scholarly journals Salicylate-Induced Auditory Perceptual Disorders and Plastic Changes in Nonclassical Auditory Centers in Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Guang-Di Chen ◽  
Kelly E. Radziwon ◽  
Nina Kashanian ◽  
Senthilvelan Manohar ◽  
Richard Salvi
Keyword(s):  
Discharge Rate ◽  
Field Potentials ◽  
Recorded Sound ◽  
Negative Effect ◽  
Emotion And Memory ◽  
The Mean ◽  
Plastic Changes ◽  
Behavioral Evidence ◽  
Evoked Activity ◽  
Auditory Perceptual Disorders

Previous studies have shown that sodium salicylate (SS) activates not only central auditory structures, but also nonauditory regions associated with emotion and memory. To identify electrophysiological changes in the nonauditory regions, we recorded sound-evoked local field potentials and multiunit discharges from the striatum, amygdala, hippocampus, and cingulate cortex after SS-treatment. The SS-treatment produced behavioral evidence of tinnitus and hyperacusis. Physiologically, the treatment significantly enhanced sound-evoked neural activity in the striatum, amygdala, and hippocampus, but not in the cingulate. The enhanced sound evoked response could be linked to the hyperacusis-like behavior. Further analysis showed that the enhancement of sound-evoked activity occurred predominantly at the midfrequencies, likely reflecting shifts of neurons towards the midfrequency range after SS-treatment as observed in our previous studies in the auditory cortex and amygdala. The increased number of midfrequency neurons would lead to a relative higher number of total spontaneous discharges in the midfrequency region, even though the mean discharge rate of each neuron may not increase. The tonotopical overactivity in the midfrequency region in quiet may potentially lead to tonal sensation of midfrequency (the tinnitus). The neural changes in the amygdala and hippocampus may also contribute to the negative effect that patients associate with their tinnitus.

Gustatory neural coding in the monkey cortex: acid stimuli

1995 ◽  
Vol 74 (2) ◽  
pp. 556-564 ◽  
Author(s):  
C. R. Plata-Salaman ◽  
T. R. Scott ◽  
V. L. Smith-Swintosky
Keyword(s):  
Neural Coding ◽  
Discharge Rate ◽  
Insular Cortex ◽  
Spontaneous Discharge ◽  
Taste Cells ◽  
Visual Approach ◽  
Response Profiles ◽  
The Mean ◽  
Evoked Activity ◽  
Prominent Response

1. We sought to define the gustatory neural code for acidic stimuli. Therefore we analyzed the responses of 44 single neurons in the insular cortex of four alert cynomolgus macaques in response to the oral application of four basic taste stimuli (glucose, NaCl, HCl, and quinine HCl) and fruit juice, and to a series of 20 additional acids. 2. Neurons responsive to gustatory stimulation were encountered within a volume of 38.2 mm3 (3.5 mm anteroposterior x 2.1 mm mediolateral x 5.2 mm dorsoventral). Taste cells constituted 81 (5.2%) of the 1,552 neurons whose sensitivities were tested. Of these, the activity of 44 was followed through at least one complete application of the stimulus series, and those responses compose the data of this study. Nongustatory cells included those responsive to mouth movements (36.3%), tactile stimulation within the mouth (2.1%), visual approach of the taste stimulus (1.4%), and extension of the tongue (0.1%). The functions of the remaining 54.8% were not determined. 3. The mean spontaneous discharge rate of these cortical taste cells was 3.0 spikes/s (range 0.0–14.4 spikes/s). The mean breadth of tuning coefficient was a moderate 0.72 (range 0.26–0.98). Most evoked activity was excitatory, although inhibition was a prominent response option for four (9%) taste cells. 4. There was no evidence that taste cells with similar functional characteristics were clustered within the cortex, i.e., there was no apparent topographic organization of taste quality. 5. Thirty-four of the 44 cells were divisible into three functional types on the basis of their response profiles to the four basic stimuli used here.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effect of plateletpheresis on hematocrit, hemoglobin and erythrocyte count: Meta-analysis 1980–2018

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alejandro Gil-Betacur ◽  
Carmen Yulieth Mantilla-Gutiérrez ◽  
Jaiberth Antonio Cardona-Arias
Keyword(s):  
Blood Cell ◽  
Cell Count ◽  
Red Blood Cell ◽  
Meta Analysis ◽  
Erythrocyte Count ◽  
Blood Cell Count ◽  
Selection Processes ◽  
Negative Effect ◽  
Red Blood Cell Count ◽  
The Mean

