Heart rate variability is encoded in the spontaneous discharge of thalamic somatosensory neurones in cat
|
|
- Kelley Mitchell
- 5 years ago
- Views:
Transcription
1 Keywords: 0748 Journal of Physiology (2000), 526.2, Heart rate variability is encoded in the sontaneous discharge of thalamic somatosensory neurones in cat Marcello Massimini, Alberto Porta *, Maurizio Mariotti, Alberto Malliani * and Nicola Montano * Laboratorio di Neurofisiologia and * Centro Ricerche Cardiovascolari CNR, Diartimento di Scienze Precliniche Laboratorio Interdiscilinare Tecnologie Avanzate di Vialba, Universita degli Studi di Milano, Italy, Osedale Luigi Sacco, via Giovan Battista Grassi 74, Milano, Italy (Received 23 February 2000; acceted after revision 28 Aril 2000) 1. We studied the sontaneous discharge variability of thalamocortical somatosensory neurones in the awake cat in order to disclose its ossible information content. The resence of slow ( Hz) regular fluctuations in the discharge rate of these cells during the waking state has been reviously reorted. Oscillations in a similar frequency range are known to characterize the activity of central and eriheral neurones ertaining to the autonomic nervous system and the variability of heart eriod (RR interval variability). 2. A surrogate data test, erformed on our database, confirmed the resence of slow ( Hz) non-random fluctuations in firing rate. 3. Linear regression detected the resence of an inverse relationshi between the values of RR interval and the concurrent levels of neural discharge. 4. Frequency domain analysis indicated that a significant couling between the two variability signals referentially occurred in two frequency bands: in the frequency of the resiratory sinus arrhythmia and in corresondence with a slower rhythm ( Hz), the two signals being in hase oosition in most of the cases. 5. Coherent fluctuations could also be observed when eochs of evoked activity were analysed, while couling between the two variability signals aeared to be disruted after slee onset. 6. We conclude that RR interval variability, an internally generated dynamic related to basic visceral regulation, is encoded in the discharge of single somatosensory thalamocortical neurones during wakefulness. A ossible interaction with the transmission of somatosensory information has to be evaluated. The discharge roerties of thalamocortical somatosensory neurones are mainly studied in the awake animal, on the basis of a stimulus resonse rotocol. Using this aroach, the activity that is time locked to the actual stimulation of the secific eriheral recetor is extracted, while the rest of the discharge (i.e. the sontaneous discharge) cannot be interreted and some information, ossibly encoded, might not be evaluated. Werner & Mountcastle (1963) have reviously described a lack of stationarity in subsequent samles of sontaneous activity recorded from single ventrobasal neurones in the awake monkey. Non-stationarities were eliminated by shuffling the original data into random sequences. Deartures from randomness were found to be due to the resence of eriodic fluctuations in discharge rate, having a frequency ranging from 0 09 to 1 39 Hz. These slow eriodicities are unlikely to be related to intrinsic membrane roerties since, as revealed by numerous studies, thalamocortical cells, during wakefulness, fire tonically on the basis of a steadily deolarized membrane otential (Hirsch et al. 1983; Jahnsen & Llin as, 1984; Steriade & Deschḙnes, 1984; McCormick & Bal, 1997). Sontaneous eriodic changes in the discharge rate of these cells could be due to the effect of an inut different from the secific somatosensory one. The source of this inut should meet some rerequisites: its activity should be characterized by the resence of slow fluctuations in discharge rate and it should generate slow oscillatory atterns also during the waking state. Slow rhythmic fluctuations (< 1 Hz) characterize the firing attern of neurones ertaining to the autonomic nervous system. Lambertz & Langhorst (1998) detected the resence
2 388 M. Massimini, A. Porta, M. Mariotti, A. Malliani and N. Montano J. Physiol of slow oscillations in the imulse activity recorded from units located in the reticular formation and different brainstem nuclei. Such oscillations were coherent with those resent in the variability of efferent symathetic discharge and of cardiovascular signals such as heart eriod and arterial ressure. In view of this the reticular formation has been considered as art of a common brainstem system, rovided with ascending and descending rojections and integrating the regulation of somatic and visceral functions (Schulz et al. 1983, 1985; Langhorst et al. 1996). Fluctuations in discharge rate have been recorded in secific brainstem nuclei involved in cardiovascular regulation (Montano et al. 1996) and in the activity of symathetic fibres rojecting to the heart (Montano et al. 1992). Similar oscillations have been detected in muscle symathetic nerve activity recorded in awake human subjects (Pagani et al. 1997). These neural oscillations are coherent with the rhythms observable in the variability of heart eriod. In articular, sectral analysis of heart rate variability has been widely used as a tool to assess indirectly the state of symathetic and arasymathetic neural modulations to the sinus node (Malliani et al. 1991). The aim of our study was to assess whether the rate fluctuations detectable in thalamic somatosensory sontaneous discharge could be related to an oscillatory inut coming from structures ertaining to the autonomic nervous organization. Therefore, using linear regression and frequency domain analysis (via coherence and hase functions) we evaluated the ossible relationshis existing between heart rate (exressed as its recirocal the RR interval) and the discharge of single ventroosterior thalamocortical neurones in the awake cat. METHODS Surgical rocedure and signal recording Exeriments were carried out on four adult cats ( kg). Animals were chronically imlanted. Care and handling of animals was in accordance with international guidelines (NIH) and aroved by the Animal Care Commitee of the University of Milan. In order to obtain head fixation without ressure or ain during the subsequent recording sessions, two nylon cylinders, fitted to the stereotaxic bars, were cemented to the skull while the animal was anaesthetized with ketamine (15 mg kg i.m.) followed by barbiturate anaesthesia (Somnotol 35 mg kg i..). Craniotomy was erformed in the right arietal skull, to allow a stereotaxic aroach to the ventroosterolateral (VPL) and the ventroosteromedial (VPM) thalamic nuclei. The hole was then temorarily closed with bone wax. Four screws were inserted in the frontal and arietal bone on both sides of the head for EEG recording and attached to a connector. Animals were allowed to recover for three weeks and were then habituated to the stereotaxic frame. During the recording sessions, tungsten microelectrodes (9 to 12 MÙ resistance) were lowered stereotaxically (A 8 5Ï9 8; L 3Ï7 8; H +3Ï 1 5) to reach and record thalamic units, extracellularly. Needles for ECG recording were inserted subcutaneously. Resiratory rate was measured using a strain-gauge transducer connected to a small mask that was adjusted and laced a few millimetres in front of the nostrils of the cat. This signal was not calibrated and reflected only the rate of resiration and not the resiratory activity. A brief uff of air on the animal s hair was used to stimulate the eriheral recetive field of the recorded neurone. Stimuli, with a mean duration of 15 ms and a eak ressure of 6 5 g cmâ, at a frequency of 1 5 Hz, were delivered on left limbs, neck and head. Electrohysiological identification of ventroosterior (VP) units was obtained by dislaying on-line ost-stimulus histograms (PSTH; Figure 1. Criteria for database selection A, tyical resonse of a ventroosterior thalamic neurone following 100 reeated stimulations of the hairy skin (bin width 1 ms). B, eri-trigger histogram on R wave of the QRS of ECG comlex erformed on 600 beats. Mean ECG (uer trace) and discharge distribution (bin width 1 ms; lower trace) do not show relationshis between neural firing and the heart beat.
