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PubMed1994

Slowed respiration training.

A method of slowed respiration rate (RR) training is described that uses visual feedback of the respiratory cycle. Subjects assigned to the slowed RR training procedure were compared with subjects assigned to either a traditional frontal electromyographic (EMG) biofeedback condition or a control condition where no feedback was presented. RR, frontal EMG, heart rate, digital temperature, and skin conductance level were monitored simultaneously. The results indicated that RR training was effective in reducing RR, that RR training had little systematic effect on the other physiological variables, and the frontal EMG procedure did not in itself reduce RR. The advantages of the current methodological approach and the importance of respiration training were discussed along with a literature review. The relationship between RR training and the complexities of respiratory phenomena was discussed, as well as ways that future research using this method may help clarify current issues within respiration training.

Adult↗

PubMed1982

Physiological and clinical aspects of respiration control in infants with relation to the sudden infant death syndrome.

We have examined the behavior of several variables which are related to respiratory control in 114 infants (up to 6 months of age) in order to assess the risk for the sudden infant death syndrome (SIDS), 23 of the infants had already had demonstratable serious or life threatening apneas or respiratory problems during surgical anesthesia. These infants were assigned as a risk group, and the rest of the investigated babies was taken as a control group. We found that practically all infants of the risk group had apneas during sleep, which lasted longer than 8 s each. Only 22% of the infants of the control group had apneas of such a duration. As a statistical parameter, calculated from at least 1 hour recording of respiration, we defined the mean apnea duration (MA-value) as average value of apnea duration time in seconds per minute of recording. The MA-value proved to be significantly elevated in the infants of the risk group. The trend to hypoxia in the infants of the risk group was also indicated by the observation of lower transcutaneous PO2-values (tc-PO2) during sleep, when compared with control infants. In agreement with this observation is the increase of the 2,3-DPG concentration and the decrease of the density of erythrocytes of the infants of the risk group. Breathing hypoxic gas mixtures tended to depress respiration in all infants tested, and, especially in the risk group, to elicit irregular respiratory patterns. On the other hand, we observed that inhalation of pure oxygen markedly stimulated respiration in all infants investigated. We conclude from these observations that a risk for SIDS may be related to a particular response pattern of the respiratory center during the early postnatal life. We are able to distinguish infants with a higher risk for SIDS from other children by determination of the MA-value during sleep.

Aminophylline↗

PubMedDate not supplied

[Rhythmic regulation of pulse and respiration while standing in subjects with stable and labile orthostatic blood pressure].

The pulse and respiration rate of normal people in a recumbant position has a fairly high degree of coordination. This increases in a upright position. In patients with orthostatic hypotension the degree of coordination is fairly low when lying and mostly decreases when standing. - The rhythmic regulation of the bradycard subgroup of the patients with orthostatic hypotension is still relatively strong, but the hypotension is extreme; that of the tachycard subgroup is extremely unstable, but the hypotension is not so marked. As collapse occurs with the same frequency in both subgroups, blood pressure and rhythmic regulation must be able to compensate each other to a certain degree. - Normal values can be detected by observing regulative optima. The marked optimum in an upright position is found by a pulse rate of 80-85 min-1, a respiration rate of 16-18 min-1 and a QP/R of 5. A minor, second optimum exists near a pulse rate of 100-105 min-1, a respiration rate of 14-15 min-1 and a QP/R of 7. - In patients with orthostatic hypotension these optima also can occur but sometimes less markedly. It can thus be accepted that the normal regulative process is latent more or less in ill people. This becomes particularly meaningful for all methods of therapies which strengthen this regulative process. - As in pathological cases a minor, second optimum is found in the regulative process, illness cannot mean a total loss of order but merely a reorganisation.

Bradycardia↗

PubMedDate not supplied

The effects of the mediodorsal nucleus of the thalamus on respiratory neurons of the medulla oblongata and respiration in rats in conditions of hypoxia.

