Heart rate and startle responses in diving, captive harbour porpoises (Phocoena phocoena) exposed to transient noise and sonar

ABSTRACT Anthropogenic noise can alter marine mammal behaviour and physiology, but little is known about cetacean cardiovascular responses to exposures, despite evidence that acoustic stressors, such as naval sonars, may lead to decompression sickness. Here, we measured heart rate and movements of two trained harbour porpoises during controlled exposure to 6–9 kHz sonar-like sweeps and 40 kHz peak-frequency noise pulses, designed to evoke acoustic startle responses. The porpoises initially responded to the sonar sweep with intensified bradycardia despite unaltered behaviour/movement, but habituated rapidly to the stimuli. In contrast, 40 kHz noise pulses consistently evoked rapid muscle flinches (indicative of startles), but no behavioural or heart rate changes. We conclude that the autonomous startle response appears decoupled from, or overridden by, cardiac regulation in diving porpoises, whereas certain novel stimuli may motivate oxygen-conserving cardiovascular measures. Such responses to sound exposure may contribute to gas mismanagement for deeper-diving cetaceans.

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Startle Potentiation and Heart Rate as Affected by Fear and Hunger

Psychological Reports ◽

10.2466/pr0.1985.56.1.95 ◽

1985 ◽

Vol 56 (1) ◽

pp. 95-106 ◽

Cited By ~ 5

Author(s):

D. Chris Anderson ◽

Charles R. Crowell ◽

Judson S. Brown

Keyword(s):

Heart Rate ◽

Food Deprivation ◽

Startle Response ◽

Conditioned Fear ◽

Acoustic Startle ◽

Acoustic Startle Response ◽

Aversive Stimulation ◽

Depressing Effect ◽

Startle Amplitude ◽

General Drive

In a widely cited, unpublished study, abstracted at length herein, Meryman in 1952 reported that the acoustic startle response of the rat was potentiated by conditioned fear, by food deprivation, and summatively by both combined. Whereas others have verified the action of fear on startle, only scattered support has been obtained for the conclusion that startle can be potentiated by an appetitive variable. Because of the significance of this matter for general drive theory, further study is imperative. The present experiment, a replication and extension of Meryman's, was guided by a design in which two levels of fear and two of food deprivation were combined factorially. Two groups of rats, one deprived for 40 hr. and one for 1 hr., were shocked in a stabilimeter chamber to condition fear to the cues of that situation. Two other, nonfearful groups, one of which was deprived for 40 hr. and the other for 1 hr., were never shocked in the stabilimeter. Instead, they were shocked in a distinctively different chamber to control for amount of aversive stimulation across groups. Results provided by measurements of startle amplitude coincided with Meryman's in that response magnitudes increased over conditioning trials for the fearful animals but not for the controls and in that rats which were both fearful and deprived exhibited stronger reactions than fearful-only or deprived-only subjects. However, the appetitive variable alone did not exert a potentiating effect. Heart-rate recordings provided marginal evidence for the conditioning of fear. Our results and Meryman's, as well as the discrepancies between them, are explained as due to the depressing effect of near-satiation on the capacity of fear to potentiate startle.

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Spectral Characteristics of Heart Rate Variability in Noise Exposure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1079-1080.515 ◽

2014 ◽

Vol 1079-1080 ◽

pp. 515-521

Author(s):

Li Ho Tseng ◽

Ching Chang Yang ◽

Yuan Po Lee ◽

Hong Zhun Wu ◽

Chia Yi Chou

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Spectral Analysis ◽

Background Noise ◽

Low Frequency ◽

Cardiovascular Responses ◽

Frequency Noise ◽

Cardiovascular Activity ◽

Low Frequency Noise ◽

Noise Levels

Ecological studies have shown that the chronic effects of exposure to environmental noise cause annoyance. However, in the past, most studies have used questionnaires to evaluate the effects of noise pollution on psychosomatic responses. This study investigated cardiovascular activity changes in exposure to low-frequency noise at various noise intensities. The authors hypothesized that distinct noise intensities affect cardiovascular activity, which would be reflected in the spectral analysis parameters. The evaluation intensities of low frequency noises (from 20 to 200 Hz) were background noise (BN), 70-dBC, 80-dBC, and 90-dBC. The electrocardiographic (ECG) data was recorded for 5 minutes under various noise levels. The cardiovascular responses were evaluated using spectral analysis of the beat-to-beat (RR) intervals obtained from ECG signals. The results showed that the average blood pressure and mean RR interval variability did not substantially change relative to the noise levels. However, the low-frequency (LF) power and the ratio of LF power to high-frequency power (LF/HF) from ECG under the BN condition were significantly lower than the 80-dBC, and 90-dBC noise levels. In addition, the normalized LF of the background noise condition was significantly lower than the low-frequency of the noise levels at various intensities. In conclusion, the frequency-domain-based measures appear to be a powerful tool for exposure to low-frequency noise, even in short-term heart rate variability time series.

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The Acoustic Startle Response and Disruption of Aiming. 2. Modulation by Forewarning and Preliminary Stimuli

10.21236/ada217105 ◽

1989 ◽

Author(s):

John A. Foss ◽

James R. Ison ◽

James P. Torre ◽

Wansack Jr ◽

Samuel

Keyword(s):

Startle Response ◽

Acoustic Startle ◽

Acoustic Startle Response

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Cardiovascular Responses to Muscle Stretching: A Systematic Review and Meta-analysis

International Journal of Sports Medicine ◽

10.1055/a-1312-7131 ◽

2021 ◽

Author(s):

Ewan Thomas ◽

Marianna Bellafiore ◽

Ambra Gentile ◽

Antonio Paoli ◽

Antonio Palma ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Cardiovascular System ◽

Vascular Function ◽

Meta Analysis ◽

Random Effect ◽

Cardiovascular Responses ◽

Qualitative Description ◽

Cross Sectional ◽

Quantitative Synthesis

AbstractThe aim of this study will be to review the current body of literature to understand the effects of stretching on the responses of the cardiovascular system. A literature search was performed using the following databases: Scopus, NLM Pubmed and ScienceDirect. Studies regarding the effects of stretching on responses of the cardiovascular system were investigated. Outcomes regarded heart rate(HR), blood pressure, pulse wave velocity (PWV of which baPWV for brachial-ankle and cfPWV for carotid-femoral waveforms), heart rate variability and endothelial vascular function. Subsequently, the effects of each outcome were quantitatively synthetized using meta-analytic synthesis with random-effect models. A total of 16 studies were considered eligible and included in the quantitative synthesis. Groups were also stratified according to cross-sectional or longitudinal stretching interventions. Quality assessment through the NHLBI tools observed a “fair-to-good” quality of the studies. The meta-analytic synthesis showed a significant effect of d=0.38 concerning HR, d=2.04 regarding baPWV and d=0.46 for cfPWV. Stretching significantly reduces arterial stiffness and HR. The qualitative description of the studies was also supported by the meta-analytic synthesis. No adverse effects were reported, after stretching, in patients affected by cardiovascular disease on blood pressure. There is a lack of studies regarding vascular adaptations to stretching.

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