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Sample records for audiometry evoked response

  1. BRAIN STEM EVOKED RESPONSE AUDIOMETRY A REVIEW

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    Balasubramanian Thiagarajan

    2015-01-01

    Full Text Available Brain stem evoked response audiometry (BERA is a useful objective assessment of hearing. Major advantage of this procedure is its ability to test even infants in whom conventional audiometry may not be useful. This investigation can be used as a screening test for deafness in high risk infants. Early diagnosis and rehabilitation will reduce disability in these children. This article attempts to review the published literature on this subject.

  2. Auditory assessment of children with severe hearing loss using behavioural observation audiometry and brainstem evoked response audiometry

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    Rakhi Kumari; Priyanko Chakraborty; Jain, R K; Dhananjay Kumar

    2016-01-01

    Background: Early detection of hearing loss has been a long-standing priority in the field of audiology. Currently available auditory testing methods include both behavioural and non-behavioural or objective tests of hearing. This study was planned with an objective to assess hearing loss in children using behavioural observation audiometry and brain stem evoked response audiometry. Methods: A total of 105 cases suffering from severe to profound hearing loss were registered. After proper h...

  3. Prediction of hearing thresholds: Comparison of cortical evoked response audiometry and auditory steady state response audiometry techniques

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    Wong, LLN; Yeung, KNK

    2007-01-01

    The present study evaluated how well auditory steady state response (ASSR) and tone burst cortical evoked response audiometry (CERA) thresholds predict behavioral thresholds in the same participants. A total of 63 ears were evaluated. For ASSR testing, 100% amplitude modulated and 10% frequency modulated tone stimuli at a modulation frequency of 40Hz were used. Behavioral thresholds were closer to CERA thresholds than ASSR thresholds. ASSR and CERA thresholds were closer to behavioral thresho...

  4. Accuracy of Cortical Evoked Response Audiometry in estimating normal hearing thresholds

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    Mahdavi M E; Peyvandi A A

    2007-01-01

    Background: Cortical Evoked Response Audiometry (CERA) refers to prediction of behavioral pure-tone thresholds (500-4000 Hz) obtained by recording the N1-P2 complex of auditory long latency responses. CERA is the preferred method for frequency–specific estimation of audiogram in conscious adults and older children. CERA has an increased accuracy of determination of the hearing thresholds of alert patients with elevated hearing thresholds with sensory hearing loss; however few publications rep...

  5. STANDARDIZNG OF BRAINSTEM EVOKED RESPONSE AUDIOMETRY VALUES PRELIMINARY TO STARTING BERA LAB IN A HOSPITAL

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    Sivaprasad

    2014-07-01

    Full Text Available INTRODUCTION: The subjective assessment of hearing is primarily done by pure tone audiometry. It is commonly undertaken test which can tell us the hearing acuity of a person when carried under ideal conditions. However, not infrequently the otologists encounter a difficulty to do subjective audiometry or in those circumstances where the test results are not correlating with the disease in question. Hence they have to depend upon the objective tests to get a workable knowledge about the patients hearing threshold. Of the various objective tests available the most popular are Brain stem evoked response audiometry –non-invasive and more standardized parameter, Electro-cochleography, auditory steady state response. Otoacoustic Emission test (OAE Otoacoustic emission doesn’t measure the hearing acuity, it gives us an idea whether there is any deafness or not. But BERA is useful in detecting and quantification of deafness in the difficult-to-test patients like infants, mentally retarded people, malingers, deeply sedated and anaesthetized patients. It determines objectively the nature of deafness (i.e., whether sensory or neural in difficult-to-test patients. It helps to locate the site of lesion in retro-cochlear pathologies (in an area from spiral ganglion of the cochlear nerve to midbrain (inferior colliculus. Study of central auditory disorders is possible. Study of maturity of central nervous system in newborns, objective identification of brain death, assessing prognosis in comatose patients are other uses. Before starting a BERA lab in a hospital it is mandatory to standardize the normal values in a randomly selected group of persons with certain criteria like; normal ears with intact T.M and without any complaints of loss of hearing. Persons aged between 05 to 60 years are taken for this study. The study group included both males and females. The aim of this study is to assess the hearing pathway in normal hearing individuals and compare

  6. Accuracy of Cortical Evoked Response Audiometry in estimating normal hearing thresholds

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    Mahdavi M E

    2007-07-01

    Full Text Available Background: Cortical Evoked Response Audiometry (CERA refers to prediction of behavioral pure-tone thresholds (500-4000 Hz obtained by recording the N1-P2 complex of auditory long latency responses. CERA is the preferred method for frequency–specific estimation of audiogram in conscious adults and older children. CERA has an increased accuracy of determination of the hearing thresholds of alert patients with elevated hearing thresholds with sensory hearing loss; however few publications report studies regarding the use of CERA for estimating normal hearing thresholds. The purpose of this research was to further study the accuracy of CERA in predicting hearing thresholds when there is no hearing loss. Methods: Behavioral hearing thresholds of 40 alert normal hearing young adult male (40 ears screened at 20 dB HL in 500-8000Hz, predicted by recording N1-P2 complex of auditory evoked long latency responses to 10-30-10 ms tone bursts. After CERA, pure tone audiometry performed by other audiologist. All judgments about presence of responses performed visually. Stimulus rate variation and temporary interruption of stimulus presentation was used for preventing amplitude reduction of the responses. 200-250 responses were averaged near threshold. Results: In 95% of the hearing threshold predictions, N1-P2 thresholds were within 0-15 dB SL of true hearing thresholds. In the other 5%, the difference between the CERA threshold and true hearing threshold was 20-25 dB. The mean threshold obtained for tone bursts of 0.5, 1, 2 and 4 kHz were 12.6 ± 4.5, 10.9 ± 5.8, 10.8 ± 6.5 and 11.2 ± 4.1 dB, respectively, above the mean behavioral hearing thresholds for air-conducted pure tone stimuli. Conclusion: On average, CERA has a relatively high accuracy for the prediction of normal hearing sensitivity, comparable to that of previous studies performed on CERA in hearing-impaired populations.

  7. A study of brainstem evoked response audiometry in high-risk infants and children under 10 years of age

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    Ramanathan Thirunavukarasu

    2015-01-01

    Full Text Available Aims: To evaluate the hearing threshold and find the incidence of hearing loss in infants and children belonging to high-risk category and analyze the common risk factors. Subjects and Methods: Totally, 125 infants and children belonging to high-risk category were subjected to brainstem evoked response audiometry. Clicks were given at the rate of 11.1 clicks/s. Totally, 2000 responses were averaged. The intensity at which wave V just disappears was established as hearing the threshold. Degree of impairment and risk factors were analyzed. Results: Totally, 44 (35.2% were found to have sensorineural hearing loss. Totally, 30 children with hearing loss (68% belonged to age group 1-5 years. Consanguineous marriage was the most commonly associated risk factor. Majority (34 had profound hearing loss. Conclusion: Newborn screening is mandatory to identify hearing loss in the prelinguistic period to reduce the burden of handicap in the community. The need of the hour is health education and genetic counseling to decrease the hereditary hearing loss, as hearing impairment due to perinatal factors has reduced due to recent medical advancements.

  8. Audiometria de resposta evocada de acordo com sexo e idade: achados e aplicabilidade Evoked response audiometry according to gender and age: findings and usefulness

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    Edmir Américo Lourenço

    2008-08-01

    Full Text Available A audiometria de respostas evocadas (ABR é um registro não-invasivo de potenciais elétricos auditivos nos primeiros 12 milissegundos, da orelha média ao córtex auditivo. ABR é importante na avaliação otoneurológica. OBJETIVO: Esclarecer as utilidades do exame, faixas etárias e sexo com maior incidência e topodiagnóstico segundo as latências absolutas e os intervalos interpicos. CASUÍSTICA E MÉTODO: Neste estudo retrospectivo foram analisados 403 prontuários de ABR realizados em clínica particular na cidade de Jundiaí/SP, Brasil, suspeitos de alteração auditiva e/ou doença do SNC, com os pacientes divididos por sexo e faixa etária. RESULTADOS E CONCLUSÕES: ABR é um importante exame para determinar a integridade da via auditiva, limiares eletrofisiológicos e topodiagnóstico, embora o teste não indique a etiologia das alterações. Foi demonstrado que ocorreu maior incidência de achados retrococleares na faixa etária de 12-20 anos e sexo masculino, contudo crianças menores de um ano com fatores de risco não apresentaram um aumento na incidência de alterações condutivas, cocleares e retrococleares em relação à população geral estudada. As latências absolutas das ondas I, III e V foram maiores no sexo masculino e as alterações dos intervalos interpicos foram similares em ambos os sexos, sendo que o intervalo I-III foi o mais freqüentemente alterado.Auditory evoked brainstem responses (ABR is a non-invasive electrical potential registration which evaluates the auditory tract from the middle ear to the auditory cortex in the first 12 milliseconds (ms. The ABR is an important otoneurological evaluation. AIM: confirm the test's usefulness, major incidence and topography according to are range gender considering the absolute latencies of the waves and interpeak intervals. MATERIALS AND METHOD: we retrospectively analyzed 403 tests from a private clinic in the city of Jundiaí-São Paulo State-Brazil, from

  9. Objective Audiometry using Ear-EEG

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Kidmose, Preben

    . Recently, a novel EEG-method called ear-EEG that enable recording of auditory evoked potentials from a personalized earpiece was introduced. Since ear-EEG provides a discrete and non-invasive way of measuring neural signals and can be integrated into hearing aids, it has great potential for use in everyday...... life. Ear-EEG may therefore be an enabling technology for objective audiometry out of the clinic, allowing regularly fitting of the hearing aids to be made by the users in their everyday life environment. In this study we investigate the application of ear-EEG in objective audiometry....

  10. Objective Audiometry using Ear-EEG

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Kidmose, Preben

    Recently, a novel electroencephalographic (EEG) method called ear-EEG [1], that enable recording of auditory evoked potentials (AEPs) from a personalized earpiece was introduced. Initial investigations show that well established AEPs, such as ASSR and P1-N1-P2 complex can be observed from ear-EEG...... recordings [2, 3], implying a possible application for ear-EEG in audiometric characterization of hearing loss. Since the Ear-EEG method provides a discrete and non-invasive way of measuring neural signals and can be integrated into hearing aids, it has great potential for use in everyday life. Ear-EEG may...... therefore be an enabling technology for objective audiometry out of the clinic, allowing regularly fitting of the hearing aids to be made by the users in their everyday life environment. The objective of this study is to investigate the application of ear-EEG in objective audiometry....

  11. Early changes of auditory brain stem evoked response after radiotherapy for nasopharyngeal carcinoma - a prospective study

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    Lau, S.K.; Wei, W.I.; Sham, J.S.T.; Choy, D.T.K.; Hui, Y. (Queen Mary Hospital, Hong Kong (Hong Kong))

    1992-10-01

    A prospective study of the effect of radiotherapy for nasopharyngeal carcinoma on hearing was carried out on 49 patients who had pure tone, impedance audiometry and auditory brain stem evoked response (ABR) recordings before, immediately, three, six and 12 months after radiotherapy. Fourteen patients complained of intermittent tinnitus after radiotherapy. We found that 11 initially normal ears of nine patients developed a middle ear effusion, three to six months after radiotherapy. There was mixed sensorineural and conductive hearing impairment after radiotherapy. Persistent impairment of ABR was detected immediately after completion of radiotherapy. The waves I-III and I-V interpeak latency intervals were significantly prolonged one year after radiotherapy. The study shows that radiotherapy for nasopharyngeal carcinoma impairs hearing by acting on the middle ear, the cochlea and the brain stem auditory pathway. (Author).

  12. Somatosensory evoked response: application in neurology

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    Carlos A. M. Guerreiro

    1982-03-01

    Full Text Available One technique used for short-latency somatosensory evoked response (SER is described. SER following nerve stimulation is a unique non-invasive, clinical test used to evaluate the somatosensory pathways. It tests the physiological function of the median nerve, the brachial plexus, the C6-7 cervical roots, cervical spinal cord, the cuneate nuclei, the medial lemniscus, the thalamus, and the contralateral sensory cortex. It has been shown to be a reliable and useful clinical test partiicularly in multiple sclerosis and comatose patients. The promising technique of SER following peroneal nerve stimulation is mentioned.

  13. Speech Evoked Auditory Brainstem Response in Stuttering

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    Ali Akbar Tahaei

    2014-01-01

    Full Text Available Auditory processing deficits have been hypothesized as an underlying mechanism for stuttering. Previous studies have demonstrated abnormal responses in subjects with persistent developmental stuttering (PDS at the higher level of the central auditory system using speech stimuli. Recently, the potential usefulness of speech evoked auditory brainstem responses in central auditory processing disorders has been emphasized. The current study used the speech evoked ABR to investigate the hypothesis that subjects with PDS have specific auditory perceptual dysfunction. Objectives. To determine whether brainstem responses to speech stimuli differ between PDS subjects and normal fluent speakers. Methods. Twenty-five subjects with PDS participated in this study. The speech-ABRs were elicited by the 5-formant synthesized syllable/da/, with duration of 40 ms. Results. There were significant group differences for the onset and offset transient peaks. Subjects with PDS had longer latencies for the onset and offset peaks relative to the control group. Conclusions. Subjects with PDS showed a deficient neural timing in the early stages of the auditory pathway consistent with temporal processing deficits and their abnormal timing may underlie to their disfluency.

  14. A user-operated audiometry method based on the maximum likelihood principle and the two-alternative forced-choice paradigm

    DEFF Research Database (Denmark)

    Schmidt, Jesper Hvass; Brandt, Christian; Pedersen, Ellen Raben;

    2014-01-01

    Objective: To create a user-operated pure-tone audiometry method based on the method of maximum likelihood (MML) and the two-alternative forced-choice (2AFC) paradigm with high test-retest reliability without the need of an external operator and with minimal influence of subjects' fluctuating...... response criteria. User-operated audiometry was developed as an alternative to traditional audiometry for research purposes among musicians. Design: Test-retest reliability of the user-operated audiometry system was evaluated and the user-operated audiometry system was compared with traditional audiometry....... Study sample: Test-retest reliability of user-operated 2AFC audiometry was tested with 38 naïve listeners. User-operated 2AFC audiometry was compared to traditional audiometry in 41 subjects. Results: The repeatability of user-operated 2AFC audiometry was comparable to traditional audiometry with...

  15. [Cortical responses evoked by vibrotactile sensations in deaf children].

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    Quaranta, A; Cipriani, D; Mininni, F

    1980-05-30

    Vibrotactile evoked responses (VER) to 250 and 500 Hz presented respectively at 50 and 70 dB HL by BC vibrator placed on right thumb, were recorded in 20 children (10 with pathological EEG) with severe sensorineural hearing loss, or deaf since birth, both to control accuracy of cortical responses to high intensity auditory stimuli and to diagnose central non auditory pathways lesions. The results have shown that: VER are present in subjects with severe sensorineural hearing loss or deaf; in children with auditory lesions VER have parameters different from auditory evoked response (AER); VER recording is not related both to the presence of auditory lesions and to neurological pathology. PMID:7448007

  16. Conditioning effect of transcranial magnetic stimulation evoking motor‐evoked potential on V‐wave response

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    Grosprêtre, Sidney; Martin, Alain

    2014-01-01

    Abstract The aim of this study was to examine the collision responsible for the volitional V‐wave evoked by supramaximal electrical stimulation of the motor nerve during voluntary contraction. V‐wave was conditioned by transcranial magnetic stimulation (TMS) over the motor cortex at several inter‐stimuli intervals (ISI) during weak voluntary plantar flexions (n = 10) and at rest for flexor carpi radialis muscle (FCR; n = 6). Conditioning stimulations were induced by TMS with intensity eliciti...

  17. Auditory Brainstem Evoked Responses in Newborns with Down Syndrome

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    Kittler, Phyllis M.; Phan, Ha T. T.; Gardner, Judith M.; Miroshnichenko, Inna; Gordon, Anne; Karmel, Bernard Z.

    2009-01-01

    Auditory brainstem evoked responses (ABRs) were compared in 15 newborns with Down syndrome and 15 sex-, age-, and weight-matched control newborns. Participants had normal ABRs based upon values specific to 32- to 42-weeks postconceptional age. Although Wave III and Wave V component latencies and the Wave I-III interpeak latency (IPL) were shorter…

  18. Audiometry

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    ... The following conditions may affect test results: Acoustic neuroma Acoustic trauma Age-related hearing loss Alport syndrome ... Mosby Elsevier; 2010:chap 190. Read More Acoustic neuroma Acoustic trauma Age-related hearing loss Alport syndrome ...

  19. Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.

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    Sperdin, Holger F; Spierer, Lucas; Becker, Robert; Michel, Christoph M; Landis, Theodor

    2015-04-01

    Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. PMID:25487054

  20. Application of auditory brainstem response and pure tone audiometry in early diagnosis of acoustic neuroma%听性脑干反应和纯音听阈在听神经瘤早期诊断中的应用

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    赵赋; 武丽; 王博; 杨智君; 王振民; 王兴朝; 李朋; 张晶; 刘丕楠

    2015-01-01

    目的 探讨采用听性脑干反应和纯音听阈对早期诊断听神经瘤的临床应用价值.方法 回顾性分析了111例听神经瘤患者的临床资料、纯音听阈、听性脑干反应及增强磁共振结果,采用线性回归分析纯音听阈均值与肿瘤体积、病程是否存在相关性,采用卡方检验分析不同肿瘤体积在听性脑干反应异常发生率上是否存在差异.结果 听神经瘤引起感音神经性耳聋,纯音听阈均值与病程存在显著地相关性(P=0.000);听性脑干反应诊断听神经瘤的敏感度和特异度分别为98.2%和93.6%,肿瘤最大径>3 cm与≤3 cm两组,在患侧和对侧Ⅲ~Ⅳ波间期异常发生率上,差异均具有统计学意义(P值分别为0.038和0.045).结论 听性脑干反应联合纯音测听是早期诊断听神经瘤的有效方法.%Objective To investigate the clinical application value of using auditory brainstem response and pure tone audiometry for early diagnosis of acoustic neuroma.Methods The clinical data,the results of pure tone audiometry,auditory brainstem response,and enhanced MRI in 111 patients with acoustic neuroma were analyzed retrospectively.Linear regression analysis was used to analyze the correlation between the nean value of pure tone audiometry and the neuroma volune or course of disease.Chi-squared test was used to analyze the whether there were differences in the different neuroma volumes on the incidence of abnormal auditory brainstem response.Results Acoustic neuroma caused sensorineural deafness.There was a significant correlation between the mean value of pure tone audiometry and the course of disease (P =0.000).The sensitivity and specificity of auditory brainstem response for the diagnosis of acoustic neuroma were 98.2% and 93.6% respectively.The maximum diameters of neuromas were divided into 2 groups:> 3 cm or ≤3 cm.There were significant differences on the abnormal incidence of the Ⅲ to Ⅴ wave intervals of the

  1. Estimating loudness growth from tone-burst evoked responses

    OpenAIRE

    Silva, Ikaro; Epstein, Michael

    2010-01-01

    Several studies have investigated the relationship between click-evoked auditory brainstem responses (ABRs) and loudness growth in human listeners. While some of these studies have reported promising results, showing a correlative relationship between click ABR and loudness growth as a function of level, additional studies are necessary to determine if similar results can be obtained with frequency-specific stimuli and more specific details of the loudness function can be derived from ABR rec...

  2. The Effect of Threat on Novelty Evoked Amygdala Responses

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    Balderston, Nicholas L.; Schultz, Doug H.; Helmstetter, Fred J.

    2013-01-01

    A number of recent papers have suggested that the amygdala plays a role in the brain’s novelty detection circuit. In a recent study, we showed that this role may be specific to certain classes of biologically-relevant stimuli, such as human faces. The purpose of the present experiment was to determine whether other biologically-relevant stimuli also evoke novelty specific amygdala responses. To test this idea, we presented novel and repeated images of snakes and flowers while measuring BOLD. ...

  3. Auditory Evoked Potential Response and Hearing Loss: A Review

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    Paulraj, M. P; Subramaniam, Kamalraj; Yaccob, Sazali Bin; Adom, Abdul H. Bin; Hema, C.R.

    2015-01-01

    Hypoacusis is the most prevalent sensory disability in the world and consequently, it can lead to impede speech in human beings. One best approach to tackle this issue is to conduct early and effective hearing screening test using Electroencephalogram (EEG). EEG based hearing threshold level determination is most suitable for persons who lack verbal communication and behavioral response to sound stimulation. Auditory evoked potential (AEP) is a type of EEG signal emanated from the brain scalp...

  4. An evoked indirect response in the cervical vagal nerve

    OpenAIRE

    Ordelman, S.C.M.A.; Kornet, L.; Cornelussen, R.; Buschman, H.P.J.; Veltink, P.H.

    2009-01-01

    The response of fibers in the vagal nerve, evoked by electrical stimulation, has been studied in both animals and humans. These compound action potentials (CAPs) consist of components coming from thick, myelinated fibers to thin, unmyelinated fibers. In our study, the possibility is addressed of an indirect component in the CAP which is involved in reflexive control. By using multiple, consecutive electrode sites along the cervical vagal nerve, both the direction and the velocity along the ne...

  5. Brain stem auditory evoked responses in human infants and adults

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    Hecox, K.; Galambos, R.

    1974-01-01

    Brain stem evoked potentials were recorded by conventional scalp electrodes in infants (3 weeks to 3 years of age) and adults. The latency of one of the major response components (wave V) is shown to be a function both of click intensity and the age of the subject; this latency at a given signal strength shortens postnatally to reach the adult value (about 6 msec) by 12 to 18 months of age. The demonstrated reliability and limited variability of these brain stem electrophysiological responses provide the basis for an optimistic estimate of their usefulness as an objective method for assessing hearing in infants and adults.

  6. Suicide attempts, platelet monoamine oxidase and the average evoked response

    International Nuclear Information System (INIS)

    The relationship between suicides and suicide attempts and two biological measures, platelet monoamine oxidase levels (MAO) and average evoked response (AER) augmenting was examined in 79 off-medication psychiatric patients and in 68 college student volunteers chosen from the upper and lower deciles of MAO activity levels. In the patient sample, male individuals with low MAO and AER augmenting, a pattern previously associated with bipolar affective disorders, showed a significantly increased incidence of suicide attempts in comparison with either non-augmenting low MAO or high MAO patients. Within the normal volunteer group, all male low MAO probands with a family history of suicide or suicide attempts were AER augmenters themselves. Four completed suicides were found among relatives of low MAO probands whereas no high MAO proband had a relative who committed suicide. These findings suggest that the combination of low platelet MAO activity and AER augmenting may be associated with a possible genetic vulnerability to psychiatric disorders. (author)

  7. Habituation of visual evoked responses in neonates and fetuses: A MEG study

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    Matuz, Tamara; Govindan, Rathinaswamy B.; Preissl, Hubert; Siegel, Eric R; Muenssinger, Jana; Murphy, Pamela; Ware, Maureen; Curtis L Lowery; Eswaran, Hari

    2012-01-01

    In this study we aimed to develop a habituation paradigm that allows the investigation of response decrement and response recovery and examine its applicability for measuring the habituation of the visually evoked responses (VERs) in neonatal and fetal magnetoencephalographic recordings.

  8. Dorsomedial hypothalamus mediates autonomic, neuroendocrine, and locomotor responses evoked from the medial preoptic area

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    Hunt, Joseph L.; Zaretsky, Dmitry V.; Sarkar, Sumit; DiMicco, Joseph A.

    2009-01-01

    Previous studies suggest that sympathetic responses evoked from the preoptic area in anesthetized rats require activation of neurons in the dorsomedial hypothalamus. Disinhibition of neurons in the dorsomedial hypothalamus in conscious rats produces physiological and behavioral changes resembling those evoked by microinjection of muscimol, a GABAA receptor agonist and neuronal inhibitor, into the medial preoptic area. We tested the hypothesis that all of these effects evoked from the medial p...

  9. Test person operated 2-Alternative Forced Choice Audiometry compared to traditional audiometry

    DEFF Research Database (Denmark)

    Schmidt, Jesper Hvass; Brandt, Christian; Christensen-Dalsgaard, Jakob;

      Background: With a newly developed technique, hearing thresholds can be estimated with a system operated by the test persons themselves. This technique is based on the 2 Alternative Forced Choice paradigm known from the psychoacoustic research theory. Test persons can operate the system very...... easily themselves. Furthermore the system uses the theories behind the methods of maximum-likelihood fitting of the most probable psychometric function and a modification of the well known up-down methods in the estimation of the hearing thresholds. The combination of the 2AFC paradigm and the maximum...... comparison with traditional audiometry. A series of 30 persons (60 ears) have conducted traditional audiometry as well as self-operated 2AFC-audiometry. Test subjects are normal as well as moderately hearing impaired people. The different thresholds are compared.   Results: 2 AFC Audiometry is reliable and...

  10. Sensitivity of cortical auditory evoked potential detection for hearing-impaired infants in response to short speech sounds

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    Bram Van Dun

    2012-01-01

    Full Text Available

    Background: Cortical auditory evoked potentials (CAEPs are an emerging tool for hearing aid fitting evaluation in young children who cannot provide reliable behavioral feedback. It is therefore useful to determine the relationship between the sensation level of speech sounds and the detection sensitivity of CAEPs.

    Design and methods: Twenty-five sensorineurally hearing impaired infants with an age range of 8 to 30 months were tested once, 18 aided and 7 unaided. First, behavioral thresholds of speech stimuli /m/, /g/, and /t/ were determined using visual reinforcement orientation audiometry (VROA. Afterwards, the same speech stimuli were presented at 55, 65, and 75 dB SPL, and CAEP recordings were made. An automatic statistical detection paradigm was used for CAEP detection.

    Results: For sensation levels above 0, 10, and 20 dB respectively, detection sensitivities were equal to 72 ± 10, 75 ± 10, and 78 ± 12%. In 79% of the cases, automatic detection p-values became smaller when the sensation level was increased by 10 dB.

    Conclusions: The results of this study suggest that the presence or absence of CAEPs can provide some indication of the audibility of a speech sound for infants with sensorineural hearing loss. The detection of a CAEP provides confidence, to a degree commensurate with the detection probability, that the infant is detecting that sound at the level presented. When testing infants where the audibility of speech sounds has not been established behaviorally, the lack of a cortical response indicates the possibility, but by no means a certainty, that the sensation level is 10 dB or less.

  11. Regularity increases middle latency evoked and late induced beta brain response following proprioceptive stimulation

    DEFF Research Database (Denmark)

    Arnfred, Sidse M.; Hansen, Lars Kai; Parnas, Josef;

    2008-01-01

    as an indication of increased readiness. This is achieved through detailed analysis of both evoked and induced responses in the time-frequency domain. Electroencephalography in a 64 channels montage was recorded in four-teen healthy subjects. Two paradigms were explored: A Regular alternation between hand......Focal attention increases the middle-latency amplitude of somatosensory evoked potentials. Previously this effect has been suggested to be due to increased readiness in somatosensory cortex. Presently, we examine whether regularity of stimulus occurrence increases the proprioceptive evoked response...

  12. A Comparison of Thresholds in Auditory Steady - State Response with Pure Tone Audiometry in Subjects with Normal Hearing and Those with Mild and Moderate Sensorineural Hearing los

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    Sadegh Jafarzadeh

    2008-06-01

    Full Text Available Background and Aim: Among all auditory assessment tools, auditory steady state response (ASSR is a modern test. Modulation frequency for this test is usually 80 Hz. The purpose of this study, was to examined adult subjects with 40 Hz and 80 Hz ASSR and compare the results.Materials and Methods: Thirty adult (60 ears were evaluated by ASSR and PTA test, Results were divided into three groups: normal hearing, mild and moderate sensorineural hearing loss. Results: In all groups, forty hertz ASSR thresholds were relatively closer to behavioral threshold than those of 80 Hz ASSR(p<0.05. Besides, the more severe hearing loss, the lower the difference between those two thresholds. Correlation coefficients were also higher in 40 Hz ASSR(p<0.05. Conclusion: Frequency modulation thresholds with 40 Hz are more likely to be closer to the behavioral thresholds. Moreover, it has better results than the thresholds with 80 Hz.

  13. Electrically evoked auditory nerve responses in the cochlea with normal outer hair cells

    OpenAIRE

    Ren, Tianying; Guo, Menghe; He, Wenxuan; Miller, Josef M.; Nuttall, Alfred L.

    2009-01-01

    As hybrid cochlear implant devices are increasingly used for restoring hearing in patients with residual hearing it is important to understand electrically evoked responses in cochleae having functional hair cells. To test the hypothesis that extracochlear electrical stimulation (EES) from sinusoidal current can provoke an auditory nerve response with normal frequency selectivity, the EES-evoked compound action potential (ECAP) was investigated in this study. Brief sinusoidal electrical curre...

  14. Brainstem reflexes and brainstem auditory evoked responses in Huntington's chorea.

    OpenAIRE

    Bollen, E; Arts, R.J.; Roos, R A; van der Velde, E A; Buruma, O J

    1986-01-01

    Blink reflex, corneal reflex, jaw reflex, exteroceptive suppression in masseter muscles and brainstem auditory evoked potentials were measured in 20 patients with Huntington's chorea and 12 controls. A significantly increased latency of the second component of the homolateral and heterolateral blink reflex was found in the patient group as compared with the controls. The other investigations revealed no significant differences between patients and controls except for some facilitation of the ...

  15. Auditory steady-state evoked response in diagnosing and evaluating hearing in infants

    Institute of Scientific and Technical Information of China (English)

    Fei Mai; Xiaozhuang Zhang; Qunxin Lai; Yanfei Wu; Nanping Liao; Yi Ye; Zhenghui Zhong

    2006-01-01

    BACKGROUND: Auditory steady-state evoked response (ASSR) is one of the new objective electrophysiological methods to test hearing in infants. It can provide a reliable and complete audiogram with specific frequency to help the hearing diagnosis and rehabilitation of hearing and languaging following auditory screening.OBJECTIVE: To compare the response threshold of ASSR with auditory threshold of visual reinforcement audiometry (VRA) in infants failed in the hearing screening for investigating their hearing loss.DESIGN: A comparative observation.SETTINGS: Maternal and child health care hospitals of Guangdong province, Shunde city, Nanhai city and Huadu district.PARTICIPANTS: Totally 321 infants of 0-3 years undergoing ASSR test were selected from the Hearing Center of Guangdong Maternal and Child Health Care Hospital from January 2002 to December 2004.Informed consents were obtained from their guardians. There were 193 cases (60.2%) of 0-6 months, 31 cases (9.7%) of 7-12 months, 17 cases (5.3%) of 13-18 months, 14 cases (4.4%) of 19-24 months, 33 cases of 25-30 months, and 33 cases (10.2%) of 31-36 months.METHODS: ① The 321 infants failed in the hearing screening were tested under sleeping status, the ranges of response threshold distribution in ASSR of different frequencies were analyzed in each age group. ② The infants above 2 years old were also tested with VRA, and their response thresholds were compared between VRA and ASSR. ③ Evaluative standards: The response threshold was < 30 dB for normal hearing, 31-50 dB for mild hearing loss, 51-70 dB for moderate hearing loss, 71-90 dB for severe hearing loss, and > 91 dB for extremely severe hearing loss.MAIN OUTCOME MEASURES: ① ASSR results of the infants failed in the screening; ② Proportion of cases of each response threshold in each age group; ③ Comparison of ASSR response thresholds and VRA auditory thresholds in the infants of 2-3 years old.RESULTS: ①The response threshold was < 30 dB in 47

  16. Response level of the transient-evoked otoacoustic emissions on infants having a gastroesophageal reflux

    OpenAIRE

    Camboim, Elizângela Dias; Scharlach, Renata Coelho; Farias, Kelvânio Vitório de; Oliveira, Lívia Karla Gadêlha de; Vasconcelos, Dênis; de Azevedo, Marisa Frasson

    2011-01-01

    Introduction: The transient-evoked otoacoustic emissions (TEOAE) have been the most widespread technique to perform neonatal hearing screening. Scrutinizing their measures by way of an association with other alterations that may impair the infant's auditory system is important. Objective: Analyze the incidence and the response levels of the transient-evoked otoacoustic emissions on infants having a physiological gastroesophageal reflux disease (GERD). Method: A prospective study was performed...

  17. Altered Evoked Gamma-Band Responses Reveal Impaired Early Visual Processing in ADHD Children

    Science.gov (United States)

    Lenz, Daniel; Krauel, Kerstin; Flechtner, Hans-Henning; Schadow, Jeanette; Hinrichs, Hermann; Herrmann, Christoph S.

    2010-01-01

    Neurophysiological studies yield contrary results whether attentional problems of patients with attention-deficit/hyperactivity disorder (ADHD) are related to early visual processing deficits or not. Evoked gamma-band responses (GBRs), being among the first cortical responses occurring as early as 90 ms after visual stimulation in human EEG, have…

  18. Evoked and Induced EEG Responses in a Visual Oddball Task (SEEG Study)

    Czech Academy of Sciences Publication Activity Database

    Roman, R.; Brázdil, M.; Chládek, Jan; Jurák, Pavel; Rektor, I.; Kukleta, M.

    2008-01-01

    Roč. 50, č. 3 (2008), s. 81-82. ISSN 0001-7604. [International CIANS Conference 2008: Higher Brain Functions. 28.09.2008-02.10.2008, Smolenice] Institutional research plan: CEZ:AV0Z20650511 Keywords : EEG * visual odball * evoked response * induced response Subject RIV: FH - Neurology

  19. Visual and noxious electrical stimulus-evoked membrane-potential responses in anterior cingulate cortical neurons.

    Science.gov (United States)

    Ma, Li-Qing; Ning, Li; Wang, Zhiru; Wang, Ying-Wei

    2016-01-01

    Anterior cingulate cortex (ACC) is known to participate in numerous brain functions, such as memory storage, emotion, attention, as well as perception of acute and chronic pain. ACC-dependent brain functions often rely on ACC processing of various forms of environmental information. To understand the neural basis of ACC functions, previous studies have investigated ACC responses to environmental stimulation, particularly complex sensory stimuli as well as award and aversive stimuli, but this issue remains to be further clarified. Here, by performing whole-cell recording in vivo in anaesthetized adult rats, we examined membrane-potential (MP) responses of layer II/III ACC neurons that were evoked by a brief flash of visual stimulation and pain-related electrical stimulation delivered to hind paws. We found that ~54 and ~81 % ACC neurons exhibited excitatory MP responses, subthreshold or suprathreshold, to the visual stimulus and the electrical stimulus, respectively, with no cell showing inhibitory MP responses. We further found that the visually evoked ACC response could be greatly diminished by local lidocaine infusion in the visual thalamus, and only their temporal patterns but not amplitudes could be changed by large-scale visual cortical lesions. Our in vivo whole-cell recording data characterized in ACC neurons a visually evoked response, which was largely dependent on the visual thalamus but not visual cortex, as well as a noxious electrical stimulus-evoked response. These findings may provide potential mechanisms that are used for ACC functions on the basis of sensory information processing. PMID:27585569

  20. Improving spatial and temporal resolution in evoked EEG responses using surface Laplacians.

    Science.gov (United States)

    Law, S K; Rohrbaugh, J W; Adams, C M; Eckardt, M J

    1993-01-01

    Spline generated surface Laplacian temporal wave forms are presented as a method to improve both spatial and temporal resolution of evoked EEG responses. Middle latency and the N1 components of the auditory evoked response were used to compare potential-based methods with surface Laplacian methods in the time domain. Results indicate that surface Laplacians provide better estimates of underlying cortical activity than do potential wave forms. Spatial discrimination among electrode sites was markedly better with surface Laplacian than with potential wave forms. Differences in the number and latencies of peaks, and their topographic distributions, were observed for surface Laplacian, particularly during the time period encompassing the middle latency responses. Focal activities were observed in surface Laplacian wave forms and topographic maps which were in agreement with previous findings from auditory evoked response studies. Methodological issues surrounding the application of spline methods to the time domain are also discussed. Surface Laplacian methods in the time domain appear to provide an improved way for studying evoked EEG responses by increasing temporal and spatial resolution of component characteristics. PMID:7688286

  1. Brainstem auditory evoked responses and ophthalmic findings in llamas and alpacas in eastern Canada

    OpenAIRE

    Webb, Aubrey A.; Cullen, Cheryl L.; Lamont, Leigh A.

    2006-01-01

    Seventeen llamas and 23 alpacas of various coat and iris colors were evaluated for: 1) deafness by using brainstem auditory evoked response testing; and 2) for ocular abnormalities via complete ophthalmic examination. No animals were deaf. The most common ocular abnormalities noted were iris-to-iris persistent pupillary membranes and incipient cataracts.

  2. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered

    OpenAIRE

    Jean-Philippe Pialasse; Martin Descarreaux; Pierre Mercier; Jean Blouin; Martin Simoneau

    2015-01-01

    Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed an...

  3. Long-term moderate exercise accelerates the recovery of stress-evoked cardiovascular responses.

    Science.gov (United States)

    Hsu, Yuan-Chang; Tsai, Sheng-Feng; Yu, Lung; Chuang, Jih-Ing; Wu, Fong-Sen; Jen, Chauying J; Kuo, Yu-Min

    2016-01-01

    Psychological stress is an important global health problem. It is well documented that stress increases the incidences of various cardiovascular disorders. Regular exercise is known to reduce resting blood pressure (BP) and heart rate (HR). This study was designed to clarify the effects of long-term exercise on stress-evoked cardiovascular responses and to emphasize post-stress recovery effects. Male Wistar rats underwent 8 weeks of moderate treadmill training, with cardiovascular responses, autonomic nervous system activities and local Fos reactivity changes in the cardiovascular regulation center were monitored before, during and after immobilization stress. A spectral analysis of cardiovascular parameters was used to examine autonomic nervous activities. We found that long-term exercise (i) lowered resting BP, HR and sympathetic activity, but increased resting parasympathetic activity and baroreflex sensitivity (BRS); (ii) accelerated post-stress recovery of stress-evoked cardiovascular and sympathetic responses along with increased BRS and (iii) accelerated post-stress recovery of stress-evoked neuron activations in the paraventricular nucleus, but delayed it in the nucleus of the tractus solitarius. We conclude that, in rats, long-term exercise accelerated recovery of stress-evoked cardiovascular responses differentially altering hypothalamic and medullar neuron activities. PMID:26473638

  4. Improved Electrically Evoked Auditory Steady-State Response Thresholds in Humans

    OpenAIRE

    Hofmann, Michael; Wouters, Jan

    2012-01-01

    Electrically evoked auditory steady-state responses (EASSRs) are EEG potentials in response to periodic electrical stimuli presented through a cochlear implant. For low-rate pulse trains in the 40-Hz range, electrophysiological thresholds derived from response amplitude growth functions correlate well with behavioral T levels at these rates. The aims of this study were: (1) to improve the correlation between electrophysiological thresholds and behavioral T levels at 900 pps by using amplitude...

  5. Temporal coupling between stimulus-evoked neural activity and hemodynamic responses from individual cortical columns

    International Nuclear Information System (INIS)

    Using previously published data from the whisker barrel cortex of anesthetized rodents (Berwick et al 2008 J. Neurophysiol. 99 787-98) we investigated whether highly spatially localized stimulus-evoked cortical hemodynamics responses displayed a linear time-invariant (LTI) relationship with neural activity. Presentation of stimuli to individual whiskers of 2 s and 16 s durations produced hemodynamics and neural activity spatially localized to individual cortical columns. Two-dimensional optical imaging spectroscopy (2D-OIS) measured hemoglobin responses, while multi-laminar electrophysiology recorded neural activity. Hemoglobin responses to 2 s stimuli were deconvolved with underlying evoked neural activity to estimate impulse response functions which were then convolved with neural activity evoked by 16 s stimuli to generate predictions of hemodynamic responses. An LTI system more adequately described the temporal neuro-hemodynamics coupling relationship for these spatially localized sensory stimuli than in previous studies that activated the entire whisker cortex. An inability to predict the magnitude of an initial 'peak' in the total and oxy- hemoglobin responses was alleviated when excluding responses influenced by overlying arterial components. However, this did not improve estimation of the hemodynamic responses return to baseline post-stimulus cessation.

  6. Modeling auditory evoked brainstem responses to transient stimuli

    DEFF Research Database (Denmark)

    Rønne, Filip Munch; Dau, Torsten; Harte, James;

    2012-01-01

    A quantitative model is presented that describes the formation of auditory brainstem responses (ABR) to tone pulses, clicks and rising chirps as a function of stimulation level. The model computes the convolution of the instantaneous discharge rates using the “humanized” nonlinear auditory-nerve ...

  7. Determining the direction of vestibular-evoked balance responses using stochastic vestibular stimulation

    OpenAIRE

    Mian, O. S.; Day, B. L.

    2009-01-01

    As a tool for investigating vestibulo-motor function, stochastic vestibular stimulation (SVS) has some advantages over galvanic vestibular stimulation. However, there is no technique currently available for extracting direction information from SVS-evoked motor responses. It is essential to be able to measure the direction of response if one wishes to investigate the operation of key spatial transformation processes in the brain. Here we describe and validate a technique for determining the d...

  8. Response level of the transient-evoked otoacoustic emissions on infants having a gastroesophageal reflux

    Directory of Open Access Journals (Sweden)

    Camboim, Elizângela Dias

    2011-07-01

    Full Text Available Introduction: The transient-evoked otoacoustic emissions (TEOAE have been the most widespread technique to perform neonatal hearing screening. Scrutinizing their measures by way of an association with other alterations that may impair the infant's auditory system is important. Objective: Analyze the incidence and the response levels of the transient-evoked otoacoustic emissions on infants having a physiological gastroesophageal reflux disease (GERD. Method: A prospective study was performed at Santa Juliana Hospital's Otorhinolaryngology Department. 118 prematurely-born and timely-born babies, from newly-born to 6 months old, who were sent by pediatricians and gastropediatricians, participated in the study and they were divided into two groups: Study Group: 63 infants clinically diagnosed of a physiological gastroesophageal reflux disease, and Control Group: 55 infants without a physiological gastroesophageal reflux. The peripheral hearing function was evaluated by both transient-evoked otoacoustic emissions and otoscopy examinations performed by an otorhinolaryngologist. Results: The average response levels of the transient-evoked otoacoustic emissions were higher in the non-reflux group for frequency bands of 2kHz, 2.5kHz, 3kHz, 3.5kHz and 4.5kHz bilaterally, with a statistically significant difference, achieving the average values of 7.71dB and 7dB in the right ear found in the frequency bands of 2 and 4kHz, respectively. Conclusion: There was a lower incidence and a lower response level of the transient-evoked otoacoustic emissions in physiological gastroesophageal reflux children in comparison with children having no reflux.

  9. Postural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response.

    Science.gov (United States)

    Osler, Callum J; Tersteeg, M C A; Reynolds, Raymond F; Loram, Ian D

    2013-10-01

    Circumstances may render the consequence of falling quite severe, thus maximising the motivation to control postural sway. This commonly occurs when exposed to height and may result from the interaction of many factors, including fear, arousal, sensory information and perception. Here, we examined human vestibular-evoked balance responses during exposure to a highly threatening postural context. Nine subjects stood with eyes closed on a narrow walkway elevated 3.85 m above ground level. This evoked an altered psycho-physiological state, demonstrated by a twofold increase in skin conductance. Balance responses were then evoked by galvanic vestibular stimulation. The sway response, which comprised a whole-body lean in the direction of the edge of the walkway, was significantly and substantially attenuated after ~800 ms. This demonstrates that a strong reason to modify the balance control strategy was created and subjects were highly motivated to minimise sway. Despite this, the initial response remained unchanged. This suggests little effect on the feedforward settings of the nervous system responsible for coupling pure vestibular input to functional motor output. The much stronger, later effect can be attributed to an integration of balance-relevant sensory feedback once the body was in motion. These results demonstrate that the feedforward and feedback components of a vestibular-evoked balance response are differently affected by postural threat. Although a fear of falling has previously been linked with instability and even falling itself, our findings suggest that this relationship is not attributable to changes in the feedforward vestibular control of balance. PMID:23952256

  10. The feeding responses evoked by cholecystokinin are mediated by vagus and splanchnic nerves.

    Science.gov (United States)

    Brown, Thelma A L; Washington, Martha C; Metcalf, Shannon A; Sayegh, Ayman I

    2011-08-01

    Total or selective branch vagotomy attenuates the reduction of cumulative food intake by cholecystokinin (CCK)-8 and CCK-33 respectively. However, the role of the sympathetic innervation of the gut and the role of the vagus nerve in feeding responses, which include meal size (MS) and intermeal interval (IMI), evoked by CCK-8 and CCK-33 have not been evaluated. Here, we tested the effects of total subdiaphragmatic vagotomy (VGX) and celiaco-mesenteric ganglionectomy (CMGX) on the previous feeding responses by CCK-8 and CCK-33 (0, 1, 3, and 5 nmol/kg given intraperitoneally). We found (1) that both peptides reduced meal size and CCK-8 (5 nmol) and CCK-33 (1 and 3 nmol) prolonged IMI, (2) that VGX attenuated the reduction of MS but failed to attenuate the prolongation of IMI by both peptides and (3) that CMGX attenuated the reduction of meal size by CCK-8 and the prolongation of IMI by both peptides. Therefore, the feeding responses evoked by CCK-8 require intact vagus and splanchnic nerves: the reduction of MS by CCK-33 requires an intact vagus nerve, and the prolongation of IMI requires the splanchnic nerve. These findings demonstrate the differential peripheral neuronal mediation of the feeding responses evoked by CCK-8 and CCK-33. PMID:21745513

  11. Separation of multiple evoked responses using differential amplitude and latency variability

    CERN Document Server

    Knuth, K H; Bressler, S L; Ding, M; Knuth, Kevin H.; Truccolo, Wilson A.; Bressler, Steven L.; Ding, Mingzhou

    2001-01-01

    In neuroelectrophysiology one records electric potentials or magnetic fields generated by ensembles of synchronously active neurons in response to externally presented stimuli. These evoked responses are often produced by multiple generators in the presence of ongoing background activity. While source localization techniques or current source density estimation are usually used to identify generators, application of blind source separation techniques to obtain independent components has become more popular. We approach this problem by applying the Bayesian methodology to a more physiologically-realistic source model. As it is generally accepted that single trials vary in amplitude and latency, we incorporate this variability into the model. Rather than making the unrealistic assumption that these cortical components are independent of one another, our algorithm utilizes the differential amplitude and latency variability of the evoked waveforms to identify the cortical components. The algorithm is applied to i...

  12. Behavioral and electrophysiological responses evoked by chronic infrared neural stimulation of the cochlea.

    Directory of Open Access Journals (Sweden)

    Agnella Izzo Matic

    Full Text Available Infrared neural stimulation (INS has been proposed as a novel method for neural stimulation. In order for INS to translate to clinical use, which would involve the use of implanted devices over years or decades, the efficacy and safety of chronic INS needs to be determined. We examined a population of cats that were chronically implanted with an optical fiber to stimulate the cochlea with infrared radiation, the first known chronic application of INS. Through behavioral responses, the cats demonstrate that stimulation occurs and a perceptual event results. Long-term stimulation did not result in a change in the electrophysiological responses, either optically-evoked or acoustically-evoked. Spiral ganglion neuron counts and post implantation tissue growth, which was localized at the optical fiber, were similar in chronically stimulated and sham implanted cochleae. Results from chronic INS experiments in the cat cochlea support future work toward INS-based neuroprostheses for humans.

  13. Maturational differences in thalamocortical white matter microstructure and auditory evoked response latencies in autism spectrum disorders

    OpenAIRE

    Roberts, Timothy P. L.; Lanza, Matthew R.; Dell, John; Qasmieh, Saba; Hines, Katherine; Blaskey, Lisa; Zarnow, Deborah M.; Levy, Susan E; Edgar, J. Christopher; Berman, Jeffrey I.

    2013-01-01

    White matter diffusion anisotropy in the acoustic radiations was characterized as a function of development in autistic and typically developing children. Auditory-evoked neuromagnetic fields were also recorded from the same individuals and the latency of the left and right middle latency superior temporal gyrus auditory ~50ms response (M50)1 was measured. Group differences in structural and functional auditory measures were examined, as were group differences in associations between white ma...

  14. An improved algorithm for model-based analysis of evoked skin conductance responses

    OpenAIRE

    Bach, D R; Friston, K.J.; Dolan, R. J.

    2013-01-01

    Model-based analysis of psychophysiological signals is more robust to noise - compared to standard approaches - and may furnish better predictors of psychological state, given a physiological signal. We have previously established the improved predictive validity of model-based analysis of evoked skin conductance responses to brief stimuli, relative to standard approaches. Here, we consider some technical aspects of the underlying generative model and demonstrate further improvements. Most im...

  15. Habituation of evoked responses is greater in patients with familial hemiplegic migraine than in controls

    DEFF Research Database (Denmark)

    Hansen, Jakob Møller; Bolla, M; Magis, D; de Pasqua, V; Ashina, M; Thomsen, L L; Olesen, J; Schoenen, J

    2011-01-01

    Familial hemiplegic migraine (FHM) is a rare, dominantly inherited subtype of migraine with transient hemiplegia during the aura phase. Mutations in at least three different genes can produce the FHM phenotype. The mutated FHM genes code for ion transport proteins that animal and cellular studies...... have associated with disturbed ion homeostasis, altered cellular excitability, neurotransmitter release, and decreased threshold for cortical spreading depression. The common forms of migraine are characterized interictally by a habituation deficit of cortical and subcortical evoked responses that has...

  16. Evaluation of Auditory Brain Stems Evoked Response in Newborns With Pathologic Hyperbilirubinemia in Mashhad, Iran

    OpenAIRE

    Okhravi, Tooba; Tarvij Eslami, Saeedeh; Hushyar Ahmadi, Ali; Nassirian, Hossain; Najibpour, Reza

    2015-01-01

    Background: Neonatal jaundice is a common cause of sensorneural hearing loss in children. Objectives: We aimed to detect the neurotoxic effects of pathologic hyperbilirubinemia on brain stem and auditory tract by auditory brain stem evoked response (ABR) which could predict early effects of hyperbilirubinemia. Patients and Methods: This case-control study was performed on newborns with pathologic hyperbilirubinemia. The inclusion criteria were healthy term and near term (35 - 37 weeks) newbor...

  17. Is the auditory evoked P2 response a biomarker of learning?

    Science.gov (United States)

    Tremblay, Kelly L; Ross, Bernhard; Inoue, Kayo; McClannahan, Katrina; Collet, Gregory

    2014-01-01

    Even though auditory training exercises for humans have been shown to improve certain perceptual skills of individuals with and without hearing loss, there is a lack of knowledge pertaining to which aspects of training are responsible for the perceptual gains, and which aspects of perception are changed. To better define how auditory training impacts brain and behavior, electroencephalography (EEG) and magnetoencephalography (MEG) have been used to determine the time course and coincidence of cortical modulations associated with different types of training. Here we focus on P1-N1-P2 auditory evoked responses (AEP), as there are consistent reports of gains in P2 amplitude following various types of auditory training experiences; including music and speech-sound training. The purpose of this experiment was to determine if the auditory evoked P2 response is a biomarker of learning. To do this, we taught native English speakers to identify a new pre-voiced temporal cue that is not used phonemically in the English language so that coinciding changes in evoked neural activity could be characterized. To differentiate possible effects of repeated stimulus exposure and a button-pushing task from learning itself, we examined modulations in brain activity in a group of participants who learned to identify the pre-voicing contrast and compared it to participants, matched in time, and stimulus exposure, that did not. The main finding was that the amplitude of the P2 auditory evoked response increased across repeated EEG sessions for all groups, regardless of any change in perceptual performance. What's more, these effects are retained for months. Changes in P2 amplitude were attributed to changes in neural activity associated with the acquisition process and not the learned outcome itself. A further finding was the expression of a late negativity (LN) wave 600-900 ms post-stimulus onset, post-training exclusively for the group that learned to identify the pre-voiced contrast

  18. Is the auditory evoked P2 response a biomarker of learning?

    Directory of Open Access Journals (Sweden)

    Kelly eTremblay

    2014-02-01

    Full Text Available Even though auditory training exercises for humans have been shown to improve certain perceptual skills of individuals with and without hearing loss, there is a lack of knowledge pertaining to which aspects of training are responsible for the perceptual gains, and which aspects of perception are changed. To better define how auditory training impacts brain and behavior, electroencephalography and magnetoencephalography have been used to determine the time course and coincidence of cortical modulations associated with different types of training. Here we focus on P1-N1-P2 auditory evoked responses (AEP, as there are consistent reports of gains in P2 amplitude following various types of auditory training experiences; including music and speech-sound training. The purpose of this experiment was to determine if the auditory evoked P2 response is a biomarker of learning. To do this, we taught native English speakers to identify a new pre-voiced temporal cue that is not used phonemically in the English language so that coinciding changes in evoked neural activity could be characterized. To differentiate possible effects of repeated stimulus exposure and a button-pushing task from learning itself, we examined modulations in brain activity in a group of participants who learned to identify the pre-voicing contrast and compared it to participants, matched in time, and stimulus exposure, that did not. The main finding was that the amplitude of the P2 auditory evoked response increased across repeated EEG sessions for all groups, regardless of any change in perceptual performance. What’s more, these effects were retained for months. Changes in P2 amplitude were attributed to changes in neural activity associated with the acquisition process and not the learned outcome itself. A further finding was the expression of a late negativity (LN wave 600-900 ms post-stimulus onset, post-training, exclusively for the group that learned to identify the pre

  19. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat

    Science.gov (United States)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.

    2014-03-01

    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  20. Correlation of hippocampal theta rhythm with changes in cutaneous temperature. [evoked neuron response in thermoregulation

    Science.gov (United States)

    Horowitz, J. M.; Saleh, M. A.; Karem, R. D.

    1974-01-01

    A possible role for the hippocampus in alerting an animal to changes in cutaneous temperature was examined. Following local warming or cooling of the ears of unanesthetized, loosely restrained rabbits, theta waves (4-7 Hz EEG waves) were recorded from electrodes straddling the hippocampus. The onset of the hippocampal theta rhythm was correlated with changes in cutaneous temperature, an observation consistent with studies indicating that the theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Additional data from cats and rabbits were correlated with specific neurons within the hippocampus, namely pyramidal cells. Post stimulus time histograms obtained by excitation of the dorsal fornix were interpreted in terms of excitatory and inhibitory inputs to pyramidal cells. Thus, the theta rhythm, which appears to be evoked by changes in cutaneous temperature, can be related to a specific type of hippocampal neuron which is in turn connected with other areas of the brain involved in temperature regulation.

  1. Brain-stem auditory evoked responses during microvascular decompression for trigeminal neuralgia: Predicting post-operative hearing loss

    Directory of Open Access Journals (Sweden)

    Ramnarayan Ramachandran

    2006-01-01

    Full Text Available Context: The importance of brainstem auditory evoked potential monitoring in reducing hearing loss during microvascular decompression for trigeminal neuralgia is now accepted. However the extent of the changes in the pattern of these potentials and the safe limits to which these changes are relevant in reducing postoperative hearing loss have not been established. Aims: The aim of this study is to quantify these changes and relate these to the postoperative hearing loss. Settings and Design: This study was done at the Walton Centre for neurology and neurosurgery, Liverpool, United Kingdom. The study was designed to give a measure of the change in the wave pattern following microvascular decompression and relate it to postoperative hearing loss. Materials and Methods: Seventy-five patients undergoing microvascular decompression for trigeminal neuralgia had preoperative and postoperative hearing assessments and intraoperative brainstem auditory evoked potential monitoring. Statistical Analysis Used: Chi-square tests. Results: It was found that the wave V latency was increased by more than 0.9ms in nine patients, eight of whom suffered significant postoperative hearing loss as demonstrated by audiometry. It was also seen that progressive decrease in amplitude of wave V showed progressive hearing loss with 25% loss when amplitude fell by 50 and 100% loss when wave V was lost completely. However most of the patients did not have a clinically manifest hearing loss. Conclusions: A per-operative increase in the latency of wave V greater than 0.9 ms and a fall of amplitude of wave V of more than 50% indicates a risk to hearing.

  2. Comparing the Performance of Popular MEG/EEG Artifact Correction Methods in an Evoked-Response Study

    DEFF Research Database (Denmark)

    Haumann, Niels Trusbak; Parkkonen, Lauri; Kliuchko, Marina;

    2016-01-01

    We here compared results achieved by applying popular methods for reducing artifacts in magnetoencephalography (MEG) and electroencephalography (EEG) recordings of the auditory evoked Mismatch Negativity (MMN) responses in healthy adult subjects. We compared the Signal Space Separation (SSS) and...

  3. Cortical evoked potentials in response to rapid balloon distension of the rectum and anal canal

    DEFF Research Database (Denmark)

    Haas, S; Brock, C; Krogh, K; Gram, M; Nissen, T D; Laurberg, S; Drewes, A M

    BACKGROUND: Neurophysiological evaluation of anorectal sensory function is hampered by a paucity of methods. Rapid balloon distension (RBD) has been introduced to describe the cerebral response to rectal distension, but it has not successfully been applied to the anal canal. METHODS: Nineteen...... healthy women received 30 RBDs in the rectum and the anal canal at intensities corresponding to sensory and unpleasantness thresholds, and response was recorded as cortical evoked potentials (CEPs) in 64-channels. The anal canal stimulations at unpleasantness level were repeated after 4 min to test the...

  4. Leber's optic neuropathy: clinical and visual evoked response studies in asymptomatic and symptomatic members of a 4-generation family.

    OpenAIRE

    Livingstone, I R; Mastaglia, F. L.; Howe, J W; Aherne, G E

    1980-01-01

    A clinical and neuro-ophthalmological examination using tests of visual acuity, quantitative visual field analysis, tests of colour discrimination, ophthalmoscopy, and pattern visual evoked responses was performed on 2 symptomatic and 16 asymptomatic members of a family with Leber's optic neuropathy. The visual evoked responses were abnormal in the 2 clinically affected males and in 1 asymptomatic male. Tests of colour discrimination with Ishihara plates, the Farnsworth-Munsell 100 hue test, ...

  5. Signaling pathways involved in PDGF-evoked cellular responses in human RPE cells

    International Nuclear Information System (INIS)

    We examined whether PDGF may directly stimulate the expression of VEGF by retinal pigment epithelial (RPE) cells in vitro, and the involvement of three signal transduction pathways in the regulation of PDGF-evoked cell proliferation, migration, and production of VEGF-A was investigated. PDGF stimulated the gene and protein expression of VEGF-A by RPE cells, and increased cell proliferation and chemotaxis. PDGF activated all signaling pathways investigated, as determined by increased phosphorylation levels of ERK1/2, p38, and Akt proteins. The three signaling pathways were involved in the mediation of PDGF-evoked cell proliferation, while p38 and PI3K mediated cell migration, and PI3K mediated secretion of VEGF-A. In addition to VEGF-A, the cells expressed mRNAs for various members of the VEGF family and for their receptors, including VEGF-B, -C, -D, flt-1, and KDR. The data indicate that PDGF selectively stimulates the expression of VEGF-A in RPE cells. PDGF evokes at least three signal transduction pathways which are differentially involved in various cellular responses

  6. Identification of visual evoked response parameters sensitive to pilot mental state

    Science.gov (United States)

    Zacharias, G. L.

    1988-01-01

    Systems analysis techniques were developed and demonstrated for modeling the electroencephalographic (EEG) steady state visual evoked response (ssVER), for use in EEG data compression and as an indicator of mental workload. The study focused on steady state frequency domain stimulation and response analysis, implemented with a sum-of-sines (SOS) stimulus generator and an off-line describing function response analyzer. Three major tasks were conducted: (1) VER related systems identification material was reviewed; (2) Software for experiment control and data analysis was developed and implemented; and (3) ssVER identification and modeling was demonstrated, via a mental loading experiment. It was found that a systems approach to ssVER functional modeling can serve as the basis for eventual development of a mental workload indicator. The review showed how transient visual evoked response (tVER) and ssVER research are related at the functional level, the software development showed how systems techniques can be used for ssVER characterization, and the pilot experiment showed how a simple model can be used to capture the basic dynamic response of the ssVER, under varying loads.

  7. Cell-attached recordings of responses evoked by photorelease of GABA in the immature cortical neurons

    Directory of Open Access Journals (Sweden)

    Guzel Valeeva

    2013-05-01

    Full Text Available We present a novel non-invasive technique to measure the polarity of GABAergic responses based on cell-attached recordings of currents activated by laser-uncaging of GABA. For these recordings, a patch pipette was filled with a solution containing RuBi-GABA, and GABA was released from this complex by a laser beam conducted to the tip of the patch pipette via an optic fiber. In cell-attached recordings from neocortical and hippocampal neurons in postnatal days P2-5 rat brain slices in vitro, we found that laser-uncaging of GABA activates integral cell-attached currents mediated by tens of GABA(A channels. The initial response was inwardly directed, indicating a depolarizing response to GABA. The direction of the initial response was dependent on the pipette potential and analysis of its slope-voltage relationships revealed a depolarizing driving force of +11 mV for the currents through GABA channels. Initial depolarizing responses to GABA uncaging were inverted to hyperpolarizing in the presence of the NKCC1 blocker bumetanide. Current-voltage relationships of the currents evoked by Rubi-GABA uncaging using voltage-ramps at the peak of responses not only revealed a bumetanide-sensitive depolarizing reversal potential of the GABA(A receptor mediated responses, but also showed a strong voltage-dependent hysteresis. Upon desensitization of the uncaged-GABA response, current-voltage relationships of the currents through single GABA(A channels revealed depolarizing responses with the driving force values similar to those obtained for the initial response. Thus, cell-attached recordings of the responses evoked by local intrapipette GABA uncaging are suitable to assess the polarity of the GABA(A-Rs mediated signals in small cell compartments.

  8. Changes of paired-pulse evoked responses during the development of epileptic activity in the hippocampus

    Institute of Scientific and Technical Information of China (English)

    Zhou-yan FENG; Xiao-jing ZHENG; Cong TIAN; Yang WANG; Hao-yu XING

    2011-01-01

    Dysfunction of inhibitory synaptic transmission can destroy the balance between excitatory and inhibitory synaptic inputs in neurons,thereby inducing epileptic activity.The aim of the paper is to investigate the effects of successive excitatory inputs on the epileptic activity induced in the absence of inhibitions.Paired-pulse orthodromic and antidromic stimulations were used to test the changes in the evoked responses in the hippocampus.Picrotoxin (PTX),y-aminobutyric acid (GABA) type A (GABAA) receptor antagonist,was added to block the inhibitory synaptic transmission and to establish the epileptic model.Extracellular evoked population spike (PS) was recorded in the CA1 region of the hippocampus.The results showed that the application of PTX induced a biphasic change in the paired-pulse ratio of PS amplitude.A short latency increase of the second PS (PS2) was later followed by a reappearance of PS2 depression.This type of depression was observed in both orthodromic and antidromic paired-pulse responses,whereas the GABAergic PS2 depression [called paired-pulse depression (PPD)] during baseline recordings only appeared in orthodromic-evoked responses.In addition,the depression duration at approximately 100 ms was consistent with a relative silent period observed within spontaneous burst discharges induced by prolonged application of PTX.In conclusion,the neurons may ignore the excitatory inputs and intrinsically generate bursts during epileptic activity.The depolarization block could be the mechanisms underlying the PPD in the absence of GABAA inhibitions.The distinct neuronal responses to stimulations during different epileptic stages may implicate the different antiepileptic effects of electrical stimulation.

  9. The Role of Immittance Audiometry in Detecting Middle Ear Disease

    OpenAIRE

    Jacobson, John T.

    1981-01-01

    Immittance audiometry is an objective technique which evaluates middle ear function by three procedures: static immittance, tympanometry, and the measurement of acoustic reflex threshold sensitivity. This article discusses the technique's ability to identify middle ear effusion, the single leading ear disease in children.

  10. Modulatory Effects of Sex Steroids Progesterone and Estradiol on Odorant Evoked Responses in Olfactory Receptor Neurons

    Science.gov (United States)

    Scholz, Paul; Mohrhardt, Julia; Gisselmann, Günter; Hatt, Hanns

    2016-01-01

    The influence of the sex steroid hormones progesterone and estradiol on physiology and behavior during menstrual cycles and pregnancy is well known. Several studies indicate that olfactory performance changes with cyclically fluctuating steroid hormone levels in females. Knowledge of the exact mechanisms behind how female sex steroids modulate olfactory signaling is limited. A number of different known genomic and non-genomic actions that are mediated by progesterone and estradiol via interactions with different receptors may be responsible for this modulation. Next generation sequencing-based RNA-Seq transcriptome data from the murine olfactory epithelium (OE) and olfactory receptor neurons (ORNs) revealed the expression of several membrane progestin receptors and the estradiol receptor Gpr30. These receptors are known to mediate rapid non-genomic effects through interactions with G proteins. RT-PCR and immunohistochemical staining results provide evidence for progestin and estradiol receptors in the ORNs. These data support the hypothesis that steroid hormones are capable of modulating the odorant-evoked activity of ORNs. Here, we validated this hypothesis through the investigation of steroid hormone effects by submerged electro-olfactogram and whole cell patch-clamp recordings of ORNs. For the first time, we demonstrate that the sex steroid hormones progesterone and estradiol decrease odorant-evoked signals in the OE and ORNs of mice at low nanomolar concentrations. Thus, both of these sex steroids can rapidly modulate the odor responsiveness of ORNs through membrane progestin receptors and the estradiol receptor Gpr30. PMID:27494699

  11. Comparison of BCG artifact removal methods for evoked responses in simultaneous EEG-fMRI.

    Science.gov (United States)

    Shams, Nasim; Alain, Claude; Strother, Stephen

    2015-04-30

    Simultaneous recording of electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) has gained attention due to the complimentary properties of the two imaging modalities. Their combined recording enables the study of brain function while taking advantage of the high temporal resolution of EEG and high spatial resolution of fMRI. However EEG data recorded inside the MR scanner is significantly contaminated by two main sources of artifacts: MR gradient artifacts and ballistocardiogram (BCG) artifacts. Most existing removal approaches for these artifacts fall into two main categories: average artifact subtraction (AAS) and optimal basis selection (OBS). While these techniques can improve the data quality significantly, highly effective removal of artifacts - particularly the BCG artifact - from the data is still lacking. Here, we compared two of the most commonly used algorithms for BCG artifact removal (OBS and AAS) based on the estimated signal-to-noise ratio (SNR) of auditory and visual evoked responses recorded during fMRI acquisition. We also further compared optimization of OBS for groups, and at the individual subject and run level. The results suggest that performance of the OBS algorithm can be significantly improved by choosing the optimum number of principal components. Furthermore, optimizing the number of principal components at the individual participant and run level results in significant improvements in the SNR of evoked responses compared to group optimization. PMID:25721269

  12. A test method comparison on the brainstem auditory evoked potentials and the audiometry methods testing aircraft noise - induced hearing losses%飞机噪声性听力损伤的脑干听觉诱发电位及电测听方法比较

    Institute of Scientific and Technical Information of China (English)

    任力; 刘英; 叶舜华

    2002-01-01

    目的对飞机噪声暴露人群同时进行脑干听觉诱发电位(Brainstem anditory evoked potentials,BAEP)及电测听检查,比较两种方法检测听力损伤的价值.方法①对60名飞机维修保养人员及120名对照人群同时用脑干听觉诱发电位及电测听方法进行听力损伤检测.②用相关性分析及主成分分析等统计方法对该两种方法检测听力损伤的价值进行比较.结果①职业接触人群的BAEP潜伏期值与电测听1、2、4、6、8 KHz等频率及PTA、HPTA上的听觉阈值呈正相关,且与高频听觉阈值的相关性好.②用电测听4 kHz频率上的听觉阈值与BAEP的Ⅰ~Ⅴ波的峰间潜伏期做主成分分析:4 kHz频率上的听觉阈值的贡献率为78.9%,BAEP的Ⅰ~Ⅴ波的峰间潜伏期的贡献率为21.1%.结论电测听方法能反映主要的听力损伤状况,BAEP数据可预测飞机噪声对听力的早期影响,作为敏感性指标,对飞机噪声危害引起的听力损伤的早期发现具有较大价值.