The effects of the associated mediodorsal nucleus of the thalamus on spike activity of respiratory neurons in the medulla oblongata and on respiration were studied in normal conditions and in oxygen insufficiency. At normal atmospheric pressure, before animals were elevated to low pressures, electrical stimulation of the mediodorsal nucleus of the thalamus had predominantly inhibitory effects. At the initial phase of hypoxia, at a "height" of 4,000-5,000 m, hypoxic activation of neuron discharge frequency occurred. with an increase in the frequency of respiration. In these conditions, the inhibitory effect of stimulation of the mediodorsal nucleus of the thalamus was less marked than in normoxic conditions. The opposite effect occurred at the second phase of hypoxia (7,500-8,000 m)-inhibition of activity in the medulla oblongata and thalamic center. In severe hypoxia, there was inhibition of neuron spike activity and a decrease in the frequency of respiration, which became superficial; in these conditions, the inhibitory effect of the thalamus was insignificant.

Action Potentials↗

PubMed1995

Multivariate autoregressive modelling combined with transcephalic electrical impedance: method to relate neonatal systemic circulation and respiration to cerebral circulation.

We studied the pulsatile component of cerebral circulation with transcephalic electrical impedance (delta Z) in six preterm newborns, three of whom had severe cerebral bleeding, peri-intraventricular haemorrhage (PIVH). The transcephalic electrical impedance delta Z signal, ECG, arterial blood pressure, (aBP) and respirogram were recorded on analogue magnetic tape for 30 min. Artefact-free stationary segments (lasting for 2 min) of the four signals were digitised. A digital multivariate autoregressive (MAR) model was used to study frequency-specific variability in the signals and to quantify interrelations between the variabilities of delta Z, HR, aBP and respiratory signals. MAR modelling describes a system where all the signals simultaneously explain each other. The inherent variability of delta Z was lower and the influences of respiration and aBP on delta Z significantly greater in infants with severe PIVH than in controls. These changes were observed at high frequencies corresponding to respiration and heart rate. This may be interpreted as a marker of pressure passivism in the cerebral circulation following PIVH. We conclude that in preterm babies the application of MAR modelling, together with transcephalic impedance, may be a new, helpful and quantitative method for the study of simultaneous interrelations between variables of cerebral and systemic circulations and respiration.

Cerebral Hemorrhage↗

PubMed1998

[The effect of temperature and humidity on breath samples. Measurement of breath ethanol concentration in artificially respirated patients].

UNLABELLED: When looking for the possible cause of distortions in values measured for the determination of breath ethanol concentration (BEC) in artificially respirated patients, consideration must be given to the humidity and temperature of the gas examined. In the present study, the effects of humidified and warmed and of dry and cold air on the accuracy of a newly developed BEC measuring device, as compared to a reference model and to a conventional system, were examined in a lung model. METHODS: A temperature-regulated pediatric incubator was used containing a 10 I gas reservoir and a breath humidifier with temperature regulated water bath. This setup provided constant temperature and humidity in the gas examined during measurement period. In the 'expiration' the air was directed from the breath humidifier through a measuring unit via a 'mouthpiece' into the reference system (Alcotest 7110, Dräger Inc., Lübeck) and then out. The measuring unit consisted of sensors for the temperature and relative humidity, and of a connector for the three sample extraction systems (PES). PES I was the conventional system with a 100-cm gas-sample pipe (Alcomed 3010), PES II the newly developed system (AlcoMed 3011, both from Envitec, Wismar) with a 10-cm gas-sample pipe, and PES III with a 20-cm heated gas-sample pipe. During 'inspiration' 2 l of air was fed into the system to rinse the measuring unit and to fill the reservoir. 61 measurements were performed with dry and cold air, and 71 with humidified and warmed air, in the course of which the ethanol concentration was increased from 0 to 1.5/1000. Data were evaluated using regression analysis and the Bland & Altman method. RESULTS AND CONCLUSIONS: The constancy of the values set for temperature, relative humidity and absolute humidity in the lung model was given for all measurements. In the dry and cold air, the results from all three test systems coincided almost perfectly with the reference values. The measured BEC in the humidified and warmed air using sample-extraction systems II and III corresponded to a high degree with the reference, while in the case of PES I, only a moderate linear correlation was achieved. The temperature and humidity of the expired gas during artificial respiration influence the gas samples extracted for the purposes of BEC measurement. Newly developed sample-extraction systems II and III coincide with the reference system, even under respiration-simulated gas conditions.

Breath Tests↗

PubMed2003

Creatine kinase and mitochondrial respiration in hearts of trout, cod and freshwater turtle.

