

    Full Text Available BACKGROUND: Spontaneous intracerebral hemorrhage (ICH represents about 15% of all strokes and is associated with high mortality rates. Our aim was to identify the gene expression changes and biological pathways altered in the brain following ICH. METHODOLOGY/PRINCIPAL FINDINGS: Twelve brain samples were obtained from four deceased patients who suffered an ICH including perihematomal tissue (PH and the corresponding contralateral white (CW and grey (CG matter. Affymetrix GeneChip platform for analysis of over 47,000 transcripts was conducted. Microarray Analysis Suite 5.0 was used to process array images and the Ingenuity Pathway Analysis System was used to analyze biological mechanisms and functions of the genes. We identified 468 genes in the PH areas displaying a different expression pattern with a fold change between -3.74 and +5.16 when compared to the contralateral areas (291 overexpressed and 177 underexpressed. The top genes which appeared most significantly overexpressed in the PH areas codify for cytokines, chemokines, coagulation factors, cell growth and proliferation factors while the underexpressed codify for proteins involved in cell cycle or neurotrophins. Validation and replication studies at gene and protein level in brain samples confirmed microarray results. CONCLUSIONS: The genomic responses identified in this study provide valuable information about potential biomarkers and target molecules altered in the perihematomal regions.

  13. Effects of thalamic deep brain stimulation on spontaneous language production.

    Science.gov (United States)

    Ehlen, Felicitas; Vonberg, Isabelle; Kühn, Andrea A; Klostermann, Fabian

    2016-08-01

    The thalamus is thought to contribute to language-related processing, but specifications of this notion remain vague. An assessment of potential effects of thalamic deep brain stimulation (DBS) on spontaneous language may help to delineate respective functions. For this purpose, we analyzed spontaneous language samples from thirteen (six female / seven male) patients with essential tremor treated with DBS of the thalamic ventral intermediate nucleus (VIM) in their respective ON vs. OFF conditions. Samples were obtained from semi-structured interviews and examined on multidimensional linguistic levels. In the VIM-DBS ON condition, participants used a significantly higher proportion of paratactic as opposed to hypotactic sentence structures. This increase correlated negatively with the change in the more global cognitive score, which in itself did not change significantly. In conclusion, VIM-DBS appears to induce the use of a simplified syntactic structure. The findings are discussed in relation to concepts of thalamic roles in language-related cognitive behavior. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Estrogen alters the diurnal rhythm of alpha 1-adrenergic receptor densities in selected brain regions

    International Nuclear Information System (INIS)

    Weiland, N.G.; Wise, P.M.

    1987-01-01

    Norepinephrine regulates the proestrous and estradiol-induced LH surge by binding to alpha 1-adrenergic receptors. The density of alpha 1-receptors may be regulated by estradiol, photoperiod, and noradrenergic neuronal activity. We wished to determine whether alpha 1-receptors exhibit a diurnal rhythm in ovariectomized and/or estradiol-treated female rats, whether estradiol regulates alpha 1-receptors in those areas of brain involved with LH secretion and/or sexual behavior, and whether the concentrations of alpha-receptors vary inversely relative to previously reported norepinephrine turnover patterns. Young female rats, maintained on a 14:10 light-dark cycle were ovariectomized. One week later, half of them were outfitted sc with Silastic capsules containing estradiol. Groups of animals were decapitated 2 days later at 0300, 1000, 1300, 1500, 1800, and 2300 h. Brains were removed, frozen, and sectioned at 20 micron. Sections were incubated with [ 3 H]prazosin in Tris-HCl buffer, washed, dried, and exposed to LKB Ultrofilm. The densities of alpha 1-receptors were quantitated using a computerized image analysis system. In ovariectomized rats, the density of alpha 1-receptors exhibited a diurnal rhythm in the suprachiasmatic nucleus (SCN), medial preoptic nucleus (MPN), and pineal gland. In SCN and MPN, receptor concentrations were lowest during the middle of the day and rose to peak levels at 1800 h. In the pineal gland, the density of alpha 1-receptors was lowest at middark phase, rose to peak levels before lights on, and remained elevated during the day. Estradiol suppressed the density of alpha 1 binding sites in the SCN, MPN, median eminence, ventromedial nucleus, and the pineal gland but had no effect on the lateral septum. Estrogen treatment altered the rhythm of receptor densities in MPN, median eminence, and the pineal gland

  15. Estrogen alters the diurnal rhythm of alpha 1-adrenergic receptor densities in selected brain regions

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, N.G.; Wise, P.M.

    1987-11-01

    Norepinephrine regulates the proestrous and estradiol-induced LH surge by binding to alpha 1-adrenergic receptors. The density of alpha 1-receptors may be regulated by estradiol, photoperiod, and noradrenergic neuronal activity. We wished to determine whether alpha 1-receptors exhibit a diurnal rhythm in ovariectomized and/or estradiol-treated female rats, whether estradiol regulates alpha 1-receptors in those areas of brain involved with LH secretion and/or sexual behavior, and whether the concentrations of alpha-receptors vary inversely relative to previously reported norepinephrine turnover patterns. Young female rats, maintained on a 14:10 light-dark cycle were ovariectomized. One week later, half of them were outfitted sc with Silastic capsules containing estradiol. Groups of animals were decapitated 2 days later at 0300, 1000, 1300, 1500, 1800, and 2300 h. Brains were removed, frozen, and sectioned at 20 micron. Sections were incubated with (/sup 3/H)prazosin in Tris-HCl buffer, washed, dried, and exposed to LKB Ultrofilm. The densities of alpha 1-receptors were quantitated using a computerized image analysis system. In ovariectomized rats, the density of alpha 1-receptors exhibited a diurnal rhythm in the suprachiasmatic nucleus (SCN), medial preoptic nucleus (MPN), and pineal gland. In SCN and MPN, receptor concentrations were lowest during the middle of the day and rose to peak levels at 1800 h. In the pineal gland, the density of alpha 1-receptors was lowest at middark phase, rose to peak levels before lights on, and remained elevated during the day. Estradiol suppressed the density of alpha 1 binding sites in the SCN, MPN, median eminence, ventromedial nucleus, and the pineal gland but had no effect on the lateral septum. Estrogen treatment altered the rhythm of receptor densities in MPN, median eminence, and the pineal gland.

  16. New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter

    Science.gov (United States)

    Tozzi, Arturo; Zare, Marzieh; Benasich, April A.

    2016-01-01

    Spontaneous brain activity has received increasing attention as demonstrated by the exponential rise in the number of published article on this topic over the last 30 years. Such “intrinsic” brain activity, generated in the absence of an explicit task, is frequently associated with resting-state or default-mode networks (DMN)s. The focus on characterizing spontaneous brain activity promises to shed new light on questions concerning the structural and functional architecture of the brain and how they are related to “mind”. However, many critical questions have yet to be addressed. In this review, we focus on a scarcely explored area, specifically the energetic requirements and constraints of spontaneous activity, taking into account both thermodynamical and informational perspectives. We argue that the “classical” definitions of spontaneous activity do not take into account an important feature, that is, the critical thermodynamic energetic differences between spontaneous and evoked brain activity. Spontaneous brain activity is associated with slower oscillations compared with evoked, task-related activity, hence it exhibits lower levels of enthalpy and “free-energy” (i.e., the energy that can be converted to do work), thus supporting noteworthy thermodynamic energetic differences between spontaneous and evoked brain activity. Increased spike frequency during evoked activity has a significant metabolic cost, consequently, brain functions traditionally associated with spontaneous activity, such as mind wandering, require less energy that other nervous activities. We also review recent empirical observations in neuroscience, in order to capture how spontaneous brain dynamics and mental function can be embedded in a non-linear dynamical framework, which considers nervous activity in terms of phase spaces, particle trajectories, random walks, attractors and/or paths at the edge of the chaos. This takes us from the thermodynamic free-energy, to the realm

  17. Relation between functional connectivity and rhythm discrimination in children who do and do not stutter

    Directory of Open Access Journals (Sweden)

    Soo-Eun Chang

    2016-01-01

    Full Text Available Our ability to perceive and produce rhythmic patterns in the environment supports fundamental human capacities ranging from music and language processing to the coordination of action. This article considers whether spontaneous correlated brain activity within a basal ganglia-thalamocortical (rhythm network is associated with individual differences in auditory rhythm discrimination. Moreover, do children who stutter with demonstrated deficits in rhythm perception have weaker links between rhythm network functional connectivity and rhythm discrimination? All children in the study underwent a resting-state fMRI session, from which functional connectivity measures within the rhythm network were extracted from spontaneous brain activity. In a separate session, the same children completed an auditory rhythm-discrimination task, where behavioral performance was assessed using signal detection analysis. We hypothesized that in typically developing children, rhythm network functional connectivity would be associated with behavioral performance on the rhythm discrimination task, but that this relationship would be attenuated in children who stutter. Results supported our hypotheses, lending strong support for the view that (1 children who stutter have weaker rhythm network connectivity and (2 the lack of a relation between rhythm network connectivity and rhythm discrimination in children who stutter may be an important contributing factor to the etiology of stuttering.

  18. The Neural Association between Tendency to Forgive and Spontaneous Brain Activity in Healthy Young Adults

    OpenAIRE

    Haijiang Li; Jiamei Lu

    2017-01-01

    The tendency to forgive (TTF) refers to one’s global dispositional level of forgiveness across situations and relationships. Previous brain imaging studies examined activation patterns underlying forgiving process, yet the association between individual differences in the TTF and spontaneous brain activity at resting-state remains unknown. In this study, resting-state functional magnetic resonance imaging (fMRI) was used to investigate the correlation between the TTF and spontaneous brain act...

  19. Transcranial electrical currents to probe EEG brain rhythms and memory consolidation during sleep in humans.

    Directory of Open Access Journals (Sweden)

    Lisa Marshall

    Full Text Available Previously the application of a weak electric anodal current oscillating with a frequency of the sleep slow oscillation (∼0.75 Hz during non-rapid eye movement sleep (NonREM sleep boosted endogenous slow oscillation activity and enhanced sleep-associated memory consolidation. The slow oscillations occurring during NonREM sleep and theta oscillations present during REM sleep have been considered of critical relevance for memory formation. Here transcranial direct current stimulation (tDCS oscillating at 5 Hz, i.e., within the theta frequency range (theta-tDCS is applied during NonREM and REM sleep. Theta-tDCS during NonREM sleep produced a global decrease in slow oscillatory activity conjoint with a local reduction of frontal slow EEG spindle power (8-12 Hz and a decrement in consolidation of declarative memory, underlining the relevance of these cortical oscillations for sleep-dependent memory consolidation. In contrast, during REM sleep theta-tDCS appears to increase global gamma (25-45 Hz activity, indicating a clear brain state-dependency of theta-tDCS. More generally, results demonstrate the suitability of oscillating-tDCS as a tool to analyze functions of endogenous EEG rhythms and underlying endogenous electric fields as well as the interactions between EEG rhythms of different frequencies.

  20. Sensorimotor rhythm-based brain-computer interface training: the impact on motor cortical responsiveness

    Science.gov (United States)

    Pichiorri, F.; De Vico Fallani, F.; Cincotti, F.; Babiloni, F.; Molinari, M.; Kleih, S. C.; Neuper, C.; Kübler, A.; Mattia, D.

    2011-04-01

    The main purpose of electroencephalography (EEG)-based brain-computer interface (BCI) technology is to provide an alternative channel to support communication and control when motor pathways are interrupted. Despite the considerable amount of research focused on the improvement of EEG signal detection and translation into output commands, little is known about how learning to operate a BCI device may affect brain plasticity. This study investigated if and how sensorimotor rhythm-based BCI training would induce persistent functional changes in motor cortex, as assessed with transcranial magnetic stimulation (TMS) and high-density EEG. Motor imagery (MI)-based BCI training in naïve participants led to a significant increase in motor cortical excitability, as revealed by post-training TMS mapping of the hand muscle's cortical representation; peak amplitude and volume of the motor evoked potentials recorded from the opponens pollicis muscle were significantly higher only in those subjects who develop a MI strategy based on imagination of hand grasping to successfully control a computer cursor. Furthermore, analysis of the functional brain networks constructed using a connectivity matrix between scalp electrodes revealed a significant decrease in the global efficiency index for the higher-beta frequency range (22-29 Hz), indicating that the brain network changes its topology with practice of hand grasping MI. Our findings build the neurophysiological basis for the use of non-invasive BCI technology for monitoring and guidance of motor imagery-dependent brain plasticity and thus may render BCI a viable tool for post-stroke rehabilitation.

  1. Harnessing functional segregation across brain rhythms as a means to detect EEG oscillatory multiplexing during music listening.

    Science.gov (United States)

    Adamos, Dimitrios A; Laskaris, Nikolaos A; Micheloyannis, Sifis

    2018-06-01

    Music, being a multifaceted stimulus evolving at multiple timescales, modulates brain function in a manifold way that encompasses not only the distinct stages of auditory perception, but also higher cognitive processes like memory and appraisal. Network theory is apparently a promising approach to describe the functional reorganization of brain oscillatory dynamics during music listening. However, the music induced changes have so far been examined within the functional boundaries of isolated brain rhythms. Using naturalistic music, we detected the functional segregation patterns associated with different cortical rhythms, as these were reflected in the surface electroencephalography (EEG) measurements. The emerged structure was compared across frequency bands to quantify the interplay among rhythms. It was also contrasted against the structure from the rest and noise listening conditions to reveal the specific components stemming from music listening. Our methodology includes an efficient graph-partitioning algorithm, which is further utilized for mining prototypical modular patterns, and a novel algorithmic procedure for identifying 'switching nodes' (i.e. recording sites) that consistently change module during music listening. Our results suggest the multiplex character of the music-induced functional reorganization and particularly indicate the dependence between the networks reconstructed from the δ and β H rhythms. This dependence is further justified within the framework of nested neural oscillations and fits perfectly within the context of recently introduced cortical entrainment to music. Complying with the contemporary trends towards a multi-scale examination of the brain network organization, our approach specifies the form of neural coordination among rhythms during music listening. Considering its computational efficiency, and in conjunction with the flexibility of in situ electroencephalography, it may lead to novel assistive tools for real

  2. High Frequency Deep Brain Stimulation and Neural Rhythms in Parkinson's Disease.

    Science.gov (United States)

    Blumenfeld, Zack; Brontë-Stewart, Helen

    2015-12-01

    High frequency (HF) deep brain stimulation (DBS) is an established therapy for the treatment of Parkinson's disease (PD). It effectively treats the cardinal motor signs of PD, including tremor, bradykinesia, and rigidity. The most common neural target is the subthalamic nucleus, located within the basal ganglia, the region most acutely affected by PD pathology. Using chronically-implanted DBS electrodes, researchers have been able to record underlying neural rhythms from several nodes in the PD network as well as perturb it using DBS to measure the ensuing neural and behavioral effects, both acutely and over time. In this review, we provide an overview of the PD neural network, focusing on the pathophysiological signals that have been recorded from PD patients as well as the mechanisms underlying the therapeutic benefits of HF DBS. We then discuss evidence for the relationship between specific neural oscillations and symptoms of PD, including the aberrant relationships potentially underlying functional connectivity in PD as well as the use of different frequencies of stimulation to more specifically target certain symptoms. Finally, we briefly describe several current areas of investigation and how the ability to record neural data in ecologically-valid settings may allow researchers to explore the relationship between brain and behavior in an unprecedented manner, culminating in the future automation of neurostimulation therapy for the treatment of a variety of neuropsychiatric diseases.

  3. The Brain Prize 2011: From Microcircuit Organization to Constellations of Brain Rhythms.

    Science.gov (United States)

    Soltesz, Ivan

    2011-10-01

    The Grete Lundbeck European Brain Research Foundation awarded the inaugural Brain Prize 2011 to Péter Somogyi, Tamás Freund and György Buzsáki 'for their wide-ranging, technically and conceptually brilliant research on the functional organization of neuronal circuits in the cerebral cortex, especially in the hippocampus, a region that is crucial for certain forms of memory'. The present article highlights key findings and major conceptual contributions by these three scientists that were recognized by the award. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans.

    Science.gov (United States)

    Hattori, Yuko; Tomonaga, Masaki; Matsuzawa, Tetsuro

    2015-01-01

    Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum) and auditory rhythms (e.g., hearing music while walking). Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse), suggesting a tight link between the auditory and motor systems in the human brain. However, the evolutionary origin of spontaneous responses to auditory rhythms is unclear. Here, we report that chimpanzees and humans show a similar distractor effect in perceiving isochronous rhythms during rhythmic movement. We used isochronous auditory rhythms as distractor stimuli during self-paced alternate tapping of two keys of an electronic keyboard by humans and chimpanzees. When the tempo was similar to their spontaneous motor tempo, tapping onset was influenced by intermittent entrainment to auditory rhythms. Although this effect itself is not an advanced rhythmic ability such as dancing or singing, our results suggest that, to some extent, the biological foundation for spontaneous responses to auditory rhythms was already deeply rooted in the common ancestor of chimpanzees and humans, 6 million years ago. This also suggests the possibility of a common attentional mechanism, as proposed by the dynamic attending theory, underlying the effect of perceiving external rhythms on motor movement.

  5. Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans.

    Directory of Open Access Journals (Sweden)

    Yuko Hattori

    Full Text Available Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum and auditory rhythms (e.g., hearing music while walking. Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse, suggesting a tight link between the auditory and motor systems in the human brain. However, the evolutionary origin of spontaneous responses to auditory rhythms is unclear. Here, we report that chimpanzees and humans show a similar distractor effect in perceiving isochronous rhythms during rhythmic movement. We used isochronous auditory rhythms as distractor stimuli during self-paced alternate tapping of two keys of an electronic keyboard by humans and chimpanzees. When the tempo was similar to their spontaneous motor tempo, tapping onset was influenced by intermittent entrainment to auditory rhythms. Although this effect itself is not an advanced rhythmic ability such as dancing or singing, our results suggest that, to some extent, the biological foundation for spontaneous responses to auditory rhythms was already deeply rooted in the common ancestor of chimpanzees and humans, 6 million years ago. This also suggests the possibility of a common attentional mechanism, as proposed by the dynamic attending theory, underlying the effect of perceiving external rhythms on motor movement.

  6. Influence of Brain Stem on Axial and Hindlimb Spinal Locomotor Rhythm Generating Circuits of the Neonatal Mouse

    Directory of Open Access Journals (Sweden)

    Céline Jean-Xavier

    2018-02-01

    Full Text Available The trunk plays a pivotal role in limbed locomotion. Yet, little is known about how the brain stem controls trunk activity during walking. In this study, we assessed the spatiotemporal activity patterns of axial and hindlimb motoneurons (MNs during drug-induced fictive locomotor-like activity (LLA in an isolated brain stem-spinal cord preparation of the neonatal mouse. We also evaluated the extent to which these activity patterns are affected by removal of brain stem. Recordings were made in the segments T7, L2, and L5 using calcium imaging from individual axial MNs in the medial motor column (MMC and hindlimb MNs in lateral motor column (LMC. The MN activities were analyzed during both the rhythmic and the tonic components of LLA, the tonic component being used as a readout of generalized increase in excitability in spinal locomotor networks. The most salient effect of brain stem removal was an increase in locomotor rhythm frequency and a concomitant reduction in burst durations in both MMC and LMC MNs. The lack of effect on the tonic component of LLA indicated specificity of action during the rhythmic component. Cooling-induced silencing of the brain stem reproduced the increase in rhythm frequency and accompanying decrease in burst durations in L2 MMC and LMC, suggesting a dependency on brain stem neuron activity. The work supports the idea that the brain stem locomotor circuits are operational already at birth and further suggests an important role in modulating trunk activity. The brain stem may influence the axial and hindlimb spinal locomotor rhythm generating circuits by extending their range of operation. This may represent a critical step of locomotor development when learning how to walk in different conditions and environments is a major endeavor.

  7. Neurofeedback tunes scale-free dynamics in spontaneous brain activity

    NARCIS (Netherlands)

    Ros, T.; Frewen, P.A.; Thé berge, J.; Michela, A.; Kluetsch, R.C.; Mü ller, A.; Candrian, G.; Jetly, R.; Vuilleumier, P.; Lanius, R.

    2017-01-01

    Brain oscillations exhibit long-range temporal correlations (LRTCs), which reflect the regularity of their fluctuations: low values representing more random (decorrelated) while high values more persistent (correlated) dynamics. LRTCs constitute supporting evidence that the brain operates near

  8. Intact blood-brain barrier during spontaneous attacks of migraine without aura

    DEFF Research Database (Denmark)

    Amin, F M; Hougaard, A; Cramer, S P

    2017-01-01

    , brain stem, posterior pons and whole brain. The paired samples t test was used to compare Ki (permeability) values between the attack and headache-free days. RESULTS: Nineteen patients completed the study. Median time from onset of migraine attack to scan was 6.5 h (range 4.0-15.5 h). No change......BACKGROUND AND PURPOSE: The integrity of the blood-brain barrier (BBB) has been questioned in migraine, but BBB permeability has never been investigated during spontaneous migraine attacks. In the present study, BBB permeability during spontaneous attacks of migraine without aura was investigated...

  9. Study of SCN Neurochemistry using In Vivo Microdialysis in the Conscious Brain: Correlation with Circadian Activity Rhythms.

    Science.gov (United States)

    1992-12-29

    Hydroxyindole -acetic acid In vivo brain microdialysis was used to characterize the daily pattern of 5 -hy- Suprachiasmatic nucleus droxyindole-acetic acid...principal serotonin metabolite, 5 - hydroxyindole - SCN is comprised of cells that exhibit a self-generating acetic acid ( 5 -HIAA), in the SCN. The...significance of pacemaker activity [3, 4] and is richly innervated by amino the 5 -HIAA rhythm is not certain, however, because acid, peptidergic and

  10. Circadian influences on dopamine circuits of the brain: regulation of striatal rhythms of clock gene expression and implications for psychopathology and disease [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Michael Verwey

    2016-08-01

    Full Text Available Circadian clock proteins form an autoregulatory feedback loop that is central to the endogenous generation and transmission of daily rhythms in behavior and physiology. Increasingly, circadian rhythms in clock gene expression are being reported in diverse tissues and brain regions that lie outside of the suprachiasmatic nucleus (SCN, the master circadian clock in mammals. For many of these extra-SCN rhythms, however, the region-specific implications are still emerging. In order to gain important insights into the potential behavioral, physiological, and psychological relevance of these daily oscillations, researchers have begun to focus on describing the neurochemical, hormonal, metabolic, and epigenetic contributions to the regulation of these rhythms. This review will highlight important sites and sources of circadian control within dopaminergic and striatal circuitries of the brain and will discuss potential implications for psychopathology and disease. For example, rhythms in clock gene expression in the dorsal striatum are sensitive to changes in dopamine release, which has potential implications for Parkinson’s disease and drug addiction. Rhythms in the ventral striatum and limbic forebrain are sensitive to psychological and physical stressors, which may have implications for major depressive disorder. Collectively, a rich circadian tapestry has emerged that forces us to expand traditional views and to reconsider the psychopathological, behavioral, and physiological importance of these region-specific rhythms in brain areas that are not immediately linked with the regulation of circadian rhythms.

  11. The spinning dancer illusion and spontaneous brain fluctuations: an fMRI study.

    Science.gov (United States)

    Bernal, Byron; Guillen, Magno; Marquez, Juan Camilo

    2014-01-01

    The brain activation associated with the Spinning Dancer Illusion, a cognitive visual illusion, is not entirely known. Inferences from other study modalities point to the involvement of the dorso-parieto-occipital areas in the spontaneous switchings of perception in other bistable non-kinetic illusions. fMRI is a mature technique used to investigate the brain responses associated with mental changes. Resting-state fMRI is a novel technique that may help ascertain the effects of spontaneous brain changes in the top-down regulation of visual perception. The purpose of this report is to describe the brain activation associated with the subjective illusory changes of perception of a kinetic bistable stimulus. We hypothesize that there is a relationship between the perception phases with the very slow cortical spontaneous fluctuations, recently described. A single normal subject who was trained to produce voluntarily perception phase switches underwent a series of fMRI studies whose blocks were either defined post-hoc or accordingly with a predefined timeline to assess spontaneous and voluntarily evoked visual perception switches, respectively. Correlation of findings with resting-state fMRI and independent component analysis of the task series was sought. Phases of the rotation direction were found associated with right parietal activity. Independent component analysis of the task series and their comparison with basal resting-state components suggest that this activity is related to one of the very slow spontaneous brain fluctuations. The spontaneous fluctuations of the cortical activity may explain the subjective changes in perception of direction of the Spinning Dancer Illusion. This observation is a proof-of-principle, suggesting that the spontaneous brain oscillations may influence top-down sensory regulation.

  12. Using a virtual cortical module implementing a neural field model to modulate brain rhythms in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Julien Modolo

    2010-06-01

    Full Text Available We propose a new method for selective modulation of cortical rhythms based on neural field theory, in which the activity of a cortical area is extensively monitored using a two-dimensional microelectrode array. The example of Parkinson's disease illustrates the proposed method, in which a neural field model is assumed to accurately describe experimentally recorded activity. In addition, we propose a new closed-loop stimulation signal that is both space- and time- dependent. This method is especially designed to specifically modulate a targeted brain rhythm, without interfering with other rhythms. A new class of neuroprosthetic devices is also proposed, in which the multielectrode array is seen as an artificial neural network interacting with biological tissue. Such a bio-inspired approach may provide a solution to optimize interactions between the stimulation device and the cortex aiming to attenuate or augment specific cortical rhythms. The next step will be to validate this new approach experimentally in patients with Parkinson's disease.

  13. Circadian Rhythms and Clock Genes in Reproduction: Insights From Behavior and the Female Rabbit’s Brain

    Directory of Open Access Journals (Sweden)

    Mario Caba

    2018-03-01

    Full Text Available Clock gene oscillations are necessary for a successful pregnancy and parturition, but little is known about their function during lactation, a period demanding from the mother multiple physiological and behavioral adaptations to fulfill the requirements of the offspring. First, we will focus on circadian rhythms and clock genes in reproductive tissues mainly in rodents. Disruption of circadian rhythms or proper rhythmic oscillations of clock genes provoke reproductive problems, as found in clock gene knockout mice. Then, we will focus mainly on the rabbit doe as this mammal nurses the young just once a day with circadian periodicity. This daily event synchronizes the behavior and the activity of specific brain regions critical for reproductive neuroendocrinology and maternal behavior, like the preoptic area. This region shows strong rhythms of the PER1 protein (product of the Per1 clock gene associated with circadian nursing. Additionally, neuroendocrine cells related to milk production and ejections are also synchronized to daily nursing. A threshold of suckling is necessary to entrain once a day nursing; this process is independent of milk output as even virgin does (behaving maternally following anosmia can display circadian nursing behavior. A timing motivational mechanism may regulate such behavior as mesolimbic dopaminergic cells are entrained by daily nursing. Finally, we will explore about the clinical importance of circadian rhythms. Indeed, women in chronic shift-work schedules show problems in their menstrual cycles and pregnancies and also have a high risk of preterm delivery, making this an important field of translational research.

  14. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Science.gov (United States)

    Svendsen, Jon C; Genz, Janet; Anderson, W Gary; Stol, Jennifer A; Watkinson, Douglas A; Enders, Eva C

    2014-01-01

    Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons). Using juvenile lake sturgeon (Acipenser fulvescens), the objective of this study was to test four hypotheses: 1) A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2) A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3) measurements of forced maximum metabolic rate (MMR(F)) are repeatable in individual fish; and 4) MMR(F) correlates positively with spontaneous maximum metabolic rate (MMR(S)). Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F). Trials lasting 24 h were used to measure standard metabolic rate (SMR) and MMR(S). Repeatability and correlations between MMR(F) and MMR(S) were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat))), demonstrating oxygen regulation. In contrast, MMR(F) was affected by hypoxia and decreased across the range from 100% O(2sat) to 70% O(2sat). MMR(F) was repeatable in individual fish, and MMR(F) correlated positively with MMR(S), but the relationships between MMR(F) and MMR(S) were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor). Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F) and MMR(S) support the conjecture that MMR(F) represents a measure of organism performance that could be a target of natural selection.

  15. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Directory of Open Access Journals (Sweden)

    Jon C Svendsen

    Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

  16. Circadian rhythm disturbance after radiotherapy for brain tumor in infantile period; Clinical effect of L-thyroxine and vitamin B[sub 12

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Masaya; Shinozaki, Masako (Metropolitan Medical Center for the Severely Handicapped, Fuchu, Tokyo (Japan)); Sasaki, Hideo

    1993-08-01

    We report a 19-year-old man suffering from circadian sleep-wake (S-W) rhythm disturbance after total tumor resection and whole brain irradiation. The patient was diagnosed as having astrocytoma in the right temporal lobe by CT scan and angiography at the age of 6 months. After total tumor resection and whole brain irradiation ([sup 60]Co 60 Gy), he showed profound psychomotor retardation, endoclinologic dysfunction including hypothyroidism and growth hormone deficiency, and S-W rhythm disturbance. At age 19, brain MRI revealed asymmetrical low intensity in the hypothalamic region. On endoclinological examination panhypopituitarism due to primary hypothalamic lesion was evident. His S-W rhythm was disturbed; i.e., sleep periods were dispersedly distributed throughout 24 hours. He showed a lethargic tendency in the daytime. All-day polysomnography revealed abnormal sleep structure such as the absence of sleep spindle and hump, peripheral apnea, snoring and low oxygen saturation. After L-thyroxine supplementation his daily activity improved gradually. The decrease in short time sleep and tendency of a free-running rhythm were observed and oxygen saturation improved remarkably. Peripheral apnea and snoring disappeared. This wakening effect of L-thyroxine administration may be due to improvement of hypothyroidism symptom such as myxoedematous pharynx. It also seems related to the alteration of the central S-W rhythm regulation, because free-running rhythm appeared after L-thyroxine administration. Vitamin B[sub 12] (VB[sub 12]), which has been reported to be effective for S-W rhythm disorders, was not effective for our patient's free-running rhythm. Compared with the patients responding to VB[sub 12], our patient's organic brain damage was more evident radiologically and endoclinologically. Following the hypothesis that VB[sub 12] has a potential to reinforce the entrainment of circadian rhythm, our patient's organic brain damage may include entrainment

  17. Dissipation and spontaneous symmetry breaking in brain dynamics

    International Nuclear Information System (INIS)

    Freeman, Walter J; Vitiello, Giuseppe

    2008-01-01

    We compare the predictions of the dissipative quantum model of the brain with neurophysiological data collected from electroencephalograms resulting from high-density arrays fixed on the surfaces of primary sensory and limbic areas of trained rabbits and cats. Functional brain imaging in relation to behavior reveals the formation of coherent domains of synchronized neuronal oscillatory activity and phase transitions predicted by the dissipative model

  18. An adaptive singular spectrum analysis method for extracting brain rhythms of electroencephalography

    Directory of Open Access Journals (Sweden)

    Hai Hu

    2017-06-01

    Full Text Available Artifacts removal and rhythms extraction from electroencephalography (EEG signals are important for portable and wearable EEG recording devices. Incorporating a novel grouping rule, we proposed an adaptive singular spectrum analysis (SSA method for artifacts removal and rhythms extraction. Based on the EEG signal amplitude, the grouping rule determines adaptively the first one or two SSA reconstructed components as artifacts and removes them. The remaining reconstructed components are then grouped based on their peak frequencies in the Fourier transform to extract the desired rhythms. The grouping rule thus enables SSA to be adaptive to EEG signals containing different levels of artifacts and rhythms. The simulated EEG data based on the Markov Process Amplitude (MPA EEG model and the experimental EEG data in the eyes-open and eyes-closed states were used to verify the adaptive SSA method. Results showed a better performance in artifacts removal and rhythms extraction, compared with the wavelet decomposition (WDec and another two recently reported SSA methods. Features of the extracted alpha rhythms using adaptive SSA were calculated to distinguish between the eyes-open and eyes-closed states. Results showed a higher accuracy (95.8% than those of the WDec method (79.2% and the infinite impulse response (IIR filtering method (83.3%.

  19. Synergetic fMRI-EEG brain mapping in alpha-rhythm voluntary control mode.

    Science.gov (United States)

    Shtark, M B; Verevkin, E G; Kozlova, L I; Mazhirina, K G; Pokrovskii, M A; Petrovskii, E D; Savelov, A A; Starostin, A S; Yarosh, S V

    2015-03-01

    For the first time in neurobiology-related issues, the synergistic spatial dynamics of EEG and fMRI (BOLD phenomenon) was studied during cognitive alpha biofeedback training in the operant conditioning mode (acoustic reinforcement of alpha-rhythm development and stability). Significant changes in alpha-rhythm intensity were found in T6 electrode area (Brodmann area 37). Brodmann areas related to solving alpha-training tasks and maximally involved in the formation of new neuronal network were middle and superior temporal gyri (areas 21, 22, and 37), fusiform gyrus, inferior frontal gyrus (areas 4, 6, and 46), anterior cingulate gyrus (areas 23 and 24), cuneus, and precuneus (area 7). Wide involvement of Brodmann areas is determined by psychological architecture of alpha-rhythm generating system control that includes complex cognitive activities: decision making, retrieval of long-term memory, evaluation of the reward and control efficiency during alpha-EEG biofeedback.

  20. The Neural Association between Tendency to Forgive and Spontaneous Brain Activity in Healthy Young Adults.

    Science.gov (United States)

    Li, Haijiang; Lu, Jiamei

    2017-01-01

    The tendency to forgive (TTF) refers to one's global dispositional level of forgiveness across situations and relationships. Previous brain imaging studies examined activation patterns underlying forgiving process, yet the association between individual differences in the TTF and spontaneous brain activity at resting-state remains unknown. In this study, resting-state functional magnetic resonance imaging (fMRI) was used to investigate the correlation between the TTF and spontaneous brain activity in a young adult sample. Participants were 178 young students (55 men) who completed the TTF scale and underwent a resting-state fMRI scan. Multiple regression analysis was conducted to assess the association between the regional amplitude of low-frequency fluctuations (ALFF) and TTF scores corrected for age and sex. Results showed that the ALFF value in the right dorsomedial prefrontal cortex (dmPFC), precuneus and inferior parietal lobule (IPL) were negatively associated with TTF scores. These findings suggest that the spontaneous brain activity of brain regions like the dmPFC, precuneus and IPL which are implicated in mentalizing and empathic response are associated with individual differences in the TTF.

  1. Significance of circadian rhythms in severely brain-injured patients: A clue to consciousness?

    Science.gov (United States)

    Blume, Christine; Lechinger, Julia; Santhi, Nayantara; del Giudice, Renata; Gnjezda, Maria-Teresa; Pichler, Gerald; Scarpatetti, Monika; Donis, Johann; Michitsch, Gabriele; Schabus, Manuel

    2017-05-16

    To investigate the relationship between the presence of a circadian body temperature rhythm and behaviorally assessed consciousness levels in patients with disorders of consciousness (DOC; i.e., vegetative state/unresponsive wakefulness syndrome or minimally conscious state). In a cross-sectional study, we investigated the presence of circadian temperature rhythms across 6 to 7 days using external skin temperature sensors in 18 patients with DOC. Beyond this, we examined the relationship between behaviorally assessed consciousness levels and circadian rhythmicity. Analyses with Lomb-Scargle periodograms revealed significant circadian rhythmicity in all patients (range 23.5-26.3 hours). We found that especially scores on the arousal subscale of the Coma Recovery Scale-Revised were closely linked to the integrity of circadian variations in body temperature. Finally, we piloted whether bright light stimulation could boost circadian rhythmicity and found positive evidence in 2 out of 8 patients. The study provides evidence for an association between circadian body temperature rhythms and arousal as a necessary precondition for consciousness. Our findings also make a case for circadian rhythms as a target for treatment as well as the application of diagnostic and therapeutic means at times when cognitive performance is expected to peak. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  2. Identification of circadian brain photoreceptors mediating photic entrainment of behavioural rhythms in lizards.

    NARCIS (Netherlands)

    Pasqualetti, M.; Bertolucci, C.; Ori, M.; Innocenti, A.; Magnone, M.C.; Grip, W.J. de; Nardi, I.; Foa, A.

    2003-01-01

    We have shown previously that in ruin lizards (Podarcis sicula) the ablation of all known photoreceptive structures (lateral eyes, pineal and parietal eye) in the same individual animal does not prevent entrainment of their circadian locomotor rhythms to light. The present study was aimed at

  3. Impaired Pitch Production and Preserved Rhythm Production in a Right Brain-Damaged Patient with Amusia

    Science.gov (United States)

    Murayama, Junko; Kashiwagi, Toshihiro; Kashiwagi, Asako; Mimura, Masaru

    2004-01-01

    Pre- and postmorbid singing of a patient with amusia due to a right-hemispheric infarction was analyzed acoustically. This particular patient had a premorbid tape recording of her own singing without accompaniment. Appropriateness of pitch interval and rhythm was evaluated based on ratios of pitch and duration between neighboring notes. The…

  4. Circadian rhythms of hedonic drinking behavior in mice.

    Science.gov (United States)

    Bainier, Claire; Mateo, Maria; Felder-Schmittbuhl, Marie-Paule; Mendoza, Jorge

    2017-05-04

    In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus is the site of the main circadian clock, synchronized by the light-dark cycle, which generates behavioral rhythms like feeding, drinking and activity. Notwithstanding, the main role of the SCN clock on the control of all circadian rhythms has been questioned due to the presence of clock activity in many brain areas, including those implicated in the regulation of feeding and reward. Moreover, whether circadian rhythms of particular motivated behaviors exist is unknown. Here, we evaluated the spontaneous daily and circadian behavior of consumption of a sweet caloric solution (5-10% sucrose), and the effects of sucrose intake on the expression of clock genes in the mouse brain. Mice showed a daily (in a light-dark cycle) and a circadian (in constant darkness conditions) rhythm in the intake and sucrose preference with a rise for both parameters at night (or subjective night). In addition, we observed changes in the circadian day-night expression of the clock gene Per2 in the SCN, cortex and striatum of animals ingesting sucrose compared to control mice on pure water. Finally, daily rhythms of sucrose intake and preference were abolished in Per2 Brdm1 - and double Per1 -/- Per2 Brdm1 -mutant animals. These data indicate that the expression of circadian rhythms of hedonic feeding behaviors may be controlled by brain circadian clocks and Per gene expression. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. The effects of embodied rhythm and robotic interventions on the spontaneous and responsive verbal communication skills of children with Autism Spectrum Disorder (ASD): A further outcome of a pilot randomized controlled trial.

    Science.gov (United States)

    Srinivasan, Sudha M; Eigsti, Inge-Marie; Gifford, Timothy; Bhat, Anjana N

    2016-07-01

    The current manuscript is the second in a mini-series of manuscripts reporting the effects of alternative, movement-based, rhythm and robotic interventions on the social communication skills of 36 school-age children with ASD. This pilot randomized controlled trial compared the effects of 8-weeks of rhythm and robotic interventions to those of a standard-of-care, comparison intervention. The first manuscript reported intervention effects on the spontaneous and responsive social attention skills of children. In this manuscript, we report intervention effects on the spontaneous and responsive verbal communication skills of children. Communication skills were assessed within a standardized test of responsive communication during the pretest and posttest as well as using training-specific measures of social verbalization during early, mid, and late training sessions. The rhythm and comparison groups improved on the standardized test in the posttest compared to the pretest. The rhythm and robot groups increased levels of social verbalization across training sessions. Movement-based and stationary contexts afforded different types and amounts of communication in children with ASD. Overall, movement-based interventions are a promising tool to enhance verbal and non-verbal communication skills in children with ASD.

  6. Changes in Mice Brain Spontaneous Electrical Activity during Cortical Spreading Depression due to Mobile Phone Radiation.

    Science.gov (United States)

    Sallam, Samera M; Mohamed, Ehab I; Dawood, Abdel-Fattah B

    2008-06-01

    The objective of the present study was to investigate changes in spontaneous EEG activity during cortical spreading depression (CSD) in mice brain. The cortical region of anaesthetized mice were exposed to the electromagnetic fields (EMFs) emitted from a mobile phone (MP, 935.2-960.2 MHz, 41.8 mW/cm(2)). The effect of EMFs on EEG was investigated before and after exposure to different stimuli (MP, 2% KCl, and MP & 2% KCl). The records of brain spontaneous EEG activity, slow potential changes (SPC), and spindle shaped firings were obtained through an interfaced computer. The results showed increases in the amplitude of evoked spindles by about 87%, 17%, and 226% for MP, 2% KCl, and MP & 2% KCl; respectively, as compared to values for the control group. These results showed that the evoked spindle is a more sensitive indicator of the effect of exposure to EMFs from MP.

  7. TOR signaling pathway and autophagy are involved in the regulation of circadian rhythms in behavior and plasticity of L2 interneurons in the brain of Drosophila melanogaster.

    Science.gov (United States)

    Kijak, Ewelina; Pyza, Elżbieta

    2017-01-01

    Drosophila melanogaster is a common model used to study circadian rhythms in behavior and circadian clocks. However, numerous circadian rhythms have also been detected in non-clock neurons, especially in the first optic neuropil (lamina) of the fly's visual system. Such rhythms have been observed in the number of synapses and in the structure of interneurons, which exhibit changes in size and shape in a circadian manner. Although the patterns of these changes are known, the mechanism remains unclear. In the present study, we investigated the role of the TOR signaling pathway and autophagy in regulating circadian rhythms based on the behavior and structural plasticity of the lamina L2 monopolar cell dendritic trees. In addition, we examined the cyclic expression of the TOR signaling pathway (Tor, Pi3K class 1, Akt1) and autophagy (Atg5 and Atg7) genes in the fly's brain. We observed that Tor, Atg5 and Atg7 exhibit rhythmic expressions in the brain of wild-type flies in day/night conditions (LD 12:12) that are abolished in per01 clock mutants. The silencing of Tor in per expressing cells shortens a period of the locomotor activity rhythm of flies. In addition, silencing of the Tor and Atg5 genes in L2 cells disrupts the circadian plasticity of the L2 cell dendritic trees measured in the distal lamina. In turn, silencing of the Atg7 gene in L2 cells changes the pattern of this rhythm. Our results indicate that the TOR signaling pathway and autophagy are involved in the regulation of circadian rhythms in the behavior and plasticity of neurons in the brain of adult flies.

  8. Brain-machine interfaces in space: Using spontaneous rather than intentionally generated brain signals

    NARCIS (Netherlands)

    Coffey, E.B.J.; Brouwer, A.M.; Wilschut, E.S.; Erp, J.B.F. van

    2010-01-01

    De auteurs bespreken de beperkingen en mogelijkheden van gesuggereerde BMI toepassingen in een ruimtevaart en breken een lans voor BMIs die zijn gebaseerd op spontane in plaats van op doelbewuste hersensignalen

  9. Brain dynamics in the comprehension of action-related language. A time-frequency analysis of mu rhythms.

    Science.gov (United States)

    Moreno, Iván; de Vega, Manuel; León, Inmaculada; Bastiaansen, Marcel; Glen Lewis, Ashley; Magyari, Lilla

    2015-04-01

    EEG mu rhythms (8-13 Hz) recorded at fronto-central electrodes are generally considered as markers of motor cortical activity in humans, because they are modulated when participants perform an action, when they observe another's action or even when they imagine performing an action. In this study, we analyzed the time-frequency (TF) modulation of mu rhythms while participants read action language ("You will cut the strawberry cake"), abstract language ("You will doubt the patient's argument"), and perceptive language ("You will notice the bright day"). The results indicated that mu suppression at fronto-central sites is associated with action language rather than with abstract or perceptive language. Also, the largest difference between conditions occurred quite late in the sentence, while reading the first noun, (contrast Action vs. Abstract), or the second noun following the action verb (contrast Action vs. Perceptive). This suggests that motor activation is associated with the integration of words across the sentence beyond the lexical processing of the action verb. Source reconstruction localized mu suppression associated with action sentences in premotor cortex (BA 6). The present study suggests (1) that the understanding of action language activates motor networks in the human brain, and (2) that this activation occurs online based on semantic integration across multiple words in the sentence. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Human Brain Basis of Musical Rhythm Perception: Common and Distinct Neural Substrates for Meter, Tempo, and Pattern

    Directory of Open Access Journals (Sweden)

    Michael H. Thaut

    2014-06-01

    Full Text Available Rhythm as the time structure of music is composed of distinct temporal components such as pattern, meter, and tempo. Each feature requires different computational processes: meter involves representing repeating cycles of strong and weak beats; pattern involves representing intervals at each local time point which vary in length across segments and are linked hierarchically; and tempo requires representing frequency rates of underlying pulse structures. We explored whether distinct rhythmic elements engage different neural mechanisms by recording brain activity of adult musicians and non-musicians with positron emission tomography (PET as they made covert same-different discriminations of (a pairs of rhythmic, monotonic tone sequences representing changes in pattern, tempo, and meter, and (b pairs of isochronous melodies. Common to pattern, meter, and tempo tasks were focal activities in right, or bilateral, areas of frontal, cingulate, parietal, prefrontal, temporal, and cerebellar cortices. Meter processing alone activated areas in right prefrontal and inferior frontal cortex associated with more cognitive and abstract representations. Pattern processing alone recruited right cortical areas involved in different kinds of auditory processing. Tempo processing alone engaged mechanisms subserving somatosensory and premotor information (e.g., posterior insula, postcentral gyrus. Melody produced activity different from the rhythm conditions (e.g., right anterior insula and various cerebellar areas. These exploratory findings suggest the outlines of some distinct neural components underlying the components of rhythmic structure.

  11. Human brain basis of musical rhythm perception: common and distinct neural substrates for meter, tempo, and pattern.

    Science.gov (United States)

    Thaut, Michael H; Trimarchi, Pietro Davide; Parsons, Lawrence M

    2014-06-17

    Rhythm as the time structure of music is composed of distinct temporal components such as pattern, meter, and tempo. Each feature requires different computational processes: meter involves representing repeating cycles of strong and weak beats; pattern involves representing intervals at each local time point which vary in length across segments and are linked hierarchically; and tempo requires representing frequency rates of underlying pulse structures. We explored whether distinct rhythmic elements engage different neural mechanisms by recording brain activity of adult musicians and non-musicians with positron emission tomography (PET) as they made covert same-different discriminations of (a) pairs of rhythmic, monotonic tone sequences representing changes in pattern, tempo, and meter, and (b) pairs of isochronous melodies. Common to pattern, meter, and tempo tasks were focal activities in right, or bilateral, areas of frontal, cingulate, parietal, prefrontal, temporal, and cerebellar cortices. Meter processing alone activated areas in right prefrontal and inferior frontal cortex associated with more cognitive and abstract representations. Pattern processing alone recruited right cortical areas involved in different kinds of auditory processing. Tempo processing alone engaged mechanisms subserving somatosensory and premotor information (e.g., posterior insula, postcentral gyrus). Melody produced activity different from the rhythm conditions (e.g., right anterior insula and various cerebellar areas). These exploratory findings suggest the outlines of some distinct neural components underlying the components of rhythmic structure.

  12. Amelioration of psychiatric symptoms through exposure to music individually adapted to brain rhythm disorders - a randomised clinical trial on the basis of fundamental research.

    Science.gov (United States)

    Müller, Wolf; Haffelder, Günter; Schlotmann, Angelika; Schaefers, Andrea T U; Teuchert-Noodt, Gertraud

    2014-01-01

    This pilot study examined, whether long-term exposure of psychiatric patients to music that was individually adapted to brain rhythm disorders associated with psychoticism could act to ameliorate psychiatric symptoms. A total of 50 patients with various psychiatric diagnoses were randomised in a 1:1 ratio to listen to CDs containing either music adapted to brain rhythm anomalies associated with psychoticism - measured via a specific spectral analysis - or standard classical music. Participants were instructed to listen to the CDs over the next 18 months. Psychiatric symptoms in both groups were assessed at baseline and at 4, 8 and 18 months, using the Brief Symptom Inventory (BSI). At 18 months, patients in the experimental group showed significantly decreased BSI scores compared to control patients. Intriguingly, this effect was not only seen for symptoms of psychoticism and paranoia but also for anxiety, phobic anxiety and somatisation. Exposure to the adapted music was effective in ameliorating psychotic, anxiety and phobic anxiety symptoms. Based on the theories of neuroplasticity and brain rhythms, it can be hypothesised that this intervention may be enhancing brain-rhythm synchronisation and plasticity in prefrontal-hippocampal circuits that are implicated in both psychosis/paranoia and anxiety/phobic anxiety.

  13. Brain response to a rhythm deviant in adolescent cochlear implant users before and after an intensive musical training program

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Weed, Ethan; Hansen, Mads

    Music and prosody share many of the same relevant acoustic features: pitch, rhythm, and timbre. For cochlear implant (CI) users perception of all of these is challenging. While previous studies have primarily examined implant outcome in adult CI-recipients with an acquired hearing loss (HL), few...... studies have investigated perception of music, prosody, and speech in the growing population of adolescent CI users with a congenital HL. However, recent studies indicate that to keep pace with their normal hearing (NH) peers, supplementary measures of rehabilitation are important throughout adolescence....... This study aimed to investigate auditory brain processing of musical sounds relevant to prosody processing in adolescent CI-users who have received their implant in childhood. Furthermore, we aimed to investigate the potential impact of intensive musical training on adolescent CI-users’ discrimination...

  14. A Novel Mu Rhythm-based Brain Computer Interface Design that uses a Programmable System on Chip.

    Science.gov (United States)

    Joshi, Rohan; Saraswat, Prateek; Gajendran, Rudhram

    2012-01-01

    This paper describes the system design of a portable and economical mu rhythm based Brain Computer Interface which employs Cypress Semiconductors Programmable System on Chip (PSoC). By carrying out essential processing on the PSoC, the use of an extra computer is eliminated, resulting in considerable cost savings. Microsoft Visual Studio 2005 and PSoC Designer 5.01 are employed in developing the software for the system, the hardware being custom designed. In order to test the usability of the BCI, preliminary testing is carried out by training three subjects who were able to demonstrate control over their electroencephalogram by moving a cursor present at the center of the screen towards the indicated direction with an average accuracy greater than 70% and a bit communication rate of up to 7 bits/min.

  15. Spontaneous Wheel Running Exercise Induces Brain Recovery via Neurotrophin-3 Expression Following Experimental Traumatic Brain Injury in Rats.

    Science.gov (United States)

    Koo, Hyun Mo; Lee, Sun Min; Kim, Min Hee

    2013-09-01

    [Purpose] The aim of the present study was to investigate the expression of neurotrophin-3 (NT-3) after applying spontaneous wheel running exercises (SWR) after experimental traumatic brain injury (TBI). [Subjects and Methods] Thirty male Sprague-Dawley rats were divided into 3 groups; 20 rats were subjected to controlled cortical impact for TBI, and then, animals were randomly collected from the SWR group and subjected to wheel running exercise for 3 weeks. Ten rats were not subjected to any injury or running exercise to compare with the effect of TBI and SWR. Immunohistochemistry, Western blotting, skilled ladder rung walking test, and 2,3,5-triphenyltetrazolium chloride staining analysis for the evaluation of NT-3 expression were used to assess brain damage and recovery. [Results] The TBI-induced decrease in NT-3 expression was recovered by wheel running exercise. Moreover, decreased ischemic volume and progressive neurobehavioral outcome were observed in the SWR group. [Conclusion] Spontaneous running exercise promotes brain recovery and motor function through an increase in expression of NT-3.

  16. Fast sparsely synchronized brain rhythms in a scale-free neural network.

    Science.gov (United States)

    Kim, Sang-Yoon; Lim, Woochang

    2015-08-01

    We consider a directed version of the Barabási-Albert scale-free network model with symmetric preferential attachment with the same in- and out-degrees and study the emergence of sparsely synchronized rhythms for a fixed attachment degree in an inhibitory population of fast-spiking Izhikevich interneurons. Fast sparsely synchronized rhythms with stochastic and intermittent neuronal discharges are found to appear for large values of J (synaptic inhibition strength) and D (noise intensity). For an intensive study we fix J at a sufficiently large value and investigate the population states by increasing D. For small D, full synchronization with the same population-rhythm frequency fp and mean firing rate (MFR) fi of individual neurons occurs, while for large D partial synchronization with fp>〈fi〉 (〈fi〉: ensemble-averaged MFR) appears due to intermittent discharge of individual neurons; in particular, the case of fp>4〈fi〉 is referred to as sparse synchronization. For the case of partial and sparse synchronization, MFRs of individual neurons vary depending on their degrees. As D passes a critical value D* (which is determined by employing an order parameter), a transition to unsynchronization occurs due to the destructive role of noise to spoil the pacing between sparse spikes. For D

  17. Fast sparsely synchronized brain rhythms in a scale-free neural network

    Science.gov (United States)

    Kim, Sang-Yoon; Lim, Woochang

    2015-08-01

    We consider a directed version of the Barabási-Albert scale-free network model with symmetric preferential attachment with the same in- and out-degrees and study the emergence of sparsely synchronized rhythms for a fixed attachment degree in an inhibitory population of fast-spiking Izhikevich interneurons. Fast sparsely synchronized rhythms with stochastic and intermittent neuronal discharges are found to appear for large values of J (synaptic inhibition strength) and D (noise intensity). For an intensive study we fix J at a sufficiently large value and investigate the population states by increasing D . For small D , full synchronization with the same population-rhythm frequency fp and mean firing rate (MFR) fi of individual neurons occurs, while for large D partial synchronization with fp> ( : ensemble-averaged MFR) appears due to intermittent discharge of individual neurons; in particular, the case of fp>4 is referred to as sparse synchronization. For the case of partial and sparse synchronization, MFRs of individual neurons vary depending on their degrees. As D passes a critical value D* (which is determined by employing an order parameter), a transition to unsynchronization occurs due to the destructive role of noise to spoil the pacing between sparse spikes. For D change depending on their degrees, unlike in the case of full synchronization. Consequently, dynamics of individual neurons reveal the inhomogeneous network structure for the case of partial and sparse synchronization, which is in contrast to the case of statistically homogeneous random graphs and small-world networks. Finally, we investigate the effect of network architecture on sparse synchronization for fixed values of J and D in the following three cases: (1) variation in the degree of symmetric attachment, (2) asymmetric preferential attachment of new nodes with different in- and out-degrees, and (3) preferential attachment between pre-existing nodes (without addition of new nodes). In these

  18. Spontaneous sleep-like brain state alternations and breathing characteristics in urethane anesthetized mice.

    Directory of Open Access Journals (Sweden)

    Silvia Pagliardini

    Full Text Available Brain state alternations resembling those of sleep spontaneously occur in rats under urethane anesthesia and they are closely linked with sleep-like respiratory changes. Although rats are a common model for both sleep and respiratory physiology, we sought to determine if similar brain state and respiratory changes occur in mice under urethane. We made local field potential recordings from the hippocampus and measured respiratory activity by means of EMG recordings in intercostal, genioglossus, and abdominal muscles. Similar to results in adult rats, urethane anesthetized mice displayed quasi-periodic spontaneous forebrain state alternations between deactivated patterns resembling slow wave sleep (SWS and activated patterns resembling rapid eye movement (REM sleep. These alternations were associated with an increase in breathing rate, respiratory variability, a depression of inspiratory related activity in genioglossus muscle and an increase in expiratory-related abdominal muscle activity when comparing deactivated (SWS-like to activated (REM-like states. These results demonstrate that urethane anesthesia consistently induces sleep-like brain state alternations and correlated changes in respiratory activity across different rodent species. They open up the powerful possibility of utilizing transgenic mouse technology for the advancement and translation of knowledge regarding sleep cycle alternations and their impact on respiration.

  19. Relationships of Blood Pressure Circadian Rhythm and Brain Natriuretic Peptide with Left Ventricular Hypertrophy in the Patients with Primary Hypertension.

    Science.gov (United States)

    Kou, Hui-Juan; Wang, Xin; Gao, Deng-Feng; Dong, Xin; Wei, Jin; Ma, Rui

    2016-10-10

    Objective To investigate the relationships of blood pressure circadian rhythm and brain natriuretic peptide (BNP) with left ventricular hypertrophy (LVH) in patients with primary hypertension. Methods Totally 349 patients (74 with LVH and 275 without LVH) with primary hypertension were enrolled in this study.Echocardiography was performed to determine left ventricular mass index (LVMI) using the Devereux formula. The nocturnal blood pressure decline rate,24-hour blood pressure (24 h PP; especially 24 h mean systolic blood pressure,24 h SBP) and blood pressure index (PPI) were determined by 24 h-ambulatory blood pressure monitoring. These 349 hypertensive patients were divided into four groups including supper-dipper group (defined as≥;20%, n=7),dipper group (defined as 10%- 20%, n=77),non-dipper group (defined as 0- 10%, n=173),and anti-dipper group (defined ashypertension (85.1% vs. 46.9%;χ 2 =34.428,Pblood pressure decline rate [(1.30±8.02)% vs. (5.68±7.25)%; t=-4.510,Phypertensive group had significantly higher BNP level (87.8 pg/ml vs. 28.8 pg/ml; t=2.170,P=0.034) and LVMI (135.1 g/m 2 vs. 88.7 g/m 2 ; t=15.285,Phypertension. Conclusion With the increasing of plasma BNP level,the left ventricular hypertrophy is closely related to abnormal blood pressure circadian rhythm and the grade of hypertension in primary hypertensive patients.

  20. Altered spontaneous brain activity in patients with acute spinal cord injury revealed by resting-state functional MRI.

    Directory of Open Access Journals (Sweden)

    Ling Zhu

    Full Text Available Previous neuroimaging studies have provided evidence of structural and functional reorganization of brain in patients with chronic spinal cord injury (SCI. However, it remains unknown whether the spontaneous brain activity changes in acute SCI. In this study, we investigated intrinsic brain activity in acute SCI patients using a regional homogeneity (ReHo analysis based on resting-state functional magnetic resonance imaging.A total of 15 patients with acute SCI and 16 healthy controls participated in the study. The ReHo value was used to evaluate spontaneous brain activity, and voxel-wise comparisons of ReHo were performed to identify brain regions with altered spontaneous brain activity between groups. We also assessed the associations between ReHo and the clinical scores in brain regions showing changed spontaneous brain activity.Compared with the controls, the acute SCI patients showed decreased ReHo in the bilateral primary motor cortex/primary somatosensory cortex, bilateral supplementary motor area/dorsal lateral prefrontal cortex, right inferior frontal gyrus, bilateral dorsal anterior cingulate cortex and bilateral caudate; and increased ReHo in bilateral precuneus, the left inferior parietal lobe, the left brainstem/hippocampus, the left cingulate motor area, bilateral insula, bilateral thalamus and bilateral cerebellum. The average ReHo values of the left thalamus and right insula were negatively correlated with the international standards for the neurological classification of spinal cord injury motor scores.Our findings indicate that acute distant neuronal damage has an immediate impact on spontaneous brain activity. In acute SCI patients, the ReHo was prominently altered in brain regions involved in motor execution and cognitive control, default mode network, and which are associated with sensorimotor compensatory reorganization. Abnormal ReHo values in the left thalamus and right insula could serve as potential biomarkers for

  1. Biological Rhythms Workshop IB: neurophysiology of SCN pacemaker function.

    Science.gov (United States)

    Kuhlman, S J

    2007-01-01

    Pacemakers are functional units capable of generating oscillations that synchronize downstream rhythms. In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus is a circadian pacemaker composed of individual neurons that intrinsically express a near 24-hour rhythm in gene expression. Rhythmic gene expression is tightly coupled to a rhythm in spontaneous firing rate via intrinsic daily regulation of potassium current. Recent progress in the field indicates that SCN pacemaking is a specialized property that emerges from intrinsic features of single cells, structural connectivity among cells, and activity dynamics within the SCN. The focus of this chapter is on how Nature built a functional pacemaker from many individual oscillators that is capable of coordinating the daily timing of essential brain and physiological processes.

  2. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    Keywords. Circadian rhythms, biological clocks, geophysical cycles, en- trainment. Living organisms ranging from bacteria to human beings exhibit 24-h rhythms in various behaviours and physiological processes. Matching of the period of such rhythms with that of the daily environmental cycles gives an impression that.

  3. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 7. Circadian Rhythms - From Daily Rhythms to Biological Clocks. Koustubh M Vaze Vijay Kumar Sharma. Series Article Volume 18 Issue 7 July 2013 pp 662- ... Keywords. Circadian rhythms; biological clocks; geophysical cycles; entrainment.

  4. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    hunger and sleep at the same time as the body would not be in the right state to metabolise food efficiently. Thus, synchronization of internal rhythms is an essential aspect of physiology, and circadian rhythms benefit living beings by bringing about such temporal order. In other words, circadian rhythms are thought to.

  5. A carnivore species (Canis familiaris) expresses circadian melatonin rhythm in the peripheral blood and melatonin receptors in the brain

    International Nuclear Information System (INIS)

    Stankov, B.; Moeller, M.; Lucini, V.; Capsono, S.; Fraschini, F.