AbstractThe effects of platelet donation by apheresis on different parameters of the erythrogram are still unclear. The objective was to meta-analyze the effect of plateletpheresis on hematocrit, hemoglobin, and erythrocyte count, with a systematic review with random effects meta-analysis of the mean difference. The PRISMA guidelines were considered, as well as 133 search strategies on four different databases. Reproducibility was guaranteed and methodological quality was evaluated. Heterogeneity was evaluated with Galbraith and DerSimonian-Laird’s, publication bias with a funnel plot and a Begg’s test, sensitivity analysis and a cumulative meta-analysis were also conducted. Eighteen (18) articles were included, 17 evaluated the effects on hematocrit in 2,564 donors; 13 on hemoglobin in 1,640 donors; and 4 on red blood cell count in 243 donors. A decrease of 2.26% (CI95% = 2.11–2.41) was observed in hematocrit, of 0.80 g/dL (CI95% = 0.75–0.86) in hemoglobin and −0.21 × 1012/L (CI95% = −0.13; −0.29) in red blood cell count. Plateletpheresis has a negative effect on the erythrogram parameters, explained by blood loss in the kits used for the procedure and cell lysis. Such evidence is relevant to secure the efficiency and safety of the procedure, improve selection processes or determine the number of donations that can be performed without affecting donors’ health.

Canine visual acuity: retinal and cortical field potentials evoked by pattern stimulation

1983 ◽  
Vol 245 (5) ◽  
pp. R637-R641 ◽  
Author(s):  
J. V. Odom ◽  
N. M. Bromberg ◽  
W. W. Dawson
Keyword(s):  
Neuromuscular Block ◽  
Pattern Detection ◽  
Field Potentials ◽  
Retinal Processing ◽  
Pattern Stimulation ◽  
Last Stage ◽  
The Mean ◽  
The Difference ◽  
Mean Luminance ◽  
Cortical Field

The visual acuities (i.e., visual thresholds for pattern detection) of four dogs under neuromuscular block were measured using visually evoked cortical potentials (VECP) and/or pattern-evoked retinal potentials (PERR). Stimuli were phase-reversing square-wave gratings with a mean luminance of 86 cd/m2 and 70% contrast. The mean of the VECP thresholds of two dogs tested was 12.59 cycles per degree (cycles/deg). The mean of the PERR thresholds of four dogs tested was 11.61 cycles/deg. The difference between VECP and PERR thresholds was not statistically significant. VECP acuities appear to be determined at or before the last stage of retinal processing (PERR). Our estimates of canine acuity are 1.3–2 times those reported for cats and 0.2–0.4 times those reported for primates when tested under comparable luminance and contrast conditions.

Central compensation of vestibular deficits. IV. Responses of lateral vestibular neurons to neck rotation after labyrinth deafferentation

1985 ◽  
Vol 54 (4) ◽  
pp. 1006-1025 ◽  
Author(s):  
C. Xerri ◽  
S. Gianni ◽  
D. Manzoni ◽  
O. Pompeiano
Keyword(s):  
Conduction Velocity ◽  
Vestibular Nucleus ◽  
Discharge Rate ◽  
Acute Stage ◽  
Vestibular Neurectomy ◽  
Peak Displacement ◽  
Response Characteristics ◽  
Neck Rotation ◽  
The Mean ◽  
Decerebrate Cats

The response characteristics of neurons located in the lateral vestibular nucleus (LVN) to neck rotation at 0.026 Hz, 10 degrees peak displacement, have been investigated in precollicular decerebrate cats submitted to ipsilateral acute (aVN) or chronic vestibular neurectomy (cVN). On the whole, 105 units were tested after aVN (i.e., during the first postoperative hours) and 132 units after cVN (i.e., after full compensation of the postural and locomotor deficits). The neurons were histologically located either in the rostroventral (rvLVN) or the dorsocaudal part (dcLVN) of Deiters' nucleus, which are known to project mainly to the cervical and the lumbosacral cord, respectively. Moreover, 55 units in the former group and 66 units in the latter group were identified as vestibulospinal neurons projecting to lumbosacral segments of the spinal cord. The responses of these 237 LVN neurons to the neck input were then compared with those of 120 LVN neurons recorded previously in decerebrate cats with intact labyrinths. Whereas 58.3% of the LVN units recorded in control experiments were responsive to neck rotation, 69.5% of the units were affected by this stimulation at the acute stage of the neurectomy and 74.2% at the chronic stage. This increase in responsive units after aVN and cVN with respect to the controls was found exclusively in the dcLVN. The mean discharge rate of the responsive LVN neurons decreased from 40.7 +/- 48.9 (SD) imp/s in control experiments to 22.1 +/- 15.8 (SD) imp/s after a VN. Similar value was also obtained after cVN [25.0 +/- 17.2 (SD) imp/s], suggesting that compensation of the postural deficits elicited by the vestibular neurectomy results from a redistribution of the excitatory drive within different populations of LVN neurons. Indeed, the relation found in control experiments, i.e., that the faster the conduction velocity of vestibulospinal axons the lower was the unit discharge at rest, was lost after aVN, due to a decrease in resting discharge of the slow units. The mean discharge rate of the slow units, however, recovered after cVN, so that the negative correlation between resting discharge rate and axonal conduction velocity was reestablished. The average gain and sensitivity of the first harmonic response of the LVN neurons to neck rotation recorded after aVN and cVN were comparable to those obtained in preparations with the vestibular nerves intact.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Evaluating the influence of anxiety and depression on academic performance in high school students

