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Sample records for supraliminal nonpainful stimulation

  1. Altered functional magnetic resonance imaging responses to nonpainful sensory stimulation in fibromyalgia patients.

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    López-Solà, Marina; Pujol, Jesus; Wager, Tor D; Garcia-Fontanals, Alba; Blanco-Hinojo, Laura; Garcia-Blanco, Susana; Poca-Dias, Violant; Harrison, Ben J; Contreras-Rodríguez, Oren; Monfort, Jordi; Garcia-Fructuoso, Ferran; Deus, Joan

    2014-11-01

    Fibromyalgia (FM) is a disorder characterized by chronic pain and enhanced responses to acute noxious events. However, the sensory systems affected in FM may extend beyond pain itself, as FM patients show reduced tolerance to non-nociceptive sensory stimulation. Characterizing the neural substrates of multisensory hypersensitivity in FM may thus provide important clues about the underlying pathophysiology of the disorder. The aim of this study was to characterize brain responses to non-nociceptive sensory stimulation in FM patients and their relationship to subjective sensory sensitivity and clinical pain severity. Functional magnetic resonance imaging (MRI) was used to assess brain response to auditory, visual, and tactile motor stimulation in 35 women with FM and 25 matched controls. Correlation and mediation analyses were performed to establish the relationship between brain responses and 3 types of outcomes: subjective hypersensitivity to daily sensory stimulation, spontaneous pain, and functional disability. Patients reported increased subjective sensitivity (increased unpleasantness) in response to multisensory stimulation in daily life. Functional MRI revealed that patients showed reduced task-evoked activation in primary/secondary visual and auditory areas and augmented responses in the insula and anterior lingual gyrus. Reduced responses in visual and auditory areas were correlated with subjective sensory hypersensitivity and clinical severity measures. FM patients showed strong attenuation of brain responses to nonpainful events in early sensory cortices, accompanied by an amplified response at later stages of sensory integration in the insula. These abnormalities are associated with core FM symptoms, suggesting that they may be part of the pathophysiology of the disease. Copyright © 2014 by the American College of Rheumatology.

  2. Differential effects of painful and non-painful stimulation on tactile processing in fibromyalgia syndrome and subjects with masochistic behaviour.

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    Bettina Pollok

    Full Text Available BACKGROUND: In healthy subjects repeated tactile stimulation in a conditioning test stimulation paradigm yields attenuation of primary (S1 and secondary (S2 somatosensory cortical activation, whereas a preceding painful stimulus results in facilitation. METHODOLOGY/PRINCIPAL FINDINGS: Since previous data suggest that cognitive processes might affect somatosensory processing in S1, the present study aims at investigating to what extent cortical reactivity is altered by the subjective estimation of pain. To this end, the effect of painful and tactile stimulation on processing of subsequently applied tactile stimuli was investigated in patients with fibromyalgia syndrome (FMS and in subjects with masochistic behaviour (MB by means of a 122-channel whole-head magnetoencephalography (MEG system. Ten patients fulfilling the criteria for the diagnosis of FMS, 10 subjects with MB and 20 control subjects matched with respect to age, gender and handedness participated in the present study. Tactile or brief painful cutaneous laser stimuli were applied as conditioning stimulus (CS followed by a tactile test stimulus (TS 500 ms later. While in FMS patients significant attenuation following conditioning tactile stimulation was evident, no facilitation following painful stimulation was found. By contrast, in subjects with MB no attenuation but significant facilitation occurred. Attenuation as well as facilitation applied to cortical responses occurring at about 70 ms but not to early S1 or S2 responses. Additionally, in FMS patients the amount of attenuation was inversely correlated with catastrophizing tendency. CONCLUSION: The present results imply altered cortical reactivity of the primary somatosensory cortex in FMS patients and MB possibly reflecting differences of individual pain experience.

  3. Towards a physiology-based measure of pain: patterns of human brain activity distinguish painful from non-painful thermal stimulation.

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    Justin E Brown

    Full Text Available Pain often exists in the absence of observable injury; therefore, the gold standard for pain assessment has long been self-report. Because the inability to verbally communicate can prevent effective pain management, research efforts have focused on the development of a tool that accurately assesses pain without depending on self-report. Those previous efforts have not proven successful at substituting self-report with a clinically valid, physiology-based measure of pain. Recent neuroimaging data suggest that functional magnetic resonance imaging (fMRI and support vector machine (SVM learning can be jointly used to accurately assess cognitive states. Therefore, we hypothesized that an SVM trained on fMRI data can assess pain in the absence of self-report. In fMRI experiments, 24 individuals were presented painful and nonpainful thermal stimuli. Using eight individuals, we trained a linear SVM to distinguish these stimuli using whole-brain patterns of activity. We assessed the performance of this trained SVM model by testing it on 16 individuals whose data were not used for training. The whole-brain SVM was 81% accurate at distinguishing painful from non-painful stimuli (p<0.0000001. Using distance from the SVM hyperplane as a confidence measure, accuracy was further increased to 84%, albeit at the expense of excluding 15% of the stimuli that were the most difficult to classify. Overall performance of the SVM was primarily affected by activity in pain-processing regions of the brain including the primary somatosensory cortex, secondary somatosensory cortex, insular cortex, primary motor cortex, and cingulate cortex. Region of interest (ROI analyses revealed that whole-brain patterns of activity led to more accurate classification than localized activity from individual brain regions. Our findings demonstrate that fMRI with SVM learning can assess pain without requiring any communication from the person being tested. We outline tasks that should be

  4. Space-Valence Priming with Subliminal and Supraliminal Words

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    Ulrich eAnsorge

    2013-02-01

    Full Text Available To date it is unclear whether (1 awareness-independent non-evaluative semantic processes influence affective semantics and whether (2 awareness-independent affective semantics influence non-evaluative semantic processing. In the current study, we investigated these questions with the help of subliminal (masked primes and visible targets in a space-valence across-category congruence effect. In line with (1, we found that subliminal space prime words influenced valence classification of supraliminal target words (Experiment 1: Classifications were faster with a congruent prime (e.g., the prime ‘up’ before the target ‘happy’ than with an incongruent prime (e.g., the prime ‘up’ before the target ‘sad’. In contrast to (2, no influence of subliminal valence primes on the classification of supraliminal space targets into up- and down-words was found (Experiment 2. Control conditions showed that standard masked response-priming effects were found with both subliminal prime types, and that an across-category congruence effect was also found with supraliminal valence primes and spatial target words. The final Experiment 3 confirmed that the across-category congruence effect indeed reflected priming of target categorization of a relevant meaning category. Together, the data jointly confirmed prediction (1 that awareness-independent non-evaluative semantic priming influences valence judgments.

  5. Subliminally and Supraliminally Acquired Long-Term Memories Jointly Bias Delayed Decisions.

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    Ruch, Simon; Herbert, Elizabeth; Henke, Katharina

    2017-01-01

    Common wisdom and scientific evidence suggest that good decisions require conscious deliberation. But growing evidence demonstrates that not only conscious but also unconscious thoughts influence decision-making. Here, we hypothesize that both consciously and unconsciously acquired memories guide decisions. Our experiment measured the influence of subliminally and supraliminally presented information on delayed (30-40 min) decision-making. Participants were presented with subliminal pairs of faces and written occupations for unconscious encoding. Following a delay of 20 min, participants consciously (re-)encoded the same faces now presented supraliminally along with either the same written occupations, occupations congruous to the subliminally presented occupations (same wage-category), or incongruous occupations (opposite wage-category). To measure decision-making, participants viewed the same faces again (with occupations absent) and decided on the putative income of each person: low, low-average, high-average, or high. Participants were encouraged to decide spontaneously and intuitively. Hence, the decision task was an implicit or indirect test of relational memory. If conscious thought alone guided decisions (= H 0 ), supraliminal information should determine decision outcomes independently of the encoded subliminal information. This was, however, not the case. Instead, both unconsciously and consciously encoded memories influenced decisions: identical unconscious and conscious memories exerted the strongest bias on income decisions, while both incongruous and congruous (i.e., non-identical) subliminally and supraliminally formed memories canceled each other out leaving no bias on decisions. Importantly, the increased decision bias following the formation of identical unconscious and conscious memories and the reduced decision bias following to the formation of non-identical memories were determined relative to a control condition, where conscious memory

  6. High pain sensitivity is distinct from high susceptibility to non-painful sensory input at threshold level.

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    Hummel, Thomas; Springborn, Maria; Croy, Ilona; Kaiser, Jochen; Lötsch, Jörn

    2011-04-01

    Individuals may differ considerably in their sensitivity towards various painful stimuli supporting the notion of a person as stoical or complaining about pain. Molecular and functional imaging research provides support that this may extend also to other sensory qualities. Whether a person can be characterized as possessing a generally high or low sensory acuity is unknown. This was therefore assessed with thresholds to painful and non-painful stimuli, with a focus on chemical stimuli that besides pain may evoke clearly non-painful sensations such as taste or smell. In 36 healthy men and 78 women (ages 18 to 52 years), pain thresholds to chemo-somatosensory (intranasal gaseous CO(2)) and electrical stimuli (cutaneous stimulation) were significantly correlated (ρ(2)=0.2268, psensory qualities, i.e., for the rose-like odor phenyl ethyl alcohol and gustatory thresholds for sour (citric acid) and salty (NaCl). Similarly, pain clusters showed no differences in thresholds to other stimuli. Moreover, no clustering was obtained for thresholds to both painful and non-painful stimuli together. Thus, individuals could not be characterized as highly sensitive (or insensitive) to all chemical stimuli no matter of evoking pain. This suggests that pain is primarily a singular sensory perception distinct from others such as olfaction or taste. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Neural correlates of heart rate variability in PTSD during sub- and supraliminal processing of trauma-related cues.

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    Rabellino, Daniela; D'Andrea, Wendy; Siegle, Greg; Frewen, Paul A; Minshew, Reese; Densmore, Maria; Neufeld, Richard W; Théberge, Jean; McKinnon, Margaret C; Lanius, Ruth A

    2017-10-01

    Posttraumatic stress disorder (PTSD) is characterized by dysregulated arousal and altered cardiac autonomic response as evidenced by decreased high-frequency heart rate variability (HF-HRV), an indirect measure of parasympathetic modulation of the heart. Indeed, subtle threatening cues can cause autonomic dysregulation, even without explicit awareness of the triggering stimulus. Accordingly, examining the neural underpinnings associated with HF-HRV during both sub- and supraliminal exposure to trauma-related cues is critical to an enhanced understanding of autonomic nervous system dysfunction in PTSD. We compared neural activity in brain regions associated with HF-HRV in PTSD (n = 18) and healthy controls (n = 18) during exposure to sub- and supraliminal processing of personalized trauma-related words. As compared to controls, PTSD exhibited decreased HF-HRV reactivity in response to sub- and supraliminal cues. Notably, during subliminal processing of trauma-related versus neutral words, as compared to controls, PTSD showed decreased neural response associated with HF-HRV within the left dorsal anterior insula. By contrast, during supraliminal processing of trauma-related versus neutral words, decreased neural activity associated with HF-HRV within the posterior insula/superior temporal cortex, and increased neural activity associated with HF-HRV within the left centromedial amygdala was observed in PTSD as compared to controls. Impaired parasympathetic modulation of autonomic arousal in PTSD appears related to altered activation of cortical and subcortical regions involved in the central autonomic network. Interestingly, both sub- and supraliminal trauma-related cues appear to elicit dysregulated arousal and may contribute to the maintenance of hyperarousal in PTSD. Hum Brain Mapp 38:4898-4907, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Modulation of self-esteem in self- and other-evaluations primed by subliminal and supraliminal faces.

