scholarly journals Cardiac-generated sympathetic stress alters heart-brain communication, reduces EEG-theta activity, and increases locomotor behavior

2021 ◽  
Author(s):  
Jacopo Agrimi ◽  
Danilo Menicucci ◽  
Marco Laurino ◽  
Chelsea Mackey ◽  
Laila Hasnain ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rhythm ◽  
Simultaneous Recording ◽  
Cardiac Performance ◽  
Autonomic Control ◽  
Theta Activity ◽  
Movement Speed ◽  
Brain Functions ◽  
Sympathetic Stress

Brain modulation of myocardial activity via the autonomic nervous system is increasingly well characterized. Conversely, how primary alterations in cardiac function, such as an intrinsic increase in heart rate or contractility, reverberate on brain signaling/adaptive behaviors - in a bottom-up modality - remains largely unclear. Mice with cardiac-selective overexpression of adenylyl cyclase type 8 (TGAC8) display increased heart rate and reduced heart rhythm complexity associated with a nearly abolished response to external sympathetic inputs. Here, we tested whether chronically elevated intrinsic cardiac performance alters the heart-brain informational flow, affecting brain signaling and, thus, behavior. To this end, we employed dual lead telemetry for simultaneous recording of EEG and EKG time series in awake, freely behaving TGAC8 mice and wild-type (WT) littermates. We recorded EEG and EKG signals, while monitoring mouse behavior with established tests. Using heart rate variability (HRV) in vivo and isolated atria response to sympathomimetic agents, we first confirmed that the TGAC8 murine heart evades autonomic control. The EEG analysis revealed a substantial drop in theta-2 (4-7 Hz) activity in these transgenic mice. Next, we traced the informational flow between EKG and EEG in the theta-2 frequency band via the Granger causality statistical approach and we found a substantial decrement in the extent of heart/brain bidirectional communication. Finally, TGAC8 mice displayed heightened locomotor activity in terms of behavior, with higher total time mobile, distance traveled, and movement speed while freezing behavior was reduced. Increased locomotion correlated negatively with theta-2 waves count and amplitude. Our study shows that cardiac-born persistent sympathetic stress disrupts the information flow between the heart and brain while influencing central physiological patterns, such as theta activity that controls locomotion. Thus, cardiac-initiated disorders, such as persistently elevated cardiac performance that escapes autonomic control, are penetrant enough to alter brain functions and, thus, primary adaptive behavioral responses.

scholarly journals Non-invasive quantification of cardiac stroke volume in the edible crab Cancer pagurus

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Bastian Maus ◽  
Sebastian Gutsfeld ◽  
Hans-Otto Pörtner ◽  
Christian Bock
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Cardiac Performance ◽  
Severe Hypoxia ◽  
Cine Mri ◽  
Performance Parameters ◽  
Non Invasive ◽  
Cancer Pagurus ◽  
Cardiac Stroke Volume

Abstract Background Brachyuran crabs can effectively modulate cardiac stroke volume independently of heart rate in response to abiotic drivers. Non-invasive techniques can help to improve the understanding of cardiac performance parameters of these animals. This study demonstrates the in vivo quantification of cardiac performance parameters through magnetic resonance imaging (MRI) on the edible crab Cancer pagurus. Furthermore, the suitability of signal integrals of infra-red photoplethysmographs as a qualitative tool is assessed under severe hypoxia. Results Multi-slice self-gated cardiac cinematic (CINE) MRI revealed the structure and motion of the ventricle to quantify heart rates, end-diastolic volume, end-systolic volume, stroke volume and ejection fraction. CINE MRI showed that stroke volumes increased under hypoxia because of a reduction of end-systolic volumes at constant end-diastolic volumes. Plethysmograph recordings allowed for automated heart rate measurements but determination of a qualitative stroke volume proxy strongly depended on the position of the sensor on the animal. Both techniques revealed a doubling in stroke volumes after 6 h under severe hypoxia (water PO2 = 15% air saturation). Conclusions MRI has allowed for detailed descriptions of cardiac performance in intact animals under hypoxia. The temporal resolution of quantitative non-invasive CINE MRI is limited but should encourage further refining. The stroke volume proxy based on plethysmograph recordings is feasible to complement other cardiac measurements over time. The presented methods allow for non-destructive in vivo determinations of multiple cardiac performance parameters, with the possibility to study neuro-hormonal or environmental effects on decapod cardio physiology.