The importance of the creatine kinase system in the cardiac muscle of ectothermic vertebrates is unclear. Mammalian cardiac muscle seems to be structurally organized in a manner that compartmentalizes the intracellular environment as evidenced by the substantially higher mitochondrial apparent Km for ADP in skinned fibres compared to isolated mitochondria. A mitochondrial fraction of creatine kinase is functionally coupled to the mitochondrial respiration, and the transport of phosphocreatine and creatine as energy equivalents of ATP and ADP, respectively, increases the mitochondrial apparent ADP affinity, i.e. lowers the Km. This function of creatine kinase seems to be absent in hearts of frog species. To find out whether this applies to hearts of ectothermic vertebrate species in general, we investigated the effect of creatine on the mitochondrial respiration of saponin-skinned fibres from the ventricle of rainbow trout, Atlantic cod and freshwater turtle. For all three species, the apparent Km for ADP appeared to be substantially higher than for isolated mitochondria. Creatine lowered this Km in trout and turtle, thus indicating a functional coupling between mitochondrial creatine kinase and respiration. However, creatine had no effect on Km in cod ventricle. In conclusion, the creatine kinase-system in trout and turtle hearts seems to fulfil the same functions as in the mammalian heart, i.e. facilitating energy transport and communication between cellular compartments. In cod heart, however, this does not seem to be the case.

Adenosine Diphosphate↗

PubMed2005

Response of heart rate and cloacal ventilation in the bimodally respiring freshwater turtle, Rheodytes leukops, to experimental changes in aquatic PO2.

Changes in heart rate (f(H)) and cloacal ventilation frequency (f(C)) were investigated in the Fitzroy turtle, Rheodytes leukops, under normoxic (17.85 kPa) and hypoxic (3.79 kPa) conditions at 25 degrees C. Given R. leukops' high reliance on aquatic respiration via the cloacal bursae, the objective of this study was to examine the effect of varying aquatic PO(2) levels upon the expression of a bradycardia in a freely diving, bimodally respiring turtle. In normoxia, mean diving f(H) and f(C) for R. leukops remained constant with increasing submergence length, indicating that a bradycardia failed to develop during extended dives of up to 3 days. Alternatively, exposure to aquatic hypoxia resulted in the expression of a bradycardia as recorded by a decreasing mean diving f(H) with increasing dive duration. The observed bradycardia is attributed to a hypoxic-induced metabolic depression, possibly facilitated by a concurrent decrease in f(C). Results suggest that R. leukops alters its strategy from aquatic O(2) extraction via cloacal respiration in normoxia to O(2) conservation when exposed to aquatic hypoxia for the purpose of extending dive duration. Upon surfacing, a significant tachycardia was observed for R. leukops regardless of aquatic PO(2), presumably functioning to rapidly equilibrate blood and tissue gas tensions with alveolar gas to reduce surfacing duration.

Animals↗

PubMed2005

Differential respirable dust related lung function effects between current and former South African coal miners.

Dust-related dose-response decrements in lung function among coal miners have been reported in several studies, with varying magnitudes across populations. Few studies have compared differences between current and former coal miners. No studies on dose response relationships with lung function have been conducted in South African coal mines, one of the top three producers of coal internationally. The objectives of this study were (1) to describe the relationship between respirable dust exposure and lung function among current and former South African coal miners and to determine whether differential dust related effects were present between these employment categories; (2) to examine dust related dose response relationships, controlling for potential confounding by smoking and a history of tuberculosis (TB). Six hundred and eighty-four current and 188 ex-miners from three bituminous coal mines in Mpumalanga Province were studied. Interviews assessing work histories, smoking profiles and other risk factors were conducted. Work histories were also obtained from company records. Standardised spirometry was performed by trained technicians. Cumulative respirable dust exposure (CDE) estimates were constructed from company-collected sampling and measurements conducted by the researchers. Regression models examined the associations of CDE with per cent predicted FEV(1) and FVC, controlling for smoking, past history of TB and employment status. A statistically significant decline in FEV(1) of 1.1 and 2.2 ml/mg-year/m(3) was found in representative 40-year-old, 1.7-m tall current and former miners, respectively. Significant differences were found between the highest and medium exposure categories. Ex-miners had a lower mean per cent predicted lung function than current miners for each cumulative exposure category, suggesting a "healthy worker" effect. Past history of TB contributed to 21 and 14% declines in per cent predicted FEV(1) and FVC, respectively. Thus, in this cohort, a dose-related decline in lung function was associated with respirable dust exposure, with a magnitude of effect similar to that seen in other studies and important differences between current and former employees. A "healthy worker" effect may have attenuated the magnitude of this relationship. TB was a significant contributor to lung function loss.

