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Sample records for auditory brain stem implantation

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

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    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.

  2. Auditory brain-stem responses in syphilis.

    OpenAIRE

    Rosenhall, U; Roupe, G

    1981-01-01

    Analysis of auditory brain-stem electrical responses (BSER) provides an effective means of detecting lesions in the auditory pathways. In the present study the wave patterns were analysed in 11 patients with secondary or latent syphilis with no clinical symptoms referrable to the central nervous system and in two patients with congenital syphilis and general paralysis. Decreased amplitudes and prolonged latencies occurred frequently in patients with secondary and with advanced syphilis. This ...

  3. [Auditory hallucinations in lesions of the brain stem].

    Science.gov (United States)

    Cambier, J; Decroix, J P; Masson, C

    1987-01-01

    Since the publication by Jean Lhermitte in 1922 of his paper on hallucinosis, the peduncular type has been described as a purely visual phenomenon. However, limited brain stem lesions can give rise to analogous manifestations in the auditory field. Five cases of auditory hallucinosis are reviewed, the first four resulting from a lesion of tegmentum of pons responsible for contralateral hemi-anesthesia and homolateral facial palsy with paralysis of laterality. Central type hypoacusis and a severe disorder of localization of sounds revealed a lesion of trapezoid body. The fifth case resulted from a peduncular lesion in region supplied by superior cerebellar artery, the auditory deficit being related to a lesion of inferior corpus quadrigeminum. In one patient, the auditory hallucinosis was followed by a period of visual hallucinations and oneiric delusions. Both auditory and visual hallucinosis can be related to hypnagogic hallucinations. Dream mechanisms (the geniculo-occipital spikes system) escape from normal inhibitory control exerted by the raphe nuclei. Auditory deafferentation could predispose to auditory hallucinosis. PMID:3629075

  4. 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...

  5. Auditory Brain Stem Processing in Reptiles and Amphibians: Roles of Coupled Ears

    DEFF Research Database (Denmark)

    Willis, Katie L.; Christensen-Dalsgaard, Jakob; Carr, Catherine

    2014-01-01

    Comparative approaches to the auditory system have yielded great insight into the evolution of sound localization circuits, particularly within the nonmammalian tetrapods. The fossil record demonstrates multiple appearances of tympanic hearing, and examination of the auditory brain stem of various...... groups can reveal the organizing effects of the ear across taxa. If the peripheral structures have a strongly organizing influence on the neural structures, then homologous neural structures should be observed only in groups with a homologous tympanic ear. Therefore, the central auditory systems of...... anurans (frogs), reptiles (including birds), and mammals should all be more similar within each group than among the groups. Although there is large variation in the peripheral auditory system, there is evidence that auditory brain stem nuclei in tetrapods are homologous and have similar functions among...

  6. 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.

  7. Correlation of auditory brain stem response and the MRI measurements in neuro-degenerative disorders

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    Kamei, Hidekazu (Tokyo Women' s Medical Coll. (Japan))

    1989-06-01

    The purpose of this study is to elucidate correlations of several MRI measurements of the cranium and brain, functioning as a volume conductor, to the auditory brain stem response (ABR) in neuro-degenerative disorders. The subjects included forty-seven patients with spinocerebellar degeneration (SCD) and sixteen of amyotrophic lateral sclerosis (ALS). Statistically significant positive correlations were found between I-V and III-V interpeak latencies (IPLs) and the area of cranium and brain in the longitudinal section of SCD patients, and between I-III and III-V IPLs and the area in the longitudinal section of those with ALS. And, also there were statistically significant correlations between the amplitude of the V wave and the area of brain stem as well as that of the cranium in the longitudinal section of SCD patients, and between the amplitude of the V wave and the area of the cerebrum in the longitudinal section of ALS. In conclusion, in the ABR, the IPLs were prolonged and the amplitude of the V wave was decreased while the MRI size of the cranium and brain increased. When the ABR is applied to neuro-degenerative disorders, it might be important to consider not only the conduction of the auditory tracts in the brain stem, but also the correlations of the size of the cranium and brain which act as a volume conductor. (author).

  8. Correlation of auditory brain stem response and the MRI measurements in neuro-degenerative disorders

    International Nuclear Information System (INIS)

    The purpose of this study is to elucidate correlations of several MRI measurements of the cranium and brain, functioning as a volume conductor, to the auditory brain stem response (ABR) in neuro-degenerative disorders. The subjects included forty-seven patients with spinocerebellar degeneration (SCD) and sixteen of amyotrophic lateral sclerosis (ALS). Statistically significant positive correlations were found between I-V and III-V interpeak latencies (IPLs) and the area of cranium and brain in the longitudinal section of SCD patients, and between I-III and III-V IPLs and the area in the longitudinal section of those with ALS. And, also there were statistically significant correlations between the amplitude of the V wave and the area of brain stem as well as that of the cranium in the longitudinal section of SCD patients, and between the amplitude of the V wave and the area of the cerebrum in the longitudinal section of ALS. In conclusion, in the ABR, the IPLs were prolonged and the amplitude of the V wave was decreased while the MRI size of the cranium and brain increased. When the ABR is applied to neuro-degenerative disorders, it might be important to consider not only the conduction of the auditory tracts in the brain stem, but also the correlations of the size of the cranium and brain which act as a volume conductor. (author)

  9. 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).

  10. Effect of Acupuncture on the Auditory Evoked Brain Stem Potential in Parkinson's Disease

    Institute of Scientific and Technical Information of China (English)

    王玲玲; 何崇; 刘跃光; 朱莉莉

    2002-01-01

    @@ Under the auditory evoked brain stem potential (ABP) examination, the latent period of V wave and the intermittent periods of III-V peak and I-V peak were significantly shortened in Parkinson's disease patients of the treatment group (N=29) after acupuncture treatment. The difference of cumulative scores in Webster's scale was also decreased in correlation analysis. The increase of dopamine in the brain and the excitability of the dopamine neurons may contribute to the therapeutic effects, in TCM terms, of subduing the pathogenic wind and tranquilizing the mind.

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

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    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.

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

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    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.

  13. Auditory brain-stem evoked potentials in cat after kainic acid induced neuronal loss. II. Cochlear nucleus.

    Science.gov (United States)

    Zaaroor, M; Starr, A

    1991-01-01

    Auditory brain-stem potentials (ABRs) were studied in cats for up to 6 weeks after kainic acid had been injected unilaterally into the cochlear nucleus (CN) producing extensive neuronal destruction. The ABR components were labeled by the polarity at the vertex (P, for positive) and their order of appearance (the arabic numerals 1, 2, etc.). Component P1 can be further subdivided into 2 subcomponents, P1a and P1b. The assumed correspondence between the ABR components in cat and man is indicated by providing human Roman numeral designations in parentheses following the feline notation, e.g., P2 (III). To stimulation of the ear ipsilateral to the injection, the ABR changes consisted of a loss of components P2 (III) and P3 (IV), and an attenuation and prolongation of latency of components P4 (V) and P5 (VI). The sustained potential shift from which the components arose was not affected. Wave P1a (I) was also slightly but significantly attenuated compatible with changes of excitability of nerve VIII in the cochlea secondary to cochlear nucleus destruction. Unexpectedly, to stimulation of the ear contralateral to the injection side, waves P2 (III), P3 (IV), and P4 (V) were also attenuated and delayed in latency but to a lesser degree than to stimulation of the ear ipsilateral to the injection. Changes in binaural interaction of the ABR following cochlear nucleus lesions were similar to those produced in normal animals by introducing a temporal delay of the input to one ear. The results of the present set of studies using kainic acid to induce neuronal loss in auditory pathway when combined with prior lesion and recording experiments suggest that each of the components of the ABR requires the integrity of an anatomically diffuse system comprising a set of neurons, their axons, and the neurons on which they terminate. Disruption of any portion of the system will alter the amplitude and/or the latency of that component. PMID:1716569

  14. AUDITORY HAIR CELL EXPLANT CO-CULTURES PROMOTE THE DIFFERENTIATION OF STEM CELLS INTO BIPOLAR NEURONS

    OpenAIRE

    Coleman, B.; Fallon, J. B.; Gillespie, L.N.; Silva, M.G.; Shepherd, R.K.

    2006-01-01

    Auditory neurons, the target neurons of the cochlear implant, degenerate following a sensorineural hearing loss. The goal of this research is to direct the differentiation of embryonic stem cells (SCs) into bipolar auditory neurons that can be used to replace degenerating neurons in the deafened mammalian cochlea. Successful replacement of auditory neurons is likely to result in improved clinical outcomes for cochlear implant recipients. We examined two post-natal auditory co-culture models w...

  15. Evaluation of brain stem auditory evoked potentials in stable patients with chronic obstructive pulmonary disease

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    Gupta Prem

    2008-01-01

    Full Text Available Though there are few studies addressing brainstem auditory evoked potentials (BAEP in patients with chronic obstructive pulmonary disease (COPD, subclinical BAEP abnormalities in stable COPD patients have not been studied. The present study aimed to evaluate the BAEP abnormalities in this study group. Materials and Methods : In the present study, 80 male subjects were included: COPD group comprised 40 smokers with stable COPD with no clinical neuropathy; 40 age-matched healthy volunteers served as the control group. Latencies of BAEP waves I, II, III, IV, and V, together with interpeak latencies (IPLs of I-III, I-V, and III-V, and amplitudes of waves I-Ia and V-Va were studied in both the groups to compare the BAEP abnormalities in COPD group; the latter were correlated with patient characteristics and Mini-Mental Status Examination Questionnaire (MMSEQ scores to seek any significant correlation. Results: Twenty-six (65% of the 40 COPD patients had BAEP abnormalities. We observed significantly prolonged latencies of waves I, III, V over left ear and waves III, IV, V over right ear; increased IPLs of I-V, III-V over left ear and of I-III, I-V, III-V over right side. Amplitudes of waves I-Ia and V-Va were decreased bilaterally. Over left ear, the latencies of wave I and III were significantly correlated with FEV 1 ; and amplitude of wave I-Ia, with smoking pack years. A weak positive correlation between amplitude of wave I-Ia and duration of illness; and a weak negative correlation between amplitude of wave V-Va and MMSEQ scores were seen over right side. Conclusions : We observed significant subclinical BAEP abnormalities on electrophysiological evaluation in studied stable COPD male patients having mild-to-moderate airflow obstruction.

  16. Auditory brain-stem evoked potentials in cat after kainic acid induced neuronal loss. I. Superior olivary complex.

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    Zaaroor, M; Starr, A

    1991-01-01

    Auditory brain-stem potentials (ABRs) were studied in cats for up to 45 days after kainic acid had been injected unilaterally or bilaterally into the superior olivary complex (SOC) to produce neuronal destruction while sparing fibers of passage and the terminals of axons of extrinsic origin connecting to SOC neurons. The components of the ABR in cat were labeled by their polarity at the vertex (P, for positive) and their order of appearance (the arabic numerals 1, 2, etc.). Component P1 can be further subdivided into 2 subcomponents labeled P1a and P1b. The correspondences we have assumed between the ABR components in cat and man are indicated by providing a Roman numeral designation for the human component in parentheses following the feline notation, e.g., P4 (V). With bilateral SOC destruction, there was a significant and marked attenuation of waves P2 (III), P3 (IV), P4 (V), P5 (VI), and the sustained potential shift (SPS) amounting to as much as 80% of preoperative values. Following unilateral SOC destruction the attenuation of many of these same ABR components, in response to stimulation of either ear, was up to 50%. No component of the ABR was totally abolished even when the SOC was lesioned 100% bilaterally. In unilaterally lesioned cats with extensive neuronal loss (greater than 75%) the latencies of the components beginning at P3 (IV) were delayed to stimulation of the ear ipsilateral to the injection site but not to stimulation of the ear contralateral to the injection. Binaural interaction components of the ABR were affected in proportion to the attenuation of the ABR. These results are compatible with multiple brain regions contributing to the generation of the components of the ABR beginning with P2 (III) and that components P3 (IV), P4 (V), and P5 (VI) and the sustained potential shift depend particularly on the integrity of the neurons of the SOC bilaterally. The neurons of the lateral subdivision (LSO) and the medial nucleus of the trapezoid body

  17. 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

  18. 脑干听觉诱发电位在脑干梗死诊断中的应用%Application of brain stem auditory evoked potential machine in diagnosis of brain stem infarction

    Institute of Scientific and Technical Information of China (English)

    蒙凌

    2015-01-01

    目的 对脑干听觉诱发电位(BAEP)检测在脑干梗死诊断中的应用价值进行分析探讨.方法 30例脑干梗死患者作为观察组, 对其分别进行头颅CT或核磁共振(MRI)及BAEP检查, 对比3种检查方法 检测阳性率.以30例健康志愿者作为对照组, 对比两组研究对象的BAEP检测结果 .结果 BAEP检测阳性率为83.33%, MRI检测阳性率为56.67%, CT检测阳性率为46.67%, BAEP检测阳性率明显高于MRI及CT, 差异有统计学意义(P<0.05).观察组患者Ⅲ波及Ⅴ波潜伏期(PL), Ⅰ~Ⅲ波及Ⅲ~Ⅴ波峰间潜伏期(IPL)延长同对照组比较, 差异有统计学意义(P<0.05).结论 对脑干梗死患者采用BAEP检查敏感性较高, 可为该病的早期诊断提供依据.%Objective To analyze and investigate application value of brain stem auditory evoked potential machine (BAEP) in diagnosis of brain stem infarction.Methods There were 30 patients with brain stem infarction as observation group. They received head CT or magnetic resonance imaging (MRI) and BAEP for examination. Comparison was made on positive rate across the 3 examination methods. Another 30 healthy volunteers were taken as control group. BAEP detection outcomes were compared between the two groups.Results Positive rate of BAEP was 83.33%, that of MRI was 56.67%, and that of CT was 46.67%. BAEP had much higher positive rate than MRI and CT, and the difference had statistical significance (P<0.05). The difference of prolonged Ⅲ wave and Ⅴ wave peak latencies (PL), Ⅰ~Ⅲ wave and Ⅲ~Ⅴ wave interpeak latencies (IPL) had statistical significance between the observation group and the control group (P<0.05).Conclusion Implement of BAEP for brain stem infarction patients shows high sensitivity in detection, and it can provide reference for early diagnosis.

  19. Cochlear Implants and Brain Plasticity

    OpenAIRE

    Fallon, James B.; Irvine, Dexter R. F.; Shepherd, Robert K.

    2002-01-01

    Cochlear implants have been implanted in over 110,000 deaf adults and children worldwide and provide these patients with important auditory cues necessary for auditory awareness and speech perception via electrical stimulation of the auditory nerve (AN). In 1942 Woolsey & Walzl presented the first report of cortical responses to localised electrical stimulation of different sectors of the AN in normal hearing cats, and established the cochleotopic organization of the projections to primary au...

  20. 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…

  1. Implanted stem cells - a promising tool for therapy of brain and spinal cord injuries

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva

    Krakow, 2004. s. 24. [Annual Meeting of the European Stem Cell Therapeutics Excellence Centre (STEC) /2./. 07.06.2004-08.06.2004, Krakow] R&D Projects: GA MŠk LN00A065 Keywords : bone marrow stem cells * bone marow hematopoetic cells Subject RIV: FH - Neurology

  2. Hydrogel limits stem cell dispersal in the deaf cochlea: implications for cochlear implants

    Science.gov (United States)

    Nayagam, Bryony A.; Backhouse, Steven S.; Cimenkaya, Cengiz; Shepherd, Robert K.

    2012-12-01

    Auditory neurons provide the critical link between a cochlear implant and the brain in deaf individuals, therefore their preservation and/or regeneration is important for optimal performance of this neural prosthesis. In cases where auditory neurons are significantly depleted, stem cells (SCs) may be used to replace the lost population of neurons, thereby re-establishing the critical link between the periphery (implant) and the brain. For such a therapy to be therapeutically viable, SCs must be differentiated into neurons, retained at their delivery site and damage caused to the residual auditory neurons minimized. Here we describe the transplantation of SC-derived neurons into the deaf cochlea, using a peptide hydrogel to limit their dispersal. The described approach illustrates that SCs can be delivered to and are retained within the basal turn of the cochlea, without a significant loss of endogenous auditory neurons. In addition, the tissue response elicited from this surgical approach was restricted to the surgical site and did not extend beyond the cochlear basal turn. Overall, this approach illustrates the feasibility of targeted cell delivery into the mammalian cochlea using hydrogel, which may be useful for future cell-based transplantation strategies, for combined treatment with a cochlear implant to restore function.

  3. Therapeutic potential of stem cells in auditory hair cell repair

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    Ryuji Hata

    2009-01-01

    Full Text Available The prevalence of acquired hearing loss is very high. About 10% of the total population and more than one third of the population over 65 years suffer from debilitating hearing loss. The most common type of hearing loss in adults is idiopathic sudden sensorineural hearing loss (ISSHL. In the majority of cases, ISSHL is permanent and typically associated with loss of sensory hair cells in the organ of Corti. Following the loss of sensory hair cells, the auditory neurons undergo secondary degeneration. Sensory hair cells and auditory neurons do not regenerate throughout life, and loss of these cells is irreversible and cumulative. However, recent advances in stem cell biology have gained hope that stem cell therapy comes closer to regenerating sensory hair cells in humans. A major advance in the prospects for the use of stem cells to restore normal hearing comes with the recent discovery that hair cells can be generated ex vivo from embryonic stem (ES cells, adult inner ear stem cells and neural stem cells. Furthermore, there is increasing evidence that stem cells can promote damaged cell repair in part by secreting diffusible molecules such as growth factors. These results suggest that stem-cell-based treatment regimens can be applicable to the damaged inner ear as future clinical applications.Previously we have established an animal model of cochlear ischemia in gerbils and showed progressive hair cell loss up to 4 days after ischemia. Auditory brain stem response (ABR recordings have demonstrated that this gerbil model displays severe deafness just after cochlear ischemia and gradually recovers thereafter. These pathological findings and clinical manifestations are reminiscent of ISSHL in humans. In this study, we have shown the effectiveness of stem cell therapy by using this animal model of ISSHL.

  4. Assessment of auditory cortical function in cochlear implant patients using 15O PET

    International Nuclear Information System (INIS)

    Full text: Cochlear implantation has been an extraordinarily successful method of restoring hearing and the potential for full language development in pre-lingually and post-lingually deaf individuals (Gibson 1996). Post-lingually deaf patients, who develop their hearing loss later in life, respond best to cochlear implantation within the first few years of their deafness, but are less responsive to implantation after several years of deafness (Gibson 1996). In pre-lingually deaf children, cochlear implantation is most effect in allowing the full development language skills when performed within a critical period, in the first 8 years of life. These clinical observations suggest considerable neural plasticity of the human auditory cortex in acquiring and retaining language skills (Gibson 1996, Buchwald 1990). Currently, electrocochleography is used to determine the integrity of the auditory pathways to the auditory cortex. However, the functional integrity of the auditory cortex cannot be determined by this method. We have defined the extent of activation of the auditory cortex and auditory association cortex in 6 normal controls and 6 cochlear implant patients using 15O PET functional brain imaging methods. Preliminary results have indicated the potential clinical utility of 15O PET cortical mapping in the pre-surgical assessment and post-surgical follow up of cochlear implant patients. Copyright (1998) Australian Neuroscience Society

  5. Imaging the fate of implanted stem cells in brain and spinal cord injury

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva

    Innsbruck : organizátor, 2003, s. 1. [FENS Winter School 2003. Kitzbuehel (AT), 07.12.2003-14.12.2003] R&D Projects: GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z5039906 Keywords : Stem cells * spinal cord injury Subject RIV: FH - Neurology

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

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    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.

  7. Noise-gated encoding of slow inputs by auditory brain stem neurons with a low-threshold K+ current.

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    Gai, Yan; Doiron, Brent; Kotak, Vibhakar; Rinzel, John

    2009-12-01

    Phasic neurons, which do not fire repetitively to steady depolarization, are found at various stages of the auditory system. Phasic neurons are commonly described as band-pass filters because they do not respond to low-frequency inputs even when the amplitude is large. However, we show that phasic neurons can encode low-frequency inputs when noise is present. With a low-threshold potassium current (I(KLT)), a phasic neuron model responds to rising and falling phases of a subthreshold low-frequency signal with white noise. When the white noise was low-pass filtered, the phasic model also responded to the signal's trough but still not to the peak. In contrast, a tonic neuron model fired mostly to the signal's peak. To test the model predictions, whole cell slice recordings were obtained in the medial (MSO) and lateral (LSO) superior olivary neurons in gerbil from postnatal day 10 (P10) to 22. The phasic MSO neurons with strong I(KLT), mostly from gerbils aged P17 or older, showed firing patterns consistent with the preceding predictions. Moreover, injecting a virtual I(KLT) into weak-phasic MSO and tonic LSO neurons with putative weak or no I(KLT) (from gerbils younger than P17) shifted the neural response from the signal's peak to the rising phase. These findings advance our knowledge about how noise gates the signal pathway and how phasic neurons encode slow envelopes of sounds with high-frequency carriers. PMID:19812289

  8. Auditory brain-stem response, CT and MR imaging in a family with classical type Pelizaeus-Merzbacher Disease

    International Nuclear Information System (INIS)

    A family in which 5 males in successive generations were clinically suspected to be affected with the classical X-linked recessive form of Pelizaeus-Merzbacher disease (PMD) is presented. Two brothers and their maternal uncle were examined by one of the author (MS). In two brothers, aged 3 years and 2 years, the disease became obvious within a month after birth with nystagmus and head tremor. Head control and sitting were achieved at the age of 18 months at which time they began to speak. They could not stand nor walk without support. They had dysmetria, weakness and hyper-reflexia of lower extremities, and mild mental retardation. Their maternal uncle, aged 37 years, showed psychomotor retardation from birth and subsequently developed spastic paraplegia. He had been able to walk with crutches until adolescence. He had dysmetria, scanning speech, athetoid posture of fingers and significant intellectual deficits. Auditory brainstem response in both brothers revealed well defined waves I and II, low amplitude wave III and an absence of all subsequent components. CT demonstrated mild cerebral atrophy in the elder brother and was normal in the younger brother, but in their uncle, CT showed atrophy of the brainstem, cerebellum and cerebrum, and low density of the white matter of the centrum semiovale. MRI was performed in both brothers. Although the brainstem, the internal capsule and the thalamus were myelinated, the myelination in the subcortical white matter was restricted to periventricular regions on IR sequence scans. On SE sequence, the subcortical white matter was imaged as a brighter area than the cerebral cortex. These results demonstrate that the degree of myelination in these patients was roughly equal to that of 3-to 6-month old infants. (J.P.N.)

  9. Auditory brain-stem response, CT and MR imaging in a family with classical type Pelizaeus-Merzbacher Disease

    Energy Technology Data Exchange (ETDEWEB)

    Shiomi, M.; Ookuni, H.; Sugita, T.

    1987-05-01

    A family in which 5 males in successive generations were clinically suspected to be affected with the classical X-linked recessive form of Pelizaeus-Merzbacher disease (PMD) is presented. Two brothers and their maternal uncle were examined by one of the authors (MS). In two brothers, aged 3 years and 2 years, the disease became obvious within a month after birth with nystagmus and head tremor. Head control and sitting were achieved at the age of 18 months at which time they began to speak. They could not stand nor walk without support. They had dysmetria, weakness and hyper-reflexia of lower extremities, and mild mental retardation. Their maternal uncle, aged 37 years, showed psychomotor retardation from birth and subsequently developed spastic paraplegia. He had been able to walk with crutches until adolescence. He had dysmetria, scanning speech, athetoid posture of fingers and significant intellectual deficits. Auditory brainstem response in both brothers revealed well defined waves I and II, low amplitude wave III and an absence of all subsequent components. CT demonstrated mild cerebral atrophy in the elder brother and was normal in the younger brother, but in their uncle, CT showed atrophy of the brainstem, cerebellum and cerebrum, and low density of the white matter of the centrum semiovale. MRI was performed in both brothers. Although the brainstem, the internal capsule and the thalamus were myelinated, the myelination in the subcortical white matter was restricted to periventricular regions on IR sequence scans. On SE sequence, the subcortical white matter was imaged as a brighter area than the cerebral cortex. These results demonstrate that the degree of myelination in these patients was roughly equal to that of 3-to 6-month old infants.

  10. Modeling of Auditory Neuron Response Thresholds with Cochlear Implants

    OpenAIRE

    Frederic Venail; Thibault Mura; Mohamed Akkari; Caroline Mathiolon; Sophie Menjot de Champfleur; Jean Pierre Piron; Marielle Sicard; Françoise Sterkers-Artieres; Michel Mondain; Alain Uziel

    2015-01-01

    The quality of the prosthetic-neural interface is a critical point for cochlear implant efficiency. It depends not only on technical and anatomical factors such as electrode position into the cochlea (depth and scalar placement), electrode impedance, and distance between the electrode and the stimulated auditory neurons, but also on the number of functional auditory neurons. The efficiency of electrical stimulation can be assessed by the measurement of e-CAP in cochlear implant users. In the ...

  11. Brain tumor stem cells.

    Science.gov (United States)

    Palm, Thomas; Schwamborn, Jens C

    2010-06-01

    Since the end of the 'no-new-neuron' theory, emerging evidence from multiple studies has supported the existence of stem cells in neurogenic areas of the adult brain. Along with this discovery, neural stem cells became candidate cells being at the origin of brain tumors. In fact, it has been demonstrated that molecular mechanisms controlling self-renewal and differentiation are shared between brain tumor stem cells and neural stem cells and that corruption of genes implicated in these pathways can direct tumor growth. In this regard, future anticancer approaches could be inspired by uncovering such redundancies and setting up treatments leading to exhaustion of the cancer stem cell pool. However, deleterious effects on (normal) neural stem cells should be minimized. Such therapeutic models underline the importance to study the cellular mechanisms implicated in fate decisions of neural stem cells and the oncogenic derivation of adult brain cells. In this review, we discuss the putative origins of brain tumor stem cells and their possible implications on future therapies. PMID:20370314

  12. Central auditory development in children with cochlear implants: clinical implications.

    Science.gov (United States)

    Sharma, Anu; Dorman, Michael F

    2006-01-01

    A common finding in developmental neurobiology is that stimulation must be delivered to a sensory system within a narrow window of time (a sensitive period) during development in order for that sensory system to develop normally. Experiments with congenitally deaf children have allowed us to establish the existence and time limits of a sensitive period for the development of central auditory pathways in humans. Using the latency of cortical auditory evoked potentials (CAEPs) as a measure we have found that central auditory pathways are maximally plastic for a period of about 3.5 years. If the stimulation is delivered within that period CAEP latencies reach age-normal values within 3-6 months after stimulation. However, if stimulation is withheld for more than 7 years, CAEP latencies decrease significantly over a period of approximately 1 month following the onset of stimulation. They then remain constant or change very slowly over months or years. The lack of development of the central auditory system in congenitally deaf children implanted after 7 years is correlated with relatively poor development of speech and language skills [Geers, this vol, pp 50-65]. Animal models suggest that the primary auditory cortex may be functionally decoupled from higher order auditory cortex due to restricted development of inter- and intracortical connections in late-implanted children [Kral and Tillein, this vol, pp 89-108]. Another aspect of plasticity that works against late-implanted children is the reorganization of higher order cortex by other sensory modalities (e.g. vision). The hypothesis of decoupling of primary auditory cortex from higher order auditory cortex in children deprived of sound for a long time may explain the speech perception and oral language learning difficulties of children who receive an implant after the end of the sensitive period. PMID:16891837

  13. Auditory steady-state responses in cochlear implant users: Effect of modulation frequency and stimulation artifacts.

    Science.gov (United States)

    Gransier, Robin; Deprez, Hanne; Hofmann, Michael; Moonen, Marc; van Wieringen, Astrid; Wouters, Jan

    2016-05-01

    Previous studies have shown that objective measures based on stimulation with low-rate pulse trains fail to predict the threshold levels of cochlear implant (CI) users for high-rate pulse trains, as used in clinical devices. Electrically evoked auditory steady-state responses (EASSRs) can be elicited by modulated high-rate pulse trains, and can potentially be used to objectively determine threshold levels of CI users. The responsiveness of the auditory pathway of profoundly hearing-impaired CI users to modulation frequencies is, however, not known. In the present study we investigated the responsiveness of the auditory pathway of CI users to a monopolar 500 pulses per second (pps) pulse train modulated between 1 and 100 Hz. EASSRs to forty-three modulation frequencies, elicited at the subject's maximum comfort level, were recorded by means of electroencephalography. Stimulation artifacts were removed by a linear interpolation between a pre- and post-stimulus sample (i.e., blanking). The phase delay across modulation frequencies was used to differentiate between the neural response and a possible residual stimulation artifact after blanking. Stimulation artifacts were longer than the inter-pulse interval of the 500pps pulse train for recording electrodes ipsilateral to the CI. As a result the stimulation artifacts could not be removed by artifact removal on the bases of linear interpolation for recording electrodes ipsilateral to the CI. However, artifact-free responses could be obtained in all subjects from recording electrodes contralateral to the CI, when subject specific reference electrodes (Cz or Fpz) were used. EASSRs to modulation frequencies within the 30-50 Hz range resulted in significant responses in all subjects. Only a small number of significant responses could be obtained, during a measurement period of 5 min, that originate from the brain stem (i.e., modulation frequencies in the 80-100 Hz range). This reduced synchronized activity of brain stem

  14. Modeling of Auditory Neuron Response Thresholds with Cochlear Implants

    Directory of Open Access Journals (Sweden)

    Frederic Venail

    2015-01-01

    Full Text Available The quality of the prosthetic-neural interface is a critical point for cochlear implant efficiency. It depends not only on technical and anatomical factors such as electrode position into the cochlea (depth and scalar placement, electrode impedance, and distance between the electrode and the stimulated auditory neurons, but also on the number of functional auditory neurons. The efficiency of electrical stimulation can be assessed by the measurement of e-CAP in cochlear implant users. In the present study, we modeled the activation of auditory neurons in cochlear implant recipients (nucleus device. The electrical response, measured using auto-NRT (neural responses telemetry algorithm, has been analyzed using multivariate regression with cubic splines in order to take into account the variations of insertion depth of electrodes amongst subjects as well as the other technical and anatomical factors listed above. NRT thresholds depend on the electrode squared impedance (β = −0.11 ± 0.02, P<0.01, the scalar placement of the electrodes (β = −8.50 ± 1.97, P<0.01, and the depth of insertion calculated as the characteristic frequency of auditory neurons (CNF. Distribution of NRT residues according to CNF could provide a proxy of auditory neurons functioning in implanted cochleas.

  15. Modeling of Auditory Neuron Response Thresholds with Cochlear Implants.

    Science.gov (United States)

    Venail, Frederic; Mura, Thibault; Akkari, Mohamed; Mathiolon, Caroline; Menjot de Champfleur, Sophie; Piron, Jean Pierre; Sicard, Marielle; Sterkers-Artieres, Françoise; Mondain, Michel; Uziel, Alain

    2015-01-01

    The quality of the prosthetic-neural interface is a critical point for cochlear implant efficiency. It depends not only on technical and anatomical factors such as electrode position into the cochlea (depth and scalar placement), electrode impedance, and distance between the electrode and the stimulated auditory neurons, but also on the number of functional auditory neurons. The efficiency of electrical stimulation can be assessed by the measurement of e-CAP in cochlear implant users. In the present study, we modeled the activation of auditory neurons in cochlear implant recipients (nucleus device). The electrical response, measured using auto-NRT (neural responses telemetry) algorithm, has been analyzed using multivariate regression with cubic splines in order to take into account the variations of insertion depth of electrodes amongst subjects as well as the other technical and anatomical factors listed above. NRT thresholds depend on the electrode squared impedance (β = -0.11 ± 0.02, P electrodes (β = -8.50 ± 1.97, P < 0.01), and the depth of insertion calculated as the characteristic frequency of auditory neurons (CNF). Distribution of NRT residues according to CNF could provide a proxy of auditory neurons functioning in implanted cochleas. PMID:26236725

  16. Benefits and detriments of unilateral cochlear implant use on bilateral auditory development in children who are deaf

    Directory of Open Access Journals (Sweden)

    Karen A. Gordon

    2013-10-01

    Full Text Available We have explored both the benefits and detriments of providing electrical input through a cochlear implant in one ear to the auditory system of young children. A cochlear implant delivers electrical pulses to stimulate the auditory nerve, providing children who are deaf with access to sound. The goals of implantation are to restrict reorganization of the deprived immature auditory brain and promote development of hearing and spoken language. It is clear that limiting the duration of deprivation is a key factor. Additional considerations are the onset, etiology, and use of residual hearing as each of these can have unique effects on auditory development in the pre-implant period. New findings show that many children receiving unilateral cochlear implants are developing mature-like brainstem and thalamo-cortical responses to sound with long term use despite these sources of variability; however, there remain considerable abnormalities in cortical function. The most apparent, determined by implanting the other ear and measuring responses to acute stimulation, is a loss of normal cortical response from the deprived ear. Recent data reveal that this can be avoided in children by early implantation of both ears simultaneously or with limited delay. We conclude that auditory development requires input early in development and from both ears.

  17. The brain stem function in patients with brain bladder

    International Nuclear Information System (INIS)

    A syndrome of detrusor-sphincter dyssynergia (DSD) is occasionally found in patients with brain bladder. To evaluate the brain stem function in cases of brain bladder, urodynamic study, dynamic CT scan of the brain stem (DCT) and auditory brainstem response (ABR) were performed. The region of interest of DCT aimed at the posterolateral portion of the pons. The results were analysed in contrast with the presense of DSD in urodynamic study. DCT studies were performed in 13 cases with various brain diseases and 5 control cases without neurological diseases. Abnormal patterns of the time-density curve consisted of low peak value, prolongation of filling time and low rapid washout ratio (low clearance ratio) of the contrast medium. Four of 6 cases with DSD showed at least one of the abnormal patterns of the time-density curve bilaterally. In 7 cases without DSD none showed bilateral abnormality of the curve and in 2 of 7 cases only unilateral abnormality was found. ABR was performed in 8 patients with brain diseases. The interpeak latency of the wave I-V (I-V IPL) was considered to be prolonged in 2 cases with DSD compared to that of 4 without DSD. In 2 cases with DSD who had normal DCT findings, measurement of the I-V IPL was impossible due to abnormal pattern of the ABR wave. Above mentioned results suggests the presence of functional disturbance at the posterolateral portion of the pons in cases of brain bladder with DSD. (author)

  18. 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

  19. Auditory Rehabilitation in Rhesus Macaque Monkeys (Macaca mulatta) with Auditory Brainstem Implants

    Institute of Scientific and Technical Information of China (English)

    Zhen-Min Wang; Zhi-Jun Yang; Fu Zhao; Bo Wang; Xing-Chao Wang; Pei-Ran Qu; Pi-Nan Liu

    2015-01-01

    Background:The auditory brainstem implants (ABIs) have been used to treat deafness for patients with neurofibromatosis Type 2 and nontumor patients.The lack of an appropriate animal model has limited the study of improving hearing rehabilitation by the device.This study aimed to establish an animal model of ABI in adult rhesus macaque monkey (Macaca mulatta).Methods:Six adult rhesus macaque monkeys (M.mulatta) were included.Under general anesthesia,a multichannel ABI was implanted into the lateral recess of the fourth ventricle through the modified suboccipital-retrosigmoid (RS) approach.The electrical auditory brainstem response (EABR) waves were tested to ensure the optimal implant site.After the operation,the EABR and computed tomography (CT) were used to test and verify the effectiveness via electrophysiology and anatomy,respectively.The subjects underwent behavioral observation for 6 months,and the postoperative EABR was tested every two weeks from the 1st month after implant surgery.Result:The implant surgery lasted an average of 5.2 h,and no monkey died or sacrificed.The averaged latencies of peaks Ⅰ,Ⅱ and Ⅳ were 1.27,2.34 and 3.98 ms,respectively in the ABR.One-peak EABR wave was elicited in the operation,and one-or two-peak waves were elicited during the postoperative period.The EABR wave latencies appeared to be constant under different stimulus intensities;however,the amplitudes increased as the stimulus increased within a certain scope.Conclusions:It is feasible and safe to implant ABIs in rhesus macaque monkeys (M.mulatta) through a modified suboccipital RS approach,and EABR and CT are valid tools for animal model establishment.In addition,this model should be an appropriate animal model for the electrophysiological and behavioral study of rhesus macaque monkey with ABI.

  20. Prospects for replacement of auditory neurons by stem cells.

    Science.gov (United States)

    Shi, Fuxin; Edge, Albert S B

    2013-03-01

    Sensorineural hearing loss is caused by degeneration of hair cells or auditory neurons. Spiral ganglion cells, the primary afferent neurons of the auditory system, are patterned during development and send out projections to hair cells and to the brainstem under the control of largely unknown guidance molecules. The neurons do not regenerate after loss and even damage to their projections tends to be permanent. The genesis of spiral ganglion neurons and their synapses forms a basis for regenerative approaches. In this review we critically present the current experimental findings on auditory neuron replacement. We discuss the latest advances with a focus on (a) exogenous stem cell transplantation into the cochlea for neural replacement, (b) expression of local guidance signals in the cochlea after loss of auditory neurons, (c) the possibility of neural replacement from an endogenous cell source, and (d) functional changes from cell engraftment. PMID:23370457

  1. Surgical findings and auditory performance after cochlear implant revision surgery.

    Science.gov (United States)

    Manrique-Huarte, R; Huarte, A; Manrique, M J

    2016-03-01

    The objective of this study was to review cochlear reimplantation outcomes in the tertiary hospital and analyze whether facts such as type of failure, surgical findings, or etiology of deafness have an influence. A retrospective study including 38 patients who underwent cochlear implant revision surgery in a tertiary center is performed. Auditory outcomes (pure tone audiometry,  % disyllabic words) along with etiology of deafness, type of complication, issues with insertion, and cochlear findings are included. Complication rate is 2.7 %. Technical failure rate is 57.9 % (50 % hard failure and 50 % soft failure), and medical failure (device infection or extrusion, migration, wound, or flap complication) is seen in 42.1 % of the cases. Management of cochlear implant complications and revision surgery is increasing due to a growing number of implantees. Cases that require explantation and reimplantation of the cochlear implant are safe procedures, where the depth of insertion and speech perception results are equal or higher in most cases. Nevertheless, there must be an increasing effort on using minimally traumatic electrode arrays and surgical techniques to improve currently obtained results. PMID:25814389

  2. The Effect of Age of Cochlear Implantation on the Improvement of the Auditory Performance in the Children Undergoing Cochlear Implantation

    Directory of Open Access Journals (Sweden)

    L Monshizadeh

    2013-03-01

    Full Text Available Introduction: Hearing is one of the premier human senses. Being deprived from hearing is not only being unable to hear the sounds, but it is also the disability to gain a lot of helpful experiences. Cochlear implantation is introduced worldwide in order to treat the severe to profound hearing loss. Therefore, the present study aims to determine the effect of age of cochlear implantation on improvement of the auditory performance. Methods: The present follow-up study was conducted on 96 children who had referred to Fars Cochlear Implantation Center. The patients’ information was gathered from their profiles both before and after the operation. In addition, the auditory performance score was obtained in 3 stages – 6 months, 1 year, and 2 years after the implantation – through the Cap test. Also, non-parametric tests of Fridman, Willcoxon, and Mann-Withney U were utilized in order to analyze the data of the study. Results: The mean of the children’s auditory performance 6 months, 1 year, and 2 years after the implantation was measured as 2.8+1.03, 4.36+1.04, and 5.34+1.02, respectively. Besides, the median of their auditory performance 6 months, 1 year, and 2 years after the implantation was calculated as 3, 5, and 5, respectively. Also, a statistically significant relationship was observed between the independent variable of age of cochlear implantation and the auditory performance score 6 months, 1 year, and 2 years after the implantation. Conclusion: In line with other studies conducted on the issue, the present study showed the improvement of the auditory performance in the children who benefited from cochlear implantation. Moreover, the results of the present study revealed that the age of cochlear implantation can be of great help in determining the candidates of cochlear implantation. In other words, it can be a major prognostic factor of the response to the treatment

  3. Achieving early functional auditory access in paediatric cochlear implantation.

    Science.gov (United States)

    Orzan, E; Muzzi, E; Marchi, R; Falzone, C; Battelino, S; Ciciriello, E

    2016-02-01

    Cochlear implantation (CI) is a viable option for providing access to auditory stimulation in severe-to-profound hearing loss/impairment of cochlear origin. It has been demonstrated that CI is safe and effective for deaf children. Younger age at activation after CI is linked with better outcomes. It is important to study variables and issues that can interfere with an early fitting and access to sound after CI. They range from patient characteristics, family compliance and support, to technical, medical or organisational problems. A SWOT analysis and a subsequent TOWS matrix was conducted to discuss issues and propose recommendations to be considered when operating an early switch on of the CI. PMID:27054390

  4. Lymphoscintigraphy and autologous stem cell implantation

    International Nuclear Information System (INIS)

    Lymphoscintigraphy is the criterion standard technique for the diagnosis of lymphedema. Advances of the application of autologous hematopoietic stem cells in ischemic disorders of lower limbs have increased the attention of researchers in this field. Aim: To determine the usefulness of lymphoscintigraphy for the assessment the efficacy of autologous stem cell implantation in patients with chronic lymphedema of the upper and lower limbs. Methods: Sixty-five patients were included. Clinical evaluation and lymphoscintigraphy were performed before and six months after stem cells implantation. The stem cells implantations were carried out by multiple superficial and deep injections in the trajectory of the lymphatic vessels and also in the inguinal region. A volume of 0.75 to 1.00 mL of cell suspension (1.0-2.2 x 109 stem cells) was administered in each injection site. Lymphoscintigraphy: Whole-body scans were acquired at 20 minutes, 1 hour, and 3 hours after administration of 185 to 259 MBq (5–7mCi) of 99mTc-albumin nanocolloids in the interdigital space of both limbs. The anatomy and function of the lymphatic system were evaluated. Results: Functional assessment before implantation of stem cells showed that 69.2% of the patients had severe lymphatic insufficiency. The 61.5% of patients showed clinical improvement, confirmed by the results of the lymphoscintigraphy. The 46.1% of the cases evaluated showed a clear improvement. The study showed that the isotopic lymphography can evaluate the therapeutic response and its intensity. Conclusion: Lymphoscintigraphy is a useful technique for the evaluation and monitoring of autologous stem cell transplantation in patients with chronic lymphedema. (author)

  5. The convergence of cochlear implantation with induced pluripotent stem cell therapy.

    Science.gov (United States)

    Gunewardene, Niliksha; Dottori, Mirella; Nayagam, Bryony A

    2012-09-01

    According to 2010 estimates from The National Institute on Deafness and other Communication Disorders, approximately 17% (36 million) American adults have reported some degree of hearing loss. Currently, the only clinical treatment available for those with severe-to-profound hearing loss is a cochlear implant, which is designed to electrically stimulate the auditory nerve in the absence of hair cells. Whilst the cochlear implant has been revolutionary in terms of providing hearing to the severe-to-profoundly deaf, there are variations in cochlear implant performance which may be related to the degree of degeneration of auditory neurons following hearing loss. Hence, numerous experimental studies have focused on enhancing the efficacy of cochlear implants by using neurotrophins to preserve the auditory neurons, and more recently, attempting to replace these dying cells with new neurons derived from stem cells. As a result, several groups are now investigating the potential for both embryonic and adult stem cells to replace the degenerating sensory elements in the deaf cochlea. Recent advances in our knowledge of stem cells and the development of induced pluripotency by Takahashi and Yamanaka in 2006, have opened a new realm of science focused on the use of induced pluripotent stem (iPS) cells for therapeutic purposes. This review will provide a broad overview of the potential benefits and challenges of using iPS cells in combination with a cochlear implant for the treatment of hearing loss, including differentiation of iPS cells into an auditory neural lineage and clinically relevant transplantation approaches. PMID:21956409

  6. Cooperative dynamics in auditory brain response

    CERN Document Server

    Kwapien, J; Liu, L C; Ioannides, A A

    1998-01-01

    Simultaneous estimates of the activity in the left and right auditory cortex of five normal human subjects were extracted from Multichannel Magnetoencephalography recordings. Left, right and binaural stimulation were used, in separate runs, for each subject. The resulting time-series of left and right auditory cortex activity were analysed using the concept of mutual information. The analysis constitutes an objective method to address the nature of inter-hemispheric correlations in response to auditory stimulations. The results provide a clear evidence for the occurrence of such correlations mediated by a direct information transport, with clear laterality effects: as a rule, the contralateral hemisphere leads by 10-20ms, as can be seen in the average signal. The strength of the inter-hemispheric coupling, which cannot be extracted from the average data, is found to be highly variable from subject to subject, but remarkably stable for each subject.

  7. Auditory distraction transmitted by a cochlear implant alters allocation of attentional resources.

    Science.gov (United States)

    Finke, Mareike; Sandmann, Pascale; Kopp, Bruno; Lenarz, Thomas; Büchner, Andreas

    2015-01-01

    Cochlear implants (CIs) are auditory prostheses which restore hearing via electrical stimulation of the auditory nerve. The successful adaptation of auditory cognition to the CI input depends to a substantial degree on individual factors. We pursued an electrophysiological approach toward an analysis of cortical responses that reflect perceptual processing stages and higher-level responses to CI input. Performance and event-related potentials on two cross-modal discrimination-following-distraction (DFD) tasks from CI users and normal-hearing (NH) individuals were compared. The visual-auditory distraction task combined visual distraction with following auditory discrimination performance. Here, we observed similar cortical responses to visual distractors (Novelty-N2) and slowed, less accurate auditory discrimination performance in CI users when compared to NH individuals. Conversely, the auditory-visual distraction task was used to combine auditory distraction with visual discrimination performance. In this task we found attenuated cortical responses to auditory distractors (Novelty-P3), slowed visual discrimination performance, and attenuated cortical P3-responses to visual targets in CI users compared to NH individuals. These results suggest that CI users process auditory distractors differently than NH individuals and that the presence of auditory CI input has an adverse effect on the processing of visual targets and the visual discrimination ability in implanted individuals. We propose that this attenuation of the visual modality occurs through the allocation of neural resources to the CI input. PMID:25798083

  8. Music and the auditory brain: where is the connection?

    Directory of Open Access Journals (Sweden)

    Israel eNelken

    2011-09-01

    Full Text Available Sound processing by the auditory system is understood in unprecedented details, even compared with sensory coding in the visual system. Nevertheless, we don't understand yet the way in which some of the simplest perceptual properties of sounds are coded in neuronal activity. This poses serious difficulties for linking neuronal responses in the auditory system and music processing, since music operates on abstract representations of sounds. Paradoxically, although perceptual representations of sounds most probably occur high in auditory system or even beyond it, neuronal responses are strongly affected by the temporal organization of sound streams even in subcortical stations. Thus, to the extent that music is organized sound, it is the organization, rather than the sound, which is represented first in the auditory brain.

  9. Auditory distraction transmitted by a cochlear implant alters allocation of attentional resources

    OpenAIRE

    Finke, Mareike; Sandmann, Pascale; Kopp, Bruno; Lenarz, Thomas; Büchner, Andreas

    2015-01-01

    Cochlear implants (CIs) are auditory prostheses which restore hearing via electrical stimulation of the auditory nerve. The successful adaptation of auditory cognition to the CI input depends to a substantial degree on individual factors. We pursued an electrophysiological approach toward an analysis of cortical responses that reflect perceptual processing stages and higher-level responses to CI input. Performance and event-related potentials on two cross-modal discrimination-following-distra...

  10. Auditory Speech Perception Tests in Relation to the Coding Strategy in Cochlear Implant

    OpenAIRE

    Bazon, Aline Cristine; Mantello, Erika Barioni; Gonçales, Alina Sanches; Isaac, Myriam de Lima; Hyppolito, Miguel Angelo; Reis, Ana Cláudia Mirândola Barbosa

    2015-01-01

    Introduction  The objective of the evaluation of auditory perception of cochlear implant users is to determine how the acoustic signal is processed, leading to the recognition and understanding of sound. Objective  To investigate the differences in the process of auditory speech perception in individuals with postlingual hearing loss wearing a cochlear implant, using two different speech coding strategies, and to analyze speech perception and handicap perception in relation to the strategy us...

  11. Shaping the aging brain: Role of auditory input patterns in the emergence of auditory cortical impairments

    Directory of Open Access Journals (Sweden)

    Brishna Soraya Kamal

    2013-09-01

    Full Text Available Age-related impairments in the primary auditory cortex (A1 include poor tuning selectivity, neural desynchronization and degraded responses to low-probability sounds. These changes have been largely attributed to reduced inhibition in the aged brain, and are thought to contribute to substantial hearing impairment in both humans and animals. Since many of these changes can be partially reversed with auditory training, it has been speculated that they might not be purely degenerative, but might rather represent negative plastic adjustments to noisy or distorted auditory signals reaching the brain. To test this hypothesis, we examined the impact of exposing young adult rats to 8 weeks of low-grade broadband noise on several aspects of A1 function and structure. We then characterized the same A1 elements in aging rats for comparison. We found that the impact of noise exposure on A1 tuning selectivity, temporal processing of auditory signal and responses to oddball tones was almost indistinguishable from the effect of natural aging. Moreover, noise exposure resulted in a reduction in the population of parvalbumin inhibitory interneurons and cortical myelin as previously documented in the aged group. Most of these changes reversed after returning the rats to a quiet environment. These results support the hypothesis that age-related changes in A1 have a strong activity-dependent component and indicate that the presence or absence of clear auditory input patterns might be a key factor in sustaining adult A1 function.

  12. 正常青年人气、骨导听性脑干反应的比较研究%A comparative research on auditory brain stem reaction of air conduction and bone conduction in normal young people

    Institute of Scientific and Technical Information of China (English)

    钱宇虹; 梁力; 江刚

    2004-01-01

    conduction and bone conduction are different because of different auditory characteristics of these two transducers.OBJECTIVE: To discuss and compare the difference of auditory brain stem reaction(ABR) on air conduction(AC) and bone conduction(BC) for providing a gist in clinical application of bone-conducted auditory brain stem reaction.DESIGN: A self and inter control study was conducted.SETTING and PARTICIPANTS: The research was completed in a sound insulated and electric screened room of Department of Otolaryngology, Zhujiang Hospital, First Military Medical University. All subjects were a group of young people with normal hearing(31 male ears and 30 female ears) and an age from 19 to 23 years old(average 21.7 years old).INTERVENTIONS: American NicoIet spirit inducing electric potential instrument was introduced. The earphones for air conduction and bone conduction testing were TDH-39P and Radioear B-71 models, which accorded with GB/T 4851. 1 and GB/T 4854. 3 criteria after adjustment. The impedances of electrode were all less than 5 kΩ, and the impedance between electrodes was ≤4 kΩ. Short sound air-conducted and bone-conducted ABR for both ears were tested separately. The strength of stimulant started from 100 dB(nHL) (the maximum output of the machine) and decreased in turn by 20 dB(nHL), which was set as one grade, recorded twice. And 5 dB was chosen as one grade when closed to reactive threshold to induce the minimum repeatable sound strength as ABR threshold. Once ABR reactive threshold obtained, 60 dB(nHL) above threshold stimulant was operated to test air and bone conducted ABR and the latency of Ⅰ, Ⅲ, Ⅴ wave was recorded separately. Two groups of data obtained from same ear were self-paired for t test. The test results among normal young males and females were gone through unpaired t test.MAIN OUTCOME MEASURES: Threshold of air conduction and bone conduction for short sound in both males and females, latency and interval of each wave in air and bone

  13. Auditory implant research at the House Ear Institute 1989-2013.

    Science.gov (United States)

    Shannon, Robert V

    2015-04-01

    The House Ear Institute (HEI) had a long and distinguished history of auditory implant innovation and development. Early clinical innovations include being one of the first cochlear implant (CI) centers, being the first center to implant a child with a cochlear implant in the US, developing the auditory brainstem implant, and developing multiple surgical approaches and tools for Otology. This paper reviews the second stage of auditory implant research at House - in-depth basic research on perceptual capabilities and signal processing for both cochlear implants and auditory brainstem implants. Psychophysical studies characterized the loudness and temporal perceptual properties of electrical stimulation as a function of electrical parameters. Speech studies with the noise-band vocoder showed that only four bands of tonotopically arrayed information were sufficient for speech recognition, and that most implant users were receiving the equivalent of 8-10 bands of information. The noise-band vocoder allowed us to evaluate the effects of the manipulation of the number of bands, the alignment of the bands with the original tonotopic map, and distortions in the tonotopic mapping, including holes in the neural representation. Stimulation pulse rate was shown to have only a small effect on speech recognition. Electric fields were manipulated in position and sharpness, showing the potential benefit of improved tonotopic selectivity. Auditory training shows great promise for improving speech recognition for all patients. And the Auditory Brainstem Implant was developed and improved and its application expanded to new populations. Overall, the last 25 years of research at HEI helped increase the basic scientific understanding of electrical stimulation of hearing and contributed to the improved outcomes for patients with the CI and ABI devices. This article is part of a Special Issue entitled . PMID:25449009

  14. The development of auditory skills in young children with Mondini dysplasia after cochlear implantation.

    Directory of Open Access Journals (Sweden)

    Xueqing Chen

    Full Text Available The aim of this study is to survey and compare the development of auditory skills in young children with Mondini dysplasia and profoundly-deaf young children with radiologically normal inner ears over a period of 3 years after cochlear implantation. A total of 545 young children (age 7 to 36 months with prelingual, severe to profound hearing loss participated in this study. All children received cochlear implantation. Based on whether or not there was a Mondini dysplasia as diagnosed with CT scanning, the subjects were divided into 2 groups: (A 514 young children with radiologically normal inner ears and (B 31 young children with Mondini dysplasia. The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS was used to assess the children's auditory skills that include vocalization changes, spontaneous alerting to sounds in everyday living environments, and the ability to derive meaning from sounds. The assessment was performed prior to surgery and at 1, 3, 6, 9, 12, 24, and 36 months after implant device switch-on. The mean scores for overall auditory skills were not significantly different between groups A and B at pre-surgery, 1, 12, 24, and 36 months post-surgery, but were significantly different at 3, 6, and 9 months post-surgery. The mean scores for all auditory skills in children with Mondini dysplasia showed significant improvement over time. The mean scores for the three subcategories of auditory skills in children with Mondini dysplasia also showed significant differences at pre-surgery, 1, 3, 6, and 9 months, however, there were no significant differences at 12, 24, and 36 months. Overall, the auditory skills of young children with Mondini dysplasia developed rapidly after cochlear implantation, in a similar manner to that of young children with radiologically normal inner ears. Cochlear implantation is an effective intervention for young children with Mondini dysplasia.

  15. Minimal effects of visual memory training on auditory performance of adult cochlear implant users

    Directory of Open Access Journals (Sweden)

    Sandra I. Oba, MS

    2013-02-01

    Full Text Available Auditory training has been shown to significantly improve cochlear implant (CI users’ speech and music perception. However, it is unclear whether posttraining gains in performance were due to improved auditory perception or to generally improved attention, memory, and/or cognitive processing. In this study, speech and music perception, as well as auditory and visual memory, were assessed in 10 CI users before, during, and after training with a nonauditory task. A visual digit span (VDS task was used for training, in which subjects recalled sequences of digits presented visually. After the VDS training, VDS performance significantly improved. However, there were no significant improvements for most auditory outcome measures (auditory digit span, phoneme recognition, sentence recognition in noise, digit recognition in noise, except for small (but significant improvements in vocal emotion recognition and melodic contour identification. Posttraining gains were much smaller with the nonauditory VDS training than observed in previous auditory training studies with CI users. The results suggest that posttraining gains observed in previous studies were not solely attributable to improved attention or memory and were more likely due to improved auditory perception. The results also suggest that CI users may require targeted auditory training to improve speech and music perception.

  16. Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

    Institute of Scientific and Technical Information of China (English)

    Guanqun Qiao; Qingquan Li; Gang Peng; Jun Ma; Hongwei Fan; Yingbin Li

    2013-01-01

    Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are stil unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models (c-myc+/SV40Tag+/Tet-on+) to explore the malignant trans-formation potential of neural stem cells by observing the differences of neural stem cel s and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cel s were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibril ary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibril ary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibril ary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cel s. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.

  17. Auditory Cortical Maturation in a Child with Cochlear Implant: Analysis of Electrophysiological and Behavioral Measures

    Science.gov (United States)

    Silva, Liliane Aparecida Fagundes; Couto, Maria Inês Vieira; Tsuji, Robinson Koji; Bento, Ricardo Ferreira; de Carvalho, Ana Claudia Martinho; Matas, Carla Gentile

    2015-01-01

    The purpose of this study was to longitudinally assess the behavioral and electrophysiological hearing changes of a girl inserted in a CI program, who had bilateral profound sensorineural hearing loss and underwent surgery of cochlear implantation with electrode activation at 21 months of age. She was evaluated using the P1 component of Long Latency Auditory Evoked Potential (LLAEP); speech perception tests of the Glendonald Auditory Screening Procedure (GASP); Infant Toddler Meaningful Auditory Integration Scale (IT-MAIS); and Meaningful Use of Speech Scales (MUSS). The study was conducted prior to activation and after three, nine, and 18 months of cochlear implant activation. The results of the LLAEP were compared with data from a hearing child matched by gender and chronological age. The results of the LLAEP of the child with cochlear implant showed gradual decrease in latency of the P1 component after auditory stimulation (172 ms–134 ms). In the GASP, IT-MAIS, and MUSS, gradual development of listening skills and oral language was observed. The values of the LLAEP of the hearing child were expected for chronological age (132 ms–128 ms). The use of different clinical instruments allow a better understanding of the auditory habilitation and rehabilitation process via CI. PMID:26881163

  18. Increment of brain temporal perfusion during auditory stimulation

    International Nuclear Information System (INIS)

    A study on the dynamic exploration of the auditory pathway is presented, in which technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPET) was used in volunteers with normal hearing. Changes in 99mTc-HMPAO distribution were calculated using a region of interest/whole-brain count ratio. The results showed a temporal perfusion increment of 17% (right) and 19% (left) during tonal supraliminar stimulation, which was significantly different from the control ROI. Sensitivity tests for the method were requested before any clinical application. (orig.)

  19. Enhanced audio-visual interactions in the auditory cortex of elderly cochlear-implant users.

    Science.gov (United States)

    Schierholz, Irina; Finke, Mareike; Schulte, Svenja; Hauthal, Nadine; Kantzke, Christoph; Rach, Stefan; Büchner, Andreas; Dengler, Reinhard; Sandmann, Pascale

    2015-10-01

    Auditory deprivation and the restoration of hearing via a cochlear implant (CI) can induce functional plasticity in auditory cortical areas. How these plastic changes affect the ability to integrate combined auditory (A) and visual (V) information is not yet well understood. In the present study, we used electroencephalography (EEG) to examine whether age, temporary deafness and altered sensory experience with a CI can affect audio-visual (AV) interactions in post-lingually deafened CI users. Young and elderly CI users and age-matched NH listeners performed a speeded response task on basic auditory, visual and audio-visual stimuli. Regarding the behavioral results, a redundant signals effect, that is, faster response times to cross-modal (AV) than to both of the two modality-specific stimuli (A, V), was revealed for all groups of participants. Moreover, in all four groups, we found evidence for audio-visual integration. Regarding event-related responses (ERPs), we observed a more pronounced visual modulation of the cortical auditory response at N1 latency (approximately 100 ms after stimulus onset) in the elderly CI users when compared with young CI users and elderly NH listeners. Thus, elderly CI users showed enhanced audio-visual binding which may be a consequence of compensatory strategies developed due to temporary deafness and/or degraded sensory input after implantation. These results indicate that the combination of aging, sensory deprivation and CI facilitates the coupling between the auditory and the visual modality. We suggest that this enhancement in multisensory interactions could be used to optimize auditory rehabilitation, especially in elderly CI users, by the application of strong audio-visually based rehabilitation strategies after implant switch-on. PMID:26302946

  20. Cancer stem cells and brain tumors

    OpenAIRE

    Pérez Castillo, Ana; Aguilar Morante, Diana; Morales-García, José A.; Dorado, Jorge

    2008-01-01

    Besides the role of normal stem cells in organogenesis, cancer stem cells are thought to be crucial for tumorigenesis. Most current research on human tumors is focused on molecular and cellular analysis of the bulk tumor mass. However, evidence in leukemia and, more recently, in solid tumors suggests that the tumor cell population is heterogeneous. In recent years, several groups have described the existence of a cancer stem cell population in different brain tumors. These neural cancer stem ...

  1. Brain tumor stem cell dancing

    Directory of Open Access Journals (Sweden)

    Giuseppina Bozzuto

    2014-09-01

    Full Text Available Background. Issues regarding cancer stem cell (CSC movement are important in neurosphere biology as cell-cell or cell-environment interactions may have significant impacts on CSC differentiation and contribute to the heterogeneity of the neurosphere. Aims. Despite the growing body of literature data on the biology of brain tumor stem cells, floating CSC-derived neurospheres have been scarcely characterized from a morphological and ultrastructural point of view. Results. Here we report a morphological and ultrastructural characterization performed by live imaging and scanning electron microscopy. Glioblastoma multiforme (GBM CSC-derived neurospheres are heterogeneous and are constituted by cells, morphologically different, capable of forming highly dynamic structures. These dynamic structures are regulated by not serendipitous cell-cell interactions, and they synchronously pulsate following a cyclic course made of "fast" and "slow" alternate phases. Autocrine/paracrine non canonical Wnt signalling appears to be correlated with the association status of neurospheres. Conclusions. The results obtained suggest that GBM CSCs can behave both as independents cells and as "social" cells, highly interactive with other members of its species, giving rise to a sort of "multicellular organism".

  2. Demonstration of prosthetic activation of central auditory pathways using ( sup 14 C)-2-deoxyglucose

    Energy Technology Data Exchange (ETDEWEB)

    Evans, D.A.; Niparko, J.K.; Altschuler, R.A.; Frey, K.A.; Miller, J.M. (Univ. of Michigan Medical Center, Ann Arbor (USA))

    1990-02-01

    The cochlear prosthesis is not applicable to patients who lack an implantable cochlea or an intact vestibulocochlear nerve. Direct electrical stimulation of the cochlear nucleus (CN) of the brain stem might provide a method for auditory rehabilitation of these patients. A penetrating CN electrode has been developed and tissue tolerance to this device demonstrated. This study was undertaken to evaluate metabolic activation of central nervous system (CNS) auditory tracts produced by such implants. Regional cerebral glucose use resulting from CN stimulation was estimated in a series of chronically implanted guinea pigs with the use of ({sup 14}C)-2-deoxyglucose (2-DG). Enhanced 2-DG uptake was observed in structures of the auditory tract. The activation of central auditory structures achieved with CN stimulation was similar to that produced by acoustic stimulation and by electrical stimulation of the modiolar portion of the auditory nerve in control groups. An interesting banding pattern was observed in the inferior colliculus following CN stimulation, as previously described with acoustic stimulation. This study demonstrates that functional metabolic activation of central auditory pathways can be achieved with a penetrating CNS auditory prosthesis.

  3. Demonstration of prosthetic activation of central auditory pathways using [14C]-2-deoxyglucose

    International Nuclear Information System (INIS)

    The cochlear prosthesis is not applicable to patients who lack an implantable cochlea or an intact vestibulocochlear nerve. Direct electrical stimulation of the cochlear nucleus (CN) of the brain stem might provide a method for auditory rehabilitation of these patients. A penetrating CN electrode has been developed and tissue tolerance to this device demonstrated. This study was undertaken to evaluate metabolic activation of central nervous system (CNS) auditory tracts produced by such implants. Regional cerebral glucose use resulting from CN stimulation was estimated in a series of chronically implanted guinea pigs with the use of [14C]-2-deoxyglucose (2-DG). Enhanced 2-DG uptake was observed in structures of the auditory tract. The activation of central auditory structures achieved with CN stimulation was similar to that produced by acoustic stimulation and by electrical stimulation of the modiolar portion of the auditory nerve in control groups. An interesting banding pattern was observed in the inferior colliculus following CN stimulation, as previously described with acoustic stimulation. This study demonstrates that functional metabolic activation of central auditory pathways can be achieved with a penetrating CNS auditory prosthesis

  4. Altered cortical activity in prelingually deafened cochlear implant users following long periods of auditory deprivation.

    Science.gov (United States)

    Lammers, Marc J W; Versnel, Huib; van Zanten, Gijsbert A; Grolman, Wilko

    2015-02-01

    Auditory stimulation during childhood is critical for the development of the auditory cortex in humans and with that for hearing in adulthood. Age-related changes in morphology and peak latencies of the cortical auditory evoked potential (CAEP) have led to the use of this cortical response as a biomarker of auditory cortical maturation including studies of cortical development after deafness and subsequent cochlear implantation. To date, it is unknown whether prelingually deaf adults, with early onset deafness (before the age of 2 years) and who received a cochlear implant (CI) only during adulthood, would display absent or aberrant CAEP waveforms as predicted from CAEP studies in late implanted prelingually deaf children. In the current study, CAEP waveforms were recorded in response to electric stimuli in prelingually deaf adults, who received their CI after the age of 21 years. Waveform morphology and peak latencies were compared to the CAEP responses obtained in postlingually deaf adults, who became deaf after the age of 16. Unexpectedly, typical CAEP waveforms with adult-like P1-N1-P2 morphology could be recorded in the prelingually deaf adult CI users. On visual inspection, waveform morphology was comparable to the CAEP waveforms recorded in the postlingually deaf CI users. Interestingly, however, latencies of the N1 peak were significantly shorter and amplitudes were significantly larger in the prelingual group than in the postlingual group. The presence of the CAEP together with an early and large N1 peak might represent activation of the more innate and less complex components of the auditory cortex of the prelingually deaf CI user, whereas the CAEP in postlingually deaf CI users might reflect activation of the mature neural network still present in these patients. The CAEPs may therefore be helpful in the assessment of developmental state of the auditory cortex. PMID:25315357

  5. The auditory and non-auditory brain areas involved in tinnitus. An emergent property of multiple parallel overlapping subnetworks.

    Science.gov (United States)

    Vanneste, Sven; De Ridder, Dirk

    2012-01-01

    Tinnitus is the perception of a sound in the absence of an external sound source. It is characterized by sensory components such as the perceived loudness, the lateralization, the tinnitus type (pure tone, noise-like) and associated emotional components, such as distress and mood changes. Source localization of quantitative electroencephalography (qEEG) data demonstrate the involvement of auditory brain areas as well as several non-auditory brain areas such as the anterior cingulate cortex (dorsal and subgenual), auditory cortex (primary and secondary), dorsal lateral prefrontal cortex, insula, supplementary motor area, orbitofrontal cortex (including the inferior frontal gyrus), parahippocampus, posterior cingulate cortex and the precuneus, in different aspects of tinnitus. Explaining these non-auditory brain areas as constituents of separable subnetworks, each reflecting a specific aspect of the tinnitus percept increases the explanatory power of the non-auditory brain areas involvement in tinnitus. Thus, the unified percept of tinnitus can be considered an emergent property of multiple parallel dynamically changing and partially overlapping subnetworks, each with a specific spontaneous oscillatory pattern and functional connectivity signature. PMID:22586375

  6. The auditory and non-auditory brain areas involved in tinnitus. An emergent property of multiple parallel overlapping subnetworks.

    Directory of Open Access Journals (Sweden)

    Sven Vanneste

    2012-05-01

    Full Text Available Tinnitus is the perception of a sound in the absence of an external sound source. It is characterized by sensory components such as the perceived loudness, the lateralization, the tinnitus type (pure tone, noise-like and associated emotional components, such as distress and mood changes. Source localization of qEEG data demonstrate the involvement of auditory brain areas as well as several non-auditory brain areas such as the anterior cingulate cortex (dorsal and subgenual, auditory cortex (primary and secondary, dorsal lateral prefrontal cortex, insula, supplementary motor area, orbitofrontal cortex (including the inferior frontal gyrus, parahippocampus, posterior cingulate cortex and the precuneus, in different aspects of tinnitus. Explaining these non-auditory brain areas as constituents of separable subnetworks, each reflecting a specific aspect of the tinnitus percept increases the explanatory power of the non-auditory brain areas involvement in tinnitus. Thus the unified percept of tinnitus can be considered an emergent property of multiple parallel dynamically changing and partially overlapping subnetworks, each with a specific spontaneous oscillatory pattern and functional connectivity signature.

