scholarly journals Noise-induced hyperactivity in the inferior colliculus: its relationship with hyperactivity in the dorsal cochlear nucleus

2012 ◽  
Vol 108 (4) ◽  
pp. 976-988 ◽  
Author(s):  
N. F. Manzoor ◽  
F. G. Licari ◽  
M. Klapchar ◽  
R. L. Elkin ◽  
Y. Gao ◽  
...  
Keyword(s):  
Spontaneous Activity ◽  
Inferior Colliculus ◽  
Cochlear Nucleus ◽  
Time Course ◽  
Noise Exposure ◽  
Dorsal Cochlear Nucleus ◽  
Control Group ◽  
Before And After ◽  
Intense Noise ◽  
And Control

Intense noise exposure causes hyperactivity to develop in the mammalian dorsal cochlear nucleus (DCN) and inferior colliculus (IC). It has not yet been established whether the IC hyperactivity is driven by hyperactivity from extrinsic sources that include the DCN or instead is maintained independently of this input. We have investigated the extent to which IC hyperactivity is dependent on input from the contralateral DCN by comparing recordings of spontaneous activity in the IC of noise-exposed and control hamsters before and after ablation of the contralateral DCN. One group of animals was binaurally exposed to intense sound (10 kHz, 115 dB SPL, 4 h), whereas the control group was not. Both groups were studied electrophysiologically 2–3 wk later by first mapping spontaneous activity along the tonotopic axis of the IC to confirm induction of hyperactivity. Spontaneous activity was then recorded at a hyperactive IC locus over two 30-min periods, one with DCNs intact and the other after ablation of the contralateral DCN. In a subset of animals, activity was again mapped along the tonotopic axis after the time course of the activity was recorded before and after DCN ablation. Following recordings, the brains were fixed, and histological evaluations were performed to assess the extent of DCN ablation. Ablation of the DCN resulted in major reductions of IC hyperactivity. Levels of postablation activity in exposed animals were similar to the levels of activity in the IC of control animals, indicating an almost complete loss of hyperactivity in exposed animals. The results suggest that hyperactivity in the IC is dependent on support from extrinsic sources that include and may even begin with the DCN. This finding does not rule out longer term compensatory or homeostatic adjustments that might restore hyperactivity in the IC over time.

scholarly journals Acute and Long-Term Effects of Noise Exposure on the Neuronal Spontaneous Activity in Cochlear Nucleus and Inferior Colliculus Brain Slices

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Moritz Gröschel ◽  
Jana Ryll ◽  
Romy Götze ◽  
Arne Ernst ◽  
Dietmar Basta
Keyword(s):  
Hearing Loss ◽  
Spontaneous Activity ◽  
Inferior Colliculus ◽  
Cochlear Nucleus ◽  
Noise Exposure ◽  
Brain Slices ◽  
Noise Induced Hearing Loss ◽  
Long Term Effects ◽  
Noise Trauma

Noise exposure leads to an immediate hearing loss and is followed by a long-lasting permanent threshold shift, accompanied by changes of cellular properties within the central auditory pathway. Electrophysiological recordings have demonstrated an upregulation of spontaneous neuronal activity. It is still discussed if the observed effects are related to changes of peripheral input or evoked within the central auditory system. The present study should describe the intrinsic temporal patterns of single-unit activity upon noise-induced hearing loss of the dorsal and ventral cochlear nucleus (DCN and VCN) and the inferior colliculus (IC) in adult mouse brain slices. Recordings showed a slight, but significant, elevation in spontaneous firing rates in DCN and VCN immediately after noise trauma, whereas no differences were found in IC. One week postexposure, neuronal responses remained unchanged compared to controls. At 14 days after noise trauma, intrinsic long-term hyperactivity in brain slices of the DCN and the IC was detected for the first time. Therefore, increase in spontaneous activity seems to develop within the period of two weeks, but not before day 7. The results give insight into the complex temporal neurophysiological alterations after noise trauma, leading to a better understanding of central mechanisms in noise-induced hearing loss.

scholarly journals Activity of CaMKIIa+ dorsal cochlear nucleus neurons are crucial for tinnitus perception but not for tinnitus induction

2021 ◽  
Author(s):  
Thawann Malfatti ◽  
Barbara Ciralli ◽  
Markus M Hilscher ◽  
Richardson N Leao ◽  
Katarina E Leao
Keyword(s):  
Cochlear Nucleus ◽  
Noise Exposure ◽  
Acoustic Startle ◽  
Auditory Brainstem ◽  
Dorsal Cochlear Nucleus ◽  
Homeostatic Plasticity ◽  
Designer Drugs ◽  
Auditory Brainstem Responses ◽  
Control Group ◽  
Sound Perception