  13. Audiometry and ossicular condition in chronic otitis media

    OpenAIRE

    mohsen Rajati Haghi; Mohamad Mahdi Ghasemi; Mehdi Bakhshaee; Atefeh Taghati; Atefeh Shahabipour

    2009-01-01

      Introduction: Ossicular chain injury is one of the most common causes of hearing loss in chronic otitis media (COM). Although definite diagnosis of ossicular discontinuity is made intraoperatively, preoperative determination of ossicular chain injury will help the surgeon decide about reconstruction options and hearing prognosis of the patient. In this study we compared preoperative pure tone audiometry (PTA) findings of COM patients with the ossicular condition determined during surgery. M...

  14. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered.

    Science.gov (United States)

    Pialasse, Jean-Philippe; Descarreaux, Martin; Mercier, Pierre; Blouin, Jean; Simoneau, Martin

    2015-01-01

    Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20) or severe (n = 16) spine deformation were compared to those of healthy control adolescents (n = 16). Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes. PMID:26580068

  15. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered.

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Pialasse

    Full Text Available Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20 or severe (n = 16 spine deformation were compared to those of healthy control adolescents (n = 16. Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes.

  16. Evaluation of misonidazole peripheral neurotoxicity in rats by analysis of nerve trains evoked response

    International Nuclear Information System (INIS)

    The clinical use of misonidazole and other nitroimidazole radiosensitizing agents is limited by the peripheral and central neurotoxicity that is produced in animals and humans. In a blinded study, rats treated with misonidazole at either 100 mg/kg or 300 mg/kg, 5 days/week for 3 weeks, were evaluated for peripheral neurotoxicity using nerve trains evoked responses. Only one rat treated at a dose of 100 mg/kg developed symptoms and signs of neurotoxicity, while all rats treated at 300 mg/kg developed these signs and symptoms. Nerve trains analysis made possible a diagnosis of neurotoxicity before overt clinical signs appeared. This test is non-invasive and may be useful for evaluating patients receiving nitroimidazole radiosensitizers as part of a radiation therapy regimen

  17. Infant temperament and the brainstem auditory evoked response in later childhood.

    Science.gov (United States)

    Woodward, S A; McManis, M H; Kagan, J; Deldin, P; Snidman, N; Lewis, M; Kahn, V

    2001-07-01

    Brainstem auditory evoked responses (BAERs) were evaluated on 10-12-year-old children (N = 56) who had been classified as high or low reactive to unfamiliar stimuli at 4 months of age. BAER measurement was selected because high reactive infants tend to become inhibited or fearful young children, and adult introverts have a faster latency to wave V of the BAER than do extroverts. Children previously classified as high reactive at 4 months had larger wave V components than did low reactive children, a finding that possibly suggests greater excitability in projections to the inferior colliculus. The fact that a fundamental feature of brainstem activity differentiated preadolescent children belonging to two early temperamental groups supports the value of gathering physiological data in temperament research. PMID:11444488

  18. Synaptic responses evoked by tactile stimuli in Purkinje cells in mouse cerebellar cortex Crus II in vivo.

    Directory of Open Access Journals (Sweden)

    Chun-Ping Chu

    Full Text Available BACKGROUND: Sensory stimuli evoke responses in cerebellar Purkinje cells (PCs via the mossy fiber-granule cell pathway. However, the properties of synaptic responses evoked by tactile stimulation in cerebellar PCs are unknown. The present study investigated the synaptic responses of PCs in response to an air-puff stimulation on the ipsilateral whisker pad in urethane-anesthetized mice. METHODS AND MAIN RESULTS: Thirty-three PCs were recorded from 48 urethane-anesthetized adult (6-8-week-old HA/ICR mice by somatic or dendritic patch-clamp recording and pharmacological methods. Tactile stimulation to the ipsilateral whisker pad was delivered by an air-puff through a 12-gauge stainless steel tube connected with a pressurized injection system. Under current-clamp conditions (I = 0, the air-puff stimulation evoked strong inhibitory postsynaptic potentials (IPSPs in the somata of PCs. Application of SR95531, a specific GABA(A receptor antagonist, blocked IPSPs and revealed stimulation-evoked simple spike firing. Under voltage-clamp conditions, tactile stimulation evoked a sequence of transient inward currents followed by strong outward currents in the somata and dendrites in PCs. Application of SR95531 blocked outward currents and revealed excitatory postsynaptic currents (EPSCs in somata and a temporal summation of parallel fiber EPSCs in PC dendrites. We also demonstrated that PCs respond to both the onset and offset of the air-puff stimulation. CONCLUSIONS: These findings indicated that tactile stimulation induced asynchronous parallel fiber excitatory inputs onto the dendrites of PCs, and failed to evoke strong EPSCs and spike firing in PCs, but induced the rapid activation of strong GABA(A receptor-mediated inhibitory postsynaptic currents in the somata and dendrites of PCs in the cerebellar cortex Crus II in urethane-anesthetized mice.

  19. The Duration of Motor Responses Evoked with Intracortical Microstimulation in Rats Is Primarily Modulated by Stimulus Amplitude and Train Duration.

    Directory of Open Access Journals (Sweden)

    Meghan Watson

    Full Text Available Microstimulation of brain tissue plays a key role in a variety of sensory prosthetics, clinical therapies and research applications, however the effects of stimulation parameters on the responses they evoke remain widely unknown. In particular, the effects of parameters when delivered in the form of a stimulus train as opposed to a single pulse are not well understood despite the prevalence of stimulus train use. We aimed to investigate the contribution of each parameter of a stimulus train to the duration of the motor responses they evoke in forelimb muscles. We used constant-current, biphasic, square wave pulse trains in acute terminal experiments under ketamine anaesthesia. Stimulation parameters were systematically tested in a pair-wise fashion in the caudal forelimb region of the motor cortex in 7 Sprague-Dawley rats while motor evoked potential (MEP recordings from the forelimb were used to quantify the influence of each parameter in the train. Stimulus amplitude and train duration were shown to be the dominant parameters responsible for increasing the total duration of the MEP, while interphase interval had no effect. Increasing stimulus frequency from 100-200 Hz or pulse duration from 0.18-0.34 ms were also effective methods of extending response durations. Response duration was strongly correlated with peak time and amplitude. Our findings suggest that motor cortex intracortical microstimulations are often conducted at a higher frequency rate and longer train duration than necessary to evoke maximal response duration. We demonstrated that the temporal properties of the evoked response can be both predicted by certain response metrics and modulated via alterations to the stimulation signal parameters.

  20. The Duration of Motor Responses Evoked with Intracortical Microstimulation in Rats Is Primarily Modulated by Stimulus Amplitude and Train Duration

    Science.gov (United States)

    Watson, Meghan; Sawan, Mohamad

    2016-01-01

    Microstimulation of brain tissue plays a key role in a variety of sensory prosthetics, clinical therapies and research applications, however the effects of stimulation parameters on the responses they evoke remain widely unknown. In particular, the effects of parameters when delivered in the form of a stimulus train as opposed to a single pulse are not well understood despite the prevalence of stimulus train use. We aimed to investigate the contribution of each parameter of a stimulus train to the duration of the motor responses they evoke in forelimb muscles. We used constant-current, biphasic, square wave pulse trains in acute terminal experiments under ketamine anaesthesia. Stimulation parameters were systematically tested in a pair-wise fashion in the caudal forelimb region of the motor cortex in 7 Sprague-Dawley rats while motor evoked potential (MEP) recordings from the forelimb were used to quantify the influence of each parameter in the train. Stimulus amplitude and train duration were shown to be the dominant parameters responsible for increasing the total duration of the MEP, while interphase interval had no effect. Increasing stimulus frequency from 100–200 Hz or pulse duration from 0.18–0.34 ms were also effective methods of extending response durations. Response duration was strongly correlated with peak time and amplitude. Our findings suggest that motor cortex intracortical microstimulations are often conducted at a higher frequency rate and longer train duration than necessary to evoke maximal response duration. We demonstrated that the temporal properties of the evoked response can be both predicted by certain response metrics and modulated via alterations to the stimulation signal parameters. PMID:27442588

  1. Continued Maturation of the Click-Evoked Auditory Brainstem Response in Preschoolers

    Science.gov (United States)

    Spitzer, Emily; White-Schwoch, Travis; Carr, Kali Woodruff; Skoe, Erika; Kraus, Nina

    2016-01-01

    Background Click-evoked auditory brainstem responses (ABRs) are a valuable tool for probing auditory system function and development. Although it has long been thought that the human auditory brainstem is fully mature by age 2 yr, recent evidence indicates a prolonged developmental trajectory. Purpose The purpose of this study was to determine the time course of ABR maturation in a preschool population and fill a gap in the knowledge of development. Research Design Using a cross-sectional design, we investigated the effect of age on absolute latencies, interwave latencies, and amplitudes (waves I, III, V) of the click-evoked ABR. Study Sample A total of 71 preschoolers (ages 3.12–4.99 yr) participated in the study. All had normal peripheral auditory function and IQ. Data Collection and Analysis ABRs to a rarefaction click stimulus presented at 31/sec and 80 dB SPL (73 dB nHL) were recorded monaurally using clinically-standard recording and filtering procedures while the participant sat watching a movie. Absolute latencies, interwave latencies, and amplitudes were then correlated to age. Results Developmental changes were restricted to absolute latencies. Wave V latency decreased significantly with age, whereas wave I and III latencies remained stable, even in this restricted age range. Conclusions The ABR does not remain static after age 2 yr, as seen by a systematic decrease in wave V latency between ages 3 and 5 yr. This finding suggests that the human brainstem has a continued developmental time course during the preschool years. Latency changes in the age 3–5 yr range should be considered when using ABRs as a metric of hearing health. PMID:25597458

  2. Habituation of Auditory Steady State Responses Evoked by Amplitude-Modulated Acoustic Signals in Rats

    Science.gov (United States)

    Prado-Gutierrez, Pavel; Castro-Fariñas, Anisleidy; Morgado-Rodriguez, Lisbet; Velarde-Reyes, Ernesto; Martínez, Agustín D.; Martínez-Montes, Eduardo

    2015-01-01

    Generation of the auditory steady state responses (ASSR) is commonly explained by the linear combination of random background noise activity and the stationary response. Based on this model, the decrease of amplitude that occurs over the sequential averaging of epochs of the raw data has been exclusively linked to the cancelation of noise. Nevertheless, this behavior might also reflect the non-stationary response of the ASSR generators. We tested this hypothesis by characterizing the ASSR time course in rats with different auditory maturational stages. ASSR were evoked by 8-kHz tones of different supra-threshold intensities, modulated in amplitude at 115 Hz. Results show that the ASSR amplitude habituated to the sustained stimulation and that dishabituation occurred when deviant stimuli were presented. ASSR habituation increased as animals became adults, suggesting that the ability to filter acoustic stimuli with no-relevant temporal information increased with age. Results are discussed in terms of the current model of the ASSR generation and analysis procedures. They might have implications for audiometric tests designed to assess hearing in subjects who cannot provide reliable results in the psychophysical trials. PMID:26557360

  3. Habituation of auditory steady state responses evoked by amplitudemodulated acoustic signals in rats

    Directory of Open Access Journals (Sweden)

    Pavel Prado-Gutierrez

    2015-01-01

    Full Text Available Generation of the auditory steady state responses (ASSR is commonly explained by the linear combination of random background noise activity and the stationary response. Based on this model, the decrease of amplitude that occurs over the sequential averaging of epochs of the raw data has been exclusively linked to the cancelation of noise. Nevertheless, this behavior might also reflect the non-stationary response of the ASSR generators. We tested this hypothesis by characterizing the ASSR time course in rats with different auditory maturational stages. ASSR were evoked by 8-kHz tones of different supra-threshold intensities, modulated in amplitude at 115 Hz. Results show that the ASSR amplitude habituated to the sustained stimulation and that dishabituation occurred when deviant stimuli were presented. ASSR habituation increased as animals became adults, suggesting that the ability to filter acoustic stimuli with no-relevant temporal information increased with age. Results are discussed in terms of the current model of the ASSR generation and analysis procedures. They might have implications for audiometric tests designed to assess hearing in subjects who cannot provide reliable results in the psychophysical trials.

  4. Gender differences in rival characteristics that evoke jealousy in response to emotional versus sexual infidelity

    NARCIS (Netherlands)

    Buunk, Abraham (Bram); Dijkstra, Pieternel

    2004-01-01

    Previous research has shown that in men jealousy is evoked more by a rival's status-related characteristics than in women, whereas in women jealousy is evoked more by a rival's physical attractiveness than in men. The present study examined whether the occurrence of this gender difference depends up

  5. Middle components of the auditory evoked response in bilateral temporal lobe lesions. Report on a patient with auditory agnosia

    DEFF Research Database (Denmark)

    Parving, A; Salomon, G; Elberling, Claus;

    1980-01-01

    An investigation of the middle components of the auditory evoked response (10--50 msec post-stimulus) in a patient with auditory agnosia is reported. Bilateral temporal lobe infarctions were proved by means of brain scintigraphy, CAT scanning, and regional cerebral blood flow measurements. The mi...

  6. Sex differences and endocrine regulation of auditory-evoked, neural responses in African clawed frogs (Xenopus).

    Science.gov (United States)

    Hall, Ian C; Woolley, Sarah M N; Kwong-Brown, Ursula; Kelley, Darcy B

    2016-01-01

    Mating depends on the accurate detection of signals that convey species identity and reproductive state. In African clawed frogs, Xenopus, this information is conveyed by vocal signals that differ in temporal patterns and spectral features between sexes and across species. We characterized spectral sensitivity using auditory-evoked potentials (AEPs), commonly known as the auditory brainstem response, in males and females of four Xenopus species. In female X. amieti, X. petersii, and X. laevis, peripheral auditory sensitivity to their species own dyad-two, species-specific dominant frequencies in the male advertisement call-is enhanced relative to males. Males were most sensitive to lower frequencies including those in the male-directed release calls. Frequency sensitivity was influenced by endocrine state; ovariectomized females had male-like auditory tuning while dihydrotestosterone-treated, ovariectomized females maintained female-like tuning. Thus, adult, female Xenopus demonstrate an endocrine-dependent sensitivity to the spectral features of conspecific male advertisement calls that could facilitate mating. Xenopus AEPs resemble those of other species in stimulus and level dependence, and in sensitivity to anesthetic (MS222). AEPs were correlated with body size and sex within some species. A frequency following response, probably encoded by the amphibian papilla, might facilitate dyad source localization via interaural time differences. PMID:26572136

  7. Restoration of auditory evoked responses by human ES-cell-derived otic progenitors.

    Science.gov (United States)

    Chen, Wei; Jongkamonwiwat, Nopporn; Abbas, Leila; Eshtan, Sarah Jacob; Johnson, Stuart L; Kuhn, Stephanie; Milo, Marta; Thurlow, Johanna K; Andrews, Peter W; Marcotti, Walter; Moore, Harry D; Rivolta, Marcelo N

    2012-10-11

    Deafness is a condition with a high prevalence worldwide, produced primarily by the loss of the sensory hair cells and their associated spiral ganglion neurons (SGNs). Of all the forms of deafness, auditory neuropathy is of particular concern. This condition, defined primarily by damage to the SGNs with relative preservation of the hair cells, is responsible for a substantial proportion of patients with hearing impairment. Although the loss of hair cells can be circumvented partially by a cochlear implant, no routine treatment is available for sensory neuron loss, as poor innervation limits the prospective performance of an implant. Using stem cells to recover the damaged sensory circuitry is a potential therapeutic strategy. Here we present a protocol to induce differentiation from human embryonic stem cells (hESCs) using signals involved in the initial specification of the otic placode. We obtained two types of otic progenitors able to differentiate in vitro into hair-cell-like cells and auditory neurons that display expected electrophysiological properties. Moreover, when transplanted into an auditory neuropathy model, otic neuroprogenitors engraft, differentiate and significantly improve auditory-evoked response thresholds. These results should stimulate further research into the development of a cell-based therapy for deafness. PMID:22972191

  8. Is the motion system relatively spared in amblyopia? Evidence from cortical evoked responses.

    Science.gov (United States)

    Kubová, Z; Kuba, M; Juran, J; Blakemore, C

    1996-01-01

    Visual evoked potentials (VEPs) produced by pattern reversal were compared with those elicited by onset of motion in 37 amblyopic children (20 with anisometropic amblyopia, seven with strabismic amblyopia and 10 with both anisometropia and strabismus). The amplitudes and peak latencies of the main P1 peak in the pattern-reversal VEP and of the motion-specific N2 peak in the motion-onset VEP through the amblyopic eye were compared with those through the normal fellow eye. Regardless of the type of amblyopia, the amplitude of the pattern-reversal VEP for full-field stimulation was significantly smaller and its latency significantly longer through the amblyopic eye (P central visual field (5 or 2 deg diameter) or to the peripheral field (excluding the central 5 deg), motion-onset responses were indistinguishable through the two eyes, while pattern-reversal responses always differed significantly in amplitude. These results suggest that the source of motion-onset VEPs (probably an extrastriate motion-sensitive area) is less affected in amblyopia than that of pattern-reversal VEPs (probably the striate cortex). The motion pathway, presumably deriving mainly from the magnocellular layers of the lateral geniculate nucleus, may be relatively spared in amblyopia. PMID:8746252

  9. Shifts in striatal responsivity evoked by chronic stimulation of dopamine and glutamate systems.

    Science.gov (United States)

    Canales, J J; Capper-Loup, C; Hu, D; Choe, E S; Upadhyay, U; Graybiel, A M

    2002-10-01

    Dopamine and glutamate are key neurotransmitters in cortico-basal ganglia loops affecting motor and cognitive function. To examine functional convergence of dopamine and glutamate neurotransmitter systems in the basal ganglia, we evaluated the long-term effects of chronic stimulation of each of these systems on striatal responses to stimulation of the other. First we exposed rats to chronic intermittent cocaine and used early-gene assays to test the responsivity of the striatum to subsequent acute motor cortex stimulation by application of the GABA(A) (gamma-aminobutyric acid alpha subunit) receptor antagonist, picrotoxin. Reciprocally, we studied the effects of chronic intermittent motor cortex stimulation on the capacity for subsequent acute dopaminergic treatments to induce early-gene activation in the striatum. Prior treatment with chronic intermittent cocaine induced motor sensitization and significantly potentiated the striatal expression of Fos-family early genes in response to stimulation of the motor cortex. Contrary to this, chronic intermittent stimulation of the motor cortex down-regulated cocaine-induced gene expression in the striatum, but enhanced striatal gene expression induced by a full D1 receptor agonist (SKF 81297) and did not change the early-gene response elicited by a D2 receptor antagonist (haloperidol). These findings suggests that repeated dopaminergic stimulation produces long-term enhancement of corticostriatal signalling from the motor cortex, amplifying cortically evoked modulation of the basal ganglia. By contrast, persistent stimulation of the motor cortex inhibits cocaine-stimulated signalling in the striatum, but not signalling mediated by individual dopamine receptor sites, suggesting that chronic cortical hyperexcitability produces long-term impairment of dopaminergic activity and compensation at the receptor level. These findings prompt a model of the basal ganglia function as being regulated by opposing homeostatic dopamine

  10. Feedforward versus feedback modulation of human vestibular-evoked balance responses by visual self-motion information

    OpenAIRE

    Day, B. L.; Guerraz, M.

    2007-01-01

    Visual information modulates the balance response evoked by a pure vestibular perturbation (galvanic vestibular stimulation, GVS). Here we investigate two competing hypotheses underlying this visual-vestibular interaction. One hypothesis assumes vision acts in a feedforward manner by altering the weight of the vestibular channel of balance control. The other assumes vision acts in a feedback manner through shifts in the retinal image produced by the primary response. In the first experiment w...

  11. Osmotic modulation of stimulus-evoked responses in the rat supraoptic nucleus.

    Science.gov (United States)

    Bhumbra, G S; Orlans, H O; Dyball, R E J

    2008-04-01

    Neural information is conveyed by action potentials along axons to downstream synaptic targets. Synapses permit functionally relevant modulation of the information transmitted by converging inputs. Previous studies have measured the amount of information associated with a given stimulus based either on spike counts or on the relative frequencies of spike sequences represented as binary strings. Here we apply information theory to the phase-interval stimulus histogram (PhISH) to measure the extent of the stimulus-evoked response using the statistical relationship between each interspike interval and its phase within the stimulus cycle. We used the PhISH as a novel approach to investigate how different osmotic states affect the flow of information through the osmoreceptor complex of the hypothalamus. The amount of information conveyed from one (afferent) element of the complex, the anteroventral region of the third ventricle (AV3V), to another (an efferent element), the supraoptic nucleus, was increased by hypertonic stimulation (intravenous mannitol, z = 4.39, P value of the novel approach is that its use is not limited to the osmoreceptor ensemble but it can be used to investigate the flow of information throughout the central nervous system. PMID:18412620

  12. Neuromagnetic oscillations predict evoked-response latency delays and core language deficits in autism spectrum disorders.

    Science.gov (United States)

    Edgar, J Christopher; Khan, Sarah Y; Blaskey, Lisa; Chow, Vivian Y; Rey, Michael; Gaetz, William; Cannon, Katelyn M; Monroe, Justin F; Cornew, Lauren; Qasmieh, Saba; Liu, Song; Welsh, John P; Levy, Susan E; Roberts, Timothy P L

    2015-02-01

    Previous studies have observed evoked response latency as well as gamma band superior temporal gyrus (STG) auditory abnormalities in individuals with autism spectrum disorders (ASD). A limitation of these studies is that associations between these two abnormalities, as well as the full extent of oscillatory phenomena in ASD in terms of frequency and time, have not been examined. Subjects were presented pure tones at 200, 300, 500, and 1,000 Hz while magnetoencephalography assessed activity in STG auditory areas in a sample of 105 children with ASD and 36 typically developing controls (TD). Findings revealed a profile such that auditory STG processes in ASD were characterized by pre-stimulus abnormalities across multiple frequencies, then early high-frequency abnormalities followed by low-frequency abnormalities. Increased pre-stimulus activity was a 'core' abnormality, with pre-stimulus activity predicting post-stimulus neural abnormalities, group membership, and clinical symptoms (CELF-4 Core Language Index). Deficits in synaptic integration in the auditory cortex are associated with oscillatory abnormalities in ASD as well as patient symptoms. Increased pre-stimulus activity in ASD likely demonstrates a fundamental signal-to-noise deficit in individuals with ASD, with elevations in oscillatory activity suggesting an inability to maintain an appropriate 'neural tone' and an inability to rapidly return to a resting state prior to the next stimulus. PMID:23963591

  13. Rapid stimulus-evoked astrocyte Ca2+ elevations and hemodynamic responses in mouse somatosensory cortex in vivo

    DEFF Research Database (Denmark)

    Lind, Barbara Lykke; Brazhe, Alexey; Jessen, Sanne Barsballe;

    2013-01-01

    Increased neuron and astrocyte activity triggers increased brain blood flow, but controversy exists over whether stimulation-induced changes in astrocyte activity are rapid and widespread enough to contribute to brain blood flow control. Here, we provide evidence for stimulus-evoked Ca(2......+) elevations with rapid onset and short duration in a large proportion of cortical astrocytes in the adult mouse somatosensory cortex. Our improved detection of the fast Ca(2+) signals is due to a signal-enhancing analysis of the Ca(2+) activity. The rapid stimulation-evoked Ca(2+) increases identified in...... astrocyte somas, processes, and end-feet preceded local vasodilatation. Fast Ca(2+) responses in both neurons and astrocytes correlated with synaptic activity, but only the astrocytic responses correlated with the hemodynamic shifts. These data establish that a large proportion of cortical astrocytes have...

  14. In vivo comparison of the charge densities required to evoke motor responses using novel annular penetrating microelectrodes

    OpenAIRE

    Brunton, Emma K.; Winther-Jensen, Bjorn; Wang, Chun; Yan, Edwin B; Hagh Gooie, Saman; Lowery, Arthur J.; Rajan, Ramesh

    2015-01-01

    Electrodes for cortical stimulation need to deliver current to neural tissue effectively and safely. We have developed electrodes with a novel annular geometry for use in cortical visual prostheses. Here, we explore a critical question on the ideal annulus height to ensure electrical stimulation will be safe and effective. We implanted single electrodes into the motor cortex of anesthetized rats and measured the current required to evoke a motor response to stimulation, and the charge injecti...

  15. In-vivo comparison of the charge densities required to evoke motor responses using novel annular penetrating microelectrodes

    OpenAIRE

    Emma Kate Brunton; Bjorn eWinther-Jensen; Chun eWang; Edwin Bingbing Yan; Saman eHagh Gooie; Arthur James Lowery; Ramesh eRajan

    2015-01-01

    Electrodes for cortical stimulation need to deliver current to neural tissue effectively and safely. We have developed electrodes with a novel annular geometry for use in cortical visual prostheses. Here we explore a critical question on the ideal annulus height to ensure electrical stimulation will be safe and effective. We implanted single electrodes into the motor cortex of anesthetized rats and measured the current required to evoke a motor response to stimulation, and the charge injectio...

  16. Validation of fetal auditory evoked cortical responses to enhance the assessment of early brain development using fetal MEG measurements

    International Nuclear Information System (INIS)

    The maturation of fetal auditory evoked cortical responses (fAECRs) is an important aspect of developmental medicine, but their reliable identification is limited due to the technical restrictions in prenatal diagnosis. The signal-to-noise ratio of the fAECRs extracted exclusively from fetal magnetoencephalography is a known issue which limits their analysis as markers of brain development. The objective of this work was to develop a signal analysis strategy to address these problems and find appropriate processing steps. In this study, a group of 147 normal fetuses with gestations between 26 and 41 weeks underwent auditory evoked response testing. We combine different approaches that address data cleaning, fAECR determination and statistical fAECR validation to reduce the uncertainty in the detection of the auditory evoked responses. For the statistical validation of the evoked responses, we use parameters computed from bootstrap-based test statistics and the correlation between different averaging modes. Appropriate thresholds for those parameters are identified using linear regression analyses by looking at the maximum correlation coefficients. The results show that by using different validation parameters, the selected fAECRs conduct to similar regression slopes with an average of −13.6 ms/week gestational age which agree with previous studies. Our novel processing framework provides an objective way to identify and eliminate non-physiological variation in the data induced by artifacts. This approach has the potential to produce more reliable data needed in clinical studies for fetal brain maturation as well as extending the investigations to high-risk groups

  17. Objective assessment of spectral ripple discrimination in cochlear implant listeners using cortical evoked responses to an oddball paradigm.

    Science.gov (United States)

    Lopez Valdes, Alejandro; Mc Laughlin, Myles; Viani, Laura; Walshe, Peter; Smith, Jaclyn; Zeng, Fan-Gang; Reilly, Richard B

    2014-01-01

    Cochlear implants (CIs) can partially restore functional hearing in deaf individuals. However, multiple factors affect CI listener's speech perception, resulting in large performance differences. Non-speech based tests, such as spectral ripple discrimination, measure acoustic processing capabilities that are highly correlated with speech perception. Currently spectral ripple discrimination is measured using standard psychoacoustic methods, which require attentive listening and active response that can be difficult or even impossible in special patient populations. Here, a completely objective cortical evoked potential based method is developed and validated to assess spectral ripple discrimination in CI listeners. In 19 CI listeners, using an oddball paradigm, cortical evoked potential responses to standard and inverted spectrally rippled stimuli were measured. In the same subjects, psychoacoustic spectral ripple discrimination thresholds were also measured. A neural discrimination threshold was determined by systematically increasing the number of ripples per octave and determining the point at which there was no longer a significant difference between the evoked potential response to the standard and inverted stimuli. A correlation was found between the neural and the psychoacoustic discrimination thresholds (R2=0.60, ppotential tool for the evaluation and follow-up of CI listeners who have difficulty performing psychoacoustic tests, such as pediatric or new users. PMID:24599314

  18. Proprioceptive evoked potentials in man: cerebral responses to changing weight loads on the hand

    DEFF Research Database (Denmark)

    Arnfred, S; He, Chen; Eder, D;

    2000-01-01

    We studied cerebral evoked potentials on the scalp to the stimulation of the right hand from a change in weight of 400-480 g in ten subjects. Rise-time was 20g/10 ms, Inter Stimulus Interval 2s and stimulus duration was 100 ms. The cerebral activations were a double positive contralateral C3'/P70......, P190, and a single negative frontal Fz/N70 component. We conclude that a brisk change of a hand held load elicits a significant evoked potential (EP) unlike the electrical somato-sensory EP (SEP). The stimulus is perceived as applied force. For this reason we call it a proprioceptive EP (PEP...

  19. Normalization of Pain-Evoked Neural Responses Using Spontaneous EEG Improves the Performance of EEG-Based Cross-Individual Pain Prediction

    Science.gov (United States)

    Bai, Yanru; Huang, Gan; Tu, Yiheng; Tan, Ao; Hung, Yeung Sam; Zhang, Zhiguo

    2016-01-01

    An effective physiological pain assessment method that complements the gold standard of self-report is highly desired in pain clinical research and practice. Recent studies have shown that pain-evoked electroencephalography (EEG) responses could be used as a readout of perceived pain intensity. Existing EEG-based pain assessment is normally achieved by cross-individual prediction (i.e., to train a prediction model from a group of individuals and to apply the model on a new individual), so its performance is seriously hampered by the substantial inter-individual variability in pain-evoked EEG responses. In this study, to reduce the inter-individual variability in pain-evoked EEG and to improve the accuracy of cross-individual pain prediction, we examined the relationship between pain-evoked EEG, spontaneous EEG, and pain perception on a pain EEG dataset, where a large number of laser pulses (>100) with a wide energy range were delivered. Motivated by our finding that an individual's pain-evoked EEG responses is significantly correlated with his/her spontaneous EEG in terms of magnitude, we proposed a normalization method for pain-evoked EEG responses using one's spontaneous EEG to reduce the inter-individual variability. In addition, a nonlinear relationship between the level of pain perception and pain-evoked EEG responses was obtained, which inspired us to further develop a new two-stage pain prediction strategy, a binary classification of low-pain and high-pain trials followed by a continuous prediction for high-pain trials only, both of which used spontaneous-EEG-normalized magnitudes of evoked EEG responses as features. Results show that the proposed normalization strategy can effectively reduce the inter-individual variability in pain-evoked responses, and the two-stage pain prediction method can lead to a higher prediction accuracy. PMID:27148028

  20. Evaluation of auditory brain-stem evoked response in middle: Aged type 2 diabetes mellitus with normal hearing subjects

    Directory of Open Access Journals (Sweden)

    Debadatta Mahallik

    2014-01-01

    Full Text Available Background: Diabetes mellitus (DM is commonly metabolic disorders of carbohydrate in which blood glucose levels are abnormally high due to relative or absolute insulin deficiency. In addition, it is characterized by abnormal metabolism of fat, protein resulting from insulin deficit or insulin action, or both. There are two broad categories of DM are designated as type 1 and type 2. Type 2 diabetes is due to predominantly insulin resistance with relative insulin deficiency noninsulin-dependent DM. Type 2 diabetes is much more common than insulin-dependent DM. Objectives: The aim of this study was to assess, if there is any abnormality in neural conduction in auditory brain-stem pathway in type 2 DM patients having normal hearing sensitivity when compared to age-matched healthy populations. Materials and Methods: This study included middle - aged 25 subjects having normal hearing with diabetes type 2 mellitus. All were submitted to the full audiological history taking, otological examination, basic audiological evaluation and auditory brain-stem response audiometry which was recorded in both ears, followed by calculation of the absolute latencies of wave I, III and V, as well as interpeak latencies I-III, III-V, I-V. Results: Type 2 DM patients showed significant prolonged absolute latencies of I, III (P = 0.001 and interpeak latencies I-III, III-V and I-V in left ear (P = 0.001 and absolute latencies of I, V (P = 0.001, interpeak latencies III-V was statistically significant in right ear. Conclusions: The prolonged absolute latencies and interpeak latencies suggests abnormal neural firing synchronization or in the transmission in the auditory pathways in normal hearing type 2 diabetes mellitus patients.

  1. Extended High Frequency Audiometry in Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    Cuneyt Kucur

    2013-01-01

    and BMI of PCOS and control groups were comparable. Each subject was tested with low (250–2000 Hz, high (4000–8000 Hz, and extended high frequency audiometry (8000–20000. Hormonal and biochemical values including LH, LH/FSH, testosterone, fasting glucose, fasting insulin, HOMA-I, and CRP were calculated. Results. PCOS patients showed high levels of LH, LH/FSH, testosterone, fasting insulin, glucose, HOMA-I, and CRP levels. The hearing thresholds of the groups were similar at frequencies of 250, 500, 1000, 2000, and 4000 Hz; statistically significant difference was observed in 8000–14000 Hz in PCOS group compared to control group. Conclusion. PCOS patients have hearing impairment especially in extended high frequencies. Further studies are needed to help elucidate the mechanism behind hearing impairment in association with PCOS.

  2. Somatosensory Evoked Potentials and Dopaminergic Responsiveness to Apomorphine and Levodopa in Parkinsonian Patients

    OpenAIRE

    Miranda, M.; J. L. Castillo; Araya, F.

    1996-01-01

    Short-latency somatosensory evoked potentials (SSEPs) were recorded from 10 parkinsonian patients in ‘off’ and ‘on’ states induced by apomorphine and levodopa. The effects of apomorphine and long-term levodopa treatment on the frontal N30 component were assessed and compared with healthy controls. Nine of 10 patients tested with apomorphine showed a significant improvement (p

  3. Unilateral Floor Stiffness Perturbations Systematically Evoke Contralateral Leg Muscle Responses: A New Approach to Robot-Assisted Gait Therapy.

    Science.gov (United States)

    Skidmore, Jeffrey; Artemiadis, Panagiotis

    2016-04-01

    A variety of robotic rehabilitation devices have been proposed for gait rehabilitation after stoke, but have only produced moderate results when compared to conventional physiotherapy. We suggest a novel approach to robotic interventions which takes advantage of mechanisms of inter-limb coordination. In order to test the viability of this approach, we apply unilateral floor stiffness perturbations via a unique robotic device and observe evoked contralateral leg responses in kinematics, as well as muscle activations, in healthy subjects. The real-time control of floor stiffness is utilized to uniquely differentiate force and kinematic feedback, creating novel sensory perturbations. We present results of repeatable and scalable evoked kinematic and muscular response of the unperturbed leg in healthy subjects. Moreover, we provide insight into the fundamental sensorimotor mechanisms of inter-leg coordination. We also lay the foundation for model-based rehabilitation strategies for impaired walkers by presenting a mathematical model that accurately describes the relationship between the magnitude of the stiffness perturbation and the evoked muscle activity. One of the most significant advantages of this approach over current practices is the safety of the patient, since this does not require any direct manipulation of the impaired leg. The novel methods and results presented in this paper set the foundation for a paradigm shift in robotic interventions for gait rehabilitation. PMID:25872216

  4. Contrast sensitivity test and conventional and high frequency audiometry: information beyond that required to prescribe lenses and headsets

    Science.gov (United States)

    Comastri, S. A.; Martin, G.; Simon, J. M.; Angarano, C.; Dominguez, S.; Luzzi, F.; Lanusse, M.; Ranieri, M. V.; Boccio, C. M.

    2008-04-01

    In Optometry and in Audiology, the routine tests to prescribe correction lenses and headsets are respectively the visual acuity test (the first chart with letters was developed by Snellen in 1862) and conventional pure tone audiometry (the first audiometer with electrical current was devised by Hartmann in 1878). At present there are psychophysical non invasive tests that, besides evaluating visual and auditory performance globally and even in cases catalogued as normal according to routine tests, supply early information regarding diseases such as diabetes, hypertension, renal failure, cardiovascular problems, etc. Concerning Optometry, one of these tests is the achromatic luminance contrast sensitivity test (introduced by Schade in 1956). Concerning Audiology, one of these tests is high frequency pure tone audiometry (introduced a few decades ago) which yields information relative to pathologies affecting the basal cochlea and complements data resulting from conventional audiometry. These utilities of the contrast sensitivity test and of pure tone audiometry derive from the facts that Fourier components constitute the basis to synthesize stimuli present at the entrance of the visual and auditory systems; that these systems responses depend on frequencies and that the patient's psychophysical state affects frequency processing. The frequency of interest in the former test is the effective spatial frequency (inverse of the angle subtended at the eye by a cycle of a sinusoidal grating and measured in cycles/degree) and, in the latter, the temporal frequency (measured in cycles/sec). Both tests have similar duration and consist in determining the patient's threshold (corresponding to the inverse multiplicative of the contrast or to the inverse additive of the sound intensity level) for each harmonic stimulus present at the system entrance (sinusoidal grating or pure tone sound). In this article the frequencies, standard normality curves and abnormal threshold shifts

  5. Disruption of Lateral Efferent Pathways: Functional Changes in Auditory Evoked Responses

    OpenAIRE

    Le Prell, Colleen G.; Shore, Susan E.; Hughes, Larry F.; Bledsoe, Sanford C.

    2003-01-01

    The functional consequences of selectively lesioning the lateral olivocochlear efferent system in guinea pigs were studied. The lateral superior olive (LSO) contains the cell bodies of lateral olivocochlear neurons. Melittin, a cytotoxic chemical, was injected into the brain stem using stereotaxic coordinates and near-field evoked potentials to target the LSO. Brain stem histology revealed discrete damage to the LSO following the injections. Functional consequences of this damage were reflect...

  6. Somatosensory Evoked Potentials and Dopaminergic Responsiveness to Apomorphine and Levodopa in Parkinsonian Patients

    Directory of Open Access Journals (Sweden)

    M. Miranda

    1996-01-01

    Full Text Available Short-latency somatosensory evoked potentials (SSEPs were recorded from 10 parkinsonian patients in ‘off’ and ‘on’ states induced by apomorphine and levodopa. The effects of apomorphine and long-term levodopa treatment on the frontal N30 component were assessed and compared with healthy controls. Nine of 10 patients tested with apomorphine showed a significant improvement (p

  7. A STUDY OF HEARING EVALUATION FOR NEONATES WITH HYPERBILIRUBINEMIA USING OTOACOUSTIC EMISSION AND BRAIN STEM AUDITORY EVOKED RESPONSE

    Directory of Open Access Journals (Sweden)

    Poornima

    2014-03-01

    Full Text Available Jaundice is one of the most common problems occurring in newborns. Although most of jaundiced patients are normal; because of the bilirubin toxicity, high serum levels can lead to kernicterus. It is important to identify and evaluate the jaundice early to prevent complications like bilirubin encephalopathy leading to hearing loss. Such early detection is possible only if some form of routine screening is used, one of which is otoacoustic emission. By detecting the hearing loss in time with screening methods we can ensure normal language development by appropriate intervention like hearing aids and infant stimulation. In this study otoacoustic emission will be followed by brain stem auditory evoked response and the results will be analyzed to look for the effectiveness of using otoacoustic emission for mass screening. METHODOLOGY: after obtaining approval and clearance from the institutional ethics committee this study included 105 children which satisfied the inclusion criteria. A standard case record was maintained for each subject. The neonate was subjected to otoacoustic emission just before discharge from the hospital. Otoacoustic emission was followed by brain stem auditory evoked response and the results compiled. Result of brain stem auditory evoked response was taken as gold standard and the results were analyzed. RESULTS: Abnormal OAE changes were seen in 6 and abnormal BERA was seen in 9 babies out of a total of 105 babies tested with hyperbilirubinemia. CONCLUSION: use of otoacoustic emissions as initial screening test provides as easy, cost effective and quick method to detect infants with hearing loss. As it is less invasive and less time consuming than BERA, dpOAE can be used as initial screening method for hearing loss in infants with BERA being reserved for infants that fail dpOAE.

  8. Signal Refinement: Principal Component Analysis and Wavelet Transform of Visual Evoked Response

    Directory of Open Access Journals (Sweden)

    Ahmed Almurshedi

    2015-01-01

    Full Text Available This study presents an analysis on Visual Evoked Potentials (VEPs recorded mainly from the occipital area of the brain. Accumulation of segmented windows (time locked averaging, Coiflet wavelet decomposition with dyadic filter bank and Principle Component Analysis (PCA of three stages were utilized in order to decompose the recorded VEPs signal, to improve the Signal to Noise Ratio (SNR and to reveal statistical information. The results shown that the wavelet transformation offer a significant SNR improvement at around four times compared to PCA as long as the shape of the original signal is retained. These techniques show significant advantages of decomposing the EEG signals into its details frequency bands.

  9. Audiometry and ossicular condition in chronic otitis media

    Directory of Open Access Journals (Sweden)

    mohsen Rajati Haghi

    2009-07-01

    Full Text Available   Introduction: Ossicular chain injury is one of the most common causes of hearing loss in chronic otitis media (COM. Although definite diagnosis of ossicular discontinuity is made intraoperatively, preoperative determination of ossicular chain injury will help the surgeon decide about reconstruction options and hearing prognosis of the patient. In this study we compared preoperative pure tone audiometry (PTA findings of COM patients with the ossicular condition determined during surgery. Materials and Methods: 97 Patients with COM who underwent ear surgery for the first time were included in the study. A checklist of preoperative clinical findings, audiometric parameters and intraoperative findings was filled out for all patients. Results: Mean amount of Air-Bone Gap (ABG, Bone Conduction threshold (BC and Air Conduction threshold (AC of 97 Patients were 35.17, 13.13 and 48.30 respectively. In ears with or without cholesteatoma, granulation tissue, or otorrhea, mean of AC, BC, and ABG were not significantly different. In ossicular erosion and discontinuity (OD, mean of AC and BC thresholds increased significantly but ABG didn’t change significantly. Conclusion: According to the results of this study, in preoperative assessment of COM patients to predict ossicular condition we recommend considering AC, BC and ABG levels together instead of using ABG alone as is routine in our daily practice.

  10. The relation of ongoing brain activity, evoked neural responses, and cognition

    Directory of Open Access Journals (Sweden)

    Sepideh Sadaghiani

    2010-06-01

    Full Text Available Ongoing brain activity has been observed since the earliest neurophysiological recordings and is found over a wide range of temporal and spatial scales. It is characterized by remarkably large spontaneous modulations. Here, we review evidence for the functional role of these ongoing activity fluctuations and argue that they constitute an essential property of the neural architecture underlying cognition. The role of spontaneous activity fluctuations is probably best understood when considering both their spatiotemporal structure and their functional impact on cognition. We first briefly argue against a ‘segregationist’ view on ongoing activity, both in time and space, countering this view with an emphasis on integration within a hierarchical spatiotemporal organization of intrinsic activity. We then highlight the flexibility and context-sensitivity of intrinsic functional connectivity that suggest its involvement in functionally relevant information processing. This role in information processing is pursued by reviewing how ongoing brain activity interacts with afferent and efferent information exchange of the brain with its environment. We focus on the relationship between the variability of ongoing and evoked brain activity, and review recent reports that tie ongoing brain activity fluctuations to variability in human perception and behavior. Finally, these observations are discussed within the framework of the free-energy principle which – applied to human brain function - provides a theoretical account for a non-random, coordinated interaction of ongoing and evoked activity in perception and behaviour.

  11. Task-specific modulation of human auditory evoked responses in a delayed-match-to-sample task

    Directory of Open Access Journals (Sweden)

    Feng eRong

    2011-05-01

    Full Text Available In this study, we focus our investigation on task-specific cognitive modulation of early cortical auditory processing in human cerebral cortex. During the experiments, we acquired whole-head magnetoencephalography (MEG data while participants were performing an auditory delayed-match-to-sample (DMS task and associated control tasks. Using a spatial filtering beamformer technique to simultaneously estimate multiple source activities inside the human brain, we observed a significant DMS-specific suppression of the auditory evoked response to the second stimulus in a sound pair, with the center of the effect being located in the vicinity of the left auditory cortex. For the right auditory cortex, a non-invariant suppression effect was observed in both DMS and control tasks. Furthermore, analysis of coherence revealed a beta band (12 ~ 20 Hz DMS-specific enhanced functional interaction between the sources in left auditory cortex and those in left inferior frontal gyrus, which has been shown to involve in short-term memory processing during the delay period of DMS task. Our findings support the view that early evoked cortical responses to incoming acoustic stimuli can be modulated by task-specific cognitive functions by means of frontal-temporal functional interactions.

  12. Effects of OnabotulintoxinA on Habituation of Laser Evoked Responses in Chronic Migraine.

    Science.gov (United States)

    de Tommaso, Marina; Delussi, Marianna; Ricci, Katia; Montemurno, Anna; Carbone, Irene; Vecchio, Eleonora

    2016-01-01

    Onabotulintoxin A (BontA) is an efficacious preventive treatment for chronic migraine, though the specific mechanism of action is still under discussion. The study aims: (1) To evaluate pain processing modifications in chronic migraine patients (CM) under single BontA administration in pericranial muscles, by means of CO² Laser Evoked Potentials (LEPs) obtained by the stimulation of the skin over the right frontal and trapezius injection sites and hand dorsum, in a double blind placebo controlled crossover design. (2) To correlate main LEPs findings with clinical outcome after one year of BontA treatment. Twenty refractory CM patients were included in the analysis. The LEPs were recorded in basal conditions and seven days after BontA (PREEMPT protocol) and saline solution injection. The N1, N2 and P2 amplitude and latencies and N2P2 habituation index were evaluated and correlated with the percent change of headache frequency after one year of toxin treatment. After seven days of BontA treatment, a normalization of the trigeminal habituation index was observed, which was correlated with the clinical outcome after one year of BontA therapy. Patients displaying trigeminal LEPs facilitation at T0 time showed a more efficient therapeutic outcome. Neurotoxin may exert a modulating effect on trigeminal nociception, normalizing central neurotransmission. PMID:27231940

  13. Development of Guideline for Rating the Physical Impairment of Otolaryngologic Field

    OpenAIRE

    Park, Chul Won; Do, Nam Yong; Rha, Ki Sang; Chung, Sung Min; Kwon, Young Jun

    2009-01-01

    We develop a guideline for rating the physical impairment of otolaryngologic fields. Assessment of hearing disturbance and tinnitus required physical examination, pure tone audiometry, speech audiometry, impedance audiometry, brainstem evoked response audiometry, Bekesy audiometry, otoacoustic emission test, and imaging examination. History taking, physical examination, and radiological examination for the vestibular organ and brain, righting reflex test, electronystagmography, and caloric te...

  14. Assessment of Electrically Evoked Auditory Brain Stem Response of 30 Implanted Patients With Nucleus Multichannel Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Dr. Soqrat Faghihzadeh

    2001-05-01

    Full Text Available Methods and Materials: Investigation of electrically evoked auditory brain stem response (EABR is a new issue, especially in implanted patients. Experiments were performed in C.I Center of Iranian Institute for Science and research expansion,1996 on 30 implanted patients with 22 spectra and MSP cochlear implant system and 30 normal subjects with the range of 3-33 years. Findings: I- EABR was obtained in the implanted patients. 2- Absolute latency of EABR waves is 1-1.5 ms shorter than ABR waves ‘P<0.05. 3-Absolute latency of wave V decreases as a function of electric stimulus magnitude (P<0.05. 4- No significant difference was observed in IPL Ill-V between ABR and EABR.

  15. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...... a minor effect on the power spectra, i.e. the maximum jumps from one spectral peak to another. Experiments with deconvolution demonstrate that the emission generating system at least at a fixed intensity can be regarded as being linear and characterized by its impulse response which is similar to...... the emission evoked by click stimuli. It is concluded that significant information is obtained by the click rather than by the tonal stimuli. The click-evoked emissions were also recorded from both ears in a consecutive series of 100 full-term and otherwise normal babies 2-4 days after birth. The...

  16. Mathematical impairment associated with high-contrast abnormalities in change detection and magnocellular visual evoked response.

    Science.gov (United States)

    Jastrzebski, Nicola R; Crewther, Sheila G; Crewther, David P

    2015-10-01

    The cause of developmental dyscalculia, a specific deficit in acquisition of arithmetic skills, particularly of enumeration, has never been investigated with respect to the patency of the visual magnocellular system. Here, the question of dysfunction of the afferent magnocellular cortical input and its dorsal stream projections was tested directly using nonlinear analysis of the visual evoked potential (VEP) and through the psychophysical ability to rapidly detect visual change. A group of young adults with self-reported deficiencies of arithmetical ability, showed marked impairment in magnitude estimation and enumeration performance-though not in lexical decision reaction times when compared with an arithmetically capable group controlled for age and handedness. Multifocal nonlinear VEPs were recorded at low (24 %) and high (96 %) contrast. First- and second-order VEP kernels were comparable between groups at low contrast, but not at high contrast. The mathematically impaired group showed an abnormal lack of contrast saturation in the shortest latency first-order peak (N60) and a delayed P100 positivity in the first slice of the second-order kernel. Both features have previously been argued to be physiological markers of magnocellular function. Mathematically impaired participants also performed worse on a gap paradigm change detection for digit task showing increased reaction times for high-contrast stimuli but not for low-contrast stimuli compared with controls. The VEP results give direct evidence of abnormality in the occipital processing of magnocellular information in those with mathematical impairment. The anomalous high visual contrast physiological and psychophysical performance suggests an abnormality in the inhibitory processes that normally result in saturation of contrast gain in the magnocellular system. PMID:26195163

  17. Effect of subarachnoid hemorrhage on contractile responses and noradrenaline release evoked in cat cerebral arteries by histamine

    International Nuclear Information System (INIS)

    This study analyzes the changes induced by subarachnoid hemorrhage (SAH) on the contractile responses and the noradrenaline release evoked in cat cerebral arteries by histamine. The dose-dependent vasoconstriction induced by histamine on the cerebral arteries of normal cats was significantly reduced by diphenhydramine and phentolamine. When SAH was produced 3 and 7 days before the experiment, the histamine-induced vasoconstriction also decreased. Thereafter, a tendency to normalization in the contractile vascular responses was observed such that in 15 days after the hemorrhage it was not significantly different from that found in controls animals. The decrease in the contractile responses to histamine provoked by SAH was similar to that seen after pretreatment with intracisternal injections of 6-hydroxydopamine. The amount of radioactivity released by histamine following preincubation with 3H-noradrenaline from the cerebral arteries of cats exposed to SAH 3, 7, and 15 days before the experiment was significantly reduced when compared with controls. Moreover, the basal level of tritium release and the radioactivity retained at the end of the experiment were also decreased after SAH. Results indicate histamine releases noradrenaline from cat cerebral arteries, and SAH produce a transient denervation of the perivascular adrenergic nerve endings, which explained by the impairment of the indirect adrenergic mechanism involved in the overall contractile response elicited by this amine in cerebral arteries. Histamine does not seem to play a significant role in the production of the cerebral vasospasm occurring after SAH

  18. Electrically evoked long loop responses (LLR): normative data for upper and lower extremities.

    Science.gov (United States)

    Deletis, V; Beric, A

    1989-01-01

    Long loop responses can be obtained repeatedly in all neurologically healthy subjects with low variability of onset and peak latencies. Long loop responses showed characteristic features separate from microreflexes of Bickford. Normative data will help us to elucidate the characteristic alterations of these reflexes in different pathologies which involve somatosensory pyramidal and extrapyramidal systems. PMID:2606069

  19. A Pilot Study of Phase-Evoked Acoustic Responses From the Ears of Human Subjects

    DEFF Research Database (Denmark)

    Christensen, Anders Tornvig; Dewey, James; Dhar, Sumitrajit; Ordoñez, Rodrigo Pizarro; Hammershøi, Dorte

    2014-01-01

    Temporal properties of otoacoustic emissions (OAEs) are of interest as they help understand the dynamic behavior and spatial distribution of the generating mechanisms. In particular, the ringing behavior of responses to clicks and tone bursts have been investigated, and times of arrival and...... cochlear excitation revealing properties of the nonlinearity responsible for OAE generation. To explore the temporal properties of OAEs further, we studied acoustic responses from the ears of nine young, normal-hearing human subjects to abrupt changes in the phase of pure tones. The measurement paradigm...

  20. Visual responses in the lateral geniculate evoked by Cx36-independent rod pathways

    OpenAIRE

    Timothy M Brown; Annette E Allen; Wynne, Jonathan; Paul, David L.; Piggins, Hugh D; Lucas, Robert J.

    2010-01-01

    Emerging evidence indicates rods can communicate with retinal ganglion cells (RGCs) via pathways that do not involve gap-junctions. Here we investigated the significance of such pathways for central visual responses, using mice lacking a key gap junction protein (Cx36−/−) and carrying a mutation that disrupts cone phototransduction (Gnat2cpfl3). Electrophysiological recordings spanning the lateral geniculate revealed rod-mediated ON and OFF visual responses in virtually every cell from all ma...

  1. Sex-Specific Automatic Responses to Infant Cries: TMS Reveals Greater Excitability in Females than Males in Motor Evoked Potentials

    Science.gov (United States)

    Messina, Irene; Cattaneo, Luigi; Venuti, Paola; de Pisapia, Nicola; Serra, Mauro; Esposito, Gianluca; Rigo, Paola; Farneti, Alessandra; Bornstein, Marc H.

    2016-01-01

    Neuroimaging reveals that infant cries activate parts of the premotor cortical system. To validate this effect in a more direct way, we used event-related transcranial magnetic stimulation (TMS). Here, we investigated the presence and the time course of modulation of motor cortex excitability in young adults who listened to infant cries. Specifically, we recorded motor evoked potentials (MEPs) from the biceps brachii (BB) and interosseus dorsalis primus (ID1) muscles as produced by TMS delivered from 0 to 250 ms after sound onset in six steps of 50 ms in 10 females and 10 males. We observed an excitatory modulation of MEPs at 100 ms from the onset of infant cry specific to females and to the ID1 muscle. We regard this modulation as a response to natural cry sounds because it was attenuated to stimuli increasingly different from natural cry and absent in a separate group of females who listened to non-cry stimuli physically matched to natural infant cries. Furthermore, the 100-ms latency of this response is not compatible with a voluntary reaction to the stimulus but suggests an automatic, bottom-up audiomotor association. The brains of adult females appear to be tuned to respond to infant cries with automatic motor excitation. PMID:26779061

  2. A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans

    DEFF Research Database (Denmark)

    Vianna, Lauro C; Fadel, Paul J; Secher, Niels H; Fisher, James P

    2015-01-01

    A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the...... muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle blood flow rapidly occurs as a consequence of multiple redundant mechanisms. We recorded blood pressure (BP; brachial artery), stroke volume (pulse contour analysis), cardiac output, and systemic vascular...

  3. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice

    Directory of Open Access Journals (Sweden)

    John Martin Barrett

    2015-08-01

    Full Text Available Retinitis pigmentosa (RP is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity.We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2 in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-ß-glycyrrhetinic acid (18BGA, another gap junction blocker or flupirtine (Flu, a Kv7 potassium channel opener. All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses.Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic

  4. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice.

    Science.gov (United States)

    Barrett, John M; Degenaar, Patrick; Sernagor, Evelyne

    2015-01-01

    Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR) of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity. We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2) in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-β-glycyrrhetinic acid (18BGA, another gap junction blocker) or flupirtine (Flu, a Kv7 potassium channel opener). All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses. Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic prostheses

  5. Basic properties of somatosensory-evoked responses in the dorsal hippocampus of the rat.

    Science.gov (United States)

    Bellistri, Elisa; Aguilar, Juan; Brotons-Mas, Jorge R; Foffani, Guglielmo; de la Prida, Liset Menendez

    2013-05-15

    The hippocampus is a pivotal structure for episodic memory function. This ability relies on the possibility of integrating different features of sensory stimuli with the spatio-temporal context in which they occur. While recent studies now suggest that somatosensory information is already processed by the hippocampus, the basic mechanisms still remain unexplored. Here, we used electrical stimulation of the paws, the whisker pad or the medial lemniscus to probe the somatosensory pathway to the hippocampus in the anaesthetized rat, and multisite electrodes, in combination with tetrode and intracellular recordings, to look at the properties of somatosensory hippocampal responses. We found that peripheral and lemniscal stimulation elicited small local field potential responses in the dorsal hippocampus about 35-40 ms post-stimulus. Current source density analysis established the local nature of these responses, revealing associated synaptic sinks that were consistently confined to the molecular layer (ML) of the dentate gyrus (DG), with less regular activation of the CA1 stratum lacunosum moleculare (SLM). A delayed (40-45 ms), potentially active, current source that outlasted the SLM sink was present in about 50% cases around the CA1 pyramidal cell layer. Somatosensory stimulation resulted in multi-unit firing increases in the majority of DG responses (79%), whereas multi-unit firing suppression was observed in the majority of CA1 responses (62%). Tetrode and intracellular recordings of individual cells confirmed different firing modulation in the DG and the CA1 region, and verified the active nature of both the early ML sink and delayed somatic CA1 source. Hippocampal responses to somatosensory stimuli were dependent on fluctuations in the strength and composition of synaptic inputs due to changes of the ongoing local (hippocampal) and distant (cortical) state. We conclude that somatosensory signals reach the hippocampus mainly from layer II entorhinal cortex to

  6. High frequency switched-mode stimulation can evoke postsynaptic responses in cerebellar principal neurons

    Directory of Open Access Journals (Sweden)

    Marijn Van Dongen

    2015-03-01

    These findings are subsequently verified using in vitro experiments in which the response of a Purkinje cell is measured due to a stimulation signal in the molecular layer of the cerebellum of a mouse. For this purpose a stimulator circuit is developed that is able to produce a monophasic high frequency switched-mode stimulation signal. The results confirm the modeling by showing that switched-mode stimulation is able to induce similar responses in the Purkinje cell as classical stimulation using a constant current source. This conclusion opens up possibilities for novel stimulation designs that can improve the performance of the stimulator circuitry. Care has to be taken to avoid losses in the system due to the higher operating frequency.

  7. Restoration of auditory evoked responses by human ES cell-derived otic progenitors

    OpenAIRE

    Chen, Wei; Jongkamonwiwat, Nopporn; Abbas, Leila; Eshtan, Sarah Jacob; Johnson, Stuart L.; Kuhn, Stephanie; Milo, Marta; Thurlow, Johanna K.; Peter W Andrews; Marcotti, Walter; Moore, Harry D.; Rivolta, Marcelo N

    2012-01-01

    Deafness is a condition with a high prevalence worldwide, produced primarily by the loss of the sensory hair cells and their associated spiral ganglion neurons (SGNs). Of all the forms of deafness, auditory neuropathy is of a particular concern. This condition, defined primarily by damage to the SGNs with relative preservation of the hair cells 1 , is responsible for a substantial proportion of patients with hearing impairment 2 . While the loss of hair cells can be circumvented partially by ...

  8. Electroacupuncture reduces the evoked responses of the spinal dorsal horn neurons in ankle-sprained rats

    OpenAIRE

    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon; Chung, Jin Mo

    2011-01-01

    Acupuncture is shown to be effective in producing analgesia in ankle sprain pain in humans and animals. To examine the underlying mechanisms of the acupuncture-induced analgesia, the effects of electroacupuncture (EA) on weight-bearing forces (WBR) of the affected foot and dorsal horn neuron activities were examined in a rat model of ankle sprain. Ankle sprain was induced manually by overextending ligaments of the left ankle in the rat. Dorsal horn neuron responses to ankle movements or compr...

  9. PET measured evoked cerebral blood flow responses in an awake monkey

    International Nuclear Information System (INIS)

    We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments

  10. Taste-evoked responses to sweeteners in the nucleus of the solitary tract differ between C57BL/6ByJ and 129P3/J mice.

    Science.gov (United States)

    McCaughey, Stuart A

    2007-01-01

    C57BL/6ByJ (B6) and 129P3/J (129) mice have different alleles of Tas1r3, which is thought to influence gustatory transduction of sweeteners, but studies have provided conflicting results regarding differences in sweetness perception between these strains. Single-unit taste-evoked activity was measured in the nucleus of the solitary tract (NST) in anesthetized B6 and 129 mice to address this controversy and to provide the first electrophysiological characterization of this nucleus in mice. Neurons had properties similar to those of NST cells in other species, including mean breadth-of-tuning of 0.8 +/- 0.0. There were no strain differences in neural responses at 600 or 900 ms after onset, but, with a 5 s evoked period, responses to the sweeteners sucrose, maltose, acesulfame-K, SC-45647, and D-phenylalanine were significantly larger in B6 relative to 129 mice. The strains did not differ in their mean response to NaSaccharin, but it evoked an across-neuron pattern of activity that was more similar to that of sucrose and less similar to that of NaCl in B6 mice compared with 129 mice. Neurons were classified as sucrose, NaCl, or HCl responsive, with the former more common in B6 than 129 mice. Relative to other neurons, sucrose-responsive cells had delayed but more sustained sweetener responses in both strains. The results suggest that B6 mice perceive some sweeteners as more intense, but NaSaccharin as sweeter and less salty, relative to 129 mice. Furthermore, activity evoked by sweeteners includes a phasic response sent to different NST cells than a later tonic response, and only the latter differs between B6 and 129 mice. PMID:17202470

  11. Noise-evoked otoacoustic emissions in humans

    NARCIS (Netherlands)

    Maat, B; Wit, HP; van Dijk, P

    2000-01-01

    Click-evoked otoacoustic emissions (CEOAEs) and acoustical responses evoked by bandlimited Gaussian noise (noise-evoked otoacoustic emissions; NEOAEs) were measured in three normal-hearing subjects. For the NEOAEs the first- and second-order Wiener kernel and polynomial correlation functions up to t

  12. Cell-attached recordings of responses evoked by photorelease of GABA in the immature cortical neurons

    OpenAIRE

    Marat eMinlebaev; Guzel eValeeva; Vadim eTcheremiskine; Gaelle eCoustillier; Rustem eKhazipov

    2013-01-01

    We present a novel non-invasive technique to measure the polarity of GABAergic responses based on cell-attached recordings of currents activated by laser-uncaging of GABA. For these recordings, a patch pipette was filled with a solution containing RuBi-GABA, and GABA was released from this complex by a laser beam conducted to the tip of the patch pipette via an optic fiber. In cell-attached recordings from neocortical and hippocampal neurons in postnatal days P2-5 rat brain slices in vitro, w...

  13. Auditory cortical responses evoked by pure tones in healthy and sensorineural hearing loss subjects: functional MRI and magnetoencephalography

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-ting; GENG Zuo-jun; ZHANG Quan; LI Wei; ZHANG Jing

    2006-01-01

    hearing loss and the healthy subjects, the most evident audio evoked fields activated by pure tone were N100m,which located precisely on the Heschl's gyms. Compared with the hearing loss subjects, N100m of the healthy subjects was stronger and had longer latencies in fight hemisphere.Conclusions Under proper pure tone stimulus the activation of auditory cortex can be elicited both in the healthy and the sensorineural hearing loss subjects. Either at objective equivalent stimuli or at subjectively perceived equivalent stimuli, the auditory responses were more intensive in healthy subjects than hearing loss subjects. The tone stimuli were processed in a network in human brain and there was an intrinsic relation between the auditory and visual cortex. Blood oxygen level dependent fMRI and magnetoencephalography could reinforce each other.

  14. Sex-specific automatic responses to infant cries: TMS reveals greater excitability in females than males in motor evoked potentials

    Directory of Open Access Journals (Sweden)

    Irene eMessina

    2016-01-01

    Full Text Available Neuroimaging reveals that infant cries activate parts of the premotor cortical system. To validate this effect in a more direct way, we used event-related transcranial magnetic stimulation (TMS. Here, we investigated the presence and the time course of modulation of motor cortex excitability in young adults who listened to infant cries. Specifically, we recorded motor evoked potentials (MEPs from the biceps brachii (BB and interosseus dorsalis primus (ID1 muscles as produced by TMS delivered from 0 to 250 ms from sound onset in six steps of 50 ms in 10 females and 10 males. We observed an excitatory modulation of MEPs at 100 ms from the onset of the infant cry specific to females and to the ID1 muscle. We regard this modulation as a response to natural cry sounds because it was delayed, attenuated to stimuli increasingly different from natural cry, and was absent in a separate group of females who listened to non-cry stimuli physically matched to natural infant cries. Furthermore, the 100-ms latency of this modulation is not compatible with a voluntary reaction to the stimulus but suggests an automatic, bottom-up audiomotor association. The brains of adult females appear to be tuned to respond to infant cries with automatic motor excitation. This effect may reflect the greater and longstanding burden on females in caregiving infants.

  15. Comparing the Performance of Popular MEG/EEG Artifact Correction Methods in an Evoked-Response Study

    Science.gov (United States)

    Kliuchko, Marina; Vuust, Peter

    2016-01-01

    We here compared results achieved by applying popular methods for reducing artifacts in magnetoencephalography (MEG) and electroencephalography (EEG) recordings of the auditory evoked Mismatch Negativity (MMN) responses in healthy adult subjects. We compared the Signal Space Separation (SSS) and temporal SSS (tSSS) methods for reducing noise from external and nearby sources. Our results showed that tSSS reduces the interference level more reliably than plain SSS, particularly for MEG gradiometers, also for healthy subjects not wearing strongly interfering magnetic material. Therefore, tSSS is recommended over SSS. Furthermore, we found that better artifact correction is achieved by applying Independent Component Analysis (ICA) in comparison to Signal Space Projection (SSP). Although SSP reduces the baseline noise level more than ICA, SSP also significantly reduces the signal—slightly more than it reduces the artifacts interfering with the signal. However, ICA also adds noise, or correction errors, to the waveform when the signal-to-noise ratio (SNR) in the original data is relatively low—in particular to EEG and to MEG magnetometer data. In conclusion, ICA is recommended over SSP, but one should be careful when applying ICA to reduce artifacts on neurophysiological data with relatively low SNR. PMID:27524998

  16. Effects of glutamate receptor agonists on the P13 auditory evoked potential and startle response in the rat

    Directory of Open Access Journals (Sweden)

    EdgarGarcia-Rill

    2011-01-01

    Full Text Available The P13 potential is the rodent equivalent of the P50 potential, which is an evoked response recorded at the vertex (Vx 50 msec following an auditory stimulus in humans. Both the P13 and P50 potentials are only present during waking and rapid eye movement (REM sleep, and are considered to be measures of level of arousal. The source of the P13 and P50 potentials appears to be the pedunculopontine nucleus (PPN, a brainstem nucleus with indirect ascending projections to the cortex through the intralaminar thalamus (ILT, mediating arousal, and descending inhibitory projections to the caudal pontine reticular formation (CPRF, which mediates the auditory startle response (SR. We tested the hypothesis that intracranial microinjection (ICM of glutamate (GLU or GLU receptor agonists will increase the activity of PPN neurons, resulting in an increased P13 potential response, and decreased SR due to inhibitory projections from the PPN to the CPRF, in freely moving animals. Cannulae were inserted into the PPN to inject neuroactive agents, screws were inserted into the Vx in order to record the P13 potential, and electrodes inserted into the dorsal nuchal muscle to record electromyograms (EMGs and SR amplitude. Our results showed that ICM of GLU into the PPN dose-dependently increased the amplitude of the P13 potential and decreased the amplitude of the SR. Similarly, ICM of NMDA or KA into the PPN increased the amplitude of the P13 potential. These findings indicate that glutamatergic input to the PPN plays a role in arousal control in vivo, and changes in glutamatergic input, or excitability of PPN neurons, could be implicated in a number of neuropsychiatric disorders with the common symptoms of hyperarousal and REM sleep dysregulation.