    1994-01-01

    Dogs kept under controlled photoperiodic conditions of 12h light and 12h dark expressed a clear diurnal melatonin rhythm in the peripheral blood, with a swift peak restricted to the late part of the scotophase. The highest density of high-affinity, G-protein-linked 2-[ 125 I]iodomelatonin binding sites was found in the pars tuberalis of the pituitary gland. Binding sites were found also in the pars distalis, and light microscopy/high-resolution autoradiography showed that binding was located exclusively over the chromophobe and basophilic cells forming the adenopituitary zona tuberalis, well developed in the species, and extending into the gland as a continuation of pars tuberalis. Cords of basophilic cells located in the pars distalis proper also expressed high receptor density. Quantitative autoradiography inhibition experiments revealed that the apparent melatonin inhibitory constant in all those areas was around 0.1 nmol/l, which is a physiologically appropriate value considering the peripheral blood melatonin levels. Co-incubation with guanosine 3-thiotriphosphate led to a consequential decrease in the binding density. Collectively, these data show that the dog possesses all the prerequisites for an efficient network adapted to photoperiodic time measurements. A circadian melatonin signal in the peripheral blood and an apparently functional readout receptor system located in key positions within the brain are both present in this species. 43 refs. 6 figs., 1 tabs

  6. Abnormal Spontaneous Brain Activity in Patients With Anisometropic Amblyopia Using Resting-State Functional Magnetic Resonance Imaging.

    Science.gov (United States)

    Tang, Angcang; Chen, Taolin; Zhang, Junran; Gong, Qiyong; Liu, Longqian

    2017-09-01

    To explore the abnormality of spontaneous activity in patients with anisometropic amblyopia under resting-state functional magnetic resonance imaging (Rs-fMRI). Twenty-four participants were split into two groups. The anisometropic amblyopia group had 10 patients, all of whom had anisometropic amblyopia of the right eye, and the control group had 14 healthy subjects. All participants underwent Rs-fMRI scanning. Measurement of amplitude of low frequency fluctuations of the brain, which is a measure of the amplitudes of spontaneous brain activity, was used to investigate brain changes between the anisometropic amblyopia and control groups. Compared with an age- and gender-matched control group, the anisometropic amblyopia group showed increased amplitude of low frequency fluctuations of spontaneous brain activity in the left superior temporal gyrus, the left inferior parietal lobe, the left pons, and the right inferior semi-lunar lobe. The anisometropic amblyopia group also showed decreased amplitude of low frequency fluctuations in the bilateral medial frontal gyrus. This study demonstrated abnormal spontaneous brain activities in patients with anisometropic amblyopia under Rs-fMRI, and these abnormalities might contribute to the neuropathological mechanisms of anisometropic amblyopia. [J Pediatr Ophthalmol Strabismus. 2017;54(5):303-310.]. Copyright 2017, SLACK Incorporated.

  7. Circadian Rhythms in Fear Conditioning: An Overview of Behavioral, Brain System, and Molecular Interactions

    Directory of Open Access Journals (Sweden)

    Anne Albrecht

    2017-01-01

    Full Text Available The formation of fear memories is a powerful and highly evolutionary conserved mechanism that serves the behavioral adaptation to environmental threats. Accordingly, classical fear conditioning paradigms have been employed to investigate fundamental molecular processes of memory formation. Evidence suggests that a circadian regulation mechanism allows for a timestamping of such fear memories and controlling memory salience during both their acquisition and their modification after retrieval. These mechanisms include an expression of molecular clocks in neurons of the amygdala, hippocampus, and medial prefrontal cortex and their tight interaction with the intracellular signaling pathways that mediate neural plasticity and information storage. The cellular activities are coordinated across different brain regions and neural circuits through the release of glucocorticoids and neuromodulators such as acetylcholine, which integrate circadian and memory-related activation. Disturbance of this interplay by circadian phase shifts or traumatic experience appears to be an important factor in the development of stress-related psychopathology, considering these circadian components are of critical importance for optimizing therapeutic approaches to these disorders.

  8. High frequency deep brain stimulation attenuates subthalamic and cortical rhythms in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Diane eWhitmer

    2012-06-01

    Full Text Available Parkinson’s disease (PD is marked by excessive synchronous activity in the beta (8-35 Hz band throughout the cortico-basal ganglia network. The optimal location of high frequency deep brain stimulation (HF DBS within the subthalamic nucleus (STN region and the location of maximal beta hypersynchrony are currently matters of debate. Additionally, the effect of STN HF DBS on neural synchrony in functionally connected regions of motor cortex is unknown and of great interest. Scalp EEG studies demonstrated that stimulation of the STN can activate motor cortex antidromically, but the spatial specificity of this effect has not been examined. The present study examined the effect of STN HF DBS on neural synchrony within the cortico-basal ganglia network in patients with PD. We measured local field potentials dorsal to and within the STN of PD patients, and additionally in the motor cortex in a subset of these patients. We used diffusion tensor imaging (DTI to guide the placement of subdural cortical surface electrodes over the DTI-identified origin of the hyperdirect pathway between motor cortex and the STN. The results demonstrated that local beta power was attenuated during HF DBS both dorsal to and within the STN. The degree of attenuation was monotonic with increased DBS voltages in both locations, but this voltage-dependent effect was greater in the central STN than dorsal to the STN (p < 0.05. Cortical signals over the estimated origin of the hyperdirect pathway also demonstrated attenuation of beta hypersynchrony during DBS dorsal to or within STN, whereas signals from non-specific regions of motor cortex were not attenuated. The spatially specific suppression of beta synchrony in the motor cortex support the hypothesis that DBS may treat Parkinsonism by reducing excessive synchrony in the functionally connected sensorimotor network.

  9. Visuo-motor coordination ability predicts performance with brain-computer interfaces controlled by modulation of sensorimotor rhythms (SMR

    Directory of Open Access Journals (Sweden)

    Eva Maria Hammer

    2014-08-01

    Full Text Available Modulation of sensorimotor rhythms (SMR was suggested as a control signal for brain-computer interfaces (BCI. Yet, there is a population of users estimated between 10 to 50% not able to achieve reliable control and only about 20% of users achieve high (80-100% performance. Predicting performance prior to BCI use would facilitate selection of the most feasible system for an individual, thus constitute a practical benefit for the user, and increase our knowledge about the correlates of BCI control. In a recent study, we predicted SMR-BCI performance from psychological variables that were assessed prior to the BCI sessions and BCI control was supported with machine-learning techniques. We described two significant psychological predictors, namely the visuo-motor coordination ability and the ability to concentrate on the task. The purpose of the current study was to replicate these results thereby validating these predictors within a neurofeedback based SMR-BCI that involved no machine learning. Thirty-three healthy BCI novices participated in a calibration session and three further neurofeedback training sessions. Two variables were related with mean SMR-BCI performance: (1 A measure for the accuracy of fine motor skills, i.e. a trade for a person’s visuo-motor control ability and (2 subject’s attentional impulsivity. In a linear regression they accounted for almost 20% in variance of SMR-BCI performance, but predictor (1 failed significance. Nevertheless, on the basis of our prior regression model for sensorimotor control ability we could predict current SMR-BCI performance with an average prediction error of M = 12.07%. In more than 50% of the participants, the prediction error was smaller than 10%. Hence, psychological variables played a moderate role in predicting SMR-BCI performance in a neurofeedback approach that involved no machine learning. Future studies are needed to further consolidate (or reject the present predictors.

  10. Moving on time: brain network for auditory-motor synchronization is modulated by rhythm complexity and musical training.

    Science.gov (United States)

    Chen, Joyce L; Penhune, Virginia B; Zatorre, Robert J

    2008-02-01

    Much is known about the motor system and its role in simple movement execution. However, little is understood about the neural systems underlying auditory-motor integration in the context of musical rhythm, or the enhanced ability of musicians to execute precisely timed sequences. Using functional magnetic resonance imaging, we investigated how performance and neural activity were modulated as musicians and nonmusicians tapped in synchrony with progressively more complex and less metrically structured auditory rhythms. A functionally connected network was implicated in extracting higher-order features of a rhythm's temporal structure, with the dorsal premotor cortex mediating these auditory-motor interactions. In contrast to past studies, musicians recruited the prefrontal cortex to a greater degree than nonmusicians, whereas secondary motor regions were recruited to the same extent. We argue that the superior ability of musicians to deconstruct and organize a rhythm's temporal structure relates to the greater involvement of the prefrontal cortex mediating working memory.

  11. [Circadian rhythms and systems biology].

    Science.gov (United States)

    Goldbeter, Albert; Gérard, Claude; Leloup, Jean-Christophe

    2010-01-01

    Cellular rhythms represent a field of choice for studies in system biology. The examples of circadian rhythms and of the cell cycle show how the experimental and modeling approaches contribute to clarify the conditions in which periodic behavior spontaneously arises in regulatory networks at the cellular level. Circadian rhythms originate from intertwined positive and negative feedback loops controlling the expression of several clock genes. Models can be used to address the dynamical bases of physiological disorders related to dysfunctions of the mammalian circadian clock. The cell cycle is driven by a network of cyclin-dependent kinases (Cdks). Modeled in the form of four modules coupled through multiple regulatory interactions, the Cdk network operates in an oscillatory manner in the presence of sufficient amounts of growth factor. For circadian rhythms and the cell cycle, as for other recently observed cellular rhythms, periodic behavior represents an emergent property of biological systems related to their regulatory structure.

  12. Alterations in substance P binding in brain nuclei of spontaneously hypertensive rats

    International Nuclear Information System (INIS)

    Shigematsu, K.; Niwa, M.; Kurihara, M.; Castren, E.; Saavedra, J.M.

    1987-01-01

    Substance P binding sites were characterized in brain nuclei of young (4-wk-old) and adult (16-wk-old) spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto (WKY) control rats by quantitative autoradiography. Young SHR presented higher affinity constants (K/sub A/) than young WKY. The changes were restricted to locus coeruleus, the area postrema, the dorsal motor nucleus of the vagus, and to discrete areas located in lobes 9 and 10 of the vermis cerebelli of SHR. There were no differences in the maximal binding capacity (B/sub max/) except in the nucleus ambiguus where the B/sub max/ was lower than WKY. Conversely, the number of substance P binding sites was higher in the locus coeruleus, the nucleus tegmentalis dorsalis, the nucleus ambiguus, the dorsal motor nucleus of the vagus, the hypoglossal nucleus, the inferior olivary nucleus, and lobes 9 and 10 of the vermis cerebelli of adult SHR when compared with adult WKY. The results support the hypothesis of a role for brain substance P in blood pressure regulation and in genetic hypertension in rats

  13. Brain activity dynamics in human parietal regions during spontaneous switches in bistable perception.

    Science.gov (United States)

    Megumi, Fukuda; Bahrami, Bahador; Kanai, Ryota; Rees, Geraint

    2015-02-15

    The neural mechanisms underlying conscious visual perception have been extensively investigated using bistable perception paradigms. Previous functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies suggest that the right anterior superior parietal (r-aSPL) and the right posterior superior parietal lobule (r-pSPL) have opposite roles in triggering perceptual reversals. It has been proposed that these two areas are part of a hierarchical network whose dynamics determine perceptual switches. However, how these two parietal regions interact with each other and with the rest of the brain during bistable perception is not known. Here, we investigated such a model by recording brain activity using fMRI while participants viewed a bistable structure-from-motion stimulus. Using dynamic causal modeling (DCM), we found that resolving such perceptual ambiguity was specifically associated with reciprocal interactions between these parietal regions and V5/MT. Strikingly, the strength of bottom-up coupling between V5/MT to r-pSPL and from r-pSPL to r-aSPL predicted individual mean dominance duration. Our findings are consistent with a hierarchical predictive coding model of parietal involvement in bistable perception and suggest that visual information processing underlying spontaneous perceptual switches can be described as changes in connectivity strength between parietal and visual cortical regions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  14. The Kantian brain: brain dynamics from a neurophenomenological perspective.

    Science.gov (United States)

    Fazelpour, Sina; Thompson, Evan

    2015-04-01

    Current research on spontaneous, self-generated brain rhythms and dynamic neural network coordination cast new light on Immanuel Kant's idea of the 'spontaneity' of cognition, that is, the mind's capacity to organize and synthesize sensory stimuli in novel, unprecedented ways. Nevertheless, determining the precise nature of the brain-cognition mapping remains an outstanding challenge. Neurophenomenology, which uses phenomenological information about the variability of subjective experience in order to illuminate the variability of brain dynamics, offers a promising method for addressing this challenge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    rhythms especially their endogenous, self-sustained nature, ability to entrain to environmental cycles and. PRCs, greatly resemble those of self-sustained physical oscillators; which led them to propose that circadian rhythms function like physical oscillators and named such biological oscillators as 'endogenous self- ...

  16. A Pilot Study on the Effects of Transcranial Direct Current Stimulation on Brain Rhythms and Entropy during Self-Paced Finger Movement using the Epoc Helmet.

    Science.gov (United States)

    Bodranghien, Florian C A A; Langlois Mahe, Margot; Clément, Serge; Manto, Mario U

    2017-01-01

    Transcranial direct current stimulation (tDCS) of the cerebellum is emerging as a novel non-invasive tool to modulate the activity of the cerebellar circuitry. In a single blinded study, we applied anodal tDCS (atDCS) of the cerebellum to assess its effects on brain entropy and brain rhythms during self-paced sequential finger movements in a group of healthy volunteers. Although wearable electroencephalogram (EEG) systems cannot compete with traditional clinical/laboratory set-ups in terms of accuracy and channel density, they have now reached a sufficient maturity to envision daily life applications. Therefore, the EEG was recorded with a comfortable and easy to wear 14 channels wireless helmet (Epoc headset; electrode location was based on the 10-20 system). Cerebellar neurostimulation modified brain rhythmicity with a decrease in the delta band (electrode F3 and T8, p Epoc headset.

  17. Tangible User Interface and Mu Rhythm Suppression: The Effect of User Interface on the Brain Activity in Its Operator and Observer

    Directory of Open Access Journals (Sweden)

    Kazuo Isoda

    2017-03-01

    Full Text Available The intuitiveness of tangible user interface (TUI is not only for its operator. It is quite possible that this type of user interface (UI can also have an effect on the experience and learning of observers who are just watching the operator using it. To understand the possible effect of TUI, the present study focused on the mu rhythm suppression in the sensorimotor area reflecting execution and observation of action, and investigated the brain activity both in its operator and observer. In the observer experiment, the effect of TUI on its observers was demonstrated through the brain activity. Although the effect of the grasping action itself was uncertain, the unpredictability of the result of the action seemed to have some effect on the mirror neuron system (MNS-related brain activity. In the operator experiment, in spite of the same grasping action, the brain activity was activated in the sensorimotor area when UI functions were included (TUI. Such activation of the brain activity was not found with a graphical user interface (GUI that has UI functions without grasping action. These results suggest that the MNS-related brain activity is involved in the effect of TUI, indicating the possibility of UI evaluation based on brain activity.

  18. Diffuse pachymeningeal enhancement on brain MRI: spontaneous intracranial hypotension and head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Chang Woo; Lee, Byung Hee; Lee, Seung Ik; Kim, Young A; Kim, Hee Jin; Ko, Young Sik [Pochon CHA Univ. College of Medicine, Sungnam (Korea, Republic of)

    1998-11-01

    We evaluated the MRI finding of pachymeningeal enhancement in patients with intracranial hypotension and head trauma with particular attention to differential findings and change in follow-up study, and in order to support the knowledge about the pathophysiology of dural enhancement. The findings of enhanced brain MRI of fifteen patients who showed diffuse pachymeningeal enhancement were retrospectively examined. Seven of fifteen patients were finally diagnosed as spontaneous intracranial hypotension (SIH). Eight of fifteen patients had a recent history of head trauma. We analyzed the shape, thickness, continuity and extent of dural enhancement, and the others concerned with positive MR findings. We also analyzed findings suggested displacement of brain parenchyma-displacement of the iter and cerebellar tonsil, and flattening of the anterior aspect of the pons-. Four of seven patients with SIH and four of eight patients with head trauma, underwent follow-up MRI. In the follow-up study, the presence of resolving pachymeningeal enhancement and symptom improvement was investigated. In all cases of SIH, the dura showed diffuse, even 31mm thick, global and contiguous enhancement along both cerebral convexities, both tentoria, and the falx. Displacement of the iter was noted in six cases and flattening of the anterior aspect of the pons in five. Displacement of the cerebellar tonsil was noted in one case. Five of seven cases showed small amount of subdural fluid collection. In all cases of head trauma, the dura was enhanced diffusely and asymmetrically, and showed no contiguity. Its distribution was consistent with the locations of traumatic lesions. Displacement of the iter was noted in one case. In four cases of SIH, clinical symptoms had improved, and three showed complete resolution of dural enhancement, in one patient continuously showed partial dural enhancement. Four cases of head trauma showed complete resolution of dural enhancement. Reversible diffuse

  19. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 11. Circadian Rhythms - Circadian Timing Systems: How are they Organized? Koustubh M Vaze Vijay Kumar Sharma. Series Article Volume 18 Issue 11 November 2013 pp 1032-1050 ...

  20. Comparative Analysis of Human and Rodent Brain Primary Neuronal Culture Spontaneous Activity Using Micro-Electrode Array Technology.

    Science.gov (United States)

    Napoli, Alessandro; Obeid, Iyad

    2016-03-01

    Electrical activity in embryonic brain tissue has typically been studied using Micro Electrode Array (MEA) technology to make dozens of simultaneous recordings from dissociated neuronal cultures, brain stem cell progenitors, or brain slices from fetal rodents. Although these rodent neuronal primary culture electrical properties are mostly investigated, it has not been yet established to what extent the electrical characteristics of rodent brain neuronal cultures can be generalized to those of humans. A direct comparison of spontaneous spiking activity between rodent and human primary neurons grown under the same in vitro conditions using MEA technology has never been carried out before and will be described in the present study. Human and rodent dissociated fetal brain neuronal cultures were established in-vitro by culturing on a glass grid of 60 planar microelectrodes neurons under identical conditions. Three different cultures of human neurons were produced from tissue sourced from a single aborted fetus (at 16-18 gestational weeks) and these were compared with seven different cultures of embryonic rat neurons (at 18 gestational days) originally isolated from a single rat. The results show that the human and rodent cultures behaved significantly differently. Whereas the rodent cultures demonstrated robust spontaneous activation and network activity after only 10 days, the human cultures required nearly 40 days to achieve a substantially weaker level of electrical function. These results suggest that rat neuron preparations may yield inferences that do not necessarily transfer to humans. © 2015 Wiley Periodicals, Inc.

  1. Combining task-evoked and spontaneous activity to improve pre-operative brain mapping with fMRI

    Science.gov (United States)

    Fox, Michael D.; Qian, Tianyi; Madsen, Joseph R.; Wang, Danhong; Li, Meiling; Ge, Manling; Zuo, Huan-cong; Groppe, David M.; Mehta, Ashesh D.; Hong, Bo; Liu, Hesheng

    2016-01-01

    Noninvasive localization of brain function is used to understand and treat neurological disease, exemplified by pre-operative fMRI mapping prior to neurosurgical intervention. The principal approach for generating these maps relies on brain responses evoked by a task and, despite known limitations, has dominated clinical practice for over 20 years. Recently, pre-operative fMRI mapping based on correlations in spontaneous brain activity has been demonstrated, however this approach has its own limitations and has not seen widespread clinical use. Here we show that spontaneous and task-based mapping can be performed together using the same pre-operative fMRI data, provide complimentary information relevant for functional localization, and can be combined to improve identification of eloquent motor cortex. Accuracy, sensitivity, and specificity of our approach are quantified through comparison with electrical cortical stimulation mapping in eight patients with intractable epilepsy. Broad applicability and reproducibility of our approach is demonstrated through prospective replication in an independent dataset of six patients from a different center. In both cohorts and every individual patient, we see a significant improvement in signal to noise and mapping accuracy independent of threshold, quantified using receiver operating characteristic curves. Collectively, our results suggest that modifying the processing of fMRI data to incorporate both task-based and spontaneous activity significantly improves functional localization in pre-operative patients. Because this method requires no additional scan time or modification to conventional pre-operative data acquisition protocols it could have widespread utility. PMID:26408860

  2. Spontaneous Brain Activity Did Not Show the Effect of Violent Video Games on Aggression: A Resting-State fMRI Study

    OpenAIRE

    Wei Pan; Wei Pan; Wei Pan; Xuemei Gao; Shuo Shi; Fuqu Liu; Chao Li

    2018-01-01

    A great many of empirical researches have proved that longtime exposure to violent video game can lead to a series of negative effects. Although research has focused on the neural basis of the correlation between violent video game and aggression, little is known whether the spontaneous brain activity is associated with violent video game exposure. To address this question, we measured the spontaneous brain activity using resting-state functional magnetic resonance imaging (fMRI). We used the...

  3. Circadian rhythms in Macaca mulatta monkeys during Bion 11 flight

    Science.gov (United States)

    Alpatov, A. M.; Hoban-Higgins, T. M.; Klimovitsky, V. Y.; Tumurova, E. G.; Fuller, C. A.

    2000-01-01

    Circadian rhythms of primate brain temperature, head and ankle skin temperature, motor activity, and heart rate were studied during spaceflight and on the ground. In space, the circadian rhythms of all the parameters were synchronized with diurnal Zeitgebers. However, in space the brain temperature rhythm showed a significantly more delayed phase angle, which may be ascribed to an increase of the endogenous circadian period.

  4. Biological rhythms

    Science.gov (United States)

    Halberg, F.

    1975-01-01

    An overview is given of basic features of biological rhythms. The classification of periodic behavior of physical and psychological characteristics as circadian, circannual, diurnal, and ultradian is discussed, and the notion of relativistic time as it applies in biology is examined. Special attention is given to circadian rhythms which are dependent on the adrenocortical cycle. The need for adequate understanding of circadian variations in the basic physiological indicators of an individual (heart rate, body temperature, systolic and diastolic blood pressure, etc.) to ensure the effectiveness of prophylactic and therapeutic measures is stressed.

  5. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    We all experience robust cycles of light and darkness, occurring as a consequence of continuous rotation of the earth about its axis and we call such a twenty-four hour cycle, 'a day'. Almost all living beings are exposed to such daily environmental cycles and they too exhibit daily rhythms in various biological processes.

  6. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    internal/physiological (endogenous) mechanism that drives them? Such questions have intrigued scientists for several decades and paved the way for the exploration of biological timing systems and their underlying mechanisms. Research on a wide variety of organisms has established that these rhythms are generated by.

  7. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    significance. (right) Vijay Kumar Sharma is a Professor at the. Evolutionary and. Organismal Biology Unit,. JNCASR, Bangalore. His major research interests presently are in understand- ing circadian organization of fruit flies and ants, adaptive significance of circadian clocks, neurogenetics of circadian egg-laying rhythm.

  8. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2. Circadian Rhythms: Why do Living Organisms Have Them? Koustubh M Vaze K L Nikhil Vijay Kumar Sharma. Series Article Volume 19 Issue 2 February 2014 pp 175-189 ...

  9. DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests.

    Science.gov (United States)

    López-Gil, Xavier; Amat-Roldan, Iván; Tudela, Raúl; Castañé, Anna; Prats-Galino, Alberto; Planas, Anna M; Farr, Tracy D; Soria, Guadalupe

    2014-01-01

    The identification of biomarkers of vascular cognitive impairment is urgent for its early diagnosis. The aim of this study was to detect and monitor changes in brain structure and connectivity, and to correlate them with the decline in executive function. We examined the feasibility of early diagnostic magnetic resonance imaging (MRI) to predict cognitive impairment before onset in an animal model of chronic hypertension: Spontaneously Hypertensive Rats. Cognitive performance was tested in an operant conditioning paradigm that evaluated learning, memory, and behavioral flexibility skills. Behavioral tests were coupled with longitudinal diffusion weighted imaging acquired with 126 diffusion gradient directions and 0.3 mm(3) isometric resolution at 10, 14, 18, 22, 26, and 40 weeks after birth. Diffusion weighted imaging was analyzed in two different ways, by regional characterization of diffusion tensor imaging (DTI) indices, and by assessing changes in structural brain network organization based on Q-Ball tractography. Already at the first evaluated times, DTI scalar maps revealed significant differences in many regions, suggesting loss of integrity in white and gray matter of spontaneously hypertensive rats when compared to normotensive control rats. In addition, graph theory analysis of the structural brain network demonstrated a significant decrease of hierarchical modularity, global and local efficacy, with predictive value as shown by regional three-fold cross validation study. Moreover, these decreases were significantly correlated with the behavioral performance deficits observed at subsequent time points, suggesting that the diffusion weighted imaging and connectivity studies can unravel neuroimaging alterations even overt signs of cognitive impairment become apparent.

  10. [Biological rhythms for anaesthesia and intensive care].

    Science.gov (United States)

    Dispersyn, G; Chassard, D; Pain, L

    2010-06-01

    Knowledge of biological rhythms has led to better understanding of the time-of-day dependent effects of anaesthetic drugs. These chronopharmacological effects are currently explained by the biological rhythms modulating the pharmacokinetic, toxic and pharmacodynamic parameters of these substances. Such effect has been described for general anesthetics, local anaesthetics, analgesics as well as for antibiotics. But recent data also highlight that general anaesthetics, probably part of their brain effects, also alter the regulation of biological rhythms, including the sleep-wake or the endogenous circadian temperature rhythms. This desynchronization of biological rhythms can led to disturbance of the circadian secretion of many substances, including hormones. Finally, biological rhythms have been also described with regard to physiology of pain and cardiovascular physiopathology. The concept of biological rhythm should be present in mind not only for the clinical management of patients but also for setting studies in the field of anaesthesia, pain and intensive care. 2010. Published by Elsevier SAS.

  11. Combining task-evoked and spontaneous activity to improve pre-operative brain mapping with fMRI.

    Science.gov (United States)

    Fox, Michael D; Qian, Tianyi; Madsen, Joseph R; Wang, Danhong; Li, Meiling; Ge, Manling; Zuo, Huan-Cong; Groppe, David M; Mehta, Ashesh D; Hong, Bo; Liu, Hesheng

    2016-01-01

    Noninvasive localization of brain function is used to understand and treat neurological disease, exemplified by pre-operative fMRI mapping prior to neurosurgical intervention. The principal approach for generating these maps relies on brain responses evoked by a task and, despite known limitations, has dominated clinical practice for over 20years. Recently, pre-operative fMRI mapping based on correlations in spontaneous brain activity has been demonstrated, however this approach has its own limitations and has not seen widespread clinical use. Here we show that spontaneous and task-based mapping can be performed together using the same pre-operative fMRI data, provide complimentary information relevant for functional localization, and can be combined to improve identification of eloquent motor cortex. Accuracy, sensitivity, and specificity of our approach are quantified through comparison with electrical cortical stimulation mapping in eight patients with intractable epilepsy. Broad applicability and reproducibility of our approach are demonstrated through prospective replication in an independent dataset of six patients from a different center. In both cohorts and every individual patient, we see a significant improvement in signal to noise and mapping accuracy independent of threshold, quantified using receiver operating characteristic curves. Collectively, our results suggest that modifying the processing of fMRI data to incorporate both task-based and spontaneous activity significantly improves functional localization in pre-operative patients. Because this method requires no additional scan time or modification to conventional pre-operative data acquisition protocols it could have widespread utility. Copyright © 2015. Published by Elsevier Inc.

  12. The formation and regional distribution of prostaglandins D2 and F2 alpha in the brain of spontaneously convulsing gerbils.

    Science.gov (United States)

    Seregi, A; Förstermann, U; Heldt, R; Hertting, G

    1985-06-24

    The distribution of the two major cyclooxygenase products prostaglandin D2 (PGD2) and prostaglandin F2 alpha (PGF2 alpha) in 7 different regions of the brain (medulla, cerebellum, hypothalamus, striatum, midbrain, hippocampus and cerebral cortex) was studied. Basal levels were highest in hypothalamus and cortex. Following convulsions elicited by environmental stress prostaglandin concentrations increased in all areas, with largest increases (10-20-fold) in hippocampus and cortex, reaching 70 ng/g PGD2 in hippocampus and 115 ng/g PGD2 in cortex. These results demonstrate that, during spontaneous seizures, there is a greater increase in prostanoid production in those areas involved in the convulsive process.

  13. Spontaneous ischaemic stroke lesions in a dog brain: neuropathological characterisation and comparison to human ischaemic stroke

    DEFF Research Database (Denmark)

    Thomsen, Barbara Blicher; Gredal, Hanne; Wirenfeldt, Martin

    2017-01-01

    Background Dogs develop spontaneous ischaemic stroke with a clinical picture closely resembling human ischaemic stroke patients. Animal stroke models have been developed, but it has proved difficult to translate results obtained from such models into successful therapeutic strategies in human....../macrophages and astrocytes. Conclusions The neuropathological changes reported in the present study were similar to findings in human patients with ischaemic stroke. The dog with spontaneous ischaemic stroke is of interest as a complementary spontaneous animal model for further neuropathological studies....... stroke patients. In order to face this apparent translational gap within stroke research, dogs with ischaemic stroke constitute an opportunity to study the neuropathology of ischaemic stroke in an animal species. Case presentation A 7 years and 8 months old female neutered Rottweiler dog suffered...

  14. Brain spontaneous fluctuations in sensorimotor regions were directly related to eyes open and eyes closed: evidences from a machine learning approach

    Directory of Open Access Journals (Sweden)

    Bishan eLiang

    2014-08-01

    Full Text Available Previous studies have demonstrated that the difference between resting-state brain activations depends on whether the subject was eyes open (EO or eyes closed (EC. However, whether the spontaneous fluctuations are directly related to these two different resting states are still largely unclear. In the present study, we acquired resting-state functional magnetic resonance imaging data from 24 healthy subjects (11 males, 20.17 ± 2.74 years under the EO and EC states. The amplitude of the spontaneous brain activity in low-frequency band was subsequently investigated by using the metric of fractional amplitude of low frequency fluctuation (fALFF for each subject under each state. A support vector machine (SVM analysis was then applied to evaluate whether the category of resting states could be determined from the brain spontaneous fluctuations. We demonstrated that these two resting states could be decoded from the identified pattern of brain spontaneous fluctuations, predominantly based on fALFF in the sensorimotor module. Specifically, we observed prominent relationships between increased fALFF for EC and decreased fALFF for EO in sensorimotor regions. Overall, the present results indicate that a SVM performs well in the discrimination between the brain spontaneous fluctuations of distinct resting states and provide new insight into the neural substrate of the resting states during EC and EO.

  15. Effects of stress, circadian rhythms, and dietary sodium on brain cell-nuclear uptake of aldosterone and corticosterone

    International Nuclear Information System (INIS)

    Yongue, B.G.

    1985-01-01

    The binding of the adrenal steroid hormones aldosterone (ALD) and corticosterone (CORT) in brain cell-nuclei has been implicated as a necessary step in the behavioral and physiological actions of these hormones. In vivo uptake of radioactively labeled ALD and CORT in adrenalectomized (ADX) rats indicates a strong cell-nuclear localization of both of these hormones in limbic brain regions (such as hippocampus, septum and amygdala). Research using sub-cellular fractionation and radioimmunoassay (RIA), has confirmed both the presence of endogenously secreted CORT in cell-nuclei and its limbic localization in the brains of adrenal-intact rats. In this study, environmental and dietary factors were manipulated to induce variation in serum ALD and CORT. A series of experiments employing sub-cellular fractionation and RIA were performed, which reveal that: (1) endogenously secreted ALD and CORT, are concentrated by cell-nuclei of the brain in adrenal-intact rats, (2) the majority of the corticosteroids measured in ethanol extracts of brain cell-nuclei are associated with receptor molecules, and (3) the regional distribution of endogenously secreted ALD differs markedly from the predominantly limbic pattern predicted from in vivo uptake of labeled ALD in ADX rats. Instead, brain cell-nuclear ALD is heavily concentrated in the hypothalamus, which supports the hypothesized relationship between the interaction of ALD and angiotensin in the brain and the behavioral regulation of fluid/electrolyte balance

  16. Tinnitus perception and distress is related to abnormal spontaneous brain activity as measured by magnetoencephalography.

    Directory of Open Access Journals (Sweden)

    2005-06-01

    Full Text Available BACKGROUND: The neurophysiological mechanisms underlying tinnitus perception are not well understood. Surprisingly, there have been no group studies comparing abnormalities in ongoing, spontaneous neuronal activity in individuals with and without tinnitus perception. METHODS AND FINDINGS: Here, we show that the spontaneous neuronal activity of a group of individuals with tinnitus (n = 17 is characterised by a marked reduction in alpha (8-12 Hz power together with an enhancement in delta (1.5-4 Hz as compared to a normal hearing control group (n = 16. This pattern was especially pronounced for temporal regions. Moreover, correlations with tinnitus-related distress revealed strong associations with this abnormal spontaneous activity pattern, particularly in right temporal and left frontal areas. Overall, effects were stronger for the alpha than for the delta frequency band. A data stream of 5 min, recorded with a whole-head neuromagnetometer under a resting condition, was sufficient to extract the marked differences. CONCLUSIONS: Despite some limitations, there are arguments that the regional pattern of abnormal spontaneous activity we found could reflect a tinnitus-related cortical network. This finding, which suggests that a neurofeedback approach could reduce the adverse effects of this disturbing condition, could have important implications for the treatment of tinnitus.

  17. Flaws in current human training protocols for spontaneous Brain-Computer Interfaces: lessons learned from instructional design

    Directory of Open Access Journals (Sweden)

    Fabien eLotte

    2013-09-01

    Full Text Available While recent research on Brain-Computer Interfaces (BCI has highlighted their potential for many applications, they remain barely used outside laboratories. The main reason is their lack of robustness. Indeed, with current BCI, mental state recognition is usually slow and often incorrect. Spontaneous BCI (i.e., mental imagery-based BCI often rely on mutual learning efforts by the user and the machine, with BCI users learning to produce stable EEG patterns (spontaneous BCI control being widely acknowledged as a skill while the computer learns to automatically recognize these EEG patterns, using signal processing. Most research so far was focused on signal processing, mostly neglecting the human in the loop. However, how well the user masters the BCI skill is also a key element explaining BCI robustness. Indeed, if the user is not able to produce stable and distinct EEG patterns, then no signal processing algorithm would be able to recognize them. Unfortunately, despite the importance of BCI training protocols, they have been scarcely studied so far, and used mostly unchanged for years.In this paper, we advocate that current human training approaches for spontaneous BCI are most likely inappropriate. We notably study instructional design literature in order to identify the key requirements and guidelines for a successful training procedure that promotes a good and efficient skill learning. This literature study highlights that current spontaneous BCI user training procedures satisfy very few of these requirements and hence are likely to be suboptimal. We therefore identify the flaws in BCI training protocols according to instructional design principles, at several levels: in the instructions provided to the user, in the tasks he/she has to perform, and in the feedback provided. For each level, we propose new research directions that are theoretically expected to address some of these flaws and to help users learn the BCI skill more efficiently.

  18. Flaws in current human training protocols for spontaneous Brain-Computer Interfaces: lessons learned from instructional design.

    Science.gov (United States)

    Lotte, Fabien; Larrue, Florian; Mühl, Christian

    2013-01-01

    While recent research on Brain-Computer Interfaces (BCI) has highlighted their potential for many applications, they remain barely used outside laboratories. The main reason is their lack of robustness. Indeed, with current BCI, mental state recognition is usually slow and often incorrect. Spontaneous BCI (i.e., mental imagery-based BCI) often rely on mutual learning efforts by the user and the machine, with BCI users learning to produce stable ElectroEncephaloGraphy (EEG) patterns (spontaneous BCI control being widely acknowledged as a skill) while the computer learns to automatically recognize these EEG patterns, using signal processing. Most research so far was focused on signal processing, mostly neglecting the human in the loop. However, how well the user masters the BCI skill is also a key element explaining BCI robustness. Indeed, if the user is not able to produce stable and distinct EEG patterns, then no signal processing algorithm would be able to recognize them. Unfortunately, despite the importance of BCI training protocols, they have been scarcely studied so far, and used mostly unchanged for years. In this paper, we advocate that current human training approaches for spontaneous BCI are most likely inappropriate. We notably study instructional design literature in order to identify the key requirements and guidelines for a successful training procedure that promotes a good and efficient skill learning. This literature study highlights that current spontaneous BCI user training procedures satisfy very few of these requirements and hence are likely to be suboptimal. We therefore identify the flaws in BCI training protocols according to instructional design principles, at several levels: in the instructions provided to the user, in the tasks he/she has to perform, and in the feedback provided. For each level, we propose new research directions that are theoretically expected to address some of these flaws and to help users learn the BCI skill more

  19. Phase synchronization for classification of spontaneous EEG signals in brain-computer interfaces

    OpenAIRE

    Gysels, Elly; Kunt, Murat; Celka, Patrick

    2007-01-01

    By directly analyzing brain activity, Brain-Computer Interfaces (BCIs) allow for communication that does not rely on any muscular control and therefore constitute a possible communication channel for the completely paralyzed. Typically, the user performs different mental tasks, that correspond to different output commands as recognized by the system. From the recorded brain signals (Electroencephalogram, EEG), features that characterize the mental tasks and allow their discrimination by a cla...

  20. Phase synchronization for classification of spontaneous EEG signals in brain-computer interfaces

    OpenAIRE

    Gysels, Elly

    2005-01-01

    By directly analyzing brain activity, Brain-Computer Interfaces (BCIs) allow for communication that does not rely on any muscular control and therefore constitute a possible communication channel for the completely paralyzed. Typically, the user performs different mental tasks, that correspond to different output commands as recognized by the system. From the recorded brain signals (Electroencephalogram, EEG), features that characterize the mental tasks and allow their discrimination by a cla...

  1. Targeted Doxorubicin Delivery to Brain Tumors via Minicells: Proof of Principle Using Dogs with Spontaneously Occurring Tumors as a Model.

    Science.gov (United States)

    MacDiarmid, Jennifer A; Langova, Veronika; Bailey, Dale; Pattison, Scott T; Pattison, Stacey L; Christensen, Neil; Armstrong, Luke R; Brahmbhatt, Vatsala N; Smolarczyk, Katarzyna; Harrison, Matthew T; Costa, Marylia; Mugridge, Nancy B; Sedliarou, Ilya; Grimes, Nicholas A; Kiss, Debra L; Stillman, Bruce; Hann, Christine L; Gallia, Gary L; Graham, Robert M; Brahmbhatt, Himanshu

    2016-01-01

    Cytotoxic chemotherapy can be very effective for the treatment of cancer but toxicity on normal tissues often limits patient tolerance and often causes long-term adverse effects. The objective of this study was to assist in the preclinical development of using modified, non-living bacterially-derived minicells to deliver the potent chemotherapeutic doxorubicin via epidermal growth factor receptor (EGFR) targeting. Specifically, this study sought to evaluate the safety and efficacy of EGFR targeted, doxorubicin loaded minicells (designated EGFRminicellsDox) to deliver doxorubicin to spontaneous brain tumors in 17 companion dogs; a comparative oncology model of human brain cancers. EGFRminicellsDox were administered weekly via intravenous injection to 17 dogs with late-stage brain cancers. Biodistribution was assessed using single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI). Anti-tumor response was determined using MRI, and blood samples were subject to toxicology (hematology, biochemistry) and inflammatory marker analysis. Targeted, doxorubicin-loaded minicells rapidly localized to the core of brain tumors. Complete resolution or marked tumor regression (>90% reduction in tumor volume) were observed in 23.53% of the cohort, with lasting anti-tumor responses characterized by remission in three dogs for more than two years. The median overall survival was 264 days (range 49 to 973). No adverse clinical, hematological or biochemical effects were observed with repeated administration of EGFRminicellsDox (30 to 98 doses administered in 10 of the 17 dogs). Targeted minicells loaded with doxorubicin were safely administered to dogs with late stage brain cancer and clinical activity was observed. These findings demonstrate the strong potential for clinical applications of targeted, doxorubicin-loaded minicells for the effective treatment of patients with brain cancer. On this basis, we have designed a Phase 1 clinical study of EGFR

  2. Targeted Doxorubicin Delivery to Brain Tumors via Minicells: Proof of Principle Using Dogs with Spontaneously Occurring Tumors as a Model.

    Directory of Open Access Journals (Sweden)

    Jennifer A MacDiarmid

    Full Text Available Cytotoxic chemotherapy can be very effective for the treatment of cancer but toxicity on normal tissues often limits patient tolerance and often causes long-term adverse effects. The objective of this study was to assist in the preclinical development of using modified, non-living bacterially-derived minicells to deliver the potent chemotherapeutic doxorubicin via epidermal growth factor receptor (EGFR targeting. Specifically, this study sought to evaluate the safety and efficacy of EGFR targeted, doxorubicin loaded minicells (designated EGFRminicellsDox to deliver doxorubicin to spontaneous brain tumors in 17 companion dogs; a comparative oncology model of human brain cancers.EGFRminicellsDox were administered weekly via intravenous injection to 17 dogs with late-stage brain cancers. Biodistribution was assessed using single-photon emission computed tomography (SPECT and magnetic resonance imaging (MRI. Anti-tumor response was determined using MRI, and blood samples were subject to toxicology (hematology, biochemistry and inflammatory marker analysis. Targeted, doxorubicin-loaded minicells rapidly localized to the core of brain tumors. Complete resolution or marked tumor regression (>90% reduction in tumor volume were observed in 23.53% of the cohort, with lasting anti-tumor responses characterized by remission in three dogs for more than two years. The median overall survival was 264 days (range 49 to 973. No adverse clinical, hematological or biochemical effects were observed with repeated administration of EGFRminicellsDox (30 to 98 doses administered in 10 of the 17 dogs.Targeted minicells loaded with doxorubicin were safely administered to dogs with late stage brain cancer and clinical activity was observed. These findings demonstrate the strong potential for clinical applications of targeted, doxorubicin-loaded minicells for the effective treatment of patients with brain cancer. On this basis, we have designed a Phase 1 clinical study of

  3. Aberrant spontaneous brain activity in chronic tinnitus patients revealed by resting-state functional MRI

    Directory of Open Access Journals (Sweden)

    Yu-Chen Chen

    2014-01-01

    Conclusions: The present study confirms that chronic tinnitus patients have aberrant ALFF in many brain regions, which is associated with specific clinical tinnitus characteristics. ALFF disturbance in specific brain regions might be used to identify the neuro-pathophysiological mechanisms in chronic tinnitus patients.

  4. Regional homogeneity of spontaneous brain activity in adult patients with obsessive-compulsive disorder before and after cognitive behavioural therapy.

    Science.gov (United States)

    Yang, Xiang-Yun; Sun, Jing; Luo, Jia; Zhong, Zhao-Xi; Li, Ping; Yao, Shu-Min; Xiong, Hong-Fang; Huang, Fang-Fang; Li, Zhan-Jiang

    2015-12-01

    Cognitive behavioural therapy (CBT) is an effective treatment for obsessive-compulsive disorder (OCD). Several neuroimaging studies have explored alterations of brain function in OCD patients as they performed tasks after CBT. However, the effects of CBT on the neural activityin OCD during rest remain unknown. Therefore, we investigated changes in regional homogeneity (ReHo) in OCD patients before and after CBT. Twenty-two OCD patients and 22 well-matched healthy controls participated in the resting-state functional magnetic resonance imaging scans. We compared differences in ReHo between the OCD and control groups before treatment and investigated the changes of ReHo in 17 OCD patients who responded to CBT. Compared to healthy controls, OCD patients exhibited higher ReHo in the right orbitofrontal cortex (OFC), bilateral middle frontal cortex, right precuneus, left cerebellum, and vermis, as well as lower ReHo in the bilateral caudate, right calcarine, right posterior cingulate cortex, and right middle temporal cortex. Along with the clinical improvement in OCD patients after CBT, we found decreased ReHo in the right OFC, bilateral middle frontal cortex, left cerebellum and vermis, and increased ReHo in the left caudate. Improvement of OCD symptoms was significantly correlated with the changed ReHo in the right OFC and left cerebellum. Although these findings are preliminary and need to be replicated in larger samples, they indicate the presence of abnormal spontaneous brain activity of the prefrontal-striatal-cerebellar circuit in OCD patients, and provide evidence that CBT can selectively modulate the spontaneous brain activity of this circuit in OCD patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests

    Directory of Open Access Journals (Sweden)

    Xavier eLópez-Gil

    2014-07-01

    Full Text Available The identification of biomarkers of vascular cognitive impairment is urgent for its early diagnosis. The aim of this study was to detect and monitor changes in brain structure and connectivity, and to correlate them with the decline in executive function. We examined the feasibility of early diagnostic magnetic resonance imaging to predict cognitive impairment before onset in an animal model of chronic hypertension: Spontaneously Hypertensive Rats. Cognitive performance was tested in an operant conditioning paradigm that evaluated learning, memory and behavioral flexibility skills. Behavioral tests were coupled with longitudinal diffusion weighted imaging acquired with 126 diffusion gradient directions and 0.3 mm3 isometric resolution at 10, 14, 18, 22, 26 and 40 weeks after birth. Diffusion weighted imaging was analyzed in 2 different ways, by regional characterization of diffusion tensor imaging indices, and by assessing changes in structural brain network organization based on Q-Ball tractography. Already at the first evaluated times, diffusion tensor imaging scalar maps revealed significant differences in many regions, suggesting loss of integrity in white and grey matter of spontaneously hypertensive rats when compared to normotensive control rats. In addition, graph theory analysis of the structural brain network demonstrated a significant decrease of hierarchical modularity, global and local efficacy, with predictive value as shown by regional 3-fold cross validation study. Moreover, these decreases were significantly correlated with the behavioral performance deficits observed at subsequent time points, suggesting that the diffusion weighted imaging and connectivity studies can unravel neuroimaging alterations even overt signs of cognitive impairment become apparent.

  6. Timing of host feeding drives rhythms in parasite replication

    KAUST Repository

    Prior, Kimberley F

    2017-12-07

    Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host\\'s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host\\'s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

  7. Timing of host feeding drives rhythms in parasite replication

    KAUST Repository

    Prior, Kimberley F.

    2018-02-26

    Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host’s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host’s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

  8. Amyloid Plaque in the Human Brain Can Decompose from Aβ(1-40/1-42) by Spontaneous Nonenzymatic Processes.

    Science.gov (United States)

    Lyons, Brian; Friedrich, Michael; Raftery, Mark; Truscott, Roger

    2016-03-01

    The degradation of long-lived proteins in the body is an important aspect of aging, and much of the breakdown is due to the intrinsic instability of particular amino acids. In this study, peptides were examined to discover if spontaneous nonenzymatic reactions could be responsible for the composition of Alzheimer's (AD) plaque in the human brain. The great majority of AD plaque consists of N-terminally truncated versions of Aβ(1-40/1-42), with the most abundant peptide commencing with Glu (residue 3 in Aβ1-40/1-42) that is present as pyroGlu. Several Asp residues are racemized in Aβ plaque, with residue 1 being predominantly l-isoAsp and peptide bond cleavage next to Ser 8 is also evident. In peptides, loss of the two N-terminal amino acids as a diketopiperazine was demonstrated at pH 7. For the Aβ N-terminal hexapeptide, AspAlaGluPheArgHis, this resulted in the removal of AspAla diketopiperazine and the generation of Glu as the new N-terminal residue. The Glu cyclized readily to pyroGlu. This pathway was altered significantly by zinc, which promoted pyroGlu formation but decreased AspAla diketopiperazine release. Zinc also facilitated cleavage on the N-terminal side of Ser 8. Racemization of the original N-terminal Asp to l-isoAsp was also detected and loss of one amino acid from the N-terminus. These data are therefore entirely consistent with plaque in the human brain forming from deposition of Aβ(1-40/1-42) and, over time, decomposing spontaneously. Since amyloid plaque is present in the human brain for years prior to the onset of AD, gradual spontaneous changes to the polypeptides within it will alter its properties and those of the oligomers that can diffuse from it. Such incremental changes in composition may therefore contribute to the origin of AD-associated cytotoxicity.

  9. Opiate antagonist binding sites in discrete brain regions of spontaneously hypertensive and normotensive Wistar-Kyoto rats

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, N.H.; Gulati, A.; Bhargava, H.N. (Univ. of Illinois, Chicago (USA))

    1991-01-01

    The binding of {sup 3}H-naltrexone, an opiate receptor antagonist, to membranes of discrete brain regions and spinal cord of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined. The brain regions examined were hypothalamus, amygdala, hippocampus, corpus striatum, pons and medulla, midbrain and cortex. {sup 3}H-Naltrexone bound to membranes of brain regions and spinal cord at a single high affinity site with an apparent dissociation constant value of 3 nM. The highest density of {sup 3}H-naltrexone binding sites were in hippocampus and lowest in the cerebral cortex. The receptor density (B{sub max}value) and apparent dissociation constant (K{sub d} value) values of {sup 3}H-naltrexone to bind to opiate receptors on the membranes of amygdala, hippocampus, corpus striatum, pons and medulla, midgrain, cortex and spinal cord of WKY and SHR rates did not differ. The B{sub max} value of {sup 3}H-naltrexone binding to membranes of hypothalamus of SHR rates was 518% higher than WKY rats but the K{sub d} values in the two strains did not differ. It is concluded that SHR rats have higher density of opiate receptors labeled with {sup 3}H-naltrexone in the hypothalamus only, in comparison with WKY rats, and that such a difference in the density of opiate receptors may be related to the elevated blood pressure in SHR rats.

  10. Spontaneous Brain Activity Did Not Show the Effect of Violent Video Games on Aggression: A Resting-State fMRI Study

    Directory of Open Access Journals (Sweden)

    Wei Pan

    2018-01-01

    Full Text Available A great many of empirical researches have proved that longtime exposure to violent video game can lead to a series of negative effects. Although research has focused on the neural basis of the correlation between violent video game and aggression, little is known whether the spontaneous brain activity is associated with violent video game exposure. To address this question, we measured the spontaneous brain activity using resting-state functional magnetic resonance imaging (fMRI. We used the amplitude of low-frequency fluctuations (ALFF and fractional ALFF (fALFF to quantify spontaneous brain activity. The results showed there is no significant difference in ALFF, or fALFF, between violent video game group and the control part, indicating that long time exposure to violent video games won’t significantly influence spontaneous brain activity, especially the core brain regions such as execution control, moral judgment and short-term memory. This implies the adverse impact of violent video games is exaggerated.

  11. Spontaneous Brain Activity Did Not Show the Effect of Violent Video Games on Aggression: A Resting-State fMRI Study.

    Science.gov (United States)

    Pan, Wei; Gao, Xuemei; Shi, Shuo; Liu, Fuqu; Li, Chao

    2017-01-01

    A great many of empirical researches have proved that longtime exposure to violent video game can lead to a series of negative effects. Although research has focused on the neural basis of the correlation between violent video game and aggression, little is known whether the spontaneous brain activity is associated with violent video game exposure. To address this question, we measured the spontaneous brain activity using resting-state functional magnetic resonance imaging (fMRI). We used the amplitude of low-frequency fluctuations (ALFF) and fractional ALFF (fALFF) to quantify spontaneous brain activity. The results showed there is no significant difference in ALFF, or fALFF, between violent video game group and the control part, indicating that long time exposure to violent video games won't significantly influence spontaneous brain activity, especially the core brain regions such as execution control, moral judgment and short-term memory. This implies the adverse impact of violent video games is exaggerated.

  12. Spontaneous Brain Activity Did Not Show the Effect of Violent Video Games on Aggression: A Resting-State fMRI Study

    Science.gov (United States)

    Pan, Wei; Gao, Xuemei; Shi, Shuo; Liu, Fuqu; Li, Chao

    2018-01-01

    A great many of empirical researches have proved that longtime exposure to violent video game can lead to a series of negative effects. Although research has focused on the neural basis of the correlation between violent video game and aggression, little is known whether the spontaneous brain activity is associated with violent video game exposure. To address this question, we measured the spontaneous brain activity using resting-state functional magnetic resonance imaging (fMRI). We used the amplitude of low-frequency fluctuations (ALFF) and fractional ALFF (fALFF) to quantify spontaneous brain activity. The results showed there is no significant difference in ALFF, or fALFF, between violent video game group and the control part, indicating that long time exposure to violent video games won’t significantly influence spontaneous brain activity, especially the core brain regions such as execution control, moral judgment and short-term memory. This implies the adverse impact of violent video games is exaggerated. PMID:29375416

  13. The Role of Rhythm in Speech and Language Rehabilitation: The SEP Hypothesis

    Directory of Open Access Journals (Sweden)

    Shinya eFujii

    2014-10-01

    Full Text Available For thousands of years, humans have engaged in rhythmic activities such as drumming, dancing, and singing. Rhythm can be a powerful medium to stimulate communication and social interactions, due to the strong sensorimotor coupling. For example, the mere presence of an underlying beat or pulse can result in spontaneous motor responses such as hand clapping, foot stepping, and rhythmic vocalizations. Examining the relationship between rhythm and speech is fundamental not only to our understanding of the origins of human communication, but also in the treatment of neurological disorders. In this paper, we explore whether rhythm has therapeutic potential for promoting recovery from speech and language dysfunctions. Although clinical studies are limited to date, existing experimental evidence demonstrates rich rhythmic organization in both music and language, as well as overlapping brain networks that are crucial in the design of rehabilitation approaches. Here, we propose the SEP hypothesis, which postulates that 1 Sound Envelope Processing and 2 Synchronization and Entrainment to Pulse may help stimulate brain networks that underlie human communication. Ultimately, we hope that the SEP hypothesis will provide a useful framework for facilitating rhythm-based research in various patient populations.

  14. The Role of Rhythm in Speech and Language Rehabilitation: The SEP Hypothesis.

    Science.gov (United States)

    Fujii, Shinya; Wan, Catherine Y

    2014-01-01

    For thousands of years, human beings have engaged in rhythmic activities such as drumming, dancing, and singing. Rhythm can be a powerful medium to stimulate communication and social interactions, due to the strong sensorimotor coupling. For example, the mere presence of an underlying beat or pulse can result in spontaneous motor responses such as hand clapping, foot stepping, and rhythmic vocalizations. Examining the relationship between rhythm and speech is fundamental not only to our understanding of the origins of human communication but also in the treatment of neurological disorders. In this paper, we explore whether rhythm has therapeutic potential for promoting recovery from speech and language dysfunctions. Although clinical studies are limited to date, existing experimental evidence demonstrates rich rhythmic organization in both music and language, as well as overlapping brain networks that are crucial in the design of rehabilitation approaches. Here, we propose the "SEP" hypothesis, which postulates that (1) "sound envelope processing" and (2) "synchronization and entrainment to pulse" may help stimulate brain networks that underlie human communication. Ultimately, we hope that the SEP hypothesis will provide a useful framework for facilitating rhythm-based research in various patient populations.

  15. Formation of sulphidopeptide-leukotrienes in brain tissue of spontaneously convulsing gerbils.

    Science.gov (United States)

    Simmet, T; Seregi, A; Hertting, G

    1987-01-01

    Five minutes after the onset of seizures high amounts of immunoreactive prostaglandin (PG) F2 alpha and smaller amounts of sulphidopeptide (SP)-leukotriene (LT)-like immunoreactivity could be detected in gerbil brain tissue. Bilateral carotid artery ligation followed by 15 min of reperfusion even more enhanced brain tissue contents of PGF2 alpha and SP-LT-like material. Analysis of the immunoreactive SP-LT-like material by reversed phase high pressure liquid chromatography (h.p.l.c.) revealed immunoreactivity co-eluting with authentic LTC4 and LTD4.

  16. Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity.

    Science.gov (United States)

    Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

    2017-01-01

    A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG) was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS) before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

  17. Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity

    Directory of Open Access Journals (Sweden)

    Nantawachara Jirakittayakorn

    2017-06-01

    Full Text Available A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

  18. Changes in lipid composition of the brain cellular membranes of an hibernating mammal during its circannual rhythm.

    Science.gov (United States)

    Robert, J; Montaudon, D; Dubourg, L; Rebel, G; Miro, J L; Canguilhem, B

    1982-01-01

    The lipid composition of whole brain hemispheres and subcellular fractions of European Hamsters (Cricetus cricetus) was investigated at four different periods of the year. 1. No difference was observed in winter between hibernating animals and active animals awake for 24 hr. 2. A slight increase of cholesterol/phospholipid molar ratio was observed in winter. 3. A slight increase of the ratio ethanolamine phosphoglycerides/choline phosphoglycerides was observed in summer and autumn. 4. Some changes in sugar moieties proportions of gangliosides were observed, with a tendency of increased polysialylation in winter. 5. An increase of docosahexaenoic acid was observed in summer, while a slight increase of linoleic acid and of the monounsaturated fatty acids was observed in winter. These changes were mainly exhibited in the synaptosomal fraction. All the changes observed were of very small magnitude and might not be sufficient for the maintenance of a fluid state of membranes during hibernation.

  19. Self-regulation of brain rhythms in the precuneus: a novel BCI paradigm for patients with ALS

    Science.gov (United States)

    Fomina, Tatiana; Lohmann, Gabriele; Erb, Michael; Ethofer, Thomas; Schölkopf, Bernhard; Grosse-Wentrup, Moritz

    2016-12-01

    Objective. Electroencephalographic (EEG) brain-computer interfaces (BCIs) hold promise in restoring communication for patients with completely locked-in stage amyotrophic lateral sclerosis (ALS). However, these patients cannot use existing EEG-based BCIs, arguably because such systems rely on brain processes that are impaired in the late stages of ALS. In this work, we introduce a novel BCI designed for patients in late stages of ALS based on high-level cognitive processes that are less likely to be affected by ALS. Approach. We trained two ALS patients via EEG-based neurofeedback to use self-regulation of theta or gamma oscillations in the precuneus for basic communication. Because there is a tight connection between the precuneus and consciousness, precuneus oscillations are arguably generated by high-level cognitive processes, which are less likely to be affected by ALS than processes linked to the peripheral nervous system. Main results. Both patients learned to self-regulate their precuneus oscillations and achieved stable online decoding accuracy over the course of disease progression. One patient achieved a mean online decoding accuracy in a binary decision task of 70.55% across 26 training sessions, and the other patient achieved 59.44% across 16 training sessions. We provide empirical evidence that these oscillations were cortical in nature and originated from the intersection of the precuneus, cuneus, and posterior cingulate. Significance. Our results establish that ALS patients can employ self-regulation of precuneus oscillations for communication. Such a BCI is likely to be available to ALS patients as long as their consciousness supports communication.

  20. Spontaneous brain activity and EEG microstates. A novel EEG/fMRI analysis approach to explore resting-state networks.

    Science.gov (United States)

    Musso, F; Brinkmeyer, J; Mobascher, A; Warbrick, T; Winterer, G

    2010-10-01

    The brain is active even in the absence of explicit input or output as demonstrated from electrophysiological as well as imaging studies. Using a combined approach we measured spontaneous fluctuations in the blood oxygen level dependent (BOLD) signal along with electroencephalography (EEG) in eleven healthy subjects during relaxed wakefulness (eyes closed). In contrast to other studies which used the EEG frequency information to guide the functional MRI (fMRI) analysis, we opted for transient EEG events, which identify and quantify brain electric microstates as time epochs with quasi-stable field topography. We then used this microstate information as regressors for the BOLD fluctuations. Single trial EEGs were segmented with a specific module of the LORETA (low resolution electromagnetic tomography) software package in which microstates are represented as normalized vectors constituted by scalp electric potentials, i.e., the related 3-dimensional distribution of cortical current density in the brain. Using the occurrence and the duration of each microstate, we modeled the hemodynamic response function (HRF) which revealed BOLD activation in all subjects. The BOLD activation patterns resembled well known resting-state networks (RSNs) such as the default mode network. Furthermore we "cross validated" the data performing a BOLD independent component analysis (ICA) and computing the correlation between each ICs and the EEG microstates across all subjects. This study shows for the first time that the information contained within EEG microstates on a millisecond timescale is able to elicit BOLD activation patterns consistent with well known RSNs, opening new avenues for multimodal imaging data processing. Copyright 2010. Published by Elsevier Inc.

  1. Fractal analysis of spontaneous fluctuations of the BOLD signal in the human brain networks.

    Science.gov (United States)

    Li, Yi-Chia; Huang, Yun-An

    2014-05-01

    To investigate what extent brain regions are continuously interacting during resting-state, independent component analyses (ICA) was applied to analyze resting-state functional MRI (RS-fMRI) data. According to the analyzed results, it was surprisingly found that low frequency fluctuations (LFFs), which belong to the 1/f signal (a signal with power spectrum whose power spectral density is inversely proportional to the frequency), have been classified into groups using ICA; furthermore, the spatial distributions of these groups within the brain were found to resemble the spatial distributions of different networks, which manifests that the signal characteristics of RS LFFs are distinct across networks. In our work, we applied the 1/f model in the fractal analyses to further investigate this distinction. Twenty healthy participants got involved in this study. They were scanned to acquire the RS-fMRI data. The acquired data were first processed with ICA to obtain the networks of the resting brain. Afterward, the blood-oxygenation level dependent (BOLD) signals of these networks were processed with the fractal analyses for obtaining the fractal parameter α. α was found to significantly vary across networks, which reveals that the fractal characteristic of LFFs differs across networks. According to prior literatures, this difference could be brought by the discrepancy of hemodynamic response amplitude (HRA) between networks. Hence, in our work, we also performed the computational simulation to discover the relationship between α and HRA. Based on the simulation results, HRA is highly linear-correlated with the fractal characteristics of LFFs which is revealed by α. Our results support that the origin of RS-fMRI signals contains arterial fluctuations. Hence, in addition to the commonly used method such as synchrony analysis and power spectral analysis, another approach, the fractal analysis, is suggested for acquiring the information of hemodynamic responses by means

  2. Anticonvulsive effects of endogenous prostaglandins formed in brain of spontaneously convulsing gerbils.

    Science.gov (United States)

    Förstermann, U; Seregi, A; Hertting, G

    1984-06-01

    Seizures were induced in a strain of epileptic gerbils by moderate environmental stress. Concentrations of five different cyclooxygenase products (PGD2, PGF2 alpha, PGE2, 6-keto-PGF1 alpha and thromboxane B2) were measured in brain by specific radioimmunoassays before and at different time intervals after the onset of clonic-tonic convulsions. All prostanoids markedly increased subsequent to the convulsions. Maximal concentrations were reached after about 15 min. The major compound detected was PGD2, followed by PGF2 alpha and lower concentrations of the other cyclooxygenase products. Indomethacin completely prevented the convulsion-induced formation of prostanoids. Fifteen min after a first seizure almost all animals proved to be protected against a second convulsion. Indomethacin pretreatment markedly reduced the number of convulsion-resistant animals. These findings are compatible with the hypothesis that endogenous prostaglandins exert anticonvulsive effects.

