Acoustic detection by sound-producing fishes (Mormyridae): the role of gas-filled tympanic bladders

2001 ◽  
Vol 204 (2) ◽  
pp. 175-183 ◽  
Author(s):  
L.B. Fletcher ◽  
J.D. Crawford
Keyword(s):  
Acoustic Pressure ◽  
Physiological Saline ◽  
Auditory Sensitivity ◽  
Sham Operation ◽  
Acoustic Detection ◽  
Detection Thresholds ◽  
Hearing Range ◽  
Normal Fish ◽  
Tone Detection

Mormyrid electric fish use sounds for communication and have unusual ears. Each ear has a small gas-filled tympanic bladder coupled to the sacculus. Although it has long been thought that this gas-filled structure confers acoustic pressure sensitivity, this has never been evaluated experimentally. We examined tone detection thresholds by measuring behavioral responses to sounds in normal fish and in fish with manipulations to one or to both of the tympanic bladders. We found that the tympanic bladders increase auditory sensitivity by approximately 30 dB in the middle of the animal's hearing range (200–1200 Hz). Normal fish had their best tone detection thresholds in the range 400–500 Hz, with thresholds of approximately 60 dB (re 1 microPa). When the gas was displaced from the bladders with physiological saline, the animals showed a dramatic loss of auditory sensitivity. In contrast, control animals in which only one bladder was manipulated or in which a sham operation had been performed on both sides had normal hearing.

scholarly journals The Nutraceutical N-Palmitoylethanolamide (PEA) Reveals Widespread Molecular Effects Unmasking New Therapeutic Targets in Murine Varicocele

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 734
Author(s):  
Pietro Antonuccio ◽  
Herbert Ryan Marini ◽  
Antonio Micali ◽  
Carmelo Romeo ◽  
Roberta Granese ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Therapeutic Targets ◽  
Sham Operation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Pyrin Domain ◽  
Age Related ◽  
Extracellular Signal ◽  
Morphometric Assessment

Varicocele is an age-related disease with no current medical treatments positively impacting infertility. Toll-like receptor 4 (TLR4) expression is present in normal testis with an involvement in the immunological reactions. The role of peroxisome proliferator-activated receptor-α (PPAR-α), a nuclear receptor, in fertility is still unclear. N-Palmitoylethanolamide (PEA), an emerging nutraceutical compound present in plants and animal foods, is an endogenous PPAR-α agonist with well-demonstrated anti-inflammatory and analgesics characteristics. In this model of mice varicocele, PPAR-α and TLR4 receptors’ roles were investigated through the administration of ultra-micronized PEA (PEA-um). Male wild-type (WT), PPAR-α knockout (KO), and TLR4 KO mice were used. A group underwent sham operation and administration of vehicle or PEA-um (10 mg/kg i.p.) for 21 days. Another group (WT, PPAR-α KO, and TLR4 KO) underwent surgical varicocele and was treated with vehicle or PEA-um (10 mg/kg i.p.) for 21 days. At the end of treatments, all animals were euthanized. Both operated and contralateral testes were processed for histological and morphometric assessment, for PPAR-α, TLR4, occludin, and claudin-11 immunohistochemistry and for PPAR-α, TLR4, transforming growth factor-beta3 (TGF-β3), phospho-extracellular signal-Regulated-Kinase (p-ERK) 1/2, and nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) Western blot analysis. Collectively, our data showed that administration of PEA-um revealed a key role of PPAR-α and TLR4 in varicocele pathophysiology, unmasking new nutraceutical therapeutic targets for future varicocele research and supporting surgical management of male infertility.

scholarly journals Camelina Oil Supplementation Improves Bone Parameters in Ovariectomized Rats

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1343
Author(s):  
Iwona Puzio ◽  
Dorota Graboś ◽  
Marek Bieńko ◽  
Radosław P. Radzki ◽  
Aneta Nowakiewicz ◽  
...  
Keyword(s):  
Serum Level ◽  
Recovery Period ◽  
Physiological Saline ◽  
Ovariectomized Rats ◽  
Control Group ◽  
Sham Operation ◽  
Type I ◽  
Camelina Oil ◽  
Bone Parameters ◽  
Ovx Rats