scholarly journals In vivo Modelling of Toxicity of Eight Commercial Artificial Sweeteners in Daphnia Neonates and Zebrafish Embryos through Cardiac Performance Assessments

2020 ◽  
Author(s):  
Ferry Saputra ◽  
Yu-Heng Lai ◽  
Rey Arturo Fernandez ◽  
Allan Patrick G. Macabeo ◽  
Hong-Thih Lai ◽  
...  
Keyword(s):  
Heart Rate ◽  
Adverse Effects ◽  
Cardiac Performance ◽  
Calorie Intake ◽  
Artificial Sweeteners ◽  
Artificial Sweetener ◽  
Food Ingredients ◽  
Zebrafish Larvae ◽  
Sodium Cyclamate

Artificial sweeteners are widely used food ingredients in beverages and drinks to lower calorie intake which in turn prevent lifestyle diseases such as obesity. Epidemiological evidences suggest that an overdose of artificial sweeteners could result to adverse effects after consumption. Thus, our study aims to systematically explore the potential adverse effects of eight commercial artificial sweeteners, including acesulfame-K, alitame, aspartame, sodium cyclamate, dulcin, neotame, saccharin and sucralose on cardiac performances of zebrafish (Danio rerio) and Daphnia as model animals. Embryonic zebrafish and Daphnia were exposed to eight artificial sweeteners at 100 ppb concentrations and their cardiac performance (heart rate, ejection fraction, fractional shortening, stroke volume, cardiac output and heartbeat regularity) were measured and compared. Saccharin significantly increased the heart rate of zebrafish larvae while a significant decrease was observed in Daphnia. Significant increase was also noted in zebrafish heart rate variability after incubation in acesulfame K, dulcin, sodium cyclamate, and sucralose. However, a significant increase in Daphnia was only observed after incubation in dulcin. Based on Principal Component Analysis (PCA) and hierarchical clustering results, several artificial sweetener samples were species-specific to zebrafish and Daphnia. Our study demonstrates the potential adverse physiological effects of artificial sweeteners in cardiovascular systems of zebrafish larvae and Daphnia.

Developmental changes in in vivo cardiac performance in the moth Manduca sexta

2000 ◽  
Vol 203 (2) ◽  
pp. 369-378 ◽  
Author(s):  
A.W. Smits ◽  
W.W. Burggren ◽  
D. Oliveras
Keyword(s):  
Heart Rate ◽  
Developmental Stage ◽  
Manduca Sexta ◽  
Propagation Velocity ◽  
Developmental Stages ◽  
Cardiac Activity ◽  
Cardiac Performance ◽  
Complex Pattern ◽  
Heart Rates