  7. Brain-derived neurotrophic factor modulates auditory function in the hearing cochlea.

    Science.gov (United States)

    Sly, David J; Hampson, Amy J; Minter, Ricki L; Heffer, Leon F; Li, Jack; Millard, Rodney E; Winata, Leon; Niasari, Allen; O'Leary, Stephen J

    2012-02-01

    Neurotrophins prevent spiral ganglion neuron (SGN) degeneration in animal models of ototoxin-induced deafness and may be used in the future to improve the hearing of cochlear implant patients. It is increasingly common for patients with residual hearing to undergo cochlear implantation. However, the effect of neurotrophin treatment on acoustic hearing is not known. In this study, brain-derived neurotrophic factor (BDNF) was applied to the round window membrane of adult guinea pigs for 4 weeks using a cannula attached to a mini-osmotic pump. SGN survival was first assessed in ototoxically deafened guinea pigs to establish that the delivery method was effective. Increased survival of SGNs was observed in the basal and middle cochlear turns of deafened guinea pigs treated with BDNF, confirming that delivery to the cochlea was successful. The effects of BDNF treatment in animals with normal hearing were then assessed using distortion product otoacoustic emissions (DPOAEs), pure tone, and click-evoked auditory brainstem responses (ABRs). DPOAE assessment indicated a mild deficit of 5 dB SPL in treated and control groups at 1 and 4 weeks after cannula placement. In contrast, ABR evaluation showed that BDNF lowered thresholds at specific frequencies (8 and 16 kHz) after 1 and 4 weeks posttreatment when compared to the control cohort receiving Ringer's solution. Longer treatment for 4 weeks not only widened the range of frequencies ameliorated from 2 to 32 kHz but also lowered the threshold by at least 28 dB SPL at frequencies ≥16 kHz. BDNF treatment for 4 weeks also increased the amplitude of the ABR response when compared to either the control cohort or prior to treatment. We show that BDNF applied to the round window reduces auditory thresholds and could potentially be used clinically to protect residual hearing following cochlear implantation. PMID:22086147

  8. Lateralized auditory brain function in children with normal reading ability and in children with dyslexia.

    Science.gov (United States)

    Johnson, Blake W; McArthur, Genevieve; Hautus, Michael; Reid, Melanie; Brock, Jon; Castles, Anne; Crain, Stephen

    2013-03-01

    We examined central auditory processing in typically- and atypically-developing readers. Concurrent EEG and MEG brain measurements were obtained from a group of 16 children with dyslexia aged 8-12 years, and a group of 16 age-matched children with normal reading ability. Auditory responses were elicited using 500ms duration broadband noise. These responses were strongly lateralized in control children. Children with dyslexia showed significantly less lateralisation of auditory cortical functioning, and a different pattern of development of auditory lateralization with age. These results provide further evidence that the core neurophysiological deficit of dyslexia is a problem in the balance of auditory function between the two hemispheres. PMID:23333528

  9. Cross-Modal Functional Reorganization of Visual and Auditory Cortex in Adult Cochlear Implant Users Identified with fNIRS

    Directory of Open Access Journals (Sweden)

    Ling-Chia Chen

    2016-01-01

    Full Text Available Cochlear implant (CI users show higher auditory-evoked activations in visual cortex and higher visual-evoked activation in auditory cortex compared to normal hearing (NH controls, reflecting functional reorganization of both visual and auditory modalities. Visual-evoked activation in auditory cortex is a maladaptive functional reorganization whereas auditory-evoked activation in visual cortex is beneficial for speech recognition in CI users. We investigated their joint influence on CI users’ speech recognition, by testing 20 postlingually deafened CI users and 20 NH controls with functional near-infrared spectroscopy (fNIRS. Optodes were placed over occipital and temporal areas to measure visual and auditory responses when presenting visual checkerboard and auditory word stimuli. Higher cross-modal activations were confirmed in both auditory and visual cortex for CI users compared to NH controls, demonstrating that functional reorganization of both auditory and visual cortex can be identified with fNIRS. Additionally, the combined reorganization of auditory and visual cortex was found to be associated with speech recognition performance. Speech performance was good as long as the beneficial auditory-evoked activation in visual cortex was higher than the visual-evoked activation in the auditory cortex. These results indicate the importance of considering cross-modal activations in both visual and auditory cortex for potential clinical outcome estimation.

  10. Cerebral and brain stem Langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Two patients with central nervous system manifestations of Langerhans cell histiocytosis, both with brain stem involvement, are reported. The onset of symptoms was at an age when the diagnosis might not have been considered. (orig.)

  11. Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

    OpenAIRE

    Qiao, Guanqun; Li, Qingquan; Peng, Gang; Ma, Jun; Fan, Hongwei; Li, Yingbin

    2013-01-01

    Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models (c-myc+/SV40Tag+/Tet-on+) to explore the malignant trans-formation potential of neural stem cells by observing the differences of neural stem cells and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain t...

  12. Brain stem death and organ donation.

    OpenAIRE

    1989-01-01

    Organs for donation are in short supply in the United Kingdom, resulting in allegations that relatives of potential donors are not being asked for consent. Legislation on "required request" has been proposed to overcome this. The incidence, causes, complications, and patterns of organ donation in brain stem dead patients in one referral centre were studied over 12 months. Data were collected on all patients fulfilling criteria for brain stem death or considered suitable for donating organs af...

  13. Diffusion tensor imaging of dolphin brains reveals direct auditory pathway to temporal lobe

    OpenAIRE

    Berns, Gregory S.; Cook, Peter F.; Foxley, Sean; Jbabdi, Saad; Miller, Karla L.; Marino, Lori

    2015-01-01

    The brains of odontocetes (toothed whales) look grossly different from their terrestrial relatives. Because of their adaptation to the aquatic environment and their reliance on echolocation, the odontocetes' auditory system is both unique and crucial to their survival. Yet, scant data exist about the functional organization of the cetacean auditory system. A predominant hypothesis is that the primary auditory cortex lies in the suprasylvian gyrus along the vertex of the hemispheres, with this...

  14. Brain response to a rhythm deviant in adolescent cochlear implant users before and after an intensive musical training program

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Weed, Ethan; Hansen, Mads;

    . This study aimed to investigate auditory brain processing of musical sounds relevant to prosody processing in adolescent CI-users who have received their implant in childhood. Furthermore, we aimed to investigate the potential impact of intensive musical training on adolescent CI-users’ discrimination...... making supplemented with daily computer based listening exercises. NH participants received no training. Nine of the CI-users had bilateral implants and two had unilateral implants. The mean implant experience was 9.47 years (range: 1.8-15.2). Ten NH peers (M.age = 16.2 years) formed a reference group...... the CI group at both sessions. Our results suggest that adolescent CI users, who have only experienced sound through the implant, show brain responses to musical stimuli resembling those of NH peers, and that this response can be altered by intensive musical training. The finding points toward...

  15. Prospects for Replacement of Auditory Neurons by Stem Cells

    OpenAIRE

    Shi, Fuxin; Edge, Albert S. B.

    2013-01-01

    Sensorineural hearing loss is caused by degeneration of hair cells or auditory neurons. Spiral ganglion cells, the primary afferent neurons of the auditory system, are patterned during development and send out projections to hair cells and to the brainstem under the control of largely unknown guidance molecules. The neurons do not regenerate after loss and even damage to their projections tends to be permanent. The genesis of spiral ganglion neurons and their synapses forms a basis for regene...

  16. Cochlear implant

    Science.gov (United States)

    ... are sent along the auditory nerve to the brain. A deaf person does not have a functioning inner ear. A cochlear implant tries to replace the function of the inner ear by ... signals to the brain. Sound is picked up by a microphone worn ...

  17. A Case Report of Brain Stem Tumor

    Directory of Open Access Journals (Sweden)

    R Nazari

    2004-07-01

    Full Text Available Background: Brain and spinal cord tumors are the most frequent neoplasms after leukemia in children. Brain stem glioma is responsible for 10-20% of brain tumors in this group and often found in pons presenting with cerebellar signs, cranial nerve palsies, pyramidal signs and eventually increased intracranial pressure Case Report: In this article we reported an 11 year old girl affected with brain stem tumor with signs of headache, dizziness, vomiting and ataxia. Strabismus due to palsy of sixth cranial nerve, and dysarthria was observed. Conclusion: Children complaining of vomiting, headache and dizziness for a long time must be assessed for brain tumor in posterior fossa that sometimes may lead to increased intracranial pressure. An exact neurological examination can be worth guide to diagnosis.

  18. Direct recordings from the auditory cortex in a cochlear implant user.

    Science.gov (United States)

    Nourski, Kirill V; Etler, Christine P; Brugge, John F; Oya, Hiroyuki; Kawasaki, Hiroto; Reale, Richard A; Abbas, Paul J; Brown, Carolyn J; Howard, Matthew A

    2013-06-01

    Electrical stimulation of the auditory nerve with a cochlear implant (CI) is the method of choice for treatment of severe-to-profound hearing loss. Understanding how the human auditory cortex responds to CI stimulation is important for advances in stimulation paradigms and rehabilitation strategies. In this study, auditory cortical responses to CI stimulation were recorded intracranially in a neurosurgical patient to examine directly the functional organization of the auditory cortex and compare the findings with those obtained in normal-hearing subjects. The subject was a bilateral CI user with a 20-year history of deafness and refractory epilepsy. As part of the epilepsy treatment, a subdural grid electrode was implanted over the left temporal lobe. Pure tones, click trains, sinusoidal amplitude-modulated noise, and speech were presented via the auxiliary input of the right CI speech processor. Additional experiments were conducted with bilateral CI stimulation. Auditory event-related changes in cortical activity, characterized by the averaged evoked potential and event-related band power, were localized to posterolateral superior temporal gyrus. Responses were stable across recording sessions and were abolished under general anesthesia. Response latency decreased and magnitude increased with increasing stimulus level. More apical intracochlear stimulation yielded the largest responses. Cortical evoked potentials were phase-locked to the temporal modulations of periodic stimuli and speech utterances. Bilateral electrical stimulation resulted in minimal artifact contamination. This study demonstrates the feasibility of intracranial electrophysiological recordings of responses to CI stimulation in a human subject, shows that cortical response properties may be similar to those obtained in normal-hearing individuals, and provides a basis for future comparisons with extracranial recordings. PMID:23519390

  19. Biointerface: protein enhanced stem cells binding to implant surface.

    Science.gov (United States)

    Chrzanowski, W; Kondyurin, A; Lee, Jae Ho; Lord, Megan S; Bilek, M M M; Kim, Hae-Won

    2012-09-01

    The number of metallic implantable devices placed every year is estimated at 3.7 million. This number has been steadily increasing over last decades at a rate of around 8 %. In spite of the many successes of the devices the implantation of biomaterial into tissues almost universally leads to the development of an avascular sac, which consists of fibrous tissue around the device and walls off the implant from the body. This reaction can be detrimental to the function of implant, reduces its lifetime, and necessitates repeated surgery. Clearly, to reduce the number of revision surgeries and improve long-term implant function it is necessary to enhance device integration by modulating cell adhesion and function. In this paper we have demonstrated that it is possible to enhance stem cell attachment using engineered biointerfaces. To create this functional interface, samples were coated with polymer (as a precursor) and then ion implanted to create a reactive interface that aids the binding of biomolecules--fibronectin. Both AFM and XPS analyses confirmed the presence of protein layers on the samples. The amount of protein was significant greater for the ion implanted surfaces and was not disrupted upon washing with detergent, hence the formation of strong bonds with the interface was confirmed. While, for non ion implanted surfaces, a decrease of protein was observed after washing with detergent. Finally, the number of stem cells attached to the surface was enhanced for ion implanted surfaces. The studies presented confirm that the developed bionterface with immobilised fibronectin is an effective means to modulate stem cell attachment. PMID:22714559

  20. Human Nerual Stem Cells for Brain Repair

    OpenAIRE

    Kim, Seung U.; Lee, Hong J.; In H Park; Chu, Kon; Lee, Soon T.; Kim, Manho; Roh, Jae K.; Kim, Seung K.; Wang, Kyu C.

    2008-01-01

    Cell replacement therapy and gene transfer to the diseased or injured brain have provided the basis for the development of potentially powerful new therapeutic strategies for a broad spectrum of human neurological diseases including Parkinson disease, Huntington disease, amyotrophic lateral sclerosis (ALS), Alzheimer disease, multiple sclerosis (MS), stroke, spinal cord injury and brain cancer. In recent years, neurons and glial cells have successfully been generated from neural stem cells, a...

  1. Multitarget surgical neuromodulation: Combined C2 and auditory cortex implantation for tinnitus.

    Science.gov (United States)

    De Ridder, Dirk; Vanneste, Sven

    2015-03-30

    Tinnitus, as a phantom sound can express itself as a pure tone and as a noise-like sound. It is notoriously difficult to treat, and in medically, psychologically and audiologically intractable tinnitus patients sometimes intracranial electrodes overlying the auditory cortex are implanted. In this case report, we describe a patient who had a complete resolution of the pure tone component of his tinnitus by an auditory cortex implant, without any beneficial effect on the noise-like aspect of his tinnitus, even after changing the stimulation design to burst stimulation, which is known to treat noise-like tinnitus better than tonic stimulation. After an initial successful treatment of his noise-like component with transcutaneus electrical nerve stimulation, a wire electrode is inserted subcutaneously and connected to his internal pulse generator. With the dual stimulation his pure tone tinnitus remains abolished after 5 years of stimulation and his noise-like tinnitus is improved by 50%, from 8/10 to 4/10. This case report suggests that multi-target stimulation might be better than single target implantation in selected cases. PMID:25703225

  2. Topodiagnostic investigations on the sympathoexcitatory brain stem pathway using a new method of three dimensional brain stem mapping

    OpenAIRE

    Marx, J.; IANNETTI, G.; Mika-Gruettner, A; Thoemke, F; Fitzek, S; Vucurevic, G; Urban, P.; Stoeter, P; Cruccu, G.; Hopf, H.

    2004-01-01

    Objectives: To study the incompletely understood sympathoexcitatory pathway through the human brain stem, using a new method of three dimensional brain stem mapping on the basis of digitally postprocessed magnetic resonance imaging (MRI).

  3. Neural correlates of auditory-cognitive processing in older adult cochlear implant recipients.

    Science.gov (United States)

    Henkin, Yael; Yaar-Soffer, Yifat; Steinberg, Meidan; Muchnik, Chava

    2014-01-01

    With the growing number of older adults receiving cochlear implants (CI), there is general agreement that substantial benefits can be gained. Nonetheless, variability in speech perception performance is high, and the relative contribution and interactions among peripheral, central-auditory, and cognitive factors are not fully understood. The goal of the present study was to compare auditory-cognitive processing in older-adult CI recipients with that of older normal-hearing (NH) listeners by means of behavioral and electrophysiologic manifestations of a high-load cognitive task. Auditory event-related potentials (AERPs) were recorded from 9 older postlingually deafened adults with CI (age at CI >60) and 10 age-matched listeners with NH, while performing an auditory Stroop task. Participants were required to classify the speaker's gender (male/female) that produced the words 'mother' or 'father' while ignoring the irrelevant congruent or incongruent word meaning. Older CI and NH listeners exhibited comparable reaction time, performance accuracy, and initial sensory-perceptual processing (i.e. N1 potential). Nonetheless, older CI recipients showed substantially prolonged and less efficient perceptual processing (i.e. P3 potential). Congruency effects manifested in longer reaction time (i.e. Stroop effect), execution time, and P3 latency to incongruent versus congruent stimuli in both groups in a similar fashion; however, markedly prolonged P3 and shortened execution time were evident in older CI recipients. Collectively, older adults (CI and NH) employed a combined perceptual and postperceptual conflict processing strategy; nonetheless, the relative allotment of perceptual resources was substantially enhanced to maintain adequate performance in CI recipients. In sum, the recording of AERPs together with the simultaneously obtained behavioral measures during a Stroop task exposed a differential time course of auditory-cognitive processing in older CI recipients that

  4. Computed tomography of the brain stem with intrathecal metrizamide. Part 1: the normal brain stem

    International Nuclear Information System (INIS)

    Detailed anatomy of the brain stem and cervicomedullary junction can be accurately demonstrated with metrizamide computed tomographic cisternography. Specifically surface anatomy is unusually well outlined. Nine distinct and easily recognizable levels of section are described: four levels in the medulla, three in the pons, and two in the mesencephalon. Surface features of the brain stem, fine details in the floor of the fourth ventricle, cranial nerves, and vascular structures are shown and discussed

  5. Development of functional human embryonic stem cell-derived neurons in mouse brain

    OpenAIRE

    Muotri, Alysson R.; Nakashima, Kinichi; Toni, Nicolas; Sandler, Vladislav M.; Gage, Fred H

    2005-01-01

    Human embryonic stem cells are pluripotent entities, theoretically capable of generating a whole-body spectrum of distinct cell types. However, differentiation of these cells has been observed only in culture or during teratoma formation. Our results show that human embryonic stem cells implanted in the brain ventricles of embryonic mice can differentiate into functional neural lineages and generate mature, active human neurons that successfully integrate into the adult mouse forebrain. Moreo...

  6. Role of bimodal stimulation for auditory-perceptual skills development in children with a unilateral cochlear implant.

    Science.gov (United States)

    Marsella, P; Giannantonio, S; Scorpecci, A; Pianesi, F; Micardi, M; Resca, A

    2015-12-01

    This is a prospective randomised study that evaluated the differences arising from a bimodal stimulation compared to a monaural electrical stimulation in deaf children, particularly in terms of auditory-perceptual skills development. We enrolled 39 children aged 12 to 36 months, suffering from severe-to-profound bilateral sensorineural hearing loss with residual hearing on at least one side. All were unilaterally implanted: 21 wore only the cochlear implant (CI) (unilateral CI group), while the other 18 used the CI and a contralateral hearing aid at the same time (bimodal group). They were assessed with a test battery designed to appraise preverbal and verbal auditory-perceptual skills immediately before and 6 and 12 months after implantation. No statistically significant differences were observed between groups at time 0, while at 6 and 12 months children in the bimodal group had better scores in each test than peers in the unilateral CI group. Therefore, although unilateral deafness/hearing does not undermine hearing acuity in normal listening, the simultaneous use of a CI and a contralateral hearing aid (binaural hearing through a bimodal stimulation) provides an advantage in terms of acquisition of auditory-perceptual skills, allowing children to achieve the basic milestones of auditory perception faster and in greater number than children with only one CI. Thus, "keeping awake" the contralateral auditory pathway, albeit not crucial in determining auditory acuity, guarantees benefits compared with the use of the implant alone. These findings provide initial evidence to establish shared guidelines for better rehabilitation of patients undergoing unilateral cochlear implantation, and add more evidence regarding the correct indications for bilateral cochlear implantation. PMID:26900251

  7. 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...

  8. Optimizing Performance in Adult Cochlear Implant Users through Clinician Directed Auditory Training.

    Science.gov (United States)

    Plant, Geoff; Bernstein, Claire Marcus; Levitt, Harry

    2015-11-01

    Clinician-directed auditory training using the KTH Speech Tracking Procedure can be a powerful approach for maximizing outcomes with adult cochlear implant (CI) users. This article first reviews prior research findings from an 8-week clinician-directed auditory training (AT) program using speech tracking that yielded significant gains in speech tracking rate and sentence recognition scores following training. The second focus of the article is to illustrate the value of intensive face-to-face long-term AT using speech tracking with adult CI users. A detailed case study report is presented that demonstrates major ongoing and progressive gains in tracking rate, sentence recognition, and improvements in self-perceived competence and confidence over the course of intensive long-term training. Given the potential of both short- and long-term clinician-directed auditory training via KTH speech tracking to help CI users reach their optimal performance level, consideration for more widespread clinical use is proposed in the overall rehabilitation of adult CI users. PMID:27587916

  9. Auditory event-related brain potentials for an early discrimination between normal and pathological brain aging

    Institute of Scientific and Technical Information of China (English)

    Juliana Dushanova; Mario Christov

    2013-01-01

    The brain as a system with gradually decreasing resources maximizes its chances by reorganizing neural networks to ensure efficient performance. Auditory event-related potentials were recorded in 28 healthy volunteers comprising 14 young and 14 elderly subjects in auditory discrimination motor task (low frequency tone – right hand movement and high frequency tone – left hand movement). The amplitudes of the sensory event-related potential components (N1, P2) were more pronounced with increasing age for either tone and this effect for P2 amplitude was more pronounced in the frontal region. The latency relationship of N1 between the groups was tone-dependent, while that of P2 was tone-independent with a prominent delay in the elderly group over all brain regions. The amplitudes of the cognitive components (N2, P3) diminished with increasing age and the hemispheric asymmetry of N2 (but not for P3) reduced with increasing age. Prolonged N2 latency with increasing age was widespread for either tone while between-group difference in P3 latency was tone-dependent. High frequency tone stimulation and movement requirements lead to P3 delay in the elderly group. The amplitude difference of the sensory components between the age groups could be due to a general greater alertness, less expressed habituation, or decline in the ability to retreat attentional resources from the stimuli in the elderly group. With aging, a neural circuit reorganization of the brain activity affects the cognitive processes. The approach used in this study is useful for an early discrimination between normal and pathological brain aging for early treatment of cognitive alterations and dementia.

  10. Experience-based auditory predictions modulate brain activity to silence as do real sounds

    OpenAIRE

    Chouiter, Leila; Tzovara, Athina; Dieguez, Sebastian; Annoni, Jean-Marie; Magezi, David; De Lucia, Marzia; Spierer, Lucas

    2016-01-01

    Interactions between stimuli's acoustic features and experience-based internal models of the environment enable listeners to compensate for the disruptions in auditory streams that are regularly encountered in noisy environments. However, whether auditory gaps are filled in predictively or restored a posteriori remains unclear. The current lack of positive statistical evidence that internal models can actually shape brain activity as would real sounds precludes accepting predictive accou...

  11. BRAIN STEM EVOKED RESPONSE AUDIOMETRY A REVIEW

    Directory of Open Access Journals (Sweden)

    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.

  12. Prediction of auditory and visual p300 brain-computer interface aptitude.

    Directory of Open Access Journals (Sweden)

    Sebastian Halder

    Full Text Available OBJECTIVE: Brain-computer interfaces (BCIs provide a non-muscular communication channel for patients with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS or otherwise motor impaired people and are also used for motor rehabilitation in chronic stroke. Differences in the ability to use a BCI vary from person to person and from session to session. A reliable predictor of aptitude would allow for the selection of suitable BCI paradigms. For this reason, we investigated whether P300 BCI aptitude could be predicted from a short experiment with a standard auditory oddball. METHODS: Forty healthy participants performed an electroencephalography (EEG based visual and auditory P300-BCI spelling task in a single session. In addition, prior to each session an auditory oddball was presented. Features extracted from the auditory oddball were analyzed with respect to predictive power for BCI aptitude. RESULTS: Correlation between auditory oddball response and P300 BCI accuracy revealed a strong relationship between accuracy and N2 amplitude and the amplitude of a late ERP component between 400 and 600 ms. Interestingly, the P3 amplitude of the auditory oddball response was not correlated with accuracy. CONCLUSIONS: Event-related potentials recorded during a standard auditory oddball session moderately predict aptitude in an audiory and highly in a visual P300 BCI. The predictor will allow for faster paradigm selection. SIGNIFICANCE: Our method will reduce strain on patients because unsuccessful training may be avoided, provided the results can be generalized to the patient population.

  13. Auditory Neural Prostheses – A Window to the Future

    Directory of Open Access Journals (Sweden)

    Mohan Kameshwaran

    2015-06-01

    or absent on both sides and hence, a cochlear implant (CI would be inef­fective. In such patients, the brainstem implant bypasses the damaged / absent cochlear nerves and directly stimulates the cochlear nucleus in the brainstem.  The auditory midbrain implant (AMI has been designed for stimulation of the auditory midbrain, particularly the central nucleus of inferior colliculus (ICC. It is used especially in patients with large neurofibromatosis type 2 (NF2 wherein tumor induced damage to the brain­stem/cochlear nucleus often co-exists. The efficacy and safety of auditory neural prostheses is well proven. Advancements in technology will enhance the benefit provided by these prostheses.  Hearing loss is one of the commonest congenital anomalies to affect children world-over. The incidence of congenital hearing loss is more pronounced in developing countries like the Indian sub-continent, especially with the problems of consanguinity. Hearing loss is a double tragedy, as it leads to not only deafness but also language deprivation. However, hearing loss is the only truly remediable handicap, due to remarkable advances in biomedical engineering and surgical techniques. Auditory neural prostheses help to augment or restore hearing by integration of an external circuitry with the peripheral hearing apparatus and the central circuitry of the brain. A cochlear implant (CI is a surgically implantable device that helps restore hearing in patients with severe-profound hearing loss, unresponsive to amplification by conventional hearing aids. CIs are electronic devices designed to detect mechanical sound energy and convert it into electrical signals that can be delivered to the coch­lear nerve, bypassing the damaged hair cells of the coch­lea. The only true prerequisite is an intact auditory nerve. The emphasis is on implantation as early as possible to maximize speech understanding and perception. Bilateral CI has significant benefits which include improved speech

  14. Diffusion tensor imaging of dolphin brains reveals direct auditory pathway to temporal lobe.

    Science.gov (United States)

    Berns, Gregory S; Cook, Peter F; Foxley, Sean; Jbabdi, Saad; Miller, Karla L; Marino, Lori

    2015-07-22

    The brains of odontocetes (toothed whales) look grossly different from their terrestrial relatives. Because of their adaptation to the aquatic environment and their reliance on echolocation, the odontocetes' auditory system is both unique and crucial to their survival. Yet, scant data exist about the functional organization of the cetacean auditory system. A predominant hypothesis is that the primary auditory cortex lies in the suprasylvian gyrus along the vertex of the hemispheres, with this position induced by expansion of 'associative' regions in lateral and caudal directions. However, the precise location of the auditory cortex and its connections are still unknown. Here, we used a novel diffusion tensor imaging (DTI) sequence in archival post-mortem brains of a common dolphin (Delphinus delphis) and a pantropical dolphin (Stenella attenuata) to map their sensory and motor systems. Using thalamic parcellation based on traditionally defined regions for the primary visual (V1) and auditory cortex (A1), we found distinct regions of the thalamus connected to V1 and A1. But in addition to suprasylvian-A1, we report here, for the first time, the auditory cortex also exists in the temporal lobe, in a region near cetacean-A2 and possibly analogous to the primary auditory cortex in related terrestrial mammals (Artiodactyla). Using probabilistic tract tracing, we found a direct pathway from the inferior colliculus to the medial geniculate nucleus to the temporal lobe near the sylvian fissure. Our results demonstrate the feasibility of post-mortem DTI in archival specimens to answer basic questions in comparative neurobiology in a way that has not previously been possible and shows a link between the cetacean auditory system and those of terrestrial mammals. Given that fresh cetacean specimens are relatively rare, the ability to measure connectivity in archival specimens opens up a plethora of possibilities for investigating neuroanatomy in cetaceans and other species

  15. Waveform efficiency analysis of auditory nerve fiber stimulation for cochlear implants

    International Nuclear Information System (INIS)

    Evaluation of the electrical stimulation efficiency of various stimulating waveforms is an important issue for efficient neural stimulator design. Concerning the implantable micro devices design, it is also necessary to consider the feasibility of hardware implementation of the desired waveforms. In this paper, the charge, power and energy efficiency of four waveforms (i.e. square, rising ramp, triangular and rising ramp-decaying exponential) in various durations have been simulated and evaluated based on the computational model of the auditory nerve fibers. Moreover, for a fair comparison of their feasibility, a fully integrated current generator circuit has been developed so that the desired stimulating waveforms can be generated. The simulation results show that stimulation with the square waveforms is a proper choice in short and intermediate durations while the rising ramp-decaying exponential or triangular waveforms can be employed for long durations.

  16. 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

  17. 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

  18. Mechanical and Biological Interactions of Implants with the Brain and Their Impact on Implant Design.

    Science.gov (United States)

    Prodanov, Dimiter; Delbeke, Jean

    2016-01-01

    Neural prostheses have already a long history and yet the cochlear implant remains the only success story about a longterm sensory function restoration. On the other hand, neural implants for deep brain stimulation are gaining acceptance for variety of disorders including Parkinsons disease and obsessive-compulsive disorder. It is anticipated that the progress in the field has been hampered by a combination of technological and biological factors, such as the limited understanding of the longterm behavior of implants, unreliability of devices, biocompatibility of the implants among others. While the field's understanding of the cell biology of interactions at the biotic-abiotic interface has improved, relatively little attention has been paid on the mechanical factors (stress, strain), and hence on the geometry that can modulate it. This focused review summarizes the recent progress in the understanding of the mechanisms of mechanical interaction between the implants and the brain. The review gives an overview of the factors by which the implants interact acutely and chronically with the tissue: blood-brain barrier (BBB) breach, vascular damage, micromotions, diffusion etc. We propose some design constraints to be considered in future studies. Aspects of the chronic cell-implant interaction will be discussed in view of the chronic local inflammation and the ways of modulating it. PMID:26903786

  19. Brain tumour stem cells: the undercurrents of human brain cancer and their relationship to neural stem cells

    OpenAIRE

    Dirks, Peter B.

    2007-01-01

    Conceptual and technical advances in neural stem cell biology are being applied to the study of human brain tumours. These studies suggest that human brain tumours are organized as a hierarchy and are maintained by a small number of tumour cells that have stem cell properties. Most of the bulk population of human brain tumours comprise cells that have lost the ability to initiate and maintain tumour growth. Although the cell of origin for human brain tumours is uncertain, recent evidence poin...

  20. Effects of scanner acoustic noise on intrinsic brain activity during auditory stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Yakunina, Natalia [Kangwon National University, Institute of Medical Science, School of Medicine, Chuncheon (Korea, Republic of); Kangwon National University Hospital, Neuroscience Research Institute, Chuncheon (Korea, Republic of); Kang, Eun Kyoung [Kangwon National University Hospital, Department of Rehabilitation Medicine, Chuncheon (Korea, Republic of); Kim, Tae Su [Kangwon National University Hospital, Department of Otolaryngology, Chuncheon (Korea, Republic of); Kangwon National University, School of Medicine, Department of Otolaryngology, Chuncheon (Korea, Republic of); Min, Ji-Hoon [University of Michigan, Department of Biopsychology, Cognition, and Neuroscience, Ann Arbor, MI (United States); Kim, Sam Soo [Kangwon National University Hospital, Neuroscience Research Institute, Chuncheon (Korea, Republic of); Kangwon National University, School of Medicine, Department of Radiology, Chuncheon (Korea, Republic of); Nam, Eui-Cheol [Kangwon National University Hospital, Neuroscience Research Institute, Chuncheon (Korea, Republic of); Kangwon National University, School of Medicine, Department of Otolaryngology, Chuncheon (Korea, Republic of)

    2015-10-15

    Although the effects of scanner background noise (SBN) during functional magnetic resonance imaging (fMRI) have been extensively investigated for the brain regions involved in auditory processing, its impact on other types of intrinsic brain activity has largely been neglected. The present study evaluated the influence of SBN on a number of intrinsic connectivity networks (ICNs) during auditory stimulation by comparing the results obtained using sparse temporal acquisition (STA) with those using continuous acquisition (CA). Fourteen healthy subjects were presented with classical music pieces in a block paradigm during two sessions of STA and CA. A volume-matched CA dataset (CAm) was generated by subsampling the CA dataset to temporally match it with the STA data. Independent component analysis was performed on the concatenated STA-CAm datasets, and voxel data, time courses, power spectra, and functional connectivity were compared. The ICA revealed 19 ICNs; the auditory, default mode, salience, and frontoparietal networks showed greater activity in the STA. The spectral peaks in 17 networks corresponded to the stimulation cycles in the STA, while only five networks displayed this correspondence in the CA. The dorsal default mode and salience networks exhibited stronger correlations with the stimulus waveform in the STA. SBN appeared to influence not only the areas of auditory response but also the majority of other ICNs, including attention and sensory networks. Therefore, SBN should be regarded as a serious nuisance factor during fMRI studies investigating intrinsic brain activity under external stimulation or task loads. (orig.)

  1. Effects of scanner acoustic noise on intrinsic brain activity during auditory stimulation

    International Nuclear Information System (INIS)

    Although the effects of scanner background noise (SBN) during functional magnetic resonance imaging (fMRI) have been extensively investigated for the brain regions involved in auditory processing, its impact on other types of intrinsic brain activity has largely been neglected. The present study evaluated the influence of SBN on a number of intrinsic connectivity networks (ICNs) during auditory stimulation by comparing the results obtained using sparse temporal acquisition (STA) with those using continuous acquisition (CA). Fourteen healthy subjects were presented with classical music pieces in a block paradigm during two sessions of STA and CA. A volume-matched CA dataset (CAm) was generated by subsampling the CA dataset to temporally match it with the STA data. Independent component analysis was performed on the concatenated STA-CAm datasets, and voxel data, time courses, power spectra, and functional connectivity were compared. The ICA revealed 19 ICNs; the auditory, default mode, salience, and frontoparietal networks showed greater activity in the STA. The spectral peaks in 17 networks corresponded to the stimulation cycles in the STA, while only five networks displayed this correspondence in the CA. The dorsal default mode and salience networks exhibited stronger correlations with the stimulus waveform in the STA. SBN appeared to influence not only the areas of auditory response but also the majority of other ICNs, including attention and sensory networks. Therefore, SBN should be regarded as a serious nuisance factor during fMRI studies investigating intrinsic brain activity under external stimulation or task loads. (orig.)

  2. Discovery of Undescribed Brain Tissue Changes Around Implanted Microelectrode Arrays

    OpenAIRE

    Himanshi Desai

    2012-01-01

    Brain-implantable microelectrode arrays are devicesdesigned to record or electrically stimulate the activity ofneurons in the brain. These devices hold the potential tohelp treat epilepsy, paralysis, blindness, and deafness, andalso provide researchers with insights into a varietyof neural processes, such as memory formation.While these devices have a very promising future,researchers are discovering that their long-termfunctionality is greatly limited by the brain’s naturalimmune response to...

  3. A Case Study Assessing the Auditory and Speech Development of Four Children Implanted with Cochlear Implants by the Chronological Age of 12 Months

    Directory of Open Access Journals (Sweden)

    Birgit May-Mederake

    2013-01-01

    Full Text Available Children with severe hearing loss most likely receive the greatest benefit from a cochlear implant (CI when implanted at less than 2 years of age. Children with a hearing loss may also benefit greater from binaural sensory stimulation. Four children who received their first CI under 12 months of age were included in this study. Effects on auditory development were determined using the German LittlEARS Auditory Questionnaire, closed- and open-set monosyllabic word tests, aided free-field, the Mainzer and Göttinger speech discrimination tests, Monosyllabic-Trochee-Polysyllabic (MTP, and Listening Progress Profile (LiP. Speech production and grammar development were evaluated using a German language speech development test (SETK, reception of grammar test (TROG-D and active vocabulary test (AWST-R. The data showed that children implanted under 12 months of age reached open-set monosyllabic word discrimination at an age of 24 months. LiP results improved over time, and children recognized 100% of words in the MTP test after 12 months. All children performed as well as or better than their hearing peers in speech production and grammar development. SETK showed that the speech development of these children was in general age appropriate. The data suggests that early hearing loss intervention benefits speech and language development and supports the trend towards early cochlear implantation. Furthermore, the data emphasizes the potential benefits associated with bilateral implantation.

  4. Jumpstarting auditory learning in children with cochlear implants through music experiences.

    Science.gov (United States)

    Barton, Christine; Robbins, Amy McConkey

    2015-09-01

    Musical experiences are a valuable part of the lives of children with cochlear implants (CIs). In addition to the pleasure, relationships and emotional outlet provided by music, it serves to enhance or 'jumpstart' other auditory and cognitive skills that are critical for development and learning throughout the lifespan. Musicians have been shown to be 'better listeners' than non-musicians with regard to how they perceive and process sound. A heuristic model of music therapy is reviewed, including six modulating factors that may account for the auditory advantages demonstrated by those who participate in music therapy. The integral approach to music therapy is described along with the hybrid approach to pediatric language intervention. These approaches share the characteristics of placing high value on ecologically valid therapy experiences, i.e., engaging in 'real' music and 'real' communication. Music and language intervention techniques used by the authors are presented. It has been documented that children with CIs consistently have lower music perception scores than do their peers with normal hearing (NH). On the one hand, this finding matters a great deal because it provides parameters for setting reasonable expectations and highlights the work still required to improve signal processing with the devices so that they more accurately transmit music to CI listeners. On the other hand, the finding might not matter much if we assume that music, even in its less-than-optimal state, functions for CI children, as for NH children, as a developmental jumpstarter, a language-learning tool, a cognitive enricher, a motivator, and an attention enhancer. PMID:26561888

  5. 192Ir high dose rate (HDR) interstitial brain implant: optimisation

    International Nuclear Information System (INIS)

    The new modality of stepping source dosimetry system (SSDs) illustrates a remarkable improvement in attaining the uniform and homogeneous dose distribution within the target volume. The technique enables the physicist to correct for a certain amount of misplacement or curvature of implant geometry. The short course of brachytherapy provides good palliation in terms of functional improvements with low and acceptable toxicity in high-grade glioma. With continual refinements of the technique, brachytherapy performed by a skilled brachytherapy team offers an opportunity to improve patient survival and quality of life. Since 1997, micro selectron HDR 192Ir treatments are done including gynecological, oesophageal, breast, surface mould, soft tissue sarcoma (STS) and brain in our hospital. In this paper, procedure of interstitial brain implant in glioma as implant technique, simulation and treatment planning will be discussed

  6. Using auditory steady state responses to outline the functional connectivity in the tinnitus brain.

    Directory of Open Access Journals (Sweden)

    Winfried Schlee

    Full Text Available BACKGROUND: Tinnitus is an auditory phantom perception that is most likely generated in the central nervous system. Most of the tinnitus research has concentrated on the auditory system. However, it was suggested recently that also non-auditory structures are involved in a global network that encodes subjective tinnitus. We tested this assumption using auditory steady state responses to entrain the tinnitus network and investigated long-range functional connectivity across various non-auditory brain regions. METHODS AND FINDINGS: Using whole-head magnetoencephalography we investigated cortical connectivity by means of phase synchronization in tinnitus subjects and healthy controls. We found evidence for a deviating pattern of long-range functional connectivity in tinnitus that was strongly correlated with individual ratings of the tinnitus percept. Phase couplings between the anterior cingulum and the right frontal lobe and phase couplings between the anterior cingulum and the right parietal lobe showed significant condition x group interactions and were correlated with the individual tinnitus distress ratings only in the tinnitus condition and not in the control conditions. CONCLUSIONS: To the best of our knowledge this is the first study that demonstrates existence of a global tinnitus network of long-range cortical connections outside the central auditory system. This result extends the current knowledge of how tinnitus is generated in the brain. We propose that this global extend of the tinnitus network is crucial for the continuos perception of the tinnitus tone and a therapeutical intervention that is able to change this network should result in relief of tinnitus.

  7. Neurogenesis in the brain auditory pathway of a marsupial, the northern native cat (Dasyurus hallucatus)

    International Nuclear Information System (INIS)

    Neurogenesis in the auditory pathway of the marsupial Dasyurus hallucatus was studied. Intraperitoneal injections of tritiated thymidine (20-40 microCi) were made into pouch-young varying from 1 to 56 days pouch-life. Animals were killed as adults and brain sections were prepared for autoradiography and counterstained with a Nissl stain. Neurons in the ventral cochlear nucleus were generated prior to 3 days pouch-life, in the superior olive at 5-7 days, and in the dorsal cochlear nucleus over a prolonged period. Inferior collicular neurogenesis lagged behind that in the medial geniculate, the latter taking place between days 3 and 9 and the former between days 7 and 22. Neurogenesis began in the auditory cortex on day 9 and was completed by about day 42. Thus neurogenesis was complete in the medullary auditory nuclei before that in the midbrain commenced, and in the medial geniculate before that in the auditory cortex commenced. The time course of neurogenesis in the auditory pathway of the native cat was very similar to that in another marsupial, the brushtail possum. For both, neurogenesis occurred earlier than in eutherian mammals of a similar size but was more protracted

  8. Neurogenesis in the brain auditory pathway of a marsupial, the northern native cat (Dasyurus hallucatus)

    Energy Technology Data Exchange (ETDEWEB)

    Aitkin, L.; Nelson, J.; Farrington, M.; Swann, S. (Department of Physiology, Monash University, Melbourne (Australia))

    1991-07-08

    Neurogenesis in the auditory pathway of the marsupial Dasyurus hallucatus was studied. Intraperitoneal injections of tritiated thymidine (20-40 microCi) were made into pouch-young varying from 1 to 56 days pouch-life. Animals were killed as adults and brain sections were prepared for autoradiography and counterstained with a Nissl stain. Neurons in the ventral cochlear nucleus were generated prior to 3 days pouch-life, in the superior olive at 5-7 days, and in the dorsal cochlear nucleus over a prolonged period. Inferior collicular neurogenesis lagged behind that in the medial geniculate, the latter taking place between days 3 and 9 and the former between days 7 and 22. Neurogenesis began in the auditory cortex on day 9 and was completed by about day 42. Thus neurogenesis was complete in the medullary auditory nuclei before that in the midbrain commenced, and in the medial geniculate before that in the auditory cortex commenced. The time course of neurogenesis in the auditory pathway of the native cat was very similar to that in another marsupial, the brushtail possum. For both, neurogenesis occurred earlier than in eutherian mammals of a similar size but was more protracted.

  9. Auditory, Visual, and Auditory-Visual Speech Perception by Individuals with Cochlear Implants versus Individuals with Hearing Aids

    Science.gov (United States)

    Most, Tova; Rothem, Hilla; Luntz, Michal

    2009-01-01

    The researchers evaluated the contribution of cochlear implants (CIs) to speech perception by a sample of prelingually deaf individuals implanted after age 8 years. This group was compared with a group with profound hearing impairment (HA-P), and with a group with severe hearing impairment (HA-S), both of which used hearing aids. Words and…

  10. Milrinone in Enterovirus 71 Brain Stem Encephalitis

    Science.gov (United States)

    Wang, Shih-Min

    2016-01-01

    Enterovirus 71 (EV71) was implicated in a widespread outbreak of hand-foot-and-mouth disease (HFMD) across the Asia Pacific area since 1997 and has also been reported sporadically in patients with brain stem encephalitis. Neurogenic shock with pulmonary edema (PE) is a fatal complication of EV71 infection. Among inotropic agents, milrinone is selected as a therapeutic agent for EV71- induced PE due to its immunopathogenesis. Milrinone is a type III phosphodiesterase inhibitor that has both inotropic and vasodilator effects. Its clinical efficacy has been shown by modulating inflammation, reducing sympathetic over-activity, and improving survival in patients with EV71-associated PE. Milrinone exhibits immunoregulatory and anti-inflammatory effects in the management of systemic inflammatory responses in severe EV71 infection. PMID:27065870

  11. Milrinone in Enterovirus 71 Brain Stem Encephalitis.

    Science.gov (United States)

    Wang, Shih-Min

    2016-01-01

    Enterovirus 71 (EV71) was implicated in a widespread outbreak of hand-foot-and-mouth disease (HFMD) across the Asia Pacific area since 1997 and has also been reported sporadically in patients with brain stem encephalitis. Neurogenic shock with pulmonary edema (PE) is a fatal complication of EV71 infection. Among inotropic agents, milrinone is selected as a therapeutic agent for EV71- induced PE due to its immunopathogenesis. Milrinone is a type III phosphodiesterase inhibitor that has both inotropic and vasodilator effects. Its clinical efficacy has been shown by modulating inflammation, reducing sympathetic over-activity, and improving survival in patients with EV71-associated PE. Milrinone exhibits immunoregulatory and anti-inflammatory effects in the management of systemic inflammatory responses in severe EV71 infection. PMID:27065870

  12. Reestablishing speech understanding through musical ear training after cochlear implantation: a study of the potential cortical plasticity in the brain

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Mortensen, Malene V; Gjedde, Albert;

    2009-01-01

    Cochlear implants (CIs) provide impressive speech perception for persons with severe hearing loss, but many CI recipients fail in perceiving speech prosody and music. Successful rehabilitation depends on cortical plasticity in the brain and postoperative measures. The present study evaluates the...... behavioral and neurologic effects of musical ear training on CI users' speech and music perception. The goal is to find and work out musical methods to improve CI users' auditory capabilities and, in a longer perspective, provide an efficient strategy for improving speech understanding for both adults and...

  13. Localized brain activation related to the strength of auditory learning in a parrot.

    Directory of Open Access Journals (Sweden)

    Hiroko Eda-Fujiwara

    Full Text Available Parrots and songbirds learn their vocalizations from a conspecific tutor, much like human infants acquire spoken language. Parrots can learn human words and it has been suggested that they can use them to communicate with humans. The caudomedial pallium in the parrot brain is homologous with that of songbirds, and analogous to the human auditory association cortex, involved in speech processing. Here we investigated neuronal activation, measured as expression of the protein product of the immediate early gene ZENK, in relation to auditory learning in the budgerigar (Melopsittacus undulatus, a parrot. Budgerigar males successfully learned to discriminate two Japanese words spoken by another male conspecific. Re-exposure to the two discriminanda led to increased neuronal activation in the caudomedial pallium, but not in the hippocampus, compared to untrained birds that were exposed to the same words, or were not exposed to words. Neuronal activation in the caudomedial pallium of the experimental birds was correlated significantly and positively with the percentage of correct responses in the discrimination task. These results suggest that in a parrot, the caudomedial pallium is involved in auditory learning. Thus, in parrots, songbirds and humans, analogous brain regions may contain the neural substrate for auditory learning and memory.

  14. Effects of visual working memory on brain information processing of irrelevant auditory stimuli.

    Directory of Open Access Journals (Sweden)

    Jiagui Qu

    Full Text Available Selective attention has traditionally been viewed as a sensory processing modulator that promotes cognitive processing efficiency by favoring relevant stimuli while inhibiting irrelevant stimuli. However, the cross-modal processing of irrelevant information during working memory (WM has been rarely investigated. In this study, the modulation of irrelevant auditory information by the brain during a visual WM task was investigated. The N100 auditory evoked potential (N100-AEP following an auditory click was used to evaluate the selective attention to auditory stimulus during WM processing and at rest. N100-AEP amplitudes were found to be significantly affected in the left-prefrontal, mid-prefrontal, right-prefrontal, left-frontal, and mid-frontal regions while performing a high WM load task. In contrast, no significant differences were found between N100-AEP amplitudes in WM states and rest states under a low WM load task in all recorded brain regions. Furthermore, no differences were found between the time latencies of N100-AEP troughs in WM states and rest states while performing either the high or low WM load task. These findings suggested that the prefrontal cortex (PFC may integrate information from different sensory channels to protect perceptual integrity during cognitive processing.

  15. The Effect of Short-Term Auditory Training on Speech in Noise Perception and Cortical Auditory Evoked Potentials in Adults with Cochlear Implants.

    Science.gov (United States)

    Barlow, Nathan; Purdy, Suzanne C; Sharma, Mridula; Giles, Ellen; Narne, Vijay

    2016-02-01

    This study investigated whether a short intensive psychophysical auditory training program is associated with speech perception benefits and changes in cortical auditory evoked potentials (CAEPs) in adult cochlear implant (CI) users. Ten adult implant recipients trained approximately 7 hours on psychophysical tasks (Gap-in-Noise Detection, Frequency Discrimination, Spectral Rippled Noise [SRN], Iterated Rippled Noise, Temporal Modulation). Speech performance was assessed before and after training using Lexical Neighborhood Test (LNT) words in quiet and in eight-speaker babble. CAEPs evoked by a natural speech stimulus /baba/ with varying syllable stress were assessed pre- and post-training, in quiet and in noise. SRN psychophysical thresholds showed a significant improvement (78% on average) over the training period, but performance on other psychophysical tasks did not change. LNT scores in noise improved significantly post-training by 11% on average compared with three pretraining baseline measures. N1P2 amplitude changed post-training for /baba/ in quiet (p = 0.005, visit 3 pretraining versus visit 4 post-training). CAEP changes did not correlate with behavioral measures. CI recipients' clinical records indicated a plateau in speech perception performance prior to participation in the study. A short period of intensive psychophysical training produced small but significant gains in speech perception in noise and spectral discrimination ability. There remain questions about the most appropriate type of training and the duration or dosage of training that provides the most robust outcomes for adults with CIs. PMID:27587925

  16. Central Auditory Processing of Temporal and Spectral-Variance Cues in Cochlear Implant Listeners.

    Directory of Open Access Journals (Sweden)

    Carol Q Pham

    Full Text Available Cochlear implant (CI listeners have difficulty understanding speech in complex listening environments. This deficit is thought to be largely due to peripheral encoding problems arising from current spread, which results in wide peripheral filters. In normal hearing (NH listeners, central processing contributes to segregation of speech from competing sounds. We tested the hypothesis that basic central processing abilities are retained in post-lingually deaf CI listeners, but processing is hampered by degraded input from the periphery. In eight CI listeners, we measured auditory nerve compound action potentials to characterize peripheral filters. Then, we measured psychophysical detection thresholds in the presence of multi-electrode maskers placed either inside (peripheral masking or outside (central masking the peripheral filter. This was intended to distinguish peripheral from central contributions to signal detection. Introduction of temporal asynchrony between the signal and masker improved signal detection in both peripheral and central masking conditions for all CI listeners. Randomly varying components of the masker created spectral-variance cues, which seemed to benefit only two out of eight CI listeners. Contrastingly, the spectral-variance cues improved signal detection in all five NH listeners who listened to our CI simulation. Together these results indicate that widened peripheral filters significantly hamper central processing of spectral-variance cues but not of temporal cues in post-lingually deaf CI listeners. As indicated by two CI listeners in our study, however, post-lingually deaf CI listeners may retain some central processing abilities similar to NH listeners.

  17. Differential maturation of brain signal complexity in the human auditory and visual system

    OpenAIRE

    Sarah Lippe; Randy McIntosh

    2009-01-01

    Brain development carries with it a large number of structural changes at the local level which impact on the functional interactions of distributed neuronal networks for perceptual processing. Such changes enhance information processing capacity, which can be indexed by estimation of neural signal complexity. Here, we show that during development, EEG signal complexity increases from one month to 5 years of age in response to auditory and visual stimulation. However, the rates of change in...

  18. Differential Maturation of Brain Signal Complexity in the Human Auditory and Visual System

    OpenAIRE

    Lippé, Sarah; Kovacevic, Natasa; McIntosh, Anthony Randal

    2009-01-01

    Brain development carries with it a large number of structural changes at the local level which impact on the functional interactions of distributed neuronal networks for perceptual processing. Such changes enhance information processing capacity, which can be indexed by estimation of neural signal complexity. Here, we show that during development, EEG signal complexity increases from one month to 5 years of age in response to auditory and visual stimulation. However, the rates of change in c...

  19. Localized Brain Activation Related to the Strength of Auditory Learning in a Parrot

    OpenAIRE

    Hiroko Eda-Fujiwara; Takuya Imagawa; Masanori Matsushita; Yasushi Matsuda; Hiro-Aki Takeuchi; Ryohei Satoh; Aiko Watanabe; Zandbergen, Matthijs A.; Kazuchika Manabe; Takashi Kawashima; Johan J Bolhuis

    2012-01-01

    Parrots and songbirds learn their vocalizations from a conspecific tutor, much like human infants acquire spoken language. Parrots can learn human words and it has been suggested that they can use them to communicate with humans. The caudomedial pallium in the parrot brain is homologous with that of songbirds, and analogous to the human auditory association cortex, involved in speech processing. Here we investigated neuronal activation, measured as expression of the protein product of the imm...

  20. Brain Cancer Stem Cells: Current Status on Glioblastoma Multiforme

    Directory of Open Access Journals (Sweden)

    Gilbert Bernier

    2011-03-01

    Full Text Available Glioblastoma multiforme (GBM, an aggressive brain tumor of astrocytic/neural stem cell origin, represents one of the most incurable cancers. GBM tumors are highly heterogeneous. However, most tumors contain a subpopulation of cells that display neural stem cell characteristics in vitro and that can generate a new brain tumor upon transplantation in mice. Hence, previously identified molecular pathways regulating neural stem cell biology were found to represent the cornerstone of GBM stem cell self-renewal mechanism. GBM tumors are also notorious for their resistance to radiation therapy. Notably, GBM “cancer stem cells” were also found to be responsible for this radioresistance. Herein, we will analyze the data supporting or not the cancer stem cell model in GBM, overview the current knowledge regarding GBM stem cell self-renewal and radioresistance molecular mechanisms, and discuss the potential therapeutic application of these findings.

  1. Brain Cancer Stem Cells: Current Status on Glioblastoma Multiforme

    Energy Technology Data Exchange (ETDEWEB)

    Facchino, Sabrina; Abdouh, Mohamed [Developmental Biology Laboratory, Hopital Maisonneuve-Rosemont, 5415 Boul. l' Assomption, Montreal, H1T 2M4 (Canada); Bernier, Gilbert, E-mail: gbernier.hmr@ssss.gouv.qc.ca [Developmental Biology Laboratory, Hopital Maisonneuve-Rosemont, 5415 Boul. l' Assomption, Montreal, H1T 2M4 (Canada); Faculté de Médecine, Université de Montréal, Montréal, H3T 1J4 (Canada)

    2011-03-30

    Glioblastoma multiforme (GBM), an aggressive brain tumor of astrocytic/neural stem cell origin, represents one of the most incurable cancers. GBM tumors are highly heterogeneous. However, most tumors contain a subpopulation of cells that display neural stem cell characteristics in vitro and that can generate a new brain tumor upon transplantation in mice. Hence, previously identified molecular pathways regulating neural stem cell biology were found to represent the cornerstone of GBM stem cell self-renewal mechanism. GBM tumors are also notorious for their resistance to radiation therapy. Notably, GBM “cancer stem cells” were also found to be responsible for this radioresistance. Herein, we will analyze the data supporting or not the cancer stem cell model in GBM, overview the current knowledge regarding GBM stem cell self-renewal and radioresistance molecular mechanisms, and discuss the potential therapeutic application of these findings.

  2. Brain Cancer Stem Cells: Current Status on Glioblastoma Multiforme

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM), an aggressive brain tumor of astrocytic/neural stem cell origin, represents one of the most incurable cancers. GBM tumors are highly heterogeneous. However, most tumors contain a subpopulation of cells that display neural stem cell characteristics in vitro and that can generate a new brain tumor upon transplantation in mice. Hence, previously identified molecular pathways regulating neural stem cell biology were found to represent the cornerstone of GBM stem cell self-renewal mechanism. GBM tumors are also notorious for their resistance to radiation therapy. Notably, GBM “cancer stem cells” were also found to be responsible for this radioresistance. Herein, we will analyze the data supporting or not the cancer stem cell model in GBM, overview the current knowledge regarding GBM stem cell self-renewal and radioresistance molecular mechanisms, and discuss the potential therapeutic application of these findings

  3. Discovery of Undescribed Brain Tissue Changes Around Implanted Microelectrode Arrays

    Directory of Open Access Journals (Sweden)

    Himanshi Desai

    2012-01-01

    Full Text Available Brain-implantable microelectrode arrays are devicesdesigned to record or electrically stimulate the activity ofneurons in the brain. These devices hold the potential tohelp treat epilepsy, paralysis, blindness, and deafness, andalso provide researchers with insights into a varietyof neural processes, such as memory formation.While these devices have a very promising future,researchers are discovering that their long-termfunctionality is greatly limited by the brain’s naturalimmune response to foreign objects. To improve thefunctional lifetime of these devices, one solution lies infully characterizing and understanding this tissue response.Roles for microglia and astrocytes in this biologicalresponse have been characterized. However, changesto oligodendrocytes, cells that myelinate axons, remainpoorly understood. These cells provide insulationto the axons, which is required for proper neuralfunctioning. Here we report on the changes that occurwith oligodendrocyte processes in tissue aroundmicroelectrode implants in the brain.Six rats were surgically implanted with microelectrodearrays and allowed to recover for 1, 2, or 4 weeks.Subjects were then sacrificed and the brain tissue wasprocessed using our recently developed method, Device-Capture Histology. Immunohistochemistry and confocalmicroscopy was employed to assess the responsearound the device. Results indicated a decrease inoligodendrocyte density and a loss in typical directionalorientation of oligodendrocyte processes in tissue near thedevice. These results suggest alterations in the underlyingneuronal networks around these devices, which maygreatly impact the current functional utility of thesepromising devices.

  4. Auditory Neuropathy

    Science.gov (United States)

    ... field differ in their opinions about the potential benefits of hearing aids, cochlear implants, and other technologies for people with auditory neuropathy. Some professionals report that hearing aids and personal listening devices such as frequency modulation (FM) systems are ...

  5. Radiation effects of iridium-192 implants in the cat brain

    International Nuclear Information System (INIS)

    The radiation effects of 192Ir permanent implants into the cat brain were studied with respect to morphological changes, blood flow, brain water and electrolytes. 192Ir wires (10 animals) and non-radioactive silver wires (5 control animals) were placed stereotactically into the left internal capsule. Activity of 192Ir was 0.31 mCi, the accumulated dose at 5 mm distance was 3060 rad after 21 days and 4680 rad after 35 days, respectively. None of the animals presented a neurological deficit, and the EEG recording was without significant changes. Histological damage which could be attributed to the radiation was not observed. Serum proteins, however, were detected immunohistochemically in reactive astrocytes (3 x), in macrophages (2 x) and as diffuse perivascular accumulation. Brain water in the white matter near the implantation site increased from 68.6 to 73.2%, corresponding to a volume increase of about 17%. There was no change in the grey matter or the opposite hemisphere. Cerebral blood flow decreased slightly but there was no relationship with the development of edema. The findings suggest that low dose rate topical irradiation of the brain produces primarily membrane-dependent changes, resulting in local brain edema. (orig.)

  6. Can you hear me now? Musical training shapes functional brain networks for selective auditory attention and hearing speech in noise

    Directory of Open Access Journals (Sweden)

    Dana L Strait

    2011-06-01

    Full Text Available Even in the quietest of rooms, our senses are perpetually inundated by a barrage of sounds, requiring the auditory system to adapt to a variety of listening conditions in order to extract signals of interest (e.g., one speaker’s voice amidst others. Brain networks that promote selective attention are thought to sharpen the neural encoding of a target signal, suppressing competing sounds and enhancing perceptual performance. Here, we ask: does musical training benefit cortical mechanisms that underlie selective attention to speech? To answer this question, we assessed the impact of selective auditory attention on cortical auditory-evoked response variability in musicians and nonmusicians. Outcomes indicate strengthened brain networks for selective auditory attention in musicians in that musicians but not nonmusicians demonstrate decreased prefrontal response variability with auditory attention. Results are interpreted in the context of previous work from our laboratory documenting perceptual and subcortical advantages in musicians for the hearing and neural encoding of speech in background noise. Musicians’ neural proficiency for selectively engaging and sustaining auditory attention to language indicates a potential benefit of music for auditory training. Given the importance of auditory attention for the development of language-related skills, musical training may aid in the prevention, habilitation and remediation of children with a wide range of attention-based language and learning impairments.

  7. Neurosyphilis Involving Cranial Nerves in Brain Stem: 2 Case Reports

    International Nuclear Information System (INIS)

    Neurosyphilis uncommonly presents with cranial neuropathies in acute syphilitic meningitis and meningovascular neurosyphilis. We now report two cases in which the meningeal form of neurosyphilis involved cranial nerves in the brain stem: the oculomotor and trigeminal nerve.

  8. Ischemic and hemorrhagic brain stem lesions mimicking diabetic ophthalmoplegia.

    Science.gov (United States)

    Fujioka, T; Segawa, F; Ogawa, K; Kurihara, T; Kinoshita, M

    1995-05-01

    Two patients with diabetes mellitus, one of them with an isolated third cranial nerve palsy and the other with an isolated sixth cranial nerve palsy, are presented. MRI investigations including diffusion-weighted MRI revealed a small ischemic brain stem lesion in the former and a small hemorrhagic brain stem lesion in the latter. In the former case wallerian degeneration of the nerve fascicle within the mesencephalon was also detected. These cases indicate that vascular accidents of the brain stem may masquerade as fascicular or infranuclear disturbance of the oculomotor or abducens nerve; therefore, it is important to include brain stem lesions into the differential diagnosis of isolated ophthalmoplegia. Thorough investigation by MRI including diffusion-weighted MRI is helpful for correct diagnosis. PMID:7656493

  9. Neurosyphilis Involving Cranial Nerves in Brain Stem: 2 Case Reports

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Ji Hye [Dept. of Radiology, Kyung Hee University College of Medicine, Seoul (Korea, Republic of); Choi, Woo Suk; Kim, Eui Jong [Dept. of Radiology, Kyung Hee University Hospital, Seoul (Korea, Republic of); Yoon, Sung Sang; Heo, Sung Hyuk [Dept. of Neurology, Kyung Hee University Hospital, Seoul (Korea, Republic of)

    2012-01-15

    Neurosyphilis uncommonly presents with cranial neuropathies in acute syphilitic meningitis and meningovascular neurosyphilis. We now report two cases in which the meningeal form of neurosyphilis involved cranial nerves in the brain stem: the oculomotor and trigeminal nerve.

  10. Neonatal bilateral diaphragmatic paralysis caused by brain stem haemorrhage.

    OpenAIRE

    Blazer, S; Hemli, J A; Sujov, P O; Braun, J

    1989-01-01

    We describe a neonate with severe bilateral diaphragmatic paralysis caused by haemorrhage in the lower brain stem. To our knowledge this association has not been previously reported in the English medical literature.

  11. Study on correlation of brain stem auditory evoked potential and psychosomatic symptom of soldiers with insomnia%军人失眠症患者脑干听觉诱发电位与心身症状的相关性研究*

    Institute of Scientific and Technical Information of China (English)

    梁学军; 甘景梨; 高存友; 赵兰民; 张夏莲; 刘立志

    2015-01-01

    目的:探讨军人失眠症患者的脑干听觉诱发电位(BAEP)的变异特点及其与心身症状的关系。方法对48例军人失眠症患者(研究组)进行BAEP检测,采用中国心身健康量表(CPSHS)对心身症状进行评定,并同50名对照组进行对比。结果研究组与对照组比较,Ⅲ、Ⅴ波潜伏期(PL)和Ⅰ~Ⅲ波间期(IPL)均延迟,Ⅲ~Ⅴ波间期缩短,Ⅴ/Ⅰ波幅比值降低(P<0.05或0.01);研究组CPSHS总分、呼吸系统、心血管系统、消化系统、骨骼肌肉、焦虑、抑郁因子分显著高于对照组(P<0.05或0.01);研究组BAEP各波的观察指标与大部分心身症状均呈显著性相关(r=0.31~0.63,P<0.05或0.01)。结论军人失眠症患者的BAEP存在明显异常,并与身心症状密切相关。因此,BAEP可以作为失眠症诊断的一种辅助的手段。%Objective To explore the relationship of the brain stem auditory evoked potential (BAEP) and psychosomatic symptom of the soldiers with insomnia. Method The 48 soldiers with insomnia and 50 normal controls were measured with BAEP and Chinese Psychosomatic Health Scale(CPSHS). Results Compared with the control group,the soldiers with insomnia showed more prolonged wave Ⅲ, Ⅴ latency and wave Ⅰ-Ⅲ inter-peak latency,shorter wave Ⅲ-Ⅴ inter-peak latency,and amplitude ratio of wave Ⅴ/Ⅰ,and higher scores of CPSHS, systema respiratorium,cardiovascular system,digestive system,somatic muscle,anxiety and depression (P<0.05 or 0.01). Most items of BAEP were significantly related to psychosomatic symptoms (r=0.31-0.63,P<0.05 or 0.01). Conclusion There is the significant difference of BAEP with soldiers with insomnia,which is correlated evidently to psychosomatic health. BAEP test can provides one adjunctive means in diagnosis of insomnia.

  12. Subacute sclerosing panencephalitis: brain stem involvement in a peculiar pattern

    International Nuclear Information System (INIS)

    The most common pattern in subacute sclerosing panencephalitis, is in the cerebral hemisphere white matter on T2-weighted images with or without atrophy. Brain-stem lesions are rare. We report brain-stem involvement in two children with subacute sclerosing panencephalitis. A peculiar pattern, with involvement of the pons with extension to both middle cerebellar peduncles and substantia nigra but sparing the pontine tegmentum, is suggested. (orig.)

  13. Referências anatômicas na cirurgia do implante auditivo de tronco cerebral Anatomical landmarks in auditory brainstem implant surgery

    Directory of Open Access Journals (Sweden)

    Rubens Vuono Brito Neto

    2005-06-01

    Full Text Available O implante auditivo de tronco cerebral é uma opção os pacientes surdos que não têm a integridade das vias auditivas preservada. A cirurgia, por sua complexidade anatômica e funcional, requer treinamento específico em laboratório de anatomia por parte do cirurgião. OBJETIVOS: Estudar a anatomia cirúrgica da cirurgia do implante auditivo de tronco cerebral. FORMA DE ESTUDO: Estudo anatômico. MATERIAL E MÉTODO: Neste estudo dissecamos cadáver fresco preparado com solução corante injetada nas artérias e veias intra-cranianas. O local de inserção do eletrodo do implante auditivo de tronco cerebral foi estudado através do acesso translabiríntico. RESULTADOS: A técnica cirúrgica utilizada para a implantação do eletrodo de tronco cerebral é semelhante à utilizada na remoção do shwannoma vestibular. O complexo de núcleo coclear, composto pelo núcleo coclear ventral e dorsal, é o local para a colocação do eletrodo. O núcleo coclear ventral é o principal núcleo de transmissão de impulsos neurais do VIII par e seus axônios formam a principal via ascendente do nervo coclear. Tanto o núcleo ventral como o dorsal não são visíveis durante a cirurgia e sua localização depende de identificação de estruturas anatômicas adjacentes. CONCLUSÃO: A região de implantação do eletrodo do implante auditivo de tronco cerebral apresenta referências anatômicas que permitem sua fácil identificação durante a cirurgia.Auditory brainstem implant (ABI is an option for deaf patients who do not have the whole auditory pathways preserved. The surgery, because of its anatomical and functional complexity, requires specific training of the surgeon in an anatomy lab. AIM: To study the surgical anatomy of the auditory brainstem implant surgery. STUDY DESIGN: Anatomic study. MATERIAL AND METHOD: In the present study, we dissected a fresh cadaver prepared with a dye solution injected into the arteries and intracranial veins. The

  14. Training stem cells for treatment of malignant brain tumors

    Institute of Scientific and Technical Information of China (English)

    Shengwen; Calvin; Li; Mustafa; H; Kabeer; Long; T; Vu; Vic; Keschrumrus; Hong; Zhen; Yin; Brent; A; Dethlefs; Jiang; F; Zhong; John; H; Weiss; William; G; Loudon

    2014-01-01

    The treatment of malignant brain tumors remains a challenge. Stem cell technology has been applied in the treatment of brain tumors largely because of the ability of some stem cells to infiltrate into regions within the brain where tumor cells migrate as shown in preclinical studies. However, not all of these efforts can translate in the effective treatment that improves the quality of life for pa-tients. Here, we perform a literature review to identify the problems in the field. Given the lack of efficacy of most stem cell-based agents used in the treatment of malignant brain tumors, we found that stem cell distribution(i.e., only a fraction of stem cells applied capable of targeting tumors) are among the limiting factors. We provide guidelines for potential improvements in stem cell distribution. Specifically, we use an engineered tissue graft platform that replicates the in vivo microenvironment, and provide our data to validate that this culture platform is viable for producing stem cells that have better stem cell distribution than with the Petri dish culture system.