The aim of the present study was to determine the effect of administration of Camelina sativa oil (CO) as a source of polyunsaturated fatty acids (PUFA) on bone parameters in ovariectomized rats (OVX). Overall, 40 10-week-old healthy female Wistar rats were divided into 4 groups with 10 animals in each. Rats in the control group (SHO) were subjected to a sham operation, whereas experimental rats (OVX) were ovariectomized. After a 7-day recovery period, the SHO the rats received orally 1 mL of physiological saline for the next 6 weeks. The OVX rats received orally 1 mL of physiological saline (OVX-PhS), 5 g/kg BW (OVX-CO5), or 9 g/kg BW (OVX-CO9) of camelina oil. The use of camelina oil had a significant effect on body weight, lean mass, and fat mass. The camelina oil administration suppressed the decrease in the values of some densitometric, tomographic, and mechanical parameters of femur caused by estrogen deficiency. The CO treatment increased significantly the serum level of osteocalcin and decreased the serum level of C-terminal telopeptide of type I collagen in the OVX rats. In conclusion, camelina oil exerts a positive osteotropic effect by inhibiting ovariectomy-induced adverse changes in bones. Camelina oil supplementation can be used as an efficient method for improving bone health in a disturbed state. However, further research must be carried out on other animal species supplemented with the oil.

Is central hyperacusis a symptom of 5-hydroxytryptamine (5-HT) dysfunction?

1995 ◽  
Vol 109 (10) ◽  
pp. 915-921 ◽  
Author(s):  
Josephine Marriage ◽  
N. M. Barnes
Keyword(s):  
Common Factor ◽  
Subjective Symptom ◽  
Research Literature ◽  
Auditory Sensitivity ◽  
Sensory Modulation ◽  
Hearing Sensitivity ◽  
Symptom Profile ◽  
Neurological Conditions

AbstractThe subjective symptom of hyperacusis is described. The terms ‘hyperacusis’ and ‘phonophobia’ are considered to be synonymous as there is no recognized distinction between these two descriptions. Peripheral auditory pathologies with associated hearing sensitivity are reviewed and the likely mechanisms underlying the hyperacusis are listed. The neurological conditions, which have been reported to occur with hyperacusis, are reviewed. A separate aetiology of central hyperacusis is therefore proposed, with a symptom profile distinct from the peripheral hyperacusisA common factor to neurological conditions with hyperacusis, is disturbance of 5-HT (5-hydroxytryptamine) or serotonin function. The research literature on the role of 5-HT in sensory modulation (specifically auditory startle) in animals is presented. It is proposed that 5-HT dysfunction is a probable cause of increased auditory sensitivity manifested as central hyperacusis or phonophobia

Role of the spleen in the development of steatohepatitis in high-fat-diet-induced obese rats

2012 ◽  
Vol 237 (4) ◽  
pp. 461-470 ◽  
Author(s):  
Megumi Inoue ◽  
Koro Gotoh ◽  
Masataka Seike ◽  
Takayuki Masaki ◽  
Koichi Honda ◽  
...  
Keyword(s):  
Fatty Liver ◽  
Hepatic Steatosis ◽  
Liver Tissue ◽  
Sham Operation ◽  
Low Grade ◽  
Sprague Dawley ◽  
High Fat ◽  
Obese Rats ◽  
Inflammatory State

Obesity is considered a systemic low-grade inflammatory state. Although the spleen is the main immune organ with a close anatomical relationship with the liver, its role in the progression of fatty liver disease remains uncertain. Therefore, we sought to clarify the functional role of the spleen in the development of steatohepatitis in high-fat (HF)-diet-induced obese rats. Male Sprague-Dawley rats were fed HF food and divided into two groups, a splenectomy (SPX) group and a sham-operation (Sham) group. The liver and abdominal white adipose tissue (WAT) were removed one and six months after surgery, and we evaluated the effects of SPX on WAT and HF-induced fatty liver. SPX rats exhibited worse dyslipidemia and inflammatory changes in WAT one month after surgery. Hepatic steatosis and inflammation were accelerated by SPX, based on the time after surgery. At one month after surgery, the tissue triglyceride content increased in SPX rats, compared with Sham controls ( P < 0.05). The liver histology also showed a worsening of steatosis in those rats. At six months after SPX, dramatic inflammatory and fibrotic changes were observed in liver tissue sections. Hepatic carnitine palmitoyltransferase-1 was suppressed at one and six months after SPX ( P < 0.05 for each). WAT and liver tissue levels of inflammatory markers such as tumor necrosis factor- α, and the expression of Kupffer cells were all increased at six months in SPX rats, compared with Sham controls ( P < 0.05 for each). Our results indicate that the preservation of the spleen contributes to the prevention of the progression of hepatic steatosis to steatohepatitis in obese rats.

Influence of thymectomy on growth of secondary reproductive structures in rats

1964 ◽  
Vol 206 (1) ◽  
pp. 193-197 ◽  
Author(s):  
Constance R. Martin
Keyword(s):  
Sexual Development ◽  
Seminal Vesicles ◽  
Thymus Gland ◽  
Ventral Prostate ◽  
Sham Operation ◽  
Rapid Phase ◽  
Reproductive Structures ◽  
Response To Stress ◽  
Long Evans

Ventral prostate glands and seminal vesicles of Long-Evans rats, thymectomized at 6–6 1/2 weeks of age and autopsied 3 weeks later, were significantly heavier than those of sham-operated rats. Values for thymectomized rats were as great as or greater than those for unoperated controls. The influence of thymectomy and sham operation was less pronounced when surgery was performed on rats which had not yet entered or had completed the most rapid phase of sexual development. A possible role of the thymus gland in the response to stress is discussed.