The dorsal cochlear nucleus (DCN) is a region known to integrate somatosensory and auditory inputs and is identified as a potential key structure in the generation of phantom sound perception, especially noise-induced tinnitus. Yet, how altered homeostatic plasticity of the DCN induces and maintains the sensation of tinnitus is not clear. Here, we chemogenetically decrease activity of a subgroup of DCN neurons, Ca2+/Calmodulin kinase 2α (CaMKIIα) positive DCN neurons, using Gi-coupled human M4 Designer Receptors Exclusively Activated by Designer Drugs (hM4Di DREADDs), to investigate their role in noise-induced tinnitus. Mice were over-exposed to loud noise (9-11kHz, 90dBSPL, 1h, followed by 2h of silence) and auditory brainstem responses (ABRs) and gap prepulse inhibition of acoustic startle (GPIAS) were recorded two days before and two weeks after noise exposure to identify animals with a significantly decreased inhibition of startle, indicating tinnitus but without permanent hearing loss. Neuronal activity of CaMKIIα+ neurons expressing hM4Di in the DCN was lowered by administration of clozapine-N-oxide (CNO). We found that acutely decreasing firing rate of CaMKIIα+ DCN units decrease tinnitus-like responses (p = 0.038, n = 11 mice), compared to the control group that showed no improvement in GPIAS (control virus; CaMKIIα-YFP + CNO, p = 0.696, n = 7 mice). Extracellular recordings confirmed CNO to decrease unit firing frequency of CaMKIIα-hM4Di+ mice and alter best frequency and tuning width of response to sound. However, these effects were not seen if CNO had been previously administered during the noise overexposure (n = 6 experimental and 6 control mice). Our results suggest that CaMKIIα-hM4Di positive cells in the DCN are not crucial for tinnitus induction but play a significant role in maintaining tinnitus perception in mice.

Effects of Time and Perceptual Orientation on Actors' and Observers' Attributions

1984 ◽  
Vol 58 (1) ◽  
pp. 23-30
Author(s):  
Donald S. Martin ◽  
Ming-Shiunn Huang
Keyword(s):  
Video Recording ◽  
Control Group ◽  
Control Groups ◽  
Video Recordings ◽  
Before And After ◽  
Perceptual Orientation ◽  
Initial Difference ◽  
Variety Show ◽  
And Control ◽  
Unrelated Variety

The actor/observer effect was examined by Storms in a 1973 study which manipulated perceptual orientation using video recordings. Storms' study was complex and some of his results equivocal. The present study attempted to recreate the perceptual reorientation effect using a simplified experimental design and an initial difference between actors and observers which was the reverse of the original effect. Female undergraduates performed a motor co-ordination task as actors while watched by observers. Each person made attributions for the actor's behaviour before and after watching a video recording of the performance. For a control group the video recording was of an unrelated variety show excerpt. Actors' initial attributions were less situational than observers'. Both actors and observers became more situational after the video replay but this effect occurred in both experimental and control groups. It was suggested the passage of time between first and second recording of attributions could account for the findings and care should be taken when interpreting Storms' (1973) study and others which did not adequately control for temporal effects.

Melatonin Improves Erythropoietin Hyporesponsiveness via Suppression of Inflammation

2019 ◽  
Vol 14 (3) ◽  
pp. 203-208
Author(s):  
Evan Noori Hameed ◽  
Haydar F. Hadi AL Tukmagi ◽  
Hayder Ch Assad Allami
Keyword(s):  
Iron Status ◽  
Transferrin Saturation ◽  
Control Group ◽  
Base Line ◽  
Inadequate Response ◽  
Inflammatory Parameters ◽  
Tnf Α ◽  
Before And After ◽  
And Control ◽  
Controlled Clinical Study