  3. Altered Spontaneous Brain Activity in Cortical and Subcortical Regions in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Jie Xiang

    2016-01-01

    Full Text Available Purpose. The present study aimed to explore the changes of amplitude of low-frequency fluctuations (ALFF at rest in patients with Parkinson’s disease (PD. Methods. Twenty-four PD patients and 22 healthy age-matched controls participated in the study. ALFF was measured on the whole brain of all participants. A two-sample t-test was then performed to detect the group differences with age, gender, education level, head motion, and gray matter volume as covariates. Results. It was showed that PD patients had significantly decreased ALFF in the left thalamus/caudate and right insula/inferior prefrontal gyrus, whereas they had increased ALFF in the right medial prefrontal cortex (BA 8/6 and dorsolateral prefrontal cortex (BA 9/10. Conclusions. Our results indicated that significant alterations of ALFF in the subcortical regions and prefrontal cortex have been detected in PD patients, independent of age, gender, education, head motion, and structural atrophy. The current findings further provide insights into the biological mechanism of the disease.

  4. Primary angle-closure glaucomas disturb regional spontaneous brain activity in the visual pathway: an fMRI study

    Directory of Open Access Journals (Sweden)

    Chen W

    2017-05-01

    Full Text Available Wei Chen, Li Zhang, Yong-gen Xu, Kai Zhu, Man Luo Department of Ophthalmology, Shaoxing People’s Hospital, Shaoxing, Zhejiang, People’s Republic of China Objective: To explore the underlying regional brain activity deficits in the visual cortex in patients with primary angle-closure glaucoma (PACG relative to normal controls (NCs using regional homogeneity (ReHo method, and its relationship with behavioral performances. Patients: Twenty PACG patients (10 females, 10 males; mean age ± standard deviation [SD]: 54.42±9.46 years and 20 age-, and sex status-matched NCs (10 females, 10 males; mean age ± SD: 53.75±9.16 years were included in this study. Measurements and results: Compared with NCs, patients with PACG showed significant atrophic peripapillary retinal nerve fiber layer (pRNFL and neuroretinal rim area, increased optic disk cup-to-disc ratio (CDR and optic disk volume (P<0.05, higher ReHo value in the left fusiform gyrus, left cerebellum anterior lobe, right frontal-temporal space, and right insula, and lower ReHo value in the bilateral middle occipital gyrus, left claustrum, and right paracentral lobule lobe. The receiver operating characteristic analysis revealed these different areas with high value of area under curve, and high degree of sensitivity and specificity. The mean beta values of these different areas were extracted. In PACG, the duration of disease showed a negative correlation with the mean beta value of left cerebellum anterior lobe (r=-0.453, P=0.045 and a positive correlation with right middle occipital gyrus (r=0.586, P=0.007; left middle occipital gyrus showed positive correlations with duration of disease (r=0.562, P=0.01 and left pRNFL (r=0.49, P=0.028; left claustrum had a positive correlation with left CDR (r=0.515, P=0.02; and right paracentral lobule lobe demonstrated a positive correlation with left pRNFL (r=0.623, P=0.003. Conclusion: PACG is involved in abnormal spontaneous brain activity in multiple

  5. Visible Battle Rhythm

    National Research Council Canada - National Science Library

    Cort, Brian; Bouchard, Alain; Gouin, Denis; Proulx, Pascale; Wright, William

    2006-01-01

    .... Visual Battle Rhythm (VBR) is a software prototype which updates the battle rhythm process with modern technology and careful information design to improve the synchronization, situational awareness and decision making ability of commanders...

  6. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  7. Dysrhythmia: a specific congenital rhythm perception deficit

    Directory of Open Access Journals (Sweden)

    Jacques eLaunay

    2014-02-01

    Full Text Available Why do some people have problems ‘feeling the beat’? Here we investigate participants with congenital impairments in musical rhythm perception and production. A web-based version of the Montreal Battery of Evaluation of Amusia (MBEA was used to screen for difficulties with rhythmic processing in a large sample and we identified three ‘dysrhythmic’ individuals who scored below cut-off for the rhythm subtest, but not the pitch-based subtests. Follow-up testing in the laboratory was conducted to characterize the nature of both rhythm perception and production deficits in these dysrhythmic individuals. We found that they differed from control participants when required to synchronize their tapping to an external stimulus with a metrical pulse, but not when required to tap spontaneously (with no external stimulus or to tap in time to an isochronous stimulus. Dysrhythmics exhibited a general tendency to tap at half the expected tempo when asked to synchronize to the beat of strongly metrical rhythms. These results suggest that the individuals studied here did not have motor production problems, but suffer from a selective rhythm perception deficit that influences the ability to entrain to metrical rhythms.

  8. Whole-brain 320-detector row dynamic volume CT perfusion detected crossed cerebellar diaschisis after spontaneous intracerebral hemorrhage

    International Nuclear Information System (INIS)

    Fu, Jun; Chen, Wei-jian; Wang, Mei-hao; Li, Jian-ce; Zhang, Qian; Xia, Neng-zhi; Yang, Yun-jun; Wu, Gui-yun; Cheng, Jing-liang; Zhang, Yong; Zhuge, Qichuan

    2015-01-01

    The purpose of this study was to evaluate the value of 320-detector row CT used to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial spontaneous intracerebral hemorrhage (SICH). We investigated 62 of 156 patients with unilateral supratentorial SICH using 320-detector row CT scanning. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), and time to peak (rTTP) levels were measured in different regions of interest (ROIs) that were manually outlined on computed tomography perfusion (CTP) for the cerebrum, including normal-appearing brain tissue that surrounded the perilesional low-density area (NA) and the perihematomal low-density area (PA) in all patients and the cerebellum (ipsilateral and contralateral) in CCD-positive patients. Of 62 cases, a total of 14 met the criteria for CCD due to cerebellar perfusion asymmetry on CTP maps. In the quantitative analysis, significant differences were found in the perfusion parameters between the contralateral and ipsilateral cerebellum in CCD-positive cases. No significant differences were found between the CCD-positive group and the CCD-negative group according to the hematoma volume, NIHSS scores, and cerebral perfusion abnormality (each P > 0.05). The correlation analysis of the degree of NA, PA perfusion abnormality, and the degree of CCD severity showed negative and significant linear correlations (R, -0.66∝-0.56; P < 0.05). 320-detector row CT is a robust and practicable method for the comprehensive primary imaging work-up of CCD in unilateral supratentorial SICH patients. (orig.)

  9. Whole-brain 320-detector row dynamic volume CT perfusion detected crossed cerebellar diaschisis after spontaneous intracerebral hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jun; Chen, Wei-jian; Wang, Mei-hao; Li, Jian-ce; Zhang, Qian; Xia, Neng-zhi; Yang, Yun-jun [Wenzhou Medical University, Department of Radiology, First Affiliated Hospital, Wenzhou (China); Wu, Gui-yun [Cleveland Clinics Foundation, Department of Nuclear Medicine, Imaging Institute, Cleveland, OH (United States); Cheng, Jing-liang; Zhang, Yong [Zhengzhou University, Department of Radiology, First Affiliated Hospital, Zhengzhou (China); Zhuge, Qichuan [Wenzhou Medical University, Department of Neurosurgery, First Affiliated Hospital, Wenzhou (China)

    2014-11-09

    The purpose of this study was to evaluate the value of 320-detector row CT used to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial spontaneous intracerebral hemorrhage (SICH). We investigated 62 of 156 patients with unilateral supratentorial SICH using 320-detector row CT scanning. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), and time to peak (rTTP) levels were measured in different regions of interest (ROIs) that were manually outlined on computed tomography perfusion (CTP) for the cerebrum, including normal-appearing brain tissue that surrounded the perilesional low-density area (NA) and the perihematomal low-density area (PA) in all patients and the cerebellum (ipsilateral and contralateral) in CCD-positive patients. Of 62 cases, a total of 14 met the criteria for CCD due to cerebellar perfusion asymmetry on CTP maps. In the quantitative analysis, significant differences were found in the perfusion parameters between the contralateral and ipsilateral cerebellum in CCD-positive cases. No significant differences were found between the CCD-positive group and the CCD-negative group according to the hematoma volume, NIHSS scores, and cerebral perfusion abnormality (each P > 0.05). The correlation analysis of the degree of NA, PA perfusion abnormality, and the degree of CCD severity showed negative and significant linear correlations (R, -0.66∝-0.56; P < 0.05). 320-detector row CT is a robust and practicable method for the comprehensive primary imaging work-up of CCD in unilateral supratentorial SICH patients. (orig.)

  10. Sensorimotor rhythm neurofeedback as adjunct therapy for Parkinson's disease.

    Science.gov (United States)

    Philippens, Ingrid H C H M; Wubben, Jacqueline A; Vanwersch, Raymond A P; Estevao, Dave L; Tass, Peter A

    2017-08-01

    Neurofeedback may enhance compensatory brain mechanisms. EEG-based sensorimotor rhythm neurofeedback training was suggested to be beneficial in Parkinson's disease. In a placebo-controlled study in parkinsonian nonhuman primates we here show that sensorimotor rhythm neurofeedback training reduces MPTP-induced parkinsonian symptoms and both ON and OFF scores during classical L-DOPA treatment. Our findings encourage further development of sensorimotor rhythm neurofeedback training as adjunct therapy for Parkinson's disease which might help reduce L-DOPA-induced side effects.

  11. Rhythm information represented in the fronto-parieto-cerebellar motor system.

    Science.gov (United States)

    Konoike, Naho; Kotozaki, Yuka; Miyachi, Shigehiro; Miyauchi, Carlos Makoto; Yomogida, Yukihito; Akimoto, Yoritaka; Kuraoka, Koji; Sugiura, Motoaki; Kawashima, Ryuta; Nakamura, Katsuki

    2012-10-15

    Rhythm is an essential element of human culture, particularly in language and music. To acquire language or music, we have to perceive the sensory inputs, organize them into structured sequences as rhythms, actively hold the rhythm information in mind, and use the information when we reproduce or mimic the same rhythm. Previous brain imaging studies have elucidated brain regions related to the perception and production of rhythms. However, the neural substrates involved in the working memory of rhythm remain unclear. In addition, little is known about the processing of rhythm information from non-auditory inputs (visual or tactile). Therefore, we measured brain activity by functional magnetic resonance imaging while healthy subjects memorized and reproduced auditory and visual rhythmic information. The inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum exhibited significant activations during both encoding and retrieving rhythm information. In addition, most of these areas exhibited significant activation also during the maintenance of rhythm information. All of these regions functioned in the processing of auditory and visual rhythms. The bilateral inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum are thought to be essential for motor control. When we listen to a certain rhythm, we are often stimulated to move our body, which suggests the existence of a strong interaction between rhythm processing and the motor system. Here, we propose that rhythm information may be represented and retained as information about bodily movements in the supra-modal motor brain system. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Diurnal and seasonal molecular rhythms in human neocortex and their relation to Alzheimer's disease.

    Science.gov (United States)

    Lim, Andrew S P; Klein, Hans-Ulrich; Yu, Lei; Chibnik, Lori B; Ali, Sanam; Xu, Jishu; Bennett, David A; De Jager, Philip L

    2017-04-03

    Circadian and seasonal rhythms are seen in many species, modulate several aspects of human physiology, including brain functions such as mood and cognition, and influence many neurological and psychiatric illnesses. However, there are few data regarding the genome-scale molecular correlates underlying these rhythms, especially in the human brain. Here, we report widespread, site-specific and interrelated diurnal and seasonal rhythms of gene expression in the human brain, and show their relationship with parallel rhythms of epigenetic modification including histone acetylation, and DNA methylation. We also identify transcription factor-binding sites that may drive these effects. Further, we demonstrate that Alzheimer's disease pathology disrupts these rhythms. These data suggest that interrelated diurnal and seasonal epigenetic and transcriptional rhythms may be an important feature of human brain biology, and perhaps human biology more broadly, and that changes in such rhythms may be consequences of, or contributors to, diseases such as Alzheimer's disease.

  13. Circadian Rhythm Sleep Disorders

    Directory of Open Access Journals (Sweden)

    Erhan Akinci

    2016-06-01

    Full Text Available The circadian rhythm sleep disorders define the clinical conditions where sleep and ndash;wake rhythm is disrupted despite optimum environmental and social conditions. They occur as a result of the changes in endogenous circadian hours or non-compatibility of environmental factors or social life with endogenous circadian rhythm. The sleep and ndash;wake rhythm is disrupted continuously or in repeating phases depending on lack of balance between internal and external cycles. This condition leads to functional impairments which cause insomnia, excessive sleepiness or both in people. Application of detailed sleep anamnesis and sleep diary with actigraphy record, if possible, will be sufficient for diagnosis. The treatment aims to align endogenous circadian rhythm with environmental conditions. The purpose of this article is to review pathology, clinical characteristics, diagnosis and treatment of circadian rhythm disorder. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(2: 178-189

  14. Altered spontaneous brain activity pattern in patients with high myopia using amplitude of low-frequency fluctuation: a resting-state fMRI study

    Directory of Open Access Journals (Sweden)

    Huang X

    2016-11-01

    Full Text Available Xin Huang,1,2,* Fu-Qing Zhou,3,* Yu-Xiang Hu,1 Xiao-Xuan Xu,1 Xiong Zhou,4 Yu-Lin Zhong,1 Jun Wang,4 Xiao-Rong Wu1 1Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, 2Department of Ophthalmology, The First People’s Hospital of Jiujiang City, Jiujiang, 3Department of Radiology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Medical Imaging Research Institute, 4Second Department of Respiratory Disease, Jiangxi Provincial People’s Hospital, Nanchang, Jiangxi, People’s Republic of China *These authors contributed equally to this work Objective: Many previous reports have demonstrated significant neural anatomy changes in the brain of high myopic (HM patients, whereas the spontaneous brain activity changes in the HM patients at rest are not well studied. Our objective was to use amplitude of low-frequency fluctuation (ALFF method to investigate the changes in spontaneous brain activity in HM patients and their relationships with clinical features. Methods: A total of 38 patients with HM (17 males and 21 females and 38 healthy controls (HCs (17 males and 21 females closely matched in age, sex, and education underwent resting-state functional magnetic resonance imaging scans. The ALFF method was used to assess local features of spontaneous brain activity. The relationship between the mean ALFF signal values in many brain regions and the clinical features in HM patients was calculated by correlation analysis. Results: Compared with HCs, the HM patients had significantly lower ALFF in the right inferior and middle temporal gyrus, left middle temporal gyrus, left inferior frontal gyrus/putamen, right inferior frontal gyrus/putamen/insula, right middle frontal gyrus, and right inferior parietal lobule and higher ALFF values in the bilateral midcingulate cortex, left postcentral gyrus, and left precuneus/inferior parietal lobule. However, no relationship was found between the mean ALFF

  15. Rhythm perception, production and synchronization during the perinatal period

    Directory of Open Access Journals (Sweden)

    Joëlle ePROVASI

    2014-09-01

    Full Text Available Sensori-motor synchronization (SMS is the coordination of rhythmic movement with an external rhythm. It plays a central role in motor, cognitive, and social behavior. SMS is commonly studied in adults and in children from four years of age onward. Prior to this age, the ability has rarely been investigated due to a lack of available methods. The present paper reviews what is known about SMS in young children, infants, newborns, and fetuses. The review highlights fetal and infant perception of rhythm and cross modal perception of rhythm, fetal and infant production of rhythm and cross modal production of rhythm, and the contexts in which production of rhythm can be observed in infants. A primary question is whether infants, even newborns, can modify their spontaneous rhythmical motor behavior in response to external rhythmical stimulation. Spontaneous sucking, crying, and leg movements have been studied in the presence or absence of rhythmical auditory stimulation. Findings suggest that the interaction between movement and sound is present at birth and that SMS can be observed in special conditions and within a narrow range of tempi, particularly near the infant’s own spontaneous motor tempo. The discussion centers on the fundamental role of SMS in interaction and communication at the beginning of life.

  16. Circadian Sleep-Wake Rhythm of Older Adults with Intellectual Disabilities

    Science.gov (United States)

    Maaskant, Marijke; van de Wouw, Ellen; van Wijck, Ruud; Evenhuis, Heleen M.; Echteld, Michael A.

    2013-01-01

    The circadian sleep-wake rhythm changes with aging, resulting in a more fragmented sleep-wake pattern. In individuals with intellectual disabilities (ID), brain structures regulating the sleep-wake rhythm might be affected. The aims of this study were to compare the sleep-wake rhythm of older adults with ID to that of older adults in the general…

  17. Circadian sleep-wake rhythm of older adults with intellectual disabilities

    NARCIS (Netherlands)

    Maaskant, Marijke; van de Wouw, Ellen; van Wijck, Ruud; Evenhuis, Heleen M.; Echteld, Michael A.

    The circadian sleep-wake rhythm changes with aging, resulting in a more fragmented sleep-wake pattern. In individuals with intellectual disabilities (ID), brain structures regulating the sleep-wake rhythm might be affected. The aims of this study were to compare the sleep-wake rhythm of older adults

  18. Ischemic stroke destabilizes circadian rhythms

    Directory of Open Access Journals (Sweden)

    Borjigin Jimo

    2008-10-01

    Full Text Available Abstract Background The central circadian pacemaker is a remarkably robust regulator of daily rhythmic variations of cardiovascular, endocrine, and neural physiology. Environmental lighting conditions are powerful modulators of circadian rhythms, but regulation of circadian rhythms by disease states is less clear. Here, we examine the effect of ischemic stroke on circadian rhythms in rats using high-resolution pineal microdialysis. Methods Rats were housed in LD 12:12 h conditions and monitored by pineal microdialysis to determine baseline melatonin timing profiles. After demonstration that the circadian expression of melatonin was at steady state, rats were subjected to experimental stroke using two-hour intralumenal filament occlusion of the middle cerebral artery. The animals were returned to their cages, and melatonin monitoring was resumed. The timing of onset, offset, and duration of melatonin secretion were calculated before and after stroke to determine changes in circadian rhythms of melatonin secretion. At the end of the monitoring period, brains were analyzed to determine infarct volume. Results Rats demonstrated immediate shifts in melatonin timing after stroke. We observed a broad range of perturbations in melatonin timing in subsequent days, with rats exhibiting onset/offset patterns which included: advance/advance, advance/delay, delay/advance, and delay/delay. Melatonin rhythms displayed prolonged instability several days after stroke, with a majority of rats showing a day-to-day alternation between advance and delay in melatonin onset and duration. Duration of melatonin secretion changed in response to stroke, and this change was strongly determined by the shift in melatonin onset time. There was no correlation between infarct size and the direction or amplitude of melatonin phase shifting. Conclusion This is the first demonstration that stroke induces immediate changes in the timing of pineal melatonin secretion, indicating

  19. Markets, Bodies, Rhythms

    DEFF Research Database (Denmark)

    Borch, Christian; Bondo Hansen, Kristian; Lange, Ann-Christina

    2015-01-01

    This article explores the relationship between bodily rhythms and market rhythms in two distinctly different financial market configurations, namely the open-outcry pit (prevalent especially in the early 20th century) and present-day high-frequency trading. Drawing on Henri Lefebvre's rhythmanaly......This article explores the relationship between bodily rhythms and market rhythms in two distinctly different financial market configurations, namely the open-outcry pit (prevalent especially in the early 20th century) and present-day high-frequency trading. Drawing on Henri Lefebvre...... of financial markets, it also suggests that high-frequency trading in particular might produce new types of market rhythms that, contra Lefebvre, do not revolve around traders' bodies....

  20. Regional brain catecholamine levels and the development of hypertension in the spontaneously hypertensive rat: the effect of 6-hydroxydopamine

    NARCIS (Netherlands)

    Jong, Wybren de; Buuse, M. van den; Kloet, E.R. de; Versteeg, D.H.G.

    1984-01-01

    To investigate the role of central catecholaminergic pathways in the development of hypertension in the spontaneously hypertensive rat (SHR) the effects of intracerebroventricular (i.c.v.) injections of 6-hydroxydopamine (6-OHDA) were compared with those of local injections near the main ascending

  1. Neural Entrainment to Auditory Imagery of Rhythms

    Directory of Open Access Journals (Sweden)

    Haruki Okawa

    2017-10-01

    Full Text Available A method of reconstructing perceived or imagined music by analyzing brain activity has not yet been established. As a first step toward developing such a method, we aimed to reconstruct the imagery of rhythm, which is one element of music. It has been reported that a periodic electroencephalogram (EEG response is elicited while a human imagines a binary or ternary meter on a musical beat. However, it is not clear whether or not brain activity synchronizes with fully imagined beat and meter without auditory stimuli. To investigate neural entrainment to imagined rhythm during auditory imagery of beat and meter, we recorded EEG while nine participants (eight males and one female imagined three types of rhythm without auditory stimuli but with visual timing, and then we analyzed the amplitude spectra of the EEG. We also recorded EEG while the participants only gazed at the visual timing as a control condition to confirm the visual effect. Furthermore, we derived features of the EEG using canonical correlation analysis (CCA and conducted an experiment to individually classify the three types of imagined rhythm from the EEG. The results showed that classification accuracies exceeded the chance level in all participants. These results suggest that auditory imagery of meter elicits a periodic EEG response that changes at the imagined beat and meter frequency even in the fully imagined conditions. This study represents the first step toward the realization of a method for reconstructing the imagined music from brain activity.

  2. Rhythm in language acquisition.

    Science.gov (United States)

    Langus, Alan; Mehler, Jacques; Nespor, Marina

    2017-10-01

    Spoken language is governed by rhythm. Linguistic rhythm is hierarchical and the rhythmic hierarchy partially mimics the prosodic as well as the morpho-syntactic hierarchy of spoken language. It can thus provide learners with cues about the structure of the language they are acquiring. We identify three universal levels of linguistic rhythm - the segmental level, the level of the metrical feet and the phonological phrase level - and discuss why primary lexical stress is not rhythmic. We survey experimental evidence on rhythm perception in young infants and native speakers of various languages to determine the properties of linguistic rhythm that are present at birth, those that mature during the first year of life and those that are shaped by the linguistic environment of language learners. We conclude with a discussion of the major gaps in current knowledge on linguistic rhythm and highlight areas of interest for future research that are most likely to yield significant insights into the nature, the perception, and the usefulness of linguistic rhythm. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Pitx2 modulates a Tbx5-dependent gene regulatory network to maintain atrial rhythm

    NARCIS (Netherlands)

    Nadadur, Rangarajan D.; Broman, Michael T.; Boukens, Bastiaan; Mazurek, Stefan R.; Yang, Xinan; van den Boogaard, Malou; Bekeny, Jenna; Gadek, Margaret; Ward, Tarsha; Zhang, Min; Qiao, Yun; Martin, James F.; Seidman, Christine E.; Seidman, Jon; Christoffels, Vincent; Efimov, Igor R.; McNally, Elizabeth M.; Weber, Christopher R.; Moskowitz, Ivan P.

    2016-01-01

    Cardiac rhythm is extremely robust, generating 2 billion contraction cycles during the average human life span. Transcriptional control of cardiac rhythm is poorly understood. We found that removal of the transcription factor gene Tbx5 from the adult mouse caused primary spontaneous and sustained

  4. ENTRAINMENT OF THE BREATHING RHYTHM OF THE CARP BY IMPOSED OSCILLATION OF THE GILL ARCHES

    NARCIS (Netherlands)

    DEGRAAF, PJF; ROBERTS, BL

    Artificial oscillation imposed onto the gill arches could modify the respiratory rhythm in the carp Cyprinus carpio. The degree of modification depended upon the frequency and amplitude of the applied movement. Oscillation at frequencies close to the spontaneous respiratory rhythm and at amplitudes

  5. Acute and late reactions following boron neutron capture epithermal-neutron therapy in dogs with spontaneous brain tumors

    International Nuclear Information System (INIS)

    Gavin, P.R.; DeHaan, C.E.; Kraft, S.L.; Moore, M.P.; Wendling, L.R.; Dorn, R.V. III.

    1992-01-01

    Dogs have a relatively high incidence of primary tumors of the central nervous system and have proven to be good models for new therapeutic investigation. The pharmacokinetics of borocaptate sodium have been well documented in the dog. Preliminary investigations of the normal tissue tolerance and was designed to ensure a therapeutic margin was present for the dogs with spontaneous tumors; i.e., a measurable effect could be had on the tumor at doses considered safe for the normal tissues

  6. MRI-constrained spectral imaging of benzodiazepine modulation of spontaneous neuromagnetic activity in human cortex.

    Science.gov (United States)

    Ahveninen, Jyrki; Lin, Fa-Hsuan; Kivisaari, Reetta; Autti, Taina; Hämäläinen, Matti; Stufflebeam, Steven; Belliveau, John W; Kähkönen, Seppo

    2007-04-01

    Spontaneous electromagnetic brain rhythms have been widely used in human neuropharmacology, but their applicability is complicated by the difficulties to localize their origins in the human cortex. Here, we used a novel multi-modal non-invasive imaging approach to localize lorazepam (30 microg/kg i.v.) modulation of cortical generators of spontaneous brain rhythms. Eight healthy subjects were measured with 306-channel magnetoencephalography (MEG) in a double-blind, randomized, placebo-controlled (saline), crossover design. For anatomically realistic source modeling, wavelet-transformed MEG data were combined with high-resolution MRI to constrain the current locations to the cortical mantle, after which individual data were co-registered to surface-based coordinate system for the calculation of group statistical parametric maps of drug effects. The distributed MRI-constrained MEG source estimates demonstrated decreased alpha (10 Hz) activity in and around the parieto-occipital sulcus and in the calcarine sulcus of the occipital lobe, following from increased GABA(A)-inhibition by lorazepam. Anatomically constrained spectral imaging displays the cortical loci of drug effects on oscillatory brain activity, providing a novel tool for human pharmacological neuroimaging.

  7. Response of peripheral rhythms to the timing of food intake.

    Science.gov (United States)

    Hatori, Megumi; Panda, Satchidananda

    2015-01-01

    Metabolism and physiology in animals show diurnal rhythm to adapt to the daily cycles of activity-rest and the associated rhythm in feeding and fasting. Accordingly, gene expression, protein activities, and numerous metabolites show daily rhythm in abundance. The significance of these rhythms in promoting healthy lifespan and preventing disease has recently come to light. Mice with genetic disruption of circadian rhythm, mice, and humans under shift-work paradigm, and mice fed high-fat diet ad libitum exhibit chronic disruption of feeding-fasting rhythm and dampened daily rhythms in physiology, metabolism, and gene expression. These dampened rhythms are associated with metabolic diseases. Conversely, time-restricted feeding, in which mice are fed for certain number of hours every day, restores rhythms and can prevent obesity and metabolic diseases even when mice are fed high-fat diet. These observations seek mechanistic explanations, which will require careful experiments in which feeding duration, genotype, nutrient, and feeding time relative to light:dark cycle will be manipulated and molecular changes in peripheral organs and a few brain regions will be assessed. This chapter will primarily focus on the use of mouse as an experimental animal and the experimental setup so that the molecular readouts can be better interpreted. © 2015 Elsevier Inc. All rights reserved.

  8. Abnormality of spontaneous brain activities in patients with chronic neck and shoulder pain: A resting-state fMRI study.

    Science.gov (United States)

    Yu, Cheng-Xin; Ji, Ting-Ting; Song, Hao; Li, Bo; Han, Qiang; Li, Liang; Zhuo, Zhi-Zheng

    2017-02-01

    Objectives Chronic gneck and shoulder pain (CNSP) is a common clinical symptom of cervical spondylotic radiculopathy. Several studies using resting-state functional magnetic resonance imaging (rs-fMRI) have reported that most chronic pain diseases are accompanied by structural and functional changes in the brain. However, few rs-fMRI studies have examined CNSP. The current study investigated cerebral structural and functional changes in CNSP patients. Methods In total, 25 CNSP patients and 20 healthy volunteers participated in the study. 3D-T1W and rs-fMRI images were acquired. Voxel-based morphometry analysis was applied to structural images, and regional homogeneity (ReHo) was extracted from rs-fMRI. Statistical analysis was performed on post-processing images and ReHo parameter maps. Results The results revealed no significant differences in brain structure between the two groups. In the patient group, ReHo values were significantly increased in the bilateral middle frontal gyrus and decreased in the left insula, superior frontal gyrus, middle cingulate gyrus, supplementary motor area, right postcentral gyrus, and superior parietal lobule. Conclusions This initial structural and rs-fMRI study of CNSP revealed characteristic features of spontaneous brain activity of CNSP patients. These findings may be helpful for increasing our understanding of the neuropathology of CNSP.

  9. Brain ultrasound features in multiple births due to spontaneous conception compared with assisted reproductive techniques: a cross-sectional, population-based study.

    Science.gov (United States)

    Smilari, P; Praticò, A D; Salafia, S; Praticò, E R; Cilauro, S; Saporito, A; Pavone, P; Ruggieri, M

    2014-02-01

    Multiple pregnancies from spontaneous conception and obtained by assisted reproductive techniques (ART) are associated with a disproportionate share of complications compared with natural singleton pregnancies. The outcome of multiple pregnancies obtained by ART is still the subject of controversial opinions in the medical literature as they are associated with increased rates of perinatal complications, and perinatal mortality, as well as maternal complications. Aim of this study was to determine whether there are differences between these two groups of infants. We examined the imaging findings by means of brain ultrasound (performed at birth and sequentially up to their 6th month of age) in a cohort of 296 twins and triplets born following different techniques of assisted fertilization (63 pregnancies; 119 neonates) vs. spontaneous conception (94 pregnancies; 177 neonates). We did record, by means of X square corrected test, statistically significant differences (P=0.002) between the two populations at birth in the number of normal ultrasound scans (ARTassisted conceptions (P=0.959) at long-term follow-up have been noticed.

  10. Dissociation of changes in the permeability of the blood-brain barrier from catecholamine-induced changes in blood pressure of normotensive and spontaneously hypertensive rats

    International Nuclear Information System (INIS)

    Sankar, R.; Domer, F.R.; Taylor, B.

    1982-01-01

    Researchers have studied the effects of the pressor catecholamine, dopamine, and the depressor catecholamine, isoproterenol, on the systemic blood pressure and the permeability of the blood-brain barrier (BBB) to albumin in normotensive (WKY) and spontaneously hypertensive (SHR) rats. The rats were anesthetized with pentobarbital. The permeability of the BBB to protein was measured by the extravasation of radioiodinated serum albumin (RISA). The permeability was decreased by both catecholamines despite the dose-dependent, yet opposite, changes in blood pressure in the WKY rats. The blood pressure response to both of the catecholamines was enhanced in the SHR rats. Isoproterenol caused a decrease in the permeability of the BBB in the SHR but dopamine did not. Results with both WKY and SHR rats are suggestive of an adrenergically-mediated decrease in movement across the BBB of compounds of large molecular weight, regardless of changes in blood pressure

  11. A natural basis for efficient brain-actuated control

    Science.gov (United States)

    Makeig, S.; Enghoff, S.; Jung, T. P.; Sejnowski, T. J.

    2000-01-01

    The prospect of noninvasive brain-actuated control of computerized screen displays or locomotive devices is of interest to many and of crucial importance to a few 'locked-in' subjects who experience near total motor paralysis while retaining sensory and mental faculties. Currently several groups are attempting to achieve brain-actuated control of screen displays using operant conditioning of particular features of the spontaneous scalp electroencephalogram (EEG) including central mu-rhythms (9-12 Hz). A new EEG decomposition technique, independent component analysis (ICA), appears to be a foundation for new research in the design of systems for detection and operant control of endogenous EEG rhythms to achieve flexible EEG-based communication. ICA separates multichannel EEG data into spatially static and temporally independent components including separate components accounting for posterior alpha rhythms and central mu activities. We demonstrate using data from a visual selective attention task that ICA-derived mu-components can show much stronger spectral reactivity to motor events than activity measures for single scalp channels. ICA decompositions of spontaneous EEG would thus appear to form a natural basis for operant conditioning to achieve efficient and multidimensional brain-actuated control in motor-limited and locked-in subjects.

  12. Rhythm perception and production by the bottlenose dolphin

    Science.gov (United States)

    Harley, Heidi E.; Crowell, Sara E.; Fellner, Wendi; Odell, Kim; Larsen-Plott, Leslie

    2005-09-01

    Rhythm is an important component of many natural communication systems, but it has rarely been the focus of laboratory studies of nonhuman species. Recent cognitive studies with a bottlenose dolphin confirm that a dolphin can discriminate among six different 14-kHz 4-s acoustic rhythms at 94% accuracy, and can transfer that discrimination across multiple frequency (93%) and tempo (16%-93%) shifts. In addition, a dolphin has learned to produce six different rhythms in an object-labeling paradigm. Original training required the dolphin to produce the rhythms using a pneumatic switch that led to the in-air projection of computer-generated tones. However, the dolphin spontaneously began to produce the rhythms vocally as well. To date, the dolphin has accurately labeled five objects with unique rhythms at 87% accuracy using the switch and at 83% accuracy using his own vocalizations. Confusions at the various tempos in the perception study and the variability of some characteristics and stability of others in the production study provide insight into how dolphins represent rhythm and have implications for natural communication in this species.

  13. Disturbed spontaneous brain activity pattern in patients with primary angle-closure glaucoma using amplitude of low-frequency fluctuation: a fMRI study

    Directory of Open Access Journals (Sweden)

    Huang X

    2015-07-01

    Full Text Available Xin Huang,1,* Yu-Lin Zhong,1,* Xian-Jun Zeng,2 Fuqing Zhou,2 Xin-Hua Liu,1 Pei-Hong Hu,1 Chong-Gang Pei,1 Yi Shao,1 Xi-Jian Dai21Department of Ophthalmology, 2Department of Radiology, The First Affiliated Hospital of Nanchang University, Nangchang, Jiangxi, People’s Republic of China*These authors contributed equally to this workObjective: The aim of this study is to use amplitude of low-frequency fluctuation (ALFF as a method to explore the local features of spontaneous brain activity in patients with primary angle -closure glaucoma (PACG and ALFFs relationship with the behavioral performances.Methods: A total of twenty one patients with PACG (eight males and 13 females, and twenty one healthy subjects (nine males and twelve females closely matched in age, sex, and education, each underwent a resting-state functional magnetic resonance imaging scan. The ALFF method was used to assess the local features of spontaneous brain activity. The correlation analysis was used to explore the relationships between the observed mean ALFF signal values of the different areas in PACG patients and the thickness of the retinal nerve fiber layer (RNFL. Results: Compared with the healthy subjects, patients with PACG had significant lower ALFF areas in the left precentral gyrus, bilateral middle frontal gyrus, bilateral superior frontal gyrus, right precuneus, and right angular gyrus, and higher areas in the right precentral gyrus. In the PACG group, there were significant negative correlations between the mean ALFF signal value of the right middle frontal gyrus and the left mean RNFL thickness (r=-0.487, P=0.033, and between the mean ALFF signal value of the left middle frontal gyrus and the right mean RNFL thickness (r=-0.504, P=0.020. Conclusion: PACG mainly involved in the dysfunction in the frontal lobe, which may reflect the underlying pathologic mechanism of PACG.Keywords: angle-closure glaucoma, amplitude of low-frequency fluctuation, functional

  14. Reality = relevance? Insights from spontaneous modulations of the brain's default network when telling apart reality from fiction.

    Science.gov (United States)

    Abraham, Anna; von Cramon, D Yves

    2009-01-01

    Although human beings regularly experience fictional worlds through activities such as reading novels and watching movies, little is known about what mechanisms underlie our implicit knowledge of the distinction between reality and fiction. The first neuroimaging study to address this issue revealed that the mere exposure to contexts involving real entities compared to fictional characters led to engagement of regions in the anterior medial prefrontal and posterior cingulate cortices (amPFC, PCC). As these core regions of the brain's default network are involved during self-referential processing and autobiographical memory retrieval, it was hypothesized that real entities may be conceptually coded as being more personally relevant to us than fictional characters. In the present functional magnetic resonance imaging (fMRI) study, we directly test the hypothesis that entity-associated personal relevance is the critical factor underlying the differential engagement of these brain regions by comparing the brain's response when processing contexts involving family or friends (high relevance), famous people (medium relevance), or fictional characters (low relevance). In line with predictions, a gradient pattern of activation was observed such that higher entity-associated personal relevance was associated with stronger activation in the amPFC and the PCC. The results of the study have several important implications. Firstly, they provide informed grounds for characterizing the dynamics of reality-fiction distinction. Secondly, they provide further insights into the functions of the amPFC and the PCC. Thirdly, in view of the current debate related to the functional relevance and specificity of brain's default network, they reveal a novel approach by which the functions of this network can be further explored.

  15. Reality = Relevance? Insights from Spontaneous Modulations of the Brain's Default Network when Telling Apart Reality from Fiction

    Science.gov (United States)

    Abraham, Anna; von Cramon, D. Yves

    2009-01-01

    Background Although human beings regularly experience fictional worlds through activities such as reading novels and watching movies, little is known about what mechanisms underlie our implicit knowledge of the distinction between reality and fiction. The first neuroimaging study to address this issue revealed that the mere exposure to contexts involving real entities compared to fictional characters led to engagement of regions in the anterior medial prefrontal and posterior cingulate cortices (amPFC, PCC). As these core regions of the brain's default network are involved during self-referential processing and autobiographical memory retrieval, it was hypothesized that real entities may be conceptually coded as being more personally relevant to us than fictional characters. Methodology/Principal Findings In the present functional magnetic resonance imaging (fMRI) study, we directly test the hypothesis that entity-associated personal relevance is the critical factor underlying the differential engagement of these brain regions by comparing the brain's response when processing contexts involving family or friends (high relevance), famous people (medium relevance), or fictional characters (low relevance). In line with predictions, a gradient pattern of activation was observed such that higher entity-associated personal relevance was associated with stronger activation in the amPFC and the PCC. Conclusions/Significance The results of the study have several important implications. Firstly, they provide informed grounds for characterizing the dynamics of reality-fiction distinction. Secondly, they provide further insights into the functions of the amPFC and the PCC. Thirdly, in view of the current debate related to the functional relevance and specificity of brain's default network, they reveal a novel approach by which the functions of this network can be further explored. PMID:19277108

  16. Nonrandom ventricular rhythm in horses with atrial fibrillation and its significance for patients

    NARCIS (Netherlands)

    Meijler, F.L.; Kroneman, J.; Tweel, I. van der; Herbschleb, J.N.; Heethaar, R.M.; Borst, C.

    RR interval sequences during spontaneous atrial fibrillation in eight horses were analyzed as in previous studies in patients and dogs using histograms and serial autocorrelograms. In patients and dogs with spontaneous atrial fibrillation, ventricular rhythms were always random. In the horses, the

  17. Spontaneous conversion of first onset atrial fibrillation

    DEFF Research Database (Denmark)

    Lindberg, Søren Østergaard; Hansen, Sidsel; Nielsen, Tonny

    2011-01-01

    Background  We studied all patients admitted to hospital with first onset atrial fibrillation (AF) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion. Methods and Results  We retrospectively reviewed charts of 438...

  18. Effect of Pilates Training on Alpha Rhythm

    Science.gov (United States)

    Bian, Zhijie; Sun, Hongmin; Lu, Chengbiao; Yao, Li; Chen, Shengyong; Li, Xiaoli

    2013-01-01

    In this study, the effect of Pilates training on the brain function was investigated through five case studies. Alpha rhythm changes during the Pilates training over the different regions and the whole brain were mainly analyzed, including power spectral density and global synchronization index (GSI). It was found that the neural network of the brain was more active, and the synchronization strength reduced in the frontal and temporal regions due to the Pilates training. These results supported that the Pilates training is very beneficial for improving brain function or intelligence. These findings maybe give us some line evidence to suggest that the Pilates training is very helpful for the intervention of brain degenerative diseases and cogitative dysfunction rehabilitation. PMID:23861723

  19. Effect of Pilates Training on Alpha Rhythm

    Directory of Open Access Journals (Sweden)

    Zhijie Bian

    2013-01-01

    Full Text Available In this study, the effect of Pilates training on the brain function was investigated through five case studies. Alpha rhythm changes during the Pilates training over the different regions and the whole brain were mainly analyzed, including power spectral density and global synchronization index (GSI. It was found that the neural network of the brain was more active, and the synchronization strength reduced in the frontal and temporal regions due to the Pilates training. These results supported that the Pilates training is very beneficial for improving brain function or intelligence. These findings maybe give us some line evidence to suggest that the Pilates training is very helpful for the intervention of brain degenerative diseases and cogitative dysfunction rehabilitation.

  20. RHYTHM STRUCTURE IN NEWS READING

    Directory of Open Access Journals (Sweden)

    Lluís Mas Manchón

    2013-06-01

    Full Text Available Rhythm is central to news reading in radio and television programs. This paper proposes a three level structure for rhythm in news discourse. It gives a comprehensive definition of rhythm and types of rhythm. Firstly, the Base Rhythm Structure consists of semantic and pragmatic rhythmic accents, coincident with very specific words. Secondly, these accents are grouped together according to type, frequency and order, thereby configuring three types of “rhythmic units” (the Internal Rhythm Structure: starting, main and end units. A last structure level presents four discursive factors that are very important in integrating the overall time structure of news announcing (the Melodic Rhythm Structure. This integral structure for news announcing rhythm should be further tested in acoustic-experimental studies under the criterion of information transmission efficacy.

  1. Biological Clocks & Circadian Rhythms

    Science.gov (United States)

    Robertson, Laura; Jones, M. Gail

    2009-01-01

    The study of biological clocks and circadian rhythms is an excellent way to address the inquiry strand in the National Science Education Standards (NSES) (NRC 1996). Students can study these everyday phenomena by designing experiments, gathering and analyzing data, and generating new experiments. As students explore biological clocks and circadian…

  2. Biological and physiological rhythms

    Science.gov (United States)

    Strughold, H.; Hale, H. B.

    1975-01-01

    Circadian rhythms, particularly that of sleep and wakefulness, are discussed. The sleep-wakefulness experiences of astronauts during several space missions are described, and predictions are made for future space activities, including Mars missions, interstellar flight, and life on permanent space stations.

  3. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...

  4. Correlation of brain Magnetic Resonance Imaging of spontaneously lead poisoned bald eagles (Haliaeetus leucocephalus) with histological lesions: A pilot study.

    Science.gov (United States)

    de Francisco, Olga Nicolas; Feeney, Daniel; Armién, Anibal G; Wuenschmann, Arno; Redig, Patrick T

    2016-04-01

    Six bald eagles with severe, acute lead poisoning based on blood lead values were analyzed by Magnetic Resonance Imaging (MRI) of the brain and histopathology. The aims of the study were to use MRI to locate brain lesions and correlate the changes in MRI signal with the histological character of the lesions at necropsy. All of the bald eagles presented with neurologic and non-neurologic signs suggestive of severe lead poisoning and had blood lead levels in excess of 1.0 ppm. Areas of change in image intensity in the brainstem, midbrain and cerebellum were detected in the MRI scans. Histopathology confirmed the presence of all suspected lesions. The character of the lesions suggested vascular damage as the primary insult. MRI was useful for detecting lesions and defining their three-dimensional distribution and extent. Future studies are needed to evaluate the utility of MRI for detection of lesions in less severely lead poisoned eagles and determining prognosis for treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. How and why do neurons generate complex rhythms with various frequencies?

    Directory of Open Access Journals (Sweden)

    Teresa Ree Chay

    1998-01-01

    Full Text Available Some neurons generate endogenous rhythms with a period of a few hundred milliseconds,while others generate rhythms with a period of a few tens of seconds. Sometimes rhythms appear chaotic. Explaining how these neurons can generate various modes of oscillation with a widely ranging frequency is a challenge. In the first part of this review, we illustrate that such rhythms can be generated from simple yet elegant mathematical models. Chaos embedded in rhythmic activity has interesting characteristics that are not seen in other physical systems. Understanding of how these neurons utilizes endogenous rhythms to communicate with each other is important in elucidating where the brain gets various rhythms and why it can pervert into abnormal rhythms under diseased conditions. Using the islet of Langerhans in pancreas as an example, in the second part of this review, we illustrate how insulin secreting β-cells communicate with glucagon secreting α-cells to achieve an optimal insulin release.

  6. Spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Davari R

    1996-07-01

    Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease

  7. Regulating the Access to Awareness: Brain Activity Related to Probe-related and Spontaneous Reversals in Binocular Rivalry.

    Science.gov (United States)

    Metzger, Brian A; Mathewson, Kyle E; Tapia, Evelina; Fabiani, Monica; Gratton, Gabriele; Beck, Diane M

    2017-06-01

    Research on the neural correlates of consciousness (NCC) has implicated an assortment of brain regions, ERP components, and network properties associated with visual awareness. Recently, the P3b ERP component has emerged as a leading NCC candidate. However, typical P3b paradigms depend on the detection of some stimulus change, making it difficult to separate brain processes elicited by the stimulus itself from those associated with updates or changes in visual awareness. Here we used binocular rivalry to ask whether the P3b is associated with changes in awareness even in the absence of changes in the object of awareness. We recorded ERPs during a probe-mediated binocular rivalry paradigm in which brief probes were presented over the image in either the suppressed or dominant eye to determine whether the elicited P3b activity is probe or reversal related. We found that the timing of P3b (but not its amplitude) was closely related to the timing of the report of a perceptual change rather than to the onset of the probe. This is consistent with the proposal that P3b indexes updates in conscious awareness, rather than being related to stimulus processing per se. Conversely, the probe-related P1 amplitude (but not its latency) was associated with reversal latency, suggesting that the degree to which the probe is processed increases the likelihood of a fast perceptual reversal. Finally, the response-locked P3b amplitude (but not its latency) was associated with the duration of an intermediate stage between reversals in which parts of both percepts coexist (piecemeal period). Together, the data suggest that the P3b reflects an update in consciousness and that the intensity of that process (as indexed by P3b amplitude) predicts how immediate that update is.

  8. Altered vasodilator role of nitric oxide synthase in the pancreas, heart and brain of rats with spontaneous type 2 diabetes.

    Science.gov (United States)

    Song, Dongzhe; Yao, Reina; Pang, Catherine C Y

    2008-09-04

    Type 2 diabetes is associated with altered regional blood flow and expression of nitric oxide synthase (NOS). We examined the functional role of constitutive and inducible NOS synthase (cNOS and iNOS, respectively) on regional blood flow in thiobutabarbital-anesthetized Zucker diabetic fatty (ZDF) and control rats via the radioactive microspheres technique. Blood flow was measured at baseline (1 h after surgery), after i.v. administration of 1400W (N-3-aminomethyl-benzyl-acetamidine, selective iNOS inhibitor, 3 mg/kg), and again after i.v. N(G)-nitro-l-arginine methyl ester (L-NAME, non-selective NOS inhibitor, 8 mg/kg). Both groups had similar baseline mean arterial pressure, cardiac output and total peripheral resistance, but the ZDF rats had lower heart rate relative to the control rats (272 versus 305 beats/min). Whereas 1400W did not alter mean arterial pressure or blood flow in either group, L-NAME markedly increased mean arterial pressure and total peripheral resistance, and reduced cardiac output, heart rate, blood flow and arterial conductance in all organs/tissues of both the control and ZDF rats. L-NAME caused greater vasoconstriction in the heart (1.5-times the constriction in control rats) and brain (1.5-times) of the ZDF rats, but less in the pancreas (0.6-times). Thus, cNOS had greater vasodilator control of the heart and brain, but less in the pancreas of the ZDF than control rats. iNOS has negligible influence on blood flow in both groups of rats.

  9. Biological rhythms and melatonin in mood disorders and their treatments.

    Science.gov (United States)

    Lanfumey, Laurence; Mongeau, Raymond; Hamon, Michel

    2013-05-01

    Affective disorders such as major depression, bipolar disorders and seasonal affective disorders have been described as alterations of various neuronal systems. In addition to the classical monoaminergic hypotheses that have been long proposed to explain the pathophysiology of these disorders, a strong association between circadian rhythms and mood regulation has been suggested in the light of several clinical and preclinical findings. In this review, we summarize the different hypotheses on pathophysiology mechanisms underlying depressive disorders and put a special emphasis on the alterations of melatonin secretion and associated changes in biological rhythms that characterize mood disorders. Causal relationships between alterations in circadian rhythms and mood disorders are strongly supported by the antidepressant efficacy of innovative pharmacological treatments aimed at resynchronizing endogenous rhythms in depressed patients. Genetic, epigenetic and environmental factors generating desynchronization between endogenous biological rhythms and exogenous rhythms driven by environmental and societal constraints are very probably involved in the vulnerability to mood disorders. Further investigations of the molecular/cellular bases of the relationships between stress axis dysfunctions, endogenous biological rhythm dysregulations and associated functional and anatomical brain alterations should allow important progress in the knowledge of pathophysiological mechanisms of affective disorders and the downstream development of innovative, more effective and better tolerated, therapies. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Synchronization, non-linear dynamics and low-frequency fluctuations: Analogy between spontaneous brain activity and networked single-transistor chaotic oscillators

    Science.gov (United States)

    Minati, Ludovico; Chiesa, Pietro; Tabarelli, Davide; D'Incerti, Ludovico; Jovicich, Jorge

    2015-03-01

    In this paper, the topographical relationship between functional connectivity (intended as inter-regional synchronization), spectral and non-linear dynamical properties across cortical areas of the healthy human brain is considered. Based upon functional MRI acquisitions of spontaneous activity during wakeful idleness, node degree maps are determined by thresholding the temporal correlation coefficient among all voxel pairs. In addition, for individual voxel time-series, the relative amplitude of low-frequency fluctuations and the correlation dimension (D2), determined with respect to Fourier amplitude and value distribution matched surrogate data, are measured. Across cortical areas, high node degree is associated with a shift towards lower frequency activity and, compared to surrogate data, clearer saturation to a lower correlation dimension, suggesting presence of non-linear structure. An attempt to recapitulate this relationship in a network of single-transistor oscillators is made, based on a diffusive ring (n = 90) with added long-distance links defining four extended hub regions. Similarly to the brain data, it is found that oscillators in the hub regions generate signals with larger low-frequency cycle amplitude fluctuations and clearer saturation to a lower correlation dimension compared to surrogates. The effect emerges more markedly close to criticality. The homology observed between the two systems despite profound differences in scale, coupling mechanism and dynamics appears noteworthy. These experimental results motivate further investigation into the heterogeneity of cortical non-linear dynamics in relation to connectivity and underline the ability for small networks of single-transistor oscillators to recreate collective phenomena arising in much more complex biological systems, potentially representing a future platform for modelling disease-related changes.

  11. Synchronization, non-linear dynamics and low-frequency fluctuations: Analogy between spontaneous brain activity and networked single-transistor chaotic oscillators

    International Nuclear Information System (INIS)

    Minati, Ludovico; Chiesa, Pietro; Tabarelli, Davide; Jovicich, Jorge; D'Incerti, Ludovico

    2015-01-01

    In this paper, the topographical relationship between functional connectivity (intended as inter-regional synchronization), spectral and non-linear dynamical properties across cortical areas of the healthy human brain is considered. Based upon functional MRI acquisitions of spontaneous activity during wakeful idleness, node degree maps are determined by thresholding the temporal correlation coefficient among all voxel pairs. In addition, for individual voxel time-series, the relative amplitude of low-frequency fluctuations and the correlation dimension (D 2 ), determined with respect to Fourier amplitude and value distribution matched surrogate data, are measured. Across cortical areas, high node degree is associated with a shift towards lower frequency activity and, compared to surrogate data, clearer saturation to a lower correlation dimension, suggesting presence of non-linear structure. An attempt to recapitulate this relationship in a network of single-transistor oscillators is made, based on a diffusive ring (n = 90) with added long-distance links defining four extended hub regions. Similarly to the brain data, it is found that oscillators in the hub regions generate signals with larger low-frequency cycle amplitude fluctuations and clearer saturation to a lower correlation dimension compared to surrogates. The effect emerges more markedly close to criticality. The homology observed between the two systems despite profound differences in scale, coupling mechanism and dynamics appears noteworthy. These experimental results motivate further investigation into the heterogeneity of cortical non-linear dynamics in relation to connectivity and underline the ability for small networks of single-transistor oscillators to recreate collective phenomena arising in much more complex biological systems, potentially representing a future platform for modelling disease-related changes

  12. Circadian rhythms in cognitive performance: implications for neuropsychological assessment

    Directory of Open Access Journals (Sweden)

    Valdez P

    2012-12-01

    Full Text Available Pablo Valdez, Candelaria Ramírez, Aída GarcíaLaboratory of Psychophysiology, School of Psychology, University of Nuevo León, Monterrey, Nuevo León, MéxicoAbstract: Circadian variations have been found in human performance, including the efficiency to execute many tasks, such as sensory, motor, reaction time, time estimation, memory, verbal, arithmetic calculations, and simulated driving tasks. Performance increases during the day and decreases during the night. Circadian rhythms have been found in three basic neuropsychological processes (attention, working memory, and executive functions, which may explain oscillations in the performance of many tasks. The time course of circadian rhythms in cognitive performance may be modified significantly in patients with brain disorders, due to chronotype, age, alterations of the circadian rhythm, sleep deprivation, type of disorder, and medication. This review analyzes the recent results on circadian rhythms in cognitive performance, as well as the implications of these rhythms for the neuropsychological assessment of patients with brain disorders such as traumatic head injury, stroke, dementia, developmental disorders, and psychiatric disorders.Keywords: human circadian rhythms, cognitive performance, neuropsychological assessment, attention, working memory, executive functions

  13. Circadian rhythm and menopause.

    Science.gov (United States)

    Pines, A

    2016-12-01

    Circadian rhythm is an internal biological clock which initiates and monitors various physiological processes with a fixed time-related schedule. The master circadian pacemaker is located in the suprachiasmatic nucleus in the hypothalamus. The circadian clock undergoes significant changes throughout the life span, at both the physiological and molecular levels. This cyclical physiological process, which is very complex and multifactorial, may be associated with metabolic alterations, atherosclerosis, impaired cognition, mood disturbances and even development of cancer. Sex differences do exist, and the well-known sleep disturbances associated with menopause are a good example. Circadian rhythm was detected in the daily pattern of hot flushes, with a peak in the afternoons. Endogenous secretion of melatonin decreases with aging across genders, and, among women, menopause is associated with a significant reduction of melatonin levels, affecting sleep. Although it might seem that hot flushes and melatonin secretion are likely related, there are not enough data to support such a hypothesis.

  14. Circadian Rhythms in Cyanobacteria

    Science.gov (United States)

    Golden, Susan S.

    2015-01-01

    SUMMARY Life on earth is subject to daily and predictable fluctuations in light intensity, temperature, and humidity created by rotation of the earth. Circadian rhythms, generated by a circadian clock, control temporal programs of cellular physiology to facilitate adaptation to daily environmental changes. Circadian rhythms are nearly ubiquitous and are found in both prokaryotic and eukaryotic organisms. Here we introduce the molecular mechanism of the circadian clock in the model cyanobacterium Synechococcus elongatus PCC 7942. We review the current understanding of the cyanobacterial clock, emphasizing recent work that has generated a more comprehensive understanding of how the circadian oscillator becomes synchronized with the external environment and how information from the oscillator is transmitted to generate rhythms of biological activity. These results have changed how we think about the clock, shifting away from a linear model to one in which the clock is viewed as an interactive network of multifunctional components that are integrated into the context of the cell in order to pace and reset the oscillator. We conclude with a discussion of how this basic timekeeping mechanism differs in other cyanobacterial species and how information gleaned from work in cyanobacteria can be translated to understanding rhythmic phenomena in other prokaryotic systems. PMID:26335718

  15. Sleep and Sleep-wake Rhythm in Older Adults with Intellectual Disabilities

    NARCIS (Netherlands)

    E. van de Wouw-Van Dijk (Ellen)

    2013-01-01

    textabstractEveryone who has experienced poor sleep knows how it affects daytime functioning and wellbeing. A good night’s rest and a stable sleep-wake rhythm are therefore very important. The sleep-wake rhythm is regulated by several brain structures. People with an intellectual disability (ID) all

  16. Comparing brain activity patterns during spontaneous exploratory and cue-instructed learning using single photon-emission computed tomography (SPECT) imaging of regional cerebral blood flow in freely behaving rats.

    Science.gov (United States)

    Mannewitz, A; Bock, J; Kreitz, S; Hess, A; Goldschmidt, J; Scheich, H; Braun, Katharina

    2018-05-01

    Learning can be categorized into cue-instructed and spontaneous learning types; however, so far, there is no detailed comparative analysis of specific brain pathways involved in these learning types. The aim of this study was to compare brain activity patterns during these learning tasks using the in vivo imaging technique of single photon-emission computed tomography (SPECT) of regional cerebral blood flow (rCBF). During spontaneous exploratory learning, higher levels of rCBF compared to cue-instructed learning were observed in motor control regions, including specific subregions of the motor cortex and the striatum, as well as in regions of sensory pathways including olfactory, somatosensory, and visual modalities. In addition, elevated activity was found in limbic areas, including specific subregions of the hippocampal formation, the amygdala, and the insula. The main difference between the two learning paradigms analyzed in this study was the higher rCBF observed in prefrontal cortical regions during cue-instructed learning when compared to spontaneous learning. Higher rCBF during cue-instructed learning was also observed in the anterior insular cortex and in limbic areas, including the ectorhinal and entorhinal cortexes, subregions of the hippocampus, subnuclei of the amygdala, and the septum. Many of the rCBF changes showed hemispheric lateralization. Taken together, our study is the first to compare partly lateralized brain activity patterns during two different types of learning.

  17. [Affective disorders and biological rhythms].

    Science.gov (United States)

    Le Strat, Y; Ramoz, N; Gorwood, P

    2008-06-01

    Disruptions of circadian rhythms are described in affective disorders, including unipolar and bipolar disorder, but also seasonal affective disorder. Sleep-wake and hormone circadian rhythms are among the most quoted examples. Depression could be conceptualized as a desynchronization between the endogenous circadian pacemaker and the exogenous stimuli, such as sunlight and social rhythms. Accordingly, Clock genes have been studied and the literature suggests that variants in these genes confer a higher risk of relapse, more sleep disturbances associated with depression, as well as incomplete treatment response. Most of therapeutic interventions in depression have an impact on biological rhythms. Some of them exclusively act via a biological pathway, such as sleep deprivation or light therapy. Some psychosocial interventions are specifically focusing on social rhythms, particularly in bipolar disorder, in which the promotion of stabilization is emphasized. Finally, all antidepressant medications could improve biological rhythms, but some new agents are now totally focusing this novel approach for the treatment of depression.

  18. Stochastic feedback and the regulation of biological rhythms

    Science.gov (United States)

    Nunes Amaral, L. A.; Goldberger, A. L.; Stanley, H. E.

    1998-01-01

    We propose a general approach to the question of how biological rhythms spontaneously self-regulate, based on the concept of "stochastic feedback". We illustrate this approach by considering at a coarse-grained level the neuroautonomic regulation of the heart rate. The model generates complex dynamics and successfully acounts for key characteristics of cardiac variability, including the l/f power spectrum, the functional form and scaling of the distribution of variations, and correlations in the Fourier phases indicating nonlinear dynamics.

  19. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  20. A Causal Rhythm Grouping

    DEFF Research Database (Denmark)

    Jensen, Karl Kristoffer

    2005-01-01

    This paper presents a method to identify segment boundaries in music. The method is based on a multi-step model; first a features is measured from the audio, then a measure of rhythm is calculated from the feature, the diagonal of a self-similarity matrix is calculated, and finally the segment...... boundaries are found on a smoothed novelty measure, calculated from the self-similarity matrix. All the steps of the model have been accompanied with an informal evaluation, and the final system is tested on a variety of rhythmic songs with good results. The paper introduces a new feature that is shown...