3 J. Physiol VP sontaneous discharge and RR interval ms bin) (Fig. 1A; Mariotti & Formenti, 1990). Both sontaneous and evoked neuronal activity were recorded during wakefulness and, in some cases, after slee onset. Activity of 10 to 15 min was recorded for each neurone. At the end of the exerimental cycle, animals were given a lethal dose of Nembutal (100 mg kg ). Signal rerocessing All signals were stored on tae and off-line AÏD converted with a samling frequency of 18 khz. Neural activity was then retrieved and visually insected; only neurones with a high and stable signalto-noise ratio were selected. Peri-trigger histograms on R wave of the electrocardiogram (ECG) were calculated for all neurones in order to detect the resence of heart beat related siking, which may reflect artifacts resulting from ulsatile movement (Fig. 1B). Neurones whose discharge was correlated to the heart beat were thus excluded from further analysis. Visual scoring of EEG and neural discharge, together with intersike interval histograms, were used to select eriods of tonic discharge low voltage EEG and eriods of burst discharge high voltage EEG. Time series extraction The ECG signal was comressed to 600 Hz, QRS comlexes were automatically detected using a threshold derivative algorithm and the time occurring between each R wave was calculated in order to obtain a time series of RR interval variability (tachogram). The resiratory signal was comressed to 600 Hz and samled once er cardiac beat. Sikes from VP were discriminated by means of a digital threshold and were counted on a 20 ms time basis roducing a ste-wise signal (the counted VP) with levels roortional to the number of detected sikes. The counted signal was comressed to 600 Hz and low-ass filtered at 1 Hz with a finite imulse resonse (FIR) filter (2400 coefficients, Hanning windowed). The filtered neuronal signal was then samled once er cardiac beat giving a beat-to-beat time series of neural discharge variability (neurogram) synchronous with the tachogram. The tachogram and the neurogram of each neurone were suerimosed and visually insected. Stable segments of about 250 beats were selected for further analysis. The criteria for stability were the absence of artifacts in the series due to error in R wave detection and the absence of transients due to sudden increases or decreases in neuronal firing or very slow trends in the mean values of RR interval and discharge rate. Series smaller than 250 samles did not allow reliable detection of oscillations with a frequency lower than 0 05 Hz (considering a maximum heart rate of 3 Hz). Data analysis Linear correlation. Linear regression in the lane (VP(i), RR(i)) was erformed to assess the tye and degree of correlation between the tachograms and neurograms. A direct relationshi (ositive changes in RR interval determine ositive variations in VP) was detected by a ositive sloe (a > 0). An inverse relationshi was found when a is negative. The strength of the relationshi was quantified by the correlation coefficient r. Signals were considered significantly correlated for P < Power sectral density estimation Power sectral analysis was utilized to assess the ower and the frequency of the oscillations resent in the beat-to-beat variability signals of RR interval and VP. A beat-to-beat series x =(x(i)), where i is the rogressive cardiac beat, is described as an autoregressive (AR) rocess (Kay & Marle 1981): x(i) = Óa kx(i k) + e (i), (1) k =1 where ak are the coefficients of the model and e(i) is a white noise with zero mean and variance ëâ. The identification of the coefficients ak and of the variance ëâ of the white noise e(i) was erformed by Levinson-Durbin recursion (Kay & Marle, 1981) and the model order was chosen according to the Akaike figure of merit (Akaike, 1974). The ower sectral decomosition (PSD) rocedure (Baselli et al. 1997) allowed us to decomose the PSD in a sum of sectral eaks and to calculate ower and central frequency of these eaks. Surrogate data aroach In order to assess if the beat-to-beat neural discharge variability series is a coloured rocess (i.e. it is different from a white noise) a surrogate data test was erformed. The counted VP signal was shuffled by randomizing the levels reresenting the number of sikes found in 20 ms. Ten different surrogate realizations of the same original signal were obtained by changing the random sequence utilized to shuffle. The surrogate signals are rocessed like the original series to derive the beat-to-beat series of the VP discharge. The ower of the oscillations evaluated in the original series was comared with the ower found in the surrogate series. Rhythmicity in a given frequency band was considered significant if the ower in the original series was larger than the mean ower lus two times the standard deviation calculated in the surrogate data (Fig. 3) (Theiler et al. 1985). Phase relationshi and coherence function estimation The analysis of the relationshis between RR interval and VP was erformed via calculation of the hase relationshi and coherence function. The linear relationshi between two beat-to-beat variability series x =(x(i)) and y =(y(i)) are described by a bivariate AR rocess (Morf et al. 1985): x(i) = Óa11 kx(i k) + Óa12 ky(i k) + e 1(i), (2) k=1 k=1 y(i) = Óa21 kx(i k) + Óa22 ky(i k) + e 2(i), (3) k=1 k=1 where a11k, a12k, a21k, a22k are the coefficients of the bivariate AR rocess setting the influences of several ast values on the current one and the effects of one signal on the other one. The joint rocess v = xy can be seen as the outut of the 2 ² 2 transfer matrix H(z) with elements: A11(z) =1 Óa11kz k, A12(z) = Óa12 kz k,a21(z) = Óa21kz k, k =1 k =1 k =1 and A22(z) =1 Óa22 kz k. k =1 After identification of the coefficients of the bivariate model via the least squared method (Baselli et al. 1997), the cross-sectrum Sxy(f) was obtained as the non-diagonal terms of the matrix: S(f) =H(z)Ë 2 H'(z 1 ) z = ex(2ðjft), (4) where H'(z 1 ) is the transose of H(z 1 ) and Ë 2 is the variance matrix of the joint rocess e = e1 eµ. The hase relationshi is the
4 390 M. Massimini, A. Porta, M. Mariotti, A. Malliani and N. Montano J. Physiol hase of the cross-sectrum Sxy(f), where x leads for ositive hase values. The squared coherence function k Â(f) is obtained by normalizing the squared modulus of the cross-sectrum by the roduct of the two sectra Sx(f) and Sy(f). The coherence function ranges from 0 to 1 and measures the degree of linear correlation between two oscillations found in the two signals at the same frequency. A k Â(f) > 0 5 was considered significant (De Boer et al. 1985). Phase values were evaluated only in corresondence with significant coherence values. RESULTS One hundred and twenty-seven of the recorded neurones were selected for analysis. Neurones included in our database dislayed in the PSTHs a tyical resonse to hairy skin recetor stimulation. The resonse was characterized by a eak of facilitation (with latency around 20 ms) followedby a reduction of cell discharge, lasting about ms (Mariotti & Formenti, 1990) as shown in Fig. 1A. Noneof the selected neurones showed the resence of sikes in hase with the QRS comlexes of the ECG. Mean frequency of sontaneous tonic firing during wakefulness was 26 9 Hz (s.e.m. ± 1 9). Linear regression between neural discharge and RR interval The time series extracted from the 127 neurones were analysed in terms of their relationshi to RR interval using a linear regression. For 108 cells (85 %) the sloe (a) of the regression line was negative, indicating an imulse activity increasing with the decrease of RR interval. The discharge of 46 neurones (33 %) dislayed a significant correlation (P < 0 01) with the RR interval (Fig. 2). Figure 2. Linear regression between RR interval and neural discharge variability A, examle of time series of RR interval (thin line) and VP sontaneous discharge (thick line) in awake conditions. B, linear regression analysis is erformed on the same eriod. Notice that the sloe of the regression line is negative (a = 5 3) indicating an increased neural firing associated with shorter RR intervals and vice versa. C, smaller arts of the segments on which linear regression has been erformed are suerimosed in order to visually insect the recirocal relationshis between the two variability signals.
5 J. Physiol VP sontaneous discharge and RR interval 391 Figure 3. Surrogate data test erformed on the variability of neural discharge Examle of surrogate-data analysis. Sectra erformed on the neurogram (300 beats length) extracted from the real signal (thick line) and from the time series derived from ten different surrogate realizations of the same signal (dotted lines). The sectrum of the original signal met the criteria for a coloured rocess. Frequency domain analysis According to the surrogate data test, eochs characterized by non-random fluctuations (below 1 Hz) during wakefulness werefoundin94neuronesoutofthe127(fig. 3). Sectral analysis of RR interval variability revealed the resence of two major oscillatory comonents, the higher one being synchronous with the dominant oscillation detectable in the sectral rofile of the resiratory signal. In Figure 4. Sectral comonents of RR interval, neural discharge variability and resiration Time series of RR interval, VP sontaneous discharge and resiration (Res; left anels) and their variability sectra (right anels). Two oscillatory comonents are detectable in RR and VP sectra, the higher frequency ones being centred around the major resiratory frequency eak. We termed as resiratory-related frequency (RRF) the sectral comonents synchronous with resiration and as nonresiratory-related frequency (NRRF) the lower frequency comonent.