Background: Inadequate response to Erythropoietin Stimulating Agents (ESA) despite using relatively larger doses regimen represents a potential risk factor of Cardiovascular (CV) related mortality in addition to health-care economic problems in anemic patients with Chronic Kidney Disease (CKD). Erythropoietin (EPO) hyporesponsiveness related to inflammation has been increased progressively. Melatonin is well known as a potent anti-inflammatory agent. Therefore, the current study was designed to evaluate whether melatonin could improve anemic patients response to EPO. Methods: This single controlled clinical study was carried out in 41 CKD patients with hemoglobin (Hb) levels less than 11g/dl divided randomly in a 1:1 ratio into 2 groups; treatment group who received 5mg melatonin plus their regular treatments and control group who received their regular treatments only. Hematological and iron status parameters include Hb level, serum iron (S. iron), Transferrin Saturation Ratio (TSAT) and serum ferritin (S. ferritin) in addition to inflammatory parameters that include tissue necrotic factor alfa (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6) determined before and after 12 weeks of treatment. Results: Melatonin remarkably increases the Hb level with a significant increase in S. iron and TSAT compared to baseline. The elevation of S. iron and TSAT was significantly higher in the melatonin group. Additionally, all inflammatory markers estimated were reduced significantly by melatonin compared to base line and control group. Conclusion: The results of the current study showed that melatonin has an advantageous effect on improving EPO response in anemic patients with CKD.

scholarly journals Toe Clearance Rehabilitative Slippers for Older Adults With Fall Risk: A Randomized Controlled Trial

2021 ◽  
Vol 12 ◽  
pp. 215145932110291
Author(s):  
Atsuko Satoh ◽  
Yukoh Kudoh ◽  
Sangun Lee ◽  
Masumi Saitoh ◽  
Miwa Miura ◽  
...  
Keyword(s):  
Older Adults ◽  
Fall Risk ◽  
Controlled Trial ◽  
Intervention Group ◽  
Berg Balance Scale ◽  
Control Group ◽  
Mobility Assessment ◽  
Before And After ◽  
Day Services ◽  
And Control

Introduction: To evaluate fall-prevention rehabilitative slippers for use by self-caring, independent older adults. Materials and Methods: This assessor-blinded, randomized, and controlled 1-year study included 59 self-caring, independent participants (49 women) who attended day services. The mean age of participants was 84.0 ± 5.3 years. Participants were randomly selected from 8 nursing homes. We tested slippers top-weighted with a lead bead (200, 300, or 400 g). Intervention group participants walked while wearing the slippers for 10-20 min, 1-3 days/week at the day service center. Fall risk was measured using the Berg Balance Scale and the Tinetti Performance-Oriented Mobility Assessment (POMA) before and at 3-month intervals after the intervention/control phase. Results: After 12 months, the intervention group demonstrated significant improvement. Berg Balance and POMA compared to the control group ( p < .05 p < .01, respectively). Mobility scores improved significantly for both measurements in the intervention group before and after ( p < .01), but the control group had significantly lower scores. Discussion: Overall, falls decreased in the intervention group from 10 to 7, and control group falls increased from 9 to 16 ( p = .02). No adverse events related to the intervention were reported. Conclusions: Rehabilitation training slippers may reduce falls in older adults.

The effectiveness of emotional freedom techniques (EFT) on depression of postmenopausal women: a randomized controlled trial

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Asieh Mehdipour ◽  
Parvin Abedi ◽  
Somayeh Ansari ◽  
Maryam Dastoorpoor
Keyword(s):  
Randomized Controlled Trial ◽  
Postmenopausal Women ◽  
Controlled Trial ◽  
Intervention Group ◽  
Control Group ◽  
Randomized Controlled ◽  
Moderate Depression ◽  
Before And After ◽  
The Mean ◽  
And Control

Abstract Objectives Postmenopausal women are at greater risk of depression. Depression may negatively affect the quality of life of women. An emotional freedom technique (EFT) is an evidence-based therapy combining cognitive and exposure components with acupressure. This study aimed to evaluate the effect of EFT on depression in postmenopausal women. Methods This was a randomized controlled trial in which 88 women with mild to moderate depression recruited from a menopausal clinic in Ahvaz, Iran, and randomly assigned into two groups of EFT (n=44) and control for sham therapy (n=44). Women in the EFT group received two sessions of training and asked to continue EFT for 8 weeks, one time per day. The Beck Depression Inventory (BDI2) completed by women before and after the intervention. The control group received training on sham acupressure points similar to the intervention group. Data collected using a demographic and BDI2. Women requested to complete the BDI2 before and after the intervention. The independent t-test, chi-square, and ANCOVA were used to analyze data. Results The mean depression score in the intervention group reduced from 20.93 ± 4.6 to 10.96 ± 4.38 in comparison to the control group that reduced from 19.18 ± 2.79 to 17.01 ± 6.05 after intervention (p=0.001). After the 8 week intervention, the frequency of moderate depression decreased from 56.8 to 9.35% in the intervention and from 50 to 29.5% in the control group. In total, 63.4 and 34.15% in the intervention and control groups were free of depression respectively after the intervention (p<0.001). Conclusions The results of this study showed that using EFT for 8 weeks could significantly reduce the mean score of depression in postmenopausal women. Using this method in public health centers for postmenopausal women is recommended.