  17. Transiently Evoked Otoacoustic Emissions in Children with Otitis Media with Effusion

    Directory of Open Access Journals (Sweden)

    Dimitris G. Balatsouras

    2012-01-01

    Full Text Available Introduction. Otitis media with effusion is a common pediatric disease whose diagnosis is based on pneumatic otoscopy, pure-tone audiometry, and tympanometry. The aim of this study was to evaluate transiently evoked otoacoustic emissions in the diagnosis of otitis media with effusion as compared to tympanometry. Patients and Methods. 38 children with bilateral otitis media with effusion were studied. 40 normal children of similar age and sex were used as controls. All subjects underwent pneumatic otoscopy, standard pure-tone audiometry, tympanometry, and transiently evoked otoacoustic emissions. Results. In the group of children with bilateral otitis media, transiently evoked otoacoustic emissions were absent in 51 ears (67%. In the remaining 25 ears (33% the mean emission amplitude was reduced, as compared to the mean value of the control group. Conclusions. Transiently evoked otoacoustic emissions should be included in the diagnostic workup of otitis media with effusion because it is a fast, reliable, and objective test. Transiently evoked otoacoustic emissions should always be used in conjunction with tympanometry, because a more meaningful interpretation of transiently evoked otoacoustic emissions measures is possible.

  18. Plasticity in Tumor-Promoting Inflammation: Impairment of Macrophage Recruitment Evokes a Compensatory Neutrophil Response

    Directory of Open Access Journals (Sweden)

    Jessica C. Pahler

    2008-04-01

    Full Text Available Previous studies in the K14-HPV/E2 mouse model of cervical carcinogenesis demonstrated that infiltrating macrophages are the major source of matrix metalloproteinase 9 (MMP-9, a metalloprotease important for tumor angiogenesis and progression. We observed increased expression of the macrophage chemoattractant, CCL2, and its receptor, CCR2, concomitant with macrophage influx and MMP-9 expression. To study the role of CCL2-CCR2 signaling in cervical tumorigenesis, we generated CCR2-deficient K14-HPV/E2 mice. Cervixes of CCR2-null mice contained significantly fewer macrophages. Surprisingly, there was only a modest delay in time to progression from dysplasia to carcinoma in the CCR2-deficient mice, and no difference in end-stage tumor incidence or burden. Moreover, there was an unexpected persistence of MMP-9 activity, associated with increased abundance of MMP-9+ neutrophils in tumors from CCR2-null mice. In vitro bioassays revealed that macrophages produce soluble factor(s that can suppress neutrophil dynamics, as evidenced by reduced chemotaxis in response to CXCL8, and impaired invasion into three-dimensional tumor masses grown in vitro. Our data suggest a mechanism whereby CCL2 attracts proangiogenic CCR2+ macrophages with the ancillary capability to limit infiltration by neutrophils. If such tumor-promoting macrophages are suppressed, MMP-9+ neutrophils are then recruited, providing alternative paracrine support for tumor angiogenesis and progression.

  19. Efficacy of intrathecal esmolol on heat-evoked responses in a postoperative pain model.

    Science.gov (United States)

    Ono, Hitomi; Ohtani, Norimasa; Matoba, Atsuko; Kido, Kanta; Yasui, Yutaka; Masaki, Eiji

    2015-01-01

    Perioperative tachycardia and hypertension are often treated with esmolol, a short-acting β1-adrenoceptor antagonist. Besides its cardiac effect, esmolol is reported to exert antinociceptive effects. This study examined the efficacy of intrathecal (IT) esmolol on pain responses in a postoperative pain model. Male Sprague-Dawley rats (250-300 g) were anesthetized with sevoflurane and an IT catheter was implanted. Six days after catheter implantation, a postoperative pain model was established by plantar incision under sevoflurane anesthesia. Withdrawal latencies were assessed by applying a focused radiant heat source before plantar incision; 1 day after the incision (before esmolol administration); and 5, 10, and 15 minutes after bolus administration of IT esmolol. Plantar incision produced hypersensitivity in the postoperative pain model expressed as decreased withdrawal latency to heat stimulation (before incision: 13.9 ± 0.29 seconds and 1 day after incision: 6.3 ± 0.26 seconds). These decreased latencies caused by incision were significantly increased by esmolol administration (40 μg, 80 μg) at 5 minutes (10.7 ± 1.16 seconds, 10.5 ± 1.16 seconds). No postoperative antinociceptive effects of esmolol were observed at 10 or 15 minutes. IT administration of esmolol produced antinociceptive effects of short duration in a rat postoperative pain model. These results suggest that IT esmolol could offer a new strategy for managing perioperative pain, although an alternative approach is necessary to lengthen the duration of the analgesia. PMID:23411610

  20. Imaging the impact of cortical microcirculation on synaptic structure and sensory-evoked hemodynamic responses in vivo.

    Directory of Open Access Journals (Sweden)

    Shengxiang Zhang

    2007-05-01

    Full Text Available In vivo two-photon microscopy was used to image in real time dendrites and their spines in a mouse photothrombotic stroke model that reduced somatosensory cortex blood flow in discrete regions of cortical functional maps. This approach allowed us to define relationships between blood flow, cortical structure, and function on scales not previously achieved with macroscopic imaging techniques. Acute ischemic damage to dendrites was triggered within 30 min when blood flow over >0.2 mm(2 of cortical surface was blocked. Rapid damage was not attributed to a subset of clotted or even leaking vessels (extravasation alone. Assessment of stroke borders revealed a remarkably sharp transition between intact and damaged synaptic circuitry that occurred over tens of mum and was defined by a transition between flowing and blocked vessels. Although dendritic spines were normally ~13 microm from small flowing vessels, we show that intact dendritic structure can be maintained (in areas without flowing vessels by blood flow from vessels that are on average 80 microm away. Functional imaging of intrinsic optical signals associated with activity-evoked hemodynamic responses in somatosensory cortex indicated that sensory-induced changes in signal were blocked in areas with damaged dendrites, but were present ~400 microm away from the border of dendritic damage. These results define the range of influence that blood flow can have on local cortical fine structure and function, as well as to demonstrate that peri-infarct tissues can be functional within the first few hours after stroke and well positioned to aid in poststroke recovery.

  1. Stimulus dependency of object-evoked responses in human visual cortex: an inverse problem for category specificity.

    Directory of Open Access Journals (Sweden)

    Britta Graewe

    Full Text Available Many studies have linked the processing of different object categories to specific event-related potentials (ERPs such as the face-specific N170. Despite reports showing that object-related ERPs are influenced by visual stimulus features, there is consensus that these components primarily reflect categorical aspects of the stimuli. Here, we re-investigated this idea by systematically measuring the effects of visual feature manipulations on ERP responses elicited by both structure-from-motion (SFM-defined and luminance-defined object stimuli. SFM objects elicited a novel component at 200-250 ms (N250 over parietal and posterior temporal sites. We found, however, that the N250 amplitude was unaffected by restructuring SFM stimuli into meaningless objects based on identical visual cues. This suggests that this N250 peak was not uniquely linked to categorical aspects of the objects, but is strongly determined by visual stimulus features. We provide strong support for this hypothesis by parametrically manipulating the depth range of both SFM- and luminance-defined object stimuli and showing that the N250 evoked by SFM stimuli as well as the well-known N170 to static faces were sensitive to this manipulation. Importantly, this effect could not be attributed to compromised object categorization in low depth stimuli, confirming a strong impact of visual stimulus features on object-related ERP signals. As ERP components linked with visual categorical object perception are likely determined by multiple stimulus features, this creates an interesting inverse problem when deriving specific perceptual processes from variations in ERP components.

  2. Effect of current frequency during electrical stunning in a water bath on somatosensory evoked responses in turkey's brain.

    Science.gov (United States)

    Mouchonière, M; Le Pottier, G; Fernandez, X

    2000-08-01

    Somatosensory evoked responses (SEP) in a turkey's brain were determined after water-bath stunning with a 150-mA (constant current) delivered with 50, 300 or 600 Hz, or with 75 mA, delivered with 50-Hz alternating current (AC) in order to evaluate the effectiveness of stunning. Ninety-four BUT 9 turkey hens 12 weeks of age were surgically implanted with EEG recording and left wing nerve stimulating electrodes 4 hours before stunning. They were individually stunned by immersion of the head and upper part of the neck in a water bath for 4 s. Using a 150-mA current, all birds stunned at 50 Hz showed cardiac arrest and a flat EEG immediately after the stun with no SEP recovery. The incidence of cardiac arrest at stunning decreased with increasing current frequency but SEP were lost in all birds. In birds that survived the stun, the duration of SEP abolition was on average 69 and 34 seconds at 300 and 600 Hz, respectively. Stunning with a 75-mA AC, delivered with 50 Hz, induced cardiac arrest in 32 per cent of turkeys. SEP were abolished in only 71 per cent of the birds that survived the stun, with an average duration of SEP of 66 seconds. The results indicate that increasing the frequency of a 150-mA AC current leads to a decreased stunning efficiency. A current of 75 mA per bird is unacceptable since 29 per cent of the birds do not show SEP abolition. PMID:10924394

  3. Effects of (MET-5) enkephalin on the electrically-evoked mechanical responses in longitudinal and circular strips of the cat terminal ileum.

    Science.gov (United States)

    Radomirov, R; Pencheva, N; Venkova, K; Davidoff, M

    1990-09-01

    In longitudinal and circular strips from cat terminal ileum field electrical stimulation at a frequency of 2 Hz evoked contractile responses. Stimulation at frequencies of 10 or 30 Hz elicited contractions of the longitudinal muscle and relaxations of the circular strips. (Met-5) enkephalin (1 nM) naloxone-dependently reduced the contractile and increased the inhibitory responses. Atropine (3 microM) converted the contractile responses to slight relaxations and potentiated the inhibitory responses. After atropine (3 microM) and guanethidine (50 microM) both longitudinal and circular strips responded to electrical stimulation with relaxations. In atropine-pretreated strips (Met-5) enkephalin was effective only in the circular strips, increasing the inhibitory responses. In contrast, after atropine and guanethidine (Met-5) enkephalin decreased these inhibitory responses. In unstimulated strips (Met-5) enkephalin failed to change the responses to acetylcholine and noradrenaline. It is concluded that (Met-5) enkephalin reduces the excitatory cholinergic components of the electrically-evoked responses in both longitudinal and circular strips as well as the excitatory adrenergic and the inhibitory non-adrenergic, non-cholinergic components of the responses in the circular strips by acting presynaptically. Demonstration of (Met-5) enkephalin-like immunoreactivity showed immunostaining in nerves of the myenteric plexus and in nerve fibers between the smooth muscle cells suggesting that (Met-5) enkephalin effects could be also of physiological significance. PMID:2274118

  4. Vestibular Evoked Myogenic Potential Produced by Bone-Conducted Stimuli: A Study on its Basics and Clinical Applications in Patients With Conductive and Sensorineural Hearing Loss and a Group With Vestibular Schawannoma

    Directory of Open Access Journals (Sweden)

    Parvane Mahdi

    2013-06-01

    Full Text Available Introduction: Vestibular evoked myogenic potential (VEMP has recently been broadly studied in vestibular disorders. As it is evoked by loud sound stimulation, even mild conductive hearing loss may affect VEMP results. Bone-conducted (BC stimulus is an alternative stimulation for evoking this response. This study aims to assess the characteristics of BC-VEMP in different groups of patients.   Materials and Methods: We performed a cross sectional analysis on 20 healthy volunteers with normal pure-tone audiometry as a control group; and on a group of patients consisted of 20 participants with conductive hearing loss, five with bilateral sensorineural hearing loss and four with vestibular schawannoma. AC and BC-VEMP were performed in all participants.   Results: In control group the VEMP responses to both kinds of stimuli had an acceptable morphology and consisted of p13 and n23 waves. Latency value of these main components in each type of stimulus was not significantly different (P>0.05. However, the mean amplitude was larger in BC modality than AC stimulation (P=0.025. In the group with conductive hearing loss, the VEMP response was absent in fifteen (46.87% of the 32 ears using the AC method, whereas all (100% displayed positive elicitability of VEMP by BC method. Normal VEMP responses in both stimuli were evoked in all patients with sensorineural hearing loss. In patients with unilateral vestibular schwannomas (VS, 2 (50.00% had neither AC-VEMP nor BC-VEMP. Conclusion:  Auditory stimuli delivered by bone conduction can evoke VEMP response. These responses are of vestibular origin and can be used in vestibular evaluation of patients with conductive hearing loss.

  5. Emotion responses under evoked consumption contexts: A focus on the consumers’ frequency of product consumption and the stability of responses

    NARCIS (Netherlands)

    Piqueras Fiszman, B.; Jaeger, S.R.

    2014-01-01

    Previous research has demonstrated that the context in which a certain food is consumed (even if imagined) can affect consumers’ associative emotional responses to that product. In three separate studies we extended this line of research by: (1) replicating these previous findings with consumers fro

  6. Time Course Analysis of the Effects of Botulinum Neurotoxin Type A on Pain and Vasomotor Responses Evoked by Glutamate Injection into Human Temporalis Muscles

    Directory of Open Access Journals (Sweden)

    Larissa Bittencourt da Silva

    2014-02-01

    Full Text Available The effect of botulinum neurotoxin type A (BoNTA on glutamate-evoked temporalis muscle pain and vasomotor responses was investigated in healthy men and women over a 60 day time course. Subjects participated in a pre-BoNTA session where their responses to injection of glutamate (1 M, 0.2 mL and saline (0.2 mL into the temporalis muscles were assessed. On Day 1, BoNTA (5 U was injected into one temporalis muscle and saline into the contralateral temporalis muscle, in a randomized order. Subjects then received intramuscular injections of glutamate (1 M, 0.2 mL into the left and right temporalis muscles at 3 h and subsequently 7, 30 and 60 days post-injection of BoNTA. Pain intensity, pain area, and neurogenic inflammation (skin temperature and skin blood perfusion were recorded. Prior to BoNTA treatment, glutamate evoked significantly greater pain and vasomotor reactions (P < 0.001 than saline. BoNTA significantly reduced glutamate-evoked pain intensity (P < 0.05, pain area (P < 0.01, skin blood perfusion (P < 0.05, and skin temperature (P < 0.001. The inhibitory effect of BoNTA was present at 3 h after injection, peaked after 7 days and returned to baseline by 60 days. Findings from the present study demonstrated a rapid action of BoNTA on glutamate-evoked pain and neurogenic inflammation, which is in line with animal studies.

  7. Dose-response characteristics of methylphenidate on locomotor behavior and on sensory evoked potentials recorded from the VTA, NAc, and PFC in freely behaving rats

    Directory of Open Access Journals (Sweden)

    Swann Alan C

    2006-01-01

    Full Text Available Abstract Background Methylphenidate (MPD is a psychostimulant commonly prescribed for attention deficit/hyperactivity disorder. The mode of action of the brain circuitry responsible for initiating the animals' behavior in response to psychostimulants is not well understood. There is some evidence that psychostimulants activate the ventral tegmental area (VTA, nucleus accumbens (NAc, and prefrontal cortex (PFC. Methods The present study was designed to investigate the acute dose-response of MPD (0.6, 2.5, and 10.0 mg/kg on locomotor behavior and sensory evoked potentials recorded from the VTA, NAc, and PFC in freely behaving rats previously implanted with permanent electrodes. For locomotor behavior, adult male Wistar-Kyoto (WKY; n = 39 rats were given saline on experimental day 1 and either saline or an acute injection of MPD (0.6, 2.5, or 10.0 mg/kg, i.p. on experimental day 2. Locomotor activity was recorded for 2-h post injection on both days using an automated, computerized activity monitoring system. Electrophysiological recordings were also performed in the adult male WKY rats (n = 10. Five to seven days after the rats had recovered from the implantation of electrodes, each rat was placed in a sound-insulated, electrophysiological test chamber where its sensory evoked field potentials were recorded before and after saline and 0.6, 2.5, and 10.0 mg/kg MPD injection. Time interval between injections was 90 min. Results Results showed an increase in locomotion with dose-response characteristics, while a dose-response decrease in amplitude of the components of sensory evoked field responses of the VTA, NAc, and PFC neurons. For example, the P3 component of the sensory evoked field response of the VTA decreased by 19.8% ± 7.4% from baseline after treatment of 0.6 mg/kg MPD, 37.8% ± 5.9% after 2.5 mg/kg MPD, and 56.5% ± 3.9% after 10 mg/kg MPD. Greater attenuation from baseline was observed in the NAc and PFC. Differences in the intensity of

  8. Eugenol and carvacrol excite first- and second-order trigeminal neurons and enhance their heat-evoked responses

    OpenAIRE

    Klein, Amanda H.; Joe, Christopher L.; Davoodi, Auva; Takechi, Kenichi; Carstens, Mirela Iodi; Carstens, E.

    2014-01-01

    Eugenol and carvacrol from clove and oregano, respectively, are agonists of the warmth-sensitive transient receptor potential channel TRPV3 and the irritant-sensitive TRPA1. Eugenol and carvacrol induce oral irritation that rapidly desensitizes, accompanied by brief enhancement of innocuous warmth and heat pain in humans. We presently investigated if eugenol and carvacrol activate nociceptive primary afferent and higher-order trigeminal neurons and enhance their heat-evoked ...

  9. Emotional facial expressions evoke faster orienting responses, but weaker emotional responses at neural and behavioural levels compared to scenes: A simultaneous EEG and facial EMG study.

    Science.gov (United States)

    Mavratzakis, Aimee; Herbert, Cornelia; Walla, Peter

    2016-01-01

    In the current study, electroencephalography (EEG) was recorded simultaneously with facial electromyography (fEMG) to determine whether emotional faces and emotional scenes are processed differently at the neural level. In addition, it was investigated whether these differences can be observed at the behavioural level via spontaneous facial muscle activity. Emotional content of the stimuli did not affect early P1 activity. Emotional faces elicited enhanced amplitudes of the face-sensitive N170 component, while its counterpart, the scene-related N100, was not sensitive to emotional content of scenes. At 220-280ms, the early posterior negativity (EPN) was enhanced only slightly for fearful as compared to neutral or happy faces. However, its amplitudes were significantly enhanced during processing of scenes with positive content, particularly over the right hemisphere. Scenes of positive content also elicited enhanced spontaneous zygomatic activity from 500-750ms onwards, while happy faces elicited no such changes. Contrastingly, both fearful faces and negative scenes elicited enhanced spontaneous corrugator activity at 500-750ms after stimulus onset. However, relative to baseline EMG changes occurred earlier for faces (250ms) than for scenes (500ms) whereas for scenes activity changes were more pronounced over the whole viewing period. Taking into account all effects, the data suggests that emotional facial expressions evoke faster attentional orienting, but weaker affective neural activity and emotional behavioural responses compared to emotional scenes. PMID:26453930

  10. The excitatory and inhibitory modulation of primary afferent fibre-evoked responses of ventral roots in the neonatal rat spinal cord exerted by nitric oxide.

    OpenAIRE

    Kurihara, T.; Yoshioka, K.

    1996-01-01

    1. We investigated the role of nitric oxide (NO) in modulating spinal synaptic responses evoked by electrical and noxious sensory stimuli in the neonatal rat spinal cord in vitro. 2. Potentials were recorded extracellularly from a ventral root (L3-L5) of the isolated spinal cord preparation or spinal cord-saphenous nerve-skin preparation of 0- to 2-day-old rats. Spinal reflexes were elicited by electrical stimulation of the ipsilateral dorsal root or by noxious skin stimulation. 3. In the spi...

  11. Use of the novel contact heat evoked potential stimulator (CHEPS) for the assessment of small fibre neuropathy: correlations with skin flare responses and intra-epidermal nerve fibre counts

    OpenAIRE

    Chizh Boris A; Misra V Peter; Roberts Katherine M; Facer Paul; Atherton Duncan D; Bountra Chas; Anand Praveen

    2007-01-01

    Abstract Background The Contact Heat Evoked Potential Stimulator (CHEPS) rapidly stimulates cutaneous small nerve fibres, and resulting evoked potentials can be recorded from the scalp. We have studied patients with symptoms of sensory neuropathy and controls using CHEPS, and validated the findings using other objective measures of small nerve fibres i.e. the histamine-induced skin flare response and intra-epidermal fibres (IEF), and also quantitative sensory testing (QST), a subjective measu...

  12. An integrated AMLAB-based system for acquisition, processing and analysis of evoked EMG and mechanical responses of upper limb muscles.

    Science.gov (United States)

    Jaberzadeh, S; Nazeran, H; Scutter, S; Warden-Flood, A

    2003-06-01

    An integrated multi-channel AMLAB-based data acquisition, processing and analysis system has been developed to simultaneously display, quantify and correlate electromyographic (EMG) activity, resistive torque, range of motion, and pain responses evoked by passive elbow extension in humans. The system was designed around the AMLAB analog modules and software objects called ICAMs. Each channel consisted of a time and frequency domain block, a torque and angle measurement block, an experiment number counter block and a data storage and retrieval block. The captured data in each channel was used to display and quantify: raw EMG, rectified EMG, smoothed rectified EMG, root-mean-squared EMG, fast Fourier transformed (FFT) EMG, and normalized power spectrum density (NPSD) of EMG. Torque and angle signals representing elbow extension measured by a KIN-COM dynamometer during neural tension testing, as well as signals from an electronic pain threshold marker were interfaced to AMLAB and presented in one integrated display. Although this system has been designed to specifically study the patterns and nature of evoked motor responses during clinical investigation of carpal tunnel syndrome (CTS) patients, it could equally well be modified to allow acquisition, processing and analysis of EMG signals in other studies and applications. In this paper, we present for the first time the steps involved in the design, implementation and testing of an integrated AMLAB-based system to study and analyse the mechanically evoked electromyographic, torque and ROM signals and correlate various levels of pain to these signals. We also present samples of resistive torque ROM, and raw and processed EMG recordings during passive elbow extension. PMID:12956188

  13. Inflammation-mediating cytokine response to acute handcycling exercise with/without functional electrical stimulation-evoked lower-limb cycling

    Directory of Open Access Journals (Sweden)

    Thomas A. W. Paulson, MSc

    2014-07-01

    Full Text Available This feasibility study compared the plasma inflammation-mediating cytokine response to an acute bout of handcycling (HC with and without the addition of functional electrical stimulation (FES-evoked lower-limb cycling. On two separate occasions, five recreationally active, community-based participants with motor complete paraplegia (thoracic 5–7 performed 30 min HC and hybrid exercise (HYB at a fixed power output. Venous blood samples were collected at rest, immediately postexercise, 1 h postexercise (post+1 and 2 h postexercise (post+2. Plasma interleukin (IL-6, IL-10, IL-1 receptor antagonist (IL-1ra, adrenaline, and cortisol concentrations were determined via enzyme-linked immunoassay. Plasma IL-6 concentrations were significantly (p 0.05 increase in IL-6 was observed at post+1 in HC, with concentrations significantly higher in HYB at post+2 (p < 0.02. Plasma IL-1ra was unaffected in both trials. Although not reaching statistical significance (p = 0.15, a ~1-fold increase in IL-10 concentration was seen in HYB at post+2. In contrast, increases in adrenaline (p < 0.04 and cortisol (p = 0.08 were observed immediately postexercise in HC and HYB. Initial findings suggest paralyzed skeletal muscle releases IL-6 in response to FES-evoked contractions. HYB may provide a greater anti-inflammatory potential in individuals with a thoracic spinal cord injury compared with HC alone.

  14. An Idle-State Detection Algorithm for SSVEP-Based Brain-Computer Interfaces Using a Maximum Evoked Response Spatial Filter.

    Science.gov (United States)

    Zhang, Dan; Huang, Bisheng; Wu, Wei; Li, Siliang

    2015-11-01

    Although accurate recognition of the idle state is essential for the application of brain-computer interfaces (BCIs) in real-world situations, it remains a challenging task due to the variability of the idle state. In this study, a novel algorithm was proposed for the idle state detection in a steady-state visual evoked potential (SSVEP)-based BCI. The proposed algorithm aims to solve the idle state detection problem by constructing a better model of the control states. For feature extraction, a maximum evoked response (MER) spatial filter was developed to extract neurophysiologically plausible SSVEP responses, by finding the combination of multi-channel electroencephalogram (EEG) signals that maximized the evoked responses while suppressing the unrelated background EEGs. The extracted SSVEP responses at the frequencies of both the attended and the unattended stimuli were then used to form feature vectors and a series of binary classifiers for recognition of each control state and the idle state were constructed. EEG data from nine subjects in a three-target SSVEP BCI experiment with a variety of idle state conditions were used to evaluate the proposed algorithm. Compared to the most popular canonical correlation analysis-based algorithm and the conventional power spectrum-based algorithm, the proposed algorithm outperformed them by achieving an offline control state classification accuracy of 88.0 ± 11.1% and idle state false positive rates (FPRs) ranging from 7.4 ± 5.6% to 14.2 ± 10.1%, depending on the specific idle state conditions. Moreover, the online simulation reported BCI performance close to practical use: 22.0 ± 2.9 out of the 24 control commands were correctly recognized and the FPRs achieved as low as approximately 0.5 event/min in the idle state conditions with eye open and 0.05 event/min in the idle state condition with eye closed. These results demonstrate the potential of the proposed algorithm for implementing practical SSVEP BCI systems. PMID

  15. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

    Directory of Open Access Journals (Sweden)

    Baird Bill

    2006-02-01

    Full Text Available Abstract Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves. Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1 Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2 These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3 The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide

  16. Chandelier cells control excessive cortical excitation: characteristics of whisker-evoked synaptic responses of layer 2/3 nonpyramidal and pyramidal neurons.

    Science.gov (United States)

    Zhu, Yinghua; Stornetta, Ruth L; Zhu, J Julius

    2004-06-01

    Chandelier cells form inhibitory axo-axonic synapses on pyramidal neurons with their characteristic candlestick-like axonal terminals. The functional role of chandelier cells is still unclear, although the preferential loss of this cell type at epileptic loci suggests a role in epilepsy. Here we report an examination of whisker- and spontaneous activity-evoked responses in chandelier cells and other fast-spiking nonpyramidal neurons and regular-spiking pyramidal neurons in layer 2/3 of the barrel cortex. Fast-spiking nonpyramidal neurons, including chandelier cells, basket cells, neurogliaform cells, double bouquet cells, net basket cells, bitufted cells, and regular-spiking pyramidal neurons all respond to stimulation of multiple whiskers on the contralateral face. Whisker stimulation, however, evokes small, delayed EPSPs preceded by an earlier IPSP and no action potentials in chandelier cells, different from other nonpyramidal and pyramidal neurons. In addition, chandelier cells display a larger receptive field with lower acuity than other fast-spiking nonpyramidal neurons and pyramidal neurons. Notably, simultaneous dual whole-cell in vivo recordings show that chandelier cells, which rarely fire action potentials spontaneously, fire more robustly than other types of cortical neurons when the overall cortical excitation increases. Thus, chandelier cells may not process fast ascending sensory information but instead may be reserved to prevent excessive excitatory activity in neuronal networks. PMID:15175379

  17. Electrically evoked itch in humans.

    Science.gov (United States)

    Ikoma, Akihiko; Handwerker, Hermann; Miyachi, Yoshiki; Schmelz, Martin

    2005-01-01

    We compared itch sensations and axon reflex flare induced by transcutaneous electrical (0.08-8 ms, 2-200 Hz) and chemical (histamine iontophoresis; 100 microC) stimulation. Stimuli were applied to non-lesional volar wrist skin in 20 healthy human subjects and 10 patients with atopic dermatitis. Intensity of evoked itch and pain sensations were rated on a numerical rating scale (NRS) of 0 (no sensation) to 10 (the maximum sensation imaginable). The axon reflex erythema was measured by laser Doppler imager and areas of alloknesis (itch evoked by light brushing) and hyperknesis (itch evoked by pricking) were assessed psychophysically. Electrical stimulation was most effective for stimulus durations >or=2 ms and frequencies >or=50 Hz. It evoked pure itch as threshold sensation in 80% of the subjects that was perceived with a delay of approximately 1 s. Itch intensities of up to 7/10 were not accompanied by an axon reflex flare. In contrast, histamine provoked a massive increase of axon reflex erythema and maximum itch ratings of 3.1+/-0.2. The extention of alloknesis areas (2.3+/-0.5 cm) evoked by electrical stimulation clearly exceeded those induced by histamine (0.7+/-0.3 cm). Healthy subjects and patients with atopic dermatitis did not differ significantly in their response to either stimulation. We conclude that C-fiber activation underlies the electrically evoked itch sensation. The low electrical thresholds and the absence of an axon reflex flare suggest that these fibers are not identical with the previously described mechano-insensitive histamine responsive C fibers, but represent a separate peripheral neuronal system for the induction of itch. PMID:15621375

  18. The role of calcium, calcium-activated K+ channels, and tyrosine/kinase in psoralen-evoked responses in human melanoma cells

    Directory of Open Access Journals (Sweden)

    Isoldi M.C.

    2004-01-01

    Full Text Available 8-Methoxy psoralen (8-MOP exerts a short-term (24 h mitogenic action, and a long-term (48-72 h anti-proliferative and melanogenic action on two human melanoma cell lines, SK-Mel 28 and C32TG. An increase of intracellular calcium concentration was observed by spectrofluorometry immediately after the addition of 0.1 mM 8-MOP to both cell lines, previously incubated with calcium probe fluo-3 AM (5 µM. The intracellular Ca2+ chelator BAPTA/AM (1 µM blocked both early (mitogenic and late (anti-proliferative and melanogenic 8-MOP effects on both cell lines, thus revealing the importance of the calcium signal in both short- and long-term 8-MOP-evoked responses. Long-term biological assays with 5 and 10 mM tetraethylammonium chloride (TEA, an inhibitor of Ca2+-dependent K+ channels did not affect the responses to psoralen; however, in 24-h assays 10 mM TEA blocked the proliferative peak, indicating a modulation of Ca2+-dependent K+ channels by 8-MOP. No alteration of cAMP basal levels or forskolin-stimulated cAMP levels was promoted by 8-MOP in SK-Mel 28 cells, as determined by radioimmunoassay. However, in C32TG cells forskolin-stimulated cAMP levels were further increased in the presence of 8-MOP. In addition, assays with 1 µM protein kinase C and calcium/calmodulin-dependent kinase inhibitors, Ro 31-8220 and KN-93, respectively, excluded the participation of these kinases in the responses evoked by 8-MOP. Western blot with antibodies anti-phosphotyrosine indicated a 92% increase of the phosphorylated state of a 43-kDa band, suggesting that the phosphorylation of this protein is a component of the cascade that leads to the increase of tyrosinase activity.

  19. Wiener kernel analysis of a noise-evoked otoacoustic emission

    NARCIS (Netherlands)

    van Dijk, P; Maat, A; Wit, H P

    1997-01-01

    In one specimen of the frog species, Rana esculenta, the following were measured: (1) a spontaneous otoacoustic emission; (2) a click-evoked otoacoustic emissions; and (3) a noise evoked otoacoustic emission. From the noise evoked emission response, a first-and a second-order Wiener kernel and the f

  20. SNPs in genes implicated in radiation response are associated with radiotoxicity and evoke roles as predictive and prognostic biomarkers

    International Nuclear Information System (INIS)

    Biomarkers are needed to individualize cancer radiation treatment. Therefore, we have investigated the association between various risk factors, including single nucleotide polymorphisms (SNPs) in candidate genes and late complications to radiotherapy in our nasopharyngeal cancer patients. A cohort of 155 patients was included. Normal tissue fibrosis was scored using RTOG/EORTC grading system. A total of 45 SNPs in 11 candidate genes (ATM, XRCC1, XRCC3, XRCC4, XRCC5, PRKDC, LIG4, TP53, HDM2, CDKN1A, TGFB1) were genotyped by direct genomic DNA sequencing. Patients with severe fibrosis (cases, G3-4, n = 48) were compared to controls (G0-2, n = 107). Univariate analysis showed significant association (P < 0.05) with radiation complications for 6 SNPs (ATM G/A rs1801516, HDM2 promoter T/G rs2279744 and T/A rs1196333, XRCC1 G/A rs25487, XRCC5 T/C rs1051677 and TGFB1 C/T rs1800469). In addition, Kaplan-Meier analyses have also highlighted significant association between genotypes and length of patients’ follow-up after radiotherapy. Multivariate logistic regression has further sustained these results suggesting predictive and prognostic roles of SNPs. Univariate and multivariate analysis suggest that radiation toxicity in radiotherapy patients are associated with certain SNPs, in genes including HDM2 promoter studied for the 1st time. These results support the use of SNPs as genetic predictive markers for clinical radiosensitivity and evoke a prognostic role for length of patients’ follow-up after radiotherapy

  1. Modeling of region-specific fMRI BOLD neurovascular response functions in rat brain reveals residual differences that correlate with the differences in regional evoked potentials.

    Science.gov (United States)

    Pawela, Christopher P; Hudetz, Anthony G; Ward, B Douglas; Schulte, Marie L; Li, Rupeng; Kao, Dennis S; Mauck, Matthew C; Cho, Younghoon R; Neitz, Jay; Hyde, James S

    2008-06-01

    The response of the rat visual system to flashes of blue light has been studied by blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI). The BOLD temporal response is dependent on the number of flashes presented and demonstrates a refractory period that depends on flash frequency. Activated brain regions included the primary and secondary visual cortex, superior colliculus (SC), dorsal lateral geniculate (DLG), and lateral posterior nucleus (LP), which were found to exhibit differing temporal responses. To explain these differences, the BOLD neurovascular response function was modeled. A second-order differential equation was developed and solved numerically to arrive at region-specific response functions. Included in the model are the light input from the diode (duty cycle), a refractory period, a transient response following onset and cessation of stimulus, and a slow adjustment to changes in the average level of the signal. Constants in the differential equation were evaluated for each region by fitting the model to the experimental BOLD response from a single flash, and the equation was then solved for multiple flashes. The simulation mimics the major features of the data; however, remaining differences in the frequency dependence of the response between the cortical and subcortical regions were unexplained. We hypothesized that these discrepancies were due to regional-specific differences in neuronal response to flash frequency. To test this hypothesis, cortical visual evoked potentials (VEPs) were recorded using the same stimulation protocol as the fMRI. Cortical VEPs were more suppressed than subcortical VEPs as flash frequency increased, supporting our hypothesis. This is the first report that regional differences in neuronal activation to the same stimulus lead to differential BOLD activation. PMID:18406628

  2. Age-Related Differences in Response to Music-Evoked Emotion among Children and Adolescents with Autism Spectrum Disorders

    Science.gov (United States)

    Stephenson, K. G.; Quintin, E. M.; South, M.

    2016-01-01

    While research regarding emotion recognition in ASD has focused primarily on social cues, musical stimuli also elicit strong emotional responses. This study extends and expands the few previous studies of response to music in ASD, measuring both psychophysiological and behavioral responses in younger children (ages 8-11) as well as older…

  3. Ultra-low-noise EEG/MEG systems enable bimodal non-invasive detection of spike-like human somatosensory evoked responses at 1 kHz

    International Nuclear Information System (INIS)

    Non-invasive EEG detection of very high frequency somatosensory evoked potentials featuring frequencies up to and above 1 kHz has been recently reported. Here, we establish the detectability of such components by combined low-noise EEG/MEG. We recorded SEP/SEF simultaneously using median nerve stimulation in five healthy human subjects inside an electromagnetically shielded room, combining a low-noise EEG custom-made amplifier (4.7 nV/√Hz) and a custom-made single-channel low-noise MEG (0.5 fT/√Hz @ 1 kHz). Both, low-noise EEG and MEG revealed three spectrally distinct and temporally overlapping evoked components: N20 (<100 Hz), sigma-burst (450–750 Hz), and kappa-burst (850–1200 Hz). The two recording modalities showed similar relative scaling of signal amplitude in all three frequencies domains (EEG [10 nV] ≅ MEG [1 fT]). Pronounced waveform (peak-by-peak) overlap of EEG and MEG signals is observed in the sigma band, whereas in the kappa band overlap was only partial. A decreasing signal-to-noise ratio (SNR; calculated for n = 12.000 averages) from sigma to kappa components characterizes both, electric and magnetic field recordings: Sigma-band SNR was 12.9  ±  5.5/19.8  ±  12.6 for EEG/MEG, and kappa-band SNR at 3.77  ±  0.8/4.5  ±  2.9. High-frequency performance of a tailor-made MEG matches closely with simultaneously recorded low-noise EEG for the non-invasive detection of somatosensory evoked activity at and above 1 kHz. Thus, future multi-channel dual-mode low-noise technology could offer complementary views for source reconstruction of the neural generators underlying such high-frequency responses, and render neural high-frequency processes related to multi-unit spike discharges accessible in non-invasive recordings. (paper)

  4. Brainstem auditory evoked potentials in children with lead exposure

    Directory of Open Access Journals (Sweden)

    Katia de Freitas Alvarenga

    2015-02-01

    Full Text Available Introduction: Earlier studies have demonstrated an auditory effect of lead exposure in children, but information on the effects of low chronic exposures needs to be further elucidated. Objective: To investigate the effect of low chronic exposures of the auditory system in children with a history of low blood lead levels, using an auditory electrophysiological test. Methods: Contemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6 years, 8 months ± 3 years, 2 months. Results: The mean time-integrated cumulative blood lead index was 12 µg/dL (SD ± 5.7, range:2.433. All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I-III, III-V, and I-V, and the cumulative lead values. Conclusion: No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area.

  5. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef;

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able to...

  6. The Nicotine-Evoked Locomotor Response: A Behavioral Paradigm for Toxicity Screening in Zebrafish (Danio rerio) Embryos and Eleutheroembryos Exposed to Methylmercury

    Science.gov (United States)

    Mora-Zamorano, Francisco X.; Svoboda, Kurt R.; Carvan, Michael J.

    2016-01-01

    This study is an adaptation of the nicotine-evoked locomotor response (NLR) assay, which was originally utilized for phenotype-based neurotoxicity screening in zebrafish embryos. Zebrafish embryos do not exhibit spontaneous swimming until roughly 4 days post-fertilization (dpf), however, a robust swimming response can be induced as early as 36 hours post-fertilization (hpf) by means of acute nicotine exposure (30–240μM). Here, the NLR was tested as a tool for early detection of locomotor phenotypes in 36, 48 and 72 hpf mutant zebrafish embryos of the non-touch-responsive maco strain; this assay successfully discriminated mutant embryos from their non-mutant siblings. Then, methylmercury (MeHg) was used as a proof-of-concept neurotoxicant to test the effectiveness of the NLR assay as a screening tool in toxicology. The locomotor effects of MeHg were evaluated in 6 dpf wild type eleutheroembryos exposed to waterborne MeHg (0, 0.01, 0.03 and 0.1μM). Afterwards, the NLR assay was tested in 48 hpf embryos subjected to the same MeHg exposure regimes. Embryos exposed to 0.01 and 0.03μM of MeHg exhibited significant increases in locomotion in both scenarios. These findings suggest that similar locomotor phenotypes observed in free swimming fish can be detected as early as 48 hpf, when locomotion is induced with nicotine. PMID:27123921

  7. Auditory Evoked M100 Response Latency is Delayed in Children with 16p11.2 Deletion but not 16p11.2 Duplication.

    Science.gov (United States)

    Jenkins, Julian; Chow, Vivian; Blaskey, Lisa; Kuschner, Emily; Qasmieh, Saba; Gaetz, Leah; Edgar, J Christopher; Mukherjee, Pratik; Buckner, Randall; Nagarajan, Srikantan S; Chung, Wendy K; Spiro, John E; Sherr, Elliott H; Berman, Jeffrey I; Roberts, Timothy P L

    2016-05-01

    Individuals with the 16p11.2 BP4-BP5 copy number variant (CNV) exhibit a range of behavioral phenotypes that may include mild impairment in cognition and clinical diagnoses of autism spectrum disorder (ASD). To better understand auditory processing impairments in populations with this chromosomal variation, auditory evoked responses were examined in children with the 16p11.2 deletion, 16p11.2 duplication, and age-matched controls. Stimuli consisted of sinusoidal binaural tones presented passively while children underwent recording with magnetoencephalography (MEG). The primary indicator of auditory processing impairment was the latency of the ∼100-ms "M100" auditory response detected by MEG, with the 16p11.2 deletion population exhibiting profoundly delayed M100 latencies relative to controls. This delay remained even after controlling for potential confounds such as age and cognitive ability. No significant difference in M100 latency was observed between 16p11.2 duplication carriers and controls. Additionally, children meeting diagnostic criteria for ASD (16p11.2 deletion carriers) exhibited nonsignificant latency delays when compared with the corresponding CNV carriers not meeting criteria for ASD. Present results indicate that 16p11.2 deletion is associated with auditory processing delays analogous to (but substantially more pronounced than) those previously reported in "idiopathic" ASD. PMID:25678630

  8. Nerve conduction, visual evoked responses and electroretinography in tunnel workers previously exposed to acrylamide and N-methylolacrylamide containing grouting agents.

    Science.gov (United States)

    Goffeng, Lars Ole; Heier, Mona Skard; Kjuus, Helge; Sjöholm, Hans; Sørensen, Kjell Aage; Skaug, Vidar

    2008-01-01

    The study examines possible persisting effects on the peripheral nervous system and visual system in tunnel workers previously exposed to acrylamide and N-methylolacrylamide during grouting work. We compared neurophysiological function in 44 tunnel workers previously exposed during grouting operations (2-10 years post exposure), with 49 tunnel workers with no history of exposure to acrylamide. Nerve conduction velocities (NCV), distal delay, F-response and amplitude in median and ulnar nerves of the right arm, peroneal, sural and tibial nerves of the right leg, visual evoked response (VER) and electroretinography (ERG) were measured. VER and ERG were also performed in 24 subjects more recently exposed to acrylamide grout (16 months post exposure). Exposure to acrylamide containing grouts was assessed by questionnaires. A statistically significant reduction in the mean sensory NCV of the sural nerve (p=0.005), as well as a non-significant reduction of sural amplitude was found in the previously exposed group compared to the control group. VER latencies to the onset of the occipital potential (N75) were prolonged in both exposed groups compared to the control group (pgrouting operations. PMID:18353610

  9. Acupuncture-Evoked Response in Somatosensory and Prefrontal Cortices Predicts Immediate Pain Reduction in Carpal Tunnel Syndrome

    Directory of Open Access Journals (Sweden)

    Yumi Maeda

    2013-01-01

    Full Text Available The linkage between brain response to acupuncture and subsequent analgesia remains poorly understood. Our aim was to evaluate this linkage in chronic pain patients with carpal tunnel syndrome (CTS. Brain response to electroacupuncture (EA was evaluated with functional MRI. Subjects were randomized to 3 groups: (1 EA applied at local acupoints on the affected wrist (PC-7 to TW-5, (2 EA at distal acupoints (contralateral ankle, SP-6 to LV-4, and (3 sham EA at nonacupoint locations on the affected wrist. Symptom ratings were evaluated prior to and following the scan. Subjects in the local and distal groups reported reduced pain. Verum EA produced greater reduction of paresthesia compared to sham. Compared to sham EA, local EA produced greater activation in insula and S2 and greater deactivation in ipsilateral S1, while distal EA produced greater activation in S2 and deactivation in posterior cingulate cortex. Brain response to distal EA in prefrontal cortex (PFC and brain response to verum EA in S1, SMA, and PFC were correlated with pain reduction following stimulation. Thus, while greater activation to verum acupuncture in these regions may predict subsequent analgesia, PFC activation may specifically mediate reduced pain when stimulating distal acupoints.

  10. Effects of Prenatal Sensory-Evoked Arousal on Postnatal Behavior and Perceptual Responsiveness in Bobwhite Quail (Colinus virginianus)

    OpenAIRE

    Reynolds, Gregory Durelle

    2002-01-01

    Prenatal sensory stimulation can have facilitative or interfering effects upon subsequent perceptual learning and development in bobwhite quail. Exposure to moderate amounts of unimodal prenatal sensory stimulation has been shown to accelerate early intersensory responsiveness, while exposure to concurrent prenatal bimodal sensory stimulation has been shown to interfere with perceptual learning and development. An immediate mechanism that may underlie this developmental intersensory interfe...

  11. Cyclopropyl glycine and proline-containing preparation noopept evoke two types of membrane potential responses in synaptoneurosomes.

    Science.gov (United States)

    Lutsenko, V K; Vukolova, M N; Gudasheva, T A

    2003-06-01

    Proline, cyclo(Pro-Gly), and acyl-prolyl-containing dipeptide GVS-111 decreased synaptoneurosome membrane potential in a Ca2+-free medium. The efficiency of these preparations decreased in the following order: GVS>cyclo(Pro-Gly)>proline. Depolarization responses induced by endogenous nootropic agent cyclo(Pro-Gly) was dose-dependent and saturable; the threshold concentration of cyclo(Pro-Gly) was 10(-9) M. In a Ca2+-containing medium GVS and cyclo(Pro-Gly) induced both hyperpolarizing and depolarizing membrane responses of synaptoneurosomes. Possible mechanisms underlying changes in the membrane potential of synaptoneurosomes induced by nootropic agents are discussed. It was interesting whether modulation of electrogenesis can improve memory and potentiate the neuroprotective effect of the test nootropic agents. PMID:12937673

  12. Corticotropin-Releasing Factor Acting at the Locus Coeruleus Disrupts Thalamic and Cortical Sensory-Evoked Responses

    OpenAIRE

    Devilbiss, David M.; WATERHOUSE, BARRY D.; Berridge, Craig W.; Valentino, Rita

    2012-01-01

    Stress and stress-related psychiatric disorders, including post-traumatic stress disorder, are associated with disruptions in sensory information processing. The neuropeptide, corticotropin-releasing factor (CRF), coordinates the physiological and behavioral responses to stress, in part, by activating the locus coeruleus-norepinephrine (LC-NE) projection system. Although the LC-NE system is an important modulator of sensory information processing, to date, the consequences of CRF activation o...

  13. Prevention by NMDA receptor antagonists of the centrally-evoked increases of cardiac inotropic responses in rabbits.

    OpenAIRE

    Monassier, L.; Tibiriça, E.; Roegel, J. C.; Mettauer, B.; Feldman, J.; Bousquet, P.

    1994-01-01

    1. The purpose of this study was to investigate further the role of the excitatory amino acid (EAA) system of neurotransmission, particularly of the NMDA receptor, in the central regulation of cardiac function. 2. Electrical stimulation of the paraventricular nucleus of the hypothalamus (PVN) in pentobarbitone anaesthetized rabbits induced a cardiovascular response mainly characterized by a positive inotropic effect, hypertension and a marked increase in the myocardial oxygen demand index. 3....

  14. Sulphur dioxide evokes a large scale reprogramming of the grape berry transcriptome associated with oxidative signalling and biotic defence responses.

    Science.gov (United States)

    Giraud, Estelle; Ivanova, Aneta; Gordon, Colin S; Whelan, James; Considine, Michael J

    2012-02-01

    The grape and wine industries are heavily reliant on sulphite preservatives. However, the view that sulphites act directly on bacterial and fungal pathogens may be simplistic. Mechanisms of sulphur-enhanced defences are largely unknown; many sulphur-rich compounds enhance plant defences and sulphite can also have oxidative consequences via production of H(2)O(2) or sulphitolysis. To investigate the effects of sulphur dioxide (SO(2) ) on fresh table grapes (Vitis vinifera L. 'Crimson Seedless'), transcriptome analysis was carried out on berries treated with SO(2) under commercial conditions for 21 d. We found a broad perturbation of metabolic processes, consistent with a large-scale stress response. Transcripts encoding putative sulphur-metabolizing enzymes indicated that sulphite was directed towards chelation and conjugation, and away from oxidation to sulphate. The results indicated that redox poise was altered dramatically by SO(2) treatment, evidenced by alterations in plastid and mitochondrial alternative electron transfer pathways, up-regulation of fermentation transcripts and numerous glutathione S-transferases, along with a down-regulation of components involved in redox homeostasis. Features of biotic stress were up-regulated, notably signalling via auxin, ethylene and jasmonates. Taken together, this inventory of transcriptional responses is consistent with a long-term cellular response to oxidative stress, similar to the effects of reactive oxygen species. PMID:21689113

  15. Estudo dos potenciais evocados auditivos em autismo Study of auditory evoked potentials in autism

    Directory of Open Access Journals (Sweden)

    Fernanda Cristina Leite Magliaro

    2010-03-01

    Full Text Available TEMA: avaliação eletrofisiológica da audição em indivíduos com autismo. OBJETIVO: caracterizar os achados das avaliações eletrofisiológicas da audição em indivíduos com autismo, bem como comparar seus resultados aos obtidos em indivíduos com desenvolvimento típico da mesma faixa etária. MÉTODO: foram realizadas anamnese, audiometria tonal, logoaudiometria, medidas de imitância acústica, potenciais evocados auditivos de tronco encefálico (PEATE e de média latência (PEAML, e potencial cognitivo (P300, em 16 indivíduos com autismo (grupo pesquisa e 25 normais (grupo controle, com idades entre oito e 20 anos. RESULTADOS: o grupo pesquisa apresentou resultados alterados em todos os potenciais evocados auditivos, havendo diferença estatisticamente significante quando comparado ao grupo controle. Foi observada uma maior ocorrência de alteração do tipo tronco encefálico baixo no PEATE, do tipo Ambas no PEAML, e ausência de resposta no P300, para o grupo pesquisa. Na análise dos dados quantitativos, verificou-se que apenas para o PEATE ocorreu diferença estatisticamente significante entre os grupos, com relação às latências das ondas III e V e interpicos I-III e I-V. CONCLUSÃO: indivíduos com autismo apresentam alterações no PEATE e P300, sugerindo comprometimento da via auditiva em tronco encefálico, áreas subcorticais e corticais.BACKGROUND: electrophysiological assessment of hearing in autistic individuals. AIM: to characterize the findings obtained in the electrophysiological assessments of autistic individuals, as well as to compare these to the results obtained for individuals of the same age who present typical development. METHOD: 16 individuals with autism (study group and 25 normal individuals (control group, ranging in age from eight to 20 years underwent anamnesis, pure tone audiometry, speech audiometry, acoustic immitance measures, brainstem auditory evoked potential (BAEP, middle latency response

  16. Synaptically evoked dendritic action potentials in rat neocortical pyramidal neurons.

    Science.gov (United States)

    Schwindt, P C; Crill, W E

    1998-05-01

    In a previous study iontophoresis of glutamate on the apical dendrite of layer 5 pyramidal neurons from rat neocortex was used to identify sites at which dendritic depolarization evoked small, prolonged Ca2+ spikes and/or low-threshold Na+ spikes recorded by an intracellular microelectrode in the soma. These spikes were identified as originating in the dendrite. Here we evoke similar dendritic responses by electrical stimulation of presynaptic elements near the tip of the iontophoretic electrode with the use of a second extracellular electrode. In 9 of 12 recorded cells, electrically evoked excitatory postsynaptic potentials (EPSPs) above a minimum size triggered all-or-none postsynaptic responses similar to those evoked by dendritic glutamate iontophoresis at the same site. Both the synaptically evoked and the iontophoretically evoked depolarizations were abolished reversibly by blockade of glutamate receptors. In all recorded cells, the combination of iontophoresis and an EPSP, each of which was subthreshold for the dendritic spike when given alone, evoked a dendritic spike similar to that evoked by a sufficiently large iontophoresis. In one cell tested, dendritic spikes could be evoked by the summation of two independent subthreshold EPSPs evoked by stimulation at two different locations. We conclude that the dendritic spikes are not unique to the use of glutamate iontophoresis because similar spikes can be evoked by EPSPs. We discuss the implications of these results for synaptic integration and for the interpretation of recorded synaptic potentials. PMID:9582218

  17. Odour-evoked responses to queen pheromone components and to plant odours using optical imaging in the antennal lobe of the honey bee drone Apis mellifera L.

    Science.gov (United States)

    Sandoz, Jean-Christophe

    2006-09-01

    The primordial functional role of honey bee males (drones) is to mate with virgin queens, a behaviour relying heavily on the olfactory detection of queen pheromone. In the present work I studied olfactory processing in the drone antennal lobe (AL), the primary olfactory centre of the insect brain. In drones, the AL consists of about 103 ordinary glomeruli and four enlarged glomeruli, the macroglomeruli (MG). Two macroglomeruli (MG1 and MG2) and approximately 20 ordinary glomeruli occupy the anterior surface of the antennal lobe and are thus accessible to optical recordings. Calcium imaging was used to measure odour-evoked responses to queen pheromonal components and plant odours. MG2 responded specifically to the main component of the queen mandibular pheromone, 9-ODA. The secondary components HOB and HVA each triggered activity in one, but not the same, ordinary glomerulus. MG1 did not respond to any of the tested stimuli. Plant odours induced signals only in ordinary glomeruli in a combinatorial manner, as in workers. This study thus shows that the major queen pheromonal component is processed in the most voluminous macroglomerulus of the drone antennal lobe, and that plant odours, as well as some queen pheromonal components, are processed in ordinary glomeruli. PMID:16943499

  18. Brainstem auditory evoked response characteristics in normal-hearing subjects with chronic tinnitus and in non-tinnitus group

    Directory of Open Access Journals (Sweden)

    Shadman Nemati

    2014-06-01

    Full Text Available Background and Aim: While most of the people with tinnitus have some degrees of hearing impairment, a small percent of patients admitted to ear, nose and throat clinics or hearing evaluation centers are those who complain of tinnitus despite having normal hearing thresholds. This study was performed to better understanding of the reasons of probable causes of tinnitus and to investigate possible changes in the auditory brainstem function in normal-hearing patients with chronic tinnitus.Methods: In this comparative cross-sectional, descriptive and analytic study, 52 ears (26 with and 26 without tinnitus were examined. Components of the auditory brainstem response (ABR including wave latencies and wave amplitudes were determined in the two groups and analyzed using appropriate statistical methods.Results: The mean differences between the absolute latencies of waves I, III and V was less than 0.1 ms between the two groups that was not statistically significant. Also, the interpeak latency values of waves I-III, III-V and I-V in both groups had no significant difference. Only, the V/I amplitude ratio in the tinnitus group was significantly higher (p=0.04.Conclusion: The changes observed in amplitude of waves, especially in the latter ones, can be considered as an indication of plastic changes in neuronal activity and its possible role in generation of tinnitus in normal-hearing patients.

  19. Cortisol, Chromogranin A, and Pupillary Responses Evoked by Speech Recognition Tasks in Normally Hearing and Hard-of-Hearing Listeners: A Pilot Study.

    Science.gov (United States)

    Kramer, Sophia E; Teunissen, Charlotte E; Zekveld, Adriana A

    2016-01-01

    Pupillometry is one method that has been used to measure processing load expended during speech understanding. Notably, speech perception (in noise) tasks can evoke a pupil response. It is not known if there is concurrent activation of the sympathetic nervous system as indexed by salivary cortisol and chromogranin A (CgA) and whether such activation differs between normally hearing (NH) and hard-of-hearing (HH) adults. Ten NH and 10 adults with mild-to-moderate hearing loss (mean age 52 years) participated. Two speech perception tests were administered in random order: one in quiet targeting 100% correct performance and one in noise targeting 50% correct performance. Pupil responses and salivary samples for cortisol and CgA analyses were collected four times: before testing, after the two speech perception tests, and at the end of the session. Participants rated their perceived accuracy, effort, and motivation. Effects were examined using repeated-measures analyses of variance. Correlations between outcomes were calculated. HH listeners had smaller peak pupil dilations (PPDs) than NH listeners in the speech in noise condition only. No group or condition effects were observed for the cortisol data, but HH listeners tended to have higher cortisol levels across conditions. CgA levels were larger at the pretesting time than at the three other test times. Hearing impairment did not affect CgA. Self-rated motivation correlated most often with cortisol or PPD values. The three physiological indicators of cognitive load and stress (PPD, cortisol, and CgA) are not equally affected by speech testing or hearing impairment. Each of them seem to capture a different dimension of sympathetic nervous system activity. PMID:27355762

  20. BAER - brainstem auditory evoked response

    Science.gov (United States)

    ... a sign of hearing loss , multiple sclerosis , acoustic neuroma , or stroke. Abnormal results may also be due ... Butterworth-Heinemann; 2012:chap 32A. Read More Acoustic neuroma Central pontine myelinolysis Hearing loss Multiple sclerosis Stroke ...

  1. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.; Mørup, Morten

    2007-01-01

    evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure of...

  2. Somatosensory evoked potentials by paraspinal stimulation in acute transverse myelitis.

    Directory of Open Access Journals (Sweden)

    Murthy J

    1999-04-01

    Full Text Available Somatosensory evoked potentials by paraspinal stimulation were studied in 6 patients with acute transverse myelitis. In one patient in whom posterior tibial somatosensory evoked potentials were not recordable, a poorly formed response was seen with paraspinal stimulation. Slowing of conduction across the involved segment was seen in the remaining 5 patients and fairly correlated with the clinical localization.

  3. Somatosensory evoked potentials by paraspinal stimulation in acute transverse myelitis.

    OpenAIRE

    Murthy J

    1999-01-01

    Somatosensory evoked potentials by paraspinal stimulation were studied in 6 patients with acute transverse myelitis. In one patient in whom posterior tibial somatosensory evoked potentials were not recordable, a poorly formed response was seen with paraspinal stimulation. Slowing of conduction across the involved segment was seen in the remaining 5 patients and fairly correlated with the clinical localization.

  4. Motor evoked potential polyphasia

    OpenAIRE

    Chowdhury, Fahmida A.; Pawley, Adam D.; Ceronie, Bryan; Nashef, Lina; Robert D C Elwes; Richardson, Mark P

    2015-01-01

    Objective: We compared the motor evoked potential (MEP) phases using transcranial magnetic stimulation in patients with idiopathic generalized epilepsy (IGE), their relatives, and healthy controls, hypothesizing that patients and their unaffected relatives may share a subtle pathophysiologic abnormality. Methods: In a cross-sectional study, we investigated 23 patients with IGE, 34 first-degree relatives, and 30 matched healthy controls. Transcranial magnetic stimulation was performed to produ...

  5. Selecting and evoking innovators

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Christiansen, Ellen

    2006-01-01

    The practical undertaking of selecting users to work as innovators and of evoking their creative potential is crucial, but underexposed in the literature on user involvement in design. This paper reports findings from a recent case of user-driven innovation, the FEEDBACK-project, where the author...... theories of learning we try to explain how our way of working with selection and evoking of innovators has contributed to this positive result and how our approach to user-driven innovation can be regarded as a way to combine democracy and creativity in design.......The practical undertaking of selecting users to work as innovators and of evoking their creative potential is crucial, but underexposed in the literature on user involvement in design. This paper reports findings from a recent case of user-driven innovation, the FEEDBACK-project, where the authors...... prepared for and conducted selection of and collaboration with innovators. The outcome was successful in the sense that the innovators produced excellent foundation for conceptual interaction design by creating mock-ups and explanations incarnating their preferences, attitudes and habits. By referring to...

  6. Brainstem evoked potentials in infantile spasms

    International Nuclear Information System (INIS)

    In ten patients with infantile spasms, brainstem evoked potentials and MRI examinations were performed to evaluate the brainstem involvement. The result of short latency somatosensory evoked potentials (SSEP) following the right median nerve stimulation revealed abnormal findings including the absence or low amplitudes of the waves below wave P3 and delayed central conduction time in 7 of the ten patients. The result of auditory brainstem responses (ABR) revealed abnormal findings including low amplitudes of wave V, prolonged interpeak latency of waves I-V and absence of the waves below wave IV in 5 of the ten patients. The result of the MRI examinations revealed various degrees of the brainstem atrophy in 6 of the ten patients, all of whom showed abnormal brainstem evoked potentials. The result of this study demonstrates that patients with infantile spasms are frequently associated with brainstem dysfunction and raises the possibility that brainstem atrophy might be a cause of infantile spasms. (author)

  7. Taste-Evoked Responses to Sweeteners in the Nucleus of the Solitary Tract Differ between C57BL/6ByJ and 129P3/J Mice

    OpenAIRE

    McCaughey, Stuart A.

    2007-01-01

    C57BL/6ByJ (B6) and 129P3/J (129) mice have different alleles of Tas1r3, which is thought to influence gustatory transduction of sweeteners, but studies have provided conflicting results regarding differences in sweetness perception between these strains. Single-unit taste-evoked activity was measured in the nucleus of the solitary tract (NST) in anesthetized B6 and 129 mice to address this controversy and to provide the first electrophysiological characterization of this nucleus in mice. Neu...

  8. International Evoked Potentials Symposium

    CERN Document Server

    1980-01-01

    The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

  9. Music evokes vivid autobiographical memories.

    Science.gov (United States)

    Belfi, Amy M; Karlan, Brett; Tranel, Daniel

    2016-08-01

    Music is strongly intertwined with memories-for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces. PMID:26259098

  10. Achieving Presence through Evoked Reality

    Directory of Open Access Journals (Sweden)

    Jayesh S.Pillai

    2013-02-01

    Full Text Available The sense of ‘Presence’ (evolving from ‘telepresence’ has always been associated with virtual reality research and is still an exceptionally mystifying constituent. Now the study of presence clearly spans over various disciplines associated with cognition. This paper attempts to put forth a concept that argues that it’s an experience of an 'Evoked Reality’ (illusion of reality that triggers an ‘Evoked Presence’ (sense of presence in our minds. A Three Pole Reality Model is proposed to explain this phenomenon. The poles range from Dream Reality to Simulated Reality with Primary (Physical Reality at the center. To demonstrate the relationship between Evoked Reality and Evoked Presence, a Reality-Presence Map is developed. We believe that this concept of Evoked Reality and the proposed model may have significant applications in the study of presence, and in exploring the possibilities of not just virtual reality but also what we call ‘reality’.

  11. Visual evoked potentials in the horse

    OpenAIRE

    Ström, L.; Ekesten, B.

    2016-01-01

    Background Electrical potentials generated in the central nervous system in response to brief visual stimuli, flash visual evoked potentials (FVEPs), can be recorded non-invasively over the occipital cortex. FVEPs are used clinically in human medicine and also experimentally in a number of animal species, but the method has not yet been evaluated in the horse. The method would potentially allow the ophthalmologist and equine clinician to evaluate visual impairment caused by disorders affectin...

  12. Brainstem evoked potentials in panic disorder.

    OpenAIRE

    Knott, V J; Bakish, D; Barkley, J.

    1994-01-01

    Patient reports and laboratory tests support the notion that panic attacks are generated by stimulation of brainstem nuclei. Scalp-recorded brainstem auditory evoked potentials may serve as a unique measurement strategy for the noninvasive assessment of the role of brainstem functioning in panic disorder. Ipsilateral and contralateral BSAEP recordings were examined in response to separate left and right ear click stimulation in 28 patients with a diagnosis of panic disorder and in 18 normal c...

  13. Pattern reversal visual evoked responses of V1/V2 and V5/MT as revealed by MEG combined with probabilistic cytoarchitectonic maps.

    Science.gov (United States)

    Barnikol, Utako B; Amunts, Katrin; Dammers, Jürgen; Mohlberg, Hartmut; Fieseler, Thomas; Malikovic, Aleksandar; Zilles, Karl; Niedeggen, Michael; Tass, Peter A

    2006-05-15

    Pattern reversal stimulation provides an established tool for assessing the integrity of the visual pathway and for studying early visual processing. Numerous magnetoencephalographic (MEG) and electroencephalographic (EEG) studies have revealed a three-phasic waveform of the averaged pattern reversal visual evoked potential/magnetic field, with components N75(m), P100(m), and N145(m). However, the anatomical assignment of these components to distinct cortical generators is still a matter of debate, which has inter alia connected with considerable interindividual variations of the human striate and extrastriate cortex. The anatomical variability can be compensated for by means of probabilistic cytoarchitectonic maps, which are three-dimensional maps obtained by an observer-independent statistical mapping in a sample of ten postmortem brains. Transformed onto a subject's brain under consideration, these maps provide the probability with which a given voxel of the subject's brain belongs to a particular cytoarchitectonic area. We optimize the spatial selectivity of the probability maps for V1 and V2 with a probability threshold which optimizes the self- vs. cross-overlap in the population of postmortem brains used for deriving the probabilistic cytoarchitectonic maps. For the first time, we use probabilistic cytoarchitectonic maps of visual cortical areas in order to anatomically identify active cortical generators underlying pattern reversal visual evoked magnetic fields as revealed by MEG. The generators are determined with magnetic field tomography (MFT), which reconstructs the current source density in each voxel. In all seven subjects, our approach reveals generators in V1/V2 (with a greater overlap with V1) and in V5 unilaterally (right V5 in three subjects, left V5 in four subjects) and consistent time courses of their stimulus-locked activations, with three peak activations in V1/V2 (contributing to C1m/N75m, P100m, and N145m) and two peak activations in V5

  14. Analysis of evoked lumbosacral potentials in man.

    Science.gov (United States)

    Delbeke, J; McComas, A J; Kopec, S J

    1978-04-01

    Surface electrodes have been used to record potentials evoked in the lumbosacral region of 15 healthy volunteers after tibial nerve stimulation. By monitoring the M waves and H reflexes in the triceps surae muslces and by comparing the responses recorded over the roots with those over the lower cord, it was possible to identify the neural substrates responsible for several of the components in the responses. The findings are compared with those of previous studies in man and in other mammalian preparations. PMID:650237

  15. Swimming exercise changes hemodynamic responses evoked by blockade of excitatory amino receptors in the rostral ventrolateral medulla in spontaneously hypertensive rats.

    Science.gov (United States)

    Ogihara, Cristiana A; Schoorlemmer, Gerhardus H M; Lazari, Maria de Fátima M; Giannocco, Gisele; Lopes, Oswaldo U; Colombari, Eduardo; Sato, Monica A

    2014-01-01

    Exercise training reduces sympathetic activity in hypertensive humans and rats. We hypothesized that the swimming exercise would change the neurotransmission in the rostral ventrolateral medulla (RVLM), a key region involved in sympathetic outflow, and hemodynamic control in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. Bilateral injections of kynurenic acid (KYN) were carried out in the RVLM in sedentary- (S-) or exercised- (E-) SHR and WKY rats submitted to swimming for 6 weeks. Rats were α-chloralose anesthetized and artificially ventilated, with Doppler flow probes around the lower abdominal aorta and superior mesenteric artery. Injections into the RVLM were made before and after i.v. L-NAME (nitric oxide synthase, NOS, inhibitor). Injections of KYN into the RVLM elicited a major vasodilation in the hindlimb more than in the mesenteric artery in E-SHR compared to S-SHR, but similar decrease in arterial pressure was observed in both groups. Injections of KYN into the RVLM after i.v. L-NAME attenuated the hindlimb vasodilation evoked by KYN and increased the mesenteric vasodilation in E-SHR. Swimming exercise can enhance the hindlimb vasodilation mediated by peripheral NO release, reducing the activation of neurons with EAA receptors in the RVLM in SHR. PMID:24696852

  16. Swimming Exercise Changes Hemodynamic Responses Evoked by Blockade of Excitatory Amino Receptors in the Rostral Ventrolateral Medulla in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Cristiana A. Ogihara

    2014-01-01

    Full Text Available Exercise training reduces sympathetic activity in hypertensive humans and rats. We hypothesized that the swimming exercise would change the neurotransmission in the rostral ventrolateral medulla (RVLM, a key region involved in sympathetic outflow, and hemodynamic control in spontaneously hypertensive rats (SHR and Wistar-Kyoto (WKY rats. Bilateral injections of kynurenic acid (KYN were carried out in the RVLM in sedentary- (S- or exercised- (E- SHR and WKY rats submitted to swimming for 6  weeks. Rats were α-chloralose anesthetized and artificially ventilated, with Doppler flow probes around the lower abdominal aorta and superior mesenteric artery. Injections into the RVLM were made before and after i.v. L-NAME (nitric oxide synthase, NOS, inhibitor. Injections of KYN into the RVLM elicited a major vasodilation in the hindlimb more than in the mesenteric artery in E-SHR compared to S-SHR, but similar decrease in arterial pressure was observed in both groups. Injections of KYN into the RVLM after i.v. L-NAME attenuated the hindlimb vasodilation evoked by KYN and increased the mesenteric vasodilation in E-SHR. Swimming exercise can enhance the hindlimb vasodilation mediated by peripheral NO release, reducing the activation of neurons with EAA receptors in the RVLM in SHR.