2021 ◽  
Author(s):  
Waleed Ahmed Shahzad
Keyword(s):  
High School ◽  
Academic Performance ◽  
High School Students ◽  
Anxiety And Depression ◽  
Small Scale ◽  
School Students ◽  
Cross Sectional ◽  
Grade Point ◽  
Negative Effect ◽  
The Mean

The purpose of this study was to evaluate whether anxiety and depression have a negative effect on academic performance. This small-scale study assessed the relationship between these factors. A cross-sectional questionnaire survey was carried out. A randomized sample of 52 high school students based in various schools across Lahore participated in the survey. Of the participants, 32 were males and 20 were females. As a measure of anxiety and depression 14 questions from the DASS-21 were utilized (The 7 questions pertaining to the measure of stress were not included in this study). Based on the DASS-21 score obtained by the respondents they were classified under categories of normal, mild, moderate, severe and extremely severe levels of anxiety and depression. As a measure of academic performance, the Grade Point Average (GPA) of the students was obtained via the survey. The mean average GPA was calculated for all the students falling under the aforementioned categories pertaining to anxiety and depression separately and these averages were compared. It was found that the mean average GPA was highest in students falling under the categories of normal and mild levels of anxiety and depression. Whereas, mean average GPA was lower in students suffering from severe levels of anxiety and depression. These findings suggest the need to come up with methods to combat anxiety and depression in high school students as these factors impede academic performance.

scholarly journals Intelligence, consistency, and Emerson's dilemma

2019 ◽  
Author(s):  
Kimmo Sorjonen ◽  
Tomas Hemmingsson ◽  
Bo Melin
Keyword(s):  
Reading Ability ◽  
Statistical Power ◽  
Positive Association ◽  
Response Style ◽  
Measurement Instruments ◽  
Negative Effect ◽  
The Mean ◽  
Regression Toward The Mean ◽  
Response Consistency ◽  
Large Representative

In a large representative sample of Swedish male conscripts (N = 49,246), we demonstrate a positive association between intelligence and response consistency on items measuring endorsement of a strong military defense. This association is accentuated, to some degree, by an apparent difficulty to handle reversed items among those with low intelligence. Consequently, due to regression toward the mean, reversed items in measurement instruments would tend to have a negative effect on statistical power when analyzing the association between whatever the instrument is measuring and intelligence. On the other hand, the presence of reversed items could mitigate bias in the measurement due to an acquiescent response style among those with low intelligence. Lack of motivation/carelessness and inadequate reading ability among some subjects are two possible confounders for the found association in the present study.

Gustatory neural coding in the monkey cortex: stimulus intensity

1991 ◽  
Vol 65 (1) ◽  
pp. 76-86 ◽  
Author(s):  
T. R. Scott ◽  
C. R. Plata-Salaman ◽  
V. L. Smith ◽  
B. K. Giza
Keyword(s):  
Neural Coding ◽  
Discharge Rate ◽  
Taste Intensity ◽  
Response Functions ◽  
Somatosensory Stimulation ◽  
Gustatory Cortex ◽  
Intensity Response ◽  
Taste Cells ◽  
The Mean ◽  
Gustatory Neurons