  15. Widespread Brain Areas Engaged during a Classical Auditory Streaming Task Revealed by Intracranial EEG

    Directory of Open Access Journals (Sweden)

    Andrew R Dykstra

    2011-08-01

    Full Text Available The auditory system must constantly decompose the complex mixture of sound arriving at the ear into perceptually-independent streams constituting accurate representations of individual sources in the acoustic environment. How the brain accomplishes this task is not well understood. The present study combined a classic behavioral paradigm with direct cortical recordings from neurosurgical patients with epilepsy in order to further describe the neural correlates of auditory streaming. Participants listened to sequences of pure tones alternating in frequency and indicated whether they heard one or two “streams.” The intracranial EEG was simultaneously recorded from sub-dural electrodes placed over temporal, frontal, and parietal cortex. Like healthy subjects, patients heard one stream when the frequency separation between tones was small and two when it was large. Robust evoked-potential correlates of frequency separation were observed over widespread brain areas. Waveform morphology was highly variable across individual electrode sites both within and across gross brain regions. Surprisingly, few evoked-potential correlates of perceptual organization were observed after controlling for physical stimulus differences. The results indicate that the cortical areas engaged during the streaming task is more complex and widespread than has been demonstrated by previous work, and that, by-and-large, correlates of bi-stability during streaming are probably located on a spatial scale not assessed – or in a brain area not examined – by the present study.

  16. Differential maturation of brain signal complexity in the human auditory and visual system

    Directory of Open Access Journals (Sweden)

    Sarah Lippe

    2009-11-01

    Full Text Available Brain development carries with it a large number of structural changes at the local level which impact on the functional interactions of distributed neuronal networks for perceptual processing. Such changes enhance information processing capacity, which can be indexed by estimation of neural signal complexity. Here, we show that during development, EEG signal complexity increases from one month to 5 years of age in response to auditory and visual stimulation. However, the rates of change in complexity were not equivalent for the two responses. Infants’ signal complexity for the visual condition was greater than auditory signal complexity, whereas adults showed the same level of complexity to both types of stimuli. The differential rates of complexity change may reflect a combination of innate and experiential factors on the structure and function of the two sensory systems.

  17. MRI of the incisural plane: assessment of normal brain stem position by age and transtentorial brain stem shift in disease

    International Nuclear Information System (INIS)

    The standardization on MRI of an anatomic plane passing through the tectum of the midbrain based on fixed landmarks allows assessment of the position of the brain stem during development and in normal adulthood, and comparison with its position in disease states. The level of the tectum relative to this incisural plane changes during normal cranial growth as well as in the presence of masses, frank brain stem herniation correlating with altered consciousness. (orig.)

  18. The Wellcome Prize Lecture. A map of auditory space in the mammalian brain: neural computation and development.

    Science.gov (United States)

    King, A J

    1993-09-01

    The experiments described in this review have demonstrated that the SC contains a two-dimensional map of auditory space, which is synthesized within the brain using a combination of monaural and binaural localization cues. There is also an adaptive fusion of auditory and visual space in this midbrain nucleus, providing for a common access to the motor pathways that control orientation behaviour. This necessitates a highly plastic relationship between the visual and auditory systems, both during postnatal development and in adult life. Because of the independent mobility of difference sense organs, gating mechanisms are incorporated into the auditory representation to provide up-to-date information about the spatial orientation of the eyes and ears. The SC therefore provides a valuable model system for studying a number of important issues in brain function, including the neural coding of sound location, the co-ordination of spatial information between different sensory systems, and the integration of sensory signals with motor outputs. PMID:8240794

  19. Nanomedicine Approaches to Modulate Neural Stem Cells in Brain Repair.

    Science.gov (United States)

    Santos, Tiago; Boto, Carlos; Saraiva, Cláudia M; Bernardino, Liliana; Ferreira, Lino

    2016-06-01

    We explore the concept of modulating neural stem cells and their niches for brain repair using nanotechnology-based approaches. These approaches include stimulating cell proliferation, recruitment, and differentiation to functionally recover damaged areas. Nanoscale-engineered materials potentially overcome limited crossing of the blood-brain barrier, deficient drug delivery, and cell targeting. PMID:26917252

  20. Psychophysical and neural correlates of noised-induced tinnitus in animals: Intra- and inter-auditory and non-auditory brain structure studies.

    Science.gov (United States)

    Zhang, Jinsheng; Luo, Hao; Pace, Edward; Li, Liang; Liu, Bin

    2016-04-01

    Tinnitus, a ringing in the ear or head without an external sound source, is a prevalent health problem. It is often associated with a number of limbic-associated disorders such as anxiety, sleep disturbance, and emotional distress. Thus, to investigate tinnitus, it is important to consider both auditory and non-auditory brain structures. This paper summarizes the psychophysical, immunocytochemical and electrophysiological evidence found in rats or hamsters with behavioral evidence of tinnitus. Behaviorally, we tested for tinnitus using a conditioned suppression/avoidance paradigm, gap detection acoustic reflex behavioral paradigm, and our newly developed conditioned licking suppression paradigm. Our new tinnitus behavioral paradigm requires relatively short baseline training, examines frequency specification of tinnitus perception, and achieves sensitive tinnitus testing at an individual level. To test for tinnitus-related anxiety and cognitive impairment, we used the elevated plus maze and Morris water maze. Our results showed that not all animals with tinnitus demonstrate anxiety and cognitive impairment. Immunocytochemically, we found that animals with tinnitus manifested increased Fos-like immunoreactivity (FLI) in both auditory and non-auditory structures. The manner in which FLI appeared suggests that lower brainstem structures may be involved in acute tinnitus whereas the midbrain and cortex are involved in more chronic tinnitus. Meanwhile, animals with tinnitus also manifested increased FLI in non-auditory brain structures that are involved in autonomic reactions, stress, arousal and attention. Electrophysiologically, we found that rats with tinnitus developed increased spontaneous firing in the auditory cortex (AC) and amygdala (AMG), as well as intra- and inter-AC and AMG neurosynchrony, which demonstrate that tinnitus may be actively produced and maintained by the interactions between the AC and AMG. PMID:26299842

  1. Cochlear implantation at the ear, nose and throat clinic of the Clinical center of Vojvodina

    OpenAIRE

    Komazec Zoran; Dankuc Dragan; Vlaški Ljiljana; Lemajić-Komazec Slobodanka; Nedeljkov Spomenka; Sokolovac Ivana

    2007-01-01

    Introduction. A cochlear implant is a small electronic device that can provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. Cochlear implants bypass the damaged hearing systems and directly stimulate the auditory nerve. Signals generated by the implant are sent by way of the auditory nerve to the brain, which recognizes the signals as sound. Hearing through a cochlear implant differs from normal hearing and takes time to learn or relearn. Cochlear implantat...

  2. Brain

    Science.gov (United States)

    ... will return after updating. Resources Archived Modules Updates Brain Cerebrum The cerebrum is the part of the ... the outside of the brain and spinal cord. Brain Stem The brain stem is the part of ...

  3. Brain stem hypoplasia associated with Cri-du-Chat syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jin Ho; Lee, Ha Young; Lim, Myung Kwan; Kim, Mi Young; Kang, Young Hye; Lee, Kyung Hee; Cho, Soon Gu [Dept. of Radiology, Inha University Hospital, Inha University School of Medicine, Incheon (Korea, Republic of)

    2013-12-15

    Cri-du-Chat syndrome, also called the 5p-syndrome, is a rare genetic abnormality, and only few cases have been reported on its brain MRI findings. We describe the magnetic resonance imaging findings of a 1-year-old girl with Cri-du-Chat syndrome who showed brain stem hypoplasia, particularly in the pons, with normal cerebellum and diffuse hypoplasia of the cerebral hemispheres. We suggest that Cri-du-Chat syndrome chould be suspected in children with brain stem hypoplasia, particularly for those with high-pitched cries.

  4. Brain stem hypoplasia associated with Cri-du-Chat syndrome

    International Nuclear Information System (INIS)

    Cri-du-Chat syndrome, also called the 5p-syndrome, is a rare genetic abnormality, and only few cases have been reported on its brain MRI findings. We describe the magnetic resonance imaging findings of a 1-year-old girl with Cri-du-Chat syndrome who showed brain stem hypoplasia, particularly in the pons, with normal cerebellum and diffuse hypoplasia of the cerebral hemispheres. We suggest that Cri-du-Chat syndrome chould be suspected in children with brain stem hypoplasia, particularly for those with high-pitched cries.

  5. Brain stem and thalamus antioxidative defense in experimental sepsis

    OpenAIRE

    Ninković Milica; Maličević Ž.; Stojanović Dragica; Vasiljević Ivana; Jovanović Marina; Đukić Mirjana

    2008-01-01

    Although brain complications in sepsis are not rare, early pathophysiologic events had not been made clear yet. We have considered antioxidative components-glutathione peroxidase (GSHPx) activity and reduced glutathione (GSH) concentration in two brain integrative centers, i.e the brain stem (BS) and thalamus. Sepsis was induced in adult male Wistar rats (200-250 g) by cecal ligation and perforation (CLP) with inoculation of Escherichia coli suspension (ATCC 25922) (n=40). The control group w...

  6. The use of auditory and visual context in speech perception by listeners with normal hearing and listeners with cochlear implants

    Directory of Open Access Journals (Sweden)

    MatthewWinn

    2013-11-01

    Full Text Available There is a wide range of acoustic and visual variability across different talkers and different speaking contexts. Listeners with normal hearing accommodate that variability in ways that facilitate efficient perception, but it is not known whether listeners with cochlear implants can do the same. In this study, listeners with normal hearing (NH and listeners with cochlear implants (CIs were tested for accommodation to auditory and visual phonetic contexts created by gender-driven speech differences as well as vowel coarticulation and lip rounding in both consonants and vowels. Accommodation was measured as the shifting of perceptual boundaries between /s/ and /ʃ/ sounds in various contexts, as modeled by mixed-effects logistic regression. Owing to the spectral contrasts thought to underlie these context effects, CI listeners were predicted to perform poorly, but showed considerable success. Listeners with cochlear implants not only showed sensitivity to auditory cues to gender, they were also able to use visual cues to gender (i.e. faces as a supplement or proxy for information in the acoustic domain, in a pattern that was not observed for listeners with normal hearing. Spectrally-degraded stimuli heard by listeners with normal hearing generally did not elicit strong context effects, underscoring the limitations of noise vocoders and/or the importance of experience with electric hearing. Visual cues for consonant lip rounding and vowel lip rounding were perceived in a manner consistent with coarticulation and were generally used more heavily by listeners with CIs. Results suggest that listeners with cochlear implants are able to accommodate various sources of acoustic variability either by attending to appropriate acoustic cues or by inferring them via the visual signal.

  7. Are there fetal stem cells in the maternal brain?

    Science.gov (United States)

    Demirhan, Osman; Cekin, Necmi; Taştemir, Deniz; Tunç, Erdal; Güzel, Ali İrfan; Meral, Demet; Demirbek, Bülent

    2013-03-01

    Fetal cells can enter maternal blood during pregnancy but whether they can also cross the blood-brain barrier to enter the maternal brain remains poorly understood. Previous results suggest that fetal cells are summoned to repair damage to the mother's brain. If this is confirmed, it would open up new and safer avenues of treatment for brain damage caused by strokes and neural diseases. In this study, we aimed to investigate whether a baby's stem cells can enter the maternal brain during pregnancy. Deceased patients who had at least one male offspring and no history of abortion and blood transfusion were included in this study. DNA was extracted from brain tissue samples of deceased women using standard phenol-chloroform extraction and ethanol precipitation methods. Genomic DNA was screened by quantitative fluorescent-polymerase chain reaction amplification together with short tandem repeat markers specific to the Y chromosome, and 13, 18, 21 and X. Any foreign DNA residues that could be used to interpret the presence of fetal stem cells in the maternal brain were monitored. Results indicated that fetal stem cells can not cross the blood-brain barrier to enter the maternal brain. PMID:25206703

  8. Are there fetal stem cells in the maternal brain?

    Institute of Scientific and Technical Information of China (English)

    Osman Demirhan; Necmi (C)ekin; Deniz Ta(s)temir; Erdal Tun(c); Ali irfan Güzel; Demet Meral; Bülent Demirbek

    2013-01-01

    Fetal cells can enter maternal blood during pregnancy but whether they can also cross the blood-brain barrier to enter the maternal brain remains poorly understood. Previous results suggest that fetal cells are summoned to repair damage to the mother's brain. If this is confirmed, it would open up new and safer avenues of treatment for brain damage caused by strokes and neural diseases. In this study, we aimed to investigate whether a baby's stem cells can enter the maternal brain during pregnancy. Deceased patients who had at least one male offspring and no history of abortion and blood transfusion were included in this study. DNA was extracted from brain tissue samples of deceased women using standard phenol-chloroform extraction and ethanol precipitation methods. Genomic DNA was screened by quantitative fluorescent-polymerase chain reaction amplification together with short tandem repeat markers specific to the Y chromosome, and 13, 18, 21 and X. Any foreign DNA residues that could be used to interpret the presence of fetal stem cells in the maternal brain were monitored. Results indicated that fetal stem cells can not cross the blood-brain barrier to enter the maternal brain.

  9. A miniaturized neuroprosthesis suitable for implantation into the brain

    Science.gov (United States)

    Mojarradi, Mohammad; Binkley, David; Blalock, Benjamin; Andersen, Richard; Ulshoefer, Norbert; Johnson, Travis; Del Castillo, Linda

    2003-01-01

    This paper presents current research on a miniaturized neuroprosthesis suitable for implantation into the brain. The prosthesis is a heterogeneous integration of a 100-element microelectromechanical system (MEMS) electrode array, front-end complementary metal-oxide-semiconductor (CMOS) integrated circuit for neural signal preamplification, filtering, multiplexing and analog-to-digital conversion, and a second CMOS integrated circuit for wireless transmission of neural data and conditioning of wireless power. The prosthesis is intended for applications where neural signals are processed and decoded to permit the control of artificial or paralyzed limbs. This research, if successful, will allow implantation of the electronics into the brain, or subcutaneously on the skull, and eliminate all external signal and power wiring. The neuroprosthetic system design has strict size and power constraints with each of the front-end preamplifier channels fitting within the 400 x 400-microm pitch of the 100-element MEMS electrode array and power dissipation resulting in less than a 1 degree C temperature rise for the surrounding brain tissue. We describe the measured performance of initial micropower low-noise CMOS preamplifiers for the neuroprosthetic.

  10. Brain responses to language-relevant musical features in adolescent cochlear implant users before and after an intensive music training program

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Weed, Ethan; Hansen, Mads;

    Brain responses to language-relevant musical features in adolescent cochlear implant users before and after an intensive music training program Petersen B.1,2, Weed E.1,3, Hansen M.1,4, Sørensen S.D.3 , Sandmann P.5 , Vuust P.1,2 1Center of Functionally Integrative Neuroscience, Aarhus University...... with a congenital hearing loss. However, recent studies indicate that to keep pace with their normal-hearing (NH) peers, supplementary measures of rehabilitation are important throughout adolescence. This study aimed to 1) investigate auditory brain processing of musical sounds relevant to prosody processing...... produced significantly higher average scores than the CI group at both sessions. Our results suggest that adolescent CI users, who have only experienced sound through the implant, show brain responses to musical stimuli resembling those of NH peers, and that this response can be altered by intensive...

  11. Auditory vocabulary of the right hemisphere following brain bisection or hemidecortication.

    Science.gov (United States)

    Zaidel, E

    1976-09-01

    Unilateral scores of two commissurotomy and three (one left and two right) hemispherectomy patients were obtained on standardized auditory language comprehension tests which use pointing responses to a pictorial array. Unilateral performance by the commissurotomy patients was achieved by restricting the pictorial array to one visual half field, using a novel contact lens system which permits ocular scanning of the lateralized stimulus and self-monitoring of task performance. Using the Peabody and Ammons Picture Vocabulary Tests, the auditory vocabulary in the disconnected or isolated right hemispheres was found to be equivalent to that of normal subjects of ages 8:1 to 16:3 with a mean of 11:7 (eleven years and 7 months old). At the same time, standardized aphasia tests showed that the picture vocabulary in the right hemispheres is similar to that of a heterogeneous population of aphasics, even though the right hemispheres did not behave quite like any classical aphasic diagnostic group. No significant differences were found between right hemisphere comprehension of object vs. action names. Results indicated that vocabulary as a function of word frequency followed the same pattern in the right and left hemisphere although the right hemisphere was consistently lower. This parallel between the two hemispheres was conjectured to reflect some similar or even shared lexical structures in the two hemispheres. Together with other data on the performance of the right hemisphere on the Token Test (Zaidel, 1976), the results suggest a complex model of the development of language laterality in the brain, in which some, but not all, auditory language functions continue to develop in the right hemisphere past what is generally regarded as the critical period for language acquistion. In general, auditory language comprehension is better characterized as that of an "average aphasic" than that of a child of a specific age. PMID:1000988

  12. Implants and Decoding for Intracortical Brain Computer Interfaces

    OpenAIRE

    Homer, Mark L.; Nurmikko, Arto V.; Donoghue, John P.; Hochberg, Leigh R.

    2013-01-01

    Intracortical brain computer interfaces (iBCIs) are being developed to enable a person to drive an output device, such as a computer cursor, directly from their neural activity. One goal of the technology is to help people with severe paralysis or limb loss. Key elements of an iBCI are the implanted sensor that records the neural signals and the software which decodes the user’s intended movement from those signals. Here, we focus on recent advances in these two areas, with special attention ...

  13. STUDY OF MAIS (MEANINGFUL AUDITORY INTEGRATION SCALE SCORE POST UNILATERAL COCHLEAR IMPLANTATION IN PRELINGUAL DEAF PATIENTS

    Directory of Open Access Journals (Sweden)

    Neha Lala

    2015-07-01

    Full Text Available Objective: To evaluate speech perception skills in everyday situations following Unilateral Cochlear Implantation in prelingual deaf patients in relation to the age of implantation. Method: 45 prelingual deaf patients who underwent unilateral Cochlear Implantation under B.J. Medical College Cochlear and Hearing Implant Programme from April 2007 to August 2010 were included in the study. Participants were divided into 5 groups on basis of age at which participants underwent implantation: ≤3 years, 3 to 6 years, 6 to 9 years, 9 to 12 years, 12 to 15 years. The MAIS Questionnaire was administered before implantation unaided and at three post-implant switch-on time periods 6 months, 1 year and 2 years with Cochlear Implant alone. The study was retrospective and prospective comparative interventional type. Significance of difference between individual preoperative and postoperative scores was evaluated using the post hoc test of repeated measure analysis. Results: Pre-op average MAIS Questionnaire score was ≤8/40 in all implanted age groups with score increasing over time to attain average score ranging from 34 to 37.44/40 in all implanted age groups after two years of implantation. The score increased significantly (p<0.05 in all implanted age groups from pre- to post-CI. Improved ratings were found for those implanted at younger age (≤3 years than those implanted later. Discussion: There is significant improvement in speech perception skills in everyday situations after cochlear implantation which continues to improve over time. Better results were seen in those implanted at younger age.

  14. Development of neural stem cell in the adult brain

    OpenAIRE

    Duan, Xin; Kang, Eunchai; Liu, Cindy Y.; Ming, Guo-li; Song, Hongjun

    2008-01-01

    New neurons are continuously generated in the dentate gyrus of the mammalian hippocampus and in the subventricular zone of the lateral ventricles throughout life. The origin of these new neurons is believed to be from multipotent adult neural stem cells. Aided by new methodologies, significant progress has been made in the characterization of neural stem cells and their development in the adult brain. Recent studies have also begun to reveal essential extrinsic and intrinsic molecular mechani...

  15. Scaffold and stem cell based modeling of brain disease

    OpenAIRE

    Karpiak, Jerome V.

    2016-01-01

    Cellular models of brain disease involve genetic modulation, geometric patterning, neurophysiologic monitoring and analyses of both primary and immortalized cell lines. Additionally, recent neurological disease models often necessitate in vitro directed differentiation and maturation of human stem cell lines. To advance human stem cell based neural disease models within this evolving field, adaptive approaches of progressive complexity are essential. First, I invented an adaptable 3D laminar ...

  16. A glucose fuel cell for implantable brain-machine interfaces.

    Directory of Open Access Journals (Sweden)

    Benjamin I Rapoport

    Full Text Available We have developed an implantable fuel cell that generates power through glucose oxidation, producing 3.4 μW cm(-2 steady-state power and up to 180 μW cm(-2 peak power. The fuel cell is manufactured using a novel approach, employing semiconductor fabrication techniques, and is therefore well suited for manufacture together with integrated circuits on a single silicon wafer. Thus, it can help enable implantable microelectronic systems with long-lifetime power sources that harvest energy from their surrounds. The fuel reactions are mediated by robust, solid state catalysts. Glucose is oxidized at the nanostructured surface of an activated platinum anode. Oxygen is reduced to water at the surface of a self-assembled network of single-walled carbon nanotubes, embedded in a Nafion film that forms the cathode and is exposed to the biological environment. The catalytic electrodes are separated by a Nafion membrane. The availability of fuel cell reactants, oxygen and glucose, only as a mixture in the physiologic environment, has traditionally posed a design challenge: Net current production requires oxidation and reduction to occur separately and selectively at the anode and cathode, respectively, to prevent electrochemical short circuits. Our fuel cell is configured in a half-open geometry that shields the anode while exposing the cathode, resulting in an oxygen gradient that strongly favors oxygen reduction at the cathode. Glucose reaches the shielded anode by diffusing through the nanotube mesh, which does not catalyze glucose oxidation, and the Nafion layers, which are permeable to small neutral and cationic species. We demonstrate computationally that the natural recirculation of cerebrospinal fluid around the human brain theoretically permits glucose energy harvesting at a rate on the order of at least 1 mW with no adverse physiologic effects. Low-power brain-machine interfaces can thus potentially benefit from having their implanted units

  17. Stereotaxic interstitial implantation for the treatment of malignant brain tumors

    International Nuclear Information System (INIS)

    The Brain Tumor Study Group (BTSG) demonstrated that patients with malignant gliomas who were treated with radiation therapy to a dose of 50 Gray (Gy) or more to the whole brain survived significantly longer than patients treated with surgery alone. A dose-response analysis of the BTSG data for 621 patients, 90% of whom had glioblastoma multiforme, showed a stepwise improvement in survival in patient groups receiving 50, 55, or 60 Gy. The median survival times were 28, 36, and 42 weeks, respectively (difference between 50 and 60 Gy significant at rho = .004). However, all tumors recurred and all patients died of their disease. If higher doses of radiation therapy could be delivered, improved local tumor control might be achieved. However, the delivery of doses of external irradiation in excess of 60 Gy is accompanied by radiation-induced brain necrosis. Experimental therapeutic strategies in the treatment of malignant brain tumors have involved the use of systemic chemotherapy. However, because of the localized nature of malignant glial tumors, it would seem logical to consider additional local treatment modalities. As radiation therapy has proven to be the most effective adjunct to surgery in the treatment of malignant brain tumors, there has been considerable recent interest in interstitial radiation therapy. Using interstitial radiation sources, high-dose radiation therapy can be delivered to the primary tumor with relative sparing of surrounding normal tissues. Interstitial implantation could be employed alone or to augment the dose delivered by external beam irradiation for the treatment of primary brain tumors, and would allow radical re-irradiation of recurrent malignant gliomas

  18. A Femur-Implant Model for the Prediction of Bone Remodeling Behavior Induced by Cementless Stem

    Institute of Scientific and Technical Information of China (English)

    He Gong; Lingyan Kong; Rui Zhang; Juan Fang; Meisheng Zhao

    2013-01-01

    Bone remodeling simulation is an effective tool for the prediction of long-term effect of implant on the bone tissue,as well as the selection of an appropriate implant in terms of architecture and material.In this paper,a finite element model of proximal femur was develop.ed to simulate the structures of internal trabecular and cortical bones by incorporating quantitative bone functional adaptation theory with finite element analysis.Cementless stems made of titanium,two types of Functionally Graded Material (FGM) and flexible 'iso-elastic' material as comparison were implanted in the structure of proximal femur respectively to simulate the bone remodeling behaviors of host bone.The distributions of bone density,von Mises stress,and interface shear stress were obtained.All the prosthetic stems had effects on the bone remodeling behaviors of proximal femur,but the degrees of stress shielding were different.The amount of bone loss caused by titanium implant was in agreement with the clinical observation.The FGM stems caused less bone loss than that of the titanium stem,in which FGM I stem (titanium richer at the top to more HAP/Col towards the bottom) could relieve stress shielding effectively,and the interface shear stresses were more evenly distributed in the model with FGM I stem in comparison with those in the models with FGM II (titanium and bioglass) and titanium stems.The numerical simulations in the present study provided theoretical basis for FGM as an appropriate material of femoral implant from a biomechanical point of view.The next steps are to fabricate FGM stem and to conduct animal experiments to investigate the effects of FGM stem on the remodeling behaviors using animal model.

  19. The short stem GHEs in total hip replacement – experience after 380 implantations

    Directory of Open Access Journals (Sweden)

    Ghanem, Mohamed

    2013-11-01

    Full Text Available Introduction: Standard straight stems have been recognized as a gold standard implant in the field of hip replacement surgery. However, lately uncemented bone-preserving short stems started to gain more and more popularity. This was reflected in the increasing variety of available models. Up till now, short and mid-term results are available.Patients and methods: In 2002, the cementless short stemmed GHEs was introduced. 380 patients were included in our study between 2002 and 2008. Only GHEs short stems were implanted. The clinical and radiological evaluations were performed in the Orthopaedic Department, Leipzig University Hospitals, on the average of 24 months (3 to 60 months postoperatively.Results: 365 primary implantations and 15 revision implantations were carried out. Average age 60 years. Favourable clinical and radiological outcome was seen in 361/380 patients (95%. Postoperative complications were seen in 19/380 patients (5%: 8 fissures/fractures (2.1%, 5 infections (1.3%, 4 aseptic loosenings (1.1%, 2 dislocations (0.5%.Conclusions: Short stem implants, including our own experience with GHEs model, are satisfying and promising. They represent a valuable supplementation of the treatment modalities in hip replacement surgery. However, long term results are still awaited.

  20. Auditory agnosia.

    Science.gov (United States)

    Slevc, L Robert; Shell, Alison R

    2015-01-01

    Auditory agnosia refers to impairments in sound perception and identification despite intact hearing, cognitive functioning, and language abilities (reading, writing, and speaking). Auditory agnosia can be general, affecting all types of sound perception, or can be (relatively) specific to a particular domain. Verbal auditory agnosia (also known as (pure) word deafness) refers to deficits specific to speech processing, environmental sound agnosia refers to difficulties confined to non-speech environmental sounds, and amusia refers to deficits confined to music. These deficits can be apperceptive, affecting basic perceptual processes, or associative, affecting the relation of a perceived auditory object to its meaning. This chapter discusses what is known about the behavioral symptoms and lesion correlates of these different types of auditory agnosia (focusing especially on verbal auditory agnosia), evidence for the role of a rapid temporal processing deficit in some aspects of auditory agnosia, and the few attempts to treat the perceptual deficits associated with auditory agnosia. A clear picture of auditory agnosia has been slow to emerge, hampered by the considerable heterogeneity in behavioral deficits, associated brain damage, and variable assessments across cases. Despite this lack of clarity, these striking deficits in complex sound processing continue to inform our understanding of auditory perception and cognition. PMID:25726291

  1. Utilising reinforcement learning to develop strategies for driving auditory neural implants

    Science.gov (United States)

    Lee, Geoffrey W.; Zambetta, Fabio; Li, Xiaodong; Paolini, Antonio G.

    2016-08-01

    Objective. In this paper we propose a novel application of reinforcement learning to the area of auditory neural stimulation. We aim to develop a simulation environment which is based off real neurological responses to auditory and electrical stimulation in the cochlear nucleus (CN) and inferior colliculus (IC) of an animal model. Using this simulator we implement closed loop reinforcement learning algorithms to determine which methods are most effective at learning effective acoustic neural stimulation strategies. Approach. By recording a comprehensive set of acoustic frequency presentations and neural responses from a set of animals we created a large database of neural responses to acoustic stimulation. Extensive electrical stimulation in the CN and the recording of neural responses in the IC provides a mapping of how the auditory system responds to electrical stimuli. The combined dataset is used as the foundation for the simulator, which is used to implement and test learning algorithms. Main results. Reinforcement learning, utilising a modified n-Armed Bandit solution, is implemented to demonstrate the model’s function. We show the ability to effectively learn stimulation patterns which mimic the cochlea’s ability to covert acoustic frequencies to neural activity. Time taken to learn effective replication using neural stimulation takes less than 20 min under continuous testing. Significance. These results show the utility of reinforcement learning in the field of neural stimulation. These results can be coupled with existing sound processing technologies to develop new auditory prosthetics that are adaptable to the recipients current auditory pathway. The same process can theoretically be abstracted to other sensory and motor systems to develop similar electrical replication of neural signals.

  2. High-Resolution Mapping of Myeloarchitecture In Vivo: Localization of Auditory Areas in the Human Brain.

    Science.gov (United States)

    De Martino, Federico; Moerel, Michelle; Xu, Junqian; van de Moortele, Pierre-Francois; Ugurbil, Kamil; Goebel, Rainer; Yacoub, Essa; Formisano, Elia

    2015-10-01

    The precise delineation of auditory areas in vivo remains problematic. Histological analysis of postmortem tissue indicates that the relation of areal borders to macroanatomical landmarks is variable across subjects. Furthermore, functional parcellation schemes based on measures of, for example, frequency preference (tonotopy) remain controversial. Here, we propose a 7 Tesla magnetic resonance imaging method that enables the anatomical delineation of auditory cortical areas in vivo and in individual brains, through the high-resolution visualization (0.6 × 0.6 × 0.6 mm(3)) of intracortical anatomical contrast related to myelin. The approach combines the acquisition and analysis of images with multiple MR contrasts (T1, T2*, and proton density). Compared with previous methods, the proposed solution is feasible at high fields and time efficient, which allows collecting myelin-related and functional images within the same measurement session. Our results show that a data-driven analysis of cortical depth-dependent profiles of anatomical contrast allows identifying a most densely myelinated cortical region on the medial Heschl's gyrus. Analyses of functional responses show that this region includes neuronal populations with typical primary functional properties (single tonotopic gradient and narrow frequency tuning), thus indicating that it may correspond to the human homolog of monkey A1. PMID:24994817

  3. A brain-computer interface controlled auditory event-related potential (p300) spelling system for locked-in patients.

    Science.gov (United States)

    Kübler, Andrea; Furdea, Adrian; Halder, Sebastian; Hammer, Eva Maria; Nijboer, Femke; Kotchoubey, Boris

    2009-03-01

    Using brain-computer interfaces (BCI) humans can select letters or other targets on a computer screen without any muscular involvement. An intensively investigated kind of BCI is based on the recording of visual event-related brain potentials (ERP). However, some severely paralyzed patients who need a BCI for communication have impaired vision or lack control of gaze movement, thus making a BCI depending on visual input no longer feasible. In an effort to render the ERP-BCI usable for this group of patients, the ERP-BCI was adapted to auditory stimulation. Letters of the alphabet were assigned to cells in a 5 x 5 matrix. Rows of the matrix were coded with numbers 1 to 5, and columns with numbers 6 to 10, and the numbers were presented auditorily. To select a letter, users had to first select the row and then the column containing the desired letter. Four severely paralyzed patients in the end-stage of a neurodegenerative disease were examined. All patients performed above chance level. Spelling accuracy was significantly lower with the auditory system as compared with a similar visual system. Patients reported difficulties in concentrating on the task when presented with the auditory system. In future studies, the auditory ERP-BCI should be adjusted by taking into consideration specific features of severely paralyzed patients, such as reduced attention span. This adjustment in combination with more intensive training will show whether an auditory ERP-BCI can become an option for visually impaired patients. PMID:19351359

  4. Oral Implant-Prostheses: New Teeth for a Brighter Brain.

    Directory of Open Access Journals (Sweden)

    Vincenzo De Cicco

    Full Text Available Several studies have demonstrated that chewing can be regarded as a preventive measure for cognitive impairment, whereas masticatory deficiency, associated with soft-diet feeding, is a risk factor for the development of dementia. At present the link between orofacial sensorimotor activity and cognitive functions is unknown. In subjects with unilateral molar loss we have shown asymmetries in both pupil size and masticatory muscles electromyographic (EMG activity during clenching: the molar less side was characterized by a lower EMG activity and a smaller pupil. Since implant-prostheses, greatly reduced both the asymmetry in EMG activity and in pupil's size, trigeminal unbalance, leading to unbalance in the activity of the Locus Coeruleus (LC, may be responsible for the pupil's asymmetry. According to the findings obtained in animal models, we propose that the different activity of the right and left LC may induce an asymmetry in brain activity, thus leading to cognitive impairment. According to this hypothesis, prostheses improved the performance in a complex sensorimotor task and increased the mydriasis associated with haptic tasks. In conclusion, the present study indicates that the implant-prosthesis therapy, which reduces the unbalance of trigeminal proprioceptive afferents and the asymmetry in pupil's size, may improve arousal, boosting performance in a complex sensorimotor task.

  5. Treatment Options for Childhood Brain Stem Glioma

    Science.gov (United States)

    ... tests to check the brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro ...

  6. Stages of Childhood Brain Stem Glioma

    Science.gov (United States)

    ... tests to check the brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro ...

  7. Os resultados do implante coclear em crianças portadoras de Neuropatia Auditiva: revisão de literatura The results of cochlear implants in children with Auditory Neuropathy: literature review

    Directory of Open Access Journals (Sweden)

    Rafaela Carolina Lopez Silva

    2007-09-01

    Full Text Available A Neuropatia Auditiva é um distúrbio na condução do estímulo sonoro, provavelmente relacionado à alteração da mielinização das fibras do nervo auditivo. Os avanços tecnológicos têm levado ao aumento nos recursos de diagnóstico e intervenção nos casos de deficiência auditiva por etiologia de Neuropatia Auditiva. O objetivo do presente estudo foi pesquisar na literatura os resultados obtidos em crianças com Neuropatia Auditiva após implante coclear. Foi realizado um trabalho de revisão bibliográfica em livros, periódicos e internet dos últimos dez anos sobre crianças com Neuropatia Auditiva usuárias de implante coclear. As pesquisas sugerem que a estimulação elétrica é capaz de compensar a dessincronia do nervo e que o implante coclear é um recurso para a (rehabilitação da audição em crianças portadoras de Neuropatia Auditiva. O uso do implante coclear permite melhoria significativa nas habilidades da audição e da comunicação. No entanto, as habilidades adquiridas parecem sofrer influência de diversos fatores como: tempo de uso do dispositivo, existência de um processo terapêutico sistemático, época do diagnóstico e a idade da criança.Auditory Neuropathy is a disorder in the transmission of the sound stimulus, probably related to mielinization alterations of auditory nerve fibers. Technology advances have been increasing diagnostic and intervention resources in cases of hearing loss caused by auditory neuropathy. The aim of the present study was to research the available literature about the results obtained with children with Auditory Neuropathy after cochlear implants. An ample review was conducted on books, articles and the internet, over the last 10 years, regarding children with Auditory Neuropathy, users of cochlear implants. The available data suggest that electric stimulation can compensate neural asynchrony and that cochlear implants aid in the rehabilitation process of children with Auditory

  8. Stability, Survival, and Tolerability of an Auditory Osseointegrated Implant for Bone Conduction Hearing: Long-Term Follow-Up of a Randomized Controlled Trial

    Science.gov (United States)

    den Besten, Christine A.; Stalfors, Joacim; Wigren, Stina; Blechert, Johan Ivarsson; Flynn, Mark; Eeg-Olofsson, Måns; Aggarwal, Rohini; Green, Kevin; Nelissen, Rik C.; Mylanus, Emmanuel A. M.; Hol, Myrthe K. S.

    2016-01-01

    Objective: To compare implant stability, survival, and soft tissue reactions for a novel (test) and previous generation (control) percutaneous auditory osseointegrated implant for bone conduction hearing at long-term follow-up of 5 years. Study Design: Single follow-up visit of a previously completed multicenter, randomized, controlled trial. Patients: Fifty-seven of the 77 participants of a completed randomized controlled trial on a new auditory osseointegrated implant underwent a single follow-up visit 5 years after implantation, which comprised implant stability measurements and collection of Holgers scores. Additionally, implant survival was recorded for all 77 patients from the original trial. Results: The test implant showed significantly higher implant stability quotient (ISQ) values compared with the control implant throughout the 5-year follow-up. Mean area under the curve of ISQ high from baseline to 5 years was 71.6 (standard deviation [SD] ±2.0) and 66.7 (SD ±3.4) for the test and control implant, respectively (p < 0.0001). For both implants, the mean ISQ value recorded at 5 years was higher compared with implantation (test group +2.03 [SD ±2.55, within group p < 0.0001] and control group +2.25 [SD ±4.95, within group p = 0.12]). No difference was noticed in increase from baseline between groups (p = 0.64). Furthermore, evaluation of soft tissue reactions continued to show superiority of the test implant. At the 5-year follow-up visit, one patient (2.5%) presented with a Holgers grade 2 in the test group, compared with four patients (23.5%) in the control group (p = 0.048); no patient presented with more severe soft tissue reactions. Excluding explantations, the survival rate was 95.8% for the test group and 95.0% for the control group. The corresponding rates including explantations were 93.9 and 90.0%. Conclusion: The test implant showed superiority in terms of higher mean ISQ values and less adverse soft tissue reactions, both

  9. Bone Marrow Derived Adult Stem Cell Implantation: A Possible Permanent Treatment Modality for Type 2 Diabetics

    OpenAIRE

    R.S. KAHLON; M.K. Manchanda; P. KANWAL

    2011-01-01

    Introduction: Diabetes is one of the most prevalent chronic disease that exists in the world. Type 2Diabetes is the predominant type of diabetes. Management is basically limited to exercise, diet and oralhypoglycemic drugs before insulin therapy has to be instituted. But bone marrow derived stem cellimplantation into the islets has shown very encouraging results for diabetics.Methods: Bone marrow derived stem cells when implanted in the pancreas leads to regeneration ofinsulin producing Beta ...

  10. Transplantation of Neural Differentiated Human Mesenchymal Stem Cells into the Cochlea of an Auditory-neuropathy Guinea Pig Model

    OpenAIRE

    Cho, Yong-Bum; Cho, Hyong-Ho; Jang, Sujeong; Jeong, Han-Seong; Park, Jong-Seong

    2011-01-01

    The aim of this study was to determine the effects of transplanted neural differentiated human mesenchymal stem cells (hMSCs) in a guinea pig model of auditory neuropathy. In this study, hMSCs were pretreated with a neural-induction protocol and transplanted into the scala tympani of the guinea pig cochlea 7 days after ouabain injury. A control model was made by injection of Hanks balanced salt solution alone into the scala tympani of the guinea pig cochlea 7 days after ouabain injury. We est...

  11. Hybrid adipogenic implants from adipose stem cells for soft tissue reconstruction in vivo.

    Science.gov (United States)

    Moioli, Eduardo K; Chen, Mo; Yang, Rujing; Shah, Bhranti; Wu, June; Mao, Jeremy J

    2010-11-01

    A critical barrier in tissue regeneration is scale-up. Bioengineered adipose tissue implants have been limited to ∼10  mm in diameter. Here, we devised a 40-mm hybrid implant with a cellular layer encapsulating an acellular core. Human adipose-derived stem cells (ASCs) were seeded in alginate. Poly(ethylene)glycol-diacrylate (PEGDA) was photopolymerized into 40-mm-diameter dome-shaped gel. Alginate-ASC suspension was painted onto PEGDA surface. Cultivation of hybrid constructs ex vivo in adipogenic medium for 28 days showed no delamination. Upon 4-week in vivo implantation in athymic rats, hybrid implants well integrated with host subcutaneous tissue and could only be surgically separated. Vascularized adipose tissue regenerated in the thin, painted alginate layer only if ASC-derived adipogenic cells were delivered. Contrastingly, abundant fibrous tissue filled ASC-free alginate layer encapsulating the acellular PEGDA core in control implants. Human-specific peroxisome proliferator-activated receptor-γ (PPAR-γ) was detected in human ASC-seeded implants. Interestingly, rat-specific PPAR-γ was absent in either human ASC-seeded or ASC-free implants. Glycerol content in ASC-delivered implants was significantly greater than that in ASC-free implants. Remarkably, rat-specific platelet/endothelial cell adhesion molecule (PECAM) was detected in both ASC-seeded and ASC-free implants, suggesting anastomosis of vasculature in bioengineered tissue with host blood vessels. Human nuclear staining revealed that a substantial number of adipocytes were of human origin, whereas endothelial cells of vascular wall were of chemaric human and nonhuman (rat host) origins. Together, hybrid implant appears to be a viable scale-up approach with volumetric retention attributable primarily to the acellular biomaterial core, and yet has a biologically viable cellular interface with the host. The present 40-mm soft tissue implant may serve as a biomaterial tissue expander for

  12. Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks

    Directory of Open Access Journals (Sweden)

    Mona eMoisala

    2015-02-01

    Full Text Available Using functional magnetic resonance imaging, we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking, divided attention (i.e., dual-tasking did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.

  13. Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation Around Solid Implants

    KAUST Repository

    Jain, Harsh Vardhan

    2012-07-01

    Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O(2)) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O(2)-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O(2) pressure (pO(2)) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO(2) to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases.

  14. An online brain-computer interface based on shifting attention to concurrent streams of auditory stimuli

    Science.gov (United States)

    Hill, N. J.; Schölkopf, B.

    2012-04-01

    We report on the development and online testing of an electroencephalogram-based brain-computer interface (BCI) that aims to be usable by completely paralysed users—for whom visual or motor-system-based BCIs may not be suitable, and among whom reports of successful BCI use have so far been very rare. The current approach exploits covert shifts of attention to auditory stimuli in a dichotic-listening stimulus design. To compare the efficacy of event-related potentials (ERPs) and steady-state auditory evoked potentials (SSAEPs), the stimuli were designed such that they elicited both ERPs and SSAEPs simultaneously. Trial-by-trial feedback was provided online, based on subjects' modulation of N1 and P3 ERP components measured during single 5 s stimulation intervals. All 13 healthy subjects were able to use the BCI, with performance in a binary left/right choice task ranging from 75% to 96% correct across subjects (mean 85%). BCI classification was based on the contrast between stimuli in the attended stream and stimuli in the unattended stream, making use of every stimulus, rather than contrasting frequent standard and rare ‘oddball’ stimuli. SSAEPs were assessed offline: for all subjects, spectral components at the two exactly known modulation frequencies allowed discrimination of pre-stimulus from stimulus intervals, and of left-only stimuli from right-only stimuli when one side of the dichotic stimulus pair was muted. However, attention modulation of SSAEPs was not sufficient for single-trial BCI communication, even when the subject's attention was clearly focused well enough to allow classification of the same trials via ERPs. ERPs clearly provided a superior basis for BCI. The ERP results are a promising step towards the development of a simple-to-use, reliable yes/no communication system for users in the most severely paralysed states, as well as potential attention-monitoring and -training applications outside the context of assistive technology.

  15. Stem Cell Implants for Cancer Therapy: TRAIL-Expressing Mesenchymal Stem Cells Target Cancer Cells In Situ

    OpenAIRE

    Reagan, Michaela Ruth; Seib, F. Philipp; McMillin, Douglas William; Elizabeth K. Sage; Mitsiades, Constantine S; Janes, Sam M.; Ghobrial, Irene; Kaplan, David L.

    2012-01-01

    Purpose Tumor-specific delivery of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), an apoptosis-inducing peptide, at effective doses remains challenging. Herein we demonstrate the utility of a scaffold-based delivery system for sustained therapeutic cell release that capitalizes on the tumor-homing properties of mesenchymal stem cells (MSCs) and their ability to express genetically-introduced therapeutic genes. Methods: Implants were formed from porous, biocompatible silk sca...

  16. Feasibility of a Recasting and Auditory Bombardment Treatment with Young Cochlear Implant Users

    Science.gov (United States)

    Encinas, Danielle; Plante, Elena

    2016-01-01

    Purpose: There is little to guide clinicians in terms of evidence-based interventions for children with cochlear implants who demonstrate morpheme errors. This feasibility study tested the utility of a treatment targeting grammatical morpheme errors. Method: Three children (ages 4-5 years) received Enhanced Conversational Recast treatment, a…

  17. Gene regulatory networks in embryonic stem cells and brain development

    OpenAIRE

    Ghosh, Dhimankrishna; Yan, Xiaowei; Tian, Qiang

    2009-01-01

    Embryonic stem cells (ESCs) are endowed with the ability to generate multiple cell lineages and carries great therapeutic potentials in regenerative medicines. Future application of ESCs in human health and diseases will embark on the delineation of molecular mechanisms that define the biology of ESCs. Here we discuss how the finite ESC components mediate the intriguing task of brain development and exhibits biomedical potentials to cure diverse neurological disorders.

  18. Pediatric brain stem tumors: analysis of 25 cases

    International Nuclear Information System (INIS)

    The charts of 25 pediatric patients with brain stem tumors have been reviewed. The use of computed tomography was found to have been valuable in diagnosis and follow-up, as well as in the design of radiation therapy portals. Radiotherapy and combination chemotherapy with VM-26 (4'-1 demethyl-epipodophyllo toxin B-D-thenylidene glucoside) and CCNU(1-2-chloroethyl-methyl-3-Cyclohexyl-1-nitrosourea) were the treatment employed. (M.A.C.)

  19. Role of adrenal catecholamines in cerebrovasodilation evoked from brain stem

    International Nuclear Information System (INIS)

    The authors studied whether adrenal medullary catecholamines (CAs) contribute to the metabolically linked increase in regional cerebral blood flow (rCBF) elicited by electrical stimulation of the dorsal medullary reticular formation (DMRF). Rats were anesthetized, paralyzed, and artificially ventilated. The DMRF was electrically stimulated with intermittent trains of pulses through microelectrodes stereotaxically implanted. Blood gases were controlled and, during stimulation, arterial pressure was maintained within the autoregulated range for rCBF. rCBF and blood-brain barrier (BBB) permeability were determined in homogenates of brain regions by using [14C]iodoantipyrine and α-aminoisobutyric acid (AIB), respectively, as tracers. Plasma CAs (epinephrine and norepinephrine) were measured radioenzymatically. DMRF stimulation increased rCBF throughout the brain and elevated plasma CAs substantially. Acute bilateral adrenalectomy abolished the increase in plasma epinephrine, reduced the increases in flow in cerebral cortex, and abolished them elsewhere in brain. They conclude that the increases in rCBF elicited from the DMRF has two components, one dependent on, and the other independent of CAs. Since the BBB is impermeable to CAs and DMRF stimulation fails to open the BBB, the results suggest that DMRF stimulations allows, through a mechanism not yet determined, circulating CAs to act on brain and affect brain function

  20. Behavioral and brain pattern differences between acting and observing in an auditory task

    Directory of Open Access Journals (Sweden)

    Ventouras Errikos M

    2009-01-01

    Full Text Available Abstract Background Recent research has shown that errors seem to influence the patterns of brain activity. Additionally current notions support the idea that similar brain mechanisms are activated during acting and observing. The aim of the present study was to examine the patterns of brain activity of actors and observers elicited upon receiving feedback information of the actor's response. Methods The task used in the present research was an auditory identification task that included both acting and observing settings, ensuring concurrent ERP measurements of both participants. The performance of the participants was investigated in conditions of varying complexity. ERP data were analyzed with regards to the conditions of acting and observing in conjunction to correct and erroneous responses. Results The obtained results showed that the complexity induced by cue dissimilarity between trials was a demodulating factor leading to poorer performance. The electrophysiological results suggest that feedback information results in different intensities of the ERP patterns of observers and actors depending on whether the actor had made an error or not. The LORETA source localization method yielded significantly larger electrical activity in the supplementary motor area (Brodmann area 6, the posterior cingulate gyrus (Brodmann area 31/23 and the parietal lobe (Precuneus/Brodmann area 7/5. Conclusion These findings suggest that feedback information has a different effect on the intensities of the ERP patterns of actors and observers depending on whether the actor committed an error. Certain neural systems, including medial frontal area, posterior cingulate gyrus and precuneus may mediate these modulating effects. Further research is needed to elucidate in more detail the neuroanatomical and neuropsychological substrates of these systems.

  1. Auditory Hallucinations in Acute Stroke

    Directory of Open Access Journals (Sweden)

    Yair Lampl

    2005-01-01

    Full Text Available Auditory hallucinations are uncommon phenomena which can be directly caused by acute stroke, mostly described after lesions of the brain stem, very rarely reported after cortical strokes. The purpose of this study is to determine the frequency of this phenomenon. In a cross sectional study, 641 stroke patients were followed in the period between 1996–2000. Each patient underwent comprehensive investigation and follow-up. Four patients were found to have post cortical stroke auditory hallucinations. All of them occurred after an ischemic lesion of the right temporal lobe. After no more than four months, all patients were symptom-free and without therapy. The fact the auditory hallucinations may be of cortical origin must be taken into consideration in the treatment of stroke patients. The phenomenon may be completely reversible after a couple of months.

  2. BDNF Increases Survival and Neuronal Differentiation of Human Neural Precursor Cells Cotransplanted with a Nanofiber Gel to the Auditory Nerve in a Rat Model of Neuronal Damage

    Directory of Open Access Journals (Sweden)

    Yu Jiao

    2014-01-01

    Full Text Available Objectives. To study possible nerve regeneration of a damaged auditory nerve by the use of stem cell transplantation. Methods. We transplanted HNPCs to the rat AN trunk by the internal auditory meatus (IAM. Furthermore, we studied if addition of BDNF affects survival and phenotypic differentiation of the grafted HNPCs. A bioactive nanofiber gel (PA gel, in selected groups mixed with BDNF, was applied close to the implanted cells. Before transplantation, all rats had been deafened by a round window niche application of β-bungarotoxin. This neurotoxin causes a selective toxic destruction of the AN while keeping the hair cells intact. Results. Overall, HNPCs survived well for up to six weeks in all groups. However, transplants receiving the BDNF-containing PA gel demonstrated significantly higher numbers of HNPCs and neuronal differentiation. At six weeks, a majority of the HNPCs had migrated into the brain stem and differentiated. Differentiated human cells as well as neurites were observed in the vicinity of the cochlear nucleus. Conclusion. Our results indicate that human neural precursor cells (HNPC integration with host tissue benefits from additional brain derived neurotrophic factor (BDNF treatment and that these cells appear to be good candidates for further regenerative studies on the auditory nerve (AN.

  3. A reliable method for intracranial electrode implantation and chronic electrical stimulation in the mouse brain

    OpenAIRE

    Jeffrey, Melanie; Lang, Min; Gane, Jonathan; Wu, Chiping; Burnham, W McIntyre; Zhang, Liang

    2013-01-01

    Background Electrical stimulation of brain structures has been widely used in rodent models for kindling or modeling deep brain stimulation used clinically. This requires surgical implantation of intracranial electrodes and subsequent chronic stimulation in individual animals for several weeks. Anchoring screws and dental acrylic have long been used to secure implanted intracranial electrodes in rats. However, such an approach is limited when carried out in mouse models as the thin mouse skul...

  4. Further In-vitro Characterization of an Implantable Biosensor for Ethanol Monitoring in the Brain

    OpenAIRE

    Gaia Rocchitta; Pier Andrea Serra; Robert D. O'Neill; Maria Speranza Desole; Rossana Migheli; Marco Pirisinu; Gianfranco Bazzu; Ylenia Spissu; Manuel Zinellu; Ottavio Secchi

    2013-01-01

    Ethyl alcohol may be considered one of the most widespread central nervous system (CNS) depressants in Western countries. Because of its toxicological and neurobiological implications, the detection of ethanol in brain extracellular fluid (ECF) is of great importance. In a previous study, we described the development and characterization of an implantable biosensor successfully used for the real-time detection of ethanol in the brain of freely-moving rats. The implanted biosensor, integrated ...

  5. Developmental neuroplasticity after cochlear implantation.

    Science.gov (United States)

    Kral, Andrej; Sharma, Anu

    2012-02-01

    Cortical development is dependent on stimulus-driven learning. The absence of sensory input from birth, as occurs in congenital deafness, affects normal growth and connectivity needed to form a functional sensory system, resulting in deficits in oral language learning. Cochlear implants bypass cochlear damage by directly stimulating the auditory nerve and brain, making it possible to avoid many of the deleterious effects of sensory deprivation. Congenitally deaf animals and children who receive implants provide a platform to examine the characteristics of cortical plasticity in the auditory system. In this review, we discuss the existence of time limits for, and mechanistic constraints on, sensitive periods for cochlear implantation and describe the effects of multimodal and cognitive reorganization that result from long-term auditory deprivation. PMID:22104561

  6. Rescue of Brain Function Using Tunneling Nanotubes Between Neural Stem Cells and Brain Microvascular Endothelial Cells.

    Science.gov (United States)

    Wang, Xiaoqing; Yu, Xiaowen; Xie, Chong; Tan, Zijian; Tian, Qi; Zhu, Desheng; Liu, Mingyuan; Guan, Yangtai

    2016-05-01

    Evidence indicates that neural stem cells (NSCs) can ameliorate cerebral ischemia in animal models. In this study, we investigated the mechanism underlying one of the neuroprotective effects of NSCs: tunneling nanotube (TNT) formation. We addressed whether the control of cell-to-cell communication processes between NSCs and brain microvascular endothelial cells (BMECs) and, particularly, the control of TNT formation could influence the rescue function of stem cells. In an attempt to mimic the cellular microenvironment in vitro, a co-culture system consisting of terminally differentiated BMECs from mice in a distressed state and NSCs was constructed. Additionally, engraftment experiments with infarcted mouse brains revealed that control of TNT formation influenced the effects of stem cell transplantation in vivo. In conclusion, our findings provide the first evidence that TNTs exist between NSCs and BMECs and that regulation of TNT formation alters cell function. PMID:26041660

  7. Communication and control by listening: towards optimal design of a two-class auditory streaming brain-computer interface

    Directory of Open Access Journals (Sweden)

    N. Jeremy Hill

    2012-12-01

    Full Text Available Most brain-computer interface (BCI systems require users to modulate brain signals in response to visual stimuli. Thus, they may not be useful to people with limited vision, such as those with severe paralysis. One important approach for overcoming this issue is auditory streaming, an approach whereby a BCI system is driven by shifts of attention between two dichotically presented auditory stimulus streams. Motivated by the long-term goal of translating such a system into a reliable, simple yes-no interface for clinical usage, we aim to answer two main questions. First, we asked which of two previously-published variants provides superior performance: a fixed-phase (FP design in which the streams have equal period and opposite phase, or a drifting-phase (DP design where the periods are unequal. We found FP to be superior to DP (p = 0.002: average performance levels were 80% and 72% correct, respectively. We were also able to show, in a pilot with one subject, that auditory streaming can support continuous control and neurofeedback applications: by shifting attention between ongoing left and right auditory streams, the subject was able to control the position of a paddle in a computer game. Second, we examined whether the system is dependent on eye movements, since it is known that eye movements and auditory attention may influence each other, and any dependence on the ability to move one’s eyes would be a barrier to translation to paralyzed users. We discovered that, despite instructions, some subjects did make eye movements that were indicative of the direction of attention. However, there was no correlation, across subjects, between the reliability of the eye movement signal and the reliability of the BCI system, indicating that our system was configured to work independently of eye movement. Together, these findings are an encouraging step forward toward BCIs that provide practical communication and control options for the most severely

  8. Brain Responses to Musical Feature Changes in Adolescent Cochlear Implant Users

    Directory of Open Access Journals (Sweden)

    Bjørn ePetersen

    2015-02-01

    Full Text Available Cochlear implants (CIs are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (EEG, we recorded the mismatch negativity (MMN of the auditory event-related potential (ERP to changes in musical features in adolescent CI users and in normal-hearing age mates. EEG recordings and behavioral testing were carried out before (T1 and after (T2 a 2-week music training program for the CI users and in two sessions equally separated in time for normal-hearing (NH controls. We found significant MMNs in adolescent CI users for deviations in timbre, intensity and rhythm, indicating residual neural prerequisites for musical feature processing. By contrast, only one of the two pitch deviants elicited an MMN in CI users. This pitch discrimination deficit was supported by behavioral measures, in which CI users scored significantly below the NH level. Overall MMN amplitudes were significantly smaller in CI users than in NH controls, suggesting poorer music discrimination ability. Despite compliance from the CI-participants, we found no effect of the music training, likely resulting from the brevity of the program. This is the first study showing significant brain responses to musical feature changes in prelingually deaf adolescent CI users and their associations with behavioral measures, implying neural predispositions for at least some aspects of music processing. Future studies should test any beneficial effects of a longer lasting music intervention in adolescent CI users.

  9. Brain Responses to Musical Feature Changes in Adolescent Cochlear Implant Users

    Science.gov (United States)

    Petersen, Bjørn; Weed, Ethan; Sandmann, Pascale; Brattico, Elvira; Hansen, Mads; Sørensen, Stine Derdau; Vuust, Peter

    2015-01-01

    Cochlear implants (CIs) are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (EEG), we recorded the mismatch negativity (MMN) of the auditory event-related potential to changes in musical features in adolescent CI users and in normal-hearing (NH) age mates. EEG recordings and behavioral testing were carried out before (T1) and after (T2) a 2-week music training program for the CI users and in two sessions equally separated in time for NH controls. We found significant MMNs in adolescent CI users for deviations in timbre, intensity, and rhythm, indicating residual neural prerequisites for musical feature processing. By contrast, only one of the two pitch deviants elicited an MMN in CI users. This pitch discrimination deficit was supported by behavioral measures, in which CI users scored significantly below the NH level. Overall, MMN amplitudes were significantly smaller in CI users than in NH controls, suggesting poorer music discrimination ability. Despite compliance from the CI participants, we found no effect of the music training, likely resulting from the brevity of the program. This is the first study showing significant brain responses to musical feature changes in prelingually deaf adolescent CI users and their associations with behavioral measures, implying neural predispositions for at least some aspects of music processing. Future studies should test any beneficial effects of a longer lasting music intervention in adolescent CI users. PMID:25705185

  10. Brain responses to musical feature changes in adolescent cochlear implant users.

    Science.gov (United States)

    Petersen, Bjørn; Weed, Ethan; Sandmann, Pascale; Brattico, Elvira; Hansen, Mads; Sørensen, Stine Derdau; Vuust, Peter

    2015-01-01

    Cochlear implants (CIs) are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (EEG), we recorded the mismatch negativity (MMN) of the auditory event-related potential to changes in musical features in adolescent CI users and in normal-hearing (NH) age mates. EEG recordings and behavioral testing were carried out before (T1) and after (T2) a 2-week music training program for the CI users and in two sessions equally separated in time for NH controls. We found significant MMNs in adolescent CI users for deviations in timbre, intensity, and rhythm, indicating residual neural prerequisites for musical feature processing. By contrast, only one of the two pitch deviants elicited an MMN in CI users. This pitch discrimination deficit was supported by behavioral measures, in which CI users scored significantly below the NH level. Overall, MMN amplitudes were significantly smaller in CI users than in NH controls, suggesting poorer music discrimination ability. Despite compliance from the CI participants, we found no effect of the music training, likely resulting from the brevity of the program. This is the first study showing significant brain responses to musical feature changes in prelingually deaf adolescent CI users and their associations with behavioral measures, implying neural predispositions for at least some aspects of music processing. Future studies should test any beneficial effects of a longer lasting music intervention in adolescent CI users. PMID:25705185

  11. Treatment of radiation syndrome with emphasis on stem cell implantation

    International Nuclear Information System (INIS)

    Within few years, the possibility that the human body contains cells that can repair and regenerate damaged and diseased tissue has gone from an unlikely proposition to a virtual certainty. Patients who have received doses of radiation in the potentially low to mid-lethal range (2-6 Gy) will have depression in bone-marrow function with cessation of blood-cell production leading to pancytopenia. Selection of cases for stem cell transplantation is based upon clinical signs and symptoms. Hematopoietic stem cell which produces blood cell progeny provides support for hematopoietic and other cells within the marrow, and has also been a focus for possible tissue repair. Another cell type termed mesenchymal or stromal also exists in the marrow. This cell provides support for hematopoietic and other cells within the marrow, and has also been a focus for possible tissue repair. Stem cells are obtained from bone marrow, peripheral blood, placental and umbilical cord blood, embryonic stem cells and embryonic germ cells. These cells have great potential for clinical research due to their potential to regenerate tissue. As well known, the cryo preservation process can store any cell type, particularly blood cells, for an indeterminate time. (author)

  12. Changes in strain patterns after implantation of a short stem with metaphyseal anchorage compared to a standard stem: an experimental study in synthetic bone

    Directory of Open Access Journals (Sweden)

    Jens Gronewold

    2014-03-01

    Full Text Available Short stem hip arthroplasties with predominantly metaphyseal fixation, such as the METHA® stem (Aesculap, Tuttlingen, Germany, are recommended because they are presumed to allow a more physiologic load transfer and thus a reduction of stress-shielding. However, the hypothesized metaphyseal anchorage associated with the aforementioned benefits still needs to be verified. Therefore, the METHA short stem and the Bicontact® standard stem (Aesculap, Tuttlingen, Germany were tested biomechanically in synthetic femora while strain gauges monitored their corresponding strain patterns. For the METHA stem, the strains in all tested locations including the region of the calcar (87% of the non-implanted femur were similar to conditions of synthetic bone without implanted stem. The Bicontact stem showed approximately the level of strain of the non-implanted femur on the lateral and medial aspect in the proximal diaphysis of the femur. On the anterior and posterior aspect of the proximal metaphysis the strains reached averages of 78% and 87% of the non-implanted femur, respectively. This study revealed primary metaphyseal anchorage of the METHA short stem, as opposed to a metaphyseal-diaphyseal anchorage of the Bicontact stem.

  13. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation.

    Science.gov (United States)

    Wallentin, Mikkel; Skakkebæk, Anne; Bojesen, Anders; Fedder, Jens; Laurberg, Peter; Østergaard, John R; Hertz, Jens Michael; Pedersen, Anders Degn; Gravholt, Claus Højbjerg

    2016-01-01

    Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words "GREEN" or "RED" were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying "GREEN" or "RED" had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system. PMID:26958463

  14. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation

    Directory of Open Access Journals (Sweden)

    Mikkel Wallentin

    2016-01-01

    Full Text Available Klinefelter syndrome (47, XXY (KS is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49 responded to whether the words “GREEN” or “RED” were displayed in green or red (incongruent versus congruent colors. One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying “GREEN” or “RED” had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system.

  15. A Cochlear Implant Performance Prognostic Test Based on Electrical Field Interactions Evaluated by eABR (Electrical Auditory Brainstem Responses)

    Science.gov (United States)

    Guevara, Nicolas; Hoen, Michel; Truy, Eric; Gallego, Stéphane

    2016-01-01

    Background Cochlear implants (CIs) are neural prostheses that have been used routinely in the clinic over the past 25 years. They allow children who were born profoundly deaf, as well as adults affected by hearing loss for whom conventional hearing aids are insufficient, to attain a functional level of hearing. The “modern” CI (i.e., a multi-electrode implant using sequential coding strategies) has yielded good speech comprehension outcomes (recognition level for monosyllabic words about 50% to 60%, and sentence comprehension close to 90%). These good average results however hide a very important interindividual variability as scores in a given patients’ population often vary from 5 to 95% in comparable testing conditions. Our aim was to develop a prognostic model for patients with unilateral CI. A novel method of objectively measuring electrical and neuronal interactions using electrical auditory brainstem responses (eABRs) is proposed. Methods and Findings The method consists of two measurements: 1) eABR measurements with stimulation by a single electrode at 70% of the dynamic range (four electrodes distributed within the cochlea were tested), followed by a summation of these four eABRs; 2) Measurement of a single eABR with stimulation from all four electrodes at 70% of the dynamic range. A comparison of the eABRs obtained by these two measurements, defined as the monaural interaction component (MIC), indicated electrical and neural interactions between the stimulation channels. Speech recognition performance without lip reading was measured for each patient using a logatome test (64 "vowel-consonant-vowel"; VCV; by forced choice of 1 out of 16). eABRs were measured in 16 CI patients (CIs with 20 electrodes, Digisonic SP; Oticon Medical ®, Vallauris, France). Significant correlations were found between speech recognition performance and the ratio of the amplitude of the V wave of the eABRs obtained with the two measurements (Pearson's linear regression

  16. A Cochlear Implant Performance Prognostic Test Based on Electrical Field Interactions Evaluated by eABR (Electrical Auditory Brainstem Responses.

    Directory of Open Access Journals (Sweden)

    Nicolas Guevara

    Full Text Available Cochlear implants (CIs are neural prostheses that have been used routinely in the clinic over the past 25 years. They allow children who were born profoundly deaf, as well as adults affected by hearing loss for whom conventional hearing aids are insufficient, to attain a functional level of hearing. The "modern" CI (i.e., a multi-electrode implant using sequential coding strategies has yielded good speech comprehension outcomes (recognition level for monosyllabic words about 50% to 60%, and sentence comprehension close to 90%. These good average results however hide a very important interindividual variability as scores in a given patients' population often vary from 5 to 95% in comparable testing conditions. Our aim was to develop a prognostic model for patients with unilateral CI. A novel method of objectively measuring electrical and neuronal interactions using electrical auditory brainstem responses (eABRs is proposed.The method consists of two measurements: 1 eABR measurements with stimulation by a single electrode at 70% of the dynamic range (four electrodes distributed within the cochlea were tested, followed by a summation of these four eABRs; 2 Measurement of a single eABR with stimulation from all four electrodes at 70% of the dynamic range. A comparison of the eABRs obtained by these two measurements, defined as the monaural interaction component (MIC, indicated electrical and neural interactions between the stimulation channels. Speech recognition performance without lip reading was measured for each patient using a logatome test (64 "vowel-consonant-vowel"; VCV; by forced choice of 1 out of 16. eABRs were measured in 16 CI patients (CIs with 20 electrodes, Digisonic SP; Oticon Medical ®, Vallauris, France. Significant correlations were found between speech recognition performance and the ratio of the amplitude of the V wave of the eABRs obtained with the two measurements (Pearson's linear regression model, parametric correlation: r

  17. Anatomy, Physiology and Function of the Auditory System

    Science.gov (United States)

    Kollmeier, Birger

    The human ear consists of the outer ear (pinna or concha, outer ear canal, tympanic membrane), the middle ear (middle ear cavity with the three ossicles malleus, incus and stapes) and the inner ear (cochlea which is connected to the three semicircular canals by the vestibule, which provides the sense of balance). The cochlea is connected to the brain stem via the eighth brain nerve, i.e. the vestibular cochlear nerve or nervus statoacusticus. Subsequently, the acoustical information is processed by the brain at various levels of the auditory system. An overview about the anatomy of the auditory system is provided by Figure 1.

  18. Hybrid Adipogenic Implants from Adipose Stem Cells for Soft Tissue Reconstruction In Vivo

    OpenAIRE

    MOIOLI, EDUARDO K.; Chen, Mo; Yang, Rujing; Shah, Bhranti; Wu, June; Mao, Jeremy J

    2010-01-01

    A critical barrier in tissue regeneration is scale-up. Bioengineered adipose tissue implants have been limited to ∼10 mm in diameter. Here, we devised a 40-mm hybrid implant with a cellular layer encapsulating an acellular core. Human adipose-derived stem cells (ASCs) were seeded in alginate. Poly(ethylene)glycol-diacrylate (PEGDA) was photopolymerized into 40-mm-diameter dome-shaped gel. Alginate-ASC suspension was painted onto PEGDA surface. Cultivation of hybrid constructs ex vivo in adipo...

  19. The taxonomy of brain cancer stem cells: what's in a name?

    OpenAIRE

    Gutmann, David H.

    2014-01-01

    With the increasing recognition that stem cells play vital roles in the formation, maintenance, and potential targeted treatment of brain tumors, there has been an exponential increase in basic laboratory and translational research on these cell types. However, there are several different classes of stem cells germane to brain cancer, each with distinct capabilities and functions. In this perspective, we discuss the types of stem cells relevant to brain tumor pathogenesis, and suggest a nomen...