Adult↗

PubMed2001

Increased levels of adenine nucleotides modify the interaction between starch synthesis and respiration when adenine is supplied to discs from growing potato tubers.

To investigate the importance of the overall size of the total adenine nucleotide pool for the regulation of primary metabolism in growing potato tubers, freshly cut discs were provided with zero or 2 mM adenine in the presence of 1 or 100 mM [U-14C]glucose or 100 mM [U-14C]sucrose in the presence and absence of 20 mM orthophosphate (Pi). Adenine led to a 150-250% increase of the total adenine nucleotide pool, which included an increase of ADP, a larger increase of ATP and an increase of the ATP:ADP ratio. There was a 50-100% increase of ADP-glucose (ADPGlc), and starch synthesis was stimulated. Respiratory oxygen uptake was stimulated, and the levels of glycerate-3-phosphate, phosphoenolpyruvate and alpha-ketoglutarate decreased. The response to adenine was not modified by Pi. It is proposed that increased ATP stimulates ADPGlc pyrophosphorylase, leading to a higher rate of starch synthesis. The impact on starch synthesis is constrained, however, because increased ADP can lead to a stimulation of respiration and decline of glycerate-3-phosphate, which will inhibit ADPGlc pyrophosphorylase. The quantitative impact depends on the conditions. In the presence of 1 mM glucose, the levels of phosphorylated intermediates and the rate of starch synthesis were low. Adenine led to a relatively large stimulation of respiration, but only a small stimulation of starch synthesis. In the presence of 100 mM glucose, discs contained high levels of phosphorylated intermediates, low ATP:ADP ratios (< 3) and low rates of starch synthesis (< 20% of the metabolised glucose). Adenine led to marked increase of ATP and 2- to 4-fold stimulation of starch synthesis. Discs incubated with 100 mM sucrose already had high ATP:ADP ratios (> 8) and high rates of starch synthesis (> 50% of the metabolised sucrose). Adenine led to a further increase, but the stimulation was less marked than in high glucose. These results have implications for the function of nucleotide cofactors in segregating sucrose mobilisation and respiration, and the need for energy conservation during sugar-starch conversions.

Adenine↗

PubMed2004

Lichens show that fungi can acclimate their respiration to seasonal changes in temperature.

Five species of lichens, the majority members of a soil-crust community ( Cladonia convoluta, Diploschistes muscorum, Fulgensia fulgens, Lecanora muralis, Squamarina lentigera) showed seasonal changes of temperature sensitivity of their dark respiration (DR) to such an extent that several substantially met the definition of full acclimation, i.e. near identical DR under different nocturnal temperature conditions during the course of the year. C. convoluta, for example, had maximal DR at 5 degrees C of -0.42, -1.11 and -0.09 nmol CO(2) g(-1) s(-1) in autumn, winter, and summer, respectively, a tenfold range. However, at the mean night temperatures for the same three seasons, 9.7 degrees C, 4.2 degrees C and 13.6 degrees C, maximal DR were almost identical at -1.11, -0.93, and -1.45 nmol CO(2) g(-1) s(-1). The information was extracted from measurements using automatic cuvettes that continuously recorded a sample lichen's gas exchange every 30 min under near-natural conditions. The longest period (for L. muralis) covered 15 months and 22,000 data sets whilst, for the other species studied, data blocks were available throughout the calendar year. The acclimation of DR means that maximal net carbon fixation rates remain substantially similar throughout the year and are not depressed by increased carbon loss by respiration in warmer seasons. This is especially important for lichens because of their normally high rate of DR compared to net photosynthesis. We suggest that lichens, especially soil-crust species, could be a suitable model for fungi generally, a group of organisms for which little is known about temperature acclimation because of the great difficulty in separating the organism from its growth medium. Fungi, whether saprophytic, symbiotic or parasitic, including soil lichens, are important components of soil ecosystems and contribute much of the respired CO(2) from these systems. Temperature acclimation by fungi would mean that expected increases in carbon losses caused by global climate warming from soil ecosystems might not be as extensive as first thought. This would ameliorate this positive feedback loop present in some climate models and might substantially lower the predicted warming.