  1. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human......On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  2. Influence of spontaneous rhythm on movement-related cortical potential

    DEFF Research Database (Denmark)

    Yao, Lin; Chen, Mei Lin; Sheng, Xinjun

    2017-01-01

    in variability as a novel task is learned, which in turn significantly decreases the detection accuracy. In the current study we sought to investigate if tactile stimulation, often implemented in rehabilitation, may act as a primer to our associative BCI by decreasing MRCP variability. Six chronic stroke...... patients were exposed to one session of tactile stimulation, and the MRCP of an arm lifting task, repeated 30 times, extracted. Results reveal that for three patients the MRCP detection accuracy expressed as the rate of true and false positives was improved. In two patients however the detection accuracy...... declined while one patient was unable to complete the experiment. Since tactile stimulation is a common tool implemented by physiotherapists to train patients to perform dynamic movements with the appropriate muscle pattern to avoid compensatory actions by other muscles it will be important to decipher why...

  3. Are circadian rhythms new pathways to understand Autism Spectrum Disorder?

    Science.gov (United States)

    Geoffray, M-M; Nicolas, A; Speranza, M; Georgieff, N

    2016-11-01

    Autism Spectrum Disorder (ASD) is a frequent neurodevelopmental disorder. ASD is probably the result of intricate interactions between genes and environment altering progressively the development of brain structures and functions. Circadian rhythms are a complex intrinsic timing system composed of almost as many clocks as there are body cells. They regulate a variety of physiological and behavioral processes such as the sleep-wake rhythm. ASD is often associated with sleep disorders and low levels of melatonin. This first point raises the hypothesis that circadian rhythms could have an implication in ASD etiology. Moreover, circadian rhythms are generated by auto-regulatory genetic feedback loops, driven by transcription factors CLOCK and BMAL1, who drive transcription daily patterns of a wide number of clock-controlled genes (CCGs) in different cellular contexts across tissues. Among these, are some CCGs coding for synapses molecules associated to ASD susceptibility. Furthermore, evidence emerges about circadian rhythms control of time brain development processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. The Rhetorical Nature of Rhythm

    NARCIS (Netherlands)

    Balint, Mihaela; Dascalu, Mihai; Trausan-Matu, Stefan

    2017-01-01

    Up to date, linguistic rhythm has been studied for speech, but the rhythm of written texts has been merely recognized, and not analyzed or interpreted in connection to natural language tasks. We provide an extension of the textual rhythmic features we proposed in previous work, and

  5. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  6. Systems biology of cellular rhythms.

    Science.gov (United States)

    Goldbeter, A; Gérard, C; Gonze, D; Leloup, J-C; Dupont, G

    2012-08-31

    Rhythms abound in biological systems, particularly at the cellular level where they originate from the feedback loops present in regulatory networks. Cellular rhythms can be investigated both by experimental and modeling approaches, and thus represent a prototypic field of research for systems biology. They have also become a major topic in synthetic biology. We review advances in the study of cellular rhythms of biochemical rather than electrical origin by considering a variety of oscillatory processes such as Ca++ oscillations, circadian rhythms, the segmentation clock, oscillations in p53 and NF-κB, synthetic oscillators, and the oscillatory dynamics of cyclin-dependent kinases driving the cell cycle. Finally we discuss the coupling between cellular rhythms and their robustness with respect to molecular noise.

  7. Orchestrating intensities and rhythms

    DEFF Research Database (Denmark)

    Staunæs, Dorthe; Juelskjær, Malou

    2016-01-01

    The aim of this article is to trace how contemporary (post)psychologies, when used as psy-leadership tools in order to reach new standards, may create new work around the standards and may also create new subjectivities. It is well known that education is a field in which standardization and the ......The aim of this article is to trace how contemporary (post)psychologies, when used as psy-leadership tools in order to reach new standards, may create new work around the standards and may also create new subjectivities. It is well known that education is a field in which standardization...... environmentality and learning-centered governance standards has dramatic and performative effects for the production of (educational) subjectivities. This implies a shift from governing identities, categories and structures towards orchestrating affective intensities and rhythms. Finally, the article discusses...... possible new worries and vulnerabilities when school goes post-psychological....

  8. Dissipative structures and biological rhythms

    Science.gov (United States)

    Goldbeter, Albert

    2017-10-01

    Sustained oscillations abound in biological systems. They occur at all levels of biological organization over a wide range of periods, from a fraction of a second to years, and with a variety of underlying mechanisms. They control major physiological functions, and their dysfunction is associated with a variety of physiological disorders. The goal of this review is (i) to give an overview of the main rhythms observed at the cellular and supracellular levels, (ii) to briefly describe how the study of biological rhythms unfolded in the course of time, in parallel with studies on chemical oscillations, (iii) to present the major roles of biological rhythms in the control of physiological functions, and (iv) the pathologies associated with the alteration, disappearance, or spurious occurrence of biological rhythms. Two tables present the main examples of cellular and supracellular rhythms ordered according to their period, and their role in physiology and pathophysiology. Among the rhythms discussed are neural and cardiac rhythms, metabolic oscillations such as those occurring in glycolysis in yeast, intracellular Ca++ oscillations, cyclic AMP oscillations in Dictyostelium amoebae, the segmentation clock that controls somitogenesis, pulsatile hormone secretion, circadian rhythms which occur in all eukaryotes and some bacteria with a period close to 24 h, the oscillatory dynamics of the enzymatic network driving the cell cycle, and oscillations in transcription factors such as NF-ΚB and tumor suppressors such as p53. Ilya Prigogine's concept of dissipative structures applies to temporal oscillations and allows us to unify within a common framework the various rhythms observed at different levels of biological organization, regardless of their period and underlying mechanism.

  9. Is there an endogenous tidal foraging rhythm in marine iguanas?

    Science.gov (United States)

    Wikelski, M; Hau, M

    1995-12-01

    As strictly herbivorous reptiles, Galápagos marine iguanas graze on algae in the intertidal areas during low tide. Daily foraging rhythms were observed on two islands during 3 years to determine the proximate factors underlying behavioral synchrony with the tides. Marine iguanas walked to their intertidal foraging grounds from far-off resting areas in anticipation of the time of low tide. Foraging activity was restricted to daytime, resulting in a complex bitidal rhythm including conspicuous switches from afternoon foraging to foraging during the subsequent morning when low tide occurred after dusk. The animals anticipated the daily low tide by a maximum of 4 h. The degree of anticipation depended on environmental parameters such as wave action and food supply. "Early foragers" survived in greater numbers than did animals arriving later at foraging sites, a result indicating selection pressure on the timing of anticipation. The timing of foraging trips was better predicted by the daily changes in tabulated low tide than it was by the daily changes in actual exposure of the intertidal foraging flats, suggesting an endogenous nature of the foraging rhythms. Endogenous rhythmicity would also explain why iguanas that had spontaneously fasted for several days nevertheless went foraging at the "right" time of day. A potential lunar component of the foraging rhythmicity of marine iguanas showed up in their assemblage on intertidal rocks during neap tide nights. This may indicate that iguanas possessed information on the semi-monthly rhythms in tide heights. Enclosure experiments showed that bitidal foraging rhythms of iguanas may free run in the absence of direct cues from the intertidal areas and operate independent of the light:dark cycle and social stimuli. Therefore, the existence of a circatidal oscillator in marine iguanas is proposed. The bitidal foraging pattern may result from an interaction of a circadian system with a circatidal system. Food intake or related

  10. Circadian Rhythm Management System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The value of measuring sleep-wake cycles is significantly enhanced by measuring other physiological signals that depend on circadian rhythms (such as heart rate and...

  11. Effect of rosary prayer and yoga mantras on autonomic cardiovascular rhythms: comparative study.

    Science.gov (United States)

    Bernardi, L; Sleight, P; Bandinelli, G; Cencetti, S; Fattorini, L; Wdowczyc-Szulc, J; Lagi, A

    To test whether rhythmic formulas such as the rosary and yoga mantras can synchronise and reinforce inherent cardiovascular rhythms and modify baroreflex sensitivity. Comparison of effects of recitation of the Ave Maria (in Latin) or of a mantra, during spontaneous and metronome controlled breathing, on breathing rate and on spontaneous oscillations in RR interval, and on blood pressure and cerebral circulation. Florence and Pavia, Italy. 23 healthy adults. Breathing rate, regularity of breathing, baroreflex sensitivity, frequency of cardiovascular oscillations. Both prayer and mantra caused striking, powerful, and synchronous increases in existing cardiovascular rhythms when recited six times a minute. Baroreflex sensitivity also increased significantly, from 9.5 (SD 4.6) to 11.5 (4.9) ms/mm Hg, P<0.05. Rhythm formulas that involve breathing at six breaths per minute induce favourable psychological and possibly physiological effects.

  12. Circalunidian clocks control tidal rhythms of locomotion in the American horseshoe crab, Limulus polyphemus

    Science.gov (United States)

    Chabot, Christopher C.; Ramberg-Pihl, Nicole C.; Watson, Winsor H.

    2016-01-01

    While many intertidal animals exhibit circatidal rhythms, the nature of the underlying endogenous clocks that control these rhythms has been controversial. In this study American horseshoe crabs, Limulus polyphemus, were used to test the circalunidian hypothesis by exposing them to four different tidal regimes. Overall, the results obtained support the circalunidian hypothesis: each of the twice-daily rhythms of activity appears to be controlled by a separate clock, each with an endogenous period of approximately 24.8h. First, spontaneous “skipping” of one of the daily bouts was observed under several different conditions. Second, the presence of two bouts of activity/day, with different periods, was observed. Lastly, we were able to separately synchronize bouts of activity to two artificial tidal regimes with different periods. These results, taken together, argue in favor of two separate circalunidian clocks in Limulus, each of which controls one of the two bouts of their daily tidal activity rhythms. PMID:27559270

  13. Brain activation for spontaneous and explicit false belief tasks overlaps: new fMRI evidence on belief processing and violation of expectation.

    Science.gov (United States)

    Bardi, Lara; Desmet, Charlotte; Nijhof, Annabel; Wiersema, Jan R; Brass, Marcel

    2017-03-01

    There is extensive discussion on whether spontaneous and explicit forms of ToM are based on the same cognitive/neural mechanisms or rather reflect qualitatively different processes. For the first time, we analyzed the BOLD signal for false belief processing by directly comparing spontaneous and explicit ToM task versions. In both versions, participants watched videos of a scene including an agent who acquires a true or false belief about the location of an object (belief formation phase). At the end of the movies (outcome phase), participants had to react to the presence of the object. During the belief formation phase, greater activity was found for false vs true belief trials in the right posterior parietal cortex. The ROI analysis of the right temporo-parietal junction (TPJ), confirmed this observation. Moreover, the anterior medial prefrontal cortex (aMPFC) was active during the outcome phase, being sensitive to violation of both the participant's and agent's expectations about the location of the object. Activity in the TPJ and aMPFC was not modulated by the spontaneous/explicit task. Overall, these data show that neural mechanisms for spontaneous and explicit ToM overlap. Interestingly, a dissociation between TPJ and aMPFC for belief tracking and outcome evaluation, respectively, was also found. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  14. Circadian Rhythms, Sleep Deprivation, and Human Performance

    Science.gov (United States)

    Goel, Namni; Basner, Mathias; Rao, Hengyi; Dinges, David F.

    2014-01-01

    Much of the current science on, and mathematical modeling of, dynamic changes in human performance within and between days is dominated by the two-process model of sleep–wake regulation, which posits a neurobiological drive for sleep that varies homeostatically (increasing as a saturating exponential during wakefulness and decreasing in a like manner during sleep), and a circadian process that neurobiologically modulates both the homeostatic drive for sleep and waking alertness and performance. Endogenous circadian rhythms in neurobehavioral functions, including physiological alertness and cognitive performance, have been demonstrated using special laboratory protocols that reveal the interaction of the biological clock with the sleep homeostatic drive. Individual differences in circadian rhythms and genetic and other components underlying such differences also influence waking neurobehavioral functions. Both acute total sleep deprivation and chronic sleep restriction increase homeostatic sleep drive and degrade waking neurobehavioral functions as reflected in sleepiness, attention, cognitive speed, and memory. Recent evidence indicating a high degree of stability in neurobehavioral responses to sleep loss suggests that these trait-like individual differences are phenotypic and likely involve genetic components, including circadian genes. Recent experiments have revealed both sleep homeostatic and circadian effects on brain metabolism and neural activation. Investigation of the neural and genetic mechanisms underlying the dynamically complex interaction between sleep homeostasis and circadian systems is beginning. A key goal of this work is to identify biomarkers that accurately predict human performance in situations in which the circadian and sleep homeostatic systems are perturbed. PMID:23899598

  15. A stochastic model of input effectiveness during irregular gamma rhythms.

    Science.gov (United States)

    Dumont, Grégory; Northoff, Georg; Longtin, André

    2016-02-01

    Gamma-band synchronization has been linked to attention and communication between brain regions, yet the underlying dynamical mechanisms are still unclear. How does the timing and amplitude of inputs to cells that generate an endogenously noisy gamma rhythm affect the network activity and rhythm? How does such "communication through coherence" (CTC) survive in the face of rhythm and input variability? We present a stochastic modelling approach to this question that yields a very fast computation of the effectiveness of inputs to cells involved in gamma rhythms. Our work is partly motivated by recent optogenetic experiments (Cardin et al. Nature, 459(7247), 663-667 2009) that tested the gamma phase-dependence of network responses by first stabilizing the rhythm with periodic light pulses to the interneurons (I). Our computationally efficient model E-I network of stochastic two-state neurons exhibits finite-size fluctuations. Using the Hilbert transform and Kuramoto index, we study how the stochastic phase of its gamma rhythm is entrained by external pulses. We then compute how this rhythmic inhibition controls the effectiveness of external input onto pyramidal (E) cells, and how variability shapes the window of firing opportunity. For transferring the time variations of an external input to the E cells, we find a tradeoff between the phase selectivity and depth of rate modulation. We also show that the CTC is sensitive to the jitter in the arrival times of spikes to the E cells, and to the degree of I-cell entrainment. We further find that CTC can occur even if the underlying deterministic system does not oscillate; quasicycle-type rhythms induced by the finite-size noise retain the basic CTC properties. Finally a resonance analysis confirms the relative importance of the I cell pacing for rhythm generation. Analysis of whole network behaviour, including computations of synchrony, phase and shifts in excitatory-inhibitory balance, can be further sped up by orders of

  16. Introduction to Focus Issue: Rhythms and Dynamic Transitions in Neurological Disease: Modeling, Computation, and Experiment

    International Nuclear Information System (INIS)

    Kaper, Tasso J.; Kramer, Mark A.; Rotstein, Horacio G.

    2013-01-01

    Rhythmic neuronal oscillations across a broad range of frequencies, as well as spatiotemporal phenomena, such as waves and bumps, have been observed in various areas of the brain and proposed as critical to brain function. While there is a long and distinguished history of studying rhythms in nerve cells and neuronal networks in healthy organisms, the association and analysis of rhythms to diseases are more recent developments. Indeed, it is now thought that certain aspects of diseases of the nervous system, such as epilepsy, schizophrenia, Parkinson's, and sleep disorders, are associated with transitions or disruptions of neurological rhythms. This focus issue brings together articles presenting modeling, computational, analytical, and experimental perspectives about rhythms and dynamic transitions between them that are associated to various diseases

  17. Introduction to Focus Issue: Rhythms and Dynamic Transitions in Neurological Disease: Modeling, Computation, and Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kaper, Tasso J., E-mail: tasso@bu.edu; Kramer, Mark A., E-mail: mak@bu.edu [Department of Mathematics and Statistics, Boston University, Boston, Massachusetts 02215 (United States); Rotstein, Horacio G., E-mail: horacio@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

    2013-12-15

    Rhythmic neuronal oscillations across a broad range of frequencies, as well as spatiotemporal phenomena, such as waves and bumps, have been observed in various areas of the brain and proposed as critical to brain function. While there is a long and distinguished history of studying rhythms in nerve cells and neuronal networks in healthy organisms, the association and analysis of rhythms to diseases are more recent developments. Indeed, it is now thought that certain aspects of diseases of the nervous system, such as epilepsy, schizophrenia, Parkinson's, and sleep disorders, are associated with transitions or disruptions of neurological rhythms. This focus issue brings together articles presenting modeling, computational, analytical, and experimental perspectives about rhythms and dynamic transitions between them that are associated to various diseases.

  18. Introduction to Focus Issue: Rhythms and Dynamic Transitions in Neurological Disease: Modeling, Computation, and Experiment

    Science.gov (United States)

    Kaper, Tasso J.; Kramer, Mark A.; Rotstein, Horacio G.

    2013-12-01

    Rhythmic neuronal oscillations across a broad range of frequencies, as well as spatiotemporal phenomena, such as waves and bumps, have been observed in various areas of the brain and proposed as critical to brain function. While there is a long and distinguished history of studying rhythms in nerve cells and neuronal networks in healthy organisms, the association and analysis of rhythms to diseases are more recent developments. Indeed, it is now thought that certain aspects of diseases of the nervous system, such as epilepsy, schizophrenia, Parkinson's, and sleep disorders, are associated with transitions or disruptions of neurological rhythms. This focus issue brings together articles presenting modeling, computational, analytical, and experimental perspectives about rhythms and dynamic transitions between them that are associated to various diseases.

  19. Conduction system disease in fetuses evaluated for irregular cardiac rhythm.

    Science.gov (United States)

    Cuneo, Bettina F; Strasburger, Janette F; Wakai, Ronald T; Ovadia, Marc

    2006-01-01

    To determine the prevalence of 1st and 2nd degree AV block in fetuses with an irregular cardiac rhythm, and to summarize outcome of these pregnancies. The diagnosis of irregular cardiac rhythm or 'skipped beats' includes isolated ectopy that resolves spontaneously. Recently, Doppler measurements of the 'mechanical' PR interval have been shown to identify AV conduction disease prenatally. Prenatal therapy of these conduction abnormalities may limit the progression to more advanced disease either in utero or after birth. A retrospective review was performed of fetuses evaluated between 1996 and 2004 with the findings of irregular cardiac rhythm. 1st or 2nd degree AV block was diagnosed on Doppler and M-mode recordings, and confirmed using either fetal magnetocardiography (fMCG) or postnatal 12-lead ECG. Dexamethasone was administered to 4 mothers with abnormal fetal AV conduction in the setting of anti-Ro/anti-La antibodies. Of 702 fetuses initially referred for arrhythmia, 306 had an irregular rhythm. Eight (2.6%) had intermittent 1st or 2nd degree AV block confirmed by fMCG and/or postnatal 12-lead ECG. AV block was presumed idiopathic in 2, associated with congenital long QT syndrome in 2 or with clinically unsuspected maternal anti-Ro or anti-La antibodies in 4. During the intrauterine period there was no progression to complete AV block and all were born alive at 34-40 weeks of gestation. A small but clinically significant population of fetuses with irregular rhythm will have 1st or 2nd degree AV block. Transplacental therapy may limit the intrauterine progression to more advanced disease. Copyright 2006 S. Karger AG, Basel.

  20. Time-Dependent Effects of Training on Cardiovascular Control in Spontaneously Hypertensive Rats: Role for Brain Oxidative Stress and Inflammation and Baroreflex Sensitivity

    OpenAIRE

    Masson, Gustavo S.; Costa, Tassia S. R.; Yshii, Lidia; Fernandes, Denise C.; Soares, Pedro Paulo Silva; Laurindo, Francisco R.; Scavone, Cristoforo; Michelini, Lisete C.

    2014-01-01

    Baroreflex dysfunction, oxidative stress and inflammation, important hallmarks of hypertension, are attenuated by exercise training. In this study, we investigated the relationships and time-course changes of cardiovascular parameters, pro-inflammatory cytokines and pro-oxidant profiles within the hypothalamic paraventricular nucleus of the spontaneously hypertensive rats (SHR). Basal values and variability of arterial pressure and heart rate and baroreflex sensitivity were measured in traine...

  1. The correlation between white-matter microstructure and the complexity of spontaneous brain activity: a difussion tensor imaging-MEG study.

    OpenAIRE

    Fernández, A; Ríos-Lago, M; Abásolo, D; Hornero, R; Alvarez-Linera, J; Paul, N; Maestú, F; Ortiz, T

    2011-01-01

    The advent of new signal processing methods, such as non-linear analysis techniques, represents a new perspective which adds further value to brain signals' analysis. Particularly, Lempel–Ziv's Complexity (LZC) has proven to be useful in exploring the complexity of the brain electromagnetic activity. However, an important problem is the lack of knowledge about the physiological determinants of these measures. Although acorrelation between complexity and connectivity has been proposed, this hy...

  2. Dorsomedial prefontal cortex supports spontaneous thinking per se.

    Science.gov (United States)

    Raij, T T; Riekki, T J J

    2017-06-01

    Spontaneous thinking, an action to produce, consider, integrate, and reason through mental representations, is central to our daily experience and has been suggested to serve crucial adaptive purposes. Such thinking occurs among other experiences during mind wandering that is associated with activation of the default mode network among other brain circuitries. Whether and how such brain activation is linked to the experience of spontaneous thinking per se remains poorly known. We studied 51 healthy subjects using a comprehensive experience-sampling paradigm during 3T functional magnetic resonance imaging. In comparison with fixation, the experiences of spontaneous thinking and spontaneous perception were related to activation of wide-spread brain circuitries, including the cortical midline structures, the anterior cingulate cortex and the visual cortex. In direct comparison of the spontaneous thinking versus spontaneous perception, activation was observed in the anterior dorsomedial prefrontal cortex. Modality congruence of spontaneous-experience-related brain activation was suggested by several findings, including association of the lingual gyrus with visual in comparison with non-verbal-non-visual thinking. In the context of current literature, these findings suggest that the cortical midline structures are involved in the integrative core substrate of spontaneous thinking that is coupled with other brain systems depending on the characteristics of thinking. Furthermore, involvement of the anterior dorsomedial prefrontal cortex suggests the control of high-order abstract functions to characterize spontaneous thinking per se. Hum Brain Mapp 38:3277-3288, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Rhythms and Dance. Games of Low Organization.

    Science.gov (United States)

    Montgomery County Public Schools, Rockville, MD.

    This guide provides activities, resources, and ideas for elementary physical education and classroom teachers. The activities in the basic rhythms program are divided into five classifications: movement patterns, dramatic activities, singing games, creative rhythms-dance, and rhythmic gymnastics. At the beginning of the basic rhythms sections is a…

  4. The International Sweethearts of Rhythm.

    Science.gov (United States)

    Sher, Liz

    1987-01-01

    The International Sweethearts of Rhythm, a popular, long-lived, all-female jazz band of the 1940s, were the first racially integrated women's band in America. Their achievement has been largely neglected by music historians. A brief history of the band is presented, and their significance is discussed. (BJV)

  5. Circadian rhythms in microalgae production

    NARCIS (Netherlands)

    Winter, de L.

    2015-01-01

    Abstract Thesis: Circadian rhythms in microalgae production

    Lenneke de Winter

    The sun imposes a daily cycle of light and dark on nearly all organisms. The circadian clock evolved to help organisms program their activities at an appropriate time during this daily

  6. ADHD, circadian rhythms and seasonality

    NARCIS (Netherlands)

    Wynchank, Dora S.; Bijlenga, Denise; Lamers, Femke; Bron, Tannetje I.; Winthorst, Wim H.; Vogel, Suzan W.; Penninx, Brenda W.; Beekman, Aartjan T.; Kooij, J. Sandra

    2016-01-01

    Objective: We evaluated whether the association between Adult Attention-Deficit/Hyperactivity Disorder (ADHD) and Seasonal Affective Disorder (SAD) was mediated by the circadian rhythm. Method: Data of 2239 persons from the Netherlands Study of Depression and Anxiety (NESDA) were used. Two groups

  7. Rhythm Deficits in "Tone Deafness"

    Science.gov (United States)

    Foxton, Jessica M.; Nandy, Rachel K.; Griffiths, Timothy D.

    2006-01-01

    It is commonly observed that "tone deaf" individuals are unable to hear the beat of a tune, yet deficits on simple timing tests have not been found. In this study, we investigated rhythm processing in nine individuals with congenital amusia ("tone deafness") and nine controls. Participants were presented with pairs of 5-note sequences, and were…

  8. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  9. Cortical layers, rhythms and BOLD signals.

    Science.gov (United States)

    Scheeringa, René; Fries, Pascal

    2017-11-03

    This review investigates how laminar fMRI can complement insights into brain function derived from the study of rhythmic neuronal synchronization. Neuronal synchronization in various frequency bands plays an important role in neuronal communication between brain areas, and it does so on the backbone of layer-specific interareal anatomical projections. Feedforward projections originate predominantly in supragranular cortical layers and terminate in layer 4, and this pattern is reflected in inter-laminar and interareal directed gamma-band influences. Thus, gamma-band synchronization likely subserves feedforward signaling. By contrast, anatomical feedback projections originate predominantly in infragranular layers and terminate outside layer 4, and this pattern is reflected in inter-laminar and interareal directed alpha- and/or beta-band influences. Thus, alpha-beta band synchronization likely subserves feedback signaling. Furthermore, these rhythms explain part of the BOLD signal, with independent contributions of alpha-beta and gamma. These findings suggest that laminar fMRI can provide us with a potentially useful method to test some of the predictions derived from the study of neuronal synchronization. We review central findings regarding the role of layer-specific neuronal synchronization for brain function, and regarding the link between neuronal synchronization and the BOLD signal. We discuss the role that laminar fMRI could play by comparing it to invasive and non-invasive electrophysiological recordings. Compared to direct electrophysiological recordings, this method provides a metric of neuronal activity that is slow and indirect, but that is uniquely non-invasive and layer-specific with potentially whole brain coverage. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Human biological rhythm in traditional Chinese medicine

    Directory of Open Access Journals (Sweden)

    Tianxing Zhang

    2016-10-01

    Full Text Available Traditional Chinese medicine (TCM has a comprehensive and thorough understanding of biological rhythm. Biological rhythm is an inherent connotation of “harmony between human and nature”, one of the thoughts in TCM. TCM discusses emphatically circadian rhythm, syzygial rhythm and seasonal rhythm, and particularly circadian and seasonal rhythms. Theories of Yin Yang and Five Elements are the principles and methods, with which TCM understands biological rhythms. Based on theories in TCM, biological rhythm in essence is a continuous variation of the human body state synchronized with natural rhythms, and theories of Yin Yang and Five Elements are both language tools to describe this continuous variation and theoretical tools for its investigation and application. The understandings of biological rhythm in TCM can be applied to etiology, health care, disease control and treatment. Many understandings in TCM have been confirmed by modern research and clinical reports, but there are still some pending issues. TCM is distinguished for its holistic viewpoint on biological rhythms.

  11. Analysing Biological Rhythms in Fibromyalgia Syndrome.

    Science.gov (United States)

    Ucar, M; Sarp, Ü; Gül, A I; Tanik, N; Yetisgin, A; Arik, H O; Nas, O; Yılmaz, Y K

    2015-06-01

    This study evaluated biological rhythm disorders in patients with fibromyalgia syndrome (FMS). The study enrolled 82 patients with FMS and 82 controls. Pain intensity was evaluated using a visual analogue scale (VAS). The psychological conditions of the patients were evaluated using the Beck Depression Inventory (BDI). The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) was used to assess disturbances in biological rhythms (ie sleep, activity, social and eating patterns). There was no difference between the two groups at baseline (all p > 0.05). The BDI, BRIAN total, sleep, activity, social, and eating scores were higher in patients with FMS than in the controls (all p biological rhythms and BDI scores (p biological rhythm disturbances in FMS. There is an important relationship between rhythm disorders and FMS. The disturbances in sleep, functional activities, social participation, and disordered rhythms like eating patterns show the need for a multidisciplinary approach to treating patients with FMS.

  12. Music and speech prosody: A common rhythm

    Directory of Open Access Journals (Sweden)

    Maija eHausen

    2013-09-01

    Full Text Available Disorders of music and speech perception, known as amusia and aphasia, have traditionally been regarded as dissociated deficits based on studies of brain damaged patients. This has been taken as evidence that music and speech are perceived by largely separate and independent networks in the brain. However, recent studies of congenital amusia have broadened this view by showing that the deficit is associated with problems in perceiving speech prosody, especially intonation and emotional prosody. In the present study the association between the perception of music and speech prosody was investigated with healthy Finnish adults (n = 61 using an on-line music perception test including the Scale subtest of Montreal Battery of Evaluation of Amusia (MBEA and Off-Beat and Out-of-key tasks as well as a prosodic verbal task that measures the perception of word stress. Regression analyses showed that there was a clear association between prosody perception and music perception, especially in the domain of rhythm perception. This association was evident after controlling for music education, age, pitch perception, visuospatial perception and working memory. Pitch perception was significantly associated with music perception but not with prosody perception. The association between music perception and visuospatial perception (measured using analogous tasks was less clear. Overall, the pattern of results indicates that there is a robust link between music and speech perception and that this link can be mediated by rhythmic cues (time and stress.

  13. Music and speech prosody: a common rhythm.

    Science.gov (United States)

    Hausen, Maija; Torppa, Ritva; Salmela, Viljami R; Vainio, Martti; Särkämö, Teppo

    2013-01-01

    Disorders of music and speech perception, known as amusia and aphasia, have traditionally been regarded as dissociated deficits based on studies of brain damaged patients. This has been taken as evidence that music and speech are perceived by largely separate and independent networks in the brain. However, recent studies of congenital amusia have broadened this view by showing that the deficit is associated with problems in perceiving speech prosody, especially intonation and emotional prosody. In the present study the association between the perception of music and speech prosody was investigated with healthy Finnish adults (n = 61) using an on-line music perception test including the Scale subtest of Montreal Battery of Evaluation of Amusia (MBEA) and Off-Beat and Out-of-key tasks as well as a prosodic verbal task that measures the perception of word stress. Regression analyses showed that there was a clear association between prosody perception and music perception, especially in the domain of rhythm perception. This association was evident after controlling for music education, age, pitch perception, visuospatial perception, and working memory. Pitch perception was significantly associated with music perception but not with prosody perception. The association between music perception and visuospatial perception (measured using analogous tasks) was less clear. Overall, the pattern of results indicates that there is a robust link between music and speech perception and that this link can be mediated by rhythmic cues (time and stress).

  14. Music and speech prosody: a common rhythm

    Science.gov (United States)

    Hausen, Maija; Torppa, Ritva; Salmela, Viljami R.; Vainio, Martti; Särkämö, Teppo

    2013-01-01

    Disorders of music and speech perception, known as amusia and aphasia, have traditionally been regarded as dissociated deficits based on studies of brain damaged patients. This has been taken as evidence that music and speech are perceived by largely separate and independent networks in the brain. However, recent studies of congenital amusia have broadened this view by showing that the deficit is associated with problems in perceiving speech prosody, especially intonation and emotional prosody. In the present study the association between the perception of music and speech prosody was investigated with healthy Finnish adults (n = 61) using an on-line music perception test including the Scale subtest of Montreal Battery of Evaluation of Amusia (MBEA) and Off-Beat and Out-of-key tasks as well as a prosodic verbal task that measures the perception of word stress. Regression analyses showed that there was a clear association between prosody perception and music perception, especially in the domain of rhythm perception. This association was evident after controlling for music education, age, pitch perception, visuospatial perception, and working memory. Pitch perception was significantly associated with music perception but not with prosody perception. The association between music perception and visuospatial perception (measured using analogous tasks) was less clear. Overall, the pattern of results indicates that there is a robust link between music and speech perception and that this link can be mediated by rhythmic cues (time and stress). PMID:24032022

  15. Rhythm and timing in autism: Learning to dance

    Directory of Open Access Journals (Sweden)

    Pat eAmos

    2013-04-01

    Full Text Available In recent years, a significant body of research has focused on challenges to neural connectivity as a key to understanding autism. In contrast to attempts to identify a single static, primarily brain-based deficit, children and adults diagnosed with autism are increasingly perceived as out of sync with their internal and external environments in dynamic ways that must also involve operations of the peripheral nervous systems. The noisiness that seems to occur in both directions of neural flow may help explain challenges to movement and sensing, and ultimately to entrainment with circadian rhythms and social interactions. across the autism spectrum. Profound differences in the rhythm and timing of movement have been tracked to infancy. Difficulties with self-synchrony inhibit praxis, and can disrupt the dance of relationships through which caregiver and child build meaning. Different sensory aspects of a situation may fail to match up; ultimately, intentions and actions themselves may be uncoupled. This uncoupling may help explain the expressions of alienation from the actions of one’s body which recur in the autobiographical autism literature. Multi-modal/cross-modal coordination of different types of sensory information into coherent events may be difficult to achieve because amodal properties (e.g. rhythm and tempo that help unite perceptions are unreliable. One question posed to the connectivity research concerns the role of rhythm and timing in this operation, and whether these can be mobilized to reduce overload and enhance performance. A case is made for developmental research addressing how people with autism actively explore and make sense of their environments. The parent/author recommends investigating approaches such as scaffolding interactions via rhythm, following the person’s lead, slowing the pace, discriminating between intentional communication and stray motor patterns, and organizing information through one sensory mode at

  16. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  17. Neural Correlates of Phrase Rhythm: An EEG Study of Bipartite vs. Rondo Sonata Form

    Directory of Open Access Journals (Sweden)

    Antonio Fernández-Caballero

    2017-04-01

    Full Text Available This paper introduces the neural correlates of phrase rhythm. In short, phrase rhythm is the rhythmic aspect of phrase construction and the relationships between phrases. For the sake of establishing the neural correlates, a musical experiment has been designed to induce music-evoked stimuli related to phrase rhythm. Brain activity is monitored through electroencephalography (EEG by using a brain–computer interface. The power spectral value of each EEG channel is estimated to obtain how power variance distributes as a function of frequency. Our experiment shows statistical differences in theta and alpha bands in the phrase rhythm variations of two classical sonatas, one in bipartite form and the other in rondo form.

  18. Neural underpinnings of music: the polyrhythmic brain.

    Science.gov (United States)

    Vuust, Peter; Gebauer, Line K; Witek, Maria A G

    2014-01-01

    Musical rhythm, consisting of apparently abstract intervals of accented temporal events, has the remarkable ability to move our minds and bodies. Why do certain rhythms make us want to tap our feet, bop our heads or even get up and dance? And how does the brain process rhythmically complex rhythms during our experiences of music? In this chapter, we describe some common forms of rhythmic complexity in music and propose that the theory of predictive coding can explain how rhythm and rhythmic complexity are processed in the brain. We also consider how this theory may reveal why we feel so compelled by rhythmic tension in music. First, musical-theoretical and neuroscientific frameworks of rhythm are presented, in which rhythm perception is conceptualized as an interaction between what is heard ('rhythm') and the brain's anticipatory structuring of music ('the meter'). Second, three different examples of tension between rhythm and meter in music are described: syncopation, polyrhythm and groove. Third, we present the theory of predictive coding of music, which posits a hierarchical organization of brain responses reflecting fundamental, survival-related mechanisms associated with predicting future events. According to this theory, perception and learning is manifested through the brain's Bayesian minimization of the error between the input to the brain and the brain's prior expectations. Fourth, empirical studies of neural and behavioral effects of syncopation, polyrhythm and groove will be reported, and we propose how these studies can be seen as special cases of the predictive coding theory. Finally, we argue that musical rhythm exploits the brain's general principles of anticipation and propose that pleasure from musical rhythm may be a result of such anticipatory mechanisms.

  19. Temporal interactions between cortical rhythms

    Directory of Open Access Journals (Sweden)

    Anita K Roopun

    2008-12-01

    Full Text Available Multiple local neuronal circuits support different, discrete frequencies of network rhythm in neocortex. Relationships between different frequencies correspond to mechanisms designed to minimise interference, couple activity via stable phase interactions, and control the amplitude of one frequency relative to the phase of another. These mechanisms are proposed to form a framework for spectral information processing. Individual local circuits can also transform their frequency through changes in intrinsic neuronal properties and interactions with other oscillating microcircuits. Here we discuss a frequency transformation in which activity in two coactive local circuits may combine sequentially to generate a third frequency whose period is the concatenation sum of the original two. With such an interaction, the intrinsic periodicity in each component local circuit is preserved – alternate, single periods of each original rhythm form one period of a new frequency - suggesting a robust mechanism for combining information processed on multiple concurrent spatiotemporal scales.

  20. Circadian genes, rhythms and the biology of mood disorders.

    Science.gov (United States)

    McClung, Colleen A

    2007-05-01

    For many years, researchers have suggested that abnormalities in circadian rhythms may underlie the development of mood disorders such as bipolar disorder (BPD), major depression and seasonal affective disorder (SAD). Furthermore, some of the treatments that are currently employed to treat mood disorders are thought to act by shifting or "resetting" the circadian clock, including total sleep deprivation (TSD) and bright light therapy. There is also reason to suspect that many of the mood stabilizers and antidepressants used to treat these disorders may derive at least some of their therapeutic efficacy by affecting the circadian clock. Recent genetic, molecular and behavioral studies implicate individual genes that make up the clock in mood regulation. As well, important functions of these genes in brain regions and neurotransmitter systems associated with mood regulation are becoming apparent. In this review, the evidence linking circadian rhythms and mood disorders, and what is known about the underlying biology of this association, is presented.

  1. Framing the Life-Rhythm

    DEFF Research Database (Denmark)

    Munch, Anders V.

    2011-01-01

    Tracing of the notion 'rhytm' among the neo classicist architect in Denmark around 1920 that tried to vitalize the pure forms of architecture. Several of the project contributed to the artistic competions being part of the Olympic Games in that period.Both the gymnastic programme of Niels Bukh an...... and the music training of Jacques-Dalcroze based on rhythm can be seen as background, and there are elements of this vitalism developing further into modernistic architecture....

  2. Increased STAT5 signaling in the ring dove brain in response to prolactin administration and spontaneous elevations in prolactin during the breeding cycle

    Science.gov (United States)

    Buntin, John D.; Buntin, Linda

    2014-01-01

    Prolactin acts on target cells in the central nervous system (CNS) to stimulate behavioral changes associated with parental care in birds, but the signaling mechanisms that mediate these actions have not been characterized. In mammals, the Janus Kinase 2-Signal Transducer and Activator of Transcription 5 (JAK2-STAT5) signaling pathway mediates many of the actions of prolactin. To assess the importance of this pathway in prolactin-sensitive target cells in the avian brain, we measured changes in activated (phosphorylated) STAT5 (pSTAT5) in the forebrain of female ring doves sampled as plasma prolactin levels change during the breeding cycle and in prolactin-treated, non-breeding females. The anatomical distribution of cells exhibiting pSTAT5 immunoreactivity in dove brain closely paralleled the distribution of prolactin receptors in this species. The density of pSTAT5 immunoreactive (pSTAT5-ir) cells were highest in the preoptic area, the suprachiasmatic, paraventricular, ventromedial hypothalamic nuclei, the lateral and tuberal hypothalamic regions, the lateral bed nucleus of the stria terminalis, and the lateral septum. Mean pSTAT5-ir cell densities in these eight brain areas were several fold higher in breeding females during late incubation/early post-hatching when plasma prolactin levels have been observed to peak than in non-breeding females or breeding females sampled at earlier stages when prolactin titers have been reported to be lower. Similar differences were observed between prolactin-treated and vehicle-treated females in all three of the forebrain regions that were compared. We conclude that JAK2-STAT5 signaling is strongly activated in response to prolactin stimulation in the ring dove brain and could potentially mediate some of the centrally-mediated behavioral effects of this hormone. PMID:24530808

  3. Alterations in Spontaneous Brain Activity and Functional Network Reorganization following Surgery in Children with Medically Refractory Epilepsy: A Resting-State Functional Magnetic Resonance Imaging Study

    Directory of Open Access Journals (Sweden)

    Yongxin Li

    2017-08-01

    Full Text Available For some patients with medically refractory epilepsy (MRE, surgery is a safe and effective treatment for controlling epilepsy. However, the functional consequences of such surgery on brain activity and connectivity in children remain unknown. In the present study, we carried out a longitudinal study using resting-state functional magnetic resonance imaging in 10 children with MRE before and again at a mean of 79 days after surgery, as well as in a group of 28 healthy controls. Compared with the controls, children with epilepsy exhibited abnormalities in intrinsic activity in the thalamus, putamen, pallidum, insula, hippocampus, cerebellum, and cingulate gyrus both before and after surgery. Longitudinal analyses showed that the amplitude of low frequency fluctuations (ALFF increased in the parietal–frontal cortex and decreased in the deep nuclei from pre- to post-surgery. The percentage changes in ALFF values in the deep nuclei were positively correlated with the age of epilepsy onset. Functional connectivity (FC analyses demonstrated a reorganization of FC architecture after surgery. These changes in brain activity and FC after surgery might indicate that the previously disrupted functional interactions were reorganized after surgery. All these results provide preliminary evidence that the age of epilepsy onset may have some potential to predict the outcome of brain functional reorganization after surgery in children with MRE.

  4. Biological Rhythms in the Skin

    Directory of Open Access Journals (Sweden)

    Mary S. Matsui

    2016-05-01

    Full Text Available Circadian rhythms, ≈24 h oscillations in behavior and physiology, are reflected in all cells of the body and function to optimize cellular functions and meet environmental challenges associated with the solar day. This multi-oscillatory network is entrained by the master pacemaker located in the suprachiasmatic nucleus (SCN of the hypothalamus, which directs an organism’s rhythmic expression of physiological functions and behavior via a hierarchical system. This system has been highly conserved throughout evolution and uses transcriptional–translational autoregulatory loops. This master clock, following environmental cues, regulates an organism’s sleep pattern, body temperature, cardiac activity and blood pressure, hormone secretion, oxygen consumption and metabolic rate. Mammalian peripheral clocks and clock gene expression have recently been discovered and are present in all nucleated cells in our body. Like other essential organ of the body, the skin also has cycles that are informed by this master regulator. In addition, skin cells have peripheral clocks that can function autonomously. First described in 2000 for skin, this review summarizes some important aspects of a rapidly growing body of research in circadian and ultradian (an oscillation that repeats multiple times during a 24 h period cutaneous rhythms, including clock mechanisms, functional manifestations, and stimuli that entrain or disrupt normal cycling. Some specific relationships between disrupted clock signaling and consequences to skin health are discussed in more depth in the other invited articles in this IJMS issue on Sleep, Circadian Rhythm and Skin.

  5. Biological Rhythms in the Skin.

    Science.gov (United States)

    Matsui, Mary S; Pelle, Edward; Dong, Kelly; Pernodet, Nadine

    2016-05-24

    Circadian rhythms, ≈24 h oscillations in behavior and physiology, are reflected in all cells of the body and function to optimize cellular functions and meet environmental challenges associated with the solar day. This multi-oscillatory network is entrained by the master pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus, which directs an organism's rhythmic expression of physiological functions and behavior via a hierarchical system. This system has been highly conserved throughout evolution and uses transcriptional-translational autoregulatory loops. This master clock, following environmental cues, regulates an organism's sleep pattern, body temperature, cardiac activity and blood pressure, hormone secretion, oxygen consumption and metabolic rate. Mammalian peripheral clocks and clock gene expression have recently been discovered and are present in all nucleated cells in our body. Like other essential organ of the body, the skin also has cycles that are informed by this master regulator. In addition, skin cells have peripheral clocks that can function autonomously. First described in 2000 for skin, this review summarizes some important aspects of a rapidly growing body of research in circadian and ultradian (an oscillation that repeats multiple times during a 24 h period) cutaneous rhythms, including clock mechanisms, functional manifestations, and stimuli that entrain or disrupt normal cycling. Some specific relationships between disrupted clock signaling and consequences to skin health are discussed in more depth in the other invited articles in this IJMS issue on Sleep, Circadian Rhythm and Skin.

  6. A neural mass model of interconnected regions simulates rhythm propagation observed via TMS-EEG.

    Science.gov (United States)

    Cona, F; Zavaglia, M; Massimini, M; Rosanova, M; Ursino, M

    2011-08-01

    Knowledge of cortical rhythms represents an important aspect of modern neuroscience, to understand how the brain realizes its functions. Recent data suggest that different regions in the brain may exhibit distinct electroencephalogram (EEG) rhythms when perturbed by Transcranial Magnetic Stimulation (TMS) and that these rhythms can change due to the connectivity among regions. In this context, in silico simulations may help the validation of these hypotheses that would be difficult to be verified in vivo. Neural mass models can be very useful to simulate specific aspects of electrical brain activity and, above all, to analyze and identify the overall frequency content of EEG in a cortical region of interest (ROI). In this work we implemented a model of connectivity among cortical regions to fit the impulse responses in three ROIs recorded during a series of TMS/EEG experiments performed in five subjects and using three different impulse intensities. In particular we investigated Brodmann Area (BA) 19 (occipital lobe), BA 7 (parietal lobe) and BA 6 (frontal lobe). Results show that the model can reproduce the natural rhythms of the three regions quite well, acting on a few internal parameters. Moreover, the model can explain most rhythm changes induced by stimulation of another region, and inter-subject variability, by estimating just a few long-range connectivity parameters among ROIs. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Rhythmic complexity and predictive coding: A novel approach to modeling rhythm and meter perception in music

    Directory of Open Access Journals (Sweden)

    Peter eVuust

    2014-10-01

    Full Text Available Musical rhythm, consisting of apparently abstract intervals of accented temporal events, has a remarkable capacity to move our minds and bodies. How does the cognitive system enable our experiences of rhythmically complex music? In this paper, we describe some common forms of rhythmic complexity in music and propose the theory of predictive coding as a framework for understanding how rhythm and rhythmic complexity are processed in the brain. We also consider why we feel so compelled by rhythmic tension in music. First, we consider theories of rhythm and meter perception, which provide hierarchical and computational approaches to modeling. Second, we present the theory of predictive coding, which posits a hierarchical organization of brain responses reflecting fundamental, survival-related mechanisms associated with predicting future events. According to this theory, perception and learning is manifested through the brain’s Bayesian minimization of the error between the input to the brain and the brain’s prior expectations. Third, we develop a predictive coding model of musical rhythm, in which rhythm perception is conceptualized as an interaction between what is heard (‘rhythm’ and the brain’s anticipatory structuring of music (‘meter’. Finally, we review empirical studies of the neural and behavioral effects of syncopation, polyrhythm and groove, and propose how these studies can be seen as special cases of the predictive coding theory. We argue that musical rhythm exploits the brain’s general principles of prediction and propose that pleasure and desire for sensorimotor synchronization from musical rhythm may be a result of such mechanisms.

  8. Decreased spontaneous activity in AMPK alpha 2 muscle specific kinase dead mice is not caused by changes in brain dopamine metabolism

    DEFF Research Database (Denmark)

    Møller, Lisbeth Liliendal Valbjørn; Sylow, Lykke; Gøtzsche, Casper René

    2016-01-01

    It is well known that physical activity has several health benefits, yet many people do not exercise. Dopamine levels in the striatum of the brain are thought to be important for the motivation to exercise. Conversely, we hypothesized that muscle quality can affect the motivation to exercise...... DOPAC and HVA were also similar between genotypes. These findings show that decreased AMPK activity in muscle leads to decreased voluntary activity which is not due to secondary abnormalities in dopamine levels in the ventral striatum or sensitivity to cocaine. Thus, decreased voluntary activity in AMPK...

  9. Pitx2 modulates a Tbx5-dependent gene regulatory network to maintain atrial rhythm.

    Science.gov (United States)

    Nadadur, Rangarajan D; Broman, Michael T; Boukens, Bastiaan; Mazurek, Stefan R; Yang, Xinan; van den Boogaard, Malou; Bekeny, Jenna; Gadek, Margaret; Ward, Tarsha; Zhang, Min; Qiao, Yun; Martin, James F; Seidman, Christine E; Seidman, Jon; Christoffels, Vincent; Efimov, Igor R; McNally, Elizabeth M; Weber, Christopher R; Moskowitz, Ivan P

    2016-08-31

    Cardiac rhythm is extremely robust, generating 2 billion contraction cycles during the average human life span. Transcriptional control of cardiac rhythm is poorly understood. We found that removal of the transcription factor gene Tbx5 from the adult mouse caused primary spontaneous and sustained atrial fibrillation (AF). Atrial cardiomyocytes from the Tbx5-mutant mice exhibited action potential abnormalities, including spontaneous depolarizations, which were rescued by chelating free calcium. We identified a multitiered transcriptional network that linked seven previously defined AF risk loci: TBX5 directly activated PITX2, and TBX5 and PITX2 antagonistically regulated membrane effector genes Scn5a, Gja1, Ryr2, Dsp, and Atp2a2 In addition, reduced Tbx5 dose by adult-specific haploinsufficiency caused decreased target gene expression, myocardial automaticity, and AF inducibility, which were all rescued by Pitx2 haploinsufficiency in mice. These results defined a transcriptional architecture for atrial rhythm control organized as an incoherent feed-forward loop, driven by TBX5 and modulated by PITX2. TBX5/PITX2 interplay provides tight control of atrial rhythm effector gene expression, and perturbation of the co-regulated network caused AF susceptibility. This work provides a model for the molecular mechanisms underpinning the genetic implication of multiple AF genome-wide association studies loci and will contribute to future efforts to stratify patients for AF risk by genotype. Copyright © 2016, American Association for the Advancement of Science.

  10. Statistics for Sleep and Biological Rhythms Research.

    Science.gov (United States)

    Klerman, Elizabeth B; Wang, Wei; Phillips, Andrew J K; Bianchi, Matt T

    2017-02-01

    This article is part of a Journal of Biological Rhythms series exploring analysis and statistical topics relevant to researchers in biological rhythms and sleep research. The goal is to provide an overview of the most common issues that arise in the analysis and interpretation of data in these fields. In this article, we address issues related to the collection of multiple data points from the same organism or system at different times, since such longitudinal data collection is fundamental to the assessment of biological rhythms. Rhythmic longitudinal data require additional specific statistical considerations, ranging from curve fitting to threshold definitions to accounting for correlation structure. We discuss statistical analyses of longitudinal data including issues of correlational structure and stationarity, markers of biological rhythms, demasking of biological rhythms, and determining phase, waveform, and amplitude of biological rhythms.

  11. Integration of biological clocks and rhythms.

    Science.gov (United States)

    Refinetti, Roberto

    2012-04-01

    Animals, plants, and microorganisms exhibit numerous biological rhythms that are generated by numerous biological clocks. This article summarizes experimental data pertinent to the often-ignored issue of integration of multiple rhythms. Five contexts of integration are discussed: (i) integration of circadian rhythms of multiple processes within an individual organism, (ii) integration of biological rhythms operating in different time scales (such as tidal, daily, and seasonal), (iii) integration of rhythms across multiple species, (iv) integration of rhythms of different members of a species, and (v) integration of rhythmicity and physiological homeostasis. Understanding of these multiple rhythmic interactions is an important first step in the eventual thorough understanding of how organisms arrange their vital functions temporally within and without their bodies. © 2012 American Physiological Society. Compr Physiol 2:1213-1239, 2012.

  12. Acquisition of speech rhythm in first language.

    Science.gov (United States)

    Polyanskaya, Leona; Ordin, Mikhail

    2015-09-01

    Analysis of English rhythm in speech produced by children and adults revealed that speech rhythm becomes increasingly more stress-timed as language acquisition progresses. Children reach the adult-like target by 11 to 12 years. The employed speech elicitation paradigm ensured that the sentences produced by adults and children at different ages were comparable in terms of lexical content, segmental composition, and phonotactic complexity. Detected differences between child and adult rhythm and between rhythm in child speech at various ages cannot be attributed to acquisition of phonotactic language features or vocabulary, and indicate the development of language-specific phonetic timing in the course of acquisition.

  13. Factors influencing circadian rhythms in acetaminophen lethality.

    Science.gov (United States)

    Schnell, R C; Bozigian, H P; Davies, M H; Merrick, B A; Park, K S; McMillan, D A

    1984-01-01

    Experiments were conducted to examine the effects of changes in lighting schedules and food consumption on circadian rhythms in acetaminophen lethality and hepatic glutathione levels in male mice. Under a normal lighting schedule (light: 06.00-18.00 h), male mice exhibited a circadian rhythm in acetaminophen lethality (peak: 18.00 h; nadir: 06.00, 10.00 h) and an inverse rhythm in hepatic glutathione concentrations (peak: 06.00, 10.00 h; nadir: 18.00 h). Under a reversed lighting schedule (light: 18.00-06.00 h) the glutathione rhythm was reversed and the rhythm in acetaminophen lethality was altered showing greater sensitivity to the drug. Under continuous light, there was a shift in the acetaminophen lethality and the hepatic glutathione rhythms. Under continuous dark, both rhythms were abolished. Under a normal lighting regimen, hepatic glutathione levels were closely correlated with food consumption; i.e., both were increased during the dark phase and decreased during the light phase. Fasting the mice for 12 h abolished the rhythms in acetaminophen lethality and hepatic glutathione levels; moreover, the lethality was increased and the hepatic glutathione levels were decreased. These experiments show that both lighting schedules and feeding can alter the circadian rhythms in acetaminophen lethality and hepatic glutathione levels in male mice.

  14. Time-dependent effects of training on cardiovascular control in spontaneously hypertensive rats: role for brain oxidative stress and inflammation and baroreflex sensitivity.

    Directory of Open Access Journals (Sweden)

    Gustavo S Masson

    Full Text Available Baroreflex dysfunction, oxidative stress and inflammation, important hallmarks of hypertension, are attenuated by exercise training. In this study, we investigated the relationships and time-course changes of cardiovascular parameters, pro-inflammatory cytokines and pro-oxidant profiles within the hypothalamic paraventricular nucleus of the spontaneously hypertensive rats (SHR. Basal values and variability of arterial pressure and heart rate and baroreflex sensitivity were measured in trained (T, low-intensity treadmill training and sedentary (S SHR at weeks 0, 1, 2, 4 and 8. Paraventricular nucleus was used to determine reactive oxygen species (dihydroethidium oxidation products, HPLC, NADPH oxidase subunits and pro-inflammatory cytokines expression (Real time PCR, p38 MAPK and ERK1/2 expression (Western blotting, NF-κB content (electrophoretic mobility shift assay and cytokines immunofluorescence. SHR-S vs. WKY-S (Wistar Kyoto rats as time control showed increased mean arterial pressure (172±3 mmHg, pressure variability and heart rate (358±7 b/min, decreased baroreflex sensitivity and heart rate variability, increased p47phox and reactive oxygen species production, elevated NF-κB activity and increased TNF-α and IL-6 expression within the paraventricular nucleus of hypothalamus. Two weeks of training reversed all hypothalamic changes, reduced ERK1/2 phosphorylation and normalized baroreflex sensitivity (4.04±0.31 vs. 2.31±0.19 b/min/mmHg in SHR-S. These responses were followed by increased vagal component of heart rate variability (1.9-fold and resting bradycardia (-13% at the 4th week, and, by reduced vasomotor component of pressure variability (-28% and decreased mean arterial pressure (-7% only at the 8th week of training. Our findings indicate that independent of the high pressure levels in SHR, training promptly restores baroreflex function by disrupting the positive feedback between high oxidative stress and increased pro

  15. Altered pattern of spontaneous brain activity in the patients with end-stage renal disease: a resting-state functional MRI study with regional homogeneity analysis.

    Directory of Open Access Journals (Sweden)

    Xue Liang

    Full Text Available PURPOSE: To investigate the pattern of spontaneous neural activity in patients with end-stage renal disease (ESRD with and without neurocognitive dysfunction using resting-state functional magnetic resonance imaging (rs-fMRI with a regional homogeneity (ReHo algorithm. MATERIALS AND METHODS: rs-fMRI data were acquired in 36 ESRD patients (minimal nephro-encephalopathy [MNE], n = 19, 13 male, 37±12.07 years; non-nephro-encephalopathy [non-NE], n = 17, 11 male, 38±12.13 years and 20 healthy controls (13 male, 7 female, 36±10.27 years. Neuropsychological (number connection test type A [NCT-A], digit symbol test [DST] and laboratory tests were performed in all patients. The Kendall's coefficient of concordance (KCC was used to measure the regional homogeneity for each subject. The regional homogeneity maps were compared using ANOVA tests among MNE, non-NE, and healthy control groups and post hoc t -tests between each pair in a voxel-wise way. A multiple regression analysis was performed to evaluate the relationships between ReHo index and NCT-A, DST scores, serum creatinine and urea levels, disease and dialysis duration. RESULTS: Compared with healthy controls, both MNE and non-NE patients showed decreased ReHo in the multiple areas of bilateral frontal, parietal and temporal lobes. Compared with the non-NE, MNE patients showed decreased ReHo in the right inferior parietal lobe (IPL, medial frontal cortex (MFC and left precuneus (PCu. The NCT-A scores and serum urea levels of ESRD patients negatively correlated with ReHo values in the frontal and parietal lobes, while DST scores positively correlated with ReHo values in the bilateral PCC/precuneus, MFC and inferior parietal lobe (IPL (all P0.05, AlphaSim corrected. CONCLUSION: Diffused decreased ReHo values were found in both MNE and non-NE patients. The progressively decreased ReHo in the default mode network (DMN, frontal and parietal lobes might be trait-related in MNE. The Re

  16. Time-dependent effects of training on cardiovascular control in spontaneously hypertensive rats: role for brain oxidative stress and inflammation and baroreflex sensitivity.

    Science.gov (United States)

    Masson, Gustavo S; Costa, Tassia S R; Yshii, Lidia; Fernandes, Denise C; Soares, Pedro Paulo Silva; Laurindo, Francisco R; Scavone, Cristoforo; Michelini, Lisete C

    2014-01-01

    Baroreflex dysfunction, oxidative stress and inflammation, important hallmarks of hypertension, are attenuated by exercise training. In this study, we investigated the relationships and time-course changes of cardiovascular parameters, pro-inflammatory cytokines and pro-oxidant profiles within the hypothalamic paraventricular nucleus of the spontaneously hypertensive rats (SHR). Basal values and variability of arterial pressure and heart rate and baroreflex sensitivity were measured in trained (T, low-intensity treadmill training) and sedentary (S) SHR at weeks 0, 1, 2, 4 and 8. Paraventricular nucleus was used to determine reactive oxygen species (dihydroethidium oxidation products, HPLC), NADPH oxidase subunits and pro-inflammatory cytokines expression (Real time PCR), p38 MAPK and ERK1/2 expression (Western blotting), NF-κB content (electrophoretic mobility shift assay) and cytokines immunofluorescence. SHR-S vs. WKY-S (Wistar Kyoto rats as time control) showed increased mean arterial pressure (172±3 mmHg), pressure variability and heart rate (358±7 b/min), decreased baroreflex sensitivity and heart rate variability, increased p47phox and reactive oxygen species production, elevated NF-κB activity and increased TNF-α and IL-6 expression within the paraventricular nucleus of hypothalamus. Two weeks of training reversed all hypothalamic changes, reduced ERK1/2 phosphorylation and normalized baroreflex sensitivity (4.04±0.31 vs. 2.31±0.19 b/min/mmHg in SHR-S). These responses were followed by increased vagal component of heart rate variability (1.9-fold) and resting bradycardia (-13%) at the 4th week, and, by reduced vasomotor component of pressure variability (-28%) and decreased mean arterial pressure (-7%) only at the 8th week of training. Our findings indicate that independent of the high pressure levels in SHR, training promptly restores baroreflex function by disrupting the positive feedback between high oxidative stress and increased pro

  17. The Utility of the Swine Model to Assess Biological Rhythms and Their Characteristics during Different Stages of Residence in a Simulated Intensive Care Unit: A Pilot Study.

    Science.gov (United States)

    Leyden, Katrina N; Hanneman, Sandra K; Padhye, Nikhil S; Smolensky, Michael H; Kang, Duck-Hee; Chow, Diana Shu-Lian

    2015-01-01

    The purpose of this pilot study was to explore the utility of the mammalian swine model under simulated intensive care unit (sICU) conditions and mechanical ventilation (MV) for assessment of the trajectory of circadian rhythms of sedation requirement, core body temperature (CBT), pulmonary mechanics (PM) and gas exchange (GE). Data were collected prospectively with an observational time-series design to describe and compare circadian rhythms of selected study variables in four swine mechanically ventilated for up to seven consecutive days. We derived the circadian (total variance explained by rhythms of τ between 20 and 28 h)/ultradian (total variance explained by rhythms of τ between 1 and rhythms, and compare findings between the early (first 3 days) and late (subsequent days) sICU stay. All pigs exhibited statistically significant circadian rhythms (τ between 20 and 28 h) in CBT, respiratory rate and peripheral oxygen saturation, but circadian rhythms were detected less frequently for sedation requirement, spontaneous minute volume, arterial oxygen tension, arterial carbon dioxide tension and arterial pH. Sedation did not appear to mask the circadian rhythms of CBT, PM and GE. Individual subject observations were more informative than group data, and provided preliminary evidence that (a) circadian rhythms of multiple variables are lost or desynchronized in mechanically ventilated subjects, (b) robustness of circadian rhythm varies with subject morbidity and (c) healthier pigs develop more robust circadian rhythm profiles over time in the sICU. Comparison of biological rhythm profiles among sICU subjects with similar severity of illness is needed to determine if the results of this pilot study are reproducible. Identification of consistent patterns may provide insight into subject morbidity and timing of such therapeutic interventions as weaning from MV.