  20. Brain tumor stem cells as research and treatment targets

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM) is one of the most malignant forms of human cancer. Despite intensive treatment, the mean survival of GBM patients remains about 1 year. Recent cancer studies revealed that cancer tissues are pathologically heterogeneous and only a small population of cells has the specific ability to reinitiate cancer. This small cell population is called cancer stem cells (CSCs); in brain tumors these are known as brain tumor stem cells (BTSCs). The identification of BTSCs yielded new insights into chemo- and radioresistance, by which BTSCs can survive selectively and initiate recurrence. Research focused on BTSCs as treatment targets may contribute to the discovery of new therapeutic strategies. Clinical and basic research studies gradually led to improved outcomes in patients with brain tumors. Stupp et al. reported a mean survival of 14.6 months in glioblastoma multiforme (GBM) patients treated with radiotherapy plus temozolomide and 12.1 months in those subjected to radiotherapy alone. Earlier cancer therapies primarily targeted rapidly dividing cells but not minor populations of slowly dividing cells that contain BTSCs. Accumulating evidence suggests that BTSCs may represent an excellent tool for discovering new strategies to treat GBM patients. In this review, we present evidence supporting the CSC model of tumor progression, and discuss difficulties encountered in CSC research and experimental and therapeutic implications. (author)

  1. The effects of stress on brain and adrenal stem cells.

    Science.gov (United States)

    de Celis, M F R; Bornstein, S R; Androutsellis-Theotokis, A; Andoniadou, C L; Licinio, J; Wong, M-L; Ehrhart-Bornstein, M

    2016-05-01

    The brain and adrenal are critical control centers that maintain body homeostasis under basal and stress conditions, and orchestrate the body's response to stress. It is noteworthy that patients with stress-related disorders exhibit increased vulnerability to mental illness, even years after the stress experience, which is able to generate long-term changes in the brain's architecture and function. High levels of glucocorticoids produced by the adrenal cortex of the stressed subject reduce neurogenesis, which contributes to the development of depression. In support of the brain-adrenal connection in stress, many (but not all) depressed patients have alterations in the components of the limbic-hypothalamic-pituitary-adrenal (LHPA) axis, with enlarged adrenal cortex and increased glucocorticoid levels. Other psychiatric disorders, such as post-traumatic stress disorder, bipolar disorder and depression, are also associated with abnormalities in hippocampal volume and hippocampal function. In addition, hippocampal lesions impair the regulation of the LHPA axis in stress response. Our knowledge of the functional connection between stress, brain function and adrenal has been further expanded by two recent, independent papers that elucidate the effects of stress on brain and adrenal stem cells, showing similarities in the way that the progenitor populations of these organs behave under stress, and shedding more light into the potential cellular and molecular mechanisms involved in the adaptation of tissues to stress. PMID:26809844

  2. Anaesthetic management of a patient with deep brain stimulation implant for radical nephrectomy

    Directory of Open Access Journals (Sweden)

    Monica Khetarpal

    2014-01-01

    Full Text Available A 63-year-old man with severe Parkinson′s disease (PD who had been implanted with deep brain stimulators into both sides underwent radical nephrectomy under general anaesthesia with standard monitoring. Deep brain stimulation (DBS is an alternative and effective treatment option for severe and refractory PD and other illnesses such as essential tremor and intractable epilepsy. Anaesthesia in the patients with implanted neurostimulator requires special consideration because of the interaction between neurostimulator and the diathermy. The diathermy can damage the brain tissue at the site of electrode. There are no standard guidelines for the anaesthetic management of a patient with DBS electrode in situ posted for surgery.

  3. Pediatric brain stem gliomas: Comparison of evaluation by CT and MR imaging

    International Nuclear Information System (INIS)

    This study is a direct comparison of the role of CT and MR imaging in the pretreatment and posttreatment evaluation of pediatric brain-stem gliomas. Thirty-four patients with presumed brain-stem gliomas were imaged by both CT and MR over the past 53 months. Twenty-two males and 12 females ranged in age from 3 to 17 years. Fifteen patients had tumor confirmed by biopsy. Thirteen children with nonneoplastic brain-stem lesions were imaged. MR proved superior to CT in both the pretreatment and posttreatment evaluation of patients with brain-stem gliomas. Pathologic correlation to the images is made in selected cases

  4. Tomographic criteria of gliomas in the brain stem in infants

    International Nuclear Information System (INIS)

    The relationship between Computed Tomography Imaging, histopathological and prognostic data is evaluated by reviewing 37 cases of brain stem neoplasm in infants. The results indicate a presence of a cystic lesion with solid mural nodule as the single prognostic criteria of a greater survival rate. Such finding frequently corresponds to Pilocytic Astrocytomas. No correlations between contrast enhancement and prognostic was found. The association between the prognostic value to the densitometric characteristics of the lesions was not possible. It was concluded that the evaluations of the extension of such lesion is fundamental. Therefore, Magnetic Resonance Imaging has more value than computed tomography. (M.A.C.)

  5. Establishment of 9L/F344 rat intracerebral glioma model of brain tumor stem cells

    Directory of Open Access Journals (Sweden)

    Zong-yu XIAO

    2015-04-01

    Full Text Available Objective To establish the 9L/F344 rat intracerebral glioma model of brain tumor stem cells.  Methods Rat 9L gliosarcoma stem-like cells were cultured in serum-free suspension. The expression of CD133 and nestin were tested by immunohistochemistry. A total of 48 inbredline male F344 rats were randomly divided into 2 groups, and 9L tumor sphere cells and 9L monolayer cells were respectively implanted into the right caudate nucleus of F344 rats in 2 groups. Survival time was observed and determined using the method of Kaplan-Meier survival analysis. Fourteen days after implantation or when the rats were dying, their brains were perfused and sectioned for HE staining, and CD133 and nestin were detected by immunohistochemistry.  Results Rat 9L tumor spheres were formed with suspension culture in serum-free medium. The gliomas formed in both groups were invasive without obvious capsule. More new vessels, bleeding and necrosis could be detected in 9L tumor spheres group. The tumor cells in both groups were positive for CD133 and nestin. There was no significant difference in the expression of CD133 and nestin between 2 groups (P > 0.05, for all. According to the expression of nestin, the tumors formed by 9L tumor sphere cells were more invasive. The median survival time of the rats bearing 9L tumor sphere cells was 15 d (95%CI: 15.219-15.781, and the median survival time of the rats bearing 9L monolayer cells was 21 d (95%CI: 20.395-21.605. There was significant difference between 2 groups (χ2 = 12.800, P = 0.000.  Conclusions 9L/F344 rat intracerebral glioma model of brain tumor stem cells is successfully established, which provides a glioma model for the future research. DOI: 10.3969/j.issn.1672-6731.2015.04.012

  6. Search for Chemically Defined Culture Medium to Assist Initial Regeneration of Diseased Renal Parenchyma After Stem/Progenitor Cell Implantation

    OpenAIRE

    Minuth WW; Denk L; Gruber M

    2013-01-01

    Before an intended implantation stem/progenitor cells are usually kept in the beneficial atmosphere of a selected culture medium. However, after implantation the situation is drastically changing for them. Yet stem/progenitor cells must stand the harmful fluid environment within a diseased organ. In this coherence it is unknown, to which degree alterations in molecular composition of interstitial fluid can influence the initial regeneration of parenchyma. To obtain first ins...

  7. The BRAIN Initiative Provides a Unifying Context for Integrating Core STEM Competencies into a Neurobiology Course

    OpenAIRE

    Schaefer, Jennifer E.

    2016-01-01

    The Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative introduced by the Obama Administration in 2013 presents a context for integrating many STEM competencies into undergraduate neuroscience coursework. The BRAIN Initiative core principles overlap with core STEM competencies identified by the AAAS Vision and Change report and other entities. This neurobiology course utilizes the BRAIN Initiative to serve as the unifying theme that facilitates a primary emphasis ...

  8. Comparison of biological characteristics of mesenchymal stem cells grown on two different titanium implant surfaces

    International Nuclear Information System (INIS)

    This study examined the biological characteristics of mesenchymal stem cells (MSCs) grown on sand-blasted, large-grit, acid-etched (SLA) surface and hydroxyapatite (HA) coating on the SLA (HA/SLA) surface of titanium dental implants. The HA/SLA surfaces of titanium dental implants were formed by the ion beam assisted deposition (IBAD) method. Rabbit bone marrow derived mesenchymal stem cells cultured in vitro were seeded onto the surface of SLA and HA/SLA; the growth states of MSCs on the two samples were observed by a scanning electron microscope; the proliferation index, alkaline phosphatase (ALP) activity, osteocalcin (OCN) content of MSCs and mRNA relative expression level of osteopontin (opn) were compared between two groups. MSCs were found to be easier to adhere to the HA/SLA surface compared to the SLA surface. At the same time, the ALP activity and the OCN content of MSCs grown on the HA/SLA surface were obviously higher, and the relative expression level of opn mRNA was 4.78 times higher than that on the SLA surface. The HA coating formed by the IBAD method on the SLA surface of titanium dental implants significantly improves proliferation and well-differentiated osteoblastic phenotype of MSCs, which indicates a promising method for the surface modification of titanium dental implants

  9. Brain micro-ecologies: neural stem cell niches in the adult mammalian brain

    OpenAIRE

    Riquelme, Patricio A; Drapeau, Elodie; Doetsch, Fiona

    2007-01-01

    Neurogenesis persists in two germinal regions in the adult mammalian brain, the subventricular zone of the lateral ventricles and the subgranular zone in the hippocampal formation. Within these two neurogenic niches, specialized astrocytes are neural stem cells, capable of self-renewing and generating neurons and glia. Cues within the niche, from cell–cell interactions to diffusible factors, are spatially and temporally coordinated to regulate proliferation and neurogenesis, ultimately affect...

  10. Mapping the calcitonin receptor in human brain stem.

    Science.gov (United States)

    Bower, Rebekah L; Eftekhari, Sajedeh; Waldvogel, Henry J; Faull, Richard L M; Tajti, János; Edvinsson, Lars; Hay, Debbie L; Walker, Christopher S

    2016-05-01

    The calcitonin receptor (CTR) is relevant to three hormonal systems: amylin, calcitonin, and calcitonin gene-related peptide (CGRP). Receptors for amylin and calcitonin are targets for treating obesity, diabetes, and bone disorders. CGRP receptors represent a target for pain and migraine. Amylin receptors (AMY) are a heterodimer formed by the coexpression of CTR with receptor activity-modifying proteins (RAMPs). CTR with RAMP1 responds potently to both amylin and CGRP. The brain stem is a major site of action for circulating amylin and is a rich site of CGRP binding. This study aimed to enhance our understanding of these hormone systems by mapping CTR expression in the human brain stem, specifically the medulla oblongata. Widespread CTR-like immunoreactivity was observed throughout the medulla. Dense CTR staining was noted in several discrete nuclei, including the nucleus of the solitary tract, the hypoglossal nucleus, the cuneate nucleus, spinal trigeminal nucleus, the gracile nucleus, and the inferior olivary nucleus. CTR staining was also observed in the area postrema, the lateral reticular nucleus, and the pyramidal tract. The extensive expression of CTR in the medulla suggests that CTR may be involved in a wider range of functions than currently appreciated. PMID:26911465

  11. Cytokine Immunopathogenesis of Enterovirus 71 Brain Stem Encephalitis

    Directory of Open Access Journals (Sweden)

    Shih-Min Wang

    2012-01-01

    Full Text Available Enterovirus 71 (EV71 is one of the most important causes of herpangina and hand, foot, and mouth disease. It can also cause severe complications of the central nervous system (CNS. Brain stem encephalitis with pulmonary edema is the severe complication that can lead to death. EV71 replicates in leukocytes, endothelial cells, and dendritic cells resulting in the production of immune and inflammatory mediators that shape innate and acquired immune responses and the complications of disease. Cytokines, as a part of innate immunity, favor the development of antiviral and Th1 immune responses. Cytokines and chemokines play an important role in the pathogenesis EV71 brain stem encephalitis. Both the CNS and the systemic inflammatory responses to infection play important, but distinctly different, roles in the pathogenesis of EV71 pulmonary edema. Administration of intravenous immunoglobulin and milrinone, a phosphodiesterase inhibitor, has been shown to modulate inflammation, to reduce sympathetic overactivity, and to improve survival in patients with EV71 autonomic nervous system dysregulation and pulmonary edema.

  12. Location of cat brain stem neurons that drive sweating.

    Science.gov (United States)

    Shafton, Anthony D; McAllen, Robin M

    2013-05-15

    The brain stem premotor pathways controlling most noncardiovascular sympathetic outflows are unknown. Here, we mapped the brain stem neurons that drive sweating, by microinjecting excitant amino acid (L-glutamate or D,L-homocysteate: 0.4-3 nmol) into 420 sites over the pons and medulla of eight chloralose-anesthetized cats (70 mg/kg iv). Sweating was recorded by the electrodermal potential at the ipsilateral forepaw pad. Responses were classified as immediate (10 s latency). Immediate responses were obtained from 16 sites (1-3 per animal) and were accompanied by no change in blood pressure. Those sites were clustered between the facial nucleus and the pyramidal tract in the rostral ventromedial medulla (RVMM). Microinjections into 33 surrounding sites caused delayed electrodermal responses of lesser amplitude, while the remaining 371 sites evoked none. To retrogradely label bulbospinal neurons that may mediate electrodermal responses, fluorescent latex microspheres were injected into the region of the intermediolateral cell column in the fourth thoracic segment in an earlier preparatory procedure on six of the animals. A cluster of retrogradely labeled neurons was identified between the facial nucleus and the pyramidal tract. Neurons in this discrete region of the RVMM, thus, drive sweating in the cat's paw and may do so via direct spinal projections. PMID:23467325

  13. [Non-lethal brain stem hematomas in hypertensive patients].

    Science.gov (United States)

    Morel-Maroger, A; Metzger, J; Bories, J; Gardeur, D; Verger, J B; Noël, M C

    1982-01-01

    Brain stem hemorrhages (peduncular, pontine, medullary) were demonstrated by CT scan in hypertensive patients, the outcome being favorable without surgical intervention. Such lesions are considered as being usually massive and fatal. A review of the literature show that hemorrhages in the brain stem represent 5 to 9 p. cent of intraparenchymatous hemorrhages, and are usually located in the pons. A favorable course was known to occur before the use of computed tomography: the rare cases described were often related to subacute hematomas in young normotensive subjects which could be treated by surgery with or without ventricular shunting. Clinical diagnosis is based on the rapid progressive course of the disorder and the location of the lesion. Computed tomography provides an immediate correlation between anatomical and clinical findings, and allows a better evaluation of semiological and prognostic features that were previously considered well established. A major element appears to be the degree to which the hematoma is tolerated. As far as possible neurosurgical procedures should be avoided in hypertensive patients. PMID:7146726

  14. Correlation between heat shock protein 70 expression in the brain stem and sudden death after experimental traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lian-xu; XU Xiao-hu; LIU Chao; PAN Su-yue; ZHU Jia-zhen; ZHANG Cheng

    2001-01-01

    Objective: The aim of this study was to determine the patterns of heat-shock protein 70 (HSP70) biosynthesis following traumatic brain injury, and observe the effect of HSP70 induction on the function of the vital center in the brain stem. Methods: Rat models of sudden death resulted form traumatic brain injury were produced, and HSP70 expression in the rat brain stem was determined by immunohistochemistry, the induction of HSP70 mRNA detected by RT-PCR. Results: The level of HSP70 mRNA was prominently elevated in the brain stem as early as 1 5 min following the impact injury, while HSP70 expression was only observed 3 to 6 h after the injury. It was also observed that the levels of HSP70 mRNA but not the protein were elevated in the brain stem of sudden death rats. Conclusion: The synthesis of HSP70 was significantly enhanced in the brain stem following traumatic injury, and the expression of HSP70 is beneficial to eliminate the stress agents, and to sustain the cellular protein homeostasis. When the injury disturbs the synthesis of HSP70 to disarm the protective mechanism of heat-shock proteins, dysfunction of the vital center in the brain stem, and consequently death may occur. Breach in the synchronization of HSP70 mRNA-protein can be indicative of fatal damage to the nerve cells.

  15. Tumourigenicity and Immunogenicity of Induced Neural Stem Cell Grafts Versus Induced Pluripotent Stem Cell Grafts in Syngeneic Mouse Brain

    Science.gov (United States)

    Gao, Mou; Yao, Hui; Dong, Qin; Zhang, Hongtian; Yang, Zhijun; Yang, Yang; Zhu, Jianwei; Xu, Minhui; Xu, Ruxiang

    2016-01-01

    Along with the development of stem cell-based therapies for central nervous system (CNS) disease, the safety of stem cell grafts in the CNS, such as induced pluripotent stem cells (iPSCs) and induced neural stem cells (iNSCs), should be of primary concern. To provide scientific basis for evaluating the safety of these stem cells, we determined their tumourigenicity and immunogenicity in syngeneic mouse brain. Both iPSCs and embryonic stem cells (ESCs) were able to form tumours in the mouse brain, leading to tissue destruction along with immune cell infiltration. In contrast, no evidence of tumour formation, brain injury or immune rejection was observed with iNSCs, neural stem cells (NSCs) or mesenchymal stem cells (MSCs). With the help of gene ontology (GO) enrichment analysis, we detected significantly elevated levels of chemokines in the brain tissue and serum of mice that developed tumours after ESC or iPSC transplantation. Moreover, we also investigated the interactions between chemokines and NF-κB signalling and found that NF-κB activation was positively correlated with the constantly rising levels of chemokines, and vice versa. In short, iNSC grafts, which lacked any resulting tumourigenicity or immunogenicity, are safer than iPSC grafts. PMID:27417157

  16. Connecting the ear to the brain: molecular mechanisms of auditory circuit assembly

    OpenAIRE

    Appler, Jessica M; Goodrich, Lisa V.

    2011-01-01

    Our sense of hearing depends on precisely organized circuits that allow us to sense, perceive, and respond to complex sounds in our environment, from music and language to simple warning signals. Auditory processing begins in the cochlea of the inner ear, where sounds are detected by sensory hair cells and then transmitted to the central nervous system by spiral ganglion neurons, which faithfully preserve the frequency, intensity, and timing of each stimulus. During the assembly of auditory c...

  17. Plasticity in the neural coding of auditory space in the mammalian brain

    Science.gov (United States)

    King, Andrew J.; Parsons, Carl H.; Moore, David R.

    2000-10-01

    Sound localization relies on the neural processing of monaural and binaural spatial cues that arise from the way sounds interact with the head and external ears. Neurophysiological studies of animals raised with abnormal sensory inputs show that the map of auditory space in the superior colliculus is shaped during development by both auditory and visual experience. An example of this plasticity is provided by monaural occlusion during infancy, which leads to compensatory changes in auditory spatial tuning that tend to preserve the alignment between the neural representations of visual and auditory space. Adaptive changes also take place in sound localization behavior, as demonstrated by the fact that ferrets raised and tested with one ear plugged learn to localize as accurately as control animals. In both cases, these adjustments may involve greater use of monaural spectral cues provided by the other ear. Although plasticity in the auditory space map seems to be restricted to development, adult ferrets show some recovery of sound localization behavior after long-term monaural occlusion. The capacity for behavioral adaptation is, however, task dependent, because auditory spatial acuity and binaural unmasking (a measure of the spatial contribution to the "cocktail party effect") are permanently impaired by chronically plugging one ear, both in infancy but especially in adulthood. Experience-induced plasticity allows the neural circuitry underlying sound localization to be customized to individual characteristics, such as the size and shape of the head and ears, and to compensate for natural conductive hearing losses, including those associated with middle ear disease in infancy.

  18. Demonstration of ipsilateral brain activation by noise in patients profoundly deaf with cochlear implant, or unilaterally deaf

    International Nuclear Information System (INIS)

    Two groups of patients with hearing handicaps have been investigated with PET and F-18-2-FDG. Since these patients were unilaterally deaf or profoundly deaf with a cochlear implant installed, monaural stimulation was possible excluding any effects of bone conduction to the contralateral ear. White noise was used as acoustic stimulus in unilaterally deaf patients. The peripheral auditory nerve of cochlear implant patients was stimulated by electrical impulses which were encoded from music or a 4-tone mixture by an electronic speech processor. The non-music stimuli were chosen to avoid associative cortical reactions. In both groups response to the stimuli by increase of glucose consumption (LCMRglc) was found not only in the contralateral primary auditory cortex as expected from neuroanatomical knowledge, but also in the ipsilateral auditory cortex. Furthermore there was no correlation between the hemisphere showing increased LCMRglc and the side of stimulation or the type of stimulus. The similarity of results obtained in both groups by acoustical and electrical stimulation of the auditory nerve suggests that this kind of measurement might be a tool to predict or check the performance of a cochlear implant in a profoundly deaf patient. The finding of increased LCMRglc in the area of the normal auditory cortex in patients profoundly deaf since birth contradicts the hypothesis of degeneration of this cortical center in such patients. (Author)

  19. Real-time in vivo monitoring of viable stem cells implanted on biocompatible scaffolds

    International Nuclear Information System (INIS)

    Three-dimensional fibrous scaffolds provide an environment that enhances transplanted stem cell survival in vivo and facilitates imaging their localization, viability, and growth in vivo. To assess transplanted stem cell viability on biocompatible polymer scaffolds in vivo, we developed in vivo imaging systems for evaluation of implanted viable neural stem cells (NSC) and mesenchymal stem cells (MSC) on scaffolds using luciferase or sodium/iodide symporter (NIS) genes. Firefly luciferase stably expressing-C6 cell was established (C6-Fluc). The human neural stem cell, F3, was infected with adenoviral vector carrying luciferase gene (F3-Fluc) and MSC expressing NIS controlled by ubiquitin C promoter using lentiviral vector was established by treating blasticidine for 2 weeks (MSC-NIS). Chitosan and poly l-lactic acid (PLLA) scaffolds were used for in vivo image. In vivo expression of luciferase and human NIS was examined by bioluminescence image or 99mTc-pertechnetate gamma camera image, respectively. The cell/scaffold complex was implanted into subcutaneous or abdominal area of BALB/C nude mouse. For quantitative evaluation of cell viability, regions of interest were drawn on 99mTc-pertechnetate scintigraphy by manual. The gradual increase of luciferase activity was observed in C6-Fluc seeded with chitosan according to the increase in the number of cells. C6-Fluc/chitosan complex subcutaneously implanted into nude mice showed longitudinal bioluminescence image until 34 days. Luciferase image of abdominal-injected C6-Fluc/PLLA complex was saturated in only 14 days, showing great cell growth due to abundant nutrients. F3 cells showed well-incorporated pattern with fibrous chitosan scaffold using scanning electron microscopy. F3 infected with Ad-Fluc showed >100-fold higher luciferase activity than luciferase activity in F3. Cell-number-dependent increase of luciferase activity was shown in F3-Fluc seeded on chitosan. F3-Fluc incorporation into chitosan after abdominal

  20. Transplantation of autologous bone marrow-derived mesenchymal stem cells for traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    Jindou Jiang; Xingyao Bu; Meng Liu; Peixun Cheng

    2012-01-01

    Results from the present study demonstrated that transplantation of autologous bone marrow-derived mesenchymal stem cells into the lesion site in rat brain significantly ameliorated brain tissue pathological changes and brain edema, attenuated glial cell proliferation, and increased brain-derived neurotrophic factor expression. In addition, the number of cells double-labeled for 5-bromodeoxyuridine/glial fibrillary acidic protein and cells expressing nestin increased. Finally, blood vessels were newly generated, and the rats exhibited improved motor and cognitive functions. These results suggested that transplantation of autologous bone marrow-derived mesenchymal stem cells promoted brain remodeling and improved neurological functions following traumatic brain injury.

  1. The potential of stem cells for the restoration of auditory function in humans

    OpenAIRE

    Hu, Zhengqing; Ulfendahl, Mats

    2013-01-01

    Hearing loss is one of the most common disabilities, affecting approximately 10% of the population. Hair cells and spiral ganglion neurons are usually damaged in most cases of hearing loss. Currently, there is virtually no biological approach to replace damaged hearing cells. Recent developments in stem cell technology provide new opportunities for the treatment of deafness. Two major strategies have been investigated: differentiation of endogenous stem cells into new hair cells; and introduc...

  2. Compliant intracortical implants reduce strains and strain rates in brain tissue in vivo

    Science.gov (United States)

    Sridharan, Arati; Nguyen, Jessica K.; Capadona, Jeffrey R.; Muthuswamy, Jit

    2015-06-01

    Objective. The objective of this research is to characterize the mechanical interactions of (1) soft, compliant and (2) non-compliant implants with the surrounding brain tissue in a rodent brain. Understanding such interactions will enable the engineering of novel materials that will improve stability and reliability of brain implants. Approach. Acute force measurements were made using a load cell in n = 3 live rats, each with 4 craniotomies. Using an indentation method, brain tissue was tested for changes in force using established protocols. A total of 4 non-compliant, bare silicon microshanks, 3 non-compliant polyvinyl acetate (PVAc)-coated silicon microshanks, and 6 compliant, nanocomposite microshanks were tested. Stress values were calculated by dividing the force by surface area and strain was estimated using a linear stress-strain relationship. Micromotion effects from breathing and vascular pulsatility on tissue stress were estimated from a 5 s interval of steady-state measurements. Viscoelastic properties were estimated using a second-order Prony series expansion of stress-displacement curves for each shank. Main results. The distribution of strain values imposed on brain tissue for both compliant nanocomposite microshanks and PVAc-coated, non-compliant silicon microshanks were significantly lower compared to non-compliant bare silicon shanks. Interestingly, step-indentation experiments also showed that compliant, nanocomposite materials significantly decreased stress relaxation rates in the brain tissue at the interface (p brain tissue. Understanding the material behavior at the site of tissue contact will help to improve neural implant design.

  3. Intravenous transplantation of bone marrow mesenchymal stem cells promotes neural regeneration after traumatic brain injury

    OpenAIRE

    Anbari, Fatemeh; Khalili, Mohammad Ali; Bahrami, Ahmad Reza; Khoradmehr, Arezoo; Sadeghian, Fatemeh; Fesahat, Farzaneh; Nabi, Ali

    2014-01-01

    To investigate the supplement of lost nerve cells in rats with traumatic brain injury by intravenous administration of allogenic bone marrow mesenchymal stem cells, this study established a Wistar rat model of traumatic brain injury by weight drop impact acceleration method and administered 3 × 106 rat bone marrow mesenchymal stem cells via the lateral tail vein. At 14 days after cell transplantation, bone marrow mesenchymal stem cells differentiated into neurons and astrocytes in injured rat...

  4. Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell

    International Nuclear Information System (INIS)

    Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3 × 1016 ions/cm2 was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity. - Highlights: ► Mg ion was coated onto surface of SLA treated titanium via vacuum arc source ion implantation method. ► The morphological characteristics did not change after Mg ion implantation. ► Mg ion implanted SLA Ti is highly cytocompatible. ► Initial cell adhesion of MSCs is improved by Mg ion implantation. ► Mg ion implantation improved

  5. Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Beom-Su; Kim, Jin Seong [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-ro, Seo-gu, Daejeon 302-830 (Korea, Republic of); Park, Young Min [DIO Corporation, 66, Centum seo-ro, Haeundae-gu, Busan (Korea, Republic of); Choi, Bo-Young [Department of Oral and maxillofacial Surgery, Wonkwang University Daejeon Dental Hospital, Daejeon 302-830 (Korea, Republic of); Lee, Jun, E-mail: omslee@wku.ac.kr [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-ro, Seo-gu, Daejeon 302-830 (Korea, Republic of)

    2013-04-01

    Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3 × 10{sup 16} ions/cm{sup 2} was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity. - Highlights: ► Mg ion was coated onto surface of SLA treated titanium via vacuum arc source ion implantation method. ► The morphological characteristics did not change after Mg ion implantation. ► Mg ion implanted SLA Ti is highly cytocompatible. ► Initial cell adhesion of MSCs is improved by Mg ion implantation. ► Mg ion implantation

  6. Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders

    Directory of Open Access Journals (Sweden)

    Patricia A. Broderick

    2013-04-01

    Full Text Available Cocaine is a psychostimulant in the pharmacological class of drugs called Local Anesthetics. Interestingly, cocaine is the only drug in this class that has a chemical formula comprised of a tropane ring and is, moreover, addictive. The correlation between tropane and addiction is well-studied. Another well-studied correlation is that between psychosis induced by cocaine and that psychosis endogenously present in the schizophrenic patient. Indeed, both of these psychoses exhibit much the same behavioral as well as neurochemical properties across species. Therefore, in order to study the link between schizophrenia and cocaine addiction, we used a behavioral paradigm called Acoustic Startle. We used this acoustic startle paradigm in female versus male Sprague-Dawley animals to discriminate possible sex differences in responses to startle. The startle method operates through auditory pathways in brain via a network of sensorimotor gating processes within auditory cortex, cochlear nuclei, inferior and superior colliculi, pontine reticular nuclei, in addition to mesocorticolimbic brain reward and nigrostriatal motor circuitries. This paper is the first to report sex differences to acoustic stimuli in Sprague-Dawley animals (Rattus norvegicus although such gender responses to acoustic startle have been reported in humans (Swerdlow et al. 1997 [1]. The startle method monitors pre-pulse inhibition (PPI as a measure of the loss of sensorimotor gating in the brain's neuronal auditory network; auditory deficiencies can lead to sensory overload and subsequently cognitive dysfunction. Cocaine addicts and schizophrenic patients as well as cocaine treated animals are reported to exhibit symptoms of defective PPI (Geyer et al., 2001 [2]. Key findings are: (a Cocaine significantly reduced PPI in both sexes. (b Females were significantly more sensitive than males; reduced PPI was greater in females than in males. (c Physiological saline had no effect on startle in

  7. Brain systems for encoding and retrieval of auditory-verbal memory. An in vivo study in humans.

    Science.gov (United States)

    Fletcher, P C; Frith, C D; Grasby, P M; Shallice, T; Frackowiak, R S; Dolan, R J

    1995-04-01

    Long-term auditory-verbal memory comprises, at a neuropsychological level, a number of distinct cognitive processes. In the present study we determined the brain systems engaged during encoding (experiment 1) and retrieval (experiment 2) of episodic auditory-verbal material. In the separate experiments, PET measurements of regional cerebral blood flow (rCBF), an index of neural activity, were performed in normal volunteers during either the encoding or the retrieval of paired word associates. In experiment 1, a dual task interference paradigm was used to isolate areas involved in episodic encoding from those which would be concurrently activated by other cognitive processes associated with the presentation of paired associates, notably priming. In experiment 2, we used the cued retrieval of paired associates from episodic or from semantic memory in order to isolate the neural correlates of episodic memories. Encoding of episodic memory was associated with activation of the left prefrontal cortex and the retrosplenial area of the cingulate cortex, while retrieval from episodic memory was associated with activation of the precuneus bilaterally and of the right prefrontal cortex. These results are compatible with the patterns of activation reported in a previous PET memory experiment in which encoding and retrieval were studied concurrently. They also indicate that separate brain systems are engaged during the encoding and retrieval phases of episodic auditory-verbal memory. Retrieval from episodic memory engages a different, but overlapping, system to that engaged by retrieval from semantic memory, a finding that lends functional anatomical support to this neuropsychological distinction. PMID:7735882

  8. 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

  9. The functional foetal brain: A systematic preview of methodological factors in reporting foetal visual and auditory capacity

    Directory of Open Access Journals (Sweden)

    Kirsty Dunn

    2015-06-01

    Full Text Available Due to technological advancements in functional brain imaging, foetal brain responses to visual and auditory stimuli is a growing area of research despite being relatively small with much variation between research laboratories. A number of inconsistencies between studies are, nonetheless, present in the literature. This article aims to explore the potential contribution of methodological factors to variation in reports of foetal neural responses to external stimuli. Some of the variation in reports can be explained by methodological differences in aspects of study design, such as brightness and wavelength of light source. In contrast to visual foetal processing, auditory foetal processing has been more frequently investigated and findings are more consistent between different studies. This is an early preview of an emerging field with many articles reporting small sample sizes with techniques that are yet to be replicated. We suggest areas for improvement for the field as a whole, such as the standardisation of stimulus delivery and a more detailed reporting of methods and results. This will improve our understanding of foetal functional response to light and sound. We suggest that enhanced technology will allow for a more reliable description of the developmental trajectory of foetal processing of light stimuli.

  10. Brain Networks of Novelty-Driven Involuntary and Cued Voluntary Auditory Attention Shifting

    OpenAIRE

    Tengshe, Chinmayi; Huang, Samantha; Belliveau, John William; Ahveninen, Jyrki Pekka

    2012-01-01

    In everyday life, we need a capacity to flexibly shift attention between alternative sound sources. However, relatively little work has been done to elucidate the mechanisms of attention shifting in the auditory domain. Here, we used a mixed event-related/sparse-sampling fMRI approach to investigate this essential cognitive function. In each 10-sec trial, subjects were instructed to wait for an auditory “cue” signaling the location where a subsequent “target” sound was likely to be presented....

  11. What can we expect of normally-developing children implanted at a young age with respect to their auditory, linguistic and cognitive skills?

    Science.gov (United States)

    van Wieringen, Astrid; Wouters, Jan

    2015-04-01

    As a result of neonatal hearing screening and subsequent early cochlear implantation (CI) profoundly deaf children have access to important information to process auditory signals and master spoken language skills at a young age. Nevertheless, auditory, linguistic and cognitive outcome measures still reveal great variability in individual achievements: some children with CI(s) perform within normal limits, while others lag behind. Understanding the causes of this variation would allow clinicians to offer better prognoses to CI candidates and efficient follow-up and rehabilitation. This paper summarizes what we can expect of normally developing children with CI(s) with regard to spoken language, bilateral and binaural auditory perception, speech perception and cognitive skills. Predictive factors of performance and factors influencing variability are presented, as well as some novel data on cognitive functioning and speech perception in quiet and in noise. Subsequently, we discuss technical and non-technical issues which should be considered in the future in order to optimally guide the child with profound hearing difficulties. This article is part of a Special Issue entitled . PMID:25219955

  12. Proliferation of differentiated glial cells in the brain stem.

    Science.gov (United States)

    Barradas, P C; Cavalcante, L A

    1998-02-01

    Classical studies of macroglial proliferation in muride rodents have provided conflicting evidence concerning the proliferating capabilities of oligodendrocytes and microglia. Furthermore, little information has been obtained in other mammalian orders and very little is known about glial cell proliferation and differentiation in the subclass Metatheria although valuable knowledge may be obtained from the protracted period of central nervous system maturation in these forms. Thus, we have studied the proliferative capacity of phenotypically identified brain stem oligodendrocytes by tritiated thymidine radioautography and have compared it with known features of oligodendroglial differentiation as well as with proliferation of microglia in the opossum Didelphis marsupialis. We have detected a previously undescribed ephemeral, regionally heterogeneous proliferation of oligodendrocytes expressing the actin-binding, ensheathment-related protein 2'3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), that is not necessarily related to the known regional and temporal heterogeneity of expression of CNPase in cell bodies. On the other hand, proliferation of microglia tagged by the binding of Griffonia simplicifolia B4 isolectin, which recognizes an alpha-D-galactosyl-bearing glycoprotein of the plasma membrane of macrophages/microglia, is known to be long lasting, showing no regional heterogeneity and being found amongst both ameboid and differentiated ramified cells, although at different rates. The functional significance of the proliferative behavior of these differentiated cells is unknown but may provide a low-grade cell renewal in the normal brain and may be augmented under pathological conditions. PMID:9686148

  13. Proliferation of differentiated glial cells in the brain stem

    Directory of Open Access Journals (Sweden)

    Barradas P.C.

    1998-01-01

    Full Text Available Classical studies of macroglial proliferation in muride rodents have provided conflicting evidence concerning the proliferating capabilities of oligodendrocytes and microglia. Furthermore, little information has been obtained in other mammalian orders and very little is known about glial cell proliferation and differentiation in the subclass Metatheria although valuable knowledge may be obtained from the protracted period of central nervous system maturation in these forms. Thus, we have studied the proliferative capacity of phenotypically identified brain stem oligodendrocytes by tritiated thymidine radioautography and have compared it with known features of oligodendroglial differentiation as well as with proliferation of microglia in the opossum Didelphis marsupialis. We have detected a previously undescribed ephemeral, regionally heterogeneous proliferation of oligodendrocytes expressing the actin-binding, ensheathment-related protein 2'3'-cyclic nucleotide 3'-phosphodiesterase (CNPase, that is not necessarily related to the known regional and temporal heterogeneity of expression of CNPase in cell bodies. On the other hand, proliferation of microglia tagged by the binding of Griffonia simplicifolia B4 isolectin, which recognizes an alpha-D-galactosyl-bearing glycoprotein of the plasma membrane of macrophages/microglia, is known to be long lasting, showing no regional heterogeneity and being found amongst both ameboid and differentiated ramified cells, although at different rates. The functional significance of the proliferative behavior of these differentiated cells is unknown but may provide a low-grade cell renewal in the normal brain and may be augmented under pathological conditions.

  14. Radiosensitivity of brain cancer stem cells from malignant glicoma cell line U251 in vitro

    International Nuclear Information System (INIS)

    Objective: To investigate the radiosensitivity of brain cancer stem cells of different conditions isolated from malignant glioma cell line U251 irt vitro. Methods: The brain cancer stem cells in U251 or the brain cancer stem cells isolated from U251 were irradiated by 60Co γ-rays. TUNEL and Annexin-FITC were employed to detect the apoptosis. The brain cancer stem cells were subcutaneously transplanted to nude mouse. Flow cytometry was used to detect cell cycle. Results: The brain cancer stem cells isolated from malignant glioma cell line U251 were in active cell cycle and sensitive to 60Co γ-rays. Thed apoptotic cells were increased obviously after irradiation. After subcutaneously transplanted to unde mouse, there was no tumor appear. However; the brain cancer stem cells existed in U251 were in G0-G1 and resisted to 60Co γ-rays. They differentiated into the parent glioma type after traqnsplantation. Conclusions: The brain cancer stem cells existed in the malignant glioma cell line is resisted to irradiation, and this phenomenon may explain the glioma relapse irt situ after radiation therapy. (authors)

  15. Interstitial iridium-192 implantation for malignant brain tumours: Pt. 2. Clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Chun, M.; McKeough, P.; Wu, A.; Kasdon, D.; Heros, D.; Chang, H.

    1989-02-01

    The treatment results of 37 patients with malignant brain neoplasms treated with a computed-tomography-guided stereotactic iridium-192 implant are reviewed. Of these, 29 patients with high-grade gliomas (20 with glioblastoma multiforme (GBM), nine with anaplastic astrocytoma (AA)) received an implant as part of their initial management. The median survival was 14.5 and 15.5 months in the patients with previously untreated GBM and AA, respectively. In those patients with recurrent tumour after external-beam irradiation, durable local control over a year was achieved with implantation. Increasing the total tumour dose from 120 to 160 Gy did not improve survival or local control. Karnofsky Performance Status (KPS) was used as an indicator of quality of life and was seen to decrease with a median interval of 8.5 months following treatment. No severe complications were noted in the entire group of patients treated with this implant procedure.

  16. Dosimetric response of radioactive bio glass seeds implants on rabbit brain

    International Nuclear Information System (INIS)

    Interstitial implants of radioactive seeds are used as an efficient way of treating brain tumors. Bio glasses is an interesting alternative to the metallic implanted materials, because they can be absorbed by the organism, reducing the possibilities of side effects. The present paper investigates the dosimetry by the implants performed on rabbit's brain on the NRI/UFMG research group. The spatial distribution of the specific ionizing energy deposited per unit of mass generated by Sm-153 seeds were evaluated. A computational model of the brain's region was built using the software SISCODES produced by the research group. The sections of the computer tomography of a rabbit, which was included on the experiment, were digitalized. Those were converted in a three dimensional voxel model, including the tissues, its chemical composition and density. A simulation of the particles transport is performed by the stochastic code MCNP5. The implants consist of 15 ceramic Ca-Si-Sm seeds enriched with Sm-153, with 1.1.6 mm of length and 0.3 mm diameter, implanted on the rabbit's brain. It was predicted on the model three ribbons of 5 seeds each, spaced by 1.1.2 mm, since the ribbons were in a triangular topology whose vertices were spaced by 8 mm. The activities were 120 MBq/seed. The results show isodose regions superposed over the rabbits' model, reproducing the spatial energy deposition on the brain region. The absorbed dose predicted was 3.2 Gy per 15 seed; however it was not enough to tumor control. The authors suggest to increase the number of seeds and activity, reduction of the space to 5-6 mm among ribbons, improving dose with the beta emitting. (author)

  17. Electrochemical behavior and biological response of Mesenchymal Stem Cells on cp-Ti after N-ions implantation

    International Nuclear Information System (INIS)

    Highlights: • Nitrogen ions of known dosage were implanted on cp-Ti. • Increase in surface roughness with increase in ions dose was confirmed by AFM. • TiN0.3 and Ti3N2−x nitride phases were formed and validated by XRD. • The ions implantation reduced the corrosion rate and stabilized the passive film. • Surface roughness greatly affected the morphology and growth of Mesenchymal Stem Cells. - Abstract: Titanium and its alloys are most widely used as implant materials due to their excellent biocompatibility, mechanical properties and chemical stability. In this study Nitrogen ions of known dosage were implanted over cp-Ti by Pelletron accelerator with beam energy of 0.25 MeV.The atomic force microscopy of bare and nitrogen implanted specimens confirmed increase in surface roughness with increase in nitrogen ions concentration. X-ray diffraction patterns of ions implanted surfaces validated the formation of TiN0.3 and Ti3N2-xnitride phases. The tendency to form passive film and electrochemical behavior of these surfaces in ringer lactate (RL) solution was evaluated by Potentiodynamic polarization and electrochemical impedance spectroscopy respectively. It is proved that nitrogen ions implantation was beneficial to reduce corrosion rate and stabilizing passive film by increasing charge transfer resistance in RL. It was concluded that morphology and proliferation of Mesenchymal Stem Cells on nitrogen ions implanted surfaces strongly depends on surface roughness and nitride phases

  18. Implante auditivo de tronco cerebral: técnica cirúrgica e resultados auditivos precoces em pacientes com neurofibromatose tipo 2 Auditory Brainstem Implant: surgical technique and early audiological results in patients with neurofibromatosis type 2

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira Bento

    2008-10-01

    Full Text Available O implante auditivo de tronco cerebral foi desenvolvido para restaurar alguma audição útil em pacientes que apresentam ausência de nervo coclear bilateralmente. OBJETIVOS: Discutir a indicação, cirurgia e resultados em quatro pacientes submetidos à cirurgia para colocação de implante auditivo de tronco cerebral. CASUÍSTICA E MÉTODOS: Quatro pacientes com diagnóstico de schwannomas vestibulares bilaterais foram submetidos à cirurgia para colocação de Implante Auditivo de Tronco Cerebral durante o mesmo ato cirúrgico utilizado para a exérese de um dos tumores. Aspectos clínicos e técnicos e as referências anatômicas da cirurgia e os resultados auditivos foram analisados. RESULTADOS: Em todos os casos foram identificados as referências anatômicas ao forame de Luschka. As complicações cirúrgicas se resumiram à fístula liquórica em dois pacientes. Os eletrodos foram bem posicionados e a sensação auditiva foi suficiente para reconhecimento de sons e auxílio à leitura labial. CONCLUSÃO: Os resultados auditivos de nossos pacientes abrem uma perspectiva importante aos pacientes com surdez profunda bilateral sem integridade anatômica das vias auditivas centrais.Auditory Brainstem Implants were developed to partially restore the hearing capabilities of patients without cochlear nerves bilaterally. AIM: this paper aims to discuss the clinical and surgical findings of four ABI patients. MATERIALS AND METHOD: four patients diagnosed with bilateral schwannomas received auditory brainstem implants (ABI and had one of their tumors resected in the same surgical procedure. Clinical aspects, surgical technique, anatomic landmarks, and outcomes were analyzed. RESULTS: the anatomic landmarks were identified in all four patients in relation to the foramina of Luschka. Two patients had CSF leaks. The electrodes were well positioned and hearing sensation was good enough to allow for sound recognition and assist patients perform lip

  19. NFL-lipid nanocapsules for brain neural stem cell targeting in vitro and in vivo.

    Science.gov (United States)

    Carradori, Dario; Saulnier, Patrick; Préat, Véronique; des Rieux, Anne; Eyer, Joel

    2016-09-28

    The replacement of injured neurons by the selective stimulation of neural stem cells in situ represents a potential therapeutic strategy for the treatment of neurodegenerative diseases. The peptide NFL-TBS.40-63 showed specific interactions towards neural stem cells of the subventricular zone. The aim of our work was to produce a NFL-based drug delivery system able to target neural stem cells through the selective affinity between the peptide and these cells. NFL-TBS.40-63 (NFL) was adsorbed on lipid nanocapsules (LNC) whom targeting efficiency was evaluated on neural stem cells from the subventricular zone (brain) and from the central canal (spinal cord). NFL-LNC were incubated with primary neural stem cells in vitro or injected in vivo in adult rat brain (right lateral ventricle) or spinal cord (T10). NFL-LNC interactions with neural stem cells were different depending on the origin of the cells. NFL-LNC showed a preferential uptake by neural stem cells from the brain, while they did not interact with neural stem cells from the spinal cord. The results obtained in vivo correlate with the results observed in vitro, demonstrating that NFL-LNC represent a promising therapeutic strategy to selectively deliver bioactive molecules to brain neural stem cells. PMID:27503706

  20. Children with reading disability show brain differences in effective connectivity for visual, but not auditory word comprehension.

    Directory of Open Access Journals (Sweden)

    Li Liu

    Full Text Available BACKGROUND: Previous literature suggests that those with reading disability (RD have more pronounced deficits during semantic processing in reading as compared to listening comprehension. This discrepancy has been supported by recent neuroimaging studies showing abnormal activity in RD during semantic processing in the visual but not in the auditory modality. Whether effective connectivity between brain regions in RD could also show this pattern of discrepancy has not been investigated. METHODOLOGY/PRINCIPAL FINDINGS: Children (8- to 14-year-olds were given a semantic task in the visual and auditory modality that required an association judgment as to whether two sequentially presented words were associated. Effective connectivity was investigated using Dynamic Causal Modeling (DCM on functional magnetic resonance imaging (fMRI data. Bayesian Model Selection (BMS was used separately for each modality to find a winning family of DCM models separately for typically developing (TD and RD children. BMS yielded the same winning family with modulatory effects on bottom-up connections from the input regions to middle temporal gyrus (MTG and inferior frontal gyrus(IFG with inconclusive evidence regarding top-down modulations. Bayesian Model Averaging (BMA was thus conducted across models in this winning family and compared across groups. The bottom-up effect from the fusiform gyrus (FG to MTG rather than the top-down effect from IFG to MTG was stronger in TD compared to RD for the visual modality. The stronger bottom-up influence in TD was only evident for related word pairs but not for unrelated pairs. No group differences were noted in the auditory modality. CONCLUSIONS/SIGNIFICANCE: This study revealed a modality-specific deficit for children with RD in bottom-up effective connectivity from orthographic to semantic processing regions. There were no group differences in connectivity from frontal regions, suggesting that the core deficit in RD is not

  1. Evaluating auditory stream segregation of SAM tone sequences by subjective and objective psychoacoustical tasks, and brain activity

    Directory of Open Access Journals (Sweden)

    Lena-Vanessa eDollezal

    2014-06-01

    Full Text Available Auditory stream segregation refers to a segregated percept of signal streams with different acoustic features. Different approaches have been pursued in studies of stream segregation. In psychoacoustics, stream segregation has mostly been investigated with a subjective task asking the subjects to report their percept. Few studies have applied an objective task in which stream segregation is evaluated indirectly by determining thresholds for a percept that depends on whether auditory streams are segregated or not. Furthermore, both perceptual measures and physiological measures of brain activity have been employed but only little is known about their relation. How the results from different tasks and measures are related is evaluated in the present study using examples relying on the ABA- stimulation paradigm that apply the same stimuli. We presented A and B signals that were sinusoidally amplitude modulated (SAM tones providing purely temporal, spectral or both types of cues to evaluate perceptual stream segregation and its physiological correlate. Which types of cues are most prominent was determined by the choice of carrier and modulation frequencies (fmod of the signals. In the subjective task subjects reported their percept and in the objective task we measured their sensitivity for detecting time-shifts of B signals in an ABA- sequence. As a further measure of processes underlying stream segregation we employed functional magnetic resonance imaging (fMRI. SAM tone parameters were chosen to evoke an integrated (1-stream, a segregated (2-stream or an ambiguous percept by adjusting the fmod difference between A and B tones (∆fmod. The results of both psychoacoustical tasks are significantly correlated. BOLD responses in fMRI depend on ∆fmod between A and B SAM tones. The effect of ∆fmod, however, differs between auditory cortex and frontal regions suggesting differences in representation related to the degree of perceptual ambiguity of

  2. UV-activated 7-dehydrocholesterol-coated titanium implants promote differentiation of human umbilical cord mesenchymal stem cells into osteoblasts.

    Science.gov (United States)

    Satué, María; Ramis, Joana M; Monjo, Marta

    2016-01-01

    Vitamin D metabolites are essential for bone regeneration and mineral homeostasis. The vitamin D precursor 7-dehydrocholesterol can be used after UV irradiation to locally produce active vitamin D by osteoblastic cells. Furthermore, UV-irradiated 7-dehydrocholesterol is a biocompatible coating for titanium implants with positive effects on osteoblast differentiation. In this study, we examined the impact of titanium implants surfaces coated with UV-irradiated 7-dehydrocholesterol on the osteogenic differentiation of human umbilical cord mesenchymal stem cells. First, the synthesis of cholecalciferol (D3) was achieved through the incubation of the UV-activated 7-dehydrocholesterol coating for 48 h at 23℃. Further, we investigated in vitro the biocompatibility of this coating in human umbilical cord mesenchymal stem cells and its potential to enhance their differentiation towards the osteogenic lineage. Human umbilical cord mesenchymal stem cells cultured onto UV-irradiated 7-dehydrocholesterol-coated titanium implants surfaces, combined with osteogenic supplements, upregulated the gene expression of several osteogenic markers and showed higher alkaline phosphatase activity and calcein blue staining, suggesting increased mineralization. Thus, our results show that the use of UV irradiation on 7-dehydrocholesterol -treated titanium implants surfaces generates a bioactive coating that promotes the osteogenic differentiation of human umbilical cord mesenchymal stem cells, with regenerative potential for improving osseointegration in titanium-based bone anchored implants. PMID:25899927

  3. Implantation of stem cells in the treatment of acute myocardial infarction

    International Nuclear Information System (INIS)

    A lot of investigations demonstrate the possibility of regeneration of the cardiomiocity from stem cells. A longitudinal, prospective, observational study was conducted in patients with acute myocardial infarction in CIMEQ'S hospital since January 2004 up to January 2007 with the purpose to evaluate the security and efficacy of the intracoronary transfer of autologous bone-marrow-cells during acute myocardial infarction. Patients within seven days of the onset of symptoms of a first ST-segment elevation myocardial infarction, and between 18 and 70 years old. The patients are evaluated previous to apply the procedure and 6 months for clinic, electrocardiography, echocardiography, ergometry and coronariography. The drug eluting stent is placed on the culprit lesion and the bone marrow is stimulated with granulocyte colony-stimulating factor (G-CSF). The mononuclear's cells which are obtained have been implanted using the intracoronary way. The implantation by means of the intracoronary way of stem cells, after of stimulation of bone marrow during acute myocardial infarction demonstrated to be an effective and safety procedure

  4. Developmental Neuroplasticity After Cochlear Implantation

    OpenAIRE

    Kral, Andrej; Sharma, Anu

    2011-01-01

    Cortical development is dependent on stimulus-driven learning. The absence of sensory input from birth, as occurs in congenital deafness, affects normal growth and connectivity needed to form a functional sensory system—resulting in deficits in oral language learning. Cochlear implants bypass cochlear damage by directly stimulating the auditory nerve and brain, making it possible to avoid many of the deleterious effects of sensory deprivation. Congenitally deaf animals and children who receiv...

  5. Non-invasive brain stimulation and auditory verbal hallucinations : new techniques and future directions.

    OpenAIRE

    Moseley, Peter; Alderson-Day, Ben; Ellison, Amanda; Jardri, Renaud; Fernyhough, Charles

    2016-01-01

    Auditory verbal hallucinations (AVHs) are the experience of hearing a voice in the absence of any speaker. Results from recent attempts to treat AVHs with neurostimulation (rTMS or tDCS) to the left temporoparietal junction have not been conclusive, but suggest that it may be a promising treatment option for some individuals. Some evidence suggests that the therapeutic effect of neurostimulation on AVHs may result from modulation of cortical areas involved in the ability to monitor the source...

  6. Potential of Neural Stem Cells for the Treatment of Brain Tumors

    Directory of Open Access Journals (Sweden)

    P. Taupin

    2008-01-01

    Full Text Available Neural stem cells (NSCs are self-renewing multipotent cells that generate the main phenotypes of the nervous system, neurons, astrocytes and oligodendrocytes. As such they hold the promise to treat a broad range of neurological diseases and injuries. Neural progenitor and stem cells have been isolated and characterized in vitro, from adult, fetal and post-mortem tissues, providing sources of material for cellular therapy. However, NSCs are still elusive cells and remain to be unequivocally identified and characterized, limiting their potential use for therapy. Neural progenitor and stem cells, isolated and cultured in vitro, can be genetically modified and when transplanted migrate to tumor sites in the brain. These intrinsic properties of neural progenitor and stem cells provide tremendous potential to bolster the translation of NSC research to therapy. It is proposed to combine gene therapy and cellular therapy to treat brain cancers. Hence, neural progenitor and stem cells provide new opportunities for the treatment of brain cancers.

  7. Analysis of the brain-stem white-matter tracts with diffusion tensor imaging

    International Nuclear Information System (INIS)

    The authors have reviewed the diffusion tensor imaging (DTI) of the brain stem in 19 subjects, consisting of 15 normal volunteers and four multi-system atrophy patients. The study was performed with 1.5 T MRI scanners. DTI was correlated with an automated program allowing superposition of the structural anatomy. Axial, sagittal, and coronal images demonstrated major white-matter fibers within the brain stem, including cortico-spinal tracts, transverse pontine fibers, and medial lemniscus. Smaller fibers, such as medial longitudinal fascicles and central tegmental tracts are difficult to visualize. To identify the anatomical orientation of the brain stem, white-matter fibers will help us understand the different functional disease processes, and DTI will play an important role for the evaluation of the different white matter fibers in the brain stem. (orig.)

  8. Schwann Cells Transplantation Promoted and the Repair of Brain Stem Injury in Rats

    Institute of Scientific and Technical Information of China (English)

    HONG WAN; YI-HUA AN; MEI-ZHEN SUN; YA-ZHUO ZHANG; ZHONG-CHENG WANG

    2003-01-01

    To explore the possibility of Schwann cells transplantation to promote the repair of injured brain stem reticular structure in rats. Methods Schwann cells originated from sciatic nerves of 1 to 2-day-old rats were expanded and labelled by BrdU in vitro, transplanted into rat brain stem reticular structure that was pre-injured by electric needle stimulus. Immunohistochemistry and myelin-staining were used to investigate the expression of BrdU, GAP-43 and new myelination respectively. Results BrdU positive cells could be identified for up to 8 months and their number increased by about 23%, which mainly migrated toward injured ipsilateral cortex. The GAP-43expression reached its peak in 1 month after transplantation and was significantly higher than that in the control group. New myelination could be seen in destructed brain stem areas. Conclusion The transplantation of Schwann cells can promote the restoration of injured brain stem reticular structure.

  9. Detection of neural stem cells function in rats with traumatic brain injury by manganese-enhanced magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    TANG Hai-liang; SUN Hua-ping; WU Xing; SHA Hong-ying; FENG Xiao-yuan; ZHU Jian-hong

    2011-01-01

    Background Previously we had successfully tracked adult human neural stem cells (NSCs) labeled with superparamagnetic iron oxide particles (SPIOs) in host human brain after transplantation In vivo non-invasively by magnetic resonance imaging (MRI). However, the function of the transplanted NSCs could not be evaluated by the method. In the study, we applied manganese-enhanced MRI (ME-MRI) to detect NSCs function after implantation in brain of rats with traumatic brain injury (TBI) In vivo.Methods Totally 40 TBI rats were randomly divided into 4 groups with 10 rats in each group. In group 1, the TBI rats did not receive NSCs transplantation. MnCl2-4H2O was intravenously injected, hyperosmolar mannitol was delivered to disrupt rightside blood brain barrier, and its contralateral forepaw was electrically stimulated. In group 2, the TBI rats received NSCs (labeled with SPIO) transplantation, and the ME-MRI procedure was same to group 1. In group 3, the TBI rats received NSCs (labeled with SPIO) transplantation, and the ME-MRI procedure was same to group 1, but diltiazem was introduced during the electrical stimulation period. In group 4, the TBI rats received phosphate buffered saline (PBS) injection, and the ME-MRI procedure was same to group 1.Results Hyperintense signals were detected by ME-MRI in the cortex areas associated with somatosensory in TBI rats of group 2. These signals, which could not be induced in TBI rats of groups 1 and 4, disappeared when diltiazem was introduced in TBI rats of group 3.Conclusion In this initial study, we mapped implanted NSCs activity and its functional participation within local brain area in TBI rats by ME-MRI technique, paving the way for further pre-clinical research.

  10. Thrombospondin 2-null mice display an altered brain foreign body response to polyvinyl alcohol sponge implants

    Energy Technology Data Exchange (ETDEWEB)

    Tian Weiming; Kyriakides, Themis R, E-mail: themis.kyriakides@yale.ed [Vascular Biology and Therapeutics Program, Departments of Pathology and Biomedical Engineering, Yale University, New Haven, CT 06519 (United States)

    2009-02-15

    Thrombospondin (TSP)-2 is a matricellular protein that participates in the processes of tissue repair and the foreign body response. In addition, TSP2 has been shown to influence synaptogenesis and recovery of the brain following stroke. In the present study we investigated the response following the implantation of polyvinyl alcohol (PVA) sponges in the brain. PVA sponges were implanted into the brain cortex of wild type and TSP2-null mice for a period of 4 and 8 weeks and the response was analyzed by histochemistry and quantitative immunohistochemistry. TSP2 expression was detected in the interstices of the sponge and co-localized with the extracellular matrix and astrocytes. PVA sponge invasion in TSP2-null mice was characterized by dense deposition of extracellular matrix and increased invasion of reactive astrocytes and macrophages/microglia. Furthermore, the angiogenic response was elevated and the detection of mouse serum albumin (MSA) in the brain cortex indicated excessive vessel leakage, suggesting that TSP2 plays a role in the repair/maintenance of the blood brain barrier. Finally, immunostaining demonstrated an increase in the levels of matrix metalloproteinase (MMP)-2 and MMP-9. Taken together, our observations support a role for TSP2 as critical determinant of the brain response to biomaterials.

  11. Long-range correlation properties in timing of skilled piano performance: the influence of auditory feedback and deep brain stimulation.

    Directory of Open Access Journals (Sweden)

    Maria eHerrojo Ruiz

    2014-09-01

    Full Text Available Unintentional timing deviations during musical performance can be conceived of as timing errors. However, recent research on humanizing computer-generated music has demonstrated that timing fluctuations that exhibit long-range temporal correlations (LRTC are preferred by human listeners. This preference can be accounted for by the ubiquitous presence of LRTC in human tapping and rhythmic performances. Interestingly, the manifestation of LRTC in tapping behavior seems to be driven in a subject-specific manner by the LRTC properties of resting-state background cortical oscillatory activity. In this framework, the current study aimed to investigate whether propagation of timing deviations during the skilled, memorized piano performance (without metronome of 17 professional pianists exhibits LRTC and whether the structure of the correlations is influenced by the presence or absence of auditory feedback.As an additional goal, we set out to investigate the influence of altering the dynamics along the cortico-basal-ganglia-thalamo-cortical network via deep brain stimulation (DBS on the LRTC properties of musical performance. Specifically, we investigated temporal deviations during the skilled piano performance of a non-professional pianist who was treated with subthalamic-deep brain stimulation (STN-DBS due to severe Parkinson's disease, with predominant tremor affecting his right upper extremity. In the tremor-affected right hand, the timing fluctuations of the performance exhibited random correlations with DBS OFF. By contrast, DBS restored long-range dependency in the temporal fluctuations, corresponding with the general motor improvement on DBS.Overall, the present investigations are the first to demonstrate the presence of LRTC in skilled piano performances, indicating that unintentional temporal deviations are correlated over a wide range of time scales. This phenomenon is stable after removal of the auditory feedback, but is altered by STN

  12. Long-range correlation properties in timing of skilled piano performance: the influence of auditory feedback and deep brain stimulation.

    Science.gov (United States)

    Herrojo Ruiz, María; Hong, Sang Bin; Hennig, Holger; Altenmüller, Eckart; Kühn, Andrea A

    2014-01-01

    Unintentional timing deviations during musical performance can be conceived of as timing errors. However, recent research on humanizing computer-generated music has demonstrated that timing fluctuations that exhibit long-range temporal correlations (LRTC) are preferred by human listeners. This preference can be accounted for by the ubiquitous presence of LRTC in human tapping and rhythmic performances. Interestingly, the manifestation of LRTC in tapping behavior seems to be driven in a subject-specific manner by the LRTC properties of resting-state background cortical oscillatory activity. In this framework, the current study aimed to investigate whether propagation of timing deviations during the skilled, memorized piano performance (without metronome) of 17 professional pianists exhibits LRTC and whether the structure of the correlations is influenced by the presence or absence of auditory feedback. As an additional goal, we set out to investigate the influence of altering the dynamics along the cortico-basal-ganglia-thalamo-cortical network via deep brain stimulation (DBS) on the LRTC properties of musical performance. Specifically, we investigated temporal deviations during the skilled piano performance of a non-professional pianist who was treated with subthalamic-deep brain stimulation (STN-DBS) due to severe Parkinson's disease, with predominant tremor affecting his right upper extremity. In the tremor-affected right hand, the timing fluctuations of the performance exhibited random correlations with DBS OFF. By contrast, DBS restored long-range dependency in the temporal fluctuations, corresponding with the general motor improvement on DBS. Overall, the present investigations demonstrate the presence of LRTC in skilled piano performances, indicating that unintentional temporal deviations are correlated over a wide range of time scales. This phenomenon is stable after removal of the auditory feedback, but is altered by STN-DBS, which suggests that cortico

  13. Isolation, cultivation and identification of brain glioma stem cells by magnetic bead sorting

    Institute of Scientific and Technical Information of China (English)

    Xiuping Zhou; Chao Zheng; Qiong Shi; Xiang Li; Zhigang Shen; Rutong Yu

    2012-01-01

    This study describes a detailed process for obtaining brain glioma stem cells from freshly dissected human brain glioma samples using an immunomagnetic bead technique combined with serum-free media pressure screening. Furthermore, the proliferation, differentiation and self-renewal biological features of brain glioma stem cells were identified. Results showed that a small number of CD133 positive tumor cells isolated from brain glioma samples survived as a cell suspension in serum-free media and proliferated. Subcultured CD133 positive cells maintained a potent self-renewal and proliferative ability, and expressed the stem cell-specific markers CD133 and nestin. After incubation with fetal bovine serum, the number of glial fibrillary acidic protein and microtubule associated protein 2 positive cells increased significantly, indicating that the cultured brain glioma stem cells can differentiate into astrocytes and neurons. Western blot analysis showed that tumor suppressor phosphatase and tensin homolog was highly expressed in tumor spheres compared with the differentiated tumor cells. These experimental findings indicate that the immunomagnetic beads technique is a useful method to obtain brain glioma stem cells from human brain tumors.

  14. Are human dental papilla-derived stem cell and human brain-derived neural stem cell transplantations suitable for treatment of Parkinson's disease?

    Institute of Scientific and Technical Information of China (English)

    Hyung Ho Yoon; Joongkee Min; Nari Shin; Yong Hwan Kim; Jin-Mo Kim; Yu-Shik Hwang; Jun-Kyo Francis Suh; Onyou Hwang; Sang Ryong Jeon

    2013-01-01

    Transplantation of neural stem cells has been reported as a possible approach for replacing impaired dopaminergic neurons. In this study, we tested the efficacy of early-stage human dental papilla-derived stem cells and human brain-derived neural stem cells in rat models of 6-hydroxydopamine-induced Parkinson's disease. Rats received a unilateral injection of 6-hydroxydopamine into right medial forebrain bundle, followed 3 weeks later by injections of PBS, early-stage human dental papilla-derived stem cells, or human brain-derived neural stem cells into the ipsilateral striatum. All of the rats in the human dental papilla-derived stem cell group died from tumor formation at around 2 weeks following cell transplantation. Postmortem examinations revealed homogeneous malignant tumors in the striatum of the human dental papilla-derived stem cell group. Stepping tests revealed that human brain-derived neural stem cell transplantation did not improve motor dysfunction. In apomorphine-induced rotation tests, neither the human brain-derived neural stem cell group nor the control groups (PBS injection) demonstrated significant changes. Glucose metabolism in the lesioned side of striatum was reduced by human brain-derived neural stem cell transplantation. [18 F]-FP-CIT PET scans in the striatum did not demonstrate a significant increase in the human brain-derived neural stem cell group. Tyrosine hydroxylase (dopaminergic neuronal marker) staining and G protein-activated inward rectifier potassium channel 2 (A9 dopaminergic neuronal marker) were positive in the lesioned side of striatum in the human brain-derived neural stem cell group. The use of early-stage human dental papilla-derived stem cells confirmed its tendency to form tumors. Human brain-derived neural stem cells could be partially differentiated into dopaminergic neurons, but they did not secrete dopamine.

  15. Is there a relationship between brain-derived neurotrophic factor for driving neuronal auditory circuits with onset of auditory function and the changes following cochlear injury or during aging?

    Science.gov (United States)

    Schimmang, T; Durán Alonso, B; Zimmermann, U; Knipper, M

    2014-12-26

    Brain-derived neurotrophic factor, BDNF, is one of the most important neurotrophic factors acting in the peripheral and central nervous system. In the auditory system its function was initially defined by using constitutive knockout mouse mutants and shown to be essential for survival of neurons and afferent innervation of hair cells in the peripheral auditory system. Further examination of BDNF null mutants also revealed a more complex requirement during re-innervation processes involving the efferent system of the cochlea. Using adult mouse mutants defective in BDNF signaling, it could be shown that a tonotopical gradient of BDNF expression within cochlear neurons is required for maintenance of a specific spatial innervation pattern of outer hair cells and inner hair cells. Additionally, BDNF is required for maintenance of voltage-gated potassium channels (KV) in cochlear neurons, which may form part of a maturation step within the ascending auditory pathway with onset of hearing and might be essential for cortical acuity of sound-processing and experience-dependent plasticity. A presumptive harmful role of BDNF during acoustic trauma and consequences of a loss of cochlear BDNF during aging are discussed in the context of a partial reversion of this maturation step. We compare the potentially beneficial and harmful roles of BDNF for the mature auditory system with those BDNF functions known in other sensory circuits, such as the vestibular, visual, olfactory, or somatosensory system. PMID:25064058

  16. Radiation control in the intensive care unit for high intensity iridium-192 brain implants

    International Nuclear Information System (INIS)

    A bedside lead cubicle was designed to minimize the radiation exposure of intensive care unit staff during routine interstitial brain irradiation by removable, high intensity iridium-192. The cubicle shields the patient without restricting intensive care routines. The design specifications were confirmed by exposure measurements around the shield with an implanted anthropomorphic phantom simulating the patient situation. The cubicle reduces the exposure rate around an implant patient by as much as 90%, with the exposure level not exceeding 0.1 mR/hour/mg of radium-equivalent 192Ir. Evaluation of data accumulated for the past 3 years has shown that the exposure levels of individual attending nurses are 0.12 to 0.36 mR/mg of radium-equivalent 192Ir per 12-hour shift. The corresponding range for entire nursing teams varies between 0.18 and 0.26. A radiation control index (exposure per mg of radium-equivalent 192Ir per nurse-hour) is thus defined for individual nurses and nursing teams; this index is a significant guide to the planning of nurse rotations for brain implant patients with various 192Ir loads. The bedside shield reduces exposure from 192Ir implants by a factor of about 20, as expected, and the exposure from the lower energy radioisotope iodine-125 is barely detectable

  17. Cyclosporin safety in a simplified rat brain tumor implantation model

    Directory of Open Access Journals (Sweden)

    Francisco H. C. Felix

    2012-01-01

    Full Text Available Brain cancer is the second neurological cause of death. A simplified animal brain tumor model using W256 (carcinoma 256, Walker cell line was developed to permit the testing of novel treatment modalities. Wistar rats had a cell tumor solution inoculated stereotactically in the basal ganglia (right subfrontal caudate. This model yielded tumor growth in 95% of the animals, and showed absence of extracranial metastasis and systemic infection. Survival median was 10 days. Estimated tumor volume was 17.08±6.7 mm³ on the 7th day and 67.25±19.8 mm³ on 9th day post-inoculation. Doubling time was 24.25 h. Tumor growth induced cachexia, but no hematological or biochemical alterations. This model behaved as an undifferentiated tumor and can be promising for studying tumor cell migration in the central nervous system. Dexamethasone 3.0 mg/kg/day diminished significantly survival in this model. Cyclosporine 10 mg/kg/day administration was safely tolerated.