Acclimatization↗

PubMed2006

Pulse wave transit time for monitoring respiration rate.

In this study, we investigate the beat-to-beat respiratory fluctuations in pulse wave transit time (PTT) and its subcomponents, the cardiac pre-ejection period (PEP) and the vessel transit time (VTT) in ten healthy subjects. The three transit times were found to fluctuate in pace with respiration. When applying a simple breath detecting algorithm, 88% of the breaths seen in a respiration air-flow reference could be detected correctly in PTT. Corresponding numbers for PEP and VTT were 76 and 81%, respectively. The performance during hypo- and hypertension was investigated by invoking blood pressure changes. In these situations, the error rates in breath detection were significantly higher. PTT can be derived from signals already present in most standard monitoring set-ups. The transit time technology thus has prospects to become an interesting alternative for respiration rate monitoring.

Adult↗

PubMed1994

Effects of voltage and respiration on impedance in nonthoracotomy defibrillation pathways.

The effects of applied voltage and phase of respiration on impedance of pathways used by implantable cardioverter-defibrillators were investigated. Patients were studied at implantation of cardioverter-defibrillators using epicardial (n = 12) or transvenous and subcutaneous (SQ) (n = 30) electrodes. Transvenous-SQ pathways were right ventricular cathode to SQ anode and coronary sinus cathode to SQ anode. Transvenous-transvenous pathways were right ventricle to coronary sinus and right ventricle to superior vena cava. Patients with nonthoracotomy electrode systems were studied at end-expiration and end-inspiration. Five shocks of 65 to 745 V (0.2 to 34 J) were given in random order in sinus rhythm. Over this range, end-expiratory impedance decreased monotonically for all pathways. This effect was greatest for transvenous-SQ pathways (13 +/- 3% to 17 +/- 4%, p < 0.001), intermediate for transvenous-transvenous pathways (5 +/- 4% to 8 +/- 5%, p < 0.001), and least for epicardial pathways (3 +/- 3%, p = 0.006). Paired data in inspiration and expiration showed that inspiration increased impedance in transvenous-SQ pathways (p < 0.001) but not in transvenous-transvenous pathways. Further, the effects of respiration and voltage on impedance in transvenous-SQ pathways were interactive (p < 0.001): Inspiration increased voltage-dependence of impedance. The magnitude of the inverse relationship between voltage and impedance depends on type of defibrillation pathway. The effect of respiration on impedance suggests that voltage-dependence of impedance is greatest in the lungs. These findings have potential relevance for intraoperative testing of cardioverter-defibrillators and selection of pathways for low-energy cardioversion.

Aged↗

PubMed1996

Coordination between respiration and deglutition in a preterm infant mammal, Sus scrofa.

In adult mammals, the path of a swallowed bolus of solid food crosses the laryngeal opening, so that coordination between respiration and deglutition is critical for airway protection. The nature of such coordination in preterm, low-birth-weight infants with immature nervous systems, is not clear. Using preterm pigs as a model, two measures of respiration were recorded and then coordinated with a high-resolution cineradiographic record of swallowing. Swallows, divided into three distinct events, began before inhalation ended, but expiration did not start until after the milk had passed around the laryngeal opening. These results support the idea that a high degree of coordination between swallowing and respiration exists in preterm infant pigs, although other aspects of the nervous system have not fully matured.

Animals↗

PubMed1985

Effects of enkephalin and 5-hydroxytryptamine on solitary tract neurones involved in respiration and respiratory reflexes.