1. We analyzed the activity of single neurons in gustatory cortex of alert cynomolgus monkeys in response to a range of stimulus intensities. Chemicals were deionized water, fruit juice, and several concentrations of the four prototypical taste stimuli: 10(-3)-1.0 M glucose, 10(-3)-1.0 M NaCl, 10(-4)-3 x 10(-2) M HCl, and 10(-5)-3 x 10(-3) M quinine HCl. 2. Taste-evoked responses could be recorded from a cortical gustatory area that measured 2.5 mm in its anteroposterior extent, 6.0 mm dorsoventrally, and 3.0 mm mediolaterally. Taste-responsive cells constituted 62 (3.7%) of the 1,661 neurons tested. Nongustatory cells gave responses associated with mouth movement (10.1%), somatosensory stimulation (2.2%), and approach or anticipation (0.9%). 3. Intensity-response functions were determined across 62 gustatory neurons. Neural thresholds for each stimulus quality conformed well to human psychophysical thresholds. Mean discharge rate was a direct function of stimulus concentration for glucose, NaCl, and quinine HCl. The most effective of the basic stimuli was glucose. 4. Power function exponents were calculated from the responses of neural subgroups most responsive to each basic stimulus. Those for glucose, NaCl, and quinine were within the range of psychophysically derived values. Thus the perceived intensity of each basic quality is presumably based on the activity of the appropriate neural subgroup rather than on the mean activity of all taste cells. 5. The mean breadth-of-tuning (entropy) coefficient for 62 gustatory neurons was 0.65 (range, 0.00–0.98). 6. There was no clear evidence of chemotopic organization in the gustatory cortex. 7. An analysis of taste quality indicated that sweet stimuli evoked patterns of activity that were clearly distinct from those of the nonsweet chemicals. Among the latter group, NaCl was differentiable from HCl and quinine HCl, whose patterns were closely related. 8. The response characteristics of cortical taste cells imply gustatory thresholds and intensity-response functions for the nonhuman primate that conform well to those reported in psychophysical studies of humans, reinforcing the value of this neural model for human taste intensity perception.

Development of spontaneous activity and mechanosensitivity in axotomized afferent nerve fibers during the first hours after nerve transection in rats

1995 ◽  
Vol 74 (3) ◽  
pp. 1020-1027 ◽  
Author(s):  
M. Michaelis ◽  
K. H. Blenk ◽  
W. Janig ◽  
C. Vogel
Keyword(s):  
Spontaneous Activity ◽  
Discharge Rate ◽  
Nerve Fibers ◽  
Nerve Lesion ◽  
Nerve Transection ◽  
Unmyelinated Fibers ◽  
C Fibers ◽  
Afferent Nerve Fibers ◽  
Irregular Frequency ◽  
The Mean

1. Spontaneous activity and ectopic mechanical excitability of axotomized unmyelinated and myelinated fibers in the sural nerve were examined in anesthetized rats. The analysis was performed within 30 h after the nerve lesion using single-fiber recordings that were performed proximal to the severed nerve end. 2. Among all unmyelinated fibers tested (n = 865), 4-8% exhibited persistent spontaneous activity of low and irregular frequency. The percentage of spontaneously active C fibers did not change significantly during the first 30 h. Only 6 of 796 A fibers had spontaneous activity. 3. Mechanical stimulation of the cut nerve end excited 5-8% of all C fibers under investigation. No development with time could be detected in the frequency of mechanically excitable C fibers. In contrast, beginning 6 h after nerve transection, the number of mechanically excitable A fibers rose with time, reaching 27% after 22-30 h. 4. Among the A fibers (C fibers) that exhibited mechanical excitability or spontaneous activity, only 4% (25%) had both properties, whereas 96% (75%) were either mechanosensitive or spontaneously active. 5. With time after the nerve lesion, the mean discharge rate of all spontaneously discharging C fibers decreased significantly from 49 imp/min (0.5-9 h after nerve lesion) to 11 imp/min after 22-30 h. The mean discharge rate of C fibers exhibiting solely spontaneous activity and those C fibers that were additionally mechanosensitive did not differ significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effect of Body Mass Index on Auricular Morphology and Auditory Functions

2019 ◽  
Vol 98 (7) ◽  
pp. E81-E86 ◽  
Author(s):  
Mehmet Surmeli ◽  
Ildem Deveci ◽  
Hasan Canakci ◽  
Mustafa Salih Canpolat ◽  
Burak Karabulut ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Soft Tissue ◽  
Body Mass ◽  
Significant Negative Correlation ◽  
The Body ◽  
Sulcus Angle ◽  
Soft Tissue Thickness ◽  
Negative Effect ◽  
The Mean ◽  
Auditory Functions