  18. Biological Clocks and Rhythms of Anger and Aggression.

    Science.gov (United States)

    Hood, Suzanne; Amir, Shimon

    2018-01-01

    The body's internal timekeeping system is an under-recognized but highly influential force in behaviors and emotions including anger and reactive aggression. Predictable cycles or rhythms in behavior are expressed on several different time scales such as circadian ( circa diem , or approximately 24-h rhythms) and infradian (exceeding 24 h, such as monthly or seasonal cycles). The circadian timekeeping system underlying rhythmic behaviors in mammals is constituted by a network of clocks distributed throughout the brain and body, the activity of which synchronizes to a central pacemaker, or master clock. Our daily experiences with the external environment including social activity strongly influence the exact timing of this network. In the present review, we examine evidence from a number of species and propose that anger and reactive aggression interact in multiple ways with circadian clocks. Specifically, we argue that: (i) there are predictable rhythms in the expression of aggression and anger; (ii) disruptions of the normal functioning of the circadian system increase the likelihood of aggressive behaviors; and (iii) conversely, chronic expression of anger can disrupt normal rhythmic cycles of physiological activities and create conditions for pathologies such as cardiovascular disease to develop. Taken together, these observations suggest that a comprehensive perspective on anger and reactive aggression must incorporate an understanding of the role of the circadian timing system in these intense affective states.

  19. The Role of Mammalian Glial Cells in Circadian Rhythm Regulation

    Directory of Open Access Journals (Sweden)

    Donají Chi-Castañeda

    2017-01-01

    Full Text Available Circadian rhythms are biological oscillations with a period of about 24 hours. These rhythms are maintained by an innate genetically determined time-keeping system called the circadian clock. A large number of the proteins involved in the regulation of this clock are transcription factors controlling rhythmic transcription of so-called clock-controlled genes, which participate in a plethora of physiological functions in the organism. In the brain, several areas, besides the suprachiasmatic nucleus, harbor functional clocks characterized by a well-defined time pattern of clock gene expression. This expression rhythm is not restricted to neurons but is also present in glia, suggesting that these cells are involved in circadian rhythmicity. However, only certain glial cells fulfill the criteria to be called glial clocks, namely, to display molecular oscillators based on the canonical clock protein PERIOD, which depends on the suprachiasmatic nucleus for their synchronization. In this contribution, we summarize the current information about activity of the clock genes in glial cells, their potential role as oscillators as well as clinical implications.

  20. Biological Clocks and Rhythms of Anger and Aggression

    Directory of Open Access Journals (Sweden)

    Suzanne Hood

    2018-01-01

    Full Text Available The body’s internal timekeeping system is an under-recognized but highly influential force in behaviors and emotions including anger and reactive aggression. Predictable cycles or rhythms in behavior are expressed on several different time scales such as circadian (circa diem, or approximately 24-h rhythms and infradian (exceeding 24 h, such as monthly or seasonal cycles. The circadian timekeeping system underlying rhythmic behaviors in mammals is constituted by a network of clocks distributed throughout the brain and body, the activity of which synchronizes to a central pacemaker, or master clock. Our daily experiences with the external environment including social activity strongly influence the exact timing of this network. In the present review, we examine evidence from a number of species and propose that anger and reactive aggression interact in multiple ways with circadian clocks. Specifically, we argue that: (i there are predictable rhythms in the expression of aggression and anger; (ii disruptions of the normal functioning of the circadian system increase the likelihood of aggressive behaviors; and (iii conversely, chronic expression of anger can disrupt normal rhythmic cycles of physiological activities and create conditions for pathologies such as cardiovascular disease to develop. Taken together, these observations suggest that a comprehensive perspective on anger and reactive aggression must incorporate an understanding of the role of the circadian timing system in these intense affective states.

  1. The evolutionary biology of musical rhythm: was Darwin wrong?

    Directory of Open Access Journals (Sweden)

    Aniruddh D Patel

    2014-03-01

    Full Text Available In The Descent of Man, Darwin speculated that our capacity for musical rhythm reflects basic aspects of brain function broadly shared among animals. Although this remains an appealing idea, it is being challenged by modern cross-species research. This research hints that our capacity to synchronize to a beat, i.e., to move in time with a perceived pulse in a manner that is predictive and flexible across a broad range of tempi, may be shared by only a few other species. Is this really the case? If so, it would have important implications for our understanding of the evolution of human musicality.

  2. The evolutionary biology of musical rhythm: was Darwin wrong?

    Science.gov (United States)

    Patel, Aniruddh D

    2014-03-01

    In The Descent of Man, Darwin speculated that our capacity for musical rhythm reflects basic aspects of brain function broadly shared among animals. Although this remains an appealing idea, it is being challenged by modern cross-species research. This research hints that our capacity to synchronize to a beat, i.e., to move in time with a perceived pulse in a manner that is predictive and flexible across a broad range of tempi, may be shared by only a few other species. Is this really the case? If so, it would have important implications for our understanding of the evolution of human musicality.

  3. The Patterns of Music: Young Children Learning Mathematics through Beat, Rhythm, and Melody

    Science.gov (United States)

    Geist, Kamile; Geist, Eugene A.; Kuznik, Kathleen

    2012-01-01

    Research on music and music therapy suggests that math and music are related in the brain from very early in life. Musical elements such as steady beat, rhythm, melody, and tempo possess inherent mathematical principles such as spatial properties, sequencing, counting, patterning, and one-to-one correspondence. With new understanding about the…

  4. Flexion Reflex Can Interrupt and Reset the Swimming Rhythm.

    Science.gov (United States)

    Elson, Matthew S; Berkowitz, Ari

    2016-03-02

    The spinal cord can generate the hip flexor nerve activity underlying leg withdrawal (flexion reflex) and the rhythmic, alternating hip flexor and extensor activities underlying locomotion and scratching, even in the absence of brain inputs and movement-related sensory feedback. It has been hypothesized that a common set of spinal interneurons mediates flexion reflex and the flexion components of locomotion and scratching. Leg cutaneous stimuli that evoke flexion reflex can alter the timing of (i.e., reset) cat walking and turtle scratching rhythms; in addition, reflex responses to leg cutaneous stimuli can be modified during cat and human walking and turtle scratching. Both of these effects depend on the phase (flexion or extension) of the rhythm in which the stimuli occur. However, similar interactions between leg flexion reflex and swimming have not been reported. We show here that a tap to the foot interrupted and reset the rhythm of forward swimming in spinal, immobilized turtles if the tap occurred during the swim hip extensor phase. In addition, the hip flexor nerve response to an electrical foot stimulus was reduced or eliminated during the swim hip extensor phase. These two phase-dependent effects of flexion reflex on the swim rhythm and vice versa together demonstrate that the flexion reflex spinal circuit shares key components with or has strong interactions with the swimming spinal network, as has been shown previously for cat walking and turtle scratching. Therefore, leg flexion reflex circuits likely share key spinal interneurons with locomotion and scratching networks across limbed vertebrates generally. The spinal cord can generate leg withdrawal (flexion reflex), locomotion, and scratching in limbed vertebrates. It has been hypothesized that there is a common set of spinal cord neurons that produce hip flexion during flexion reflex, locomotion, and scratching based on evidence from studies of cat and human walking and turtle scratching. We show

  5. Implications of disturbances in circadian rhythms for cardiovascular health: A new frontier in free radical biology.

    Science.gov (United States)

    Khaper, Neelam; Bailey, Craig D C; Ghugre, Nilesh R; Reitz, Cristine; Awosanmi, Zikra; Waines, Ryan; Martino, Tami A

    2017-11-13

    Cell autonomous circadian "clock" mechanisms are present in virtually every organ, and generate daily rhythms that are important for normal physiology. This is especially relevant to the cardiovascular system, for example the circadian mechanism orchestrates rhythms in heart rate, blood pressure, cardiac contractility, metabolism, gene and protein abundance over the 24-h day and night cycles. Conversely, disturbing circadian rhythms (e.g. via shift work, sleep disorders) increases cardiovascular disease risk, and exacerbates cardiac remodelling and worsens outcome. Notably, reactive oxygen species (ROS) are important contributors to heart disease, especially the pathophysiologic damage that occurs after myocardial infarction (MI, heart attack). However, little is known about how the circadian mechanism, or rhythm desynchrony, is involved in these key pathologic stress responses. This review summarizes the current knowledge on circadian rhythms in the cardiovascular system, and the implications of rhythm disturbances for cardiovascular health. Furthermore, we highlight how free radical biology coincides with the pathogenesis of myocardial repair and remodelling after MI, and indicate a role for the circadian system in the oxidative stress pathways in the heart and brain after MI. This fusion of circadian biology with cardiac oxidative stress pathways is novel, and offers enormous potential for improving our understanding and treatment of heart disease. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Spontaneous pneumothorax in weightlifters.

    Science.gov (United States)

    Marnejon, T; Sarac, S; Cropp, A J

    1995-06-01

    Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.

  7. [Biological rhythms of thyrotropin secretion].

    Science.gov (United States)

    Hugues, J N; Reinberg, A; Lagoguey, M; Modigliani, E; Sebaoun, J

    1983-01-01

    The rhythmic pattern of TSH secretion is now well-established and is characterized by a circadian (24 h) periodicity with a pre-sleep acrophase which is modulated by endogenous oscillators and environmental synchronisers. Among external synchronisers, the sleep-waking cycle has been extensively studied and sleep onset appears to have a negative influence on the nycthemeral TSH peak. Nutritional status may affect the TSH rhythmicity since a short term starvation induces a shift in the acrophase time. Major neurotransmitter involved in the TSH rhythms are serotonine which could be responsible for the TSH nadir. By contrast dopamine is not directly implicated in the circadian pattern of TSH secretion. TRH, the main neuropeptide controlling the thyrotrope cell, certainly has a major role in the mediation of the TSH rhythmicity. The involvement of somatostatine is less clear but as assumed for dopamine, its negative influence on TSH secretion would be stronger at the time of TSH peak than at the time of nadir. The major inhibitory effect of thyroid hormones on TSH secretion and release is evident on mean serum TSH levels but does not seem responsible for serum circadian variations. Likewise, the TSH rhythm is present in both sex and influence of estrogens and androgens would only be to modulate the mean serum TSH level. Finally the physiological influence of glucocorticoids on TSH secretion has not been clearly demonstrated.

  8. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  9. The Effects of Acutely Administered 3,4-Methylenedioxymethamphetamine on Spontaneous Brain Function in Healthy Volunteers Measured with Arterial Spin Labeling and Blood Oxygen Level–Dependent Resting State Functional Connectivity

    Science.gov (United States)

    Carhart-Harris, Robin L.; Murphy, Kevin; Leech, Robert; Erritzoe, David; Wall, Matthew B.; Ferguson, Bart; Williams, Luke T.J.; Roseman, Leor; Brugger, Stefan; De Meer, Ineke; Tanner, Mark; Tyacke, Robin; Wolff, Kim; Sethi, Ajun; Bloomfield, Michael A.P.; Williams, Tim M.; Bolstridge, Mark; Stewart, Lorna; Morgan, Celia; Newbould, Rexford D.; Feilding, Amanda; Curran, H. Val; Nutt, David J.

    2015-01-01

    Background The compound 3,4-methylenedioxymethamphetamine (MDMA) is a potent monoamine releaser that produces an acute euphoria in most individuals. Methods In a double-blind, placebo-controlled, balanced-order study, MDMA was orally administered to 25 physically and mentally healthy individuals. Arterial spin labeling and seed-based resting state functional connectivity (RSFC) were used to produce spatial maps displaying changes in cerebral blood flow (CBF) and RSFC after MDMA administration. Participants underwent two arterial spin labeling and two blood oxygen level–dependent scans in a 90-minute scan session; MDMA and placebo study days were separated by 1 week. Results Marked increases in positive mood were produced by MDMA. Decreased CBF only was observed after MDMA, and this was localized to the right medial temporal lobe (MTL), thalamus, inferior visual cortex, and the somatosensory cortex. Decreased CBF in the right amygdala and hippocampus correlated with ratings of the intensity of global subjective effects of MDMA. The RSFC results complemented the CBF results, with decreases in RSFC between midline cortical regions, the medial prefrontal cortex, and MTL regions, and increases between the amygdala and hippocampus. There were trend-level correlations between these effects and ratings of intense and positive subjective effects. Conclusions The MTLs appear to be specifically implicated in the mechanism of action of MDMA, but further work is required to elucidate how the drug’s characteristic subjective effects arise from its modulation of spontaneous brain activity. PMID:24495461

  10. The Effects of Acutely Administered 3,4-Methylenedioxymethamphetamine on Spontaneous Brain Function in Healthy Volunteers Measured with Arterial Spin Labeling and Blood Oxygen Level-Dependent Resting State Functional Connectivity.

    Science.gov (United States)

    Carhart-Harris, Robin L; Murphy, Kevin; Leech, Robert; Erritzoe, David; Wall, Matthew B; Ferguson, Bart; Williams, Luke T J; Roseman, Leor; Brugger, Stefan; De Meer, Ineke; Tanner, Mark; Tyacke, Robin; Wolff, Kim; Sethi, Ajun; Bloomfield, Michael A P; Williams, Tim M; Bolstridge, Mark; Stewart, Lorna; Morgan, Celia; Newbould, Rexford D; Feilding, Amanda; Curran, H Val; Nutt, David J

    2015-10-15

    The compound 3,4-methylenedioxymethamphetamine (MDMA) is a potent monoamine releaser that produces an acute euphoria in most individuals. In a double-blind, placebo-controlled, balanced-order study, MDMA was orally administered to 25 physically and mentally healthy individuals. Arterial spin labeling and seed-based resting state functional connectivity (RSFC) were used to produce spatial maps displaying changes in cerebral blood flow (CBF) and RSFC after MDMA administration. Participants underwent two arterial spin labeling and two blood oxygen level-dependent scans in a 90-minute scan session; MDMA and placebo study days were separated by 1 week. Marked increases in positive mood were produced by MDMA. Decreased CBF only was observed after MDMA, and this was localized to the right medial temporal lobe (MTL), thalamus, inferior visual cortex, and the somatosensory cortex. Decreased CBF in the right amygdala and hippocampus correlated with ratings of the intensity of global subjective effects of MDMA. The RSFC results complemented the CBF results, with decreases in RSFC between midline cortical regions, the medial prefrontal cortex, and MTL regions, and increases between the amygdala and hippocampus. There were trend-level correlations between these effects and ratings of intense and positive subjective effects. The MTLs appear to be specifically implicated in the mechanism of action of MDMA, but further work is required to elucidate how the drug's characteristic subjective effects arise from its modulation of spontaneous brain activity. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Portable wireless neurofeedback system of EEG alpha rhythm enhances memory.

    Science.gov (United States)

    Wei, Ting-Ying; Chang, Da-Wei; Liu, You-De; Liu, Chen-Wei; Young, Chung-Ping; Liang, Sheng-Fu; Shaw, Fu-Zen

    2017-11-13

    Effect of neurofeedback training (NFT) on enhancement of cognitive function or amelioration of clinical symptoms is inconclusive. The trainability of brain rhythm using a neurofeedback system is uncertainty because various experimental designs are used in previous studies. The current study aimed to develop a portable wireless NFT system for alpha rhythm and to validate effect of the NFT system on memory with a sham-controlled group. The proposed system contained an EEG signal analysis device and a smartphone with wireless Bluetooth low-energy technology. Instantaneous 1-s EEG power and contiguous 5-min EEG power throughout the training were developed as feedback information. The training performance and its progression were kept to boost usability of our device. Participants were blinded and randomly assigned into either the control group receiving random 4-Hz power or Alpha group receiving 8-12-Hz power. Working memory and episodic memory were assessed by the backward digital span task and word-pair task, respectively. The portable neurofeedback system had advantages of a tiny size and long-term recording and demonstrated trainability of alpha rhythm in terms of significant increase of power and duration of 8-12 Hz. Moreover, accuracies of the backward digital span task and word-pair task showed significant enhancement in the Alpha group after training compared to the control group. Our tiny portable device demonstrated success trainability of alpha rhythm and enhanced two kinds of memories. The present study suggest that the portable neurofeedback system provides an alternative intervention for memory enhancement.

  12. Detecting and Correcting Speech Rhythm Errors

    Science.gov (United States)

    Yurtbasi, Metin

    2015-01-01

    Every language has its own rhythm. Unlike many other languages in the world, English depends on the correct pronunciation of stressed and unstressed or weakened syllables recurring in the same phrase or sentence. Mastering the rhythm of English makes speaking more effective. Experiments have shown that we tend to hear speech as more rhythmical…

  13. Development of cortisol circadian rhythm in infancy.

    NARCIS (Netherlands)

    Weerth, C. de; Zijl, R.H.

    2003-01-01

    BACKGROUND AND AIMS: Cortisol is the final product of the hypothalamus-pituitary-adrenal (HPA) axis. It is secreted in a pulsatile fashion that displays a circadian rhythm. Infants are born without a circadian rhythm in cortisol and they acquire it during their first year of life. Studies do not

  14. Quantifying Speech Rhythm Abnormalities in the Dysarthrias

    Science.gov (United States)

    Liss, Julie M.; White, Laurence; Mattys, Sven L.; Lansford, Kaitlin; Lotto, Andrew J.; Spitzer, Stephanie M.; Caviness, John N.

    2009-01-01

    Purpose: In this study, the authors examined whether rhythm metrics capable of distinguishing languages with high and low temporal stress contrast also can distinguish among control and dysarthric speakers of American English with perceptually distinct rhythm patterns. Methods: Acoustic measures of vocalic and consonantal segment durations were…

  15. The Essential Connection between Rhythm and Movement

    Science.gov (United States)

    Perlmutter, Adam

    2009-01-01

    It is the most fundamental aspect of music, yet so many students struggle with rhythm. How does one effectively teach budding young musicians to properly feel and read the rhythms all around them? Eileen Benedict, vocal music specialist at the Edith L. Slocum School in Ronkonkoma, New York, finds it best to start teaching her young students not…

  16. Spontaneous Activity Drives Local Synaptic Plasticity In Vivo

    NARCIS (Netherlands)

    Winnubst, Johan; Cheyne, Juliette E; Niculescu, Dragos; Lohmann, C.

    2015-01-01

    Spontaneous activity fine-tunes neuronal connections in the developing brain. To explore the underlying synaptic plasticity mechanisms, we monitored naturally occurring changes in spontaneous activity at individual synapses with whole-cell patch-clamp recordings and simultaneous calcium imaging in

  17. Hybrid brain-computer interface and functional electrical stimulation for sensorimotor training in participants with tetraplegia: a proof-of-concept study.

    Science.gov (United States)

    Vučković, Aleksandra; Wallace, Leslie; Allan, David B

    2015-01-01

    Impaired hand function decreases quality of life in persons with tetraplegia. We tested functional electrical stimulation (FES) controlled by a hybrid brain-computer interface (BCI) for improving hand function in participants with tetraplegia. Two participants with subacute tetraplegia (participant 1: C5 Brown-Sequard syndrome, participant 2: complete C5 lesion) took part in this proof-of-concept study. The goal was to determine whether the BCI system could drive the FES device by accurately classifying participants' intent (open or close the hand). Participants 1 and 2 received 10 sessions and 4 sessions of BCI-FES, respectively. A novel time-switch BCI strategy based on motor imagery was used to activate the FES. In one session, we tested a hybrid BCI-FES based on 2 spontaneously generated brain rhythms: a sensory-motor rhythm during motor imagery to activate a stimulator and occipital alpha rhythms to deactivate the stimulator. Participants received BCI-FES therapy 2 to 3 times a week in addition to conventional therapy. Imagery ability and muscle strength were measured before and after treatment. Visual feedback was associated with a 4-fold increase of brain response during motor imagery in both participants. For participant 1, classification accuracy (open/closed) for motor imagery-based BCI was 83.5% (left hand) and 83.8% (right hand); participant 2 had a classification accuracy of 83.8% for the right hand. Participant 1 had moderate improvement in muscle strength, while there was no change for participant 2. We demonstrated feasibility of BCI-FES, using 2 naturally generated brain rhythms. Studies on a larger number of participants are needed to separate the effects of BCI training from effects of conventional therapy.Video Abstract available. (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A84) for more insights from the authors.

  18. Biological rhythms, sleep, and wakefulness in prolonged confinement

    Science.gov (United States)

    Siffre, Michael

    1988-01-01

    The dysynchronization of human circadian rhythms during 7 long-term (2 to 6 months) confinement experiments in temporal isolation in caves was studied. Five subjects abandon the circadian period of sleep and wakefulness (S-W) and spontaneously reach a circabidian S-W cycle (34 to 36 hr waking, 14 to 12 hr sleep) they maintain during weeks. Some subjects reach the 48 hr cycle very quickly (8 to 15 days), others after months. Polygraphic analyses of sleep show that rapid eye movement state (REMS) duration is directly proportional to the total duration of sleep and that the ultradian periodicity of REMS remains constant when S-W cycle is circadian or circabidian. When S-W cycle desynchronizes from circadian to circabidian, REMS and S-4 increase at the expense of stages I-2 and remain in constant relationship with the duration of previous wakefulness period.

  19. Effects of Resveratrol on Daily Rhythms of Locomotor Activity and Body Temperature in Young and Aged Grey Mouse Lemurs

    Directory of Open Access Journals (Sweden)

    Fabien Pifferi

    2013-01-01

    Full Text Available In several species, resveratrol, a polyphenolic compound, activates sirtuin proteins implicated in the regulation of energy balance and biological clock processes. To demonstrate the effect of resveratrol on clock function in an aged primate, young and aged mouse lemurs (Microcebus murinus were studied over a 4-week dietary supplementation with resveratrol. Spontaneous locomotor activity and daily variations in body temperature were continuously recorded. Reduction in locomotor activity onset and changes in body temperature rhythm in resveratrol-supplemented aged animals suggest an improved synchronisation on the light-dark cycle. Resveratrol could be a good candidate to restore the circadian rhythms in the elderly.

  20. Comparison of spontaneous brain activity revealed by regional homogeneity in AQP4-IgG neuromyelitis optica-optic neuritis versus MOG-IgG optic neuritis patients: a resting-state functional MRI study

    Directory of Open Access Journals (Sweden)

    Wang J

    2017-10-01

    Full Text Available Junqing Wang,1,* Yuan Tian,2,* Yi Shao,3,* Hui Feng,1 Limin Qin,1 Weiwei Xu,1 Hongjuan Liu,1 Quangang Xu,1 Shihui Wei,1 Lin Ma2 1Department of Ophthalmology, 2Department of Radiology, Chinese PLA General Hospital, Beijing, 3Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China *These authors contributed equally to this work Objective: Many previous studies have demonstrated that neuromyelitis optica (NMO patients have abnormalities of brain anatomy and function. However, differences in spontaneous brain activity between myelin oligodendrocyte glycoprotein (MOG-IgG ON and aquaporin 4(AQP4-neuromyelitis optica-optic neuritis (ON remain unknown. In the current study, we investigated the brain neural homogeneity in MOG-IgG ON versus AQP4-IgG NMO-ON subjects by regional homogeneity (ReHo method using magnetic resonance imaging (MRI. Patients and methods: A total of 32 NMO-ON and ON subjects (21 with AQP4-IgG+NMO-ON and 11 with MOG-IgG+ON and 34 healthy controls (HCs closely matched for age were recruited, and scans were performed for all subjects. A one-way analysis of variance (ANOVA was performed to determine the regions in which the ReHo was different across the three groups. NMO-ON and ON subjects were distinguished from HCs by a receiver operating characteristic (ROC curve. The relationship between the mean ReHo in many brain regions and clinical features in NMO subjects was calculated by Pearson correlation analysis. Results: Compared with HCs, MOG-IgG+ON subjects had significantly decreased ReHo values in the posterior lobe of the left cerebellum and increased ReHo values in the left inferior frontal gyrus, right prefrontal gyrus, and left precentral/postcentral gyrus. AQP4-IgG+NMO-ON subjects showed higher ReHo values in the left inferior frontal gyrus and right middle temporal/occipital gyrus. Compared with MOG-IgG+ON subjects, AQP4-IgG+NMO-ON subjects had lower Re

  1. Rats with minimal hepatic encephalopathy show reduced cGMP-dependent protein kinase activity in hypothalamus correlating with circadian rhythms alterations.

    Science.gov (United States)

    Felipo, Vicente; Piedrafita, Blanca; Barios, Juan A; Agustí, Ana; Ahabrach, Hanan; Romero-Vives, María; Barrio, Luis C; Rey, Beatriz; Gaztelu, Jose M; Llansola, Marta

    2015-01-01

    Patients with liver cirrhosis show disturbances in sleep and in its circadian rhythms which are an early sign of minimal hepatic encephalopathy (MHE). The mechanisms of these disturbances are poorly understood. Rats with porta-caval shunt (PCS), a model of MHE, show sleep disturbances reproducing those of cirrhotic patients. The aims of this work were to characterize the alterations in circadian rhythms in PCS rats and analyze the underlying mechanisms. To reach these aims, we analyzed in control and PCS rats: (a) daily rhythms of spontaneous and rewarding activity and of temperature, (b) timing of the onset of activity following turning-off the light, (c) synchronization to light after a phase advance and (d) the molecular mechanisms contributing to these alterations in circadian rhythms. PCS rats show altered circadian rhythms of spontaneous and rewarding activities (wheel running). PCS rats show more rest bouts during the active phase, more errors in the onset of motor activity and need less time to re-synchronize after a phase advance than control rats. Circadian rhythm of body temperature is also slightly altered in PCS rats. The internal period length (tau) of circadian rhythm of motor activity is longer in PCS rats. We analyzed some mechanisms by which hypothalamus modulate circadian rhythms. PCS rats show increased content of cGMP in hypothalamus while the activity of cGMP-dependent protein kinase was reduced by 41% compared to control rats. Altered cGMP-PKG pathway in hypothalamus would contribute to altered circadian rhythms and synchronization to light.

  2. Non-24-Hour Sleep-Wake Rhythm Disorder in the Totally Blind: Diagnosis and Management.

    Science.gov (United States)

    Quera Salva, Maria Antonia; Hartley, Sarah; Léger, Damien; Dauvilliers, Yves A

    2017-01-01

    Several aspects of human physiology and behavior are dominated by 24-h circadian rhythms with key impacts on health and well-being. These include mainly the sleep-wake cycle, vigilance and performance patterns, and some hormone secretions. The rhythms are generated spontaneously by an internal "pacemaker," the suprachiasmatic nuclei within the anterior hypothalamus. This master clock has, for most humans, an intrinsic rhythm slightly longer than 24 h. Daily retinal light exposure is necessary for the synchronization of the circadian rhythms with the external 24-h solar environment. This daily synchronization process generally poses no problems for sighted individuals except in the context of jetlag or working night shifts being conditions of circadian desynchrony. However, many blind subjects with no light perception had periodical circadian desynchrony, in the absence of light information to the master clock leading to poor circadian rhythm synchronization. Affected patients experience cyclical or periodic episodes of poor sleep and daytime dysfunction, severely interfering with social, academic, and professional life. The diagnosis of Non-24 Sleep-Wake Rhythm Disorder, also named free-running disorder, non-entrained disorder, or hypernycthemeral syndrome, remains challenging from a clinical point of view due to the cyclical symptoms and should be confirmed by measurements of circadian biomarkers such as urinary melatonin to demonstrate a circadian period outside the normal range. Management includes behavioral modification and melatonin. Tasimelteon, a novel melatonin receptor 1 and 2 agonist, has demonstrated its effectiveness and safety with an evening dose of 20 mg and is currently the only treatment approved by the FDA and the European Medicines Agency.

  3. Non-24-Hour Sleep–Wake Rhythm Disorder in the Totally Blind: Diagnosis and Management

    Directory of Open Access Journals (Sweden)

    Maria Antonia Quera Salva

    2017-12-01

    Full Text Available Several aspects of human physiology and behavior are dominated by 24-h circadian rhythms with key impacts on health and well-being. These include mainly the sleep–wake cycle, vigilance and performance patterns, and some hormone secretions. The rhythms are generated spontaneously by an internal “pacemaker,” the suprachiasmatic nuclei within the anterior hypothalamus. This master clock has, for most humans, an intrinsic rhythm slightly longer than 24 h. Daily retinal light exposure is necessary for the synchronization of the circadian rhythms with the external 24-h solar environment. This daily synchronization process generally poses no problems for sighted individuals except in the context of jetlag or working night shifts being conditions of circadian desynchrony. However, many blind subjects with no light perception had periodical circadian desynchrony, in the absence of light information to the master clock leading to poor circadian rhythm synchronization. Affected patients experience cyclical or periodic episodes of poor sleep and daytime dysfunction, severely interfering with social, academic, and professional life. The diagnosis of Non-24 Sleep–Wake Rhythm Disorder, also named free-running disorder, non-entrained disorder, or hypernycthemeral syndrome, remains challenging from a clinical point of view due to the cyclical symptoms and should be confirmed by measurements of circadian biomarkers such as urinary melatonin to demonstrate a circadian period outside the normal range. Management includes behavioral modification and melatonin. Tasimelteon, a novel melatonin receptor 1 and 2 agonist, has demonstrated its effectiveness and safety with an evening dose of 20 mg and is currently the only treatment approved by the FDA and the European Medicines Agency.

  4. Circadian Rhythms and Sleep inDrosophila melanogaster.

    Science.gov (United States)

    Dubowy, Christine; Sehgal, Amita

    2017-04-01

    The advantages of the model organism Drosophila melanogaster , including low genetic redundancy, functional simplicity, and the ability to conduct large-scale genetic screens, have been essential for understanding the molecular nature of circadian (∼24 hr) rhythms, and continue to be valuable in discovering novel regulators of circadian rhythms and sleep. In this review, we discuss the current understanding of these interrelated biological processes in Drosophila and the wider implications of this research. Clock genes period and timeless were first discovered in large-scale Drosophila genetic screens developed in the 1970s. Feedback of period and timeless on their own transcription forms the core of the molecular clock, and accurately timed expression, localization, post-transcriptional modification, and function of these genes is thought to be critical for maintaining the circadian cycle. Regulators, including several phosphatases and kinases, act on different steps of this feedback loop to ensure strong and accurately timed rhythms. Approximately 150 neurons in the fly brain that contain the core components of the molecular clock act together to translate this intracellular cycling into rhythmic behavior. We discuss how different groups of clock neurons serve different functions in allowing clocks to entrain to environmental cues, driving behavioral outputs at different times of day, and allowing flexible behavioral responses in different environmental conditions. The neuropeptide PDF provides an important signal thought to synchronize clock neurons, although the details of how PDF accomplishes this function are still being explored. Secreted signals from clock neurons also influence rhythms in other tissues. SLEEP is, in part, regulated by the circadian clock, which ensures appropriate timing of sleep, but the amount and quality of sleep are also determined by other mechanisms that ensure a homeostatic balance between sleep and wake. Flies have been useful

  5. Role of Spontaneous Brain Activity in Explicit and Implicit Aspects of Cognitive Flexibility under Socially Conflicting Situations: A Resting-state fMRI Study using Fractional Amplitude of Low-frequency Fluctuations.

    Science.gov (United States)

    Fujino, Junya; Tei, Shisei; Jankowski, Kathryn F; Kawada, Ryosaku; Murai, Toshiya; Takahashi, Hidehiko

    2017-12-26

    We are constantly exposed to socially conflicting situations in everyday life, and cognitive flexibility is essential for adaptively coping with such difficulties. Flexible goal choice and pursuit are not exclusively conscious, and therefore cognitive flexibility involves both explicit and implicit forms of processing. However, it is unclear how individual differences in explicit and implicit aspects of flexibility are associated with neural activity in a resting state. Here, we measured intrinsic fractional amplitude of low-frequency fluctuations (fALFF) by resting-state functional magnetic resonance imaging (RS-fMRI) as an indicator of regional brain spontaneous activity, together with explicit and implicit aspects of cognitive flexibility using the Cognitive Flexibility Scale (CFS) and Implicit Association Test (IAT). Consistent with the dual processing theory, there was a strong association between explicit aspects of flexibility (CFS score) and "rationalism" thinking style and between implicit aspects (IAT effect) and "experientialism." The level of explicit flexibility was also correlated with fALFF values in the left lateral prefrontal cortex, whereas the level of implicit flexibility was correlated with fALFF values in the right cerebellum. Furthermore, the fALFF values in both regions predicted individual preference for flexible decision-making strategy in a vignettes simulation task. These results add to our understanding of the neural mechanisms underlying flexible decision-making for solving social conflicts. More generally, our findings highlight the utility of RS-fMRI combined with both explicit and implicit psychometric measures for better understanding individual differences in social cognition. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  6. Correlation of hippocampal theta rhythm with changes in cutaneous temperature. [evoked neuron response in thermoregulation

    Science.gov (United States)

    Horowitz, J. M.; Saleh, M. A.; Karem, R. D.

    1974-01-01

    A possible role for the hippocampus in alerting an animal to changes in cutaneous temperature was examined. Following local warming or cooling of the ears of unanesthetized, loosely restrained rabbits, theta waves (4-7 Hz EEG waves) were recorded from electrodes straddling the hippocampus. The onset of the hippocampal theta rhythm was correlated with changes in cutaneous temperature, an observation consistent with studies indicating that the theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Additional data from cats and rabbits were correlated with specific neurons within the hippocampus, namely pyramidal cells. Post stimulus time histograms obtained by excitation of the dorsal fornix were interpreted in terms of excitatory and inhibitory inputs to pyramidal cells. Thus, the theta rhythm, which appears to be evoked by changes in cutaneous temperature, can be related to a specific type of hippocampal neuron which is in turn connected with other areas of the brain involved in temperature regulation.

  7. Rhythm for Reading: Evaluation Report and Executive Summary

    Science.gov (United States)

    Styles, Ben; Clarkson, Rebecca; Fowler, Katherine

    2014-01-01

    Rhythm for Reading is a programme which aims to improve children's reading ability by taking part in rhythm-based exercises such as stamping, clapping and chanting, while reading musical notation. The intervention builds on the evidence of a link between the natural rhythm and phrasing of prose and intuitive reading comprehension. Rhythm for…

  8. Spontaneous subdural hematoma associated to Duret hemorrhage

    Directory of Open Access Journals (Sweden)

    William Alves Martins, MD

    2015-03-01

    Full Text Available Subdural hematoma (SH is a neurosurgical emergency, usually caused by head trauma. Non-traumatic causes include aneurysm or arterial–venous malformation rupture, coagulopathy and others. We report the case of a 66 year-old man who developed apparently unprovoked signs of increased intracranial pressure. Brain computed tomography scan showed an acute spontaneous SH, surgically treated. Throughout surgery, a ruptured cortical artery with intensive bleeding appeared and was cauterized. After surgery, patient remained comatose and a new CT demonstrated Duret hemorrhage at the brainstem. Acute spontaneous SH of arterial origin is rare and highly lethal, in which a good prognosis relies on early diagnosis and treatment.

  9. Spontaneous uterine rupture

    African Journals Online (AJOL)

    ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...

  10. Non-peptide oxytocin receptor ligands and hamster circadian wheel running rhythms.

    Science.gov (United States)

    Gannon, Robert L

    2014-10-17

    The synchronization of circadian rhythms in sleep, endocrine and metabolic functions with the environmental light cycle is essential for health, and dysfunction of this synchrony is thought to play a part in the development of many neurological disorders. There is a demonstrable need to develop new therapeutics for the treatment of neurological disorders such as depression and schizophrenia, and oxytocin is currently being investigated for this purpose. There are no published reports describing activity of oxytocin receptor ligands on mammalian circadian rhythms and that, then, is the purpose of this study. Non-peptide oxytocin receptor ligands that cross the blood brain barrier were systemically injected in hamsters to determine their ability to modulate light-induced phase advances and delays of circadian wheel running rhythms. The oxytocin receptor agonist WAY267464 (10 mg/kg) inhibited light induced phase advances of wheel running rhythms by 55%, but had no effect on light-induced phase delays. In contrast, the oxytocin receptor antagonist WAY162720 (10 mg/kg) inhibited light-induced phase delays by nearly 75%, but had no effect on light-induced phase advances. Additionally, WAY162720 was able to antagonize the inhibitory effects of WAY267464 on light-induced phase advances. These results are consistent for a role of oxytocin in the phase-delaying effects of light on circadian activity rhythms early in the night. Therefore, oxytocin may prove to be useful in developing therapeutics for the treatment of mood disorders with a concomitant dysfunction in circadian rhythms. Investigators should also be cognizant that oxytocin ligands may negatively affect circadian rhythms during clinical trials for other conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. A riot of rhythms: neuronal and glial circadian oscillators in the mediobasal hypothalamus.

    Science.gov (United States)

    Guilding, Clare; Hughes, Alun T L; Brown, Timothy M; Namvar, Sara; Piggins, Hugh D

    2009-08-27

    In mammals, the synchronized activity of cell autonomous clocks in the suprachiasmatic nuclei (SCN) enables this structure to function as the master circadian clock, coordinating daily rhythms in physiology and behavior. However, the dominance of this clock has been challenged by the observations that metabolic duress can over-ride SCN controlled rhythms, and that clock genes are expressed in many brain areas, including those implicated in the regulation of appetite and feeding. The recent development of mice in which clock gene/protein activity is reported by bioluminescent constructs (luciferase or luc) now enables us to track molecular oscillations in numerous tissues ex vivo. Consequently we determined both clock activities and responsiveness to metabolic perturbations of cells and tissues within the mediobasal hypothalamus (MBH), a site pivotal for optimal internal homeostatic regulation. Here we demonstrate endogenous circadian rhythms of PER2::LUC expression in discrete subdivisions of the arcuate (Arc) and dorsomedial nuclei (DMH). Rhythms resolved to single cells did not maintain long-term synchrony with one-another, leading to a damping of oscillations at both cell and tissue levels. Complementary electrophysiology recordings revealed rhythms in neuronal activity in the Arc and DMH. Further, PER2::LUC rhythms were detected in the ependymal layer of the third ventricle and in the median eminence/pars tuberalis (ME/PT). A high-fat diet had no effect on the molecular oscillations in the MBH, whereas food deprivation resulted in an altered phase in the ME/PT. Our results provide the first single cell resolution of endogenous circadian rhythms in clock gene expression in any intact tissue outside the SCN, reveal the cellular basis for tissue level damping in extra-SCN oscillators and demonstrate that an oscillator in the ME/PT is responsive to changes in metabolism.

  12. A riot of rhythms: neuronal and glial circadian oscillators in the mediobasal hypothalamus

    Directory of Open Access Journals (Sweden)

    Guilding Clare

    2009-08-01

    Full Text Available Abstract Background In mammals, the synchronized activity of cell autonomous clocks in the suprachiasmatic nuclei (SCN enables this structure to function as the master circadian clock, coordinating daily rhythms in physiology and behavior. However, the dominance of this clock has been challenged by the observations that metabolic duress can over-ride SCN controlled rhythms, and that clock genes are expressed in many brain areas, including those implicated in the regulation of appetite and feeding. The recent development of mice in which clock gene/protein activity is reported by bioluminescent constructs (luciferase or luc now enables us to track molecular oscillations in numerous tissues ex vivo. Consequently we determined both clock activities and responsiveness to metabolic perturbations of cells and tissues within the mediobasal hypothalamus (MBH, a site pivotal for optimal internal homeostatic regulation. Results Here we demonstrate endogenous circadian rhythms of PER2::LUC expression in discrete subdivisions of the arcuate (Arc and dorsomedial nuclei (DMH. Rhythms resolved to single cells did not maintain long-term synchrony with one-another, leading to a damping of oscillations at both cell and tissue levels. Complementary electrophysiology recordings revealed rhythms in neuronal activity in the Arc and DMH. Further, PER2::LUC rhythms were detected in the ependymal layer of the third ventricle and in the median eminence/pars tuberalis (ME/PT. A high-fat diet had no effect on the molecular oscillations in the MBH, whereas food deprivation resulted in an altered phase in the ME/PT. Conclusion Our results provide the first single cell resolution of endogenous circadian rhythms in clock gene expression in any intact tissue outside the SCN, reveal the cellular basis for tissue level damping in extra-SCN oscillators and demonstrate that an oscillator in the ME/PT is responsive to changes in metabolism.

  13. Melanopsin resets circadian rhythms in cells by inducing clock gene Period1

    Science.gov (United States)

    Yamashita, Shuhei; Uehara, Tomoe; Matsuo, Minako; Kikuchi, Yo; Numano, Rika

    2014-02-01

    The biochemical, physiological and behavioral processes are under the control of internal clocks with the period of approximately 24 hr, circadian rhythms. The expression of clock gene Period1 (Per1) oscillates autonomously in cells and is induced immediately after a light pulse. Per1 is an indispensable member of the central clock system to maintain the autonomous oscillator and synchronize environmental light cycle. Per1 expression could be detected by Per1∷luc and Per1∷GFP plasmid DNA in which firefly luciferase and Green Fluorescence Protein were rhythmically expressed under the control of the mouse Per1 promoter in order to monitor mammalian circadian rhythms. Membrane protein, MELANOPSIN is activated by blue light in the morning on the retina and lead to signals transduction to induce Per1 expression and to reset the phase of circadian rhythms. In this report Per1 induction was measured by reporter signal assay in Per1∷luc and Per1∷GFP fibroblast cell at the input process of circadian rhythms. To the result all process to reset the rhythms by Melanopsin is completed in single cell like in the retina projected to the central clock in the brain. Moreover, the phase of circadian rhythm in Per1∷luc cells is synchronized by photo-activated Melanopsin, because the definite peak of luciferase activity in one dish was found one day after light illumination. That is an available means that physiological circadian rhythms could be real-time monitor as calculable reporter (bioluminescent and fluorescent) chronological signal in both single and groups of cells.

  14. Investigating the role of alpha and beta rhythms in functional motor networks.

    Science.gov (United States)

    Athanasiou, Alkinoos; Klados, Manousos A; Styliadis, Charis; Foroglou, Nicolas; Polyzoidis, Konstantinos; Bamidis, Panagiotis D

    2016-05-27

    It is recognized that lower electroencephalography (EEG) frequencies correspond to distributed brain activity over larger spatial regions than higher frequencies and are associated with coordination. In motor processes it has been suggested that this is not always the case. Our objective was to explore this contradiction. In our study, seven healthy subjects performed four motor tasks (execution and imagery of right hand and foot) under EEG recording. Two cortical source models were defined, model «A» with 16 regions of interest (ROIs) and model «B» with 20 ROIs over the sensorimotor cortex. Functional connectivity was calculated by Directed Transfer Function for alpha and beta rhythm networks. Four graph properties were calculated for each network: characteristic path length (CPL), clustering coefficient (CC), density (D) and small-world-ness (SW). Different network modules and in-degrees of nodes were also calculated and depicted in connectivity maps. Analysis of variance was used to determine statistical significance of observed differences in the network properties between tasks, between rhythms and between ROI models. Consistently on both models, CPL and CC were lower and D was higher in beta rhythm networks. No statistically significant difference was observed for SW between rhythms or for any property between tasks on any model. Comparing the models we observed lower CPL for both rhythms, lower CC in alpha and higher CC in beta when the number of ROIs increased. Also, denser networks with higher SW were correlated with higher number of ROIs. We propose a non-exclusive model where alpha rhythm uses greater wiring costs to engage in local information progression while beta rhythm coordinates the neurophysiological processes in sensorimotor tasks. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Circadian Rhythm Management System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The value of measuring sleep-wake cycles is significantly enhanced by measuring other physiological signals that depend on circadian rhythms (such as heart rate and...

  16. Rhythm, Movement and Synchrony. Effective Teaching Tools.

    Science.gov (United States)

    Aldrich, Kenneth R.

    1989-01-01

    This article discusses incorporation of academic curriculum elements into movement units, synchronous movement as a teaching tool, the movement-cognition connection, and identification and use of rhythm and movement elements in the classroom. (IAH)

  17. The sensory-motor theory of rhythm and beat induction 20 years on: a new synthesis and future perspectives

    Science.gov (United States)

    Todd, Neil P. M.; Lee, Christopher S.

    2015-01-01

    Some 20 years ago Todd and colleagues proposed that rhythm perception is mediated by the conjunction of a sensory representation of the auditory input and a motor representation of the body (Todd, 1994a, 1995), and that a sense of motion from sound is mediated by the vestibular system (Todd, 1992a, 1993b). These ideas were developed into a sensory-motor theory of rhythm and beat induction (Todd et al., 1999). A neurological substrate was proposed which might form the biological basis of the theory (Todd et al., 2002). The theory was implemented as a computational model and a number of experiments conducted to test it. In the following time there have been several key developments. One is the demonstration that the vestibular system is primal to rhythm perception, and in related work several experiments have provided further evidence that rhythm perception is body dependent. Another is independent advances in imaging, which have revealed the brain areas associated with both vestibular processing and rhythm perception. A third is the finding that vestibular receptors contribute to auditory evoked potentials (Todd et al., 2014a,b). These behavioral and neurobiological developments demand a theoretical overview which could provide a new synthesis over the domain of rhythm perception. In this paper we suggest four propositions as the basis for such a synthesis. (1) Rhythm perception is a form of vestibular perception; (2) Rhythm perception evokes both external and internal guidance of somatotopic representations; (3) A link from the limbic system to the internal guidance pathway mediates the “dance habit”; (4) The vestibular reward mechanism is innate. The new synthesis provides an explanation for a number of phenomena not often considered by rhythm researchers. We discuss these along with possible computational implementations and alternative models and propose a number of new directions for future research. PMID:26379522

  18. The sensory-motor theory of rhythm and beat induction 20 years on: A new synthesis and future perspectives.

    Directory of Open Access Journals (Sweden)

    Neil Philip Todd

    2015-08-01

    Full Text Available Some 20 years ago Todd and colleagues proposed that rhythm perception is mediated by the conjunction of a sensory representation of the auditory input and a motor representation of the body (Todd 1994, 1995, and that a sense of motion from sound is mediated by the vestibular system (Todd 1992, 1993. These ideas were developed into a sensory-motor theory of rhythm and beat induction (Todd et al. 1999. A neurological substrate was proposed which might form the biological basis of the theory (Todd et al. 2002. The theory was implemented as a computational model and a number of experiments conducted to test it. In the following time there have been several key developments. One is the demonstration that the vestibular system is primal to rhythm perception, and in related work several experiments have provided further evidence that rhythm perception is body dependent. Another is independent advances in imaging, which have revealed the brain areas associated with both vestibular processing and rhythm perception. A third is the finding that vestibular receptors contribute to auditory evoked potentials (Todd et al. 2014ab. These behavioural and neurobiological developments demand a theoretical overview which could provide a new synthesis over the domain of rhythm perception. In this paper we suggest four propositions as the basis for such a synthesis. (1 Rhythm perception is a form of vestibular perception; (2 Rhythm perception evokes both external and internal guidance of somatotopic representations; (3 A link from the limbic system to the internal guidance pathway mediates the dance habit; (4 The vestibular reward mechanism is innate. The new synthesis provides an explanation for a number of phenomena not often considered by rhythm researchers. We discuss these along with possible computational implementations and alternative models and propose a number of new directions for future research.

  19. Dynamic effective connectivity of inter-areal brain circuits.

    Directory of Open Access Journals (Sweden)

    Demian Battaglia

    Full Text Available Anatomic connections between brain areas affect information flow between neuronal circuits and the synchronization of neuronal activity. However, such structural connectivity does not coincide with effective connectivity (or, more precisely, causal connectivity, related to the elusive question "Which areas cause the present activity of which others?". Effective connectivity is directed and depends flexibly on contexts and tasks. Here we show that dynamic effective connectivity can emerge from transitions in the collective organization of coherent neural activity. Integrating simulation and semi-analytic approaches, we study mesoscale network motifs of interacting cortical areas, modeled as large random networks of spiking neurons or as simple rate units. Through a causal analysis of time-series of model neural activity, we show that different dynamical states generated by a same structural connectivity motif correspond to distinct effective connectivity motifs. Such effective motifs can display a dominant directionality, due to spontaneous symmetry breaking and effective entrainment between local brain rhythms, although all connections in the considered structural motifs are reciprocal. We show then that transitions between effective connectivity configurations (like, for instance, reversal in the direction of inter-areal interactions can be triggered reliably by brief perturbation inputs, properly timed with respect to an ongoing local oscillation, without the need for plastic synaptic changes. Finally, we analyze how the information encoded in spiking patterns of a local neuronal population is propagated across a fixed structural connectivity motif, demonstrating that changes in the active effective connectivity regulate both the efficiency and the directionality of information transfer. Previous studies stressed the role played by coherent oscillations in establishing efficient communication between distant areas. Going beyond these early

  20. BK channels regulate spontaneous action potential rhythmicity in the suprachiasmatic nucleus.

    Directory of Open Access Journals (Sweden)

    Jack Kent

    Full Text Available BACKGROUND: Circadian ( approximately 24 hr rhythms are generated by the central pacemaker localized to the suprachiasmatic nucleus (SCN of the hypothalamus. Although the basis for intrinsic rhythmicity is generally understood to rely on transcription factors encoded by "clock genes", less is known about the daily regulation of SCN neuronal activity patterns that communicate a circadian time signal to downstream behaviors and physiological systems. Action potentials in the SCN are necessary for the circadian timing of behavior, and individual SCN neurons modulate their spontaneous firing rate (SFR over the daily cycle, suggesting that the circadian patterning of neuronal activity is necessary for normal behavioral rhythm expression. The BK K(+ channel plays an important role in suppressing spontaneous firing at night in SCN neurons. Deletion of the Kcnma1 gene, encoding the BK channel, causes degradation of circadian behavioral and physiological rhythms. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis that loss of robust behavioral rhythmicity in Kcnma1(-/- mice is due to the disruption of SFR rhythms in the SCN, we used multi-electrode arrays to record extracellular action potentials from acute wild-type (WT and Kcnma1(-/- slices. Patterns of activity in the SCN were tracked simultaneously for up to 3 days, and the phase, period, and synchronization of SFR rhythms were examined. Loss of BK channels increased arrhythmicity but also altered the amplitude and period of rhythmic activity. Unexpectedly, Kcnma1(-/- SCNs showed increased variability in the timing of the daily SFR peak. CONCLUSIONS/SIGNIFICANCE: These results suggest that BK channels regulate multiple aspects of the circadian patterning of neuronal activity in the SCN. In addition, these data illustrate the characteristics of a disrupted SCN rhythm downstream of clock gene-mediated timekeeping and its relationship to behavioral rhythms.

  1. Drugs of Abuse Can Entrain Circadian Rhythms

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    Ann E. K. Kosobud

    2007-01-01

    Full Text Available Circadian rhythms prepare organisms for predictable events during the Earth's 24-h day. These rhythms are entrained by a variety of stimuli. Light is the most ubiquitous and best known zeitgeber, but a number of others have been identified, including food, social cues, locomotor activity, and, most recently drugs of abuse. Given the diversity of zeitgebers, it is probably not surprising that genes capable of clock functions are located throughout almost all organs and tissues. Recent evidence suggests that drugs of abuse can directly entrain some circadian rhythms. We have report here that entrainment by drugs of abuse is independent of the suprachiasmatic nucleus and the light/dark cycle, is not dependent on direct locomotor stimulation, and is shared by a variety of classes of drugs of abuse. We suggest that drug-entrained rhythms reflect variations in underlying neurophysiological states. This could be the basis for known daily variations in drug metabolism, tolerance, and sensitivity to drug reward. These rhythms could also take the form of daily periods of increased motivation to seek and take drugs, and thus contribute to abuse, addiction and relapse.

  2. Biological clocks and rhythms in intertidal crustaceans.

    Science.gov (United States)

    de la Iglesia, Horacio O; Hsu, Yun-Wei A

    2010-06-01

    Animals with habitats within the intertidal zone are exposed to environmental cycles that include the ebb and flow of tidal waters, changes in tidal levels associated with the lunar month, the light-dark cycle and the alternation of seasons. This intricate temporal environment results in the selection of biological timing systems with endogenous clocks that can oscillate with this wide range of periodicities. Whereas great progress has been made in our understanding of the molecular and neural bases of circadian rhythms, that is, endogenous rhythms synchronized to the solar day, there is little understanding on how circatidal rhythms, namely endogenous rhythms synchronized to tides, are generated. Intertidal crustaceans have been a pivotal group for the demonstration of the endogenous nature of circatidal rhythms and their mechanisms of entrainment. We review here some of the classic work using intertidal crustaceans to unmask basic properties of circatidal systems, as well as work from our laboratory that aims to identify putative chemical signals that could be involved in the circatidal systems of decapod crustaceans.

  3. [Dynamic Attending Binds Time and Rhythm Perception].

    Science.gov (United States)

    Kuroda, Tsuyoshi; Ono, Fuminori; Kadota, Hiroshi

    2017-11-01

    Relations between time and rhythm perception are discussed in this review of psychophysical research relevant to the multiple-look effect and dynamic-attending theory. Discrimination of two neighboring intervals that are marked by three successive sounds is improved when the presentation of the first (standard, S) interval is repeated before that of the second (comparison, C), as SSSSC. This improvement in sensitivity, called the multiple-look effect, occurs because listeners (1) perceive regular rhythm during the repetition of the standard interval, (2) predict the timing of subsequent sounds, and (3) detect sounds that are deviated from the predicted timing. The dynamic-attending theory attributes such predictions to the entrainment of attentional rhythms. An endogenous attentional rhythm is synchronized with the periodic succession of sounds marking the repeated standard. The standard and the comparison are discriminated on the basis of whether the ending marker of the comparison appears at the peak of the entrained attentional rhythm. This theory is compatible with the findings of recent neurophysiological studies that relate temporal prediction to neural oscillations.

  4. Effects of adrenaline on rhythm transitions in out-of-hospital cardiac arrest.

    Science.gov (United States)

    Neset, Andres; Nordseth, Trond; Kramer-Johansen, Jo; Wik, Lars; Olasveengen, Theresa M

    2013-11-01

    We wanted to study the effects of intravenous (i.v.) adrenaline (epinephrine) on rhythm transitions during cardiac arrest with initial or secondary ventricular fibrillation/tachycardia (VF/VT). Post hoc analysis of patients included in a randomised controlled trial of i.v. drugs in adult, non-traumatic out-of-hospital cardiac arrest patients who were defibrillated and had a readable electrocardiography recording. Patients who received adrenaline were compared with patients who did not. Cardiac rhythms were annotated manually using the defibrillator data. Eight hundred and forty-nine patients were included in the randomised trial of which 223 were included in this analysis; 119 in the adrenaline group and 104 in the no-adrenaline group. The proportion of patients with one or more VF/VT episodes after temporary return of spontaneous circulation (ROSC) was higher in the adrenaline than in the no-adrenaline group, 24% vs. 12%, P = 0.03. Most relapses from ROSC to VF/VT in the no-adrenaline group occurred during the first 20 min of resuscitation, whereas patients in the adrenaline group experienced such relapses even after 20 min. Fibrillations from asystole or pulseless electrical activity, shock resistant VF/VT and the number of rhythm transitions per patient was higher in the adrenalin group compared with the no-adrenalin group: 90% vs. 69%, P adrenaline had more rhythm transitions from ROSC and non-shockable rhythms to VF/VT. © 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  5. Spontaneous prediction error generation in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Yuichi Yamashita

    Full Text Available Goal-directed human behavior is enabled by hierarchically-organized neural systems that process executive commands associated with higher brain areas in response to sensory and motor signals from lower brain areas. Psychiatric diseases and psychotic conditions are postulated to involve disturbances in these hierarchical network interactions, but the mechanism for how aberrant disease signals are generated in networks, and a systems-level framework linking disease signals to specific psychiatric symptoms remains undetermined. In this study, we show that neural networks containing schizophrenia-like deficits can spontaneously generate uncompensated error signals with properties that explain psychiatric disease symptoms, including fictive perception, altered sense of self, and unpredictable behavior. To distinguish dysfunction at the behavioral versus network level, we monitored the interactive behavior of a humanoid robot driven by the network. Mild perturbations in network connectivity resulted in the spontaneous appearance of uncompensated prediction errors and altered interactions within the network without external changes in behavior, correlating to the fictive sensations and agency experienced by episodic disease patients. In contrast, more severe deficits resulted in unstable network dynamics resulting in overt changes in behavior similar to those observed in chronic disease patients. These findings demonstrate that prediction error disequilibrium may represent an intrinsic property of schizophrenic brain networks reporting the severity and variability of disease symptoms. Moreover, these results support a systems-level model for psychiatric disease that features the spontaneous generation of maladaptive signals in hierarchical neural networks.

  6. Neurofeedback training on sensorimotor rhythm in marmoset monkeys.

    Science.gov (United States)

    Philippens, Ingrid H C H M; Vanwersch, Raymond A P

    2010-03-31

    Neurofeedback research in a model closely related to humans is recommended to rule out placebo effects and unspecific factors bridging the gap between nonvalidated empirical and standardized controlled research. In this article, telemetric sensorimotor rhythm (SMR; 11-14 Hz) feedback training in the marmoset monkey is applied to examine the monkey's capability to voluntary control their brain activity. Four monkeys, provided with two epidural bioelectric electrodes above the sensorimotor cortex, were trained with positive reinforcement on SMR measured by online analyses of 1.28 s electroencephalogram epochs in 30-min sessions. These monkeys learned within five sessions to increase their alpha activity. The first evidence of nonhuman primates having an operant control over the SMR is provided, an initial step for a much-needed scientific basis to neurofeedback.

  7. Microarray analysis of natural socially regulated plasticity in circadian rhythms of honey bees.

    Science.gov (United States)

    Rodriguez-Zas, Sandra L; Southey, Bruce R; Shemesh, Yair; Rubin, Elad B; Cohen, Mira; Robinson, Gene E; Bloch, Guy

    2012-02-01

    Honey bee workers care for ("nurse") the brood around the clock without circadian rhythmicity, but then they forage outside with strong circadian rhythms and a consolidated nightly rest. This chronobiological plasticity is associated with variation in the expression of the canonical "clock genes" that regulate the circadian clock: nurse bees show no brain rhythms of expression, while foragers do. These results suggest that the circadian system is organized differently in nurses and foragers. Nurses switch to activity with circadian rhythms shortly after being removed from the hive, suggesting that at least some clock cells in their brain continue to measure time while in the hive. We performed a microarray genome-wide survey to determine general patterns of brain gene expression in nurses and foragers sampled around the clock. We found 160 and 541 transcripts that exhibited significant sinusoidal oscillations in nurses and foragers, respectively, with peaks of expression distributed throughout the day in both task groups. Consistent with earlier studies, transcripts of genes involved in circadian rhythms, including Clockwork Orange that has not been studied before in bees, oscillated in foragers but not in nurses. The oscillating transcripts also were enriched for genes involved in the visual system, "development" and "response to stimuli" (foragers), "muscle contraction" and "microfilament motor gene expression" (nurses), and "generation of precursor metabolites" and "energy" (both). Transcripts of genes encoding P450 enzymes oscillated in both nurses and foragers but with a different phase. This study identified new putative clock-controlled genes in the honey bee and suggests that some brain functions show circadian rhythmicity even in nurse bees that are active around the clock.

  8. Microarray Analysis of Natural Socially-Regulated Plasticity in Circadian Rhythms of Honey Bees

    Science.gov (United States)

    Rodriguez-Zas, Sandra L.; Southey, Bruce R.; Shemesh, Yair; Rubin, Elad B.; Cohen, Mira; Robinson, Gene E.; Bloch, Guy

    2012-01-01

    Honey bee workers care for ("nurse") the brood around the clock without circadian rhythmicity, but then they forage outside with strong circadian rhythms and a consolidated nightly rest. This chronobiological plasticity is associated with variation in the expression of the canonical “clock genes” that regulate the circadian clock: nurse bees show no brain rhythms of expression, while foragers do. These results suggest that the circadian system is organized differently in nurses and foragers. Nurses switch to activity with circadian rhythms shortly after removed from the hive suggesting that at least some clock cells in their brain continue to measure time while in the hive. We performed a microarray genome-wide survey to determine general patterns of brain gene expression in nurses and foragers sampled around the clock. We found 160 and 541 transcripts that exhibited significant sinusoidal oscillations in nurses and foragers, respectively, with peaks of expression distributed throughout the day in both task groups. Consistent with earlier studies, transcripts of genes involved in circadian rhythms, including Clockwork Orange that has not been studied before in bees, oscillated in foragers but not in nurses. The oscillating transcripts also were enriched for genes involved in the visual system, “development” and “response to stimuli” (foragers), “muscle contraction” and “microfilament motor gene expression” (nurses), and “generation of precursor metabolites” and “energy” (both). Transcripts of genes encoding P450 enzymes oscillated in both nurses and foragers but with a different phase. This study identified new putative clock-controlled genes in the honey bee and suggests that some brain functions show circadian rhythmicity even in nurse bees that are active around the clock. PMID:22306970

  9. Analyzing biological rhythms in clinical trials.

    Science.gov (United States)

    Elkum, Naser B; Myles, James D; Kumar, Pranesh

    2008-09-01

    The human body exhibits a variety of biological rhythms. There are patterns that correspond, among others, to the daily wake / sleep cycle, a yearly seasonal cycle and, in women, the menstrual cycle. Sine/cosine functions are often used to model biological patterns for continuous data, but this model is not appropriate for analysis of biological rhythms in failure time data. We consider a method appropriate for analysis of biological rhythms in clinical trials. We present a method to provide an estimate and confidence interval of the time when the minimum hazard is achieved. A motivating example from a clinical trial of adjuvant of pre-menopausal breast cancer patients provides an important illustration of the methodology in practice. Adapting the Cosinor method to the Weibull proportional hazards model is proposed as useful way of modeling the biological rhythm data. It presents a method to estimate the time that achieves the minimum hazard along with its associated confidence interval. The application of this technique to the breast cancer data revealed that the optimal day for pre-resection incisional or excisional biopsy of 28-day cycle (i.e. the day associated with the lowest recurrence rate) is day 8 with 95% CI 5-10. We found that older age, fewer positive nodes, smaller tumor size, and experimental treatment are important prognostic factors of longer relapse-free survival. The analysis of biological/circadian rhythms is usually handled by Cosinor rhythmometry method. However, in FTD this is simply not possible. In this case, we propose to adapt the Cosinor method to the Weibull proportional hazard model. The advantage of the proposed method is its ability to model survival data. This method is not limited to breast cancer data, and may be applied to any biological rhythms linked to right censored data.