Both enkephalin and 5-hydroxytryptamine (5-HT) have been implicated in neural mechanisms underlying the central control of respiration. In view of the role of the nuclei tractus solitarii (NTS) in respiratory regulation, we carried out a study in artificially ventilated, chloralose-anaesthetized cats of the effects of the microiontophoretic application of [D-Ala2, Met5]-enkephalinamide (DAME) and 5-HT on functionally identified NTS neurones implicated in the control of respiration and respiratory tract reflexes. The neurones examined belonged primarily to two groups: respiratory neurones having a rhythmic activity in phase with the simultaneously recorded phrenic nerve rhythm (viz inspiratory neurones), and presumed reflex interneurones which had no rhythmic activity but which could be orthodromically excited by vagus nerve (X) or superior laryngeal nerve (SLN) stimulation. Application of DAME produced a slow, prolonged depression in 9 of 20 respiratory neurones and 4 of 5 reflex interneurones tested: the remaining neurones showed no change in activity with DAME. The DAME-induced depression was reversed by the intravenous administration of naloxone in the 4 neurones tested. The predominant effect of 5-HT on the 26 respiratory neurones examined was a facilitatory effect of slow onset and long duration; this was noted in 15 neurones. A small number (n = 2) showed a prolonged depression, and the remaining 9 were unaffected. With the reflex interneurones, in contrast, facilitation was not seen with the application of 5-HT; instead, 4 were depressed and 4 unaffected. These findings on functionally identified NTS neurones provide support for the view that both endogenous 5-HT and opiate-related mechanisms are involved in the control of respiration and respiratory tract reflexes. Our findings suggest that they may operate, at least in part, by differing modulatory actions on neurones in the NTS involved in these respiratory-related functions, with enkephalin exerting depressive actions and 5-HT having both facilitatory and depressive effects.

Animals↗

PubMed1986

Inhibitory effects of cerebellar lesions on respiration in the spontaneously breathing, anesthetized cat.

Acute cerebellectomy depressed spontaneous respiration in cats anesthetized with chloralose-urethane. After cerebellectomy there was an increased interbreath interval (TTOT) accompanied by increased inspiratory and expiratory durations (TI and TE, respectively). However, the change of TE exceeded that of TI so that TI/TTOT decreased. Tidal volume (VT) and mean inspiratory flow (VT/TI) were not affected. No respiratory variable was significantly altered when cerebellectomy was performed subsequent to bilateral vagotomy. Bilateral lesions of the rostral fastigial nuclei (FN) in cats with intact vagi also caused a reduction in ventilation due to increased TTOT. In this case TI and VT/TI increased, but VT and TI/TTOT remained unchanged. Bilateral control lesions that usually included portions of the dentate nuclei did not influence respiration. The results suggest that in the anesthetized cat the cerebellum tonically excites respiratory centers controlling respiratory rate and the termination of inspiration. A part of this influence may be mediated by the rostral FN. In addition, vagal input appears to be important in the expression of the cerebellar influence on spontaneous respiration.

Anesthesia↗

PubMed1991

Descending inhibitory pathway responsible for simultaneous suppression of postural tone and respiration in decerebrate cats.

The present study was performed in order to elucidate whether the suppressive effects on postural tone and respiration evoked by stimulation of the dorsal tegmental field (DTF) of the pons are relayed through the neurons in the ponto-medullary reticular formation. First, the DTF was functionally identified, and then a microelectrode was inserted into the caudal pontine and medullary reticular formation to investigate the distribution of the neurons monosynaptically activated by stimulation of the DTF. The monosynaptically activated neurons were distributed within the nucleus reticularis gigantocellularis (NRGc) in the caudal pons and medulla. The spinal cord (L1) was stimulated to study whether such monosynaptically activated neurons project to the spinal cord. Almost all the neurons monosynaptically activated by DTF stimulation were antidromically activated by spinal stimulation. This result indicates that the neurons in the NRGc activated monosynaptically by DTF stimulation send axons to the spinal cord. Tonic micro-stimulation was then delivered to the site in the NRGc, from which the monosynaptically driven units were recorded by DTF stimulation. The stimulation resulted in the parallel suppression of postural tone and respiration, similar to the suppressive effects elicited by DTF stimulation. The present study suggests the possible existence of a descending inhibitory pathway through the reticulospinal neurons in the NRGc responsible for parallel suppression of postural tone and respiration.

Animals↗

PubMed1980

Respiration-linked 'limbic spindles': vibration artifact recorded from nasopharyngeal and intracerebral electrodes.

Respiration-linked 20-40 c/sec spindles were recorded simultaneously from nasopharyngeal, sphenoidal and limbic depth electrodes in 10 patients under evaluation for temporal lobectomy. In addition, a piezo-electrode at the tip of one nasopharyngeal electrode recorded vibration from the nasopharynx in 3 patients. Results demonstrated that respiration-linked 20-40 c/sec spindles recorded from nasopharyngeal and sphenoidal electrodes are vibration artifact. In addition, similar vibration artifact also occurred in the limbic depth, indicating that at least some respiration-linked intracerebrally recorded limbic spindles also are not of neuronal origin.

Electroencephalography↗