While an extensive literature on cardiovascular development exists for insects, almost all studies focus on in vitro preparations, and very few report on more than a single developmental stage. The present study examines in vivo cardiac performance in the intact, unanesthetized larvae, pupae and adults of the tobacco hornworm Manduca sexta. For all three stages, electrode pairs of fine steel wire were inserted subcuticularly at two dorsal abdominal locations. Impedance signals produced by contraction of the dorsal abdominal vessel (tube heart) were amplified and recorded. In addition to providing heart rate, a comparison of the relative timing of the signal from each electrode pair allowed the calculation of the propagation velocity and direction of heart contraction. Experimental treatments of intact animals included exposure to hypoxia and hyperoxia (21 %, 15 %, 10 %, 5 %, 0 % and 100 % O(2)), to hypercapnia (0 %, 4 %, 8 %, 16 %, 20 % and 24 % CO(2)), to temperature variation (10, 20 and 30 degrees C) and to 2 min periods of forced activity. The pattern of contraction of the dorsal abdominal vessel of M. sexta changed substantially with developmental stage. Larvae showed a relatively simple, invariably posterior-to-anterior pattern (mean rate 34.8+/−1.16 beats min(−)(1)). The heart rate pattern in pupal M. sexta displayed great variability in rate, amplitude and direction. Periods of regular heart beats (21.5+/−1.09 beats min(−)(1)) were frequently and irregularly interrupted by periods of cardiac arrests ranging from a few seconds to over 20 min. Adults showed a highly stereotypic but complex pattern, with periods of ‘fast forward’ (FF; rate 47.6+/−2.6 beats min(−)(1)), ‘slow forward’ (SL; 32.8+/−3.0 beats min(−)(1)) and ‘reversed’ (R; 32.2+/−2.4 beats min(−)(1)) beating. The contraction propagation velocity in larvae and pupae averaged 5. 52+/−0.36 and 2.03+/−0.11 cm s(−)(1), respectively. The SF, R and FF phases of the adults had average propagation velocities of 5.52+/−0. 51, 5.05+/−0.52 and 5.43+/−0.37 cm s(−)(1), respectively. Heart rate and contraction propagation velocity were remarkably resistant to ambient hypoxia and hypercapnia at all developmental stages, decreasing significantly only at 0 % O(2) or 24 % CO(2). As expected, the heart rates of all three developmental stages increased significantly with increasing temperature, with heart rate Q(10) values for larvae, pupae and adults of 2.33, 3.14 and 1.61, respectively, between 10 and 20 degrees C. Corresponding Q(10) values for these stages between 20 and 30 degrees C were 2.22, 2.03 and 2.29. Larval heart rates showed no significant response to forced activity induced by prodding. In contrast, adult heart rate increased nearly fivefold from 50.1 beats min(−)(1) during rest to 223.5 beats min(−)(1) after 1 min of prodding. The activity-induced tachycardia in adults ceased within 10–12 min. Patterns of cardiac contraction in larval, pupal and adult M. sexta were as dissimilar as their morphological appearances and revealed a gradation from simple to complex. These developmentally based distinctive cardiac patterns are undoubtedly related to developmental differences in both morphology and life-style. Larvae are anatomically ‘homogeneous’ compared with other stages, with no distinct head, thorax and abdominal region (or wings) that might require selective perfusion or drainage. The far more complex pattern of heart activity seen in pupae probably relates to the dramatic changes in internal morphology during this stage. Simultaneous degradation and synthesis of tissues throughout the body may expose the heart to numerous peptides or neurohormones that affect cardiac activity. In adult moths, the complex and repetitive pattern of cardiac activity is reflected in the previously described complexity of hemolymph movement, together with thermoregulatory capabilities in this species that depend on well-regulated hemolymph movements between the thorax, wings and abdomen.

scholarly journals Influence of the coronary circulation on thermal tolerance and cardiac performance during warming in rainbow trout

2017 ◽  
Vol 312 (4) ◽  
pp. R549-R558 ◽  
Author(s):  
Andreas Ekström ◽  
Michael Axelsson ◽  
Albin Gräns ◽  
Jeroen Brijs ◽  
Erik Sandblom
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Rainbow Trout ◽  
Cardiac Function ◽  
Thermal Tolerance ◽  
Coronary Flow ◽  
Coronary Circulation ◽  
Cardiac Performance ◽  
Juvenile Trout