  10. Daily rhythm of cerebral blood flow velocity

    Directory of Open Access Journals (Sweden)

    Spielman Arthur J

    2005-03-01

    Full Text Available Abstract Background CBFV (cerebral blood flow velocity is lower in the morning than in the afternoon and evening. Two hypotheses have been proposed to explain the time of day changes in CBFV: 1 CBFV changes are due to sleep-associated processes or 2 time of day changes in CBFV are due to an endogenous circadian rhythm independent of sleep. The aim of this study was to examine CBFV over 30 hours of sustained wakefulness to determine whether CBFV exhibits fluctuations associated with time of day. Methods Eleven subjects underwent a modified constant routine protocol. CBFV from the middle cerebral artery was monitored by chronic recording of Transcranial Doppler (TCD ultrasonography. Other variables included core body temperature (CBT, end-tidal carbon dioxide (EtCO2, blood pressure, and heart rate. Salivary dim light melatonin onset (DLMO served as a measure of endogenous circadian phase position. Results A non-linear multiple regression, cosine fit analysis revealed that both the CBT and CBFV rhythm fit a 24 hour rhythm (R2 = 0.62 and R2 = 0.68, respectively. Circadian phase position of CBT occurred at 6:05 am while CBFV occurred at 12:02 pm, revealing a six hour, or 90 degree difference between these two rhythms (t = 4.9, df = 10, p Conclusion In conclusion, time of day variations in CBFV have an approximately 24 hour rhythm under constant conditions, suggesting regulation by a circadian oscillator. The 90 degree-phase angle difference between the CBT and CBFV rhythms may help explain previous findings of lower CBFV values in the morning. The phase difference occurs at a time period during which cognitive performance decrements have been observed and when both cardiovascular and cerebrovascular events occur more frequently. The mechanisms underlying this phase angle difference require further exploration.

  11. Neural Oscillations Carry Speech Rhythm through to Comprehension.

    Science.gov (United States)

    Peelle, Jonathan E; Davis, Matthew H

    2012-01-01

    A key feature of speech is the quasi-regular rhythmic information contained in its slow amplitude modulations. In this article we review the information conveyed by speech rhythm, and the role of ongoing brain oscillations in listeners' processing of this content. Our starting point is the fact that speech is inherently temporal, and that rhythmic information conveyed by the amplitude envelope contains important markers for place and manner of articulation, segmental information, and speech rate. Behavioral studies demonstrate that amplitude envelope information is relied upon by listeners and plays a key role in speech intelligibility. Extending behavioral findings, data from neuroimaging - particularly electroencephalography (EEG) and magnetoencephalography (MEG) - point to phase locking by ongoing cortical oscillations to low-frequency information (~4-8 Hz) in the speech envelope. This phase modulation effectively encodes a prediction of when important events (such as stressed syllables) are likely to occur, and acts to increase sensitivity to these relevant acoustic cues. We suggest a framework through which such neural entrainment to speech rhythm can explain effects of speech rate on word and segment perception (i.e., that the perception of phonemes and words in connected speech is influenced by preceding speech rate). Neuroanatomically, acoustic amplitude modulations are processed largely bilaterally in auditory cortex, with intelligible speech resulting in differential recruitment of left-hemisphere regions. Notable among these is lateral anterior temporal cortex, which we propose functions in a domain-general fashion to support ongoing memory and integration of meaningful input. Together, the reviewed evidence suggests that low-frequency oscillations in the acoustic speech signal form the foundation of a rhythmic hierarchy supporting spoken language, mirrored by phase-locked oscillations in the human brain.

  12. Cortical Activity during Perception of Musical Rhythm; Comparing Musicians and Non-musicians.

    Science.gov (United States)

    Habibi, Assal; Wirantana, Vinthia; Starr, Arnold

    2014-06-01

    This study investigates the effects of musical training on brain activity to violations of rhythmic expectancies. We recorded behavioral and event-related brain potential (ERP) responses of musicians and non-musicians to discrepancies of rhythm between pairs of unfamiliar melodies based on Western classical rules. Rhythm deviations in the second melody involved prolongation of a note, thus creating a delay in the subsequent note; the duration of the second note was consequently shorter because the offset time was unchanged. In the first melody, on the other hand, the two notes were of equal duration. Musicians detected rhythm deviations significantly better than non-musicians. A negative auditory cortical potential in response to the omitted stimulus was observed at a latency of 150-250 ms from where the note should have been. There were no significant differences of amplitude or latency between musicians and non-musicians. In contrast, the N100 and P200 to the delayed note after the omission were significantly greater in amplitude in musicians compared to non-musicians especially in frontal and frontal-central areas. These findings indicate that long term musical training enhances brain cortical activities involved in processing temporal irregularities of unfamiliar melodies.

  13. Analysis of Rhythms in Experimental Signals

    Science.gov (United States)

    Desherevskii, A. V.; Zhuravlev, V. I.; Nikolsky, A. N.; Sidorin, A. Ya.

    2017-12-01

    We compare algorithms designed to extract quasiperiodic components of a signal and estimate the amplitude, phase, stability, and other characteristics of a rhythm in a sliding window in the presence of data gaps. Each algorithm relies on its own rhythm model; therefore, it is necessary to use different algorithms depending on the research objectives. The described set of algorithms and methods is implemented in the WinABD software package, which includes a time-series database management system, a powerful research complex, and an interactive data-visualization environment.

  14. Disruption of gene expression rhythms in mice lacking secretory vesicle proteins IA-2 and IA-2β.

    Science.gov (United States)

    Punia, Sohan; Rumery, Kyle K; Yu, Elizabeth A; Lambert, Christopher M; Notkins, Abner L; Weaver, David R

    2012-09-15

    Insulinoma-associated protein (IA)-2 and IA-2β are transmembrane proteins involved in neurotransmitter secretion. Mice with targeted disruption of both IA-2 and IA-2β (double-knockout, or DKO mice) have numerous endocrine and physiological disruptions, including disruption of circadian and diurnal rhythms. In the present study, we have assessed the impact of disruption of IA-2 and IA-2β on molecular rhythms in the brain and peripheral oscillators. We used in situ hybridization to assess molecular rhythms in the hypothalamic suprachiasmatic nuclei (SCN) of wild-type (WT) and DKO mice. The results indicate significant disruption of molecular rhythmicity in the SCN, which serves as the central pacemaker regulating circadian behavior. We also used quantitative PCR to assess gene expression rhythms in peripheral tissues of DKO, single-knockout, and WT mice. The results indicate significant attenuation of gene expression rhythms in several peripheral tissues of DKO mice but not in either single knockout. To distinguish whether this reduction in rhythmicity reflects defective oscillatory function in peripheral tissues or lack of entrainment of peripheral tissues, animals were injected with dexamethasone daily for 15 days, and then molecular rhythms were assessed throughout the day after discontinuation of injections. Dexamethasone injections improved gene expression rhythms in liver and heart of DKO mice. These results are consistent with the hypothesis that peripheral tissues of DKO mice have a functioning circadian clockwork, but rhythmicity is greatly reduced in the absence of robust, rhythmic physiological signals originating from the SCN. Thus, IA-2 and IA-2β play an important role in the regulation of circadian rhythms, likely through their participation in neurochemical communication among SCN neurons.

  15. [Atypical etiology of rhinorrhea: spontaneous bilateral temporal encephalocele].

    Science.gov (United States)

    Lorente Muñoz, Asís; Lisbona Alquézar, María Pilar; González Martínez, Luis; Sevil Navarro, Jorge; Llorente Arenas, Eva María

    2012-01-01

    Spontaneous herniation of brain parenchyma through a dural and osseous defect in the temporal bone is a rare entity and a bilateral form is even more infrequent. It usually presents as an intermittent but persistent otorrhea. Manifestation as nose cerebrospinal fluid (CSF) leak is very uncommon. Our objective is presenting this unusual case report of a spontaneous bilateral encephalocele with a bilateral tegmen tympani defect. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  16. Circadian rhythm and sleep influences on digestive physiology and disorders

    OpenAIRE

    Vaughn, Bradley; Rotolo,Sean; Roth,Heidi

    2014-01-01

    Bradley V Vaughn, Sean Rotolo, Heidi L Roth Division of Sleep Medicine, Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA Abstract: Circadian rhythms and sleep influence a variety of physiological functions, including the digestive system. The digestive system also has intrinsic rhythms that interact dynamically with circadian rhythms. New advances in understanding the interaction of these rhythms and sleep provide the prospect of evaluating their...

  17. Spontaneous Atraumatic Mediastinal Hemorrhage

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    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  18. Does Melody Assist in the Reproduction of Novel Rhythm Patterns?

    Science.gov (United States)

    Kinney, Daryl W.; Forsythe, Jere L.

    2013-01-01

    We examined music education majors' ability to reproduce rhythmic stimuli presented in melody and rhythm only conditions. Participants reproduced rhythms of two-measure music examples by immediately echo-performing through a method of their choosing (e.g., clapping, tapping, vocalizing). Forty examples were presented in melody and rhythm only…

  19. Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila

    Indian Academy of Sciences (India)

    A diverse range of organisms shows physiological and behavioural rhythms with various periods. Extensive studies have been performed to elucidate the molecular mechanisms of circadian rhythms with an approximately 24 h period in both Drosophila and mammals, while less attention has been paid to ultradian rhythms ...

  20. Monkey Lipsmacking Develops Like the Human Speech Rhythm

    Science.gov (United States)

    Morrill, Ryan J.; Paukner, Annika; Ferrari, Pier F.; Ghazanfar, Asif A.

    2012-01-01

    Across all languages studied to date, audiovisual speech exhibits a consistent rhythmic structure. This rhythm is critical to speech perception. Some have suggested that the speech rhythm evolved "de novo" in humans. An alternative account--the one we explored here--is that the rhythm of speech evolved through the modification of rhythmic facial…

  1. EFFECTS OF CIRCADIAN RHYTHM ON BALANCE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Karagul Osman

    2017-09-01

    Full Text Available Introduction. The aim of the study was to examine the effect of circadian rhythm on dynamic balance performance and to determine the role of physical activity level, body temperature, chronotype, and gender in this possible effect. Material and

  2. Makin' Music: Songs, Rhythm, and Creative Expression.

    Science.gov (United States)

    Lieberstein, Terry

    1996-01-01

    The power of music to create a coherent group is amazing. Music can be used to help focus attention, encourage group unity, involve everyone, and allow creative self-expression. Discusses different song styles, simple rhythm instruments, and song writing. Song-leading tips include song choice, teaching techniques, motions, song sheets, and three…

  3. Fourier Analysis and the Rhythm of Conversation.

    Science.gov (United States)

    Dabbs, James M., Jr.

    Fourier analysis, a common technique in engineering, breaks down a complex wave form into its simple sine wave components. Communication researchers have recently suggested that this technique may provide an index of the rhythm of conversation, since vocalizing and pausing produce a complex wave form pattern of alternation between two speakers. To…

  4. Circadian rhythms: from genes to behaviour

    Indian Academy of Sciences (India)

    located in the third ventricle of the hypothalamus by two independent groups: F. K. Stephan and Irvin ... levels of biological organization, and we have tried to represent this aspect of our discipline in this special ... nature of circadian rhythm research, because at the core of all these studies lies a genetic architecture which.

  5. Sleep and rhythm consequences of a genetically induced loss of serotonin.

    Science.gov (United States)

    Leu-Semenescu, Smaranda; Arnulf, Isabelle; Decaix, Caroline; Moussa, Fathi; Clot, Fabienne; Boniol, Camille; Touitou, Yvan; Levy, Richard; Vidailhet, Marie; Roze, Emmanuel

    2010-03-01

    A genetic deficiency in sepiapterin reductase leads to a combined deficit of serotonin and dopamine. The motor phenotype is characterized by a dopa-responsive fluctuating generalized dystonia-parkinsonism. The non-motor symptoms are poorly recognized. In particular, the effects of brain serotonin deficiency on sleep have not been thoroughly studied. We examine the sleep, sleep-wake rhythms, CSF neurotransmitters, and melatonin profile in a patient with sepiapterin reductase deficiency. The patient was a 28-year-old man with fluctuating generalized dystonia-parkinsonism caused by sepiapterin reductase deficiency. A sleep interview, wrist actigraphy, sleep log over 14 days, 48-h continuous sleep and core temperature monitoring, and measurement of CSF neurotransmitters and circadian serum melatonin and cortisol levels before and after treatment with 5-hydroxytryptophan (the precursor of serotonin) and levodopa were performed. Before treatment, the patient had mild hypersomnia with long sleep time (704 min), ultradian sleep-wake rhythm (sleep occurred every 11.8 +/- 5.3 h), organic hyperphagia, attentionlexecutive dysfunction, and no depression. The serotonin metabolism in the CSF was reduced, and the serum melatonin profile was flat, while cortisol and core temperature profiles were normal. Supplementation with 5-hydroxytryptophan, but not with levodopa, normalized serotonin metabolism in the CSF, reduced sleep time to 540 min, normalized the eating disorder and the melatonin profile, restored a circadian sleep-wake rhythm (sleep occurred every 24 +/- 1.7 h, P lack of its substrate, serotonin) may cause the ultradian sleep-wake rhythm.

  6. Circadian and feeding rhythms differentially affect rhythmic mRNA transcription and translation in mouse liver

    Science.gov (United States)

    Atger, Florian; Gobet, Cédric; Marquis, Julien; Martin, Eva; Wang, Jingkui; Weger, Benjamin; Lefebvre, Grégory; Descombes, Patrick; Naef, Felix; Gachon, Frédéric

    2015-01-01

    Diurnal oscillations of gene expression are a hallmark of rhythmic physiology across most living organisms. Such oscillations are controlled by the interplay between the circadian clock and feeding rhythms. Although rhythmic mRNA accumulation has been extensively studied, comparatively less is known about their transcription and translation. Here, we quantified simultaneously temporal transcription, accumulation, and translation of mouse liver mRNAs under physiological light–dark conditions and ad libitum or night-restricted feeding in WT and brain and muscle Arnt-like 1 (Bmal1)-deficient animals. We found that rhythmic transcription predominantly drives rhythmic mRNA accumulation and translation for a majority of genes. Comparison of wild-type and Bmal1 KO mice shows that circadian clock and feeding rhythms have broad impact on rhythmic gene expression, Bmal1 deletion affecting surprisingly both transcriptional and posttranscriptional levels. Translation efficiency is differentially regulated during the diurnal cycle for genes with 5′-Terminal Oligo Pyrimidine tract (5′-TOP) sequences and for genes involved in mitochondrial activity, many harboring a Translation Initiator of Short 5′-UTR (TISU) motif. The increased translation efficiency of 5′-TOP and TISU genes is mainly driven by feeding rhythms but Bmal1 deletion also affects amplitude and phase of translation, including TISU genes. Together this study emphasizes the complex interconnections between circadian and feeding rhythms at several steps ultimately determining rhythmic gene expression and translation. PMID:26554015

  7. Bridging music and speech rhythm: rhythmic priming and audio-motor training affect speech perception.

    Science.gov (United States)

    Cason, Nia; Astésano, Corine; Schön, Daniele

    2015-02-01

    Following findings that musical rhythmic priming enhances subsequent speech perception, we investigated whether rhythmic priming for spoken sentences can enhance phonological processing - the building blocks of speech - and whether audio-motor training enhances this effect. Participants heard a metrical prime followed by a sentence (with a matching/mismatching prosodic structure), for which they performed a phoneme detection task. Behavioural (RT) data was collected from two groups: one who received audio-motor training, and one who did not. We hypothesised that 1) phonological processing would be enhanced in matching conditions, and 2) audio-motor training with the musical rhythms would enhance this effect. Indeed, providing a matching rhythmic prime context resulted in faster phoneme detection, thus revealing a cross-domain effect of musical rhythm on phonological processing. In addition, our results indicate that rhythmic audio-motor training enhances this priming effect. These results have important implications for rhythm-based speech therapies, and suggest that metrical rhythm in music and speech may rely on shared temporal processing brain resources. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. From Biological Rhythms to Social Rhythms: Physiological Precursors of Mother-Infant Synchrony

    Science.gov (United States)

    Feldman, Ruth

    2006-01-01

    Links between neonatal biological rhythms and the emergence of interaction rhythms were examined in 3 groups (N=71): high-risk preterms (HR; birth weight less than 1,000 g), low-risk preterms (LR; birth weight=1,700-1,850 g), and full-term (FT) infants. Once a week for premature infants and on the 2nd day for FT infants, sleep-wake cyclicity was…

  9. Biologic rhythms derived from Siberian mammoths' hairs.

    Science.gov (United States)

    Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto

    2011-01-01

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  10. Biologic rhythms derived from Siberian mammoths' hairs.

    Directory of Open Access Journals (Sweden)

    Mike Spilde

    Full Text Available Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios, which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  11. Beat Keeping in a Sea Lion as Coupled Oscillation: Implications for Comparative Understanding of Human Rhythm

    Directory of Open Access Journals (Sweden)

    Andrew A Rouse

    2016-06-01

    Full Text Available Human capacity for entraining movement to external rhythms—i.e., beat keeping—is ubiquitous, but its evolutionary history and neural underpinnings remain a mystery. Recent findings of entrainment to simple and complex rhythms in non-human animals pave the way for a novel comparative approach to assess the origins and mechanisms of rhythmic behavior. The most reliable non-human beat keeper to date is a California sea lion, Ronan, who was trained to match head movements to isochronous repeating stimuli and showed spontaneous generalization of this ability to novel tempos and to the complex rhythms of music. Does Ronan’s performance rely on the same neural mechanisms as human rhythmic behavior? In the current study, we presented Ronan with simple rhythmic stimuli at novel tempos. On some trials, we introduced perturbations, altering either tempo or phase in the middle of a presentation. Ronan quickly adjusted her behavior following all perturbations, recovering her consistent phase and tempo relationships to the stimulus within a few beats. Ronan’s performance was consistent with predictions of mathematical models describing coupled oscillation: a model relying solely on phase coupling strongly matched her behavior, and the model was further improved with the addition of period coupling. These findings are the clearest evidence yet for parity in human and non-human beat keeping and support the view that the human ability to perceive and move in time to rhythm may be rooted in broadly conserved neural mechanisms.

  12. Control of hippocampal theta rhythm by serotonin: role of 5-HT2c receptors.

    Science.gov (United States)

    Sörman, Elin; Wang, Dannie; Hajos, Mihaly; Kocsis, Bernat

    2011-09-01

    The hippocampus plays an important role in learning and memory and has been implicated in a number of diseases, including epilepsy, anxiety and schizophrenia. A prominent feature of the hippocampal network is the capability to generate rhythmic oscillations. Serotonergic modulation is known to play an important role in the regulation of theta rhythm. 5-HT2c receptors represent a specific target of psychopharmacology and, in particular, the behavioral effects of the 5-HT2c receptor agonist mCPP have been thoroughly tested. The present study used this compound and the selective 5-HT2c receptor antagonist SB-242084 to elucidate the role of 5-HT2c receptors in the generation of hippocampal oscillations. Hippocampal EEG was recorded and the power in the theta frequency range was monitored in different behaviors in freely-moving rats and after brainstem stimulation in anesthetized animals. We found that in freely-moving rats, mCPP suppressed hippocampal theta rhythm and the effect was stronger during REM sleep than during waking theta states. Under urethane anesthesia, mCPP decreased the power for both spontaneous and elicited theta rhythm in a dose-dependent manner and the 5-HT2c antagonist reversed this effect. The results of this study demonstrate that 5-HT2c receptors are important element of the serotonergic modulation of hippocampal theta oscillations and thus pharmacological interactions with these receptors can modulate physiological and pathological processes associated with limbic theta activity. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Spontaneous Appendicocutaneous Fistula I

    African Journals Online (AJOL)

    M T0k0de* MB, BS and. Dr 0. A. AWOj0bi+ FMCS (Nig). ABSTRACT. Ruptured appendicitis is not a common cause of spontaneous enterocutaneous fistula. A case of ruptured retrocaecal appendicitis presenting as an enterocutaneous fistula in a Nigerian woman is presented. The literature on this disorder is also reviewed.

  14. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  15. Spontaneous Grammar Explanations.

    Science.gov (United States)

    Tjoo, Hong Sing; Lewis, Marilyn

    1998-01-01

    Describes one New Zealand university language teacher's reflection on her own grammar explanations to university-level students of Bahasa Indonesian. Examines form-focused instruction through the teacher's spontaneous answers to students' questions about the form of the language they are studying. The teacher's experiences show that it takes time…

  16. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  17. Spontaneous dimensional reduction?

    Science.gov (United States)

    Carlip, Steven

    2012-10-01

    Over the past few years, evidence has begun to accumulate suggesting that spacetime may undergo a "spontaneous dimensional reduction" to two dimensions near the Planck scale. I review some of this evidence, and discuss the (still very speculative) proposal that the underlying mechanism may be related to short-distance focusing of light rays by quantum fluctuations.

  18. Serotonin Modulation of Prefronto-Hippocampal Rhythms in Health and Disease.

    Science.gov (United States)

    Puig, M Victoria; Gener, Thomas

    2015-07-15

    There is mounting evidence that most cognitive functions depend upon the coordinated activity of neuronal networks often located far from each other in the brain. Ensembles of neurons synchronize their activity, generating oscillations at different frequencies that may encode behavior by allowing an efficient communication between brain areas. The serotonin system, by virtue of the widespread arborisation of serotonergic neurons, is in an excellent position to exert strong modulatory actions on brain rhythms. These include specific oscillatory activities in the prefrontal cortex and the hippocampus, two brain areas essential for many higher-order cognitive functions. Psychiatric patients show abnormal oscillatory activities in these areas, notably patients with schizophrenia who display psychotic symptoms as well as affective and cognitive impairments. Synchronization of neural activity between the prefrontal cortex and the hippocampus seems to be important for cognition and, in fact, reduced prefronto-hippocampal synchrony has been observed in a genetic mouse model of schizophrenia. Here, we review recent advances in the field of neuromodulation of brain rhythms by serotonin, focusing on the actions of serotonin in the prefrontal cortex and the hippocampus. Considering that the serotonergic system plays a crucial role in cognition and mood and is a target of many psychiatric treatments, it is surprising that this field of research is still in its infancy. In that regard, we point to future investigations that are much needed in this field.

  19. Effects of pacifier and taste on swallowing, esophageal motility, transit, and respiratory rhythm in human neonates.

    Science.gov (United States)

    Shubert, T R; Sitaram, S; Jadcherla, S R

    2016-04-01

    Pacifier use is widely prevalent globally despite hygienic concerns and uncertain mechanistic effects on swallowing or airway safety. The effects of pacifier and taste interventions on pharyngo-esophageal motility, bolus transit, and respiratory rhythms were investigated by determining the upper esophageal sphincter (UES), esophageal body, esophagogastric junction (EGJ) motor patterns and deglutition apnea, respiratory rhythm disturbances, and esophageal bolus clearance. Fifteen infants (six males; median gestation 31 weeks and birth weight 1.4 kg) underwent high-resolution impedance manometry at 43 (41-44) weeks postmenstrual age. Manometric, respiratory, and impedance characteristics of spontaneous swallows, pacifier-associated dry swallowing and taste (pacifier dipped in 3% sucrose)-associated swallowing were analyzed. Linear mixed and generalized estimating equation models were used. Data are presented as mean ± SEM, %, or median (IQR). Pharyngo-esophageal motility, respiratory, and impedance characteristics of 209 swallows were analyzed (85 spontaneous swallows, 63 pacifier- swallows, 61 taste- swallows). Basal UES and EGJ pressures decreased upon pacifier (p pacifier or taste interventions decreases UES and EGJ basal pressure, but has no effects on pharyngo-esophageal motility, airway interactions, or esophageal bolus transit. A decrease in central parasympathetic-cholinergic excitatory drive is likely responsible for the basal effects. © 2016 John Wiley & Sons Ltd.

  20. [Interpersonal and social rhythm therapy (IPSRT)].

    Science.gov (United States)

    Bottai, T; Biloa-Tang, M; Christophe, S; Dupuy, C; Jacquesy, L; Kochman, F; Meynard, J-A; Papeta, D; Rahioui, H; Adida, M; Fakra, E; Kaladjian, A; Pringuey, D; Azorin, J-M

    2010-12-01

    Bipolar disorder is common, recurrent, often severe and debiliting disorder. All types of bipolar disorder have a common determinant: depressive episode. It is justify to propose a psychotherapy which shown efficacy in depression. Howewer, perturbations in circadian rhythms have been implicated in the genesis of each episode of the illness. Biological circadian dysregulation can be encouraged by alteration of time-givers (Zeitgebers) or occurrence of time-disturbers (Zeitstörers). Addition of social rhythm therapy to interpersonal psychotherapy leads to create a new psychotherapy adaptated to bipolar disorders: InterPersonal and Social Rhythm Therapy (IPSRT). IPSRT, in combinaison with medication, has demonstrated efficacy as a treatment for bipolar disorders. IPSRT combines psychoeducation, behavioral strategy to regularize daily routines and interpersonal psychotherapy which help patients cope better with the multiple psychosocial and relationship problems associated with this chronic disorder. The main issues of this psychotherapy are: to take the history of the patient's illness and review of medication, to help patient for "grief for the lost healthy self" translated in the french version in "acceptance of a long-term medical condition", to give the sick role, to examinate the current relationships and changes proximal to the emergence of mood symptoms in the four problem areas (unresolved grief, interpersonal disputes, role transitions, role déficits), to examinate and increase daily routines and social rhythms. French version of IPSRT called TIPARS (with few differences), a time-limited psychotherapy, in 24 sessions during approximatively 6 months, is conducted in three phases. In the initial phase, the therapist takes a thorough history of previous episodes and their interpersonal context and a review of previous medication, provides psychoeducation, evaluates social rhythms, introduces the Social Rhythm Metric, identifies the patient's main interpersonal

  1. An Overview of Monthly Rhythms and Clocks

    Directory of Open Access Journals (Sweden)

    Florian Raible

    2017-05-01

    Full Text Available Organisms have evolved to cope with geophysical cycles of different period lengths. In this review, we focus on the adaptations of animals to the lunar cycle, specifically, on the occurrence of biological rhythms with monthly (circalunar or semi-monthly (circasemilunar period lengths. Systematic experimental investigation, starting in the early twentieth century, has allowed scientists to distinguish between mythological belief and scientific facts concerning the influence of the lunar cycle on animals. These studies revealed that marine animals of various taxa exhibit circalunar or circasemilunar reproductive rhythms. Some of these rely on endogenous oscillators (circalunar or circasemilunar clocks, whereas others are directly driven by external cues, such as the changes in nocturnal illuminance. We review current insight in the molecular and cellular mechanisms involved in circalunar rhythms, focusing on recent work in corals, annelid worms, midges, and fishes. In several of these model systems, the transcript levels of some core circadian clock genes are affected by both light and endogenous circalunar oscillations. How these and other molecular changes relate to the changes in physiology or behavior over the lunar cycle remains to be determined. We further review the possible relevance of circalunar rhythms for terrestrial species, with a particular focus on mammalian reproduction. Studies on circalunar rhythms of conception or birth rates extend to humans, where the lunar cycle was suggested to also affect sleep and mental health. While these reports remain controversial, factors like the increase in “light pollution” by artificial light might contribute to discrepancies between studies. We finally discuss the existence of circalunar oscillations in mammalian physiology. We speculate that these oscillations could be the remnant of ancient circalunar oscillators that were secondarily uncoupled from a natural entrainment mechanism, but

  2. Work related injuries; impact of circadian rhythm

    Directory of Open Access Journals (Sweden)

    Mostafa Hosseini

    2017-04-01

    Full Text Available Work related injuries make up a major part of traumatic injuries, which inflict a financial burden and huge costs on the family and society. Work related injuries result in loss of a work force of a country on one hand and cause the family to lose its financial support on the other. Therefore, this type of injury has attracted much attention. Although numerous variables play a role in occurrence of these accidents, the effect of physiologic factors cannot be overlooked in this regard. For example interference of night working shifts with the natural circadian rhythm of the body is among these factors. Age, decreased physical strength, tiredness and extent of light are among other factors that affect the level of consciousness in an individual and may lead to work related traumas. In recent years, the role of circadian rhythm in occurrence of work related traumas has been widely considered. Circadian rhythm is formed as a result of a number of clock genes in suprachiasmatic nucleus and other organs of the body. Circadian rhythm is associated with significant changes in hormone secretion and level of consciousness in an individual. Rhythms desynchrony is a phenomenon seen in those that work during the night and sleep during the day and is accompanied by increased risk of work related accidents. For example in a systematic review assessing 13 studies, it was revealed that working night shifts is associated with increased risk of work related accidents. However, there is still controversy regarding the net effect of night shifts in incidence of work related accidents. One question that has not been answered yet is that if an individual works night shifts for a long time, is their circadian rhythm affected or not? On the other hand, can using strategies that improve level of consciousness (such as using blue light in the work place decrease the incidence of these accidents? Are changes in sleep and wake conditions alone able to alter the expression

  3. Spontaneous healing of spontaneous coronary artery dissection.

    Science.gov (United States)

    Almafragi, Amar; Convens, Carl; Heuvel, Paul Van Den

    2010-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and sudden cardiac death. It should be suspected in every healthy young woman without cardiac risk factors, especially during the peripartum or postpartum periods. It is important to check for a history of drug abuse, collagen vascular disease or blunt trauma of the chest. Coronary angiography is essential for diagnosis and early management. We wonder whether thrombolysis might aggravate coronary dissection. All types of treatment (medical therapy, percutaneous intervention or surgery) improve the prognosis without affecting survival times if used appropriately according to the clinical stability and the angiographic features of the involved coronary arteries. Prompt recognition and targeted treatment improve outcomes. We report a case of SCAD in a young female free of traditional cardiovascular risk factors, who presented six hours after thrombolysis for ST elevation myocardial infarction. Coronary angiography showed a dissection of the left anterior descending and immediate branch. She had successful coronary artery bypass grafting, with complete healing of left anterior descending dissection.

  4. Brain volumetry and self-regulation of brain activity relevant for neurofeedback.

    Science.gov (United States)

    Ninaus, M; Kober, S E; Witte, M; Koschutnig, K; Neuper, C; Wood, G

    2015-09-01

    Neurofeedback is a technique to learn to control brain signals by means of real time feedback. In the present study, the individual ability to learn two EEG neurofeedback protocols - sensorimotor rhythm and gamma rhythm - was related to structural properties of the brain. The volumes in the anterior insula bilaterally, left thalamus, right frontal operculum, right putamen, right middle frontal gyrus, and right lingual gyrus predicted the outcomes of sensorimotor rhythm training. Gray matter volumes in the supplementary motor area and left middle frontal gyrus predicted the outcomes of gamma rhythm training. These findings combined with further evidence from the literature are compatible with the existence of a more general self-control network, which through self-referential and self-control processes regulates neurofeedback learning. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Cortical plasticity induced by short-term multimodal musical rhythm training.

    Directory of Open Access Journals (Sweden)

    Claudia Lappe

    Full Text Available Performing music is a multimodal experience involving the visual, auditory, and somatosensory modalities as well as the motor system. Therefore, musical training is an excellent model to study multimodal brain plasticity. Indeed, we have previously shown that short-term piano practice increase the magnetoencephalographic (MEG response to melodic material in novice players. Here we investigate the impact of piano training using a rhythmic-focused exercise on responses to rhythmic musical material. Musical training with non musicians was conducted over a period of two weeks. One group (sensorimotor-auditory, SA learned to play a piano sequence with a distinct musical rhythm, another group (auditory, A listened to, and evaluated the rhythmic accuracy of the performances of the SA-group. Training-induced cortical plasticity was evaluated using MEG, comparing the mismatch negativity (MMN in response to occasional rhythmic deviants in a repeating rhythm pattern before and after training. The SA-group showed a significantly greater enlargement of MMN and P2 to deviants after training compared to the A- group. The training-induced increase of the rhythm MMN was bilaterally expressed in contrast to our previous finding where the MMN for deviants in the pitch domain showed a larger right than left increase. The results indicate that when auditory experience is strictly controlled during training, involvement of the sensorimotor system and perhaps increased attentional recources that are needed in producing rhythms lead to more robust plastic changes in the auditory cortex compared to when rhythms are simply attended to in the auditory domain in the absence of motor production.

  6. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  7. Working night shifts affects surgeons' biological rhythm

    DEFF Research Database (Denmark)

    Amirian, Ilda; Andersen, Lærke T; Rosenberg, Jacob

    2015-01-01

    BACKGROUND: Chronic sleep deprivation combined with work during the night is known to affect performance and compromise residents' own safety. The aim of this study was to examine markers of circadian rhythm and the sleep-wake cycle in surgeons working night shifts. METHODS: Surgeons were monitored...... prospectively for 4 days: pre call, on call, post call day 1 (PC1), and post call day 2 (PC2). The urinary metabolite of melatonin and cortisol in saliva were measured to assess the circadian rhythm. Sleep and activity were measured by actigraphy. Subjective measures were assessed by the Karolinska Sleepiness...... Scale and Visual Analog Scale of fatigue, general well-being, and sleep quality. RESULTS: For both metabolite of melatonin and cortisol, a significant difference (P sleep time during the day on call...

  8. Sleep, circadian rhythms, and athletic performance.

    Science.gov (United States)

    Thun, Eirunn; Bjorvatn, Bjørn; Flo, Elisabeth; Harris, Anette; Pallesen, Ståle

    2015-10-01

    Sleep deprivation and time of day are both known to influence performance. A growing body of research has focused on how sleep and circadian rhythms impact athletic performance. This review provides a systematic overview of this research. We searched three different databases for articles on these issues and inspected relevant reference lists. In all, 113 articles met our inclusion criteria. The most robust result is that athletic performance seems to be best in the evening around the time when the core body temperature typically is at its peak. Sleep deprivation was negatively associated with performance whereas sleep extension seems to improve performance. The effects of desynchronization of circadian rhythms depend on the local time at which performance occurs. The review includes a discussion of differences regarding types of skills involved as well as methodological issues. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Increased beta rhythm as an indicator of inhibitory mechanisms in tourette syndrome

    DEFF Research Database (Denmark)

    Niccolai, Valentina; van Dijk, Hanneke; Franzkowiak, Stephanie

    2016-01-01

    BACKGROUND: Inhibitory oscillatory mechanisms subserving tic compensation have been put forward in Tourette syndrome. Modulation of the beta rhythm (15-25 Hz) as the well-established oscillatory movement execution-inhibition indicator was tested during a cognitive-motor task in patients with Tour...... that stronger inhibitory compensation accompanies less tic severity. © 2016 International Parkinson and Movement Disorder Society.......BACKGROUND: Inhibitory oscillatory mechanisms subserving tic compensation have been put forward in Tourette syndrome. Modulation of the beta rhythm (15-25 Hz) as the well-established oscillatory movement execution-inhibition indicator was tested during a cognitive-motor task in patients...... in parieto-occipital brain regions contralaterally to the response hand. Average beta power and power gain correlated negatively with tic severity. CONCLUSIONS: Increased motor inhibitory as well as visuomotor attentional processes are likely to subserve tic compensation. Correlational results suggest...

  10. Daily rhythms of benzodiazepine receptor numbers in frontal lobe and cerebellum of the rat

    International Nuclear Information System (INIS)

    Brennan, M.J.W.; Volicer, L.; Moore-Ede, M.C.; Borsook, D.

    1985-01-01

    Behavioral, biochemical and neurophysiological evidence suggests that gamma-aminobutyric acid (GABA) may play an important role in the neural control of circadian rhythms. Central receptors for benzodiazepines are functionally coupled to GABA receptors and appear to mediate behavioral effects of exogenous benzodiazepines. The binding of 3 H-flunitrazepam to synaptic plasma membranes prepared from various regions of rat brain was examined at 6-hour intervals over a 36-hour period. Prominent daily rhythms in receptor number (Bmax) were observed in the frontal lobe and the cerebellum but not in the temporoparietal regions, hypothalamus or medulla/pons. Binding was highest during periods of sleep/low activity with a significant decrease occurring just prior to waking. These results suggest that daily fluctuations in benzodiazepine receptor numbers may be related to the temporal control of sleep/wake and muscle activity cycles. 23 references, 1 figure, 1 table

  11. Hypophysectomy abolishes rhythms in rat thyroid hormones but not in the thyroid clock

    DEFF Research Database (Denmark)

    Fahrenkrug, J; Georg, B; Hannibal, J

    2017-01-01

    The endocrine body rhythms including the hypothalamic-pituitary-thyroid axis seem to be regulated by the circadian timing system, and daily rhythmicity of circulating thyroid-stimulating hormone (TSH) is well established. The circadian rhythms are generated by endogenous clocks in the central brain...... oscillator located in the hypothalamic suprachiasmatic nucleus (SCN) as well as multiple peripheral clocks, but information on the existence and function of a thyroid clock is limited. The molecular machinery in all clock cells is composed of a number of clock genes and their gene products are connected...... by autoregulatory feedback loops. Here, we provide evidence for a thyroid clock in the rat by demonstrating 24-h antiphase oscillations for the mRNA of the canonical clock genes Per1 and Bmal1, which was unaffected by hypophysectomy. By immunostaining, we supported the existence of a core oscillator...

  12. Circadian rhythms of women with fibromyalgia

    Science.gov (United States)

    Klerman, E. B.; Goldenberg, D. L.; Brown, E. N.; Maliszewski, A. M.; Adler, G. K.

    2001-01-01

    Fibromyalgia syndrome is a chronic and debilitating disorder characterized by widespread nonarticular musculoskeletal pain whose etiology is unknown. Many of the symptoms of this syndrome, including difficulty sleeping, fatigue, malaise, myalgias, gastrointestinal complaints, and decreased cognitive function, are similar to those observed in individuals whose circadian pacemaker is abnormally aligned with their sleep-wake schedule or with local environmental time. Abnormalities in melatonin and cortisol, two hormones whose secretion is strongly influenced by the circadian pacemaker, have been reported in women with fibromyalgia. We studied the circadian rhythms of 10 women with fibromyalgia and 12 control healthy women. The protocol controlled factors known to affect markers of the circadian system, including light levels, posture, sleep-wake state, meals, and activity. The timing of the events in the protocol were calculated relative to the habitual sleep-wake schedule of each individual subject. Under these conditions, we found no significant difference between the women with fibromyalgia and control women in the circadian amplitude or phase of rhythms of melatonin, cortisol, and core body temperature. The average circadian phases expressed in hours posthabitual bedtime for women with and without fibromyalgia were 3:43 +/- 0:19 and 3:46 +/- 0:13, respectively, for melatonin; 10:13 +/- 0:23 and 10:32 +/- 0:20, respectively for cortisol; and 5:19 +/- 0:19 and 4:57 +/- 0:33, respectively, for core body temperature phases. Both groups of women had similar circadian rhythms in self-reported alertness. Although pain and stiffness were significantly increased in women with fibromyalgia compared with healthy women, there were no circadian rhythms in either parameter. We suggest that abnormalities in circadian rhythmicity are not a primary cause of fibromyalgia or its symptoms.

  13. Peroxiredoxins are conserved markers of circadian rhythms

    Science.gov (United States)

    Edgar, Rachel S.; Green, Edward W.; Zhao, Yuwei; van Ooijen, Gerben; Olmedo, Maria; Qin, Ximing; Xu, Yao; Pan, Min; Valekunja, Utham K.; Feeney, Kevin A.; Maywood, Elizabeth S.; Hastings, Michael H.; Baliga, Nitin S.; Merrow, Martha; Millar, Andrew J.; Johnson, Carl H.; Kyriacou, Charalambos P.; O’Neill, John S.; Reddy, Akhilesh B.

    2012-01-01

    Summary Cellular life emerged ~3.7 billion years ago. With scant exception, terrestrial organisms have evolved under predictable daily cycles due to the Earth’s rotation. The advantage conferred upon organisms that anticipate such environmental cycles has driven the evolution of endogenous circadian rhythms that tune internal physiology to external conditions. The molecular phylogeny of mechanisms driving these rhythms has been difficult to dissect because identified clock genes and proteins are not conserved across the domains of life: Bacteria, Archaea and Eukaryota. Here we show that oxidation-reduction cycles of peroxiredoxin proteins constitute a universal marker for circadian rhythms in all domains of life, by characterising their oscillations in a variety of model organisms. Furthermore, we explore the interconnectivity between these metabolic cycles and transcription-translation feedback loops of the clockwork in each system. Our results suggest an intimate co-evolution of cellular time-keeping with redox homeostatic mechanisms following the Great Oxidation Event ~2.5 billion years ago. PMID:22622569

  14. Circadian rhythms of melatonin and cortisol in manifest Huntington's disease and in acute cortical ischemic stroke.

    Science.gov (United States)

    Adamczak-Ratajczak, A; Kupsz, J; Owecki, M; Zielonka, D; Sowinska, A; Checinska-Maciejewska, Z; Krauss, H; Michalak, S; Gibas-Dorna, M

    2017-08-01

    Recent studies indicate disruptions to the circadian system in brain injury and neurodegeneration. The results, however, are often not consistent and limited by measurement of only one circadian marker and by infrequent sampling rates. In this study, we examined diurnal rhythmicity in different stages of Huntington (HD) disease and in patients with acute moderate ischemic stroke (AIS) outside the retinohypothalamic pathway by evaluating serum concentrations of melatonin and cortisol at twelve timepoints. All study participants were subjected to the same study protocol of 12-hour light/dark cycle and controlled room conditions. Using cosinor analysis of data and comparing the results with the controls we found melatonin phase delay with lowered amplitude and mesor in stage III HD patients. These changes coexisted with phase advanced rhythm and elevated values of mesor and amplitude for cortisol. Early and mid-stages of HD showed only a phase advance in cortisol secretion. In AIS the circadian rhythm of serum melatonin was sustained without any phase shift and exhibited more flattened profile (lowered mesor and amplitude values), while advanced rhythm with higher mesor for cortisol was present. In conclusion, 1) abnormal pattern of melatonin release in the late stages of HD and in moderate AIS occurs in conjunction with phase-advanced rhythm of cortisol; 2) changes observed in late stages of HD are similar to those that occur with ageing; 3) brain regions other than the presumptive retinopineal neural pathway may play an important role in the pineal production of melatonin in humans; 4) lesion in extrahypothalamic region is related to the strong adrenal stimulation in response to AIS.

  15. Basic Principles of Interpersonal Social Rhythm Therapy in Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Gokben Hizli Sayar

    2014-08-01

    Full Text Available Interpersonal Social Rhythm Therapy is a psychotherapy modality that helps the patient recognize the relationship between disruptions in social rhythms and the onset of previous episodes of psychiatric disorders. It uses psychoeducation and behavioral techniques to maintain social rhythm and sleep/wake regularity. It is closely related to and ldquo;social zeitgeber theory and rdquo; that emphasizes the importance that social rhythm regularity may play in synchronization of circadian rhythms in individuals with or at risk for bipolar spectrum disorders. Interpersonal and social rhythm therapy have been shown to stabilize social rhythms and enhance course and outcome in bipolar disorder. This review focuses on the theoretical principles and the basic steps of interpersonal and social rhythm therapy as a psychotherapy approach in bipolar disorder. PubMed, Scopus, Google Scholar databases were searched without temporal restriction. Search terms included interpersonal social rhythm therapy, bipolar, mood disorders. Abstracts were reviewed for relevance, and randomized controlled trials of interpersonal and social rhythm therapy in bipolar disorder selected. These researches also summarized on the final part of this review. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 438-446

  16. Biologic Rhythms Derived from Siberian Mammoths Hairs

    Energy Technology Data Exchange (ETDEWEB)

    M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller

    2011-12-31

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  17. Spontaneous calcium waves in Bergman glia increase with age and hypoxia and may reduce tissue oxygen

    DEFF Research Database (Denmark)

    Mathiesen, Claus; Brazhe, Alexey; Thomsen, Kirsten Joan

    2013-01-01

    loading with OGB-1/AM and SR101. We report that the occurrence of spontaneous waves is 20 times more frequent in the cerebellar cortex of aging as compared with adult mice, which correlated with a reduction in resting brain oxygen tension. In adult mice, spontaneous glial wave activity increased...... on reducing resting brain oxygen tension, and ATP-evoked glial waves reduced the tissue O(2) tension. Finally, although spontaneous Purkinje cell (PC) activity was not associated with increased glia wave activity, spontaneous glial waves did affect intracellular Ca(2+) activity in PCs. The increased wave...... activity during aging, as well as low resting brain oxygen tension, suggests a relationship between glial waves, brain energy homeostasis, and pathology....

  18. The influence of biological rhythms on host-parasite interactions.

    Science.gov (United States)

    Martinez-Bakker, Micaela; Helm, Barbara

    2015-06-01

    Biological rhythms, from circadian control of cellular processes to annual cycles in life history, are a main structural element of biology. Biological rhythms are considered adaptive because they enable organisms to partition activities to cope with, and take advantage of, predictable fluctuations in environmental conditions. A flourishing area of immunology is uncovering rhythms in the immune system of animals, including humans. Given the temporal structure of immunity, and rhythms in parasite activity and disease incidence, we propose that the intersection of chronobiology, disease ecology, and evolutionary biology holds the key to understanding host-parasite interactions. Here, we review host-parasite interactions while explicitly considering biological rhythms, and propose that rhythms: influence within-host infection dynamics and transmission between hosts, might account for diel and annual periodicity in host-parasite systems, and can lead to a host-parasite arms race in the temporal domain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Spontaneous Thigh Compartment Syndrome

    Directory of Open Access Journals (Sweden)

    Khan, Sameer K

    2011-02-01

    Full Text Available A young man presented with a painful and swollen thigh, without any history of trauma, illness, coagulopathic medication or recent exertional exercise. Preliminary imaging delineated a haematoma in the anterior thigh, without any fractures or muscle trauma. Emergent fasciotomies were performed. No pathology could be identified intra-operatively, or on follow-up imaging. A review of thigh compartment syndromes described in literature is presented in a table. Emergency physicians and traumatologists should be cognisant of spontaneous atraumatic presentations of thigh compartment syndrome, to ensure prompt referral and definitive management of this limb-threatening condition. [West J Emerg Med. 2011;12(1:134-138].

  20. Modeling brain resonance phenomena using a neural mass model.

    Directory of Open Access Journals (Sweden)

    Andreas Spiegler

    2011-12-01

    Full Text Available Stimulation with rhythmic light flicker (photic driving plays an important role in the diagnosis of schizophrenia, mood disorder, migraine, and epilepsy. In particular, the adjustment of spontaneous brain rhythms to the stimulus frequency (entrainment is used to assess the functional flexibility of the brain. We aim to gain deeper understanding of the mechanisms underlying this technique and to predict the effects of stimulus frequency and intensity. For this purpose, a modified Jansen and Rit neural mass model (NMM of a cortical circuit is used. This mean field model has been designed to strike a balance between mathematical simplicity and biological plausibility. We reproduced the entrainment phenomenon observed in EEG during a photic driving experiment. More generally, we demonstrate that such a single area model can already yield very complex dynamics, including chaos, for biologically plausible parameter ranges. We chart the entire parameter space by means of characteristic Lyapunov spectra and Kaplan-Yorke dimension as well as time series and power spectra. Rhythmic and chaotic brain states were found virtually next to each other, such that small parameter changes can give rise to switching from one to another. Strikingly, this characteristic pattern of unpredictability generated by the model was matched to the experimental data with reasonable accuracy. These findings confirm that the NMM is a useful model of brain dynamics during photic driving. In this context, it can be used to study the mechanisms of, for example, perception and epileptic seizure generation. In particular, it enabled us to make predictions regarding the stimulus amplitude in further experiments for improving the entrainment effect.

  1. Glioblastoma Multiforme Presenting as Spontaneous Intracerebral Hemorrhage

    Directory of Open Access Journals (Sweden)

    Cagatay Ozdol

    2014-06-01

    Full Text Available Brain tumors with concomitant intracerebral hemorrhage are rarely encountered. Hemorrhage as the initial presentation of a brain tumour may pose some diagnostic problems, especially if the tumour is small or the hemorrhage is abundant. We present a 47-year-old man who admitted to the emergency department with sudden onset headache, right blurred vision and gait disturbance. A non-contrast cranial computerized tomography scan performed immediately after his admission revealed a well circumscribed right occipitoparietal haematoma with intense peripheral edema causing compression of the ipsilateral ventricles. On 6th hour of his admission the patient%u2019s neurological status deteriorated and he subsequently underwent emergent craniotomy and microsurgical evacuation of the haematoma. The histopathological examination of the mass was consistent with a glioblastoma multiforme. Neoplasms may be hidden behind each case of spontaneous intracerebral hemorrhage. Histological sampling and investigation is mandatory in the presence of preoperative radiological features suggesting a neoplasm.

  2. Spontaneously emerging cortical representations of visual attributes

    Science.gov (United States)

    Kenet, Tal; Bibitchkov, Dmitri; Tsodyks, Misha; Grinvald, Amiram; Arieli, Amos

    2003-10-01

    Spontaneous cortical activity-ongoing activity in the absence of intentional sensory input-has been studied extensively, using methods ranging from EEG (electroencephalography), through voltage sensitive dye imaging, down to recordings from single neurons. Ongoing cortical activity has been shown to play a critical role in development, and must also be essential for processing sensory perception, because it modulates stimulus-evoked activity, and is correlated with behaviour. Yet its role in the processing of external information and its relationship to internal representations of sensory attributes remains unknown. Using voltage sensitive dye imaging, we previously established a close link between ongoing activity in the visual cortex of anaesthetized cats and the spontaneous firing of a single neuron. Here we report that such activity encompasses a set of dynamically switching cortical states, many of which correspond closely to orientation maps. When such an orientation state emerged spontaneously, it spanned several hypercolumns and was often followed by a state corresponding to a proximal orientation. We suggest that dynamically switching cortical states could represent the brain's internal context, and therefore reflect or influence memory, perception and behaviour.

  3. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  4. Resting state cortical oscillations of patients with Parkinson disease and with and without subthalamic deep brain stimulation: a magnetoencephalography study.

    Science.gov (United States)

    Cao, Chunyan; Li, Dianyou; Jiang, Tianxiao; Ince, Nuri Firat; Zhan, Shikun; Zhang, Jing; Sha, Zhiyi; Sun, Bomin

    2015-04-01

    In this study, we investigate the modification to cortical oscillations of patients with Parkinson disease (PD) by subthalamic deep brain stimulation (STN-DBS). Spontaneous cortical oscillations of patients with PD were recorded with magnetoencephalography during on and off subthalamic nucleus deep brain stimulation states. Several features such as average frequency, average power, and relative subband power in regions of interest were extracted in the frequency domain, and these features were correlated with Unified Parkinson Disease Rating Scale III evaluation. The same features were also investigated in patients with PD without surgery and healthy controls. Patients with Parkinson disease without surgery compared with healthy controls had a significantly lower average frequency and an increased average power in 1 to 48 Hz range in whole cortex. Higher relative power in theta and simultaneous decrease in beta and gamma over temporal and occipital were also observed in patients with PD. The Unified Parkinson Disease Rating Scale III rigidity score correlated with the average frequency and with the relative power of beta and gamma in frontal areas. During subthalamic nucleus deep brain stimulation, the average frequency increased significantly when stimulation was on compared with off state. In addition, the relative power dropped in delta, whereas it rose in beta over the whole cortex. Through the course of stimulation, the Unified Parkinson Disease Rating Scale III rigidity and tremor scores correlated with the relative power of alpha over left parietal. Subthalamic nucleus deep brain stimulation improves the symptoms of PD by suppressing the synchronization of alpha rhythm in somatomotor region.

  5. Musical rhythms in heart period dynamics: a cross-cultural and interdisciplinary approach to cardiac rhythms.

    Science.gov (United States)

    Bettermann, H; Amponsah, D; Cysarz, D; van Leeuwen, P

    1999-11-01

    The purpose of this study was to expand classic heart period analysis methods by techniques from ethnomusicology that explicitly take complex musical rhythm principles into consideration. The methods used are based on the theory of African music, the theory of symbolic dynamics, and combinatorial theory. Heart period tachograms from 192 24-h electrocardiograms of 96 healthy subjects were transformed into binary symbol sequences that were interpretable as elementary rhythmic (percussive) patterns, the time lines in African music. Using a hierarchical rhythm pattern scheme closely related to the Derler Rhythm Classification (from jazz theory), we calculated the predominance and stability of pattern classes. The results show that during sleep certain classes, specific to individuals, occurred in a cyclically recurrent manner and many times more often than expected. Simultaneously, other classes disappeared more or less completely. Moreover, the most frequent classes obviously originate from phase-locking processes in autonomic regulation (e.g., between respiratory and cardiac cycles). In conclusion, the new interdisciplinary method presented here demonstrates that heart period patterns, in particular those occurring during night sleep, can be interpreted as musical rhythms. This method may be of great potential use in music therapy research.

  6. Standing down Straight: Jump Rhythm Technique's Rhythm-Driven, Community-Directed Approach to Dance Education

    Science.gov (United States)

    Siegenfeld, Billy

    2009-01-01

    "Standing down straight" means to stand on two feet with both stability and relaxation. Using standing down straight as the foundation of class work, Jump Rhythm Technique offers a fresh alternative to conventional systems of dance study. It bases its pedagogy on three behaviors: grounding the body so that it can move with power and efficiency,…

  7. Reactivity of dogs' brain oscillations to visual stimuli measured with non-invasive electroencephalography.

    Directory of Open Access Journals (Sweden)

    Miiamaaria V Kujala

    Full Text Available Studying cognition of domestic dogs has gone through a renaissance within the last decades. However, although the behavioral studies of dogs are beginning to be common in the field of animal cognition, the neural events underlying cognition remain unknown. Here, we employed a non-invasive electroencephalography, with adhesive electrodes attached to the top of the skin, to measure brain activity of from 8 domestic dogs (Canis familiaris while they stayed still to observe photos of dog and human faces. Spontaneous oscillatory activity of the dogs, peaking in the sensors over the parieto-occipital cortex, was suppressed statistically significantly during visual task compared with resting activity at the frequency of 15-30 Hz. Moreover, a stimulus-induced low-frequency (~2-6 Hz suppression locked to the stimulus onset was evident at the frontal sensors, possibly reflecting a motor rhythm guiding the exploratory eye movements. The results suggest task-related reactivity of the macroscopic oscillatory activity in the dog brain. To our knowledge, the study is the first to reveal non-invasively measured reactivity of brain electrophysiological oscillations in healthy dogs, and it has been based purely on positive operant conditional training, without the need for movement restriction or medication.

  8. A brain-controlled lower-limb exoskeleton for human gait training

    Science.gov (United States)

    Liu, Dong; Chen, Weihai; Pei, Zhongcai; Wang, Jianhua

    2017-10-01

    Brain-computer interfaces have been a novel approach to translate human intentions into movement commands in robotic systems. This paper describes an electroencephalogram-based brain-controlled lower-limb exoskeleton for gait training, as a proof of concept towards rehabilitation with human-in-the-loop. Instead of using conventional single electroencephalography correlates, e.g., evoked P300 or spontaneous motor imagery, we propose a novel framework integrated two asynchronous signal modalities, i.e., sensorimotor rhythms (SMRs) and movement-related cortical potentials (MRCPs). We executed experiments in a biologically inspired and customized lower-limb exoskeleton where subjects (N = 6) actively controlled the robot using their brain signals. Each subject performed three consecutive sessions composed of offline training, online visual feedback testing, and online robot-control recordings. Post hoc evaluations were conducted including mental workload assessment, feature analysis, and statistics test. An average robot-control accuracy of 80.16% ± 5.44% was obtained with the SMR-based method, while estimation using the MRCP-based method yielded an average performance of 68.62% ± 8.55%. The experimental results showed the feasibility of the proposed framework with all subjects successfully controlled the exoskeleton. The current paradigm could be further extended to paraplegic patients in clinical trials.

  9. Brain and Music: An Intraoperative Stimulation Mapping Study of a Professional Opera Singer.

    Science.gov (United States)

    Riva, Marco; Casarotti, Alessandra; Comi, Alessandro; Pessina, Federico; Bello, Lorenzo

    2016-09-01

    Music is one of the most sophisticated and fascinating functions of the brain. Yet, how music is instantiated within the brain is not fully characterized. Singing is a peculiar aspect of music, in which both musical and linguistic skills are required to provide a merged vocal output. Identifying the neural correlates of this process is relevant for both clinical and research purposes. An adult white man with a presumed left temporal glioma was studied. He is a professional opera singer. A tailored music evaluation, the Montreal Battery of Evaluation of Amusia, was performed preoperatively and postoperatively, with long-term follow-up. Intraoperative stimulation mapping (ISM) with awake surgery with a specific music evaluation battery was used to identify and preserve the cortical and subcortical structures subserving music, along with standard motor-sensory and language mapping. A total resection of a grade I glioma was achieved. The Montreal Battery of Evaluation of Amusia reported an improvement in musical scores after the surgery. ISM consistently elicited several types of errors in the superior temporal gyrus and, to a lesser extent, in the inferior frontal operculum. Most errors occurred during score reading; fewer errors were elicited during the assessment of rhythm. No spontaneous errors were recorded. These areas did not overlap with eloquent sites for counting or naming. ISM and a tailored music battery enabled better characterization of a specific network within the brain subserving score reading independently from speech with long-term clinical impact. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Multifractal Detrended Fluctuation Analysis of alpha and theta EEG rhythms with musical stimuli

    International Nuclear Information System (INIS)

    Maity, Akash Kumar; Pratihar, Ruchira; Mitra, Anubrato; Dey, Subham; Agrawal, Vishal; Sanyal, Shankha; Banerjee, Archi; Sengupta, Ranjan; Ghosh, Dipak

    2015-01-01

    Highlights: • EEG was done to record the brain electrical activity of 10 subjects in response to simple acoustical tanpura stimuli. • Empirical Mode Decomposition (EMD) technique used to make the EEG signal free from blink and other muscular artifacts. • Multifractal Detrended Fluctuation Analysis (MFDFA) performed to assess the complexity of extracted alpha and theta brain rhythms. • The findings show spectral width i.e. complexity of alpha and theta rhythms increase in all the seven frontal locations studied, under the effect of musical stimuli. - Abstract: Electroencephalography (EEG) was performed on 10 participants using a simple acoustical stimuli i.e. a tanpura drone. The tanpura drone is free from any semantic content and is used with a hypothesis that it provides a specific resting environment for the listeners. The EEG data was extracted for all the frontal electrodes viz. F3, F4, F7, F8, Fp1, Fp2 and Fz. Empirical Mode Decomposition (EMD) was applied on the acquired raw EEG signal to make it free from blink as well as other muscular artifacts. Wavelet Transform (WT) technique was used to segregate alpha and theta waves from the denoised EEG signal. Non-linear analysis in the form of Multifractal Detrended Fluctuation Analysis (MFDFA) was carried out on the extracted alpha and theta time series data to study the variation of their complexity. It was found that in all the frontal electrodes alpha as well as theta complexity increases as is evident from the increase of multifractal spectral width. This study is entirely new and gives interesting data regarding neural activation of the alpha and theta brain rhythms while listening to simple acoustical stimuli. The importance of this study lies in the context of emotion quantification using multifractal spectral width as a parameter as well as in the field of cognitive music therapy. The results are discussed in detail.

  11. Resting state cortical rhythms in athletes: a high-resolution EEG study.

    Science.gov (United States)

    Babiloni, Claudio; Marzano, Nicola; Iacoboni, Marco; Infarinato, Francesco; Aschieri, Pierluigi; Buffo, Paola; Cibelli, Giuseppe; Soricelli, Andrea; Eusebi, Fabrizio; Del Percio, Claudio

    2010-01-15

    The present electroencephalographic (EEG) study tested the working hypothesis that the amplitude of resting state cortical EEG rhythms (especially alpha, 8-12 Hz) was higher in elite athletes compared with amateur athletes and non-athletes, as a reflection of the efficiency of underlying back-ground neural synchronization mechanisms. Eyes closed resting state EEG data were recorded in 16 elite karate athletes, 20 amateur karate athletes, and 25 non-athletes. The EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). EEG cortical sources were estimated by low-resolution brain electromagnetic tomography (LORETA). Statistical results showed that the amplitude of parietal and occipital alpha 1 sources was significantly higher in the elite karate athletes than in the non-athletes and karate amateur athletes. Similar results were observed in parietal and occipital delta sources as well as in occipital theta sources. Finally, a control confirmatory experiment showed that the amplitude of parietal and occipital delta and alpha 1 sources was stronger in 8 elite rhythmic gymnasts compared with 14 non-athletes. These results supported the hypothesis that cortical neural synchronization at the basis of eyes-closed resting state EEG rhythms is enhanced in elite athletes than in control subjects.