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    Ran Tao

    Full Text Available BACKGROUND: Past research examining implicit self-evaluation often manipulated self-processing as task-irrelevant but presented self-related stimuli supraliminally. Even when tested with more indirect methods, such as the masked priming paradigm, participants' responses may still be subject to conscious interference. Our study primed participants with either their own or someone else's face, and adopted a new paradigm to actualize strict face-suppression to examine participants' subliminal self-evaluation. In addition, we investigated how self-esteem modulates one's implicit self-evaluation and validated the role of awareness in creating the discrepancy on past findings between measures of implicit self-evaluation and explicit self-esteem. METHODOLOGY/PRINCIPAL FINDINGS: Participants' own face or others' faces were subliminally presented with a Continuous Flash Suppression (CFS paradigm in Experiment 1, but supraliminally presented in Experiment 2, followed by a valence judgment task of personality adjectives. Participants also completed the Rosenberg Self-Esteem Scale in each experiment. Results from Experiment 1 showed a typical bias of self-positivity among participants with higher self-esteem, but only a marginal self-positivity bias and a significant other-positivity bias among those with lower self-esteem. However, self-esteem had no modulating effect in Experiment 2: All participants showed the self-positivity bias. CONCLUSIONS/SIGNIFICANCE: Our results provide direct evidence that self-evaluation manifests in different ways as a function of awareness between individuals with different self-views: People high and low in self-esteem may demonstrate different automatic reactions in the subliminal evaluations of the self and others; but the involvement of consciousness with supraliminally presented stimuli may reduce this dissociation.

  9. Modulation of self-esteem in self- and other-evaluations primed by subliminal and supraliminal faces.

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    Tao, Ran; Zhang, Shen; Li, Qi; Geng, Haiyan

    2012-01-01

    Past research examining implicit self-evaluation often manipulated self-processing as task-irrelevant but presented self-related stimuli supraliminally. Even when tested with more indirect methods, such as the masked priming paradigm, participants' responses may still be subject to conscious interference. Our study primed participants with either their own or someone else's face, and adopted a new paradigm to actualize strict face-suppression to examine participants' subliminal self-evaluation. In addition, we investigated how self-esteem modulates one's implicit self-evaluation and validated the role of awareness in creating the discrepancy on past findings between measures of implicit self-evaluation and explicit self-esteem. Participants' own face or others' faces were subliminally presented with a Continuous Flash Suppression (CFS) paradigm in Experiment 1, but supraliminally presented in Experiment 2, followed by a valence judgment task of personality adjectives. Participants also completed the Rosenberg Self-Esteem Scale in each experiment. Results from Experiment 1 showed a typical bias of self-positivity among participants with higher self-esteem, but only a marginal self-positivity bias and a significant other-positivity bias among those with lower self-esteem. However, self-esteem had no modulating effect in Experiment 2: All participants showed the self-positivity bias. Our results provide direct evidence that self-evaluation manifests in different ways as a function of awareness between individuals with different self-views: People high and low in self-esteem may demonstrate different automatic reactions in the subliminal evaluations of the self and others; but the involvement of consciousness with supraliminally presented stimuli may reduce this dissociation.

  10. Pain chronification: what should a non-pain medicine specialist know?

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    Morlion, Bart; Coluzzi, Flaminia; Aldington, Dominic; Kocot-Kepska, Magdalena; Pergolizzi, Joseph; Mangas, Ana Cristina; Ahlbeck, Karsten; Kalso, Eija

    2018-04-12

    Pain is one of the most common reasons for an individual to consult their primary care physician, with most chronic pain being treated in the primary care setting. However, many primary care physicians/non-pain medicine specialists lack enough awareness, education and skills to manage pain patients appropriately, and there is currently no clear, common consensus/formal definition of "pain chronification". This article, based on an international Change Pain Chronic Advisory Board meeting which was held in Wiesbaden, Germany, in October 2016, provides primary care physicians/non-pain medicine specialists with a narrative overview of pain chronification, including underlying physiological and psychosocial processes, predictive factors for pain chronification, a brief summary of preventive strategies, and the role of primary care physicians and non-pain medicine specialists in the holistic management of pain chronification. Based on currently available evidence, we propose the following consensus-based definition of pain chronification which provides a common framework to raise awareness among non-pain medicine specialists: "Pain chronification describes the process of transient pain progressing into persistent pain; pain processing changes as a result of an imbalance between pain amplification and pain inhibition; genetic, environmental and biopsychosocial factors determine the risk, the degree, and time-course of chronification." Early intervention plays an important role in preventing pain chronification and, as key influencers in the management of patients with acute pain, it is critical that primary care physicians are equipped with the necessary awareness, education and skills to manage pain patients appropriately.

  11. Cerebral cortical registration of subliminal visceral stimulation.

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    Kern, Mark K; Shaker, Reza

    2002-02-01

    Although brain registration of subliminal somatic stimulations such as masked visual stimuli and their influence on electrical and hemodynamic measures of cerebral activity have been reported previously, there have been no reports on cerebral cortical registration of subliminal visceral stimulation. Because studies evaluating the consequences of subliminal somatic stimulation have shown that subliminal stimulation can effect behavior, it is conceivable that such subliminal messages from the intestine could potentially influence intestinal sensory/motor function or effect the perception/interpretation of sensory signals originating from the gut. We studied the cerebral cortical functional magnetic resonance imaging (fMRI) response to subliminal, liminal, and supraliminal rectal distention in healthy volunteers. Study findings indicate that subliminal afferent signals originating from the gut are registered in the cerebral cortex without reaching the level of awareness. Locations of cortical activity caused by intestinal subliminal stimulation are similar to those of liminal and supraliminal stimulation but their intensity and volume are significantly lower (P Subliminal afferent signals originating from the gut are registered in the cerebral cortex and induce changes in measures of brain activity, such as hemodynamic changes detectable by fMRI.

  12. Common brain activations for painful and non-painful aversive stimuli

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    Hayes Dave J

    2012-06-01

    Full Text Available Abstract Background Identification of potentially harmful stimuli is necessary for the well-being and self-preservation of all organisms. However, the neural substrates involved in the processing of aversive stimuli are not well understood. For instance, painful and non-painful aversive stimuli are largely thought to activate different neural networks. However, it is presently unclear whether there is a common aversion-related network of brain regions responsible for the basic processing of aversive stimuli. To help clarify this issue, this report used a cross-species translational approach in humans (i.e. meta-analysis and rodents (i.e. systematic review of functional neuroanatomy. Results Animal and human data combined to show a core aversion-related network, consisting of similar cortical (i.e. MCC, PCC, AI, DMPFC, RTG, SMA, VLOFC; see results section or abbreviation section for full names and subcortical (i.e. Amyg, BNST, DS, Hab, Hipp/Parahipp, Hyp, NAc, NTS, PAG, PBN, raphe, septal nuclei, Thal, LC, midbrain regions. In addition, a number of regions appeared to be more involved in pain-related (e.g. sensory cortex or non-pain-related (e.g. amygdala aversive processing. Conclusions This investigation suggests that aversive processing, at the most basic level, relies on similar neural substrates, and that differential responses may be due, in part, to the recruitment of additional structures as well as the spatio-temporal dynamic activity of the network. This network perspective may provide a clearer understanding of why components of this circuit appear dysfunctional in some psychiatric and pain-related disorders.

  13. Painful tonic heat stimulation induces GABA accumulation in the prefrontal cortex in man

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    Kupers, Ron; Danielsen, Else R; Kehlet, Henrik

    2009-01-01

    upper leg via a fMRI-compatible Peltier element. Compared to non-painful stimulation, painful tonic heat was associated with a significant increase in GABA concentrations in the rACC. No changes in glutamate concentrations were detected during noxious stimulation. This study provides the first evidence...

  14. Different brain areas activated during imagery of painful and non-painful 'finger movements' in a subject with an amputated arm.

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    Rosén, G; Hugdahl, K; Ersland, L; Lundervold, A; Smievoll, A I; Barndon, R; Sundberg, H; Thomsen, T; Roscher, B E; Tjølsen, A; Engelsen, B

    2001-01-01

    The purpose of the present study was to investigate differences in brain activation with functional magnetic resonance imaging (fMRI) during imagery of painful and non-painful 'finger movements' and 'hand positioning' in a subject with an amputated arm. The subject was a right-handed man in his mid-thirties who lost his right arm just above the elbow in a car-train accident. MRI was performed with a 1.5 T Siemens Vision Plus scanner. The basic design involved four conditions: imagining 'painful finger movements', 'non-painful finger movements', 'painful hand positioning', 'non-painful hand positioning'. Imagery of finger movements uniquely activated the contralateral primary motor cortex which contains the classic 'hand area'. The lateral part of the anterior cerebellar lobe was also activated during imagery of finger movements. Imagery of pain uniquely activated the somatosensory area, and areas in the left insula and bilaterally in the ventral posterior lateral nucleus of the thalamus. It is suggested that the insula and thalamus may involve neuronal pathways that are critical for mental processing of pain-related experiences, which may relate to a better understanding of the neurobiology of phantom limb pain.

  15. An investigation into the effects of frequency-modulated transcutaneous electrical nerve stimulation (TENS) on experimentally-induced pressure pain in healthy human participants.

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    Chen, Chih-Chung; Johnson, Mark I

    2009-10-01

    Frequency-modulated transcutaneous electrical nerve stimulation (TENS) delivers currents that fluctuate between preset boundaries over a fixed period of time. This study compared the effects of constant-frequency TENS and frequency-modulated TENS on blunt pressure pain in healthy human volunteers. Thirty-six participants received constant-frequency TENS (80 pps), frequency-modulated TENS (20 to 100 pps), and placebo (no current) TENS at a strong nonpainful intensity in a randomized cross-over manner. Pain threshold was taken from the forearm using pressure algometry. There were no statistical differences between constant-frequency TENS and frequency-modulated TENS after 20 minutes (OR = 1.54; CI, 0.29, 8.23, P = 1.0). Both constant-frequency TENS and frequency-modulated TENS were superior to placebo TENS (OR = 59.5, P TENS does not influence hypoalgesia to any greater extent than constant-frequency TENS when currents generate a strong nonpainful paraesthesia at the site of pain. The finding that frequency-modulated TENS and constant-frequency TENS were superior to placebo TENS provides further evidence that a strong yet nonpainful TENS intensity is a prerequisite for hypoalgesia. This study provides evidence that TENS, delivered at a strong nonpainful intensity, increases pain threshold to pressure algometry in healthy participants over and above that seen with placebo (no current) TENS. Frequency-modulated TENS does not increase hypoalgesia to any appreciable extent to that seen with constant-frequency TENS.

  16. Influence of route of administration/drug formulation and other factors on adherence to treatment in rheumatoid arthritis (pain related) and dyslipidemia (non-pain related).

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    Fautrel, Bruno; Balsa, Alejandro; Van Riel, Piet; Casillas, Marta; Capron, Jean-Philippe; Cueille, Carine; de la Torre, Inmaculada

    2017-07-01

    A comprehensive review was performed to investigate the effect of route of administration on medication adherence and persistence in rheumatoid arthritis (RA) and to compare adherence/persistence with oral medications between RA and a non-painful disease (dyslipidemia). Comprehensive database searches were performed to identify studies investigating medication adherence and/or persistence in adults with RA receiving conventional synthetic or biologic agents. Similar searches were performed for studies of patients with dyslipidemia receiving statins. Studies had to be published after 1998 in English and involve ≥6 months' follow up. Adherence and persistence were compared between the different routes of drug administration in RA, and between the two diseases for oral medications. A total of 35 and 28 papers underwent data extraction for RA and dyslipidemia, respectively. Within the constraints of the analysis, adherence and persistence rates appeared broadly similar for the different routes of drug administration in RA. Adherence to oral medications was also broadly similar across the two diseases, but persistence was lower in dyslipidemia. Poor adherence has clinical consequences in both diseases: greater disease activity and risk of flare in RA, and increased serum cholesterol levels and risk of heart and cerebrovascular disease in dyslipidemia. Over 1-3 years, poor adherence to biologic RA medications led to increased resource use and medical costs but lower total direct costs due to reduced biologic drug costs. Conversely, poor adherence to dyslipidemia medications resulted in increased total direct costs. In both diseases, adherence improved with patient education/support. The route of drug administration and the symptomatic (pain) nature of the disease do not appear to be dominant factors for drug adherence or persistence in RA. The wide range of adherence and persistence values and definitions across studies made comparisons between drug formulations and

  17. An investigation into the magnitude of the current window and perception of transcutaneous electrical nerve stimulation (TENS) sensation at various frequencies and body sites in healthy human participants.