Thermal tolerance in fish may be related to an oxygen limitation of cardiac function. While the hearts of some fish species receive oxygenated blood via a coronary circulation, the influence of this oxygen supply on thermal tolerance and cardiac performance during warming remain unexplored. Here, we analyzed the effect in vivo of acute warming on coronary blood flow in adult sexually mature rainbow trout ( Onchorhynchus mykiss) and the consequences of chronic coronary ligation on cardiac function and thermal tolerance in juvenile trout. Coronary blood flow at 10°C was higher in females than males (0.56 ± 0.08 vs. 0.30 ± 0.08 ml·min−1·g ventricle−1), and averaged 0.47 ± 0.07 ml·min−1·g ventricle−1 across sexes. Warming increased coronary flow in both sexes until 14°C, at which it peaked and plateaued at 0.78 ± 0.1 and 0.61 ± 0.1 ml·min−1·g ventricle−1 in females and males, respectively. Thus, the scope for increasing coronary flow was 101% in males, but only 39% in females. Coronary-ligated juvenile trout exhibited elevated heart rate across temperatures, reduced Arrhenius breakpoint temperature for heart rate (23.0 vs. 24.6°C), and reduced upper critical thermal maximum (25.3 vs. 26.3°C). To further analyze the effects of coronary flow restriction on cardiac rhythmicity, electrocardiogram characteristics were determined before and after coronary occlusion in anesthetized trout. Occlusion resulted in reduced R-wave amplitude and an elevated S-T segment, indicating myocardial ischemia, while heart rate was unaffected. This suggests that the tachycardia in ligated trout across temperatures in vivo was mainly to compensate for reduced cardiac contractility to maintain cardiac output. Moreover, our findings show that coronary flow increases with warming in a sex-specific manner. This may improve whole animal thermal tolerance, presumably by sustaining cardiac oxygenation and contractility at high temperatures.

scholarly journals Adrenergic tone benefits cardiac performance and warming tolerance in two teleost fishes that lack a coronary circulation

2021 ◽  
Author(s):  
Andreas Ekström ◽  
Erika Sundell ◽  
Daniel Morgenroth ◽  
Erik Sandblom
Keyword(s):  
Heart Rate ◽  
Cardiac Function ◽  
High Temperatures ◽  
Oxygen Delivery ◽  
Thermal Tolerance ◽  
Heart Function ◽  
Perca Fluviatilis ◽  
Cardiac Performance ◽  
Adrenergic Stimulation

AbstractTolerance to acute environmental warming in fish is partly governed by the functional capacity of the heart to increase systemic oxygen delivery at high temperatures. However, cardiac function typically deteriorates at high temperatures, due to declining heart rate and an impaired capacity to maintain or increase cardiac stroke volume, which in turn has been attributed to a deterioration of the electrical conductivity of cardiac tissues and/or an impaired cardiac oxygen supply. While autonomic regulation of the heart may benefit cardiac function during warming by improving myocardial oxygenation, contractility and conductivity, the role of these processes for determining whole animal thermal tolerance is not clear. This is in part because interpretations of previous pharmacological in vivo experiments in salmonids are ambiguous and were confounded by potential compensatory increases in coronary oxygen delivery to the myocardium. Here, we tested the previously advanced hypothesis that cardiac autonomic control benefits heart function and acute warming tolerance in perch (Perca fluviatilis) and roach (Rutilus rutilus); two species that lack coronary arteries and rely entirely on luminal venous oxygen supplies for cardiac oxygenation. Pharmacological blockade of β-adrenergic tone lowered the upper temperature where heart rate started to decline in both species, marking the onset of cardiac failure, and reduced the critical thermal maximum (CTmax) in perch. Cholinergic (muscarinic) blockade had no effect on these thermal tolerance indices. Our findings are consistent with the hypothesis that adrenergic stimulation improves cardiac performance during acute warming, which, at least in perch, increases acute thermal tolerance.

scholarly journals Heart Rate, Body Temperature and Physical Activity Are Variously Affected During Insulin Treatment in Alloxan-Induced Type 1 Diabetic Rat

2011 ◽  
pp. 65-73 ◽  
Author(s):  
F. C. HOWARTH ◽  
M. JACOBSON ◽  
M. SHAFIULLAH ◽  
M. LJUBISAVLJEVIC ◽  
E. ADEGHATE
Keyword(s):  
Physical Activity ◽  
Heart Rate ◽  
Body Temperature ◽  
Insulin Treatment ◽  
Heart Rhythm ◽  
Cardiovascular Complications ◽  
Diabetic Rat ◽  
Qt Intervals