  12. Classification of Hand Grasp Kinetics and Types Using Movement-Related Cortical Potentials and EEG Rhythms

    Directory of Open Access Journals (Sweden)

    Mads Jochumsen

    2017-01-01

    Full Text Available Detection of single-trial movement intentions from EEG is paramount for brain-computer interfacing in neurorehabilitation. These movement intentions contain task-related information and if this is decoded, the neurorehabilitation could potentially be optimized. The aim of this study was to classify single-trial movement intentions associated with two levels of force and speed and three different grasp types using EEG rhythms and components of the movement-related cortical potential (MRCP as features. The feature importance was used to estimate encoding of discriminative information. Two data sets were used. 29 healthy subjects executed and imagined different hand movements, while EEG was recorded over the contralateral sensorimotor cortex. The following features were extracted: delta, theta, mu/alpha, beta, and gamma rhythms, readiness potential, negative slope, and motor potential of the MRCP. Sequential forward selection was performed, and classification was performed using linear discriminant analysis and support vector machines. Limited classification accuracies were obtained from the EEG rhythms and MRCP-components: 0.48±0.05 (grasp types, 0.41±0.07 (kinetic profiles, motor execution, and 0.39±0.08 (kinetic profiles, motor imagination. Delta activity contributed the most but all features provided discriminative information. These findings suggest that information from the entire EEG spectrum is needed to discriminate between task-related parameters from single-trial movement intentions.

  13. CLOCK Acetylates ASS1 to Drive Circadian Rhythm of Ureagenesis.

    Science.gov (United States)

    Lin, Ran; Mo, Yan; Zha, Haihong; Qu, Zhipeng; Xie, Pancheng; Zhu, Zheng-Jiang; Xu, Ying; Xiong, Yue; Guan, Kun-Liang

    2017-10-05

    In addition to responding to environmental entrainment with diurnal variation, metabolism is also tightly controlled by cell-autonomous circadian clock. Extensive studies have revealed key roles of transcription in circadian control. Post-transcriptional regulation for the rhythmic gating of metabolic enzymes remains elusive. Here, we show that arginine biosynthesis and subsequent ureagenesis are collectively regulated by CLOCK (circadian locomotor output cycles kaput) in circadian rhythms. Facilitated by BMAL1 (brain and muscle Arnt-like protein), CLOCK directly acetylates K165 and K176 of argininosuccinate synthase (ASS1) to inactivate ASS1, which catalyzes the rate-limiting step of arginine biosynthesis. ASS1 acetylation by CLOCK exhibits circadian oscillation in human cells and mouse liver, possibly caused by rhythmic interaction between CLOCK and ASS1, leading to the circadian regulation of ASS1 and ureagenesis. Furthermore, we also identified NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 9 (NDUFA9) and inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) as acetylation substrates of CLOCK. Taken together, CLOCK modulates metabolic rhythmicity by acting as a rhythmic acetyl-transferase for metabolic enzymes. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  15. Circadian rhythm and its role in malignancy

    Directory of Open Access Journals (Sweden)

    Mahmood Saqib

    2010-03-01

    Full Text Available Abstract Circadian rhythms are daily oscillations of multiple biological processes directed by endogenous clocks. The circadian timing system comprises peripheral oscillators located in most tissues of the body and a central pacemaker located in the suprachiasmatic nucleus (SCN of the hypothalamus. Circadian genes and the proteins produced by these genes constitute the molecular components of the circadian oscillator which form positive/negative feedback loops and generate circadian rhythms. The circadian regulation extends beyond clock genes to involve various clock-controlled genes (CCGs including various cell cycle genes. Aberrant expression of circadian clock genes could have important consequences on the transactivation of downstream targets that control the cell cycle and on the ability of cells to undergo apoptosis. This may lead to genomic instability and accelerated cellular proliferation potentially promoting carcinogenesis. Different lines of evidence in mice and humans suggest that cancer may be a circadian-related disorder. The genetic or functional disruption of the molecular circadian clock has been found in various cancers including breast, ovarian, endometrial, prostate and hematological cancers. The acquisition of current data in circadian clock mechanism may help chronotherapy, which takes into consideration the biological time to improve treatments by devising new therapeutic approaches for treating circadian-related disorders, especially cancer.

  16. Circadian mechanisms of food anticipatory rhythms in rats fed once or twice daily: clock gene and endocrine correlates.

    Directory of Open Access Journals (Sweden)

    Danica F Patton

    Full Text Available Circadian clocks in many brain regions and peripheral tissues are entrained by the daily rhythm of food intake. Clocks in one or more of these locations generate a daily rhythm of locomotor activity that anticipates a regular mealtime. Rats and mice can also anticipate two daily meals. Whether this involves 1 or 2 circadian clocks is unknown. To gain insight into how the circadian system adjusts to 2 daily mealtimes, male rats in a 12∶12 light-dark cycle were fed a 2 h meal either 4 h after lights-on or 4 h after lights-off, or a 1 h meal at both times. After 30 days, brain, blood, adrenal and stomach tissue were collected at 6 time points. Multiple clock genes from adrenals and stomachs were assayed by RT-PCR. Blood was assayed for corticosterone and ghrelin. Bmal1 expression was quantified in 14 brain regions by in situ hybridization. Clock gene rhythms in adrenal and stomach from day-fed rats oscillated in antiphase with the rhythms in night-fed rats, and at an intermediate phase in rats fed twice daily. Corticosterone and ghrelin in 1-meal rats peaked at or prior to the expected mealtime. In 2-meal rats, corticosterone peaked only prior the nighttime meal, while ghrelin peaked prior to the daytime meal and then remained elevated. The olfactory bulb, nucleus accumbens, dorsal striatum, cerebellum and arcuate nucleus exhibited significant daily rhythms of Bmal1 in the night-fed groups that were approximately in antiphase in the day-fed groups, and at intermediate levels (arrhythmic in rats anticipating 2 daily meals. The dissociations between anticipatory activity and the peripheral clocks and hormones in rats anticipating 2 daily meals argue against a role for these signals in the timing of behavioral rhythms. The absence of rhythmicity at the tissue level in brain regions from rats anticipating 2 daily meals support behavioral evidence that circadian clock cells in these tissues may reorganize into two populations coupled to different

  17. Unexpected diversity in socially synchronized rhythms of shorebirds

    NARCIS (Netherlands)

    Bulla, Martin; Valcu, Mihai; Dokter, Adriaan M; Dondua, Alexei G; Kosztolányi, András; Helm, Barbara; Sandercock, Brett K; Casler, Bruce; Ens, Bruno J.; Spiegel, Caleb S; Hassell, Chris J; Küpper, Clemens; Minton, Clive; Burgas, Daniel; Lank, David B; Payer, David C; Loktionov, Egor Y; Nol, Erica; Kwon, Eunbi; Smith, Fletcher; Gates, H River; Vitnerová, Hana; Prüter, Hanna; Johnson, James A; St Clair, James J H; Lamarre, Jean-François; Rausch, Jennie; Reneerkens, Jeroen; Conklin, Jesse R; Burger, Joanna; Liebezeit, Joe; Bêty, Joël; Coleman, Jonathan T; Figuerola, Jordi; Hooijmeijer, Joslyn; Alves, José A; Smith, Joseph A M; Weidinger, Karel; Koivula, Kari; Gosbell, Ken; Exo, Klaus-Michael; Niles, Larry; Koloski, Laura; McKinnon, Laura; Praus, Libor; Klaassen, Marcel; Giroux, Marie-Andrée; Sládeček, Martin; Boldenow, Megan L; Goldstein, Michael I; Šálek, Miroslav; Senner, Nathan; Rönkä, Nelli; Lecomte, Nicolas; Gilg, Olivier; Vincze, Orsolya; Johnson, Oscar W; Smith, Paul A; Woodard, Paul F; Tomkovich, Pavel S; Battley, Phil F; Bentzen, Rebecca; Lanctot, Richard B; Porter, Ron; Saalfeld, Sarah T; Freeman, Scott; Brown, Stephen C; Yezerinac, Stephen; Székely, Tamás; Montalvo, Tomás; Piersma, Theunis; Loverti, Vanessa; Pakanen, Veli-Matti; Tijsen, Wim; Kempenaers, Bart

    2016-01-01

    The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities

  18. Neglect of Biological Rhythms in High School Biology Texts.

    Science.gov (United States)

    Ahlgren, Andrew; Nelson, Julie Ann

    1979-01-01

    This article developed from a survey of the five most popular biology texts which promote the theory of invariant homeostasis rather than biological rhythms. The popular fad of "birthdate biorhythms" is discussed in relation to providing education on biological rhythms and its legitimacy to the public. (SA)

  19. The relationship between bipolar disorder and biological rhythms.

    Science.gov (United States)

    Gonzalez, Robert

    2014-04-01

    Rhythm disruption is a core feature of bipolar disorder and it has been hypothesized that disturbances of the circadian timing system play a fundamental role in the etiology of the disorder. We sought to investigate (1) theoretical models for biological rhythm disruptions in bipolar disorder, (2) physiological disturbances of biological rhythms in bipolar disorder, (3) clinical and therapeutic implications of biological rhythm disturbances in bipolar disorder, and (4) associations between circadian gene variations and bipolar disorder. PubMed database was searched systematically for articles that were published on or before May 5, 2013, and were written in English using the terms bipolar disorder, clock genes, endogenous clock, molecular clock, biological rhythms, circadian, suprachiasmatic nucleus, circadian rhythm, melatonin, and sleep. Seventy-four articles highlighting the objectives were included in the review. Data regarding exploring the association between bipolar disorder and circadian and chronobiological phenomena were reviewed and findings summarized. The literature reviewed suggests that circadian rhythm disturbance may be a feature of bipolar disorder. In toto, the literature suggests that circadian rhythm disturbances may be a feature of bipolar disorder. This area of research has received theoretical consideration as playing a significant role in the pathophysiology of the illness but has been understudied to this point. Further research in the field is warranted. © Copyright 2014 Physicians Postgraduate Press, Inc.

  20. Lateralization of Auditory rhythm length in temporal lobe lessions

    NARCIS (Netherlands)

    Alpherts, W.C.J.; Vermeulen, J.; Franken, M.L.O.; Hendriks, M.P.H.; Veelen, C.W.M. van; Rijen, P.C. van

    2002-01-01

    In the visual modality, short rhythmic stimuli ha c been proven to he better processed (sequentially) by the left hemisphere, while longer rhythms appear to he better (holistically) processed by the right hemisphere. This study was set up to see it the same holds in the auditory modality. The rhythm

  1. A circadian rhythm regulating hyphal melanization in Cercospora kikuchii.

    Science.gov (United States)

    Bluhm, Burton H; Burnham, A Michele; Dunkle, Larry D

    2010-01-01

    Many metabolic and developmental processes in fungi are controlled by biological rhythms. Circadian rhythms approximate a daily (24 h) cycle and have been thoroughly studied in the model fungus, Neurospora crassa. However relatively few examples of true circadian rhythms have been documented among other filamentous fungi. In this study we describe a circadian rhythm underlying hyphal melanization in Cercospora kikuchii, an important pathogen of soybean. After growth in light or light : dark cycles, colonies transferred to darkness produced zonate bands of melanized hyphae interspersed with bands of hyaline hyphae. Rhythmic production of bands was remarkably persistent in the absence of external cues, lasting at least 7 d after transfer to darkness, and was compensated over a range of temperatures. As in N. crassa, blue light but not red light was sufficient to entrain the circadian rhythm in C. kikuchii, and a putative ortholog of white collar-1, one of the genes required for light responses in N. crassa, was identified in C. kikuchii. Circadian regulation of melanization is conserved in other members of the genus: Similar rhythms were identified in another field isolate of C. kikuchii as well as field isolates of C. beticola and C. sorghi, but not in wild-type strains of C. zeae-maydis or C. zeina. This report represents the first documented circadian rhythm among Dothideomycete fungi and provides a new opportunity to dissect the molecular basis of circadian rhythms among filamentous fungi.

  2. Functional synchronization of biological rhythms in a tritrophic system.

    Science.gov (United States)

    Zhang, Sufang; Wei, Jianing; Guo, Xiaojiao; Liu, Tong-Xian; Kang, Le

    2010-06-10

    In a tritrophic system formed by a plant, an herbivore and a natural enemy, each component has its own biological rhythm. However, the rhythm correlations among the three levels and the underlying mechanisms in any tritrophic system are largely unknown. Here, we report that the rhythms exhibited bidirectional correlations in a model tritrophic system involving a lima bean, a pea leafminer and a parasitoid. From the bottom-up perspective, the rhythm was initiated from herbivore feeding, which triggered the rhythms of volatile emissions; then the rhythmic pattern of parasitoid activities was affected, and these rhythms were synchronized by a light switch signal. Increased volatile concentration can enhance the intensity of parasitoid locomotion and oviposition only under light. From the top-down perspective, naive and oviposition-experienced parasitoids were able to utilize the different volatile rhythm information from the damaged plant to locate host leafminers respectively. Our results indicated that the three interacting organisms in this system can achieve rhythmic functional synchronization under a natural light-dark photoperiod, but not under constant light or darkness. These findings provide new insight into the rhythm synchronization of three key players that contribute to the utilization of light and chemical signals, and our results may be used as potential approaches for manipulating natural enemies.

  3. Functional synchronization of biological rhythms in a tritrophic system.

    Directory of Open Access Journals (Sweden)

    Sufang Zhang

    Full Text Available In a tritrophic system formed by a plant, an herbivore and a natural enemy, each component has its own biological rhythm. However, the rhythm correlations among the three levels and the underlying mechanisms in any tritrophic system are largely unknown. Here, we report that the rhythms exhibited bidirectional correlations in a model tritrophic system involving a lima bean, a pea leafminer and a parasitoid. From the bottom-up perspective, the rhythm was initiated from herbivore feeding, which triggered the rhythms of volatile emissions; then the rhythmic pattern of parasitoid activities was affected, and these rhythms were synchronized by a light switch signal. Increased volatile concentration can enhance the intensity of parasitoid locomotion and oviposition only under light. From the top-down perspective, naive and oviposition-experienced parasitoids were able to utilize the different volatile rhythm information from the damaged plant to locate host leafminers respectively. Our results indicated that the three interacting organisms in this system can achieve rhythmic functional synchronization under a natural light-dark photoperiod, but not under constant light or darkness. These findings provide new insight into the rhythm synchronization of three key players that contribute to the utilization of light and chemical signals, and our results may be used as potential approaches for manipulating natural enemies.

  4. Rhythm-based segmentation of Popular Chinese Music

    DEFF Research Database (Denmark)

    Jensen, Karl Kristoffer

    2005-01-01

    We present a new method to segment popular music based on rhythm. By computing a shortest path based on the self-similarity matrix calculated from a model of rhythm, segmenting boundaries are found along the di- agonal of the matrix. The cost of a new segment is opti- mized by matching manual...

  5. A Rhythm Recognition Computer Program to Advocate Interactivist Perception

    Science.gov (United States)

    Buisson, Jean-Christophe

    2004-01-01

    This paper advocates the main ideas of the interactive model of representation of Mark Bickhard and the assimilation/accommodation framework of Jean Piaget, through a rhythm recognition demonstration program. Although completely unsupervised, the program progressively learns to recognize more and more complex rhythms struck on the user's keyboard.…

  6. Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila

    Indian Academy of Sciences (India)

    2014-07-20

    Jul 20, 2014 ... A diverse range of organisms shows physiological and behavioural rhythms with various periods. Extensive studies have been performed to elucidate the molecular mechanisms of circadian rhythms with an approximately 24 h period in both Drosophila and mammals, while less attention has been paid to ...

  7. Interactive Rhythm Learning System by Combining Tablet Computers and Robots

    Directory of Open Access Journals (Sweden)

    Chien-Hsing Chou

    2017-03-01

    Full Text Available This study proposes a percussion learning device that combines tablet computers and robots. This device comprises two systems: a rhythm teaching system, in which users can compose and practice rhythms by using a tablet computer, and a robot performance system. First, teachers compose the rhythm training contents on the tablet computer. Then, the learners practice these percussion exercises by using the tablet computer and a small drum set. The teaching system provides a new and user-friendly score editing interface for composing a rhythm exercise. It also provides a rhythm rating function to facilitate percussion training for children and improve the stability of rhythmic beating. To encourage children to practice percussion exercises, a robotic performance system is used to interact with the children; this system can perform percussion exercises for students to listen to and then help them practice the exercise. This interaction enhances children’s interest and motivation to learn and practice rhythm exercises. The results of experimental course and field trials reveal that the proposed system not only increases students’ interest and efficiency in learning but also helps them in understanding musical rhythms through interaction and composing simple rhythms.

  8. Biomarkers for circadian rhythm disruption independent of time of day

    NARCIS (Netherlands)

    K.C.G. van Dycke (Kirsten); J.L.A. Pennings (Jeroen L.A.); C.T.M. van Oostrom (Conny); L.W.M. Van Kerkhof (Linda W.M.); H. van Steeg (Harry); G.T.J. van der Horst (Gijsbertus); W. Rodenburg (Wendy)

    2015-01-01

    textabstractFrequent shift work causes disruption of the circadian rhythm and might on the long-term result in increased health risk. Current biomarkers evaluating the presence of circadian rhythm disturbance (CRD), including melatonin, cortisol and body temperature, require 24-hr ("around the

  9. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  10. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  11. Northern Elephant Seals Memorize the Rhythm and Timbre of Their Rivals' Voices.

    Science.gov (United States)

    Mathevon, Nicolas; Casey, Caroline; Reichmuth, Colleen; Charrier, Isabelle

    2017-08-07

    The evolutionary origin of rhythm perception, a cognitive ability essential to musicality, remains unresolved [1-5]. The ability to perceive and memorize rhythmic sounds is widely shared among humans [6] but seems rare among other mammals [7, 8]. Although the perception of temporal metrical patterns has been found in a few species, this ability has only been demonstrated through behavioral training [9] (but see [10] for an example of spontaneous tempo coordination in a bonobo), and there is no experimental evidence to indicate its biological function. Furthermore, there is no example of a non-human mammal able to remember and recognize auditory rhythmic patterns among a wide range of tempi. In the northern elephant seal Mirounga angustirostris, the calls of mature males comprise a rhythmic series of pulses, with the call of each individual characterized by its tempo and timbre; these individual vocal signatures are stable over years and across contexts [11]. Here, we report that northern elephant seal males routinely memorize and recognize the unique tempo and timbre of their rivals' voices and use this rhythmic information to individually identify competitors, which facilitates navigation within the social network of the rookery. By performing playbacks with natural and modified vocalizations, we show that males are sensitive to call rhythm disruption independently of modification of spectral features and that they use both temporal and spectral cues to identify familiar rivals. While spectral features of calls typically encode individual identity in mammalian vocalizations [12], this is the first example of this phenomenon involving sound rhythm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. ‘Ragged Time’ in Intra-panel Comics Rhythms

    Directory of Open Access Journals (Sweden)

    Corry Shores

    2016-07-01

    Full Text Available A phenomenological method of comics analysis can be useful when we need to uncover the structural features of the comics experience itself. One fruitful application would be in the study of irregular intra-panel rhythms, where the temporalized divisions are not visibly indicated but rather are only experienced. By means of Gilles Deleuze’s notion of rhythmic repetition and his elaboration of it through Olivier Messiaen’s theory of ‘kinetic’ rhythm, we will formulate a conception of visual rhythm as being based on metrical irregularity. We further explicate this concept of irregular rhythm by drawing upon the notion of ‘ragged time’ in the early jazz musical form, ragtime. We finally test its usefulness by examining how the ‘jazzy’ rhythms of Cubist-styled panels by Art Spiegelman and Mary Fleener generate an experience of ragged time.

  13. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  14. Word-by-word entrainment of speech rhythm during joint story building.

    Science.gov (United States)

    Himberg, Tommi; Hirvenkari, Lotta; Mandel, Anne; Hari, Riitta

    2015-01-01

    Movements and behavior synchronize during social interaction at many levels, often unintentionally. During smooth conversation, for example, participants adapt to each others' speech rates. Here we aimed to find out to which extent speakers adapt their turn-taking rhythms during a story-building game. Nine sex-matched dyads of adults (12 males, 6 females) created two 5-min stories by contributing to them alternatingly one word at a time. The participants were located in different rooms, with audio connection during one story and audiovisual during the other. They were free to select the topic of the story. Although the participants received no instructions regarding the timing of the story building, their word rhythms were highly entrained (øverlineR = 0.70, p story, independently of whether the subjects were connected via audio-only or audiovisual link. The observed entrainment was of similar strength as typical entrainment in finger-tapping tasks where participants are specifically instructed to synchronize their behavior. Thus, speech seems to spontaneously induce strong entrainment between the conversation partners, likely reflecting automatic alignment of their semantic and syntactic processes.

  15. Data mining using multivariate The circadian rhythm and visual elements in scorpions: A review

    Directory of Open Access Journals (Sweden)

    M. R. Warburg

    2013-12-01

    Full Text Available The purpose of this paper is to review the state of research in this field and to outline future ways how to proceed. The term: "Zeitgeber", implies 'time giver' meaning: synchronizer when an external entrainment factor synchronizes the endogenous rhythm. Is this 'time giver', the chronological date in the sense that it is related to the time of day as reflected in the natural light-dark cycles? Or does it mean cyclic phases of activity as demonstrated in the laboratory? Moreover, is it totally independent of the animal's physiological condition? This subject was studied largely in buthid species (15 of a total of only 30 scorpion species. Moreover, many (over 25% of the studies (19 were done on a single buthid species: Androctonus australis. Species diversity was observed only by one author's work who studied eye structure in seven species. Since he found variability in eye structure it would not be advisable to generalize. The fact that experimenting was carried out irrespective of species diversity, gender, ecological or physiological conditions, and was usually done on animals kept in captivity for some time before the experimenting had started, is a major drawback to this kind of study. The diurnal rhythms is triggered either directly through spontaneous arrhythmic activity in the central nervous system, or by neurosecretory material. It is possible that these differences arise from either different technical treatments or due to basic problems, and these need to be clarified.

  16. Inherent rhythm of smooth muscle cells in rat mesenteric arterioles: An eigensystem formulation

    Science.gov (United States)

    Ho, I. Lin; Moshkforoush, Arash; Hong, Kwangseok; Meininger, Gerald A.; Hill, Michael A.; Tsoukias, Nikolaos M.; Kuo, Watson

    2016-04-01

    On the basis of experimental data and mathematical equations in the literature, we remodel the ionic dynamics of smooth muscle cells (SMCs) as an eigensystem formulation, which is valid for investigating finite variations of variables from the equilibrium such as in common experimental operations. This algorithm provides an alternate viewpoint from frequency-domain analysis and enables one to probe functionalities of SMCs' rhythm by means of a resonance-related mechanism. Numerical results show three types of calcium oscillations of SMCs in mesenteric arterioles: spontaneous calcium oscillation, agonist-dependent calcium oscillation, and agonist-dependent calcium spike. For simple single and double SMCs, we demonstrate properties of synchronization among complex signals related to calcium oscillations, and show different correlation relations between calcium and voltage signals for various synchronization and resonance conditions. For practical cell clusters, our analyses indicate that the rhythm of SMCs could (1) benefit enhancements of signal communications among remote cells, (2) respond to a significant calcium peaking against transient stimulations for triggering globally oscillating modes, and (3) characterize the globally oscillating modes via frog-leap (non-molecular-diffusion) calcium waves across inhomogeneous SMCs.

  17. Continuity of visual and auditory rhythms influences sensorimotor coordination.

    Directory of Open Access Journals (Sweden)

    Manuel Varlet

    Full Text Available People often coordinate their movement with visual and auditory environmental rhythms. Previous research showed better performances when coordinating with auditory compared to visual stimuli, and with bimodal compared to unimodal stimuli. However, these results have been demonstrated with discrete rhythms and it is possible that such effects depend on the continuity of the stimulus rhythms (i.e., whether they are discrete or continuous. The aim of the current study was to investigate the influence of the continuity of visual and auditory rhythms on sensorimotor coordination. We examined the dynamics of synchronized oscillations of a wrist pendulum with auditory and visual rhythms at different frequencies, which were either unimodal or bimodal and discrete or continuous. Specifically, the stimuli used were a light flash, a fading light, a short tone and a frequency-modulated tone. The results demonstrate that the continuity of the stimulus rhythms strongly influences visual and auditory motor coordination. Participants' movement led continuous stimuli and followed discrete stimuli. Asymmetries between the half-cycles of the movement in term of duration and nonlinearity of the trajectory occurred with slower discrete rhythms. Furthermore, the results show that the differences of performance between visual and auditory modalities depend on the continuity of the stimulus rhythms as indicated by movements closer to the instructed coordination for the auditory modality when coordinating with discrete stimuli. The results also indicate that visual and auditory rhythms are integrated together in order to better coordinate irrespective of their continuity, as indicated by less variable coordination closer to the instructed pattern. Generally, the findings have important implications for understanding how we coordinate our movements with visual and auditory environmental rhythms in everyday life.

  18. P300-based brain computer interface experimental setup

    NARCIS (Netherlands)

    Arboleda, C.; Garcia Cossio, E.; Posada, A.; Torres, R.

    2009-01-01

    A Brain-Computer interface (BCI) is a communication system that enables the generation of a control signal from brain signals such as sensorymotor rhythms and evoked potentials; therefore, it constitutes a novel communication option for people with severe motor disabilities (such as Amyotrophic

  19. Sleep and circadian rhythms in space.

    Science.gov (United States)

    Stampi, C

    1994-05-01

    This paper presents a detailed critical review of the knowledge accumulated in the last three decades concerning research on sleep, work-rest schedules, and circadian rhythms in space. The focus of the paper is preceded by a brief review of the basic principles of the human circadian system and the physiology of the sleep-wake cycle, relevant to understanding the problem of astronaut work-rest scheduling. Much of what is known is based on anecdotal reports, mission log books, and debriefing of astronauts after flights. The broad literature reviewed, which includes studies from American and Soviet space missions, as well as some studies conducted under simulated weightlessness, offers just a handful of objective studies on the physiology of sleep and circadian rhythms in space. Nevertheless, the data are remarkably consistent, and indicate that sleep can be of reasonably good quality in space. The risk of sleep loss and associated performance degradation appears to be a manageable one. However, one clear conclusion arises from this review: whatever the type of mission of flight plan, its success will depend on whether the principles of circadian and sleep-wake regulation have been taken into account during the planning phase of work-rest schedules. That is, satisfactory sleep and alertness is more likely to occur if crews maintain a reasonable (i.e., constant) relation with their normal terrestrial rhythm. This is not as easy a task as it may appear; indeed, unexpected, high-intensity operational demands have been the major cause of acute problems of sleep loss and performance degradation in space. Moreover, the growing complexity of space missions indicate that emergencies will never disappear. Therefore, one of the most important research challenges for future space missions is the development of strategies that could permit astronauts to function closest to maximal efficiency during intensive and prolonged work. Countermeasures for optimizing astronaut

  20. Population calcium imaging of spontaneous respiratory and novel motor activity in the facial nucleus and ventral brainstem in newborn mice

    DEFF Research Database (Denmark)

    Persson, Karin; Rekling, Jens C

    2011-01-01

    The brainstem contains rhythm and pattern forming circuits, which drive cranial and spinal motor pools to produce respiratory and other motor patterns. Here we used calcium imaging combined with nerve recordings in newborn mice to reveal spontaneous population activity in the ventral brainstem...... in lateral and medial subnuclei. Whole-cell recordings from facial motoneurons showed weak respiratory drives, and electrical field potential recordings confirmed respiratory drive to particularly the dorsal and lateral subnuclei. Putative facial premotoneurons showed respiratory-related calcium signals...

  1. Electroencephalographic Rhythms in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Roberta Lizio

    2011-01-01

    Full Text Available Physiological brain aging is characterized by synapses loss and neurodegeneration that slowly lead to an age-related decline of cognition. Neural/synaptic redundancy and plastic remodelling of brain networking, also due to mental and physical training, promotes maintenance of brain activity in healthy elderly subjects for everyday life and good social behaviour and intellectual capabilities. However, age is the major risk factor for most common neurodegenerative disorders that impact on cognition, like Alzheimer's disease (AD. Brain electromagnetic activity is a feature of neuronal network function in various brain regions. Modern neurophysiological techniques, such as electroencephalography (EEG and event-related potentials (ERPs, are useful tools in the investigation of brain cognitive function in normal and pathological aging with an excellent time resolution. These techniques can index normal and abnormal brain aging analysis of corticocortical connectivity and neuronal synchronization of rhythmic oscillations at various frequencies. The present review suggests that discrimination between physiological and pathological brain aging clearly emerges at the group level, with suggested applications also at the level of single individual. The possibility of combining the use of EEG together with biological/neuropsychological markers and structural/functional imaging is promising for a low-cost, non-invasive, and widely available assessment of groups of individuals at-risk.

  2. Operation Brain Trauma Therapy

    Science.gov (United States)

    2012-10-01

    IL‐1B and MIP‐2  concentrations   reduced  NONE  Brain  conc at 4, 8,  12, or 24h; Dose  response seen;  5000 IV gave  highest  brain  conc  18/Xiong et...by the Operation Brain Trauma Therapy consortium Drugs Secondary Injury Mechanisms Inflammation Axonal Injury Excitotoxicity/ Neurotransmitter ...glutamatergic transmission in the prefrontal cortex of stroke-prone spontaneously hypertensive rats. Neurosci Lett. 2002;320:109–112. 45. Nakamura K

  3. Insulin sensitivity : modulation by the brain

    NARCIS (Netherlands)

    Coomans, Claudia Pascalle

    2012-01-01

    The studies in this thesis contribute to the understanding of the role of the brain in insulin sensitivity. We demonstrate that disturbances in circadian rhythm resulting in alterations in SCN output, can contribute to the development of insulin resistance. We also shown that insulin-stimulated

  4. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  5. Choreographing Compassion: A Clinical Adventure of Rhythms.

    Science.gov (United States)

    Yopst, Charles George

    2015-06-01

    Compassion is a primary catalyst motivating positive human relationships, especially of those less fortunate. Our rhythms Expand-Contract of our own non-verbal body joints movements and of the law of counter-balance, enable us to identify which of nine innate affects-emotions is directing the body's movements. With this reading, a trained person can synchronize choreography of these into fully authentic compassion between two or more persons. Primary references for this are the late Silvan S. Tomkins's four volumes "Affect Imagery Consciousness," and choreographers the late Rudolf Laban, Warren Lamb, Irmgard Bartenieff, and Marian Chace. Professionals, clinicians, and laity counselors can all use these. © The Author(s) 2015.

  6. Circadian Rhythms, Sleep, and Disorders of Aging.

    Science.gov (United States)

    Mattis, Joanna; Sehgal, Amita

    2016-04-01

    Sleep-wake cycles are known to be disrupted in people with neurodegenerative disorders. These findings are now supported by data from animal models for some of these disorders, raising the question of whether the disrupted sleep/circadian regulation contributes to the loss of neural function. As circadian rhythms and sleep consolidation also break down with normal aging, changes in these may be part of what makes aging a risk factor for disorders like Alzheimer's disease (AD). Mechanisms underlying the connection between circadian/sleep dysregulation and neurodegeneration remain unclear, but several recent studies provide interesting possibilities. While mechanistic analysis is under way, it is worth considering treatment of circadian/sleep disruption as a means to alleviate symptoms of neurodegenerative disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The Psychology of Music: Rhythm and Movement.

    Science.gov (United States)

    Levitin, Daniel J; Grahn, Jessica A; London, Justin

    2018-01-04

    The urge to move to music is universal among humans. Unlike visual art, which is manifest across space, music is manifest across time. When listeners get carried away by the music, either through movement (such as dancing) or through reverie (such as trance), it is usually the temporal qualities of the music-its pulse, tempo, and rhythmic patterns-that put them in this state. In this article, we review studies addressing rhythm, meter, movement, synchronization, entrainment, the perception of groove, and other temporal factors that constitute a first step to understanding how and why music literally moves us. The experiments we review span a range of methodological techniques, including neuroimaging, psychophysics, and traditional behavioral experiments, and we also summarize the current studies of animal synchronization, engaging an evolutionary perspective on human rhythmic perception and cognition.

  8. Genetic Disruption of Circadian Rhythms in the Suprachiasmatic Nucleus Causes Helplessness, Behavioral Despair, and Anxiety-like Behavior in Mice.

    Science.gov (United States)

    Landgraf, Dominic; Long, Jaimie E; Proulx, Christophe D; Barandas, Rita; Malinow, Roberto; Welsh, David K

    2016-12-01

    Major depressive disorder is associated with disturbed circadian rhythms. To investigate the causal relationship between mood disorders and circadian clock disruption, previous studies in animal models have employed light/dark manipulations, global mutations of clock genes, or brain area lesions. However, light can impact mood by noncircadian mechanisms; clock genes have pleiotropic, clock-independent functions; and brain lesions not only disrupt cellular circadian rhythms but also destroy cells and eliminate important neuronal connections, including light reception pathways. Thus, a definitive causal role for functioning circadian clocks in mood regulation has not been established. We stereotactically injected viral vectors encoding short hairpin RNA to knock down expression of the essential clock gene Bmal1 into the brain's master circadian pacemaker, the suprachiasmatic nucleus (SCN). In these SCN-specific Bmal1-knockdown (SCN-Bmal1-KD) mice, circadian rhythms were greatly attenuated in the SCN, while the mice were maintained in a standard light/dark cycle, SCN neurons remained intact, and neuronal connections were undisturbed, including photic inputs. In the learned helplessness paradigm, the SCN-Bmal1-KD mice were slower to escape, even before exposure to inescapable stress. They also spent more time immobile in the tail suspension test and less time in the lighted section of a light/dark box. The SCN-Bmal1-KD mice also showed greater weight gain, an abnormal circadian pattern of corticosterone, and an attenuated increase of corticosterone in response to stress. Disrupting SCN circadian rhythms is sufficient to cause helplessness, behavioral despair, and anxiety-like behavior in mice, establishing SCN-Bmal1-KD mice as a new animal model of depression. Copyright © 2016 Society of Biological Psychiatry. All rights reserved.

  9. Toward a complex system understanding of bipolar disorder: A chaotic model of abnormal circadian activity rhythms in euthymic bipolar disorder.

    Science.gov (United States)

    Hadaeghi, Fatemeh; Hashemi Golpayegani, Mohammad Reza; Jafari, Sajad; Murray, Greg

    2016-08-01

    In the absence of a comprehensive neural model to explain the underlying mechanisms of disturbed circadian function in bipolar disorder, mathematical modeling is a helpful tool. Here, circadian activity as a response to exogenous daily cycles is proposed to be the product of interactions between neuronal networks in cortical (cognitive processing) and subcortical (pacemaker) areas of the brain. To investigate the dynamical aspects of the link between disturbed circadian activity rhythms and abnormalities of neurotransmitter functioning in frontal areas of the brain, we developed a novel mathematical model of a chaotic system which represents fluctuations in circadian activity in bipolar disorder as changes in the model's parameters. A novel map-based chaotic system was developed to capture disturbances in circadian activity across the two extreme mood states of bipolar disorder. The model uses chaos theory to characterize interplay between neurotransmitter functions and rhythm generation; it aims to illuminate key activity phenomenology in bipolar disorder, including prolonged sleep intervals, decreased total activity and attenuated amplitude of the diurnal activity rhythm. To test our new cortical-circadian mathematical model of bipolar disorder, we utilized previously collected locomotor activity data recorded from normal subjects and bipolar patients by wrist-worn actigraphs. All control parameters in the proposed model have an important role in replicating the different aspects of circadian activity rhythm generation in the brain. The model can successfully replicate deviations in sleep/wake time intervals corresponding to manic and depressive episodes of bipolar disorder, in which one of the excitatory or inhibitory pathways is abnormally dominant. Although neuroimaging research has strongly implicated a reciprocal interaction between cortical and subcortical regions as pathogenic in bipolar disorder, this is the first model to mathematically represent this

  10. Circadian rhythms, sleep, and performance in space.

    Science.gov (United States)

    Mallis, M M; DeRoshia, C W

    2005-06-01

    Maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the National Aeronautics and Space Administration's (NASA's) vision "to extend humanity's reach to the Moon, Mars and beyond" to become a reality. Field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. This paper documents evidence of significant sleep loss and disruption of circadian rhythms in astronauts and associated performance decrements during several space missions, which demonstrates the need to develop effective countermeasures. Both sleep and circadian disruptions have been identified in the Behavioral Health and Performance (BH&P) area and the Advanced Human Support Technology (AHST) area of NASA's Bioastronautics Critical Path Roadmap. Such disruptions could have serious consequences on the effectiveness, health, and safety of astronaut crews, thus reducing the safety margin and increasing the chances of an accident or incident. These decrements oftentimes can be difficult to detect and counter effectively in restrictive operational environments. NASA is focusing research on the development of optimal sleep/wake schedules and countermeasure timing and application to help mitigate the cumulative effects of sleep and circadian disruption and enhance operational performance. Investing research in humans is one of NASA's building blocks that will allow for both short- and long-duration space missions and help NASA in developing approaches to manage and overcome the human limitations of space travel. In addition to reviewing the current state of knowledge concerning sleep and circadian disruptions during space operations, this paper provides an overview of NASA's broad research goals. Also, NASA-funded research, designed to evaluate the relationships between sleep quality, circadian rhythm stability, and

  11. Clinical learning environments: place, artefacts and rhythm.

    Science.gov (United States)

    Sheehan, Dale; Jowsey, Tanisha; Parwaiz, Mariam; Birch, Mark; Seaton, Philippa; Shaw, Susan; Duggan, Alison; Wilkinson, Tim

    2017-10-01

    Health care practitioners learn through experience in clinical environments in which supervision is a key component, but how that learning occurs outside the supervision relationship remains largely unknown. This study explores the environmental factors that inform and support workplace learning within a clinical environment. An observational study drawing on ethnographic methods was undertaken in a general medicine ward. Observers paid attention to interactions among staff members that involved potential teaching and learning moments that occurred and were visible in the course of routine work. General purpose thematic analysis of field notes was undertaken. A total of 376 observations were undertaken and documented. The findings suggest that place (location of interaction), rhythm (regularity of activities occurring in the ward) and artefacts (objects and equipment) were strong influences on the interactions and exchanges that occurred. Each of these themes had inherent tensions that could promote or inhibit engagement and therefore learning opportunities. Although many learning opportunities were available, not all were taken up or recognised by the participants. We describe and make explicit how the natural environment of a medical ward and flow of work through patient care contribute to the learning architecture, and how this creates or inhibits opportunities for learning. Awareness of learning opportunities was often tacit and not explicit for either supervisor or learner. We identify strategies through which tensions inherent within space, artefacts and the rhythms of work can be resolved and learning opportunities maximised. © 2017 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

  12. Biological and psychological rhythms: an integrative approach to rhythm disturbances in autistic disorder.

    Science.gov (United States)

    Botbol, Michel; Cabon, Philippe; Kermarrec, Solenn; Tordjman, Sylvie

    2013-09-01

    Biological rhythms are crucial phenomena that are perfect examples of the adaptation of organisms to their environment. A considerable amount of work has described different types of biological rhythms (from circadian to ultradian), individual differences in their patterns and the complexity of their regulation. In particular, the regulation and maturation of the sleep-wake cycle have been thoroughly studied. Its desynchronization, both endogenous and exogenous, is now well understood, as are its consequences for cognitive impairments and health problems. From a completely different perspective, psychoanalysts have shown a growing interest in the rhythms of psychic life. This interest extends beyond the original focus of psychoanalysis on dreams and the sleep-wake cycle, incorporating central theoretical and practical psychoanalytic issues related to the core functioning of the psychic life: the rhythmic structures of drive dynamics, intersubjective developmental processes and psychic containment functions. Psychopathological and biological approaches to the study of infantile autism reveal the importance of specific biological and psychological rhythmic disturbances in this disorder. Considering data and hypotheses from both perspectives, this paper proposes an integrative approach to the study of these rhythmic disturbances and offers an etiopathogenic hypothesis based on this integrative approach. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Bilateral spontaneous carotid artery dissection.

    Science.gov (United States)

    Townend, Bradley Scott; Traves, Laura; Crimmins, Denis

    2005-06-01

    Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.

  14. Spontaneous coronary artery dissection presenting as an ischaemic stroke in a middle-aged man with anti-cardiolipin antibodies: a case report

    Directory of Open Access Journals (Sweden)

    Lim F

    2010-03-01

    Full Text Available Abstract Introduction Cerebrovascular disease is a major cause of mortality and morbidity worldwide. Ischemic stroke is the most common manifestation, encompassing a wide variety of causative mechanisms. We present the case of a middle-aged male patient with spontaneous coronary artery dissection in the presence of anti-cardiolipin antibodies, leading to left ventricular thrombus and presenting with stroke. Case presentation A 56-year-old Caucasian man presented with dysarthria and right-sided weakness. There was a history of chest pain with autonomic symptoms four days earlier. Examination revealed right-sided hemiparesis. Electrocardiogram showed sinus rhythm with anterior Q waves. Magnetic resonance imaging of the brain showed large left parietal and smaller multiple cerebral infarcts. Echocardiogram showed anterior wall and apical akinesis with a large mural thrombus. Anti-cardiolipin antibodies immunoglobulin G and immunoglobulin M were strongly positive. Coronary angiography showed dissection of the mid left anterior descending artery with normal flow down the distal vessel. He was treated conservatively with anticoagulation and secondary prevention. He was in good health when seen in clinic four months later. Conclusion We highlight the importance of a comprehensive approach at obtaining the correct diagnosis, input of different specialities and the fact that the presence of anti-cardiolipin antibodies is associated with coronary artery dissection in a middle-aged male patient whose presentation was stroke.

  15. Cross-Cultural Influences on Rhythm Processing: Reproduction, Discrimination, and Beat Tapping

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2015-04-01

    Full Text Available The structures of musical rhythm differ between cultures, despite the fact that the ability to synchronize one’s movements to musical rhythms appears to be universal. To measure the influence of culture on rhythm processing, we tested East African and North American adults on the perception, production, and beat tapping of rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced both by the culture of the participant and by the culture of the rhythm. Specifically, we predicted that a participant’s ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than unfamiliar rhythms. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion.

  16. A Reliable Method for Rhythm Analysis during Cardiopulmonary Resuscitation

    Directory of Open Access Journals (Sweden)

    U. Ayala

    2014-01-01

    Full Text Available Interruptions in cardiopulmonary resuscitation (CPR compromise defibrillation success. However, CPR must be interrupted to analyze the rhythm because although current methods for rhythm analysis during CPR have high sensitivity for shockable rhythms, the specificity for nonshockable rhythms is still too low. This paper introduces a new approach to rhythm analysis during CPR that combines two strategies: a state-of-the-art CPR artifact suppression filter and a shock advice algorithm (SAA designed to optimally classify the filtered signal. Emphasis is on designing an algorithm with high specificity. The SAA includes a detector for low electrical activity rhythms to increase the specificity, and a shock/no-shock decision algorithm based on a support vector machine classifier using slope and frequency features. For this study, 1185 shockable and 6482 nonshockable 9-s segments corrupted by CPR artifacts were obtained from 247 patients suffering out-of-hospital cardiac arrest. The segments were split into a training and a test set. For the test set, the sensitivity and specificity for rhythm analysis during CPR were 91.0% and 96.6%, respectively. This new approach shows an important increase in specificity without compromising the sensitivity when compared to previous studies.

  17. Neural networks for beat perception in musical rhythm

    Directory of Open Access Journals (Sweden)

    Edward W Large

    2015-11-01

    Full Text Available Entrainment of cortical rhythms to acoustic rhythms has been hypothesized to be the neural correlate of pulse and meter perception in music. Dynamic attending theory first proposed synchronization of endogenous perceptual rhythms nearly forty years ago, but only recently has the pivotal role of neural synchrony been demonstrated. Significant progress has since been made in understanding the role of neural oscillations and the neural structures that support synchronized responses to musical rhythm. Synchronized neural activity has been observed in auditory and motor networks, and has been linked with attentional allocation and movement coordination. Here we describe a neurodynamic model that shows how self-organization of oscillations in interacting sensory and motor networks could be responsible for the formation of the pulse percept in complex rhythms. We test the model's prediction that pulse can be perceived at a frequency for which no spectral energy is present in the amplitude envelope of the acoustic rhythm. The result provides a theoretical link between oscillatory neurodynamics and the induction of pulse and meter in musical rhythm.

  18. Circadian rhythms in human performance and mood under constant conditions

    Science.gov (United States)

    Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Berga, S. L.; Jarrett, D. B.; Begley, A. E.; Kupfer, D. J.

    1997-01-01

    This study explored the relationship between circadian performance rhythms and rhythms in rectal temperature, plasma cortisol, plasma melatonin, subjective alertness and well-being. Seventeen healthy young adults were studied under 36 h of 'unmasking' conditions (constant wakeful bedrest, temporal isolation, homogenized 'meals') during which rectal temperatures were measured every minute, and plasma cortisol and plasma melatonin measured every 20 min. Hourly subjective ratings of global vigour (alertness) and affect (well-being) were obtained followed by one of two performance batteries. On odd-numbered hours performance (speed and accuracy) of serial search, verbal reasoning and manual dexterity tasks was assessed. On even-numbered hours, performance (% hits, response speed) was measured at a 25-30 min visual vigilance task. Performance of all tasks (except search accuracy) showed a significant time of day variation usually with a nocturnal trough close to the trough in rectal temperature. Performance rhythms appeared not to reliably differ with working memory load. Within subjects, predominantly positive correlations emerged between good performance and higher temperatures and better subjective alertness; predominantly negative correlations between good performance and higher plasma levels of cortisol and melatonin. Temperature and cortisol rhythms correlated with slightly more performance measures (5/7) than did melatonin rhythms (4/7). Global vigour correlated about as well with performance (5/7) as did temperature, and considerably better than global affect (1/7). In conclusion: (1) between-task heterogeneity in circadian performance rhythms appeared to be absent when the sleep/wake cycle was suspended; (2) temperature (positively), cortisol and melatonin (negatively) appeared equally good as circadian correlates of performance, and (3) subjective alertness correlated with performance rhythms as well as (but not better than) body temperature, suggesting that

  19. Circadian rhythm in Alzheimer disease after trazodone use.

    Science.gov (United States)

    Grippe, Talyta C; Gonçalves, Bruno S B; Louzada, Luciana L; Quintas, Juliana L; Naves, Janeth O S; Camargos, Einstein F; Nóbrega, Otávio T

    2015-01-01

    A circadian rhythm is a cycle of approximately 24 h, responsible for many physiological adjustments, and ageing of the circadian clock contributes to cognitive decline. Rhythmicity is severely impaired in Alzheimer disease (AD) and few therapeutic attempts succeeded in improving sleep disorders in such context. This study evaluated sleep parameters by actigraphy in 30 AD patients before and after trazodone use for 2 weeks, and we show a significant improvement in relative rhythm amplitude (RRA), compatible with a more stable daytime behavioral pattern. So, trazodone appears to produce a stabilization of the circadian rhythms in individuals with AD.

  20. Shockable rhythms and defibrillation during in-hospital pediatric cardiac arrest.

    Science.gov (United States)

    Rodríguez-Núñez, Antonio; López-Herce, Jesús; del Castillo, Jimena; Bellón, José María

    2014-03-01

    To analyze the results of cardiopulmonary resuscitation (CPR) that included defibrillation during in-hospital cardiac arrest (IH-CA) in children. A prospective multicenter, international, observational study on pediatric IH-CA in 12 European and Latin American countries, during 24 months. Data from 502 children between 1 month and 18 years were collected using the Utstein template. Patients with a shockable rhythm that was treated by electric shock(s) were included. The primary endpoint was survival at hospital discharge. Univariate logistic regression analysis was performed to find outcome factors. Forty events in 37 children (mean age 48 months, IQR: 7-15 months) were analyzed. An underlying disease was present in 81.1% of cases and 24.3% had a previous CA. The main cause of arrest was a cardiac disease (56.8%). In 17 episodes (42.5%) ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) was the first documented rhythm, and in 23 (57.5%) it developed during CPR efforts. In 11 patients (27.5%) three or more shocks were needed to achieve defibrillation. Return of spontaneous circulation (ROSC) was obtained in 25 cases (62.5%), that was sustained in 20 (50.0%); however only 12 children (32.4%) survived to hospital discharge. Children with VF/pVT as first documented rhythm had better sustained ROSC (64.7% vs. 39.1%, p=0.046) and survival to hospital discharge rates (58.8% vs. 21.7%, p=0.02) than those with subsequent VF/pVT. Survival rate was inversely related to duration of CPR. Clinical outcome was not related to the cause or location of arrest, type of defibrillator and waveform, energy dose per shock, number of shocks, or cumulative energy dose, although there was a trend to better survival with higher doses per shock (25.0% with 4Jkg(-1)) and worse with higher number of shocks and cumulative energy dose. The termination of pediatric VF/pVT in the IH-CA setting is achieved in a low percentage of instances with one electrical shock at 4Jkg(-1

  1. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  2. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  3. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  4. Surgery for spontaneous intracerebral hemorrhage: Emerging trends

    Directory of Open Access Journals (Sweden)

    Girish Menon

    2017-01-01

    Full Text Available In spite of advances in imaging and surgical techniques, spontaneous intracerebral hemorrhage (SICH has defied attempts to find a scientifically proven effective therapy. The pathophysiology of SICH suggests that early removal of the clot with minimal additional surgical trauma should prove beneficial. Trials in this direction have been few, and for some unknown reason, surgery has not proved to be superior to best medical management in most of these trials. This has led to substantial variability in the management of ICH throughout the world, and the treatment of SICH remains a controversy. SICH encompasses spectra of possible clot locations with varying volumes. Surgery so far has been reserved only for patients with large hematomas and impending brain herniation. Critical analysis of the earlier studies has now shown that surgery does help in clots in certain locations and of particular volume and when done at an optimal time. Poor grade patients with large hematomas, earlier considered poor surgical candidates are being taken up for aggressive decompressive craniectomies with fair results. In addition, minimally invasive surgical techniques complemented by thrombolytic techniques seem to providing surprisingly good results. Overall surgery seems to be going through a period of renaissance with respect to primary spontaneous ICHs.

  5. Patterns of Spontaneous Magnetoencephalographic Activity in Schizophrenic Patients

    OpenAIRE

    Siekmeier, Peter J.; Stufflebeam, Steven M.

    2010-01-01

    Magnetoencephalography (MEG) non-invasively measures the magnetic fields produced by the brain. Pertinent research articles from 1993 to 2009 that measured spontaneous, whole-head MEG activity in schizophrenic patients were reviewed. Data on localization of oscillatory activity and correlation of these findings with psychotic symptoms are summarized. While the variety of measures used by different research groups makes a quantitative meta-analysis difficult, it appears that MEG activity in pa...

  6. Investigating repetition and change in musical rhythm by functional MRI.

    Science.gov (United States)

    Danielsen, A; Otnæss, M K; Jensen, J; Williams, S C R; Ostberg, B C

    2014-09-05

    Groove-based rhythm is a basic and much appreciated feature of Western popular music. It is commonly associated with dance, movement and pleasure and is characterized by the repetition of a basic rhythmic pattern. At various points in the musical course, drum breaks occur, representing a change compared to the repeated pattern of the groove. In the present experiment, we investigated the brain response to such drum breaks in a repetitive groove. Participants were scanned with functional magnetic resonance imaging (fMRI) while listening to a previously unheard naturalistic groove with drum breaks at uneven intervals. The rhythmic pattern and the timing of its different parts as performed were the only aspects that changed from the repetitive sections to the breaks. Differences in blood oxygen level-dependent activation were analyzed. In contrast to the repetitive parts, the drum breaks activated the left cerebellum, the right inferior frontal gyrus (RIFG), and the superior temporal gyri (STG) bilaterally. A tapping test using the same stimulus showed an increase in the standard deviation of inter-tap-intervals in the breaks versus the repetitive parts, indicating extra challenges for auditory-motor integration in the drum breaks. Both the RIFG and STG have been associated with structural irregularity and increase in musical-syntactical complexity in several earlier studies, whereas the left cerebellum is known to play a part in timing. Together these areas may be recruited in the breaks due to a prediction error process whereby the internal model is being updated. This concurs with previous research suggesting a network for predictive feed-forward control that comprises the cerebellum and the cortical areas that were activated in the breaks. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Neural mechanisms of rhythm-based temporal prediction: Delta phase-locking reflects temporal predictability but not rhythmic entrainment.

    Directory of Open Access Journals (Sweden)

    Assaf Breska

    2017-02-01

    Full Text Available Predicting the timing of upcoming events enables efficient resource allocation and action preparation. Rhythmic streams, such as music, speech, and biological motion, constitute a pervasive source for temporal predictions. Widely accepted entrainment theories postulate that rhythm-based predictions are mediated by synchronizing low-frequency neural oscillations to the rhythm, as indicated by increased phase concentration (PC of low-frequency neural activity for rhythmic compared to random streams. However, we show here that PC enhancement in scalp recordings is not specific to rhythms but is observed to the same extent in less periodic streams if they enable memory-based prediction. This is inconsistent with the predictions of a computational entrainment model of stronger PC for rhythmic streams. Anticipatory change in alpha activity and facilitation of electroencephalogram (EEG manifestations of response selection are also comparable between rhythm- and memory-based predictions. However, rhythmic sequences uniquely result in obligatory depression of preparation-related premotor brain activity when an on-beat event is omitted, even when it is strategically beneficial to maintain preparation, leading to larger behavioral costs for violation of prediction. Thus, while our findings undermine the validity of PC as a sign of rhythmic entrainment, they constitute the first electrophysiological dissociation, to our knowledge, between mechanisms of rhythmic predictions and of memory-based predictions: the former obligatorily lead to resonance-like preparation patterns (that are in line with entrainment, while the latter allow flexible resource allocation in time regardless of periodicity in the input. Taken together, they delineate the neural mechanisms of three distinct modes of preparation: continuous vigilance, interval-timing-based prediction and rhythm-based prediction.

  8. Circadian and infradian rhythms in mood.

    Science.gov (United States)

    Mitsutake, G; Otsuka, K; Cornélissen, G; Herold, M; Günther, R; Dawes, C; Burch, J B; Watson, D; Halberg, F

    2001-01-01

    The aim of this study was to assess any variation in positive, negative and total affect recorded longitudinally; to compare the results with those from prior transverse or hybrid population studies, based on the same or a different method of mood rating; and to test for any association of mood with cardiovascular, hormonal and geophysical variables monitored concomitantly. The study approach was as follows. A clinically healthy 34-year-old man filled out the positive and negative affective scale (PANAS) questionnaire five times a day for 86 days. Systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) were also measured automatically at 30-minute intervals with an ambulatory monitor from May 19 to June 29, 2000, while different endpoints of heart rate variability (HRV) were also determined at 5-minute intervals from beat-to-beat electrocardiogram (ECG) monitoring for 42 days between May 3 and June 14, 2000, with only short interruptions while the subject took a shower and changed ECG tapes. Saliva samples were collected at the times of mood ratings for one month for later determination of melatonin and cortisol concentrations. Intervals of 24 hours of the record of each variable displaced in increments of 24 hours were analyzed by chronobiologic serial section at a trial period of 24 hours to assess the circadian characteristics as they changed from one day to another. Estimates of the midline-estimating statistic of rhythm (MESOR) and circadian amplitude and acrophase obtained on consecutive days were correlated among variables to assess any associations. The findings were as follows. Overall, a circadian rhythm was demonstrated for all variables. A positive association was noteworthy between the circadian amplitude of negative affect and the MESOR of both SBP (r= 0.363; P= 0.029) and DBP (r= 0.389; P= 0.019), suggesting that BP is raised in the presence of large swings in negative affect. Needing further validation was a weak association between

  9. Spontaneous Fluctuations of PO2 in the Rabbit Somatosensory Cortex.

    Science.gov (United States)

    Linsenmeier, Robert A; Aksenov, Daniil P; Faber, Holden M; Makar, Peter; Wyrwicz, Alice M

    2016-01-01

    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.

  10. Analysis of Nonstationary Time Series for Biological Rhythms Research.

    Science.gov (United States)

    Leise, Tanya L

    2017-06-01

    This article is part of a Journal of Biological Rhythms series exploring analysis and statistics topics relevant to researchers in biological rhythms and sleep research. The goal is to provide an overview of the most common issues that arise in the analysis and interpretation of data in these fields. In this article on time series analysis for biological rhythms, we describe some methods for assessing the rhythmic properties of time series, including tests of whether a time series is indeed rhythmic. Because biological rhythms can exhibit significant fluctuations in their period, phase, and amplitude, their analysis may require methods appropriate for nonstationary time series, such as wavelet transforms, which can measure how these rhythmic parameters change over time. We illustrate these methods using simulated and real time series.

  11. Language familiarity, expectation, and novice musical rhythm production.

    Science.gov (United States)

    Neuhoff, John G; Lidji, Pascale

    2014-12-01

    The music of expert musicians reflects the speech rhythm of their native language. Here, we examine this effect in amateur and novice musicians. English- and French-speaking participants were both instructed to produce simple "English" and "French" tunes using only two keys on a keyboard. All participants later rated the rhythmic variability of English and French speech samples. The rhythmic variability of the "English" and "French" tunes that were produced reflected the perceived rhythmic variability in English and French speech samples. Yet, the pattern was different for English and French participants and did not correspond to the actual measured speech rhythm variability of the speech samples. Surprise recognition tests two weeks later confirmed that the music-speech relationship remained over time. The results show that the relationship between music and speech rhythm is more widespread than previously thought and that musical rhythm production by amateurs and novices is concordant with their rhythmic expectations in the perception of speech.

  12. Melatonin in sleepless children : everything has a rhythm?

    NARCIS (Netherlands)

    van Geijlswijk, I.M.

    2011-01-01

    Every living organism has an biological clock regulating endogenous melatonin production, synchronized by exogenous impulses like daylight, temperature and feeding. Inappropriately applied bright light disturbs this melatonin rhythm. Some large swine producers apply artificial light three times a

  13. Gamification Quest: Rhythm. Music as a game mechanic

    OpenAIRE

    Granell Díaz, Marina

    2017-01-01

    Treball Final de Grau en Disseny i Desenvolupament de Videojocs. Codi: VJ1241. Curs acadèmic: 2016/2017 This document constitutes the Technical Report for the project Gamification Quest: Rhythm, music as a game mechanic for the Videogame Design and Development bachelor degree. The project consists on the design and implementation of rhythm game mechanics integrated in a gamification environment applied to education. The video game will be implemented on the game engine Unity (10), ...

  14. Accuracy of rate coding: When shorter time window and higher spontaneous activity help

    Czech Academy of Sciences Publication Activity Database

    Leváková, Marie; Tamborrino, M.; Košťál, Lubomír; Lánský, Petr

    2017-01-01

    Roč. 95, č. 2 (2017), č. článku 022310. ISSN 2470-0045 R&D Projects: GA ČR(CZ) GA15-08066S; GA MŠk(CZ) 7AMB17AT048 Institutional support: RVO:67985823 Keywords : rate coding * observation window * spontaneous activity * Fisher information * perfect integrate- and -fire model * Wiener process Subject RIV: BB - Applied Statistics, Operational Research OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 2.366, year: 2016

  15. Another place, another timer: Marine species and the rhythms of life

    OpenAIRE

    Tessmar-Raible, Kristin; Raible, Florian; Arboleda, Enrique

    2011-01-01

    The marine ecosystem is governed by a multitude of environmental cycles, all of which are linked to the periodical recurrence of the sun or the moon. In accordance with these cycles, marine species exhibit a variety of biological rhythms, ranging from circadian and circatidal rhythms to circalunar and seasonal rhythms. However, our current molecular understanding of biological rhythms and clocks is largely restricted to solar-controlled circadian and seasonal rhythms in land model species. He...