  18. Further in-vitro characterization of an implantable biosensor for ethanol monitoring in the brain

    OpenAIRE

    Secchi, Ottavio; Zinellu, Manuel; Spissu, Ylenia; Pirisinu, Marco; Bazzu, Gianfranco; Migheli, Rossana; Desole, Maria Speranza; O'Neill, Robert D.; Serra, Pier Andrea; Rocchitta, Gaia Giovanna Maria

    2013-01-01

    Ethyl alcohol may be considered one of the most widespread central nervous system (CNS) depressants in Western countries. Because of its toxicological and neurobiological implications, the detection of ethanol in brain extracellular fluid (ECF) is of great importance. In a previous study, we described the development and characterization of an implantable biosensor successfully used for the real-time detection of ethanol in the brain of freely-moving rats. The implanted biosensor, integrated ...

  19. Neural stem cells harvested from live brains by antibody-conjugated magnetic nanoparticles.

    Science.gov (United States)

    Lui, C N P; Tsui, Y P; Ho, A S L; Shum, D K Y; Chan, Y S; Wu, C T; Li, H W; Tsang, S C Edman; Yung, K K L

    2013-11-18

    It stems from the magnetism: The extraction of stem/progenitor cells from the brain of live animals is possible using antibodies conjugated to magnetic nanoparticles (Ab-MNPs). The Ab-MNPs are introduced to a rat's brain with a superfine micro-syringe. The stem cells attach to the Ab-MNPs and are magnetically isolated and removed. They can develop into neurospheres and differentiate into different types of cells outside the subject body. The rat remains alive and healthy. PMID:24108547

  20. SU-E-T-570: Management of Radiation Oncology Patients with Cochlear Implant and Other Bionic Devices in the Brain and Head and Neck Regions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, F.Q; Chen, Z; Nath, R [Yale New Haven Hospital, New Haven, CT (United States); Yale UniversitySchool of Medicine, New Haven, CT (United States)

    2014-06-01

    Purpose: To investigate the current status of clinical usage of cochlear implant (CI) and other bionic devices (BD) in the brain and head and neck regions (BH and N) and their management in patients during radiotherapy to ensure patient health and safety as well as optimum radiation delivery. Methods: Literature review was performed with both CIs and radiotherapy and their variants as keywords in PubMed, INSPEC and other sources. The focus was on CIs during radiotherapy, but it also included other BDs in BHȦN, such as auditory brainstem implant, bionic retinal implant, and hearing aids, among others. Results: Interactions between CIs and radiation may cause CIs malfunction. The presence of CIs may also cause suboptimum dose distribution if a treatment plan was not well designed. A few studies were performed for the hearing functions of CIs under irradiations of 4 MV and 6 MV x-rays. However, x-rays with higher energies (10 to 18 MV) broadly used in radiotherapy have not been explored. These higher energetic beams are more damaging to electronics due to strong penetrating power and also due to neutrons generated in the treatment process. Modern CIs are designed with more and more complicated integrated circuits, which may be more susceptible to radiation damage and malfunction. Therefore, careful management is important for safety and treatment outcomes. Conclusion: Although AAPM TG-34, TG-63, and TG-203 (update of TG-34, not published yet) reports may be referenced for management of CIs and other BDs in the brain and H and N regions, a site- and device-specified guideline should be developed for CIs and other BDs. Additional evaluation of CI functions under clinically relevant set-ups should also be performed to provide clinicians with better knowledge in clinical decision making.

  1. SU-E-T-570: Management of Radiation Oncology Patients with Cochlear Implant and Other Bionic Devices in the Brain and Head and Neck Regions

    International Nuclear Information System (INIS)

    Purpose: To investigate the current status of clinical usage of cochlear implant (CI) and other bionic devices (BD) in the brain and head and neck regions (BH and N) and their management in patients during radiotherapy to ensure patient health and safety as well as optimum radiation delivery. Methods: Literature review was performed with both CIs and radiotherapy and their variants as keywords in PubMed, INSPEC and other sources. The focus was on CIs during radiotherapy, but it also included other BDs in BHȦN, such as auditory brainstem implant, bionic retinal implant, and hearing aids, among others. Results: Interactions between CIs and radiation may cause CIs malfunction. The presence of CIs may also cause suboptimum dose distribution if a treatment plan was not well designed. A few studies were performed for the hearing functions of CIs under irradiations of 4 MV and 6 MV x-rays. However, x-rays with higher energies (10 to 18 MV) broadly used in radiotherapy have not been explored. These higher energetic beams are more damaging to electronics due to strong penetrating power and also due to neutrons generated in the treatment process. Modern CIs are designed with more and more complicated integrated circuits, which may be more susceptible to radiation damage and malfunction. Therefore, careful management is important for safety and treatment outcomes. Conclusion: Although AAPM TG-34, TG-63, and TG-203 (update of TG-34, not published yet) reports may be referenced for management of CIs and other BDs in the brain and H and N regions, a site- and device-specified guideline should be developed for CIs and other BDs. Additional evaluation of CI functions under clinically relevant set-ups should also be performed to provide clinicians with better knowledge in clinical decision making

  2. Amplification of neural stem cell proliferation by intermediate progenitor cells in Drosophila brain development

    Directory of Open Access Journals (Sweden)

    Bello Bruno C

    2008-02-01

    Full Text Available Abstract Background In the mammalian brain, neural stem cells divide asymmetrically and often amplify the number of progeny they generate via symmetrically dividing intermediate progenitors. Here we investigate whether specific neural stem cell-like neuroblasts in the brain of Drosophila might also amplify neuronal proliferation by generating symmetrically dividing intermediate progenitors. Results Cell lineage-tracing and genetic marker analysis show that remarkably large neuroblast lineages exist in the dorsomedial larval brain of Drosophila. These lineages are generated by brain neuroblasts that divide asymmetrically to self renew but, unlike other brain neuroblasts, do not segregate the differentiating cell fate determinant Prospero to their smaller daughter cells. These daughter cells continue to express neuroblast-specific molecular markers and divide repeatedly to produce neural progeny, demonstrating that they are proliferating intermediate progenitors. The proliferative divisions of these intermediate progenitors have novel cellular and molecular features; they are morphologically symmetrical, but molecularly asymmetrical in that key differentiating cell fate determinants are segregated into only one of the two daughter cells. Conclusion Our findings provide cellular and molecular evidence for a new mode of neurogenesis in the larval brain of Drosophila that involves the amplification of neuroblast proliferation through intermediate progenitors. This type of neurogenesis bears remarkable similarities to neurogenesis in the mammalian brain, where neural stem cells as primary progenitors amplify the number of progeny they generate through generation of secondary progenitors. This suggests that key aspects of neural stem cell biology might be conserved in brain development of insects and mammals.

  3. Instrument specific brain activation in sensorimotor and auditory representation in musicians.

    Science.gov (United States)

    Gebel, B; Braun, Ch; Kaza, E; Altenmüller, E; Lotze, M

    2013-07-01

    Musicians show a remarkable ability to interconnect motor patterns and sensory processing in the somatosensory and auditory domains. Many of these processes are specific for the instrument used. We were interested in the cerebral and cerebellar representations of these instrument-specific changes and therefore applied functional magnetic resonance imaging (fMRI) in two groups of instrumentalists with different instrumental training for comparable periods (approximately 15 years). The first group (trumpet players) uses tight finger and lip interaction; the second (pianists as control group) uses only the extremities for performance. fMRI tasks were balanced for instructions (piano and trumpet notes), sensory feedback (keypad and trumpet), and hand-lip interaction on the trumpet. During fMRI, both groups switched between different devices (trumpet or keypad) and performance was combined with or without auditory feedback. Playing the trumpet without any tone emission or using the mouthpiece showed an instrument training-specific activation increase in trumpet players. This was evident for the posterior-superior cerebellar hemisphere, the dominant primary sensorimotor cortex, and the left Heschl's gyrus. Additionally, trumpet players showed increased activity in the bilateral Heschl's gyrus during actual trumpet playing, although they showed significantly decreased loudness while playing with the mouthpiece in the scanner compared to pianists. PMID:23454048

  4. A critical review of cell culture strategies for modelling intracortical brain implant material reactions.

    Science.gov (United States)

    Gilmour, A D; Woolley, A J; Poole-Warren, L A; Thomson, C E; Green, R A

    2016-06-01

    The capacity to predict in vivo responses to medical devices in humans currently relies greatly on implantation in animal models. Researchers have been striving to develop in vitro techniques that can overcome the limitations associated with in vivo approaches. This review focuses on a critical analysis of the major in vitro strategies being utilized in laboratories around the world to improve understanding of the biological performance of intracortical, brain-implanted microdevices. Of particular interest to the current review are in vitro models for studying cell responses to penetrating intracortical devices and their materials, such as electrode arrays used for brain computer interface (BCI) and deep brain stimulation electrode probes implanted through the cortex. A background on the neural interface challenge is presented, followed by discussion of relevant in vitro culture strategies and their advantages and disadvantages. Future development of 2D culture models that exhibit developmental changes capable of mimicking normal, postnatal development will form the basis for more complex accurate predictive models in the future. Although not within the scope of this review, innovations in 3D scaffold technologies and microfluidic constructs will further improve the utility of in vitro approaches. PMID:26994876

  5. Stem cells modified by brain-derived neurotrophic fac-tor to promote stem cells differentiation into neurons and enhance neuromotor function after brain injury

    Institute of Scientific and Technical Information of China (English)

    ZHANG Sai; LIU Xiao-zhi; LIU Zhen-lin; WANG Yan-min; HU Qun-liang; MA Tie-zhu; SUN Shi-zhong

    2009-01-01

    Objective: To promote stem cells differentiation into neurons and enhance neuromotor function after brain in-jury through brain-derived neurotrophic factor (BDNF) induction.Methods: Recombinant adenovirus vector was ap-plied to the transfection of BDNF into human-derived um-bilical cord mesenchymal stem cells (UCMSCs). Enzyme linked immunosorbent assay (ELISA) was used to deter-mine the secretion phase of BDNF. The brain injury model of athymic mice induced by hydraulic pressure percussion was established for transplantation of stem cells into the edge of injury site. Nerve function scores were obtained, and the expression level of transfected and non-transfected BDNF, proportion of neuron specific enolase (NSE) andglial fibrillary acidic protein (GFAP), and the number of apoptosis cells were compared respectively. Results: The BDNF expression achieved its stabiliza-tion at a high level 72 hours after gene transfection. The mouse obtained a better score of nerve function, and the proportion of the NSE-positive cells increased significantly (P<0.05), but GFAP-positive cells decreased in BDNF-UCMSCs group compared with the other two groups (P<0.05). At the site of high expression of BDNF, the number of apoptosis cells decreased markedly.Conclusion: BDNF gene can promote the differentia-tion of the stem cells into neurons rather than gliai cells, and enhance neuromotor function after brain injury.

  6. Stem cell-based therapies for tumors in the brain: are we there yet?

    Science.gov (United States)

    Shah, Khalid

    2016-08-01

    Advances in understanding adult stem cell biology have facilitated the development of novel cell-based therapies for cancer. Recent developments in conventional therapies (eg, tumor resection techniques, chemotherapy strategies, and radiation therapy) for treating both metastatic and primary tumors in the brain, particularly glioblastoma have not resulted in a marked increase in patient survival. Preclinical studies have shown that multiple stem cell types exhibit inherent tropism and migrate to the sites of malignancy. Recent studies have validated the feasibility potential of using engineered stem cells as therapeutic agents to target and eliminate malignant tumor cells in the brain. This review will discuss the recent progress in the therapeutic potential of stem cells for tumors in the brain and also provide perspectives for future preclinical studies and clinical translation. PMID:27282399

  7. Characterization of TLX Expression in Neural Stem Cells and Progenitor Cells in Adult Brains

    OpenAIRE

    Shengxiu Li; Guoqiang Sun; Kiyohito Murai; Peng Ye; Yanhong Shi

    2012-01-01

    TLX has been shown to play an important role in regulating the self-renewal and proliferation of neural stem cells in adult brains. However, the cellular distribution of endogenous TLX protein in adult brains remains to be elucidated. In this study, we used immunostaining with a TLX-specific antibody to show that TLX is expressed in both neural stem cells and transit-amplifying neural progenitor cells in the subventricular zone (SVZ) of adult mouse brains. Then, using a double thymidine analo...

  8. Are there fetal stem cells in the maternal brain?☆

    OpenAIRE

    DEMIRHAN, OSMAN; Çekin, Necmi; Taştemir, Deniz; Tunç, Erdal; Güzel, Ali İrfan; Meral, Demet; Demirbek, Bülent

    2013-01-01

    Fetal cells can enter maternal blood during pregnancy but whether they can also cross the blood-brain barrier to enter the maternal brain remains poorly understood. Previous results suggest that fetal cells are summoned to repair damage to the mother's brain. If this is confirmed, it would open up new and safer avenues of treatment for brain damage caused by strokes and neural diseases. In this study, we aimed to investigate whether a baby's stem cells can enter the maternal brain during preg...

  9. A Cochlear Implant Performance Prognostic Test Based on Electrical Field Interactions Evaluated by eABR (Electrical Auditory Brainstem Responses)

    OpenAIRE

    Guevara, Nicolas; Hoen, Michel; Truy, Eric; Gallego, Stéphane

    2016-01-01

    Background Cochlear implants (CIs) are neural prostheses that have been used routinely in the clinic over the past 25 years. They allow children who were born profoundly deaf, as well as adults affected by hearing loss for whom conventional hearing aids are insufficient, to attain a functional level of hearing. The “modern” CI (i.e., a multi-electrode implant using sequential coding strategies) has yielded good speech comprehension outcomes (recognition level for monosyllabic words about 50% ...

  10. Implantation of Miniosmotic Pumps and Delivery of Tract Tracers to Study Brain Reorganization in Pathophysiological Conditions.

    Science.gov (United States)

    Sanchez-Mendoza, Eduardo H; Carballo, Jeismar; Longart, Marines; Hermann, Dirk M; Doeppner, Thorsten R

    2016-01-01

    Pharmacological treatment in animal models of cerebral disease imposes the problem of repeated injection protocols that may induce stress in animals and result in impermanent tissue levels of the drug. Additionally, drug delivery to the brain is delicate due to the blood brain barrier (BBB), thus significantly reducing intracerebral concentrations of selective drugs after systemic administration. Therefore, a system that allows both constant drug delivery without peak levels and circumvention of the BBB is in order to achieve sufficiently high intracerebral concentrations of drugs that are impermeable to the BBB. In this context, miniosmotic pumps represent an ideal system for constant drug delivery at a fixed known rate that eludes the problem of daily injection stress in animals and that may also be used for direct brain delivery of drugs. Here, we describe a method for miniosmotic pump implantation and post operatory care that should be given to animals in order to successfully apply this technique. We embed the aforementioned experimental paradigm in standard procedures that are used for studying neuroplasticity within the brain of C57BL6 mice. Thus, we exposed animals to 30 min brain infarct and implanted with miniosmotic pumps connected to the skull via a cannula in order to deliver a pro-plasticity drug. Behavioral testing was done during 30 days of treatment. After removal the animals received injections of anterograde tract tracers to analyze neuronal plasticity in the chronic phase of recovery. Results indicated that neuroprotection by the delivered drug was accompanied with increase in motor fibers crossing the midline of the brain at target structures. The results affirm the value of these techniques for drug administration and brain plasticity studies in modern neuroscience. PMID:26863287

  11. Expression of c-jun in brain stem following moderate lateral fluid percussion brain injury in rats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AIM: To study the expression of c-jun in brain stem following moderate lateral fluid percussion brain injury in rats, and to observe the temporal patterns of its expressions following percussion.METHODS: Male Sprague-Dawley rats were divided into normal control, sham operation control and injury groups. The rats of injury group subjected to moderate lateral fluid percussion injury (0.2 mPa), and then were subdivided into 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h and 12 h groups according to the time elapsed after injury. The expression of c-jun was studied by immunohistochemistry and in situ hybridization. RESULTS: After percussion for 15 min, Jun positive neurons increased in brain stem progressively, and peaked at 12h. At 5min after percussion, the induction of c-jun mRNA was increased, and remained elevated up to 1h-2h after brain injury. CONCLUSION: The induction and expression of the c-jun in brain stem after fluid percussion brain injury were increased rapidly and lasted for a long time.

  12. Implantable tissue-engineered blood vessels from human induced pluripotent stem cells.

    Science.gov (United States)

    Gui, Liqiong; Dash, Biraja C; Luo, Jiesi; Qin, Lingfeng; Zhao, Liping; Yamamoto, Kota; Hashimoto, Takuya; Wu, Hongwei; Dardik, Alan; Tellides, George; Niklason, Laura E; Qyang, Yibing

    2016-09-01

    Derivation of functional vascular smooth muscle cells (VSMCs) from human induced pluripotent stem cells (hiPSCs) to generate tissue-engineered blood vessels (TEBVs) holds great potential in treating patients with vascular diseases. Herein, hiPSCs were differentiated into alpha-smooth muscle actin (α-SMA) and calponin-positive VSMCs, which were seeded onto polymer scaffolds in bioreactors for vascular tissue growth. A functional TEBV with abundant collagenous matrix and sound mechanics resulted, which contained cells largely positive for α-SMA and smooth muscle myosin heavy chain (SM-MHC). Moreover, when hiPSC-derived TEBV segments were implanted into nude rats as abdominal aorta interposition grafts, they remained unruptured and patent with active vascular remodeling, and showed no evidence of teratoma formation during a 2-week proof-of-principle study. Our studies represent the development of the first implantable TEBVs based on hiPSCs, and pave the way for developing autologous or allogeneic grafts for clinical use in patients with vascular disease. PMID:27336184

  13. Mesenchymal stem cell interaction with ultra-smooth nanostructured diamond for wear-resistant orthopaedic implants.

    Science.gov (United States)

    Clem, William C; Chowdhury, Shafiul; Catledge, Shane A; Weimer, Jeffrey J; Shaikh, Faheem M; Hennessy, Kristin M; Konovalov, Valery V; Hill, Michael R; Waterfeld, Alfred; Bellis, Susan L; Vohra, Yogesh K

    2008-01-01

    Ultra-smooth nanostructured diamond (USND) can be applied to greatly increase the wear resistance of orthopaedic implants over conventional designs. Herein we describe surface modification techniques and cytocompatibility studies performed on this new material. We report that hydrogen (H)-terminated USND surfaces supported robust mesenchymal stem cell (MSC) adhesion and survival, while oxygen- (O) and fluorine (F)-terminated surfaces resisted cell adhesion, indicating that USND can be modified to either promote or prevent cell/biomaterial interactions. Given the favorable cell response to H-terminated USND, this material was further compared with two commonly used biocompatible metals, titanium alloy (Ti-6Al-4V) and cobalt chrome (CoCrMo). MSC adhesion and proliferation were significantly improved on USND compared with CoCrMo, although cell adhesion was greatest on Ti-6Al-4V. Comparable amounts of the pro-adhesive protein, fibronectin, were deposited from serum on the three substrates. Finally, MSCs were induced to undergo osteoblastic differentiation on the three materials, and deposition of a mineralized matrix was quantified. Similar amounts of mineral were deposited onto USND and CoCrMo, whereas mineral deposition was slightly higher on Ti-6Al-4V. When coupled with recently published wear studies, these in vitro results suggest that USND has the potential to reduce debris particle release from orthopaedic implants without compromising osseointegration. PMID:18490051

  14. [Central auditory prosthesis].

    Science.gov (United States)

    Lenarz, T; Lim, H; Joseph, G; Reuter, G; Lenarz, M

    2009-06-01

    Deaf patients with severe sensory hearing loss can benefit from a cochlear implant (CI), which stimulates the auditory nerve fibers. However, patients who do not have an intact auditory nerve cannot benefit from a CI. The majority of these patients are neurofibromatosis type 2 (NF2) patients who developed neural deafness due to growth or surgical removal of a bilateral acoustic neuroma. The only current solution is the auditory brainstem implant (ABI), which stimulates the surface of the cochlear nucleus in the brainstem. Although the ABI provides improvement in environmental awareness and lip-reading capabilities, only a few NF2 patients have achieved some limited open set speech perception. In the search for alternative procedures our research group in collaboration with Cochlear Ltd. (Australia) developed a human prototype auditory midbrain implant (AMI), which is designed to electrically stimulate the inferior colliculus (IC). The IC has the potential as a new target for an auditory prosthesis as it provides access to neural projections necessary for speech perception as well as a systematic map of spectral information. In this paper the present status of research and development in the field of central auditory prostheses is presented with respect to technology, surgical technique and hearing results as well as the background concepts of ABI and AMI. PMID:19517084

  15. Cancer Stem Cells in Brain Tumors and Their Lineage Hierarchy

    OpenAIRE

    Kong, Doo-Sik

    2012-01-01

    Despite recent advances in the development of novel targeted chemotherapies, the prognosis of malignant glioma remains dismal. The chemo-resistance of this tumor is attributed to tumor heterogeneity. To explain this unique chemo- resistance, the concept of cancer stem cells has been evoked. Cancer stem cells, a subpopulation of whole tumor cells, are now regarded as candidate therapeutic targets. Here, the author reviews and discusses the cancer stem cell concept.

  16. Auditory imagery: empirical findings.

    Science.gov (United States)

    Hubbard, Timothy L

    2010-03-01

    The empirical literature on auditory imagery is reviewed. Data on (a) imagery for auditory features (pitch, timbre, loudness), (b) imagery for complex nonverbal auditory stimuli (musical contour, melody, harmony, tempo, notational audiation, environmental sounds), (c) imagery for verbal stimuli (speech, text, in dreams, interior monologue), (d) auditory imagery's relationship to perception and memory (detection, encoding, recall, mnemonic properties, phonological loop), and (e) individual differences in auditory imagery (in vividness, musical ability and experience, synesthesia, musical hallucinosis, schizophrenia, amusia) are considered. It is concluded that auditory imagery (a) preserves many structural and temporal properties of auditory stimuli, (b) can facilitate auditory discrimination but interfere with auditory detection, (c) involves many of the same brain areas as auditory perception, (d) is often but not necessarily influenced by subvocalization, (e) involves semantically interpreted information and expectancies, (f) involves depictive components and descriptive components, (g) can function as a mnemonic but is distinct from rehearsal, and (h) is related to musical ability and experience (although the mechanisms of that relationship are not clear). PMID:20192565

  17. Spatially Controlled Delivery of siRNAs to Stem Cells in Implants Generated by Multi-Component Additive Manufacturing

    DEFF Research Database (Denmark)

    Andersen, Morten Østergaard; Le, Dang Quang Svend; Chen, Muwan;

    2013-01-01

    Additive manufacturing is a promising technique in tissue engineering, as it enables truly individualized implants to be made to fit a particular defect. As previously shown, a feasible strategy to produce complex multicellular tissues is to deposit different small interfering RNA (siRNA) in porous...... implants that are subsequently sutured together. In this study, an additive manufacturing strategy to deposit carbohydrate hydrogels containing different siRNAs is applied into an implant, in a spatially controlled manner. When the obtained structures are seeded with mesenchymal stem (stromal) cells, the...... selected siRNAs are delivered to the cells and induces specific and localized gene silencing. Here, it is demonstrated how to replicate part of a patient's spinal cord from a computed tomography scan, using an additive manufacturing technique to produce an implant with compartmentalized siRNAs in the...

  18. Electrochemical behavior and biological response of Mesenchymal Stem Cells on cp-Ti after N-ions implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rizwan, M.; Ahmad, A. [Department of Metallurgical and Materials Engineering, University of Engineering and Technology, 54890 Lahore (Pakistan); Deen, K.M. [Corrosion Control Research Cell, Department of Metallurgy and Materials Engineering, CEET, University of the Punjab, 54590 Lahore (Pakistan); Haider, W., E-mail: haiderw@utpa.edu [Mechanical Engineering Department, University of Texas Pan American, Edinburg, TX 78539 (United States)

    2014-11-30

    Highlights: • Nitrogen ions of known dosage were implanted on cp-Ti. • Increase in surface roughness with increase in ions dose was confirmed by AFM. • TiN{sub 0.3} and Ti{sub 3}N{sub 2−x} nitride phases were formed and validated by XRD. • The ions implantation reduced the corrosion rate and stabilized the passive film. • Surface roughness greatly affected the morphology and growth of Mesenchymal Stem Cells. - Abstract: Titanium and its alloys are most widely used as implant materials due to their excellent biocompatibility, mechanical properties and chemical stability. In this study Nitrogen ions of known dosage were implanted over cp-Ti by Pelletron accelerator with beam energy of 0.25 MeV.The atomic force microscopy of bare and nitrogen implanted specimens confirmed increase in surface roughness with increase in nitrogen ions concentration. X-ray diffraction patterns of ions implanted surfaces validated the formation of TiN{sub 0.3} and Ti{sub 3}N{sub 2-x}nitride phases. The tendency to form passive film and electrochemical behavior of these surfaces in ringer lactate (RL) solution was evaluated by Potentiodynamic polarization and electrochemical impedance spectroscopy respectively. It is proved that nitrogen ions implantation was beneficial to reduce corrosion rate and stabilizing passive film by increasing charge transfer resistance in RL. It was concluded that morphology and proliferation of Mesenchymal Stem Cells on nitrogen ions implanted surfaces strongly depends on surface roughness and nitride phases.

  19. MR imaging features of gadofluorine-labeled matrix-associated stem cell implants in cartilage defects.

    Directory of Open Access Journals (Sweden)

    Hossein Nejadnik

    Full Text Available OBJECTIVES: The purpose of our study was to assess the chondrogenic potential and the MR signal effects of GadofluorineM-Cy labeled matrix associated stem cell implants (MASI in pig knee specimen. MATERIALS AND METHODS: Human mesenchymal stem cells (hMSCs were labeled with the micelle-based contrast agent GadofluorineM-Cy. Ferucarbotran-labeled hMSCs, non-labeled hMSCs and scaffold only served as controls. Chondrogenic differentiation was induced and gene expression and histologic evaluation were performed. The proportions of spindle-shaped vs. round cells of chondrogenic pellets were compared between experimental groups using the Fisher's exact test. Labeled and unlabeled hMSCs and chondrocytes in scaffolds were implanted into cartilage defects of porcine femoral condyles and underwent MR imaging with T1- and T2-weighted SE and GE sequences. Contrast-to-noise ratios (CNR between implants and adjacent cartilage were determined and analyzed for significant differences between different experimental groups using the Kruskal-Wallis test. Significance was assigned for p0.017. However, hMSC differentiation into chondrocytes was superior for unlabeled and GadofluorineM-Cy-labeled cells compared with Ferucarbotran-labeled cells, as evidenced by a significantly higher proportion of spindle cells in chondrogenic pellets (p<0.05. GadofluorineM-Cy-labeled hMSCs and chondrocytes showed a positive signal effect on T1-weighted images and a negative signal effect on T2-weighted images while Ferucarbotran-labeled cells provided a negative signal effect on all sequences. CNR data for both GadofluorineM-Cy-labeled and Ferucarbotran-labeled hMSCs were significantly different compared to unlabeled control cells on T1-weighted SE and T2*-weighted MR images (p<0.017. CONCLUSION: hMSCs can be labeled by simple incubation with GadofluorineM-Cy. The labeled cells provide significant MR signal effects and less impaired chondrogenesis compared to Ferucarbotran-labeled h

  20. The preventive effects of neural stem cells and mesenchymal stem cells intra-ventricular injection on brain stroke in rats

    Directory of Open Access Journals (Sweden)

    Seyed Mojtaba Hosseini

    2015-01-01

    Full Text Available Introduction: Stroke is one of the most important causes of disability in developed countries and, unfortunately, there is no effective treatment for this major problem of central nervous system (CNS; cell therapy may be helpful to recover this disease. In some conditions such as cardiac surgeries and neurosurgeries, there are some possibilities of happening brain stroke. Inflammation of CNS plays an important role in stroke pathogenesis, in addition, apoptosis and neural death could be the other reasons of poor neurological out come after stroke. In this study, we examined the preventive effects of the neural stem cells (NSCs and mesenchymal stem cells (MSCs intra-ventricular injected on stroke in rats. Aim: The aim of this study was to investigate the preventive effects of neural and MSCs for stroke in rats. Materials and Methods: The MSCs were isolated by flashing the femurs and tibias of the male rats with appropriate media. The NSCs were isolated from rat embryo ganglion eminence and they cultured NSCs media till the neurospheres formed. Both NSCs and MSCs were labeled with PKH26-GL. One day before stroke, the cells were injected into lateral ventricle stereotactically. Results: During following for 28 days, the neurological scores indicated that there are better recoveries in the groups received stem cells and they had less lesion volume in their brain measured by hematoxylin and eosin staining. Furthermore, the activities of caspase-3 were lower in the stem cell received groups than control group and the florescent microscopy images showed that the stem cells migrated to various zones of the brains. Conclusion: Both NSCs and MSCs are capable of protecting the CNS against ischemia and they may be good ways to prevent brain stroke consequences situations.

  1. Stab injury and device implantation within the brain results in inversely multiphasic neuroinflammatory and neurodegenerative responses

    Science.gov (United States)

    Potter, Kelsey A.; Buck, Amy C.; Self, Wade K.; Capadona, Jeffrey R.

    2012-08-01

    An estimated 25 million people in the US alone rely on implanted medical devices, ˜2.5 million implanted within the nervous system. Even though many devices perform adequately for years, the host response to medical devices often severely limits tissue integration and long-term performance. This host response is believed to be particularly limiting in the case of intracortical microelectrodes, where it has been shown that glial cell encapsulation and localized neuronal cell loss accompany intracortical microelectrode implantation. Since neuronal ensembles must be within ˜50 µm of the electrode to obtain neuronal spikes and local field potentials, developing a better understanding of the molecular and cellular environment at the device-tissue interface has been the subject of significant research. Unfortunately, immunohistochemical studies of scar maturation in correlation to device function have been inconclusive. Therefore, here we present a detailed quantitative study of the cellular events and the stability of the blood-brain barrier (BBB) following intracortical microelectrode implantation and cortical stab injury in a chronic survival model. We found two distinctly inverse multiphasic profiles for neuronal survival in device-implanted tissue compared to stab-injured animals. For chronically implanted animals, we observed a biphasic paradigm between blood-derived/trauma-induced and CNS-derived inflammatory markers driving neurodegeneration at the interface. In contrast, stab injured animals demonstrated a CNS-mediated neurodegenerative environment. Collectively these data provide valuable insight to the possibility of multiple roles of chronic neuroinflammatory events on BBB disruption and localized neurodegeneration, while also suggesting the importance to consider multiphasic neuroinflammatory kinetics in the design of therapeutic strategies for stabilizing neural interfaces.

  2. Delayed radiation injury of brain stem after radiotherapy in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Objective: To study the clinical characteristics, MRI findings, diagnosis, treatment and prognostic factors of patients with radiation induced brain stem injury in nasopharyngeal carcinoma. Methods: From January 1991 to January 2001, 24 patients with radiation injury of brain stem were treated, 14 males and 10 females. The latency ranged from 6 to 38 months, with a median of 18 months. The lesions were located in the pons in 10 patients, mesencephalon + pons in 4, pons + medulla oblongata in 5, medulla oblongata in 2 and mesencephalon + pons + medulla oblongata in 3. MRI findings showed that the injury was chiefly presented as hypointensity foci on T1WI and hyperintensity foci on T2WI. Results: Eighteen patients were treated with dexamethasone in the early phase, with symptoms relieved in 12 patients but unimproved in 6 patients. Eight 44% patients died within the 8-38 months, leaving 16 patients surviving for 0.5 to 6.0 years. Conclusions: Radiation injury of brain stem has a short latency with severe symptoms, signifying poor prognosis. It is suggested that adequate reduction of irradiation volume and dose at the brain stem should be able to lower the incidence of brain stem injury

  3. Stereotactic iodine-125 brachytherapy for brain tumors: temporary versus permanent implantation

    International Nuclear Information System (INIS)

    Stereotactic brachytherapy (SBT) has been described in several publications as an effective, minimal invasive and safe highly focal treatment option in selected patients with well circumscribed brain tumors <4 cm. However, a still ongoing discussion about indications and technique is hindering the definition of a clear legitimation of SBT in modern brain tumor treatment. These controversies encompass the question of how intense the irradiation should be delivered into the target volume (dose rate). For instance, reports about the use of high does rate (HDR) implantation schemes (>40 cGy/h) in combination with adjuvant external beam radiation and/or chemotherapy for the treatment of malignant gliomas and metastases resulted in increased rates of radiation induced adverse tissue changes requiring surgical intervention. Vice versa, such effects have been only minimally observed in numerous studies applying low dose rate (LDR) regiments (3–8 cGy/h) for low grade gliomas, metastases and other rare indications. Besides these observations, there are, however, no data available directly comparing the long term incidences of tissue changes after HDR and LDR and there is, furthermore, no evidence regarding a difference between temporary or permanent LDR implantation schemes. Thus, recommendations for effective and safe implantation schemes have to be investigated and compared in future studies

  4. 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

  5. Comparison of eye tracking, electrooculography and an auditory brain-computer interface for binary communication: a case study with a participant in the locked-in state

    OpenAIRE

    Käthner, Ivo; Kübler, Andrea; Halder, Sebastian

    2015-01-01

    Background In this study, we evaluated electrooculography (EOG), an eye tracker and an auditory brain-computer interface (BCI) as access methods to augmentative and alternative communication (AAC). The participant of the study has been in the locked-in state (LIS) for 6 years due to amyotrophic lateral sclerosis. He was able to communicate with slow residual eye movements, but had no means of partner independent communication. We discuss the usability of all tested access methods and the pros...

  6. Age-Related Changes in Transient and Oscillatory Brain Responses to Auditory Stimulation during Early Adolescence

    Science.gov (United States)

    Poulsen, Catherine; Picton, Terence W.; Paus, Tomas

    2009-01-01

    Maturational changes in the capacity to process quickly the temporal envelope of sound have been linked to language abilities in typically developing individuals. As part of a longitudinal study of brain maturation and cognitive development during adolescence, we employed dense-array EEG and spatiotemporal source analysis to characterize…

  7. Implantable imaging device for brain functional imaging system using flavoprotein fluorescence

    Science.gov (United States)

    Sunaga, Yoshinori; Yamaura, Hiroshi; Haruta, Makito; Yamaguchi, Takahiro; Motoyama, Mayumi; Ohta, Yasumi; Takehara, Hiroaki; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Yoshimura, Yumiko; Ohta, Jun

    2016-03-01

    The autofluorescence of mitochondrial flavoprotein is very useful for functional brain imaging because the fluorescence intensity of flavoprotein changes as per neural activities. In this study, we developed an implantable imaging device for green fluorescence imaging and detected fluorescence changes of flavoprotein associated with visual stimulation using the device. We examined the device performance using anesthetized mice. We set the device on the visual cortex and measured fluorescence changes of flavoprotein in response to visual stimulation. A full-field sinusoidal grating with a vertical orientation was used for applying to activate the visual cortex. We successfully observed visually evoked fluorescence changes in the mouse visual cortex using our implantable device. This result suggests that we can observe the fluorescence changes of flavoprotein associated with visual stimulation in a freely moving mouse by using this technology.

  8. Anatomy of brain-stem white-matter tracts shown by diffusion-weighted imaging

    International Nuclear Information System (INIS)

    We acquired high-resolution MRI and anisotropically diffusion-weighted images (DWI) with direction-selective gradients of the brain stem in 20 healthy volunteers, to identify brain-stem structures such as white-matter tracts and nuclei which show diffusion anisotropy. After averaging and superposition of individual cuts, the images were projected onto appropriate plates of the Schaltenbrand and Wahren anatomical atlas. We identified 20 structures - white-matter tracts and some nuclei - with high contrast. The direction of fibres could be determined as areas of increased (parallel to) or decreased diffusion (perpendicular to the gradient). This study may contribute to understanding of the functional anatomy of the brain stem. (orig.)

  9. Patient-derived stem cells: pathways to drug discovery for brain diseases

    Directory of Open Access Journals (Sweden)

    Alan Mackay-Sim

    2013-03-01

    Full Text Available The concept of drug discovery through stem cell biology is based on technological developments whose genesis is now coincident. The first is automated cell microscopy with concurrent advances in image acquisition and analysis, known as high content screening (HCS. The second is patient-derived stem cells for modelling the cell biology of brain diseases. HCS has developed from the requirements of the pharmaceutical industry for high throughput assays to screen thousands of chemical compounds in the search for new drugs. HCS combines new fluorescent probes with automated microscopy and computational power to quantify the effects of compounds on cell functions. Stem cell biology has advanced greatly since the discovery of genetic reprogramming of somatic cells into induced pluripotent stem cells (iPSCs. There is now a rush of papers describing their generation from patients with various diseases of the nervous system. Although the majority of these have been genetic diseases, iPSCs have been generated from patients with complex diseases (schizophrenia and sporadic Parkinson’s disease. Some genetic diseases are also modelled in embryonic stem cells generated from blastocysts rejected during in vitro fertilisation. Neural stem cells have been isolated from post-mortem brain of Alzheimer’s patients and neural stem cells generated from biopsies of the olfactory organ of patients is another approach. These “olfactory neurosphere-derived” cells demonstrate robust disease-specific phenotypes in patients with schizophrenia and Parkinson’s disease. High content screening is already in use to find small molecules for the generation and differentiation of embryonic stem cells and induced pluripotent stem cells. The challenges for using stem cells for drug discovery are to develop robust stem cell culture methods that meet the rigorous requirements for repeatable, consistent quantities of defined cell types at the industrial scale necessary for high

  10. Brain Cancer Stem Cells Display Preferential Sensitivity to Akt Inhibition

    OpenAIRE

    Eyler, Christine E.; Foo, Wen-Chi; LaFiura, Katherine M.; McLendon, Roger E.; Hjelmeland, Anita B.; Rich, Jeremy N.

    2008-01-01

    Malignant brain tumors are among the most lethal cancers, and conventional therapies are largely limited to palliation. Novel therapies targeted against specific molecular pathways may offer improved efficacy and reduced toxicity compared to conventional therapies, but initial clinical trials of molecular targeted agents in brain cancer therapy have been frequently disappointing. In brain tumors and other cancers, subpopulations of tumor cells have recently been characterized by their ability...

  11. Dosimetric response of radioactive bio glass seeds implants on rabbit brain; Resposta radiodosimetrica de implantes de sementes de biovidros radioativos no cerebro de coelhos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, I.T.; Campos, T.P.R., E-mail: itemponi@yahoo.com.br, E-mail: campos@nuclear.ufmg.br [Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares - Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)

    2007-07-01

    Interstitial implants of radioactive seeds are used as an efficient way of treating brain tumors. Bio glasses is an interesting alternative to the metallic implanted materials, because they can be absorbed by the organism, reducing the possibilities of side effects. The present paper investigates the dosimetry by the implants performed on rabbit's brain on the NRI/UFMG research group. The spatial distribution of the specific ionizing energy deposited per unit of mass generated by Sm-153 seeds were evaluated. A computational model of the brain's region was built using the software SISCODES produced by the research group. The sections of the computer tomography of a rabbit, which was included on the experiment, were digitalized. Those were converted in a three dimensional voxel model, including the tissues, its chemical composition and density. A simulation of the particles transport is performed by the stochastic code MCNP5. The implants consist of 15 ceramic Ca-Si-Sm seeds enriched with Sm-153, with 1.1.6 mm of length and 0.3 mm diameter, implanted on the rabbit's brain. It was predicted on the model three ribbons of 5 seeds each, spaced by 1.1.2 mm, since the ribbons were in a triangular topology whose vertices were spaced by 8 mm. The activities were 120 MBq/seed. The results show isodose regions superposed over the rabbits' model, reproducing the spatial energy deposition on the brain region. The absorbed dose predicted was 3.2 Gy per 15 seed; however it was not enough to tumor control. The authors suggest to increase the number of seeds and activity, reduction of the space to 5-6 mm among ribbons, improving dose with the beta emitting. (author)

  12. Auditory Orienting and Inhibition of Return in Mild Traumatic Brain Injury: A FMRI study

    OpenAIRE

    Mayer, Andrew R.; Mannell, Maggie V.; Ling, Josef; Elgie, Robert; Gasparovic, Charles; Phillips, John P.; Doezema, David; Yeo, Ronald A

    2009-01-01

    The semi-acute phase of mild traumatic brain injury (mTBI) is associated with deficits in the cognitive domains of attention, memory, and executive function, which previous work suggests may be related to a specific deficit in disengaging attentional focus. However, to date there have only been a few studies that have employed dynamic imaging techniques to investigate the potential neurological basis of these cognitive deficits during the semi-acute stage of injury. Therefore, event-related f...

  13. Diffusion Tensor Imaging of Mouse Brain Stem and Cervical Spinal Cord

    OpenAIRE

    Kim, Joong Hee; Haldar, Justin; Liang, Zhi-Pei; Song, Sheng-Kwei

    2008-01-01

    In vivo diffusion tensor imaging measurements of the mouse brain stem and cervical spinal cord are presented. Utilizing actively decoupled transmit/receive coils, high resolution diffusion images (117 × 59 × 500 μm3) were acquired at 4.7 T within an hour. Both brain stem and cervical spine displayed clear gray-white matter contrast. The cervical spinal cord white matter showed similar tissue characteristics as seen in the thoracic cord. The coherent fiber orientation in the white matter was o...

  14. Electrical stimulation of the auditory nerve: the coding of frequency, the perception of pitch and the development of cochlear implant speech processing strategies for profoundly deaf people.

    Science.gov (United States)

    Clark, G M

    1996-09-01

    1. The development of speech processing strategies for multiple-channel cochlear implants has depended on encoding sound frequencies and intensities as temporal and spatial patterns of electrical stimulation of the auditory nerve fibres so that speech information of most importance of intelligibility could be transmitted. 2. Initial physiological studies showed that rate encoding of electrical stimulation above 200 pulses/s could not reproduce the normal response patterns in auditory neurons for acoustic stimulation in the speech frequency range above 200 Hz and suggested that place coding was appropriate for the higher frequencies. 3. Rate difference limens in the experimental animal were only similar to those for sound up to 200 Hz. 4. Rate difference limens in implant patients were similar to those obtained in the experimental animal. 5. Satisfactory rate discrimination could be made for durations of 50 and 100 ms, but not 25 ms. This made rate suitable for encoding longer duration suprasegmental speech information, but not segmental information, such as consonants. The rate of stimulation could also be perceived as pitch, discriminated at different electrode sites along the cochlea and discriminated for stimuli across electrodes. 6. Place pitch could be scaled according to the site of stimulation in the cochlea so that a frequency scale was preserved and it also had a different quality from rate pitch and was described as tonality. Place pitch could also be discriminated for the shorter durations (25 ms) required for identifying consonants. 7. The inaugural speech processing strategy encoded the second formant frequencies (concentrations of frequency energy in the mid frequency range of most importance for speech intelligibility) as place of stimulation, the voicing frequency as rate of stimulation and the intensity as current level. Our further speech processing strategies have extracted additional frequency information and coded this as place of stimulation

  15. Mesenchymal stem cell implantation in atrophic nonunion of the long bones

    Science.gov (United States)

    Phedy, P.; Kholinne, E.; Djaja, Y. P.; Kusnadi, Y.; Merlina, M.; Yulisa, N. D.

    2016-01-01

    Objectives To explore the therapeutic potential of combining bone marrow-derived mesenchymal stem cells (BM-MSCs) and hydroxyapatite (HA) granules to treat nonunion of the long bone. Methods Ten patients with an atrophic nonunion of a long bone fracture were selectively divided into two groups. Five subjects in the treatment group were treated with the combination of 15 million autologous BM-MSCs, 5g/cm3 (HA) granules and internal fixation. Control subjects were treated with iliac crest autograft, 5g/cm3 HA granules and internal fixation. The outcomes measured were post-operative pain (visual analogue scale), level of functionality (LEFS and DASH), and radiograph assessment. Results Post-operative pain evaluation showed no significant differences between the two groups. The treatment group demonstrated faster initial radiographic and functional improvements. Statistically significant differences in functional scores were present during the first (p = 0.002), second (p = 0.005) and third (p = 0.01) month. Both groups achieved similar outcomes by the end of one-year follow-up. No immunologic or neoplastic side effects were reported. Conclusions All cases of nonunion of a long bone presented in this study were successfully treated using autologous BM-MSCs. The combination of autologous BM-MSCs and HA granules is a safe method for treating nonunion. Patients treated with BM-MSCs had faster initial radiographic and functional improvements. By the end of 12 months, both groups had similar outcomes. Cite this article: H.D. Ismail, P. Phedy, E. Kholinne, Y. P. Djaja, Y. Kusnadi, M. Merlina, N. D. Yulisa. Mesenchymal stem cell implantation in atrophic nonunion of the long bones: A translational study. Bone Joint Res 2016;5:287–293. DOI: 10.1302/2046-3758.57.2000587. PMID:27412657

  16. Aberrant brain stem morphometry associated with sleep disturbance in drug-naïve subjects with Alzheimer’s disease

    Science.gov (United States)

    Lee, Ji Han; Jung, Won Sang; Choi, Woo Hee; Lim, Hyun Kook

    2016-01-01

    Objective Among patients with Alzheimer’s disease (AD), sleep disturbances are common and serious noncognitive symptoms. Previous studies of AD patients have identified deformations in the brain stem, which may play an important role in the regulation of sleep. The aim of this study was to further investigate the relationship between sleep disturbances and alterations in brain stem morphology in AD. Materials and methods In 44 patients with AD and 40 healthy elderly controls, sleep disturbances were measured using the Neuropsychiatry Inventory sleep subscale. We employed magnetic resonance imaging-based automated segmentation tools to examine the relationship between sleep disturbances and changes in brain stem morphology. Results Analyses of the data from AD subjects revealed significant correlations between the Neuropsychiatry Inventory sleep-subscale scores and structural alterations in the left posterior lateral region of the brain stem, as well as normalized brain stem volumes. In addition, significant group differences in posterior brain stem morphology were observed between the AD group and the control group. Conclusion This study is the first to analyze an association between sleep disturbances and brain stem morphology in AD. In line with previous findings, this study lends support to the possibility that brain stem structural abnormalities might be important neurobiological mechanisms underlying sleep disturbances associated with AD. Further longitudinal research is needed to confirm these findings. PMID:27601903

  17. Contacting the brain--aspects of a technology assessment of neural implants.

    Science.gov (United States)

    Decker, Michael; Fleischer, Torsten

    2008-12-01

    last years, neural implants became a subject for TA since they have gained a higher attention in both the political arena and the general public. Especially the ethical and social implications of technologies that electrically stimulate the brain and the possibilities of changing personality traits, changing moods, and perhaps enhancing human cognitive capabilities are central issues in related discussions. In this paper, we want to briefly summarize some of the key arguments as well as topics for future discussion and research. PMID:19072906

  18. Graphene Functionalized Scaffolds Reduce the Inflammatory Response and Supports Endogenous Neuroblast Migration when Implanted in the Adult Brain

    Science.gov (United States)

    Zhou, Kun; Motamed, Sepideh; Thouas, George A.; Bernard, Claude C.; Li, Dan; Parkington, Helena C.; Coleman, Harold A.; Finkelstein, David I.; Forsythe, John S.

    2016-01-01

    Electroactive materials have been investigated as next-generation neuronal tissue engineering scaffolds to enhance neuronal regeneration and functional recovery after brain injury. Graphene, an emerging neuronal scaffold material with charge transfer properties, has shown promising results for neuronal cell survival and differentiation in vitro. In this in vivo work, electrospun microfiber scaffolds coated with self-assembled colloidal graphene, were implanted into the striatum or into the subventricular zone of adult rats. Microglia and astrocyte activation levels were suppressed with graphene functionalization. In addition, self-assembled graphene implants prevented glial scarring in the brain 7 weeks following implantation. Astrocyte guidance within the scaffold and redirection of neuroblasts from the subventricular zone along the implants was also demonstrated. These findings provide new functional evidence for the potential use of graphene scaffolds as a therapeutic platform to support central nervous system regeneration. PMID:26978268

  19. Sonic hedgehog controls stem cell behavior in the postnatal and adult brain

    OpenAIRE

    Palma, Veronica; Lim, D A; Dahmane, Nadia; Sanchez, Pilar; Brionne, T. C.; Herzberg, C. D.; Gitton, Yorick; Carleton, Alan; Alvarez-Buylla, Arturo; Ruiz Altaba, Ariel

    2005-01-01

    Sonic hedgehog (Shh) signaling controls many aspects of ontogeny, orchestrating congruent growth and patterning. During brain development, Shh regulates early ventral patterning while later on it is critical for the regulation of precursor proliferation in the dorsal brain, namely in the neocortex, tectum and cerebellum. We have recently shown that Shh also controls the behavior of cells with stem cell properties in the mouse embryonic neocortex, and additional studies have implicated it in t...

  20. Physics strategies for sparing neural stem cells during whole-brain radiation treatments

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Neil; Chuang, Cynthia; Pouliot, Jean; Hwang, Andrew; Barani, Igor J. [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)

    2011-10-15

    Purpose: Currently, there are no successful long-term treatments or preventive strategies for radiation-induced cognitive impairments, and only a few possibilities have been suggested. One such approach involves reducing the dose to neural stem cell compartments (within and outside of the hippocampus) during whole-brain radiation treatments for brain metastases. This study investigates the fundamental physics issues associated with the sparing of neural stem cells during photon radiotherapy for brain metastases. Methods: Several factors influence the stem cell dose: intracranial scattering, collimator leakage, beam energy, and total number of beams. The relative importance of these factors is investigated through a set of radiation therapy plans, which are all variations of an initial 6 MV intensity-modulated radiation therapy (IMRT) plan designed to simultaneously deliver a whole-brain dose of 30 Gy and maximally reduce stem cell compartment dose. Additionally, an in-house leaf segmentation algorithm was developed that utilizes jaw motion to minimize the collimator leakage. Results: The plans are all normalized such that 50% of the PTV receives 30 Gy. For the initial 6 MV IMRT plan, 50% of the stem cells receive a dose greater than 6.3 Gy. Calculations indicate that 3.6 Gy of this dose originates from intracranial scattering. The jaw-tracking segmentation algorithm, used in conjunction with direct machine parameter optimization, reduces the 50% stem cell dose to 4.3 and 3.7 Gy for 6 and 10 MV treatment beams, respectively. Conclusions: Intracranial scattering alone is responsible for a large dose contribution to the stem cell compartment. It is, therefore, important to minimize other contributing factors, particularly the collimator leakage, to maximally reduce dose to these critical structures. The use of collimator jaw tracking in conjunction with modern collimators can minimize this leakage.

  1. Developmental and cross-modal plasticity in deafness: evidence from the P1 and N1 event related potentials in cochlear implanted children.

    Science.gov (United States)

    Sharma, Anu; Campbell, Julia; Cardon, Garrett

    2015-02-01

    Cortical development is dependent on extrinsic stimulation. As such, sensory deprivation, as in congenital deafness, can dramatically alter functional connectivity and growth in the auditory system. Cochlear implants ameliorate deprivation-induced delays in maturation by directly stimulating the central nervous system, and thereby restoring auditory input. The scenario in which hearing is lost due to deafness and then reestablished via a cochlear implant provides a window into the development of the central auditory system. Converging evidence from electrophysiologic and brain imaging studies of deaf animals and children fitted with cochlear implants has allowed us to elucidate the details of the time course for auditory cortical maturation under conditions of deprivation. Here, we review how the P1 cortical auditory evoked potential (CAEP) provides useful insight into sensitive period cut-offs for development of the primary auditory cortex in deaf children fitted with cochlear implants. Additionally, we present new data on similar sensitive period dynamics in higher-order auditory cortices, as measured by the N1 CAEP in cochlear implant recipients. Furthermore, cortical re-organization, secondary to sensory deprivation, may take the form of compensatory cross-modal plasticity. We provide new case-study evidence that cross-modal re-organization, in which intact sensory modalities (i.e., vision and somatosensation) recruit cortical regions associated with deficient sensory modalities (i.e., auditory) in cochlear implanted children may influence their behavioral outcomes with the implant. Improvements in our understanding of developmental neuroplasticity in the auditory system should lead to harnessing central auditory plasticity for superior clinical technique. PMID:24780192

  2. Nanoporous metals for biodegradable implants: Initial bone mesenchymal stem cell adhesion and degradation behavior.

    Science.gov (United States)

    Heiden, Michael; Huang, Sabrina; Nauman, Eric; Johnson, David; Stanciu, Lia

    2016-07-01

    Nanostructured Fe-Mn and Fe-Mn-Zn metal scaffolds were generated through a well-controlled selective leaching process in order to fulfill the growing demand for adjustable degradation rates and improved cellular response of resorbable materials. Mouse bone marrow mesenchymal stem cells (D1 ORL UVA) were seeded onto eleven, carefully chosen nanoporous surfaces for 24 h in vitro. Using a combination of fluorescence microscopy, scanning electron microscopy (SEM), and an MTS assay, it was discovered that scaffolds with nanoscale roughened surfaces had increased cell attachment by up to 123% compared to polished smooth Fe-Mn surfaces. Significant cell spreading and construction of cell multilayers were also apparent after 24 h, suggesting better adhesion. Additionally, static electrochemical polarization experiments revealed an improvement of up to 26% in the actual rate of biodegradation for Fe-Mn surface-modified materials. However, any residual concentration of zinc after leaching was shown to slightly increase corrosion resistance. The results demonstrate that selectively leached, nanostructured Fe-Mn surfaces have the potential of being tailored to a diverse set of transient implant scenarios, while also effectively boosting overall biocompatibility, initial cell attachment, and degradation rate. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1747-1758, 2016. PMID:26990484

  3. Implantable self-reset CMOS image sensor and its application to hemodynamic response detection in living mouse brain

    Science.gov (United States)

    Yamaguchi, Takahiro; Takehara, Hiroaki; Sunaga, Yoshinori; Haruta, Makito; Motoyama, Mayumi; Ohta, Yasumi; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Ohta, Jun

    2016-04-01

    A self-reset pixel of 15 × 15 µm2 with high signal-to-noise ratio (effective peak SNR ≃64 dB) for an implantable image sensor has been developed for intrinsic signal detection arising from hemodynamic responses in a living mouse brain. For detecting local conversion between oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) in brain tissues, an implantable imaging device was fabricated with our newly designed self-reset image sensor and orange light-emitting diodes (LEDs; λ = 605 nm). We demonstrated imaging of hemodynamic responses in the sensory cortical area accompanied by forelimb stimulation of a living mouse. The implantable imaging device for intrinsic signal detection is expected to be a powerful tool to measure brain activities in living animals used in behavioral analysis.

  4. Wireless image-data transmission from an implanted image sensor through a living mouse brain by intra body communication

    Science.gov (United States)

    Hayami, Hajime; Takehara, Hiroaki; Nagata, Kengo; Haruta, Makito; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Ohta, Jun

    2016-04-01

    Intra body communication technology allows the fabrication of compact implantable biomedical sensors compared with RF wireless technology. In this paper, we report the fabrication of an implantable image sensor of 625 µm width and 830 µm length and the demonstration of wireless image-data transmission through a brain tissue of a living mouse. The sensor was designed to transmit output signals of pixel values by pulse width modulation (PWM). The PWM signals from the sensor transmitted through a brain tissue were detected by a receiver electrode. Wireless data transmission of a two-dimensional image was successfully demonstrated in a living mouse brain. The technique reported here is expected to provide useful methods of data transmission using micro sized implantable biomedical sensors.

  5. Brain functional connectivity during the experience of thought blocks in schizophrenic patients with persistent auditory verbal hallucinations: an EEG study.

    Science.gov (United States)

    Angelopoulos, Elias; Koutsoukos, Elias; Maillis, Antonis; Papadimitriou, George N; Stefanis, Costas

    2014-03-01

    Thought blocks (TBs) are characterized by regular interruptions in the stream of thought. Outward signs are abrupt and repeated interruptions in the flow of conversation or actions while subjective experience is that of a total and uncontrollable emptying of the mind. In the very limited bibliography regarding TB, the phenomenon is thought to be conceptualized as a disturbance of consciousness that can be attributed to stoppages of continuous information processing due to an increase in the volume of information to be processed. In an attempt to investigate potential expression of the phenomenon on the functional properties of electroencephalographic (EEG) activity, an EEG study was contacted in schizophrenic patients with persisting auditory verbal hallucinations (AVHs) who additionally exhibited TBs. In this case, we hypothesized that the persistent and dense AVHs could serve the role of an increased information flow that the brain is unable to process, a condition that is perceived by the person as TB. Phase synchronization analyses performed on EEG segments during the experience of TBs showed that synchrony values exhibited a long-range common mode of coupling (grouped behavior) among the left temporal area and the remaining central and frontal brain areas. These common synchrony-fluctuation schemes were observed for 0.5 to 2s and were detected in a 4-s window following the estimated initiation of the phenomenon. The observation was frequency specific and detected in the broad alpha band region (6-12Hz). The introduction of synchrony entropy (SE) analysis applied on the cumulative synchrony distribution showed that TB states were characterized by an explicit preference of the system to be functioned at low values of synchrony, while the synchrony values are broadly distributed during the recovery state. Our results indicate that during TB states, the phase locking of several brain areas were converged uniformly in a narrow band of low synchrony values and in a

  6. Brain stem and cerebellar atrophy in chronic progressive neuro-Behçet's disease

    Energy Technology Data Exchange (ETDEWEB)

    Kanoto, Masafumi, E-mail: mkanoto@med.id.yamagata-u.ac.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan); Hosoya, Takaaki, E-mail: thosoya@med.id.yamagata-u.ac.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan); Toyoguchi, Yuuki, E-mail: c-elegans_0201g@mail.goo.ne.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan); Oda, Atsuko, E-mail: a.oda@med.id.yamagata-u.ac.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan)

    2013-01-15

    Purpose: Chronic progressive neuro-Behçet's disease (CPNBD) resembles multiple sclerosis (MS) on patient background and image findings, and therefore is difficult to diagnose. The purpose is to identify the characteristic magnetic resonance imaging (MRI) findings of CPNBD and to clarify the differences between the MRI findings of CPNBD and those of MS. Materials and methods: The subjects consist of a CPNBD group (n = 4; 1 male and 3 females; mean age, 51 y.o.), a MS group (n = 19; 3 males and 16 females; mean age, 45 y.o.) and a normal control group (n = 23; 10 males and 13 females; mean age, 45 y.o.). Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were retrospectively evaluated in each subjects. In middle sagittal brain MR images, the prepontine distance was measured as an indirect index of brain stem and cerebellar atrophy and the pontine and mesencephalic distance was measured as a direct index of brain stem atrophy. These indexes were statistically analyzed. Results: Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were seen in all CPNBD cases. Prepontine distance was significantly different between the CPNBD group and the MS group (p < 0.05), and between the CPNBD group and the normal control group (p < 0.001). Pontine and mesencephalic distance were significantly different between the CPNBD group and the MS group (p < 0.001, p < 0.01 respectively), and between the CPNBD group and the normal control group (p < 0.001). Conclusions: Chronic progressive neuro-Behçet's disease should be considered in patients with brain stem and cerebellar atrophy in addition to leukoencephalopathy similar to that seen in multiple sclerosis.

  7. Syrinx of the Spinal Cord and Brain Stem

    Science.gov (United States)

    ... imaging (MRI) of the entire spinal cord and brain is done after paramagnetic contrast agent, such as ... neurosurgeon may make a hole in a syrinx to drain it and prevent it from expanding, but surgery ...

  8. Brain-derived neurotrophic factor ameliorates brain stem cardiovascular dysregulation during experimental temporal lobe status epilepticus.

    Directory of Open Access Journals (Sweden)

    Ching-Yi Tsai

    Full Text Available BACKGROUND: Status epilepticus (SE is an acute, prolonged epileptic crisis with a mortality rate of 20-30%; the underlying mechanism is not completely understood. We assessed the hypothesis that brain stem cardiovascular dysregulation occurs during SE because of oxidative stress in rostral ventrolateral medulla (RVLM, a key nucleus of the baroreflex loop; to be ameliorated by brain-derived neurotrophic factor (BDNF via an antioxidant action. METHODOLOGY/PRINCIPAL FINDINGS: In a clinically relevant experimental model of temporal lobe SE (TLSE using Sprague-Dawley rats, sustained hippocampal seizure activity was accompanied by progressive hypotension that was preceded by a reduction in baroreflex-mediated sympathetic vasomotor tone; heart rate and baroreflex-mediated cardiac responses remained unaltered. Biochemical experiments further showed concurrent augmentation of superoxide anion, phosphorylated p47(phox subunit of NADPH oxidase and mRNA or protein levels of BDNF, tropomyosin receptor kinase B (TrkB, angiotensin AT1 receptor subtype (AT1R, nitric oxide synthase II (NOS II or peroxynitrite in RVLM. Whereas pretreatment by microinjection bilaterally into RVLM of a superoxide dismutase mimetic (tempol, a specific antagonist of NADPH oxidase (apocynin or an AT1R antagonist (losartan blunted significantly the augmented superoxide anion or phosphorylated p47(phox subunit in RVLM, hypotension and the reduced baroreflex-mediated sympathetic vasomotor tone during experimental TLSE, pretreatment with a recombinant human TrkB-Fc fusion protein or an antisense bdnf oligonucleotide significantly potentiated all those events, alongside peroxynitrite. However, none of the pretreatments affected the insignificant changes in heart rate and baroreflex-mediated cardiac responses. CONCLUSIONS/SIGNIFICANCE: We conclude that formation of peroxynitrite by a reaction between superoxide anion generated by NADPH oxidase in RVLM on activation by AT1R and NOS II

  9. Auditory Processing Disorders

    Science.gov (United States)

    Auditory Processing Disorders Auditory processing disorders (APDs) are referred to by many names: central auditory processing disorders , auditory perceptual disorders , and central auditory disorders . APDs ...

  10. Halofuginone Inhibits Angiogenesis and Growth in Implanted Metastatic Rat Brain Tumor Model-an MRI Study

    Directory of Open Access Journals (Sweden)

    Rinat Abramovitch

    2004-09-01

    Full Text Available Tumor growth and metastasis depend on angiogenesis; therefore, efforts are made to develop specific angiogenic inhibitors. Halofuginone (HF is a potent inhibitor of collagen type α1(I. In solid tumor models, HF has a potent antitumor and antiangiogenic effect in vivo, but its effect on brain tumors has not yet been evaluated. By employing magnetic resonance imaging (MRI, we monitored the effect of HF on tumor progression and vascularization by utilizing an implanted malignant fibrous histiocytoma metastatic rat brain tumor model. Here we demonstrate that treatment with HF effectively and dose-dependently reduced tumor growth and angiogenesis. On day 13, HF-treated tumors were fivefold smaller than control (P < .001. Treatment with HF significantly prolonged survival of treated animals (142%; P = .001. In HF-treated rats, tumor vascularization was inhibited by 30% on day 13 and by 37% on day 19 (P < .05. Additionally, HF treatment inhibited vessel maturation (P = .03. Finally, in HF-treated rats, we noticed the appearance of a few clusters of satellite tumors, which were distinct from the primary tumor and usually contained vessel cores. This phenomenon was relatively moderate when compared to previous reports of other antiangiogenic agents used to treat brain tumors. We therefore conclude that HF is effective for treatment of metastatic brain tumors.

  11. Autonomous control for mechanically stable navigation of microscale implants in brain tissue to record neural activity.

    Science.gov (United States)

    Anand, Sindhu; Kumar, Swathy Sampath; Muthuswamy, Jit

    2016-08-01

    Emerging neural prosthetics require precise positional tuning and stable interfaces with single neurons for optimal function over a lifetime. In this study, we report an autonomous control to precisely navigate microscale electrodes in soft, viscoelastic brain tissue without visual feedback. The autonomous control optimizes signal-to-noise ratio (SNR) of single neuronal recordings in viscoelastic brain tissue while maintaining quasi-static mechanical stress conditions to improve stability of the implant-tissue interface. Force-displacement curves from microelectrodes in in vivo rodent experiments are used to estimate viscoelastic parameters of the brain. Using a combination of computational models and experiments, we determined an optimal movement for the microelectrodes with bidirectional displacements of 3:2 ratio between forward and backward displacements and a inter-movement interval of 40 s for minimizing mechanical stress in the surrounding brain tissue. A regulator with the above optimal bidirectional motion for the microelectrodes in in vivo experiments resulted in significant reduction in the number of microelectrode movements (0.23 movements/min) and longer periods of stable SNR (53 % of the time) compared to a regulator using a conventional linear, unidirectional microelectrode movement (with 1.48 movements/min and stable SNR 23 % of the time). PMID:27457752

  12. Defunct brain stem cardiovascular regulation underlies cardiovascular collapse associated with methamphetamine intoxication

    Directory of Open Access Journals (Sweden)

    Li Faith CH

    2012-02-01

    Full Text Available Abstract Background Intoxication from the psychostimulant methamphetamine (METH because of cardiovascular collapse is a common cause of death within the abuse population. For obvious reasons, the heart has been taken as the primary target for this METH-induced toxicity. The demonstration that failure of brain stem cardiovascular regulation, rather than the heart, holds the key to cardiovascular collapse induced by the pesticide mevinphos implicates another potential underlying mechanism. The present study evaluated the hypothesis that METH effects acute cardiovascular depression by dampening the functional integrity of baroreflex via an action on brain stem nuclei that are associated with this homeostatic mechanism. Methods The distribution of METH in brain and heart on intravenous administration in male Sprague-Dawley rats, and the resultant changes in arterial pressure (AP, heart rate (HR and indices for baroreflex-mediated sympathetic vasomotor tone and cardiac responses were evaluated, alongside survival rate and time. Results Intravenous administration of METH (12 or 24 mg/kg resulted in a time-dependent and dose-dependent distribution of the psychostimulant in brain and heart. The distribution of METH to neural substrates associated with brain stem cardiovascular regulation was significantly larger than brain targets for its neurological and psychological effects; the concentration of METH in cardiac tissues was the lowest among all tissues studied. In animals that succumbed to METH, the baroreflex-mediated sympathetic vasomotor tone and cardiac response were defunct, concomitant with cessation of AP and HR. On the other hand, although depressed, those two indices in animals that survived were maintained, alongside sustainable AP and HR. Linear regression analysis further revealed that the degree of dampening of brain stem cardiovascular regulation was positively and significantly correlated with the concentration of METH in key neural

  13. Stem cells and treatment of brain and spinal cord injury

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva

    2009-01-01

    Roč. 276, Suppl.1 (2009), s. 40-40. ISSN 1742-464X. [Congress of the Federation-of-European-Biochemical-Societies /34./. 04.07.2009-09.07.2009, Prague] Institutional research plan: CEZ:AV0Z50390703 Keywords : Stem cells Subject RIV: FH - Neurology

  14. Carmustine Implant

    Science.gov (United States)

    Carmustine implant is used along with surgery and sometimes radiation therapy to treat malignant glioma (a certain type of ... Carmustine implant comes as a small wafer that is placed in the brain by a doctor during surgery to ...

