Did you mean: pressoreceptors
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European Journal of Heart Failure Apr 2024
Topics: Humans; Heart Failure; Pressoreceptors; Electric Stimulation Therapy; Treatment Outcome; Male; Female; Middle Aged
PubMed: 38660911
DOI: 10.1002/ejhf.3258 -
The Journal of Physiological Sciences :... Mar 2024The purpose of this study was to clarify sex differences in the inhibition of sympathetic vasomotor outflow which is caused by the loading of cardiopulmonary...
The purpose of this study was to clarify sex differences in the inhibition of sympathetic vasomotor outflow which is caused by the loading of cardiopulmonary baroreceptors. Ten young males and ten age-matched females participated. The participants underwent a passive leg raising (PLR) test wherein they were positioned supine (baseline, 0º), and their lower limbs were lifted passively at 10º, 20º, 30º, and 40º. Each angle lasted for 3 min. Muscle sympathetic nerve activity (MSNA) was recorded via microneurography of the left radial nerve. Baseline MSNA was lower in females compared to males. MSNA burst frequency was decreased during the PLR in both males (- 6.2 ± 0.4 bursts/min at 40º) and females (- 6.5 ± 0.4 bursts/min at 40º), but no significant difference was detected between the two groups (P = 0.61). These results suggest that sex has minimal influence on the inhibition of sympathetic vasomotor outflow during the loading of cardiopulmonary baroreceptors in young individuals.
Topics: Humans; Male; Female; Leg; Muscle, Skeletal; Sympathetic Nervous System; Pressoreceptors; Lower Extremity; Blood Pressure; Baroreflex; Heart Rate
PubMed: 38500058
DOI: 10.1186/s12576-024-00909-4 -
Science (New York, N.Y.) Feb 2024A central baroreceptor monitors arterial pressure to modulate brain activity.
A central baroreceptor monitors arterial pressure to modulate brain activity.
Topics: Blood Pressure; Brain; Heart; Heart Rate; Pressoreceptors; Animals; Mice; Rats
PubMed: 38301020
DOI: 10.1126/science.adn4942 -
Science (New York, N.Y.) Feb 2024The transmission of the heartbeat through the cerebral vascular system causes intracranial pressure pulsations. We discovered that arterial pressure pulsations can...
The transmission of the heartbeat through the cerebral vascular system causes intracranial pressure pulsations. We discovered that arterial pressure pulsations can directly modulate central neuronal activity. In a semi-intact rat brain preparation, vascular pressure pulsations elicited correlated local field oscillations in the olfactory bulb mitral cell layer. These oscillations did not require synaptic transmission but reflected baroreceptive transduction in mitral cells. This transduction was mediated by a fast excitatory mechanosensitive ion channel and modulated neuronal spiking activity. In awake animals, the heartbeat entrained the activity of a subset of olfactory bulb neurons within ~20 milliseconds. Thus, we propose that this fast, intrinsic interoceptive mechanism can modulate perception-for example, during arousal-within the olfactory bulb and possibly across various other brain areas.
Topics: Animals; Rats; Blood Pressure; Ion Channels; Neurons; Olfactory Bulb; Synaptic Transmission; Mechanotransduction, Cellular; Pressoreceptors; Rats, Wistar; Male; Mice; Mice, Inbred C57BL; Heart Rate; Pulse; Brain; Intracranial Pressure; Female
PubMed: 38301001
DOI: 10.1126/science.adk8511 -
Annual International Conference of the... Jul 2023Baroreceptors, sensors that play a role in controlling arterial blood pressure (BP), are mechanical stretch receptors located in the aortic arch and carotid sinuses....