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    Hughes, Nicola; Bennett, Michael I; Johnson, Mark I

    2013-02-01

    Strong nonpainful transcutaneous electrical nerve stimulation (TENS) is prerequisite to a successful analgesic outcome although the ease with which this sensation is achieved is likely to depend on the magnitude of current amplitude (mA) between sensory detection threshold (SDT) and pain threshold, that is, the current window. To measure the current window and participant's perception of the comfort of the TENS sensation at different body sites. A repeated measure cross-over study was conducted using 30 healthy adult volunteers. Current amplitudes (mA) of TENS [2 pulses per second (pps); 30 pps; 80 pps] at SDT, pain threshold, and strong nonpainful intensities were measured at the tibia (bone), knee joint (connective tissue), lower back [paraspinal (skeletal) muscle], volar surface of forearm (nerve) and waist (fat). The amplitude to achieve a strong nonpainful intensity was represented as a percentage of the current window. Data were analyzed using repeated measures analysis of variance. Effects were detected for body site and frequency for SDT (P<0.001, P=0.018, respectively), current window (P<0.001, P<0.001, respectively), and strong nonpainful TENS as a percentage of the current window (P=0.002, P<0.001, respectively). The current window was larger for the knee joint compared with tibia (difference [95% confidence interval]=12.76 mA [4.25, 21.28]; P=0.001) and forearm (10.33 mA [2.62, 18.40]; P=0.006), and for the lower back compared with tibia (12.10 mA [1.65, 22.52]; P=0.015) and forearm (9.65 mA [1.06, 18.24]; P=0.019). The current window was larger for 2 pps compared with 30 pps (P<0.001) and 80 pps (P<0.001). Participants rated strong nonpainful TENS as most comfortable at the lower back (P<0.001) and least comfortable at the tibia and forearm (P<0.001). TENS is most comfortable and easiest to titrate to a strong nonpainful intensity when applied over areas of muscle and soft tissue.

  18. Transcranial magnetic stimulation--may be useful as a preoperative screen of motor tract function.

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    Galloway, Gloria M; Dias, Brennan R; Brown, Judy L; Henry, Christina M; Brooks, David A; Buggie, Ed W

    2013-08-01

    Transcranial motor stimulation with noninvasive cortical surface stimulation, using a high-intensity magnetic field referred to as transcranial magnetic stimulation generally, is considered a nonpainful technique. In contrast, transcranial electric stimulation of the motor tracts typically cannot be done in unanesthesized patients. Intraoperative monitoring of motor tract function with transcranial electric stimulation is considered a standard practice in many institutions for patients during surgical procedures in which there is potential risk of motor tract impairment so that the risk of paraplegia or paraparesis can be reduced. Because transcranial electric stimulation cannot be typically done in the outpatient setting, transcranial magnetic stimulation may be able to provide a well-tolerated method for evaluation of the corticospinal motor tracts before surgery. One hundred fifty-five patients aged 5 to 20 years were evaluated preoperatively with single-stimulation nonrepetitive transcranial magnetic stimulation for preoperative assessment. The presence of responses to transcranial magnetic stimulation reliably predicted the presence of responses to transcranial electric stimulation intraoperatively. No complications occurred during the testing, and findings were correlated to the clinical history and used in the setup of the surgical monitoring.

  19. Brain Stimulation Therapies

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    ... Magnetic Seizure Therapy Deep Brain Stimulation Additional Resources Brain Stimulation Therapies Overview Brain stimulation therapies can play ... for a shorter recovery time than ECT Deep Brain Stimulation Deep brain stimulation (DBS) was first developed ...

  20. Event-related cortical processing in neuropathic pain under long-term spinal cord stimulation.

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    Weigel, Ralf; Capelle, H Holger; Flor, Herta; Krauss, Joachim K

    2015-01-01

    Several mechanisms were suggested in the past to explain the beneficial effect of spinal cord stimulation (SCS) in patients suffering from neuropathic pain. Little is known about potential supraspinal mechanisms. In this study cortical signaling of patients with neuropathic pain and successful long-term treatment with SCS was analyzed. Observational study. University hospital, neurosurgical department, outpatient clinic for movement disorders and pain, institute for cognitive and clinical neuroscience. Nine patients with neuropathic pain of a lower extremity with a lasting response to chronic SCS were included. Cortical activity was analyzed using event-related potentials of the electroencephalogram after non-painful and painful stimulation. Each patient was tested under the effect of long-term SCS and 24 hours after cessation of SCS. Cortical areas involved in the peaks of evoked potentials were localized using a source localization method based on a fixed dipole model. Detection threshold and intensity of non-painful stimulation did not differ significantly on both sides. Pain threshold was significantly lower on the neuropathic side under the effect of SCS (P = 0.03). Bilateral pain thresholds were significantly lower (P = 0.03 healthy side, P = 0.003 neuropathic side) in 5 patients with increased pain after cessation of SCS. Under the effect of SCS cortical negativities (N1, N2, N3) and positivities (P1) demonstrated bilaterally comparable amplitudes. After cessation of SCS, decreased threshold for peripheral stimulation resulted in lowered negativities on both sides. The positivity P1 was differentially regulated and was reduced more contralateral to the unaffected side. N2 was localized at the sensory representation of the leg within the homunculus. The main vector of P1 was localized within the cingular cortex (CC) and moved more anteriorly under the effect of SCS. The exact time span that SCS continues to have an effect is not known. However, due to patient

  1. Perceptual embodiment of prosthetic limbs by transcutaneous electrical nerve stimulation.

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    Mulvey, Matthew R; Fawkner, Helen J; Radford, Helen E; Johnson, Mark I

    2012-01-01

      In able-bodied participants, it is possible to induce a sense of perceptual embodiment in an artificial hand using a visual-tactile illusion. In amputee patients, electrical stimulation of sensory afferents using transcutaneous electrical nerve stimulation (TENS) has been shown to generate somatic sensations in an amputee's phantom limb(s). However, the effects of TENS on the perceptual embodiment of an artificial limb are not known. Our objective was to investigate the effects of TENS on the perceptual embodiment of an artificial limb in fully intact able-bodied participants.   We used a modified version of the rubber hand illusion presented to 30 able-bodied participants (16 women, 14 men) to convey TENS paresthesia to an artificial hand. TENS electrodes were located over superficial radial nerve on the lateral aspect of the right forearm (1 cm proximal to the wrist), which was hidden from view. TENS intensity was increased to a strong non-painful TENS sensation (electrical paresthesia) was felt beneath the electrodes and projecting into the fingers of the hand. The electrical characteristics of TENS were asymmetric biphasic electrical pulsed waves, continuous pulse pattern, 120 Hz pulse frequency (rate), and 80 µs pulse duration (width).   Participants reported significantly higher intensities of the rubber hand illusion during the two TENS conditions (mean = 5.8, standard deviation = 1.9) compared with the two non-TENS conditions (mean = 4.9, standard deviation = 1.7), p embodiment of an artificial hand. Further exploratory studies involving an amputee population are warranted. © 2011 International Neuromodulation Society.

  2. An investigation into the perceptual embodiment of an artificial hand using transcutaneous electrical nerve stimulation (TENS) in intact-limbed individuals.

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    Mulvey, Matthew; Fawkner, Helen; Johnson, Mark I

    2014-01-01

    Perceptual embodiment of an artificial limb aids manual control of prostheses and can be facilitated by somatosensory feedback. We hypothesised that transcutaneous electrical nerve stimulation (TENS) may facilitate perceptual embodiment of artificial limbs. To determine the effect of TENS on perceptual embodiment of an artificial hand in 32 intact-limbed participants. Participants were exposed to four experimental conditions in four counterbalanced blocks: (i) Vision (V) watching an artificial hand positioned congruently to the real hand (out of view); (ii) Vision and strong non-painful TENS in the real hand (V+T); Vision and Stroking (V+S) of the artificial and real hand with a brush; Vision, Stroking and TENS (V+S+T) watching artificial hand being stroked whilst real hand was stroked and receiving TENS. Repeated measure ANOVA detected effects for Condition (Pembodiment for V+S+T compared with V (Pembodiment increased for later blocks (Pembodiment. The magnitude of effect was modest.

  3. Effects of Spinal Cord Stimulation on Pain Thresholds and Sensory Perceptions in Chronic Pain Patients.

    Science.gov (United States)

    Ahmed, Shihab U; Zhang, Yi; Chen, Lucy; St Hillary, Kristin; Cohen, Abigail; Vo, Trang; Houghton, Mary; Mao, Jianren

    2015-07-01

    Spinal cord stimulation (SCS) has been in clinical use for nearly four decades. In earliest observations, researchers found a significant increase in pain threshold during SCS therapy without changes associated with touch, position, and vibration sensation. Subsequent studies yielded diverse results regarding how SCS impacts pain and other sensory thresholds. This pilot study uses quantitative sensory testing (QST) to objectively quantify the impact of SCS on warm sensation, heat pain threshold, and heat pain tolerance. Nineteen subjects with an indwelling SCS device for chronic pain were subjected to QST with heat stimuli. QST was performed on an area of pain covered with SCS-induced paresthesia and an area without pain and without paresthesia, while the SCS was turned off and on. The temperature at which the patient detected warm sensation, heat pain, and maximal tolerable heat pain was used to define the thresholds. We found that all three parameters, the detection of warm sensation, heat pain threshold, and heat pain tolerance, were increased during the period when SCS was on compared with when it was off. This increase was observed in both painful and non-painful sites. The observed pain relief during SCS therapy seems to be related to its impact on increased sensory threshold as detected in this study. The increased sensory threshold on areas without pain and without the presence of SCS coverage may indicate a central (spinal and/or supra-spinal) influence from SCS. © 2015 International Neuromodulation Society.

  4. Feldspar, Infrared Stimulated Luminescence

    DEFF Research Database (Denmark)

    Jain, Mayank

    2014-01-01

    This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

  5. Growth hormone stimulation test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003377.htm Growth hormone stimulation test To use the sharing features on this page, please enable JavaScript. The growth hormone (GH) stimulation test measures the ability of the ...

  6. Spinal cord stimulation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007560.htm Spinal cord stimulation To use the sharing features on this page, please enable JavaScript. Spinal cord stimulation is a treatment for pain that uses ...

  7. Optically stimulated luminesence dosimeter

    International Nuclear Information System (INIS)

    Liu Qiujiang; Zhu Lei; Zhu Lei; Chinese Academy of Sciences, Beijing; Chen Zhaoyang; Fan Yanwei; Ba Weizhen; Cong Xiuyun; Tang Xinqiang; Guo Qi; Lu Wu

    2007-01-01

    In this paper, the principle and makeup of optically stimulated luminescence dosimeter is described, and a measurement for radiation is carried, some actual problem is discussed. The dosimeter has high sensitive and can be reseted in-flight by stimulated light. (authors)

  8. [Transcranial magnetic stimulation].