  15. Paediatric brain-stem gliomas: MRI, FDG-PET and histological grading correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jong Won; Kim, In-One; Cheon, Jung-Eun; Kim, Woo Sun; Moon, Sung Gyu; Kim, Tae Jung; Yeon, Kyung Mo [Seoul National University Hospital, Department of Radiology, Seoul (Korea); Chi, Je Geun [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea); Wang, Kyu-Chang [Seoul National University College of Medicine, Department of Neurosurgery, Seoul (Korea); Chung, June Key [Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea)

    2006-09-15

    MRI and FDG-PET may predict the histological grading of paediatric brain-stem gliomas. To assess MRI findings and metabolic imaging using FDG-PET of brain-stem gliomas based on histological grading. Included in the study were 20 paediatric patients (age 3-14 years, mean 8.2 years) with brain-stem glioma (five glioblastomas, ten anaplastic astrocytomas and five low-grade astrocytomas). MR images were assessed for the anatomical site of tumour origin, focality, pattern of tumour growth, and enhancement. All glioblastomas were located in the pons and showed diffuse pontine enlargement with focally exophytic features. Eight anaplastic astrocytomas were located in the pons and demonstrated diffuse pontine enlargement without exophytic features. Low-grade astrocytomas were located in the pons, midbrain or medulla and showed focally exophytic growth features and peripheral enhancement. In 12 patients in whom FDG-PET was undertaken, glioblastomas showed hypermetabolic or hypometabolic lesions, anaplastic astrocytomas showed no metabolic change or hypometabolic lesions and low-grade astrocytomas showed hypometabolism compared with the cerebellum. MRI findings correlated well with histological grading of brain-stem gliomas and MRI may therefore predict the histological grading. FDG-PET may be helpful in differentiating between anaplastic astrocytoma and glioblastomas among high-grade tumours. (orig.)

  16. The role of auditory transient and deviance processing in distraction of task performance: a combined behavioral and event-related brain potential study.

    Science.gov (United States)

    Berti, Stefan

    2013-01-01

    Distraction of goal-oriented performance by a sudden change in the auditory environment is an everyday life experience. Different types of changes can be distracting, including a sudden onset of a transient sound and a slight deviation of otherwise regular auditory background stimulation. With regard to deviance detection, it is assumed that slight changes in a continuous sequence of auditory stimuli are detected by a predictive coding mechanisms and it has been demonstrated that this mechanism is capable of distracting ongoing task performance. In contrast, it is open whether transient detection-which does not rely on predictive coding mechanisms-can trigger behavioral distraction, too. In the present study, the effect of rare auditory changes on visual task performance is tested in an auditory-visual cross-modal distraction paradigm. The rare changes are either embedded within a continuous standard stimulation (triggering deviance detection) or are presented within an otherwise silent situation (triggering transient detection). In the event-related brain potentials, deviants elicited the mismatch negativity (MMN) while transients elicited an enhanced N1 component, mirroring pre-attentive change detection in both conditions but on the basis of different neuro-cognitive processes. These sensory components are followed by attention related ERP components including the P3a and the reorienting negativity (RON). This demonstrates that both types of changes trigger switches of attention. Finally, distraction of task performance is observable, too, but the impact of deviants is higher compared to transients. These findings suggest different routes of distraction allowing for the automatic processing of a wide range of potentially relevant changes in the environment as a pre-requisite for adaptive behavior. PMID:23874278

  17. The role of auditory transient and deviance processing in distraction of task performance: a combined behavioral and event-related brain potential study

    Directory of Open Access Journals (Sweden)

    Stefan Berti

    2013-07-01

    Full Text Available Distraction of goal-oriented performance by a sudden change in the auditory environment is an everyday life experience. Different types of changes can be distracting, including a sudden onset of a transient sound and a slight deviation of otherwise regular auditory background stimulation. With regard to deviance detection, it is assumed that slight changes in a continuous sequence of auditory stimuli are detected by a predictive coding mechanisms and it has been demonstrated that this mechanism is capable of distracting ongoing task performance. In contrast, it is open whether transient detection – which does not rely on predictive coding mechanisms – can trigger behavioral distraction, too. In the present study, the effect of rare auditory changes on visual task performance is tested in an auditory-visual cross-modal distraction paradigm. The rare changes are either embedded within a continuous standard stimulation (triggering deviance detection or are presented within an otherwise silent situation (triggering transient detection. In the event-related brain potentials, deviants elicited the mismatch negativity (MMN while transients elicited an enhanced N1 component, mirroring pre-attentive change detection in both conditions but on the basis of different neuro-cognitive processes. These sensory components are followed by attention related ERP components including the P3a and the reorienting negativity (RON. This demonstrates that both types of changes trigger switches of attention. Finally, distraction of task performance is observable, too, but the impact of deviants is higher compared to transients. These findings suggest different routes of distraction allowing for the automatic processing of a wide range of potentially relevant changes in the environment as a pre-requisite for adaptive behavior.

  18. Evidence of a visual-to-auditory cross-modal sensory gating phenomenon as reflected by the human P50 event-related brain potential modulation.

    Science.gov (United States)

    Lebib, Riadh; Papo, David; de Bode, Stella; Baudonnière, Pierre Marie

    2003-05-01

    We investigated the existence of a cross-modal sensory gating reflected by the modulation of an early electrophysiological index, the P50 component. We analyzed event-related brain potentials elicited by audiovisual speech stimuli manipulated along two dimensions: congruency and discriminability. The results showed that the P50 was attenuated when visual and auditory speech information were redundant (i.e. congruent), in comparison with this same event-related potential component elicited with discrepant audiovisual dubbing. When hard to discriminate, however, bimodal incongruent speech stimuli elicited a similar pattern of P50 attenuation. We concluded to the existence of a visual-to-auditory cross-modal sensory gating phenomenon. These results corroborate previous findings revealing a very early audiovisual interaction during speech perception. Finally, we postulated that the sensory gating system included a cross-modal dimension. PMID:12697279

  19. A technique for accurate planning of stereotactic brain implants prior to head ring fixation

    International Nuclear Information System (INIS)

    Purpose: A two-step procedure is described for accurate planning of stereotactic brain implants prior to head-ring fixation. Methods and Materials: Approximately 2 weeks prior to implant a CT scan without the head ring is performed for treatment-planning purposes. An entry point and a reference point, both marked with barium and later tattooed, facilitate planning and permit correlation of the images with a later CT scan. A plan is generated using a conventional treatment-planning system to determine the number and activity of I-125 seeds required and the position of each catheter. I-125 seed anisotropy is taken into account by means of a modification to the treatment planning program. On the day of the implant a second CT scan is performed with the head ring affixed to the skull and with the same points marked as in the previous scan. The planned catheter coordinates are then mapped into the coordinate system of the second CT scan by means of a manual translational correction and a computer-calculated rotational correction derived from the reference point coordinates in the two scans. Results: The rotational correction algorithm was verified experimentally in a Rando phantom before it was used clinically. For analysis of the results with individual patients a third CT scan is performed 1 day following the implant and is used for calculating the final dosimetry. Conclusion: The technique that is described has two important advantages: 1) the number and activity of seeds required can be accurately determined in advance; and 2) sufficient time is allowed to derive the best possible plan

  20. Are human dental papilla-derived stem cell and human brain-derived neural stem cell transplantations suitable for treatment of Parkinson's disease?★

    OpenAIRE

    Yoon, Hyung Ho; Min, Joongkee; Shin, Nari; Kim, Yong Hwan; Kim, Jin-Mo; Hwang, Yu-Shik; Suh, Jun-Kyo Francis; Hwang, Onyou; Jeon, Sang Ryong

    2013-01-01

    Transplantation of neural stem cells has been reported as a possible approach for replacing impaired dopaminergic neurons. In this study, we tested the efficacy of early-stage human dental papilla-derived stem cells and human brain-derived neural stem cells in rat models of 6-hydroxydopamine-induced Parkinson's disease. Rats received a unilateral injection of 6-hydroxydopamine into right medial forebrain bundle, followed 3 weeks later by injections of PBS, early-stage human dental papilla-der...

  1. Stem cells and therapy of brain and spinal cord injury

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva; Jendelová, Pavla; Glogarová, Kateřina; Urdzíková, Lucia; Lesný, Petr; Hampl, Aleš; Dvořák, Petr

    Hradec Králové, 2003, s. 65. ISBN 80-239-1413-8. [Symposium of the Czech Society of Histo- and Cytochemistry with International Participation /40./. Hradec Králové (CZ), 16.09.2003-19.09.2003] R&D Projects: GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z5039906 Keywords : stem cells Subject RIV: FH - Neurology

  2. MRI measurements of the brain stem and cerebellum in high functioning autistic children

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Toshiaki; Tayama, Masanobu; Miyazaki, Masahito; Murakawa, Kazuyoshi; Kuroda, Yasuhiro (Tokushima Univ. (Japan). School of Medicine)

    1994-01-01

    To determine involvements of the brain stem and/or cerebellum in autism, we compared midsagittal magnetic resonance images of the brains of high functioning autistic children with those of normal controls. We found that the midbrain and medulla oblongata were significantly smaller in these autistic children than in the control children. The pons area did not differ between the two groups, nor was there any difference in the cerebellar vermis area. The ratio of the brain stem and cerebellum to the posterior fossa area did not differ significantly between the high functioning autistic and the control children. The development of the cerebellar vermis area was delayed in autistic children as compared with that in the control children. Thus, it was suggested that significant anatomical changes in the midbrain and medulla oblongata existed in the autistic children. (author).

  3. MRI measurements of the brain stem and cerebellum in high functioning autistic children

    International Nuclear Information System (INIS)

    To determine involvements of the brain stem and/or cerebellum in autism, we compared midsagittal magnetic resonance images of the brains of high functioning autistic children with those of normal controls. We found that the midbrain and medulla oblongata were significantly smaller in these autistic children than in the control children. The pons area did not differ between the two groups, nor was there any difference in the cerebellar vermis area. The ratio of the brain stem and cerebellum to the posterior fossa area did not differ significantly between the high functioning autistic and the control children. The development of the cerebellar vermis area was delayed in autistic children as compared with that in the control children. Thus, it was suggested that significant anatomical changes in the midbrain and medulla oblongata existed in the autistic children. (author)

  4. Implanted hair follicle stem cells form Schwann cells that support repair of severed peripheral nerves

    OpenAIRE

    Amoh, Yasuyuki; Li, Lingna; Campillo, Raul; Kawahara, Katsumasa; Katsuoka, Kensei; Penman, Sheldon; Robert M Hoffman

    2005-01-01

    The hair follicle bulge area is an abundant, easily accessible source of actively growing, pluripotent adult stem cells. Nestin, a protein marker for neural stem cells, also is expressed in follicle stem cells and their immediate, differentiated progeny. The fluorescent protein GFP, whose expression is driven by the nestin regulatory element in transgenic mice, served to mark the follicle cell fate. The pluripotent nestin-driven GFP stem cells are positive for the stem cell marker CD34 but ne...

  5. Real Time Imaging of Biomarkers in the Parkinson's Brain Using Mini-Implantable Biosensors. II. Pharmaceutical Therapy with Bromocriptine

    OpenAIRE

    Patricia A. Broderick; Kolodny, Edwin H.

    2009-01-01

    We used Neuromolecular Imaging (NMI) and trademarked BRODERICK PROBE® mini-implantable biosensors, to selectively and separately detect neuro-transmitters in vivo, on line, within seconds in the dorsal striatal brain of the Parkinson’s Disease (PD) animal model. We directly compared our results derived from PD to the normal striatal brain of the non-Parkinson’s Disease (non-PD) animal. This advanced biotechnology enabled the imaging of dopamine (DA), serotonin (5-HT), homovanillic acid (HVA) ...

  6. Real Time Imaging of Biomarkers in the Parkinson's Brain Using Mini-Implantable Biosensors. II. Pharmaceutical Therapy with Bromocriptine

    OpenAIRE

    Patricia A. Broderick; Kolodny, Edwin H.

    2009-01-01

    We used Neuromolecular Imaging (NMI) and trademarked BRODERICK PROBE® mini-implantable biosensors, to selectively and separately detect neurotransmitters in vivo, on line, within seconds in the dorsal striatal brain of the Parkinson’s Disease (PD) animal model. We directly compared our results derived from PD to the normal striatal brain of the non-Parkinson’s Disease (non-PD) animal. This advanced biotechnology enabled the imaging of dopamine (DA), serotonin (5-HT), homovanillic acid (HVA) a...

  7. Treatment Option Overview (Childhood Brain Stem Glioma Treatment)

    Science.gov (United States)

    ... tests to check the brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro ...

  8. Stem Cells Expand Insights into Human Brain Evolution.

    Science.gov (United States)

    Dyer, Michael A

    2016-04-01

    Substantial expansion in the number of cerebral cortex neurons is thought to underlie cognitive differences between humans and other primates, although the mechanisms underlying this expansion are unclear. Otani et al. (2016) utilize PSC-derived brain organoids to study how species-specific differences in cortical progenitor proliferation may underlie cortical evolution. PMID:27058930

  9. Does State Merit-Based Aid Stem Brain Drain?

    Science.gov (United States)

    Zhang, Liang; Ness, Erik C.

    2010-01-01

    In this study, the authors use college enrollment and migration data to test the brain drain hypothesis. Their results suggest that state merit scholarship programs do indeed stanch the migration of "best and brightest" students to other states. In the aggregate and on average, the implementation of state merit aid programs increases the total…

  10. Frequency-specific disruptions of neuronal oscillations reveal aberrant auditory processing in schizophrenia.

    Science.gov (United States)

    Hayrynen, Lauren K; Hamm, Jordan P; Sponheim, Scott R; Clementz, Brett A

    2016-06-01

    Individuals with schizophrenia exhibit abnormalities in evoked brain responses in oddball paradigms. These could result from (a) insufficient salience-related cortical signaling (P300), (b) insufficient suppression of irrelevant aspects of the auditory environment, or (c) excessive neural noise. We tested whether disruption of ongoing auditory steady-state responses at predetermined frequencies informed which of these issues contribute to auditory stimulus relevance processing abnormalities in schizophrenia. Magnetoencephalography data were collected for 15 schizophrenia and 15 healthy subjects during an auditory oddball paradigm (25% targets; 1-s interstimulus interval). Auditory stimuli (pure tones: 1 kHz standards, 2 kHz targets) were administered during four continuous background (auditory steady-state) stimulation conditions: (1) no stimulation, (2) 24 Hz, (3) 40 Hz, and (4) 88 Hz. The modulation of the auditory steady-state response (aSSR) and the evoked responses to the transient stimuli were quantified and compared across groups. In comparison to healthy participants, the schizophrenia group showed greater disruption of the ongoing aSSR by targets regardless of steady-state frequency, and reduced amplitude of both M100 and M300 event-related field components. During the no-stimulation condition, schizophrenia patients showed accentuation of left hemisphere 40 Hz response to both standard and target stimuli, indicating an effort to enhance local stimulus processing. Together, these findings suggest abnormalities in auditory stimulus relevance processing in schizophrenia patients stem from insufficient amplification of salient stimuli. PMID:26933842

  11. Aberrant brain-stem morphometry associated with sleep disturbance in drug-naïve subjects with Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Lee JH

    2016-08-01

    Full Text Available Ji Han Lee,1 Won Sang Jung,2 Woo Hee Choi,3 Hyun Kook Lim4 1Washington University in St Louis, St Louis, MO, USA; 2Department of Radiology, 3Department of Nuclear Medicine, 4Department of Psychiatry, Saint Vincent Hospital, College of Medicine, The Catholic University of Korea, Suwon, South Korea Objective: Among patients with Alzheimer’s disease (AD, sleep disturbances are common and serious noncognitive symptoms. Previous studies of AD patients have identified deformations in the brain stem, which may play an important role in the regulation of sleep. The aim of this study was to further investigate the relationship between sleep disturbances and alterations in brain stem morphology in AD.Materials and methods: In 44 patients with AD and 40 healthy elderly controls, sleep disturbances were measured using the Neuropsychiatry Inventory sleep subscale. We employed magnetic resonance imaging-based automated segmentation tools to examine the relationship between sleep disturbances and changes in brain stem morphology.Results: Analyses of the data from AD subjects revealed significant correlations between the Neuropsychiatry Inventory sleep-subscale scores and structural alterations in the left posterior lateral region of the brain stem, as well as normalized brain stem volumes. In addition, significant group differences in posterior brain stem morphology were observed between the AD group and the control group.Conclusion: This study is the first to analyze an association between sleep disturbances and brain stem morphology in AD. In line with previous findings, this study lends support to the possibility that brain stem structural abnormalities might be important neurobiological mechanisms underlying sleep disturbances associated with AD. Further longitudinal research is needed to confirm these findings. Keywords: Alzheimer’s disease, sleep, brain stem, MRI, shape analysis

  12. Classic and novel stem cell niches in brain homeostasis and repair.

    Science.gov (United States)

    Lin, Ruihe; Iacovitti, Lorraine

    2015-12-01

    Neural stem cells (NSCs) critical for the continued production of new neurons and glia are sequestered in distinct areas of the brain called stem cell niches. Until recently, only two forebrain sites, the subventricular zone (SVZ) of the anterolateral ventricle and the subgranular zone (SGZ) of the hippocampus, have been recognized adult stem cell niches (Alvarez-Buylla and Lim, 2004; Doetsch et al., 1999a, 1999b; Doetsch, 2003a, 2003b; Lie et al., 2004; Ming and Song, 2005). Nonetheless, the last decade has been witness to a growing literature suggesting that in fact the adult brain contains stem cell niches along the entire extent of the ventricular system. These niches are capable of widespread neurogenesis and gliogenesis, particularly after injury (Barnabé-Heider et al., 2010; Carlén et al., 2009; Decimo et al., 2012; Lin et al., 2015; Lindvall and Kokaia, 2008; Robins et al., 2013) or other inductive stimuli (Bennett et al., 2009; Cunningham et al., 2012; Decimo et al., 2011; Kokoeva et al., 2007, 2005; Lee et al., 2012a, 2012b; Migaud et al., 2010; Pencea et al., 2001b; Sanin et al., 2013; Suh et al., 2007; Sundholm-Peters et al., 2004; Xu et al., 2005; Zhang et al., 2007). This review focuses on the role of these novel and classic brain niches in maintaining adult neurogenesis and gliogenesis in response to normal physiological and injury-related pathological cues. This article is part of a Special Issue entitled SI: Neuroprotection. PMID:25931262

  13. STEM CELL-PAVED BIOBRIDGE FACILITATES NEURAL REPAIR IN TRAUMATIC BRAIN INJURY

    Directory of Open Access Journals (Sweden)

    Ernest Yankee

    2014-06-01

    Full Text Available Modified mesenchymal stromal cells (MSCs display a unique mechanism of action during the repair phase of traumatic brain injury by exhibiting the ability to build a biobridge between the neurogenic niche and the site of injury. Immunohistochemistry and laser capture assay have visualized this biobridge in the area between the neurogenic subventricular zone and the injured cortex. This biobridge expresses high levels of extracellular matrixmetalloproteinases (MMPs, which are initially co-localized with a stream of transplanted MSCs, but later this region contains only few to non-detectable grafts and becomes overgrown by newly recruited host cells. We have reported that long-distance migration of host cells from the neurogenic niche to the injured brain site can be attained via these transplanted stem cell-paved biobridges, which serve as a key regenerative process for the initiation of endogenous repair mechanisms. Thus far the two major schools of discipline in stem cell repair mechanisms support the idea of “cell replacement” and the bystander effects of “trophic factor secretion.” Our novel observation of stem cell-paved biobridges as pathways for directed migration of host cells from neurogenic niche towards the injured brain site adds another mode of action underlying stem cell therapy. More in-depth investigations on graft-host interaction will likely aid translational research focused on advancing this stem cell-paved biobridge from its current place, as an equally potent repair mechanism as cell replacement and trophic factor secretion, into a new treatment strategy for traumatic brain injury and other neurological disorders.

  14. Getting a decent (but sparse) signal to the brain for users of cochlear implants.

    Science.gov (United States)

    Wilson, Blake S

    2015-04-01

    The challenge in getting a decent signal to the brain for users of cochlear implants (CIs) is described. A breakthrough occurred in 1989 that later enabled most users to understand conversational speech with their restored hearing alone. Subsequent developments included stimulation in addition to that provided with a unilateral CI, either with electrical stimulation on both sides or with acoustic stimulation in combination with a unilateral CI, the latter for persons with residual hearing at low frequencies in either or both ears. Both types of adjunctive stimulation produced further improvements in performance for substantial fractions of patients. Today, the CI and related hearing prostheses are the standard of care for profoundly deaf persons and ever-increasing indications are now allowing persons with less severe losses to benefit from these marvelous technologies. The steps in achieving the present levels of performance are traced, and some possibilities for further improvements are mentioned. This article is part of a Special Issue entitled . PMID:25500178

  15. Neurogenesis in the brain stem of the rabbit: an autoradiographic study

    International Nuclear Information System (INIS)

    With the aid of (3H)-thymidine autoradiography, neurogenesis was documented in the nuclear groups of the medulla oblongata, pons, and mid-brain, as well as in the brain stem reticular formation of the rabbit. Following single injections of (3H)-thymidine, counts were taken of intensely labeled neurons within the nuclei of the functional columns related to the cranial nerves, nuclei of several other functional classifications, and nuclei that did not fit into a functional category. In the brain stem as a whole, neurogenesis was found to occur between days 10.0 and 18.5 of gestation: however, the majority of nuclei studied contained intensely neurons only between days 12.0 and 15.0. Only in the pontine nucleus and the tectum were intensely labeled cells observed as late as day 18.5. Directional gradients of histogenesis were often observed within, as well as between, various nuclei. Within the nuclear columns related to the cranial nerves, a clear mediolateral spread of neurogenesis was observable such that nuclei of the motor columns reached a peak in neurogenesis before those in the sensory columns. Likewise, a mediolateral proliferation pattern was seen in the brain stem reticular formation. Other individual directional gradients were discernible; however, in the brain stem as a whole, distinct overall gradients were not observable. In many individual nuclei, gradients in neuron size were observed such that large neurons preferentially arose prior to smaller neurons. Information pertaining to gradients in neurogenesis, as well as to relationships among functionally related nuclei, are discussed

  16. cGMP modulates stem cells differentiation to neurons in brain in vivo.

    Science.gov (United States)

    Gómez-Pinedo, U; Rodrigo, R; Cauli, O; Herraiz, S; Garcia-Verdugo, J-M; Pellicer, B; Pellicer, A; Felipo, V

    2010-02-17

    During brain development neural stem cells may differentiate to neurons or to other cell types. The aim of this work was to assess the role of cGMP (cyclic GMP) in the modulation of differentiation of neural stem cells to neurons or non-neuronal cells. cGMP in brain of fetuses was reduced to 46% of controls by treating pregnant rats with nitroarginine-methylester (L-NAME) and was restored by co-treatment with sildenafil.Reducing cGMP during brain development leads to reduced differentiation of stem cells to neurons and increased differentiation to non-neuronal cells. The number of neurons in the prefrontal cortex originated from stem cells proliferating on gestational day 14 was 715+/-14/mm(2) in control rats and was reduced to 440+/-29/mm(2) (61% of control) in rats treated with L-NAME. In rats exposed to L-NAME plus sildenafil, differentiation to neurons was completely normalized, reaching 683+/-11 neurons/mm(2). In rats exposed to sildenafil alone the number of cells labelled with bromodeoxyuridine (BrdU) and NeuN was 841+/-16/mm(2). In prefrontal cortex of control rats 48% of the neural stem cells proliferating in gestational day 14 differentiate to neurons, but only 24% in rats exposed to L-NAME. This was corrected by sildenafil, 40% of cells differentiate to neurons. Similar results were obtained for neurons proliferating during all developmental period. Treatment with L-NAME did not reduce the total number of cells labelled with BrdU, further supporting that L-NAME reduces selectively the differentiation of stem cells to neurons. Similar results were obtained in hippocampus. Treatment with L-NAME reduced the differentiation of neural stem cells to neurons, although the effect was milder than in prefrontal cortex. These results support that cGMP modulates the fate of neural stem cells in brain in vivo and suggest that high cGMP levels promote its differentiation to neurons while reduced cGMP levels promote differentiation to non-neuronal cells. PMID:19958812

  17. Design of a Small Modified Minkowski Fractal Antenna for Passive Deep Brain Stimulation Implants

    Directory of Open Access Journals (Sweden)

    Sara Manafi

    2014-01-01

    Full Text Available A small planar modified Minkowski fractal antenna is designed and simulated in dual frequency bands (2.4 and 5.8 GHz for wireless energy harvesting by deep brain stimulation (DBS devices. The designed antenna, physically being confined inside a miniaturized structure, can efficiently convert the wireless signals in dual ISM frequency bands to the energy source to recharge the DBS battery or power the pulse generator directly. The performance metrics such as the return loss, the specific absorption rate (SAR, and the radiation pattern within skin and muscle-fat-skin tissues are evaluated for the designed antenna. The gain of the proposed antenna is 3.2 dBi at 2.4 GHz and 4.7 dBi at 5.8 GHz; also the averaged SAR of the antenna in human body tissue is found to be well below the legally allowed limit at both frequency bands. The link budget shows the received power at the distance of 25 cm at 2.4 GHz and 5.8 GHz are around 0.4 mW and 0.04 mW, which can empower the DBS implant. The large operational bandwidth, the physical compactness, and the efficiency in wireless signal reception make this antenna suitable in being used in implanted biomedical devices such as DBS pulse generators.

  18. Auditory Display

    DEFF Research Database (Denmark)

    volume. The conference's topics include auditory exploration of data via sonification and audification; real time monitoring of multivariate date; sound in immersive interfaces and teleoperation; perceptual issues in auditory display; sound in generalized computer interfaces; technologies supporting...

  19. 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

  20. Loss of auditory sensitivity from inner hair cell synaptopathy can be centrally compensated in the young but not old brain.

    Science.gov (United States)

    Möhrle, Dorit; Ni, Kun; Varakina, Ksenya; Bing, Dan; Lee, Sze Chim; Zimmermann, Ulrike; Knipper, Marlies; Rüttiger, Lukas

    2016-08-01

    A dramatic shift in societal demographics will lead to rapid growth in the number of older people with hearing deficits. Poorer performance in suprathreshold speech understanding and temporal processing with age has been previously linked with progressing inner hair cell (IHC) synaptopathy that precedes age-dependent elevation of auditory thresholds. We compared central sound responsiveness after acoustic trauma in young, middle-aged, and older rats. We demonstrate that IHC synaptopathy progresses from middle age onward and hearing threshold becomes elevated from old age onward. Interestingly, middle-aged animals could centrally compensate for the loss of auditory fiber activity through an increase in late auditory brainstem responses (late auditory brainstem response wave) linked to shortening of central response latencies. In contrast, old animals failed to restore central responsiveness, which correlated with reduced temporal resolution in responding to amplitude changes. These findings may suggest that cochlear IHC synaptopathy with age does not necessarily induce temporal auditory coding deficits, as long as the capacity to generate neuronal gain maintains normal sound-induced central amplitudes. PMID:27318145

  1. Mid-term study of bone remodeling after femoral cemented stem implantation: comparison between DXA and finite element simulation.

    Science.gov (United States)

    Herrera, Antonio; Rebollo, Sarai; Ibarz, Elena; Mateo, Jesús; Gabarre, Sergio; Gracia, Luis

    2014-01-01

    This five-year prospective study was designed to investigate periprosthetic bone remodeling associated with two cemented stem models, ABG-II (Stryker) and VerSys (Zimmer), randomly implanted in patients older than 75 years. The sample consisted of 64 cases (32, ABG-II; 32, VerSys). Inclusion criterion was diagnosis of osteoarthritis recommended for cemented total hip arthroplasty. Besides clinical study, Finite Element (FE) simulation was used to analyze biomechanical changes caused by hip arthroplasty. Bone Mineral Density (BMD) measurements showed a progressive increase in bone mass throughout the entire follow-up period for both stems, well correlated with FE results except in Gruen zones 4, 5, 6 for ABG-II and in zones 4, 5 for VerSys, denoting that remodeling in those zones does not depend on mechanical factors but rather on biological or physiological ones. PMID:23725926

  2. Long-term meditation is associated with increased gray matter density in the brain stem

    DEFF Research Database (Denmark)

    Vestergaard-Poulsen, Peter; Beek, Martijn van; Skewes, Joshua;

    2009-01-01

    Extensive practice involving sustained attention can lead to changes in brain structure. Here, we report evidence of structural differences in the lower brainstem of participants engaged in the long-term practice of meditation. Using magnetic resonance imaging, we observed higher gray matter...... density in lower brain stem regions of experienced meditators compared with age-matched nonmeditators. Our findings show that long-term practitioners of meditation have structural differences in brainstem regions concerned with cardiorespiratory control. This could account for some of the...... cardiorespiratory parasympathetic effects and traits, as well as the cognitive, emotional, and immunoreactive impact reported in several studies of different meditation practices....

  3. Adult-Onset Leukoencephalopathy with Brain Stem and Spinal Cord Involvement and Normal Lactate: Case Report

    Directory of Open Access Journals (Sweden)

    Özdem Ertürk

    2010-06-01

    Full Text Available Leukoencephalopathy with brain stem and spinal cord involvement and high lactate (LBSL is a recently described leukoencephalopathy with a genetically proven underlying defect. Clinical features are slowly progressive pyramidal, cerebellar and dorsal column dysfunction with childhood or rarely adult onset. The genetic basis of the disease was recently identified, which concerned mutations in the DARS2 gene encoding mitochondrial aspartly-tRNA synthetase. The disease has distinct magnetic resonance imaging findings including inhomogeneous cerebral white matter abnormalities and selective brain stem and spinal cord tract involvement. Additionally, there are usually increased lactate levels on magnetic resonance spectroscopy (MRS of the abnormal white matter. In this case report, we describe the clinical and radiological features of a patient with genetically proven adult-onset LBSL and normal lactate levels on MRS.

  4. Endovascular treatment of brain-stem arteriovenous malformations: safety and efficacy

    International Nuclear Information System (INIS)

    Our purpose was to evaluate the safety and efficacy of endovascular treatment of brain-stem arteriovenous malformations (AVMs), reviewing six cases managed in the last 5 years. There were four patients who presented with bleeding, one with a progressive neurological deficit and one with obstructive hydrocephalus. Of the six patients, one showed 100%, one 90%, two 75% and two about 50% angiographic obliteration of the AVM after embolisation; the volume decreased about 75% on average. Five patients had a good outcome and one an acceptable outcome, with a mild postprocedure neurological deficit; none had further bleeding during midterm follow-up. Endovascular management of a brain-stem AVM may be an alternative to treatment such as radiosurgery and microsurgery in selected cases. It may be not as risky as previously thought. Embolisation can reduce the size of the AVM and possibly make it more treatable by radiosurgery and decrease the possibility of radiation injury. (orig.)

  5. Evaluation of normal and pathologic appearance in skull base and brain stem with metrizamide CT cisternography

    International Nuclear Information System (INIS)

    Metrizamide CT cisternography was performed in accordance with prone 600 head-down method, to study the normal anatomy of the skull base and brain stem. Cases of empty sellae, Rathke's cleft cyst, mucocele trigeminal neurinoma, pons glioma, acoustic neurinoma and jugular foramen tumor were studied together. As side effects of MCTC there were headache, vomiting and appearance of slow waves on EEG, but no convulsion. Transient encephalopathy was noted when 250 mgI/ml, 12 ml, was used. Using MCTC, it is possible to identify the vertebral artery, posterior inferior cerebellar artery, basillar artery, vessels forming Willis ring as well as II, III, V, VII and VIII cranial nerves. Further, by measuring the brain stem parts on various levels, it may become possible to detect early changes of degenerative disease. (author)

  6. Human Umbilical Cord Blood Stem Cells: Rational for Use as a Neuroprotectant in Ischemic Brain Disease

    Directory of Open Access Journals (Sweden)

    Hadar Arien-Zakay

    2010-09-01

    Full Text Available The use of stem cells for reparative medicine was first proposed more than three decades ago. Hematopoietic stem cells from bone marrow, peripheral blood and human umbilical cord blood (CB have gained major use for treatment of hematological indications. CB, however, is also a source of cells capable of differentiating into various non-hematopoietic cell types, including neural cells. Several animal model reports have shown that CB cells may be used for treatment of neurological injuries. This review summarizes the information available on the origin of CB-derived neuronal cells and the mechanisms proposed to explain their action. The potential use of stem/progenitor cells for treatment of ischemic brain injuries is discussed. Issues that remain to be resolved at the present stage of preclinical trials are addressed.

  7. Mutations in DARS Cause Hypomyelination with Brain Stem and Spinal Cord Involvement and Leg Spasticity

    OpenAIRE

    Taft, Ryan J.; Vanderver, Adeline; Leventer, Richard J.; Damiani, Stephen A.; Simons, Cas; Grimmond, Sean M.; Miller, David; Schmidt, Johanna; Lockhart, Paul J.; Pope, Kate; Ru, Kelin; Crawford, Joanna; Rosser, Tena; de Coo, Irenaeus F.M.; Juneja, Monica

    2013-01-01

    Inherited white-matter disorders are a broad class of diseases for which treatment and classification are both challenging. Indeed, nearly half of the children presenting with a leukoencephalopathy remain without a specific diagnosis. Here, we report on the application of high-throughput genome and exome sequencing to a cohort of ten individuals with a leukoencephalopathy of unknown etiology and clinically characterized by hypomyelination with brain stem and spinal cord involvement and leg sp...

  8. Stemming the impact of health professional brain drain from Africa: a systemic review of policy options

    OpenAIRE

    Edward Zimbudzi

    2013-01-01

    Africa has been losing professionally trained health workers who are the core of the health system of this continent for many years. Faced with an increased burden of disease and coupled by a massive exodus of the health workforce, the health systems of many African nations are risking complete paralysis. Several studies have suggested policy options to reduce brain drain from Africa. The purpose of this paper is to review possible policies, which can stem the impact of health professional br...

  9. Role of the brain stem in tibial inhibition of the micturition reflex in cats.

    Science.gov (United States)

    Ferroni, Matthew C; Slater, Rick C; Shen, Bing; Xiao, Zhiying; Wang, Jicheng; Lee, Andy; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2015-08-01

    This study examined the role of the brain stem in inhibition of bladder reflexes induced by tibial nerve stimulation (TNS) in α-chloralose-anesthetized decerebrate cats. Repeated cystometrograms (CMGs) were performed by infusing saline or 0.25% acetic acid (AA) to elicit normal or overactive bladder reflexes, respectively. TNS (5 or 30 Hz) at three times the threshold (3T) intensity for inducing toe movement was applied for 30 min between CMGs to induce post-TNS inhibition or applied during the CMGs to induce acute TNS inhibition. Inhibition was evident as an increase in bladder capacity without a change in amplitude of bladder contractions. TNS applied for 30 min between saline CMGs elicited prolonged (>2 h) poststimulation inhibition that significantly (P < 0.05) increased bladder capacity to 30-60% above control; however, TNS did not produce this effect during AA irritation. TNS applied during CMGs at 5 Hz but not 30 Hz significantly (P < 0.01) increased bladder capacity to 127.3 ± 6.1% of saline control or 187.6 ± 5.0% of AA control. During AA irritation, naloxone (an opioid receptor antagonist) administered intravenously (1 mg/kg) or directly to the surface of the rostral brain stem (300-900 μg) eliminated acute TNS inhibition and significantly (P < 0.05) reduced bladder capacity to 62.8 ± 22.6% (intravenously) or 47.6 ± 25.5% (brain stem application). Results of this and previous studies indicate 1) forebrain circuitry rostral to the pons is not essential for TNS inhibition; and 2) opioid receptors in the brain stem have a critical role in TNS inhibition of overactive bladder reflexes but are not involved in inhibition of normal bladder reflexes. PMID:26017973

  10. The contribution of drug resistant cancer stem cells to paediatric brain tumours

    OpenAIRE

    Punjaruk, Wiyada

    2010-01-01

    Introduction: Recent studies have revealed that cancer stem cells (CSCs) exist in malignant disease. Additionally, it is proposed that these cells may survive following chemotherapy, and hence contribute to tumour relapse. A significant mechanism of drug resistance in CSCs is believed to be the expression of ATP-binding cassette (ABC) transporters that efflux cytotoxic agents out of cells. The objective of this study was to study the existence of CSCs in a panel of primary paediatric brain tu...

  11. Availability of transplantable organs from brain stem dead donors in intensive care units.

    OpenAIRE

    Gore, S M; Taylor, R. M.; Wallwork, J

    1991-01-01

    OBJECTIVE--By audit from January to June 1989 to quantify, separately for hearts, kidneys, liver, lungs and corneas, the possible increases in transplantable organs from brain stem dead potential donors in intensive care units and to compare them with the increases achieved in October-November 1989, during intense, national publicity about transplantation. DESIGN--Prospective audit of all deaths in intensive care units in England from 1 January to 30 June 1989 and subsequent case study of the...

  12. Mesenchymal Stem Cells Regulate Blood Brain Barrier Integrity in Traumatic Brain Injury Through Production of the Soluble Factor TIMP3

    Science.gov (United States)

    Menge, Tyler; Zhao, Yuhai; Zhao, Jing; Wataha, Kathryn; Geber, Michael; Zhang, Jianhu; Letourneau, Phillip; Redell, John; Shen, Li; Wang, Jing; Peng, Zhalong; Xue, Hasen; Kozar, Rosemary; Cox, Charles S.; Khakoo, Aarif Y.; Holcomb, John B.; Dash, Pramod K.; Pati, Shibani

    2013-01-01

    Mesenchymal stem cells (MCSs) have been shown to have therapeutic potential in multiple disease states associated with vascular instability including traumatic brain injury (TBI). In the present study, Tissue Inhibitor of Matrix Metalloproteinase-3 (TIMP3) is identified as the soluble factor produced by MSCs that can recapitulate the beneficial effects of MSCs on endothelial function and blood brain barrier (BBB) compromise in TBI. Attenuation of TIMP3 expression in MSCs completely abrogates the effect of MSCs on BBB permeability and stability, while intravenous administration of rTIMP3 alone can inhibit BBB permeability in TBI. Our results demonstrate that MSCs increase circulating levels of soluble TIMP3, which inhibits VEGF-A induced breakdown of endothelial AJs in vitro and in vivo. These findings elucidate a clear molecular mechanism for the effects of MSCs on the BBB in TBI, and directly demonstrate a role for TIMP3 in regulation of BBB integrity. PMID:23175708

  13. Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

    Directory of Open Access Journals (Sweden)

    Khayat Andre

    2011-01-01

    Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

  14. Volumetric comparison of auditory brain nuclei in ear-tufted Araucanas with those in other chicken breeds.

    Science.gov (United States)

    Frahm, H D; Rehkämper, G

    1998-01-01

    Domestic chickens of the breed Araucana have ear-tufts, which affect the structure of the ear canal. Volumes of auditory brainstem nuclei were measured in three chicken breeds in order to evaluate whether the characteristics described for ear-tufted individuals of the Araucana chicken breed (alterations in the outer and middle ear anatomy) are associated with changes in the size of the relevant auditory nuclei. Allometric comparison reveals no size reductions of the angular, laminar and superior olivary nuclei in Araucanas, compared to Japanese Bantams and Brown Leghorns, but a slight increase in the size of the magnocellular nucleus. PMID:9672109

  15. VEGF-mediated angiogenesis stimulates neural stem cell proliferation and differentiation in the premature brain

    International Nuclear Information System (INIS)

    This study investigated the effects of angiogenesis on the proliferation and differentiation of neural stem cells in the premature brain. We observed the changes in neurogenesis that followed the stimulation and inhibition of angiogenesis by altering vascular endothelial growth factor (VEGF) expression in a 3-day-old rat model. VEGF expression was overexpressed by adenovirus transfection and down-regulated by siRNA interference. Using immunofluorescence assays, Western blot analysis, and real-time PCR methods, we observed angiogenesis and the proliferation and differentiation of neural stem cells. Immunofluorescence assays showed that the number of vWF-positive areas peaked at day 7, and they were highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at every time point. The number of neural stem cells, neurons, astrocytes, and oligodendrocytes in the subventricular zone gradually increased over time in the VEGF up-regulation group. Among the three groups, the number of these cells was highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at the same time point. Western blot analysis and real-time PCR confirmed these results. These data suggest that angiogenesis may stimulate the proliferation of neural stem cells and differentiation into neurons, astrocytes, and oligodendrocytes in the premature brain.

  16. VEGF-mediated angiogenesis stimulates neural stem cell proliferation and differentiation in the premature brain

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jinqiao, E-mail: jinqiao1977@163.com [Institute of Pediatrics, Children' s Hospital of Fudan University (China); Sha, Bin [Department of Neonatology, Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China); Zhou, Wenhao, E-mail: zhou_wenhao@yahoo.com.cn [Department of Neonatology, Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China); Yang, Yi [Institute of Pediatrics, Children' s Hospital of Fudan University (China)

    2010-03-26

    This study investigated the effects of angiogenesis on the proliferation and differentiation of neural stem cells in the premature brain. We observed the changes in neurogenesis that followed the stimulation and inhibition of angiogenesis by altering vascular endothelial growth factor (VEGF) expression in a 3-day-old rat model. VEGF expression was overexpressed by adenovirus transfection and down-regulated by siRNA interference. Using immunofluorescence assays, Western blot analysis, and real-time PCR methods, we observed angiogenesis and the proliferation and differentiation of neural stem cells. Immunofluorescence assays showed that the number of vWF-positive areas peaked at day 7, and they were highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at every time point. The number of neural stem cells, neurons, astrocytes, and oligodendrocytes in the subventricular zone gradually increased over time in the VEGF up-regulation group. Among the three groups, the number of these cells was highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at the same time point. Western blot analysis and real-time PCR confirmed these results. These data suggest that angiogenesis may stimulate the proliferation of neural stem cells and differentiation into neurons, astrocytes, and oligodendrocytes in the premature brain.

  17. Brain stem global gene expression profiles in human spina bifida embryos

    Institute of Scientific and Technical Information of China (English)

    Hong Zhao; Xiang Li; Wan-I Lie; Quanren He; Ting Zhang; Xiaoying Zheng; Ran Zhou; Jun Xie

    2011-01-01

    Environmental and genetic factors influence the occurrence of neural tube defects, such as spina bifida.Specific disease expression patterns will help to elucidate the pathogenesis of disease.However, results obtained from animal models, which often exhibit organism specificity, do not fully explain the mechanisms of human spina bifida onset.In the present study, three embryos with a gestational age of approximately 17 weeks and a confirmed diagnosis of spina bifida, as well as 3 age-matched normal embryos, were obtained from abortions.Fetal brain stem tissues were dissected for RNA isolation, and microarray analyses were conducted to examine profiles of gene expression in brain stems of spina bifida and normal embryos using Affymetrix HG-U1 33A 2.0 GeneChip arrays.Of the 14 500 gene transcripts examined, a total of 182 genes exhibited at least 2.5-fold change in expression, including 140 upregulated and 42 downregulated genes.These genes were placed into 19 main functional categories according to the Gene Ontology Consortium database for biological functions.Of the 182 altered genes, approximately 50% were involved in cellular apoptosis, growth, adhesion, cell cycle, stress, DNA replication and repair, signal transduction, nervous system development, oxidoreduction, immune responses, and regulation of gene transcription.Gene expression in multiple biological pathways was altered in the brain stem of human spina bifida embryos.

  18. MRI findings of radiation encephalopathy of brain stem after radiotherapy for nasopharyngeal cancer

    International Nuclear Information System (INIS)

    Purpose: To study MRI findings and clinical manifestation of radiation encephalopathy (RE) of brain stem. Methods: MRI findings and clinical symptoms in 51 patients with RE of brain stem after radiotherapy for nasopharyngeal cancer were reviewed. Results: Clinical symptoms included number weakness or paralysis in the limbs and symptoms of damaged cranial nerves. All lesions appeared hypo- or iso-intense on spin echo(SE) T1-weighted images and inhomogeneous and mixed hyper- and iso-intense on Turbo spin echo (TSE) T2-weighted images. The lesions were located in mesencephalon, pons, medulla, basilar part of pons, basilar part of pons and medulla oblongata in 2,7,3,9 and 30 patients respectively. The enhancement patterns included irregular rings in 39 patients, spotty in 3 and no enhancement in 9 patients. Mass effect was minimal in all patients. On follow-up MRI, the lesions disappeared in 4 patients, did not change in size and shape in 8 patients and enlarged in 2 patients. Conclusion: MRI could demonstrate the characteristic findings of RE of brain stem. MRI findings sometimes are not consistent with the clinical symptoms

  19. Toward angiogenesis of implanted bio-artificial liver using scaffolds with type I collagen and adipose tissue-derived stem cells

    OpenAIRE

    Lee, Jae Geun; Bak, Seon Young; Nahm, Ji Hae; Lee, Sang Woo; Min, Seon Ok; Kim, Kyung Sik

    2015-01-01

    Backgrounds/Aims Stem cell therapies for liver disease are being studied by many researchers worldwide, but scientific evidence to demonstrate the endocrinologic effects of implanted cells is insufficient, and it is unknown whether implanted cells can function as liver cells. Achieving angiogenesis, arguably the most important characteristic of the liver, is known to be quite difficult, and no practical attempts have been made to achieve this outcome. We carried out this study to observe the ...

  20. The Role of Animacy in the Real Time Comprehension of Mandarin Chinese: Evidence from Auditory Event-Related Brain Potentials

    Science.gov (United States)

    Philipp, Markus; Bornkessel-Schlesewsky, Ina; Bisang, Walter; Schlesewsky, Matthias

    2008-01-01

    Two auditory ERP studies examined the role of animacy in sentence comprehension in Mandarin Chinese by comparing active and passive sentences in simple verb-final (Experiment 1) and relative clause constructions (Experiment 2). In addition to the voice manipulation (which modulated the assignment of actor and undergoer roles to the arguments),…

  1. Therapeutic Potential of Umbilical Cord Blood Stem Cells on Brain Damage of a Model of Stroke

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Nikravesh

    2011-11-01

    Full Text Available Introduction: Human cord blood-derived stem cells are a rich source of stem cells as well as precursors. With regard to the researchers have focused on the therapeutic potential of stem cell in the neurological disease such as stroke, the aim of this study was the investiga-tion of the therapeutic effects of human cord blood-derived stem cells in cerebral ischemia on rat. Methods: This study was carried out on young rats. Firstly, to create a laboratory model of ischemic stroke, carotid artery of animals was occluded for 30 minutes. Then, umbilical cord blood cells were isolated and labeled using bromodeoxyuridine and 2×105 cells were injected into the experimental group via the tail vein. Rats with hypoxic condi-tions were used as a sham group. A group of animals did not receive any injection or sur-geries were used as a control. Results: Obtained results were evaluated based on behavior-al responses and immunohistochemistry, with emphasis on areas of putamen and caudate nucleus in the control, sham and experimental groups. Our results indicated that behavioral recovery was observed in the experimental group compared to the either the sham or the control group. However, histological studies demonstrated a low percent of tissue injury in the experimental group in comparison with the sham group. Conclusion: Stem cell trans-plantation is beneficial for the brain tissue reparation after hypoxic ischemic cell death.

  2. A stable and reproducible human blood-brain barrier model derived from hematopoietic stem cells.

    Directory of Open Access Journals (Sweden)

    Romeo Cecchelli

    Full Text Available The human blood brain barrier (BBB is a selective barrier formed by human brain endothelial cells (hBECs, which is important to ensure adequate neuronal function and protect the central nervous system (CNS from disease. The development of human in vitro BBB models is thus of utmost importance for drug discovery programs related to CNS diseases. Here, we describe a method to generate a human BBB model using cord blood-derived hematopoietic stem cells. The cells were initially differentiated into ECs followed by the induction of BBB properties by co-culture with pericytes. The brain-like endothelial cells (BLECs express tight junctions and transporters typically observed in brain endothelium and maintain expression of most in vivo BBB properties for at least 20 days. The model is very reproducible since it can be generated from stem cells isolated from different donors and in different laboratories, and could be used to predict CNS distribution of compounds in human. Finally, we provide evidence that Wnt/β-catenin signaling pathway mediates in part the BBB inductive properties of pericytes.

  3. In Vivo Targeted Magnetic Resonance Imaging of Endogenous Neural Stem Cells in the Adult Rodent Brain

    Directory of Open Access Journals (Sweden)

    Xiao-Mei Zhong

    2015-01-01

    Full Text Available Neural stem cells in the adult mammalian brain have a significant level of neurogenesis plasticity. In vivo monitoring of adult endogenous NSCs would be of great benefit to the understanding of the neurogenesis plasticity under normal and pathological conditions. Here we show the feasibility of in vivo targeted MR imaging of endogenous NSCs in adult mouse brain by intraventricular delivery of monoclonal anti-CD15 antibody conjugated superparamagnetic iron oxide nanoparticles. After intraventricular administration of these nanoparticles, the subpopulation of NSCs in the anterior subventricular zone and the beginning of the rostral migratory stream could be in situ labeled and were in vivo visualized with 7.0-T MR imaging during a period from 1 day to 7 days after the injection. Histology confirmed that the injected targeted nanoparticles were specifically bound to CD15 positive cells and their surrounding extracellular matrix. Our results suggest that in vivo targeted MR imaging of endogenous neural stem cells in adult rodent brain could be achieved by using anti-CD15-SPIONs as the molecular probe; and this targeting imaging strategy has the advantage of a rapid in vivo monitoring of the subpopulation of endogenous NSCs in adult brains.

  4. Differentiation and characterization of human pluripotent stem cell-derived brain microvascular endothelial cells.

    Science.gov (United States)

    Stebbins, Matthew J; Wilson, Hannah K; Canfield, Scott G; Qian, Tongcheng; Palecek, Sean P; Shusta, Eric V

    2016-05-15

    The blood-brain barrier (BBB) is a critical component of the central nervous system (CNS) that regulates the flux of material between the blood and the brain. Because of its barrier properties, the BBB creates a bottleneck to CNS drug delivery. Human in vitro BBB models offer a potential tool to screen pharmaceutical libraries for CNS penetration as well as for BBB modulators in development and disease, yet primary and immortalized models respectively lack scalability and robust phenotypes. Recently, in vitro BBB models derived from human pluripotent stem cells (hPSCs) have helped overcome these challenges by providing a scalable and renewable source of human brain microvascular endothelial cells (BMECs). We have demonstrated that hPSC-derived BMECs exhibit robust structural and functional characteristics reminiscent of the in vivo BBB. Here, we provide a detailed description of the methods required to differentiate and functionally characterize hPSC-derived BMECs to facilitate their widespread use in downstream applications. PMID:26518252

  5. Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation around Solid Implants

    OpenAIRE

    Jain, H. V.; Moldovan, N. I.; Byrne, H. M.

    2012-01-01

    Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O2) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O2-sensitive crystals, consisting of a polymeric capsule limited by a nano-porous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bon...

  6. In situ monitoring of brain tissue reaction of chronically implanted electrodes with an optical coherence tomography fiber system

    Science.gov (United States)

    Xie, Yijing; Hassler, Christina; Stieglitz, Thomas; Seifert, Andreas; Hofmann, Ulrich G.

    2014-03-01

    Neural microelectrodes are well established tools for delivering therapeutic electrical pulses, and recording neural electrophysiological signals. However, long term implanted neural probes often become functionally impaired by tissue encapsulation. At present, analyzing this immune reaction is only feasible with post-mortem histology; currently no means for specific in vivo monitoring exist and most applicable imaging modalities provide no sufficient resolution for a cellular measurement in deep brain regions. Optical coherence tomography (OCT) is a well developed imaging modality, providing cellular resolution and up to 1.2 mm imaging depth in brain tissue. Further more, a fiber based spectral domain OCT was shown to be capable of minimally invasive brain intervention. In the present study, we propose to use a fiber based spectral domain OCT to monitor the the progression of the tissue's immune response and scar encapsulation of microprobes in a rat animal model. We developed an integrated OCT fiber catheter consisting of an implantable ferrule based fiber cannula and a fiber patch cable. The fiber cannula was 18.5 mm long, including a 10.5 mm ceramic ferrule and a 8.0 mm long, 125 μm single mode fiber. A mating sleeve was used to fix and connect the fiber cannula to the OCT fiber cable. Light attenuation between the OCT fiber cable and the fiber cannula through the mating sleeve was measured and minimized. The fiber cannula was implanted in rat brain together with a microelectrode in sight used as a foreign body to induce the brain tissue immune reaction. Preliminary data showed a significant enhancement of the OCT backscattering signal during the brain tissue scarring process, while the OCT signal of the flexible microelectrode was getting weaker consequentially.

  7. Induction of neuro-protective/regenerative genes in stem cells infiltrating post-ischemic brain tissue

    Directory of Open Access Journals (Sweden)

    Yilmaz Gokhan

    2010-05-01

    Full Text Available Abstract Background- Although the therapeutic potential of bone marrow-derived stromal stem cells (BMSC has been demonstrated in different experimental models of ischemic stroke, it remains unclear how stem cells (SC induce neuroprotection following stroke. In this study, we describe a novel method for isolating BMSC that infiltrate postischemic brain tissue and use this method to identify the genes that are persistently activated or depressed in BMSC that infiltrate brain tissue following ischemic stroke. Methods- Ischemic strokes were induced in C57BL/6 mice by middle cerebral artery occlusion for 1 h, followed by reperfusion. BMSC were isolated from H-2 Kb-tsA58 (immortomouse™ mice, and were administered (i.v. 24 h after reperfusion. At the peak of therapeutic improvement (14 days after the ischemic insult, infarcted brain tissue was isolated, and the BMSC were isolated by culturing at 33°C. Microarray analysis and RT-PCR were performed to compare differential gene expression between naïve and infiltrating BMSC populations. Results- Z-scoring revealed dramatic differences in the expression of extracellular genes between naïve and infiltrating BMSC. Pair-wise analysis detected 80 extracellular factor genes that were up-regulated (≥ 2 fold, P Conclusions- BMSC infiltrating the post-ischemic brain exhibit persistent epigenetic changes in gene expression for numerous extracellular genes, compared to their naïve counterparts. These genes are relevant to the neuroprotection, regeneration and angiogenesis previously described following stem cell therapy in animal models of ischemic stroke.

  8. Nanoparticle-mediated transcriptional modification enhances neuronal differentiation of human neural stem cells following transplantation in rat brain.

    Science.gov (United States)

    Li, Xiaowei; Tzeng, Stephany Y; Liu, Xiaoyan; Tammia, Markus; Cheng, Yu-Hao; Rolfe, Andrew; Sun, Dong; Zhang, Ning; Green, Jordan J; Wen, Xuejun; Mao, Hai-Quan

    2016-04-01

    Strategies to enhance survival and direct the differentiation of stem cells in vivo following transplantation in tissue repair site are critical to realizing the potential of stem cell-based therapies. Here we demonstrated an effective approach to promote neuronal differentiation and maturation of human fetal tissue-derived neural stem cells (hNSCs) in a brain lesion site of a rat traumatic brain injury model using biodegradable nanoparticle-mediated transfection method to deliver key transcriptional factor neurogenin-2 to hNSCs when transplanted with a tailored hyaluronic acid (HA) hydrogel, generating larger number of more mature neurons engrafted to the host brain tissue than non-transfected cells. The nanoparticle-mediated transcription activation method together with an HA hydrogel delivery matrix provides a translatable approach for stem cell-based regenerative therapy. PMID:26828681

  9. Cochlear Implantation (CI for prelingual deafness: the relevance of studies of brain organization and the role of first language acquisition in considering outcome success.

    Directory of Open Access Journals (Sweden)

    Ruth Campbell

    2014-10-01

    Full Text Available Cochlear implantation (CI for profound congenital hearing impairment, while often successful in restoring hearing to the deaf child, does not always result in effective speech processing. Exposure to non-auditory signals during the pre-implantation period is widely held to be responsible for such failures. Here, we question the inference that such exposure irreparably distorts the function of auditory cortex, negatively impacting the efficacy of cochlear implantation. Animal studies suggest that in congenital early deafness there is a disconnection between (disordered activation in primary auditory cortex (A1 and activation in secondary auditory cortex (A2. In humans, one factor contributing to this functional decoupling is assumed to be abnormal activation of A1 by visual projections – including exposure to sign language. In this paper we show that that this abnormal activation of A1 does not routinely occur, while A2 functions effectively supramodally and multimodally to deliver spoken language irrespective of hearing status. What, then, is responsible for poor outcomes for some individuals with CI and for apparent abnormalities in cortical organization in these people? Since infancy is a critical period for the acquisition of language, deaf children born to hearing parents are at risk of developing inefficient neural structures to support skilled language processing. A sign language, acquired by a deaf child as a first language in a signing environment, is cortically organized like a heard spoken language in terms of specialization of the dominant perisylvian system. However, very few deaf children are exposed to sign language in early infancy. Moreover, no studies to date have examined sign language proficiency in relation to cortical organization in individuals with CI. Given the paucity of such relevant findings, we suggest that the best guarantee of good language outcome after CI is the establishment of a secure first language pre-implant

  10. An auditory multiclass brain-computer interface with natural stimuli: usability evaluation with healthy participants and a motor impaired end user

    Directory of Open Access Journals (Sweden)

    Nadine eSimon

    2015-01-01

    Full Text Available Brain-computer interfaces (BCIs can serve as muscle independent communication aids. Persons, who are unable to control their eye muscles (e.g. in the completely locked-in state or have severe visual impairments for other reasons, need BCI systems that do not rely on the visual modality. For this reason, BCIs that employ auditory stimuli were suggested. In this study, a multiclass BCI spelling system was implemented that uses animal voices with directional cues to code rows and columns of a letter matrix. To reveal possible training effects with the system, 11 healthy participants performed spelling tasks on two consecutive days. In a second step, the system was tested by a participant with amyotrophic lateral sclerosis (ALS in two sessions. In the first session, healthy participants spelled with an average accuracy of 76% (3.29 bits/min that increased to 90% (4.23 bits/min on the second day. Spelling accuracy by the participant with ALS was 20% in the first and 47% in the second session. The results indicate a strong training effect for both the healthy participants and the participant with ALS. While healthy participants reached high accuracies in the first session and second session, accuracies for the participant with ALS were not sufficient for satisfactory communication in both sessions. More training sessions might be needed to improve spelling accuracies. The study demonstrated the feasibility of the auditory BCI with healthy users and stresses the importance of training with auditory multiclass BCIs, especially for potential end-users of BCI with disease.

  11. Results of Total Knee Arthroplasty with NexGen LPS-flex Implant Using Navigation System (Brain Lab): Results with a 5-year Follow-up

    OpenAIRE

    Kang, Chul Hyung; Lee, Kyung Jae; Bae, Ki Cheor; Cho, Chul Hyun; Lee, Si Wook; Shin, Hong Kwan; Lee, Young Kook; Bae, Ji Suk

    2012-01-01

    Purpose To evaluate the clinical and radiological results of patients that underwent total knee arthroplasty (TKA) with a NexGen LPS-Flex implant using a Navigation system (Brain Lab). Materials and Methods Between January 2001 and December 2005, 55 knees in 46 patients which used the NexGen LPS-Flex implant with a Navigation system (Brain Lab) for primary TKA were clinically and radiologically evaluated after a minimum follow-up of 5 years. Evaluation included preoperative and postoperative ...

  12. Methodology to assess response to stereotactic irradiation in lesions of the brain stem

    International Nuclear Information System (INIS)

    Purpose/Objective: Magnetic resonance image changes were measured at various time points after patients were treated with stereotactic irradiation to brain lesions in and around the brain stem. Results were correlated with the dose of ionizing radiation given to the same anatomical region. The methodology was developed to assess its utility in predicting brain stem injury and lesion response to high-dose, single-fraction radiation treatments. Materials and Methods: We developed a computerized system for spatially correlating and analyzing changes in T1 weighted, gadolinium enhanced, 3-D magnetic resonance (MR) image sets at multiple time points after treatment with stereotactic brain irradiation. Using this system, we were able to compare post-treatment with pre-treatment images used for computerized treatment planning. The treatment planning image sets contained the dose-volume information for each treatment. The measured quantities included pixel value, size of enhanced region, and dose point value. Twelve patients, having a minimum follow-up after radiosurgery of 6 months and brain lesions of various types, were selected for review: 1 glioma, 4 juvenile pilocytic astrocytomas, 1 cavernous hemangioma, 1 ependymoma, 1 primitive neuroectodermal tumor, 1 meningioma, and 3 metastases. Patient ages ranged from 3 to 59 years at time of treatment. The prescription doses to the lesions ranged from 12 to 20 Gy. The severity and duration of complications were noted for each. Results: Image intensity changes were measured and correlated with dose on a pixel-by-pixel basis in order to plot the time course of the changes. The estimate of spatial accuracy for locating the dose and voxel of tissue was within 2 mm. The sequelae of radiologic changes to irradiation were mixed. We observed increases as well as decreases in the density of the irradiated region with time after treatment which depended on the patient. One patient had nearly complete disappearance of the enhancing

  13. The penetration of metrizamide into the brain after routine lumbar myelography as shown by cerebral computed tomography and its effect on auditory brainstem transmission time

    International Nuclear Information System (INIS)

    Metrizamide is a widely used contrast medium with some well known adverse reactions. In a preliminary study, CT scans and Brain Stem Evoked Potentials (BAEP) were done before and 18 hours following lumbar myelography on 12 patients. A statistically significant prolongation of the BAEP was observed. Metrizamide therefore seems to be a potent substance in clinical use as indicated by its effect on BAEP. BAEP should not be done within the first few days after myelography with metrizamide. (orig.)

  14. Information processing becomes slower and predominantly serial in aging: Characterization of response-related brain potentials in an auditory-visual distraction-attention task.

    Science.gov (United States)

    Cid-Fernández, Susana; Lindín, Mónica; Díaz, Fernando

    2016-01-01

    The aim of this study was to evaluate the effects of aging and attentional capture provoked by novel auditory stimuli on behavior (reaction time [RT], hits) and on response-related brain potentials (preRFP, CRN, postRFP, parietalRP) to target visual stimuli. Twenty-two young, 27 middle-aged, and 24 old adults performed an auditory-visual distraction-attention task. The RTs and latencies of preRFP, postRFP and parietalRT were longer in old and middle-aged than in young participants, reflecting the well-established age-related slowing of processing and performance. The inter-peak latencies (P3b-preRFP, preRFP-parietalRP, parietalRP-postRFP) were also longer in old and middle-aged than in young participants, further indicating an age-related tendency to increased predominance of serial (rather than parallel) processing of information, and that preRFP, CRN, postRFP, and parietalRP represent different cognitive processes from those indexed by the stimulus-related P3b. Finally, a distraction effect in performance (all three groups) and in postRFP latency (only middle-aged group) was also observed. PMID:26589359

  15. Radiation and misonidazole in children with brain stem gliomas and supratentorial glioblastoma

    International Nuclear Information System (INIS)

    In a series of 484 children with intracranial tumors referred to the Royal Marsden Hospital for radiotherapy, there were 47 (12%) examples of inoperable pontine and medullary tumors for which the 5-year survival rate was 17%. The limited local tumor mass in brain stem tumors, the absence of cerebro-spinal or distant metastases, and their often initial good but short-lived response to irradiation, all support the trial of a chemical radiosensitizing agent with which to try and achieve greater and more prolonged local control of the disease. Since the prognosis for cerebral hemisphere glioblastoma, which is relatively uncommon in children, is also extremely poor, such cases were included in this pilot study. The problems and possible risks associated with combined radiotherapy and a chemical radiosensitizer in children with brain tumors is discussed. So far, 8 children with brain stem tumors and 3 children with cerebral hemisphere gliomas heave been treated in this study. In addtion, data is also available on 3 children re-treated for incurrent medulloblastomas. Preliminary observations regarding experience with this small series will be reported including blood misonidazole levels, drug tolerance and the possible influence of anticonvulsants and steriods on toxicity

  16. Brain stem and cerebellum volumetric analysis of Machado Joseph disease patients

    Directory of Open Access Journals (Sweden)

    S T Camargos

    2011-01-01

    Full Text Available Machado-Joseph disease, or spinocerebellar ataxia type 3(MJD/SCA3, is the most frequent late onset spinocerebellar ataxia and results from a CAG repeat expansion in the ataxin-3 gene. Previous studies have found correlation between atrophy of cerebellum and brainstem with age and CAG repeats, although no such correlation has been found with disease duration and clinical manifestations. In this study we test the hypothesis that atrophy of cerebellum and brainstem in MJD/SCA3 is related to clinical severity, disease duration and CAG repeat length as well as to other variables such as age and ICARS (International Cooperative Ataxia Rating Scale. Whole brain high resolution MRI and volumetric measurement with cranial volume normalization were obtained from 15 MJD/SCA3 patients and 15 normal, age and sex-matchedcontrols. We applied ICARS and compared the score with volumes and CAG number, disease duration and age. We found significant correlation of both brain stem and cerebellar atrophy with CAG repeat length, age, disease duration and degree of disability. The Spearman rank correlation was stronger with volumetric reduction of the cerebellum than with brain stem. Our data allow us to conclude that volumetric analysis might reveal progressive degeneration after disease onset, which in turn is linked to both age and number of CAG repeat expansions in SCA 3.

  17. Adaptor protein LNK is a negative regulator of brain neural stem cell proliferation after stroke.

    Science.gov (United States)

    Ahlenius, Henrik; Devaraju, Karthikeyan; Monni, Emanuela; Oki, Koichi; Wattananit, Somsak; Darsalia, Vladimer; Iosif, Robert E; Torper, Olof; Wood, James C; Braun, Sebastian; Jagemann, Lucas; Nuber, Ulrike A; Englund, Elisabet; Jacobsen, Sten-Eirik W; Lindvall, Olle; Kokaia, Zaal

    2012-04-11

    Ischemic stroke causes transient increase of neural stem and progenitor cell (NSPC) proliferation in the subventricular zone (SVZ), and migration of newly formed neuroblasts toward the damaged area where they mature to striatal neurons. The molecular mechanisms regulating this plastic response, probably involved in structural reorganization and functional recovery, are poorly understood. The adaptor protein LNK suppresses hematopoietic stem cell self-renewal, but its presence and role in the brain are poorly understood. Here we demonstrate that LNK is expressed in NSPCs in the adult mouse and human SVZ. Lnk(-/-) mice exhibited increased NSPC proliferation after stroke, but not in intact brain or following status epilepticus. Deletion of Lnk caused increased NSPC proliferation while overexpression decreased mitotic activity of these cells in vitro. We found that Lnk expression after stroke increased in SVZ through the transcription factors STAT1/3. LNK attenuated insulin-like growth factor 1 signaling by inhibition of AKT phosphorylation, resulting in reduced NSPC proliferation. Our findings identify LNK as a stroke-specific, endogenous negative regulator of NSPC proliferation, and suggest that LNK signaling is a novel mechanism influencing plastic responses in postischemic brain. PMID:22496561

  18. Stemming the impact of health professional brain drain from Africa: a systemic review of policy options

    Directory of Open Access Journals (Sweden)

    Edward Zimbudzi

    2013-06-01

    Full Text Available Africa has been losing professionally trained health workers who are the core of the health system of this continent for many years. Faced with an increased burden of disease and coupled by a massive exodus of the health workforce, the health systems of many African nations are risking complete paralysis. Several studies have suggested policy options to reduce brain drain from Africa. The purpose of this paper is to review possible policies, which can stem the impact of health professional brain drain from Africa. A systemic literature review was conducted. Cinahl, Science Direct and PubMed databases were searched with the following terms: health professional brain drain from Africa and policies for reducing impact of brain drain from Africa. References were also browsed for relevant articles. A total of 425 articles were available for the study but only 23 articles met the inclusion criteria. The review identified nine policy options, which were being implemented in Africa, but the most common was task shifting which had success in several African countries. This review has demonstrated that there is considerable consensus on task shifting as the most appropriate and sustainable policy option for reducing the impact of health professional brain drain from Africa.