Diabetes mellitus is associated with a variety of cardiovascular complications including impaired cardiac muscle function. The effects of insulin treatment on heart rate, body temperature and physical activity in the alloxan (ALX)-induced diabetic rat were investigated using in vivo biotelemetry techniques. The electrocardiogram, physical activity and body temperature were recorded in vivo with a biotelemetry system for 10 days before ALX treatment, for 20 days following administration of ALX (120 mg/kg) and thereafter, for 15 days whilst rats received daily insulin. Heart rate declined rapidly after administration of ALX. Pre-ALX heart rate was 321±9 beats per minute, falling to 285±12 beats per minute 15-20 days after ALX and recovering to 331±10 beats per minute 5-10 days after commencement of insulin. Heart rate variability declined and PQ, QRS and QT intervals were prolonged after administration of ALX. Physical activity and body temperature declined after administration of ALX. Pre-ALX body temperature was 37.6±0.1 °C, falling to 37.3±0.1 °C 15-20 days after ALX and recovering to 37.8±0.1 °C 5-10 days after commencement insulin. ALX-induced diabetes is associated with disturbances in heart rhythm, physical activity and body temperature that are variously affected during insulin treatment.

scholarly journals Bradycardic mice undergo effective heart rate improvement after specific homing to the sino-atrial node and differentiation of adult muscle derived stem cells

2018 ◽  
Author(s):  
Pietro Mesirca ◽  
Daria Mamaeva ◽  
Isabelle Bidaud ◽  
Matthias Baudot ◽  
Romain Davaze ◽  
...  
Keyword(s):  
Stem Cells ◽  
Heart Rate ◽  
Heart Rhythm ◽  
Mutant Mice ◽  
Recipient Mouse ◽  
Wild Type ◽  
Cardiac Pacemakers ◽  
Lineage Differentiation

AbstractCurrent treatments for heart automaticity disorders still lack a safe and efficient source of stem cells to restore normal biological pacemaking. Since adult Muscle-Derived Stem Cells (MDSC) show multi-lineage differentiation in vitro including into spontaneously beating cardiomyocytes, we questioned whether they could effectively differentiate into cardiac pacemakers, a specific population of cardiomyocytes producing electrical impulses in the sino-atrial node (SAN) of adult heart. We show here that beating cardiomyocytes, differentiated from MDSC in vitro, exhibit typical characteristics of cardiac pacemakers: expression of markers of the SAN lineage Hcn4, Tbx3 and Islet1, as well as spontaneous calcium transients and hyperpolarization-activated “funny” current and L-type Cav1.3 channels. Pacemaker-like myocytes differentiated in vitro from Cav1.3-deficient mouse stem cells produced slower rate of spontaneous Ca2+ transients, consistent with the reduced activity of native pacemakers in mutant mice. In vivo, undifferentiated wild type MDSC migrated and homed with increased engraftment to the SAN of bradycardic mutant Cav1.3-/- within 2-3 days after systemic I.P. injection. The increased homing of MDSCs corresponded to increased levels of the chemokine SDF1 and its receptor CXCR4 in mutant SAN tissue and was ensued by differentiation of MDSCs into Cav1.3-expressing pacemaker-like myocytes within 10 days and a significant improvement of the heart rate maintained for up to 40 days. Optical mapping and immunofluorescence analyses performed after 40 days on SAN tissue from transplanted wild type and mutant mice showed MDSCs integrated as pacemaking cells both electrically and functionally within recipient mouse SAN. These findings identify MDSCs as directly transplantable stem cells that efficiently home, differentiate and improve heart rhythm in mouse models of congenital bradycardia.

Adenosine increases ventilation rate, cardiac performance and haemolymph velocity in the American lobster Homarus americanus

2001 ◽  
Vol 204 (5) ◽  
pp. 947-957 ◽  
Author(s):  
E. Stegen ◽  
M.K. Grieshaber
Keyword(s):  
Heart Rate ◽  
Steady State ◽  
Adenine Nucleotides ◽  
Homarus Americanus ◽  
Ventilation Rate ◽  
Cardiac Performance ◽  
American Lobster