  17. Baroreceptor activation attenuates attentional effects on pain-evoked potentials

    OpenAIRE

    Gray, Marcus A.; Minati, Ludovico; Paoletti, Giulia; Critchley, Hugo D.

    2010-01-01

    Focused attention typically enhances neural nociceptive responses, reflected electroencephalographically as increased amplitude of pain-evoked event-related potentials (ERPs). Additionally, pain-evoked ERPs are attenuated by hypertension and baroreceptor activity, through as yet unclear mechanisms. There is indirect evidence that these two effects may interact, suggesting that baroreceptor-related modulation of nociception is more than a low-level gating phenomenon. To address this hypothesis...

  18. Use of the novel contact heat evoked potential stimulator (CHEPS for the assessment of small fibre neuropathy: correlations with skin flare responses and intra-epidermal nerve fibre counts

    Directory of Open Access Journals (Sweden)

    Chizh Boris A

    2007-08-01

    Full Text Available Abstract Background The Contact Heat Evoked Potential Stimulator (CHEPS rapidly stimulates cutaneous small nerve fibres, and resulting evoked potentials can be recorded from the scalp. We have studied patients with symptoms of sensory neuropathy and controls using CHEPS, and validated the findings using other objective measures of small nerve fibres i.e. the histamine-induced skin flare response and intra-epidermal fibres (IEF, and also quantitative sensory testing (QST, a subjective measure. Methods In patients with symptoms of sensory neuropathy (n = 41 and healthy controls (n = 9 we performed clinical examination, QST (monofilament, vibration and thermal perception thresholds, nerve conduction studies, histamine-induced skin flares and CHEPS. Skin punch biopsies were immunostained using standard ABC immunoperoxidase for the nerve marker PGP 9.5 or the heat and capsaicin receptor TRPV1. Immunoreactive IEF were counted per length of tissue section and epidermal thickness recorded. Results Amplitudes of Aδ evoked potentials (μV following face, arm or leg stimulation were reduced in patients (e.g. for the leg: mean ± SEM – controls 11.7 ± 1.95, patients 3.63 ± 0.85, p = 0.0032. Patients showed reduced leg skin flare responses, which correlated with Aδ amplitudes (rs = 0.40, p = 0.010. In patient leg skin biopsies, PGP 9.5- and TRPV1-immunoreactive IEF were reduced and correlated with Aδ amplitudes (PGP 9.5, rs = 0.51, p = 0.0006; TRPV1, rs = 0.48, p = 0.0012. Conclusion CHEPS appears a sensitive measure, with abnormalities observed in some symptomatic patients who did not have significant IEF loss and/or QST abnormalities. Some of the latter patients may have early small fibre dysfunction or ion channelopathy. CHEPS provides a clinically practical, non-invasive and objective measure, and can be a useful additional tool for the assessment of sensory small fibre neuropathy. Although further evaluation is required, the technique shows

  19. Development of the N1-P2 auditory evoked response to amplitude rise time and rate of formant transition of speech sounds.

    Science.gov (United States)

    Carpenter, Allen L; Shahin, Antoine J

    2013-06-01

    We investigated the development of weighting strategies for acoustic cues by examining the morphology of the N1-P2 auditory evoked potential (AEP) to changes in amplitude rise time (ART) and rate of formant transition (RFT) of consonant-vowel (CV) pairs in 4-6-year olds and adults. In the AEP session, individuals listened passively to the CVs /ba/, /wa/, and a /ba/ with a superimposed slower-rising /wa/ envelope (/ba/(wa)). In the behavioral session, individuals listened to the same stimuli and judged whether they heard a /ba/ or /wa/. We hypothesized that a developmental shift in weighting strategies should be reflected in a change in the morphology of the N1-P2 AEP. In 6-year olds and adults, the N1-P2 amplitude at the vertex reflected a change in RFT but not in ART. In contrast, in the 4-5-year olds, the vertex N1-P2 did not show specificity to changes in ART or RFT. In all groups, the N1-P2 amplitude at channel C4 (right hemisphere) reflected a change in ART but not in RFT. Behaviorally, 6-year olds and adults predominately utilized RFT cues (classified /ba/(wa) as /ba/) during phonetic judgments, as opposed to 4-5-year olds which utilized both cues equally. Our findings suggest that both ART and RFT are encoded in the auditory cortex, but an N1-P2 shift toward the vertex following age 4-5 indicates a shift toward an adult-like weighting strategy, such that, to utilize RFT to a greater extent. PMID:23570734

  20. Do ambient urban odors evoke basic emotions?

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    EvaHeuberger

    2014-04-01

    Full Text Available Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman’s (Ekman et al., 1983 basic emotions happiness, surprise, anger, fear, sadness and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles / bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the skin conductance response and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles / bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

  1. The Frequency of Hearing Loss and Hearing Aid Prescription in the Clients of the Avesina Education and Health Center, Audiometry Clinic, 1377

    Directory of Open Access Journals (Sweden)

    Abbas Bastani

    2003-08-01

    Full Text Available Objective: Determining the frequency of hearing disorders and hearing aid using in the clients referring to the Avesina education and health center, audiometry clinic, 1377. Method and Material: This is an assesive-descriptive survey that conducted on more than 2053 (1234 males and 819 females who referred for audiometry after examination by a physician. Case history, otoscopy, PTA, speech and immittance audiometry were conducted for all the clients. The findings were expressed in tables and diagrams of frequency. The age and sex relationship. All types of hearing losses and the number of the hearing-impaired clients need a hearing aid were assessed. Findings: 56% of this population were hearing-impaired and 44% had normal hearing were hearing. 60% were males and 40% females. Of the hearing-impaired, 44% had SNHL, 35.6% CHL and 8.2% mixed hearing loss. The hearing aid was prescribed for 204 (83 females and121 males if they need that only 20 females and 32 males wear it. Conclusion: It this sample, SNHL is of higher frequency. According to this survey, the more the age, the more the hearing aid is accepted (85% of wearer are more than 49 the prevalence of the hearing impaired males are more than females (60% versus 40%. Only 25% of the hearing-impaired wear hearing aids.

  2. Evoked emotions predict food choice.

    Directory of Open Access Journals (Sweden)

    Jelle R Dalenberg

    Full Text Available In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA and apply Multinomial Logit Models (MLM to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively. After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores.

  3. Evoked emotions predict food choice.

    Science.gov (United States)

    Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry

    2014-01-01

    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores. PMID:25521352

  4. Responses of motor units during the hind limb flexion withdrawal reflex evoked by noxious skin heating: phasic and prolonged suppression by midbrain stimulation and comparison with simultaneously recorded dorsal horn units.

    Science.gov (United States)

    Carstens, E; Campell, I G

    1992-02-01

    In rats anesthetized with sodium pentobarbital, we quantitatively analyzed descending modulation from the midbrain of a nociceptive flexion withdrawal reflex and responses of associated spinal neurons. We monitored the isometric force of hind limb withdrawal elicited by noxious heat stimuli (42-54 degrees C, 10 sec) on the hind paw. In one series of experiments, single-fiber EMG electrodes recorded responses of single muscle fibers (i.e., motor units) in biceps femoris during the hind limb withdrawal, without and during electrical stimulation in the midbrain periaqueductal gray (PAG) or lateral midbrain reticular formation (LRF). In a second series, responses of single lumbar dorsal horn neurons were also recorded simultaneously. Withdrawal force and associated motor unit responses were suppressed for prolonged periods (4 to greater than 60 min) following the initial episode of PAG or LRF stimulation in 40% of the rats, while they were suppressed phasically (i.e., only during brain stimulation) in the remainder. Motor unit responses increased in a graded fashion with increasing skin stimulus temperature from threshold (45 degrees C) to 54 degrees C. During PAG stimulation, the slope of the rate coding function was reduced with no change in threshold temperature. During LRF stimulation the rate coding function was shifted toward higher temperatures with increased threshold (47 degrees C). In 14 experiments 43 paired recordings were made from a dorsal horn and a motor unit during hind limb withdrawals. Mean latency to onset and peak of the heat-evoked response was shorter for dorsal horn compared to motor units. In 6/14 rats withdrawal force and motor unit responses were significantly suppressed for more than 8 min following mechanical placement of the stimulating electrodes and/or the initial episode of midbrain stimulation, while the simultaneously recorded dorsal horn unit responses remained constant. Following supplemental administration of pentobarbital (10

  5. The μ opioid agonist morphine modulates potentiation of capsaicin-evoked TRPV1 responses through a cyclic AMP-dependent protein kinase A pathway

    Directory of Open Access Journals (Sweden)

    Roberts-Thomson Sarah J

    2006-07-01

    Full Text Available Abstract Background The vanilloid receptor 1 (TRPV1 is critical in the development of inflammatory hyperalgesia. Several receptors including G-protein coupled prostaglandin receptors have been reported to functionally interact with the TRPV1 through a cAMP-dependent protein kinase A (PKA pathway to potentiate TRPV1-mediated capsaicin responses. Such regulation may have significance in inflammatory pain. However, few functional receptor interactions that inhibit PKA-mediated potentiation of TRPV1 responses have been described. Results In the present studies we investigated the hypothesis that the μ opioid receptor (MOP agonist morphine can modulate forskolin-potentiated capsaicin responses through a cAMP-dependent PKA pathway. HEK293 cells were stably transfected with TRPV1 and MOP, and calcium (Ca2+ responses to injection of the TRPV1 agonist capsaicin were monitored in Fluo-3-loaded cells. Pre-treatment with morphine did not inhibit unpotentiated capsaicin-induced Ca2+ responses but significantly altered capsaicin responses potentiated by forskolin. TRPV1-mediated Ca2+ responses potentiated by the direct PKA activator 8-Br-cAMP and the PKC activator Phorbol-12-myristate-13-acetatewere not modulated by morphine. Immunohistochemical studies confirmed that the TRPV1 and MOP are co-expressed on cultured Dorsal Root Ganglion neurones, pointing towards the existence of a functional relationship between the G-protein coupled MOP and nociceptive TRPV1. Conclusion The results presented here indicate that the opioid receptor agonist morphine acts via inhibition of adenylate cyclase to inhibit PKA-potentiated TRPV1 responses. Targeting of peripheral opioid receptors may therefore have therapeutic potential as an intervention to prevent potentiation of TRPV1 responses through the PKA pathway in inflammation.

  6. Cervical vestibular evoked myogenic potentials in children

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    Alcione Botelho Pereira

    2015-08-01

    Full Text Available INTRODUCTION: Cervical vestibular evoked myogenic potential is a test used in neurotological examination. It verifies the integrity of vestibular function through a muscular response evoked by an acoustic stimulation which activates the saccular macula. Normal standards in adults have been established, however, there are few published data on the normal responses in children.OBJECTIVE: To establish normal standards for vestibular myogenic responses in children without neurotological complaints.METHODS: This study's design is a cohort with cross-sectional analysis. The sample consisted of 30 subjects, 15 females (50% and 15 males (50%.RESULTS: The age of the subjects ranged between 8 and 13 years, with a mean of 10.2 (± 1.7. P1 peak showed an average latency of 17.26 (± 1.78 ms and a mean amplitude of 49.34 (± 23.07 µV, and the N2 peak showed an average latency of 24.78 (± 2.18 ms and mean amplitude of 66.23 (± 36.18 µV. P1-N2 mean amplitude was 115.6 (± 55.7 µV. There were no statistically significant differences when comparing by gender or by laterality.CONCLUSION: We established normal values of cervical myogenic vestibular responses in children between 8 and 13 years without neurotological complaints.

  7. Muscle synergies evoked by microstimulation are preferentially encoded during behavior

    Directory of Open Access Journals (Sweden)

    Simon Alexander Overduin

    2014-03-01

    Full Text Available Electrical microstimulation studies provide some of the most direct evidence for the neural representation of muscle synergies. These synergies, i.e. coordinated activations of groups of muscles, have been proposed as building blocks for the construction of motor behaviors by the nervous system. Intraspinal or intracortical microstimulation has been shown to evoke muscle patterns that can be resolved into a small set of synergies similar to those seen in natural behavior. However, questions remain about the validity of microstimulation as a probe of neural function, particularly given the relatively long trains of supratheshold stimuli used in these studies. Here, we examined whether muscle synergies evoked during intracortical microstimulation in two rhesus macaques were similarly encoded by nearby motor cortical units during a purely voluntary behavior involving object reach, grasp, and carry movements. At each microstimulation site we identified the synergy most strongly evoked among those extracted from muscle patterns evoked over all microstimulation sites. For each cortical unit recorded at the same microstimulation site, we then identified the synergy most strongly encoded among those extracted from muscle patterns recorded during the voluntary behavior. We found that the synergy most strongly evoked at an intracortical microstimulation site matched the synergy most strongly encoded by proximal units more often than expected by chance. These results suggest a common neural substrate for microstimulation-evoked motor responses and for the generation of muscle patterns during natural behaviors.

  8. Bursting response to current-evoked depolarization in rat CA1 pyramidal neurons is correlated with lucifer yellow dye coupling but not with the presence of calbindin-D28k

    International Nuclear Information System (INIS)

    Calbindin-D28k (CaBP) immunohistochemistry has been combined with electrophysiological recording and Lucifer Yellow (LY) cell identification in the CA1 region of the rat hippocampal formation. CaBP is shown to be contained within a distinct sub-population of CA1 pyramidal cells which is equivalent to the superficial layer described by Lorente de No (1934). The neurogenesis of these CaBP-positive neurons occurs 1-2 days later than the CaBP-negative neurons in the deep pyramidal cell layer, as shown by 3H-thymidine autoradiography. No correlation could be found between the presence or absence of CaBP and the type of electrophysiological response to current-evoked depolarizing pulses. The latter could be separated into bursting or non-bursting types, and the bursting-type response was nearly always found to be associated with the presence of LY dye coupling. Furthermore, when dye coupling involved three neurons, a characteristic pattern was observed which may represent the coupling of phenotypically identical neurons into distinct functional units within the CA1 pyramidal cell layer. In this particular case the three neurons were all likely to be CaBP-positive

  9. Bursting response to current-evoked depolarization in rat CA1 pyramidal neurons is correlated with lucifer yellow dye coupling but not with the presence of calbindin-D28k

    Energy Technology Data Exchange (ETDEWEB)

    Baimbridge, K.G.; Peet, M.J.; McLennan, H.; Church, J. (Department of Physiology, University of British Columbia, Vancouver (Canada))

    1991-04-01

    Calbindin-D28k (CaBP) immunohistochemistry has been combined with electrophysiological recording and Lucifer Yellow (LY) cell identification in the CA1 region of the rat hippocampal formation. CaBP is shown to be contained within a distinct sub-population of CA1 pyramidal cells which is equivalent to the superficial layer described by Lorente de No (1934). The neurogenesis of these CaBP-positive neurons occurs 1-2 days later than the CaBP-negative neurons in the deep pyramidal cell layer, as shown by 3H-thymidine autoradiography. No correlation could be found between the presence or absence of CaBP and the type of electrophysiological response to current-evoked depolarizing pulses. The latter could be separated into bursting or non-bursting types, and the bursting-type response was nearly always found to be associated with the presence of LY dye coupling. Furthermore, when dye coupling involved three neurons, a characteristic pattern was observed which may represent the coupling of phenotypically identical neurons into distinct functional units within the CA1 pyramidal cell layer. In this particular case the three neurons were all likely to be CaBP-positive.

  10. Control of cerebellar granule cell output by sensory-evoked Golgi cell inhibition

    OpenAIRE

    Duguid, Ian; BRANCO, Tiago; Chadderton, Paul; Arlt, Charlotte; Powell, Kate; Häusser, Michael

    2015-01-01

    Understanding how synaptic inhibition regulates sensory responses is a fundamental question in neuroscience. In cerebellar granule cells, sensory stimulation is thought to evoke an excitation–inhibition sequence driven by direct input from mossy fibers and followed by classical disynaptic feed-forward inhibition from nearby Golgi cells. We made, to our knowledge, the first voltage-clamp recordings of sensory-evoked inhibition in granule cells in vivo and show that, surprisingly, sensory-evoke...

  11. Relationships between Electrically Evoked Potentials and Loudness Growth in Bilateral Cochlear Implant Users

    OpenAIRE

    Kirby, Benjamin; Brown, Carolyn; Abbas, Paul; Etler, Christine; O’Brien, Sara

    2012-01-01

    Bilateral cochlear implantation has motivated efforts to ensure that sounds presented at equal levels to each ear are perceived as equally loud. Psychophysical loudness balancing is not always practical, especially with pediatric users. Electrophysiological potentials -- electrically evoked auditory brain stem response (EABR) and electrically evoked compound action potential (ECAP) measures -- may provide a means of approximating loudness balance. It was hypothesized that stimuli evoking equa...

  12. Prediction of Long-Term Treatment Response to Selective Serotonin Reuptake Inhibitors (SSRIs Using Scalp and Source Loudness Dependence of Auditory Evoked Potentials (LDAEP Analysis in Patients with Major Depressive Disorder

    Directory of Open Access Journals (Sweden)

    Bun-Hee Lee

    2015-03-01

    Full Text Available Background: Animal and clinical studies have demonstrated that the loudness dependence of auditory evoked potentials (LDAEP is inversely related to central serotonergic activity, with a high LDAEP reflecting weak serotonergic neurotransmission and vice versa, though the findings in humans have been less consistent. In addition, a high pretreatment LDAEP appears to predict a favorable response to antidepressant treatments that augment the actions of serotonin. The aim of this study was to test whether the baseline LDAEP is correlated with response to long-term maintenance treatment in patients with major depressive disorder (MDD. Methods: Scalp N1, P2 and N1/P2 LDAEP and standardized low resolution brain electromagnetic tomography-localized N1, P2, and N1/P2 LDAEP were evaluated in 41 MDD patients before and after they received antidepressant treatment (escitalopram (n = 32, 10.0 ± 4.0 mg/day, sertraline (n = 7, 78.6 ± 26.7 mg/day, and paroxetine controlled-release formulation (n = 2, 18.8 ± 8.8 mg/day for more than 12 weeks. A treatment response was defined as a reduction in the Beck Depression Inventory (BDI score of >50% between baseline and follow-up. Results: The responders had higher baseline scalp P2 and N1/P2 LDAEP than nonresponders (p = 0.017; p = 0.036. In addition, changes in total BDI score between baseline and follow-up were larger in subjects with a high baseline N1/P2 LDAEP than those with a low baseline N1/P2 LDAEP (p = 0.009. There were significantly more responders in the high-LDAEP group than in the low-LDAEP group (p = 0.041. Conclusions: The findings of this study reveal that a high baseline LDAEP is associated with a clinical response to long-term antidepressant treatment.

  13. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    OpenAIRE

    Oh, Seok-Kyun; Kim, Gwang-Won; Yang, Jong-Chul; Kim, Seok-Kwun; Kang, Heoung-Keun; Jeong, Gwang-Woo

    2012-01-01

    Objective This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. Materials and Methods A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with bot...

  14. 职业性噪声聋患者听觉诱发电位的初步研究%Study on brainstem auditory evoked potentials of patients with occupational noise deaf

    Institute of Scientific and Technical Information of China (English)

    邓龙刚; 杨寅秋; 李美娟; 何烈纯; 侯旭东

    2012-01-01

    Objective To study the correlation between auditor}1 evoked potential (AEP) and occupational noise deaf. Methods 45 cases of patients with occupational noise deaf (24 case with mild deafness, 21 cases with moderate deafness) and 25 individuals with normal healing (control group) were detected by pure tone audiometry (PTA), auditory sieady-siate evoked responses (ASSR), bralnstem auditor)" evoked potentials (BAEP) and 40 Hz auditory event-related potentials (40 Hz AEP) test. The tests results of the two groups were compared. Results There were significant difference in PTA, ASSR, BAEP and 40 Hz AEP test results between the control group and mild, moderate deafness group (P < 0.05); PTA was positively correlated with AEP reacting values (r - 0.722, 0.670, 0.835). Conclusion ASSR, BAEP, 40 Hz AEP tests can provide objective and impartial basis for the diagnosis of occupational noise deaf.%目的 探讨听觉诱发电位与噪声性聋易感性的关系.方法 使用纯音测听(PTA)、多频稳态诱发电位(ASSR)、脑干诱发电位(BAEP)、40 Hz听觉诱发电位(40 Hz AEP)检测45例职业性噪声聋患者(轻度聋24例,中度聋21例)和25例听力正常者(对照组),对PTA结果与ASSR、BAEP、40 Hz AEP反应阈检测结果进行对比研究.结果 对照组PTA、ASSR、BAEP、40 Hz AEP值与轻度和中度噪声聋比较,差异均有统计学意义(均P<0.05),FTA阈值与各听觉诱发电位反应值均存在正相关关系(r=0.722、0.670、0.835).结论 ASSR、BAEP、40 Hz AEP检测能为职业性听力损伤的诊断提供客观、公正的依据.

  15. Evoked Emotions Predict Food Choice

    NARCIS (Netherlands)

    Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

    2014-01-01

    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Th

  16. Audiometry in Young Children

    OpenAIRE

    Muller, George

    1987-01-01

    The author of this article reviews various techniques in the auditory assessment of infants and young children. The success of these tests depends on the overall functioning of the child, and not on chronological age alone. Any significant deviation from the normal auditory behaviour should raise suspicion of possible auditory impairment. Diagnostic audiology involves more than mere testing of the peripheral auditory mechanism in isolation. It necessitates investigation of possible neurologic...

  17. The effects of a series of omega-phosphonic alpha-carboxylic amino acids on electrically evoked and excitant amino acid-induced responses in isolated spinal cord preparations.

    OpenAIRE

    Evans, R H; Francis, A. A.; Jones, A W; Smith, D. A.; Watkins, J. C.

    1982-01-01

    1 The depressant actions on evoked electrical activity and the excitant amino acid antagonist properties of a range of omega-phosphonic alpha-carboxylic amino acids have been investigated in the isolated spinal cord preparations of the frog or immature rat. 2 When tested on dorsal root-evoked ventral root potentials, members of the homologous series from 2- amino-5-phosphonovaleric acid to 2-amino-8-phosphonooctanoic acid showed depressant actions which correlated with the ability of the subs...

  18. The PGF2α agonists luprostiol and d-cloprostenol reliably induce luteolysis in luteal phase mares without evoking clinical side effects or a stress response.

    Science.gov (United States)

    Kuhl, Juliane; Nagel, Christina; Ille, Natascha; Aurich, Jörg E; Aurich, Christine

    2016-05-01

    In the present study we have evaluated a possible stress reaction in response to two different PGF2α analogs-luprostiol and d-cloprostenol-and their effects on estrous cycle characteristics. In a cross-over-design eight mares received in alternating order either luprostiol (Treatment LUP; 3.75mg im), d-cloprostenol (Treatment CLO; 22.5μg im) or saline (Treatment CON; NaCl 0.9% 0.5ml im) on day 8 after ovulation. Injection of either LUP or CLO, but not of CON resulted in a significant decline of progesterone concentration in plasma to baseline concentrations within two days (time: p<0.001, treatment: p<0.01, time×treatment: p<0.05). The treatment to ovulation interval was significantly shorter in LUP and CLO than in CON cycles (LUP: 9.4±0.4 d; CLO: 9.4±1.3 d; CON: 16.1±0.8 d; p<0.001). Injection of either LUP or CLO, but not of CON significantly increased salivary cortisol concentration (immediately before injection: CON 1.3±0.2, LUP 1.4±0.3, CLO 1.4±0.3ng/ml; 60min after injection: CON 1.0±0.3, LUP 8.0±1.4, CLO 4.2±0.7ng/ml; time: p<0.01, treatment: p<0.001, time×treatment: p<0.001). Heart rate decreased over time (p<0.05) independent of treatment and no changes in heart rate variability were detected. Injection of the PGF2α analogs CLO and LUP reliably induced luteolysis and apart from a transient increase in salivary cortisol concentration no signs of a physiological stress response or apparent side effects occurred. PMID:26963045

  19. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seok Kyun; Kim, Gwang Won; Kang, Heoung Keun; Jeong, Gwang Woo [Chonnam National University, Gwangju (Korea, Republic of); Yang, Jong Chul [Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kim, Seok Kwun [Dong-A University College of Medicine, Busan (Korea, Republic of)

    2012-06-15

    This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males.

  20. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males.

  1. The paradox of music-evoked sadness: an online survey.

    Directory of Open Access Journals (Sweden)

    Liila Taruffi

    Full Text Available This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772. The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

  2. The paradox of music-evoked sadness: an online survey.

    Science.gov (United States)

    Taruffi, Liila; Koelsch, Stefan

    2014-01-01

    This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life. PMID:25330315

  3. In vivo optical microprobe imaging for intracellular Ca2+ dynamics in response to dopaminergic signaling in deep brain evoked by cocaine

    Science.gov (United States)

    Luo, Zhongchi; Pan, Yingtian; Du, Congwu

    2012-02-01

    Ca2+ plays a vital role as second messenger in signal transduction and the intracellular Ca2+ ([Ca2+]i) change is an important indicator of neuronal activity in the brain, including both cortical and subcortical brain regions. Due to the highly scattering and absorption of brain tissue, it is challenging to optically access the deep brain regions (e.g., striatum at >3mm under the brain surface) and image [Ca2+]i changes with cellular resolutions. Here, we present two micro-probe approaches (i.e., microlens, and micro-prism) integrated with a fluorescence microscope modified to permit imaging of neuronal [Ca2+]i signaling in the striatum using a calcium indicator Rhod2(AM). While a micro-prism probe provides a larger field of view to image neuronal network from cortex to striatum, a microlens probe enables us to track [Ca2+]i dynamic change in individual neurons within the brain. Both techniques are validated by imaging neuronal [Ca2+]i changes in transgenic mice with dopamine receptors (D1R, D2R) expressing EGFP. Our results show that micro-prism images can map the distribution of D1R- and D2R-expressing neurons in various brain regions and characterize their different mean [Ca2+]i changes induced by an intervention (e.g., cocaine administration, 8mg/kg., i.p). In addition, microlens images can characterize the different [Ca2+]i dynamics of D1 and D2 neurons in response to cocaine, including new mechanisms of these two types of neurons in striatum. These findings highlight the power of the optical micro-probe imaging for dissecting the complex cellular and molecular insights of cocaine in vivo.

  4. Sex and Ear Differences in Spontaneous and Click-Evoked Otoacoustic Emissions in Young Adults

    Science.gov (United States)

    Snihur, Adrian W. K.; Hampson, Elizabeth

    2011-01-01

    Effects of sex and handedness on the production of spontaneous and click-evoked otoacoustic emissions (OAEs) were explored in a non-hearing impaired population (ages 17-25 years). A sex difference in OAEs, either produced spontaneously (spontaneous OAEs or SOAEs) or in response to auditory stimuli (click-evoked OAEs or CEOAEs) has been reported in…

  5. EVOKED CAVERNOUS ACTIVITY: NEUROANATOMIC IMPLICATIONS

    OpenAIRE

    Yilmaz, Ugur; Vicars, Brenda; Yang, Claire C.

    2009-01-01

    We investigated the autonomic innervation of the penis by using evoked cavernous activity (ECA). We recruited 7 males with thoracic spinal cord injury (SCI) and sexual dysfunction and 6 males who were scheduled to have pelvic surgery (PS), specifically non-nerve-sparing radical cystoprostatectomy. In the PS subjects, ECA was performed both pre- and postoperatively. The left median nerve was electrically stimulated and ECA was recorded with two concentric electromyography needles placed into t...

  6. Evoked Emotions Predict Food Choice

    OpenAIRE

    Dalenberg, Jelle R.; Swetlana Gutjar; ter Horst, Gert J.; Kees de Graaf; Renken, Remco J.; Gerry Jager

    2014-01-01

    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well ...

  7. Single-sweep spectral analysis of contact heat evoked potentials

    DEFF Research Database (Denmark)

    Hansen, Tine M; Graversen, Carina; Frøkjaer, Jens B;

    2015-01-01

    AIMS: The cortical response to nociceptive thermal stimuli recorded as contact heat evoked potentials (CHEPs) may be altered by morphine. However, previous studies have averaged CHEPs over multiple stimuli, which are confounded by jitter between sweeps. Thus, the aim was to assess single-sweep ch...

  8. MDMA (ecstasy) modulates locomotor and prefrontal cortex sensory evoked activity.

    Science.gov (United States)

    Atkins, Kristal; Burks, Tilithia; Swann, Alan C; Dafny, Nachum

    2009-12-11

    Ingestion of 3, 4-methylenedioxymethamphetamine (MDMA) leads to heightened response to sensory stimulation; thus, MDMA is referred to as "ecstasy" because it produces pleasurable enhancement of such sensation. There have been no electrophysiological studies that report the consequences of MDMA on sensory input. The present study was initiated to study the effects of acute and chronic MDMA on locomotor activity and sensory evoked field potential from freely behaving rats previously implanted with permanent electrodes in the prefrontal cortex (PFC). The main findings of this study are that: (1) acute MDMA augments locomotor behavior and attenuates the incoming sensory input, (2) chronic treatment of MDMA elicits behavioral sensitization, (3) chronic administration of MDMA results in attenuation of the baseline activity of the sensory evoked field potential, and (4) administration of rechallenge MDMA result in enhancement of the PFC sensory evoked field potential. PMID:19769950

  9. Inner ear morphological study of guinea pigs with acoustically evoked short latency negative response%声诱发短潜伏期负电位豚鼠的内耳铺片研究

    Institute of Scientific and Technical Information of China (English)

    黄文钦; 李治美; 徐丽; 农东晓; 唐安洲; 覃焕桦; 杨甜

    2012-01-01

    Objective To establish a model of ototoxicity in guinea pigs with acoustically evoked short latency negative response (ASNR) and verify the responsible organ of ASNR based on microscopic characteristics of basal membranes,saccules,utricles and ampulla canalis semicircularis of the inner ear.Methods Total of 45 guinea pigs were employed in the experiment,which were randomly divided into the control group (15 subjects,30 ears) and the deafened group (30 subjects,60 ears). Each animal experienced auditory brainstem response ( ABR ). A quick treatment was employed for deafened group consisting of a subcutaneous injection of kanamycin at a dose of 400 mg/kg followed by jugular vein injection of ethacrynic acid at a dose of 40 mg/kg one hour later.The animals were performed ABR test from 7 to 10 days after the drug administration.The deafened group was further divided into ASNR group and non-ASNR group based on the presence of ASNR.All the guinea pigs were sacrificed after ABR tests.The Corti organ,macula sacculi,macula utriculi and crista ampullaris were observed by light microscope.Results In the deafened group (60 ears),3 subjects died postoperatively,27 subjects (54 ears) provided full data.ASNR was elicited in 19 ears (35.2%,19/54 ),the thresholds of ASNR were from 110 to 125 dBSPL with average of ( 121.7 ±4.5)dBSPL ASNR latency ranges were 1.80-2.08 ms,the average latency of thresholds were ( 1.93 ±0.07) ms.The stretched preparation results:overall hair-cell density of macula saccule,macula utriculi and crista ampullaris decreased in order of normal eontrol group,ASNR group and non-ASNR group.There was no difference between the normal group and ASNR group for cell density of macula saccule.Apart from this,statistical differences were found among other groups.Conclusions The present study evoked ASNR in an olotoxicity guinea pig model which was profound hearing loss with normal saccular function and normal saccular hair cell density.It suggested that ASNR

  10. Healthy Architecture! Can environments evoke emotional responses?

    OpenAIRE

    Roessler, Kirsten Kaya

    2012-01-01

    We find environmental psychology at the intersection between architecture and psychology. This article discusses the ways in which individuals are affected by architecture, departing from an early source on the psychology of architecture and taking three architectural examples as illustrations: a public place in Berlin, a health environment in Sweden, and a fitness centre in Denmark. Each of these architectural examples creates what might be called its own psychological emotions, and these ar...

  11. Somatosensory evoked potentials and outcome in perinatal asphyxia.

    OpenAIRE

    Gibson, N A; Graham, M.; Levene, M I

    1992-01-01

    Somatosensory evoked potentials (SEP) can be measured in the term newborn infant and given an index of function in the areas of the brain most likely to be damaged in perinatal asphyxia. We studied the median nerve SEP in 30 asphyxiated term infants over the course of their encephalopathy and until discharge from the neonatal unit. Three types of response were noted: normal waveform, abnormal waveform, or absence of cortical response. Follow up of the survivors was undertaken at a mean age of...

  12. 扫描翻转图像视觉诱发电位视力与对数视力表视力的比较%Sweep pattern visual evoked response acuity vs logarithmic visual acuity

    Institute of Scientific and Technical Information of China (English)

    朱捷; 李海生

    2001-01-01

    目的 对扫描图像视觉诱发电位视力(SPVER视力)与对数视力表视力进行比较。方法 比较50例受试者的视力表和SPVER视力在SPVER视力的测定中用了8个不同空间频率的光栅条纹连续扫描,所得数据经离散傅立叶分析后,获得振幅-空间频率曲线,并由外推法估计其视力。结果 SPVER视力与视力表视力的总体相关系数r=0.699,在视力表视力大于0.5时,SPVER视力有低估现象,而在视力表视力小于0.5时SPVER视力有高估现象。结论  SPVER视力与视力表视力有良好的相关性由于视力表视力和SPVER视力所用于评估视力的指标不同,使两者。结果 不完全相同%ObjectiveTo compare the sweep pattern visual evoked response acuity SPVER-A with the logarithmic visual acuity.MethodsSPVER-A and logarithmic visual acuity were measured and compared in 50 people. 8-squared vertical gratings were presented as stimuli continuously.The responses were averaged and displayed through the discrete fourier transform on the monitor display.The SPVER acuity was determined by extrapolating the SPVER amplitude-spatial frequency function to baseline.ResultsThe overall correlation was r=0.699 between the SPVER-A and logarithmic visual acuity.Underestimation of acuity by the SPVER when the logarithmic visual acuity is better than 0.5.On the other hand,when the logarithmic visual acuity is worse than 0.5 the SPVER-A was overestimated.ConclusionSPVER-A has a good correlation to logarithmic acuity.The difference between two methods may indicate that the grating acuity and logarithmic /visual acuity activate different system.

  13. Dexmedetomidine infusion and somatosensory evoked potentials.

    Science.gov (United States)

    Bloom, M; Beric, A; Bekker, A

    2001-10-01

    Intraoperative neurophysiologic monitoring requires information on the effects of anesthetic drugs because these drugs can directly alter evoked potentials, thus interfering with monitoring. We report on our evaluation of the effect of the recently introduced alpha2-adrenergic agonist, dexmedetomidine, on the somatosensory evoked potentials in two patients undergoing cervico-occipital fusion. Our results suggest that, although dexmedetomidine can affect the later cortical peaks of somatosensory evoked potentials (SSEPs), consistent and reproducible potentials can be recorded. PMID:11733664

  14. HYPOTHERMIA AND CHLOROPENT ANESTHESIA DIFFERENTIALLY AFFECT THE FLASH EVOKED POTENTIALS OF HOODED RATS

    Science.gov (United States)

    Anesthetics and body temperature alterations are both known to alter parameters of sensory-evoked responses. However few studies have quantitatively assessed the contributions of hypothermia to anesthetic-induced changes. Two experiments were performed. In the first, chronically ...

  15. An investigation on binocular summation response of visual evoked potential in children with hyperopia amblyopia%弱视儿童双眼总和视觉诱发电位变化的研究

    Institute of Scientific and Technical Information of China (English)

    于春红; 廖瑜俊; 杨洋; 邓燕; 彭小维; 鄢涛; 殷小龙

    2009-01-01

    Objective Conventional examination for vision function adopts subjective psychophysics methods.Pattern visual evoked potential (P-VEP) binocular summation response is a new objective way for the test of vision function.But its clinical value in evaluating vision function of amblyopia children is still in controversy.This study was to explore the binocular vision and the feature of P-VEP binocular summation in children with amblyopia and evaluate the significance of P-VEP binocular summation in binocular vision.MethodsThis is a case-controlled study.P-VEP binocular summation response and single ocular P-VEP response was respectively recorded in 151 hyperopia amblyopia children and 80 age- and gender-matched normal children.P-VEP response from children with hyperopia amblyopia was recorded under the corrected vision.The hyperopia amblyopia was diagnosed based on the standard of National Children Amblyopia and Strabismus Prevention and Treatment Working Group.The feature of P-VEP binocular summation was further analyzed and compared with monocular VEP response.Informed consent was obtained from each subject or custodian prior to the trail.ResultsNo significant difference was found in latency between P-VEP binocular summation response and monocular P-VEP response whether amblyopia children or normal children(P>0.05).Binocular response/monocular response value in amblyopia children was lower than that in normal children(P<0.05).Binocular response/monocular response value in mild or moderate amblyopia children was higher than that in severe amblyopia children(P<0.05).Binocular response/monocular response value was significantly reduced in the children with binocular vision than in the children without binocular vision (P<0.05).ConclusionP-VEP binocular vision,acting as an evaluation factor,could impartially reflect the function of binocular vision of amblyopia children.%目的 探讨弱视儿童双眼视功能及总和图形视觉诱发电位(P-VEP)反应的特

  16. Short latency vestibular evoked potentials in the chicken embryo

    Science.gov (United States)

    Jones, S. M.; Jones, T. A.

    1996-01-01

    Electrophysiological responses to pulsed linear acceleration stimuli were recorded in chicken embryos incubated for 19 or 20 days (E19/E20). Responses occurred within the first 16 ms following the stimulus onset. The evoked potentials disappeared following bilateral labyrinthectomy, but persisted following cochlear destruction alone, thus demonstrating that the responses were vestibular. Approximately 8 to 10 response peaks could be identified. The first 4 positive and corresponding negative components (early peaks with latencies birds. Mean response threshold for anesthetized embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P birds (-23.0dBre 1.0 g/ms). Latency/intensity functions (that is, slopes) were not significantly different between embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P function that occurs following 19 to 20 days of incubation. The recording of vestibular evoked potentials provides an objective, direct and noninvasive measure of peripheral vestibular function in the embryo and, as such, the method shows promise as an investigative tool. The results of the present study form the definitive basis for using vestibular evoked potentials in the detailed study of avian vestibular ontogeny and factors that may influence it.

  17. Evoked potentials in immobilized cats to a combination of clicks with painful electrocutaneous stimuli

    Science.gov (United States)

    Gilinskiy, M. A.; Korsakov, I. A.

    1979-01-01

    Averaged evoked potentials in the auditory, somatosensory, and motor cortical zones, as well as in the mesencephalic reticular formation were recorded in acute experiments on nonanesthetized, immobilized cats. Omission of the painful stimulus after a number of pairings resulted in the appearance of a delayed evoked potential, often resembling the late phases of the response to the painful stimulus. The characteristics of this response are discussed in comparison with conditioned changes of the sensory potential amplitudes.

  18. RECORDING OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

    Directory of Open Access Journals (Sweden)

    A. A. Sazgar

    2006-05-01

    Full Text Available It has been shown recently that loud clicks evoke myogenic potentials in the tonically contracting sternocleidomastoid muscles. Studies have suggested that these potentials are of vestibular origin, especially of the saccule and inferior vestibular nerve. A pilot study was undertaken in our hospital to record vestibular evoked myogenic potentials (VEMP for the first time in Iran. Eighteen healthy volunteers (32 ears without history of otologic or vestibular disorders were subjected to the VEMP test. Twenty-one patients (26 ears with unilateral (6 patients and bilateral (5 patients high frequency sensorineural hearing loss with unknown etiology, acoustic neuroma (1 patient, Meniere’s disease (4 patients and unilateral low frequency sensorineural hearing loss without vestibular complaint (5 patients were also enrolled in this study. VEMP response to clicks was obtained from 84.4% of ears of healthy subjects. These subjects demonstrated short latency waves to click stimuli during tonic neck flexor activation. Mean latencies of first positive (p13 and first negative (n23 potentials in healthy subjects were 12.45 ± 1.9 ms and 20.8 ± 3.5 ms, respectively. Median latencies of these two potentials were 12.1 and 19.3 ms, respectively. We could record VEMP in 5 patients with unilateral and all patients with high and low frequency sensorineural hearing loss without vestibular complaint. In the patient with acoustic neuroma VEMP was absent on the affected side. This technique may offer a new method to evaluate otolith and sacculocollic pathways in human.

  19. Avaliação dos limiares auditivos com e sem equipamento de proteção individual Pure tone audiometry with and without specific ear protectors

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Rodrigues de Faria

    2008-06-01

    Full Text Available Os autores realizaram estudo caso-controle audiométrico em indivíduos com e sem protetor auricular auditivo. OBJETIVOS: O objetivo do estudo foi avaliar a real atenuação individual dado pelos protetores. MATERIAL E MÉTODO: Foram avaliados 30 indivíduos (ou 60 orelhas de diferentes atividades profissionais, de ambos os sexos, com idades entre 20 e 58 anos, apresentando audição normal e tendo realizado repouso auditivo de 10 horas, submetidos a exame audiométrico com e sem protetor auricular auditivo, no período de fevereiro a julho de 2003, utilizando protetor tipo plugue. Avaliou-se as audiometrias nas vias aérea e óssea em freqüências de 500 a 4000Hz. RESULTADOS: Os resultados foram analisados estatisticamente e comparados aos dados fornecidos pelo fabricante. Assim se observou em ouvido real os níveis de atenuação auditiva obtidos com o uso destes produtos. CONCLUSÃO: Os resultados permitiram chegar à conclusão de que os índices fornecidos pelos fabricantes foram compatíveis com os que obtive nos testes.The authors evaluated pure tone audiometry with and without specific ear protectors. AIM: The purpose of this case control study was to measure the level of sound attenuation by earplugs. MATERIAL AND METHODS: The evaluation included sixty ears of 30 subjects of both sexes, aged between 20 and 58 years, of various professional activities, with normal hearing thresholds, and following ten hours of auditory rest. The statistical results of pure tone audiometry at 500 to 4000 Hertz with and without specific ear protectors were analyzed. RESULTS: These results were compared with those provided by the ear protector manufacturer. CONCLUSION: The results show that the rate of sound reduction was similar to the manufacturer's specifications.

  20. [The disposing techniques of evoked potentials].

    Science.gov (United States)

    Liu, H G; Zhou, L; Gu, J; Jing, D Z

    2000-11-01

    This paper is to bring forward the new disposing techniques of evoked potentials which include four aspect techniques of the averaging, the recording, digital sampling and filters about the averaging, evoked potential amplitude, evoked potential latency, evoked potential recording, and evoked potential generations. The technique of the averaging including signal filtering and a periodic averaging, can enhance EP dedection. The commercial EP machines also plot changes in latency between serial EP studies in order to detect trends in peak latency. The modern digital EP recording device consists of sensory stimator, recording amplifiers with analog filters, an analog-to-digital converter, a digital signal averager, and a display and storage system. A sample-and-hold function is one of the recent developments which used EP collectors that provide simultaneous recording with multiple channels employing different time and voltage scales and sampling rates. The EP data may be further processed following A-D conversion by digital filters. PMID:12583248

  1. Methodologic aspects of acetylcholine-evoked relaxation of rabbit aorta.

    Science.gov (United States)

    Hansen, K; Nedergaard, O A

    1999-08-01

    The acetylcholine-evoked relaxation of rabbit isolated thoracic aorta precontracted by phenylephrine was studied. Phenylephrine caused a steady contraction that was maintained for 6 h. In the presence of calcium disodium ethylenediaminetetraacetate (EDTA) and ascorbic acid the contraction decreased with time. N(G)-Nitro-L-arginine abolished the inhibitory effect of EDTA and ascorbic acid. Acetylcholine evoked a rapid concentration-dependent relaxation that recovered spontaneously and slowly, but fully, with time. Relaxation evoked by equieffective concentrations of carbachol and acetylcholine had the same time course. Cumulative addition of acetylcholine (10(-7)-3 x 10(-5) M) caused a marked relaxation that was reverted slightly at high concentrations. The relaxation was the same with rings derived from the upper, middle, and lower part of the thoracic aorta. Two consecutive concentration-response curves for acetylcholine obtained at a 2-h interval demonstrated a slight development of tachyphylaxis. The relaxation was inversely related to precontractile tension evoked by phenylephrine when expressed as a percentage, but independent when expressed as g tension. Storage of aorta in cold salt solution for 24 h did not alter the relaxation. EDTA and ascorbic acid did not alter the relaxation. It is concluded that (1) EDTA and ascorbic acid can not be used with impunity to stabilize catecholamines used as preconstriction agents; (2) the reversal of the acetylcholine-evoked relaxation is not due to hydrolysis of acetylcholine; (3) the relaxation is uniform in all segments of thoracic aorta; (4) cold storage of aorta does not alter the relaxation; and (5) acetylcholine releases the same amount of relaxing factor, irrespective of the precontractile tension. PMID:10691020

  2. Prestimulus amplitudes modulate P1 latencies and evoked traveling alpha waves

    Directory of Open Access Journals (Sweden)

    Nicole Alexandra Himmelstoss

    2015-05-01

    Full Text Available Traveling waves have been well documented in the ongoing, and more recently also in the evoked EEG. In the present study we investigate what kind of physiological process might be responsible for inducing an evoked traveling wave. We used a semantic judgment task which already proved useful to study evoked traveling alpha waves that coincide with the appearance of the P1 component. We found that the P1 latency of the leading electrode is significantly correlated with prestimulus amplitude size and that this event is associated with a transient change in alpha frequency. We assume that cortical background excitability, as reflected by an increase in prestimulus amplitude, is responsible for the observed change in alpha frequency and the initiation of an evoked traveling trajectory.

  3. Changes in visual-evoked potential habituation induced by hyperventilation in migraine

    OpenAIRE

    Coppola, Gianluca; Currà, Antonio; Sava, Simona Liliana; Alibardi, Alessia; Parisi, Vincenzo; Pierelli, Francesco; Schoenen, Jean

    2010-01-01

    Hyperventilation is often associated with stress, an established trigger factor for migraine. Between attacks, migraine is associated with a deficit in habituation to visual-evoked potentials (VEP) that worsens just before the attack. Hyperventilation slows electroencephalographic (EEG) activity and decreases the functional response in the occipital cortex during visual stimulation. The neural mechanisms underlying deficient-evoked potential habituation in migraineurs remain unclear. To find ...

  4. Transient evoked otoacoustic emissions testing for screening of sensorineural deafness in puppies

    OpenAIRE

    McBrearty, A; J. Penderis

    2011-01-01

    Background: Transient evoked otoacoustic emissions (TEOAE) are widely used for human neonatal deafness screening, but have not been reported for clinical use in dogs. Hypothesis/Objectives: To investigate the feasibility of TEOAE testing in conscious puppies and the ability of TEOAE testing to correctly identify deaf and hearing ears, as defined by brainstem auditory evoked response (BAER). Animals: Forty puppies from 10 litters. Methods: Prospective study on puppies presented ...

  5. Visual Evoked Potentials in Rett Syndrome

    Directory of Open Access Journals (Sweden)

    J. Gordon Millichap

    2015-11-01

    Full Text Available Investigators from the Boston Children's Hospital recorded pattern-reversal visual evoked potentials (VEPs in Mecp2 heterozygous female mice and in 34 girls with Rett syndrome (RTT.

  6. Somatosensory evoked potentials in deaferentation pain

    OpenAIRE

    Ilievska, Liljana; Gorgoska, E

    2008-01-01

    The aim of study was to examine how to the Somatosensory evoked potentials ( SEPs) are affected in patients with cerebrovascular thalamic lesions and to correlate the findings with sensory abnormalities.

  7. The Role of Odor-Evoked Memory in Psychological and Physiological Health.

    Science.gov (United States)

    Herz, Rachel S

    2016-01-01

    This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing. PMID:27447673

  8. The Role of Odor-Evoked Memory in Psychological and Physiological Health

    Directory of Open Access Journals (Sweden)

    Rachel S. Herz

    2016-07-01

    Full Text Available This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing.

  9. Baroreceptor activation attenuates attentional effects on pain-evoked potentials.

    Science.gov (United States)

    Gray, Marcus A; Minati, Ludovico; Paoletti, Giulia; Critchley, Hugo D

    2010-12-01

    Focused attention typically enhances neural nociceptive responses, reflected electroencephalographically as increased amplitude of pain-evoked event-related potentials (ERPs). Additionally, pain-evoked ERPs are attenuated by hypertension and baroreceptor activity, through as yet unclear mechanisms. There is indirect evidence that these two effects may interact, suggesting that baroreceptor-related modulation of nociception is more than a low-level gating phenomenon. To address this hypothesis, we explored in a group of healthy participants the combined effects of cue-induced expectancy and baroreceptor activity on the amplitude of pain-evoked ERPs. Brief nociceptive skin stimuli were delivered during a simple visual task; half were preceded by a visual forewarning cue, and half were unpredictable. Nociceptive stimuli were timed to coincide either with systole (maximum activation of cardiac baroreceptors) or with diastole (minimum baroreceptor activation). We observed a strong interaction between expectancy and cardiac timing for the amplitude of the P2 ERP component; no effects were observed for the N2 component. Cued stimuli were associated with larger P2 amplitude, but this effect was abolished for stimuli presented during baroreceptor activation. No cardiac timing effect was observed for un-cued stimuli. Taken together, these findings suggest a close integration of cognitive-affective aspects of expectancy and baroreceptor influences on pain, and as such may cast further light on mechanisms underlying mental and physiological contributions to clinical pain. PMID:20965656

  10. Audiogram of a formerly stranded long-finned pilot whale (Globicephala melas) measured using auditory evoked potentials.

    Science.gov (United States)

    Pacini, A F; Nachtigall, P E; Kloepper, L N; Linnenschmidt, M; Sogorb, A; Matias, S

    2010-09-15

    Long-finned pilot whales are highly social odontocetes found in temperate and subpolar regions. This species is particularly known for its interaction with fisheries as well as its mass strandings. Recent tagging work has provided some information about pilot whales in the wild but, even though they have been successfully kept in captivity, little is known about their sensory capabilities. This study investigates the hearing abilities of a rehabilitated 2 year old male long-finned pilot whale. A complete audiogram was collected using auditory evoked potential techniques that included measurements of nine frequencies from 4 to 100 kHz presented as sinusoidally amplitude-modulated tones. The results indicated that the region of best hearing was between 11.2 and 50 kHz and the subject had relatively poor high frequency hearing compared with other odontocete species. This study emphasizes the importance of collecting basic hearing measurements from new species, understanding diagnostic life histories as well as continuously increasing the sample size of audiometry measurements within and between odontocete species as animals become available. PMID:20802115

  11. Ethanol modulates facial stimulation-evoked outward currents in cerebellar Purkinje cells in vivo in mice

    Science.gov (United States)

    Wu, Mao-Cheng; Bing, Yan-Hua; Chu, Chun-Ping; Qiu, De-Lai

    2016-01-01

    Acute ethanol overdose can induce dysfunction of cerebellar motor regulation and cerebellar ataxia. In this study, we investigated the effect of ethanol on facial stimulation-evoked inhibitory synaptic responses in cerebellar Purkinje cells (PCs) in urethane-anesthetized mice, using in vivo patch-clamp recordings. Under voltage-clamp conditions, ethanol (300 mM) decreased the amplitude, half-width, rise time and decay time of facial stimulation-evoked outward currents in PCs. The ethanol-induced inhibition of facial stimulation-evoked outward currents was dose-dependent, with an IC50 of 148.5 mM. Notably, the ethanol-induced inhibition of facial stimulation-evoked outward currents were significantly abrogated by cannabinoid receptor 1 (CB1) antagonists, AM251 and O-2050, as well as by the CB1 agonist WIN55212-2. Moreover, the ethanol-induced inhibition of facial stimulation-evoked outward currents was prevented by cerebellar surface perfusion of the PKA inhibitors H-89 and Rp-cAMP, but not by intracellular administration of the PKA inhibitor PKI. Our present results indicate that ethanol inhibits the facial stimulation-evoked outward currents by activating presynaptic CB1 receptors via the PKA signaling pathway. These findings suggest that ethanol overdose impairs sensory information processing, at least in part, by inhibiting GABA release from molecular layer interneurons onto PCs. PMID:27489024

  12. Ethanol modulates facial stimulation-evoked outward currents in cerebellar Purkinje cells in vivo in mice.

    Science.gov (United States)

    Wu, Mao-Cheng; Bing, Yan-Hua; Chu, Chun-Ping; Qiu, De-Lai

    2016-01-01

    Acute ethanol overdose can induce dysfunction of cerebellar motor regulation and cerebellar ataxia. In this study, we investigated the effect of ethanol on facial stimulation-evoked inhibitory synaptic responses in cerebellar Purkinje cells (PCs) in urethane-anesthetized mice, using in vivo patch-clamp recordings. Under voltage-clamp conditions, ethanol (300 mM) decreased the amplitude, half-width, rise time and decay time of facial stimulation-evoked outward currents in PCs. The ethanol-induced inhibition of facial stimulation-evoked outward currents was dose-dependent, with an IC50 of 148.5 mM. Notably, the ethanol-induced inhibition of facial stimulation-evoked outward currents were significantly abrogated by cannabinoid receptor 1 (CB1) antagonists, AM251 and O-2050, as well as by the CB1 agonist WIN55212-2. Moreover, the ethanol-induced inhibition of facial stimulation-evoked outward currents was prevented by cerebellar surface perfusion of the PKA inhibitors H-89 and Rp-cAMP, but not by intracellular administration of the PKA inhibitor PKI. Our present results indicate that ethanol inhibits the facial stimulation-evoked outward currents by activating presynaptic CB1 receptors via the PKA signaling pathway. These findings suggest that ethanol overdose impairs sensory information processing, at least in part, by inhibiting GABA release from molecular layer interneurons onto PCs. PMID:27489024

  13. Sense Estimation and Instrumental Evaluation of Fabric-Evoked Prickle

    Institute of Scientific and Technical Information of China (English)

    敖利民; 郁崇文

    2004-01-01

    In this paper, the mechanism of fabric-evoked prickle is discussed, which indicates that the mechanical stimuli aroused by the fiber ends on the fabric surface to the skin-sensory receptors are responsible for prickle. The factors influencing the intensity of prickle are specialized and anatomized. Several means of sense estimate, including the corresponding statistical measures, are described. A few groping objective methods of evaluating prickle are analyzed, including the testing principles, the advantages and the disadvantages. At last, a new concept is proposed on the objective evaluation of prickle.

  14. Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats.

    Science.gov (United States)

    Nguyen, Christine T; Tsai, Tina I; He, Zheng; Vingrys, Algis J; Lee, Pei Y; Bui, Bang V

    2016-01-01

    The electroretinogram (ERG) and visual evoked potential (VEP) are commonly used to assess the integrity of the visual pathway. The ERG measures the electrical responses of the retina to light stimulation, while the VEP measures the corresponding functional integrity of the visual pathways from the retina to the primary visual cortex following the same light event. The ERG waveform can be broken down into components that reflect responses from different retinal neuronal and glial cell classes. The early components of the VEP waveform represent the integrity of the optic nerve and higher cortical centers. These recordings can be conducted in isolation or together, depending on the application. The methodology described in this paper allows simultaneous assessment of retinal and cortical visual evoked electrophysiology from both eyes and both hemispheres. This is a useful way to more comprehensively assess retinal function and the upstream effects that changes in retinal function can have on visual evoked cortical function. PMID:27404129

  15. Peripheral nerve injury increases glutamate-evoked calcium mobilization in adult spinal cord neurons

    Directory of Open Access Journals (Sweden)

    Doolen Suzanne

    2012-07-01

    Full Text Available Abstract Background Central sensitization in the spinal cord requires glutamate receptor activation and intracellular Ca2+ mobilization. We used Fura-2 AM bulk loading of mouse slices together with wide-field Ca2+ imaging to measure glutamate-evoked increases in extracellular Ca2+ to test the hypotheses that: 1. Exogenous application of glutamate causes Ca2+ mobilization in a preponderance of dorsal horn neurons within spinal cord slices taken from adult mice; 2. Glutamate-evoked Ca2+ mobilization is associated with spontaneous and/or evoked action potentials; 3. Glutamate acts at glutamate receptor subtypes to evoked Ca2+ transients; and 4. The magnitude of glutamate-evoked Ca2+ responses increases in the setting of peripheral neuropathic pain. Results Bath-applied glutamate robustly increased [Ca2+]i in 14.4 ± 2.6 cells per dorsal horn within a 440 x 330 um field-of-view, with an average time-to-peak of 27 s and decay of 112 s. Repeated application produced sequential responses of similar magnitude, indicating the absence of sensitization, desensitization or tachyphylaxis. Ca2+ transients were glutamate concentration-dependent with a Kd = 0.64 mM. Ca2+ responses predominantly occurred on neurons since: 1 Over 95% of glutamate-responsive cells did not label with the astrocyte marker, SR-101; 2 62% of fura-2 AM loaded cells exhibited spontaneous action potentials; 3 75% of cells that responded to locally-applied glutamate with a rise in [Ca2+]i also showed a significant increase in AP frequency upon a subsequent glutamate exposure; 4 In experiments using simultaneous on-cell recordings and Ca2+ imaging, glutamate elicited a Ca2+ response and an increase in AP frequency. AMPA/kainate (CNQX- and AMPA (GYKI 52466-selective receptor antagonists significantly attenuated glutamate-evoked increases in [Ca2+]i, while NMDA (AP-5, kainate (UBP-301 and class I mGluRs (AIDA did not. Compared to sham controls, peripheral nerve injury

  16. [Audiometry in the cellulose industry].

    Science.gov (United States)

    Corrao, C R; Milano, L; Pedulla, P; Carlesi, G; Bacaloni, A; Monaco, E

    1993-01-01

    A noise level dosimetry and audiometric testing were conducted in a cellulose factory to determine the hazardous noise level and the prevalence of noise induced hearing loss among the exposed workers. The noise level was recorded up to 90 db (A) in several working areas. 18 workers, potentially exposed to noise injury, evidenced a significant hearing loss. While no evidence of noise injury was recorded in a control group of 100 subjects. This finding suggest a strict relationship between audiometric tests, the noise level recorded in the working place and the working seniority of exposed employers. PMID:7720969

  17. Modified variance ratio for objective detection of transient evoked potentials in bottlenose dolphins (Tursiops truncatus).

    Science.gov (United States)

    Finneran, James J

    2008-12-01

    Evoked potential studies have often relied on one or more human observers to visually assess the averaged waveforms and decide if a response is present. Although simple and easy to implement, response detection strategies based on human observers are inherently subjective and depend on the observers' experience and biases. To avoid these shortcomings, some recent marine animal studies utilizing auditory steady-state responses have applied frequency-domain, statistically based objective detection methods; however, statistically based objective methods have not yet been applied to marine animal tests involving transient evoked responses, which are normally analyzed in the time domain. The present study applied a modified version of the variance ratio F(SP) to determine the presence or absence of evoked responses in two bottlenose dolphins (Tursiops truncatus) stimulated with tone pips. The appropriate degrees of freedom for the statistical tests were empirically determined in four dolphins. The modified variance ratio was found to be a useful tool and to provide an objective statistical approach for the detection of transient evoked potentials. PMID:19206829

  18. THE MECHANISM OF CEREBRAL EVOKED POTENTIALS BYREPETITIVE MAGNETIC STIMULATION OF GASTROCNEMIUS MUSCLE IN DUCHENNE MUSCULAR DYSTROPHY

    Institute of Scientific and Technical Information of China (English)

    管宇宙; 崔丽英; 汤晓芙; 李本红; 杜华

    2001-01-01

    Objective. To study the features and mechanism of the cerebral evoked potentials by repetitive stimulation of calf muscle in Duchenne muscular dystrophy (DMD) patients with obvious muscular dystrophy and psuedohypertrophy. Methods. Cerebral evoked potentials by stimulation of calf muscles and somatusensory evoked potentials(SEPs) by the stimulation of posterior tibial nerves at ankle were measured in 10 patients with DMD and 10 norreal controls matched with gender and age. The intensity of the magnetic stimulation was at 30% of maximal output (2. 1 Tesla, MagPro magnetic stimulator, Dantec) and the frequency was 1 Hz. The low intensity of magnet-ic stimulation was just sufficient to produce a contraction of the muscle belly underneath the coil. Recording electrode was placed at 2 cm posterior to the Cz, reference to Fpz. The latencies of N33, P38, N48 and P55 and ampli-tude (P38 - N48) were recorded. SEPs were recorded by routine methods. Results. In normal subjects, the amphtudes of cerebral evoked potentials by magnetic stimulation of calf mus-cle was 40% lower than that by electrical stimulation of the posterior tibial nerves at ankle. The latency of P38 was 2. 9 ± 2. 1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients, P38 latency from magnetic stimulation was remarkably prolonged ( P < 0. 01), and in 4 patients, there was no remarkable response. SEPs evoked by electrical stimulation were normal in all of the patients. Conclusion. DMD is an available model for the study of mechanism of cerebral evoked potentials by magnetic stimulating muscle. We can conclude that the responses from magnetic stimulation were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by stimulating dystrophic and psedohypertrophic muscle.

  19. Thought-evoking approaches in engineering problems

    CERN Document Server

    2014-01-01

    In creating the value-added product in not distant future, it is necessary and inevitable to establish a holistic and though-evoking approach to the engineering problem, which should be at least associated with the inter-disciplinary knowledge and thought processes across the whole engineering spheres. It is furthermore desirable to integrate it with trans-disciplinary aspects ranging from manufacturing culture, through liberal-arts engineering, and industrial sociology.   The thought-evoking approach can be exemplified and typified by representative engineering problems: unveiling essential features in ‘Tangential Force Ratio and Interface Pressure’, prototype development for ‘Bio-mimetic Needle’ and application of ‘Water-jet Machining to Artificial Hip Joint’, product innovation in ‘Heat Sink for Computer’, application of ‘Graph Theory’ to similarity evaluation of production systems, leverage among reciprocity attributes in ‘Industrial and Engineering Designs for Machine Enclosure’,...

  20. Cervicothoracic Multisegmental Transpinal Evoked Potentials in Humans

    OpenAIRE

    Einhorn, Jonathan; Li, Alan; Hazan, Royi; Knikou, Maria

    2013-01-01

    The objectives of this study were to establish the neurophysiological properties of the transpinal evoked potentials (TEPs) following transcutaneous electric stimulation of the spine (tsESS) over the cervicothoracic region, changes in the amplitude of the TEPs preceded by median nerve stimulation at group I threshold, and the effects of tsESS on the flexor carpi radialis (FCR) H-reflex in thirteen healthy human subjects while seated. Two re-usable self-adhering electrodes, connected to functi...

  1. Somatosensory evoked potentials in amyotrophic lateral sclerosis.

    OpenAIRE

    Cosi, V; Poloni, M.; Mazzini, L.; Callieco, R.

    1984-01-01

    Forty five patients with amyotrophic lateral sclerosis were investigated, by means of somatosensory evoked potentials, in order to detect the presence of subclinical sensory changes. Cervical SEPs from the median nerve and cortical SEPs from the median and tibial nerve were recorded, showing a delay of N13 and subsequent components; the latency of the first constant cortical potential was also increased in many patients. Only the SEPs from the tibial nerve showed a decrease of amplitude. Thes...

  2. Comparison of the pattern reversal visual evoked potential mediated by separate cone systems

    DEFF Research Database (Denmark)

    Johnsen, B; Frederiksen, J.L.; Larsson, H.B.

    1995-01-01

    With the purpose of recording responses mediated by the 3 cone systems visual evoked potentials (VEPs) were elicited by the reversal of monochromatic checkerboards superimposed upon strong monochromatic backgrounds (yellow, purple and blue-green). The sensitivity to light of various wave lengths...

  3. Quantifying the effect of isoflurane and nitrous oxide on somatosensory-evoked potentials

    Directory of Open Access Journals (Sweden)

    Usha Devadoss

    2010-01-01

    Full Text Available Anaesthetic techniques may have a significant effect on intraoperative-evoked potentials (EP. The present study is designed to compare Propofol anaesthesia with Isoflurane (with or without nitrous oxide during intraoperative somatosensory-evoked potential (SSEP monitoring in 15 ASA Grade I and II patients undergoing surgery for intracranial tumours. SSEPs in response to median and posterior tibial nerve stimulation were recorded under four different anaesthetic conditions: 1 Propofol infusion and ventilation with air-oxygen, 2 Isoflurane, 1.0 MAC and ventilation with air-oxygen, 3 Isoflurane 1.0 MAC and ventilation with nitrous oxide-oxygen, and 4 Return to Isoflurane, 1.0 MAC and ventilation with air-oxygen. Intraoperative monitoring of somatosensory evoked potentials is best recordable using Propofol. The morphology of the EP is reproducible with Isoflurane. This effect is exaggerated when it is advisable to avoid nitrous oxide.

  4. Clinicophysiological study of multi-modality evoked potentials and computed tomographic findings in persistent vegetative state

    International Nuclear Information System (INIS)

    The auditory brainstem response (ABR), short latency somatosensory evoked potential (SSEP) and visual evoked potential (VEP) of patients in the persistent vegetative state (PVS) are reported, and the correlations between the electrophysiological findings and the CT scan findings with the three clinical grades of the PVS (transitional, incomplete and complete vegetative syndromes) are discussed. Twenty two patients in a vegetative state caused by subarachnoid hemorrhage (3), hypertensive intracerebral hemorrhage (5), cerbral infarction (6), head injury (3), cerebral anoxia (4) and brain tumor (1). Each evoked response was evaluated for the presense or absence of abnormalities and assigned a grade ranked I to III. Briefly an evoked response was assigned a grade I, II, III if it satisfied the respective criteria of normal, moderately abnormal and severely abnormal or absent electrical activity. On the other hand CT scan findings in the PVS were evaluated for abnormal low density areas, ventricular dilatation and enlargement of the sulci and cisterns indicative of atrophy of the brain parenchym. SSEP and VEP were better correlated with the clinical grade than ABR, and upper brainstem atrophy and abnormal low density area in CT scan findings were more valuable as an index to expresses the clinical features than ventricular dilatation. On the basis of these results, it is concluded that studies of ABR, SSEP and VEP associated with CT scan findings in the PVS could be a useful diagnostic aid to evaluate the lesions of these patients. (author)

  5. Methylxanthine-evoked perturbation of spontaneous and evoked activities in isolated newborn rat hippocampal networks.

    Science.gov (United States)

    Ruangkittisakul, A; Sharopov, S; Kantor, C; Kuribayashi, J; Mildenberger, E; Luhmann, H J; Kilb, W; Ballanyi, K

    2015-08-20

    Treatment of apnea of prematurity with methylxanthines like caffeine, aminophylline or theophylline can evoke hippocampal seizures. However, it is unknown at which interstitial brain concentrations methylxanthines promote such neonatal seizures or interfere with physiological 'early network oscillations' (ENOs) that are considered as pivotal for maturation of hippocampal neural networks. We studied theophylline and caffeine effects on ENOs in CA3 neurons (CA3-ENOs) and CA3 electrical stimulation-evoked monosynaptic CA1 field potentials (CA1-FPs) in sliced and intact hippocampi, respectively, from 8 to 10-days-old rats. Submillimolar doses of theophylline and caffeine, blocking adenosine receptors and phosphodiesterase-4 (PDE4), did not affect CA3-ENOs, ENO-associated cytosolic Ca(2+) transients or CA1-FPs nor did they provoke seizure-like discharges. Low millimolar doses of theophylline (⩾1mM) or caffeine (⩾5mM), blocking GABAA and glycine receptors plus sarcoplasmic-endoplasmic reticulum Ca(2+) ATPase (SERCA)-type Ca(2+) ATPases, evoked seizure-like discharges with no indication of cytosolic Ca(2+) dysregulation. Inhibiting PDE4 with rolipram or glycine receptors with strychnine had no effect on CA3-ENOs and did not occlude seizure-like events as tested with theophylline. GABAA receptor blockade induced seizure-like discharges and occluded theophylline-evoked seizure-like discharges in the slices, but not in the intact hippocampi. In summary, submillimolar methylxanthine concentrations do not acutely affect spontaneous CA3-ENOs or electrically evoked synaptic activities and low millimolar doses are needed to evoke seizure-like discharges in isolated developing hippocampal neural networks. We conclude that mechanisms of methylxanthine-related seizure-like discharges do not involve SERCA inhibition-related neuronal Ca(2+) dysregulation, PDE4 blockade or adenosine and glycine receptor inhibition, whereas GABA(A) receptor blockade may contribute partially. PMID

  6. Electrical Circuit Modeling for Somatosensory Evoked Fields in Magnetoencephalogram

    Science.gov (United States)

    Ishihara, Shinichi; Tanaka, Keita; Uchikawa, Yoshinori; Kobayashi, Koichiro

    We measured somatosensory evoked fields (SEFs) by applying on electric stimulus to the right finger (medium nerve and ulnar nerve) and the right ankle (posterior tibial nerve) with a 39-channel SQUID system, which can measure magnetic-field components perpendicular (Br) and tangential to the scalp (Bθ, Bφ) simultaneously. To investigate the relationship between phase lag and stimulus repetition frequency (SRF), the delay time of a component synchronized with the SRFs was calculated by convoluting the reference signal and the measured SEF. The phase lag was linear to SRF for at least three different ranges of the SRFs in each SEF data. We simulated the SEF responses based on the results of phase-lag characteristics and determined the parameters for modeling. To quantitatively characterize the component of SEF, we proposed electric circuit model for the characteristics of phase-lag of the SEF with stimuli frequency.