6 392 M. Massimini, A. Porta, M. Mariotti, A. Malliani and N. Montano J. Physiol our exeriments resiratory rate varied between 0 3 and 0 85 Hz. We termed resiratory-related fluctuation (RRF) the high frequency eak and non-resiratory-related fluctuation (NRRF) the lower frequency one (Fig. 4). Crosssectral analysis between RR interval and neuronal discharge variability revealed a significant coherence (KÂ > 0 5) in at least one of the above frequency bands in 53 out of the 94 (56 %) neurones that assed the surrogate data test. In 37 out of these 53 cases (70 %) coherence was significant in the RRF band (Fig. 5A), and in 16 cases in the NRRF band (30 %) (Fig. 5B). In 12 cases coherence was simultaneouslydetectableinbothbands. Neurograms and tachograms were, in all but three cases, in hase oosition for significant levels of coherence in the RRF band (Fig. 5A). This was the case in only nine out of 16 neurones (56 %) exhibiting coherent fluctuations in the NRRF band (Fig. 5B). Correlation during evoked activity We also analysed eochs of neural activity evoked by airuff stimulation delivered at a frequency of 1 5 Hz. In these cases the low-ass FIR filter was set at 2 Hz in order to include the stimulation rate in the sectral frequency range. The effect of the rhythmic stimulation of the eriheral recetors was clearly visible in the sectral rofile, as a narrow eak centred around 1 5 Hz (Fig. 6). Lower frequencies were also resent, being coherent with the oscillatory comonents detectable in the RR variability sectra in nine out of 17 neurones (Fig. 6). Correlation after slee onset The activity of five neurones dislaying fluctuations coherent with RR interval oscillations during wakefulness was analysed also during slee. In corresondence with a marked EEG synchronization, tonic firing was relaced by burst discharge. A narrow eak after 3 5 ms was observable in the intersike interval histogram. All neurones assed the surrogate data test dislaying a coloured sectral rofile with oscillatory comonents below 1 Hz. During slee, the sectra of both tachogram and neurogram were characterized by a eak in the RRF range. Desite the resence of a very similar sectral rofile on both signals, coherence decreased below the level of significance (K Â < 0 5) in all cases (Fig. 7). Figure 5. Coherence and hase function between RR interval and neural discharge variability A, time series of RR interval (thin line) and VP sontaneous discharge (thick line; left traces). The sectra of both signals are overlotted (uer right anel). A major resiratory related comonent (RRF) can be detected. A significant coherence (K Â) and oosition of hase (dashed line) is detected within this band (lower right anel). B, same as in A, but here sectral ower is concentrated in the range of the nonresiratory-related frequency (NRRF).
7 J. Physiol VP sontaneous discharge and RR interval 393 Figure 6. Sectral analysis and coherence during evoked activity A, the RR interval variability sectrum (thin line) and the VP discharge variability sectrum (thick line), during evoked activity, are suerimosed. On the discharge variability sectra, a narrow eak, synchronous with the stimulation rate (indicated on the abscissa by a vertical bar) is observable. Slower comonents, in the same frequency range as those resent in RR interval variability, are simultaneously resent. B, cross-sectral analysis, detects the resence of coherent oscillations in the range 0 1 Hz. DISCUSSION The finding of Werner & Mountcastle (1963) has been confirmed by the surrogate data analysis we erformed on our database. Indeed, we found a high roortion of neurones (around 70 %) dislaying coloured sectra in the Hz frequency range during wakefulness. Oscillations in a similar range are known to be resent in the central and eriheral discharge variability of autonomic neurones and fibres (Langhorst et al. 1986; Malliani et al. 1991; Montano et al. 1992, 1996; Pagani et al. 1997; Lambertz & Langhorst, 1998) and in the variability of RR interval. Numerous studies have already reorted the Figure 7. Sectral analysis and coherence after slee onset Sectral analysis and coherence are calculated over 250 beats eochs before (A) and after (B) slow-wave slee onset. Small segments of RR and VP variability series (20 beats length) are suerimosed and raw (comressed) VP signal is deicted below (left anels). A, tonic discharge and the recirocal relationshi between the two variability signals are visually detectable during wakefulness. B, burst discharge and no recirocal fluctuations are observable during slee: sectral analysis shows similar oscillatory comonents (RRF band) on the two signals during both wakefulness (A, right anels) and slee (B, right anels) while coherence, after slee onset, is lost.
8 394 M. Massimini, A. Porta, M. Mariotti, A. Malliani and N. Montano J. Physiol resence of two major oscillatory comonents in the short term RR interval and arterial ressure variabilities both in humans and animals (Malliani et al. 1991). The higher frequency oscillation, the so-called resiratory sinus arrhythmia, reresents the neurally mediated effect of resiration on sinus node acemaker activity. This fluctuation is due to the alternating of relative tachycardia and bradycardia associated with the insiratory and exiratory hases of the resiratory cycle, resectively. The low frequency rhythm, on the other hand, is synchronous with arterial ressure vasomotor waves (Mayer waves) and has been attributed to the effect of a symathetic excitatory modulation (Preiss & Polosa, 1974; Malliani, 1999). In our aroach, RR interval variability, an internally generated dynamic, was used as a reference in an effort to interret the sike sequences giving rise to the intersamle variability detectable in VP neurones firing. These sequences are resent in the sontaneous discharge, and they robably fall into the noise band of the discharge distribution histogram when a secific external sensory stimulus is used as a trigger. In our rocedure the neuronal signal was counted, low-ass filtered with a cut-off at 1 Hz and samled in corresondence with each cardiac beat in order to enhance the variability in the exlored frequency range and obtain a synchronous time scale with RR interval series. A first unexected finding was a strong correlation, indeendent of the temoral sequence of the samles revealed by linear regression, between each air of RR interval and neuronal discharge values. In one third of the neurones the level of significance was maintained for eriods of at least 200 beats. Moreover, in 85 % of all analysed neurones the sloe of the regression line was negative (Fig. 2B) indicating that higher levels of neuronal firing were associated with shorter RR intervals and vice- versa. This inverse correlation was not due to transient events since eochs including very slow trends, ossibly related to shifts in the state of vigilance, or ste changes in the series due to movements or sudden arousals, were rejected. Even a simle visual insection of the two suerimosed series reveals the resence of reetitive recirocal variations as exemlified in Fig. 2C. Analysis in the frequency domain indicated that a significant couling between RR interval and neuronal discharge variability referentially occurred in articular frequency bands. Half of the neurones dislaying coloured sectra were coherent with the RR series, and in 70 % of those cells coherence was above 0 5 in the RRF band, corresonding to the resiratory sinus arrhythmia. This was true even when longer eochs (more than 600 beats) were analysed. In almost all cases, oosition of hase between the two variability signals was observed indicating an increase in neural firing in corresondence with the insiratory tachycardia (Fig. 5A). In contrast to our results, Werner & Mountcastle (1963) found no relationshi between the fluctuations in neural discharge rate and resiration, butunder quite different conditions since, in their exeriments, artificial ventilation was erformed on aralysed animals. On the other hand, Chen et al. (1992) detected, in neurones of the medial thalamus, the resence of increased firing rate related to the insiratory hase of integrated hrenic nerve activity for high levels of resiratory drive. This modulation of thalamic neural firing was not necessarily couled to the artificial ventilation-related rhythm being instead the reflection of the central neural resiratory activity. A resiratorymodulated discharge was also observed in neurones located in the midbrain (Chen et al. 1991). We suggest that the RRF observable in our VP neurones consistently reflects a widesread reresentation of the central neural resiratory attern. Since our neurones were identified as resonsive to stimulation of hairy skin eriheral recetors located on the limbs and head it is unlikely that they were affected, through secific recetors and athways, by chest wall movements. Morover, increases in discharge rate related to insiration have been observed in other strucures above the brainstem level such as the amygdala in awake humans and cats (Zhang et al. 1986; Frysinger & Harer, 1988). Couling between neuronal discharge and RR interval variability was not limited to the resiratory band, coherence being above the level of significance also in the lowerartofthesectra(fig. 5B). The NRRF band ranged from 0 07 to 0 3 Hz in our exeriments. Rhythms in this frequency range have been observed by Langhorst in different regions of the brainstem, coherent with cardiovascular variability (Langhorst et al. 1986; Lambertz & Langhorst, 1998). Similar fluctuations in discharge rate, with a eriodicity around 11 s, were reorted by Oakson & Steriade (1982) in the midbrain reticular formation of the cat during both slee and wakefulness. Our animals were not distressed during fixation in the stereotaxic aaratus; cortical EEG was indeed normal and they often fell aslee while in the aaratus. In five cases we could follow the changes in the degree of correlation between neuronal activity and RR interval variability also after slee onset. As exected, a shift from tonic mode to burst discharge was observed in all VP neurones. Desite the ersistence of coloured sectra (< 1 Hz) in neuronal discharge, a significant coherence with the RR variability series was no longer detectable (Fig. 7). In this resect, a slow cortically generated oscillation has recently been characterized both at the EEG and intracellular level in anaesthetized and naturally sleeing cats (Steriade et al. 1993). The slow cortical deolarizing hyerolarizing cycle is transmitted to thalamic reticular and relay neurones and is able to trigger and synchronize the activity of thalamocortical neurones. The slight fluctuations in discharge rate related to cardiovascular variability observable during wakefulness in VP neurones could be disruted, after slee onset, by the owerful effect of a highly synchronized cortically generated oscillation cometing for the same frequency range.