    Science.gov (United States)

    Tormos, J M; Catalá, M D; Pascual-Leone, A

    Transcranial magnetic stimulation (TMS) permits stimulation of the cerebral cortex in humans without requiring open access to the brain and is one of the newest tools available in neuroscience. There are two main types of application: single-pulse TMS and repetitive TMS. The magnetic stimulator is composed of a series of capacitors that store the voltage necessary to generate a stimulus of the sufficient intensity of generate an electric field in the stimulation coil. The safety of TMS is supported by the considerable experience derived from studies involving electrical stimulation of the cortex in animals and humans, and also specific studies on the safety of TMS in humans. In this article we review historical and technical aspects of TMS, describe its adverse effects and how to avoid them, summarize the applications of TMS in the investigation of different cerebral functions, and discuss the possibility of using TMS for the treatment of neuropsychiatric disorders.

  9. Stimulant-induced trichotillomania.

    Science.gov (United States)

    Hamalian, Gareen; Citrome, Leslie

    2010-01-01

    A prior report described the presentation of cocaine-induced trichotillomania, which resolved with the cessation of cocaine use. Here the authors describe the case of stimulant-induced trichotillomania that resolved with the discontinuation of stimulants and initiation of olanzapine. To the authors' knowledge this is the first reported adult case of stimulant-induced trichotillomania. The case is of a patient with a previous diagnosis of attention deficit hyperactivity disorder whose symptoms of trichotillomania coincide with abuse of amphetamine and with the resolution of symptoms in the absence of amphetamine use. Given the increase in exposure of prescription amphetamines among adults, further study into the association between stimulants and adverse events such as trichotillomania is needed.

  10. Vagus Nerve Stimulation

    Science.gov (United States)

    ... you do certain activities such as public speaking, singing or exercising, or when you're eating if ... of life. Research is still mixed on the benefits of vagus nerve stimulation for the treatment of ...

  11. Multipolar intrafascicular stimulation

    NARCIS (Netherlands)

    Meier, Jan H.; Meier, J.H.; Rutten, Wim

    1992-01-01

    The suppressing effect of two intrafascicular anodes on the neural recruitment elicited by one intrafascicular cathode has been studied. Recruitment curves are calculated with a nerve stimulation model and are compared to experimental curves for the peroneal nerve of rat.

  12. New York Canyon Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Raemy, Bernard

    2012-06-21

    The New York Canyon Stimulation Project was to demonstrate the commercial application of Enhanced Geothermal System techniques in Buena Vista Valley area of Pershing County, Nevada. From October 2009 to early 2012, TGP Development Company aggressively implemented Phase I of Pre-Stimulation and Site/Wellbore readiness. This included: geological studies; water studies and analyses and procurement of initial permits for drilling. Oversubscription of water rights and lack of water needed for implementation of EGS were identified and remained primary obstacles. Despite extended efforts to find alternative solutions, the water supply circumstances could not be overcome and led TGP to determine a "No Go" decision and initiate project termination in April 2012.

  13. stimulated BV2 Microglial

    African Journals Online (AJOL)

    2012-03-26

    Mar 26, 2012 ... (PGE2) as well as their regulatory genes such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-. 2), in LPS-stimulated ... mediated NF-κB activity. Keywords: Myelophycus caespitosus, Nitric oxide, Prostaglandin E2, Nuclear factor-κB. ..... induced by hypoxia and endotoxin. J Immunol. 2000 ...

  14. Brain stimulation in migraine.

    Science.gov (United States)

    Brighina, Filippo; Cosentino, Giuseppe; Fierro, Brigida

    2013-01-01

    Migraine is a very prevalent disease with great individual disability and socioeconomic burden. Despite intensive research effort in recent years, the etiopathogenesis of the disease remains to be elucidated. Recently, much importance has been given to mechanisms underlying the cortical excitability that has been suggested to be dysfunctional in migraine. In recent years, noninvasive brain stimulation techniques based on magnetic fields (transcranial magnetic stimulation, TMS) and on direct electrical currents (transcranial direct current stimulation, tDCS) have been shown to be safe and effective tools to explore the issue of cortical excitability, activation, and plasticity in migraine. Moreover, TMS, repetitive TMS (rTMS), and tDCS, thanks to their ability to interfere with and/or modulate cortical activity inducing plastic, persistent effects, have been also explored as potential therapeutic approaches, opening an interesting perspective for noninvasive neurostimulation for both symptomatic and preventive treatment of migraine and other types of headache. In this chapter we critically review evidence regarding the role of noninvasive brain stimulation in the pathophysiology and treatment of migraine, delineating the advantages and limits of these techniques together with potential development and future application. © 2013 Elsevier B.V. All rights reserved.

  15. Dorsal column stimulator applications

    OpenAIRE

    Yampolsky, Claudio; Hem, Santiago; Bendersky, Damián

    2012-01-01

    Background: Spinal cord stimulation (SCS) has been used to treat neuropathic pain since 1967. Following that, technological progress, among other advances, helped SCS become an effective tool to reduce pain. Methods: This article is a non-systematic review of the mechanism of action, indications, results, programming parameters, complications, and cost-effectiveness of SCS. Results: In spite of the existence of several studies that try to prove the mechanism of action of SCS, it still remains...

  16. Grating stimulated echo

    International Nuclear Information System (INIS)

    Dubetsky, B.; Berman, P.R.; Sleator, T.

    1992-01-01

    A theory of a grating simulated echo (GTE) is developed. The GSE involves the sequential excitation of atoms by two counterpropagating traveling waves, a standing wave, and a third traveling wave. It is shown that the echo signal is very sensitive to small changes in atomic velocity, much more sensitive than the normal stimulated echo. Use of the GSE as a collisional probe or accelerometer is discussed

  17. Low intensity transcranial electric stimulation

    DEFF Research Database (Denmark)

    Antal, A.; Alekseichuk, I.; Bikson, M.

    2017-01-01

    Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears...

  18. Physiological aspects of paired stimulation

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1965-01-01

    In this paper some physiological and clinical aspects of paired stimulation are discussed. I) The augmenting effect of paired stimulation on rnyocardial contractility is due to potentiation (increase in speed of restitution) and fusion of two contractions. 2) While using paired stimulation the

  19. Spinal Cord Stimulation

    DEFF Research Database (Denmark)

    Meier, Kaare

    2014-01-01

    Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain that is refractory to other treatment. Originally described by Shealy et al. in 1967(1), it is used to treat a range of conditions such as complex regional pain syndrome (CRPS I)(2), angina pectoris(3), radicular...... pain after failed back surgery syndrome (FBSS)(4), pain due to peripheral nerve injury, stump pain(5), peripheral vascular disease(6) and diabetic neuropathy(7,8); whereas phantom pain(9), postherpetic neuralgia(10), chronic visceral pain(11), and pain after partial spinal cord injury(12) remain more...

  20. Optically stimulated luminescence

    International Nuclear Information System (INIS)

    Espinosa, G.; Bogard, J.S.

    2007-01-01

    Full text: The use of Optically Stimulated Luminescence (OSL) for radiation dosimetry has become increasingly popular in recent years. The OSL method is based on luminescence emitted from semiconductor materials stimulated with specific wavelengths of light, after being exposed to ionizing radiation. The OSL intensity is a function of the radiation dose absorbed by the material. This work complements previous studies by the authors of the thermoluminescence (TL) response by SiO 2 commercial optical fiber exposed to ionizing radiation and provides preliminary results describing some of the material's OSL properties. Linear OSL response to beta radiation dose, along with a consistent shape of the photon emission curve with time, were observed using a green/blue OSL excitation laser. The reproducibility of OSL response after repeated irradiations and the change in intensity with time were also examined. The search and characterization of materials that exhibit this OSL response, in parallel with the continued development of OSL methodology and instrumentation, is an important scientific and commercial issue. (Author)

  1. A distributed current stimulator ASIC for high density neural stimulation.

    Science.gov (United States)

    Jeong Hoan Park; Chaebin Kim; Seung-Hee Ahn; Tae Mok Gwon; Joonsoo Jeong; Sang Beom Jun; Sung June Kim

    2016-08-01

    This paper presents a novel distributed neural stimulator scheme. Instead of a single stimulator ASIC in the package, multiple ASICs are embedded at each electrode site for stimulation with a high density electrode array. This distributed architecture enables the simplification of wiring between electrodes and stimulator ASIC that otherwise could become too complex as the number of electrode increases. The individual ASIC chip is designed to have a shared data bus that independently controls multiple stimulating channels. Therefore, the number of metal lines is determined by the distributed ASICs, not by the channel number. The function of current steering is also implemented within each ASIC in order to increase the effective number of channels via pseudo channel stimulation. Therefore, the chip area can be used more efficiently. The designed chip was fabricated with area of 0.3 mm2 using 0.18 μm BCDMOS process, and the bench-top test was also conducted to validate chip performance.

  2. Transcranial brain stimulation: closing the loop between brain and stimulation

    DEFF Research Database (Denmark)

    Karabanov, Anke; Thielscher, Axel; Siebner, Hartwig Roman

    2016-01-01

    PURPOSE OF REVIEW: To discuss recent strategies for boosting the efficacy of noninvasive transcranial brain stimulation to improve human brain function. RECENT FINDINGS: Recent research exposed substantial intra- and inter-individual variability in response to plasticity-inducing transcranial brain...... transcranial brain stimulation. Priming interventions or paired associative stimulation can be used to ‘standardize’ the brain-state and hereby, homogenize the group response to stimulation. Neuroanatomical and neurochemical profiling based on magnetic resonance imaging and spectroscopy can capture trait......-related and state-related variability. Fluctuations in brain-states can be traced online with functional brain imaging and inform the timing or other settings of transcranial brain stimulation. State-informed open-loop stimulation is aligned to the expression of a predefined brain state, according to prespecified...

  3. Distributed stimulation increases force elicited with functional electrical stimulation

    Science.gov (United States)

    Buckmire, Alie J.; Lockwood, Danielle R.; Doane, Cynthia J.; Fuglevand, Andrew J.

    2018-04-01

    Objective. The maximum muscle forces that can be evoked using functional electrical stimulation (FES) are relatively modest. The reason for this weakness is not fully understood but could be partly related to the widespread distribution of motor nerve branches within muscle. As such, a single stimulating electrode (as is conventionally used) may be incapable of activating the entire array of motor axons supplying a muscle. Therefore, the objective of this study was to determine whether stimulating a muscle with more than one source of current could boost force above that achievable with a single source. Approach. We compared the maximum isometric forces that could be evoked in the anterior deltoid of anesthetized monkeys using one or two intramuscular electrodes. We also evaluated whether temporally interleaved stimulation between two electrodes might reduce fatigue during prolonged activity compared to synchronized stimulation through two electrodes. Main results. We found that dual electrode stimulation consistently produced greater force (~50% greater on average) than maximal stimulation with single electrodes. No differences, however, were found in the fatigue responses using interleaved versus synchronized stimulation. Significance. It seems reasonable to consider using multi-electrode stimulation to augment the force-generating capacity of muscles and thereby increase the utility of FES systems.

  4. Brain stimulation for intractable epilepsy: Anterior thalamus and responsive stimulation

    Directory of Open Access Journals (Sweden)

    Vibhor Krishna

    2014-01-01

    Full Text Available Despite medications, resective surgery, and vagal nerve stimulation, some patients with epilepsy continue to have seizures. In these patients, other approaches are urgently needed. The biological basis of stimulation of anterior thalamic nucleus and epileptogenic focus is presented. Results from two large randomized controlled trials Stimulation of Anterior Nucleus of Thalamus for Epilepsy (SANTE and Neuropace pivotal trial are discussed. Neuromodulation provides effective treatment for a select group of refractory epilepsy patients. Future investigations into the mechanism underlying ′response′ to brain stimulation are desired.