Too resilient for anyone’s good

Kybernetes ◽  
2019 ◽  
Vol 48 (4) ◽  
pp. 751-768 ◽  
Author(s):  
Lance Nizami
Keyword(s):  
Auditory Stimulus ◽  
Design Methodology ◽  
Detection Thresholds ◽  
Content Type ◽  
Infant Vision ◽  
Efficacious Treatment ◽  
Stimulus Detection ◽  
First Time

Purpose This study aims to examine the observer’s role in “infant psychophysics”. Infant psychophysics was developed because the diagnosis of perceptual deficits should be done as early in a patient’s life as possible, to provide efficacious treatment and thereby reduce potential long-term costs. Infants, however, cannot report their perceptions. Hence, the intensity of a stimulus at which the infant can detect it, the “threshold”, must be inferred from the infant’s behavior, as judged by observers (watchers). But whose abilities are actually being inferred? The answer affects all behavior-based conclusions about infants’ perceptions, including the well-proselytized notion that auditory stimulus-detection thresholds improve rapidly during infancy. Design/methodology/approach In total, 55 years of infant psychophysics is scrutinized, starting with seminal studies in infant vision, followed by the studies that they inspired in infant hearing. Findings The inferred stimulus-detection thresholds are those of the infant-plus-watcher and, more broadly, the entire laboratory. The thresholds are therefore tenuous, because infants’ actions may differ with stimulus intensity; expressiveness may differ between infants; different watchers may judge infants differently; etc. Particularly, the watcher’s ability to “read” the infant may improve with the infant’s age, confounding any interpretation of perceptual maturation. Further, the infant’s gaze duration, an assumed cue to stimulus detection, may lengthen or shorten nonlinearly with infant age. Research limitations/implications Infant psychophysics investigators have neglected the role of the observer, resulting in an accumulation of data that requires substantial re-interpretation. Altogether, infant psychophysics has proven far too resilient for its own good. Originality/value Infant psychophysics is examined for the first time through second-order cybernetics. The approach reveals serious unresolved issues.

Masked and unmasked pure tone detection thresholds of a harbour seal listening in air

1991 ◽  
Vol 69 (8) ◽  
pp. 2059-2066 ◽  
Author(s):  
J. M. Terhune
Keyword(s):  
White Noise ◽  
Pure Tone ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Optimal Conditions ◽  
Vascular Changes ◽  
Detection Thresholds ◽  
Noise Masker ◽  
Auditory Systems ◽  
Tone Detection

In-air pure tone detection thresholds of a harbour seal (Phoca vitulina) were measured using behavioural psychophysical techniques. Thresholds dropped from about 70 dB re 20 μPa at 0.1 kHz to about 35 dB re 20 μ Pa at 4 kHz and then increased to about 45 dB re 20 μPa at 16 kHz. Increased sensitivities at 2 and 8 kHz, which have been reported in other pinnipeds, were not evident. In-air intensity detection thresholds averaged 32 dB above their underwater counterparts (1–16 kHz). Masking studies found the critical ratios at 0.25, 0.5, and 1 kHz to be 24, 15, and 21 dB, respectively (white noise masker). From 0.2 to 1.5 kHz, bandwidths 20 dB below the level of pure tone maskers were 0.16–0.18 kHz. Circumstantial evidence suggests the possibility that blood vascular changes associated with diving might also influence the sensitivity of the auditory systems of seals. Under optimal conditions, a pup's airborne cries may be detected by its mother at ranges of 1 km or more.

Prevention of two-kidney, one-clip renal hypertension in rat by ablation of AV3V tissue

1983 ◽  
Vol 245 (4) ◽  
pp. H683-H689 ◽  
Author(s):  
J. R. Haywood ◽  
G. D. Fink ◽  
J. Buggy ◽  
S. Boutelle ◽  
A. K. Johnson ◽  
...  
Keyword(s):  
Renal Artery ◽  
Third Ventricle ◽  
Renal Hypertension ◽  
Urine Volume ◽  
Urine Osmolality ◽  
Sham Operation ◽  
Vasopressin Release ◽  
Transient Rise ◽  
Fluid Regulation