  7. Motor behaviors in the sheep evoked by electrical stimulation of the subthalamic nucleus.

    Science.gov (United States)

    Lentz, Linnea; Zhao, Yan; Kelly, Matthew T; Schindeldecker, William; Goetz, Steven; Nelson, Dwight E; Raike, Robert S

    2015-11-01

    Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is used to treat movement disorders, including advanced Parkinson's disease (PD). The pathogenesis of PD and the therapeutic mechanisms of DBS are not well understood. Large animal models are essential for investigating the mechanisms of PD and DBS. The purpose of this study was to develop a novel sheep model of STN DBS and quantify the stimulation-evoked motor behaviors. To do so, a large sample of animals was chronically-implanted with commercial DBS systems. Neuroimaging and histology revealed that the DBS leads were implanted accurately relative to the neurosurgical plan and also precisely relative to the STN. It was also possible to repeatedly conduct controlled evaluations of stimulation-evoked motor behavior in the awake-state. The evoked motor responses depended on the neuroanatomical location of the electrode contact selected for stimulation, as contacts proximal to the STN evoked movements at significantly lower voltages. Tissue stimulation modeling demonstrated that selecting any of the contacts stimulated the STN, whereas selecting the relatively distal contacts often also stimulated thalamus but only the distal-most contact stimulated internal capsule. The types of evoked motor behaviors were specific to the stimulation frequency, as low but not high frequencies consistently evoked movements resembling human tremor or dyskinesia. Electromyography confirmed that the muscle activity underlying the tremor-like movements in the sheep was consistent with human tremor. Overall, this work establishes that the sheep is a viable a large-animal platform for controlled testing of STN DBS with objective motor outcomes. Moreover, the results support the hypothesis that exaggerated low-frequency activity within individual nodes of the motor network can drive symptoms of human movement disorders, including tremor and dyskinesia. PMID:26231574

  8. Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans

    OpenAIRE

    Cui, Jian; McQuillan, Patrick M.; Blaha, Cheryl; Kunselman, Allen R.; Sinoway, Lawrence I.

    2012-01-01

    We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an ar...

  9. The VESPA: A method for the rapid estimation of a visual evoked potential

    OpenAIRE

    Lalor, Edmund C.; Pearlmutter, Barak A.; Richard B. Reilly; McDarby, Gary; Foxe, John J.

    2006-01-01

    Faster and less obtrusive means for measuring a Visual Evoked Potential would be valuable in clinical testing and basic neuroscience research. This study presents a method for accomplishing this by smoothly modulating the luminance of a visual stimulus using a stochastic process. Despite its visually unobtrusive nature, the rich statistical structure of the stimulus enables rapid estimation of the visual system's impulse response. The profile of these responses, which we ...

  10. Brainstem Auditory Evoked Potentials Suggest a Role for the Ventral Cochlear Nucleus in Tinnitus

    OpenAIRE

    Gu, Jianwen Wendy; Herrmann, Barbara S.; Levine, Robert A.; Melcher, Jennifer R.

    2012-01-01

    Numerous studies have demonstrated elevated spontaneous and sound-evoked brainstem activity in animal models of tinnitus, but data on brainstem function in people with this common clinical condition are sparse. Here, auditory nerve and brainstem function in response to sound was assessed via auditory brainstem responses (ABR) in humans with tinnitus and without. Tinnitus subjects showed reduced wave I amplitude (indicating reduced auditory nerve activity) but enhanced wave V (reflecting eleva...

  11. Characteristics of Spontaneous and Evoked EPSPs Recorded From Dentate Spiny Hilar Cells in Rat Hippocampal Slices

    OpenAIRE

    Scharfman, Helen E.

    1993-01-01

    Excitation of the spiny subtype of hilar neurons in the fascia dentata was characterized by intracellular recording from hilar cells in hippocampal slices. Stimulation of the outer molecular layer was used to activate the perforant path. Evoked responses were examined, as well as the large spontaneous excitatory potentials that are a distinctive characteristic of spiny hilar cells.Excitatory potentials that occurred spontaneously, as well as those that occurred in response to outer molecular ...

  12. Suppressive Effects of Resveratrol Treatment on The Intrinsic Evoked Excitability of CA1 Pyramidal Neurons

    Directory of Open Access Journals (Sweden)

    Gholamhossein Meftahi

    2015-10-01

    Full Text Available Objective: Resveratrol, a phytoalexin, has a wide range of desirable biological actions. Despite a growing body of evidence indicating that resveratrol induces changes in neuronal function, little effort, if any, has been made to investigate the cellular effect of resveratrol treatment on intrinsic neuronal properties. Materials and Methods: This experimental study was performed to examine the acute effects of resveratrol (100 μM on the intrinsic evoked responses of rat Cornu Ammonis (CA1 pyramidal neurons in brain slices, using whole cell patch clamp recording under current clamp conditions. Results: Findings showed that resveratrol treatment caused dramatic changes in evoked responses of pyramidal neurons. Its treatment induced a significant (P<0.05 increase in the after hyperpolarization amplitude of the first evoked action potential. Resveratrol-treated cells displayed a significantly broader action potential (AP when compared with either control or vehicle-treated groups. In addition, the mean instantaneous firing frequency between the first two action potentials was significantly lower in resveratrol-treated neurons. It also caused a significant reduction in the time to maximum decay of AP. The rheobase current and the utilization time were both significantly greater following resveratrol treatment. Neurons exhibited a significantly depolarized voltage threshold when exposed to resveratrol. Conclusion: Results provide direct electrophysiological evidence for the inhibitory effects of resveratrol on pyramidal neurons, at least in part, by reducing the evoked neural activity.

  13. Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

    DEFF Research Database (Denmark)

    Huys, Raoul; Jirsa, Viktor K; Darokhan, Ziauddin; Valentiniene, Sonata; Roland, Per E

    2016-01-01

    by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point......Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced...... attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization is that it...

  14. Valeriana officinalis root extract suppresses physical stress by electric shock and psychological stress by nociceptive stimulation-evoked responses by decreasing the ratio of monoamine neurotransmitters to their metabolites

    OpenAIRE

    JUNG, HYO YOUNG; Yoo, Dae Young; Kim, Woosuk; Nam, Sung Min; Kim, Jong Whi; Choi, Jung Hoon; Kwak, Youn-Gil; Yoon, Yeo Sung; Hwang, In Koo

    2014-01-01

    Background In this study, we investigate the effects of valerian root extracts (VE) on physical and psychological stress responses by utilizing a communication box. Methods Eight-week-old ICR mice received oral administration of VE (100 mg/kg/0.5 ml) or equal volume of distilled water in every day for 3 weeks prior to being subjected to physical or psychological stress for 3 days, which are induced by communication box developed for physical electric shock and psychological stress by nocicept...

  15. Inferring Evoked and Consideration Set from Scanner Data

    OpenAIRE

    Wirawan Dony Dahana; Nozomi Nakajima

    2011-01-01

    Evoked and consideration set have been one of main research topics in marketing field for a long time. Using interview data, many studies have been conducted to investigate the nature of its content. However, only few studies tried to do so by using consumer purchase history. By modeling the process of evoked and consideration set formation, in this research we try to elicit consumer evoked set from scanner data. Some managerial implications for marketing decisions derived from the informatio...

  16. Infrared neural stimulation fails to evoke neural activity in the deaf guinea pig cochlea.

    Science.gov (United States)

    Thompson, Alexander C; Fallon, James B; Wise, Andrew K; Wade, Scott A; Shepherd, Robert K; Stoddart, Paul R

    2015-06-01

    At present there is some debate as to the processes by which infrared neural stimulation (INS) activates neurons in the cochlea, as the lasers used for INS can potentially generate a range of secondary stimuli e.g. an acoustic stimulus is produced when the light is absorbed by water. To clarify whether INS in the cochlea requires functioning hair cells and to explore the potential relevance to cochlear implants, experiments using INS were performed in the cochleae of both normal hearing and profoundly deaf guinea pigs. A response to laser stimulation was readily evoked in normal hearing cochlea. However, no response was evoked in any profoundly deaf cochleae, for either acute or chronic deafening, contrary to previous work where a response was observed after acute deafening with ototoxic drugs. A neural response to electrical stimulation was readily evoked in all cochleae after deafening. The absence of a response from optical stimuli in profoundly deaf cochleae suggests that the response from INS in the cochlea is hair cell mediated. PMID:25796297

  17. Relaxation of evoked contractile activity of isolated guinea-pig ileum by (+/-)-kavain.

    Science.gov (United States)

    Seitz, U; Ameri, A; Pelzer, H; Gleitz, J; Peters, T

    1997-08-01

    Kava pyrones are the pharmacologically active compounds of Piper methysticum Forst. In the present study, the effect of the synthetic kava pyrone (+/-)-kavain was investigated on evoked contractile activity of isolated guinea-pig ileum. (+/-)-Kavain (1 microM-1 mM) dose-dependently reduced contractions of ileum evoked by carbachol (10 microM), by BAY K 8644 (0.3 microM), or by substance P (0.05 microM). (+/-)-Kavain also inhibited the contractile responses induced by raising the extracellular K+ concentration from 4 to 20 mM and by blocking the K+ channel by barium chloride (1 mM) or 4-aminopyridine (0.3 mM). After pre-incubation with 1 microM nifedipine, carbachol (1 microM) evoked 18.2 +/- 14.3% of contraction at control (i.e. prior pre-incubation with nifedipine). This remaining response was completely abolished by high concentrations of (+/-)-kavain (400 microM). After treatment of the longitudinal ileum strips with pertussis toxin (PTX), carbachol (1 microM) evoked 27.0 +/- 6.2% of the control response in untreated ileum. These contractions were also blocked by (+/-)-kavain (400 microM). However, (+/-)-kavain had no effect on the caffeine-induced (20 mM) contractions of ileum strips, which were permeabilized with digitonin or beta-escin. Moreover, it failed to affect Ca(2+)-evoked contractions of skinned muscles. These results suggest that the kava pyrone (+/-)-kavain may act in a non-specific musculotropic way on the smooth muscle membrane. PMID:9270372

  18. Definition of compassion-evoking images in a Mexican sample.

    Science.gov (United States)

    Mercadillo, Roberto E; Barrios, Fernando A; Díaz, José Luis

    2007-10-01

    To assemble a calibrated set of compassion-eliciting visual stimuli, 60 clinically healthy Mexican volunteers (36 women, 24 men; M age = 27.5 yr., SD = 2.4) assessed 84 pictures selected from the International Affective Picture System catalogue using the dimensions of Valence, Arousal, and Dominance included in the Self-assessment Manikin scale and an additional dimension of Compassion. Pictures showing suffering in social contexts and expressions of sadness elicited similar responses of compassion. The highest compassion response was reported for pictures showing illness and pain. Men and women differed in the intensity but not the quality of the compassionate responses. Compassion included attributes of negative emotions such as displeasure. The quality of the emotional response was not different from that previously reported for samples in the U.S.A., Spain, and Brazil. A set of 28 pictures was selected as high-compassion-evoking images and 28 as null-compassion controls suitable for studies designed to ascertain the neural substrates of this moral emotion. PMID:18065091

  19. Auditory evoked fields elicited by spectral, temporal, and spectral-temporal changes in human cerebral cortex

    Directory of Open Access Journals (Sweden)

    ChristoPantev

    2012-05-01

    Full Text Available Natural sounds contain complex spectral components, which are temporally modulated as time-varying signals. Recent studies have suggested that the auditory system encodes spectral and temporal sound information differently. However, it remains unresolved how the human brain processes sounds containing both spectral and temporal changes. In the present study, we investigated human auditory evoked responses elicited by spectral, temporal, and spectral-temporal sound changes by means of magnetoencephalography (MEG. The auditory evoked responses elicited by the spectral-temporal change were very similar to those elicited by the spectral change, but those elicited by the temporal change were delayed by 30 – 50 ms and differed from the others in morphology. The results suggest that human brain responses corresponding to spectral sound changes precede those corresponding to temporal sound changes, even when the spectral and temporal changes occur simultaneously.

  20. Glucagon-like peptide-2 modulates neurally evoked mucosal chloride secretion in guinea pig small intestine in vitro.

    Science.gov (United States)

    Baldassano, Sara; Liu, Sumei; Qu, Mei-Hu; Mulè, Flavia; Wood, Jackie D

    2009-10-01

    Glucagon-like peptide-2 (GLP-2) is an important neuroendocrine peptide in intestinal physiology. It influences digestion, absorption, epithelial growth, motility, and blood flow. We studied involvement of GLP-2 in intestinal mucosal secretory behavior. Submucosal-mucosal preparations from guinea pig ileum were mounted in Ussing chambers for measurement of short-circuit current (I(sc)) as a surrogate for chloride secretion. GLP-2 action on neuronal release of acetylcholine was determined with ELISA. Enteric neuronal expression of the GLP-2 receptor (GLP-2R) was studied with immunohistochemical methods. Application of GLP-2 (0.1-100 nM) to the serosal or mucosal side of the preparations evoked no change in baseline I(sc) and did not alter transepithelial ionic conductance. Transmural electrical field stimulation (EFS) evoked characteristic biphasic increases in I(sc), with an initially rapid rising phase followed by a sustained phase. Application of GLP-2 reduced the EFS-evoked biphasic responses in a concentration-dependent manner. The GLP-2R antagonist GLP-2-(3-33) significantly reversed suppression of the EFS-evoked responses by GLP-2. Tetrodotoxin, scopolamine, and hexamethonium, but not vasoactive intestinal peptide type 1 receptor (VPAC1) antagonist abolished or reduced to near zero the EFS-evoked responses. GLP-2 suppressed EFS-evoked acetylcholine release as measured by ELISA. Pretreatment with GLP-2-(3-33) offset this action of GLP-2. In the submucosal plexus, GLP-2R immunoreactivity (-IR) was expressed in choline acetyltransferase-IR neurons, somatostatin-IR neurons, neuropeptide Y-IR neurons, and vasoactive intestinal peptide-IR neurons. We conclude that submucosal neurons in the guinea pig ileum express GLP-2R. Activation of GLP-2R decreases neuronally evoked epithelial chloride secretion by suppressing acetylcholine release from secretomotor neurons. PMID:19628655

  1. Vestibular Dysfunctions in Cochlear Implant Patients; A Vestibular Evoked Myogenic Potential Study

    Directory of Open Access Journals (Sweden)

    Masoud Motasaddi Zarandy

    2011-12-01

    Full Text Available Background and Aim: Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals.Methods: Thirty-three unilateral cochlear implanted patients (mean age 19.96 years and 30 normal hearing individuals (mean age 24-27 years as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups.Results: Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48% from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear.Conclusion: Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

  2. Music evokes vicarious emotions in listeners.

    Science.gov (United States)

    Kawakami, Ai; Furukawa, Kiyoshi; Okanoya, Kazuo

    2014-01-01

    Why do we listen to sad music? We seek to answer this question using a psychological approach. It is possible to distinguish perceived emotions from those that are experienced. Therefore, we hypothesized that, although sad music is perceived as sad, listeners actually feel (experience) pleasant emotions concurrent with sadness. This hypothesis was supported, which led us to question whether sadness in the context of art is truly an unpleasant emotion. While experiencing sadness may be unpleasant, it may also be somewhat pleasant when experienced in the context of art, for example, when listening to sad music. We consider musically evoked emotion vicarious, as we are not threatened when we experience it, in the way that we can be during the course of experiencing emotion in daily life. When we listen to sad music, we experience vicarious sadness. In this review, we propose two sides to sadness by suggesting vicarious emotion. PMID:24910621

  3. Music evokes vicarious emotions in listeners

    Directory of Open Access Journals (Sweden)

    Ai eKawakami

    2014-05-01

    Full Text Available Why do we listen to sad music? We seek to answer this question using a psychological approach. It is possible to distinguish perceived emotions from those that are experienced. Therefore, we hypothesized that, although sad music is perceived as sad, listeners actually feel (experience pleasant emotions concurrent with sadness. This hypothesis was supported, which led us to question whether sadness in the context of art is truly an unpleasant emotion. While experiencing sadness may be unpleasant, it may also be somewhat pleasant when experienced in the context of art, for example, when listening to sad music. We consider musically evoked emotion vicarious, as we are not threatened when we experience it, in the way that we can be during the course of experiencing emotion in daily life. When we listen to sad music, we experience vicarious sadness. In this review, we propose two sides to sadness by suggesting vicarious emotion.

  4. EVOKED POTENTIALS OF OBSESSIVE-COMPULSIVE DISORDER:STATE OR TRAIT MARKER

    Institute of Scientific and Technical Information of China (English)

    肖泽萍; 陈兴时; 张明岛; 楼翡璎; 陈珏

    2004-01-01

    Objective To investigate the status of evoked potentials in obsessive-compulsive disorder (OCD). Methods Evoked potentials P300 , auditory brainstem response ( ABR ) and visual evoked potential (VEP) were recorded from 35 OCD patients and 28 normal controls (NC) with a Nicolet Spirit Instrument. 23 of the OCD patients were followed up after 5 months with the same markers. Results Compared with NC, OCD patients showed decreased P3 of P300 amplitude ( OCD group 3.5 + 1.6μv vs. NC group 5.9 +2.1 μv, P <0.01 ),delayed V latency (6.4 +0. 4ms vs. 5.5 +0.3ms, P <0.01 ) and increased V amplitude( 0.35 ±0.1μv vs. 0.16 ±0.09μv, P <0.05)of ABR and delayed P2 of VEP latency (199 ±39ms vs. 183 +28ms, P <0. 05). The followup measures of evoked potentials suggested that decreased P3 of P300 amplitude and delayed P2 of VEP latency might be state markers of OCD , while decreased V amplitude and delayed V of ABR latency might be trait markers of OCD. Conclusion The changes of P300 and VEP are related to clinical status of OCD patients, while the association between ABR and OCD symptoms need to be further investigated.

  5. A lateralized auditory evoked potential elicited when auditory objects are defined by spatial motion.

    Science.gov (United States)

    Butcher, Andrew; Govenlock, Stanley W; Tata, Matthew S

    2011-02-01

    Scene analysis involves the process of segmenting a field of overlapping objects from each other and from the background. It is a fundamental stage of perception in both vision and hearing. The auditory system encodes complex cues that allow listeners to find boundaries between sequential objects, even when no gap of silence exists between them. In this sense, object perception in hearing is similar to perceiving visual objects defined by isoluminant color, motion or binocular disparity. Motion is one such cue: when a moving sound abruptly disappears from one location and instantly reappears somewhere else, the listener perceives two sequential auditory objects. Smooth reversals of motion direction do not produce this segmentation. We investigated the brain electrical responses evoked by this spatial segmentation cue and compared them to the familiar auditory evoked potential elicited by sound onsets. Segmentation events evoke a pattern of negative and positive deflections that are unlike those evoked by onsets. We identified a negative component in the waveform - the Lateralized Object-Related Negativity - generated by the hemisphere contralateral to the side on which the new sound appears. The relationship between this component and similar components found in related paradigms is considered. PMID:21056097

  6. Recovery of Impaired Somatosensory Evoked Fields After Improvement of Tongue Sensory Deficits With Neurosurgical Reconstruction.

    Science.gov (United States)

    Maezawa, Hitoshi; Tojyo, Itaru; Yoshida, Kazuya; Fujita, Shigeyuki

    2016-07-01

    Somatosensory evoked fields (SEFs) induced by tongue stimulation can be useful as an objective parameter to assess sensory disturbances in the tongue. However, whether tongue SEFs can be useful as a clinical, objective follow-up assessment method of tongue sensation after oral surgery is unknown. We describe 2 cases in which tongue SEFs were successfully used in clinical assessment. Two patients with unilateral tongue sensory deficits caused by lingual nerve injury during lower third molar extraction were recruited. Both patients underwent surgery to repair the damaged nerve, and all tongue sensory evaluations were performed once before and once after surgery. SEFs were recorded by stimulating the affected and unaffected sides of the tongue separately, and cortical activity was evaluated over the contralateral hemisphere. The unilaterality of the deficit also was assessed. In both patients, stimulation of the unaffected side evoked reproducible cortical responses before and after surgery. Both patients also recovered some sensation after surgery, given that presurgery stimulation of the affected side failed to evoke cortical activity whereas postsurgery stimulation evoked cortical activity on both sides. Sensation was initially highly lateralized in both patients but was restored to approximately normal in the postsurgery evaluation. Finally, both patients rated their subjective tongue sensations on the affected side over 50% better after the surgical intervention. These cases indicate that tongue SEFs may have a clinical use as an objective parameter for assessing the course of tongue sensory recovery. PMID:26855025

  7. Estudo das latências e amplitudes dos potenciais evocados auditivos de média latência em indivíduos audiologicamente normais Middle latency response study of auditory evoked potentials’ amplitudes and lantencies audiologically normal individuals

    Directory of Open Access Journals (Sweden)

    Ivone Ferreira Neves

    2007-02-01

    Full Text Available Estudo de coorte contemporânea com corte transversal. O Potencial Evocado Auditivo de Média Latência (PEAML é gerado entre 10 e 80ms e possui múltiplos geradores, com maior contribuição da região tálamo-cortical. O estabelecimento de critérios de normalidade para os valores de latência e amplitude é necessário para uso clínico. OBJETIVOS: Analisar a latência e amplitude do PEAML em indivíduos sem alterações audiológicas, e verificar a confiabilidade da amplitude Pa-Nb. MATERIAL E MÉTODO: Foram coletados os PEAML de 25 indivíduos durante o ano de 2005 e analisados os componentes Na, Pa, Nb para cada orelha testada (A1 e A2, e posicionamento de eletrodo (C3 e C4. RESULTADOS: Observou-se diferença estatisticamente significante entre os valores médios de latência para C3A1 e C4A1 com relação aos componentes Na e Pa, não sendo encontrada esta diferença para o componente Nb e valores médios das amplitudes Na-Pa e Pa-Nb. CONCLUSÃO: Foram estabelecidos os valores das médias e desvios padrão para os parâmetros latência e amplitude dos componentes Na, Pa, Nb, e Na-Pa e Pa-Nb, nas condições C3A1, C4A1, C3A2, C4A2, proporcionando os parâmetros para a análise e interpretação deste potencial.Contemporary cohort cross-sectional study. Introduction: The auditory middle latency response (AMLR is generated between 10 and 80 ms and has multiple generators, with a greater contribution from the thalamus-cortical pathways. The establishment of normality criteria for latency and amplitude values is necessary for clinical use. AIM: to analyze the latency and amplitude of the AMLR in individuals without audiological disorders, and verify the reliability of Pa-Nb amplitude. MATERIALS AND METHODS: The AMLR of 25 individuals was collected during 2005 and the Na, Pa, Nb components were analyzed for each tested ear (A1 and A2, and electrode positioning (C3 and C4. RESULTS: A statistically significant difference was noticed among middle

  8. Visual evoked potential (VEP) measured by simultaneous 64-channel EEG and 3T fMRI.

    Science.gov (United States)

    Bonmassar, G; Anami, K; Ives, J; Belliveau, J W

    1999-06-23

    We present the first simultaneous measurements of evoked potentials (EPs) and fMRI hemodynamic responses to visual stimulation. Visual evoked potentials (VEPs) were recorded both inside and outside the static 3T magnetic field, and during fMRI examination. We designed, constructed, and tested a non-magnetic 64-channel EEG recording cap. By using a large number of EEG channels it is possible to design a spatial filter capable of removing the artifact noise present when recording EEG/EPs within a strong magnetic field. We show that the designed spatial filter is capable of recovering the ballistocardiogram-contaminated original EEG signal. Isopotential plots of the electrode array recordings at the peak of the VEP response (approximately 100ms) correspond well with simultaneous fMRI observed activated areas of primary and secondary visual cortices. PMID:10501528

  9. A Study of Relationship between the Acoustic Sensitivity of Vestibular System and the Ability to Trigger Sound-Evoked Muscle Reflex of the Middle Ear in Adults with Normal Hearing

    Directory of Open Access Journals (Sweden)

    S.F. Emami

    2014-07-01

    Full Text Available Introduction & Objective: The vestibular system is sound sensitive and the sensitivity is related to the saccule. The vestibular afferents are projected to the middle ear muscles (such as the stapedius. The goal of this research was studying the relationship between the vestibular hearing and the sound-evoked muscle reflex of the middle ear to 500 HZ. Materials & Methods: This study was a cross sectional-comparison done in audiology department of Sheikholreis C‍‍linic (Hamadan, Iran. The study groups consisted of thirty healthy people and thirty patients with benign paroxysmal positional vertigo. Inclusion criteria of the present study were to have normal hearing on pure tone audiometry, acoustic reflex, and speech discrimination scores. Based on ipsilateral acoustic reflex test at 500HZ, they were divided to normal and abnormal groups. Then they were evaluated by cervical vestibular evoked myogenic potentials (cVEMPs and finally classified in three groups (N Normal ear , (CVUA Contra lateral vertiginous ear with unaffected saccular sensitivity to sound,(IVA Ipsilateral vertiginous ear with affected saccular sensitivity to sound. Results: Thirty affected ears (IVA with decreased vestibular excitability as detected by ab-normal cVEMPs, revealed abnormal findings of acoustic reflex at 500HZ. Whereas, both un-affected (CVUA and normal ears (N had normal results. Multiple comparisons of mean values of cVEMPs (p13,n23 and acoustic reflex at500HZ among the three groups were sig-nificant. The correlation between acoustic reflex at 500HZ and p13 latencies was significant. The n23 latencies showed significant correlation with acoustic reflex at 500HZ. Conclusion: The vestibular sensitivity to sound retains the ability to trigger sound-evoked re-flex of the middle ear at 500 HZ. (Sci J Hamadan Univ Med Sci 2014; 21 (2:99-104

  10. Intermittent MTII Application Evokes Repeated Anorexia and Robust Fat and Weight Loss

    OpenAIRE

    Zhang, Yi; Collazo, Renata; Gao, Yongxin; Li, Gang; Scarpace, Philip J

    2009-01-01

    Central melanocortins (MC) evoke potent but transient anorectic responses with tachyphylaxis developing within days. We hypothesized that intermittent therapy using the MC analog, melanotan II (MTII), would minimize the tachyphylaxis and enhance the long-term efficacy of MTII treatment. F344/BN rats were infused with MTII or vehicle into the lateral ventricle by mini pump for 14 days. Half the MTII-infused rats were then given vehicle (MTII-On/Off), while the remaining received fresh MTII (MT...

  11. Selectivity and Plasticity in a Sound-Evoked Male-Male Interaction in Drosophila

    OpenAIRE

    Jeonghyeon Yoon; Eriko Matsuo; Daichi Yamada; Hiroshi Mizuno; Takako Morimoto; Hiroyoshi Miyakawa; Setsuo Kinoshita; Hiroshi Ishimoto; Azusa Kamikouchi

    2013-01-01

    During courtship, many animals, including insects, birds, fish, and mammals, utilize acoustic signals to transmit information about species identity. Although auditory communication is crucial across phyla, the neuronal and physiologic processes are poorly understood. Sound-evoked chaining behavior, a display of homosexual courtship behavior in Drosophila males, has long been used as an excellent model for analyzing auditory behavior responses, outcomes of acoustic perception and higher-order...

  12. Auditory Evoked Fields Elicited by Spectral, Temporal, and Spectral–Temporal Changes in Human Cerebral Cortex

    OpenAIRE

    ChristoPantev; HidehikoOkamoto

    2012-01-01

    Natural sounds contain complex spectral components, which are temporally modulated as time-varying signals. Recent studies have suggested that the auditory system encodes spectral and temporal sound information differently. However, it remains unresolved how the human brain processes sounds containing both spectral and temporal changes. In the present study, we investigated human auditory evoked responses elicited by spectral, temporal, and spectral-temporal sound changes by means of magnetoe...

  13. Trigeminal evoked potentials in patients with symptomatic trigeminal neuralgia due to intracranial mass lesions.

    OpenAIRE

    Sundaram P; Hegde A; Chandramouli B; Das B

    1999-01-01

    Trigeminal evoked potentials (TEP) were recorded by electrical stimulation of the lips in 7 patients with symptomatic trigeminal neuralgia due to CT proved mass lesions involving the trigeminal nerve. All the patients showed TEP abnormalities on the affected side. Chronic compression and irritation of the trigeminal nerve may be responsible for these changes. The results obtained were compared with other similar studies and TEP abnormalities observed in idiopathic trigeminal neuralgia. As all...

  14. Short-latency somatosensory evoked potentials in degenerative and vascular dementia.

    OpenAIRE

    Abbruzzese, G; Reni, L.; Cocito, L; Ratto, S; Abbruzzese, M; Favale, E

    1984-01-01

    Short-latency somatosensory evoked potentials (SEPs) were recorded from 54 patients with dementia as compared to 32 age-matched controls. SEPs were generally normal in patients with senile dementia of Alzheimer type, while patients with multi-infarct dementia showed a prolonged central conduction time, an increased latency of both N13 and N20 and a reduction of the primary cortical response amplitude. These findings suggest that recording SEPs may be useful in the differential diagnosis betwe...

  15. Somatosensory evoked potentials after multisegmental lower limb stimulation in focal lesions of the lumbosacral spinal cord

    OpenAIRE

    Restuccia, D; Insola, A; Valeriani, M; Santilli, V; Bedini, L.; Le Pera, D.; Barba, C.; Denaro, F.; Tonali, P.

    2000-01-01

    OBJECTIVES—Recording techniques permit the separate analysis of the response from cauda equina roots and the spinal potential that is probably generated by the activation of dorsal horn cells. To improve the functional assessment of focal lesions of the lumbosacral cord, lower limb somatosensory evoked potentials (SEPs) were measured by multisegmental stimulation.
METHODS—Common peroneal and tibial nerves SEPs were recorded in 14 patients in whom MRI demonstrated compress...

  16. On the significance of giant somatosensory evoked potentials in cortical myoclonus.

    OpenAIRE

    Rothwell, J. C.; Obeso, J A; Marsden, C D

    1984-01-01

    Four patients with cortical myoclonus were studied. All had reflex muscle jerking and grossly enlarged somatosensory evoked responses (SEPs) following electrical stimulation of the digital nerves. In addition, three of the patients had spontaneous or action-induced myoclonus. Back-averaging the EEG from these spontaneous muscle jerks showed a large positive wave over the contralateral somatomotor cortex which preceded the jerk by about 20 ms. Administration of lisuride (0.1 mg iv) reduced the...

  17. Evolution of separate predation- and defence-evoked venoms in carnivorous cone snails

    OpenAIRE

    Dutertre, Sébastien; Jin, Ai-Hua; Vetter, Irina; Hamilton, Brett; Sunagar, Kartik; Lavergne, Vincent; Dutertre, Valentin; Fry, Bryan G.; Antunes, Agostinho; Venter, Deon J.; Alewood, Paul F.; Lewis, Richard J.

    2014-01-01

    Venomous animals are thought to inject the same combination of toxins for both predation and defence, presumably exploiting conserved target pharmacology across prey and predators. Remarkably, cone snails can rapidly switch between distinct venoms in response to predatory or defensive stimuli. Here, we show that the defence-evoked venom of Conus geographus contains high levels of paralytic toxins that potently block neuromuscular receptors, consistent with its lethal effects on humans. In con...

  18. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

    OpenAIRE

    Roberto Vincis; Samuel Lagier; Dimitri Van De Ville; Ivan Rodriguez; Alan Carleton

    2015-01-01

    Functional brain-imaging techniques used in humans and animals, such as functional MRI and intrinsic optical signal (IOS) imaging, are thought to largely rely on neurovascular coupling and hemodynamic responses. Here, taking advantage of the well-described micro-architecture of the mouse olfactory bulb, we dissected the nature of odor-evoked IOSs. Using in vivo pharmacology in transgenic mouse lines reporting activity in different cell types, we show that parenchymal IOSs are largely independ...

  19. Effects of Insomnia Disorder and Knee Osteoarthritis on Resting and Pain-Evoked Inflammatory Markers

    OpenAIRE

    Quartana, Phillip J.; Finan, Patrick H.; Page, Gayle G.; Smith, Michael T

    2014-01-01

    Osteoarthritis is the most prevalent arthritic condition. Systemic inflammatory cytokines appear to have an important role in the onset and maintenance of the disease. Sleep disturbances are prevalent in osteoarthritis and associated with alterations in systemic inflammatory cytokines, suggesting a common pathophysiology across these conditions. A comparative investigation of the effects of insomnia disorder and osteoarthritis on pain-evoked cytokine responses has yet to be undertaken. We exa...

  20. Long-Term Effects of Acoustic Trauma on Electrically Evoked Otoacoustic Emission

    OpenAIRE

    Halsey, Kärin; Fegelman, Karen; Raphael, Yehoash; Grosh, Karl; Dolan, David F.

    2005-01-01

    Electrically evoked otoacoustic emissions (EEOAEs) are sounds measured in the ear canal when alternating current (AC) stimulation is passed into the cochlea. These sounds are attributed to the motile responses of outer hair cells (OHCs). The EEOAE has characteristic amplitude, phase, and fine structure. Multicomponent analysis of the EEOAE shows short (SDC) and long delay components (LDC) that are thought to originate from OHCs near the AC stimulating site and from OHCs at more remote locatio...

  1. Effects of carnosine on the evoked potentials in hippocampal CA1 region*

    OpenAIRE

    Feng, Zhou-yan; Zheng, Xiao-jing; Wang, Jing

    2009-01-01

    Objective: To directly examine the effects of carnosine on neuronal excitation and inhibition in rat hippocampus in vivo. Methods: Artificial cerebrospinal fluid with carnosine was directly administrated over the exposed rat hippocampus. The changes of neuron activity in the CA1 region of hippocampus were evaluated by orthodromically- and antidromically-evoked potentials, as well as paired-pulse stimulation paradigm. Results: In both orthodromic and antidromic response potentials, carnosine t...

  2. Neural mechanisms of evoked oscillations: stability and interaction with transient events.

    Science.gov (United States)

    Moratti, Stephan; Clementz, Brett A; Gao, Yuan; Ortiz, Tomás; Keil, Andreas

    2007-12-01

    There is increasing evidence that early event-related potentials are a result of phase alignment of ongoing background oscillations of the electroencephalogram rather than additive amplitude modulation. Steady state visual-evoked potentials (ssVEPs) can be recorded using an intensity modulated stimulus, resulting in an evoked brain response at a known frequency, i.e. the stimulation frequency. Given this property, the ssVEP is ideally suited for examining the relationship between single-trial fluctuations in phase/amplitude and the evoked brain potential resulting from averaging across trials. To address this issue, the current study investigated the contribution of single trial power and intertrial phase locking to ssVEP generation by presenting a peripheral flicker. Further, transient stimuli were presented during flicker and at three increasing latency lags following flicker offset to examine (1) to what extent a stimulus can disturb the ssVEP oscillation and (2) how phase alignment during P1-N1-P2 time windows is affected during presence of evoked oscillations. The former assessment evaluates the stability of ssVEPs and the latter the phase alignment processes to transient stimuli under experimentally induced background oscillations. We observed that ssVEPs are a result of phase alignment rather than single trial amplitude modulation. In addition, ssVEP oscillations were not disturbed by transient stimuli. Finally, phase alignment in P1-N1-P2 time windows was distorted during and shortly after steady state stimulation. We conclude that ssVEPs represent strongly phase locked oscillations sharing the same generation mechanisms as early evoked potentials. PMID:17274017

  3. External QX-314 inhibits evoked cranial primary afferent synaptic transmission independent of TRPV1.

    Science.gov (United States)

    Hofmann, Mackenzie E; Largent-Milnes, Tally M; Fawley, Jessica A; Andresen, Michael C

    2014-12-01

    The cell-impermeant lidocaine derivative QX-314 blocks sodium channels via intracellular mechanisms. In somatosensory nociceptive neurons, open transient receptor potential vanilloid type 1 (TRPV1) receptors provide a transmembrane passageway for QX-314 to produce long-lasting analgesia. Many cranial primary afferents express TRPV1 at synapses on neurons in the nucleus of the solitary tract and caudal trigeminal nucleus (Vc). Here, we investigated whether QX-314 interrupts neurotransmission from primary afferents in rat brain-stem slices. Shocks to the solitary tract (ST) activated highly synchronous evoked excitatory postsynaptic currents (ST-EPSCs). Application of 300 μM QX-314 increased the ST-EPSC latency from TRPV1+ ST afferents, but, surprisingly, it had similar actions at TRPV1- ST afferents. Continued exposure to QX-314 blocked evoked ST-EPSCs at both afferent types. Neither the time to onset of latency changes nor the time to ST-EPSC failure differed between responses for TRPV1+ and TRPV1- inputs. Likewise, the TRPV1 antagonist capsazepine failed to prevent the actions of QX-314. Whereas QX-314 blocked ST-evoked release, the frequency and amplitude of spontaneous EPSCs remained unaltered. In neurons exposed to QX-314, intracellular current injection evoked action potentials suggesting a presynaptic site of action. QX-314 acted similarly at Vc neurons to increase latency and block EPSCs evoked from trigeminal tract afferents. Our results demonstrate that QX-314 blocked nerve conduction in cranial primary afferents without interrupting the glutamate release mechanism or generation of postsynaptic action potentials. The TRPV1 independence suggests that QX-314 either acted extracellularly or more likely entered these axons through an undetermined pathway common to all cranial primary afferents. PMID:25185814

  4. Glucagon-like peptide-1 modulates neurally evoked mucosal chloride secretion in guinea pig small intestine in vitro.

    Science.gov (United States)

    Baldassano, Sara; Wang, Guo-Du; Mulè, Flavia; Wood, Jackie D

    2012-02-01

    Glucagon-like peptide-1 (GLP-1) acts at the G protein-coupled receptor, GLP-1R, to stimulate secretion of insulin and to inhibit secretion of glucagon and gastric acid. Involvement in mucosal secretory physiology has received negligible attention. We aimed to study involvement of GLP-1 in mucosal chloride secretion in the small intestine. Ussing chamber methods, in concert with transmural electrical field stimulation (EFS), were used to study actions on neurogenic chloride secretion. ELISA was used to study GLP-1R effects on neural release of acetylcholine (ACh). Intramural localization of GLP-1R was assessed with immunohistochemistry. Application of GLP-1 to serosal or mucosal sides of flat-sheet preparations in Ussing chambers did not change baseline short-circuit current (I(sc)), which served as a marker for chloride secretion. Transmural EFS evoked neurally mediated biphasic increases in I(sc) that had an initial spike-like rising phase followed by a sustained plateau-like phase. Blockade of the EFS-evoked responses by tetrodotoxin indicated that the responses were neurally mediated. Application of GLP-1 reduced the EFS-evoked biphasic responses in a concentration-dependent manner. The GLP-1 receptor antagonist exendin-(9-39) suppressed this action of GLP-1. The GLP-1 inhibitory action on EFS-evoked responses persisted in the presence of nicotinic or vasoactive intestinal peptide receptor antagonists but not in the presence of a muscarinic receptor antagonist. GLP-1 significantly reduced EFS-evoked ACh release. In the submucosal plexus, GLP-1R immunoreactivity (IR) was expressed by choline acetyltransferase-IR neurons, neuropeptide Y-IR neurons, somatostatin-IR neurons, and vasoactive intestinal peptide-IR neurons. Our results suggest that GLP-1R is expressed in guinea pig submucosal neurons and that its activation leads to a decrease in neurally evoked chloride secretion by suppressing release of ACh at neuroepithelial junctions in the enteric neural networks

  5. Topographic distribution of the tibial somatosensory evoked potential using coherence

    Directory of Open Access Journals (Sweden)

    D.B. Melges

    2008-12-01

    Full Text Available The objective of the present study was to determine the adequate cortical regions based on the signal-to-noise ratio (SNR for somatosensory evoked potential (SEP recording. This investigation was carried out using magnitude-squared coherence (MSC, a frequency domain objective response detection technique. Electroencephalographic signals were collected (International 10-20 System from 38 volunteers, without history of neurological pathology, during somatosensory stimulation. Stimuli were applied to the right posterior tibial nerve at the rate of 5 Hz and intensity slightly above the motor threshold. Response detection was based on rejecting the null hypothesis of response absence (significance level α= 0.05 and M = 500 epochs. The best detection rates (maximum percentage of volunteers for whom the response was detected for the frequencies between 4.8 and 72 Hz were obtained for the parietal and central leads mid-sagittal and ipsilateral to the stimulated leg: C4 (87%, P4 (82%, Cz (89%, and Pz (89%. The P37-N45 time-components of the SEP can also be observed in these leads. The other leads, including the central and parietal contralateral and the frontal and fronto-polar leads, presented low detection capacity. If only contralateral leads were considered, the centro-parietal region (C3 and P3 was among the best regions for response detection, presenting a correspondent well-defined N37; however, this was not observed in some volunteers. The results of the present study showed that the central and parietal regions, especially sagittal and ipsilateral to the stimuli, presented the best SNR in the gamma range. Furthermore, these findings suggest that the MSC can be a useful tool for monitoring purposes.

  6. Cervicothoracic multisegmental transpinal evoked potentials in humans.

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    Jonathan Einhorn

    Full Text Available The objectives of this study were to establish the neurophysiological properties of the transpinal evoked potentials (TEPs following transcutaneous electric stimulation of the spine (tsESS over the cervicothoracic region, changes in the amplitude of the TEPs preceded by median nerve stimulation at group I threshold, and the effects of tsESS on the flexor carpi radialis (FCR H-reflex in thirteen healthy human subjects while seated. Two re-usable self-adhering electrodes, connected to function as one electrode (cathode, were placed bilaterally on the clavicles. A re-usable electrode (anode was placed on the cervicothoracic region covering from Cervical 4-Thoracic 2 and held under constant pressure throughout the experiment. TEPs were recorded bilaterally from major arm muscles with subjects seated at stimulation frequencies of 1.0, 0.5, 0.33, 0.2, 0.125, and 0.1 Hz, and upon double tsESS pulses delivered at an inter-stimulus interval of 40 ms. TEPs from the arm muscles were also recorded following median nerve stimulation at the conditioning-test (C-T intervals of 2, 3, 5, 8, and 10 ms. The FCR H-reflex was evoked and recorded according to conventional methods following double median nerve pulses at 40 ms, and was also conditioned by tsESS at C-T intervals that ranged from -10 to +50 ms. The arm TEPs amplitude was not decreased at low-stimulation frequencies and upon double tsESS pulses in all but one subject. Ipsilateral and contralateral arm TEPs were facilitated following ipsilateral median nerve stimulation, while the FCR H-reflex was depressed by double pulses and following tsESS at short and long C-T intervals. Non-invasive transpinal stimulation can be used as a therapeutic modality to decrease spinal reflex hyper-excitability in neurological disorders and when combined with peripheral nerve stimulation to potentiate spinal output.

  7. Surface electrical stimulation to evoke referred sensation.

    Science.gov (United States)

    Forst, Johanna C; Blok, Derek C; Slopsema, Julia P; Boss, John M; Heyboer, Lane A; Tobias, Carson M; Polasek, Katharine H

    2015-01-01

    Surface electrical stimulation (SES) is being investigated as a noninvasive method to evoke natural sensations distal to electrode location. This may improve treatment for phantom limb pain as well as provide an alternative method to deliver sensory feedback. The median and/or ulnar nerves of 35 subjects were stimulated at the elbow using surface electrodes. Strength-duration curves of hand sensation were found for each subject. All subjects experienced sensation in their hand, which was mostly described as a paresthesia-like sensation. The rheobase and chronaxie values were found to be lower for the median nerve than the ulnar nerve, with no significant difference between sexes. Repeated sessions with the same subject resulted in sufficient variability to suggest that recalculating the strength-duration curve for each electrode placement is necessary. Most of the recruitment curves in this study were generated with 28 to 36 data points. To quickly reproduce these curves with limited increase in error, we recommend 10 data points. Future studies will focus on obtaining different sensations using SES with the strength-duration curve defining the threshold of the effective parameter space. PMID:26348194

  8. Auditory evoked potential measurements in elasmobranchs

    Science.gov (United States)

    Casper, Brandon; Mann, David

    2005-04-01

    Auditory evoked potentials (AEP) were first used to examine hearing in elasmobranchs by Corwin and Bullock in the late 1970s and early 1980s, marking the first time AEPs had been measured in fishes. Results of these experiments identified the regions of the ear and brain in which sound is processed, though no actual hearing thresholds were measured. Those initial experiments provided the ground work for future AEP experiments to measure fish hearing abilities in a manner that is much faster and more convenient than classical conditioning. Data will be presented on recent experiments in which AEPs were used to measure the hearing thresholds of two species of elasmobranchs: the nurse shark, Ginglymostoma cirratum, and the yellow stingray, Urobatis jamaicencis. Audiograms were analyzed and compared to previously published audiograms obtained using classical conditioning with results indicating that hearing thresholds were similar for the two methods. These data suggest that AEP testing is a viable option when measuring hearing in elasmobranchs and can increase the speed in which future hearing measurements can be obtained.

  9. Auditory evoked potential measurements with cetaceans

    Science.gov (United States)

    Mann, David; Cook, Mandy; Bauer, Gordon; Fellner, Wendi; Wells, Randy

    2005-04-01

    Auditory evoked potentials (AEPs) allow researchers to measure the hearing abilities of animals that would be difficult or impossible to train for behavioral measurements of hearing. The hearing abilities of live-stranded cetaceans and wild dolphins can only be made with AEP techniques. In these situations, time with the animal is often restricted to an hour or less, and there is often little control over the acoustic environment in which the tests are performed. AEP measurements may be made while the animals are in air or in shallow pools. For cetaceans in air, sounds are typically presented with a suction cup jawphone. For cetaceans in water, sounds may be presented in a direct field (with the transducer located at some distance from the test subject) or with a jawphone. In each of these situations it is important to understand how thresholds derived from AEP measurements compare with behavioral hearing measurements. Examples of AEP measurements from wild and live-stranded cetaceans are presented to illustrate their usefulness and the constraints under which these measurements must be made. AEP measurements from bottlenose dolphins in air and in water are also compared with their behavioral audiograms.

  10. Mechanical Stimulation by Postnasal Drip Evokes Cough

    Science.gov (United States)

    Iwata, Toshiyuki; Ito, Isao; Niimi, Akio; Ikegami, Koji; Marumo, Satoshi; Tanabe, Naoya; Nakaji, Hitoshi; Kanemitsu, Yoshihiro; Matsumoto, Hisako; Kamei, Junzo; Setou, Mitsutoshi; Mishima, Michiaki

    2015-01-01

    Cough affects all individuals at different times, and its economic burden is substantial. Despite these widespread adverse effects, cough research relies on animal models, which hampers our understanding of the fundamental cause of cough. Postnasal drip is speculated to be one of the most frequent causes of chronic cough; however, this is a matter of debate. Here we show that mechanical stimuli by postnasal drip cause chronic cough. We distinguished human cough from sneezes and expiration reflexes by airflow patterns. Cough and sneeze exhibited one-peak and two-peak patterns, respectively, in expiratory airflow, which were also confirmed by animal models of cough and sneeze. Transgenic mice with ciliary dyskinesia coughed substantially and showed postnasal drip in the pharynx; furthermore, their cough was completely inhibited by nasal airway blockade of postnasal drip. We successfully reproduced cough observed in these mice by injecting artificial postnasal drip in wild-type mice. These results demonstrated that mechanical stimulation by postnasal drip evoked cough. The findings of our study can therefore be used to develop new antitussive drugs that prevent the root cause of cough. PMID:26581078

  11. Mechanical Stimulation by Postnasal Drip Evokes Cough.

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    Toshiyuki Iwata

    Full Text Available Cough affects all individuals at different times, and its economic burden is substantial. Despite these widespread adverse effects, cough research relies on animal models, which hampers our understanding of the fundamental cause of cough. Postnasal drip is speculated to be one of the most frequent causes of chronic cough; however, this is a matter of debate. Here we show that mechanical stimuli by postnasal drip cause chronic cough. We distinguished human cough from sneezes and expiration reflexes by airflow patterns. Cough and sneeze exhibited one-peak and two-peak patterns, respectively, in expiratory airflow, which were also confirmed by animal models of cough and sneeze. Transgenic mice with ciliary dyskinesia coughed substantially and showed postnasal drip in the pharynx; furthermore, their cough was completely inhibited by nasal airway blockade of postnasal drip. We successfully reproduced cough observed in these mice by injecting artificial postnasal drip in wild-type mice. These results demonstrated that mechanical stimulation by postnasal drip evoked cough. The findings of our study can therefore be used to develop new antitussive drugs that prevent the root cause of cough.

  12. THE MECHANISM OF CEREBRAL EVOKED POTENTIALS BY REPETITIVE MAGNETIC STIMULATION OF GASTROCNEMIUS MUSCLE IN DUCHENNE MUSCULAR DYSTROPHY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective. To study the features and mechanism of the cerebral evoked potentials by repetitive stimulation of calf muscle in Duchenne muscular dystrophy (DMD) patients with obvious muscular dystrophy and psuedohypertrophy. Methods. Cerebral evoked potentials by stimulation of calf muscles and somatosensory evoked potentials (SEPs) by the stimulation of posterior tibial nerves at ankle were measured in 10 patients with DMD and 10 normal controls matched with gender and age. The intensity of the magnetic stimulation was at 30% of maximal output (2.1 Tesla, MagPro magnetic stimulator, Dantec) and the frequency was 1 Hz. The low intensity of magnetic stimulation was just sufficient to produce a contraction of the muscle belly underneath the coil. Recording electrode was placed at 2 cm posterior to the Cz, reference to Fpz. The latencies of N33, P38, N48 and P55 and amplitude (P38- N48) were recorded. SEPs were recorded by routine methods. Results. In normal subjects, the amplitudes of cerebral evoked potentials by magnetic stimulation of calf muscle was 40% lower than that by electrical stimulation of the posterior tibial nerves at ankle. The latency of P38 was 2.9± 2.1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients, P38 latency from magnetic stimulation was remarkably prolonged (P<0.01), and in 4 patients, there was no remarkable response. SEPs evoked by electrical stimulation were normal in all of the patients.? Conclusion. DMD is an available model for the study of mechanism of cerebral evoked potentials by magnetic stimulating muscle. We can conclude that the responses from magnetic stimulation were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by stimulating dystrophic and psedohypertrophic muscle.

  13. Sensory deficits of a nerve root lesion can be objectively documented by somatosensory evoked potentials elicited by painful infrared laser stimulations: a case study.

    OpenAIRE

    Lorenz, J.; Hansen, H C; Kunze, K; Bromm, B.

    1996-01-01

    Somatosensory evoked potentials (SEPs) in response to painful laser stimuli were measured in a patient with a unilateral sensory deficit due to radiculopathy at cervical levels C7 and C8. Laser evoked potentials (LEPs) were compared with SEPs using standard electrical stimulation of median and ulnar nerves at the wrist and mechanical stimulation of the fingertips by means of a mechanical stimulator. Early and late ulnar and median nerve SEPs were normal. Mechanical stimulation resulted in w s...

  14. Auditory evoked fields measured noninvasively with small-animal MEG reveal rapid repetition suppression in the guinea pig

    OpenAIRE

    Christianson, G. B.; Chait, M; De CheveignÉ, A.; Linden, J. F.

    2014-01-01

    In animal models, single-neuron response properties such as stimulus-specific adaptation (SSA) have been described as possible precursors to the mismatch negativity (MMN), a human brain response to stimulus change. Here, we attempt to bridge the gap between human and animal studies by characterising responses to changes in the frequency of repeated tone series in the anaesthetised guinea pig using small-animal magnetoencephalography (MEG). We show that: (1) auditory evoked fields (AEFs) quali...

  15. Transient evoked otoacoustic emission input/output function and cochlear reflectivity: experiment and model.

    Science.gov (United States)

    Sisto, Renata; Moleti, Arturo

    2008-11-01

    The complex input/output function of transient evoked otoacoustic emissions is evaluated at different stimulus levels. The experimental response functions were best fitted to the reflectivity functions predicted by theoretical one-dimensional transmission-line models in the perturbative limit. Along with the otoacoustic emission sources usually considered, linear reflection from roughness (place-fixed) and nonlinear distortion (wave-fixed), a wave-fixed scattering potential is also considered, associated with the breaking of the scale-invariance symmetry, as a new additional mechanism for otoacoustic emission generation. A good fit was obtained, across stimulus level and frequency, for roughness, and not for nonlinear distortion, nor for scale-invariance violation. The phase-gradient delay of the same transient evoked otoacoustic emissions was consistent with the latency measured using a wavelet time-frequency technique, at all stimulus levels and frequencies. The results suggest that cochlear reflectivity is dominated by a component with a rapidly rotating phase, at all stimulus levels, in apparent contradiction with the usual assumption that, at high stimulus levels, a significant contribution to the transient evoked otoacoustic response should come from nonlinear distortion. Possible interpretations of this phenomenology are critically reviewed and discussed, considering the theoretical uncertainties and the limitations of the experimental technique. PMID:19045787

  16. Childhood physical abuse predicts stressor-evoked activity within central visceral control regions.

    Science.gov (United States)

    Banihashemi, Layla; Sheu, Lei K; Midei, Aimee J; Gianaros, Peter J

    2015-04-01

    Early life experience differentially shapes later stress reactivity, as evidenced by both animal and human studies. However, early experience-related changes in the function of central visceral neural circuits that control stress responses have not been well characterized, particularly in humans. The paraventricular nucleus of the hypothalamus (PVN), bed nucleus of the stria terminalis (BNST), amygdala (Amyg) and subgenual anterior cingulate cortex (sgACC) form a core visceral stress-responsive circuit. The goal of this study is to examine how childhood emotional and physical abuse relates to adulthood stressor-evoked activity within these visceral brain regions. To evoke acute states of mental stress, participants (n = 155) performed functional magnetic resonance imaging (fMRI)-adapted versions of the multi-source interference task (MSIT) and the Stroop task with simultaneous monitoring of mean arterial pressure (MAP) and heart rate. Regression analyses revealed that childhood physical abuse correlated positively with stressor-evoked changes in MAP, and negatively with unbiased, a priori extractions of fMRI blood-oxygen level-dependent signal change values within the sgACC, BNST, PVN and Amyg (n = 138). Abuse-related changes in the function of visceral neural circuits may reflect neurobiological vulnerability to adverse health outcomes conferred by early adversity. PMID:24847113

  17. Audiometria de altas frequências no diagnóstico complementar em audiologia: uma revisão da literatura nacional High-frequency audiometry in audiological complementary diagnosis: a revision of the national literature

    Directory of Open Access Journals (Sweden)

    Karlin Fabianne Klagenberg

    2011-03-01

    Full Text Available A audiometria de altas frequências (AAF é um exame audiológico importante na detecção precoce de perdas auditivas por lesões na base do ducto coclear. Nos últimos anos, a sua utilização foi facilitada pelo fato de os audiômetros comercializados passarem a incorporar frequências superiores a 8 kHz. Porém, existem diferenças relacionadas aos equipamentos utilizados, às metodologias empregadas e/ou aos resultados e interpretação. Assim, o objetivo deste artigo foi analisar a produção científica nacional sobre a aplicação clínica com AAF, para compreender sua utilização atual. Foram pesquisados textos publicados e indexados nas bases de dados LILACS, SciELO e Medline, num período de tempo de dez anos, utilizando como descritor "audiometria de altas frequências/high-frequency audiometry". Encontraram-se 24 artigos científicos nacionais utilizando AAF, cuja população avaliada, em sua maioria, apresentava de 18 a 50 anos de idade; 13 dos estudos determinaram os limiares utilizando como referência decibel nível de audição (dBNA; alguns estudos realizaram a comparação dos limiares auditivos tonais entre grupos para definir a normalidade; os autores relataram diferenças significativas nos limiares auditivos de altas frequências entre as idades. A AAF é utilizada na clínica audiológica para identificação precoce de alterações auditivas e no acompanhamento da audição de sujeitos expostos a drogas ototóxicas e/ou agentes otoagressores.High-frequency audiometry (HFA is an important audiological test for early detection of hearing losses caused by leasions in the base of the cochlear duct. In recent years, its use was facilitated because audiometers began to identify frequencies higher than 8 kHz. However, there are differences related to the equipment used, the methodologies followed, and/or to the results and their interpretation. Therefore, the aim of this study was to analyze the national scientific production

  18. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling.

    Science.gov (United States)

    Vincis, Roberto; Lagier, Samuel; Van De Ville, Dimitri; Rodriguez, Ivan; Carleton, Alan

    2015-07-14

    Functional brain-imaging techniques used in humans and animals, such as functional MRI and intrinsic optical signal (IOS) imaging, are thought to largely rely on neurovascular coupling and hemodynamic responses. Here, taking advantage of the well-described micro-architecture of the mouse olfactory bulb, we dissected the nature of odor-evoked IOSs. Using in vivo pharmacology in transgenic mouse lines reporting activity in different cell types, we show that parenchymal IOSs are largely independent of neurotransmitter release and neurovascular coupling. Furthermore, our results suggest that odor-evoked parenchymal IOSs originate from changes in light scattering of olfactory sensory neuron axons, mostly due to water movement following action potential propagation. Our study sheds light on a direct correlate of neuronal activity, which may be used for large-scale functional brain imaging. PMID:26146075

  19. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

    Directory of Open Access Journals (Sweden)

    Roberto Vincis

    2015-07-01

    Full Text Available Functional brain-imaging techniques used in humans and animals, such as functional MRI and intrinsic optical signal (IOS imaging, are thought to largely rely on neurovascular coupling and hemodynamic responses. Here, taking advantage of the well-described micro-architecture of the mouse olfactory bulb, we dissected the nature of odor-evoked IOSs. Using in vivo pharmacology in transgenic mouse lines reporting activity in different cell types, we show that parenchymal IOSs are largely independent of neurotransmitter release and neurovascular coupling. Furthermore, our results suggest that odor-evoked parenchymal IOSs originate from changes in light scattering of olfactory sensory neuron axons, mostly due to water movement following action potential propagation. Our study sheds light on a direct correlate of neuronal activity, which may be used for large-scale functional brain imaging.

  20. Pudendal somatosensory evoked potentials in normal women

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    Geraldo A. Cavalcanti

    2007-12-01

    Full Text Available OBJECTIVE: Somatosensory evoked potential (SSEP is an electrophysiological test used to evaluate sensory innervations in peripheral and central neuropathies. Pudendal SSEP has been studied in dysfunctions related to the lower urinary tract and pelvic floor. Although some authors have already described technical details pertaining to the method, the standardization and the influence of physiological variables in normative values have not yet been established, especially for women. The aim of the study was to describe normal values of the pudendal SSEP and to compare technical details with those described by other authors. MATERIALS AND METHODS: The clitoral sensory threshold and pudendal SSEP latency was accomplished in 38 normal volunteers. The results obtained from stimulation performed on each side of the clitoris were compared to ages, body mass index (BMI and number of pregnancies. RESULTS: The values of clitoral sensory threshold and P1 latency with clitoral left stimulation were respectively, 3.64 ± 1.01 mA and 37.68 ± 2.60 ms. Results obtained with clitoral right stimulation were 3.84 ± 1.53 mA and 37.42 ± 3.12 ms, respectively. There were no correlations between clitoral sensory threshold and P1 latency with age, BMI or height of the volunteers. A significant difference was found in P1 latency between nulliparous women and volunteers who had been previously submitted to cesarean section. CONCLUSIONS: The SSEP latency represents an accessible and reproducible method to investigate the afferent pathways from the genitourinary tract. These results could be used as normative values in studies involving genitourinary neuropathies in order to better clarify voiding and sexual dysfunctions in females.

  1. Vestibular evoked myogenic potentials (VEMPs) in central neurological disorders.

    Science.gov (United States)

    Venhovens, J; Meulstee, J; Verhagen, W I M

    2016-01-01

    Several types of acoustic stimulation (i.e. tone bursts or clicks), bone-conducted vibration, forehead taps, and galvanic stimulation elicit myogenic potentials. These can be recorded in cervical and ocular muscles, the so called vestibular evoked myogenic potentials (VEMPs). The cervical VEMP (cVEMP) resembles the vestibulo-collic reflex and the responses can be recorded from the ipsilateral sternocleidomastoid muscle. The ocular VEMP resembles the vestibulo-ocular reflex and can be recorded from extra-ocular muscles by a surface electrode beneath the contralateral infraorbital margin. Initially, the literature concerning VEMPs was limited to peripheral vestibular disorders, however, the field of VEMP testing is rapidly expanding, with an increasing focus on central neurological disorders. The current literature concerning VEMP abnormalities in central neurological disorders is critically reviewed, especially regarding the methodological aspects in relation to quality as well as the clinical interpretation of the VEMP results. Suggestions for further research are proposed as well as some clinically useful indications. PMID:25649969

  2. Alterations in oropharyngeal sensory evoked potentials (PSEP) with Parkinson's disease.

    Science.gov (United States)

    Pitts, Teresa; Hegland, Karen Wheeler; Sapienza, Christine M; Bolser, Donald C; Davenport, Paul W

    2016-07-15

    Movement of a food bolus from the oral cavity into the oropharynx activates pharyngeal sensory mechanoreceptors. Using electroencephalography, somatosensory cortical-evoked potentials resulting from oropharyngeal mechanical stimulation (PSEP) have been studied in young healthy individuals. However, limited information is known about changes in processing of oropharyngeal afferent signals with Parkinson's disease (PD). To determine if sensory changes occurred with a mechanical stimulus (air-puff) to the oropharynx, two stimuli (S1-first; S2-s) were delivered 500ms apart. Seven healthy older adults (HOA; 3 male and 4 female; 72.2±6.9 years of age), and thirteen persons diagnosed with idiopathic Parkinson's disease (PD; 11 male and 2 female; 67.2±8.9 years of age) participated. Results demonstrated PSEP P1, N1, and P2 component peaks were identified in all participants, and the N2 peak was present in 17/20 participants. Additionally, the PD participants had a decreased N2 latency and gated the P1, P2, and N2 responses (S2/S1 under 0.6). Compared to the HOAs, the PD participants had greater evidence of gating the P1 and N2 component peaks. These results suggest that persons with PD experience changes in sensory processing of mechanical stimulation of the pharynx to a greater degree than age-matched controls. In conclusion, the altered processing of sensory feedback from the pharynx may contribute to disordered swallow in patients with PD. PMID:27090350

  3. Source localisation of visual evoked potentials in congenitally deaf individuals.

    Science.gov (United States)

    Hauthal, Nadine; Thorne, Jeremy D; Debener, Stefan; Sandmann, Pascale

    2014-05-01

    Previous studies have suggested that individuals deprived of auditory input can compensate with specific superior abilities in the remaining sensory modalities. To better understand the neural basis of deafness-induced changes, the present study used electroencephalography to examine visual functions and cross-modal reorganization of the auditory cortex in deaf individuals. Congenitally deaf participants and hearing controls were presented with reversing chequerboard stimuli that were systematically modulated in luminance ratio. The two groups of participants showed similar modulation of visual evoked potential (VEP) amplitudes (N85, P110) and latencies (P110) as a function of luminance ratio. Analysis of VEPs revealed faster neural processing in deaf participants compared with hearing controls at early stages of cortical visual processing (N85). Deaf participants also showed higher amplitudes (P110) than hearing participants. In contrast to our expectations, the results from VEP source analysis revealed no clear evidence for cross-modal reorganization in the auditory cortex of deaf participants. However, deaf participants tended to show higher activation in posterior parietal cortex (PPC). Moreover, modulation of PPC responses as a function of luminance was also stronger in deaf than in hearing participants. Taken together, these findings are an indication of more efficient neural processing of visual information in the deaf, which may relate to functional changes, in particular in multisensory parietal cortex, as a consequence of early auditory deprivation. PMID:24337445

  4. Ocular vestibular evoked myogenic potentials in normal-hearing adults

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    Mohammad Kamali

    2012-06-01

    Full Text Available Background and Aim: Ocular vestibular-evoked myogenic potential (oVEMP is a novel vestibular function test. This short-latency response can be recorded through contracting extraocular muscles by high-intensity acoustic stimulation and can be used to evaluate contralateral ocular-vestibular reflex. The aim of this study was to record and compare the amplitude, latency, asymmetry ratio and occurrence percentage of oVEMP (n10 and cervical VEMP (p13 responses in a group of normal adult subjects.Methods: We carried out a cross-sectional study on 20 adult subjects' mean age 22.18 years, SD=2.19 with normal hearing sensitivity and no history of vestibular diseases. oVEMP and cVEMP responses in both ears were recorded using air conducted stimuli 500 Hz short tone burst, 95 dB nHL via insert earphone and compared.Results: cVEMP was recorded in all subjects but oVEMP was absent in two subjects. Mean amplitude and latency were 140.77 μv and 15.56 ms in p13; and 3.18 μv and 9.32 ms in n10. There were statistically significant differences between p13 and n10 amplitudes (p<0.001.Conclusion: This study showed that occurrence percentage and amplitude of oVEMP were less than those of cVEMP. Since these two tests originate from different sections of vestibular nerve, we can consider them as parallel vestibular function tests and utilize them for evaluation of vestibular disorders.

  5. Limb suction evoked during arterial occlusion causes systemic sympathetic activity in humans.

    Science.gov (United States)

    Cui, Jian; Blaha, Cheryl; Herr, Michael D; Drew, Rachel C; Muller, Matthew D; Sinoway, Lawrence I

    2015-09-01

    Venous saline infusions in an arterially occluded forearm evokes reflex increases in muscle sympathetic nerve activity (MSNA) and blood pressure (BP). We hypothesized that the application of suction to the human limbs would activate this venous distension reflex and raise sympathetic outflow. We placed airtight pressure tanks and applied 100 mmHg negative pressure to an arterially occluded limb (occlusion and suction, O&S) to induce tissue deformation without fluid translocation. BP, heart rate (HR), and MSNA were assessed in 19 healthy subjects during 2 min of arm or leg O&S. Occlusion without suction served as a control. During a separate visit, saline (5% forearm volume) was infused into veins of the arterially occluded arm (n = 13). The O&S increased limb circumference, MSNA burst rate (arm: Δ6.7 ± 0.7; leg: Δ6.8 ± 0.7 bursts/min), and total activity (arm: Δ199 ± 14; leg: Δ172 ± 22 units/min) and BP (arm: Δ4.3 ± 0.3; leg: Δ9.4 ± 1.4 mmHg) from the baseline. The MSNA and BP responses during arm O&S correlated with those during leg O&S. Occlusion alone had no effect on MSNA and BP. MSNA (r = 0.607) responses during arm O&S correlated with those evoked by the saline infusion into the arm. These correlations suggest that sympathetic activation during limb O&S is likely, at least partially, to be evoked via the venous distension reflex. These data suggest that suction of an occluded limb evokes sympathetic activation and that the limb venous distension reflex exists in arms and legs of normal humans. PMID:26136530

  6. Click- and chirp-evoked human compound action potentials

    OpenAIRE

    Chertoff, Mark; Lichtenhan, Jeffery; Willis, Marie

    2010-01-01

    In the experiments reported here, the amplitude and the latency of human compound action potentials (CAPs) evoked from a chirp stimulus are compared to those evoked from a traditional click stimulus. The chirp stimulus was created with a frequency sweep to compensate for basilar membrane traveling wave delay using the O-Chirp equations from Fobel and Dau [(2004). J. Acoust. Soc. Am. 116, 2213–2222] derived from otoacoustic emission data. Human cochlear traveling wave delay estimates were obta...