Baroreceptors, sensors that play a role in controlling arterial blood pressure (BP), are mechanical stretch receptors located in the aortic arch and carotid sinuses. Factors affecting the degree of stretch in the vessel wall with BP, such as increased arterial stiffness, may compromise baroreceptor sensitivity (BRS) to BP changes. Yet, evidence of this is scattered, as both baroreceptor sensitivity (BRS) and arterial stiffness are calculated variables with multiple methodological approaches. This pilot study (n=10) investigates the correlation of arterial stiffness and BRS using multiple BRS calculation techniques (spectral and sequence methodologies at aortic and finger sites) and arterial stiffness measurement [carotid-femoral pulse wave velocity (cfPWV), carotid compliance and distensibility]. BRS was assessed under resting BP conditions and during BP altered by maneuvers (0.1 Hz controlled breathing and leg ischemia). Magnitude of arterial stiffness - BRS correlation was positive for carotid distensibility and compliance, and negative for cfPWV, supporting the theory. A sample size of 100 participants (not rounded - exact figure by power calculation) would be required to confirm or reject all permutations of correlation between BRS by multiple calculation methods and large artery stiffness by PWV and compliance/distensibility measures.
Topics: Humans; Pressoreceptors; Pilot Projects; Pulse Wave Analysis; Carotid Arteries; Arterial Pressure
PubMed: 38083315
DOI: 10.1109/EMBC40787.2023.10340723 -
American Journal of Physiology.... Feb 2024Although Gaussian white noise (GWN) inputs offer a theoretical framework for identifying higher-order nonlinearity, an actual application to the data of the neural arc...
Although Gaussian white noise (GWN) inputs offer a theoretical framework for identifying higher-order nonlinearity, an actual application to the data of the neural arc of the carotid sinus baroreflex did not succeed in fully predicting the well-known sigmoidal nonlinearity. In the present study, we assumed that the neural arc can be approximated by a cascade of a linear dynamic (LD) component and a nonlinear static (NS) component. We analyzed the data obtained using GWN inputs with a mean of 120 mmHg and standard deviations (SDs) of 10, 20, and 30 mmHg for 15 min each in anesthetized rats ( = 7). We first estimated the linear transfer function from carotid sinus pressure to sympathetic nerve activity (SNA) and then plotted the measured SNA against the linearly predicted SNA. The predicted and measured data pairs exhibited an inverse sigmoidal distribution when grouped into 10 bins based on the size of the linearly predicted SNA. The sigmoidal nonlinearity estimated via the LD-NS model showed a midpoint pressure (104.1 ± 4.4 mmHg for SD of 30 mmHg) lower than that estimated by a conventional stepwise input (135.8 ± 3.9 mmHg, < 0.001). This suggests that the NS component is more likely to reflect the nonlinearity observed during pulsatile inputs that are physiological to baroreceptors. Furthermore, the LD-NS model yielded higher values compared with the linear model and the previously suggested second-order Uryson model in the testing dataset. We examined the input-size dependence of the baroreflex neural arc transfer characteristics during Gaussian white noise inputs. A linear dynamic-static nonlinear model yielded higher values compared with a linear model and captured the well-known sigmoidal nonlinearity of the neural arc, indicating that the nonlinear dynamics contributed to determining sympathetic nerve activity. Ignoring such nonlinear dynamics might reduce our ability to explain underlying physiology and significantly limit the interpretation of experimental data.
Topics: Rats; Animals; Baroreflex; Blood Pressure; Pressoreceptors; Sympathetic Nervous System; Carotid Sinus
PubMed: 38047314
DOI: 10.1152/ajpregu.00199.2023 -
Hypertension Research : Official... Feb 2024Electrode-based electrophysiological interfaces with peripheral nerves have come a long way since the 1960s, with several neurostimulation applications witnessing... (Review)
Review
Electrode-based electrophysiological interfaces with peripheral nerves have come a long way since the 1960s, with several neurostimulation applications witnessing widespread clinical implementation since then. In resistant hypertension, previous clinical trials have shown that "carotid" baroreflex stimulation using device-based baroreflex activation therapy (BAT) can effectively lower blood pressure (BP). However, device-based "aortic" baroreflex stimulation remains untouched for clinical translation. The rat is a remarkable animal model that facilitates exploration of mechanisms pertaining to the baroreceptor reflex and preclinical development of novel therapeutic strategies for BP modulation and hypertension treatment. Specifically, the aortic depressor nerve (ADN) in rats carries a relatively pure population of barosensitive afferent neurons, which enable selective investigation of the aortic baroreflex function. In a rat model of essential hypertension, the spontaneously hypertensive rat (SHR), we have recently investigated the aortic baroreceptor afferents as an alternate target for BP modulation, and showed that "low intensity" stimulation is able to evoke clinically meaningful reductions in BP. Deriving high quality short-term and long-term data on aortic baroreflex modulation in rats is currently hampered by a number of unresolved experimental challenges, including anatomical variations across rats which complicates identification of the ADN, the use of unrefined neurostimulation tools or paradigms, and issues arising from anesthetized and conscious surgical preparations. With the goal of refining existing experimental protocols designed for preclinical investigation of the baroreflex, this review seeks to outline current challenges hindering further progress in aortic baroreflex modulation studies in rats and present some practical considerations and recently emerging ideas to overcome them. Aortic baroreflex modulation.