  5. Vagus Nerve Stimulation.

    Science.gov (United States)

    Ekmekçi, Hakan; Kaptan, Hülagu

    2017-06-15

    The vagus nerve stimulation (VNS) is an approach mainly used in cases of intractable epilepsy despite all the efforts. Also, its benefits have been shown in severe cases of depression resistant to typical treatment. The aim of this study was to present current knowledge of vagus nerve stimulation. A new value has emerged just at this stage: VNS aiming the ideal treatment with new hopes. It is based on the placement of a programmable generator on the chest wall. Electric signals from the generator are transmitted to the left vagus nerve through the connection cable. Control on the cerebral bioelectrical activity can be achieved by way of these signal sent from there in an effort for controlling the epileptic discharges. The rate of satisfactory and permanent treatment in epilepsy with monotherapy is around 50%. This rate will increase by one-quarters (25%) with polytherapy. However, there is a patient group roughly constituting one-thirds of this population, and this group remains unresponsive or refractory to all the therapies and combined regimes. The more the number of drugs used, the more chaos and side effects are observed. The anti-epileptic drugs (AEDs) used will have side effects on both the brain and the systemic organs. Cerebral resection surgery can be required in some patients. The most commonly encountered epilepsy type is the partial one, and the possibility of benefiting from invasive procedures is limited in most patients of this type. Selective amygdala-hippocampus surgery is a rising value in complex partial seizures. Therefore, as epilepsy surgery can be performed in very limited numbers and rather developed centres, success can also be achieved in limited numbers of patients. The common ground for all the surgical procedures is the target of preservation of memory, learning, speaking, temper and executive functions as well as obtaining a good control on seizures. However, the action mechanism of VNS is still not exactly known. On the other hand

  6. Engagement sensitive visual stimulation

    Directory of Open Access Journals (Sweden)

    Deepesh Kumar

    2016-06-01

    Full Text Available Stroke is one of leading cause of death and disability worldwide. Early detection during golden hour and treatment of individual neurological dysfunction in stroke using easy-to-access biomarkers based on a simple-to-use, cost-effective, clinically-valid screening tool can bring a paradigm shift in healthcare, both urban and rural. In our research we have designed a quantitative automatic home-based oculomotor assessment tool that can play an important complementary role in prognosis of neurological disorders like stroke for the neurologist. Once the patient has been screened for stroke, the next step is to design proper rehabilitation platform to alleviate the disability. In addition to the screening platform, in our research, we work in designing virtual reality based rehabilitation exercise platform that has the potential to deliver visual stimulation and in turn contribute to improving one’s performance.

  7. Stimulated coherent transition radiation

    International Nuclear Information System (INIS)

    Hung-chi Lihn.

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed

  8. Motor stimulation with interferential currents.

    Science.gov (United States)

    DE Domenico, G G; Strauss, G R

    1985-01-01

    The stimulation of motor nerves to produce muscle contraction in normally innervated muscles is a long established part of orthodox physiotherapy. Recently however, a revival of interest in the area has occurred, particularly in the U.S.A. Recent research has indicated that such stimulation can improve muscle strength, reduce muscle spasm and modulate spasticity, in addition to the more usual re-educative role of electrical stimulation. The concept of functional electrical stimulation (F.E.S.) seems destined to become an integral part of many programmes for the neurologically handicapped patient. This paper describes the technique of motor stimulation using interferential currents. The stimulating parameters and electrode placement are considered, along with a detailed explanation of the pre-modulated system of electrode arrangement. Copyright © 1985 Australian Physiotherapy Association. Published by . All rights reserved.

  9. Prefrontal versus motor cortex transcranial direct current stimulation (tDCS) effects on post-surgical opioid use.

    Science.gov (United States)

    Borckardt, Jeffrey J; Reeves, Scott T; Milliken, Cole; Carter, Brittan; Epperson, Thomas I; Gunselman, Ryan J; Madan, Alok; Del Schutte, H; Demos, Harry A; George, Mark S

    Pain is often a complaint that precedes total knee arthroplasty (TKA), however the procedure itself is associated with considerable post-operative pain lasting days to weeks which can predict longer-term surgical outcomes. Previously, we reported significant opioid-sparing effects of motor cortex transcranial direct current stimulation from a single-blind trial. In the present study, we used double-blind methodology to compare motor cortex tDCS and prefrontal cortex tDCS to both sham and active-control (active electrodes over non-pain modulating brain areas) tDCS. 58 patients undergoing unilateral TKA were randomly assigned to receive 4 20-min sessions (a total of 80 min) of tDCS (2 mA) post-surgery with electrodes placed to create 4 groups: 1) MOTOR (n = 14); anode-motor/cathode-right prefrontal, 2) PREFRONTAL (n = 16); anode-left-prefrontal/cathode-right-sensory, 3) ACTIVE-CONTROL (n = 15); anode-left-temporal-occipital junction/cathode-medial-anterior-premotor-area, and 4) SHAM (n = 13); 0 mA-current stimulation using placements 1 or 2. Patient controlled analgesia (PCA; hydromorphone) use was tracked during the ∼72-h post-surgery. Patients in the sham group and the active-control group used 15.4 mg (SD = 14.1) and 16.0 mg (SD = 9.7) of PCA hydromorphone respectively. There was no difference between the slopes of the cumulative PCA usage curves between these two groups (p = 0.25; ns). Patients in the prefrontal tDCS group used an average of 11.7 mg (SD = 5.0) of PCA hydromporhone, and the slope of the cumulative PCA usage curve was significantly lower than sham (p prefrontal cortex may be a reasonable approach to reducing post-TKA opioid requirements. Given the unexpected finding that motor cortex failed to produce an opioid sparing effect in this follow-up trial, further research in the area of post-operative cortical stimulation is still needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Stimulating Language: Insights from TMS

    Science.gov (United States)

    Devlin, Joseph T.; Watkins, Kate E.

    2007-01-01

    Fifteen years ago, Pascual-Leone and colleagues used transcranial magnetic stimulation (TMS) to investigate speech production in pre-surgical epilepsy patients and in doing so, introduced a novel tool into language research. TMS can be used to non-invasively stimulate a specific cortical region and transiently disrupt information processing. These…

  11. Atomic oxygen stimulated outgassing

    Science.gov (United States)

    Linton, Roger C.; Reynolds, John M.

    1991-01-01

    The passive Long Duration Exposure Facility (LDEF) Experiment A0034, Atomic Oxygen Simulated Outgassing, consisted of two identical one-sixth tray modules, exposing selected thermal control coatings to atomic oxygen and the combined space environment on the leading edge and, for reference, to the relative wake environment on the trailing edge. Optical mirrors were included adjacent to the thermal coatings for deposition of outgassing products. Ultraviolet grade windows and metal covers were provided for additional assessment of the effects of the various environmental factors. Preliminary results indicate that orbital atomic oxygen is both a degrading and a optically restorative factor in the thermo-optical properties of selected thermal coatings. There is evidence of more severe optical degradation on collector mirrors adjacent to coatings that were exposed to the RAM-impinging atomic oxygen. This evidence of atomic oxygen stimulated outgassing is discussed in relation to alternative factors that could affect degradation. The general effects of the space environment on the experiment hardware as well as the specimens are discussed.

  12. Vagal nerve stimulation therapy: what is being stimulated?

    Directory of Open Access Journals (Sweden)

    Guy Kember

    Full Text Available Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

  13. Electrical stimulation in exercise training

    Science.gov (United States)

    Kroll, Walter

    1994-01-01

    Electrical stimulation has a long history of use in medicine dating back to 46 A.D. when the Roman physician Largus found the electrical discharge of torpedo fishes useful in the treatment of pain produced by headache and gout. A rival Greek physician, Dioscorides, discounted the value of the torpedo fish for headache relief but did recommend its use in the treatment of hemorrhoids. In 1745, the Leyden jar and various sized electrostatic generators were used to treat angina pectoris, epilepsy, hemiplegia, kidney stones, and sciatica. Benjamin Franklin used an electrical device to treat successfully a young woman suffering from convulsive fits. In the late 1800's battery powered hydroelectric baths were used to treat chronic inflammation of the uterus while electrified athletic supporters were advertised for the treatment of male problems. Fortunately, such an amusing early history of the simple beginnings of electrical stimulation did not prevent eventual development of a variety of useful therapeutic and rehabilitative applications of electrical stimulation. Over the centuries electrical stimulation has survived as a modality in the treatment of various medical disorders with its primary application being in the rehabilitation area. Recently, a surge of new interest in electrical stimulation has been kindled by the work of a Russian sport scientist who reported remarkable muscle strength and endurance improvements in elite athletes. Yakov Kots reported his research on electric stimulation and strength improvements in 1977 at a Canadian-Soviet Exchange Symposium held at Concordia University in Montreal. Since then an explosion of new studies has been seen in both sport science and in medicine. Based upon the reported works of Kots and the present surge of new investigations, one could be misled as to the origin of electrical stimulation as a technique to increase muscle strength. As a matter of fact, electric stimulation has been used as a technique to improve

  14. Noninvasive Stimulation of the Human Brain

    DEFF Research Database (Denmark)

    Di Lazzaro, Vincenzo; Rothwell, John; Capogna, Marco

    2017-01-01

    Noninvasive brain stimulation methods, such as transcranial electric stimulation and transcranial magnetic stimulation are widely used tools for both basic research and clinical applications. However, the cortical circuits underlying their effects are poorly defined. Here we review the current...

  15. Enteral feeding without pancreatic stimulation

    DEFF Research Database (Denmark)

    Kaushik, Neeraj; Pietraszewski, Marie; Holst, Jens Juul

    2005-01-01

    .5 g protein/kg ideal body weight/d. Plasma gut peptide responses were monitored in 15 subjects. RESULTS: In comparison with basal fasting trypsin secretion rates (mean = 134 [standard error = 22] U/h), duodenal feeding with the polymeric and elemental formulae stimulated trypsin secretion (mean = 408...... in enteral feeding without pancreatic stimulation, with particular reference to trypsin, because the avoidance of trypsin stimulation may optimize enteral feeding in acute pancreatitis. METHODS: The pancreatic secretory responses to feeding were studied in 36 healthy volunteers by standard double...... [standard error = 51] U/h; P standard error = 34] U/h) and mid-distal jejunal (mean = 119 [standard error = 16] U/h) did not. Stimulation was associated with an increase in plasma cholecystokinin, whereas distal jejunal feeding resulted in an increase...

  16. Demultiplexer circuit for neural stimulation

    Science.gov (United States)

    Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

    2012-10-09

    A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

  17. Growth hormone stimulation test (image)

    Science.gov (United States)

    ... stimulation test is usually performed to identify if hGH (human growth hormone) is deficient. The test is ... amino acid arginine in a vein to raise hGH levels. The test measures the ability of the ...

  18. Economics of nuclear gas stimulation

    International Nuclear Information System (INIS)

    Frank, G.W.; Coffer, H.F.; Luetkehans, G.R.

