Experimental Characterization and Correlation of MayerWaves in Retinal Vessel Diameter and Arterial Blood Pressure Retinal vessels show various biological temporal variations that can impact diagnosis using a static vessel analysis. In this study, Mayerwaves in the retinal vessel diameter and arterial blood pressure (BP) signals were characterized, and the temporal correlation between these two vessel diameters were correlated. The highest correlation values between the signals were observed for shifts of 1 or 0 periods. The spectrum and amplitudes of the Mayerwaves showed a high variability. The Mayerwaves in the retinal vessel diameters showed the same characteristics as those in the arterial BP. A temporal dependency between the oscillations in the arterial BP and retinal vessel
Physiological Effects of Continuous Colored Light Exposure on MayerWave Activity in Cerebral Hemodynamics: A Functional Near-Infrared Spectroscopy (fNIRS) Study. We are increasingly exposed to colored light, but its impact on human physiology is not yet extensively investigated. In the present study we aimed to determine the effects of colored light on human cerebral Mayerwave activity (MWA
Cerebral functional connectivity and Mayerwaves in mice: Phenomena and separability. Resting-state functional connectivity is a growing neuroimaging approach that analyses the spatiotemporal structure of spontaneous brain activity, often using low-frequency (<0.08 Hz) hemodynamics. In addition to these fluctuations, there are two other low-frequency hemodynamic oscillations in a nearby spectral region (0.1-0.4 Hz) that have been reported in the brain: vasomotion and Mayerwaves. Despite how close in frequency these phenomena exist, there is little research on how vasomotion and Mayerwaves are related to or affect resting-state functional connectivity. In this study, we analyze spontaneous hemodynamic fluctuations over the mouse cortex using optical intrinsic signal imaging. We found
Mayerwaves reduce the accuracy of estimated hemodynamic response functions in functional near-infrared spectroscopy Analysis of cerebral hemodynamics reveals a wide spectrum of oscillations ranging from 0.0095 to 2 Hz. While most of these oscillations can be filtered out during analysis of functional near-infrared spectroscopy (fNIRS) signals when estimating stimulus evoked hemodynamic responses concentration (HbO), Mayerwave oscillations with an amplitude > ~1 µM at 0.1 Hz reduce the accuracy of the estimated response as quantified by a 3 fold increase in the mean squared error and decrease in correlation (R(2) below 0.78) when compared to the true HRF. These results indicate that the amplitude of oscillations at 0.1 Hz can serve as an objective metric of the expected HRF estimation accuracy
The vasovagal response of the rat: its relation to the vestibulosympathetic reflex and to Mayerwaves Vasovagal responses (VVRs) are characterized by transient drops in blood pressure (BP) and heart rate (HR) and increased amplitude of low-frequency oscillations in the Mayerwave frequency range. Typical VVRs were induced in anesthetized, male, Long-Evans rats by sinusoidal galvanic vestibular stimulation (sGVS). VVRs were also produced by single sinusoids that transiently increased BP and HR, by 70-90° nose-up tilts, and by 60° tilts of the gravitoinertial acceleration vector using translation while rotating (TWR). The average power of the BP signal in the Mayerwave range increased substantially when tilts were >70° (0.91 g), i.e., when linear accelerations in the x-z plane were ≥0.9-1.0 g
and lower detectability of spontaneous systolic pressure oscillation at 0.1 Hz (Mayerwave - baroreflex arc) during SB compared to 53 never-infected and 14 fully-recovered HCWs (19%, 42% and 40%, respectively, p=0.027). During SPB, the increase in this parameter was close to controls (91.2%, 100% and 100%, respectively, p=0.09). No other differences in HRV parameters were found among groups. Resting
. In the endothelial band (0.003-0.02 Hz), the stimulated Broca's area became the strongest hub of outgoing information flow, whereas in the neurogenic band (0.02-0.04 Hz) the contralateral homologous area became the strongest information outflow source. In the myogenic band (0.04-0.15 Hz), only global patterns were seen, independent of tDCS stimulation that were interpreted as Mayerwaves. These findings showcase
the patients with severe ICA stenosis according to preoperative state of DCA and to assess its dynamics after surgery. Thirty-five patients with severe ICA stenosis having different clinical type of disease underwent reconstructive surgery. DCA was assessed with transfer function analysis (TFA) by calculating phase shift (PS) between Mayerwaves of blood flow velocity (BFV) and blood pressure (BP) before
death. Available evidence suggests a role of the sympathetic nervous system. We have used biophysically detailed models integrating ventricular electrophysiology, calcium dynamics, mechanics and β-adrenergic signaling to investigate the underlying mechanisms. The main results were: (1) Phasic beta-adrenergic stimulation (β-AS) at a Mayerwave frequency between 0.03 and 0.15Hz resulted in a gradual decrease of action potential (AP) duration (APD) with concomitant small APD oscillations. (2) After 3-4minutes of phasic β-AS, the mean APD adapted and oscillations of APD became apparent. (3) Phasic changes in haemodynamic loading at the same Mayerwave frequency (a known accompaniment of enhanced sympathetic nerve activity), simulated as variations in the sarcomere length, also induced APD oscillations