  7. Optogenetic stimulation of the cochlear nucleus using channelrhodopsin-2 evokes activity in the central auditory pathway

    Science.gov (United States)

    Darrow, Keith N.; Slama, Michaël C. C.; Owoc, Maryanna; Kozin, Elliott; Hancock, Kenneth; Kempfle, Judith; Edge, Albert; Lacour, Stephanie; Boyden, Edward; Polley, Daniel; Brown, M. Christian; Lee, Daniel J.

    2016-01-01

    Optogenetics has become an important research tool and is being considered as the basis for several neural prostheses. However, few studies have applied optogenetics to the auditory brainstem. This study explored whether optical activation of the cochlear nucleus (CN) elicited responses in neurons in higher centers of the auditory pathway, and it measured the evoked response to optical stimulation. Viral-mediated gene transfer was used to express channelrhodopsin-2 (ChR2) in the mouse CN. Blue light was delivered via an optical fiber placed near the surface of the infected CN and recordings were made in higher-level centers. Optical stimulation evoked excitatory multiunit spiking activity throughout the tonotopic axis of central nucleus of the inferior colliculus (IC) and the auditory cortex (Actx). The pattern and magnitude of IC activity elicited by optical stimulation was comparable to that obtained with a 50 dB SPL acoustic click stimulus. This broad pattern of activity was consistent with histological confirmation of GFP label of cell bodies and axons throughout the CN. Increasing pulse rates up to 320 Hz did not significantly affect threshold or bandwidth of the IC responses, but rates higher than 50 Hz resulted in desynchronized activity. Optical stimulation also evoked an auditory brainstem response, which had a simpler waveform than the response to acoustic stimulation. Control cases showed no responses to optical stimulation. These data suggest that optogenetic control of central auditory neurons is feasible, but opsins with faster channel kinetics will be necessary to convey information in rates typical of many auditory signals. PMID:25481416

  8. Visual evoked potentials in infants and children.

    Science.gov (United States)

    Taylor, M J; McCulloch, D L

    1992-07-01

    Visual evoked potential (VEP) studies are of great value in a wide variety of pediatric patients, including those with disorders of the sensory visual pathway and those at risk for visual pathway damage. VEPs are simple, non-invasive, and are particularly appropriate for infants and young children who cannot communicate visual symptoms or cooperate for standard vision assessment. VEPs in pediatric patients have the following main purposes: (1) detecting lesions causing dysfunction of the sensory visual pathways (the VEP is a sensitive indicator of subclinical lesions and can be used to differentiate visual impairment from visual inattention in young infants); (2) confirming functional loss when disorders of the visual system are present; (3) quantifying visual impairment in patients with known visual disorders, accomplished either empirically by noting the severity of the VEP abnormality to flash and pattern stimuli or by visual acuity estimation studies (early quantification of vision loss allows referral to early intervention programs, which can ameliorate the long-term consequences of the disability); (4) monitoring patients who are at risk for visual complications either from diseases (such as hydrocephalus or neurofibromatosis) or as a complication of therapeutic intervention (e.g., neurosurgery, chemotherapy) to help detect and avoid long-term sequelae of such therapies on the developing nervous system; (5) establishing prognosis for visual and systemic recovery based on flash VEPs for specific pediatric disorders including perinatal asphyxia in full-term neonates, acute-onset cortical blindness, and, to a fair extent, in comatose children; and (6) in some cases, contributing to the differential diagnosis. Abnormalities of flash and/or pattern VEPs are generally nonspecific to the type of exact location of the lesion, except in distinguishing prefrom postchiasmal lesions. However, in certain conditions, such as the hereditary ataxias of childhood, VEP

  9. Evoked potentials are useful for diagnosis of neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Ohnari, Keiko; Okada, Kazumasa; Takahashi, Toshiyuki; Mafune, Kosuke; Adachi, Hiroaki

    2016-05-15

    Neuromyelitis optica spectrum disorder (NMOSD) has been differentiated from relapsing-remitting multiple sclerosis (RRMS) by clinical, laboratory, and pathological findings, including the presence of the anti-aquaporin 4 antibody. Measurement of evoked potentials (EPs) is often used for the diagnosis of RRMS, although the possibility of applying EPs to the diagnosis of NMOSD has not been investigated in detail. Eighteen patients with NMOSD and 28 patients with RRMS were included in this study. The patients' neurological symptoms and signs were examined and their EPs were recorded. Characteristic findings were absence of visual evoked potentials and absence of motor evoked potentials in the lower extremities in patients with NMOSD, and a delay in these potentials in patients with RRMS. Most patients with NMOSD did not present abnormal subclinical EPs, whereas many patients with RRMS did. None of the patients with NMOSD showed abnormalities in auditory brainstem responses. NMOSD can be differentiated from RRMS by EP data obtained in the early stages of these diseases. PMID:27084224

  10. Auditory evoked potentials in the West Indian Manatee (Sirenia: Trichechus manatus)

    Science.gov (United States)

    Bullock, Theodore H.; O'Shea, Thomas J.; McClune, Michael C.

    1982-01-01

    Potentials evoked by clicks and tone pips were recorded by fine wires inserted extracranially in four West Indian manatees (Trichechus manatus) in air. Sounds were delivered via padded ear phones. Averaging a few thousand trials at 20/s reveals early peaks at N5.4 (‘vertex’ negativity to a frontal reference, at 5.4 ms), P7.6, N8.8, P9.5 — probably equivalent to waves IV and VII of the typical mammalian auditory brainstem response (ABR). Averaging 100 trials at Using tone pips with a rise and fall time of 2–5 ms the carrier frequency becomes important. Evoked potential wave forms are not the same at different frequencies, bringing out the fact that frequency is not a scalar that can be compensated for by intensity. Therefore the method was not used to obtain audiograms; however the largest EPs occur in the range of 1–1.5 kHz. EPs are found up to 35 kHz; almost no evoked potential is discernible at 40 kHz but the undistorted intensity available was limited. This is in reasonable agreement with the theoretical expectation for the upper limit of behavioral hearing from Heffner and Masterton based on head size and aquatic medium.

  11. Evolution of separate predation- and defence-evoked venoms in carnivorous cone snails.

    Science.gov (United States)

    Dutertre, Sébastien; Jin, Ai-Hua; Vetter, Irina; Hamilton, Brett; Sunagar, Kartik; Lavergne, Vincent; Dutertre, Valentin; Fry, Bryan G; Antunes, Agostinho; Venter, Deon J; Alewood, Paul F; Lewis, Richard J

    2014-01-01

    Venomous animals are thought to inject the same combination of toxins for both predation and defence, presumably exploiting conserved target pharmacology across prey and predators. Remarkably, cone snails can rapidly switch between distinct venoms in response to predatory or defensive stimuli. Here, we show that the defence-evoked venom of Conus geographus contains high levels of paralytic toxins that potently block neuromuscular receptors, consistent with its lethal effects on humans. In contrast, C. geographus predation-evoked venom contains prey-specific toxins mostly inactive at human targets. Predation- and defence-evoked venoms originate from the distal and proximal regions of the venom duct, respectively, explaining how different stimuli can generate two distinct venoms. A specialized defensive envenomation strategy is widely evolved across worm, mollusk and fish-hunting cone snails. We propose that defensive toxins, originally evolved in ancestral worm-hunting cone snails to protect against cephalopod and fish predation, have been repurposed in predatory venoms to facilitate diversification to fish and mollusk diets. PMID:24662800

  12. Mismatch negativity and adaptation measures of the late auditory evoked potential in cochlear implant users.

    Science.gov (United States)

    Zhang, Fawen; Hammer, Theresa; Banks, Holly-Lolan; Benson, Chelsea; Xiang, Jing; Fu, Qian-Jie

    2011-05-01

    A better understanding of the neural correlates of large variability in cochlear implant (CI) patients' speech performance may allow us to find solutions to further improve CI benefits. The present study examined the mismatch negativity (MMN) and the adaptation of the late auditory evoked potential (LAEP) in 10 CI users. The speech syllable /da/ and 1-kHz tone burst were used to examine the LAEP adaptation. The amount of LAEP adaptation was calculated according to the averaged N1-P2 amplitude for the LAEPs evoked by the last 3 stimuli and the amplitude evoked by the first stimulus. For the MMN recordings, the standard stimulus (1-kHz tone) and the deviant stimulus (2-kHz tone) were presented in an oddball condition. Additionally, the deviants alone were presented in a control condition. The MMN was derived by subtracting the response to the deviants in the control condition from the oddball condition. Results showed that good CI performers displayed a more prominent LAEP adaptation than moderate-to-poor performers. Speech performance was significantly correlated to the amount of LAEP adaptation for the 1-kHz tone bursts. Good performers displayed large MMNs and moderate-to-poor performers had small or absent MMNs. The abnormal electrophysiological findings in moderate-to-poor performers suggest that long-term deafness may cause damage not only at the auditory cortical level, but also at the cognitive level. PMID:21129468

  13. Nociceptive-Evoked Potentials Are Sensitive to Behaviorally Relevant Stimulus Displacements in Egocentric Coordinates.

    Science.gov (United States)

    Moayedi, M; Di Stefano, G; Stubbs, M T; Djeugam, B; Liang, M; Iannetti, G D

    2016-01-01

    Feature selection has been extensively studied in the context of goal-directed behavior, where it is heavily driven by top-down factors. A more primitive version of this function is the detection of bottom-up changes in stimulus features in the environment. Indeed, the nervous system is tuned to detect fast-rising, intense stimuli that are likely to reflect threats, such as nociceptive somatosensory stimuli. These stimuli elicit large brain potentials maximal at the scalp vertex. When elicited by nociceptive laser stimuli, these responses are labeled laser-evoked potentials (LEPs). Although it has been shown that changes in stimulus modality and increases in stimulus intensity evoke large LEPs, it has yet to be determined whether stimulus displacements affect the amplitude of the main LEP waves (N1, N2, and P2). Here, in three experiments, we identified a set of rules that the human nervous system obeys to identify changes in the spatial location of a nociceptive stimulus. We showed that the N2 wave is sensitive to: (1) large displacements between consecutive stimuli in egocentric, but not somatotopic coordinates; and (2) displacements that entail a behaviorally relevant change in the stimulus location. These findings indicate that nociceptive-evoked vertex potentials are sensitive to behaviorally relevant changes in the location of a nociceptive stimulus with respect to the body, and that the hand is a particularly behaviorally important site. PMID:27419217

  14. Voluntary and evoked behavioral correlates in neuropathic pain states under different social housing conditions

    Science.gov (United States)

    Pitzer, Claudia; Kuner, Rohini

    2016-01-01

    Background There is an urgent need to develop and incorporate novel behavioral tests in classically used preclinical pain models. Most rodent studies are based upon stimulus-evoked hindpaw measurements even though chronic pain is usually a day and night experience. Chronic pain is indeed a debilitating condition that influences the sociability and the ability for voluntary tasks, but the relevant behavioral readouts for these aspects are mostly under-represented in the literature. Moreover, we lack standardization in most behavioral paradigms to guarantee reproducibility and ensure adequate discussion between different studies. This concerns not only the combination, application, and duration of particular behavioral tasks but also the effects of different housing conditions implicating social isolation. Results Our aim was to thoroughly characterize the classically used spared nerve injury model for 12 weeks following surgery. We used a portfolio of classical stimulus-evoked response measurements, detailed gait analysis with two different measuring systems (Dynamic weight bearing (DWB) system and CatWalk), as well as observer-independent voluntary wheel running and home cage monitoring (Laboras system). Additionally, we analyzed the effects of social isolation in all behavioral tasks. We found that evoked hypersensitivity temporally matched changes in static gait parameters, whereas some dynamic gait parameters were changed in a time-dependent manner. Interestingly, voluntary wheel running behavior was not affected in spared nerve injury mice but by social isolation. Besides a reduced climbing activity, spared nerve injury mice did not showed tremendous alterations in the home cage activity. Conclusion This is the first longitudinal study providing detailed insights into various voluntary behavioral parameters related to pain and highlights the importance of social environment on spontaneous non-evoked behaviors in a mouse model of chronic neuropathy. Our results

  15. Head movements evoked in alert rhesus monkey by vestibular prosthesis stimulation: implications for postural and gaze stabilization.

    Directory of Open Access Journals (Sweden)

    Diana E Mitchell

    Full Text Available The vestibular system detects motion of the head in space and in turn generates reflexes that are vital for our daily activities. The eye movements produced by the vestibulo-ocular reflex (VOR play an essential role in stabilizing the visual axis (gaze, while vestibulo-spinal reflexes ensure the maintenance of head and body posture. The neuronal pathways from the vestibular periphery to the cervical spinal cord potentially serve a dual role, since they function to stabilize the head relative to inertial space and could thus contribute to gaze (eye-in-head + head-in-space and posture stabilization. To date, however, the functional significance of vestibular-neck pathways in alert primates remains a matter of debate. Here we used a vestibular prosthesis to 1 quantify vestibularly-driven head movements in primates, and 2 assess whether these evoked head movements make a significant contribution to gaze as well as postural stabilization. We stimulated electrodes implanted in the horizontal semicircular canal of alert rhesus monkeys, and measured the head and eye movements evoked during a 100 ms time period for which the contribution of longer latency voluntary inputs to the neck would be minimal. Our results show that prosthetic stimulation evoked significant head movements with latencies consistent with known vestibulo-spinal pathways. Furthermore, while the evoked head movements were substantially smaller than the coincidently evoked eye movements, they made a significant contribution to gaze stabilization, complementing the VOR to ensure that the appropriate gaze response is achieved. We speculate that analogous compensatory head movements will be evoked when implanted prosthetic devices are transitioned to human patients.

  16. Slow negative evoked potentials in the rhesus monkey (Macaca mulatta): myogenic versus neurogenic influences.

    Science.gov (United States)

    Fria, T J; Saad, M M; Doyle, W J; Cantekin, E I

    1984-02-01

    The influence of myogenic activity on the generation of slow negative evoked potentials (SN10) to octave, toneburst stimuli (0.5-2 Hz) was investigated in 5 rhesus monkeys (M. mulatta) by comparing responses obtained prior to and during total paralysis induced with curare. The SN10 could be easily elicited during paralysis, regardless of stimulus intensity, rate, or frequency. During paralysis, there were no systematic changes in either response latency or amplitude; variability in latency was less than 10% and changes in response amplitude were within 30%. These findings suggest that the myogenic contribution to the SN10 response is negligible and that this response is of neurogenic origin in the rhesus monkey. PMID:6198169

  17. Spatiotemporal characteristics of cerebral blood volume changes in different microvascular compartments evoked by sciatic nerve stimulation in rat somatosensory cortex

    Science.gov (United States)

    Li, Pengcheng; Luo, Qingming; Luo, Weihua; Chen, Shanbin; Cheng, Haiying; Zeng, Shaoqun

    2003-07-01

    The spatio-temporal characteristics of changes in cerebral blood volume associated with neuronal activity were investigated in the hindlimb somatosensory cortex of α-chloralose/urethan anesthetized rats (n=10) with optical imaging at 570nm through a thinned skull. Activation of cortex was carried out by electrical stimulation of the contralateral sciatic nerve with 5Hz, 0.3V pulses (0.5ms) for duration of 2s. The stimulation evoked a monophasic optical reflectance decrease at cortical parenchyma and arteries sites rapidly after the onset of stimulation, whereas no similar response was observed at vein compartments. The optical signal changes reached 10% of the peak response 0.70+/-0.32s after stimulation onset and no significant time lag in this 10% start latency time was observed between the response at cortical parenchyma and arteries compartments. The evoked optical reflectance decrease reached the peak (0.25%+/-0.047%) 2.66+/-0.61s after the stimulus onset at parenchyma site, 0.40+/-0.20s earlier (P<0.05) than that at arteries site (0.50+/-0.068% 3.06+/-0.70s). Variable location within the cortical parenchyma and arteries compartment themselves didn"t affect the temporal characteristics of the evoked signal significantly. These results suggest that the sciatic nerve stimulation evokes a local blood volume increase at both capillaries (cortical parenchyma) and arterioles rapidly after the stimulus onset but the evoked blood volume increase in capillaries could not be entirely accounted for by the dilation of arterioles.

  18. Axially evoked postural reflexes: influence of task

    OpenAIRE

    Govender, Sendhil; Dennis, Danielle L.; Colebatch, James G.

    2014-01-01

    Postural reflexes were recorded in healthy subjects (n = 17) using brief axial accelerations and tap stimuli applied at the vertebra prominens (C7) and manubrium sterni. Short latency (SL) responses were recorded from the soleus, hamstrings and tibialis anterior muscles and expressed as a percentage of the background EMG prior to stimulus onset. In the majority of postural conditions tested, subjects were recorded standing erect and leaning forward with their feet together. The SL response wa...

  19. Stimulator with arbitrary waveform for auditory evoked potentials

    Energy Technology Data Exchange (ETDEWEB)

    Martins, H R; Romao, M; Placido, D; Provenzano, F; Tierra-Criollo, C J [Universidade Federal de Minas Gerais (UFMG), Departamento de Engenharia Eletrica (DEE), Nucleo de Estudos e Pesquisa em Engenharia Biomedica NEPEB, Av. Ant. Carlos, 6627, sala 2206, Pampulha, Belo Horizonte, MG, 31.270-901 (Brazil)

    2007-11-15

    The technological improvement helps many medical areas. The audiometric exams involving the auditory evoked potentials can make better diagnoses of auditory disorders. This paper proposes the development of a stimulator based on Digital Signal Processor. This stimulator is the first step of an auditory evoked potential system based on the ADSP-BF533 EZ KIT LITE (Analog Devices Company - USA). The stimulator can generate arbitrary waveform like Sine Waves, Modulated Amplitude, Pulses, Bursts and Pips. The waveforms are generated through a graphical interface programmed in C++ in which the user can define the parameters of the waveform. Furthermore, the user can set the exam parameters as number of stimuli, time with stimulation (Time ON) and time without stimulus (Time OFF). In future works will be implemented another parts of the system that includes the acquirement of electroencephalogram and signal processing to estimate and analyze the evoked potential.

  20. A longitudinal study of auditory evoked field and language development in young children.

    Science.gov (United States)

    Yoshimura, Yuko; Kikuchi, Mitsuru; Ueno, Sanae; Shitamichi, Kiyomi; Remijn, Gerard B; Hiraishi, Hirotoshi; Hasegawa, Chiaki; Furutani, Naoki; Oi, Manabu; Munesue, Toshio; Tsubokawa, Tsunehisa; Higashida, Haruhiro; Minabe, Yoshio

    2014-11-01

    The relationship between language development in early childhood and the maturation of brain functions related to the human voice remains unclear. Because the development of the auditory system likely correlates with language development in young children, we investigated the relationship between the auditory evoked field (AEF) and language development using non-invasive child-customized magnetoencephalography (MEG) in a longitudinal design. Twenty typically developing children were recruited (aged 36-75 months old at the first measurement). These children were re-investigated 11-25 months after the first measurement. The AEF component P1m was examined to investigate the developmental changes in each participant's neural brain response to vocal stimuli. In addition, we examined the relationships between brain responses and language performance. P1m peak amplitude in response to vocal stimuli significantly increased in both hemispheres in the second measurement compared to the first measurement. However, no differences were observed in P1m latency. Notably, our results reveal that children with greater increases in P1m amplitude in the left hemisphere performed better on linguistic tests. Thus, our results indicate that P1m evoked by vocal stimuli is a neurophysiological marker for language development in young children. Additionally, MEG is a technique that can be used to investigate the maturation of the auditory cortex based on auditory evoked fields in young children. This study is the first to demonstrate a significant relationship between the development of the auditory processing system and the development of language abilities in young children. PMID:25067819

  1. Functional imaging of glucose-evoked rat islet activities using transient intrinsic optical signals

    OpenAIRE

    Yao, Xin-Cheng; Cui, Wan-Xing; Li, Yi-Chao; Zhang, Wei; Lu, Rong-Wen; Thompson, Anthony; Amthor, Franklin; Wang, Xu-Jing

    2012-01-01

    We demonstrate intrinsic optical signal (IOS) imaging of intact rat islet, which consists of many endocrine cells working together. A near-infrared digital microscope was employed for optical monitoring of islet activities evoked by glucose stimulation. Dynamic NIR images revealed transient IOS responses in the islet activated by low-dose (2.75mM) and high-dose (5.5mM) glucose stimuli. Comparative experiments and quantitative analysis indicated that both glucose metabolism and calcium/insulin...

  2. Cortical evoked potential and extracellular K+ and H+ at critical levels of brain ischemia

    DEFF Research Database (Denmark)

    Astrup, J; Symon, L; Branston, N M; Lassen, N A

    1977-01-01

    evoked response. This study tests the hypothesis that electrical failure in ischemia may be directly associated with a massive release of intracellular K+ or with a critical degree of extracellular acidosis. By microelectrode techniques, measurements of blood flow, extracellular activity of K+ and H+ as...... occurred at 18 greater than 6 greater than 2 ml/100 gm per minute (median with 5% confidence limits). Thus a dual threshold in ischemia for neuronal function is described, the threshold for release of K+ being clearly lower than the threshold for complete electrical failure. Further, the findings support...

  3. Evaluation of New Methods for Artifacts Rejection in Evoked Auditory Steady-State Potentials

    Directory of Open Access Journals (Sweden)

    Cyndi González Alfonso

    2014-11-01

    Full Text Available This paper presents two alternative methods to the traditional method of artifact rejectionequipment currently used in evoked potential recording steady state (ASSR in order to improveefficiency based on the use of a larger number of individual records. The first method proposedis to replace the traditional use of rejection threshold amplitude, while the second version is afaster implementation of the weighted averaging used today, which is applicable also in thetransient Auditory Brainstem Response (ABR. These changes have been made in order toimplement these methods in a real time microprocessor.

  4. Effect of experimental hypothyroidism on hearing in adult guinea pigs.

    OpenAIRE

    Stearns, M; Goodwin, P

    1983-01-01

    A group of guinea pigs was rendered hypothyroid using propylthiouracil solution in their drinking water. The animals were hypothyroid for at least 120 days. During this time no change was noted in their hearing thresholds for high-frequency clicks. The audiometric evaluation was performed using brainstem evoked response audiometry.

  5. Lack of ciprofloxacin ototoxicity after repeated ototopical application.

    OpenAIRE

    J. Claes; Govaerts, P J; Van de Heyning, P H; Peeters, S.

    1991-01-01

    The possible side effects of ototopically applied ciprofloxacin on inner ear function were investigated. The hearing function of pigmented guinea pigs was evaluated by daily frequency-specific evoked response audiometry after repeated application of the drug to both ears. Ciprofloxacin appeared to have no statistically significant effect on the hearing thresholds of the experimental animals.

  6. High frequency bone conduction auditory evoked potentials in the guinea pig: Assessing cochlear injury after ossicular chain manipulation.

    Science.gov (United States)

    Bergin, M J; Bird, P A; Vlajkovic, S M; Thorne, P R

    2015-12-01

    Permanent high frequency (>4 kHz) sensorineural hearing loss following middle ear surgery occurs in up to 25% of patients. The aetiology of this loss is poorly understood and may involve transmission of supra-physiological forces down the ossicular chain to the cochlea. Investigating the mechanisms of this injury using animal models is challenging, as evaluating cochlear function with evoked potentials is confounded when ossicular manipulation disrupts the normal air conduction (AC) pathway. Bone conduction (BC) using clinical bone vibrators in small animals is limited by poor transducer output at high frequencies sensitive to trauma. The objectives of the present study were firstly to evaluate a novel high frequency bone conduction transducer with evoked auditory potentials in a guinea pig model, and secondly to use this model to investigate the impact of middle ear surgical manipulation on cochlear function. We modified a magnetostrictive device as a high frequency BC transducer and evaluated its performance by comparison with a calibrated AC transducer at frequencies up to 32 kHz using the auditory brainstem response (ABR), compound action potential (CAP) and summating potential (SP). To mimic a middle ear traumatising stimulus, a rotating bur was brought in to contact with the incudomalleal complex and the effect on evoked cochlear potentials was observed. BC-evoked potentials followed the same input-output function pattern as AC potentials for all ABR frequencies. Deterioration in CAP and SP thresholds was observed after ossicular manipulation. It is possible to use high frequency BC to evoke responses from the injury sensitive basal region of the cochlea and so not rely on AC with the potential confounder of conductive hearing loss. Ongoing research explores how these findings evolve over time, and ways in which injury may be reduced and the cochlea protected during middle ear surgery. PMID:26493491

  7. Valores de latencia y respuestas electrofisiológicas de los diferentes componentes de los potenciales evocados auditivos del tallo cerebral en mono rhesus a diferentes intensidades (70-30 dB Latency values and electrophysiological responses of the different components of the brainstem auditory evoked potentials in rhesus monkeys at different intensities (70-30 dB

    Directory of Open Access Journals (Sweden)

    A Ibáñez-Contreras

    2012-01-01

    Full Text Available El registro de los Potenciales Evocados Auditivos de Tallo Cerebral (PEATC es sensible a las diferencias en los parámetros de estimulación, condiciones del registro y características de la especie utilizada, por lo que es imprescindible poseer valores de normalidad para cada laboratorio. El objetivo de este estudio fue obtener datos normativos acerca de los valores de latencia y de las respuestas electrofisiológicas de los diferentes componentes de los PEATC en el mono rhesus, en diferentes intensidades (70-30 dB. Se utilizaron 14 monos rhesus (Macaca mulatta con una edad promedio de siete años, divididos en siete machos con un peso promedio de 7 kg y siete hembras con un peso aproximado de 5 kg. Los PEATC se obtuvieron mediante la estimulación de los oídos con "clicks" de rarefacción a 70, 50 y 30 dB de intensidad. La actividad eléctrica cerebral fue recogida por medio de electrodos de disco, colocados en las derivaciones Cz (+, A1, A2 (- y Fz como tierra, según el sistema 10/20 internacional. Se observaron cuatro ondas constantes y definidas en las diferentes intensidades utilizadas, tanto en machos como en hembras. Debido a que no se encontraron diferencias significativas en t de Student por aferencias separadas, se unificaron las aferencias, evaluando las latencias absolutas de las cuatro ondas obtenidas, así como los intervalos I-II, II-IV y I-IV en los 14 sujetos, en las diferentes intensidades.The records of the Brainstem Auditory Evoked Potentials (BAEPs are sensitive to differences in stimulation parameters, conditions of registration and characteristics of the species, so it is essential to have normal values for each laboratory. The aim of our study was to obtain normative data on the latency values and electrophysiological responses of the different components of the BAEPs in the rhesus monkey, at different intensities (70-30 dB. This study was performed using 14 non-human primates of the Macaca mulatta species, with an

  8. Event-related evoked potentials in chronic respiratory encephalopathy

    Directory of Open Access Journals (Sweden)

    A R Al Tahan

    2010-02-01

    limited by the small number of tested patients. P300 latency changes correlated significantly with age as well as severity of respiratory failure. P300 was also significantly delayed whether hypoxia occurred with or without hypercapnia.Conclusion: Results show a significant delay of P300 latency in patients with severe and mild respiratory failure. This was associated with subclinical encephalopathy in most patients, evidenced by a near-normal MMSE score. Apart from confirming the importance of P300 latency measurement as a marker of respiratory encephalopathy, this study asserts the causal relationship between hypoxemia and cognitive derangement. Furthermore, it promotes the early use of oxygen therapy in a selected group of patients with mild or moderate respiratory failure, who have responsibilities which involve taking rapid critical decisions.Keywords: event-related evoked potentials, hypoxic–hypercapnic encephalopathy, respiratory failure, chronic respiratory encephalopathy

  9. Extracellular alkaline-acid pH shifts evoked by iontophoresis of glutamate and aspartate in turtle cerebellum.

    Science.gov (United States)

    Chesler, M; Rice, M E

    1991-01-01

    The effect of glutamate and aspartate iontophoresis on extracellular pH was investigated in the turtle cerebellum in vitro. Both amino acids produced a rapid alkaline transient, typically followed by a prolonged acidification. These responses could be evoked in all layers of the cerebellum. Transition from bicarbonate to N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered media amplified the pH shifts. Similar alkaline-acid transients could be evoked in the molecular layer by electrical stimulation of the parallel fibers or the ipsilateral peduncle, or by superfusion of glutamate or aspartate. However, no alkaline shifts were evoked in the granular layer by either parallel fiber or peduncle stimulation. In contrast, the iontophoretically induced alkaline shifts were largest in the granular layer. Compared with the stimulus-evoked alkalinizations, the iontophoretic alkaline shifts were relatively insensitive to Mn2+ or Cd2+. These data suggest that the activity-dependent alkalinization of brain extracellular space is generated by a bicarbonate-independent mechanism related to excitatory synaptic transmission. The results are consistent with a flux of hydrogen ions through cationic channels, but do not support a direct role for voltage-dependent Ca2+ channels. In view of the sensitivity of ion channels to changes in external pH, and the magnitude of the amino acid-induced pH shifts, these results indicate that extracellular pH could play an important modulatory role in excitatory synaptic transmission. PMID:1711651

  10. Temporal features of pain evoked spike trains

    OpenAIRE

    Tara Dezhdar; Tobias Albert

    2012-01-01

    A large portion of peripheral nociceptors are unmyelinated C-fibers. Most C-fiber nociceptors are polymodal, responding to multiple noxious modalities such as thermal and mechanical stimuli. Nevertheless, distinct noxious modalities can be dissociated behaviorally [1], raising the question how the nervous system achieves to determine the modality of the stimulus. To shed light on this question, we investigated the response of C-fiber nociceptors to noxious heat and mechanical stimulation at...

  11. Contact heat evoked potentials using simultaneous EEG and fMRI and their correlation with evoked pain

    Directory of Open Access Journals (Sweden)

    Atherton Duncan

    2008-12-01

    Full Text Available Abstract Background The Contact Heat Evoked Potential Stimulator (CHEPS utilises rapidly delivered heat pulses with adjustable peak temperatures to stimulate the differential warm/heat thresholds of receptors expressed by Aδ and C fibres. The resulting evoked potentials can be recorded and measured, providing a useful clinical tool for the study of thermal and nociceptive pathways. Concurrent recording of contact heat evoked potentials using electroencephalogram (EEG and functional magnetic resonance imaging (fMRI has not previously been reported with CHEPS. Developing simultaneous EEG and fMRI with CHEPS is highly desirable, as it provides an opportunity to exploit the high temporal resolution of EEG and the high spatial resolution of fMRI to study the reaction of the human brain to thermal and nociceptive stimuli. Methods In this study we have recorded evoked potentials stimulated by 51°C contact heat pulses from CHEPS using EEG, under normal conditions (baseline, and during continuous and simultaneous acquisition of fMRI images in ten healthy volunteers, during two sessions. The pain evoked by CHEPS was recorded on a Visual Analogue Scale (VAS. Results Analysis of EEG data revealed that the latencies and amplitudes of evoked potentials recorded during continuous fMRI did not differ significantly from baseline recordings. fMRI results were consistent with previous thermal pain studies, and showed Blood Oxygen Level Dependent (BOLD changes in the insula, post-central gyrus, supplementary motor area (SMA, middle cingulate cortex and pre-central gyrus. There was a significant positive correlation between the evoked potential amplitude (EEG and the psychophysical perception of pain on the VAS. Conclusion The results of this study demonstrate the feasibility of recording contact heat evoked potentials with EEG during continuous and simultaneous fMRI. The combined use of the two methods can lead to identification of distinct patterns of brain

  12. Evaluation of Evoked Potentials to Dyadic Tones after Cochlear Implantation

    Science.gov (United States)

    Sandmann, Pascale; Eichele, Tom; Buechler, Michael; Debener, Stefan; Jancke, Lutz; Dillier, Norbert; Hugdahl, Kenneth; Meyer, Martin

    2009-01-01

    Auditory evoked potentials are tools widely used to assess auditory cortex functions in clinical context. However, in cochlear implant users, electrophysiological measures are challenging due to implant-created artefacts in the EEG. Here, we used independent component analysis to reduce cochlear implant-related artefacts in event-related EEGs of…

  13. Value of transcranial motor evoked potentials during spinal operations

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ To the Editor: We read the interesting recent article by Ding et al1 concerning the value of somatosensory evoked potentials (SEPs) in the diagnosis and prognosis of cervical spondylotic myelopathy, as well as the usefulness of monitoring intraoperative potentials in terms of safety and predictive factors.

  14. Cortical Auditory Evoked Potentials in Unsuccessful Cochlear Implant Users

    Science.gov (United States)

    Munivrana, Boska; Mildner, Vesna

    2013-01-01

    In some cochlear implant users, success is not achieved in spite of optimal clinical factors (including age at implantation, duration of rehabilitation and post-implant hearing level), which may be attributed to disorders at higher levels of the auditory pathway. We used cortical auditory evoked potentials to investigate the ability to perceive…

  15. The effects of ultraviolet-A radiation on visual evoked potentials in the young human eye

    International Nuclear Information System (INIS)

    A recent study from this laboratory using visual evoked potentials (VEPs) demonstrated that children's eyes are capable of detecting ultraviolet radiation. The aim of this study was to compare dose-response relationships in two age groups, 6-10 years (n=10) and 20-25 years (n=10). Under photopic viewing conditions (550 lux), exposures of monochromatic UV-A (339 nm) and visible radiation (502 nm) were correlated to VEPs. The results demonstrate that monochromatic UV-A can elicit age and dose dependent responses in the human visual system, suggesting that the eyes of children are more responsive to UV stimuli than the eyes of young adults. (au) 17 refs

  16. Synchronous and asynchronous electrically evoked motor activities during wind-up stimulation are differentially modulated following an acute spinal transection

    OpenAIRE

    Frigon, Alain; Hurteau, Marie-France; Johnson, Michael D; Heckman, C.J.; Telonio, Alessandro; Thibaudier, Yann

    2012-01-01

    In this study, we used a novel technique to study reflex wind-up when the spinal cord is intact and following an acute spinal transection. Specifically, we evaluated reflex responses evoked by a series of 10 electrical pulses to the tibial or superficial peroneal nerves in 9 decerebrate adult cats, before and after an acute spinal transection. Electromyograms were recorded in four hindlimb muscles (lateral gastrocnemius, tibialis anterior, semitendinosus, and sartorius) to evaluate reflex amp...

  17. Steady-state evoked potentials to study the processing of tactile and nociceptive somatosensory input in the human brain.

    OpenAIRE

    Colon, Elisabeth; Legrain, Valéry; Mouraux, André

    2012-01-01

    The periodic presentation of a sensory stimulus induces, at certain frequencies of stimulation, a sustained electroencephalographic response of corresponding frequency, known as steady-state evoked potentials (SS-EP). In visual, auditory and vibrotactile modalities, studies have shown that SS-EP reflect mainly activity originating from early, modality-specific sensory cortices. Furthermore, it has been shown that SS-EP have several advantages over the recording of transient event-related brai...

  18. Vestibular evoked myogenic potentials: an overview Potencial evocado miogênico vestibular: uma visão geral

    OpenAIRE

    Renato Cal; Fayez Bahmad Jr.

    2009-01-01

    The vestibular evoked myogenic potential (VEMP) test is a relatively new diagnostic tool that is in the process of being investigated in patients with specific vestibular disorders. Briefly, the VEMP is a biphasic response elicited by loud clicks or tone bursts recorded from the tonically contracted sternocleidomastoid muscle, being the only resource available to assess the function of the saccule and the lower portion of the vestibular nerve. AIM: In this review, we shall highlight the histo...

  19. Waveform Similarity Analysis: A Simple Template Comparing Approach for Detecting and Quantifying Noisy Evoked Compound Action Potentials.

    Directory of Open Access Journals (Sweden)

    Jason Robert Potas

    Full Text Available Experimental electrophysiological assessment of evoked responses from regenerating nerves is challenging due to the typical complex response of events dispersed over various latencies and poor signal-to-noise ratio. Our objective was to automate the detection of compound action potential events and derive their latencies and magnitudes using a simple cross-correlation template comparison approach. For this, we developed an algorithm called Waveform Similarity Analysis. To test the algorithm, challenging signals were generated in vivo by stimulating sural and sciatic nerves, whilst recording evoked potentials at the sciatic nerve and tibialis anterior muscle, respectively, in animals recovering from sciatic nerve transection. Our template for the algorithm was generated based on responses evoked from the intact side. We also simulated noisy signals and examined the output of the Waveform Similarity Analysis algorithm with imperfect templates. Signals were detected and quantified using Waveform Similarity Analysis, which was compared to event detection, latency and magnitude measurements of the same signals performed by a trained observer, a process we called Trained Eye Analysis. The Waveform Similarity Analysis algorithm could successfully detect and quantify simple or complex responses from nerve and muscle compound action potentials of intact or regenerated nerves. Incorrectly specifying the template outperformed Trained Eye Analysis for predicting signal amplitude, but produced consistent latency errors for the simulated signals examined. Compared to the trained eye, Waveform Similarity Analysis is automatic, objective, does not rely on the observer to identify and/or measure peaks, and can detect small clustered events even when signal-to-noise ratio is poor. Waveform Similarity Analysis provides a simple, reliable and convenient approach to quantify latencies and magnitudes of complex waveforms and therefore serves as a useful tool for

  20. Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation

    OpenAIRE

    G.S. Souza; H.B. Schakelford; Moura, A.L.A.; Gomes, B.D.; D.F. Ventura; M.E.C. Fitzgerald; L.C.L. Silveira

    2012-01-01

    This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP) elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359). Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m² mean lu...

  1. The Effectiveness of FES-Evoked EMG Potentials to Assess Muscle Force and Fatigue in Individuals with Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Morufu Olusola Ibitoye

    2014-07-01

    Full Text Available The evoked electromyographic signal (eEMG potential is the standard index used to monitor both electrical changes within the motor unit during muscular activity and the electrical patterns during evoked contraction. However, technical and physiological limitations often preclude the acquisition and analysis of the signal especially during functional electrical stimulation (FES-evoked contractions. Hence, an accurate quantification of the relationship between the eEMG potential and FES-evoked muscle response remains elusive and continues to attract the attention of researchers due to its potential application in the fields of biomechanics, muscle physiology, and rehabilitation science. We conducted a systematic review to examine the effectiveness of eEMG potentials to assess muscle force and fatigue, particularly as a biofeedback descriptor of FES-evoked contractions in individuals with spinal cord injury. At the outset, 2867 citations were identified and, finally, fifty-nine trials met the inclusion criteria. Four hypotheses were proposed and evaluated to inform this review. The results showed that eEMG is effective at quantifying muscle force and fatigue during isometric contraction, but may not be effective during dynamic contractions including cycling and stepping. Positive correlation of up to r = 0.90 (p < 0.05 between the decline in the peak-to-peak amplitude of the eEMG and the decline in the force output during fatiguing isometric contractions has been reported. In the available prediction models, the performance index of the eEMG signal to estimate the generated muscle force ranged from 3.8% to 34% for 18 s to 70 s ahead of the actual muscle force generation. The strength and inherent limitations of the eEMG signal to assess muscle force and fatigue were evident from our findings with implications in clinical management of spinal cord injury (SCI population.

  2. Dynamic causal modeling of touch-evoked potentials in the rubber hand illusion.

    Science.gov (United States)

    Zeller, Daniel; Friston, Karl J; Classen, Joseph

    2016-09-01

    The neural substrate of bodily ownership can be disclosed by the rubber hand illusion (RHI); namely, the illusory self-attribution of an artificial hand that is induced by synchronous tactile stimulation of the subject's hand that is hidden from view. Previous studies have pointed to the premotor cortex (PMC) as a pivotal area in such illusions. To investigate the effective connectivity between - and within - sensory and premotor areas involved in bodily perceptions, we used dynamic causal modeling of touch-evoked responses in 13 healthy subjects. Each subject's right hand was stroked while viewing their own hand ("REAL"), or an artificial hand presented in an anatomically plausible ("CONGRUENT") or implausible ("INCONGRUENT") position. Bayesian model comparison revealed strong evidence for a differential involvement of the PMC in the generation of touch-evoked responses under the three conditions, confirming a crucial role of PMC in bodily self-attribution. In brief, the extrinsic (forward) connection from left occipital cortex to left PMC was stronger for CONGRUENT and INCONGRUENT as compared to REAL, reflecting the augmentation of bottom-up visual input when multisensory integration is challenged. Crucially, intrinsic connectivity in the primary somatosensory cortex (S1) was attenuated in the CONGRUENT condition, during the illusory percept. These findings support predictive coding models of the functional architecture of multisensory integration (and attenuation) in bodily perceptual experience. PMID:27241481

  3. Multichannel somato sensory evoked potential study demonstrated abnormalities in cervical cord function in brachial monomelic amyotrophy

    Directory of Open Access Journals (Sweden)

    Nalini A

    2008-01-01

    Full Text Available Background: Brachial monomelic amyotrophy (BMMA is known to affect the central cervical cord gray matter resulting in single upper limb atrophy and weakness. Settings and Design: Case series of BMMA patients who underwent somatosensory evoked potentials (SEP studies at a tertiary referral center. Aims: We proposed to record Multichannel Somatosensory Evoked Potentials (MCSSEP from median and ulnar nerves with neck in neutral and neck fully flexed position in 17 patients with classical BMMA seen over three years. Materials and Methods: Recordings were done from both median (MN and ulnar nerves (UN. N9, P9, N13, N20 potentials were recorded and amplitudes measured. SSEPs were performed in 22 age-matched healthy men. Amplitudes of cervical response were calculated by N13/P9 ratio and compared in both positions. Results: Among the controls N13 amplitude was always normal {MN: mean N13/P9 - 0.96 in neutral; 0.95 in flexed}{UN: mean N13/P9 - 0.82 in neutral; 0.83 in flexed}, and mean amplitudes did not reveal any difference in both conditions ( P >0.05. Among 17 patients N9, P9 and N20 responses were normal in neutral position. Flexion showed no change in latency or amplitude of N9 and N20 responses ( P -0.63 whereas the N13 response was abnormal in at least one tested nerve in the affected limb (MN: P < 0.01; UN: P < 0.01. During flexion, N13 response was abnormal in 14 (82% patients after MN stimulation and in all 17(100% after UN stimulation {MN: mean N13/P9 - 0.62 in neutral; 0.38 in flexed}{UN: mean N13/P9 - 0.55 in neutral; 0.31 in flexed}. Conclusion: MCSSEP in BMMA with neck flexion caused a significant reduction of the cervical N13 response indicating segmental cervical cord dysfunction.

  4. Time-varying bispectral analysis of visually evoked multi-channel EEG

    Science.gov (United States)

    Chandran, Vinod

    2012-12-01

    Theoretical foundations of higher order spectral analysis are revisited to examine the use of time-varying bicoherence on non-stationary signals using a classical short-time Fourier approach. A methodology is developed to apply this to evoked EEG responses where a stimulus-locked time reference is available. Short-time windowed ensembles of the response at the same offset from the reference are considered as ergodic cyclostationary processes within a non-stationary random process. Bicoherence can be estimated reliably with known levels at which it is significantly different from zero and can be tracked as a function of offset from the stimulus. When this methodology is applied to multi-channel EEG, it is possible to obtain information about phase synchronization at different regions of the brain as the neural response develops. The methodology is applied to analyze evoked EEG response to flash visual stimulii to the left and right eye separately. The EEG electrode array is segmented based on bicoherence evolution with time using the mean absolute difference as a measure of dissimilarity. Segment maps confirm the importance of the occipital region in visual processing and demonstrate a link between the frontal and occipital regions during the response. Maps are constructed using bicoherence at bifrequencies that include the alpha band frequency of 8Hz as well as 4 and 20Hz. Differences are observed between responses from the left eye and the right eye, and also between subjects. The methodology shows potential as a neurological functional imaging technique that can be further developed for diagnosis and monitoring using scalp EEG which is less invasive and less expensive than magnetic resonance imaging.

  5. An inventory and update of jealousy-evoking partner behaviours in modern society.

    NARCIS (Netherlands)

    Dijkstra, Pieternel; Barelds, Dick P. H.; Groothof, Hinke A. K.

    2010-01-01

    The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's e

  6. A level stimulator programmed for audiometry

    International Nuclear Information System (INIS)

    This stimulator has been designed for automated audiometric experiments on lemurians. The variations of the transmission level are programmed on punched tape whose reading is controlled by an audiofrequency attenuator. The positive answers of the animal are stored in a seven-counter memory and the results are read by display

  7. Do twisted laser beams evoke nuclear hyperpolarization?

    Science.gov (United States)

    Schmidt, A B; Andrews, D L; Rohrbach, A; Gohn-Kreuz, C; Shatokhin, V N; Kiselev, V G; Hennig, J; von Elverfeldt, D; Hövener, J-B

    2016-07-01

    able to induce electronic (e.g. in rubidium) and subsequent nuclear hyperpolarization. Compared to the plane wave, the additional transitions caused by a twisted wave are of the order of 10(-3) less. This suggests that the twist of the laser is unlikely to be responsible for the hyperpolarization of nuclear spins, unless a new mechanism of momentum transfer is identified. PMID:27179228

  8. Do twisted laser beams evoke nuclear hyperpolarization?

    Science.gov (United States)

    Schmidt, A. B.; Andrews, D. L.; Rohrbach, A.; Gohn-Kreuz, C.; Shatokhin, V. N.; Kiselev, V. G.; Hennig, J.; von Elverfeldt, D.; Hövener, J.-B.

    2016-07-01

    able to induce electronic (e.g. in rubidium) and subsequent nuclear hyperpolarization. Compared to the plane wave, the additional transitions caused by a twisted wave are of the order of 10-3 less. This suggests that the twist of the laser is unlikely to be responsible for the hyperpolarization of nuclear spins, unless a new mechanism of momentum transfer is identified.

  9. Abdominal acupuncture reduces laser-evoked potentials in healthy subjects

    DEFF Research Database (Denmark)

    Pazzaglia, C.; Liguori, S.; Minciotti, I.;

    2015-01-01

    Objective: Acupuncture is known to reduce clinical pain, although the exact mechanism is unknown. The aim of the current study was to investigate the effect of acupuncture on laser-evoked potential amplitudes and laser pain perception. Methods: In order to evaluate whether abdominal acupuncture is...... able to modify pain perception, 10 healthy subjects underwent a protocol in which laser-evoked potentials (LEPs) and laser pain perception were collected before the test (baseline), during abdominal acupuncture, and 15. min after needle removal. The same subjects also underwent a similar protocol in...... real acupuncture, although the difference was marginally significant (p = 0.06). Conclusions: Our results show that abdominal acupuncture reduces LEP amplitude in healthy subjects. Significance: Our results provide a theoretical background for the use of abdominal acupuncture as a therapeutic approach...

  10. Inhibitory and potentiating influences of glycine on N-methyl-D-aspartate-evoked dopamine release from cultured rat mesencephalic cells

    International Nuclear Information System (INIS)

    In the presence of 1.2 mM Mg2+, glycine (30-100 microM) inhibited [3H]dopamine ([3H]DA) release stimulated by N-methyl-D-aspartate (NMDA), in fetal rat mesencephalic cell cultures. Strychnine (1 microM) blocked the inhibitory effect of 100 microM glycine, indicating an action via strychnine-sensitive inhibitory glycine receptors. A higher concentration of strychnine (100 microM), by itself, inhibited NMDA-evoked [3H]DA release in the presence or absence of Mg2+. Spontaneous [3H]DA release and [3H]DA release stimulated by kainate and quisqualate were unaffected by glycine (less than or equal to 100 microM) or strychnine (less than or equal to 100 microM), indicating that glycine and strychnine modulatory effects are only associated with the NMDA receptor subtype. [3H]DA release evoked by K+ (56 mM) was unaffected by glycine (less than or equal to 100 microM) but was attenuated by a high concentration of strychnine (100 microM). In the absence of exogenous Mg2+, glycine (30-100 microM) potentiated NMDA-evoked [3H]DA release by a strychnine-insensitive mechanism. A selective antagonist of the NMDA-associated glycine receptor, 7-chlorokynurenate (10 microM), attenuated NMDA-evoked [3H]DA release in the absence of Mg2+. The effect of 10 microM 7-chlorokynurenate was overcome by 1 microM glycine. Also, when tested in the presence of 1.2 nM Mg2+ and 1 microM strychnine, 100 microM 7-chlorokynurenate inhibited NMDA-evoked [3H]DA release, and this antagonism was overcome by 30 to 100 microM glycine. These results indicate that two distinct glycine receptors modulate NMDA-stimulated [3H]DA release from mesencephalic cells in culture. Manipulation of extracellular Mg2+ permits the differentiation of a strychnine-sensitive glycine response (inhibition of NMDA-evoked [3H]DA release) from a strychnine-insensitive glycine response

  11. [Evoked cortical somatosensory potentials in painful cervicobrachial radicular syndromes].

    Science.gov (United States)

    Domzał, T; Marks, E; Miszczak, J

    1978-01-01

    The authors determined the subjective, objective and maximal pain threshold by means of electrical stimulation in two groups of subjects. Group I comprised healthy subjects, group II patients with right-sided radicular cervicobrachial pains. The method applied by the authors for objective determination of pain threshold with evoked cortical somatosensory potential differentiated both groups which suggests its practical usefulness in clinical practice and expertise. PMID:683429

  12. Hindlimb venous distention evokes a pressor reflex in decerebrated rats

    OpenAIRE

    Yamauchi, Katsuya; Audrey J. Stone; Kaufman, Marc P.

    2014-01-01

    Abstract The distention of small vessels caused by an increase in blood flow to dynamically exercising muscles has been proposed as a stimulus that activates the thin fiber (groups III and IV) afferents evoking the exercise pressor reflex. This theory has been supported by evidence obtained from both humans and animals. In decerebrated unanesthetized rats with either freely perfused femoral arteries or arteries that were ligated 3 days before the experiment, we attempted to provide evidence i...

  13. Influence of temperature on the sound-evoked vestibular potential.

    Science.gov (United States)

    Wit, H P; Dijkgraaf, E

    1985-01-01

    The sound-evoked vestibular potential, measured with gross electrodes after fenestration of a lateral semicircular canal in pigeons, is delayed with respect to the acoustic stimulus. The influence of temperature of the vestibular system on this delay can most easily be explained by assuming chemically mediated transmission to take place between vestibular hair cells and their primary afferents. The possibility of electrotonic transmission, however, cannot be excluded. PMID:3878654

  14. Multimodality evoked potentials in HTLV-I associated myelopathy.

    OpenAIRE

    Kakigi, R; Shibasaki, H; Kuroda, Y; Endo, C; Oda, K.; Ikeda, A.; Hashimoto, K.

    1988-01-01

    Multimodality evoked potentials (EPs) consisting of somatosensory EPs (SEPs), visual EPs (VEPs) and brainstem auditory EPs (BAEPs) were studied in 16 cases with HTLV-I associated myelopathy (HAM). Median nerve SEPs were normal in all cases. In posterior tibial nerve SEPs, the potential recorded at the 12th thoracic spinal process was normal in every case but cortical components were significantly prolonged in 10 cases, although five of these showed no sensory impairment. BAEPs were normal in ...

  15. Functional prognosis in stroke: use of somatosensory evoked potentials.

    OpenAIRE

    Zeman, B D; Yiannikas, C

    1989-01-01

    Median nerve somatosensory evoked potentials (SEPs) were performed on 35 patients with acute stroke and correlated with functional outcome as measured by placement, length of stay and an activities of daily living index (Barthel Index). There was a statistically significant correlation of both SEP and sensory examination at the 0.05 level to eventual functional outcome. SEPs were better than age, sex and side of CVA in predicting functional outcome as measured by these scores. SEPs and sensor...

  16. Somatosensory evoked potentials in workers exposed to toluene and styrene.

    OpenAIRE

    Stĕtkárová, I; Urban, P.; Procházka, B; Lukás, E

    1993-01-01

    Somatosensory evoked potentials (SEPs) were used to evaluate possible subclinical impairment of the nervous system due to occupational exposure to toluene and styrene. A group of 36 rotogravure printers with severe exposure to toluene, 20 workers with severe exposure to styrene in a glass laminate manufacturing plant, and a comparison group of healthy subjects were studied. The severity of exposure was documented by measurements of toluene and styrene concentrations in breathing zone air, by ...

  17. Pain-related somatosensory evoked potentials in cortical reflex myoclonus.

    OpenAIRE

    Kakigi, R; Shibasaki, H; Neshige, R; Ikeda, A.; Mamiya, K.; Kuroda, Y

    1990-01-01

    To elucidate the sensitivity to pain stimuli in patients with cortical reflex myoclonus, pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation and conventional electrically-stimulated SEPs (electric SEPs) were compared in four patients with cortical reflex myoclonus. The P25 peak of electric SEPs was considerably enhanced but the P320 potential of pain SEPs was of normal amplitude in all patients. After medication, myoclonus was reduced and the amplitude of ...

  18. The Dynamic Functional Capacity Theory: Music Evoked Emotions

    OpenAIRE

    Klineburger, Philip C

    2014-01-01

    The music-evoked emotion literature implicates many brain regions involved in emotional processing but is currently lacking a model that specifically explains how they temporally and dynamically interact to produce intensely pleasurable emotions. A conceptual model, The Dynamic Functional Capacity Theory (DFCT), is proposed that provides a foundation for the further understanding of how brain regions interact to produce intense intensely pleasurable emotions. The DFCT claims th...

  19. The impact of emotion on respiratory-related evoked potentials

    OpenAIRE

    von Leupoldt, Andreas; Vovk, Andrea; Bradley, Margaret M.; Keil, Andreas; Lang, Peter J.; Davenport, Paul W.

    2010-01-01

    Emotion influences the perception of respiratory sensations, although the specific mechanism underlying this modulation is not yet clear. We examined the impact of viewing pleasant, neutral, and unpleasant affective pictures on the respiratory-related evoked potential (RREP) elicited by a short inspiratory occlusion in healthy volunteers. Reduced P3 amplitude of the RREP was found for respiratory probes presented when viewing pleasant or unpleasant series, when compared to those presented dur...

  20. An evoked potential mapping of transcallosal projections in the cat

    OpenAIRE

    A. Cukiert; C. Timo-Iaria

    1989-01-01

    In ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity) were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions were determined on a cartesian map of most of the exposable neocortical areas and the potentials were analysed as to their components, voltage and latency. Passive spread and electrotonic potentials a...

  1. Event-related evoked potentials in chronic respiratory encephalopathy

    OpenAIRE

    Tahan, A R Al; Zaidan, R.; Jones, S; Husain, A.; Mobeireek, A; Bahammam, A

    2010-01-01

    Background: Cognitive event-related potential (P300) is an index of cognitive processing time. It was found to be prolonged in dementia, renal, and hepatic encephalopathies, but was not extensively assessed in respiratory failure. Objective: To evaluate P300 changes in patients with respiratory failure, and especially those with mild or subclinical hypoxic–hypercapnic encephalopathy. Methods: Auditory event-related evoked potential P300 latency was measured using an oddball paradigm in patien...

  2. Assessment of visual disability using visual evoked potentials

    OpenAIRE

    Jeon Jihoon; Oh Seiyul; Kyung Sungeun

    2012-01-01

    Abstract Background The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. Methods A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for regist...

  3. A Sequential Detection Method for Late Auditory Evoked Potentials

    OpenAIRE

    Hoppe, U; Eysholdt, U; Weiss, S.

    1996-01-01

    This work presents a novel mechanism for detection of late auditory evoked potentials (AEP). AEPs, which are an important diagnostic tool to detect hearing deficiencies, are contained within the electroencephalogram (EEG) at a very low SNR. Our proposed automatic detection of AEPs is based on the Wavelet-Transform of EEG data for feature extraction. Several transform coefficients are then used for a classification by a neural network; its decisions on successive EEG segments are judged by a s...

  4. Visual evoked potentials in succinate semialdehyde dehydrogenase (SSADH) Deficiency

    OpenAIRE

    Di Rosa, G.; Malaspina, P; P. Blasi(INAF Arcetri); Dionisi-Vici, C.; Rizzo, C; Tortorella, G; Crutchfield, S. R.; Gibson, K. M.

    2009-01-01

    In mammals, increased GABA in the central nervous system has been associated with abnormalities of visual evoked potentials (VEPs), predominantly manifested as increased latency of the major positive component P100. Accordingly, we hypothesized that patients with a defect in GABA metabolism, succinate semialdehyde dehydrogenase (SSADH) deficiency (in whom supraphysiological levels of GABA accumulate), would manifest VEP anomalies. We evaluated VEPs on two patients with confirmed SSADH deficie...

  5. Functional imaging of glucose-evoked rat islet activities using transient intrinsic optical signals

    Science.gov (United States)

    Yao, Xin-Cheng; Cui, Wan-Xing; Li, Yi-Chao; Zhang, Wei; Lu, Rong-Wen; Thompson, Anthony; Amthor, Franklin; Wang, Xu-Jing

    2012-05-01

    We demonstrate intrinsic optical signal (IOS) imaging of intact rat islet, which consists of many endocrine cells working together. A near-infrared digital microscope was employed for optical monitoring of islet activities evoked by glucose stimulation. Dynamic NIR images revealed transient IOS responses in the islet activated by low-dose (2.75 mM) and high-dose (5.5 mM) glucose stimuli. Comparative experiments and quantitative analysis indicated that both glucose metabolism and calcium/insulin dynamics might contribute to the observed IOS responses. Further investigation of the IOS imaging technology may provide a high resolution method for ex vivo functional examination of the islet, which is important for advanced study of diabetes associated islet dysfunctions and for improved quality control of donor islets for transplantation.

  6. Light scattering changes follow evoked potentials from hippocampal Schaeffer collateral stimulation

    DEFF Research Database (Denmark)

    Rector, D M; Poe, G R; Kristensen, Morten Pilgaard; Harper, R M

    1997-01-01

    complex population synaptic potential that lasted 100-200 ms depending on stimulus intensity and electrode position. Light scattering changes peaked 20 ms after stimuli and occurred simultaneously with population spikes. A long-lasting light scattering component peaked 100-500 ms after the stimulus...... response pattern that paralleled the photodiode measurements and depended on stimulation electrode position. Light scattering changes accompanied fast electrical responses, occurred too rapidly for perfusion, and showed a stimulus intensity relationship not consistent with glial changes.......We assessed relationships of evoked electrical and light scattering changes from cat dorsal hippocampus following Schaeffer collateral stimulation. Under anesthesia, eight stimulating electrodes were placed in the left hippocampal CA field and an optic probe, coupled to a photodiode or a charge...

  7. Optical suppression of drug-evoked phasic dopamine release

    Directory of Open Access Journals (Sweden)

    James Edgar Mccutcheon

    2014-09-01

    Full Text Available Brief fluctuations in dopamine concentration (dopamine transients play a key role in behavior towards rewards, including drugs of abuse. Drug-evoked dopamine transients may result from actions at both dopamine cell bodies and dopamine terminals. Inhibitory opsins can be targeted to dopamine neurons permitting their firing activity to be suppressed. However, as dopamine transients can become uncoupled from firing, it is unknown whether optogenetic hyperpolarization at the level of the soma is able to suppress dopamine transients. Here, we used in vivo fast-scan cyclic voltammetry to record transients evoked by cocaine and raclopride in nucleus accumbens (NAc of urethane-anesthetized rats. We targeted halorhodopsin (NpHR specifically to dopamine cells by injecting Cre-inducible virus into ventral tegmental area (VTA of transgenic rats that expressed Cre recombinase under control of the tyrosine hydroxylase promoter (TH-Cre+ rats. Consistent with previous work, co-administration of cocaine and raclopride led to the generation of dopamine transients in NAc shell. Illumination of VTA with laser strongly suppressed the frequency of transients in NpHR-expressing rats, but not in control rats. Laser did not have any effect on amplitude of transients. Thus, optogenetics can effectively reduce the occurrence of drug-evoked transients and is therefore a suitable approach for studying the functional role of such transients in drug-associated behavior.

  8. Vestibular-evoked myogenic potentials in miniature pigs

    Institute of Scientific and Technical Information of China (English)

    Xi Shi; Yan Zhang; Ya Li; Shiwei Qiu; Shili Zhang; Yaohan Li; Na Yuan; Yuehua Qiao; Shiming Yang

    2016-01-01

    Objective:To report detection of vestibular-evoked myogenic potentials (VEMPs) in the miniature pig. Methods:Potentials evoked by 1000 Hz tone bursts were recorded from neck extensor muscles and the masseter muscles in normal adult Bama miniature pigs anesthetized with 3%pentobarbital sodium and Carbachol II. Results:The latency of the first positive wave P from neck extensor muscles was 7.65 ± 0.64 ms, with an amplitude of 1.66 ± 0.34 uv and a rate of successful induction of 75%at 80 dB SPL. The latency of potentials evoked from the masseter muscles was 7.60 ± 0.78 ms, with an amplitude of 1.31 ± 0.28 uv and a rate successful induction of 66%at 80 dB SPL. Conclusion:The latencies and thresholds of VEMPs recorded from the neck extensor muscle and the masseter muscle appear to be comparable in normal adult Bama miniature pigs, although the amplitude recorded from the neck extensor muscle seems to be higher than that from the masseter muscle. However, because of their usually relatively superficial and easily accessible location, as well as their large volume and strong contractions, masseter muscles may be better target muscles for recording myogenic potentials.

  9. Brainstem auditory evoked potential abnormalities in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Sharat Gupta

    2013-01-01

    Full Text Available Background: Diabetes mellitus represents a syndrome complex in which multiple organ systems, including the central nervous system, are affected. Aim: The study was conducted to determine the changes in the brainstem auditory evoked potentials in type 2 diabetes mellitus. Materials and Methods: A cross sectional study was conducted on 126 diabetic males, aged 35-50 years, and 106 age-matched, healthy male volunteers. Brainstem auditory evoked potentials were recorded and the results were analyzed statistically using student′s unpaired t-test. The data consisted of wave latencies I, II, III, IV, V and interpeak latencies I-III, III-V and I-V, separately for both ears. Results: The latency of wave IV was significantly delayed only in the right ear, while the latency of waves III, V and interpeak latencies III-V, I-V showed a significant delay bilaterally in diabetic males. However, no significant difference was found between diabetic and control subjects as regards to the latency of wave IV unilaterally in the left ear and the latencies of waves I, II and interpeak latency I-III bilaterally. Conclusion: Diabetes patients have an early involvement of central auditory pathway, which can be detected with fair accuracy with auditory evoked potential studies.

  10. Different action of a specific NR2B/NMDA antagonist Ro 25-6981 on cortical evoked potentials and epileptic afterdischarges in immature rats

    Czech Academy of Sciences Publication Activity Database

    Szczurowska, Ewa; Mareš, Pavel

    2015-01-01

    Roč. 111, Jan 2015 (2015), s. 1-8. ISSN 0361-9230 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : cortical evoked responses * epileptic afterdischarges * subunits of NMDA receptors * ontogeny * rat Subject RIV: FH - Neurology Impact factor: 2.718, year: 2014

  11. Neural activity patterns evoked by a spouse's incongruent emotional reactions when recalling marriage-relevant experiences.

    Science.gov (United States)

    Petrican, Raluca; Rosenbaum, Rachel Shayna; Grady, Cheryl

    2015-10-01

    Resonance with the inner states of another social actor is regarded as a hallmark of emotional closeness. Nevertheless, sensitivity to potential incongruities between one's own and an intimate partner's subjective experience is reportedly also important for close relationship quality. Here, we tested whether perceivers show greater neurobehavioral responsiveness to a spouse's positive (rather than negative) context-incongruent emotions, and whether this effect is influenced by the perceiver's satisfaction with the relationship. Thus, we used fMRI to scan older long-term married female perceivers while they judged either their spouse's or a stranger's affect, based on incongruent nonverbal and verbal cues. The verbal cues were selected to evoke strongly polarized affective responses. Higher perceiver marital satisfaction predicted greater neural processing of the spouse's (rather than the strangers) nonverbal cues. Nevertheless, across all perceivers, greater neural processing of a spouse's (rather than a stranger's) nonverbal behavior was reliably observed only when the behavior was positive and the context was negative. The spouse's positive (rather than negative) nonverbal behavior evoked greater activity in putative mirror neuron areas, such as the bilateral inferior parietal lobule (IPL). This effect was related to a stronger inhibitory influence of cognitive control areas on mirror system activity in response to a spouse's negative nonverbal cues, an effect that strengthened with increasing perceiver marital satisfaction. Our valence-asymmetric findings imply that neurobehavioral responsiveness to a close other's emotions may depend, at least partly, on cognitive control resources, which are used to support the perceiver's interpersonal goals (here, goals that are relevant to relationship stability). PMID:26219536

  12. Limitations in the rapid extraction of evoked potentials using parametric modeling.

    Science.gov (United States)

    De Silva, A C; Sinclair, N C; Liley, D T J

    2012-05-01

    The rapid extraction of variations in evoked potentials (EPs) is of great clinical importance. Parametric modeling using autoregression with an exogenous input (ARX) and robust evoked potential estimator (REPE) are commonly used methods for extracting EPs over the conventional moving time average. However, a systematic study of the efficacy of these methods, using known synthetic EPs, has not been performed. Therefore, the current study evaluates the restrictions of these methods in the presence of known and systematic variations in EP component latency and signal-to-noise ratios (SNR). In the context of rapid extraction, variations of wave V of the auditory brainstem in response to stimulus intensity were considered. While the REPE methods were better able to recover the simulated model of the EP, morphology and the latency of the ARX-estimated EPs was a closer match to the actual EP than than that of the REPE-estimated EPs. We, therefore, concluded that ARX rapid extraction would perform better with regards to the rapid tracking of latency variations. By tracking simulated and empirically induced latency variations, we conclude that rapid EP extraction using ARX modeling is only capable of extracting latency variations of an EP in relatively high SNRs and, therefore, should be used with caution in low-noise environments. In particular, it is not a suitable method for the rapid extraction of early EP components such as the auditory brainstem potential. PMID:22394572

  13. N-hexane-induced changes in nerve conduction velocities and somatosensory evoked potentials

    Energy Technology Data Exchange (ETDEWEB)

    Mutti, A.; Lucertini, S.; Franchini, I.; Ferri, F.; Lommi, G.

    1982-11-01

    Fifteen women from a shoe factory were examined clinically and their cerebral evoked responses to 256 electrical stimulations of the median nerve were averaged. Neurophysiological investigations included maximal motor (MCV) and distal sensory (dSCV) nerve conduction velocity measurement on ulnar, median, and peroneal nerves. A referent group was composed of 15 age-matched women without exposure to neurotoxic chemicals. MCVs and dSCVs of the exposed workers were significantly reduced vs referents, while P/sub 15/ and N/sub 20/ components of the somatosensory evoked potentials (SEP) showed an increased latency. A negative linear relationship was found between dSCV and P/sub 15/ latency. However, two subjects with an abnormally low dSCV showed normal SEP latency, and two other subjects, displayed abnormal SEP latency, while their dSCV was in the normal range. Therefore, SEP investigation may give additional information on nervous system function, even in subjects with peripheral neuropathy. The later SEP components were much flatter in the exposed than in the referent group, suggesting some neurotoxic effects of n-hexane on the central nervous system too.