In this study, we aimed to investigate the relationship between the body mass index (BMI) and the morphometric properties of auricula and its acoustic gain characteristics. A total of 45 participants between 18 and 45 years of age were enrolled into the study. Participants’ height and weight measurements were recorded for the BMI calculation. On both sides, the morphometric properties of the auricula were measured and recorded. Additionally, the participants were subjected to multidirectional dynamic real ear measurements (REMs) to specify the intensity and frequency values of the maximum hearing gain. Participants consisted of 24 women and 21 men. The mean BMI was 23.42. The mean auricular area was 22.70 cm2. Statistically significant positive correlation was found between the auricular area and BMI ( r = 0.427, P = .03). The mean postauricular sulcus angle was 20.99°. The mastoid-helix distance was 16.07 mm. There was no statistically significant correlation between BMI level and postauricular sulcus angle and mastoid-helix distance ( P > .05). The mean dynamic REM measurement was evaluated. The maximum acoustic gain at anterior, lateral, and posterior vectorial stimulation was calculated as 20.9, 24.2, and 20.7 dB Sound Presure Level (SPL), respectively. Statistically significant negative correlation was found between the three directions acoustic gain level and BMI in the statistical examination ( r = −0.365, r = −0.386, r = −0.453, respectively, and P < .05 for all). The results of acoustic gain frequency were 2967.4, 2963, and 2934 Hz, respectively. There was no statistically significant correlation between acoustic gain frequency and BMI ( P > .05). When participants were grouped according to their BMI, participants with a BMI >25 had a statistically significantly bigger auricular area and lower maximum acoustic gain when compared with those with BMI <25 ( P < .05). We found that the auricular area increased with BMI. We think that this is related to soft tissue thickening of the auricula related to high BMI. In addition, we found that the acoustic gain level decreased inversely with BMI. We believe that the decrease in acoustic gain is due to the increase of acoustic resistance after the increase of soft tissue thickness. In conclusion, we think that BMI has a negative effect on auditory function according to findings in our study.

scholarly journals Biomarkers of environmental manganese exposure and associations with childhood neurodevelopment: a systematic review and meta-analysis

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Weiwei Liu ◽  
Yongjuan Xin ◽  
Qianwen Li ◽  
Yanna Shang ◽  
Zhiguang Ping ◽  
...  
Keyword(s):  
Sex Differences ◽  
Motor Skills ◽  
Meta Analysis ◽  
Fold Increase ◽  
Behavioral Performance ◽  
Cross Sectional ◽  
Manganese Exposure ◽  
Negative Effect ◽  
The Mean ◽  
Cross Sectional Studies

Abstract Background Although prior studies showed a correlation between environmental manganese (Mn) exposure and neurodevelopmental disorders in children, the results have been inconclusive. There has yet been no consistent biomarker of environmental Mn exposure. Here, we summarized studies that investigated associations between manganese in biomarkers and childhood neurodevelopment and suggest a reliable biomarker. Methods We searched PubMed and Web of Science for potentially relevant articles published until December 31th 2019 in English. We also conducted a meta-analysis to quantify the effects of manganese exposure on Intelligence Quotient (IQ) and the correlations of manganese in different indicators. Results Of 1754 citations identified, 55 studies with 13,388 subjects were included. Evidence from cohort studies found that higher manganese exposure had a negative effect on neurodevelopment, mostly influencing cognitive and motor skills in children under 6 years of age, as indicated by various metrics. Results from cross-sectional studies revealed that elevated Mn in hair (H-Mn) and drinking water (W-Mn), but not blood (B-Mn) or teeth (T-Mn), were associated with poorer cognitive and behavioral performance in children aged 6–18 years old. Of these cross-sectional studies, most papers reported that the mean of H-Mn was more than 0.55 μg/g. The meta-analysis concerning H-Mn suggested that a 10-fold increase in hair manganese was associated with a decrease of 2.51 points (95% confidence interval (CI), − 4.58, − 0.45) in Full Scale IQ, while the meta-analysis of B-Mn and W-Mn generated no such significant effects. The pooled correlation analysis revealed that H-Mn showed a more consistent correlation with W-Mn than B-Mn. Results regarding sex differences of manganese associations were inconsistent, although the preliminary meta-analysis found that higher W-Mn was associated with better Performance IQ only in boys, at a relatively low water manganese concentrations (most below 50 μg/L). Conclusions Higher manganese exposure is adversely associated with childhood neurodevelopment. Hair is the most reliable indicator of manganese exposure for children at 6–18 years of age. Analysis of the publications demonstrated sex differences in neurodevelopment upon manganese exposure, although a clear pattern has not yet been elucidated for this facet of our study.

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