The effects of adenosine and adenine nucleotides on haemolymph velocity and on heart rate and scaphognathite frequency were investigated in the American lobster Homarus americanus. The infusion of 0.25-2.4 nmol g(−1) min(−1) adenosine produced steady-state concentrations of 2–3 micromol l(−1) adenosine and approximately 80 micromol l(−1) inosine in the haemolymph. No hanges in haemolymph concentration of AMP, hypoxanthine, xanthine or IMP were observed. Adenosine increases haemolymph velocity in the sternal artery from 55+/−29 to 204+/−53 mm s(−1) and in the posterior aorta from 21+/−7 to 54+/−28 mm s(−1)and reduces haemolymph velocity in the lateral arteries from 98+/−92 to 74+/−69 mm s(−1). Heart rate is increased from 69.3+/−7.4 to 81.2+/−6.2 beats min(−1) and scaphognathite frequency from 86.9+/−29.0 to 147.1+/−35.0 beats min(−1). The effects of adenosine are rapidly reversed after the cessation of the infusion of this purine. The adenylates cause similar but lesser changes and the effects are protracted, probably because of low in vivo activities of nucleotidases.

Nursing Diagnosis for Potential Organ Donors: Accuracy Study

2021 ◽  
pp. 105477382110194
Author(s):  
Luciana Nabinger Menna Barreto ◽  
Éder Marques Cabral ◽  
Marina Raffin Buffon ◽  
Juliana Elenice Pereira Mauro ◽  
Lisiane Pruinelli ◽  
...  
Keyword(s):  
Heart Rate ◽  
Diagnostic Accuracy ◽  
Medical Records ◽  
Heart Rhythm ◽  
Organ Donors ◽  
Predictive Capacity ◽  
Nursing Diagnosis ◽  
Accuracy Study ◽  
Altered Blood ◽  
Accuracy Data

The objective was to analyze the diagnostic accuracy of Impaired physiological balance syndrome in potential brain-dead organ donors. It is a study of diagnostic accuracy. Data was retrospectively collected from 145 medical records through the filling out of an instrument containing 25 indicators of the nursing diagnosis (ND). Descriptive and inferential statistics were used. The prevalence of the ND was 77 (53.1%). The indicator with the best measures of accuracy was altered heart rate. Therefore, it has the best predictive capacity for determining the ND. It was identified that the absence of the indicators altered heart rate, hyperglycemia, and altered blood pressure is associated with the absence of the ND, while the presence of the indicators hyperthermia, hypothermia, and altered heart rhythm is associated with the presence of the ND. Accurate indicators will assist in diagnostic inference and the interventions and results will have greater chances of targeting and effectiveness.

scholarly journals Effect of ethanol and cocaine on [11C]MPC-6827 uptake in SH-SY5Y cells

2021 ◽  
Author(s):  
Naresh Damuka ◽  
Miranda Orr ◽  
Paul W. Czoty ◽  
Jeffrey L. Weiner ◽  
Thomas J. Martin ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Ex Vivo ◽  
Neuroblastoma Cells ◽  
Proper Function ◽  
Brain Functions ◽  
Biodistribution Studies ◽  
Positron Emission ◽  
Vitro Binding

AbstractMicrotubules (MTs) are structural units in the cytoskeleton. In brain cells they are responsible for axonal transport, information processing, and signaling mechanisms. Proper function of these processes is critical for healthy brain functions. Alcohol and substance use disorders (AUD/SUDs) affects the function and organization of MTs in the brain, making them a potential neuroimaging marker to study the resulting impairment of overall neurobehavioral and cognitive processes. Our lab reported the first brain-penetrant MT-tracking Positron Emission Tomography (PET) ligand [11C]MPC-6827 and demonstrated its in vivo utility in rodents and non-human primates. To further explore the in vivo imaging potential of [11C]MPC-6827, we need to investigate its mechanism of action. Here, we report preliminary in vitro binding results in SH-SY5Y neuroblastoma cells exposed to ethanol (EtOH) or cocaine in combination with multiple agents that alter MT stability. EtOH and cocaine treatments increased MT stability and decreased free tubulin monomers. Our initial cell-binding assay demonstrated that [11C]MPC-6827 may have high affinity to free/unbound tubulin units. Consistent with this mechanism of action, we observed lower [11C]MPC-6827 uptake in SH-SY5Y cells after EtOH and cocaine treatments (e.g., fewer free tubulin units). We are currently performing in vivo PET imaging and ex vivo biodistribution studies in rodent and nonhuman primate models of AUD and SUDs and Alzheimer's disease.

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