9 J. Physiol VP sontaneous discharge and RR interval 395 The major finding of our study is that the sontaneous tonic firing of thalamocortical somatosensory neurones is not randomly distributed, having instead an information content. Indeed, during wakefulness, art of the discharge rate fluctuations of these cells is tightly couled to the variability of RR interval, which contains information related to the autonomic regulation of cardiovascular function. Moreover, sectral analysis erformed on eochs of evoked discharge detected the resence of a stimulus-related oscillation, together with slower fluctuations coherent with those resent in RR interval variability. This variability is internally generated and aeared to be relayed by thalamocortical somatosensory neurones to the cortex, together with information conveyed by secific recetors and athways from the external environment. Aart from a few studies in the field of sychohysiology (Nakayama & Hori, 1966), some electrohysiological evidence suggests an effect exherted by vegetative correlates on somatosensory transmission. For examle, resiratory-related modifications have been reorted in cutaneously evoked cortical otentials of man and cats (Shimamura & Mori, 1982), while it has been observed that chemorecetor stimulation is caable of reducing the latency and increasing the robability of discharge of somatosensory thalamocortical neurones in resonse to foreaw stimulation in the anaesthetized rat (Angel & Harris, 1998). In conclusion, these results rovide evidence that RR interval variability is encoded in the sontaneous discharge of thalamic somatosensory neurones. The resence of an imulse activity related to internal basic visceral regulation, within a neural system, characterized by a very high satiotemorally defined coding of external inuts, raises the question whether it may reresent a continuous rhythmic inut integrating andïor modulating the transmission of the somatosensory information to the cortex or whether it is justaninterferencehenomenon. Akaike, H. (1974). A new look at the statistical novel identification. IEEE Transactions on Autonomic Control 19, Angel, A. & Harris, M. C. (1998). The effect of chemorecetor stimulation on the centrietal transfer of somatosensory information in the urethane-anaesthetized rat. Neuroscience 86, Baselli, G., Porta, A., Rimoldi, O., Pagani, M. & Cerutti, S. (1997). Sectral decomosition in multichannel recordings based on multivariate arametric identification. IEEE Transactions on Biomedical Engineering 44, Chen, Z., Eldridge, F. L. & Wagner, P. (1991). Resiratoryassociated rhythmic firing of midbrain neurones in cats: relation to thelevelofresiratorydrive. Journal of Physiology 437, Chen, Z., Eldridge, F. L. & Wagner, P. (1992). Resiratoryassociated thalamic activity is related to level of resiratory drive. Resiration Physiology 90, De Boer, J. M., Karemaker, M. & Strackee, J. (1985). Relationshis between short-term blood ressure fluctuations and heart rate variability in resting subjects. Medical and Biological Engineering and Comuting 23, Frysinger, R. & Harer, R. M. (1989). Cardiac and resiratory correlations with unit discharge in human amygdala and hiocamus. Electroencehalograhy and Clinical Neurohysiology 72, Hirsch, J. C., Fourment, A. & Marc, M. E. (1983) Slee-related variations of membrane otential in the lateral geniculate body relayneuronesofthecat. Brain Research 259, Jahnsen, H. & Llin as, R. (1984). Electrohysiological roerties of guinea-ig thalamic neurones: an in vitro study. Journal of Physiology 349, Kay, S. M. & Marle, S. L. (1981). Sectrum analysis: a modern ersective. Proceedings of IEEE 69, Lambertz, M. & Langhorst, P. (1998). Simultaneous changes of rhythmic organization in brainstem neurons, resiration, cardiovascular system and EEG between 0 05 Hz and 0 5 Hz. Journal of the Autonomic Nervous System 68, Langhorst, P., Lambertz, M. & Shulz, G. (1986). Assessment of rhythmicity in the visceral nervous system. In Neural Mechanisms and Cardiovascular Diseases, ed. Lown, B., Malliani, A. & Prosdocimi, M., Liviana Press, Padova. Langhorst, P., Schulz, G., Seller, H. & Koechen, H. P. (1996). Convergence of visceral and somatic afferents on single neurones in the reticular formation of the lower brainstem. Journal of the Autonomic Nervous System 57, McCormick, D. A. & Bal, T. (1997). Slee and arousal: thalamocortical mechanisms. Annual Review of Neurosciences 20, Malliani, A. (1999). The attern of symathovagal balance exlored in the frequency domain. News in Physiological Sciences 14, Malliani, A., Pagani, M., Lombardi, F. & Cerutti, S. (1991). Cardiovascular neural regulation exlored in the frequency domain. Circulation 84, Mariotti, M. & Formenti, A. (1990). Somatosensory transmission through the ventroosterolateral thalamic nucleus during wake and slee. The Dyencehalon and Slee, ed. Mancia, M. & Marini, G., Raven Press Ltd, New York. Montano, N., Gnecchi-Ruscone, T., Porta, A., Lombardi, F., Malliani, A. & Barman, S. M. (1996). Presence of vasomotor and resiratory rhythms in the discharge of single medullary neurons involved in the regulation of the cardiovascular system. Journal of the Autonomic Nervous System 57, Montano, N., Lombardi, F., Gnecchi-Ruscone, T., Contini, M., Finocchiaro, M. L., Baselli, G., Porta, A., Cerutti, S. & Malliani, M. (1992). Sectral analysis of symathetic discharge, RR interval, and systolic arterial ressure in decerebrate cats. Journal of the Autonomic Nervous System 40, Morf, A., Viera, T. L. & Kailath. T. (1985). Recursive multichannel maximum entroy sectral estimates in the study of electrical brain activity. Biological Cybernetics 51, Oakson, G. & Steriade, M. (1982). Slow rhythmic rate fluctuation of cat midbrain reticular neurons in syncronized slee and waking. Brain Research 247, Nakayama, T. & Hori, T. (1966). Cortical evoked otential and subjective sensation to electric stimulation of the skin: effects of osture and resiratory movement. Jaanese Journal of Physiology 16, Pagani, M., Montano, N., Porta, A., Malliani, A., Abboud, F. M., Birkett, C. L. & Somers, V. K. (1997). Relationshi between sectral comonents of cardiovascular variabilities and direct measures of muscle symathetic nerve activity in humans. Circulation 95,
10 396 M. Massimini, A. Porta, M. Mariotti, A. Malliani and N. Montano J. Physiol Preiss, G. & Polosa, C. (1974) Patterns of symathetic neuron activity associated with Mayer waves. American Journal of Physiology 226, Schulz, B., Lamberts, M., Schulz, G. & Langhorst, P. (1983). Reticular formation of the lower brainstem. A common system for cardioresiratory and somatomotor functions: discharge atterns of neighboring neurons influenced by somatosensory afferents. Journal the of Autonomic Nervous System 9, Schulz, B., Lamberts, M., Schulz, G. & Langhorst, P. (1985). Reticular formation of the lower brainstem. A common system for cardioresiratory and somatomotor functions. Cross-correlation analysis of discharge atterns of neighboring neurons. Journal of the Autonomic Nervous System 12, Shimamura M. & Mori, A. (1982). Sensory evoked otentials and their changes with resiration in mnd cat. Electroencehalograhy and Clinical Neurohysiology, sul. 36, Steriade, M., Contreras, D., Curro Dossi, D., Nuñez, A. (1993). The slow (< 1 Hz) oscillation in reticular thalamic and thalamocortical neurons: scenario of slee rhythm generation in interacting thalamic and neocortical networks. Journal of Neuroscience 13, Steriade, M. & Deschḙnes, M. (1984). The thalamus as a neuronal oscillator. Brain Research Reviews 8, Theiler, A., Eubank, S., Longtin, A. & Galdrikian, J. (1992). Testing for nonlinearity in time series: the method of surrogate data. Physica 58, Werner, G. & Mountcastle, V. B. (1963). The variability of central neural activity in a sensory system, and its imlications for the central reflection of sensory events. Journal of Neurohysiology 26, Zhang, J., Harer, R. M. & Frysinger, C. (1986). Resiratory modulation of neuronal discharge in the central nucleus of the amygdala during slee and waking state. Exerimental Neurology 91, Acknowledgements We gratefully acknowledge Renato Calcaterra for his helful technical assistance and Marzia Martina and Mario Rosanova for their highly valued collaborative work. Corresonding author M. Massimini: Diartimento di Scienze Precliniche Laboratorio Interdiscilinare Tecnologie Avanzate di Vialba, Universita degli Studi di Milano, Italy, Osedale Luigi Sacco, via Giovan Battista Grassi 74, Milano, Italy. marcello@mailserver.unimi.it