OP08 Levels and sources of stress reported by first year paramedic students associated with their first ambulance placement

2021 ◽  
Vol 38 (9) ◽  
pp. A4.2-A4
Author(s):  
Matthew Warren-James ◽  
Julie Hanson ◽  
Belinda Flanagan ◽  
Mary Katsikitis ◽  
Bill Lord
Keyword(s):  
Death And Dying ◽  
Educational Interventions ◽  
Fear Of Failure ◽  
Anxiety And Depression ◽  
Control Group ◽  
First Year ◽  
Before And After ◽  
Quasi Experimental ◽  
And Control ◽  
Experimental Group

BackgroundWhilst there is evidence to suggest paramedics experience significant stress when working in the ambulance setting little is known about the experiences of first year paramedic students. This research aimed to: (i) identify whether levels of stress, anxiety and depression experienced by first year paramedic students changed after ambulance placement compared to a control group, and (ii) identify the main perceived and actual sources of stress around ambulance placement.MethodsA before-and-after quasi-experimental design was used to compare whether the experience of ambulance placement altered the levels of stress, anxiety and depression in an experimental group that attended an ambulance placement (n = 20) and the control group who did not (n = 10). Online surveys encompassing the Depression, Anxiety and Stress Scale (DASS-21) and qualitative questions about sources of stress were concurrently deployed to both the experimental and control groups before and after the ambulance placement. Participants were first year paramedic students working in Queensland Ambulance Service, Australia.ResultsThere was a significant reduction in levels of stress in participants after undertaking their first ambulance placement (Mdn = -4.00) when compared to a control group (Mdn = 0.00), U = 52.5, p = .035, n2 = 0.15. Responses to survey questions suggest anticipation about experiencing death and dying of patients was the most frequently reported stressor of student paramedics before undertaking ambulance placements, however insecurity about knowledge, competence and fear of failure was the most frequently experienced stressor reported after completing ambulance placements.ConclusionsThe findings from this study suggest that the fear of the unknown may be worse than the reality. Anticipatory stress is the foremost problem for first year paramedic students attending their first ambulance placement. Placement pre-briefing should focus on educational interventions to build knowledge and skills competency to reduce stress levels and fear of failure.

The Effect of Passive Smoking on Mucociliary Clearance and Inferior Concha Reactivity

2020 ◽  
pp. 194589242096761
Author(s):  
Osman Kılıç ◽  
Aslı Şahin Yılmaz ◽  
Çağatay Oysu
Keyword(s):  
Cigarette Smoke ◽  
Passive Smoking ◽  
Mucociliary Clearance ◽  
Inferior Turbinate ◽  
Control Group ◽  
Nasal Decongestants ◽  
Significant Difference ◽  
Mucosal Response ◽  
Before And After ◽  
And Control

Introduction The aim of this study is to investigate the effect of cigarette smoke on turbinate reactivity and mucociliary clearance (MCC) in passive smokers. Methods 60 adult patients (30 passive smokers and 30 healthy subjects as the control group) were recruited for this study. Following a questionnaire on passive smoke exposure, MCC measurement using the saccharin test was carried out to all participants. The baseline and after decongestant acoustic rhinometry values (MCA1, MCA2, VOL1, VOL2) were measured and the percentage changes between the two test values (ie; response to nasal decongestants = concha reactivity) were recorded. Results All 60 patients, including 37 women (61.7%) and 23 men (38.3%) were between 18–57 years of age . MCC’s average measurements were 11.13 minutes in the passive smokers group, 7.87 minutes in the control group, which was statistically significantly different (p < 0.05). There was a statistically significant difference between the passive smokers and control group for acoustic rhinometric measurement of the ratio of MCA2 and VOL2 values before and after decongestant application (p < 0.05). Discussion Passive smoking can damage the nasal mucosa at least as active smoking. The number of studies on this subject is limited. There are no studies in the literature showing the effect of cigarette smoke on the inferior turbinate mucosal response. In our study, the inferior turbinate decongestant capacity was found to be significantly decreased in the passive smokers compared to the control group. Conclusion As a result of cigarette exposure, the erectile function of the lower turbines may be impaired. The task of the ENT physicians is to warn the passive smokers in this regard.

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