  14. Defensiveness, anxiety and the amplitude/intensity function of auditory-evoked potentials.

    Science.gov (United States)

    Kline, J P; Schwartz, G E; Fitzpatrick, D F; Hendricks, S E

    1993-07-01

    This study measured relationships between defensiveness, anxiety, and auditory-evoked potentials to tones of varied intensity. Subjects were designated as defensive if they scored > or = 7 on the L-scale of the Eysenck Personality Questionnaire, and high-anxious if they scored > or = 11 on the N-scale. Four groups resulted: 'high anxious', 'defensive high anxious', 'repressors' (i.e., defensive low anxious) and 'low anxious'. Evoked potentials were recorded from FZ, CZ, PZ, C3, C4, T3 and T4, referenced to linked ears in response to 74, 84, 94 and 104 dB SPL tones. High-defensive subjects showed lower P2 amplitudes to the 94 and 104 dB tones and lower amplitude/intensity slopes at FZ, CZ, C3 and C4. High-anxious subjects showed lower P2 amplitudes to all four stimulus intensities at FZ, CZ and PZ. The results are consistent with the hypothesis that defensiveness is associated with desensitization to intense or painful stimulation. PMID:8407437

  15. Can a finding of cervical vestibular evoked myogenic potentials contribute to vestibular migraine diagnostics?

    Directory of Open Access Journals (Sweden)

    Tihana Vešligaj

    2016-02-01

    Full Text Available Aim To investigate differences in vestibular evoked myogenic potentials (VEMP results with patients suffering from vestibular migraine and healthy people, taking into consideration values of threshold and latency of occurrence of the characteristic wave complex, size of amplitude, and interaural amplitude ratio. According to the results, determine the importance and usefulness of VEMP in vestibular migraine diagnostics. Methods A total number of 62 subjects were included in the study, 32 of them belonging to a group of patients suffering from vestibular migraine (VM, while other 30 were in a control group of healthy subjects. Information was collected during the diagnostic evaluation. General and otoneurological history of patients and bedside tests, audiological results, videonystagmography and cervical vestibular evoked myogenic potentials (cVEMP were made. Results There was a difference in an interaural ratio of amplitudes in the experimental and control groups, but it was not found to be clinically significant. By ToneBurst 500 Hz method, the interaural amplitude ratio higher than 35% was measured in 46.97% subjects, while the response was totally unilaterally missing in 28.8% patients. Conclusion Even the sophisticated method as cVEMP does not give the ultimate result confirming the vestibular migraine diagnosis, and neither do other diagnostic methods. cVEMP result can contribute to the completion of full mosaic of vestibular migraine diagnostics.

  16. Prognosis in prolonged coma patients with diffuse axonal injury assessed by somatosensory evoked potential

    Institute of Scientific and Technical Information of China (English)

    Xiujue Zheng; Mantao Chen; Jingqi Li; Fei Cao

    2013-01-01

    A total of 43 prolonged coma patients with diffuse axonal injury received the somatosensory evoked potential examination one month after injury in the First Affiliated Hospital, School of Medicine, Zhejiang University in China. Somatosensory evoked potentials were graded as normal, abnormal or absent (grades I–III) according to N20 amplitude and central conduction time. The outcome in patients with grade III somatosensory evoked potential was in each case unfavorable. The prognostic accuracy of grade III somatosensory evoked potential for unfavorable and non-awakening outcome was 100% and 80%, respectively. The prognostic accuracy of grade I somatosensory evoked potential for favorable and wakening outcome was 86% and 100%, respectively. These results suggest that somatosensory evoked potential grade is closely correlated with coma severity and degree of recovery. Somatosensory evoked potential is a valuable diagnostic tool to assess prognosis in prolonged coma patients with diffuse axonal injury.

  17. Characterization of cardiovascular reflexes evoked by airway stimulation with allylisothiocyanate, capsaicin, and ATP in Sprague-Dawley rats.

    Science.gov (United States)

    Hooper, J S; Hadley, S H; Morris, K F; Breslin, J W; Dean, J B; Taylor-Clark, T E

    2016-03-15

    Acute inhalation of airborne pollutants alters cardiovascular function and evidence suggests that pollutant-induced activation of airway sensory nerves via the gating of ion channels is critical to these systemic responses. Here, we have investigated the effect of capsaicin [transient receptor potential (TRP) vanilloid 1 (TRPV1) agonist], AITC [TRP ankyrin 1 (TRPA1) agonist], and ATP (P2X2/3 agonist) on bronchopulmonary sensory activity and cardiovascular responses of conscious Sprague-Dawley (SD) rats. Single fiber recordings show that allyl isothiocyanate (AITC) and capsaicin selectively activate C fibers, whereas subpopulations of both A and C fibers are activated by stimulation of P2X2/3 receptors. Inhalation of the agonists by conscious rats caused significant bradycardia, atrioventricular (AV) block, and prolonged PR intervals, although ATP-induced responses were lesser than those evoked by AITC or capsaicin. Responses to AITC were inhibited by the TRP channel blocker ruthenium red and the muscarinic antagonist atropine. AITC inhalation also caused a biphasic blood pressure response: a brief hypertensive phase followed by a hypotensive phase. Atropine accentuated the hypertensive phase, while preventing the hypotension. AITC-evoked bradycardia was not abolished by terazosin, the α1-adrenoceptor inhibitor, which prevented the hypertensive response. Anesthetics had profound effects on AITC-evoked bradycardia and AV block, which was abolished by urethane, ketamine, and isoflurane. Nevertheless, AITC inhalation caused bradycardia and AV block in paralyzed and ventilated rats following precollicular decerebration. In conclusion, we provide evidence that activation of ion channels expressed on nociceptive airway sensory nerves causes significant cardiovascular effects in conscious SD rats via reflex modulation of the autonomic nervous system. PMID:26718787

  18. The inhibitory neurotransmitter GABA evokes long-lasting Ca(2+) oscillations in cortical astrocytes.

    Science.gov (United States)

    Mariotti, Letizia; Losi, Gabriele; Sessolo, Michele; Marcon, Iacopo; Carmignoto, Giorgio

    2016-03-01

    Studies over the last decade provided evidence that in a dynamic interaction with neurons glial cell astrocytes contribut to fundamental phenomena in the brain. Most of the knowledge on this derives, however, from studies monitoring the astrocyte Ca(2+) response to glutamate. Whether astrocytes can similarly respond to other neurotransmitters, including the inhibitory neurotransmitter GABA, is relatively unexplored. By using confocal and two photon laser-scanning microscopy the astrocyte response to GABA in the mouse somatosensory and temporal cortex was studied. In slices from developing (P15-20) and adult (P30-60) mice, it was found that in a subpopulation of astrocytes GABA evoked somatic Ca(2+) oscillations. This response was mediated by GABAB receptors and involved both Gi/o protein and inositol 1,4,5-trisphosphate (IP3 ) signalling pathways. In vivo experiments from young adult mice, revealed that also cortical astrocytes in the living brain exibit GABAB receptor-mediated Ca(2+) elevations. At all astrocytic processes tested, local GABA or Baclofen brief applications induced long-lasting Ca(2+) oscillations, suggesting that all astrocytes have the potential to respond to GABA. Finally, in patch-clamp recordings it was found that Ca(2+) oscillations induced by Baclofen evoked astrocytic glutamate release and slow inward currents (SICs) in pyramidal cells from wild type but not IP3 R2(-/-) mice, in which astrocytic GABAB receptor-mediated Ca(2+) elevations are impaired. These data suggest that cortical astrocytes in the mouse brain can sense the activity of GABAergic interneurons and through their specific recruitment contribut to the distinct role played on the cortical network by the different subsets of GABAergic interneurons. PMID:26496414

  19. Rcpititative magnetic stimulation of gastrocnemius muscle evokes cerebral potentials in Duchcnnc muscular dystrophy

    Institute of Scientific and Technical Information of China (English)

    Cui Liying; Guan Yuzhou; Tang Xiaofu; Li Benhong

    2000-01-01

    OBJECTIVE: To study the function and mechanism of the ccrebral evoked potentials by repititative stimulation of calf muscle in Duchcnne mucular dystrophy (DMD) patients with obvious muscular dystrophy and pseudohyocrtrophy. METHODS: Wc measured cerebral cvoked potcntials by stimulation of calf muscles and SEP by stimulation of posterior tibial nerves at ankle in ten patients with DMD and ten normal controls matched with sex and age. The intensity of the magnetic stimulation was at 30% of maximal output (2.1 Tcsla) and the trcquency was I Hz. The low intensity of magnetic stimulation was just sufficient to produce a contraction of the muscle belly underncath the coil. Recording electrode was placed at 2 cm posterior to the Cz. referencc to Fpz. Thc latencics of N33. P38, N48 and P55 and amplitude (P38-N48) were recorded. SEP was recorded by routine methods. RESULTS: in normal subjects. thc amplitude of magnetic stimulation of calf muscle was 40% lower. and the latency of P38 was 2.9±2.1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients. P38 latency from magnetic stimulation was remarkable prolonged (P<0.01). and in 4 patients. there no any response was found. SElP from electrical stimulation was normal in all patients. CONCLUSTION: DMD is an available model for the study of meclhanism of cerebral evoked potentials by magnetic stimulating muscles. Wc can coneludc that thc responses were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by muscular dystrophy and pscudohypcrtrophy.

  20. Auditory evoked potentials: predicting speech therapy outcomes in children with phonological disorders

    Directory of Open Access Journals (Sweden)

    Renata Aparecida Leite

    2014-03-01

    Full Text Available OBJECTIVES: This study investigated whether neurophysiologic responses (auditory evoked potentials differ between typically developed children and children with phonological disorders and whether these responses are modified in children with phonological disorders after speech therapy. METHODS: The participants included 24 typically developing children (Control Group, mean age: eight years and ten months and 23 children clinically diagnosed with phonological disorders (Study Group, mean age: eight years and eleven months. Additionally, 12 study group children were enrolled in speech therapy (Study Group 1, and 11 were not enrolled in speech therapy (Study Group 2. The subjects were submitted to the following procedures: conventional audiological, auditory brainstem response, auditory middle-latency response, and P300 assessments. All participants presented with normal hearing thresholds. The study group 1 subjects were reassessed after 12 speech therapy sessions, and the study group 2 subjects were reassessed 3 months after the initial assessment. Electrophysiological results were compared between the groups. RESULTS: Latency differences were observed between the groups (the control and study groups regarding the auditory brainstem response and the P300 tests. Additionally, the P300 responses improved in the study group 1 children after speech therapy. CONCLUSION: The findings suggest that children with phonological disorders have impaired auditory brainstem and cortical region pathways that may benefit from speech therapy.

  1. Ocular Vestibular Evoked Myogenic Potentials Using Head Striker Stimulation

    Science.gov (United States)

    De Dios, Y. E.; Gadd, N. E.; Kofman, I. S.; Peters, B. T.; Reschke, M.; Bloomberg, J. J.; Wood, S. J.; Noohibezanjani, F.; Kinnaird, C.; Seidler, R. D.; Mulavara, A. P.

    2016-01-01

    Introduction: Over the last two decades, several studies have been published on the impact of long-duration (i.e., 22 days or longer) spaceflight on the central nervous system (CNS). In consideration of the health and performance of crewmembers in flight and post-flight, we are conducting a controlled prospective longitudinal study to investigate the effects of spaceflight on the extent, longevity and neural bases of sensorimotor, cognitive, and neural changes. Multiple studies have demonstrated the effects of spaceflight on the vestibular system. One of the supporting tests conducted in this protocol is the Vestibular Evoked Myogenic Potential (VEMP) test that provides a unilateral measure of otolith (saccule and utricle) function. A different approach was taken for ocular VEMP (oVEMP) testing using a head striker system (Wackym et al. 2012). The oVEMP is generally considered to be a measure of utricle function. The the otolithic input to the inferior oblique muscle is predominately from the utricular macula. Thus, quantitatively, oVEMP tests utricular function. Another practical extension of these relationships is that the oVEMP reflects the superior vestibular nerve function. Methods: Ground testing was administered on 16 control subjects and for 8 subjects over four repeated sessions spanning 70 days. The oVEMP was elicitied via a hand held striker by a vibrotactile pulse presented at the rate of 1 Hz for 24 seconds on the side of the head as subjects lay supine on a gurney. Subjects were directed to gaze approximately 25 degrees above straight ahead in semi-darkness. For the oVEMP electromyograms will be recorded with active bipolar electrodes (Delsys Inc., Boston, MA) on the infra-orbital ridge 1 cm below the eyelid with a reference electrode on the below the knee cap. The EMG potentials were amplified; band-pass filtered using a BagnoliTM Desktop EMG System (Delsys Inc., Boston, MA, USA). This EMG signal is sampled at 10 kHz and the data stimulus onset to

  2. Conventional protein kinase C isoforms differentially regulate ADP- and thrombin-evoked Ca²⁺ signalling in human platelets.

    Science.gov (United States)

    Lever, Robert A; Hussain, Azhar; Sun, Benjamin B; Sage, Stewart O; Harper, Alan G S

    2015-12-01

    Rises in cytosolic Ca(2+) concentration ([Ca(2+)]cyt) are central in platelet activation, yet many aspects of the underlying mechanisms are poorly understood. Most studies examine how experimental manipulations affect agonist-evoked rises in [Ca(2+)]cyt, but these only monitor the net effect of manipulations on the processes controlling [Ca(2+)]cyt (Ca(2+) buffering, sequestration, release, entry and removal), and cannot resolve the source of the Ca(2+) or the transporters or channels affected. To investigate the effects of protein kinase C (PKC) on platelet Ca(2+) signalling, we here monitor Ca(2+) flux around the platelet by measuring net Ca(2+) fluxes to or from the extracellular space and the intracellular Ca(2+) stores, which act as the major sources and sinks for Ca(2+) influx into and efflux from the cytosol, as well as monitoring the cytosolic Na(+) concentration ([Na(+)]cyt), which influences platelet Ca(2+) fluxes via Na(+)/Ca(2+) exchange. The intracellular store Ca(2+) concentration ([Ca(2+)]st) was monitored using Fluo-5N, the extracellular Ca(2+) concentration ([Ca(2+)]ext) was monitored using Fluo-4 whilst [Ca(2+)]cyt and [Na(+)]cyt were monitored using Fura-2 and SFBI, respectively. PKC inhibition using Ro-31-8220 or bisindolylmaleimide I potentiated ADP- and thrombin-evoked rises in [Ca(2+)]cyt in the absence of extracellular Ca(2+). PKC inhibition potentiated ADP-evoked but reduced thrombin-evoked intracellular Ca(2+) release and Ca(2+) removal into the extracellular medium. SERCA inhibition using thapsigargin and 2,5-di(tert-butyl) l,4-benzohydroquinone abolished the effect of PKC inhibitors on ADP-evoked changes in [Ca(2+)]cyt but only reduced the effect on thrombin-evoked responses. Thrombin evokes substantial rises in [Na(+)]cyt which would be expected to reduce Ca(2+) removal via the Na(+)/Ca(2+) exchanger (NCX). Thrombin-evoked rises in [Na(+)]cyt were potentiated by PKC inhibition, an effect which was not due to altered changes in non

  3. Cortical modulation of short-latency TMS-evoked potentials

    Directory of Open Access Journals (Sweden)

    Domenica eVeniero

    2013-01-01

    Full Text Available Transcranial magnetic stimulation - electroencephalogram (TMS-EEG co-registration offers the opportunity to test reactivity of brain areas across distinct conditions through TMS-evoked potentials (TEPs. Several TEPs have been described, their functional meaning being largely unknown. In particular, short-latency potentials peaking at 5 (P5 and 8 (N8 ms after the TMS pulse have been recently described, but because of their huge amplitude, the problem of whether their origin is cortical or not has been opened. To gain information about these components, we employed a protocol that modulates primary motor cortex excitability (MI through an exclusively cortical phenomena: low frequency stimulation of premotor area (PMC. TMS was applied simultaneously with EEG recording from 70 electrodes. Amplitude of TEPs evoked by 200 single-pulses TMS delivered over MI at 110% of resting motor threshold was measured before and after applying 900 TMS conditioning stimuli to left premotor cortex with 1 Hz repetition rate. Single subject analyses showed reduction in TEPs amplitude after PMC conditioning in a sample of participants and increase in TEPs amplitude in two subjects. No effects were found on corticospinal excitability as recorded by motor evoked potentials (MEPs. Furthermore, correlation analysis showed an inverse relation between the effects of the conditioning protocol on P5-N8 complex amplitude and MEPs amplitude. Because the effects of the used protocol have been ascribed to a cortical interaction between premotor area and MI, we suggest that despite the sign of P5-N8 amplitude modulation is not consistent across participant, this modulation could indicate, at least in part, their cortical origin. We conclude that with an accurate experimental procedure early-latency components can be used to evaluate the reactivity of the stimulated cortex.

  4. Dynamic properties of human visual evoked and omitted stimulus potentials

    OpenAIRE

    Bullock, T.H.; Karamürsel, Sacit; Achimowicz, Jerzy Z.; C., McClune Michael; Canan, Baar-Eroglu

    1994-01-01

    Visual evoked potentials (VEP) and omitted stimulus potentials (OSPs) are reexamined in scalp recordings from 19 healthy subjects. The principal finding is a distinction in form, latency and properties between OSPs in the conditioning stimulus range 5 Hz, used in previous studies of selected elasmobranchs, teleost fish and reptiles. We cannot find OSPs between 2 and 5 Hz. The high frequency ("fast,"ca. 6 to >40 Hz) and the low frequency ("slow," ca. 0.3-1.6 Hz) OSPs have different forms and l...

  5. Visual evoked potentials to colour change of a moving bar

    OpenAIRE

    Carolina eMurd; Kairi eKreegipuu; Nele eKuldkepp; Aire eRaidvee; Maria eTamm; Jüri eAllik

    2014-01-01

    In our previous study we found that it takes less time to detect colour change in a moving object compared to colour change in a stationary one (Kreegipuu et al., 2006, Vision Research 46(11), 1848-1855). Here, we replicated the experiment, but in addition to reaction times we measured visual evoked potentials, to see whether this effect of motion is revealed at the cortical level of information processing. We asked our subjects to detect colour changes in stationary (0º/s) and moving bars (4...

  6. Clinical application of vestibular evoked myogenic potential (VEMP).

    Science.gov (United States)

    Murofushi, Toshihisa

    2016-08-01

    The author reviewed clinical aspects of vestibular evoked myogenic potentials (VEMPs). Now two types of VEMPs are available. The first one is cervical VEMP, which is recorded in the sternocleidomastoid muscle and predominantly reflects sacculo-collic reflex. The other is ocular VEMP, which is usually recorded below the lower eye lid and predominantly reflects utriculo-ocular reflex. VEMPs play important roles not only for assessment of common vestibular diseases but also for establishment of new clinical entities. Clinical application in Meniere's disease, vestibular neuritis, benign paroxysmal positional vertigo, vestibular migraine, idiopathic otolithic vertigo, and central vertigo/dizziness was reviewed. PMID:26791591

  7. Somatosensory evoked potentials assess the efficacy of circumcision for premature ejaculation.

    Science.gov (United States)

    Xia, J-D; Jiang, H-S; Zhu, L-L; Zhang, Z; Chen, H; Dai, Y-T

    2016-07-01

    To assess the efficacy and mechanism of circumcision in the treatment of premature ejaculation (PE) with redundant prepuce, we enrolled a total of 81 PE patients who received circumcision. The patients' ejaculatory ability and sexual performances were evaluated before and after circumcision by using questionnaires (Intravaginal ejaculation latency time (IELT), Chinese Index of PE with 5 questions (CIPE-5) and International Index of Erectile function- 5 (IIEF-5)). Furthermore, somatosensory evoked potentials (SEPs) including dorsal nerve (DNSEP) and glans penis (GPSEP) of the patients were also measured. The mean IELTs of preoperation and post operation were 1.10±0.55 and 2.48±2.03 min, respectively (Pejaculation time improvement after circumcision is so small, and equal to placebo response, therefore it could not be interpreted as a therapeutic method in men with PE. PMID:27193064

  8. Addition of visual noise boosts evoked potential-based brain-computer interface.

    Science.gov (United States)

    Xie, Jun; Xu, Guanghua; Wang, Jing; Zhang, Sicong; Zhang, Feng; Li, Yeping; Han, Chengcheng; Li, Lili

    2014-01-01

    Although noise has a proven beneficial role in brain functions, there have not been any attempts on the dedication of stochastic resonance effect in neural engineering applications, especially in researches of brain-computer interfaces (BCIs). In our study, a steady-state motion visual evoked potential (SSMVEP)-based BCI with periodic visual stimulation plus moderate spatiotemporal noise can achieve better offline and online performance due to enhancement of periodic components in brain responses, which was accompanied by suppression of high harmonics. Offline results behaved with a bell-shaped resonance-like functionality and 7-36% online performance improvements can be achieved when identical visual noise was adopted for different stimulation frequencies. Using neural encoding modeling, these phenomena can be explained as noise-induced input-output synchronization in human sensory systems which commonly possess a low-pass property. Our work demonstrated that noise could boost BCIs in addressing human needs. PMID:24828128

  9. Effects of carnosine on the evoked potentials in hippocampal CA1 region

    Institute of Scientific and Technical Information of China (English)

    Zhou-yan FENG; Xiao-jing ZHENG; Jing WANG

    2009-01-01

    Objective: To directly examine the effects of carnosine on neuronal excitation and inhibition in rat hippocampus in vivo. Methods: Artificial cerebrospinal fluid with carnosine was directly administrated over the exposed rat hippocampus. The changes of neuron activity in the CA1 region of hippocampus were evaluated by orthodromically- and antidromically-evoked potentials, as well as paired-pulse stimulation paradigm. Results: In both orthodromic and antidromic response potentials, carnosine transformed population spikes (PSs) with single spike into epileptiform multiple spikes. In addition, similar to the effect of γ-aminobutyric acidA (GABAA) antagonist picrotoxin, carnosine decreased paired-pulse stimulating depression significantly.However, no significant change was observed in the spontaneous field potentials during the application of carnosine. Conclusion:The results indicate a disinhibition-induced excitation effect of carnosine on the CA1 pyramidal neurons. It provides important information against the application of carnosine as a potential anticonvulsant in clinical treatment.

  10. Effects of background noise on transiently evoked otoacoustic emissions in newborn hearing screening

    Directory of Open Access Journals (Sweden)

    Chandrakant Vishwakarma

    2015-01-01

    Full Text Available Introduction: Newborn hearing screening program is one of the services offered in Neonatal Intensive Care Units (NICU by most of the neonatologist today. Aim of the Study: Present study aimed to investigate the ambient noise levels which allow successful transient evoked otoacoustic emission testing. Method: 25 normal hearing neonates (group 1 and 25 normal hearing adults (group 2 participated in the study. Both groups were tested at 30 dB sound pressure level (SPL, 40 dB SPL and 50 dB SPL noise levels. Results and Discussion: Tests results showed with increase in noise levels number of passing subjects decreased and also testing was done at times more than once. Conclusion: Tester should take care of noise levels while doing the test in NICU, which can give false negative responses.

  11. Nonlocal two dimensional denoising of frequency specific chirp evoked ABR single trials.

    Science.gov (United States)

    Schubert, J Kristof; Teuber, Tanja; Steidl, Gabriele; Strauss, Daniel J; Corona-Strauss, Farah I

    2012-01-01

    Recently, we have shown that denoising evoked potential (EP) images is possible using two dimensional diffusion filtering methods. This restoration allows for an integration of regularities over multiple stimulations into the denoising process. In the present work we propose the nonlocal means (NLM) method for EP image denoising. The EP images were constructed using auditory brainstem responses (ABR) collected in young healthy subjects using frequency specific and broadband chirp stimulations. It is concluded that the NLM method is more efficient than conventional approaches in EP imaging denoising, specially in the case of ABRs, where the relevant information can be easily masked by the ongoing EEG activity, i.e., signals suffer from rather low signal-to-noise ratio SNR. The proposed approach is for the a posteriori denoising of single trials after the experiment and not for real time applications. PMID:23366439

  12. Laser-evoked potentials as a tool for assessing the efficacy of antinociceptive drugs

    Science.gov (United States)

    Truini, A.; Panuccio, G.; Galeotti, F.; Maluccio, M.R.; Sartucci, F.; Avoli, M.; Cruccu, G.

    2016-01-01

    Laser-evoked potentials (LEPs) are brain responses to laser radiant heat pulses and reflect the activation of Aδ nociceptors. LEPs are to date the reference standard technique for studying nociceptive pathway function in patients with neuropathic pain. To find out whether LEPs also provide a useful neurophysiological tool for assessing antinociceptive drug efficacy, in this double-blind placebo-controlled study we measured changes induced by the analgesic tramadol on LEPs in 12 healthy subjects. We found that tramadol decreased the amplitude of LEPs, whereas placebo left LEPs unchanged. The opioid antagonist naloxone partially reversed the tramadol-induced LEP amplitude decrease. We conclude that LEPs may be reliably used in clinical practice and research for assessing the efficacy of antinociceptive drugs. PMID:19477145

  13. Exchange transfusion with fluorocarbon for studying synaptically evoked optical signal in rat cortex.

    Science.gov (United States)

    Nomura, Y; Fujii, F; Sato, C; Nemoto, M; Tamura, M

    2000-02-01

    . Zieglgansberger, The intrinsic optical signal evoked by chiasm stimulation in the rat suprachiasmatic nuclei exhibits GABAergic day-night variation, Eur. J. Neurosci. 8 (1996) 319-328] [3] [9] [13] [24]. A spectral fitting method with three components is used for the analysis of intrinsic optical signal [M. Nemoto, Y. Nomura, C. Sato, M. Tamura, K. Houkin, I. Koyanagi, H. Abe, Analysis of optical signals evoked by peripheral nerve stimulation in rat somatosensory cortex: dynamic changes in hemoglobin concentration and oxygenation, J. Cereb. Blood Flow Metab. 19 (1999) 246-259] [17]. In order to validate the analysis, we need the knowledge on contribution of signal resulted from hemoglobin to total intrinsic optical signal. The exchange transfusion with fluorocarbon has the advantage that can change the spectral contribution of hemoglobin [M. Ferrari, M.A. Williams, D.A. Wilson, N.V. Thakor, R.J. Traystman, D.F. Hanley, Cat brain cytochrome-c oxidase redox changes induced by hypoxia after blood-fluorocarbon exchange transfusion, Am. J. Physiol. 269 (1995) H417-H424; A.L. Sylvia, C.A. Piantadosi, O(2) dependence of in vivo brain cytochrome redox responses and energy metabolism in bloodless rats, J. Cereb. Blood Flow Metab. 8 (1988) 163-172] [6] [23]. Here we describe a new method of the reduction of hemoglobin signal from somatosensory evoked optical intrinsic signal in rat cortex by the combination of exchange transfusion with fluorocarbon and imaging system of thinned skull cranial window. The method allows for the study of the synaptically evoked changes in light scattering as well as fluorescence of calcium indicator or voltage-sensitive dye without absorption of hemoglobin. PMID:10719260

  14. BDNF up-regulates evoked GABAergic transmission in developing hippocampus by potentiating presynaptic N- and P/Q-type Ca2+ channels signalling.

    Science.gov (United States)

    Baldelli, P; Novara, M; Carabelli, V; Hernández-Guijo, J M; Carbone, E

    2002-12-01

    Chronic application of brain-derived neurotrophic factor (BDNF) induces new selective synthesis of non-L-type Ca2+ channels (N, P/Q, R) at the soma of cultured hippocampal neurons. As N- and P/Q-channels support neurotransmitter release in the hippocampus, this suggests that BDNF-treatment may enhance synaptic transmission by increasing the expression of presynaptic Ca2+ channels as well. To address this issue we studied the long-term effects of BDNF on miniature and stimulus-evoked GABAergic transmission in rat embryo hippocampal neurons. We found that BDNF increased the frequency of miniature currents (mIPSCs) by approximately 40%, with little effects on their amplitude. BDNF nearly doubled the size of evoked postsynaptic currents (eIPSCs) with a marked increase of paired-pulse depression, which is indicative of a major increase in presynaptic activity. The potentiation of eIPSCs was more relevant during the first two weeks in culture, when GABAergic transmission is depolarizing. BDNF action was mediated by TrkB-receptors and had no effects on: (i) the amplitude and dose-response of GABA-evoked IPSCs and (ii) the number of GABA(A) receptor clusters and the total functioning synapses, suggesting that the neurotrophin unlikely acted postsynaptically. In line with this, BDNF affected the contribution of voltage-gated Ca2+ channels mediating evoked GABAergic transmission. BDNF drastically increased the fraction of evoked IPSCs supported by N- and P/Q-channels while it decreased the contribution associated with R- and L-types. This selective action resembles the previously observed up-regulatory effects of BDNF on somatic Ca2+ currents in developing hippocampus, suggesting that potentiation of presynaptic N- and P/Q-channel signalling belongs to a manifold mechanism by which BDNF increases the efficiency of stimulus-evoked GABAergic transmission. PMID:12492424

  15. High-frequency combination coding-based steady-state visual evoked potential for brain computer interface

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Feng; Zhang, Xin; Xie, Jun; Li, Yeping; Han, Chengcheng; Lili, Li; Wang, Jing [School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Xu, Guang-Hua [School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710054 (China)

    2015-03-10

    This study presents a new steady-state visual evoked potential (SSVEP) paradigm for brain computer interface (BCI) systems. The goal of this study is to increase the number of targets using fewer stimulation high frequencies, with diminishing subject’s fatigue and reducing the risk of photosensitive epileptic seizures. The new paradigm is High-Frequency Combination Coding-Based High-Frequency Steady-State Visual Evoked Potential (HFCC-SSVEP).Firstly, we studied SSVEP high frequency(beyond 25 Hz)response of SSVEP, whose paradigm is presented on the LED. The SNR (Signal to Noise Ratio) of high frequency(beyond 40 Hz) response is very low, which is been unable to be distinguished through the traditional analysis method; Secondly we investigated the HFCC-SSVEP response (beyond 25 Hz) for 3 frequencies (25Hz, 33.33Hz, and 40Hz), HFCC-SSVEP produces n{sup n} with n high stimulation frequencies through Frequence Combination Code. Further, Animproved Hilbert-huang transform (IHHT)-based variable frequency EEG feature extraction method and a local spectrum extreme target identification algorithmare adopted to extract time-frequency feature of the proposed HFCC-SSVEP response.Linear predictions and fixed sifting (iterating) 10 time is used to overcome the shortage of end effect and stopping criterion,generalized zero-crossing (GZC) is used to compute the instantaneous frequency of the proposed SSVEP respondent signals, the improved HHT-based feature extraction method for the proposed SSVEP paradigm in this study increases recognition efficiency, so as to improve ITR and to increase the stability of the BCI system. what is more, SSVEPs evoked by high-frequency stimuli (beyond 25Hz) minimally diminish subject’s fatigue and prevent safety hazards linked to photo-induced epileptic seizures, So as to ensure the system efficiency and undamaging.This study tests three subjects in order to verify the feasibility of the proposed method.

  16. High-frequency combination coding-based steady-state visual evoked potential for brain computer interface

    International Nuclear Information System (INIS)

    This study presents a new steady-state visual evoked potential (SSVEP) paradigm for brain computer interface (BCI) systems. The goal of this study is to increase the number of targets using fewer stimulation high frequencies, with diminishing subject’s fatigue and reducing the risk of photosensitive epileptic seizures. The new paradigm is High-Frequency Combination Coding-Based High-Frequency Steady-State Visual Evoked Potential (HFCC-SSVEP).Firstly, we studied SSVEP high frequency(beyond 25 Hz)response of SSVEP, whose paradigm is presented on the LED. The SNR (Signal to Noise Ratio) of high frequency(beyond 40 Hz) response is very low, which is been unable to be distinguished through the traditional analysis method; Secondly we investigated the HFCC-SSVEP response (beyond 25 Hz) for 3 frequencies (25Hz, 33.33Hz, and 40Hz), HFCC-SSVEP produces nn with n high stimulation frequencies through Frequence Combination Code. Further, Animproved Hilbert-huang transform (IHHT)-based variable frequency EEG feature extraction method and a local spectrum extreme target identification algorithmare adopted to extract time-frequency feature of the proposed HFCC-SSVEP response.Linear predictions and fixed sifting (iterating) 10 time is used to overcome the shortage of end effect and stopping criterion,generalized zero-crossing (GZC) is used to compute the instantaneous frequency of the proposed SSVEP respondent signals, the improved HHT-based feature extraction method for the proposed SSVEP paradigm in this study increases recognition efficiency, so as to improve ITR and to increase the stability of the BCI system. what is more, SSVEPs evoked by high-frequency stimuli (beyond 25Hz) minimally diminish subject’s fatigue and prevent safety hazards linked to photo-induced epileptic seizures, So as to ensure the system efficiency and undamaging.This study tests three subjects in order to verify the feasibility of the proposed method

  17. BRAIN DYSFUNCTION OF PATIENTS WITH QIGONG INDUCED MENTAL DISORDER REVEALED BY EVOKED POTENTIALS RECORDING

    Institute of Scientific and Technical Information of China (English)

    LU Yingzhi; ZONG Wenbin; CHEN Xingshi

    2003-01-01

    Objective: In order to investigate the brain function of patients with Qigong induced mental disorder (QIMD), this study was carried out. Methods: Four kinds of evoked potentials, including contingent negative variation (CNV), auditory evoked potentials (AEP), visual evoked potentials (VEP), and somatosensory evoked potentials (SEP), were recorded from 12 patients with Qigong induced mental disorder.Comparison of their evoked potentials with the data from some normal controls was made. Results: The results revealed that there were 3 kinds of abnormal changes in evoked potentials of patients with QIMD that is latency prolongation, amplitude increase and amplitude decrease, as compared with normal controls. Conclusion: Brain dysfunction of patients with QIMD was confirmed. Its biological mechanism needs further studying.

  18. Recording Visual Evoked Potentials and Auditory Evoked P300 at 9.4T Static Magnetic Field

    OpenAIRE

    Arrubla, Jorge; Neuner, Irene; Hahn, David; Boers, Frank; Shah, N J

    2013-01-01

    Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has shown a number of advantages that make this multimodal technique superior to fMRI alone. The feasibility of recording EEG at ultra-high static magnetic field up to 9.4T was recently demonstrated and promises to be implemented soon in fMRI studies at ultra high magnetic fields. Recording visual evoked potentials are expected to be amongst the most simple for simultaneous EEG/fMRI at ultr...

  19. Optimal stimulus scheduling for active estimation of evoked brain networks

    Science.gov (United States)

    Kafashan, MohammadMehdi; Ching, ShiNung

    2015-12-01

    Objective. We consider the problem of optimal probing to learn connections in an evoked dynamic network. Such a network, in which each edge measures an input-output relationship between sites in sensor/actuator-space, is relevant to emerging applications in neural mapping and neural connectivity estimation. Approach. We show that the problem of scheduling nodes to a probe (i.e., stimulate) amounts to a problem of optimal sensor scheduling. Main results. By formulating the evoked network in state-space, we show that the solution to the greedy probing strategy has a convenient form and, under certain conditions, is optimal over a finite horizon. We adopt an expectation maximization technique to update the state-space parameters in an online fashion and demonstrate the efficacy of the overall approach in a series of detailed numerical examples. Significance. The proposed method provides a principled means to actively probe time-varying connections in neuronal networks. The overall method can be implemented in real time and is particularly well-suited to applications in stimulation-based cortical mapping in which the underlying network dynamics are changing over time.

  20. Perceived causality influences brain activity evoked by biological motion.

    Science.gov (United States)

    Morris, James P; Pelphrey, Kevin A; McCarthy, Gregory

    2008-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated brain activity in an observer who watched the hand and arm motions of an individual when that individual was, or was not, the cause of the motion. Subjects viewed a realistic animated 3D character who sat at a table containing four pistons. On Intended Motion trials, the character raised his hand and arm upwards. On Unintended Motion trials, the piston under one of the character's hands pushed the hand and arm upward with the same motion. Finally, during Non-Biological Motion control trials, a piston pushed a coffee mug upward in the same smooth motion. Hand and arm motions, regardless of intention, evoked significantly more activity than control trials in a bilateral region that extended ventrally from the posterior superior temporal sulcus (pSTS) region and which was more spatially extensive in the right hemisphere. The left pSTS near the temporal-parietal junction, robustly differentiated between the Intended Motion and Unintended Motion conditions. Here, strong activity was observed for Intended Motion trials, while Unintended Motion trials evoked similar activity as the coffee mug trials. Our results demonstrate a strong hemispheric bias in the role of the pSTS in the perception of causality of biological motion. PMID:18633843

  1. Similar itch and nociceptive sensations evoked by punctate cutaneous application of capsaicin, histamine and cowhage

    OpenAIRE

    Sikand, Parul; Shimada, Steven G.; Green, Barry G.; LaMotte, Robert H.

    2009-01-01

    Itch evoked by cowhage or histamine is reduced or blocked by capsaicin desensitization, suggesting that pruriceptive neurons are capsaicin-sensitive. Topical capsaicin can evoke both nociceptive sensations and itch, whereas intradermal injection of capsaicin evokes only burning pain. To dissociate the pruritic and nociceptive sensory effects caused by the chemical activation of sensory neurons, chemicals were applied in a punctiform manner to the skin of the forearm using individual, heat-ina...

  2. Image color transfer to evoke different emotions based on color combinations

    OpenAIRE

    He, Li; Qi, Hairong; Zaretzki, Russell

    2013-01-01

    In this paper, a color transfer framework to evoke different emotions for images based on color combinations is proposed. The purpose of this color transfer is to change the "look and feel" of images, i.e., evoking different emotions. Colors are confirmed as the most attractive factor in images. In addition, various studies in both art and science areas have concluded that other than single color, color combinations are necessary to evoke specific emotions. Therefore, we propose a novel frame...

  3. Spatio-temporal characteristics of cerebral blood volume changes in different microvascular compartments evoked by sciatic nerve stimulation in rat somatosensory cortex

    Science.gov (United States)

    Li, Pengcheng; Luo, Qingming; Luo, Weihua; Chen, Shangbin; Chen, Haiying; Zeng, Shaoqun

    2003-10-01

    The spatio-temporal characteristics of changes in cerebral blood volume associated with neuronal activity were investigated in the hindlimb somatosensory cortex of α-chloralose/urethan anesthetized rats (n=10) with optical imaging at 570nm through a thinned skull. Activation of cortex was carried out by electrical stimulation of the contralateral sciatic nerve with 5Hz, 0.3V pulses (0.5ms) for duration of 2s. The stimulation evoked a monophasic optical reflectance decrease at cortical parenchyma and arteries sites rapidly after the onset of stimulation, whereas no similar response was observed at vein compartments. The optical signal changes reached 10% of the peak response 0.70+/-0.32s after stimulation onset and no significant time lag in this 10% start latency time was observed between the response at cortical parenchyma and arteries compartments. The evoked optical reflectance decrease reached the peak (0.25%+/-0.047%)2.66+/-0.61s after the stimulus onset at parenchyma site, 0.40+/-0.20s earlier (P<0.05) than that at arteries site (0.50%+/-0.068% 3.06+/-0.70s). Variable location within the cortical parenchyma and arteries compartment themselves didn"t affect the temporal characteristics of the evoked signal significantly. These results suggest that the sciatic nerve stimulation evokes a local blood volume increase at both capillaries (cortical parenchyma) and arterioles rapidly after the stimulus onset but the evoked blood volume increase in capillaries could not be entirely accounted for by the dilation of arterioles.

  4. Skill-specific changes in somatosensory-evoked potentials and reaction times in baseball players.

    Science.gov (United States)

    Yamashiro, Koya; Sato, Daisuke; Onishi, Hideaki; Yoshida, Takuya; Horiuchi, Yoko; Nakazawa, Sho; Maruyama, Atsuo

    2013-03-01

    Athletic training is known to induce neuroplastic alterations in specific somatosensory circuits, which are reflected by changes in short-latency somatosensory-evoked potentials (SEPs). The aim of this study is to clarify whether specific training in athletes affects the long-latency SEPs related to information processing of stimulation. The long-latency SEPs P100 and N140 were recorded at midline cortical electrode positions (Fz, Cz, and Pz) in response to stimulation of the index finger of the dominant hand in fifteen baseball players (baseball group) and in fifteen athletes in sports such as swimming, track and field events, and soccer (sports group) that do not require fine somatosensory discrimination or motor control of the hand. The long-latency SEPs were measured under a passive condition (no response required) and a reaction time (RT) condition in which subjects were instructed to rapidly push a button in response to stimulus presentation. The peak P100 and peak N140 latencies and RT were significantly shorter in the baseball group than the sports group. Moreover, there were significant positive correlations between RT and both the peak P100 and the peak N140 latencies. Specific athletic training regimens that involve the hand may induce neuroplastic alterations in the cortical hand representation areas playing a vital role in rapid sensory processing and initiation of motor responses. PMID:23224701

  5. Human cortical activity evoked by the assignment of authenticity when viewing works of art

    Directory of Open Access Journals (Sweden)

    Mengfei eHuang

    2011-11-01

    Full Text Available The expertise of others is a major social influence on our everyday decisions and actions. Many viewers of art, whether expert or naïve, are convinced that the full aesthetic appreciation of an artwork depends upon the assurance that the work is genuine rather than fake. Rembrandt portraits provide an interesting image set for testing this idea, as there is a large number of them and recent scholarship has determined that quite a few fakes and copies exist. Use of this image set allowed us to separate the brain's response to images of genuine and fake pictures from the brain's response to external advice about the authenticity of the paintings. Using functional magnetic resonance imaging, viewing of artworks assigned as ‘copy’, rather than ‘authentic’, evoked stronger responses in frontopolar cortex (FPC and right precuneus, regardless of whether the portrait was actually genuine. Advice about authenticity had no direct effect on the cortical visual areas responsive to the paintings, but there was a significant psychophysiological interaction between the FPC and the lateral occipital area, which suggests that these visual areas may be modulated by FPC. We propose that the activation of brain networks rather than a single cortical area in this paradigm supports the art-scholars’ view that aesthetic judgments are multi-faceted and multi-dimensional in nature.

  6. Electroencephalogram and evoked potential parameters examined in Chinese mild head injury patients for forensic medicine

    Institute of Scientific and Technical Information of China (English)

    Xi-Ping CHEN; Lu-Yang TAO; Andrew CN CHEN

    2006-01-01

    Objective To evaluate the usefulness of quantitative electroencephalogram (QEEG), flash visual evoked potential (F-VEP) and auditory brainstem responses (ABR) as indicators of general neurological status. Methods Comparison was conducted on healthy controls (N=30) and patients with brain concussion (N=60) within 24 h after traumatic brain injury. Follow-up study of patient group was completed with the same standard paradigm 3 months later. All participants were recorded in multi-modality related potential testing in both early and late concussion at the same clinical setting. Glasgow coma scale, CT scanning, and physical examinations of neuro-psychological function, optic and auditory nervous system were performed before electroencephalogram (EEG) and evoked potential (EEG-EP) testing. Any participants showed abnormal changes of clinical examinations were excluded from the study. Average power of frequency spectrum and power ratios were selected for QEEG testing, and latency and amplitude of F-VEP and ABR were recorded.Results Between patients and normal controls, the results indicated: (1) Highly significance (P < 0.01) in average power of α1 and power ratios of θ/α1, θ/α2, α1/α2 of EEG recording; (2) N70-P100 amplitude of F-VEP in significant difference at early brain concussion; and (3) apparent prolongation of Ⅰ~Ⅲ inter-peak latency of ABR appeared in some individuals at early stage after concussion. The follow-up study showed that some patients with concussion were also afflicted with characteristic changes of EEG components for both increments of α1 average power and θ/α2 power ratio after 3 months recording. Conclusion EEG testing has been shown to be more effective and sensitive than evoked potential tests alone on detecting functional state of patients with mild traumatic brain injury (MTBI). Increments of α1 average power and θ/α2 power ratio are the sensitive EEG parameters to determining early concussion and evaluating outcome of

  7. Population synaptic potentials evoked in lumbar motoneurons following stimulation of the nucleus reticularis gigantocellularis during carbachol-induced atonia.

    Science.gov (United States)

    Yamuy, J; Jiménez, I; Morales, F; Rudomin, P; Chase, M

    1994-03-14

    The effect of electrical stimulation of the medullary nucleus reticularis gigantocellularis (NRGc) on lumbar spinal cord motoneurons was studied in the decerebrate cat using sucrose-gap recordings from ventral roots. The NRGc was stimulated ipsi- and contralaterally before and during atonia elicited by the microinjection of carbachol into the pontine reticular formation. Prior to carbachol administration, the NRGc-induced response recorded from the sucrose-gap consisted of two consecutive excitatory population synaptic potentials followed by a long-lasting, small amplitude inhibitory population synaptic potential. Following carbachol injection, the same NRGc stimulus evoked a distinct, large amplitude inhibitory population synaptic potential, whereas the excitatory population synaptic potentials decreased in amplitude. In addition, after carbachol administration, the amplitude of the monosynaptic excitatory population synaptic potential, which was evoked by stimulation of group Ia afferents in hindlimb nerves, was reduced by 18 to 43%. When evoked at the peak of the NRGc-induced inhibitory response, this potential was further decreased in amplitude. Systemic strychnine administration (0.07-0.1 mg/kg, i.v.) blocked the NRGc-induced inhibitory population synaptic potential and promoted an increase in the amplitude of the excitatory population synaptic potentials induced by stimulation of the NRGc and group Ia afferents. These data indicate that during the state of carbachol-induced atonia, the NRGc effects on ipsi- and contralateral spinal cord motoneurons are predominantly inhibitory and that glycine is likely to be involved in this inhibitory process. These results support the hypothesis that the nucleus reticularis gigantocellularis is part of the system responsible for state-dependent somatomotor inhibition that occurs during active sleep. PMID:8205484

  8. Single Trial Predictors for Gating Motor-Imagery Brain-Computer Interfaces Based on Sensorimotor Rhythm and Visual Evoked Potentials

    Science.gov (United States)

    Geronimo, Andrew; Kamrunnahar, Mst; Schiff, Steven J.

    2016-01-01

    For brain-computer interfaces (BCIs) that utilize visual cues to direct the user, the neural signals extracted by the computer are representative of ongoing processes, visual evoked responses, and voluntary modulation. We proposed to use three brain signatures for predicting success on a single trial of a BCI task. The first two features, the amplitude and phase of the pre-trial mu amplitude, were chosen as a correlate for cortical excitability. The remaining feature, related to the visually evoked response to the cue, served as a possible measure of fixation and attention to the task. Of these three features, mu rhythm amplitude over the central electrodes at the time of cue presentation and to a lesser extent the single trial visual evoked response were correlated with the success on the subsequent imagery task. Despite the potential for gating trials using these features, an offline gating simulation was limited in its ability to produce an increase in device throughput. This discrepancy highlights a distinction between the identification of predictive features, and the use of this knowledge in an online BCI. Using such a system, we cannot assume that the user will respond similarly when faced with a scenario where feedback is altered by trials that are gated on a regular basis. The results of this study suggest the possibility of using individualized, pre-task neural signatures for personalized, and asynchronous (self-paced) BCI applications, although these effects need to be quantified in a real-time adaptive scenario in a future study. PMID:27199630

  9. SOMATOSENSORY EVOKED POTENTIALS IN DIABETES MELLITUS TYPE - 2

    Directory of Open Access Journals (Sweden)

    Rekha

    2015-10-01

    Full Text Available Diabetes mellitus is the most common metabolic disorder affecting majority of population. It is estimated that over 400 million people throughout the world have diabetes. It has progressed to be a pandemic from an epidemic causing morbidity and mortality in the population. Among the many complications of diabetes, diabetic neuropathies contribute majorly to the morbidity associated with the disease. Axonal conduction is affected by elevated levels of protein kinase c causing neuronal ischemia; decreased ce llular myoinositol affecting sodium potassium ATPase pump leads to decreased nerve conduction; Somatosensory E voked P otentials (SSEPs reflect the activity of somatosensory pathways mediated through the dorsal columns of the spinal cord and the specific so matosensory cortex. Recording of Somatosensory Evoked Potentials in diabetics is done to assess the sensory involvement of spinal cord. Presence of SEPs provides clear evidence for axonal continuity and by using different stimulation sites, the rate of reg eneration can be determined. Both onset and peak latencies of all SEP components are prolonged in patients with diabetes. Present study is done to compare somatosensory evoked potentials in diabetics and normal subjects. MATERIALS AND METHOD S: The present study was undertaken at the Upgraded Department of Physiology, Osmania Medical College, Koti, Hyderabad. The study was conducted on subjects, both male and female in the age group of 45 to 55 years, suffering from type II diabetes excluding other neurologi cal disorders. Non - invasive method of estimation of nerve conduction studies using SFEMG/EP — Electromyography or evoked potential system (Nicolet systems — USA using surface electrodes with automated computerized monitor attached with printer is used. RESUL TS : ANOVA showed statistically significant N9 latency (right & left sides. Latencies of all the components of SSEPs were more significant than amplitudes in Diabetic

  10. Success rate of motor evoked potentials for intraoperative neurophysiologic monitoring: effects of age, lesion location, and preoperative neurologic deficits.

    Science.gov (United States)

    Chen, Xi; Sterio, Djordje; Ming, Xu; Para, Devaki D; Butusova, Marri; Tong, Teresa; Beric, Aleksandar

    2007-06-01

    Transcranial electrical stimulation with myogenic motor evoked potential (MEP) recording was used for intraoperative neurophysiologic monitoring in 341 consecutive "high-risk" neurosurgical or orthopedic procedures. Overall, the success rate for establishing reliable MEP response was 94.8% for upper extremities and 66.6% for lower extremities. The rate was only 39.1% for lower extremities in patients with preoperative motor deficit and up to 81% in neurologically intact adults. Further analysis demonstrated that extremes of age or the presence of a lesion in the spinal cord and motor deficit contributed to failure in obtaining reliable MEPs. PMID:17545833

  11. The effects of cyclic dicarboxylic acids on spontaneous and amino acid-evoked activity of rat cortical neurones.

    OpenAIRE

    Birley, S.; Collins, J F; Perkins, M. N.; Stone, T. W.

    1982-01-01

    1 A series of cyclic dicarboxylic acids were applied by microiontophoresis to neurones in the cerebral cortex of rats anaesthetized with urethane. The object was to examine effects on spontaneous firing rates and any ability to antagonize responses to excitatory amino acids. 2 At relatively low ejecting currents (10-25 nA) cis-2,3-piperidine dicarboxylic acid (cis-2,3-PDA) had no effect on spontaneous firing but selectively antagonized the excitation evoked by n-methyl-D-aspartate (NMDA) with...

  12. Multimodal evoked potentials in spinocerebellar ataxia types 1, 2, and 3

    Directory of Open Access Journals (Sweden)

    Vijay Chandran

    2014-01-01

    Full Text Available Aims: Spinocerebellar ataxias (SCA are a clinically heterogeneous group of disorders that are characterized by ataxia and an autosomal dominant pattern of inheritance. The aim of our study was to describe the findings of evoked potentials (EPs among genetically proven SCA types 1, 2, and 3 and to additionally evaluate if EPs can be used to differentiate between them. Materials and Methods: Forty-three cases of genetically proven SCA (SCA1 = 19, SCA2 = 13, and SCA3 = 11 were evaluated with median somatosensory-EP (mSSEP, visual-EP (VEP, and brainstem auditory-evoked response (BAER by standard procedures and compared with normative laboratory data. An EP was considered abnormal if latency was prolonged (>mean + 3 standard deviation (SD of laboratory control data or the waveform was absent or poorly defined. The waves studied were as follows: mSSEP - N20, VEP - P100 and BAER - interpeak latency 1-3 and 3-5. Results: EPs were abnormal in at least one modality in 90.9% of patients. The most common abnormality was of BAER (86.1% followed by VEP (34.9% and mSSEP (30.2%. The degree of abnormality in VEP, mSSEP, and BAER among patients with SCA1 was 42.1, 41.2, and 73.3%, respectively; among patients with SCA2 was 38.5, 27.3, and 100%, respectively; and among patients with SCA3 was 18.2, 37.5, and 88.9%, respectively. The differences between the subgroups of SCAs were not statistically significant. Conclusions: BAER was the most frequent abnormality in SCA types 1, 2, and 3; abnormalities of mSSEP were comparable in the three SCAs; whereas, abnormality of VEP was less often noted in SCA3.

  13. Using evoked potentials to match interaural electrode pairs with bilateral cochlear implants.

    Science.gov (United States)

    Smith, Zachary M; Delgutte, Bertrand

    2007-03-01

    Bilateral cochlear implantation seeks to restore the advantages of binaural hearing to the profoundly deaf by providing binaural cues normally important for accurate sound localization and speech reception in noise. Psychophysical observations suggest that a key issue for the implementation of a successful binaural prosthesis is the ability to match the cochlear positions of stimulation channels in each ear. We used a cat model of bilateral cochlear implants with eight-electrode arrays implanted in each cochlea to develop and test a noninvasive method based on evoked potentials for matching interaural electrodes. The arrays allowed the cochlear location of stimulation to be independently varied in each ear. The binaural interaction component (BIC) of the electrically evoked auditory brainstem response (EABR) was used as an assay of binaural processing. BIC amplitude peaked for interaural electrode pairs at the same relative cochlear position and dropped with increasing cochlear separation in either direction. To test the hypothesis that BIC amplitude peaks when electrodes from the two sides activate maximally overlapping neural populations, we measured multiunit neural activity along the tonotopic gradient of the inferior colliculus (IC) with 16-channel recording probes and determined the spatial pattern of IC activation for each stimulating electrode. We found that the interaural electrode pairings that produced the best aligned IC activation patterns were also those that yielded maximum BIC amplitude. These results suggest that EABR measurements may provide a method for assigning frequency-channel mappings in bilateral implant recipients, such as pediatric patients, for which psychophysical measures of pitch ranking or binaural fusion are unavailable. PMID:17225976

  14. Electrocorticogram spectral analysis and somatosensory evoked potentials as tools to assess electrical stunning efficiency in ducks.

    Science.gov (United States)

    Beyssen, C; Babile, R; Fernandez, X

    2004-06-01

    1. Fast Fourier transformations (FFTs) of electrocorticogram (ECoG) signals and averaging of somatosensory evoked potentials (SEPs) were used for assessing the impact of electrical stunning of ducks in a waterbath set to deliver a constant current of 150 mA, 600 Hz alternating current (AC) for 4 s. The effectiveness of stunning was determined on the basis of induction of epileptiform activity in the ECoG followed by a decrease in total power content to less than 10% of pre-stun values and abolition of SEPs. 2. One out of 10 birds was killed by the stun. FFT analysis of the ECoG signals of the remaining 9 birds showed that only one bird had a decrease of the total power to less than 10% of the pre-stun values for up to 70 s post-stun. The SEPs were retained in 6 out of 9 ducks and and 4 of them retained the evoked responses throughout the post-stun period. In the two birds showing abolition of SEPs, this was associated with a decrease in the total power content to below 10% of the pre-stun value. 3. The present experiment confirmed that the abolition of SEPs and the decrease of the total power below 10% of the pre-stun value for assessing unconsciousness after an electrical stunning in various species are also applicable to ducks. Based on this, it is concluded that electrical waterbath stunning of ducks using 150 mA of 600 Hz AC is ineffective. PMID:15327129

  15. Vestibular myogenic and acoustical brainstem evoked potentials in neurological practice

    Directory of Open Access Journals (Sweden)

    O. S. Korepina

    2012-01-01

    Full Text Available Along with the inspection of acoustical cortex and brainstem EP in neurologic, otoneurologic and audiologic practice recently start to use so-called vestibular evoked myogenic potentials (VEMP. It is shown, that at ear stimulation by a loud sound and record of sterno-cleidomastoid contraction is possible to estimate function of the inferior vestibular nerve and vestibulospinal pathways, a sacculo-cervical reflex. In article some methodical and clinical questions of application of these kinds are presented. Combine research acoustic brainstem EP and VEMP allows to confirm effectively lesions of acoustical and vestibular ways at brainstem. The conclusion becomes, that this kind of inspection is important for revealing demielinisation and defeats in vestibulospinal tract, that quite often happens at MS, and at estimation of efficiency of treatment

  16. Temporal suppression and augmentation of click-evoked otoacoustic emissions

    DEFF Research Database (Denmark)

    Verhulst, Sarah; Harte, James; Dau, Torsten

    2008-01-01

    This study investigates and models temporal suppression of click-evoked otoacoustic emissions (CEOAEs). This suppression-effect is created when a suppressor-click is presented close in time to a test-click. The analysis was carried out for short time-frames of short- and long-latency CEOAEs. The...... latter is defined as a CEOAE with duration greater than 20 ms, typically observed for test subjects with spontaneous otoacoustic emissions (SOAEs). Previous studies have tended to exclude these test subjects but they are incorporated here. The results from six exemplary subjects demonstrate that temporal...... temporal suppression and augmentation of CEOAEs. Recently, a feedback automatic gain control (AGC) system has been used to model CEOAE suppression. However, this system cannot account for augmentation and therefore another, dynamic nonlinear model was developed. Suppression and augmentation were modeled...

  17. Auditory evoked field measurement using magneto-impedance sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, K., E-mail: o-kabou@echo.nuee.nagoya-u.ac.jp; Tajima, S.; Song, D.; Uchiyama, T. [Graduate School of Engineering, Nagoya University, Nagoya (Japan); Hamada, N.; Cai, C. [Aichi Steel Corporation, Tokai (Japan)

    2015-05-07

    The magnetic field of the human brain is extremely weak, and it is mostly measured and monitored in the magnetoencephalography method using superconducting quantum interference devices. In this study, in order to measure the weak magnetic field of the brain, we constructed a Magneto-Impedance sensor (MI sensor) system that can cancel out the background noise without any magnetic shield. Based on our previous studies of brain wave measurements, we used two MI sensors in this system for monitoring both cerebral hemispheres. In this study, we recorded and compared the auditory evoked field signals of the subject, including the N100 (or N1) and the P300 (or P3) brain waves. The results suggest that the MI sensor can be applied to brain activity measurement.

  18. Auditory evoked field measurement using magneto-impedance sensors

    International Nuclear Information System (INIS)

    The magnetic field of the human brain is extremely weak, and it is mostly measured and monitored in the magnetoencephalography method using superconducting quantum interference devices. In this study, in order to measure the weak magnetic field of the brain, we constructed a Magneto-Impedance sensor (MI sensor) system that can cancel out the background noise without any magnetic shield. Based on our previous studies of brain wave measurements, we used two MI sensors in this system for monitoring both cerebral hemispheres. In this study, we recorded and compared the auditory evoked field signals of the subject, including the N100 (or N1) and the P300 (or P3) brain waves. The results suggest that the MI sensor can be applied to brain activity measurement

  19. Source localization of auditory evoked potentials after cochlear implantation.

    Science.gov (United States)

    Debener, Stefan; Hine, Jemma; Bleeck, Stefan; Eyles, Julie

    2008-01-01

    Little is known about how the auditory cortex adapts to artificial input as provided by a cochlear implant (CI). We report the case of a 71-year-old profoundly deaf man, who has successfully used a unilateral CI for 4 years. Independent component analysis (ICA) of 61-channel EEG recordings could separate CI-related artifacts from auditory-evoked potentials (AEPs), even though it was the perfectly time-locked CI stimulation that caused the AEPs. AEP dipole source localization revealed contralaterally larger amplitudes in the P1-N1 range, similar to normal hearing individuals. In contrast to normal hearing individuals, the man with the CI showed a 20-ms shorter N1 latency ipsilaterally. We conclude that ICA allows the detailed study of AEPs in CI users. PMID:17910729

  20. Premature infants display increased noxious-evoked neuronal activity in the brain compared to healthy age-matched term-born infants.

    Science.gov (United States)

    Slater, Rebeccah; Fabrizi, Lorenzo; Worley, Alan; Meek, Judith; Boyd, Stewart; Fitzgerald, Maria

    2010-08-15

    This study demonstrates that infants who are born prematurely and who have experienced at least 40days of intensive or special care have increased brain neuronal responses to noxious stimuli compared to healthy newborns at the same postmenstrual age. We have measured evoked potentials generated by noxious clinically-essential heel lances in infants born at term (8 infants; born 37-40weeks) and in infants born prematurely (7 infants; born 24-32weeks) who had reached the same postmenstrual age (mean age at time of heel lance 39.2+/-1.2weeks). These noxious-evoked potentials are clearly distinguishable from shorter latency potentials evoked by non-noxious tactile sensory stimulation. While the shorter latency touch potentials are not dependent on the age of the infant at birth, the noxious-evoked potentials are significantly larger in prematurely-born infants. This enhancement is not associated with specific brain lesions but reflects a functional change in pain processing in the brain that is likely to underlie previously reported changes in pain sensitivity in older ex-preterm children. Our ability to quantify and measure experience-dependent changes in infant cortical pain processing will allow us to develop a more rational approach to pain management in neonatal intensive care. PMID:20438855

  1. The Effects of NMDA Antagonists on Neuronal Activity in Cat Spinal Cord Evoked by Acute Inflammation in the Knee Joint.

    Science.gov (United States)

    Schaible, Hans-Georg; Grubb, Blair D.; Neugebauer, Volker; Oppmann, Maria

    1991-01-01

    In alpha-chloralose-anaesthetized, spinalized cats we examined the effects of NMDA antagonists on the discharges of 71 spinal neurons which had afferent input from the knee joint. These neurons were rendered hyperexcitable by acute arthritis in the knee induced by kaolin and carrageenan. They were located in the deep dorsal and ventral horn and some of them had ascending axons. The N-methyl-d-aspartate (NMDA) antagonists ketamine and d-2-amino-5-phosphonovalerate (AP5), were administered ionophoretically, and ketamine was also administered intravenously. In some of the experiments the antagonists were tested against the agonists NMDA and quisqualate. The effects of the NMDA antagonists consisted of a significant reduction in the resting activity of neurons and/or the responses of the same neurons to mechanical stimulation of the inflamed knee. Intravenous ketamine was most effective in suppressing the resting and mechanically evoked activity in 25 of 26 neurons tested. Ionophoretically applied ketamine had a suppressive effect in 11 of 21 neurons, and AP5 decreased activity in 17 of 24 cells. The reduction in the resting and/or the mechanically evoked discharges was achieved with doses of the antagonists which suppressed the responses to NMDA but not those to quisqualate. These results suggest that NMDA receptors are involved in the enhanced responses and basal activity of spinal neurons induced by inflammation in the periphery. PMID:12106256

  2. Light-evoked S-nitrosylation in the retina.

    Science.gov (United States)

    Tooker, Ryan E; Vigh, Jozsef

    2015-10-01

    Nitric oxide (NO) synthesis in the retina is triggered by light stimulation. NO has been shown to modulate visual signal processing at multiple sites in the vertebrate retina, via activation of the most sensitive target of NO signaling, soluble guanylate cyclase. NO can also alter protein structure and function and exert biological effects directly by binding to free thiol groups of cysteine residues in a chemical reaction called S-nitrosylation. However, in the central nervous system, including the retina, this reaction has not been considered to be significant under physiological conditions. Here we provide immunohistochemical evidence for extensive S-nitrosylation that takes place in the goldfish and mouse retinas under physiologically relevant light intensities, in an intensity-dependent manner, with a strikingly similar pattern in both species. Pretreatment with N-ethylmaleimide (NEM), which occludes S-nitrosylation, or with 1-(2-trifluromethylphenyl)imidazole (TRIM), an inhibitor of neuronal NO synthase, eliminated the light-evoked increase in S-nitrosylated protein immunofluorescence (SNI) in the retinas of both species. Similarly, light did not increase SNI, above basal levels, in retinas of transgenic mice lacking neuronal NO synthase. Qualitative analysis of the light-adapted mouse retina with mass spectrometry revealed more than 300 proteins that were S-nitrosylated upon illumination, many of which are known to participate directly in retinal signal processing. Our data strongly suggest that in the retina light-evoked NO production leads to extensive S-nitrosylation and that this process is a significant posttranslational modification affecting a wide range of proteins under physiological conditions. PMID:25823749

  3. Can Treadmill Perturbations Evoke Stretch Reflexes in the Calf Muscles?

    Directory of Open Access Journals (Sweden)

    Lizeth H Sloot

    Full Text Available Disinhibition of reflexes is a problem amongst spastic patients, for it limits a smooth and efficient execution of motor functions during gait. Treadmill belt accelerations may potentially be used to measure reflexes during walking, i.e. by dorsal flexing the ankle and stretching the calf muscles, while decelerations show the modulation of reflexes during a reduction of sensory feedback. The aim of the current study was to examine if belt accelerations and decelerations of different intensities applied during the stance phase of treadmill walking can evoke reflexes in the gastrocnemius, soleus and tibialis anterior in healthy subjects. Muscle electromyography and joint kinematics were measured in 10 subjects. To determine whether stretch reflexes occurred, we assessed modelled musculo-tendon length and stretch velocity, the amount of muscle activity, as well as the incidence of bursts or depressions in muscle activity with their time delays, and co-contraction between agonist and antagonist muscle. Although the effect on the ankle angle was small with 2.8±1.0°, the perturbations caused clear changes in muscle length and stretch velocity relative to unperturbed walking. Stretched muscles showed an increasing incidence of bursts in muscle activity, which occurred after a reasonable electrophysiological time delay (163-191 ms. Their amplitude was related to the muscle stretch velocity and not related to co-contraction of the antagonist muscle. These effects increased with perturbation intensity. Shortened muscles showed opposite effects, with a depression in muscle activity of the calf muscles. The perturbations only slightly affected the spatio-temporal parameters, indicating that normal walking was retained. Thus, our findings showed that treadmill perturbations can evoke reflexes in the calf muscles and tibialis anterior. This comprehensive study could form the basis for clinical implementation of treadmill perturbations to functionally

  4. Comparison of visual evoked potentials and retinal nerve fibre layer thickness in Alzheimer‘s disease

    Directory of Open Access Journals (Sweden)

    SvenCBeutelspacher

    2013-12-01

    We demonstrated that pattern visual evoked potentials did not show any significant correlation despite subtle loss in retinal nerve fibre layer thickness. It remains open whether additional flash visual evoked potentials combined with retinal nerve fibre layer thickness analysis may be useful in diagnosing Alzheimer‘s disease, particularly for mild-to-moderate stages of the disease.

  5. A simple model for the generation of the vestibular evoked myogenic potential (VEMP)

    NARCIS (Netherlands)

    Wit, HP; Kingma, CM

    2006-01-01

    Objective: To describe the mechanism by which the vestibular evoked myogenic potential is generated. Methods: Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long

  6. The effect of changes in perilymphatic K+ on the vestibular evoked potential in the guinea pig

    NARCIS (Netherlands)

    Kingma, C. M.; Wit, H. P.