Author's personal copy
Vision Research 48 (2008) 1837 1851 Contents lists available at ScienceDirect Vision Research journal homeage: www.elsevier.com/locate/visres Bias and sensitivity in two-interval forced choice rocedures:
More informationComparative analysis of fetal electrocardiogram (ECG) extraction techniques using system simulation
International Journal of the Physical Sciences Vol. 6(21),. 4952-4959, 30 Setember, 2011 Available online at htt://www.academicjournals.org/ijps DOI: 10.5897/IJPS11.415 ISSN 1992-1950 2011 Academic Journals
More informationQuadriceps muscles vastus medialis obliques, rectus femoris and vastus lateralis compared via electromyogram bicoherence analysis
Australasian Physical & Engineering Sciences in Medicine Volume 26 Number 3, 2003 TECHNICA REPORT Quadrices muscles vastus medialis obliues, rectus femoris and vastus lateralis comared via electromyogram
More informationSPECTRAL ENVELOPE ANALYSIS OF SNORING SIGNALS
SPECTRAL ENVELOPE ANALYSIS OF SNORING SIGNALS Mustafa Çavuşoğlu, Mustafa Kamaşak 2, Tolga Çiloğlu 3,Yeşim Serinağaoğlu 3,Osman Eroğul 4 Max Planck Instıtute for Biological Cybernetics, High Field MR Center,
More informationBursting dynamics in the brain. Jaeseung Jeong, Department of Biosystems, KAIST
Bursting dynamics in the brain Jaeseung Jeong, Department of Biosystems, KAIST Tonic and phasic activity A neuron is said to exhibit a tonic activity when it fires a series of single action potentials
More informationNeuroscience of Consciousness I
1 C83MAB: Mind and Brain Neuroscience of Consciousness I Tobias Bast, School of Psychology, University of Nottingham 2 What is consciousness? 3 Consciousness State of consciousness - Being awake/alert/attentive/responsive
More informationGRUNDFOS DATA BOOKLET. Hydro Grundfos Hydro 2000 booster sets with 2 to 6 CR(E) pumps 50 Hz
GRUNDFOS DATA OOKET ydro Grundfos ydro booster sets with 2 to 6 CR(E) ums z Contents Product data Performance range 3 ydro 4 Control 4 Functions 4 Alication and need 5 Water suly 5 Industry 5 Irrigation
More informationPrefrontal cortex fmri signal changes are correlated with working memory load
Cognitive Neuroscience and Neurosychology NeuroReort 8, 545 549 (997) WE investigated whether a nonsatial working memory (WM) task would activate dorsolateral refrontal cortex (DLPFC) and whether activation
More informationAutomatic System for Retinal Disease Screening
Automatic System for Retinal Disease Screening Arathy.T College Of Engineering Karunagaally Abstract This work investigates discrimination caabilities in the texture of fundus images to differentiate between
More informationHHS Public Access Author manuscript Nat Neurosci. Author manuscript; available in PMC 2014 September 19.
Selective optical drive of thalamic reticular nucleus generates thalamic bursts & cortical spindles Michael M. Halassa 1,2,4, Joshua H. Siegle 2,4, Jason T. Ritt 3, Jonathan T. Ting 2, Guoping Feng 2,
More informationFigure removed due to copyright restrictions.
Harvard-MIT Division of Health Sciences and Technology HST.071: Human Reproductive Biology Course Director: Professor Henry Klapholz IN SUMMARY HST 071 An Example of a Fetal Heart Rate Tracing Figure removed
More informationThe duration of the attentional blink in natural scenes depends on stimulus category
Vision Research 47 (2007) 597 7 www.elsevier.com/locate/visres The duration of the attentional blink in natural scenes deends on stimulus category Wolfgang Einhäuser a, *, Christof Koch a,b, Scott Makeig
More informationDecision Analysis Rates, Proportions, and Odds Decision Table Statistics Receiver Operating Characteristic (ROC) Analysis
Decision Analysis Rates, Proortions, and Odds Decision Table Statistics Receiver Oerating Characteristic (ROC) Analysis Paul Paul Barrett Barrett email: email:.barrett@liv.ac.uk htt://www.liv.ac.uk/~barrett/aulhome.htm
More informationDo People s First Names Match Their Faces?
First names and faces 1 Journal of Articles in Suort of the Null Hyothesis Vol. 12, No. 1 Coyright 2015 by Reysen Grou. 1539-8714 www.jasnh.com Do Peole s First Names Match Their Faces? Robin S. S. Kramer
More informationEmbryological origin of thalamus
diencephalon Embryological origin of thalamus The diencephalon gives rise to the: Thalamus Epithalamus (pineal gland, habenula, paraventricular n.) Hypothalamus Subthalamus (Subthalamic nuclei) The Thalamus:
More informationMagdalena Wojtczak, Anna C. Schroder, Ying-Yee Kong, and David A. Nelson
EFFECT OF BASILAR MEMBRANE COMPRESSION ON MASKING PERIOD PATTERNS (MPPS) A aer resented to the 138 th Acoustical Society of Aerica Colubus, Ohio Noveber 2, 1999 Magdalena Wojtczak, Anna C. Schroder, Ying-Yee
More informationSyncope in Children and Adolescents
Aril 1997:1039 45 1039 Syncoe in Children and Adolescents DAVID J. DRISCOLL, MD, FACC, STEVEN J. JACOBSEN, MD, PHD, CO-BURN J. PORTER, MD, FACC, PETER C. WOLLAN, PHD Rochester, Minnesota Objectives. The
More informationBrain regions supporting intentional and incidental memory: a PET study
Learning and Memory NeuroReort 8, 283 287 (997) REGIONAL brain activity associated with intentional and incidental memory retrieval was studied with PET. Previously studied and new words were resented
More informationSIMULATIONS OF ERROR PROPAGATION FOR PRIORITIZING DATA ACCURACY IMPROVEMENT EFFORTS (Research-in-progress)
SIMLATIONS OF ERROR PROPAGATION FOR PRIORITIZING DATA ACCRACY IMPROEMENT EFFORTS (Research-in-rogress) Irit Askira Gelman niversity of Arizona Askirai@email.arizona.edu Abstract: Models of the association
More informationEvaluation of EEG features during Overt Visual Attention during Neurofeedback Game
2014 IEEE International Conference on Systems, Man, and Cybernetics October 5-8, 2014, San Diego, CA, USA Evaluation of EEG features during Overt Visual Attention during Neurofeedback Game Kavitha P Thomas
More informationPatterns of Inheritance
atterns of Inheritance Introduction Dogs are one of man s longest genetic exeriments. Over thousands of years, humans have chosen and mated dogs with secific traits. The results : an incredibly diversity
More informationCocktail party listening in a dynamic multitalker environment
Percetion & Psychohysics 2007, 69 (1), 79-91 Cocktail arty listening in a dynamic multitalker environment DOUGLAS S. BRUNGART AND BRIAN D. SIMPSON Air Force Research Laboratory, Wright-Patterson Air Force
More informationIntroducing Two-Way and Three-Way Interactions into the Cox Proportional Hazards Model Using SAS
Paer SD-39 Introducing Two-Way and Three-Way Interactions into the Cox Proortional Hazards Model Using SAS Seungyoung Hwang, Johns Hokins University Bloomberg School of Public Health ABSTRACT The Cox roortional
More informationHeart-rate Variability Christoph Guger,
Heart-rate Variability Christoph Guger, 10.02.2004 Heart-rate Variability (HRV) 1965 Hon & Lee Fetal distress alterations in interbeat intervals before heart rate (HR) changed 1980 HRV is strong and independent
More informationSevere Psychiatric Disorders in Mid-Life and Risk of Dementia in Late- Life (Age Years): A Population Based Case-Control Study
Send Orders for Rerints to rerints@benthamscience.net Current Alzheimer Research, 2014, 11, 681-693 681 Severe Psychiatric Disorders in Mid-Life and Risk of Dementia in Late- Life (Age 65-84 Years): A
More informationEffects of involuntary auditory attention on visual task performance and brain activity
Cognitive Neurosciences and Neurosychology Website ublication 24 Setember 1997 NeuroReort 8, 3233 3237 (1997) INVOLUNTARY attention to auditory stimulus changes during a visual discrimination task was
More informationState-Trace Analysis of the Face Inversion Effect
State-Trace Analysis of the Face Inversion Effect Melissa Prince (Melissa.Prince@newcastle.edu.au) School of Psychology, The University of Newcastle University Drive, Callaghan, 2308, NSW Australia Andrew
More informationApplication of Tsallis Entropy to EEG: Quantifying the Presence of Burst Suppression after Asphyxial Cardiac Arrest in Rats