    1970-01-01

    Nuclear stimulation of the Mesaverde Formation in the Piceance Basin appears to be the only available method that can release the contained gas economically. In the Rulison Field alone estimates show six to eight trillion cubic feet of gas may be made available by nuclear means, and possibly one hundred trillion cubic feet could be released in the Piceance Basin. Several problems remain to be solved before this tremendous gas reserve can be tapped. Among these are (1) rates of production following nuclear stimulation; (2) costs of nuclear stimulation; (3) radioactivity of the chimney gas; and (4) development of the ideal type of device to carry out the stimulations. Each of these problems is discussed in detail with possible solutions suggested. First and foremost is the rate at which gas can be delivered following nuclear stimulation. Calculations have been made for expected production behavior following a 5-kiloton device and a 40-kiloton device with different permeabilities. These are shown, along with conventional production history. The calculations show that rates of production will be sufficient if costs can be controlled. Costs of nuclear stimulation must be drastically reduced for a commercial process. Project Rulison will cost approximately $3.7 million, excluding lease costs, preliminary tests, and well costs. At such prices, nothing can possibly be commercial; however, these costs can come down in a logical step-wise fashion. Radiation contamination of the gas remains a problem. Three possible solutions to this problem are included. (author)

  19. Biomarkers and Stimulation Algorithms for Adaptive Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Kimberly B. Hoang

    2017-10-01

    Full Text Available The goal of this review is to describe in what ways feedback or adaptive stimulation may be delivered and adjusted based on relevant biomarkers. Specific treatment mechanisms underlying therapeutic brain stimulation remain unclear, in spite of the demonstrated efficacy in a number of nervous system diseases. Brain stimulation appears to exert widespread influence over specific neural networks that are relevant to specific disease entities. In awake patients, activation or suppression of these neural networks can be assessed by either symptom alleviation (i.e., tremor, rigidity, seizures or physiological criteria, which may be predictive of expected symptomatic treatment. Secondary verification of network activation through specific biomarkers that are linked to symptomatic disease improvement may be useful for several reasons. For example, these biomarkers could aid optimal intraoperative localization, possibly improve efficacy or efficiency (i.e., reduced power needs, and provide long-term adaptive automatic adjustment of stimulation parameters. Possible biomarkers for use in portable or implanted devices span from ongoing physiological brain activity, evoked local field potentials (LFPs, and intermittent pathological activity, to wearable devices, biochemical, blood flow, optical, or magnetic resonance imaging (MRI changes, temperature changes, or optogenetic signals. First, however, potential biomarkers must be correlated directly with symptom or disease treatment and network activation. Although numerous biomarkers are under consideration for a variety of stimulation indications the feasibility of these approaches has yet to be fully determined. Particularly, there are critical questions whether the use of adaptive systems can improve efficacy over continuous stimulation, facilitate adjustment of stimulation interventions and improve our understanding of the role of abnormal network function in disease mechanisms.

  20. Deep Brain Stimulation for Parkinson's Disease

    Science.gov (United States)

    ... Home » Disorders » All Disorders Deep Brain Stimulation for Parkinson's Disease Information Page Deep Brain Stimulation for Parkinson's Disease Information Page What research is being done? The ...

  1. Ovarian stimulation, endometrium and implantation

    Directory of Open Access Journals (Sweden)

    mandana Beigi Boroujeni

    2011-03-01

    Full Text Available In the Paper article, the collection of the studies related to the effect of ovarian stimulation on endometrium of uterus and implantation have been investigated. History: Monash group used ovarian stimulation method for the first time in infertility treatment and also, they could increase the pregnancy rate using this method. However, the percentage of successful embryonic implantation has been decreased by this method due to imbalance of hormones and the effect of these hormonal changes on endometrium. Materials and Methods: Studies done by researchers have shown that ovarian stimulation causes undesirable changes in endometrium which in turn such alterations lead to inadequate attachment of embryo to endometrium and finally decrease the percentage of embryonic implantation. Conclusion: Based on several researches and the importance of using the ovarian stimulation method in treatment of infertility, also due to undesirable effects that ovarian stimulation has on endometrium during embryonic implantation it is inevitable that more investigations should be done for improvement of treatment methods in infertility clinics.

  2. Evoked Electromyographically Controlled Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Hayashibe

    2016-07-01

    Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.

  3. The Electrical Stimulation Modifies the Cerebral Function

    Science.gov (United States)

    Rocha, Luisa Lilia; López-Meraz, María Leonor; Cuéllar-Herrera, Manola; Neri-Bazán., Leticia

    2002-08-01

    Electrical stimulation has been used for therapeuthic purposes. In this review, we present the clinical and scientific bases for using electrical stimulation as a treatment for pharmacological refractory epilepsy. We also describe results in receptors of inhibitory neurotransmitters obtained in rat brain with or without epilepsy, undergoing brain stimulation. Brain electrical stimulation may improve our understanding of brain function and neuroplasticity.

  4. Mechanisms of deep brain stimulation

    Science.gov (United States)

    Cheng, Jennifer J.; Eskandar, Emad N.

    2015-01-01

    Deep brain stimulation (DBS) is widely used for the treatment of movement disorders including Parkinson's disease, essential tremor, and dystonia and, to a lesser extent, certain treatment-resistant neuropsychiatric disorders including obsessive-compulsive disorder. Rather than a single unifying mechanism, DBS likely acts via several, nonexclusive mechanisms including local and network-wide electrical and neurochemical effects of stimulation, modulation of oscillatory activity, synaptic plasticity, and, potentially, neuroprotection and neurogenesis. These different mechanisms vary in importance depending on the condition being treated and the target being stimulated. Here we review each of these in turn and illustrate how an understanding of these mechanisms is inspiring next-generation approaches to DBS. PMID:26510756

  5. Comparison of mild stimulation and conventional stimulation in ART outcome.

    Science.gov (United States)

    Karimzadeh, Mohammad Ali; Ahmadi, Shahnaz; Oskouian, Homa; Rahmani, Elham

    2010-04-01

    To provide a treatment for particular condition that is the most effective treatment with the least risk and cost for the patient we compared the efficacy of using clomiphene 100 mg + delayed low dose gonadotropin + flexible GnRH antagonist administration for ovarian stimulation protocol and GnRH agonist + gonadotropin for stimulation protocol in IVF outcome. Clinical outcome of 243 women with regularly menstruation who were candidate for IVF. They had undergone stimulation with GnRH agonist and gonadotropin (group A) or clomiphene citrate, gonadotropin and GnRH antagonist (group B). Main outcome was ongoing pregnancy. There were no significant difference in mean age, cause of infertility, basal FSH, BMI, duration of infertility, endometrial thickness on the day HCG administration in two groups. The number of recovered oocytes, obtained embryos, transferred embryos, peak of estradiol on the day HCG administration and OHSS were significantly higher in group A. Significantly more patients in control group had embryos for cryopreservation. There were no significant difference in clinical pregnancy rate and ongoing pregnancy rate between two groups. Clomiphene + delayed low dose gonadotropin + flexible GnRH - antagonist stimulation is an acceptable alternative protocol for IVF in patients with regularly menstruation.

  6. Enteral feeding without pancreatic stimulation

    DEFF Research Database (Denmark)

    Kaushik, Neeraj; Pietraszewski, Marie; Holst, Jens Juul

    2005-01-01

    OBJECTIVE: All forms of commonly practiced enteral feeding techniques stimulate pancreatic secretion, and only intravenous feeding avoids it. In this study, we explored the possibility of more distal enteral infusions of tube feeds to see whether activation of the ileal brake mechanism can result...... in plasma glucagon-like peptide-1 and peptide YY concentrations. CONCLUSIONS: Our results suggest that enteral feeding can be given without stimulating pancreatic trypsin secretion provided it is delivered into the mid-distal jejunum. The mechanism may involve activation of the ileal brake mechanism....

  7. Thermally stimulated properties of amber

    International Nuclear Information System (INIS)

    Bowlt, C.

    1983-01-01

    Thermoelectrets yielded thermally stimulated currents but radioelectrets could not be produced even following exposures of 16000 R of ionising radiation. It is concluded that the thermally stimulated currents are due to the depolarisation of dipoles, with activation energy of 1.4 +- 0.1 eV, rather than to discharge of trapped charge carriers. Amber exhibits thermal luminescence following exposure to light of lambda < 500 nm but not to ionising radiation after exposures up to 5500 R, indicating localised impurity/trap/recombination complexes in the specimen surface, with a trap depth of 1.5 +- 0.1 eV. (author)

  8. Noninvasive Transcranial Brain Stimulation and Pain

    OpenAIRE

    Rosen, Allyson C.; Ramkumar, Mukund; Nguyen, Tam; Hoeft, Fumiko

    2009-01-01

    Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are two noninvasive brain stimulation techniques that can modulate activity in specific regions of the cortex. At this point, their use in brain stimulation is primarily investigational; however, there is clear evidence that these tools can reduce pain and modify neurophysiologic correlates of the pain experience. TMS has also been used to predict response to surgically implanted stimulation for the tre...

  9. Optimizing performance by stimulating conflict

    NARCIS (Netherlands)

    van de Vliert, E.; de Dreu, C.K.W.

    1994-01-01

    To enhance the quality of group decision making, to promote affective acceptance of decisions by all participants involved, or to increase joint outcomes, a principal party or a third party may stimulate social conflict. We argue that when conflict focuses on identity issues, when tension level is

  10. Stimulated emission during axial channeling

    International Nuclear Information System (INIS)

    Ternov, I.M.; Khalilov, V.R.; Kholomai, B.V.

    1985-01-01

    A quantum-mechanical analysis shows that it would be possible to achieve stimulated emission in an axisymmetric focusing electric field by a mechanism based on the nonuniform spacing of levels in the electron energy spectrum and on recoil effects during the emission and absorption of photons by the electrons

  11. Optimizing performance by conflict stimulation

    NARCIS (Netherlands)

    Van de Vliert, E; De Dreu, C K W

    To enhance the quality of group decision making, to promote affective acceptance of decisions by all participants involved, or to increase joint outcomes, a principal party or a third party may stimulate social conflict. We argue that when conflict focuses on identity issues, when tension level is

  12. Transcranial magnetic stimulation in schizophrenia.

    Science.gov (United States)

    Zaman, Rashid; Thind, Dilraj; Kocmur, Marga

    2008-11-01

    Transcranial magnetic stimulation (TMS) is a non-invasive and painless way of stimulating the neural tissue (cerebral cortex, spinal roots, and cranial and peripheral nerves). The first attempts at stimulating the neural tissue date back to 1896 by d'Arsonval; however, it was successfully carried out by Barker and colleagues in Sheffield, UK, in 1985. It soon became a useful tool in neuroscience for neurophysiologists and neurologists and psychiatrists. The original single-pulse TMS, largely used as an investigative tool, was further refined and developed in the early 1990s into what is known as repetitive TMS (rTMS), having a frequency range of 1-60 Hz. The stimulation by both TMS and rTMS of various cortical regions displayed alteration of movement, mood, and behavior, leading researchers to investigate a number of psychiatric and neuropsychiatric disorders, as well as to explore its therapeutic potential. There is now a large amount of literature on the use of TMS/rTMS in depression; however, its use in schizophrenia, both as an investigative and certainly as a therapeutic tool is relatively recent with a limited but increasing number of publications. In this article, we will outline the principles of TMS/rTMS and critically review their use in schizophrenia both as investigative and potential therapeutic tools.

  13. Thermally stimulated luminescence and photoluminescence ...

    Indian Academy of Sciences (India)

    2012-01-13

    Jan 13, 2012 ... Peltier cooled photo-multiplier tube as detector (Jain et al. 2008). The acquisition and analysis of the data were carried out by F-900 software supplied by Edinburgh Analytical. Instruments, UK. Thermally stimulated luminescence (TSL) glow curves were recorded using home-built unit between. 300 and ...

  14. Ovarian stimulation and embryo quality

    NARCIS (Netherlands)

    Baart, Esther; Macklon, Nick S.; Fauser, Bart J. C. M.