This study examined the role of the anteroventral third ventricle (AV3V) in the renin-dependent two-kidney, one-clip model of renal hypertension. AV3V lesion and sham lesion rats were subjected to the placement of a clip on one renal artery or a sham operation. The sham lesion-renal artery clip rats experienced an increase in systolic blood pressure; however, AV3V lesioned animals experienced only a transient rise in arterial pressure during the 1st wk after clip. Body fluid regulation studies during the course of the hypertension revealed that there were no differences in water intake and urine volume between the lesion- and sham lesion-renal artery clip animals. Although significantly greater plasma and blood volumes were demonstrated in the AV3V lesion-sham clip rats compared with sham lesion animals, no differences in vascular volumes were detected in the renal artery clip rats. Finally, the rats were water deprived for 3 days to maximally stimulate vasopressin release. Urine osmolality increased significantly in all groups of rats except the AV3V lesion-renal artery clip animals protected against the hypertension.

scholarly journals Acylated Ghrelin and The Regulation of Lipid Metabolism in The Intestine

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Auclair ◽  
N. Patey ◽  
L. Melbouci ◽  
Y. Ou ◽  
L. Magri-Tomaz ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Lipid Droplets ◽  
Physiological Saline ◽  
Fatty Acid Uptake ◽  
Intimate Relationship ◽  
Acid Uptake ◽  
Acylated Ghrelin ◽  
Adipose Tissues ◽  
Syrian Golden Hamsters

AbstractAcylated ghrelin (AG) is a gastrointestinal (GI) peptide mainly secreted by the stomach that promotes cytosolic lipid droplets (CLD) hypertrophy in adipose tissues and liver. However, the role of AG in the regulation of lipid metabolism in the intestine remains unexplored. This study aimed at determining whether AG influences CLD production and chylomicron (CM) secretion in the intestine. The effects of AG and oleic acid on CLD accumulation and CM secretion were first investigated in cultured Caco-2/15 enterocytes. Intestinal lipid metabolism was also studied in Syrian Golden Hamsters submitted to conventional (CD) or Western (WD) diets for 8 weeks and continuously administered with AG or physiological saline for the ultimate 2 weeks. In cultured Caco-2/15 enterocytes, CLD accumulation influenced CM secretion while AG reduced fatty acid uptake. In WD hamsters, continuous AG treatment amplified chylomicron output while reducing postprandial CLD accumulation in the intestine. The present study supports the intimate relationship between CLD accumulation and CM secretion in the intestine and it underlines the importance of further characterizing the mechanisms through which AG exerts its effects on lipid metabolism in the intestine.

scholarly journals The role of PI3K-mediated AMPA receptor changes in post-conditioning of propofol in brain protection

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Chenxu Wang ◽  
Ying Wei ◽  
Yuan Yuan ◽  
Yonghao Yu ◽  
Keliang Xie ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Sham Operation ◽  
Short Term ◽  
Selective Antagonist ◽  
Cerebral Artery Occlusion

Abstract Background We aimed to study the role of amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) glutamate receptor 2 (GluR2) subunit trafficking, and activity changes in short-term neuroprotection provided by propofol post-conditioning. We also aimed to determine the role of phosphoinositide-3-kinase (PI3K) in the regulation of these processes. Methods Rats underwent 1 h of focal cerebral ischemia followed by 23 h of reperfusion were randomly divided into 6 groups (n = 36 per group): sham- operation (S), ischemia–reperfusion (IR), propofol (P group, propofol 20 mg/kg/h at the onset of reperfusion for 2 h after 60 min of occlusion), and LY294002 (PI3K non-selective antagonist) + sham (L + S, LY294002 of 1.5 mg/kg was infused 30 min before sham operation), LY294002+ ischemia–reperfusion (L + IR, LY294002 of 1.5 mg/kg was infused 30 min before middle cerebral artery occlusion), LY294002 + IR + propofol (L + P, LY294002 of 1.5 mg/kg was infused 30 min before middle cerebral artery occlusion and propofol 20 mg/kg/h at the onset of reperfusion for 2 h after 60 min of occlusion). Results Compared with group IR, rats in group P had significant lower neurologic defect scores and infarct volume. Additionally, consistent with enhanced expression of PI3K-AMPAR GluR2 subunit complex substances in ipsilateral hippocampus, GluR2 subunits showed increased levels in both the plasma and postsynaptic membranes of neurons, while pGluR2 expression was reduced in group P. Furthermore, LY294002, the PI3K non-selective antagonist, blocked those effects. Conclusion These observations demonstrated that propofol post-conditioning revealed acute neuroprotective role against transient MCAO in rats. The short-term neuroprotective effect was contributed by enhanced GluR2 subunits trafficking to membrane and postsynaptic membranes of neurons, as well as down-regulated the expression of pGluR2 in damaged hippocampus. Finally, the above-mentioned protective mechanism might be contributed by increased combination of PI3K to AMPAR GluR2 subunit, thus maintained the expression and activation of AMPAR GluR2 in the ipsilateral hippocampus.

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