of cardiac fluctuations around a vocalization cannot be completely predicted by the animal's respiration or movement. Moreover, the timing of vocal production was tightly correlated to the phase of a 0.1-Hz autonomic nervous system rhythm known as the Mayerwave. Finally, a compilation of the state space of arousal dynamics during vocalization illustrated that perturbations to the resting state space
), and systemic arterial blood pressure (ABP). The analysis covered cerebral perfusion pressure (CPP), the index of pressure-volume compensatory reserve (RAP), and phase shift angles between Mayerwaves (3 to 9 cpm) in ABP and MCA-FV or PCA-FV. Due to intraventricular infusion, the pressure-volume reserve was exhausted (RAP) 0.84+/-0.1 and ICP was increased from baseline 11.5+/-5.6 to plateau levels of 20.7
rhythmic fluctuations during this stage referred to as “Mayerwaves” [62] with an approximate 10-second period (0.1Hz). Similar periodicity is shared by fluctuations in heart rate, sympathetic nerve activity, and peripheral resistance. The fluctuations are the closed loop time for sympathetic baroreflex response (i.e., the time it takes for detection and compensation for BP changes). [63] Oscillations baroreflex efferent arms are impaired prior to fainting, and Mayerwaves disappear. Similarly cerebral autoregulation becomes impaired with entrainment of CBF, BP, and HR by an extrinsic signal, which may be hyperpneic respiration. [4, 68] Why baroreflex integrity is lost is not yet known, but this results in abnormal BP-HR and BP-MSNA functional relationships such that HR, BP, and sympathetic nerve
of Mayerwaves: Facts and models. Cardiovasc Res. 2006. 70:12-21. [QxMD MEDLINE Link]. 63. Hammer PE and Saul JP. Resonance in a mathematical model of baroreflex control: arterial blood pressure waves accompanying postural stress. Am J Physiol Regul Integr Comp Physiol. 2005. 288:R1637-R1648. [QxMD MEDLINE Link]. 64. Cooke WH, Rickards CA, Ryan KL, Kuusela TA and Convertino VA
of Mayerwaves: Facts and models. Cardiovasc Res. 2006. 70:12-21. [QxMD MEDLINE Link]. 63. Hammer PE and Saul JP. Resonance in a mathematical model of baroreflex control: arterial blood pressure waves accompanying postural stress. Am J Physiol Regul Integr Comp Physiol. 2005. 288:R1637-R1648. [QxMD MEDLINE Link]. 64. Cooke WH, Rickards CA, Ryan KL, Kuusela TA and Convertino VA
rhythmic fluctuations during this stage referred to as “Mayerwaves” [62] with an approximate 10-second period (0.1Hz). Similar periodicity is shared by fluctuations in heart rate, sympathetic nerve activity, and peripheral resistance. The fluctuations are the closed loop time for sympathetic baroreflex response (i.e., the time it takes for detection and compensation for BP changes). [63] Oscillations baroreflex efferent arms are impaired prior to fainting, and Mayerwaves disappear. Similarly cerebral autoregulation becomes impaired with entrainment of CBF, BP, and HR by an extrinsic signal, which may be hyperpneic respiration. [4, 68] Why baroreflex integrity is lost is not yet known, but this results in abnormal BP-HR and BP-MSNA functional relationships such that HR, BP, and sympathetic nerve
-frequency oscillations (0.1 Hz) associated with Traube-Hering-Mayerwaves of BP . It was found that a decrease in HRV was a strong predictor of mortality after acute myocardial infarction . HRV is assessed by either time or frequency domain methods. EFFECT OF MUSIC ON BLOOD PRESSURE:Many studies have shown that there is a modification of cardiorespiratory parameters on repeated rhythymic recitation
outflow and increased norepinephrine release on the heart and blood vessels, increasing blood pressure.[citation needed]Effect on heart rate variability[edit]The baroreflex may be responsible for a part of the low-frequency component of heart rate variability, the so-called Mayerwaves, at 0.1 Hz.[4]Baroreflex activation therapy[edit]Baroreflex activation is distinct from vagal stimulation. It works
, the physiologic response is decreased blood flow peripherally, which can present as Mayerwaves. These are simply pathologic waves seen in HR tracings (i.e., arterial lines, electrocardiograph (ECG, etc.), which reflect decreased intravascular blood flow. This decreased flow often causes a reflexive HTN, or hypertension (increase in blood pressure) despite the actual decrease in intravascular volume.[7
. To bridge the important gap in the literature, we used the fNIRS methodology to investigate the neural mechanisms of facial emotion recognition for the patients with depression. We hypothesize the physiological feature of the hemodynamic responses in prefrontal cortex measured by fNIRS under the task of face emotion recognition, including the difference of the median, the Mayerwave power, the mean cross
become the conventionally accepted term to describe beat-to-beat alteration in HR, and RR intervals in ECG. The cause of HRV is considered to be respiratory sinus arrhythmia as well as low-frequency oscillations (0.1 Hz) associated with Traube-Hering-Mayerwaves of BP . It was found that a decrease in HRV was a strong predictor of mortality after acute myocardial infarction . HRV is assessed by either