    To Study the effects of different ovarian stimulation approaches on oocyte and embryo quality, it is imperative to assess embryo quality with a reliable and objective method. Embryos rated as high quality by standardized morphological assessment are associated with higher implantation and pregnancy

  15. Breast Cancer Stimulation of Osteolysis

    Science.gov (United States)

    2000-09-01

    number seen in osteoporosis . M- increase osteoclast activity. Paracrine stimulation of osteo-clas aciviy my bea pi ay mchansm y wich CSF also promotes the...effects on gies, including periodontitis and orthopedic implant loos- kidney and bone metabolism. Paracrine actions of ening. Antibody blockade of

  16. Orientation selective deep brain stimulation

    Science.gov (United States)

    Lehto, Lauri J.; Slopsema, Julia P.; Johnson, Matthew D.; Shatillo, Artem; Teplitzky, Benjamin A.; Utecht, Lynn; Adriany, Gregor; Mangia, Silvia; Sierra, Alejandra; Low, Walter C.; Gröhn, Olli; Michaeli, Shalom

    2017-02-01

    Objective. Target selectivity of deep brain stimulation (DBS) therapy is critical, as the precise locus and pattern of the stimulation dictates the degree to which desired treatment responses are achieved and adverse side effects are avoided. There is a clear clinical need to improve DBS technology beyond currently available stimulation steering and shaping approaches. We introduce orientation selective neural stimulation as a concept to increase the specificity of target selection in DBS. Approach. This concept, which involves orienting the electric field along an axonal pathway, was tested in the corpus callosum of the rat brain by freely controlling the direction of the electric field on a plane using a three-electrode bundle, and monitoring the response of the neurons using functional magnetic resonance imaging (fMRI). Computational models were developed to further analyze axonal excitability for varied electric field orientation. Main results. Our results demonstrated that the strongest fMRI response was observed when the electric field was oriented parallel to the axons, while almost no response was detected with the perpendicular orientation of the electric field relative to the primary fiber tract. These results were confirmed by computational models of the experimental paradigm quantifying the activation of radially distributed axons while varying the primary direction of the electric field. Significance. The described strategies identify a new course for selective neuromodulation paradigms in DBS based on axonal fiber orientation.

  17. Photoluminescence, thermally stimulated luminescence and ...

    Indian Academy of Sciences (India)

    an important role in the development of thermolumine- scent dosimeters (Vohra et al 1980; Shinde et al 1996) and offer a very fertile area for further studies to eluci- date the thermally stimulated reactions resulting in lumine- scence. Actinide doped alkaline-earth sulphates are of spe- cial interest due to an array of defect ...

  18. Thalamic stimulation in absence epilepsy

    NARCIS (Netherlands)

    Luttjohann, A.K.; Luijtelaar, E.L.J.M. van

    2013-01-01

    Purpose The site specific effects of two different types of electrical stimulation of the thalamus on electroencephalic epileptic activity as generated in the cortico-thalamo-cortical system were investigated in genetic epileptic WAG/Rij rats, a well characterized and validated absence

  19. Stimulation of phagocytosis by sulforaphane

    Energy Technology Data Exchange (ETDEWEB)

    Suganuma, Hiroyuki, E-mail: hsuganu1@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Fahey, Jed W., E-mail: jfahey@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Bryan, Kelley E., E-mail: kbryanm1@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Healy, Zachary R., E-mail: zhealy1@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Talalay, Paul, E-mail: ptalalay@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States)

    2011-02-04

    Research highlights: {yields} Sulforaphane stimulates the phagocytosis of RAW 264.7 macrophages under conditions of serum deprivation. {yields} This effect does not require Nrf2-dependent induction of phase 2 genes. {yields} Inactivation of macrophage migration inhibitory factor (MIF) by sulforaphane may be involved in stimulation of phagocytosis by sulforaphane. -- Abstract: Sulforaphane, a major isothiocyanate derived from cruciferous vegetables, protects living systems against electrophile toxicity, oxidative stress, inflammation, and radiation. A major protective mechanism is the induction of a network of endogenous cytoprotective (phase 2) genes that are regulated by transcription factor Nrf2. To obtain a more detailed understanding of the anti-inflammatory and immunomodulatory effects of sulforaphane, we evaluated its effect on the phagocytosis activity of RAW 264.7 murine macrophage-like cells by measuring the uptake of 2-{mu}m diameter polystyrene beads. Sulforaphane raised the phagocytosis activity of RAW 264.7 cells but only in the absence or presence of low concentrations (1%) of fetal bovine serum. Higher serum concentrations depressed phagocytosis and abolished its stimulation by sulforaphane. This stimulation did not depend on the induction of Nrf2-regulated genes since it occurred in peritoneal macrophages of nrf2{sup -/-} mice. Moreover, a potent triterpenoid inducer of Nrf2-dependent genes did not stimulate phagocytosis, whereas sulforaphane and another isothiocyanate (benzyl isothiocyanate) had comparable inducer potencies. It has been shown recently that sulforaphane is a potent and direct inactivator of macrophage migration inhibitory factor (MIF), an inflammatory cytokine. Moreover, the addition of recombinant MIF to RAW 264.7 cells attenuated phagocytosis, but sulforaphane-inactivated MIF did not affect phagocytosis. The inactivation of MIF may therefore be involved in the phagocytosis-enhancing activity of sulforaphane.

  20. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    OpenAIRE

    Hui Zhou; Yi Lu; Wanzhen Chen; Zhen Wu; Haiqing Zou; Ludovic Krundel; Guanglin Li

    2015-01-01

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel ele...

  1. "Slinky" coils for neuromagnetic stimulation.

    Science.gov (United States)

    Zimmermann, K P; Simpson, R K

    1996-04-01

    Future advances in neuromagnetic stimulation depend significantly on the design of coils with improved focality. Although in the absence of internal current sources, no true focusing of magnetically induced currents is possible, improvements in the focality of current concentrations passing through an area of biologic tissue are achievable through variations of the shape, orientation and size of neuromagnetic stimulating coils. The "butterfly" and the "4-leaf" coils are two examples of planar designs which achieve improved focality through centralization of the maximum coil current and peripheral distribution of the return currents. We introduce the "slinky" coil design as a 3-dimensional generalization of the principle of peripheral distribution of return currents and demonstrate its advantages over planar designs.

  2. Vagal stimulation in heart failure.

    Science.gov (United States)

    De Ferrari, Gaetano M

    2014-04-01

    Heart failure (HF) is accompanied by an autonomic imbalance that is almost always characterized by both increased sympathetic activity and withdrawal of vagal activity. Experimentally, vagal stimulation has been shown to exert profound antiarrhythmic activity and to improve cardiac function and survival in HF models. A open-label pilot clinical study in 32 patients with chronic HF has shown safety and tolerability of chronic vagal stimulation associated with subjective (improved quality of life and 6-min walk test) and objective improvements (reduced left ventricular systolic volumes and improved left ventricular ejection fraction). Three larger clinical studies, including a phase III trial are currently ongoing and will evaluate the clinical role of this new approach.

  3. Stimulated Superconductivity at Strong Coupling

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Ning; Dong, Xi; Silverstein, Eva; Torroba, Gonzalo; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC

    2011-08-12

    Stimulating a system with time dependent sources can enhance instabilities, thus increasing the critical temperature at which the system transitions to interesting low-temperature phases such as superconductivity or superfluidity. After reviewing this phenomenon in non-equilibrium BCS theory (and its marginal fermi liquid generalization) we analyze the effect in holographic superconductors. We exhibit a simple regime in which the transition temperature increases parametrically as we increase the frequency of the time-dependent source.

  4. Transcranial Magnetic Stimulation in Children

    OpenAIRE

    Garvey, Marjorie A.; Mall, Volker

    2008-01-01

    Developmental disabilities (e.g. attention deficit disorder; cerebral palsy) are frequently associated with deviations of the typical pattern of motor skill maturation. Neurophysiologic tools, such as transcranial magnetic stimulation (TMS), which probe motor cortex function, can potentially provide insights into both typical neuromotor maturation and the mechanisms underlying the motor skill deficits in children with developmental disabilities. These insights may set the stage for finding ef...

  5. Deep brain stimulation in psychiatry.

    Science.gov (United States)

    Mohr, Pavel

    2008-11-01

    Deep brain stimulation (DBS) is a reversible surgical procedure that involves stereotactic implantation of electrodes into the targeted brain regions, with a subcutaneously placed pulse generator powering the electrodes via one or two leads. The mechanism of action can be explained by the stimulation-induced modulation of impaired network activity. So far, the main use of DBS has been for neurological conditions, such as essential tremor, motor symptoms in Parkinson's disease, dystonia, epilepsy, and chronic pain. In psychiatry, case series and open studies indicate treatment efficacy of DBS in Gilles de la Tourette syndrome, treatment-resistant obsessive-compulsive disorder, and refractory major depression. Neuroimaging studies have confirmed the effects of DBS on the brain regions implicated in specific neuropsychiatric disorders. It is a well-tolerated method with relatively few serious side effects. Additional well-designed and appropriately powered controlled clinical trials are needed to conclusively establish the efficacy and safety of DBS and to identify the patient population(s) who may benefit most. Ongoing research with stimulation techniques may also significantly contribute to our understanding of major neuropsychiatric disorders.

  6. Performance Enhancement by Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Parisa Gazerani

    2017-09-01

    Full Text Available Number of substances and strategies are available to increase performance in sport (Catlin and Murray, 1996. Since 2004, the World Anti-Doping Agency (WADA posts an updated list of substances and methods prohibited to athletes. Drugs (e.g., steroids, stimulants are a major part of this list; however, technologies and methods (e.g., gene doping are increasingly being identified and added (WADA, 2017. Among technologies and methods that might exert a potential effect on athletic performance, brain stimulation has recently been subjected to extensive discussion. Neuro-enhancement for doping purposes has been termed “neurodoping” in the literature (Davis, 2013; however, this concept needs further documentation before the term “neurodoping” can be used properly. Two major non-invasive techniques of brain stimulations are transcranial magnetic stimulation (TMS (Hallett, 2007; Rossi et al., 2009, and transcranial direct current stimulation (tDCS (Stagg and Nitsche, 2011. In TMS, an electric coil held over the head applies magnetic pulses to create currents in the brain. In tDCS, a low, continuous electrical current is delivered to the brain by using surface electrodes attached on the scalp. TMS and tDCS have been used in both research and clinic (Shin and Pelled, 2017 for example to examine alterations in cognitive function or motor skills or to assist in recovering motor function after a stroke (Gomez Palacio Schjetnan et al., 2013 or reducing fatigue in patients with multiple sclerosis (Saiote et al., 2014. In an opinion paper, it was proposed that use of emerging brain stimulation techniques might also enhance physical and mental performance in sports (Davis, 2013. The assumption was based on several reports. For example some studies have shown that TMS could shorten reaction times to visual, auditory and touch stimuli, reduce tremor, and enhance the acquisition of complex motor skills. Based on the current evidence, a recent review (Colzato

  7. Optical stimulated luminescence (OSL) dating

    International Nuclear Information System (INIS)

    Banerjee, D.

    1999-01-01

    Since the pioneering work by Huntley et al. (1985), optical dating is being increasingly recognised as an important technique for establishing a time frame of deposition of sediments (Aitken, 1998). Optical dating differs from thermoluminescence (TL) dating in that visible/infrared light from lasers or LEDs (light-emitting-diodes) is used as a means of stimulation, in contrast to thermal stimulation. It has several advantages over TL dating: (i) the resetting of the OSL (optically stimulated luminescence) clock is more effective than that of TL clock; for sediments transported under water or in other situations where the sediment grains have undergone inhomogeneous bleaching, this property ensures that ages based on optical dating are generally more reliable than TL ages, (ii) the optical dating technique is non-destructive, and multiple readouts of the optical signal is possible; this feature has resulted in the development of single-aliquot and single-grain protocols (Murray and Wintle, 1999; Banerjee et al. 1999), (iii) the sample is not heated as in TL; thus, spurious luminescence is avoided and there is a significant reduction in blackbody radiation. Dating of materials which change phase on heating is also practical, and finally, (iv) thermal quenching of luminescence is negligible, allowing accurate estimation of kinetic parameters using standard techniques and providing access to deep OSL traps. This characteristic may be helpful in extending the limits of optical dating beyond the last 150 ka from a global point of view

  8. Vagus Nerve Stimulation for Treating Epilepsy

    Science.gov (United States)

    ... and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you ... how vagus nerve stimulation (VNS) may help treat epilepsy. The American Academy of Neurology (AAN) is the ...