    2010-01-01

    To investigate the effect on the functioning of the vestibular system of a rupture of Reissner's membrane, artificial endolymph was injected in scala media of ten guinea pigs and vestibular evoked potentials (VsEPs), evoked by vertical acceleration pulses, were measured. Directly after injection of

  7. Cervical vestibular evoked myogenic potentials in children with spastic cerebral palsy and normal children with 7-12 years of age

    Directory of Open Access Journals (Sweden)

    Nazila Akbarfahimi

    2014-10-01

    Full Text Available Background and Aim: Cervical vestibular-evoked myogenic potential (cVEMP is one of the diagnostic tests used in assessing vestibular function. Two aims of this study were to investigate implications of cervical vestibular evoked myogenic potential in children with spastic cerebral palsy (7-12 years, and to compare vestibular function in these children and normal children.Methods: In this cross-sectional study, myogenic potential was recorded in 31 children with spastic cerebral palsy (8 girls, 23 boys,7-12 years of age, with mean age of 8.77 years old and standard deviation of 1.52 years and 31 normal children (13 girls, 18 boys with mean age of 8.77 years and standard deviation of 1.52 years. Cervical vestibular evoked myogenic potential was recorded with 500 Hz tone burst. The recorded parameters included p13 and n23 latency, p13-n23 pick to pick amplitude, and threshold.Results: Myogenic Potential was recorded in 31 normal children. They had bilateral responses. In children with cerebral palsy, 21 children showed bilateral responses, 3 children had only right-sided responses, 8 children had only left-sided responses, and two children did not show any responses. The statistical significant differences were shown between the two groups in n23, p13-n23 pick to pick amplitude, and threshold (p<0.05.Conclusion: These findings showed that cervical vestibular evoked myogenic potential can be used in children with cerebral palsy. There were significant differences in myogenic potential parameters between the two groups. More studies are needed to investigate the causes of these differences.

  8. Delayed P100-Like Latencies in Multiple Sclerosis: A Preliminary Investigation Using Visual Evoked Spread Spectrum Analysis.

    Science.gov (United States)

    Kiiski, Hanni S M; Ní Riada, Sinéad; Lalor, Edmund C; Gonçalves, Nuno R; Nolan, Hugh; Whelan, Robert; Lonergan, Róisín; Kelly, Siobhán; O'Brien, Marie Claire; Kinsella, Katie; Bramham, Jessica; Burke, Teresa; Ó Donnchadha, Seán; Hutchinson, Michael; Tubridy, Niall; Reilly, Richard B

    2016-01-01

    Conduction along the optic nerve is often slowed in multiple sclerosis (MS). This is typically assessed by measuring the latency of the P100 component of the Visual Evoked Potential (VEP) using electroencephalography. The Visual Evoked Spread Spectrum Analysis (VESPA) method, which involves modulating the contrast of a continuous visual stimulus over time, can produce a visually evoked response analogous to the P100 but with a higher signal-to-noise ratio and potentially higher sensitivity to individual differences in comparison to the VEP. The main objective of the study was to conduct a preliminary investigation into the utility of the VESPA method for probing and monitoring visual dysfunction in multiple sclerosis. The latencies and amplitudes of the P100-like VESPA component were compared between healthy controls and multiple sclerosis patients, and multiple sclerosis subgroups. The P100-like VESPA component activations were examined at baseline and over a 3-year period. The study included 43 multiple sclerosis patients (23 relapsing-remitting MS, 20 secondary-progressive MS) and 42 healthy controls who completed the VESPA at baseline. The follow-up sessions were conducted 12 months after baseline with 24 MS patients (15 relapsing-remitting MS, 9 secondary-progressive MS) and 23 controls, and again at 24 months post-baseline with 19 MS patients (13 relapsing-remitting MS, 6 secondary-progressive MS) and 14 controls. The results showed P100-like VESPA latencies to be delayed in multiple sclerosis compared to healthy controls over the 24-month period. Secondary-progressive MS patients had most pronounced delay in P100-like VESPA latency relative to relapsing-remitting MS and controls. There were no longitudinal P100-like VESPA response differences. These findings suggest that the VESPA method is a reproducible electrophysiological method that may have potential utility in the assessment of visual dysfunction in multiple sclerosis. PMID:26726800

  9. Early effects of whole-body supralethal 20 MeV. Electron irradiation on the sensory evoked potentials of monkeys

    International Nuclear Information System (INIS)

    Early Transient Incapacitation (ETI) is inability to perform a task shortly after lethal radiation, usually followed in minutes by returning capacity to perform. Electrophysiological methods of sensory evoked potentials (EP) were used to investigate mechanisms and anatomy of this radiation sickness. Monkeys (Macaca fasicularis) were irradiated with 7500 rad midline tissue doses of 20 MeV electrons. Mean arterial blood pressure (MAP), electrocardiogram (EKG), electroencephalogram (EEG), visual evoked responses (VER), and somatosensory evoked responses (SER) were recorded. MAP dropped 12--37 mm Hg in minutes, with return to pre-irradiation levels. Shortly after irradiation, the peak to peak amplitudes of early components of the ipsilateral and contralateral SERs were greatly diminished and early VER components diminished transiently. The appearance and behavior of the animals was similar to those in previous experiments, and correlated with temporary electrophysiologic malfunctioning. Such radiation doses release significant histamine. To model ETI, histamine was injected into Rhesus monkeys. Experiments were repeated with the same dose of histamine and prior injections of antihistamines or angiotensin infusion to maintain normal MAP. There was a correlation between MAP and the amplitudes of the VER. A total flattening of VER when MAP fell below 30 mm Hg, was prevented by maintaining MAP above 40 mm Hg. Maintaining MAP above a threshold prevented a shift to slow waves and a dramatic decrease of total power in the EEG. No dramatic VER changes were caused by massive amounts of blood histamine unless accompanied by severe hypotension. The small MAP decreases, but dramatic EP changes in the radiation experiments suggest that some factor other than low blood pressure is implicated in ETI

  10. Auditory evoked potentials to spectro-temporal modulation of complex tones in normal subjects and patients with severe brain injury.

    Science.gov (United States)

    Jones, S J; Vaz Pato, M; Sprague, L; Stokes, M; Munday, R; Haque, N

    2000-05-01

    In order to assess higher auditory processing capabilities, long-latency auditory evoked potentials (AEPs) were recorded to synthesized musical instrument tones in 22 post-comatose patients with severe brain injury causing variably attenuated behavioural responsiveness. On the basis of normative studies, three different types of spectro-temporal modulation were employed. When a continuous 'clarinet' tone changes pitch once every few seconds, N1/P2 potentials are evoked at latencies of approximately 90 and 180 ms, respectively. Their distribution in the fronto-central region is consistent with generators in the supratemporal cortex of both hemispheres. When the pitch is modulated at a much faster rate ( approximately 16 changes/s), responses to each change are virtually abolished but potentials with similar distribution are still elicited by changing the timbre (e.g. 'clarinet' to 'oboe') every few seconds. These responses appear to represent the cortical processes concerned with spectral pattern analysis and the grouping of frequency components to form sound 'objects'. Following a period of 16/s oscillation between two pitches, a more anteriorly distributed negativity is evoked on resumption of a steady pitch. Various lines of evidence suggest that this is probably equivalent to the 'mismatch negativity' (MMN), reflecting a pre-perceptual, memory-based process for detection of change in spectro-temporal sound patterns. This method requires no off-line subtraction of AEPs evoked by the onset of a tone, and the MMN is produced rapidly and robustly with considerably larger amplitude (usually >5 microV) than that to discontinuous pure tones. In the brain-injured patients, the presence of AEPs to two or more complex tone stimuli (in the combined assessment of two authors who were 'blind' to the clinical and behavioural data) was significantly associated with the demonstrable possession of discriminative hearing (the ability to respond differentially to verbal commands

  11. The involuntary nature of music-evoked autobiographical memories in Alzheimer's disease.

    Science.gov (United States)

    El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

    2012-03-01

    The main objective of this paper was to examine the involuntary nature of music-evoked autobiographical memories. For this purpose, young adults, older adults, and patients with a clinical diagnosis of probable Alzheimer's disease (AD) were asked to remember autobiographical events in two conditions: after being exposed to their own chosen music, and in silence. Compared to memories evoked in silence, memories evoked in the "Music" condition were found to be more specific, accompanied by more emotional content and impact on mood, and retrieved faster. In addition, these memories engaged less executive processes. Thus, with all these characteristics and the fact that they are activated by a perceptual cue (i.e., music), music-evoked autobiographic memories have all the features to be considered as involuntary memories. Our paper reveals several characteristics of music-evoked autobiographical memories in AD patients and offers a theoretical background for this phenomenon. PMID:22265372

  12. N-methyl-d-aspartate-evoked release of [{sup 3}H]acetylcholine in striatal compartments of the rat: regulatory roles of dopamine and GABA

    Energy Technology Data Exchange (ETDEWEB)

    Glowinski, J.; Perez, S.; Desban, M.; Gauchy, C.; Kemel, M.L.; Blanchet, F. [Chaire de Neuropharmacologie, INSERM U114, College de France, 11 place Marcelin Berthelot, 75231 Paris (France)

    1997-08-26

    The N-methyl-d-aspartate-evoked release of [{sup 3}H]acetylcholine previously formed from [{sup 3}H]choline was estimated in striosome- (identified by [{sup 3}H]naloxone binding) or matrix-enriched areas of the rat striatum using an in vitro microsuperfusion procedure. Experiments were performed in either the absence or the presence of dopaminergic and/or GABAergic receptor antagonists. Although the cell bodies of the cholinergic interneurons were mainly found in the matrix, in the absence of magnesium, N-methyl-d-aspartate (50 {mu}M) stimulated the release of [{sup 3}H]acetylcholine in both striatal compartments. These responses were blocked by either magnesium, dizocilpine maleate, 7-chlorokynurenate or tetrodotoxin. N-Methyl-d-aspartate responses were concentration-dependent, but the 1 mM N-methyl-d-aspartate response was higher in striosomes than in the matrix. The co-application of d-serine (10 {mu}M) enhanced the 10 {mu}M N-methyl-d-aspartate response in both compartments, but reduced those induced by 1 mM N-methyl-d-aspartate, this reduction being higher in striosomes. The blockade of dopaminergic transmission with the D{sub 2} and D{sub 1} dopaminergic receptor antagonists, (-)-sulpiride (1 {mu}M) and SCH23390 (1 {mu}M), was without effect on the 50 {mu}M N-methyl-d-aspartate-evoked release of [{sup 3}H]acetylcholine, but markedly enhanced the 1 mM N-methyl-d-aspartate + d-serine-evoked response in striosomes and to a lesser extent in the matrix. Disinhibitory responses of similar amplitude were observed not only in striosomes but also in the matrix when (-)-sulpiride was used alone, while SCH23390 alone enhanced the 1 mM N-methyl-d-aspartate + d-serine response only in striosomes and to a lower extent than (-)-sulpiride. These results indicate that D{sub 2} receptors are mainly involved in the inhibitory effect of dopamine on the 1 mM N-methyl-d-aspartate + d-serine-evoked release of [{sup 3}H]acetylcholine. They also show that the stimulation of D{sub 1

  13. Vestibular Evoked Myogenic Potential (VEMP) Triggered by Galvanic Vestibular Stimulation (GVS): A Promising Tool to Assess Spinal Cord Function in Schistosomal Myeloradiculopathy

    OpenAIRE

    Júlia Fonseca de Morais Caporali; Denise Utsch Gonçalves; Ludimila Labanca; Leonardo Dornas Oliveira; Guilherme Vaz de Melo Trindade; Thiago Almeida Pereira; Pedro Henrique Diniz Cunha; Marina Santos Falci Mourão; José Roberto Lambertucci

    2016-01-01

    Background Schistosomal myeloradiculopathy (SMR), the most severe and disabling ectopic form of Schistosoma mansoni infection, is caused by embolized ova eliciting local inflammation in the spinal cord and nerve roots. The treatment involves the use of praziquantel and long-term corticotherapy. The assessment of therapeutic response relies on neurological examination. Supplementary electrophysiological exams may improve prediction and monitoring of functional outcome. Vestibular evoked myogen...

  14. Interactions of Dopamine D1 and N-methyl-D-Aspartate Receptors are Required for Acute Cocaine-Evoked Nitric Oxide Efflux in the Dorsal Striatum

    OpenAIRE

    Lee, Dong Kun; Ahn, Sung Min; Shim, Yoon-Bo; Koh, Wei Choon Alvin; Shim, Insop; Choe, Eun Sang

    2011-01-01

    Alterations in nitric oxide (NO) release in response to psychostimulants in the striatum cause a plastic change contributing to the development and expression of addiction. In this study, regulation of NO efflux evoked by acute cocaine in the dorsal striatum was investigated using real-time detection of NO in vivo. We found that acute systemic injection of cocaine (20 mg/kg) increased NO efflux, which was reduced by the intrastriatal infusion of the dopamine D1 receptor antagonist, SCH23390 (...

  15. Comparison of sensitivity of magnetic resonance imaging and evoked potentials in the detection of brainstem involvement in multiple sclerosis

    International Nuclear Information System (INIS)

    A comparison was made of the sensitivity of magnetic resonance imaging and the combined use of Brainstem Auditory Evoked Potential and Median Somatosensory Evoked Potential in the detection of brainstem dysfunction in 54 multiple sclerosis patients. 10 refs.; 2 tabs

  16. Laminar and Columnar Structure of Sensory-Evoked Multineuronal Spike Sequences in Adult Rat Barrel Cortex In Vivo.

    Science.gov (United States)

    Reyes-Puerta, Vicente; Sun, Jyh-Jang; Kim, Suam; Kilb, Werner; Luhmann, Heiko J

    2015-08-01

    One of the most relevant questions regarding the function of the nervous system is how sensory information is represented in populations of cortical neurons. Despite its importance, the manner in which sensory-evoked activity propagates across neocortical layers and columns has yet not been fully characterized. In this study, we took advantage of the distinct organization of the rodent barrel cortex and recorded with multielectrode arrays simultaneously from up to 74 neurons localized in several functionally identified layers and columns of anesthetized adult Wistar rats in vivo. The flow of activity within neuronal populations was characterized by temporally precise spike sequences, which were repeatedly evoked by single-whisker stimulation. The majority of the spike sequences representing instantaneous responses were led by a subgroup of putative inhibitory neurons in the principal column at thalamo-recipient layers, thus revealing the presence of feedforward inhibition. However, later spike sequences were mainly led by infragranular excitatory neurons in neighboring columns. Although the starting point of the sequences was anatomically confined, their ending point was rather scattered, suggesting that the population responses are structurally dispersed. Our data show for the first time the simultaneous intra- and intercolumnar processing of information at high temporal resolution. PMID:24518757

  17. THE EFFECTS OF SALICYLATE ON AUDITORY EVOKED POTENTIAL AMPLITWDE FROM THE AUDITORY CORTEX AND AUDITORY BRAINSTEM

    Institute of Scientific and Technical Information of China (English)

    Brian Sawka; SUN Wei

    2014-01-01

    Tinnitus has often been studied using salicylate in animal models as they are capable of inducing tempo-rary hearing loss and tinnitus. Studies have recently observed enhancement of auditory evoked responses of the auditory cortex (AC) post salicylate treatment which is also shown to be related to tinnitus like behavior in rats. The aim of this study was to observe if enhancements of the AC post salicylate treatment are also present at structures in the brainstem. Four male Sprague Dawley rats with AC implanted electrodes were tested for both AC and auditory brainstem response (ABR) recordings pre and post 250 mg/kg intraperitone-al injections of salicylate. The responses were recorded as the peak to trough amplitudes of P1-N1 (AC), ABR wave V, and ABR waveⅡ. AC responses resulted in statistically significant enhancement of ampli-tude at 2 hours post salicylate with 90 dB stimuli tone bursts of 4, 8, 12, and 20 kHz. Wave V of ABR re-sponses at 90 dB resulted in a statistically significant reduction of amplitude 2 hours post salicylate and a mean decrease of amplitude of 31%for 16 kHz. WaveⅡamplitudes at 2 hours post treatment were signifi-cantly reduced for 4, 12, and 20 kHz stimuli at 90 dB SPL. Our results suggest that the enhancement chang-es of the AC related to salicylate induced tinnitus are generated superior to the level of the inferior colliculus and may originate in the AC.

  18. Comparing the habituation of late auditory evoked potentials to loud and soft sound

    International Nuclear Information System (INIS)

    The objective fitting of hearing aids and cochlear implants remains a challenge. In particular, the determination of whether sound is perceived as too loud or comfortable represents an unsolved problem in noncooperative patients. In a first step of an ongoing study, we assess the feasibility of habituation correlates in late auditory evoked potentials (LAEPs) to discriminate between a soft sound (SS) of 50 dB SPL and a loud sound (LS) of 100 dB SPL. We applied a new sweep-to-sweep time-scale coherence measure to analyse the habituation in LAEPs, i.e., relative changes within sweep sequences. From the comparison between both stimulation levels, a total discrimination of responses to SS and LS in the individual normal hearing subject was possible. As just relative changes in SS and LS sweep sequences were considered, purely exogenously driven morphological alternations in the responses such as intensity related amplitude and latency changes were excluded from the analysis. It is concluded that the proposed method allows for the reliable detection of auditory habituation and differentiation of SS from LS. The proposed scheme might provide an electrophysiological measurement and signal processing framework for the objective detection of the most comfortable loudness level and can be used in further, more clinically oriented studies

  19. Masking the Auditory Evoked Potential in TMS-EEG: A Comparison of Various Methods.

    Science.gov (United States)

    ter Braack, Esther M; de Vos, Cecile C; van Putten, Michel J A M

    2015-05-01

    There is growing interest in combining transcranial magnetic stimulation (TMS) with electroencephalography (EEG). Because TMS pulses are accompanied by a clicking sound, it is very likely that part of the response in the EEG consists of an auditory evoked potential (AEP). Different methods have been applied to mask the sound of TMS. However, it is unclear which masking method is most effective in reducing the AEP. In this study we explore the presumed contribution of the AEP to the response and evaluate different ways to mask the TMS clicking sound. Twelve healthy subjects and one completely deaf subject participated in this study. Eight different masking conditions were evaluated in nine hearing subjects. The amplitude of the N100-P180 complex was compared between the different masking conditions. We were not able to completely suppress the N100-P180 when the coil was placed on top of the head. Using an earmuff or exposing the subjects to white or adapted noise caused a small but significant reduction in N100-P180 amplitude, but the largest reduction was achieved when combining a layer of foam, placed between coil and head, with white or adapted noise. The deaf subject also showed a N100-P180 complex. We conclude that both the TMS clicking sound and cortical activation by the magnetic pulse contribute to the N100-P180 amplitude. PMID:23996091

  20. Amylin evokes protein p20 phosphorylation and insulin resistance in rat skeletal muscle extensor digitorum longus

    Institute of Scientific and Technical Information of China (English)

    LEE; Shaochin(李晓钦); Garth; Cooper

    2002-01-01

    In the present study, we investigate effect of amylin on the insulin sensitivity of rat skeletal muscle extensor digitorum longus (EDL) using in vitro intact muscle incubation in combination with metabolic radioactive labeling. The molecular basis of the amylin action was further examined using proteomic analysis. In particular, proteins of interest were characterized using an integrated microcharacterization procedure that involved in-gel trypsin digestion, organic solvent extraction, high performance liquid chromatography separation, microsequencing and microsequence analysis. We found that amylin significantly decreased the insulin-stimulated glucose incorporation into glycogen (p < 0.01) and produced a protein spot of approximately 20 ku in size. This amylin responsive protein (hereby designated as amylin responsive protein 1, APR1) was identified to be protein p20. Moreover, ARP1 spots on gels were found to consistently produce a corresponding radioactive spot on X-ray films in 32Pi but not in 35S-methionine labeling experiments. In conclusion, our results showed that in vitro amylin concomitantly evoked the production of ARP1 and caused insulin resistance in EDL muscle. It is suggested that protein p20 may be involved in amylin signal transduction and the appearance of ARP1 may be a step in a molecular pathway leading to the development of insulin resistance. ARP1 might therefore be a useful molecular marker for amylin action, insulin resistance and Type 2 diabetes.

  1. Subclinical hepatic encephalopathy: the diagnostic value of evoked potentials.

    Science.gov (United States)

    Kullmann, F; Hollerbach, S; Holstege, A; Schölmerich, J

    1995-01-01

    Brainstem auditory (BAEPs) and somatosensory evoked potentials (SEPs) have been shown to be useful in detecting brainstem or cortical dysfunction in neurological diseases and in combination with other methods to diagnose brain death (37,38). These neurophysiological methods are simple and easy to perform. BAEPs and SEPs can even be easily recorded in intensive care units and guarantee a standardized examination. Moreover, these methods require no extensive patient cooperation and are not heavily influenced by learning effects. The role of BAEPs in the evaluation and diagnosis of hepatic encephalopathy is not clear. BAEPs are obviously strongly influenced by the etiology of liver disease and are normal in viral hepatitis, but prolonged in alcoholic liver disease, Wilson's disease or in hepatic coma (8,12). Unfortunately, BAEPs were not compared to psychometric tests. There was no clear-cut differentiation between various hepatic encephalopathy-gradings. At present, the use of BAEPs in the detection of subclinical hepatic encephalopathy cannot be recommended, whereas in comatose patients BAEPs can be useful as a prognostic marker and for follow-up examinations (12). Recently, Pozessere et al. (12) examined 13 comatose patients with advanced coma stages (Glasgow coma scale 5-10) and recorded unspecific changes in their EEG tracings. In all cases of hepatic coma and in one intoxicated patient they found prolongation of interpeak latencies. In addition, in this small study the interpeak latencies correlated well with the clinical outcome of the patients. Only two studies were performed using SEPs to detect neurophysiological alterations in hepatic encephalopathy (32,33). The design as well as the results of these studies are quite different. Despite the small number of patients (n = 10), the prolongation of late components in 50% of patients with hepatic encephalopathy stage 0 could be a promising result (32). The value of SEPs in detecting subclinical hepatic

  2. Analysis of brain-stem auditory evoked potential and visual evoked potential in patients with Parkinson disease

    Institute of Scientific and Technical Information of China (English)

    Qiaorong Deng; Jianzhong Deng; Yanmin Zhao; Xiaohai Yan; Pin Chen

    2006-01-01

    BACKGROUND: With the development of neuroelectrophysiology, it had been identified that all kinds of evoked potentials might reflect the functional status of corresponding pathway. Evoked potentials recruited in the re search of PD, it can be known whether other functional pathway of nervous system is impaired. OBJECTIVE: To observe whether brainstem auditory and visual passageway are impaired in patients with Parkinson disease (PD), and compare with non-PD patients concurrently. DESIGN: A non-randomized concurrent controlled observation. SETTINGS: Henan Provincial Tumor Hospital; Anyang District Hospital. PARTICIPANTS: Thirty-two cases of PD outpatients and inpatients, who registered in the Department of Neurology, Anyang District Hospital from October 1997 to February 2006, were enrolled as the PD group, including 20 males and 12 females, aged 50-72 years old. Inclusive criteria: In accordance with the diagnostic criteria of PD recommended by the dyskinesia and PD group of neurology branch of Chinese Medical Association. Patients with diseases that could cause Parkinson syndrome were excluded by CT scanning or MRI examination. Meanwhile, 30 cases with non-neurological disease were selected from the Department of Internal Medicine of our hospital as the control group, including 19 males and 11 females, aged 45-70 years old. Including criteria: Without history of neurological disease or psychiatric disease; showing normal image on CT. And PD, Parkinson syndrome and Parkinsonism-plus were excluded by professional neurologist. All the patients were informed and agreed with the examination and clinical observation. METHODS: The electrophysiological examination and clinical observation of the PD patients and controls were conducted. The Reporter type 4-channel evoked potential machine (Italy) was used to check brain-stem auditory evoked potential (BAEP) and visual evoked potential (VEP). Why to be examined was explained to test taker. BAEP recording electrode was plac

  3. Regionally distinct cutaneous afferent populations contribute to reflex modulation evoked by stimulation of the tibial nerve during walking.

    Science.gov (United States)

    Nakajima, Tsuyoshi; Suzuki, Shinya; Futatsubashi, Genki; Ohtsuska, Hiroyuki; Mezzarane, Rinaldo A; Barss, Trevor S; Klarner, Taryn; Zehr, E Paul; Komiyama, Tomoyoshi

    2016-07-01

    During walking, cutaneous reflexes in ankle flexor muscle [tibialis anterior (TA)] evoked by tibial nerve (TIB) stimulation are predominantly facilitatory at early swing phase but reverse to suppression at late swing phase. Although the TIB innervates a large portion of the skin of the foot sole, the extent to which specific foot-sole regions contribute to the reflex reversals during walking remains unclear. Therefore, we investigated regional cutaneous contributions from discrete portions of the foot sole on reflex reversal in TA following TIB stimulation during walking. Summation effects on reflex amplitudes, when applying combined stimulation from foot-sole regions with TIB, were examined. Middle latency responses (MLRs; 70-120 ms) after TIB stimulation were strongly facilitated during the late stance to mid-swing phases and reversed to suppression just before heel (HL) strike. Both forefoot-medial (f-M) and forefoot-lateral stimulation in the foot sole induced facilitation during stance-to-swing transition phases, but HL stimulation evoked suppression during the late stance to the end of swing phases. At the stance-to-swing transition, a summation of MLR amplitude occurred only for combined f-M&TIB stimulation. However, the same was not true for the combined HL&TIB stimulation. At the swing-to-stance transition, there was a suppressive reflex summation only for HL&TIB stimulation. In contrast, this summation was not observed for the f-M&TIB stimulation. Our results suggest that reflex reversals evoked by TIB stimulation arise from distinct reflex pathways to TA produced by separate afferent populations innervating specific regions of the foot sole. PMID:27075541

  4. A Subspace Method for Dynamical Estimation of Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Stefanos D. Georgiadis

    2007-01-01

    Full Text Available It is a challenge in evoked potential (EP analysis to incorporate prior physiological knowledge for estimation. In this paper, we address the problem of single-channel trial-to-trial EP characteristics estimation. Prior information about phase-locked properties of the EPs is assesed by means of estimated signal subspace and eigenvalue decomposition. Then for those situations that dynamic fluctuations from stimulus-to-stimulus could be expected, prior information can be exploited by means of state-space modeling and recursive Bayesian mean square estimation methods (Kalman filtering and smoothing. We demonstrate that a few dominant eigenvectors of the data correlation matrix are able to model trend-like changes of some component of the EPs, and that Kalman smoother algorithm is to be preferred in terms of better tracking capabilities and mean square error reduction. We also demonstrate the effect of strong artifacts, particularly eye blinks, on the quality of the signal subspace and EP estimates by means of independent component analysis applied as a prepossessing step on the multichannel measurements.

  5. ISCEV standard for clinical visual evoked potentials: (2016 update).

    Science.gov (United States)

    Odom, J Vernon; Bach, Michael; Brigell, Mitchell; Holder, Graham E; McCulloch, Daphne L; Mizota, Atsushi; Tormene, Alma Patrizia

    2016-08-01

    Visual evoked potentials (VEPs) can provide important diagnostic information regarding the functional integrity of the visual system. This document updates the ISCEV standard for clinical VEP testing and supersedes the 2009 standard. The main changes in this revision are the acknowledgment that pattern stimuli can be produced using a variety of technologies with an emphasis on the need for manufacturers to ensure that there is no luminance change during pattern reversal or pattern onset/offset. The document is also edited to bring the VEP standard into closer harmony with other ISCEV standards. The ISCEV standard VEP is based on a subset of stimulus and recording conditions that provide core clinical information and can be performed by most clinical electrophysiology laboratories throughout the world. These are: (1) Pattern-reversal VEPs elicited by checkerboard stimuli with large 1 degree (°) and small 0.25° checks. (2) Pattern onset/offset VEPs elicited by checkerboard stimuli with large 1° and small 0.25° checks. (3) Flash VEPs elicited by a flash (brief luminance increment) which subtends a visual field of at least 20°. The ISCEV standard VEP protocols are defined for a single recording channel with a midline occipital active electrode. These protocols are intended for assessment of the eye and/or optic nerves anterior to the optic chiasm. Extended, multi-channel protocols are required to evaluate postchiasmal lesions. PMID:27443562

  6. Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

    International Nuclear Information System (INIS)

    The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [3H]dopamine and [3H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [3H]dopamine and [3H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [3H]norepinephrine or [3H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

  7. Long-latency evoked potentials to irrelevant, deviant stimuli

    Science.gov (United States)

    Snyder, E.; Hillyard, S. A.

    1976-01-01

    Occasional shifts of loudness in a repetitive train of clicks elicited a late-positive wave (P3a) in nonattending subjects which peaked at a mean latency of 258 msec and had a frontocentral scalp distribution; P3a was typically preceded by an 'N2' component at 196 msec. The P3a wave was distinguishable from the longer-latency (378 msec) parietocentrally distributed 'P3b' wave that was evoked by the same stimulus in an actively attending subject, thus confirming the findings of Squires et al. (1975). Infrequently presented single sounds did not produce large or consistent N2-P3a components; the critical condition for the generation of an N2-P3a wave seemed to be that the infrequent sounds represent a deviation (intensity increment or decrement) from a repetitive background. Furthermore, increasing the repetition rate of the background clicks drastically reduced N1-P2 amplitude but had little effect on the amplitude of N2-P3a. This suggests that N2-P3a is not simply a delayed N1-P2 'vertex potential', but rather reflects the operation of a 'mismatch' detector, which registers deviations from an ongoing auditory background.

  8. Flash visual evoked potentials in diurnal birds of prey.

    Science.gov (United States)

    Dondi, Maurizio; Biaggi, Fabio; Di Ianni, Francesco; Dodi, Pier Luigi; Quintavalla, Fausto

    2016-01-01

    The objective of this pilot study was to evaluate the feasibility of Flash Visual Evoked Potentials (FVEPs) testing in birds of prey in a clinical setting and to describe the protocol and the baseline data for normal vision in this species. FVEP recordings were obtained from 6 normal adult birds of prey: n. 2 Harris's Hawks (Parabuteo unicinctus), n. 1 Lanner Falcon (Falco biarmicus), n. 2 Gyrfalcons (Falco rusticolus) and n. 1 Saker Falcon (Falco cherrug). Before carrying out VEP tests, all animals underwent neurologic and ophthalmic routine examination. Waveforms were analysed to identify reproducible peaks from random variation of baseline. At least three positive and negative peaks were highlighted in all tracks with elevated repeatability. Measurements consisted of the absolute and relative latencies of these peaks (P1, N1, P2, N2, P3, and N3) and their peak-to-peak amplitudes. Both the peak latency and wave morphology achieved from normal animals were similar to those obtained previously in other animal species. This test can be easily and safely performed in a clinical setting in birds of prey and could be useful for an objective assessment of visual function. PMID:27547536

  9. An evoked potential mapping of transcallosal projections in the cat

    Directory of Open Access Journals (Sweden)

    A. Cukiert

    1989-03-01

    Full Text Available In ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions were determined on a cartesian map of most of the exposable neocortical areas and the potentials were analysed as to their components, voltage and latency. Passive spread and electrotonic potentials and the effects of increasing frequency were also analysed. The results showed large transcallosal potentials in some areas and an increase of potentials in the caudorostral direction, attaining the highest values in anteromedial areas of the suprasylvian gyrus. Confirming anatomical studies, a few silent spots were found in the motor and somesthetic cortex and in restricted posterior regions of the visual cortex, where small or zero voltages occurred. While causing weak contralateral potentials, stimulation of some posterior sites provoked high voltage potentials in anterior regions of the side being stimulated and in the corresponding area of the opposite site. These posterior sites are. poorly interconnected by the corpus callosum. The L-shaped indirect connection described in this work may be involved in some types of epilepsy and may explain the effectiveness of partial callosotomy in their treatment.

  10. Online Classification of Evoked EEG Signals Due to RGB Colors

    Directory of Open Access Journals (Sweden)

    Eman Alharbi

    2016-03-01

    Full Text Available Recently, the impact of colors on the brain signals has become one of the leading researches in BCI systems. These researches are based on studying the brain behavior after color stimulus, and finding a way to classify its signals offline without considering the real time. Moving to the next step, we present a real time classification model (online for EEG signals evoked by RGB colors stimuli, which is not presented in previous studies. In this research, EEG signals were recorded from 7 subjects through BCI2000 toolbox. The Empirical Mode Decomposition (EMD technique was used at the signal analysis stage. Various feature extraction methods were investigated to find the best and reliable set, including Event-related spectral perturbations (ERSP, Target mean with Feast Fourier Transform (FFT, Wavelet Packet Decomposition (WPD, Auto Regressive model (AR and EMD residual. A new feature selection method was created based on the peak's time of EEG signal when red and blue colors stimuli are presented. The ERP image was used to find out the peak's time, which was around 300 ms for the red color and around 450 ms for the blue color. The classification was performed using the Support Vector Machine (SVM classifier, LIBSVM toolbox being used for that purpose. The EMD residual was found to be the most reliable method that gives the highest classification accuracy with an average of 88.5% and with an execution time of only 14 seconds.

  11. Brainstem auditory evoked potential testing in Dalmatian dogs in Brazil

    Directory of Open Access Journals (Sweden)

    M.I.P. Palumbo

    2014-04-01

    Full Text Available The brain stem auditory-evoked potential (BAEP is an electrophysiologic test that detects and records the electrical activity in the auditory system from cochlea to midbrain, generated after an acoustic stimulus applied to the external ear. The aim of this study is to obtain normative data for BAEP in Dalmatian dogs in order to apply this to the evaluation of deafness and other neurologic disorders. BAEP were recorded from 30 Dalmatian dogs for a normative Brazilian study. Mean latencies for waves I, III, and V were 1.14 (±0.09, 2.62 (±0.10, and 3.46 (±0.14 ms, respectively. Mean inter-peak latencies for I-III, III-V, and I-V intervals were 1.48 (±0.17, 0.84 (±0.12, and 2.31 (±0.18 ms, respectively. Unilateral abnormalities were found in 16.7% of animals and bilateral deafness was seen in one dog. The normative data obtained in this paper is compatible with other published data. As far as we know this is the first report of deafness occurrence in Dalmatian dogs in Brazil.

  12. Auditory steady state response in hearing assessment in infants with cytomegalovirus

    Directory of Open Access Journals (Sweden)

    Daniela Polo C. Silva

    2013-12-01

    Full Text Available OBJECTIVE: To report an infant with congenital cytomegalovirus and progressive sensorineural hearing loss, who was assessed by three methods of hearing evaluation. CASE DESCRIPTION: In the first audiometry, at four months of age, the infant showed abnormal response in Otoacoustic Emissions and normal Auditory Brainstem Response (ABR, with electrophysiological threshold in 30dBnHL, in both ears. With six months of age, he showed bilateral absence of the ABR at 100dBnHL. The behavioral observational audiometry was impaired due to the delay in neuropsychomotor development. At eight months of age, he was submitted to Auditory Steady State Response (ASSR and the thresholds were 50, 70, absent in 110 and in 100dB, respectively for 500, 1,000, 2,000 and 4,000Hz in the right ear, and 70, 90, 90 and absent in 100dB, respectively for 500, 1,000, 2,000 and 4,000Hz in the left ear. COMMENTS: In the first evaluation, the infant had abnormal Otoacoustic Emission and normal ABR, which became altered at six months of age. The hearing loss severity could be identified only by the ASSR, which allowed the best procedure for hearing aids adaptation. The case description highlights the importance of the hearing status follow-up for children with congenital cytomegalovirus.

  13. Music-evoked emotions: principles, brain correlates, and implications for therapy.

    Science.gov (United States)

    Koelsch, Stefan

    2015-03-01

    This paper describes principles underlying the evocation of emotion with music: evaluation, resonance, memory, expectancy/tension, imagination, understanding, and social functions. Each of these principles includes several subprinciples, and the framework on music-evoked emotions emerging from these principles and subprinciples is supposed to provide a starting point for a systematic, coherent, and comprehensive theory on music-evoked emotions that considers both reception and production of music, as well as the relevance of emotion-evoking principles for music therapy. PMID:25773635

  14. Case Report of Vestibularly evoked Visual Hallucinations in a Patient with Cortical Blindness.

    Science.gov (United States)

    Kolev, Ognyan I

    2016-08-01

    Previous work has shown that caloric vestibular stimulation may evoke elementary visual hallucinations in healthy humans, such as different colored lines or dots. Surprisingly, the present case report reveals that the same stimulation can evoke visual hallucinations in a patient with cortical blindness, but with fundamentally different characteristics. The visual hallucinations evoked were complex and came from daily life experiences. Moreover, they did not include other senses beyond vision. This case report suggests that in conditions of cerebral pathology, vestibular-visual interaction may stimulate hallucinogenic subcortical, or undamaged cortical structures, and arouse mechanisms that can generate visual images exclusively. PMID:27246956

  15. Change in Speech Perception and Auditory Evoked Potentials over Time after Unilateral Cochlear Implantation in Postlingually Deaf Adults.

    Science.gov (United States)

    Purdy, Suzanne C; Kelly, Andrea S

    2016-02-01

    Speech perception varies widely across cochlear implant (CI) users and typically improves over time after implantation. There is also some evidence for improved auditory evoked potentials (shorter latencies, larger amplitudes) after implantation but few longitudinal studies have examined the relationship between behavioral and evoked potential measures after implantation in postlingually deaf adults. The relationship between speech perception and auditory evoked potentials was investigated in newly implanted cochlear implant users from the day of implant activation to 9 months postimplantation, on five occasions, in 10 adults age 27 to 57 years who had been bilaterally profoundly deaf for 1 to 30 years prior to receiving a unilateral CI24 cochlear implant. Changes over time in middle latency response (MLR), mismatch negativity, and obligatory cortical auditory evoked potentials and word and sentence speech perception scores were examined. Speech perception improved significantly over the 9-month period. MLRs varied and showed no consistent change over time. Three participants aged in their 50s had absent MLRs. The pattern of change in N1 amplitudes over the five visits varied across participants. P2 area increased significantly for 1,000- and 4,000-Hz tones but not for 250 Hz. The greatest change in P2 area occurred after 6 months of implant experience. Although there was a trend for mismatch negativity peak latency to reduce and width to increase after 3 months of implant experience, there was considerable variability and these changes were not significant. Only 60% of participants had a detectable mismatch initially; this increased to 100% at 9 months. The continued change in P2 area over the period evaluated, with a trend for greater change for right hemisphere recordings, is consistent with the pattern of incremental change in speech perception scores over time. MLR, N1, and mismatch negativity changes were inconsistent and hence P2 may be a more robust measure

  16. Administration of Lactobacillus evokes coordinated changes in the intestinal expression profile of genes regulating energy homeostasis and immune phenotype in mice.

    Science.gov (United States)

    Nerstedt, Annika; Nilsson, Elisabeth C; Ohlson, Kajsa; Håkansson, Janet; Thomas Svensson, L; Löwenadler, Björn; Svensson, Ulla K; Mahlapuu, Margit

    2007-06-01

    Lactic acid bacteria are probiotics widely used in functional food products, with a variety of beneficial effects reported. Recently, intense research has been carried out to provide insight into the mechanism of the action of probiotic bacteria. We have used gene array technology to map the pattern of changes in the global gene expression profile of the host caused by Lactobacillus administration. Affymetrix microarrays were applied to comparatively characterize differences in gene transcription in the distal ileum of normal microflora (NMF) and germ-free (GF) mice evoked by oral administration of two Lactobacillus strains used in fermented dairy products today - Lactobacillus paracasei ssp. paracasei F19 (L. F19) or Lactobacillus acidophilus NCFB 1748. We show that feeding either of the two strains caused very similar effects on the transcriptional profile of the host. Both L. F19 and L. acidophilus NCFB 1748 evoked a complex response in the gut, reflected by differential regulation of a number of genes involved in essential physiological functions such as immune response, regulation of energy homeostasis and host defence. Notably, the changes in intestinal gene expression caused by Lactobacillus were different in the mice raised under GF v. NMF conditions, underlying the complex and dynamic nature of the host-commensal relationship. Differential expression of an array of genes described in this report evokes novel hypothesis of possible interactions between the probiotic bacteria and the host organism and warrants further studies to evaluate the functional significance of these transcriptional changes on the metabolic profile of the host. PMID:17433125

  17. Responsibilities

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    ONE day in 1993, a woman named Xing Jun came to the Organization Department of Tianjin’s Municipal Party Committee. She approached the door to the director’s office, opened it, and walked straight into the responsibility for training, examining, recommending and appointing cadres at all levels of the municipal government. Because the office has so much influence over the fate of many cadres, the director’s position commands much respect and awe. However, people see no

  18. "What's Your Taste in Music?" A Comparison of the Effectiveness of Various Soundscapes in Evoking Specific Tastes.

    Science.gov (United States)

    Wang, Qian Janice; Woods, Andy T; Spence, Charles

    2015-12-01

    We report on the results of two online experiments designed to compare different soundtracks that had been composed (by various researchers and sound designers) in order to evoke/match different basic tastes. In Experiment 1, 100 participants listened to samples from 24 soundtracks and chose the taste (sweet, sour, salty, or bitter) that best matched each sample. Overall, the sweet soundtracks most effectively evoked the taste intended by the composer (participants chose sweet 56.9% of the time for the sweet soundtracks), whereas the bitter soundtracks were the least effective (participants chose bitter 31.4% of the time for the bitter soundtracks), compared with chance (choosing any specific taste 25% of the time). In Experiment 2, 50 participants rated their emotional responses (in terms of pleasantness and arousal) to the same 24 soundtrack samples and also to imaginary sweet/sour/salty/bitter-tasting foods. Associations between soundtracks and tastes were partly mediated by pleasantness for the sweet and bitter tastes and partly by arousal for the sour tastes. These results demonstrate how emotion mediation may be an additional mechanism behind sound-taste correspondences. PMID:27551365

  19. Intraoperative Transcranial Motor-Evoked Potential Monitoring of the Facial Nerve during Cerebellopontine Angle Tumor Resection

    OpenAIRE

    Cosetti, Maura K.; Xu, Ming; Rivera, Andrew; Jethanamest, Daniel; Kuhn, Maggie A.; Beric, Aleksandar; Golfinos, John G.; Roland, J. Thomas

    2012-01-01

    Objective To determine whether transcranial motor-evoked potential (TCMEP) monitoring of the facial nerve (FN) during cerebellopontine angle (CPA) tumor resection can predict both immediate and long-term postoperative FN function.

  20. Assessment evaluation of transient evoked otoacoustic emission by contralateral suppression in tinnitus patient with normal hearing

    Directory of Open Access Journals (Sweden)

    Helnaz Mokrian

    2014-01-01

    Conclusion: The suppression of the transient evoked otoacoustic emission by contralateral white noise did not reach statistically significant levels in tinnitus patients while the amplitude in control group reduced significantly.

  1. Magnetic stimulation of muscle evokes cerebral potentials in assessment of paraspinal muscle spasm.

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Objectlve: To assess the muscle spasm by magnetic stimulation of muscle evokes cerebral potentials (MMSEP). Methods: Paraspinal MMSEP and function assessment was recorded in detail before and after treat-

  2. Brainstem auditory-evoked potential in Boxer dogs

    Directory of Open Access Journals (Sweden)

    Mariana Isa Poci Palumbo

    2014-10-01

    Full Text Available Brainstem auditory-evoked potential (BAEP has been widely used for different purposes in veterinary practice and is commonly used to identify inherited deafness and presbycusis. In this study, 43 Boxer dogs were evaluated using the BAEP. Deafness was diagnosed in 3 dogs (2 bilateral and 1 unilateral allowing the remaining 40 Boxers to be included for normative data analysis including an evaluation on the influence of age on the BAEP. The animals were divided into 2 groups of 20 Boxers each based on age. The mean age was 4.54 years (range, 1-8 in group I, and 9.83 years (range, 8.5-12 in group II. The mean latency for I, III, and V waves were 1.14 (±0.07, 2.64 (±0.11, and 3.48 (±0.10 ms in group I, and 1.20 (±0.12, 2.73 (±0.15, and 3.58 (±0.22 ms in group II, respectively. The mean inter-peak latencies for the I-III, III-V and I-V intervals were 1.50 (±0.15, 0.84 (±0.15, and 2.34 (±0.11 ms in group I, and 1.53 (±0.16, 0.85 (±0.15, and 2.38 (±0.19 ms in group II, respectively. Latencies of waves I and III were significant different between group I and II. For the I-III, III-V and I-V intervals, no significant differences were observed between the 2 groups. As far as we know, this is the first normative study of BAEP obtained from Boxer dogs.

  3. Long Latency Auditory Evoked Potential in Term and Premature Infants

    Directory of Open Access Journals (Sweden)

    Didoné, Dayane Domeneghini

    2014-01-01

    Full Text Available Introduction The research in long latency auditory evokes potentials (LLAEP in newborns is recent because of the cortical structure maturation, but studies note that these potentials may be evidenced at this age and could be considered as indicators of cognitive development. Purpose To research the exogenous potentials in term and premature infants during their first month of life. Materials and Methods The sample consisted of 25 newborns, 15 term and 10 premature infants. The infants with gestational age under 37 weeks were considered premature. To evaluate the cortical potentials, the infants remained in natural sleep. The LLAEPs were researched binaurally, through insertion earphones, with frequent /ba/ and rare /ga/ speech stimuli in the intensity of 80 dB HL (decibel hearing level. The frequent stimuli presented a total of 80% of the presentations, and the rare, 20%. The data were statistically analyzed. Results The average gestational age of the term infants was 38.9 weeks (± 1.3 and for the premature group, 33.9 weeks (± 1.6. It was possible to observe only the potentials P1 and N1 in both groups, but there was no statistically significant difference for the latencies of the components P1 and N1 (p > 0.05 between the groups. Conclusion It was possible to observe the exogenous components P1 and N1 of the cortical potentials in both term and preterm newborns of no more than 1 month of age. However, there was no difference between the groups.

  4. Long latency auditory evoked potential in term and premature infants.

    Science.gov (United States)

    Didoné, Dayane Domeneghini; Garcia, Michele Vargas; da Silveira, Aron Ferreira

    2014-01-01

    Introduction The research in long latency auditory evokes potentials (LLAEP) in newborns is recent because of the cortical structure maturation, but studies note that these potentials may be evidenced at this age and could be considered as indicators of cognitive development. Purpose To research the exogenous potentials in term and premature infants during their first month of life. Materials and Methods The sample consisted of 25 newborns, 15 term and 10 premature infants. The infants with gestational age under 37 weeks were considered premature. To evaluate the cortical potentials, the infants remained in natural sleep. The LLAEPs were researched binaurally, through insertion earphones, with frequent /ba/ and rare /ga/ speech stimuli in the intensity of 80 dB HL (decibel hearing level). The frequent stimuli presented a total of 80% of the presentations, and the rare, 20%. The data were statistically analyzed. Results The average gestational age of the term infants was 38.9 weeks (± 1.3) and for the premature group, 33.9 weeks (± 1.6). It was possible to observe only the potentials P1 and N1 in both groups, but there was no statistically significant difference for the latencies of the components P1 and N1 (p > 0.05) between the groups. Conclusion It was possible to observe the exogenous components P1 and N1 of the cortical potentials in both term and preterm newborns of no more than 1 month of age. However, there was no difference between the groups. PMID:25992057

  5. Evoked electromyography-based closed-loop torque control in functional electrical stimulation.

    Science.gov (United States)

    Zhang, Qin; Hayashibe, Mitsuhiro; Azevedo-Coste, Christine

    2013-08-01

    This paper proposed a closed-loop torque control strategy of functional electrical stimulation (FES) with the aim of obtaining an accurate, safe, and robust FES system. Generally, FES control systems are faced with the challenge of how to deal with time-variant muscle dynamics due to physiological and biochemical factors (such as fatigue). The degraded muscle force needs to be compensated in order to ensure the accuracy of the motion restored by FES. Another challenge concerns the fact that implantable sensors are unavailable to feedback torque information for FES in humans. As FES-evoked electromyography (EMG) represents the activity of stimulated muscles, and also enables joint torque prediction as presented in our previous studies, here we propose an EMG-feedback predictive controller of FES to control joint torque adaptively. EMG feedback contributes to taking the activated muscle state in the FES torque control system into account. The nature of the predictive controller facilitates prediction of the muscle mechanical response and the system can therefore control joint torque from EMG feedback and also respond to time-variant muscle state changes. The control performance, fatigue compensation and aggressive control suppression capabilities of the proposed controller were evaluated and discussed through experimental and simulation studies. PMID:23529189

  6. Longitudinal Evaluation of Residual Cortical and Subcortical Motor Evoked Potentials in Spinal Cord Injured Rats.

    Science.gov (United States)

    Redondo-Castro, Elena; Navarro, Xavier; García-Alías, Guillermo

    2016-05-15

    We have applied transcranial electrical stimulation to rats with spinal cord injury and selectively tested the motor evoked potentials (MEPs) conveyed by descending motor pathways with cortical and subcortical origin. MEPs were elicited by electrical stimulation to the brain and recorded on the tibialis anterior muscles. Stimulation parameters were characterized and changes in MEP responses tested in uninjured rats, in rats with mild or moderate contusion, and in animals with complete transection of the spinal cord. All injuries were located at the T8 vertebral level. Two peaks, termed N1 and N2, were obtained when changing from single pulse stimulation to trains of 9 pulses at 9 Hz. Selective injuries to the brain or spinal cord funiculi evidenced the subcortical origin of N1 and the cortical origin of N2. Animals with mild contusion showed small behavioral deficits and abolished N1 but maintained small amplitude N2 MEPs. Substantial motor deficits developed in rats with moderate contusion, and these rats had completely eliminated N1 and N2 MEPs. Animals with complete cord transection had abolished N1 and N2 and showed severe impairment of locomotion. The results indicate the reliability of MEP testing to longitudinally evaluate over time the degree of impairment of cortical and subcortical spinal pathways after spinal cord injuries of different severity. PMID:26560177

  7. High-resolution measurement of electrically-evoked vagus nerve activity in the anesthetized dog

    Science.gov (United States)

    Yoo, Paul B.; Lubock, Nathan B.; Hincapie, Juan G.; Ruble, Stephen B.; Hamann, Jason J.; Grill, Warren M.

    2013-04-01

    Objective. Not fully understanding the type of axons activated during vagus nerve stimulation (VNS) is one of several factors that limit the clinical efficacy of VNS therapies. The main goal of this study was to characterize the electrical recruitment of both myelinated and unmyelinated fibers within the cervical vagus nerve. Approach. In anesthetized dogs, recording nerve cuff electrodes were implanted on the vagus nerve following surgical excision of the epineurium. Both the vagal electroneurogram (ENG) and laryngeal muscle activity were recorded in response to stimulation of the right vagus nerve. Main results. Desheathing the nerve significantly increased the signal-to-noise ratio of the ENG by 1.2 to 9.9 dB, depending on the nerve fiber type. Repeated VNS following nerve transection or neuromuscular block (1) enabled the characterization of A-fibers, two sub-types of B-fibers, and unmyelinated C-fibers, (2) confirmed the absence of stimulation-evoked reflex compound nerve action potentials in both the ipsilateral and contralateral vagus nerves, and (3) provided evidence of stimulus spillover into muscle tissue surrounding the stimulating electrode. Significance. Given the anatomical similarities between the canine and human vagus nerves, the results of this study provide a template for better understanding the nerve fiber recruitment patterns associated with VNS therapies.

  8. A multi-task learning approach for the extraction of single-trial evoked potentials.

    Science.gov (United States)

    D'Avanzo, Costanza; Goljahani, Anahita; Pillonetto, Gianluigi; De Nicolao, Giuseppe; Sparacino, Giovanni

    2013-05-01

    Evoked potentials (EPs) are of great interest in neuroscience, but their measurement is difficult as they are embedded in background spontaneous electroencephalographic (EEG) activity which has a much larger amplitude. The widely used averaging technique requires the delivery of a large number of identical stimuli and yields only an "average" EP which does not allow the investigation of the possible variability of single-trial EPs. In the present paper, we propose the use of a multi-task learning method (MTL) for the simultaneous extraction of both the average and the N single-trial EPs from N recorded sweeps. The technique is developed within a Bayesian estimation framework and uses flexible stochastic models to describe the average response and the N shifts between the single-trial EPs and this average. Differently from other single-trial estimation approaches proposed in the literature, MTL can provide estimates of both the average and the N single-trial EPs in a single stage. In the present paper, MTL is successfully assessed on both synthetic (100 simulated recording sessions with N=20 sweeps) and real data (11 subjects with N=20 sweeps) relative to a cognitive task carried out for the investigation of the P300 component of the EP. PMID:23261078

  9. Cholinergic pairing with visual activation results in long-term enhancement of visual evoked potentials.

    Directory of Open Access Journals (Sweden)

    Jun Il Kang

    Full Text Available Acetylcholine (ACh contributes to learning processes by modulating cortical plasticity in terms of intensity of neuronal activity and selectivity properties of cortical neurons. However, it is not known if ACh induces long term effects within the primary visual cortex (V1 that could sustain visual learning mechanisms. In the present study we analyzed visual evoked potentials (VEPs in V1 of rats during a 4-8 h period after coupling visual stimulation to an intracortical injection of ACh analog carbachol or stimulation of basal forebrain. To clarify the action of ACh on VEP activity in V1, we individually pre-injected muscarinic (scopolamine, nicotinic (mecamylamine, alpha7 (methyllycaconitine, and NMDA (CPP receptor antagonists before carbachol infusion. Stimulation of the cholinergic system paired with visual stimulation significantly increased VEP amplitude (56% during a 6 h period. Pre-treatment with scopolamine, mecamylamine and CPP completely abolished this long-term enhancement, while alpha7 inhibition induced an instant increase of VEP amplitude. This suggests a role of ACh in facilitating visual stimuli responsiveness through mechanisms comparable to LTP which involve nicotinic and muscarinic receptors with an interaction of NMDA transmission in the visual cortex.

  10. The Insulin-Mediated Modulation of Visually Evoked Magnetic Fields Is Reduced in Obese Subjects

    Science.gov (United States)

    Tschritter, Otto; Rogic, Maja; Heni, Martin; Stingl, Katarina; Hallschmid, Manfred; Häring, Hans-Ulrich; Fritsche, Andreas; Preissl, Hubert; Hennige, Anita M.

    2011-01-01

    Background Insulin is an anorexigenic hormone that contributes to the termination of food intake in the postprandial state. An alteration in insulin action in the brain, named “cerebral insulin resistance”, is responsible for overeating and the development of obesity. Methodology/Principal Findings To analyze the direct effect of insulin on food-related neuronal activity we tested 10 lean and 10 obese subjects. We conducted a magnetencephalography study during a visual working memory task in both the basal state and after applying insulin or placebo spray intranasally to bypass the blood brain barrier. Food and non-food pictures were presented and subjects had to determine whether or not two consecutive pictures belonged to the same category. Intranasal insulin displayed no effect on blood glucose, insulin or C-peptide concentrations in the periphery; however, it led to an increase in the components of evoked fields related to identification and categorization of pictures (at around 170 ms post stimuli in the visual ventral stream) in lean subjects when food pictures were presented. In contrast, insulin did not modulate food-related brain activity in obese subjects. Conclusions/Significance We demonstrated that intranasal insulin increases the cerebral processing of food pictures in lean whereas this was absent in obese subjects. This study further substantiates the presence of a “cerebral insulin resistance” in obese subjects and might be relevant in the pathogenesis of obesity. PMID:21589921

  11. A lower limb exoskeleton control system based on steady state visual evoked potentials

    Science.gov (United States)

    Kwak, No-Sang; Müller, Klaus-Robert; Lee, Seong-Whan

    2015-10-01

    Objective. We have developed an asynchronous brain-machine interface (BMI)-based lower limb exoskeleton control system based on steady-state visual evoked potentials (SSVEPs). Approach. By decoding electroencephalography signals in real-time, users are able to walk forward, turn right, turn left, sit, and stand while wearing the exoskeleton. SSVEP stimulation is implemented with a visual stimulation unit, consisting of five light emitting diodes fixed to the exoskeleton. A canonical correlation analysis (CCA) method for the extraction of frequency information associated with the SSVEP was used in combination with k-nearest neighbors. Main results. Overall, 11 healthy subjects participated in the experiment to evaluate performance. To achieve the best classification, CCA was first calibrated in an offline experiment. In the subsequent online experiment, our results exhibit accuracies of 91.3 ± 5.73%, a response time of 3.28 ± 1.82 s, an information transfer rate of 32.9 ± 9.13 bits/min, and a completion time of 1100 ± 154.92 s for the experimental parcour studied. Significance. The ability to achieve such high quality BMI control indicates that an SSVEP-based lower limb exoskeleton for gait assistance is becoming feasible.

  12. Prey capture behaviour evoked by simple visual stimuli in larval zebrafish

    Directory of Open Access Journals (Sweden)

    Isaac Henry Bianco

    2011-12-01

    Full Text Available Understanding how the nervous system recognises salient stimuli in the environ- ment and selects and executes the appropriate behavioural responses is a fundamen- tal question in systems neuroscience. To facilitate the neuroethological study of visually-guided behaviour in larval zebrafish, we developed “virtual reality” assays in which precisely controlled visual cues can be presented to larvae whilst their behaviour is automatically monitored using machine-vision algorithms. Freely swimming larvae responded to moving stimuli in a size-dependent manner: they directed multiple low amplitude orienting turns (∼ 20◦ towards small moving spots (1◦ but reacted to larger spots (10◦ with high-amplitude aversive turns (∼ 60◦. The tracking of small spots led us to examine how larvae respond to prey during hunting routines. By analysing movie sequences of larvae hunting parame- cia, we discovered that all prey capture routines commence with eye convergence and larvae maintain their eyes in a highly converged position for the duration of the prey-tracking and capture swim phases. We adapted our virtual reality assay to deliver artificial visual cues to partially restrained larvae and found that small moving spots evoked convergent eye movements and J-turns of the tail, which are defining features of natural hunting. We propose that eye convergence represents the engagement of a predatory mode of behaviour in larval fish and serves to increase the region of binocular visual space to enable stereoscopic targeting of prey.

  13. Membrane permeable C-terminal dopamine transporter peptides attenuate amphetamine-evoked dopamine release

    DEFF Research Database (Denmark)

    Rickhag, Karl Mattias; Owens, WA; Winkler, Marie-Therese;

    2013-01-01

    The dopamine transporter (DAT) is responsible for sequestration of extracellular dopamine (DA). The psychostimulant amphetamine (AMPH) is a DAT substrate, which is actively transported into the nerve terminal, eliciting vesicular depletion and reversal of DA transport via DAT. Here, we investigate....../Discs-large/ZO-1 (PDZ)-binding sequence of DAT, was made membrane-permeable by fusing it to the cell membrane transduction domain of the HIV-1 Tat protein (TAT-C24WT). The ability of TAT-C24WT but not a scrambled peptide (TAT-C24Scr) to block the CaMKIIα-DAT interaction was supported by co......-binding sequence, but preserved CaMKIIα binding (TAT-C24AAA), to diminish AMPH-evoked DA efflux in vivo to the same extent as TAT-C24WT. Finally, AMPH-induced locomotor hyperactivity was attenuated following systemic administration of TAT-C24WT but not TAT-C24Scr. Summarized, our findings substantiate that DAT C...

  14. High-threshold mechanosensitive ion channels blocked by a novel conopeptide mediate pressure-evoked pain.

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    Liam J Drew

    Full Text Available Little is known about the molecular basis of somatosensory mechanotransduction in mammals. We screened a library of peptide toxins for effects on mechanically activated currents in cultured dorsal root ganglion neurons. One conopeptide analogue, termed NMB-1 for noxious mechanosensation blocker 1, selectively inhibits (IC(50 1 microM sustained mechanically activated currents in a subset of sensory neurons. Biotinylated NMB-1 retains activity and binds selectively to peripherin-positive nociceptive sensory neurons. The selectivity of NMB-1 was confirmed by the fact that it has no inhibitory effects on voltage-gated sodium and calcium channels, or ligand-gated channels such as acid-sensing ion channels or TRPA1 channels. Conversely, the tarantula toxin, GsMTx-4, which inhibits stretch-activated ion channels, had no effects on mechanically activated currents in sensory neurons. In behavioral assays, NMB-1 inhibits responses only to high intensity, painful mechanical stimulation and has no effects on low intensity mechanical stimulation or thermosensation. Unexpectedly, NMB-1 was found to also be an inhibitor of rapid FM1-43 loading (a measure of mechanotransduction in cochlear hair cells. These data demonstrate that pharmacologically distinct channels respond to distinct types of mechanical stimuli and suggest that mechanically activated sustained currents underlie noxious mechanosensation. NMB-1 thus provides a novel diagnostic tool for the molecular definition of channels involved in hearing and pressure-evoked pain.

  15. Temporary deafferentation evoked by cutaneous anesthesia: behavioral and electrophysiological findings in healthy subjects.

    Science.gov (United States)

    Sehle, Aida; Büsching, Imke; Vogt, Eva; Liepert, Joachim

    2016-05-01

    Motor function and motor excitability can be modulated by changes of somatosensory input. Here, we performed a randomized single-blind trial to investigate behavioral and neurophysiological changes during temporary deafferentation of left upper arm and forearm in 31 right-handed healthy adults. Lidocaine cream was used to anesthetize the skin from wrist to shoulder, sparing the hand. As control condition, on a different day, a neutral cream was applied to the same skin area. The sequence (first Lidocaine, then placebo or vice versa) was randomized. Behavioral measures included the Grating Orientation Task, the Von Frey hair testing and the Nine-hole-peg-test. Transcranial magnetic stimulation was used to investigate short-interval intracortical inhibition, stimulus response curves, motor evoked potential amplitudes during pre-innervation and the cortical silent period (CSP). Recordings were obtained from left first dorsal interosseous muscle and from left flexor carpi radialis muscle. During deafferentation, the threshold of touch measured at the forearm was significantly worse. Other behavioral treatment-related changes were not found. The CSP showed a significant interaction between treatment and time in first dorsal interosseous muscle. CSP duration was longer during Lidocaine application and shorter during placebo exposure. We conclude that, in healthy subjects, temporary cutaneous deafferentation of upper and lower arm may have minor effects on motor inhibition, but not on sensory or motor function for the adjacent non-anesthetized hand. PMID:26983925

  16. Effects of light deprivation on visual evoked potentials in migraine without aura

    Directory of Open Access Journals (Sweden)

    Pierelli Francesco

    2011-07-01

    Full Text Available Abstract Background The mechanisms underlying the interictal habituation deficit of cortical visual evoked potentials (VEP in migraine are not well understood. Abnormal long-term functional plasticity of the visual cortex may play a role and it can be assessed experimentally by light deprivation (LD. Methods We have compared the effects of LD on VEP in migraine patients without aura between attacks (MO, n = 17 and in healthy volunteers (HV, n = 17. Six sequential blocks of 100 averaged VEP at 3.1 Hz were recorded before and after 1 hour of LD. We measured VEP P100 amplitude of the 1st block of 100 sweeps and its change over 5 sequential blocks of 100 responses. Results In HV, the consequence of LD was a reduction of 1st block VEP amplitude and of the normal habituation pattern. By contrast, in MO patients, the interictal habituation deficit was not significantly modified, although 1st block VEP amplitude, already lower than in HV before LD, further decreased after LD. Conclusions Light deprivation is thought to decrease both excitatory and subsequent inhibitory processes in visual cortex, which is in line with our findings in healthy volunteers. The VEP results in migraine patients suggest that early excitation was adequately suppressed, but not the inhibitory mechanisms occurring during long term stimulation and habituation. Accordingly, deficient intracortical inhibition is unlikely to be a primary factor in migraine pathophysiology and the habituation deficit.

  17. 3D graphics, virtual reality, and motion-onset visual evoked potentials in neurogaming.

    Science.gov (United States)

    Beveridge, R; Wilson, S; Coyle, D

    2016-01-01

    A brain-computer interface (BCI) offers movement-free control of a computer application and is achieved by reading and translating the cortical activity of the brain into semantic control signals. Motion-onset visual evoked potentials (mVEP) are neural potentials employed in BCIs and occur when motion-related stimuli are attended visually. mVEP dynamics are correlated with the position and timing of the moving stimuli. To investigate the feasibility of utilizing the mVEP paradigm with video games of various graphical complexities including those of commercial quality, we conducted three studies over four separate sessions comparing the performance of classifying five mVEP responses with variations in graphical complexity and style, in-game distractions, and display parameters surrounding mVEP stimuli. To investigate the feasibility of utilizing contemporary presentation modalities in neurogaming, one of the studies compared mVEP classification performance when stimuli were presented using the oculus rift virtual reality headset. Results from 31 independent subjects were analyzed offline. The results show classification performances ranging up to 90% with variations in conditions in graphical complexity having limited effect on mVEP performance; thus, demonstrating the feasibility of using the mVEP paradigm within BCI-based neurogaming. PMID:27590974

  18. Diffusion tensor imaging of the inferior colliculus and brainstem auditory-evoked potentials in preterm infants

    International Nuclear Information System (INIS)

    Preterm and low-birth-weight infants have an increased risk of sensorineural hearing loss. Brainstem auditory-evoked potentials (BAEP) are an effective method to detect subtle deficits in impulse conduction in the auditory pathway. Abnormalities on diffusion tensor imaging (DTI) have been shown to be associated with perinatal white-matter injury and reduced fractional anisotropy (FA) has been reported in patients with sensorineural hearing loss. To evaluate the possibility of a correlation between BAEP and DTI of the inferior colliculus in preterm infants. DTI at term age and BAEP measurements were performed on all very-low-birth-weight or very preterm study infants (n=56). FA and apparent diffusion coefficient (ADC) of the inferior colliculus were measured from the DTI. Shorter BAEP wave I, III, and V latencies and I-III and I-V intervals and higher wave V amplitude correlated with higher FA of the inferior colliculus. The association between the DTI findings of the inferior colliculus and BAEP responses suggests that DTI can be used to assess the integrity of the auditory pathway in preterm infants. (orig.)

  19. Evoked bioelectrical activity of efferent fibers of the sciatic nerve of white rats in experimental menopause

    Directory of Open Access Journals (Sweden)

    Rodinsky A.G.

    2016-03-01

    Full Text Available The aim of our work was analysis of the bioelectrical activity of efferent fibers of the sciatic nerve in experimental menopause condition. Experiments were performed on 25 female white rats, divided into experimental and control groups. Menopause was modeled by total ovariohysterectomy. In 120 days after modeling we had recorded evoked action potentials of fibers of isolated ventral root L5 induced by stimulation of sciatic nerve with rectangular pulses. Threshold, chronaxia, latency, amplitude and duration of the action potential (AP were analysed. Refractory phenomenon was investigated by applying paired stimuli at intervals of 2 to 20 ms. In the context of long-term hypoestrogenemy threshold of AP appearance was 55,32±7,69%, chronaxy – 115,09±2,67%, latent period – 112,62±1,74% as compared with the control animals (p<0.01. In conditions of paired stimuli applying the amplitude of response to the testing stimulus in animals with ovariohysterectomy at intervals 3 and 4 ms was 61,25±36,45% and 53,48±18,64% (p<0.05 respectively.

  20. Sensory-evoked and spontaneous gamma and spindle bursts in neonatal rat motor cortex.

    Science.gov (United States)

    An, Shuming; Kilb, Werner; Luhmann, Heiko J

    2014-08-13

    Self-generated neuronal activity originating from subcortical regions drives early spontaneous motor activity, which is a hallmark of the developing sensorimotor system. However, the neural activity patterns and role of primary motor cortex (M1) in these early movements are still unknown. Combining voltage-sensitive dye imaging (VSDI) with simultaneous extracellular multielectrode recordings in postnatal day 3 (P3)-P5 rat primary somatosensory cortex (S1) and M1 in vivo, we observed that tactile forepaw stimulation induced spindle bursts in S1 and gamma and spindle bursts in M1. Approximately 40% of the spontaneous gamma and spindle bursts in M1 were driven by early motor activity, whereas 23.7% of the M1 bursts triggered forepaw movements. Approximately 35% of the M1 bursts were uncorrelated to movements and these bursts had significantly fewer spikes and shorter burst duration. Focal electrical stimulation of layer V neurons in M1 mimicking physiologically relevant 40 Hz gamma or 10 Hz spindle burst activity reliably elicited forepaw movements. We conclude that M1 is already involved in somatosensory information processing during early development. M1 is mainly activated by tactile stimuli triggered by preceding spontaneous movements, which reach M1 via S1. Only a fraction of M1 activity transients trigger motor responses directly. We suggest that both spontaneously occurring and sensory-evoked gamma and spindle bursts in M1 contribute to the maturation of corticospinal and sensorimotor networks required for the refinement of sensorimotor coordination. PMID:25122889