Role of noise and music as anxiety modulators: Relationship with ovarian hormones in the rat

Selected Acoustic Frequencies Have a Positive Impact on Behavioural and Physiological Welfare Indicators in Thoroughbred Racehorses

(1) Background: Since antiquity, it is considered that sounds influence human emotional states and health. Acoustic enrichment has also been proposed for domestic animals. However, in both humans and animals, effects vary according to the type of sound. Human studies suggest that frequencies, more than melodies, play a key role. Low and high frequencies, music tuning frequency and even EEG slow waves used for 'neurofeedback' produce effects. (2) Methods: We tested the possible impact of such pure frequencies on racehorses' behavior and physiology. A commercial non-audible acoustic stimulus, composed of an array of the above-mentioned frequencies, was broadcasted twice daily and for three weeks to 12 thoroughbred horses in their home stall. (3) Results: The results show a decrease in stereotypic behaviors and other indicators such as yawning or vacuum chewing, an increase in the time spent in recumbent resting and foraging, and better hematological measures during and after the playback phase for 4 of the 10 physiological parameters measured. (4) Conclusions: These results open new lines of research on possible ways of alleviating the stress related to housing and training conditions in racehorses and of improving physical recovery.

Emotional responses of piglets under long-term exposure to negative and positive auditory stimuli

The stress caused by sound is inevitable. The stress caused by noise and the positive effects of music can affect the endocrine of animals and their welfare. In this study, a total of 72 hybrid piglets (Large White × Duroc × Min pig) were randomly divided into 3 groups, including music (Mozart K.448, 60-70 dB), noise (recorded mechanical noise, 80-85 dB), and control (natural background sound, <40 dB) groups. S-IgA (secretory immunoglobulin A), IL-6 (interleukin-6), IL-8 (interleukin-8), and positive emotion-related behaviors were used as indicators to discuss whether noise induced stress and inflammation in piglets or whether music could have positive effects. Six hours of auditory exposure were given daily (10:00-16:00), which lasted for 56 days. Behavioral responses of the piglets were observed, and the concentrations of salivary S-IgA and serum IL-6 and IL-8 were measured. The results showed that the concentration of S-IgA increased in the noise and control groups on the 57th day (P < 0.05); S-IgA concentration in the music group was unchanged after long-term music exposure. The concentrations of IL-6 and IL-8 showed that long-term noise exposure might lead to stress and inflammation in piglets. Tail-wagging and play behaviors of the piglets in the music group were significantly greater than those in the noise and control groups, which implied that long-term music exposure improved the emotional state of the piglets in a restricted and barren environment.

Classical music restored fertility status in rat model of premature ovarian failure

BACKGROUND

The restorative effect of classical music was assessed on the cyclophosphamide-induced animal model of premature ovarian failure (POF).

METHODS

Mozart's piano classical music (K.448) was used for up to 4 and 8 weeks. Rats were exposed to music 6 h every day using a stereo system with a volume of 65-70 dB. Sera and ovarian tissue samples were collected for the evaluation of FSH, LH, and E2 and histopathological examination. At the same time points, samples were taken from the hypothalamus and hippocampus to monitor the expression of Ntrk2, Crh, and Pomc using real-time PCR. Mating trial was performed to evaluate the fertility status of POF rats.

RESULTS

Histopathological examination revealed a significant increase (p < 0.05) in the numbers of morphologically normal follicles at all the developmental stages in POF rats after music therapy compared to the POF group (p < 0.05). Music therapy decreased FSH and LH levels to near-to-normal levels conidied with elevation of E2 (p < 0.05). Ntrk2, Crh, and Pomc expressions were down-regulated in POF rats. Music therapy increasaed the expression of Ntrk2 in the hypothalamus of POF rats (p < 0.05). In contrast, Crh and Pomc failed to reach the detection limit before intervention and four weeks after the intervention however, these genes were expressed eight weeks after music therapy. Fertility status was increased (p < 0.05) in terms of litter size in POF rats after being exposed to music compared to the non-treated POF control group (p < 0.05).

CONCLUSION

Results showed that music can exert therapeutic effects on POF rats via the alteration of sex-related hormones.

Animal Signals, Music and Emotional Well-Being

Playing music or natural sounds to animals in human care is thought to have beneficial effects. An analysis of published papers on the use of human-based music with animals demonstrates a variety of different results even within the same species. These mixed results suggest the value of tailoring music to the sensory systems of the species involved and in selecting musical structures that are likely to produce the desired effects. I provide a conceptual framework based on the combined knowledge of the natural communication system of a species coupled with musical structures known to differentially influence emotional states, e.g., calming an agitated animal versus stimulating a lethargic animal. This new concept of animal-based music, which is based on understanding animal communication, will lead to more consistent and specific effects of music. Knowledge and appropriate use of animal-based music are important in future research and applications if we are to improve the well-being of animals that are dependent upon human care for their survival.

Music Affects Rodents: A Systematic Review of Experimental Research

Background: There is rapidly emerging interest in music interventions in healthcare. Music interventions are widely applicable, inexpensive, without side effects, and easy to use. It is not precisely known how they exert positive effects on health outcomes. Experimental studies in animal models might reveal more about the pathophysiological mechanisms of music interventions. Methods: We performed a systematic review of experimental research in rodents. The electronic databases EMBASE, Medline(ovidSP), Web-Of-Science, PsycINFO, Cinahl, PubMed publisher, Cochrane, and Google scholar were searched for publications between January 1st 1960 and April 22nd 2017. Eligible were English-written, full-text publications on experimental research in rodents comparing music vs. a control situation. Outcomes were categorized in four domains: brain structure and neuro-chemistry; behavior; immunology; and physiology. Additionally, an overview was generated representing the effects of various types of music on outcomes. Bias in studies was assessed with the SYRCLE Risk of Bias tool. A meta-analysis was not feasible due to heterogeneous outcomes and lack of original outcome data. Results: Forty-two studies were included. Music-exposed rodents showed statistically significant increases in neuro-chemistry, such as higher BDNF levels, as well as an enhanced propensity for neurogenesis and neuroplasticity. Furthermore, music exposure was linked with statistically significantly improved spatial and auditory learning, reduced anxiety-related behavior, and increased immune responses. Various statistically significant changes occurred in physiological parameters such as blood pressure and (para)sympathetic nerve activity following music interventions. The majority of studies investigated classical music interventions, but other types of music exerted positive effects on outcomes as well. The SYRCLE risk of bias assessment revealed unclear risk of bias in all studies. Conclusions: Music interventions seem to improve brain structure and neuro-chemistry; behavior; immunology; and physiology in rodents. Further research is necessary to explore and optimize the effect of music interventions, and to evaluate its effects in humans.

Behavioral responses to emotional challenges in female rats living in a seminatural environment: The role of estrogen receptors

Estrogen receptors (ERs) are involved in sexual as well as non-sexual behaviors. In the present study we assessed the effects of stimuli inducing positive or negative affect on sociosexual, exploratory and fear-related behaviors of female rats housed in groups (4 females, 3 males) in a seminatural environment. Ovariectomized females were treated with oil, 17β‑estradiol benzoate (EB, 18 μg/kg), the ERα agonist propylpyrazoletriol (PPT), or the ERβ agonist diarylpropionitrile (DPN) (both 2 × 10 mg/rat). On the test day, the females were exposed to a sequence of events consisting of lavender odor, Mozart's Sonata for Two Pianos K448, chocolate pellets, white noise and fox odor (2,3,5‑Trimethyl‑3‑thiazoline, TMT). All these events are known to induce positive or negative affect. Behavior was carefully observed from the video record. White noise suppressed sexual behaviors and reduced the time spent in the open area of the environment. TMT had no consistent effect whereas exposure to music caused avoidance of the open area. Exposure to chocolate increased exploratory and social behavior. Lavender odor enhanced exploratory behavior. PPT and EB stimulated sexual behaviors, whereas DPN was ineffective. Co-occurrence analyses of the sequence of behavioral patterns revealed that PPT and EB consistently belonged to clusters different from oil and DPN, whereas DPN was separate from oil only under fear-inducing experimental conditions. These data, from a procedure with external validity, confirm that the ERα is crucial for sexual behaviors, that these behaviors are reduced under stressful conditions, and that the ERβ may have some role in fear-related behaviors.

Comparison of group cognitive behavioral therapy and interactive lectures in reducing anxiety during pregnancy: A quasi experimental trial

BACKGROUND

Anxiety during pregnancy and its adverse effects on mother and baby is a health concern worldwide. This study aimed to investigate the effects of group cognitive behavioral therapy (GCBT) compared with interactive lectures (IL) on anxiety during pregnancy.

METHODS

This quasi experimental trial was conducted in Sari city, in north Iran, from March to July 2015. Participants were 91 obstetrically and medically low-risk nulliparous women with a mild to moderate anxiety level, as assessed by Spielberger's State-Trait Anxiety Inventory. Participants were selected from the general population by cluster sampling and assigned to 3 groups: a cognitive behavioral therapy (CBT) group (n = 31), an IL group (n = 30), and a control group (n = 30). All participants completed a demographic characteristics form and the Speilberger State-Trait Anxiety Inventory. The inventory was completed again by the CBT and IL groups 4 weeks after the interventions, and 4 weeks after the initial questionnaire by the control group. Data were analyzed with chi-squared tests, independent t-tests, paired t-tests, ANOVA, and Dunnett post hoc test.

RESULTS

A significant decline in state and trait anxiety was found in the CBT and IL groups at 4 weeks (P < 0.001). GCBT was more effective than IL in reducing participants' anxiety, but the difference was not significant (P > 0.05).

CONCLUSION

GCBT and IL had beneficial effects in reducing anxiety in pregnancy. The psychological status of pregnant women in prenatal care services should be investigated and either of these methods used to manage maternal anxiety, depending on the available healthcare service resources.