  19. Functional effect of mouse embryonic stem cell implantation after spinal cord injury

    OpenAIRE

    Lee, Tae-Hoon

    2013-01-01

    We transplanted mouse embryonic stem cells (mESCs) to improve functional loss in a rat model of clip-compression spinal cord injury (SCI). The mouse embryonic stem cells were transplanted to injured cord 7 days after injury. We include minimizing the progression of secondary injury, manipulating the neuroinhibitory environment of the spinal cord, replacing lost tissue with transplanted cells and substantial improvement of motor. A number of potential approaches optimize functional recovery af...

  20. 语前聋患者人工耳蜗植入术后听觉言语康复相关影响因素的研究%Research on the Influencing Factors of Auditory and Speech Rehabilitation Outcomes of Prelingually Deaf Patients with Cochlear Implants

    Institute of Scientific and Technical Information of China (English)

    张斯斯; 林有辉; 张榕; 叶胜难

    2013-01-01

    目的探讨语前聋人工耳蜗植入患者的听觉言语康复效果及其相关影响因素。方法对159例人工耳蜗植入患者家长和康复教师进行调查随访。根据听觉行为分级标准(Categories of Auditory Performance,CAP)和言语可懂度分级标准(Speech Intelligibility Rating,SIR),对患者的听觉能力和言语能力进行分级评估。用组内单因素秩和检验和多因素Logistic回归分析CAP和SIR分级结果与性别、惯用手、内耳发育、颅脑影像学情况、术前助听器使用、术前语训、植入耳侧、植入电极类型、植入年龄、植入后时间、术后语言环境、术后康复模式、家庭经济状况等13个因素的关系。结果单因素分析结果显示,不同的术前助听器使用情况、术前语训、植入后时间、家庭经济状况组间CAP分级结果有显著性差异(P值均<0.05);不同的植入耳侧、植入后时间、家庭经济状况组间SIR分级结果有显著性差异(P值均<0.05)。多因素Logistic回归分析结果显示,植入后时间、家庭经济状况与CAP、SIR分级结果均有显著相关。结论植入后时间、家庭经济状况对人工耳蜗植入术后患者的听觉言语康复效果起决定性的作用。%Objective To explore the auditory and speech rehabilitation outcomes of prelingually hearing-impaired patients with cochlear implants and the related influencing factors. Methods One hundred fifty-nine cochlear implantees were recruited in this study.The parents or teachers were interviewed to assess the auditory and speech abilities of the subjects using Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR). The relationships were investigated between auditory and speech rehabilitation outcomes represented by CAP/SIR results and 13 possible influencing factors including gender, handedness, inner ear malformations, brain abnormalities, hearing aid use, language training before

  1. Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Mehrnaz Karimi

    1992-04-01

    Full Text Available People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss . In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter, stimulator and receiver, and electrode array.

  2. Comparitive Study Between Cnventional and Hyperfractionaltion Radiation Therapy for The Treatment of Brain Stem Tumors

    Directory of Open Access Journals (Sweden)

    Laila Fares * (MD, Mamdouh Salama** (MD Manal Moawad

    2001-06-01

    Full Text Available Brain stem tumors are special challenge because primarily of their location and the neurologic effect caused by these groups of tumors (Paul 1997. Radiation therapy improves survival for brain stem tumors and stabilizes or reverses neurologic dysfunction in 75-90% of patients. The main domain of applicability of hyperfractionation would be in tumor sites where the dose limiting tissue is late reacting and whose effective control requires the delivery of doses beyond tolerance (Awwad, 1990, hence the rationale for the use of hyperfractionation in brain stem lesions. The purpose of this work is to find out the best radiation protocol in this group of patients comparing conventional fractionation and hyperafractionation. This study included 46 patients which brainstem tumors treated in Radiation Oncology and Neurosurgery Departments Ain Shams University between February 1998 and May 2000. These patients had been randomly distributed in 2 groups A and B. The first group treated by conventional radiotherapy protocol and the second group treated by hyperfractionation radiation protocol. By the end of the study, the median over all survival and median time for disease progression were calculated for each group. Age, neurologic status at presentation and anatomical location were significant prognostic factors. By the end of this study clicinal evalualion had no significant difference between both groups but the median over all survival for the two groups was 10.5 months, the median survival for group A was 9.4 months and that for group B was 11.5 months which was statistically significant P < 0.02. On the other hand the percentage of patient with one year survival for group A & B (22%, 32% respectively. The rate of acute (early reaction of radiation is slightly higher in hyperfracticmaticm than conventional fractionation but the late reactions occur with same frequency with both regimens.

  3. Dosimetric analysis of trigeminal nerve, brain stem doses in CyberKnife radiosurgery of trigeminal neuralgia

    International Nuclear Information System (INIS)

    CyberKnife radiosurgery treatment of Trigeminal neuralgia (TN) is performed as a non-invasive image guided procedure. The prescription dose for TN is very high. The brainstem is the adjacent critical organ at risk (OAR) which is prone to receive the very high target dose of TN. The present study is to analyze the dose distribution inside the tiny trigeminal nerve target and also to analyze the dose fall off in the brain stem. Seven TN cases treated between November 2010 and January 2012 were taken for this study retrospectively. The treatment plans were analyzed for target dose conformity, homogeneity and dose coverage. In the brainstem the volume doses D1% and D2% were taken for analyzing the higher doses in the brain stem. The dose fall off was analyzed in terms of D5% and D10%. The mean value of maximum dose within the trigeminal nerve target was 73.5±2.1 Gy (P=0.0007) and the minimum dose was 50.0±4.1Gy (P=0.1315). The mean conformity index was 2.19 and the probable reason could be the smallest CyberKnife collimator of 5mm used in the treatment plan. The mean D1%, of the brainstem was 10.5±2.1Gy(P=0.5316) and the mean value of the maximum point dose within the brainstem was 35.6±3.8Gy. This shows the degree of dose fall off within the brainstem. Though the results of the present study are showing superior sparing of brain stem and reasonable of target coverage, it is necessary to execute the treatment plan with greater accuracy in CyberKnife as the immobilization is noninvasive and frameless. (author)

  4. The treatment of brain stem and thalamic gliomas with 78 Gy of hyperfractionated radiation therapy

    International Nuclear Information System (INIS)

    Purpose: To see whether increasing the dose of hyperfractionated radiation therapy from 72 to 78 Gy would increase survival time in patients with gliomas, particularly those with brain stem or thalamic tumors. Methods: Seventy-eight patients with a clinical and radiographic diagnosis of a brain stem or thalamic glioma were enrolled in a trial to receive 78 Gy (1.0 Gy twice a day). Six patients with disease in other sites were also treated. The initial response to therapy was determined by comparing pretreatment magnetic resonance images and neurological examinations with those obtained within 2 weeks of completing therapy; subsequent responses were determined from bimonthly follow-up images. Time-to-tumor progression was measured from the date radiation therapy began until the date of documented radiographic or clinical progression. Survival time was measured from the date radiation therapy began until the date of death. Cox proportional hazards analysis was used to estimate the effects of specific variables on survival. Results: Of 81 evaluable patients, 68 received ≥ 76 Gy, 10 received between 70 and 75 Gy, and 3 received between 60 and 68 Gy. The overall response or stabilization rate was 70.4%. Tumor size decreased in 30.8% of patients; 39.5% had stable disease, and 29.6% had immediate progression. The median survival time was 12.7 months (16.1 months for adults and 10.8 months for children). The median time to tumor progression was 9.0 months (11.4 months for adults and 8.4 months for children). A duration of symptoms ≤ 2 months and a diffuse lesion were each associated with shorter survival and progression times. Conclusions: For patients with brain stem or thalamic gliomas, increasing the dose of radiation therapy from 72 to 78 Gy did not significantly improve survival. Different treatment strategies are clearly needed

  5. Auditory and Visual Sensations

    CERN Document Server

    Ando, Yoichi

    2010-01-01

    Professor Yoichi Ando, acoustic architectural designer of the Kirishima International Concert Hall in Japan, presents a comprehensive rational-scientific approach to designing performance spaces. His theory is based on systematic psychoacoustical observations of spatial hearing and listener preferences, whose neuronal correlates are observed in the neurophysiology of the human brain. A correlation-based model of neuronal signal processing in the central auditory system is proposed in which temporal sensations (pitch, timbre, loudness, duration) are represented by an internal autocorrelation representation, and spatial sensations (sound location, size, diffuseness related to envelopment) are represented by an internal interaural crosscorrelation function. Together these two internal central auditory representations account for the basic auditory qualities that are relevant for listening to music and speech in indoor performance spaces. Observed psychological and neurophysiological commonalities between auditor...

  6. 660 nm red light-enhanced bone marrow mesenchymal stem cell transplantation for hypoxic-ischemic brain damage treatment

    Institute of Scientific and Technical Information of China (English)

    Xianchao Li; Wensheng Hou; Xiaoying Wu; Wei Jiang; Haiyan Chen; Nong Xiao; Ping Zhou

    2014-01-01

    Bone marrow mesenchymal stem cell transplantation is an effective treatment for neonatal hy-poxic-ischemic brain damage. However, the in vivo transplantation effects are poor and their survival, colonization and differentiation efifciencies are relatively low. Red or near-infrared light from 600-1,000 nm promotes cellular migration and prevents apoptosis. Thus, we hypothesized that the combination of red light with bone marrow mesenchymal stem cell transplantation would be effective for the treatment of hypoxic-ischemic brain damage. In this study, the migra-tion and colonization of cultured bone marrow mesenchymal stem cells on primary neurons after oxygen-glucose deprivation were detected using Transwell assay. The results showed that, after a 40-hour irradiation under red light-emitting diodes at 660 nm and 60 mW/cm2, an increasing number of green lfuorescence-labeled bone marrow mesenchymal stem cells migrated towards hypoxic-ischemic damaged primary neurons. Meanwhile, neonatal rats with hypoxic-ischemic brain damage were given an intraperitoneal injection of 1 × 106 bone marrow mesenchymal stem cells, followed by irradiation under red light-emitting diodes at 660 nm and 60 mW/cm2 for 7 successive days. Shuttle box test results showed that, after phototherapy and bone marrow mesenchymal stem cell transplantation, the active avoidance response rate of hypoxic-ischemic brain damage rats was significantly increased, which was higher than that after bone marrow mesenchymal stem cell transplantation alone. Experimental ifndings indicate that 660 nm red light emitting diode irradiation promotes the migration of bone marrow mesenchymal stem cells, thereby enhancing the contribution of cell transplantation in the treatment of hypox-ic-ischemic brain damage.

  7. Accuracy and precision of targeting using frameless stereotactic system in deep brain stimulator implantation surgery

    Directory of Open Access Journals (Sweden)

    Mayur Sharma

    2014-01-01

    Full Text Available Objectives: To assess the accuracy of targeting using NexFrame frameless targeting system during deep brain stimulation (DBS surgery. Materials and Methods: Fifty DBS leads were implanted in 33 patients using the NexFrame (Medtronic, Minneapolis, MN targeting system. Postoperative thin cut CT scans were used for lead localization. X, Y, Z coordinates of the tip of the lead were calculated and compared with the intended target coordinates to assess the targeting error. Comparative frame-based data set was obtained from randomly selected 33 patients during the same period that underwent 65 lead placements using Leksell stereotactic frame. Euclidean vector was calculated for directional error. Multivariate analysis of variance was used to compare the accuracy between two systems. Results: The mean error of targeting using frameless system in medio-lateral plane was 1.4 mm (SD ± 1.3, in antero-posterior plane was 0.9 mm (SD ± 1.0 and in supero-inferior plane Z was 1.0 mm (SD ± 0.9. The mean error of targeting using frame-based system in medio-lateral plane was 1.0 mm (SD ± 0.7, in antero-posterior plane was 0.9 mm (SD ± 0.5 and in supero-inferior plane Z was 0.7 mm (SD ± 0.6. The error in targeting was significantly more (P = 0.03 in the medio-lateral plane using the frameless system as compared to the frame-based system. Mean targeting error in the Euclidean directional vector using frameless system was 2.2 (SD ± 1.6 and using frame-based system was 1.7 (SD ± 0.6 (P = 0.07. There was significantly more error in the first 25 leads placed using the frameless system than the second 25 leads (P = 0.0015. Conclusion: The targeting accuracy of the frameless system was lower as compared to frame-based system in the medio-lateral direction. Standard deviations (SDs were higher using frameless system as compared to the frame-based system indicating lower accuracy of this system. Error in targeting should be considered while using frameless

  8. Science Letters: Brain natriuretic peptide: A potential indicator of cardiomyogenesis after autologous mesenchymal stem cell transplantation?

    Institute of Scientific and Technical Information of China (English)

    LI Nan; WANG Jian-an

    2006-01-01

    We observed in a pilot study that there was a transient elevation of brain natriuretic peptide (BNP) level shortly after the transplantation in the patient with ischemic heart failure, which is unexplainable by the simultaneous increase of the cardiac output and six-minute walk distance. Similar findings were observed in the phase I trial. We postulated on the basis of the finding of Fukuda in vitro that this transient elevation of BNP level against the improvement of cardiac function and exercise capacity might indicate cardiomyogenesis in patients after mesenchymal stem cell transplantation. Further study is warranted to verify the hypothesis.

  9. Apples to origins: Identifying brain tumor stem cell genes by comparing transcriptomes of normal and cancer stem cells

    OpenAIRE

    Wortham, Matthew; Yan, Hai

    2012-01-01

    The mechanisms whereby medulloblastoma stem cells coordinate tumor propagation are poorly understood. Utilizing microarray analysis, Corno and colleagues draw parallels and distinctions between medulloblastoma stem cells from the Ptch+/− mouse and normal neural stem cells, identifying Ebf3 as a cancer stem cell-specific transcript critical for tumor growth.

  10. The pros and cons of intraoperative CT scan in evaluation of deep brain stimulation lead implantation: A retrospective study

    Science.gov (United States)

    Servello, Domenico; Zekaj, Edvin; Saleh, Christian; Pacchetti, Claudio; Porta, Mauro

    2016-01-01

    Background: Deep brain stimulation (DBS) is an established therapy for movement disorders, such as Parkinson's disease (PD), dystonia, and tremor. The efficacy of DBS depends on the correct lead positioning. The commonly adopted postoperative radiological evaluation is performed with computed tomography (CT) scan and/or magnetic resonance imaging (MRI). Methods: We conducted a retrospective study on 202 patients who underwent DBS from January 2009 to October 2013. DBS indications were PD, progressive supranuclear palsy, tremor, dystonia, Tourette syndrome, obsessive compulsive disorder, depression, and Huntington's disease. Preoperatively, all patients underwent brain MRI and brain CT scan with the stereotactic frame positioned. The lead location was confirmed intraoperatively with CT. The CT images were subsequently transferred to the Stealth Station Medtronic and merged with the preoperative planning. On the first or second day after, implantation we performed a brain MRI to confirm the correct position of the lead. Results: In 14 patients, leads were in suboptimal position after intraoperative CT scan positioning. The cases with alteration in the Z-axis were corrected immediately under fluoroscopic guidance. In all the 14 patients, an immediate repositioning was done. Conclusions: Based on our data, intraoperative CT scan is fast, safe, and a useful tool in the evaluation of the position of the implanted lead. It also reduces the patient's discomfort derived from the transfer of the patient from the operating room to the radiological department. However, intraoperative CT should not be considered as a substitute for postoperative MRI.

  11. The surgical viability and radiological monitoring of brain implants of bioactive micro-seeds in an animal model

    Directory of Open Access Journals (Sweden)

    Giane X. O. Silva

    2005-10-01

    Full Text Available The interstitial implant is a therapeutic modality in brachytherapy of the head and neck. Presently, the seeds implanted in tumors in the central nervous system are metallic I-125. After the full emission of the radionuclide, the seed remains inert in the implanted area. Bioactive ceramic seeds have been prepared for this research group incorporating Sm-152 to be active in Sm-153. The main goal of the present study is the development of a the surgical technique for implanting the biodegradable radioactive micro-seeds in the brains of rabbits, as well as the observation of the clinical reactions of the animal after implantation of two sets of three seeds. The surgical procedure consisted of performing two separate perforations 10 mm from each other in the skull, permitting the implantation of two groups of three seeds, totaling six seeds. The results of the pilot study showed the effectiveness of the surgical procedure and of the biocompatibility of the seeds and the lack of presence of adverse reactions, functional sequels, or inflammation in a follow up 50 days post-surgery. Such seeds of reduced volume, 0.2 x 1.6 mm, could be monitored by computerized tomography 30 days after implanting.Os implantes intersticiais podem ser utilizados em braquiterapia de cabeça e pescoço. Atualmente as sementes implantadas no CNS são de I-125 metálicas. Após o decaimento do radioisótopo, a semente fica inerte na região implantada. Sementes cerâmicas bioativas tem sido preparadas pelo grupo de pesquisa incorporando Sm-152. O presente estudo tem o objetivo de viabilizar a técnica cirúrgica de implantes de microsementes biodegradáveis não radioativas no cérebro de coelhos, bem como verificar as reações clínicas e funcionais do animal ao corpo estranho implantado. O procedimento cirúrgico compreendeu em proceder duas perfurações separadas em 10mm na calota craniana onde foi possível a implantação de dois conjuntos de três sementes

  12. COCHLEAR IMPLANTATION: MY EXPERIENCE

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    Shankar

    2015-12-01

    Full Text Available Cochlear implant is a small, surgically implanted complex electronic device that can help to provide a sense of sound to a person with severe to profound sensorineural hearing loss. This type of hearing loss, typically involves damage to hair cells in the cochlea, as a result sound cannot reach the auditory nerve which usually receives information from hair cells. A cochlear implant skips the damaged hair cells and to stimulate the auditory nerve directly. An implant does not restore normal hearing, instead it can give a deaf person a useful representation of sounds in the environment and help him or her to understand speech. I am here presenting this article in relation to the indications, intraoperative and postoperative complications of cochlear implantation in our institute since January 2013. Children who receive implants at earlier age, outperform their peers who are implanted at a later age. This is reflected in all the areas of speech and language development.

  13. Biocompatibility of Implantable Electrodes Coated with PVA Films in the Brain of Rats:a Histological Evaluation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qin; LI Tao; LI Chengyan; YE Ming; LU Yi; DUAN Yanwen

    2009-01-01

    The biocompatibility of silicone rubber(SR)based electrodes coating with poly (vinyl alcohol)(PVA)films after implanted in the brain of rats was investigated.Twenty-two Wistar rats were used and implanted with SR electrodes and PVA/PAA films coated electrodes in left and right cerebral cortex respectively.After 4 and 8 weeks,the expression of glial fibrillary acidic protein (GFAP,a specific marker of astrocytes)and cluster of differentiation 68(CD68,a specific marker of macrophages)were evaluated by immunohistochemistry.After 8 weeks,GFAP and CD68 expressions around PVA electrodes were significantly lower than those around SR electrodes in every stratified area(0-50μm,50-100μm,100μm from further up to the electrode-tissue interface).The results show that PVA coating can reduce the expressions of GFAP and CD68,suggesting the PVA coating can improve the biocompatibility of the SR while it is implanted in brain.

  14. Nanotechnology and Dental Implants

    OpenAIRE

    Sandrine Lavenus; Guy Louarn; Pierre Layrolle

    2010-01-01

    The long-term clinical success of dental implants is related to their early osseointegration. This paper reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone-to-implant contact is desired for a biomechanical anchoring of i...

  15. Maternal Inflammation Contributes to Brain Overgrowth and Autism-Associated Behaviors through Altered Redox Signaling in Stem and Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Janel E. Le Belle

    2014-11-01

    Full Text Available A period of mild brain overgrowth with an unknown etiology has been identified as one of the most common phenotypes in autism. Here, we test the hypothesis that maternal inflammation during critical periods of embryonic development can cause brain overgrowth and autism-associated behaviors as a result of altered neural stem cell function. Pregnant mice treated with low-dose lipopolysaccharide at embryonic day 9 had offspring with brain overgrowth, with a more pronounced effect in PTEN heterozygotes. Exposure to maternal inflammation also enhanced NADPH oxidase (NOX-PI3K pathway signaling, stimulated the hyperproliferation of neural stem and progenitor cells, increased forebrain microglia, and produced abnormal autism-associated behaviors in affected pups. Our evidence supports the idea that a prenatal neuroinflammatory dysregulation in neural stem cell redox signaling can act in concert with underlying genetic susceptibilities to affect cellular responses to environmentally altered cellular levels of reactive oxygen species.

  16. 语前聋听神经病多道人工耳蜗植入效果初步观察%Outcome of cochlear implantation in prelingual pediatric auditory neuropathy

    Institute of Scientific and Technical Information of China (English)

    李永新; 黄丽辉; 莫玲燕; 张华; 韩德民; 梁爽; 郭连生; 孔颖; 刘海红; 赵啸天; 郑军; 陈雪清; 刘博

    2008-01-01

    目的 探讨听神经病患者人工耳蜗植入后的电生理结果 变化并分析其听力言语康复效果.方法 对行人工耳蜗植入术的2例听神经病患儿进行术前听力学评估,术中、术后听觉诱发电位反应监测及开机后1年的随访,获得其开机后6个月与12个月时的听力言语康复效果,并与人工耳蜗使用时间相近的非听神经病耳蜗植入患儿的康复效果进行对比.结果 例1术中神经反应遥测henral response telemetry,NRT)及电刺激听性脑干诱发反应(electric auditory brainstem response,EABR)可引出波形,但重复性不好,EABR V波潜伏期延长.开机12个月时复查,2项电生理检查均引出可重复波形,EABR V波潜伏期在正常范围;听力言语康复效果显著提高,开机1年后有意义听觉整合量表得分优于对照组儿童;例2术中NRT未引出有意义波形,EABR可引出波形,但重复性不好;开机12个月复查,2项电生理检查均引出可重复波形,EABR V波潜伏期在正常范围;术后听力言语康复效果亦有所提高.结论 2例听神经病患者人工耳蜗植入后,术前听觉通路电活动的去同步化均得到一定程度的恢复,听力言语能力也有不同程度提高,说明人工耳蜗植入可以作为听神经病患者实现听力重建,重返主流社会的治疗和康复手段.%Objective To explore the electrophysiological results and rehabilitation outcome of two prelingually deafened pediatric cochlear implant patients with auditory neuropathy.Methods Preoperative audiological evaluation,intra-postoperative electrically evoked auditory brainstem response(EABR)and neural response telememetry(NRT)record for the two cases were conducted in Beijing Tongren Hospital.A one year follow-up was performed.Data collected before and at 6,12-month intervals after implantation were compared with that from control pediatric cochlear implant patients matched for the same duration of implant use as this two cases. Results

  17. Adaptation of the communicative brain to post-lingual deafness. Evidence from functional imaging.

    Science.gov (United States)

    Lazard, Diane S; Innes-Brown, Hamish; Barone, Pascal

    2014-01-01

    Not having access to one sense profoundly modifies our interactions with the environment, in turn producing changes in brain organization. Deafness and its rehabilitation by cochlear implantation offer a unique model of brain adaptation during sensory deprivation and recovery. Functional imaging allows the study of brain plasticity as a function of the times of deafness and implantation. Even long after the end of the sensitive period for auditory brain physiological maturation, some plasticity may be observed. In this way the mature brain that becomes deaf after language acquisition can adapt to its modified sensory inputs. Oral communication difficulties induced by post-lingual deafness shape cortical reorganization of brain networks already specialized for processing oral language. Left hemisphere language specialization tends to be more preserved than functions of the right hemisphere. We hypothesize that the right hemisphere offers cognitive resources re-purposed to palliate difficulties in left hemisphere speech processing due to sensory and auditory memory degradation. If cochlear implantation is considered, this reorganization during deafness may influence speech understanding outcomes positively or negatively. Understanding brain plasticity during post-lingual deafness should thus inform the development of cognitive rehabilitation, which promotes positive reorganization of the brain networks that process oral language before surgery. This article is part of a Special Issue entitled Human Auditory Neuroimaging. PMID:23973562

  18. Musical Brains. A study of evoked musical sensations without external auditory stimuli. Preliminary report of three cases

    International Nuclear Information System (INIS)

    Background: There are individuals, usually musicians, who are seemingly able to evoke musical sensations without external auditory stimuli. However, to date there is no available evidence to determine if it is feasible to have musical sensations without using external sensory receptors nor if there is a biological substrate to these sensations. Study design: Two single photon emission computerized tomography (SPECT) evaluations with [99mTc]-HMPAO were conducted in each of three female musicians. One was done under basal conditions (without evoking) and the other one while evoking these sensations. Results: In the NeuroSPECT studies of the musicians who were tested while evoking a musical composition, there was a significant increase in perfusion above the normal mean in the right and left hemispheres in Brodmann's areas 9 and 8 (frontal executive area) and in areas 40 on the left side (auditory center). However, under basal conditions there was no hyper perfusion of areas 9, 8, 39 and 40. In one case hyper perfusion was found under basal conditions in area 45, however it was less than when she was evoking. Conclusions: These findings are suggestive of a biological substrate to the process of evoking musical sensations (au)

  19. Neurogenic plasticity of mesenchymal stem cell, an alluring cellular replacement for traumatic brain injury.

    Science.gov (United States)

    Pati, Soumya; Muthuraju, Sangu; Hadi, Raisah Ab; Huat, Tee Jong; Singh, Shailja; Maletic-Savatic, Mirjana; Abdullah, Jafri Malin; Jaafar, Hasnan

    2016-01-01

    Traumatic brain injury (TBI) imposes horrendous neurophysiological alterations leading to most devastating forms of neuro-disability. Which includes impaired cognition, distorted locomotors activity and psychosomatic disability in both youths and adults. Emerging evidence from recent studies has identified mesenchymal stem cells (MSCs) as one of the promising category of stem cells having excellent neuroregenerative capability in TBI victims. Some of the clinical and animal studies reported that MSCs transplantation could cure neuronal damage as well as improve cognitive and locomotors behaviors in TBI. However, mechanism behind their broad spectrum neuroregenerative potential in TBI has not been reviewed yet. Therefore, in the present article, we present a comprehensive data on the important attributes of MSCs, such as neurotransdifferentiation, neuroprotection, axonal repair and plasticity, maintenance of blood-brain integrity, reduction of reactive oxygen species (ROS) and immunomodulation. We have reviewed in detail the crucial neurogenic capabilities of MSCs in vivo and provided consolidated knowledge regarding their cellular remodeling in TBI for future therapeutic implications. PMID:26763886

  20. Mutations in DARS Cause Hypomyelination with Brain Stem and Spinal Cord Involvement and Leg Spasticity

    Science.gov (United States)

    Taft, Ryan J.; Vanderver, Adeline; Leventer, Richard J.; Damiani, Stephen A.; Simons, Cas; Grimmond, Sean M.; Miller, David; Schmidt, Johanna; Lockhart, Paul J.; Pope, Kate; Ru, Kelin; Crawford, Joanna; Rosser, Tena; de Coo, Irenaeus F.M.; Juneja, Monica; Verma, Ishwar C.; Prabhakar, Prab; Blaser, Susan; Raiman, Julian; Pouwels, Petra J.W.; Bevova, Marianna R.; Abbink, Truus E.M.; van der Knaap, Marjo S.; Wolf, Nicole I.

    2013-01-01

    Inherited white-matter disorders are a broad class of diseases for which treatment and classification are both challenging. Indeed, nearly half of the children presenting with a leukoencephalopathy remain without a specific diagnosis. Here, we report on the application of high-throughput genome and exome sequencing to a cohort of ten individuals with a leukoencephalopathy of unknown etiology and clinically characterized by hypomyelination with brain stem and spinal cord involvement and leg spasticity (HBSL), as well as the identification of compound-heterozygous and homozygous mutations in cytoplasmic aspartyl-tRNA synthetase (DARS). These mutations cause nonsynonymous changes to seven highly conserved amino acids, five of which are unchanged between yeast and man, in the DARS C-terminal lobe adjacent to, or within, the active-site pocket. Intriguingly, HBSL bears a striking resemblance to leukoencephalopathy with brain stem and spinal cord involvement and elevated lactate (LBSL), which is caused by mutations in the mitochondria-specific DARS2, suggesting that these two diseases might share a common underlying molecular pathology. These findings add to the growing body of evidence that mutations in tRNA synthetases can cause a broad range of neurologic disorders. PMID:23643384

  1. 660 nm red light-enhanced bone marrow mesenchymal stem cell transplantation for hypoxic-ischemic brain damage treatment

    OpenAIRE

    Li, Xianchao; Hou, Wensheng; Wu, Xiaoying; Jiang, Wei; Chen, Haiyan; Xiao, Nong; Zhou, Ping

    2014-01-01

    Bone marrow mesenchymal stem cell transplantation is an effective treatment for neonatal hypoxic-ischemic brain damage. However, the in vivo transplantation effects are poor and their survival, colonization and differentiation efficiencies are relatively low. Red or near-infrared light from 600–1,000 nm promotes cellular migration and prevents apoptosis. Thus, we hypothesized that the combination of red light with bone marrow mesenchymal stem cell transplantation would be effective for the tr...

  2. Cortical reorganization in children with cochlear implants.

    Science.gov (United States)

    Gilley, Phillip M; Sharma, Anu; Dorman, Michael F

    2008-11-01

    Congenital deafness leads to atypical organization of the auditory nervous system. However, the extent to which auditory pathways reorganize during deafness is not well understood. We recorded cortical auditory evoked potentials in normal hearing children and in congenitally deaf children fitted with cochlear implants. High-density EEG and source modeling revealed principal activity from auditory cortex in normal hearing and early implanted children. However, children implanted after a critical period of seven years revealed activity from parietotemporal cortex in response to auditory stimulation, demonstrating reorganized cortical pathways. Reorganization of central auditory pathways is limited by the age at which implantation occurs, and may help explain the benefits and limitations of implantation in congenitally deaf children. PMID:18775684

  3. Strain differences in pH-sensitive K+ channel-expressing cells in chemosensory and nonchemosensory brain stem nuclei

    OpenAIRE

    Martino, Paul F.; Olesiak, S.; Batuuka, D.; Riley, D; Neumueller, S.; Forster, H. V.; Hodges, M. R.

    2014-01-01

    The ventilatory CO2 chemoreflex is inherently low in inbred Brown Norway (BN) rats compared with other strains, including inbred Dahl salt-sensitive (SS) rats. Since the brain stem expression of various pH-sensitive ion channels may be determinants of the CO2 chemoreflex, we tested the hypothesis that there would be fewer pH-sensitive K+ channel-expressing cells in BN relative to SS rats within brain stem sites associated with respiratory chemoreception, such as the nucleus tractus solitarius...

  4. Resultados auditivos com o implante coclear multicanal em pacientes submetidos a cirurgia no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Auditory results with multicanal cochlear implant in patients submitted to cochlear implant surgery at University of São Paulo Medical School - Hospital das Clínicas

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira Bento

    2004-10-01

    an important alert for dangerous situations in the daily life. They are also unable to hear their own voices and for this people with profound deaf do not modulate their voices. The hearing aids are the first choice to treat deafness, but there are patients with severe damage of the auditory systems who cannot receive a useful hearing from normal hearing aids. The cochlear implant is the alternative for patients that cannot have good discriminatory ability wearing a powerful hearing aid and wish or need a better hearing. AIM: To study the hearing results of the adult patients who are using a multichannel cochlear implant system at the Department of Otolaryngology - University of Sao Paulo. STUDY DESIGN: Series study. MATERIAL AND METHOD: We selected 61 patients with a severe bilateral hearing loss that have been using the cochlear implant for at least six months. The hearing evaluation performed after using the device for six months included word and sentence recognition tests. RESULTS: The PTA of four patients reached 38.7 dB. Speech perception tests showed 713% recognition of open set sentences, 86.5% of vowels and 52.60% of monosyllabic. Most of our patients are able to speak on the telephone. CONCLUSION: Most of patients showed excellent results in open-set sentence and word tests.

  5. Physical weight loading induces expression of tryptophan hydroxylase 2 in the brain stem.

    Directory of Open Access Journals (Sweden)

    Joon W Shim

    Full Text Available Sustaining brain serotonin is essential in mental health. Physical activities can attenuate mental problems by enhancing serotonin signaling. However, such activity is not always possible in disabled individuals or patients with dementia. Knee loading, a form of physical activity, has been found to mimic effects of voluntary exercise. Focusing on serotonergic signaling, we addressed a question: Does local mechanical loading to the skeleton elevate expression of tryptophan hydroxylase 2 (tph2 that is a rate-limiting enzyme for brain serotonin? A 5 min knee loading was applied to mice using 1 N force at 5 Hz for 1,500 cycles. A 5-min treadmill running was used as an exercise (positive control, and a 90-min tail suspension was used as a stress (negative control. Expression of tph2 was determined 30 min - 2 h in three brain regions --frontal cortex (FC, ventromedial hypothalamus (VMH, and brain stem (BS. We demonstrated for the first time that knee loading and treadmill exercise upregulated the mRNA level of tph2 in the BS, while tail suspension downregulated it. The protein level of tph2 in the BS was also upregulated by knee loading and downregulated by tail suspension. Furthermore, the downregulation of tph2 mRNA by tail suspension can be partially suppressed by pre-application of knee loading. The expression of tph2 in the FC and VMH was not significantly altered with knee loading. In this study we provided evidence that peripheral mechanical loading can activate central tph2 expression, suggesting that physical cues may mediate tph2-cathalyzed serotonergic signaling in the brain.

  6. Interaction between nonviral reprogrammed fibroblast stem cells and trophic factors for brain repair.

    Science.gov (United States)

    Liu, G; Anisman, H; Bobyn, J; Hayley, S

    2014-10-01

    There are currently no known treatment options that actually halt or permanently reverse the pathology evident in any neurodegenerative condition. Arguably, one of the most promising avenues for creating viable neuronal treatments could involve the combined use of cell replacement and gene therapy. Given the complexity of the neurodegenerative process, it stands to reason that adequate therapy should involve not only the replacement of loss neurons/synapses but also the interruption of multiple pro-death pathways. Thus, we propose the use of stem cells that are tailored to express specific trophic factors, thereby potentially encouraging synergistic effects between the stem cell properties and those of the trophic factors. The trophic factors, brain-derived neurotropic factor (BDNF), glial cell-derived neurotropic factor (GDNF), fibroblast growth factor (FGF) 2, and insulin-like growth factor (IGF) 1, in particular, have demonstrated neuroprotective actions in a number of animal models. Importantly, we use a nonviral approach, thereby minimizing the potential risk for DNA integration and tumor formation. The present study involved the development of a nonviral reprogramming system to transform adult mature mouse fibroblasts into progressive stages of cell development. We also tailored these stem cells to individually express each of the trophic factors, including BDNF, GDNF, FGF2, and IGF1. Significantly, central infusion of BDNF-expressing stem cells prevented the in vivo loss of neurons associated with infusion of the endotoxin, lipopolysaccharide (LPS). This is particularly important in light of the role of inflammatory processes that are posited to play in virtually all neurodegenerative states. Hence, the present results support the utility of using combined gene and cell-targeting approaches for neuronal pathology. PMID:24677069

  7. Cochlear Implant

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this text, the authors recall the main principles and data ruling cochlear implants. Then, a first circle of technical equipment for assistance is presented. This circle includes: device setting (DS), Electrically evoked Auditory Brainstem Responses (EABR), Neural Response Telemetry (NRT), Stapedial Reflex (SR) and Electrodogram Acquisition (EA). This first cycle becomes more and more important as children are implanted younger and younger; the amount of data available with this assistance makes necessary the use of models (implicit or explicit) to handle this information. Consequently, this field is more open than ever.

  8. Spatial and Functional Architecture of the Mammalian Brain Stem Respiratory Network: A Hierarchy of Three Oscillatory Mechanisms

    OpenAIRE

    Smith, J C; Abdala, A. P. L.; Koizumi, H.; Rybak, I. A.; Paton, J. F. R.

    2007-01-01

    Mammalian central pattern generators (CPGs) producing rhythmic movements exhibit extremely robust and flexible behavior. Network architectures that enable these features are not well understood. Here we studied organization of the brain stem respiratory CPG. By sequential rostral to caudal transections through the pontine-medullary respiratory network within an in situ perfused rat brain stem–spinal cord preparation, we showed that network dynamics reorganized and new rhythmogenic mechanisms ...

  9. Biocompatibility of magnesium implants in primary human reaming debris-derived cells stem cells in vitro

    OpenAIRE

    Charyeva, Olga; Dakischew, Olga; Sommer, Ursula; Heiss, Christian; Schnettler, Reinhard; Lips, Katrin Susanne

    2015-01-01

    Background Use of magnesium for resorbable metal implants is a new concept in orthopaedic and dental medicine. The majority of studies on magnesium’s biocompatibility in vitro have assessed the short-term effect of magnesium extract on cells. The aim of this study was to evaluate the influence of direct exposure to magnesium alloys on the bioactivity of primary human reaming debris-derived (HRD) cells. Materials and methods Pure Mg, Mg2Ag, WE43 and Mg10Gd were tested for biocompatibility. The...

  10. Bone marrow mesenchymal stem cells differentiation and proliferation on the surface of coral implant

    International Nuclear Information System (INIS)

    This study was designed to evaluate the ability of natural coral implant to provide an environment for marrow cells to differentiate into osteoblasts and function suitable for mineralized tissue formation. DNA content, alkaline phosptatase (ALP) activity, calcium (Ca) content and mineralized nodules, were measured at day 3, day 7 and day 14, in rat bone marrow stromal cells cultured with coral discs glass discs, while cells alone and coral disc alone cultured as control. DNA content, ALP activity, Ca content measurements showed no difference between coral, glass and cells groups at 3 day which were higher than control (coral disc alone), but there were higher asurement at day 7 and 14 in the cell cultured on coral than on glass discs, control cells and control coral discs. Mineralized nodules formation (both in area and number) was more predominant on the coral surface than in control groups. These results showed that natural coral implant provided excellent and favorable situation for marrow cell to differentiate to osteoblasts, lead to large amount of mineralized tissue formation on coral surface. This in vitro result could explain the rapid bone bonding of coral in vivo. (Author)

  11. Lab-on-a-brain: Implantable micro-optical fluidic devices for neural cell analysis in vivo

    Science.gov (United States)

    Takehara, Hiroaki; Nagaoka, Akira; Noguchi, Jun; Akagi, Takanori; Kasai, Haruo; Ichiki, Takanori

    2014-10-01

    The high-resolution imaging of neural cells in vivo has brought about great progress in neuroscience research. Here, we report a novel experimental platform, where the intact brain of a living mouse can be studied with the aid of a surgically implanted micro-optical fluidic device; acting as an interface between neurons and the outer world. The newly developed device provides the functions required for the long-term and high-resolution observation of the fine structures of neurons by two-photon laser scanning microscopy and the microfluidic delivery of chemicals or drugs directly into the brain. A proof-of-concept experiment of single-synapse stimulation by two-photon uncaging of caged glutamate and observation of dendritic spine shrinkage over subsequent days demonstrated a promising use for the present technology.

  12. Nop2 is expressed during proliferation of neural stem cells and in adult mouse and human brain

    Czech Academy of Sciences Publication Activity Database

    Kosi, N.; Alic, I.; Kolacevic, M.; Vrsaljko, N.; Milosevic, N.J.; Sobol, Margaryta; Philimonenko, Anatoly; Hozák, Pavel; Gajovic, S.; Pochet, R.; Mitrecic, D.

    2015-01-01

    Roč. 1597, FEB 9 (2015), s. 65-76. ISSN 1872-6240 R&D Projects: GA TA ČR(CZ) TE01020118; GA MPO FR-TI3/588 Institutional support: RVO:68378050 Keywords : Nop2 * Brain * Stem cells * Stroke * Nucleolus * Cell cycle Subject RIV: EB - Gene tics ; Molecular Biology

  13. Nop2 is expressed during proliferation of neural stem cells and in adult mouse and human brain

    Czech Academy of Sciences Publication Activity Database

    Kosi, N.; Alic, I.; Kolačevic, M.; Vrsaljko, N.; Miloševic, N.J.; Sobol, Margaryta; Filimonenko, Anatolij; Hozák, Pavel; Gajovic, S.; Pochet, R.; Mitrečic, D.

    2015-01-01

    Roč. 1597, February (2015), s. 65-76. ISSN 1872-6240 R&D Projects: GA TA ČR(CZ) TE01020118; GA MPO FR-TI3/588 Institutional support: RVO:68378050 Keywords : Nop2 * Brain * Stem cells * Stroke Subject RIV: EB - Gene tics ; Molecular Biology

  14. Human umbilical cord blood stem cells and brain-derived neurotrophic factor for optic nerve injury: a biomechanical evaluation

    Directory of Open Access Journals (Sweden)

    Zhong-jun Zhang

    2015-01-01

    Full Text Available Treatment for optic nerve injury by brain-derived neurotrophic factor or the transplantation of human umbilical cord blood stem cells has gained progress, but analysis by biomechanical indicators is rare. Rabbit models of optic nerve injury were established by a clamp. At 7 days after injury, the vitreous body received a one-time injection of 50 μg brain-derived neurotrophic factor or 1 × 10 6 human umbilical cord blood stem cells. After 30 days, the maximum load, maximum stress, maximum strain, elastic limit load, elastic limit stress, and elastic limit strain had clearly improved in rabbit models of optical nerve injury after treatment with brain-derived neurotrophic factor or human umbilical cord blood stem cells. The damage to the ultrastructure of the optic nerve had also been reduced. These findings suggest that human umbilical cord blood stem cells and brain-derived neurotrophic factor effectively repair the injured optical nerve, improve biomechanical properties, and contribute to the recovery after injury.

  15. Human umbilical cord blood stem cells and brain-derived neurotrophic factor for optic nerve injury:a biomechanical evaluation

    Institute of Scientific and Technical Information of China (English)

    Zhong-jun Zhang; Ya-jun Li; Xiao-guang Liu; Feng-xiao Huang; Tie-jun Liu; Dong-mei Jiang; Xue-man Lv; Min Luo

    2015-01-01

    Treatment for optic nerve injury by brain-derived neurotrophic factor or the transplantation of human umbilical cord blood stem cells has gained progress, but analysis by biomechanical indicators is rare. Rabbit models of optic nerve injury were established by a clamp. At 7 days after injury, the vitreous body received a one-time injection of 50 μg brain-derived neurotrophic factor or 1 × 106 human umbilical cord blood stem cells. After 30 days, the maximum load, max-imum stress, maximum strain, elastic limit load, elastic limit stress, and elastic limit strain had clearly improved in rabbit models of optical nerve injury after treatment with brain-derived neu-rotrophic factor or human umbilical cord blood stem cells. The damage to the ultrastructure of the optic nerve had also been reduced. These ifndings suggest that human umbilical cord blood stem cells and brain-derived neurotrophic factor effectively repair the injured optical nerve, im-prove biomechanical properties, and contribute to the recovery after injury.

  16. Brain Computer Interface human platform to control a 4-limb exoskeleton based on the ECoG-recording implant WIMAGINE®: preliminary results

    OpenAIRE

    Corinne Mestais

    2015-01-01

    The goal of CLINATEC® Brain Computer Interface Project is to improve tetraplegic subjects’ quality of life by allowing them to interact with their environment through the control of effectors with multiple degrees of freedom after training. Thanks to a long-term wireless 64-channel ECoG recording implant WIMAGINE® (Wireless Implantable Multi-channel Acquisition system for Generic Interface with NEurons) [1] and an innovative signal processing, the subject should be able to control a 4-limb ex...

  17. Cognitive improvement following transvenous adipose-derived mesenchymal stem cell transplantation in a rat model of traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    Dongfei Li; Chun Yang; Rongmei Qu; Huiying Yang; Meichun Yu; Hui Tao; Jingxing Dai; Lin Yuan

    2011-01-01

    The effects of adipose-derived mesenchymal stem cell (ADMSC) transplantation for the repair of traumatic brain injury remain poorly understood. The present study observed neurological functional changes in a rat model of traumatic brain injury following ADMSC transplantation via the tail vein.Cell transplants were observed in injured cerebral cortex, and expression of brain-derived nerve growth factor was significantly increased in the injured hippocampus following transplantation. Results demonstrated that transvenous ADMSC transplants migrated to the injured cerebral cortex and significantly improved cognitive function.

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

    OpenAIRE

    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...

  19. Modeling learning in brain stem and cerebellar sites responsible for VOR plasticity

    Science.gov (United States)

    Quinn, K. J.; Didier, A. J.; Baker, J. F.; Peterson, B. W.

    1998-01-01

    A simple model of vestibuloocular reflex (VOR) function was used to analyze several hypotheses currently held concerning the characteristics of VOR plasticity. The network included a direct vestibular pathway and an indirect path via the cerebellum. An optimization analysis of this model suggests that regulation of brain stem sites is critical for the proper modification of VOR gain. A more physiologically plausible learning rule was also applied to this network. Analysis of these simulation results suggests that the preferred error correction signal controlling gain modification of the VOR is the direct output of the accessory optic system (AOS) to the vestibular nuclei vs. a signal relayed through the cerebellum via floccular Purkinje cells. The potential anatomical and physiological basis for this conclusion is discussed, in relation to our current understanding of the latency of the adapted VOR response.

  20. Dopaminergic differentiation of human neural stem cells mediated by co-cultured rat striatal brain slices

    DEFF Research Database (Denmark)

    Anwar, Mohammad Raffaqat; Andreasen, Christian Maaløv; Lippert, Solvej Kølvraa;

    2008-01-01

    differentiation, we co-cultured cells from a human neural forebrain-derived stem cell line (hNS1) with rat striatal brain slices. In brief, coronal slices of neonatal rat striatum were cultured on semiporous membrane inserts placed in six-well trays overlying monolayers of hNS1 cells. After 12 days of co......-induced areas. The presence of dopamine in the conditioned culture medium was confirmed by HPLC analysis. Interestingly, not all striatal slice cultures induced TH-expression in underlying hNS1 cells. Common to TH-inductive cultures was, however, the presence of degenerating, necrotic areas, suggesting that...... factors released during striatal degeneration were responsible for the dopaminergic induction of the hNS1 cells. Ongoing experiments aim to identify such factors by comparing protein profiles of media conditioned by degenerating (necrotic) versus healthy striatal slice cultures....

  1. Brain stem death as the vital determinant for resumption of spontaneous circulation after cardiac arrest in rats.

    Directory of Open Access Journals (Sweden)

    Alice Y W Chang

    Full Text Available BACKGROUND: Spontaneous circulation returns to less than half of adult cardiac arrest victims who received in-hospital resuscitation. One clue for this disheartening outcome arises from the prognosis that asystole invariably takes place, after a time lag, on diagnosis of brain stem death. The designation of brain stem death as the point of no return further suggests that permanent impairment of the brain stem cardiovascular regulatory machinery precedes death. It follows that a crucial determinant for successful revival of an arrested heart is that spontaneous circulation must resume before brain stem death commences. Here, we evaluated the hypothesis that maintained functional integrity of the rostral ventrolateral medulla (RVLM, a neural substrate that is intimately related to brain stem death and central circulatory regulation, holds the key to the vital time-window between cardiac arrest and resumption of spontaneous circulation. METHODOLOGY/PRINCIPAL FINDINGS: An animal model of brain stem death employing the pesticide mevinphos as the experimental insult in Sprague-Dawley rats was used. Intravenous administration of lethal doses of mevinphos elicited an abrupt cardiac arrest, accompanied by elevated systemic arterial pressure and anoxia, augmented neuronal excitability and enhanced microvascular perfusion in RVLM. This period represents the vital time-window between cardiac arrest and resumption of spontaneous circulation in our experimental model. Animals with restored spontaneous circulation exhibited maintained neuronal functionality in RVLM beyond this critical time-window, alongside resumption of baseline tissue oxygen and enhancement of local blood flow. Intriguingly, animals that subsequently died manifested sustained anoxia, diminished local blood flow, depressed mitochondrial electron transport activities and reduced ATP production, leading to necrotic cell death in RVLM. That amelioration of mitochondrial dysfunction and

  2. Magnetic resonance tracking of implanted adult and embryonic stem cells in injured brain and spinal cord

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva; Jendelová, Pavla

    2005-01-01

    Roč. 1049, - (2005), s. 146-160. ISSN 0077-8923 R&D Projects: GA ČR GA304/03/1189; GA MŠk(CZ) 1M0538 Institutional research plan: CEZ:AV0Z5039906 Keywords : cell transplantation * magnetic resonance Subject RIV: FJ - Surgery incl. Transplants Impact factor: 1.971, year: 2005

  3. Evaluation of radiation therapy for pediatric brain stem glioma by computed tomography

    International Nuclear Information System (INIS)

    The effects of radiation therapy on 29 brain stem gliomas in childhood were evaluated by computed tomography (CT). The patients received radiation of 2 Gy/day as a single fraction, 5 day a week with a total dose of 40 to 60 Gy. Initial CT findings of brain stem gliomas were divided into two types; diffuse and localized. Of 29 children, 5 had localized and 24 had diffuse tumor. Histological diagnoses were available for 18 patients, 4 with localized and 14 with diffuse tumor. All of the localized tumors were astrocytomas and diffuse tumors included 13 anaplastic gliomas (glioblastomas), 3 anaplastic astrocytomas, and one astrocytoma. Complete response or partial response to radiation therapy was observed on CT in 100% (5/5) of the localized tumors and 46% (11/13) of the diffuse tumors at the first evaluation. Contrary to expectation, low-grade gliomas responded much better to radiation therapy than high-grade gliomas. The response rates were 80% (4/5) in astrocytoma, 67% (2/3) in anaplastic astrocytoma, and 38% (5/13) in anaplastic glioma. In the follow-up CT after radiation therapy, a delayed effect was observed in only one of the 24 diffuse tumors. Nine of 10 children who had a re-irradiation following the recurrence experienced very little benefit. None of the patients with localized tumors have shown evidence of tumor progression or recurrence, and the quality of their life has been exellent. On the other hand, all of the patients with diffuse tumor died within 20 months after initial treatment. The results of this study suggest that radiation therapy is beneficial for localized tumors but not for diffuse tumors, and new treatments need to be developed for diffuse tumors. (author)

  4. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies

    Directory of Open Access Journals (Sweden)

    Heng-feng Yuan

    2016-02-01

    Full Text Available The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p<0.001, a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p<0.01 and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01. The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings.

  5. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies.

    Science.gov (United States)

    Yuan, Heng-Feng; Zhang, Jing; Guo, Chang-An; Yan, Zuo-Qin

    2016-02-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p <0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p <0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings. PMID:26934241

  6. Real Time Imaging of Biomarkers in the Parkinson's Brain Using Mini-Implantable Biosensors. II. Pharmaceutical Therapy with Bromocriptine

    Directory of Open Access Journals (Sweden)

    Patricia A. Broderick

    2009-12-01

    Full Text Available We used Neuromolecular Imaging (NMI and trademarked BRODERICK PROBE® mini-implantable biosensors, to selectively and separately detect neurotransmitters in vivo, on line, within seconds in the dorsal striatal brain of the Parkinson’s Disease (PD animal model. We directly compared our results derived from PD to the normal striatal brain of the non-Parkinson’s Disease (non-PD animal. This advanced biotechnology enabled the imaging of dopamine (DA, serotonin (5-HT, homovanillic acid (HVA a metabolite of DA, L-tryptophan (L-TP a precursor to 5-HT and peptides, dynorphin A 1-17 (Dyn A and somatostatin (somatostatin releasing inhibitory factor (SRIF. Each neurotransmitter and neurochemical was imaged at a signature electroactive oxidation/half-wave potential in dorsal striatum of the PD as compared with the non-PD animal. Both endogenous and bromocriptine-treated neurochemical profiles in PD and non-PD were imaged using the same experimental paradigm and detection sensitivities. Results showed that we have found significant neurotransmitter peptide biomarkers in the dorsal striatal brain of endogenous and bromocriptine-treated PD animals. The peptide biomarkers were not imaged in dorsal striatal brain of non-PD animals, either endogenously or bromocriptine-treated. These findings provide new pharmacotherapeutic strategies for PD patients. Thus, our findings are highly applicable to the clinical treatment of PD.

  7. Neural prostheses and brain plasticity

    Science.gov (United States)

    Fallon, James B.; Irvine, Dexter R. F.; Shepherd, Robert K.

    2009-12-01

    The success of modern neural prostheses is dependent on a complex interplay between the devices' hardware and software and the dynamic environment in which the devices operate: the patient's body or 'wetware'. Over 120 000 severe/profoundly deaf individuals presently receive information enabling auditory awareness and speech perception from cochlear implants. The cochlear implant therefore provides a useful case study for a review of the complex interactions between hardware, software and wetware, and of the important role of the dynamic nature of wetware. In the case of neural prostheses, the most critical component of that wetware is the central nervous system. This paper will examine the evidence of changes in the central auditory system that contribute to changes in performance with a cochlear implant, and discuss how these changes relate to electrophysiological and functional imaging studies in humans. The relationship between the human data and evidence from animals of the remarkable capacity for plastic change of the central auditory system, even into adulthood, will then be examined. Finally, we will discuss the role of brain plasticity in neural prostheses in general.

  8. Preventive sparing of spinal cord and brain stem in the initial irradiation of locally advanced head and neck cancers.

    Science.gov (United States)

    Farace, Paolo; Piras, Sara; Porru, Sergio; Massazza, Federica; Fadda, Giuseppina; Solla, Ignazio; Piras, Denise; Deidda, Maria Assunta; Amichetti, Maurizio; Possanzini, Marco

    2014-01-01

    Since reirradiation in recurrent head and neck patients is limited by previous treatment, a marked reduction of maximum doses to spinal cord and brain stem was investigated in the initial irradiation of stage III/IV head and neck cancers. Eighteen patients were planned by simultaneous integrated boost, prescribing 69.3 Gy to PTV1 and 56.1 Gy to PTV2. Nine 6 MV coplanar photon beams at equispaced gantry angles were chosen for each patient. Step-and-shoot IMRT was calculated by direct machine parameter optimization, with the maximum number of segments limited to 80. In the standard plan, optimization considered organs at risk (OAR), dose conformity, maximum dose < 45 Gy to spinal cord and < 50 Gy to brain stem. In the sparing plans, a marked reduction to spinal cord and brain stem were investigated, with/without changes in dose conformity. In the sparing plans, the maximum doses to spinal cord and brain stem were reduced from the initial values (43.5 ± 2.2 Gy and 36.7 ± 14.0 Gy), without significant changes on the other OARs. A marked difference (-15.9 ± 1.9 Gy and -10.1 ± 5.7 Gy) was obtained at the expense of a small difference (-1.3% ± 0.9%) from initial PTV195% coverage (96.6% ± 0.9%). Similar difference (-15.7 ± 2.2 Gy and -10.2 ± 6.1 Gy) was obtained compromising dose conformity, but unaffecting PTV195% and with negligible decrease in PTV295% (-0.3% ± 0.3% from the initial 98.3% ± 0.8%). A marked spinal cord and brain stem preventive sparing was feasible at the expense of a decrease in dose conformity or slightly compromising target coverage. A sparing should be recommended in highly recurrent tumors, to make potential reirradiation safer. PMID:24423836

  9. Therapeutics with SPION-labeled stem cells for the main diseases related to brain aging: a systematic review

    Directory of Open Access Journals (Sweden)

    Alvarim LT

    2014-08-01

    Full Text Available Larissa T Alvarim,1,3,* Leopoldo P Nucci,2,* Javier B Mamani,1 Luciana C Marti,1 Marina F Aguiar,1,2 Helio R Silva,1,3 Gisele S Silva,1 Mariana P Nucci-da-Silva,4 Elaine A DelBel,5,6 Lionel F Gamarra1–31Hospital Israelita Albert Einstein, São Paulo, Brazil; 2Universidade Federal de São Paulo, UNIFESP, São Paulo, Brazil; 3Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, Brazil; 4Departamento de Radiologia, Hospital das Clínicas, Universidade de São Paulo, Brazil; 5Universidade de São Paulo-Faculdade de Odontologia de Ribeirão Preto, São Paulo, Brazil; 6NAPNA- Núcleo de Apoio a Pesquisa em Neurociências Aplicadas, São Paulo, Brazil*These authors contributed equally to this workAbstract: The increase in clinical trials assessing the efficacy of cell therapy for structural and functional regeneration of the nervous system in diseases related to the aging brain is well known. However, the results are inconclusive as to the best cell type to be used or the best methodology for the homing of these stem cells. This systematic review analyzed published data on SPION (superparamagnetic iron oxide nanoparticle-labeled stem cells as a therapy for brain diseases, such as ischemic stroke, Parkinson’s disease, amyotrophic lateral sclerosis, and dementia. This review highlights the therapeutic role of stem cells in reversing the aging process and the pathophysiology of brain aging, as well as emphasizing nanotechnology as an important tool to monitor stem cell migration in affected regions of the brain.Keywords: iron oxide, dementia, stem cell, stroke, Parkinson’s disease, sclerosis disease, brain aging

  10. In vitro delineation of human brain-stem anatomy using a small resonator: correlation with macroscopic and histological findings

    International Nuclear Information System (INIS)

    Our purpose was to investigate the potential of an experimental animal coil using a commercial MRI unit to delineate the anatomical structure of the human brain stem. Three formaldehyde-fixed brain-stem specimens were examined by MRI and sectioned perpendicular to their longitudinal axis. The images were compared with gross anatomy and myelin-stained histological sections. Fibre tracts and nuclei which were not evident on examination of the unstained specimen were readily identified by MRI. Due to its inherent grey/white matter contrast, MRI with a high-resolution coil delineates anatomical structures in a way comparable to the myelin-stained histological sections. However, pigmented structures, readily visible on examination of the unstained specimen were discernible on neither MRI nor on myelin-stained sections. The excellent anatomical detail and grey/white matter contrast provided by these images could make MRI a useful adjunct to the pathologist investigating brain disease. (orig.)

  11. The role of auditory transient and deviance processing in distraction of task performance: a combined behavioral and event-related brain potential study

    OpenAIRE

    Stefan Berti

    2013-01-01

    Distraction of goal-oriented performance by a sudden change in the auditory environment is an everyday life experience. Different types of changes can be distracting, including a sudden onset of a transient sound and a slight deviation of otherwise regular auditory background stimulation. With regard to deviance detection, it is assumed that slight changes in a continuous sequence of auditory stimuli are detected by a predictive coding mechanisms and it has been demonstrated that this mechani...

  12. High-resolution anatomy of the human brain stem using 7-T MRI: improved detection of inner structures and nerves?

    Energy Technology Data Exchange (ETDEWEB)

    Gizewski, Elke R. [Medical University Innsbruck, Department of Neuroradiology, Innsbruck (Austria); Maderwald, Stefan [University Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Linn, Jennifer; Bochmann, Katja [LMU Munich, Department of Neuroradiology, Munich (Germany); Dassinger, Benjamin [Medical University Innsbruck, Department of Neuroradiology, Innsbruck (Austria); Justus-Liebig-University Giessen, Department of Neuroradiology, Giessen (Germany); Forsting, Michael [University Hospital, University Duisburg-Essen, Departments of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Ladd, Mark E. [University Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); University Hospital, University Duisburg-Essen, Departments of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

    2014-03-15

    The purpose of this paper is to assess the value of 7 Tesla (7 T) MRI for the depiction of brain stem and cranial nerve (CN) anatomy. Six volunteers were examined at 7 T using high-resolution SWI, MPRAGE, MP2RAGE, 3D SPACE T2, T2, and PD images to establish scanning parameters targeted at optimizing spatial resolution. Direct comparisons between 3 and 7 T were performed in two additional subjects using the finalized sequences (3 T: T2, PD, MPRAGE, SWAN; 7 T: 3D T2, MPRAGE, SWI, MP2RAGE). Artifacts and the depiction of structures were evaluated by two neuroradiologists using a standardized score sheet. Sequences could be established for high-resolution 7 T imaging even in caudal cranial areas. High in-plane resolution T2, PD, and SWI images provided depiction of inner brain stem structures such as pons fibers, raphe, reticular formation, nerve roots, and periaqueductal gray. MPRAGE and MP2RAGE provided clear depiction of the CNs. 3D T2 images improved depiction of inner brain structure in comparison to T2 images at 3 T. Although the 7-T SWI sequence provided improved contrast to some inner structures, extended areas were influenced by artifacts due to image disturbances from susceptibility differences. Seven-tesla imaging of basal brain areas is feasible and might have significant impact on detection and diagnosis in patients with specific diseases, e.g., trigeminal pain related to affection of the nerve root. Some inner brain stem structures can be depicted at 3 T, but certain sequences at 7 T, in particular 3D SPACE T2, are superior in producing anatomical in vivo images of deep brain stem structures. (orig.)

  13. High-resolution anatomy of the human brain stem using 7-T MRI: improved detection of inner structures and nerves?

    International Nuclear Information System (INIS)

    The purpose of this paper is to assess the value of 7 Tesla (7 T) MRI for the depiction of brain stem and cranial nerve (CN) anatomy. Six volunteers were examined at 7 T using high-resolution SWI, MPRAGE, MP2RAGE, 3D SPACE T2, T2, and PD images to establish scanning parameters targeted at optimizing spatial resolution. Direct comparisons between 3 and 7 T were performed in two additional subjects using the finalized sequences (3 T: T2, PD, MPRAGE, SWAN; 7 T: 3D T2, MPRAGE, SWI, MP2RAGE). Artifacts and the depiction of structures were evaluated by two neuroradiologists using a standardized score sheet. Sequences could be established for high-resolution 7 T imaging even in caudal cranial areas. High in-plane resolution T2, PD, and SWI images provided depiction of inner brain stem structures such as pons fibers, raphe, reticular formation, nerve roots, and periaqueductal gray. MPRAGE and MP2RAGE provided clear depiction of the CNs. 3D T2 images improved depiction of inner brain structure in comparison to T2 images at 3 T. Although the 7-T SWI sequence provided improved contrast to some inner structures, extended areas were influenced by artifacts due to image disturbances from susceptibility differences. Seven-tesla imaging of basal brain areas is feasible and might have significant impact on detection and diagnosis in patients with specific diseases, e.g., trigeminal pain related to affection of the nerve root. Some inner brain stem structures can be depicted at 3 T, but certain sequences at 7 T, in particular 3D SPACE T2, are superior in producing anatomical in vivo images of deep brain stem structures. (orig.)

  14. Adult Human Nasal Mesenchymal-Like Stem Cells Restore Cochlear Spiral Ganglion Neurons After Experimental Lesion

    OpenAIRE

    Bas, Esperanza; Van De Water, Thomas R.; Lumbreras, Vicente; Rajguru, Suhrud; Goss, Garrett; Hare, Joshua M.; Goldstein, Bradley J.

    2013-01-01

    A loss of sensory hair cells or spiral ganglion neurons from the inner ear causes deafness, affecting millions of people. Currently, there is no effective therapy to repair the inner ear sensory structures in humans. Cochlear implantation can restore input, but only if auditory neurons remain intact. Efforts to develop stem cell-based treatments for deafness have demonstrated progress, most notably utilizing embryonic-derived cells. In an effort to bypass limitations of embryonic or induced p...

  15. Neural stem cells secrete factors facilitating brain regeneration upon constitutive Raf-Erk activation.

    Science.gov (United States)

    Rhee, Yong-Hee; Yi, Sang-Hoon; Kim, Joo Yeon; Chang, Mi-Yoon; Jo, A-Young; Kim, Jinyoung; Park, Chang-Hwan; Cho, Je-Yoel; Choi, Young-Jin; Sun, Woong; Lee, Sang-Hun

    2016-01-01

    The intracellular Raf-Erk signaling pathway is activated during neural stem cell (NSC) proliferation, and neuronal and astrocytic differentiation. A key question is how this signal can evoke multiple and even opposing NSC behaviors. We show here, using a constitutively active Raf (ca-Raf), that Raf-Erk activation in NSCs induces neuronal differentiation in a cell-autonomous manner. By contrast, it causes NSC proliferation and the formation of astrocytes in an extrinsic autocrine/paracrine manner. Thus, treatment of NSCs with medium (CM) conditioned in ca-Raf-transduced NSCs (Raf-CM; RCM) became activated to form proliferating astrocytes resembling radial glial cells (RGCs) or adult-type NSCs. Infusion of Raf-CM into injured mouse brains caused expansion of the NSC population in the subventricular zone, followed by the formation of new neurons that migrated to the damaged site. Our study shows an example how molecular mechanisms dissecting NSC behaviors can be utilized to develop regenerative therapies in brain disorders. PMID:27554447

  16. Implante auditivo de tronco cerebral: técnica cirúrgica e resultados auditivos precoces em pacientes com neurofibromatose tipo 2 Auditory Brainstem Implant: surgical technique and early audiological results in patients with neurofibromatosis type 2

    OpenAIRE

    Ricardo Ferreira Bento; Rubens Vuono Brito Neto; Robinson Koji Tsuji; Marcos Queiroz Telas Gomes; Maria Valéria Schmidt Goffi-Gomez

    2008-01-01

    O implante auditivo de tronco cerebral foi desenvolvido para restaurar alguma audição útil em pacientes que apresentam ausência de nervo coclear bilateralmente. OBJETIVOS: Discutir a indicação, cirurgia e resultados em quatro pacientes submetidos à cirurgia para colocação de implante auditivo de tronco cerebral. CASUÍSTICA E MÉTODOS: Quatro pacientes com diagnóstico de schwannomas vestibulares bilaterais foram submetidos à cirurgia para colocação de Implante Auditivo de Tronco Cerebral durant...

  17. Atomic layer deposited TiO2 for implantable brain-chip interfacing devices

    International Nuclear Information System (INIS)

    In this paper we investigated atomic layer deposition (ALD) TiO2 thin films deposited on implantable neuro-chips based on electrolyte-oxide-semiconductor (EOS) junctions, implementing both efficient capacitive neuron-silicon coupling and biocompatibility for long-term implantable functionality. The ALD process was performed at 295 °C using titanium tetraisopropoxide and ozone as precursors on needle-shaped silicon substrates. Engineering of the capacitance of the EOS junctions introducing a thin Al2O3 buffer layer between TiO2 and silicon resulted in a further increase of the specific capacitance. Biocompatibility for long-term implantable neuroprosthetic systems was checked upon in-vitro treatment.

  18. Atomic layer deposited TiO{sub 2} for implantable brain-chip interfacing devices

    Energy Technology Data Exchange (ETDEWEB)

    Cianci, E., E-mail: elena.cianci@mdm.imm.cnr.it [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (MB) (Italy); Lattanzio, S. [Istituto di Fisiologia, Dipartimento di Anatomia Umana e Fisiologia, Universita di Padova, 35131 Padova (Italy); Dipartimento di Ingegneria dell' Informazione, Universita di Padova, 35131 Padova (Italy); Seguini, G. [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (Italy); Vassanelli, S. [Istituto di Fisiologia, Dipartimento di Anatomia Umana e Fisiologia, Universita di Padova, 35131 Padova (Italy); Fanciulli, M. [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano-Bicocca, 20126 Milano (Italy)

    2012-05-01

    In this paper we investigated atomic layer deposition (ALD) TiO{sub 2} thin films deposited on implantable neuro-chips based on electrolyte-oxide-semiconductor (EOS) junctions, implementing both efficient capacitive neuron-silicon coupling and biocompatibility for long-term implantable functionality. The ALD process was performed at 295 Degree-Sign C using titanium tetraisopropoxide and ozone as precursors on needle-shaped silicon substrates. Engineering of the capacitance of the EOS junctions introducing a thin Al{sub 2}O{sub 3} buffer layer between TiO{sub 2} and silicon resulted in a further increase of the specific capacitance. Biocompatibility for long-term implantable neuroprosthetic systems was checked upon in-vitro treatment.