Topics: Rats; Animals; Baroreflex; Electric Stimulation; Hypertension; Pressoreceptors; Rats, Inbred SHR; Blood Pressure; Heart Rate
PubMed: 37919429
DOI: 10.1038/s41440-023-01486-6 -
Journal of Atherosclerosis and... Apr 2024The carotid sinuses and aortic arch are baroreceptor-resident arteries (BRAs) and atherosclerosis-susceptible sites of brain-supplying arteries, which would impair...
Evaluating Total Atherosclerosis Burden of Baroreceptor-Resident Arteries after Ischemic Cerebrovascular Disease for Identifying Patients with Heavy Coronary Atherosclerosis Burden.
AIM
The carotid sinuses and aortic arch are baroreceptor-resident arteries (BRAs) and atherosclerosis-susceptible sites of brain-supplying arteries, which would impair baroreflex-mediated blood pressure (BP) regulation and prompt coronary atherosclerosis. We sought to determine the relationship between total atherosclerosis burden (TAB) of BRAs and coronary atherosclerosis burden (AB) in patients with ischemic cerebrovascular disease (ICVD) and explore the potential contribution of BP profiles to this relationship.
METHODS
In this cross-sectional analysis of patients with ICVD who simultaneously undertook computed tomography angiography and 24-hour ambulatory BP monitoring, TAB of BRAs was scored based on the atherosclerotic vessel circumference ratio of the carotid sinuses and aortic arch, while the ABs of the intracranial, cervical, aortic, and coronary arteries were scored based on stenosis severity and plaque complexity as routine.
RESULTS
Among the 230 patients analyzed, coronary AB was significantly correlated with TAB of BRAs, independently of, and more tightly than the ABs of the intracranial, cervical, and aortic arteries, and the stenosis- and complexity-based AB of BRA-located arteries (bilateral common and extracranial internal carotid arteries and aortic arch). Both coronary AB and TAB of BRAs were negatively associated with the night-to-day BP dipping ratios, which was quite different from the relationship between intracranial AB and 24-hour BP characteristics. These findings were also true for patients with ICVD without a history of coronary artery disease.
CONCLUSION
Evaluating TAB of BRAs might provide a new link between atherosclerosis of brain- and heart-supplying arteries, connected partially by BP circadian rhythm. It might facilitate identifying patients with ICVD with heavy coronary AB and comprehensively managing vascular risk.
Topics: Humans; Coronary Artery Disease; Stroke; Constriction, Pathologic; Pressoreceptors; Cross-Sectional Studies; Risk Factors; Atherosclerosis; Arteries
PubMed: 37866928
DOI: 10.5551/jat.64457 -
American Journal of Physiology.... Nov 2023The purpose of these experiments was to determine if the increase in vascular conductance following a single muscle contraction (50% of maximal voluntary contraction) (6...