  16. European Heart Rhythm Association Summit report 2014.

    Science.gov (United States)

    Sutton, Richard; Leclercq, Christophe; Kuck, Karl-Heinz

    2016-05-01

    Across Europe, the role of the welfare state is constantly being questioned and even eroded. At the same time, funding sources for post-graduate medical education and training are under attack as regulators review the working relationships between physicians and industry. Both of these issues have profound consequences for cardiologists and their patients, and were, therefore, chosen as the themes of the European Heart Rhythm Association (EHRA) 2014 Spring Summit held at Heart House, Sophia Antipolis, 25-26 March 2014. The meeting noted that some of the changes are already affecting patient care standards and that this is exacerbated by a reduction in research and education programmes. The principle conclusion was that EHRA must find better means of engagement with the authorities across Europe to ensure that its views are considered and that ethical patient care is preserved. Participants were particularly alarmed by the example from Sweden in which future healthcare planning appears to exclude the views of physicians, although this is not yet the case in other countries. The demand for greater transparency in relationships between physicians and industry was also discussed. Although intended to eliminate corruption, concern was expressed that such moves would cause long-term damage to education and research, threatening the future of congresses, whose role in these areas appears underestimated by the authorities. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  17. Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

    Science.gov (United States)

    Li, Ying; Liu, Zengrong

    MicroRNAs (miRNAs) interact with 3‧untranslated region (UTR) elements of target genes to regulate mRNA stability or translation, and play a crucial role in regulating many different biological processes. bantam, a conserved miRNA, is involved in several functions, such as regulating Drosophila growth and circadian rhythm. Recently, it has been discovered that bantam plays a crucial role in the core circadian pacemaker. In this paper, based on experimental observations, a detailed dynamical model of bantam-regulated circadian clock system is developed to show the post-transcriptional behaviors in the modulation of Drosophila circadian rhythm, in which the regulation of bantam is incorporated into a classical model. The dynamical behaviors of the model are consistent with the experimental observations, which shows that bantam is an important regulator of Drosophila circadian rhythm. The sensitivity analysis of parameters demonstrates that with the regulation of bantam the system is more sensitive to perturbations, indicating that bantam regulation makes it easier for the organism to modulate its period against the environmental perturbations. The effectiveness in rescuing locomotor activity rhythms of mutated flies shows that bantam is necessary for strong and sustained rhythms. In addition, the biological mechanisms of bantam regulation are analyzed, which may help us more clearly understand Drosophila circadian rhythm regulated by other miRNAs.

  18. The phonetic rhythm/syntax headedness connection: Evidence from Tagalog

    Science.gov (United States)

    Bird, Sonya; Fais, Laurel; Werker, Janet

    2005-04-01

    Ramus, Nespor, and Mehler [Cognition (1999)] show that the rhythm of a language (broadly: stress- versus syllable- versus mora-timing) results from the proportion of vocalic material in an utterance (%V) and the standard deviation of consonantal intervals (delta-C). Based on 14 languages, Shukla, Nespor, and Mehler [submitted] further argue that rhythm is correlated with syntactic headedness: low %V is correlated with head-first languages (e.g., English); high %V is correlated with head-final languages (e.g., Japanese). Together, these proposals have important implications for language acquisition: infants can discriminate across rhythm classes [Nazzi, Bertoncini, and Mehler, J. Exp. Psych: Human Perception and Performance (1998)]. If rhythm, as defined by %V and delta-C, can predict headedness, then infants can potentially use rhythm information to bootstrap into their languages syntactic structure. This paper reports on a study analyzing rhythm in a language not yet considered: Tagalog. Results support the Shukla et al. proposal in an interesting way: based on its %V and delta-C, Tagalog falls between head-first and head-last languages, slighty closer to the head-first group. This placement correlates well with the fact that, although Tagalog is said to be primarily head-first syntactically, head-last phrases are permitted and common in the language.

  19. Educating the sense of rhythm in primary education students

    Directory of Open Access Journals (Sweden)

    Silvia GRĂDINARU

    2017-03-01

    Full Text Available Background: Rhythm as a core element of complex coordination is the key to efficient moulding of motor skills specific to sports activities in curricula. Practicing physical exercise in a varied rhythm and tempo in primary school students moulds the skill of achieving correct movement basics (direction, span, coordination, and expressivity. The use of music in sports classes improves kinetics and vestibular sensitivity. The sense of rhythm and tempo are imperative criteria in vocational schools. Purpose: This paper aims to describe a pattern of means selected to develop the sense of rhythm and to allow movements in different sports branches with increased efficiency. Methods: The test battery was applied on a sample of 15 students from the 4th grade of the “Ion Vidu” National Arts College in Timisoara, Romania, aged 9-10 years, over an entire school year, using different rhythms and tempos during sports classes, which were later used in gymnastics, athletic events, and basketball. Results: Data recorded after the application tests, processed and interpreted confirms the proposed assumption and validates the motor contents used. Conclusions: Sense of rhythm is a component of coordinative capacity that is required to be educated from an early age. Rhythmic movements are easier to automate saving energy and motivating students to an active and conscious participation.

  20. The Mood Rhythm Instrument: development and preliminary report.

    Science.gov (United States)

    de Souza, Camila M; Carissimi, Alicia; Costa, Daniele; Francisco, Ana Paula; Medeiros, Madeleine S; Ilgenfritz, Carlos A; de Oliveira, Melissa A; Frey, Benicio N; Hidalgo, Maria Paz

    2016-01-01

    To describe the initial steps in the development and validation of a new self-reported instrument designed to assess daily rhythms of mood symptoms, namely, the Mood Rhythm Instrument. A multidisciplinary group of experts took part in systematic meetings to plan the construction of the instrument. Clarity of items, their relevance to evaluation of mood states, and the consistency of findings in relation to the available evidence on the biological basis of mood disorders were investigated. The internal consistency of the questionnaire was evaluated through Cronbach's alpha. All of the items proposed in a first version were well rated in terms of clarity. The items more frequently rated as "rhythmic" were related to the somatic symptoms of mood. Their peaks in 24 hours were more frequent in the morning. The items associated with affective symptoms of mood were rated as less rhythmic, and their peak in 24 hours occurred more frequently in the afternoon and evening. Males and females behaved more similarly with respect to somatic than behavioral-affective items. The second version of the Mood Rhythm Instrument had a Cronbach's alpha of 0.73. The proposed Mood Rhythm Instrument may be able to detect individual rhythms of cognitive and behavioral measures associated with mood states. Validation in larger samples and against objective measures of rhythms, such as actigraphy, is warranted.

  1. Circadian rhythm and sleep influences on digestive physiology and disorders

    Directory of Open Access Journals (Sweden)

    Vaughn BV

    2014-09-01

    Full Text Available Bradley V Vaughn, Sean Rotolo, Heidi L Roth Division of Sleep Medicine, Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA Abstract: Circadian rhythms and sleep influence a variety of physiological functions, including the digestive system. The digestive system also has intrinsic rhythms that interact dynamically with circadian rhythms. New advances in understanding the interaction of these rhythms and sleep provide the prospect of evaluating their role in normal physiology and the link of their disruption to pathological conditions. Recent work has demonstrated that sleep and circadian factors influence appetite, nutrient absorption, and metabolism. Disruption of sleep and circadian rhythms may increase vulnerability to digestive disorders, including reflux, ulcers, inflammatory bowel issues, irritable bowel disease, and gastrointestinal cancer. As our knowledge of the link between circadian timing and gastrointestinal physiology grows, so do our opportunities to provide promising diagnostic and therapeutic approaches for gastrointestinal disorders. Keywords: digestion, digestive diseases, gastrointestinal reflux, sleep, circadian rhythm 

  2. Three-dimensional magnetic resonance reconstruction images before and after surgical therapy of spontaneous canine brain tumors Imagens de reconstrução tri-dimensional por ressonância magnética antes e depois de tratamento cirúrgico de tumores cerebrais espontâneos caninos

    Directory of Open Access Journals (Sweden)

    Julio Carlos Canola

    2007-08-01

    Full Text Available Specific software was used for reconstruction of spontaneous intracranial tumor volume from magnetic resonance images (MRI in three dogs. Histopathologically confirmed meningioma, cystic meningioma, and choroid plexus tumors were evaluated before and after surgery. The software allowed the whole-volume segmentation of the skin, brain, tumor, edema, and cyst. Manipulation of the three-dimensional images (3D allowed visualization of all anatomical structures, aided clinical understanding, surgical planning, and treatment monitoring.Um programa de computador específico foi utilizado para reconstrução do volume tumoral intracraniano espontâneo por imagens de ressonância magnética (IRM em três cães. Tumores histopatologicamente confirmados como meningioma, meningioma cístico e tumor do plexo coróide foram avaliados antes e após cirurgia. O programa de computador permitiu a segmentação por completo da pele, do cérebro, do tumor, do edema e do cisto. A manipulação das imagens tridimensionais permitiu a visibilização de todas as estruturas anatômicas, além da compreensão clínica, do planejamento cirúrgico e da monitorização do tratamento.

  3. Brain Basics

    Medline Plus

    Full Text Available ... About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain Brain ... called the hypothalamic-pituitary-adrenal (HPA) axis. Brain Basics in Real Life Brain Basics in Real Life— ...

  4. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  5. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  6. Circadian oscillators in the mouse brain

    DEFF Research Database (Denmark)

    Rath, Martin F; Rovsing, Louise; Møller, Morten

    2014-01-01

    The circadian timekeeper of the mammalian brain resides in the suprachiasmatic nucleus of the hypothalamus (SCN), and is characterized by rhythmic expression of a set of clock genes with specific 24-h daily profiles. An increasing amount of data suggests that additional circadian oscillators...... residing outside the SCN have the capacity to generate peripheral circadian rhythms. We have recently shown the presence of SCN-controlled oscillators in the neocortex and cerebellum of the rat. The function of these peripheral brain clocks is unknown, and elucidating this could involve mice...... and granular cell layers of the cerebellar cortex of the mouse brain. Among these, Per1, Per2, Cry1, Arntl, and Nr1d1 exhibit circadian rhythms suggesting that local running circadian oscillators reside within neurons of the mouse neocortex and cerebellar cortex. The temporal expression profiles of clock genes...

  7. Spontaneous perseverative turning in rats with radiation-induced hippocampal damage

    International Nuclear Information System (INIS)

    Mickley, G.A.; Ferguson, J.L.; Nemeth, T.J.; Mulvihill, M.A.; Alderks, C.E.

    1989-01-01

    This study found a new behavioral correlate of lesions specific to the dentate granule cell layer of the hippocampus: spontaneous perseverative turning. Irradiation of a portion of the neonatal rat cerebral hemispheres produced hypoplasia of the granule cell layer of the hippocampal dentate gyrus while sparing the rest of the brain. Radiation-induced damage to the hippocampal formation caused rats placed in bowls to spontaneously turn in long, slow bouts without reversals. Irradiated subjects also exhibited other behaviors characteristic of hippocampal damage (e.g., perseveration in spontaneous exploration of the arms of a T-maze, retarded acquisition of a passive avoidance task, and increased horizontal locomotion). These data extend previously reported behavioral correlates of fascia dentata lesions and suggest the usefulness of a bout analysis of spontaneous bowl turning as a measure of nondiscrete-trial spontaneous alternation and a sensitive additional indicator of radiation-induced hippocampal damage

  8. The Effect Of Reversed Light-Dark Cycle And Restricted Feeding Regime On The Circadian Rhythm Of Cortisol And Serotonin In Male Rats

    International Nuclear Information System (INIS)

    Abdel-Rahman, M.; El-Masry, H.; El-Hennamy, R.E.; Abdel-Kader, S.

    2013-01-01

    Biological clock plays an important role in the regulation of different physiological processes and behaviour. The present study aimed to investigate the effect of the reversed light-dark cycle and restricted feeding regime for one and two weeks on the circadian rhythm of cortisol and serotonin in male rats. Serum cortisol and brain serotonin levels were delayed after exposing rats to a reversed light-dark cycle for one week which may be due to the action of the gene Per2 that delay the phase of the clock. On the other hand, their levels highly elevated and peaked at the same time after two weeks which may be due to continuous stressful events. The serum cortisol reached its highest level at the meal time after one week of restricted feeding while after two weeks, its level was higher at several time intervals, which may be due to the need of the body to energy. The peak of the brain serotonin rhythm was delayed during the day after one week while after two weeks, it exhibited the same pattern of the circadian rhythm of control group. From the present results and previous studies, it could be concluded that the reversed light-dark cycle and restricted feeding regime are able to shift the phase of the circadian rhythm of the studied physiological parameters which led to many mental and physiological disorders

  9. Diurnal rhythms of blood glucose, serum ghrelin, faecal IgA and faecal corticosterone in rats subjected to restricted feeding using the diet board

    DEFF Research Database (Denmark)

    Kasanen, Iiris; Inhilä, Katja; Savontaus, Eriika

    2018-01-01

    Laboratory rats are generally fed ad libitum, although this method is associated with obesity and an increased frequency of spontaneous tumours. It has been challenging looking for ways to limit feed consumption in group-housed rats without any setbacks to animal welfare and scientific results....... The diet board, as a method of dietary restriction, was used in the present study. Diet board feeding allows group housing and should result in enhanced welfare compared with traditional methods of dietary restriction. With respect to animal model robustness and translatability of results it is important...... that the feeding regime does not affect diurnal rhythmicity of biological parameters. In the present study the effects of diet board feeding on diurnal rhythms of blood glucose, serum ghrelin, faecal immunoglobulin A (IgA) and faecal corticosterone were assessed. The diet board did not alter diurnal rhythms...

  10. Hypophysectomy abolishes rhythms in rat thyroid hormones but not in the thyroid clock.

    Science.gov (United States)

    Fahrenkrug, J; Georg, B; Hannibal, J; Jørgensen, H L

    2017-06-01

    The endocrine body rhythms including the hypothalamic-pituitary-thyroid axis seem to be regulated by the circadian timing system, and daily rhythmicity of circulating thyroid-stimulating hormone (TSH) is well established. The circadian rhythms are generated by endogenous clocks in the central brain oscillator located in the hypothalamic suprachiasmatic nucleus (SCN) as well as multiple peripheral clocks, but information on the existence and function of a thyroid clock is limited. The molecular machinery in all clock cells is composed of a number of clock genes and their gene products are connected by autoregulatory feedback loops. Here, we provide evidence for a thyroid clock in the rat by demonstrating 24-h antiphase oscillations for the mRNA of the canonical clock genes Per1 and Bmal1 , which was unaffected by hypophysectomy. By immunostaining, we supported the existence of a core oscillator in the individual thyroid cells by demonstrating a daily cytoplasmatic-nuclear shuttling of PER1 protein. In normal rats, we found a significant daily rhythmicity in the circulating thyroid hormones preceded by a peak in TSH. In hypophysectomised rats, although the thyroid clock was not affected, the oscillations in circulating thyroid hormones were abolished and the levels were markedly lowered. No daily oscillations in the expression of TSH receptor mRNA were observed in neither control rats nor hypophysectomised rats. Our findings indicate that the daily rhythm of thyroid hormone secretion is governed by SCN signalling via the rhythmic TSH secretion rather than by the local thyroid clock, which was still ticking after hypophysectomy. © 2017 The authors.

  11. Spontaneous subcapsular and perirrenal hemorrhage

    International Nuclear Information System (INIS)

    Fuster, M.J.; Saez, J.; Perez-Paya, F.J.; Fernandez, F.

    1997-01-01

    To assess the role of CT in the etiologic diagnosis of spontaneous subcapsular and perirrenal hemorrhage. The CT findings are described in 13 patients presenting subcapsular and perirrenal hemorrhage. Those patients in whom the bleeding was not spontaneous were excluded. Surgical confirmation was obtained in nine cases. In 11 of the 13 cases (84.6%), involving five adenocarcinomas, five angiomyolipoma, two complicated cysts and one case of panarterities nodosa, CT disclosed the underlying pathology. In two cases (15.4%), it only revealed the extension of the hematoma, but gave no clue to its origin. CT is the technique of choice when spontaneous subcapsular and perirrenal hemorrhage is suspected since, in most cases, it reveals the underlying pathology. (Author)

  12. Assessment of baroreflex sensitivity from spontaneous oscillations of blood pressure and heart rate: proven clinical value?

    International Nuclear Information System (INIS)

    Pinna, Gian Domenico; Maestri, Roberto; La Rovere, Maria Teresa

    2015-01-01

    The baroreceptor-heart rate reflex (baroreflex sensitivity, BRS) is a key mechanism contributing to the neural regulation of the cardiovascular system. Several methods have been proposed so far to assess BRS by analyzing the spontaneous beat-to-beat fluctuations of arterial blood pressure and heart rate. These methods are inherently simple, non-invasive and low-cost. This study is an attempt to address the question of whether spontaneous baroreflex methods have proven to be of value in the clinical setting. In the first part of this article, we critically review most representative clinical studies using spontaneous BRS techniques either for risk stratification or treatment evaluation, these being major issues in the clinical management of the patients. In the second part, we address two important aspects of spontaneous BRS measurements: measurability and reliability. Estimation of BRS in the studies selected for the review was performed according to the sequence, transfer function, alpha-index and phase-rectified signal averaging method. Arterial blood pressure was recorded non-invasively during supine, short-term (<30 min) laboratory recordings. The conclusion from this review is that spontaneous BRS techniques have been shown to be of great value in clinical practice but further work is needed to confirm the validity of previous findings and to widen the field of clinical applications. Measurability and reliability can be a major issue in the measurement of spontaneous BRS, particularly in some patient populations like post-myocardial infarction and heart failure patents. Main causes of poor measurability are: non-sinus rhythm, a high rate of ectopic beats and the need for recorded time series of RR interval and arterial blood pressure to satisfy the constraints of the different BRS estimation algorithms. As for reliability, within-subject variability is rather high in the measurements of spontaneous BRS and, therefore, should be carefully taken into account

  13. Biological Rhythms During Residence in Polar Regions

    Science.gov (United States)

    2012-01-01

    At Arctic and Antarctic latitudes, personnel are deprived of natural sunlight in winter and have continuous daylight in summer: light of sufficient intensity and suitable spectral composition is the main factor that maintains the 24-h period of human circadian rhythms. Thus, the status of the circadian system is of interest. Moreover, the relatively controlled artificial light conditions in winter are conducive to experimentation with different types of light treatment. The hormone melatonin and/or its metabolite 6-sulfatoxymelatonin (aMT6s) provide probably the best index of circadian (and seasonal) timing. A frequent observation has been a delay of the circadian system in winter. A skeleton photoperiod (2 × 1-h, bright white light, morning and evening) can restore summer timing. A single 1-h pulse of light in the morning may be sufficient. A few people desynchronize from the 24-h day (free-run) and show their intrinsic circadian period, usually >24 h. With regard to general health in polar regions, intermittent reports describe abnormalities in various physiological processes from the point of view of daily and seasonal rhythms, but positive health outcomes are also published. True winter depression (SAD) appears to be rare, although subsyndromal SAD is reported. Probably of most concern are the numerous reports of sleep problems. These have prompted investigations of the underlying mechanisms and treatment interventions. A delay of the circadian system with “normal” working hours implies sleep is attempted at a suboptimal phase. Decrements in sleep efficiency, latency, duration, and quality are also seen in winter. Increasing the intensity of ambient light exposure throughout the day advanced circadian phase and was associated with benefits for sleep: blue-enriched light was slightly more effective than standard white light. Effects on performance remain to be fully investigated. At 75°S, base personnel adapt the circadian system to night work within

  14. Spontaneous isolated celiac artery dissection

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2011-01-01

    Full Text Available Dyspepsia with mild, stabbing epigastric discomfort without history of trauma is a very common symptom that emergency physicians see in their daily practice. Vascular emergencies, mostly the aortic dissection and aneurysm, are always described in the differential diagnosis with persistent symptoms. Isolated celiac artery dissection occurring spontaneously is a very rare diagnosis. The involvement of branch vessels is generally observed and patients show various clinical signs and symptoms according to the involved branch vessel. Here we are presenting a case with spontaneous isolated celiac artery dissection, without any branch vessel involvement or visceral damage, detected by computed tomography scans taken on admission.

  15. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  16. Physiological basis for human autonomic rhythms

    Science.gov (United States)

    Eckberg, D. L.

    2000-01-01

    Oscillations of arterial pressures, heart periods, and muscle sympathetic nerve activity have been studied intensively in recent years to explore otherwise obscure human neurophysiological mechanisms. The best-studied rhythms are those occurring at breathing frequencies. Published evidence indicates that respiratory fluctuations of muscle sympathetic nerve activity and electrocardiographic R-R intervals result primarily from the action of a central 'gate' that opens during expiration and closes during inspiration. Parallel respiratory fluctuations of arterial pressures and R-R intervals are thought to be secondary to arterial baroreflex physiology: changes in systolic pressure provoke changes in the R-R interval. However, growing evidence suggests that these parallel oscillations result from the influence of respiration on sympathetic and vagal-cardiac motoneurones rather than from baroreflex physiology. There is a rapidly growing literature on the use of mathematical models of low- and high-frequency (respiratory) R-R interval fluctuations in characterizing instantaneous 'sympathovagal balance'. The case for this approach is based primarily on measurements made with patients in upright tilt. However, the strong linear relation between such measures as the ratio of low- to high-frequency R-R interval oscillations and the angle of the tilt reflects exclusively the reductions of the vagal (high-frequency) component. As the sympathetic component does not change in tilt, the low- to high-frequency R-R interval ratio provides no proof that sympathetic activity increases. Moreover, the validity of extrapolating from measurements performed during upright tilt to measurements during supine rest has not been established. Nonetheless, it is clear that measures of heart rate variability provide important prognostic information in patients with cardiovascular diseases. It is not known whether reduced heart rate variability is merely a marker for the severity of disease or a

  17. [Psychoeducation and interpersonal and social rhythm therapy for bipolar disorder].

    Science.gov (United States)

    Mizushima, Hiroko

    2011-01-01

    In treating bipolar disorder, specific psychotherapies in adjunct to pharmacotherapy have been shown to be effective in preventing new episodes and treating depressive episodes. Among those, interpersonal and social rhythm therapy (IPSRT) developed by Frank, amalgamation of interpersonal psychotherapy (IPT) with behavioral therapy focused on social rhythm has been shown to be an efficacious adjunct to mediation in preventing new episodes in bipolar I patients and in treating depression in bipolar I arid II disorder. IPSRT has also been shown to enhance total functioning, relationship functioning and life satisfaction among patients with bipolar disorder, even after pretreatment functioning and concurrent depression were covaried. IPSRT was designed to directly address the major pathways to recurrence in bipolar disorder, namely medication nonadherence, stressful life events, and disruptions in social rhythms. IPT, originated by Klerman et al., is a strategic time-limited psychotherapy focused on one or two of four current interpersonal problem areas (ie, grief, interpersonal role disputes, role transitions, and interpersonal dificits). In IPSRT, the fifth problem area "grief for the lost healthy self" has been added in order to promote acceptance of the diagnosis and the need for life-long treatment. Social rhythm therapy is a behavioral approach aiming at increasing regularity of social rhythms using the Social Rhythm Metric (SRM), a chart to record daily social activities including how stimulating they were, developed from observation that disruptions in social rhythms often trigger affective episodes in patients with bipolar disorder. IPSRT also appears to be a promising intervention for a subset of individuals with bipolar II depression as monotherapy for the acute treatment.

  18. Rhythms of mammalian body temperature can sustain peripheral circadian clocks.

    Science.gov (United States)

    Brown, Steven A; Zumbrunn, Gottlieb; Fleury-Olela, Fabienne; Preitner, Nicolas; Schibler, Ueli

    2002-09-17

    Low-amplitude temperature oscillations can entrain the phase of circadian rhythms in several unicellular and multicellular organisms, including Neurospora and Drosophila. Because mammalian body temperature is subject to circadian variations of 1 degrees C-4 degrees C, we wished to determine whether these temperature cycles could serve as a Zeitgeber for circadian gene expression in peripheral cell types. In RAT1 fibroblasts cultured in vitro, circadian gene expression could be established by a square wave temperature rhythm with a (Delta)T of 4 degrees C (12 hr 37 degrees C/12 hr 33 degrees C). To examine whether natural body temperature rhythms can also affect circadian gene expression, we first measured core body temperature cycles in the peritoneal cavities of mice by radiotelemetry. We then reproduced these rhythms with high precision in the liquid medium of cultured fibroblasts for several days by means of a homemade computer-driven incubator. While these "in vivo" temperature rhythms were incapable of establishing circadian gene expression de novo, they could maintain previously induced rhythms for multiple days; by contrast, the rhythms of control cells kept at constant temperature rapidly dampened. Moreover, circadian oscillations of environmental temperature could reentrain circadian clocks in the livers of mice, probably via the changes they imposed upon both body temperature and feeding behavior. Interestingly, these changes in ambient temperature did not affect the phase of the central circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus. We postulate that both endogenous and environmental temperature cycles can participate in the synchronization of peripheral clocks in mammals.

  19. Biological rhythms in the human life cycle and their relationship to functional changes in the suprachiasmatic nucleus

    NARCIS (Netherlands)

    Swaab, D. F.; van Someren, E. J.; Zhou, J. N.; Hofman, M. A.

    1996-01-01

    Biological rhythms play a prominent role in the human life cycle. The endogenous rhythms are entrained by the environment and have an astronomical counterpart which is obvious for daily, monthly, and yearly rhythms, and may possibly also be present in weekly rhythms. Circadian rhythms are present

  20. Mu rhythm suppression demonstrates action representation in pianists during passive listening of piano melodies.

    Science.gov (United States)

    Wu, C Carolyn; Hamm, Jeff P; Lim, Vanessa K; Kirk, Ian J

    2016-08-01

    Musicians undergo extensive training which enhances established neural links between auditory and motor areas of the brain. Long-term training develops, strengthens and enables flexibility in these connections allowing proficiency in performance. Previous research has indicated that passive listening of trained music results in the recruitment of premotor areas. It has been argued that this sound-action representation may rely on activity in mirror neuron systems and that these systems are heavily dependent on actual sensorimotor experience. Action observation studies using electroencephalography have associated changes in mu rhythm activity with the mirror neuron system in the visuomotor domain. We aimed to investigate similar effects in the audiomotor domain. We utilised a mu suppression method in our action-listening study to detect involuntary motor coactivation when pianists passively listened to piano melodies. Wavelet analysis revealed sensorimotor mu rhythm suppression while pianists listened passively to piano melodies. Thus, we show that this spectral analysis method can also be used to demonstrate that auditory stimuli can activate the human mirror neuron system when sounds are linked to actions. Mu suppression could be a useful index for further research on action representation and training-induced plasticity.

  1. Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery

    DEFF Research Database (Denmark)

    Ambühl, Lea Maria Margareta; Baandrup, Ulrik; Dybkær, Karen

    2016-01-01

    , and 10.9% (95% CI; 10.1–11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and pretermdeliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50......%, resp.), were identified to be higher compared to normal full-term pregnancies (푃 spontaneous abortion, spontaneous preterm...

  2. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  3. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  4. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  5. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  6. EAMJ Dec. Spontaneous.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... surgical abortion at one month gestation without any complication. The second pregnancy which was a year prior resulted in a spontaneous miscarriage at two months followed by evacuation of retained products of conception with no post abortion complications. Antibiotics were taken following both.

  7. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    the Yukawa-plus-exponential potential. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the ...

  8. Altered circadian rhythms of natural killer (NK) cell activity in patients with autoimmune rheumatic diseases.

    Science.gov (United States)

    Masera, R G; Carignola, R; Staurenghi, A H; Sartori, M L; Lazzero, A; Griot, G; Angeli, A

    1994-01-01

    Natural Killer (NK) cells are a lymphocyte subset actively involved in cytotoxicity against tumor-transformed and virus-infected cells; they are a reliable model for the study of neuroendocrine-immune interactions. In previous works we demonstrated that in healthy subjects NK activity of peripheral blood mononuclear cells (PBMC) and susceptibility to endogenous modifiers display statistically validated circadian rhythms. In rheumatoid arthritis (RA) and in other autoimmune rheumatic diseases abnormalities of the circadian rhythm of serum cortisol and altered levels of NK cell activity have been reported. We evaluated the circadian pattern of NK cell activity in 7 hospitalized patients with autoimmune rheumatic diseases (4 RA, 1 scleroderma, 2 mixed connective tissue disease). Temporal variations of in vitro responses to either positive recombinant (immune interferon, r IFN-gamma IFN-gamma: 650 IU/ml; recombinant interleukin-2, r IL-2 IL-2: 100 IU/ml) or negative (cortisol: 10(-6) M) modifiers were also studied. Blood was drawn at 4h intervals for 24 h, starting at 0800. PBMC preparations were immediately separated and incubated for 20h in the presence or absence of modifiers. NK activity was assessed with a direct non-radiometric 4h cytolytic assay, using K 562 cells as targets. Significant circadian variations of spontaneous NK activity were documented only in women with RA, with a peak in the evening hours and a minimum in the night or in the early morning (p < 0.05, PR 51.5%, phi 1829). Population-mean cosinor analysis did not yield detection of significant circadian variations of in vitro responsiveness to modifiers.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Social Rhythm and Mental Health: A Cross-Cultural Comparison.

    Directory of Open Access Journals (Sweden)

    Jürgen Margraf

    Full Text Available Social rhythm refers to the regularity with which one engages in social activities throughout the week, and has established links with bipolar disorder, as well as some links with depression and anxiety. The aim of the present study is to examine social rhythm and its relationship to various aspects of health, including physical health, negative mental health, and positive mental health.Questionnaire data were obtained from a large-scale multi-national sample of 8095 representative participants from the U.S., Russia, and Germany.Results indicated that social rhythm irregularity is related to increased reporting of health problems, depression, anxiety, and stress. In contrast, greater regularity is related to better overall health state, life satisfaction, and positive mental health. The effects are generally small in size, but hold even when controlling for gender, marital status, education, income, country, and social support. Further, social rhythm means differ across Russia, the U.S., and Germany. Relationships with mental health are present in all three countries, but differ in magnitude.Social rhythm irregularity is related to mental health in Russia, the U.S., and Germany.

  10. Establishment of human cell lines showing circadian rhythms of bioluminescence.

    Science.gov (United States)

    Yoshikawa, Aki; Shimada, Hiroko; Numazawa, Kahori; Sasaki, Tsukasa; Ikeda, Masaaki; Kawashima, Minae; Kato, Nobumasa; Tokunaga, Katsushi; Ebisawa, Takashi

    2008-11-28

    We have established human retinal pigment epithelial cell lines stably expressing the luciferase gene, driven by the human Bmal1 promoter, to obtain human-derived cells that show circadian rhythms of bioluminescence after dexamethasone treatment. The average circadian period of bioluminescence for the obtained clones was 24.07+/-0.48 h. Lithium (10 mM) in the medium significantly lengthened the circadian period of bioluminescence, which is consistent with previous reports, while 2 mM or 5 mM lithium had no effect. This is the first report on the establishment of human-derived cell lines that proliferate infinitely and show circadian rhythms of bioluminescence, and also the first to investigate the effects of low-dose lithium on the circadian rhythms of human-derived cells in vitro. The established cells will be useful for various in vitro studies of human circadian rhythms and for the development of new therapies for human disorders related to circadian rhythm disturbances.

  11. Rhythms in the endocrine system of fish: a review.

    Science.gov (United States)

    Cowan, Mairi; Azpeleta, Clara; López-Olmeda, Jose Fernando

    2017-12-01

    The environment which living organisms inhabit is not constant and many factors, such as light, temperature, and food availability, display cyclic and predictable variations. To adapt to these cyclic changes, animals present biological rhythms in many of their physiological variables, timing their functions to occur when the possibility of success is greatest. Among these variables, many endocrine factors have been described as displaying rhythms in vertebrates. The aim of the present review is to provide a thorough review of the existing knowledge on the rhythms of the endocrine system of fish by examining the hormones that show rhythmicity, how environmental factors control these rhythms and the variation in the responses of the endocrine system depending on the time of the day. We mainly focused on the hypothalamic-pituitary axis, which can be considered as the master axis of the endocrine system of vertebrates and regulates a great variety of functions, including reproduction, growth, metabolism, energy homeostasis, stress response, and osmoregulation. In addition, the rhythms of other hormones, such as melatonin and the factors, produced in the gastrointestinal system of fish are reviewed.

  12. Circadian rhythm in experimental granulomatous inflammation is modulated by melatonin.

    Science.gov (United States)

    Lopes, C; deLyra, J L; Markus, R P; Mariano, M

    1997-09-01

    Biological rhythms are detected in a variety of physiological and pathological conditions in man and animals, such as rheumatoid arthritis and asthma. Here we describe a circadian rhythm in experimental infectious and non-infectious granuloma. After 30 days of BCG (Bacillus Calmette-Guerin) or nystatin inoculation in the left hind foot of C57B1/6 mice, there is an oscillation with a period of approximately 24 hr in the variation of paw thickness, indicating a circadian rhythm. The acrophase occurred during the light phase, between 9:00 and 13:00 hr, while the nadir occurred in the dark phase, between 21:00 and 01:00 hr. The vascular permeability around the granulomatous lesions was higher at 12:00 hr than at 24:00 hr. This is in agreement with the observation that the thickness of a paw with granulomatous lesion is larger during the light phase. This rhythmic variation was eliminated by either pinealectomy or superior cervical ganglionectomy, which greatly reduce melatonin levels in the blood. Nocturnal replacement of melatonin in pinealectomized mice led to the re-establishment of the circadian rhythm. Thus, the rhythm of the granulomatous lesion is due to the rhythmic melatonin release by the pineal gland. This approach opens new questions regarding the modulation of chronic inflammation in inflammatory diseases that present rhythmic symptoms throughout the day.

  13. Control beliefs can predict the ability to up-regulate sensorimotor rhythm during neurofeedback training

    Directory of Open Access Journals (Sweden)

    Matthias eWitte

    2013-08-01

    Full Text Available Technological progress in computer science and neuroimaging has resulted in many approaches that aim to detect brain states and translate them to an external output. Studies from the field of brain-computer interfaces and neurofeedback have validated the coupling between brain signals and computer devices; however a cognitive model of the processes involved remains elusive. Psychological parameters usually play a moderate role in predicting the performance of brain-computer interface (BCI and neurofeedback (NF users. The concept of a locus of control, i.e. whether one’s own action is determined by internal or external causes, may help to unravel inter-individual performance capacities. Here, we present data from twenty healthy participants who performed a feedback task based on EEG recordings of the sensorimotor rhythm (SMR. One group of ten participants underwent ten training sessions where the amplitude of the SMR was coupled to a vertical feedback bar. The other group of ten participants participated in the same task but relied on sham feedback. Our analysis revealed that a locus of control score focusing on control beliefs with regard to technology negatively correlated with the power of SMR. These preliminary results suggest that participants whose confidence in control over technical devices is high might consume additional cognitive resources. This higher effort in turn may interfere with brain states of relaxation as reflected in the SMR. As a consequence, one way to improve control over brain signals in neurofeedback paradigms may be to explicitly instruct users not to force mastery but instead to aim at a state of effortless relaxation.

  14. Early administration of epinephrine (adrenaline) in patients with cardiac arrest with initial shockable rhythm in hospital: propensity score matched analysis.

    Science.gov (United States)

    Andersen, Lars W; Kurth, Tobias; Chase, Maureen; Berg, Katherine M; Cocchi, Michael N; Callaway, Clifton; Donnino, Michael W

    2016-04-06

    To evaluate whether patients who experience cardiac arrest in hospital receive epinephrine (adrenaline) within the two minutes after the first defibrillation (contrary to American Heart Association guidelines) and to evaluate the association between early administration of epinephrine and outcomes in this population. Prospective observational cohort study. Analysis of data from the Get With The Guidelines-Resuscitation registry, which includes data from more than 300 hospitals in the United States. Adults in hospital who experienced cardiac arrest with an initial shockable rhythm, including patients who had a first defibrillation within two minutes of the cardiac arrest and who remained in a shockable rhythm after defibrillation. Epinephrine given within two minutes after the first defibrillation. Survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and survival to hospital discharge with a good functional outcome. A propensity score was calculated for the receipt of epinephrine within two minutes after the first defibrillation, based on multiple characteristics of patients, events, and hospitals. Patients who received epinephrine at either zero, one, or two minutes after the first defibrillation were then matched on the propensity score with patients who were "at risk" of receiving epinephrine within the same minute but who did not receive it. 2978 patients were matched on the propensity score, and the groups were well balanced. 1510 (51%) patients received epinephrine within two minutes after the first defibrillation, which is contrary to current American Heart Association guidelines. Epinephrine given within the first two minutes after the first defibrillation was associated with decreased odds of survival in the propensity score matched analysis (odds ratio 0.70, 95% confidence interval 0.59 to 0.82; P<0.001). Early epinephrine administration was also associated with a decreased odds of return of spontaneous circulation

  15. The relationship between the age of onset of musical training and rhythm synchronization performance: Validation of sensitive period effects

    Directory of Open Access Journals (Sweden)

    Jennifer Anne Bailey

    2013-11-01

    Full Text Available A sensitive period associated with musical training has been proposed, suggesting the influence of musical training on the brain and behaviour is strongest during the early childhood years. Experiments from our laboratory have directly tested the sensitive period hypothesis for musical training by comparing musicians who began their training before age seven with those who began their training after age seven, while matching the two groups in terms of musical experience (Bailey & Penhune, 2010; 2012; Watanabe, Savion-Lemieux, & Penhune, 2007. Using this matching paradigm, the early-trained groups have demonstrated enhanced sensorimotor synchronization skills and associated differences in brain structure (Bailey, Zatorre, & Penhune, under review; Steele, Bailey, Zatorre, & Penhune, 2013. The current study takes a different approach to investigating the sensitive period hypothesis for musical training by examining a single large group of unmatched musicians (N=77 and exploring the relationship between age of onset of musical training as a continuous variable and performance on the Rhythm Synchronization Task (RST, a previously used auditory-motor rhythm synchronization task. Interestingly, age of onset was correlated with task performance for those who began training earlier; however, no such relationship was observed among those who began training in their later childhood years. In addition, years of formal training showed a similar pattern. However, individual working memory scores were predictive of task performance, regardless of age of onset of musical training. Overall, these results support the sensitive period hypothesis for musical training and suggest a non-linear relationship between age of onset of musical training and auditory-motor rhythm synchronization abilities, such that a relationship exists early in childhood but then plateaus later on in development, similar to maturational growth trajectories of brain regions implicated in

  16. Prolonged Paroxysmal Sympathetic Storming Associated with Spontaneous Subarachnoid Hemorrhage

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2013-01-01

    Full Text Available Paroxysmal sympathetic storming (PSS is a rare disorder characterized by acute onset of nonstimulated tachycardia, hypertension, tachypnea, hyperthermia, external posturing, and diaphoresis. It is most frequently associated with severe traumatic brain injuries and has been reported in intracranial tumors, hydrocephalous, severe hypoxic brain injury, and intracerebral hemorrhage. Although excessive release of catecholamine and therefore increased sympathetic activities have been reported in subarachnoid hemorrhage (SAH, there is no descriptive report of PSS primarily caused by spontaneous SAH up to date. Here, we report a case of prolonged PSS in a patient with spontaneous subarachnoid hemorrhage and consequent vasospasm. The sympathetic storming started shortly after patient was rewarmed from hypothermia protocol and symptoms responded to Labetalol, but intermittent recurrence did not resolve until 3 weeks later with treatment involving Midazolam, Fentanyl, Dexmedetomidine, Propofol, Bromocriptine, and minimizing frequency of neurological and vital checks. In conclusion, prolonged sympathetic storming can also be caused by spontaneous SAH. In this case, vasospasm might be a precipitating factor. Paralytics and hypothermia could mask the manifestations of PSS. The treatment of the refractory case will need both timely adjustment of medications and minimization of exogenous stressors or stimuli.

  17. Behavioral Modulation by Spontaneous Activity of Dopamine Neurons

    Directory of Open Access Journals (Sweden)

    Toshiharu Ichinose

    2017-12-01

    Full Text Available Dopamine modulates a variety of animal behaviors that range from sleep and learning to courtship and aggression. Besides its well-known phasic firing to natural reward, a substantial number of dopamine neurons (DANs are known to exhibit ongoing intrinsic activity in the absence of an external stimulus. While accumulating evidence points at functional implications for these intrinsic “spontaneous activities” of DANs in cognitive processes, a causal link to behavior and its underlying mechanisms has yet to be elucidated. Recent physiological studies in the model organism Drosophila melanogaster have uncovered that DANs in the fly brain are also spontaneously active, and that this activity reflects the behavioral/internal states of the animal. Strikingly, genetic manipulation of basal DAN activity resulted in behavioral alterations in the fly, providing critical evidence that links spontaneous DAN activity to behavioral states. Furthermore, circuit-level analyses have started to reveal cellular and molecular mechanisms that mediate or regulate spontaneous DAN activity. Through reviewing recent findings in different animals with the major focus on flies, we will discuss potential roles of this physiological phenomenon in directing animal behaviors.

  18. Brain Basics

    Medline Plus

    Full Text Available ... Events About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  19. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... learning more about how the brain grows and works in healthy people, and how normal brain development ...

  20. Brain Basics

    Medline Plus

    Full Text Available ... Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics provides information on how the brain works, how mental illnesses ...

  1. Event-related Desynchronization of Mu Rhythms During Concentric and Eccentric Contractions.

    Science.gov (United States)

    Park, Joo-Hee; Cynn, Heon-Seock; Cha, Kwang Su; Kim, Kyung Hwan; Jeon, Hye-Seon

    2017-09-19

    The purpose of this study was to compare the electroencephalographic (EEG) patterns and reaction times (RTs) of muscle activation between concentric and eccentric biceps brachii contractions under the RT paradigm and to evaluate how the EEG patterns and RTs changed with practice. Sixteen subjects performed 3 sets of 30 repetitions of submaximal voluntary concentric and eccentric biceps contractions. RT, event-related desynchronization (ERD) patterns of mu rhythm onset, and ERD amplitudes were selectively analyzed. Mental demand decreased as familiarity with the motor action increased due to practice regardless of contraction type. However, the 2 types of muscle contractions still have differences in brain activity regardless of decreased mental demand: eccentric contractions require earlier preparation than concentric contractions.

  2. Effects of Chronic Social Defeat Stress on Sleep and Circadian Rhythms Are Mitigated by Kappa-Opioid Receptor Antagonism.

    Science.gov (United States)

    Wells, Audrey M; Ridener, Elysia; Bourbonais, Clinton A; Kim, Woori; Pantazopoulos, Harry; Carroll, F Ivy; Kim, Kwang-Soo; Cohen, Bruce M; Carlezon, William A

    2017-08-09

    Stress plays a critical role in the neurobiology of mood and anxiety disorders. Sleep and circadian rhythms are affected in many of these conditions. Here we examined the effects of chronic social defeat stress (CSDS), an ethological form of stress, on sleep and circadian rhythms. We exposed male mice implanted with wireless telemetry transmitters to a 10 day CSDS regimen known to produce anhedonia (a depressive-like effect) and social avoidance (an anxiety-like effect). EEG, EMG, body temperature, and locomotor activity data were collected continuously during the CSDS regimen and a 5 day recovery period. CSDS affected numerous endpoints, including paradoxical sleep (PS) and slow-wave sleep (SWS), as well as the circadian rhythmicity of body temperature and locomotor activity. The magnitude of the effects increased with repeated stress, and some changes (PS bouts, SWS time, body temperature, locomotor activity) persisted after the CSDS regimen had ended. CSDS also altered mRNA levels of the circadian rhythm-related gene mPer2 within brain areas that regulate motivation and emotion. Administration of the κ-opioid receptor (KOR) antagonist JDTic (30 mg/kg, i.p.) before CSDS reduced stress effects on both sleep and circadian rhythms, or hastened their recovery, and attenuated changes in mPer2 Our findings show that CSDS produces persistent disruptions in sleep and circadian rhythmicity, mimicking attributes of stress-related conditions as they appear in humans. The ability of KOR antagonists to mitigate these disruptions is consistent with previously reported antistress effects. Studying homologous endpoints across species may facilitate the development of improved treatments for psychiatric illness. SIGNIFICANCE STATEMENT Stress plays a critical role in the neurobiology of mood and anxiety disorders. We show that chronic social defeat stress in mice produces progressive alterations in sleep and circadian rhythms that resemble features of depression as it appears in

  3. Cycle length restitution in sinoatrial node cells: a theory for understanding spontaneous action potential dynamics.

    Directory of Open Access Journals (Sweden)

    Patric Glynn

    Full Text Available Normal heart rhythm (sinus rhythm is governed by the sinoatrial node, a specialized and highly heterogeneous collection of spontaneously active myocytes in the right atrium. Sinoatrial node dysfunction, characterized by slow and/or asynchronous pacemaker activity and even failure, is associated with cardiovascular disease (e.g. heart failure, atrial fibrillation. While tremendous progress has been made in understanding the molecular and ionic basis of automaticity in sinoatrial node cells, the dynamics governing sinoatrial nodel cell synchrony and overall pacemaker function remain unclear. Here, a well-validated computational model of the mouse sinoatrial node cell is used to test the hypothesis that sinoatrial node cell dynamics reflect an inherent restitution property (cycle length restitution that may give rise to a wide range of behavior from regular periodicity to highly complex, irregular activation. Computer simulations are performed to determine the cycle length restitution curve in the computational model using a newly defined voltage pulse protocol. The ability of the restitution curve to predict sinoatrial node cell dynamics (e.g., the emergence of irregular spontaneous activity and susceptibility to termination is evaluated. Finally, ionic and tissue level factors (e.g. ion channel conductances, ion concentrations, cell-to-cell coupling that influence restitution and sinoatrial node cell dynamics are explored. Together, these findings suggest that cycle length restitution may be a useful tool for analyzing cell dynamics and dysfunction in the sinoatrial node.

  4. Intraspinal Rewiring of the Corticospinal Tract Requires Target-Derived Brain-Derived Neurotrophic Factor and Compensates Lost Function after Brain Injury

    Science.gov (United States)

    Ueno, Masaki; Hayano, Yasufumi; Nakagawa, Hiroshi; Yamashita, Toshihide

    2012-01-01

    Brain injury that results in an initial behavioural deficit is frequently followed by spontaneous recovery. The intrinsic mechanism of this functional recovery has never been fully understood. Here, we show that reorganization of the corticospinal tract induced by target-derived brain-derived neurotrophic factor is crucial for spontaneous recovery…

  5. Into the groove: can rhythm influence Parkinson's disease?

    Science.gov (United States)

    Nombela, Cristina; Hughes, Laura E; Owen, Adrian M; Grahn, Jessica A

    2013-12-01

    Previous research has noted that music can improve gait in several pathological conditions, including Parkinson's disease, Huntington's disease and stroke. Current research into auditory-motor interactions and the neural bases of musical rhythm perception has provided important insights for developing potential movement therapies. Specifically, neuroimaging studies show that rhythm perception activates structures within key motor networks, such as premotor and supplementary motor areas, basal ganglia and the cerebellum - many of which are compromised to varying degrees in Parkinson's disease. It thus seems likely that automatic engagement of motor areas during rhythm perception may be the connecting link between music and motor improvements in Parkinson's disease. This review seeks to describe the link, address core questions about its underlying mechanisms, and examine whether it can be utilized as a compensatory mechanism. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Epigenetic Regulation of Biological Rhythms: An Evolutionary Ancient Molecular Timer.

    Science.gov (United States)

    Stevenson, Tyler J

    2017-12-05

    Biological rhythms are pervasive in nature, yet our understanding of the molecular mechanisms that govern timing is far from complete. The rapidly emerging research focus on epigenetic plasticity has revealed a system that is highly dynamic and reversible. In this Opinion, I propose an epigenetic clock model that outlines how molecular modifications, such as DNA methylation, are integral components for timing endogenous biological rhythms. The hypothesis proposed is that an epigenetic clock serves to maintain the period of molecular rhythms via control over the phase of gene transcription and this timing mechanism resides in all cells, from unicellular to complex organisms. The model also provides a novel framework for the timing of epigenetic modifications during the lifespan and transgenerational inheritance of an organism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Circadian rhythms, time-restricted feeding, and healthy aging.

    Science.gov (United States)

    Manoogian, Emily N C; Panda, Satchidananda

    2017-10-01

    Circadian rhythms optimize physiology and health by temporally coordinating cellular function, tissue function, and behavior. These endogenous rhythms dampen with age and thus compromise temporal coordination. Feeding-fasting patterns are an external cue that profoundly influence the robustness of daily biological rhythms. Erratic eating patterns can disrupt the temporal coordination of metabolism and physiology leading to chronic diseases that are also characteristic of aging. However, sustaining a robust feeding-fasting cycle, even without altering nutrition quality or quantity, can prevent or reverse these chronic diseases in experimental models. In humans, epidemiological studies have shown erratic eating patterns increase the risk of disease, whereas sustained feeding-fasting cycles, or prolonged overnight fasting, is correlated with protection from breast cancer. Therefore, optimizing the timing of external cues with defined eating patterns can sustain a robust circadian clock, which may prevent disease and improve prognosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Current Conceptual Challenges in the Study of Rhythm Processing Deficits

    Directory of Open Access Journals (Sweden)

    Pauline eTranchant

    2015-06-01

    Full Text Available Interest in the study of rhythm processing deficits (RPD is currently growing in the cognitive neuroscience community, as this type of investigation constitutes a powerful tool for the understanding of normal rhythm processing. Because this field is in its infancy, it still lacks a common conceptual vocabulary to facilitate effective communication between different researchers and research groups. In this commentary, we provide a brief review of recent reports of RPD through the lens of one important empirical issue: the method by which beat perception is measured, and the consequences of method selection for the researcher’s ability to specify which mechanisms are impaired in RPD. This critical reading advocates for the importance of matching measurement tools to the putative neurocognitive mechanisms under study, and reveals the need for effective and specific assessments of the different aspects of rhythm perception and synchronization.

  9. Recent Advances in Circadian Rhythms in Cardiovascular System

    Directory of Open Access Journals (Sweden)

    Lihong eChen

    2015-04-01

    Full Text Available Growing evidence shows that intrinsic circadian clocks are tightly related to cardiovascular functions. The diurnal changes in blood pressure and heart rate are well known circadian rhythms. Endothelial function, platelet aggregation and thrombus formation exhibit circadian changes as well. The onset of many cardiovascular diseases (CVDs or events, such as myocardial infarction, stroke, arrhythmia, and sudden cardiac death, also exhibits temporal trends. Furthermore, there is strong evidence from animal models and epidemiological studies showing that disruption of circadian rhythms is a significant risk factor for many CVDs, and the intervention of CVDs may have a time dependent effect. In this mini review, we summarized recent advances in our understanding of the relationship between circadian rhythm and cardiovascular physiology and diseases including blood pressure regulation and myocardial infarction.

  10. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  11. La maladie de Grisel : Spontaneous atlantoaxial subluxation

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Hermens, RAEC

    Objective: "La maladie de Grisel" (Grisel's syndrome) is a spontaneously occurring atlantoaxial subluxation with torticollis. We present a case of atlantoaxial subluxation occurring in a 20-year period of pharyngoplasty surgery. The occurrence of a "spontaneous" atlantoaxial subluxation after oral

  12. Sleep, Circadian Rhythms, and Performance During Space Shuttle Missions

    Science.gov (United States)

    Neri, David F.; Czeisler, Charles A.; Dijk, Derk-Jan; Wyatt, James K.; Ronda, Joseph M.; Hughes, Rod J.

    2003-01-01

    Sleep and circadian rhythms may be disturbed during spaceflight, and these disturbances can affect crewmembers' performance during waking hours. The mechanisms underlying sleep and circadian rhythm disturbances in space are not well understood, and effective countermeasures are not yet available. We investigated sleep, circadian rhythms, cognitive performance, and light-dark cycles in five astronauts prior to, during, and after the 16-day STS-90 mission and the IO-day STS-95 mission. The efficacy of low-dose, alternative-night, oral melatonin administration as a countermeasure for sleep disturbances was evaluated. During these missions, scheduled rest activity cycles were 20-35 minutes shorter than 24 hours. Light levels on the middeck and in the Spacelab were very low; whereas on the flight deck (which has several windows), they were highly variable. Circadian rhythm abnormalities were observed. During the second half of the missions, the rhythm of urinary cortisol appeared to be delayed relative to the sleep-wake schedule. Performance during wakefulness was impaired. Astronauts slept only about 6.5 hours per day, and subjective sleep quality was lower in space. No beneficial effects of melatonin (0.3 mg administered prior to sleep episodes on alternate nights) were observed. A surprising finding was a marked increase in rapid eye movement (REM) sleep upon return to Earth. We conclude that these Space Shuttle missions were associated with circadian rhythm disturbances, sleep loss, decrements in neurobehavioral performance, and alterations in REM sleep homeostasis. Shorter than 24-hour rest-activity schedules and exposure to light-dark cycles inadequate for optimal circadian synchronization may have contributed to these disturbances.

  13. MRI of 'brain death'

    International Nuclear Information System (INIS)

    Nishino, Shigeki; Itoh, Takahiko; Tuchida, Shohei; Kinugasa, Kazushi; Asari, Shoji; Nishimoto, Akira; Sanou, Kazuo.

    1990-01-01

    Magnetic resonance imaging (MRI) was undertaken for two patients who suffered from severe cerebrovascular diseases and were clinically brain dead. The MRI system we used was Resona (Yokogawa Medical Systems, superconductive system 0.5 T) and the CT apparatus was Toshiba TCT-300. Initial CT and MRI were undertaken as soon as possible after admission, and repeated sequentially. After diagnosis of brain death, we performed angiography to determine cerebral circulatory arrest, and MRI obtained at the same time was compared with the angiogram and CT. Case 1 was a 77-year-old man who was admitted in an unconscious state. CT and MRI on the second day after hospitalization revealed cerebellar infarction. He was diagnosed as brain dead on day 4. Case 2 was a 35-year-old man. When he was transferred to our hospital, he was in cardiorespiratory arrested. Cardiac resuscitation was successful but no spontaneous respiration appeared. CT and MRI on admission revealed right intracerebral hemorrhage. Angiography revealed cessation of contrast medium in intracranial vessels in both of the patients. We found no 'flow signal void sign' in the bilateral internal carotid and basilar arteries on MRI images in both cases after brain death. MRI, showing us the anatomical changes of the brain, clearly revealed brain herniations, even though only nuclear findings of 'brain tamponade' were seen on CT. But in Case 1, we could not see the infarct lesions in the cerebellum on MR images obtained after brain death. This phenomenon was caused by the whole brain ischemia masking the initial ischemic lesions. We concluded that MRI was useful not only the anatomical display of lesions and brain herniation with high contrast resolution but for obtaining information on cerebral circulation of brain death. (author)

  14. Spontaneous intraparenchymal otogenic pneumocephalus presenting with abrupt onset of coma

    International Nuclear Information System (INIS)

    Scuotto, A.; Cappabianca, S.; Capasso, R.; Natale, M.; D'Oria, S.; Rotondo, M.

    2016-01-01

    We report a case of spontaneous otogenic pneumocephalus, manifesting with a rapid deterioration of consciousness level. A 37-year-old man presented a 3-days history of headache and fluctuant confusion. On admission the patient was neurologically intact except for temporo-spatial disorientation. Brain Computed Tomography (CT) scan showed a large air collection in the left temporal lobe, causing mass effect. Hyperpneumatisation of mastoid air cells was also noticed. Because of the abrupt onset of coma (Glasgow Coma Scale = 10), emergency surgical evacuation of tensive pneumocephalus was carried out. Postoperatively, the patient quickly regained a good level of consciousness and was headache-free. - Highlights: • Spontaneous otogenic pneumocephalus generally presents with subtle symptoms. • Sudden consciousness involvement is a rare onset condition. • Hyperpneumatisation of the petrous bone is a predisposing factor.

  15. Circadian rhythm of temperature selection in a nocturnal lizard.

    Science.gov (United States)

    Refinetti, R; Susalka, S J

    1997-08-01

    We recorded body temperature and locomotor activity of Tokay geckos (Gekko gecko) with free access to a heat source under a 14:10 light-dark cycle and in constant darkness. Under the light-dark cycle, the lizards selected higher temperatures during the light phase, when locomotor activity was less intense. Rhythmicity in temperature selection was transiently disrupted but later resumed when the animals were placed in constant darkness. These results demonstrate the existence of a circadian rhythm of temperature selection in nocturnal ectotherms and extend previous findings of a temporal mismatch between the rhythms of locomotor activity and temperature selection in nocturnal rodents.

  16. Latitudinal clines: an evolutionary view on biological rhythms.

    Science.gov (United States)

    Hut, Roelof A; Paolucci, Silvia; Dor, Roi; Kyriacou, Charalambos P; Daan, Serge

    2013-08-22

    Properties of the circadian and annual timing systems are expected to vary systematically with latitude on the basis of different annual light and temperature patterns at higher latitudes, creating specific selection pressures. We review literature with respect to latitudinal clines in circadian phenotypes as well as in polymorphisms of circadian clock genes and their possible association with annual timing. The use of latitudinal (and altitudinal) clines in identifying selective forces acting on biological rhythms is discussed, and we evaluate how these studies can reveal novel molecular and physiological components of these rhythms.

  17. The use of statistics in heart rhythm research: a review.

    Science.gov (United States)

    Shen, Changyu; Yu, Zhangsheng; Liu, Ziyue

    2015-06-01

    In this article, we provide a brief review of key statistical concepts/methods that are commonly used in heart rhythm research, including concepts such as standard deviation, standard error, confidence interval, statistical/clinical significance, correlation coefficients, multiple comparisons, cohort and case-control studies, and missing data, as well as methods such as statistical hypothesis testing, receiver operating characteristic curve, binary vs time-to-event outcome, competing risk methods, and analysis of correlated data. We also make recommendations on how related statistical procedures should be applied and results should be reported. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  18. Alterations in Metabolism and Diurnal Rhythms following Bilateral Surgical Removal of the Superior Cervical Ganglia in Rats

    Directory of Open Access Journals (Sweden)

    Malena L. Mul Fedele

    2018-01-01

    Full Text Available Mammalian circadian rhythms are controlled by a master pacemaker located in the suprachiasmatic nuclei (SCN, which is synchronized to the environment by photic and nonphotic stimuli. One of the main functions of the SCN is to regulate peripheral oscillators to set temporal variations in the homeostatic control of physiology and metabolism. In this sense, the SCN coordinate the activity/rest and feeding/fasting rhythms setting the timing of food intake, energy expenditure, thermogenesis, and active and basal metabolism. One of the major time cues to the periphery is the nocturnal melatonin, which is synthesized and secreted by the pineal gland. Under SCN control, arylalkylamine N-acetyltransferase (AA-NAT—the main enzyme regulating melatonin synthesis in vertebrates—is activated at night by sympathetic innervation that includes the superior cervical ganglia (SCG. Bilateral surgical removal of the superior cervical ganglia (SCGx is considered a reliable procedure to completely prevent the nocturnal AA-NAT activation, irreversibly suppressing melatonin rhythmicity. In the present work, we studied the effects of SCGx on rat metabolic parameters and diurnal rhythms of feeding and locomotor activity. We found a significant difference between SCGx and sham-operated rats in metabolic variables such as an increased body weight/food intake ratio, increased adipose tissue, and decreased glycemia with a normal glucose tolerance. An analysis of locomotor activity and feeding rhythms showed an increased daytime (lights on activity (including food consumption in the SCGx group. These alterations suggest that superior cervical ganglia-related feedback mechanisms play a role in SCN-periphery phase coordination and that SCGx is a valid model without brain-invasive surgery to explore how sympathetic innervation affects daily (24 h patterns of activity, food consumption and, ultimately, its role in metabolism homeostasis.

  19. Effects of (± 3,4-Methylenedioxymethamphetamine (MDMA on Sleep and Circadian Rhythms

    Directory of Open Access Journals (Sweden)

    Una D. McCann

    2007-01-01

    Full Text Available Abuse of stimulant drugs invariably leads to a disruption in sleep-wake patterns by virtue of the arousing and sleep-preventing effects of these drugs. Certain stimulants, such as 3,4-methylenedioxymethamphetamine (MDMA, may also have the potential to produce persistent alterations in circadian regulation and sleep because they can be neurotoxic toward brain monoaminergic neurons involved in normal sleep regulation. In particular, MDMA has been found to damage brain serotonin (5-HT neurons in a variety of animal species, including nonhuman primates, with growing evidence that humans are also susceptible to MDMA-induced brain 5-HT neurotoxicity. 5-HT is an important modulator of sleep and circadian rhythms and, therefore, individuals who sustain MDMA-induced 5-HT neurotoxicity may be at risk for developing chronic abnormalities in sleep and circadian patterns. In turn, such abnormalities could play a significant role in other alterations reported in abstinent in MDMA users (e.g., memory disturbance. This paper will review preclinical and clinical studies that have explored the effects of prior MDMA exposure on sleep, circadian activity, and the circadian pacemaker, and will highlight current gaps in knowledge and suggest areas for future research.

  20. [Changes in Spatial Organization of Cortical Rhythm Vibrations in Children uner the Influence of Music].

    Science.gov (United States)

    Shepovalnikov, A N; Egorov, M V

    2015-01-01

    Changes is systemic brain activity under influence of classical music (minor and major music) were studied at two groups of healthy children aged 5-6 years (n = 53). In 25 of studied children the Luscher test showed increased level of anxiety which significantly decreased after music therapy sessions. Bioelectrical cortical activity registered from 20 unipolar leads was subjected to correlation, coherence and factor analysis. Also the dynamics of the power spectrum for each of the EEG was studied. According to EEG all children after listening to both minor and major tones showed reorganization of brain rhythm structure accompanied by a decrease in the level of coherence and correlation of EEG; also was found significant and almost universal decrease in the EEG power spectrum. Registered EEG changes under the influence of classical music seems to reflect a decrease in excess of "internal tension" and weakening degree of "stiffness" to ensure the activity of cerebral structures responsible for mechanisms of "basic integration" which maintain constant readiness of brain to rapid and complete inclusion in action.