  19. Sleep-Disordered Breathing Affects Auditory Processing in 5–7 Year-Old Children: Evidence From Brain Recordings

    OpenAIRE

    Key, Alexandra P. F.; Molfese, Dennis L.; O’Brien, Louise; Gozal, David

    2009-01-01

    Poor sleep in children is associated with lower neurocognitive functioning and increased maladaptive behaviors. The current study examined the impact of snoring (the most common manifestation of sleep-disordered breathing) on cognitive and brain functioning in a sample of 35 asymptomatic children ages 5–7 years identified in the community as having habitual snoring (SDB). All participants completed polysomnographic, neurocognitive (NEPSY) and psychophysiological (ERPs to speech sounds) assess...

  20. A Battery-Less, Implantable Neuro-Electronic Interface for Studying the Mechanisms of Deep Brain Stimulation in Rat Models.

    Science.gov (United States)

    Lin, Yu-Po; Yeh, Chun-Yi; Huang, Pin-Yang; Wang, Zong-Ye; Cheng, Hsiang-Hui; Li, Yi-Ting; Chuang, Chi-Fen; Huang, Po-Chiun; Tang, Kea-Tiong; Ma, Hsi-Pin; Chang, Yen-Chung; Yeh, Shih-Rung; Chen, Hsin

    2016-02-01

    Although deep brain stimulation (DBS) has been a promising alternative for treating several neural disorders, the mechanisms underlying the DBS remain not fully understood. As rat models provide the advantage of recording and stimulating different disease-related regions simultaneously, this paper proposes a battery-less, implantable neuro-electronic interface suitable for studying DBS mechanisms with a freely-moving rat. The neuro-electronic interface mainly consists of a microsystem able to interact with eight different brain regions bi-directionally and simultaneously. To minimize the size of the implant, the microsystem receives power and transmits data through a single coil. In addition, particular attention is paid to the capability of recording neural activities right after each stimulation, so as to acquire information on how stimulations modulate neural activities. The microsystem has been fabricated with the standard 0.18 μm CMOS technology. The chip area is 7.74 mm (2) , and the microsystem is able to operate with a single supply voltage of 1 V. The wireless interface allows a maximum power of 10 mW to be transmitted together with either uplink or downlink data at a rate of 2 Mbps or 100 kbps, respectively. The input referred noise of recording amplifiers is 1.16 μVrms, and the stimulation voltage is tunable from 1.5 V to 4.5 V with 5-bit resolution. After the electrical functionality of the microsystem is tested, the capability of the microsystem to interface with rat brain is further examined and compared with conventional instruments. All experimental results are presented and discussed in this paper. PMID:25838526

  1. 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…

  2. Diamond for stem cell biotechnology

    OpenAIRE

    Taylor, A. C.

    2016-01-01

    The recent rise in life expectancy has led an increase in the number of cases of neurological diseases such as Alzheimer’s, Parkinson’s and macular degeneration. Traditional therapeutic approaches are ineffective as regeneration is limited in the Central Nervous System (CNS). Neural prosthetics and stem cell therapy present exciting solutions for enabling the function of the brain to be restored. Implanted materials for neuronal prosthetics must have outstanding electrical properties whilst b...

  3. Stem cell homing using local delivery of plerixafor and stromal derived growth factor-1alpha for improved bone regeneration around Ti-implants.

    Science.gov (United States)

    Karlsson, Johan; Harmankaya, Necati; Palmquist, Anders; Atefyekta, Saba; Omar, Omar; Tengvall, Pentti; Andersson, Martin

    2016-10-01

    Triggering of the early healing events, including the recruitment of progenitor cells, has been suggested to promote bone regeneration. In implantology, local drug release technologies could provide an attractive approach to promote tissue regeneration. In this study, we targeted the chemotactic SDF-1α/CXCR4 axis that is responsible e.g. for the homing of stem cells to trauma sites. This was achieved by local delivery of plerixafor, an antagonist to CXCR4, and/or SDF-1α, from titanium implants coated with mesoporous titania thin films with a pore size of 7.5 nm. In vitro drug delivery experiments demonstrated that the mesoporous coating provided a high drug loading capacity and controlled release. The subsequent in vivo study in rat tibia showed beneficial effects with respect to bone-implant anchorage and bone-formation along the surface of the implants when plerixafor and SDF-1α were delivered locally. The effect was most prominent by the finding that the combination of the drugs significantly improved the mechanical bone anchorage. These observations suggest that titanium implants with local delivery of drugs for enhanced local recruitment of progenitor cells have the ability to promote osseointegration. This approach may provide a potential strategy for the development of novel implant treatments. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2466-2475, 2016. PMID:27213764

  4. Recent advances in the involvement of long non-coding RNAs in neural stem cell biology and brain pathophysiology

    Directory of Open Access Journals (Sweden)

    PanagiotisKPolitis

    2014-04-01

    Full Text Available Exploration of non-coding genome has recently uncovered a growing list of formerly unknown regulatory long non-coding RNAs (lncRNAs with important functions in stem cell pluripotency, development and homeostasis of several tissues. Although thousands of lncRNAs are expressed in mammalian brain in a highly patterned manner, their roles in brain development have just begun to emerge. Recent data suggest key roles for these molecules in gene regulatory networks controlling neuronal and glial cell differentiation. Analysis of the genomic distribution of genes encoding for lncRNAs indicates a physical association of these regulatory RNAs with transcription factors (TFs with well-established roles in neural differentiation, suggesting that lncRNAs and TFs may form coherent regulatory networks with important functions in neural stem cells (NSCs. Additionally, many studies show that lncRNAs are involved in the pathophysiology of brain-related diseases/disorders. Here we discuss these observations and investigate the links between lncRNAs, brain development and brain-related diseases. Understanding the functions of lncRNAs in NSCs and brain organogenesis could revolutionize the basic principles of developmental biology and neuroscience.

  5. Brain injury expands the numbers of neural stem cells and progenitors in the SVZ by enhancing their responsiveness to EGF

    Directory of Open Access Journals (Sweden)

    Deborah A Lazzarino

    2009-05-01

    Full Text Available There is an increase in the numbers of neural precursors in the SVZ (subventricular zone after moderate ischaemic injuries, but the extent of stem cell expansion and the resultant cell regeneration is modest. Therefore our studies have focused on understanding the signals that regulate these processes towards achieving a more robust amplification of the stem/progenitor cell pool. The goal of the present study was to evaluate the role of the EGFR [EGF (epidermal growth factor receptor] in the regenerative response of the neonatal SVZ to hypoxic/ischaemic injury. We show that injury recruits quiescent cells in the SVZ to proliferate, that they divide more rapidly and that there is increased EGFR expression on both putative stem cells and progenitors. With the amplification of the precursors in the SVZ after injury there is enhanced sensitivity to EGF, but not to FGF (fibroblast growth factor-2. EGF-dependent SVZ precursor expansion, as measured using the neurosphere assay, is lost when the EGFR is pharmacologically inhibited, and forced expression of a constitutively active EGFR is sufficient to recapitulate the exaggerated proliferation of the neural stem/progenitors that is induced by hypoxic/ischaemic brain injury. Cumulatively, our results reveal that increased EGFR signalling precedes that increase in the abundance of the putative neural stem cells and our studies implicate the EGFR as a key regulator of the expansion of SVZ precursors in response to brain injury. Thus modulating EGFR signalling represents a potential target for therapies to enhance brain repair from endogenous neural precursors following hypoxic/ischaemic and other brain injuries.

  6. Adenovirus-mediated human brain-derived neurotrophic factor gene-modified bone marrow mesenchymal stem cell transplantation for spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Changsheng Wang; Jianhua Lin; Chaoyang Wu; Rongsheng Chen

    2011-01-01

    Rat bone marrow mesenchymal stem cells expressing brain-derived neurotrophic factor were successfully obtained using a gene transfection method, then intravenously transplanted into rats with spinal cord injury. At 1, 3, and 5 weeks after transplantation, the expression of ??brain-derived neurotrophic factor and neurofilament-200 was upregulated in the injured spinal cord, spinal cord injury was alleviated, and Basso-Beattie-Bresnahan scores of hindlimb motor function were significantly increased. This evidence suggested that intravenous transplantation of adenovirus- mediated brain-derived neurotrophic factor gene-modified rat bone marrow mesenchymal stem cells could play a dual role, simultaneously providing neural stem cells and neurotrophic factors.

  7. Establishment and Characterization of a Tumor Stem Cell-Based Glioblastoma Invasion Model

    DEFF Research Database (Denmark)

    Jensen, Stine Skov; Meyer, Morten; Petterson, Stine Asferg;

    2016-01-01

    of immuno-compromised mice. Invasion was followed in the slice cultures by confocal time-lapse microscopy. Using immunohistochemistry, we compared tumor cell invasion as well as expression of proliferation and stem cell markers between the models. RESULTS: We observed a pronounced invasion into brain...... slice cultures both by confocal time-lapse microscopy and immunohistochemistry. This invasion closely resembled the invasion in vivo. The Ki-67 proliferation indexes in spheroids implanted into brain slices were lower than in free-floating spheroids. The expression of stem cell markers varied between...... free-floating spheroids, spheroids implanted into brain slices and tumors in vivo. CONCLUSION: The established invasion model kept in stem cell medium closely mimics tumor cell invasion into the brain in vivo preserving also to some extent the expression of stem cell markers. The model is feasible and...

  8. Functional neuroanatomy of auditory scene analysis in Alzheimer's disease

    OpenAIRE

    Golden, Hannah L.; Jennifer L. Agustus; Johanna C. Goll; Downey, Laura E; Mummery, Catherine J.; Jonathan M Schott; Crutch, Sebastian J.; Jason D Warren

    2015-01-01

    Auditory scene analysis is a demanding computational process that is performed automatically and efficiently by the healthy brain but vulnerable to the neurodegenerative pathology of Alzheimer's disease. Here we assessed the functional neuroanatomy of auditory scene analysis in Alzheimer's disease using the well-known ‘cocktail party effect’ as a model paradigm whereby stored templates for auditory objects (e.g., hearing one's spoken name) are used to segregate auditory ‘foreground’ and ‘back...

  9. The influence of carmustine wafer implantation on tumor bed cysts and peritumoral brain edema.

    Science.gov (United States)

    Hasegawa, Yuzo; Iuchi, Toshihiko; Sakaida, Tsukasa; Yokoi, Sana; Kawasaki, Koichiro

    2016-09-01

    The development of perifocal edema and tumor bed cyst has been reported after implantation of biodegradable carmustine wafers for the treatment of malignant gliomas. We retrospectively evaluated these changes in a series of patients; 19 consecutive patients with malignant glioma who received carmustine wafer implantation at our hospital from January 2013 through July 2013, and 28 patients who underwent surgery prior to our institution's initiation of carmustine wafer implantation, as historical controls. The volume of the tumor bed cyst and perifocal edema was calculated on MRI acquired at four time points: ⩽72hours after surgery for baseline, and at 1-4, 5-8, and 9-12weeks after surgery. The volume of the tumor bed cyst in the wafer group increased significantly relative to the control group at all time points (p=0.04). Opening of the ventricle was inversely correlated with enlargement of the tumor bed cyst in the wafer group (p=0.04). The change in the volume of perifocal edema in the wafer group was not significantly different (p=0.48), but exhibited a considerable increase in patients with anaplastic oligodendroglioma relative to glioblastoma patients in the wafer group (p=0.01). We demonstrated significant enlargement of the tumor bed cyst volume after carmustine wafer implantation, as well as the development of marked perifocal edema in patients with anaplastic oligodendroglioma. PMID:27430412

  10. Development of an implantable wireless ECoG 128ch recording device for clinical brain machine interface.

    Science.gov (United States)

    Matsushita, Kojiro; Hirata, Masayuki; Suzuki, Takafumi; Ando, Hiroshi; Ota, Yuki; Sato, Fumihiro; Morris, Shyne; Yoshida, Takeshi; Matsuki, Hidetoshi; Yoshimine, Toshiki

    2013-01-01

    Brain Machine Interface (BMI) is a system that assumes user's intention by analyzing user's brain activities and control devices with the assumed intention. It is considered as one of prospective tools to enhance paralyzed patients' quality of life. In our group, we especially focus on ECoG (electro-corti-gram)-BMI, which requires surgery to place electrodes on the cortex. We try to implant all the devices within the patient's head and abdomen and to transmit the data and power wirelessly. Our device consists of 5 parts: (1) High-density multi-electrodes with a 3D shaped sheet fitting to the individual brain surface to effectively record the ECoG signals; (2) A small circuit board with two integrated circuit chips functioning 128 [ch] analogue amplifiers and A/D converters for ECoG signals; (3) A Wifi data communication & control circuit with the target PC; (4) A non-contact power supply transmitting electrical power minimum 400[mW] to the device 20[mm] away. We developed those devices, integrated them, and, investigated the performance. PMID:24110075

  11. Growth of G422 glioma implanted in the mouse brain was affected by the immune ability of the host

    Institute of Scientific and Technical Information of China (English)

    CHENG Ying-xin; LI Fei; LU Jia-you; LI Mei; DU Peng; XU Gui-lian; FENG Hua

    2011-01-01

    Background It is generally accepted that gliomas are the most common primary brain tumors with poor prognosis. We aimed to explore the relationship of the immunity of the central nervous system and the genesis and development of glioma. Methods G422 glioma was implanted in the brain of BALB/c mice (immuno-competent mice), nude mice (T cell related immuno-deficient) and complement C3 knock-out mice (complement C3 related immunodeficient). The survival time of the host, growth and histopathology of the tumor, and concentrations of tumor necrosis factor-α (TNF-α) and interferon-γ (INF-γ) in tumor tissues were assessed.Results Tumor spheres were formed in all mice after injection, and glial fibrillary acidic protein (GFAP) positive staining of the cells declared their glioma origin. The longest median survival time of (44.3±6.0) days was found in BALB/c mice, followed by (24.8±5.2) days in nude mice and the shortest (18.6±5.8) days in complement C3 knock-out mice. Accordingly, the growth of the tumor was fastest in complement C3 knock-out mice, followed by the nude mice and slowest in the BALB/c mice. Although the proportions of infiltrating CD68+ lymphocytes in tumor tissues showed no significant difference (P>0.05), TNF-a level in the nude and C3 knock-out mice, (28.11±4.86) μmol/L and (22.87±6.36) μmol/L respectively, were significantly lower (P<0.01) than that in the BALB/c mice, which was (230.21±39.17) μmol/L. The INF-γ level was highest in the BALB/c mice ((180.76±29.19) μmol/L), followed by the nude mice ((113.46±23.76) μmol/L) and then the C3 knock-out mice ((16.84±4.45) μmol/L).Conclusions The G422 glioma implanted in the brains of mice with different immune ability would be a useful model for studying the relationship of the immune system and tumor in the central nervous system. Furthermore, the T cells and complement C3 compartments of the immune response may affect the growth of implanted tumors and inflammatory factors such as TNF

  12. Influence of leukoncephalopathy on the auditory and speech rehabilitation in patients with congenital hearing loss after cochlear implantation%脑白质病对先天性耳聋患儿人工耳蜗术后听觉言语恢复的影响

    Institute of Scientific and Technical Information of China (English)

    朱先锋; 张婧婧; 李金环; 马冰雪; 余永强; 钱银锋

    2015-01-01

    目的:探讨脑白质病对先天性耳聋患儿人工耳蜗术后听觉言语恢复的影响,为聋儿提供术前评价及术后恢复情况的评估。方法回顾性分析86例行人工耳蜗植入术的先天性耳聋患儿,年龄10月~6岁。术前行头颅常规 MRI 和内耳水成像,根据常规 MRI 表现分为脑白质病组和无脑白质病组,观察两组内耳畸形情况。术后半年采用听觉行为分级标准(CAP)和言语可懂度分级标准(SIR)对两组患儿的听力及言语恢复水平分别评分,并进行统计学分析比较。结果86例患者中22例存在脑白质病变,其中2例伴有内耳畸形;64例无脑白质病变,其中26例伴有内耳畸形。术后半年,脑白质病组 CAP 和 SIR 评分分别为(3.95±1.00)和(2.05±0.72),无脑白质病组则分别为(5.72±1.31)和(3.08±0.74),两组间差异显著。结论脑白质病是先天性耳聋患儿人工耳蜗植入后听觉感知及言语效果恢复的不利因素。%Objective To investigate the influence of leukoncephalopathy on the auditory and speech rehabilitation in patients with con-genital hearing loss after cochlear implantation,so as to define preoperative assessment and postoperative follow-up.Methods Eighty-six patients with congenital hearing loss performed with brain conventional MR imaging and inner ear hydrography before cochlear im-plantation,ages form ten months to six years.The patients were assigned into leukoncephalopathy group and non-leukoncephalopathy group according to the appearance on conventional MR images,and the malformation of inner ear was recorded.The hearing and speech recovery level was rated by using auditory behavior grading standards (CAP)and speech intelligibility grading standards (SIR)postop-eration half a year,which were compared between two groups.Results Twenty-two patients had leukoncephalopathy,among whom two cases had inner ear malformation

  13. Listen to Yourself: The Medial Prefrontal Cortex Modulates Auditory Alpha Power During Speech Preparation.

    Science.gov (United States)

    Müller, Nadia; Leske, Sabine; Hartmann, Thomas; Szebényi, Szabolcs; Weisz, Nathan

    2015-11-01

    How do we process stimuli that stem from the external world and stimuli that are self-generated? In the case of voice perception it has been shown that evoked activity elicited by self-generated sounds is suppressed compared with the same sounds played-back externally. We here wanted to reveal whether neural excitability of the auditory cortex-putatively reflected in local alpha band power--is modulated already prior to speech onset, and which brain regions may mediate such a top-down preparatory response. In the left auditory cortex we show that the typical alpha suppression found when participants prepare to listen disappears when participants expect a self-spoken sound. This suggests an inhibitory adjustment of auditory cortical activity already before sound onset. As a second main finding we demonstrate that the medial prefrontal cortex, a region known for self-referential processes, mediates these condition-specific alpha power modulations. This provides crucial insights into how higher-order regions prepare the auditory cortex for the processing of self-generated sounds. Furthermore, the mechanism outlined could provide further explanations to self-referential phenomena, such as "tickling yourself". Finally, it has implications for the so-far unsolved question of how auditory alpha power is mediated by higher-order regions in a more general sense. PMID:24904068

  14. Frequency representation within the human brain: Stability versus plasticity

    OpenAIRE

    Lim, Hubert H.; Minoo Lenarz; Gert Joseph; Thomas Lenarz

    2013-01-01

    A topographical representation for frequency has been identified throughout the auditory brain in animals but with limited evidence in humans. Using a midbrain implant, we identified an ordering of pitch percepts for electrical stimulation of sites across the human inferior colliculus (IC) that was consistent with the IC tonotopy shown in animals. Low pitches were perceived by the subject for stimulation of superficial IC sites while higher pitches were perceived for stimulation of deeper sit...

  15. Efficient and Rapid Derivation of Primitive Neural Stem Cells and Generation of Brain Subtype Neurons From Human Pluripotent Stem Cells

    OpenAIRE

    Yan, Yiping; Shin, Soojung; Jha, Balendu Shekhar; Liu, Qiuyue; Sheng, Jianting; Li, Fuhai; Zhan, Ming; Davis, Janine; Bharti, Kapil; Zeng, Xianmin; Rao, Mahendra; Malik, Nasir; Mohan C. Vemuri

    2013-01-01

    This study developed a highly efficient serum-free pluripotent stem cell (PSC) neural induction medium that can induce human PSCs into primitive neural stem cells (NSCs) in 7 days, obviating the need for time-consuming, laborious embryoid body generation or rosette picking. This method of primitive NSC derivation sets the stage for the scalable production of clinically relevant neural cells for cell therapy applications in good manufacturing practice conditions.

  16. Functional Near-Infrared Spectroscopy Brain Imaging Investigation of Phonological Awareness and Passage Comprehension Abilities in Adult Recipients of Cochlear Implants

    Science.gov (United States)

    Bisconti, Silvia; Shulkin, Masha; Hu, Xiaosu; Basura, Gregory J.; Kileny, Paul R.; Kovelman, Ioulia

    2016-01-01

    Purpose: The aim of this study was to examine how the brains of individuals with cochlear implants (CIs) respond to spoken language tasks that underlie successful language acquisition and processing. Method: During functional near-infrared spectroscopy imaging, CI recipients with hearing impairment (n = 10, mean age: 52.7 ± 17.3 years) and…

  17. Harmonic Training and the Formation of Pitch Representation in a Neural Network Model of the Auditory Brain

    Science.gov (United States)

    Ahmad, Nasir; Higgins, Irina; Walker, Kerry M. M.; Stringer, Simon M.

    2016-01-01

    Attempting to explain the perceptual qualities of pitch has proven to be, and remains, a difficult problem. The wide range of sounds which elicit pitch and a lack of agreement across neurophysiological studies on how pitch is encoded by the brain have made this attempt more difficult. In describing the potential neural mechanisms by which pitch may be processed, a number of neural networks have been proposed and implemented. However, no unsupervised neural networks with biologically accurate cochlear inputs have yet been demonstrated. This paper proposes a simple system in which pitch representing neurons are produced in a biologically plausible setting. Purely unsupervised regimes of neural network learning are implemented and these prove to be sufficient in identifying the pitch of sounds with a variety of spectral profiles, including sounds with missing fundamental frequencies and iterated rippled noises. PMID:27047368

  18. Imaging long-term fate of intramyocardially implanted mesenchymal stem cells in a porcine myocardial infarction model.

    Directory of Open Access Journals (Sweden)

    Emerson C Perin

    Full Text Available The long-term fate of stem cells after intramyocardial delivery is unknown. We used noninvasive, repetitive PET/CT imaging with [(18F]FEAU to monitor the long-term (up to 5 months spatial-temporal dynamics of MSCs retrovirally transduced with the sr39HSV1-tk gene (sr39HSV1-tk-MSC and implanted intramyocardially in pigs with induced acute myocardial infarction. Repetitive [(18F]FEAU PET/CT revealed a biphasic pattern of sr39HSV1-tk-MSC dynamics; cell proliferation peaked at 33-35 days after injection, in periinfarct regions and the major cardiac lymphatic vessels and lymph nodes. The sr39HSV1-tk-MSC-associated [(18F]FEAU signals gradually decreased thereafter. Cardiac lymphography studies using PG-Gd-NIRF813 contrast for MRI and near-infrared fluorescence imaging showed rapid clearance of the contrast from the site of intramyocardial injection through the subepicardial lymphatic network into the lymphatic vessels and periaortic lymph nodes. Immunohistochemical analysis of cardiac tissue obtained at 35 and 150 days demonstrated several types of sr39HSV1-tk expressing cells, including fibro-myoblasts, lymphovascular cells, and microvascular and arterial endothelium. In summary, this study demonstrated the feasibility and sensitivity of [(18F]FEAU PET/CT imaging for long-term, in-vivo monitoring (up to 5 months of the fate of intramyocardially injected sr39HSV1-tk-MSC cells. Intramyocardially transplanted MSCs appear to integrate into the lymphatic endothelium and may help improve myocardial lymphatic system function after MI.

  19. Auditory short-term memory in the primate auditory cortex.

    Science.gov (United States)

    Scott, Brian H; Mishkin, Mortimer

    2016-06-01

    Sounds are fleeting, and assembling the sequence of inputs at the ear into a coherent percept requires auditory memory across various time scales. Auditory short-term memory comprises at least two components: an active ׳working memory' bolstered by rehearsal, and a sensory trace that may be passively retained. Working memory relies on representations recalled from long-term memory, and their rehearsal may require phonological mechanisms unique to humans. The sensory component, passive short-term memory (pSTM), is tractable to study in nonhuman primates, whose brain architecture and behavioral repertoire are comparable to our own. This review discusses recent advances in the behavioral and neurophysiological study of auditory memory with a focus on single-unit recordings from macaque monkeys performing delayed-match-to-sample (DMS) tasks. Monkeys appear to employ pSTM to solve these tasks, as evidenced by the impact of interfering stimuli on memory performance. In several regards, pSTM in monkeys resembles pitch memory in humans, and may engage similar neural mechanisms. Neural correlates of DMS performance have been observed throughout the auditory and prefrontal cortex, defining a network of areas supporting auditory STM with parallels to that supporting visual STM. These correlates include persistent neural firing, or a suppression of firing, during the delay period of the memory task, as well as suppression or (less commonly) enhancement of sensory responses when a sound is repeated as a ׳match' stimulus. Auditory STM is supported by a distributed temporo-frontal network in which sensitivity to stimulus history is an intrinsic feature of auditory processing. This article is part of a Special Issue entitled SI: Auditory working memory. PMID:26541581

  20. Impaired auditory selective attention ameliorated by cognitive training with graded exposure to noise in patients with traumatic brain injury.

    Science.gov (United States)

    Dundon, Neil M; Dockree, Suvi P; Buckley, Vanessa; Merriman, Niamh; Carton, Mary; Clarke, Sarah; Roche, Richard A P; Lalor, Edmund C; Robertson, Ian H; Dockree, Paul M

    2015-08-01

    Patients who suffer traumatic brain injury frequently report difficulty concentrating on tasks and completing routine activities in noisy and distracting environments. Such impairments can have long-term negative psychosocial consequences. A cognitive control function that may underlie this impairment is the capacity to select a goal-relevant signal for further processing while safeguarding it from irrelevant noise. A paradigmatic investigation of this problem was undertaken using a dichotic listening task (study 1) in which comprehension of a stream of speech to one ear was measured in the context of increasing interference from a second stream of irrelevant speech to the other ear. Controls showed an initial decline in performance in the presence of competing speech but thereafter showed adaptation to increasing audibility of irrelevant speech, even at the highest levels of noise. By contrast, patients showed linear decline in performance with increasing noise. Subsequently attempts were made to ameliorate this deficit (study 2) using a cognitive training procedure based on attention process training (APT) that included graded exposure to irrelevant noise over the course of training. Patients were assigned to adaptive and non-adaptive training schedules or to a no-training control group. Results showed that both types of training drove improvements in the dichotic listening and in naturalistic tasks of performance in noise. Improvements were also seen on measures of selective attention in the visual domain suggesting transfer of training. We also observed augmentation of event-related potentials (ERPs) linked to target processing (P3b) but no change in ERPs evoked by distractor stimuli (P3a) suggesting that training heightened tuning of target signals, as opposed to gating irrelevant noise. No changes in any of the above measures were observed in a no-training control group. Together these findings present an ecologically valid approach to measure selective

  1. Identification and culture of neural stem cells isolated from adult rat subventricular zone following fluid percussion brain injury

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Objective To analyze proliferation and differentiation of glial fibrillary acid protein(GFAP)-and nestin-positive(GFAP+/nestin+)cells isolated from the subventricular zone following fluid percussion brain injury to determine whether GFAP+/nestin+ cells exhibit characteristics of neural stem cells.Methods Male Sprague-Dawley rats,aged 12 weeks and weighing 200-250 g,were randomly and evenly assigned to normal control group and model group.In the model group,a rat model of fluid percussion brain injury was es...

  2. A wirelessly controlled implantable LED system for deep brain optogenetic stimulation

    OpenAIRE

    Rossi, Mark A.; Go, Vinson; Murphy, Tracy; Fu, Quanhai; Morizio, James; Yin, Henry H.

    2015-01-01

    In recent years optogenetics has rapidly become an essential technique in neuroscience. Its temporal and spatial specificity, combined with efficacy in manipulating neuronal activity, are especially useful in studying the behavior of awake behaving animals. Conventional optogenetics, however, requires the use of lasers and optic fibers, which can place considerable restrictions on behavior. Here we combined a wirelessly controlled interface and small implantable light-emitting diode (LED) tha...

  3. A wirelessly controlled implantable LED system for deep brain optogenetic stimulation

    OpenAIRE

    Rossi, Mark A.; Vinson eGo; Tracy eMurphy; Quanhai eFu; James eMorizio; Yin, Henry H.

    2015-01-01

    In recent years optogenetics has rapidly become an essential technique in neuroscience. Its temporal and spatial specificity, combined with efficacy in manipulating neuronal activity, are especially useful in studying the behavior of awake behaving animals. Conventional optogenetics, however, requires the use of lasers and optic fibers, which can place considerable restrictions on behavior. Here we combined a wirelessly controlled interface and small implantable light-emitting diode (LED) ...

  4. Brain Responses to Musical Feature Changes in Adolescent Cochlear Implant Users

    OpenAIRE

    Bjørn Petersen; Ethan Weed; Pascale Sandmann; Elvira Brattico; Mads Hansen

    2015-01-01

    Cochlear implants (CIs) are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (...

  5. Patterns of recurrence in brain stem gliomas: evidence for craniospinal dissemination

    International Nuclear Information System (INIS)

    Purpose: The 3-year survival rate of pediatric patients with infiltrating brain stem gliomas (BSG) is < 10%. Treatment involves local field radiation, and local failure has been the hallmark of recurrence. With therapeutic advances and improved radiographic monitoring, perceived and actual patterns of failure may change. We report patterns of recurrence in a group of patients with close follow-up, treated on an institutional protocol incorporating hyperfractionated involved-field radiation therapy and concomitant carboplatin, who have been uniformly staged and treated and have undergone MRI surveillance. Methods and Materials: From 1990-1995, 18 pediatric patients with BSG were treated on a Phase I-II trial of concurrent carboplatin and hyperfractionated radiotherapy. Eight had surgical procedures to document histology. Nine had hydrocephalus prior to death. All had pretreatment brain and spine MRIs, with and without gadolinium, that showed no other evidence of disease. Treatment consisted of 72.00 Gy involved-field hyperfractionated radiation therapy and dose-escalating concomitant carboplatin. Results: Fifteen children have had progression of disease (median PFS = 9 months); and 13 have died (median OS = 14 months). Fourteen of the 15 children with progression had local failures, 8 of whom had evidence of noncontiguous spinal (4) or intracranial (7) disease documented by MRI or autopsy. One child with local control developed an intracranial metastasis. None had clinical manifestations of leptomeningeal disease. Conclusion: Leptomeningeal dissemination occurred within 1 month of local progression in nearly 30% of our patients and, overall, occurred in 50% prior to death. This high incidence may reflect close MRI surveillance or a changing pattern of recurrence. Because the majority of leptomeningeal disease occurs in the setting of local progression, treatment efforts must be directed primarily toward local control. However, management of leptomeningeal

  6. The Brain Microenvironment Preferentially Enhances the Radioresistance of CD133+ Glioblastoma Stem-like Cells

    Directory of Open Access Journals (Sweden)

    Muhammad Jamal

    2012-02-01

    Full Text Available Brain tumor xenografts initiated from glioblastoma (GBM CD133+ tumor stem-like cells (TSCs are composed of TSC and non-TSC subpopulations, simulating the phenotypic heterogeneity of GBMs in situ. Given that the discrepancies between the radiosensitivity of GBM cells in vitro and the treatment response of patients suggest a role for the microenvironment in GBM radioresistance, we compared the response of TSCs and non-TSCs irradiated under in vitro and orthotopic conditions. As a measure of radioresponse determined at the individual cell level, γH2AX and 53BP1 foci were quantified in CD133+ cells and their differentiated (CD133- progeny. Under in vitro conditions, no difference was detected between CD133+ and CD133- cells in foci induction or dispersal after irradiation. However, irradiation of orthotopic xenografts initiated from TSCs resulted in the induction of fewer γH2AX and 53BP1 foci in CD133+ cells compared to their CD133- counterparts within the same tumor. Xenograft irradiation resulted in a tumor growth delay of approximately 7 days with a corresponding increase in the percentage of CD133+ cells at 7 days after radiation, which persisted to the onset of neurologic symptoms. These results suggest that, although the radioresponse of TSCs and non-TSCs does not differ under in vitro growth conditions, CD133+ cells are relatively radioresistant under intracerebral growth conditions. Whereas these findings are consistent with the suspected role for TSCs as a determinant of GBM radioresistance, these data also illustrate the dependence of the cellular radioresistance on the brain microenvironment.

  7. Therapy of brain stem tumors - palliative conception with prospect of curative success

    International Nuclear Information System (INIS)

    From 1969 to 1981, 23 patients with tumors in the pons region were irradiated at the Department of Radiotherapy of the West German Tumor Center in Essen. The age of the patients ranged from 18 months to 50 years. Fifteen patients (65%) were younger than 18 years, one was 25 years old, and seven were between 40 and 50 years old. In two cases the histologic diagnosis of an astrocytoma I and astrocytoma II could be confirmed by exploratory excision and cyst punction, respectively. Nineteen patients received a shunt system (ventriculoatrial shunt) prior to radiotherapy in order to achieve a pressure reduction. After a follow-up period of 1.5 to 12 years, eleven patients are alive, and twelve patients died from a local recurrence or from progressive tumor growth. The five-year survival rate is 47%. Five of the surviving patients show no or only slight adverse effects on their general condition and are able to attend school or carry out their profession (in Karnofsky: 90 to 100%). Four other patients suffering from marked remaining neurologic symptoms are able to take care of themselves (Karnofsky: 70 to 80%). Two patients need permanent nursing (Karnofsky: 50 to 60%). Because of the local propagation tendency of pons tumors, radiotherapy should be locally restricted to the brain stem and the adjacent brain structures, e.g. cerebellum and proximal neck marrow. The authors recommend target volumes of 55 to 60 Gy, which must be applied within 6 to 8 weeks, taking into account the age of patients. This palliative therapy conception should be applied routinely in the hope of bringing about a curative treatment to this group of patients. (orig.)

  8. Presenilins are required for maintenance of neural stem cells in the developing brain

    Directory of Open Access Journals (Sweden)

    Kim Woo-Young

    2008-01-01

    Full Text Available Abstract The early embryonic lethality of mutant mice bearing germ-line deletions of both presenilin genes precluded the study of their functions in neural development. We therefore employed the Cre-loxP technology to generate presenilin conditional double knockout (PS cDKO mice, in which expression of both presenilins is inactivated in neural progenitor cells (NPC or neural stem cells and their derivative neurons and glia beginning at embryonic day 11 (E11. In PS cDKO mice, dividing NPCs labeled by BrdU are decreased in number beginning at E13.5. By E15.5, fewer than 20% of NPCs remain in PS cDKO mice. The depletion of NPCs is accompanied by severe morphological defects and hemorrhages in the PS cDKO embryonic brain. Interkinetic nuclear migration of NPCs is also disrupted in PS cDKO embryos, as evidenced by displacement of S-phase and M-phase nuclei in the ventricular zone of the telencephalon. Furthermore, the depletion of neural progenitor cells in PS cDKO embryos is due to NPCs exiting cell cycle and differentiating into neurons rather than reentering cell cycle between E13.5 and E14.5 following PS inactivation in most NPCs. The length of cell cycle, however, is unchanged in PS cDKO embryos. Expression of Notch target genes, Hes1 and Hes5, is significantly decreased in PS cDKO brains, whereas Dll1 expression is up-regulated, indicating that Notch signaling is effectively blocked by PS inactivation. These findings demonstrate that presenilins are essential for neural progenitor cells to re-enter cell cycle and thus ensure proper expansion of neural progenitor pool during embryonic neural development.

  9. Tipifarnib in Treating Young Patients With Recurrent or Progressive High-Grade Glioma, Medulloblastoma, Primitive Neuroectodermal Tumor, or Brain Stem Glioma

    Science.gov (United States)

    2013-10-07

    Childhood High-grade Cerebral Astrocytoma; Childhood Oligodendroglioma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma

  10. Critical appraisal of cerebral blood flow measured from brain stem and cerebellar regions after 133 Xe inhalation in humans

    International Nuclear Information System (INIS)

    Validity of regional blood flow (rCBF) measurements recorded over the human posterior fossa after 133Xe inhalation was tested. Recording of counts from both brain stem and cerebellum (BSC) was reproducible and contamination by counts derived from surrounding anatomical structures was low and no greater than that found over hemispheres. BSC flow values showed significant correlation with the state of awareness as judged by clinical and EEG evaluation

  11. Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat.

    Science.gov (United States)

    Jones, Sarah E; Dutschmann, Mathias

    2016-05-01

    Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex (n = 5), at obex (n = 5), and 1.5 (n = 7) and 3 mm (n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation. PMID:26888109

  12. Transplantation of human neural stem cells restores cognition in an immunodeficient rodent model of traumatic brain injury

    OpenAIRE

    Haus, DL; Lopez-Velazquez, L; Gold, EM; Cunningham, KM; Perez, H; Anderson, AJ; Cummings, BJ

    2016-01-01

    Traumatic brain injury (TBI) in humans can result in permanent tissue damage and has been linked to cognitive impairment that lasts years beyond the initial insult. Clinically effective treatment strategies have yet to be developed. Transplantation of human neural stem cells (hNSCs) has the potential to restore cognition lost due to injury, however, the vast majority of rodent TBI/hNSC studies to date have evaluated cognition only at early time points, typically

  13. A meta-analysis of efficacy in pre-clinical human stem cell therapies for traumatic brain injury

    OpenAIRE

    Chang, J.; Phelan, M; Cummings, BJ

    2015-01-01

    © 2015 Elsevier Inc. Objectives: Evaluate the preclinical evidence for human cell therapies for the treatment of traumatic brain injury (TBI), determine behavioral effect sizes for modified and non-modified cells, and identify variables that correlate with greater effect sizes. Methods: A literature search identified 58 animal studies of TBI using human stem cells. Each study received a Quality Index (QI) score based on existing guidelines. Effect sizes for cell therapies were determined for ...

  14. Gene expression analysis of neuronal precursors from adult mouse brain and differential screen for neural stem cell markers

    OpenAIRE

    Pennartz, Sandra

    2004-01-01

    In the adult mouse brain, neuronal precursor cells continuously emanate from neural stem cells (NSC) in the subventricular zone (SVZ) and migrate into the olfactory bulb (OB) where they differentiate to serve as replenishment for GABAergic interneurons. During the migration process, PSA-NCAM (Polysialic acid-Neural cell adhesion molecule) specifically marks the neuronal precursors (PSA+ cells). This phenomenon was exploited in the framework of this doctoral thesis to isolate a homogeneous cel...

  15. Depletion of neural stem cells from the subventricular zone of adult mouse brain using cytosine b‐Arabinofuranoside

    OpenAIRE

    Ghanbari, Amir; Esmaeilpour, Tahereh; Bahmanpour, Soghra; Golmohammadi, Mohammad Ghasem; Sharififar, Sharareh; Azari, Hassan

    2015-01-01

    Abstract Introduction Neural stem cells (NSCs) reside along the ventricular axis of the mammalian brain. They divide infrequently to maintain themselves and the down‐stream progenitors. Due to the quiescent property of NSCs, attempts to deplete these cells using antimitotic agents such as cytosine b‐Aarabinofuranoside (Ara‐C) have not been successful. We hypothesized that implementing infusion gaps in Ara‐C kill paradigms would recruit the quiescent NSCs and subsequently eliminate them from t...

  16. C1–C2 arthrodesis after transoral odontoidectomy and suboccipital craniectomy for ventral brain stem compression in Chiari I patients

    OpenAIRE

    Hwang, Steven W.; Heilman, Carl B.; Riesenburger, Ron I.; Kryzanski, James

    2008-01-01

    Chiari I malformations are often associated with congenital craniocervical anomalies such as platybasia, basilar invagination, and retroflexion of the odontoid process. Management of ventral brain stem compression associated with Chiari I malformations remains controversial, but several authors report a significant rate of failure with suboccipital decompression alone in the presence of pronounced ventral brain stem compression (VBSC). Treatment options described in the literature for these p...

  17. Combining acellular nerve allografts with brain-derived neurotrophic factor transfected bone marrow mesenchymal stem cells restores sciatic nerve injury better than either intervention alone

    OpenAIRE

    Zhang, Yanru; Zhang, Hui; Zhang, Gechen; Ka, Ka; Huang, Wenhua

    2014-01-01

    In this study, we chemically extracted acellular nerve allografts from bilateral sciatic nerves, and repaired 10-mm sciatic nerve defects in rats using these grafts and brain-derived neurotrophic factor transfected bone marrow mesenchymal stem cells. Experiments were performed in three groups: the acellular nerve allograft bridging group, acellular nerve allograft + bone marrow mesenchymal stem cells group, and the acellular nerve allograft + brain-derived neurotrophic factor transfected bone...

  18. Susceptibility-weighted imaging of the venous networks around the brain stem

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Ming; Lin, Zhong-Xiao; Zhang, Nu [Wenzhou Medical University, Department of Neurosurgery, The 2nd Affiliated Hospital of Wenzhou Medical University, Wenzhou (China); Zhang, Xiao-Fen; Qiao, Hui-Huang; Chen, Cheng-Chun [Wenzhou Medical University, Department of Human Anatomy, Wenzhou (China); Ren, Chuan-Gen; Li, Jian-Ce [Wenzhou Medical University, Department of Radiology, The 1nd Affiliated Hospital of Wenzhou Medical University, Wenzhou (China)

    2014-10-18

    The venous network of the brainstem is complex and significant. Susceptibility-weighted imaging (SWI) is a practical technique which is sensitive to veins, especially tiny veins. Our purpose of this study was to evaluate the visualization of the venous network of brainstem by using SWI at 3.0 T. The occurrence rate of each superficial veins of brainstem was evaluated by using SWI on a 3 T MR imaging system in 60 volunteers. The diameter of the lateral mesencephalic vein and peduncular vein were measured by SWI using the reconstructed mIP images in the sagittal view. And the outflow of the veins of brainstem were studied and described according to the reconstructed images. The median anterior pontomesencephalic vein, median anterior medullary vein, peduncular vein, right vein of the pontomesencephalic sulcus, and right lateral anterior pontomesencephalic vein were detected in all the subjects (100 %). The outer diameter of peduncular vein was 1.38 ± 0.26 mm (range 0.8-1.8 mm). The lateral mesencephalic vein was found in 75 % of the subjects and the mean outer diameter was 0.81 ± 0.2 mm (range 0.5-1.2 mm). The inner veins of mesencephalon were found by using SWI. The venous networks around the brain stem can be visualized by SWI clearly. This result can not only provide data for anatomical study, but also may be available for the surgical planning in the infratentorial region. (orig.)

  19. Molecular control of brain size: Regulators of neural stem cell life, death and beyond

    International Nuclear Information System (INIS)

    The proper development of the brain and other organs depends on multiple parameters, including strictly controlled expansion of specific progenitor pools. The regulation of such expansion events includes enzymatic activities that govern the correct number of specific cells to be generated via an orchestrated control of cell proliferation, cell cycle exit, differentiation, cell death etc. Certain proteins in turn exert direct control of these enzymatic activities and thus progenitor pool expansion and organ size. The members of the Cip/Kip family (p21Cip1/p27Kip1/p57Kip2) are well-known regulators of cell cycle exit that interact with and inhibit the activity of cyclin-CDK complexes, whereas members of the p53/p63/p73 family are traditionally associated with regulation of cell death. It has however become clear that the roles for these proteins are not as clear-cut as initially thought. In this review, we discuss the roles for proteins of the Cip/Kip and p53/p63/p73 families in the regulation of cell cycle control, differentiation, and death of neural stem cells. We suggest that these proteins act as molecular interfaces, or 'pilots', to assure the correct assembly of protein complexes with enzymatic activities at the right place at the right time, thereby regulating essential decisions in multiple cellular events.

  20. Brain stem adenosine receptors modulate centrally mediated hypotensive responses in conscious rats: A review

    Directory of Open Access Journals (Sweden)

    Noha N. Nassar

    2015-05-01

    Full Text Available Adenosine is implicated in the modulation of cardiovascular responses either at the peripheral or at central level in experimental animals. However, there are no dedicated reviews on the involvement of adenosine in mediating the hypotensive response of centrally administered clonidine in general and specifically in aortically barodenervated rats (ABD. The conscious ABD rat model exhibits surgically induced baroreflex dysfunction and exaggerated hypotensive response, compared with conscious sham-operated (SO rats. The current review focuses on, the role of adenosine receptors in blood pressure (BP regulation and their possible crosstalk with other receptors e.g. imidazoline (I1 and alpha (α2A adrenergic receptor (AR. The former receptor is a molecular target for clonidine, whose hypotensive effect is enhanced approx. 3-fold in conscious ABD rats. We also discussed how the balance between the brain stem adenosine A1 and A2A receptors is regulated by baroreceptors and how such balance influences the centrally mediated hypotensive responses. The use of the ABD rat model yielded insight into the downstream signaling cascades following clonidine-evoked hypotension in a surgical model of baroreflex dysfunction.

  1. GFAP expression is regulated by Pax3 in brain glioma stem cells.

    Science.gov (United States)

    Su, Xing; Liu, Xiaojiang; Ni, Lanchun; Shi, Wei; Zhu, Hui; Shi, Jinlong; Chen, Jian; Gu, Zhikai; Gao, Yilu; Lan, Qing; Huang, Qingfeng

    2016-09-01

    Glioblastomas are understood to evolve from brain glioma stem cells (BGSCs), and yet the biology underlying this model of tumorigenesis is largely unknown. Paired box 3 protein (Pax3) is a member of the paired box (Pax) family of transcription factors that is normally expressed during embryonic development, but has recently been implicated in tumorigenesis. The present study demonstrated that Pax3 is differentially expressed in U87MG human glioma cell, BGSC and normal 1800 human astrocyte lines. Herein, we identified that the glial fibrillary acidic protein (GFAP), a major intermediate filament protein of mature astrocytes, is directly downregulated during the differentiation of BGSCs via the binding of Pax3 to the promoter region of GFAP. Moreover, siRNA silencing of Pax3 arrested BGSC differentiation, while overexpression of Pax3 promoted the differentiation in BGSCs. Furthermore, we studied the cell proliferation, invasion, apoptosis, differentiation and expression of Pax3 and GFAP in Pax3 siRNA-knockdown and Pax3-overexpressing BGSC models by CCK-8, Transwell migration, flow cytometry and western blot assays. The results indicate that Pax3 regulates GFAP expression, and that Pax3 may contribute to the evolution of BGSCs towards malignancy. PMID:27432276

  2. Wnt3a, a Protein Secreted by Mesenchymal Stem Cells Is Neuroprotective and Promotes Neurocognitive Recovery Following Traumatic Brain Injury.

    Science.gov (United States)

    Zhao, Yuhai; Gibb, Stuart L; Zhao, Jing; Moore, Anthony N; Hylin, Michael J; Menge, Tyler; Xue, Hasen; Baimukanova, Gyulnar; Potter, Daniel; Johnson, Evan M; Holcomb, John B; Cox, Charles S; Dash, Pramod K; Pati, Shibani

    2016-05-01

    Intravenous administration of bone marrow derived mesenchymal stem cells (MSCs) has been shown to reduce blood brain barrier compromise and improve neurocognition following traumatic brain injury (TBI). These effects occur in the absence of engraftment and differentiation of these cells in the injured brain. Recent studies have shown that soluble factors produced by MSCs mediate a number of the therapeutic effects. In this study, we sought to determine if intravenous administration of MSCs (IV-MSCs) could enhance hippocampal neurogenesis following TBI. Our results demonstrate that IV-MSC treatment attenuates loss of neural stem cells and promotes hippocampal neurogenesis in TBI injured mice. As Wnt signaling has been implicated in neurogenesis, we measured circulating Wnt3a levels in serum following IV-MSC administration and found a significant increase in Wnt3a. Concurrent with this increase, we detected increased activation of the Wnt/β-catenin signaling pathway in hippocampal neurons. Furthermore, IV recombinant Wnt3a treatment provided neuroprotection, promoted neurogenesis, and improved neurocognitive function in TBI injured mice. Taken together, our results demonstrate a role for Wnt3a in the therapeutic potential of MSCs and identify Wnt3a as a potential stand-alone therapy or as part of a combination therapeutic strategy for the treatment of TBI. Stem Cells 2016;34:1263-1272. PMID:26840479

  3. Human umbilical cord blood-derived stem cells and brain-derived neurotrophic factor protect injured optic nerve: viscoelasticity characterization.

    Science.gov (United States)

    Lv, Xue-Man; Liu, Yan; Wu, Fei; Yuan, Yi; Luo, Min

    2016-04-01

    The optic nerve is a viscoelastic solid-like biomaterial. Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury. We hypothesized that stress relaxation and creep properties of the optic nerve change after injury. More-over, human brain-derived neurotrophic factor or umbilical cord blood-derived stem cells may restore these changes to normal. To validate this hypothesis, a rabbit model of optic nerve injury was established using a clamp approach. At 7 days after injury, the vitreous body re-ceived a one-time injection of 50 μg human brain-derived neurotrophic factor or 1 × 10(6) human umbilical cord blood-derived stem cells. At 30 days after injury, stress relaxation and creep properties of the optic nerve that received treatment had recovered greatly, with patho-logical changes in the injured optic nerve also noticeably improved. These results suggest that human brain-derived neurotrophic factor or umbilical cord blood-derived stem cell intervention promotes viscoelasticity recovery of injured optic nerves, and thereby contributes to nerve recovery. PMID:27212930

  4. Human umbilical cord blood-derived stem cells and brain-derived neurotrophic factor protect injured optic nerve: viscoelasticity characterization

    Directory of Open Access Journals (Sweden)

    Xue-man Lv

    2016-01-01

    Full Text Available The optic nerve is a viscoelastic solid-like biomaterial. Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury. We hypothesized that stress relaxation and creep properties of the optic nerve change after injury. More-over, human brain-derived neurotrophic factor or umbilical cord blood-derived stem cells may restore these changes to normal. To validate this hypothesis, a rabbit model of optic nerve injury was established using a clamp approach. At 7 days after injury, the vitreous body re-ceived a one-time injection of 50 µg human brain-derived neurotrophic factor or 1 × 106 human umbilical cord blood-derived stem cells. At 30 days after injury, stress relaxation and creep properties of the optic nerve that received treatment had recovered greatly, with patho-logical changes in the injured optic nerve also noticeably improved. These results suggest that human brain-derived neurotrophic factor or umbilical cord blood-derived stem cell intervention promotes viscoelasticity recovery of injured optic nerves, and thereby contributes to nerve recovery.

  5. Non-virally engineered human adipose mesenchymal stem cells produce BMP4, target brain tumors, and extend survival.

    Science.gov (United States)

    Mangraviti, Antonella; Tzeng, Stephany Y; Gullotti, David; Kozielski, Kristen L; Kim, Jennifer E; Seng, Michael; Abbadi, Sara; Schiapparelli, Paula; Sarabia-Estrada, Rachel; Vescovi, Angelo; Brem, Henry; Olivi, Alessandro; Tyler, Betty; Green, Jordan J; Quinones-Hinojosa, Alfredo

    2016-09-01

    There is a need for enabling non-viral nanobiotechnology to allow safe and effective gene therapy and cell therapy, which can be utilized to treat devastating diseases such as brain cancer. Human adipose-derived mesenchymal stem cells (hAMSCs) display high anti-glioma tropism and represent a promising delivery vehicle for targeted brain tumor therapy. In this study, we demonstrate that non-viral, biodegradable polymeric nanoparticles (NPs) can be used to engineer hAMSCs with higher efficacy (75% of cells) than leading commercially available reagents and high cell viability. To accomplish this, we engineered a poly(beta-amino ester) (PBAE) polymer structure to transfect hAMSCs with significantly higher efficacy than Lipofectamine™ 2000. We then assessed the ability of NP-engineered hAMSCs to deliver bone morphogenetic protein 4 (BMP4), which has been shown to have a novel therapeutic effect by targeting human brain tumor initiating cells (BTIC), a source of cancer recurrence, in a human primary malignant glioma model. We demonstrated that hAMSCs genetically engineered with polymeric nanoparticles containing BMP4 plasmid DNA (BMP4/NP-hAMSCs) secrete BMP4 growth factor while maintaining their multipotency and preserving their migration and invasion capacities. We also showed that this approach can overcome a central challenge for brain therapeutics, overcoming the blood brain barrier, by demonstrating that NP-engineered hAMSCs can migrate to the brain and penetrate the brain tumor after both intranasal and systemic intravenous administration. Critically, athymic rats bearing human primary BTIC-derived tumors and treated intranasally with BMP4/NP-hAMSCs showed significantly improved survival compared to those treated with control GFP/NP-hAMCSs. This study demonstrates that synthetic polymeric nanoparticles are a safe and effective approach for stem cell-based cancer-targeting therapies. PMID:27240162

  6. Repair of spinal cord injury by neural stem cells transfected with brain-derived neurotrophic factor-green fluorescent protein in rats A double effect of stem cells and growth factors

    Institute of Scientific and Technical Information of China (English)

    Yansong Wang; Gang Lü

    2010-01-01

    Brain-derived neurotrophic factor(BDNF)can significantly promote nerve regeneration and repair.High expression of the BDNF-green fluorescent protein(GFP)gene persists for a long time after transfection into neural stem cells.Nevertheless,little is known about the biological characteristics of BDNF-GFP modified nerve stem cells in vivo and their ability to induce BDNF expression or repair spinal cord injury.In the present study,we transplanted BDNF-GFP transgenic neural stem cells into a hemisection model of rats.Rats with BDNF-GFP stem cells exhibited significantly increased BDNF expression and better locomotor function compared with stem cells alone.Cellular therapy with BDNF-GFP transgenic stem cells can improve outcomes better than stem cells alone and may have therapeutic potential for spinal cord injury.

  7. Auditory profile and high resolution CT scan in autism spectrum disorders children with auditory hypersensitivity.

    Science.gov (United States)

    Thabet, Elsaeid M; Zaghloul, Hesham S

    2013-08-01

    Autism is the third most common developmental disorder, following mental retardationand cerebral palsy. ASD children have been described more often as beingpreoccupied with or agitated by noise. The aim of this study was to evaluate theprevalence and clinical significance of semicircular canal dehiscence detected on CTimages in ASD children with intolerance to loud sounds in an attempt to find ananatomical correlate with hyperacusis.14 ASD children with auditory hypersensitivity and 15 ASD children without auditoryhypersensitivity as control group age and gender matched were submitted to historytaking, otological examination, tympanometry and acoustic reflex thresholdmeasurement. ABR was done to validate normal peripheral hearing and integrity ofauditory brain stem pathway. High resolution CT scan petrous and temporal boneimaging was performed to all participated children. All participants had normal hearingsensitivity in ABR testing. Absolute ABR peak waves of I and III showed no statisticallysignificant difference between the two groups, while absolute wave V peak andinterpeak latencies I-V and III-V were shorter in duration in study group whencompared to the control group. CT scans revealed SSCD in 4 out of 14 of the studygroup (29%), the dehiscence was bilateral in one patient and unilateral in threepatients. None of control group showed SSCD. In conclusion, we have reportedevidence that apparent hypersensitivity to auditory stimuli (short conduction time in ABR) despite the normal physiological measures in ASD children with auditoryhypersensitivity can provide a clinical clue of a possible SSCD. PMID:23580033

  8. Auditory Preferences of Young Children with and without Hearing Loss for Meaningful Auditory-Visual Compound Stimuli

    Science.gov (United States)

    Zupan, Barbra; Sussman, Joan E.

    2009-01-01

    Experiment 1 examined modality preferences in children and adults with normal hearing to combined auditory-visual stimuli. Experiment 2 compared modality preferences in children using cochlear implants participating in an auditory emphasized therapy approach to the children with normal hearing from Experiment 1. A second objective in both…

  9. Experimental new automatic tools for robotic stereotactic neurosurgery: towards "no hands" procedure of leads implantation into a brain target.

    Science.gov (United States)

    Mazzone, P; Arena, P; Cantelli, L; Spampinato, G; Sposato, S; Cozzolino, S; Demarinis, P; Muscato, G

    2016-07-01

    The use of robotics in neurosurgery and, particularly, in stereotactic neurosurgery, is becoming more and more adopted because of the great advantages that it offers. Robotic manipulators easily allow to achieve great precision, reliability, and rapidity in the positioning of surgical instruments or devices in the brain. The aim of this work was to experimentally verify a fully automatic "no hands" surgical procedure. The integration of neuroimaging to data for planning the surgery, followed by application of new specific surgical tools, permitted the realization of a fully automated robotic implantation of leads in brain targets. An anthropomorphic commercial manipulator was utilized. In a preliminary phase, a software to plan surgery was developed, and the surgical tools were tested first during a simulation and then on a skull mock-up. In such a way, several tools were developed and tested, and the basis for an innovative surgical procedure arose. The final experimentation was carried out on anesthetized "large white" pigs. The determination of stereotactic parameters for the correct planning to reach the intended target was performed with the same technique currently employed in human stereotactic neurosurgery, and the robotic system revealed to be reliable and precise in reaching the target. The results of this work strengthen the possibility that a neurosurgeon may be substituted by a machine, and may represent the beginning of a new approach in the current clinical practice. Moreover, this possibility may have a great impact not only on stereotactic functional procedures but also on the entire domain of neurosurgery. PMID:27194228

  10. Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    Hai-xiao Zhou; Zhi-gang Liu; Xiao-jiao Liu; Qian-xue Chen

    2016-01-01

    Transplantation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen (HBO) treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized lfuid (2.5–3.0 atm impact force). The injured rats were then administered UC-MSC transplantationvia the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function signiifcantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and signiifcantly promotes recovery of neurological functions.

  11. Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Hai-xiao Zhou

    2016-01-01

    Full Text Available Transplantation of umbilical cord-derived mesenchymal stem cells (UC-MSCs for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen (HBO treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized fluid (2.5-3.0 atm impact force. The injured rats were then administered UC-MSC transplantation via the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function significantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and significantly promotes recovery of neurological functions.

  12. Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury.

    Science.gov (United States)

    Zhou, Hai-Xiao; Liu, Zhi-Gang; Liu, Xiao-Jiao; Chen, Qian-Xue

    2016-01-01

    Transplantation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen (HBO) treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized fluid (2.5-3.0 atm impact force). The injured rats were then administered UC-MSC transplantation via the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function significantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and significantly promotes recovery of neurological functions. PMID:26981097

  13. Development of a Stereotaxic Device for Low Impact Implantation of Neural Constructs or Pieces of Neural Tissues into the Mammalian Brain

    Directory of Open Access Journals (Sweden)

    Andrzej Jozwiak

    2014-01-01

    Full Text Available Implanting pieces of tissue or scaffolding material into the mammalian central nervous system (CNS is wrought with difficulties surrounding the size of tools needed to conduct such implants and the ability to maintain the orientation and integrity of the constructs during and after their transplantation. Here, novel technology has been developed that allows for the implantation of neural constructs or intact pieces of neural tissue into the CNS with low trauma. By “laying out” (instead of forcibly expelling the implantable material from a thin walled glass capillary, this technology has the potential to enhance neural transplantation procedures by reducing trauma to the host brain during implantation and allowing for the implantation of engineered/dissected tissues or constructs in such a way that their orientation and integrity are maintained in the host. Such technology may be useful for treating various CNS disorders which require the reestablishment of point-to-point contacts (e.g., Parkinson’s disease across the adult CNS, an environment which is not normally permissive to axonal growth.

  14. In vitro and in vivo platform to evaluate the potential of superparamagnetic iron oxide nanoparticles for neural stem cell applications after mouse ischemic brain injury

    Czech Academy of Sciences Publication Activity Database

    Pongrac, I.; Dobrivojevic, M.; Brkic, L.; Babič, Michal; Manescu, A.; Regul, J.; Šlouf, Miroslav; Giuliani, A.; Horák, Daniel; Gajovic, S.

    Zagreb : University of Zagreb School of Medicine, 2015. s. 37-38. [GlowBrain Final Conference "Stem cell and biomaterial applications for brain repair". 27.05.2015-31.05.2015, Zagreb] EU Projects: European Commission(XE) 316120 - GLOWBRAIN Institutional support: RVO:61389013 Keywords : nanoparticles * biomedicine Subject RIV: CD - Macromolecular Chemistry

  15. Transplantation of primed human fetal neural stem cells improves cognitive function in rats after traumatic brain injury.

    Science.gov (United States)

    Gao, Junling; Prough, Donald S; McAdoo, David J; Grady, James J; Parsley, Margaret O; Ma, Long; Tarensenko, Yevgeniya I; Wu, Ping

    2006-10-01

    Traumatic brain injury (TBI) often produces cognitive impairments by primary or secondary neuronal loss. Stem cells are a potential tool to treat TBI. However, most previous studies using rodent stem or progenitor cells failed to correlate cell grafting and cognitive improvement. Furthermore, the efficacy of fetal human neural stem cells (hNSCs) for ameliorating TBI cognitive dysfunction is undetermined. This study therefore characterized phenotypic differentiation, neurotrophic factor expression and release and functional outcome of grafting hNSCs into TBI rat brains. Adult Sprague-Dawley rats underwent a moderate parasagittal fluid percussion TBI followed by ipsilateral hippocampal transplantation of hNSCs or vehicle 1 day post-injury. Prior to grafting, hNSCs were treated in vitro for 7 days with our previously developed priming procedure. Significant spatial learning and memory improvements were detected by the Morris water maze (MWM) test in rats 10 days after receiving hNSC grafts. Morphological analyses revealed that hNSCs survived and differentiated mainly into neurons in the injured hippocampus at 2 weeks after grafting. Furthermore, hNSCs expressed and released glial-cell-line-derived neurotrophic factor (GDNF) in vitro and when grafted in vivo, as detected by RT-PCR, immunostaining, microdialysis and ELISA. This is the first direct demonstration of the release of a neurotrophic factor in conjunction with stem cell grafting. In conclusion, human fetal neural stem cell grafts improved cognitive function of rats with acute TBI. Grafted cells survived and differentiated into neurons and expressed and released GNDF in vivo, which may help protect host cells from secondary damage and aid host regeneration. PMID:16904107

  16. Development of implantable optoelectronic module for optical brain tissue stimulation in freely moving mice

    Science.gov (United States)

    Rusakov, Konstantin; Czajkowski, Rafał; Kaźmierczak, Andrzej

    2015-09-01

    The research aims to design and manufacture of wireless optogenetics devices for freely moving animals in cages IntelliCage system. The purpose of the device is to stimulate specific brain regions using light. The constructed device consists of a light source and optical fibre structure responsible for delivering light into the corresponding region of the brain of the animal. The size of the animal (mouse) and the fact that it is freely moving imposes substantial limitations with respect to the size and weight of the optoelectronic device. The present paper describes research on optical fibre structure fabrication, assembling it to the small size (less than 500 × 500 μm2 top surface) LED chip and experimental validation of the optoelectronic stimulator.

  17. Double electrodes simultaneous stimulation and implantation technique in deep brain stimulation

    Institute of Scientific and Technical Information of China (English)

    BIAN Liu-guan; W Tirakotai; DK Schulte; H Bertalanffy; D Hellwig

    2005-01-01

    @@ Posttraumatic tremor is often one of the causes of disability in head injury patients. Usually, pharmacotherapy for this type of tremor is not effective. Since early 1970s, surgical ablation of the ventral thalamus has been used to treat various types of tremor.1 Nowadays, deep brain stimulation (DBS) confirms its efficacy in alleviating different forms of tremor, including posttraumatic tremor.2,3 Such therapy has been reported achieving around 80% success rate in the treatment of posttraumatic tremor.

  18. Intracerebral microvascular measurements during deep brain stimulation implantation using laser doppler perfusion monitoring

    OpenAIRE

    Wårdell, Karin; Blomstedt, P.; Richter, Johan; Antonsson, Johan; Eriksson, Ola; Zsigmond, Peter; Bergenheim, A.T.; Hariz, M I.

    2007-01-01

    The aim of the study was to investigate if laser Doppler perfusion monitoring (LDPM) can be used in order to differentiate between gray and white matter and to what extent microvascular perfusion can be recorded in the deep brain structures during stereotactic neurosurgery. An optical probe constructed to fit in the Leksell® Stereotactic System was used for measurements along the trajectory and in the targets (globus pallidus internus, subthalamic nucleus, zona incerta, thalamus) during the i...

  19. Repair of the myocardium infarct, with intracoronary implant of mother cells (stem cells) precocious improvement of the ventricular function and the ischemy (first reports of the TECELCOR report)

    International Nuclear Information System (INIS)

    Twenty patients who suffered extensive anterior myocardial infarction with an evolution of 5 to 72 hours were submitted to a primary PTCA with Stent. The ventricular ejection fraction oscillated between 21 to 30% in correlation to the bidimensional echocardiography. Between the 7th and 12th day, mononuclear CD 34(+) and CD 38(-) cells extracted from the patient's bone marrow were implanted through the anterior descendent coronary artery, with occlusion of the anterior coronary vein, in an average amount of 22 x 10 P6. echocardiographic controls were performed each 7 days until 60 days, noticing a progressive increment in the ejection fraction (EF) from 25 to 45% in the first 60 days, and an improvement of the EF up to 80% after 90 days. Between 90 and 120 days after, a coronary ventriculography was performed, and the permeability of all the implanted stents and an improvement of the EF up to 80% with respect to the basal EF, were observed. The Spect studies were negative with negative ergonometry at 700 kgm. This group of patients was comparing red with 16 patients who were submitted only to primary PTCA with Stent. They had an increase of only 45% of the EF respect to the basal one in the next 90 days and 12 % presented restenosis. Stems cells implant improves the left ventricular performance after a myocardial infarction and it seems to avoid the coronary post-restenosis

  20. In vivo tracking of {sup 111}In-labeled bone marrow mesenchymal stem cells in acute brain trauma model

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Joon-Kee [Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, Suwon (Korea, Republic of); Institute for Neuroregeneration and Stem Cell Research, Ajou University School of Medicine, Suwon (Korea, Republic of); Park, Bok-Nam [Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, Suwon (Korea, Republic of); Shim, Woo-Young [Institute for Neuroregeneration and Stem Cell Research, Ajou University School of Medicine, Suwon (Korea, Republic of); Department of Molecular Science and Technology, Ajou University, Suwon (Korea, Republic of); Shin, Jin Young [Institute for Neuroregeneration and Stem Cell Research, Ajou University School of Medicine, Suwon (Korea, Republic of); Department of Neurosurgery, Ajou University School of Medicine, Suwon (Korea, Republic of); Lee, Gwang [Institute for Neuroregeneration and Stem Cell Research, Ajou University School of Medicine, Suwon (Korea, Republic of); Department of Molecular Science and Technology, Ajou University, Suwon (Korea, Republic of); Brain Disease Research Center, Ajou University School of Medicine, Suwon (Korea, Republic of); Ahn, Young Hwan [Institute for Neuroregeneration and Stem Cell Research, Ajou University School of Medicine, Suwon (Korea, Republic of); Department of Neurosurgery, Ajou University School of Medicine, Suwon (Korea, Republic of)], E-mail: yhahn@ajou.ac.kr

    2010-04-15

    Introduction: This study was to evaluate the in vivo distribution of intravenously transplanted bone marrow-derived mesenchymal stem cells (BMSCs) in an acute brain trauma model by {sup 111}In-tropolone labeling. Methods: Rat BMSCs were labeled with 37 MBq {sup 111}In-tropolone. Their labeling efficiency and in vitro retention rate were measured. The viability and proliferation of labeled BMSCs were evaluated for 14 days after labeling. The biodistribution of {sup 111}In-labeled BMSCs in trauma models was compared with those of sham-operated rats and normal rats on gamma camera images. The migration of {sup 111}In-BMSCs to the traumatic brain was evaluated using confocal microscope. Results: The labeling efficiency of {sup 111}In-BMSCs was 66{+-}5%, and their retention rate was 85.3% at 1 h after labeling. There was no difference in the number of viable cells between {sup 111}In-BMSCs and controls at 48 h after labeling. However, the proliferation of {sup 111}In-BMSCs was inhibited after the third day of labeling, and it did not reach confluency. On gamma camera images, most of the {sup 111}In-BMSCs uptake was observed in the liver and spleen at the second day of injection. The brain uptake of {sup 111}In-BMSCs was detected prominently in trauma models (1.4%) than in sham-operated (0.5%) or normal rats (0.3%). Radiolabeled BMSCs were observed at the traumatic brain on the confocal microscope as they have a homing capacity, although its proliferation capacity was suppressed. Conclusion: Although growth inhibition by {sup 111}In-labeling need to be evaluated further prior to use in humans, {sup 111}In-labeled BMSCs are useful for the tracking of intravenously transplanted mesenchymal stem cells in brain disease models.