The purpose of these experiments was to determine if the increase in vascular conductance following a single muscle contraction (50% of maximal voluntary contraction) (6 male and 6 female subjects) was altered during baroceptor loading and unloading. Rapid onset vasodilation (ROV) was determined by measuring brachial artery blood flow (Doppler ultrasound) and blood pressure (Finapress monitor). Brachial artery vascular conductance was calculated by dividing blood flow by mean arterial pressure. ROV was described by the area under the Δvascular conductance (VC)-time curve during the 30 s following muscle contraction. ROV was determined using chamber pressures of +20, +10, 0, -10, -20, and -40 mmHg (lower body positive and negative pressure, LBPP, and LBNP). We tested the hypothesis that the impact of baroreceptor loading and unloading produces a proportion change in ROV. The level of ROV following each contraction was proportional to the peak force ( = 0.393, = 0.0001). Peak force was therefore used as a covariate in further analysis. ROV during application of -40 mmHg LBNP (0.345 ± 0.229 mL·mmHg) was lower than that observed at Control (0.532 ± 0.284 mL·mmHg, = 0.034) and +20 mmHg LBPP (0.658 ± 0.364 mL·mmHg, = 0.0008). ROV was linearly related to chamber pressure from -40 to +20 mmHg chamber pressure ( = 0.512, = 0.022, = 69) and from -20 to +10 mmHg chamber pressure (= 0.973, < 0.0425, = 45), Overall, vasoconstrictor tone altered with physiologically relevant baroreceptor loading and unloading resulted in a proportion change in ROV. Rapid onset vasodilation (ROV) was linearly related to the peak force of each single 1-s muscle contraction. In addition, ROV is reduced by baroreceptor unloading (LBNP: -10, -120, and -40 mmHg) and increased by baroreceptor loading (LBPP: +10 and +20 mmHg). Without accounting for peak force and the level of baroreceptor engagement makes comparison of ROV in subjects of differing muscle size or strength untenable.
Topics: Humans; Male; Female; Pressoreceptors; Vasodilation; Hemodynamics; Blood Pressure; Lower Body Negative Pressure; Heart Rate
PubMed: 37694334
DOI: 10.1152/ajpregu.00116.2023 -
Journal of Hypertension Sep 2023Altered baroreflex function is well documented in hypertension; however, the female sex remains far less studied compared with males. We have previously demonstrated a...
BACKGROUND
Altered baroreflex function is well documented in hypertension; however, the female sex remains far less studied compared with males. We have previously demonstrated a left-sided dominance in the expression of aortic baroreflex function in male spontaneously hypertensive rats (SHRs) and normotensive rats of either sex. If lateralization in aortic baroreflex function extends to hypertensive female rats remains undetermined. This study, therefore, assessed the contribution of left and right aortic baroreceptor afferents to baroreflex modulation in female SHRs.
METHOD
Anesthetized female SHRs (total n = 9) were prepared for left, right and bilateral aortic depressor nerve (ADN) stimulation (1-40 Hz, 0.2 ms, 0.4 mA for 20 s) and measurement of reflex mean arterial pressure (MAP), heart rate (HR), mesenteric vascular resistance (MVR) and femoral vascular resistance (FVR). All rats were also matched for the diestrus phase of the estrus cycle.
RESULTS
Reflex (%) reductions in MAP, HR, MVR and FVR were comparable for both left-sided and right-sided stimulation. Bilateral stimulation evoked slightly larger ( P = 0.03) reductions in MVR compared with right-sided stimulation; however, all other reflex hemodynamic measures were similar to both left-sided and right-sided stimulation.
CONCLUSION
These data show that female SHRs, unlike male SHRs, express similar central integration of left versus right aortic baroreceptor afferent input and thus show no laterization in the aortic baroreflex during hypertension. Marginal increases in mesenteric vasodilation following bilateral activation of the aortic baroreceptor afferents drive no superior depressor responses beyond that of the unilateral stimulation. Clinically, unilateral targeting of the left or right aortic baroreceptor afferents may provide adequate reductions in blood pressure in female hypertensive patients.
Topics: Rats; Male; Female; Animals; Baroreflex; Rats, Inbred SHR; Blood Pressure; Aorta; Pressoreceptors; Hypertension; Heart Rate; Electric Stimulation
PubMed: 37382160
DOI: 10.1097/HJH.0000000000003493