> TBME-00423-2009 < 1 Alication of Tsallis Entroy to EEG: Quantifying the Presence of Burst Suression after Ashyxial Cardiac Arrest in Rats Dandan Zhang, Xiaofeng Jia, Haiyan Ding, Datian Ye, and Nitish
More informationHRV ventricular response during atrial fibrillation. Valentina Corino
HRV ventricular response during atrial fibrillation Outline AF clinical background Methods: 1. Time domain parameters 2. Spectral analysis Applications: 1. Evaluation of Exercise and Flecainide Effects
More informationReinforcing Visual Grouping Cues to Communicate Complex Informational Structure
8 IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS, VOL. 20, NO. 12, DECEMBER 2014 1973 Reinforcing Visual Grouing Cues to Communicate Comlex Informational Structure Juhee Bae and Benjamin Watson
More informationBurst and tonic firing in thalamic cells of unanesthetized, behaving monkeys
Visual Neuroscience (2000), 17, 55 62. Printed in the USA. Copyright 2000 Cambridge University Press 0952-5238000 $12.50 Burst and tonic firing in thalamic cells of unanesthetized, behaving monkeys EION
More informationCALLOSAL RESPONSES OF FAST-RHYTHMIC-BURSTING NEURONS DURING SLOW OSCILLATION IN CATS
Neuroscience 147 (2007) 272 276 RAPID REPORT CALLOSAL RESPONSES OF FAST-RHYTHMIC-BURSTING NEURONS DURING SLOW OSCILLATION IN CATS Y. CISSÉ, 1,2 D. A. NITA, 2 M. STERIADE AND I. TIMOFEEV* Department of
More informationChild attention to pain and pain tolerance are dependent upon anxiety and attention
Child attention to ain and ain tolerance are deendent uon anxiety and attention control: An eye-tracking study Running Head: Child anxiety, attention control, and ain Heathcote, L.C. 1, MSc, Lau, J.Y.F.,
More informationSupporting information
Supporting information Buckley CL, Toyoizumi T (2018) A theory of how active behavior stabilises neural activity: Neural gain modulation by closed-loop environmental feedback. PLoS Comput Biol 14(1): e1005926.
More informationCognitive Load and Analogy-making in Children: Explaining an Unexpected Interaction
Cognitive Load and Analogy-making in Children: Exlaining an Unexected Interaction Jean-Pierre Thibaut, Robert French, Milena Vezneva LEAD-CNRS, UMR50, University of Burgundy, FRANCE {jean-ierre.thibaut,
More informationRegret theory and risk attitudes
J Risk Uncertain (2017) 55:147 175 htts://doi.org/10.1007/s11166-017-9268-9 Regret theory and risk attitudes Jeeva Somasundaram 1 Enrico Diecidue 1 Published online: 5 January 2018 Sringer Science+Business
More informationBehavioral generalization
Supplementary Figure 1 Behavioral generalization. a. Behavioral generalization curves in four Individual sessions. Shown is the conditioned response (CR, mean ± SEM), as a function of absolute (main) or
More informationSynaptic excitation of principal cells in the cat's lateral geniculate nucleus during focal epileptic seizures in the visual cortex
Synaptic excitation of principal cells in the cat's lateral geniculate nucleus during focal epileptic seizures in the visual cortex Andrzej wr6be11, Anders ~ edstr~m~ and Sivert ~indstrsm~ 'Department
More informationPerformance of the Vocal Source Related Features from the Linear Prediction Residual Signal in Speech Emotion Recognition
Performance of the Vocal Source Related Features from the Linear Prediction Residual Signal in Seech Emotion Recognition Rajesvary Rajoo 1, 2 and Rosalina Abdul Salam 1 1 Faculty of Science and Technology,
More informationInteractions between Symptoms and Motor and Visceral Sensory Responses of Irritable Bowel Syndrome Patients to Spasmolytics (Antispasmodics)
Interactions between Symtoms and Motor and Visceral Sensory Resonses of Irritable Bowel Syndrome Patients to Sasmolytics (Antisasmodics) Igor L.Khalif 1, Eamonn M.M.Quigley 2, P.A.Makarchuk 1, O.V.Golovenko
More informationA model of HIV drug resistance driven by heterogeneities in host immunity and adherence patterns
a. Adherence attern Based on hyothesized causes and timescales Month b. Pharmacokinetics Liver TDF TFV ME ME Cell membrane c. Pharmacodynamics TDF= R relative to WT 1.8.6.4.2 WT K65R M184V TFV MP DP -4-2
More informationIn humans, low-dose atropine decreases heart rate 1,2 and
Central Vagotonic Effects of Atropine Modulate Spectral Oscillations of Sympathetic Nerve Activity Nicola Montano, MD, PhD; Chiara Cogliati, MD; Alberto Porta, MD; Massimo Pagani, MD; Alberto Malliani,
More informationShort communication RESPONSES OF RED NUCLEUS NEURONS TO PERIPHERAL STIMULATION IN CHLORALOSE ANESTHETIZED CATS. Janusz RAJKOWSKI
ACTA NEUROBIOL. EXP. 1982. 42: 195-201 Short communication RESPONSES OF RED NUCLEUS NEURONS TO PERIPHERAL STIMULATION IN CHLORALOSE ANESTHETIZED CATS Janusz RAJKOWSKI Department of Neurophysiology, Nencki
More informationTransitive Relations Cause Indirect Association Formation between Concepts. Yoav Bar-Anan and Brian A. Nosek. University of Virginia
1 Transitive Association Formation Running head: TRANSITIVE ASSOCIATION FORMATION Transitive Relations Cause Indirect Association Formation between Concets Yoav Bar-Anan and Brian A. Nosek University of
More informationTesting the Accuracy of ECG Captured by Cronovo through Comparison of ECG Recording to a Standard 12-Lead ECG Recording Device
Testing the Accuracy of ECG Captured by through Comparison of ECG Recording to a Standard 12-Lead ECG Recording Device Data Analysis a) R-wave Comparison: The mean and standard deviation of R-wave amplitudes
More informationRemaining Useful Life Prediction of Rolling Element Bearings Based On Health State Assessment
Remaining Useful Life Prediction of Rolling Element Bearings Based On Health State Assessment Zhiliang Liu, Ming J. Zuo,2, and Longlong Zhang School of Mechanical, Electronic, and Industrial Engineering,
More informationThe vignette, task, requirement, and option (VITRO) analyses approach to operational concept development
CAN UNCLASSIFIED The vignette, task, requirement, and otion (VITRO) analyses aroach to oerational concet develoment atrick W. Dooley, Yvan Gauthier DRDC Centre for Oerational Research and Analysis Journal
More informationAnchor Selection Strategies for DIF Analysis: Review, Assessment, and New Approaches
Anchor Selection Strategies for DIF Analysis: Review, Assessment, and New Aroaches Julia Kof LMU München Achim Zeileis Universität Innsbruck Carolin Strobl UZH Zürich Abstract Differential item functioning
More informationDifferences in the local and national prevalences of chronic kidney disease based on annual health check program data
Clin Ex Nehrol (202) 6:749 754 DOI 0.007/s057-02-0628-0 ORIGINAL ARTICLE Differences in the local and national revalences of chronic kidney disease based on annual health check rogram data Minako Wakasugi
More informationPhysiology Unit 2 CONSCIOUSNESS, THE BRAIN AND BEHAVIOR
Physiology Unit 2 CONSCIOUSNESS, THE BRAIN AND BEHAVIOR In Physiology Today What the Brain Does The nervous system determines states of consciousness and produces complex behaviors Any given neuron may
More informationMotor Resonance Mechanisms during Action Imitation in Depression
Motor Resonance Mechanisms during Action Imitation in Deression Djamila Bennabi, Nicolas Carvalho, Ambra Bisio, Emmanuel Haffen, Thierry Pozzo ABSTRACT Objectives Major deressive disorder has been associated
More informationThe Relationship Between Chronic Atrial Fibrillation and Reduced Pulmonary Function in Cases of Preserved Left Ventricular Systolic Function
ORIGINAL ARTICLE DOI 10.4070 / kcj.2009.39.9.372 Print ISSN 1738-5520 / On-line ISSN 1738-5555 Coyright c 2009 The Korean Society of Cardiology The Relationshi Between Chronic Atrial Fibrillation and Reduced
More informationHeart rate variability and respiratory sinus arrhythmia assessment of affective states by bivariate autoregressive spectral analysis
Heart rate variability and respiratory sinus arrhythmia assessment of affective states by bivariate autoregressive spectral analysis The MIT Faculty has made this article openly available. Please share
More informationDuring the last decade, a lively discussion has addressed
Oscillatory Patterns in Sympathetic Neural Discharge and Cardiovascular Variables During Orthostatic Stimulus Raffaello Furlan, MD; Alberto Porta, MS, PhD; Fernando Costa, MD; Jens Tank, MD; Lemont Baker,
More informationLecture 2: Linear vs. Branching time. Temporal Logics: CTL, CTL*. CTL model checking algorithm. Counter-example generation.