  9. Follicle-stimulating hormone (FSH) blood test

    Science.gov (United States)

    ... ency/article/003710.htm Follicle-stimulating hormone (FSH) blood test To use the sharing features on this page, please enable JavaScript. The follicle stimulating hormone (FSH) blood test measures the level of FSH in blood. FSH ...

  10. Prenatal music stimulation facilitates the postnatal functional ...

    Indian Academy of Sciences (India)

    2014-01-27

    Jan 27, 2014 ... two main groups: 1. Control – incubated without any auditory stimulation and. 2. Sitar music stimulated – incubated with slow and fast sitar music. Therefore, the experimental paradigm as described by. Jain et al. (2004) for the sound stimulation was followed. Briefly, first sounds of low to mid frequencies, i.e. ...

  11. Modeling and Field Results from Seismic Stimulation

    International Nuclear Information System (INIS)

    Majer, E.; Pride, S.; Lo, W.; Daley, T.; Nakagawa, Seiji; Sposito, Garrison; Roberts, P.

    2006-01-01

    Modeling the effect of seismic stimulation employing Maxwell-Boltzmann theory shows that the important component of stimulation is mechanical rather than fluid pressure effects. Modeling using Biot theory (two phases) shows that the pressure effects diffuse too quickly to be of practical significance. Field data from actual stimulation will be shown to compare to theory

  12. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    Each of the following types of well stimulation techniques are summarized and explained: hydraulic fracturing; thermal; mechanical, jetting, and drainhole drilling; explosive and implosive; and injection methods. Current stimulation techniques, stimulation techniques for geothermal wells, areas of needed investigation, and engineering calculations for various techniques. (MHR)

  13. A Chip for an Implantable Neural Stimulator

    DEFF Research Database (Denmark)

    Gudnason, Gunnar; Bruun, Erik; Haugland, Morten

    2000-01-01

    This paper describes a chip for a multichannel neural stimulator for functional electrical stimulation (FES). The purpose of FES is to restore muscular control in disabled patients. The chip performs all the signal processing required in an implanted neural stimulator. The power and digital data...

  14. Thermally stimulated scattering in plasmas

    DEFF Research Database (Denmark)

    Dysthe, K. B.; Mjølhus, E.; Pécseli, H. L.

    1985-01-01

    this experiment local heat conduction is of little importance and the dynamic evolution for the electron temperature is dominated by heating and energy exchange with the ion component. These features are incorporated in the analysis. The resulting set of equations gives a growth rate and characteristic scale size......A theory for stimulated scattering of a laser beam is formulated where the dominant nonlinearity is the ohmic heating of the plasma. The analysis is carried out with particular reference to experimental investigations of CO2 laser heating of linear discharge plasma. In the conditions characterizing...

  15. Optical stimulator for vision-based sensors

    DEFF Research Database (Denmark)

    Rössler, Dirk; Pedersen, David Arge Klevang; Benn, Mathias

    2014-01-01

    stimulator is used as a test bench to simulate high-precision navigation by different types of camera systems that are used onboard spacecraft, planetary rovers, and for spacecraft rendezvous and proximity maneuvers. Careful hardware design and preoperational calibration of the stimulator result in high......We have developed an optical stimulator system for vision-based sensors. The stimulator is an efficient tool for stimulating a camera during on-ground testing with scenes representative of spacecraft flights. Such scenes include starry sky, planetary objects, and other spacecraft. The optical...... precision and long-term stability. The system can be continuously used over several days. By facilitating a full camera including optics in the loop, the stimulator enables the more realistic simulation of flight maneuvers based on navigation cameras than pure computer simulations or camera stimulations...

  16. Therapeutic electrical stimulation of injured peripheral nerve tissue using implantable thin-film wireless nerve stimulators.

    Science.gov (United States)

    MacEwan, Matthew R; Gamble, Paul; Stephen, Manu; Ray, Wilson Z

    2018-02-09

    OBJECTIVE Electrical stimulation of peripheral nerve tissue has been shown to accelerate axonal regeneration. Yet existing methods of applying electrical stimulation to injured peripheral nerves have presented significant barriers to clinical translation. In this study, the authors examined the use of a novel implantable wireless nerve stimulator capable of simultaneously delivering therapeutic electrical stimulation of injured peripheral nerve tissue and providing postoperative serial assessment of functional recovery. METHODS Flexible wireless stimulators were fabricated and implanted into Lewis rats. Thin-film implants were used to deliver brief electrical stimulation (1 hour, 20 Hz) to sciatic nerves after nerve crush or nerve transection-and-repair injuries. RESULTS Electrical stimulation of injured nerves via implanted wireless stimulators significantly improved functional recovery. Brief electrical stimulation was observed to increase the rate of functional recovery after both nerve crush and nerve transection-and-repair injuries. Wireless stimulators successfully facilitated therapeutic stimulation of peripheral nerve tissue and serial assessment of nerve recovery. CONCLUSIONS Implantable wireless stimulators can deliver therapeutic electrical stimulation to injured peripheral nerve tissue. Implantable wireless nerve stimulators might represent a novel means of facilitating therapeutic electrical stimulation in both intraoperative and postoperative settings.

  17. Braille line using electrical stimulation

    International Nuclear Information System (INIS)

    Puertas, A; Pures, P; Echenique, A M; Ensinck, J P Graffigna y G

    2007-01-01

    Conceived within the field of Rehabilitation Technologies for visually impaired persons, the present work aims at enabling the blind user to read written material by means of a tactile display. Once he is familiarized to operate this system, the user will be able to achieve greater performance in study, academic and job activities, thus achieving a rapid and easier social inclusion. The devise accepts any kind of text that is computer-loadable (documents, books, Internet information, and the like) which, through digital means, can be read as Braille text on the pad. This tactile display is composed of an electrodes platform that simulate, through stimulation the writing/reading Braille characters. In order to perceive said characters in similar way to the tactile feeling from paper material, the skin receptor of fingers are stimulated electrically so as to simulate the same pressure and depressions as those of the paper-based counterpart information. Once designed and developed, the display was tested with blind subjects, with relatively satisfactory results. As a continuing project, this prototype is currently being improved as regards

  18. Magnetic-motor-root stimulation: review.

    Science.gov (United States)

    Matsumoto, Hideyuki; Hanajima, Ritsuko; Terao, Yasuo; Ugawa, Yoshikazu

    2013-06-01

    Magnetic stimulation can activate the human central and peripheral nervous systems non-invasively and virtually painlessly. Magnetic stimulation over the spinal enlargements can activate spinal nerves at the neuroforamina (magnetic-neuroforamina stimulation). This stimulation method provides us with information related to the latency of compound-muscle action potential (CMAP), which is usually interpreted as peripheral motor-conduction time (PMCT). However, this stimulation method has faced several problems in clinical applications. One is that supramaximal CMAPs were unobtainable. Another is that magnetic stimulation did not usually activate the spinal nerves in the spinal canal, i.e., the cauda equina, which prevented an evaluation of its conduction. For these reasons, magnetic-neuroforamina stimulation was rarely used to evaluate the conduction of peripheral nerves. It was mainly used to evaluate the conduction of the corticospinal tract using the parameter of central motor-conduction time (CMCT), which was calculated by subtracting PMCT from the latency of motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over the primary motor cortex. Recently, supramaximal stimulation has been achieved in magnetic-neuroforamina stimulation, and this has contributed to the measurement of both CMAP size and latency. The achievement of supramaximal stimulation is ascribed to the increase in magnetic-stimulator output and a novel coil, the magnetic augmented translumbosacral stimulation (MATS) coil. The most proximal part of the cauda equina can be reliably activated using the MATS coil (magnetic-conus stimulation), thus contributing to the measurement of cauda equina conduction time (CECT) and cortico-conus motor-conduction time (CCCT). These recent developments in magnetic-motor-root stimulation enable us to more precisely evaluate the conduction of the proximal part of peripheral nerves and that of the corticospinal tract for lower-limb muscles

  19. Socioeconomic evaluation of vagus stimulation

    DEFF Research Database (Denmark)

    Jennum, Poul; Sabers, Anne; Christensen, Jakob

    2016-01-01

    PURPOSE: We aimed to determine the health costs and social outcomes in terms of education, employment and income level after insertion of a vagus nerve stimulator (VNS) in patients with epilepsy. METHODS: This is a case-control study using Danish health care and socioeconomic register data....... The analysis of the effect involved a comparison of the health care costs, occupation and income status of VNS-treated epilepsy patients with those of a control group of epilepsy patients who had a VNS implanted during the 12 months before the index date (pre-period) and during the two years after the index...... implantation. VNS implantation was not associated with changes in occupational status (including employment and income). In fact, the number of people on disability pension increased during the period. CONCLUSIONS: VNS implantation in people with epilepsy is associated with reduced health care use...

  20. Multisensory stimulation in stroke rehabilitation

    Directory of Open Access Journals (Sweden)

    Barbro Birgitta Johansson

    2012-04-01

    Full Text Available The brain has a large capacity for automatic simultaneous processing and integration of sensory information. Combining information from different sensory modalities facilitates our ability to detect, discriminate, and recognize sensory stimuli, and learning is often optimal in a multisensory environment. Currently used multisensory stimulation methods in stroke rehabilitation include motor imagery, action observation, training with a mirror or in a virtual environment, or various kinds of music therapy. Several studies have shown positive effects been reported but to give general recommendation more studies are needed. Patient heterogeneity and the interactions of age, gender, genes and environment are discussed. Randomized controlled longitudinal trials starting earlier post stroke are needed. The advance in brain network science and neuroimaging enabling longitudinal studies of structural and functional networks are likely to have an important impact on patient selection for specific interventions in future stroke rehabilitation.

  1. Non-invasive neural stimulation

    Science.gov (United States)

    Tyler, William J.; Sanguinetti, Joseph L.; Fini, Maria; Hool, Nicholas

    2017-05-01

    Neurotechnologies for non-invasively interfacing with neural circuits have been evolving from those capable of sensing neural activity to those capable of restoring and enhancing human brain function. Generally referred to as non-invasive neural stimulation (NINS) methods, these neuromodulation approaches rely on electrical, magnetic, photonic, and acoustic or ultrasonic energy to influence nervous system activity, brain function, and behavior. Evidence that has been surmounting for decades shows that advanced neural engineering of NINS technologies will indeed transform the way humans treat diseases, interact with information, communicate, and learn. The physics underlying the ability of various NINS methods to modulate nervous system activity can be quite different from one another depending on the energy modality used as we briefly discuss. For members of commercial and defense industry sectors that have not traditionally engaged in neuroscience research and development, the science, engineering and technology required to advance NINS methods beyond the state-of-the-art presents tremendous opportunities. Within the past few years alone there have been large increases in global investments made by federal agencies, foundations, private investors and multinational corporations to develop advanced applications of NINS technologies. Driven by these efforts NINS methods and devices have recently been introduced to mass markets via the consumer electronics industry. Further, NINS continues to be explored in a growing number of defense applications focused on enhancing human dimensions. The present paper provides a brief introduction to the field of non-invasive neural stimulation by highlighting some of the more common methods in use or under current development today.

  2. Noninvasive transcranial brain stimulation and pain.

    Science.gov (United States)

    Rosen, Allyson C; Ramkumar, Mukund; Nguyen, Tam; