EXPLORE THE IMPACT OF NOISE STRESS INDUCED BRAIN WAVE PATTERN AND BEHAVIOUR ALTERATIONS IN WISTAR ALBINO RATS

Objective: The aim of the study is to investigate the impact of noise-induced stress and electroencephalogram (EEG) with behavioral alteration in male Wistar albino Rats. Methods: Adult albino rats were randomly divided into three groups. Each group contains six animals. Rats exposed to acute and sub-acute noise, stress (100 dB/4 h) were compared with control animals and assessed for learning and memory using an Eight-arm radial maze, Y-maze, T-maze and also monitoring of brain electrical activity showed by the electro encephalography. Results: The reference memory and working memory error increases, in acute and sub-acute noise stress. The amplitude and frequency also increase in frontal and occipital lobar when compared to control animals. Conclusion: Animals were exposed to noise stress showed learning and memory impairment and also changes in EEG wave pattern.

Five Different Noise Intensities Robustly Affects Corticosterone, Gastrin and Endothelin-1 Responses and Initiated Gastric Tissue Damage in Wistar Rats

Likewise other stress response noise stress is also affects the homeostasis of the biological systems and produce stress response in the form of Corticosterone to prevent the damage but if the exposure is longer with higher magnitude it may disrupt the robust ability of the homeostasis and could produce the damage to the biological systems. The goal of our study was to see how five different noise intensities affected stomach tissue damage. 42 healthy rats were divided into five different stress exposure group, normal control (NC) and sham control (SC) groups. Noise stress exposure was delivered for 1 hour per day continued for 30 days in all five noise exposed groups by specially designed noise chamber whereas sham control group of animals kept in noise chamber for 1 hour per day continued for 30 days without noise stress exposure and control group of animals neither exposed to noise stress of any intensities and nor kept in noise chamber without noise but remain in the same experimental room in their homecage for 30 days respectively. Results of the study showed that animals exposed to 60 and 80 dB noise give habituated and not significant Corticosterone, Gastrin and Endothelin-1 responses compared to NC and SC groups while animals exposed to 100, 120 and 140 dB had significantly higher Corticosterone, Gastrin and Endothelin-1 response and also chronic gastric damage was observed compared to later two noise exposed groups respectively. Study concluded that not only higher but also lower noise intensities also initiated the gastric damage even after the adaptation.

Brief Negative Affect Focused Functional Imagery Training Abolishes Stress-Induced Alcohol Choice in Hazardous Student Drinkers

Introduction. Imagery-based stress management therapies are effective at reducing alcohol use. To explore the therapeutic mechanism, the current study tested whether brief functional imagery training linked to personal negative affect drinking triggers would attenuate sensitivity to noise stress-induced alcohol seeking behaviour in a laboratory model. Methods. Participants were UK-based hazardous student drinkers (N = 61, 80.3% women, aged 18–25) who reported drinking to cope with negative affect. Participants in the active intervention group (n = 31) were briefly trained to respond to personal negative drinking triggers by retrieving an adaptive strategy to mitigate negative affect, whereas participants in the control group (n = 30) received risk information about binge drinking at university. The relative value of alcohol was then measured by preference to view alcohol versus food pictures in two-alternative choice trials, before (baseline) and during noise stress induction. Results. There was a significant two-way interaction p < .04 where the control group increased their alcohol picture choice from baseline to the noise stress test p < .001 , whereas the active intervention group did not p = .33 , and the control group chose alcohol more frequently than the active group in the stress test p = .03 , but not at baseline p = .16 . Conclusions. These findings indicate that imagery-based mood management can protect against the increase in the relative value of alcohol motivated by acute stress in hazardous negative affect drinkers, suggesting this mechanism could underpin the therapeutic effect of mood management on drinking outcomes.

EFFECTS OF NOISE STRESS ON THYROID STIMULATING HORMONE IN ADULT RATS

Objective: To determine the effect of noise stress on Thyroid Stimulating Hormone in adult rats. Study Design: Laboratory-based experimental study. Place and Duration of Study: Department of Anatomy Army Medical College, Rawalpindi in collaboration with National Institute of Health, Islamabad, from Jan to Dec 2020. Methodology: A total of 30 adult Sprague Dawley rats were distributed into three groups as ten rats/group. Group A served as the control group, rats in group B were exposed to 100 dB noise for continuous 4 hours/day for four months, and the rats in group C were exposed to 100 dB noise for continuous 6 hours/day for four months. At the end of the study, serum samples were collected from the rats’ tail veins. Thyroid-stimulating hormone levels were compared among the groups. Results: At the start of the study, mean serum thyroid stimulating hormone level of control group A rats was 0.34 ± 0.15 µIU/ml. Mean serum thyroid stimulating hormone level of experimental groups B and C rats at the start of the study was 0.46 ± 0.18 µIU/ml and 0.41 ± 0.14 µIU/ml, respectively Mean serum thyroid stimulating hormone of rats did not differ statistically significantly between the group p=0.26, By the end of study mean serum thyroid stimulating hormone level of control group. A rats was 0.6 ± 0.2 µIU/ml. Mean serum thyroid stimulating hormone levels of experimental groups B and C rats at the end of the study were 1.32 ± 0.35 µIU/ml and 1.86 ± 0.67 µIU/ml, respectively.......

Noise emission of combustion engines and road vehicles - a historical review

This paper deals with the historical development of the noise emission of cars, trucks and their petrol and diesel engines; it focus on the European Union and the time period between 1910 and 2020. Combustion engines were and are important noise sources of road vehicles. Until around 1970 engine noise levels were increased strongly by higher speeds, by higher cylinder pressures and especially for truck engines by the introduction of the diesel combustion process. The noise emission was mainly caused by the drive train until the 1960ies for cars and until the 1970ies for trucks. Since then the development of acoustically more advantageous engines was forced by noise regulations and simultaneously enabled by technical advancements. As a consequence of the acoustical optimization of the engines the tire/road noise became dominant. Despite of the technical advancements the road noise stress of the population is still much too high. Therefor the necessary short-term reduction of noise stress has to be realized by regulatory measures.

Neuroprotective role of Glycyrrhiza glabra on chronic noise induced changes in Hippocampal morphology and its functions in wistar albino rats

Background: Noise has become inexorable stress due to the increase in urbanization, automobile usage, and lifestyle modification.Aim: The study aims to investigate the effect of chronic noise stress on hippocampal morphology and the neuroprotective effect of Glycyrrhiza glabra (GG) on stress-induced male Wistar albino rats. Methods: Adult albino rats were randomly divided into four groups. Each group contained six animals. Rats exposed to chronic noise stress (100 dB/4 h – 30Days), Noise + GG (150 mg/kg Bw/Oral), and GG alone were compared with control animal and assessed for behaviour using the hole-board test, marble burying test, the morphology of hippocampus by histology, DNA fragmentation and assessed the Phytochemical constitutes in GG. Results: The rats exposed to chronic noise stress showed significance (p<0.05) of behavioral alterations such as increased fear and anxiety, obsessive-compulsive behaviour, enlarged lateral ventricle, and reduced hippocampal volume. Conclusion: The results reported that chronic noise stress affects the neurobehavioral due to reduced hippocampal volume.