CS 267: Automated Verification Lecture 2: Linear vs. Branching time. Temoral Logics: CTL, CTL*. CTL model checking algorithm. Counter-examle generation. Instructor: Tevfik Bultan Linear Time vs. Branching
More informationAssessment of Reliability of Hamilton-Tompkins Algorithm to ECG Parameter Detection
Proceedings of the 2012 International Conference on Industrial Engineering and Operations Management Istanbul, Turkey, July 3 6, 2012 Assessment of Reliability of Hamilton-Tompkins Algorithm to ECG Parameter
More informationMerging of Experimental and Simulated Data Sets with a Bayesian Technique in the Context of POD Curves Determination
5 th Euroean-American Worksho on Reliability of NDE Lecture 5 Merging of Exerimental and Simulated Data Sets with a Bayesian Technique in the Context of POD Curves Determination Bastien CHAPUIS *, Nicolas
More informationBasic Mechanism for Generation of Brain Rhythms
203 Continuing Medical Education Basic Mechanism for Generation of Brain Rhythms Wei-Hung Chen Abstract- Study of the basic mechanism of brain rhythms adds to our understanding of the underlying processes
More informationChapter 2. Horm Behav Jul;60(2):
Chater The newborn rat s stress system readily habituates to reeated and rolonged maternal searation, while continuing to resond to stressors in context deendent fashion. Nikolaos P. Daskalakis 1, Sanne
More informationFunctional reorganization in thalamocortical networks: Transition between spindling and delta sleep rhythms
Proc. Natl. Acad. Sci. USA Vol. 93, pp. 15417 15422, December 1996 Neurobiology Functional reorganization in thalamocortical networks: Transition between spindling and delta sleep rhythms D. TERMAN*, A.BOSE*,
More informationIsoflurane and postoperative respiratory depression following laparoscopic surgery: A retrospective propensity-matched analysis
BOSNIAN JOURNAL OF BASIC MEDICAL SCIENCES RESEARCH ARTICLE WWW.BJBMS.ORG and ostoerative resiratory deression following laaroscoic surgery: A retrosective roensity-matched analysis Alexandre N. Cavalcante,
More informationTO help 25.8 million Americans [1] with diabetes, a growing
3108 IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, VOL. 26, NO. 11, NOVEMBER 2015 Patient Infusion Pattern based Access Control Schemes for Wireless Insulin Pum System Xiali Hei, Member, IEEE,
More informationSupplementary materials for: Executive control processes underlying multi- item working memory
Supplementary materials for: Executive control processes underlying multi- item working memory Antonio H. Lara & Jonathan D. Wallis Supplementary Figure 1 Supplementary Figure 1. Behavioral measures of
More informationThe Role of Mitral Cells in State Dependent Olfactory Responses. Trygve Bakken & Gunnar Poplawski
The Role of Mitral Cells in State Dependent Olfactory Responses Trygve akken & Gunnar Poplawski GGN 260 Neurodynamics Winter 2008 bstract Many behavioral studies have shown a reduced responsiveness to
More informationRelative Contributions of Burst and Tonic Responses to the Receptive Field Properties of Lateral Geniculate Neurons in the Cat
JOURNALOFNEUROPHYSIOLOGY Vol. 68, No. 6, December 1992. Printed in U.S.A. Relative Contributions of Burst and Tonic Responses to the Receptive Field Properties of Lateral Geniculate Neurons in the Cat
More informationLesson 14. The Nervous System. Introduction to Life Processes - SCI 102 1
Lesson 14 The Nervous System Introduction to Life Processes - SCI 102 1 Structures and Functions of Nerve Cells The nervous system has two principal cell types: Neurons (nerve cells) Glia The functions
More informationAcute Effects of Ethanol Ingestion
cute Effects of Ethanol Ingestion on the Resonse to Submaximal and Maximal Exercise in Man By GUNNR BLOMQVIST, M.D., BENGT SLTIN, M.D., ND JERE H. MrrCHELL, M.D. With the technical assistance of George
More informationThalamocortical Feedback and Coupled Oscillators
Thalamocortical Feedback and Coupled Oscillators Balaji Sriram March 23, 2009 Abstract Feedback systems are ubiquitous in neural systems and are a subject of intense theoretical and experimental analysis.
More informationSampling methods Simple random samples (used to avoid a bias in the sample)
Objectives Samling methods Simle random samles (used to avoid a bias in the samle) More reading (Section 1.3): htts://www.oenintro.org/stat/textbook.h?stat_book=os Chaters 1.3.2 and 1.3.3. Toics: Samling
More informationThalamic bursting in rats during different awake behavioral states
Thalamic bursting in rats during different awake behavioral states Erika E. Fanselow*, Koichi Sameshima, Luiz A. Baccala, and Miguel A. L. Nicolelis* *Department of Neurobiology, Duke University Medical
More informationPressor Responses to Noxious Stimuli in Hypertensive Patients
Downloaded from htt://ahajournals.org by on October 2, 2018 Pressor Resonses to Noxious Stimuli in Hyertensive Patients Effects of Guanethidine Sulfate and Alha Methyldoa By ALVIN P. SHAPIRO, M.D., AND
More informationAnalysis of in-vivo extracellular recordings. Ryan Morrill Bootcamp 9/10/2014
Analysis of in-vivo extracellular recordings Ryan Morrill Bootcamp 9/10/2014 Goals for the lecture Be able to: Conceptually understand some of the analysis and jargon encountered in a typical (sensory)
More informationOnline publication date: 01 October 2010
This article was downloaded by: [BIUS Jussieu/Paris 6] On: 10 June 2011 Access details: Access Details: [subscrition number 770172261] Publisher Psychology Press Informa Ltd Registered in England and Wales
More informationA modular neural-network model of the basal ganglia s role in learning and selecting motor behaviours
Cognitive Systems Research 3 (2002) 5 13 www.elsevier.com/ locate/ cogsys A modular neural-network model of the basal ganglia s role in learning and selecting motor behaviours Action editors: Wayne Gray
More informationPhysiology Unit 2 CONSCIOUSNESS, THE BRAIN AND BEHAVIOR
Physiology Unit 2 CONSCIOUSNESS, THE BRAIN AND BEHAVIOR What the Brain Does The nervous system determines states of consciousness and produces complex behaviors Any given neuron may have as many as 200,000
More informationEffects of Pressure, Temperature, Treatment Time, and Storage on Rheological, Textural, and Structural Properties of Heat-Induced Chickpea Gels
oods 2015, 4, 80-114; doi:10.3390/foods4020080 Article OPEN ACCESS foods ISSN 2304-8158 www.mdi.com/journal/foods Effects of Pressure, Temerature, Treatment Time, and Storage on Rheological, Textural,
More informationCOMPARISON OF LINEAR AND NON-LINEAR ANALYSIS OF HEART RATE VARIABILITY IN SEDATED CARDIAC SURGERY PATIENTS
COMPARISON OF LINEAR AND NON-LINEAR ANALYSIS OF HEART RATE VARIABILITY IN SEDATED CARDIAC SURGERY PATIENTS I. Korhonen 1, L.T. Mainardi 2, H.Yppärilä 3, T. Musialowicz 4 1 VTT Information Technology, Tampere,
More informationRelating mean blood glucose and glucose variability to the risk of multiple episodes of hypoglycaemia in type 1 diabetes
Diabetologia (2007) 50:2553 2561 DOI 10.1007/s00125-007-0820-z ARTICLE Relating mean blood glucose and glucose variability to the risk of multile eisodes of hyoglycaemia in tye 1 diabetes E. S. Kilatrick
More informationA Note on False Positives and Power in G 3 E Modelling of Twin Data
Behav Genet (01) 4:10 18 DOI 10.100/s10519-011-9480- ORIGINAL RESEARCH A Note on False Positives and Power in G E Modelling of Twin Data Sohie van der Sluis Danielle Posthuma Conor V. Dolan Received: 1
More informationAccuScreen ABR Screener
AccuScreen ABR Screener Test Methods Doc no. 7-50-1015-EN/02 0459 Copyright notice No part of this Manual or program may be reproduced, stored in a retrieval system, or transmitted, in any form or by any
More informationSUPPLEME TARY FIGURE 1 a b c
Coherent gamma oscillations couple the amygdala and striatum during learning. Popescu, Popa, Pare SUPPLEME TARY FIGURE 1 a b c LG LP LD R LA BL OT BM HF V HF VP RE VP CL PC d PU e 2 mm R f CP HF 2 mm GP
More informationPD233: Design of Biomedical Devices and Systems
PD233: Design of Biomedical Devices and Systems (Lecture-7 Biopotentials- 2) Dr. Manish Arora CPDM, IISc Course Website: http://cpdm.iisc.ac.in/utsaah/courses/ Electromyogram (EMG) Skeletal muscles are
More informationShape Analysis of the Left Ventricular Endocardial Surface and Its Application in Detecting Coronary Artery Disease
Shae Analysis of the Left Ventricular Endocardial Surface and Its Alication in Detecting Coronary Artery Disease Anirban Mukhoadhyay, Zhen Qian 2, Suchendra Bhandarkar, Tianming Liu, and Szilard Voros
More informationComplexity of cardiovascular control in amyotrophic lateral sclerosis patients is related to disease duration
Complexity of cardiovascular control in amyotrophic lateral sclerosis patients is related to disease duration 1,2, Laura Dalla Vecchia 1, Kalliopi Marinou 1, Gabriele Mora 1, Alberto Porta 3,4 ¹ IRCCS
More informationThe Application of a Cognitive Diagnosis Model via an. Analysis of a Large-Scale Assessment and a. Computerized Adaptive Testing Administration
The Alication of a Cognitive Diagnosis Model via an Analysis of a Large-Scale Assessment and a Comuterized Adative Testing Administration by Meghan Kathleen McGlohen, B.S., M. A. Dissertation Presented
More informationWhat do you notice? Woodman, Atten. Percept. Psychophys., 2010
What do you notice? Woodman, Atten. Percept. Psychophys., 2010 You are trying to determine if a small amplitude signal is a consistent marker of a neural process. How might you design an experiment to
More informationOn the tracking of dynamic functional relations in monkey cerebral cortex
Neurocomputing 32}33 (2000) 891}896 On the tracking of dynamic functional relations in monkey cerebral cortex Hualou Liang*, Mingzhou Ding, Steven L. Bressler Center for Complex Systems and Brain Sciences,
More informationThe majority of ad exposure occurs under incidental conditions where
An Examination of Different Exlanations for the Mere Exosure Effect XIANG FANG SURENDRA SINGH ROHINI AHLUWALIA* This article investigates two cometing exlanations of the mere exosure effect the cognition-based
More informationPrecise Spike Timing and Reliability in Neural Encoding of Low-Level Sensory Stimuli and Sequences
Precise Spike Timing and Reliability in Neural Encoding of Low-Level Sensory Stimuli and Sequences Temporal Structure In the World Representation in the Brain Project 1.1.2 Feldman and Harris Labs Temporal
More informationSince its introduction in 1975, extracorporeal membrane
Results of Extracororeal Membrane Oxygenation in Children With Sesis Dan M. Meyer, MD, Michael E. Jessen, MD, and the Extracororeal Life Suort Organization University of Texas Southwestern Medical Center,
More informationRandomized controlled trials: who fails run-in?
Rees et al. Trials (2016) 17:374 DOI 10.1186/s13063-016-1451-9 RESEARCH Oen Access Randomized controlled trials: who fails run-in? Judy R. Rees 1, Leila A. Mott 1, Elizabeth L. Barry 1, John A. Baron 1,2,
More informationISSN: ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 10, April 2013
ECG Processing &Arrhythmia Detection: An Attempt M.R. Mhetre 1, Advait Vaishampayan 2, Madhav Raskar 3 Instrumentation Engineering Department 1, 2, 3, Vishwakarma Institute of Technology, Pune, India Abstract
More informationLIE DETECTION SYSTEM USING ARTIFICIAL NEURAL NETWORK
Volume 5, No. 8, August 2014 Journal of Global esearch in Comuter Science ESEACH PAPE Available Online at www.jgrcs.info LIE DETECTION SYSTEM USING ATIFICIAL NEUAL NETWOK Nidhi Srivastava and Dr. Sii Dubey
More informationSensory coding and somatosensory system
Sensory coding and somatosensory system Sensation and perception Perception is the internal construction of sensation. Perception depends on the individual experience. Three common steps in all senses
More informationThis was a randomised, double-blind, vehicle-controlled, with intra-individual comparison, single centre study.
Final Reort No. MCB 0202 FRI October 24 111,2003 2 SYNOPSIS Study title: Reeat insult atch test with Daivobet!Dovobet Ointment - A Protocol number: Studied eriod: First subject in (inclusion): First study-drug
More informationCHARACTERIZATION OF A HYPERACTIVE SEGMENT AT THE RECTOSIGMOID JUNCTION
GU'I'IIO&H'I'DOLOOY 71:584-688. 1976 Coyriiht 11> 1976 by The William, & Wilkin, Co. Vol. 71. No.4 Printed in U.S.A. CHARACTERIZATION OF A HYPERACTIVE SEGMENT AT THE RECTOSIGMOID JUNCTION A. RAB CHOWDHURY,
More information1. Processes nutrients and provides energy for the neuron to function; contains the cell's nucleus; also called the soma.
1. Base of brainstem; controls heartbeat and breathing 2. tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue 3. A thick band of axons that connects the
More informationThalamo-Cortical Relationships Ultrastructure of Thalamic Synaptic Glomerulus
Central Visual Pathways V1/2 NEUR 3001 dvanced Visual Neuroscience The Lateral Geniculate Nucleus () is more than a relay station LP SC Professor Tom Salt UCL Institute of Ophthalmology Retina t.salt@ucl.ac.uk
More informationCardiology & Vascular Research
Research Article Cardiology & Vascular Research ISSN 2639-8486 Correlation of Limb Bioimedance to Echocardiograhic Indicators of Congestion in Patients with NYHA Class II/III Heart Failure Accardi AJ *,
More informationSOMATIC SENSATION PART I: ALS ANTEROLATERAL SYSTEM (or SPINOTHALAMIC SYSTEM) FOR PAIN AND TEMPERATURE
Dental Neuroanatomy Thursday, February 3, 2011 Suzanne S. Stensaas, PhD SOMATIC SENSATION PART I: ALS ANTEROLATERAL SYSTEM (or SPINOTHALAMIC SYSTEM) FOR PAIN AND TEMPERATURE Reading: Waxman 26 th ed, :
More information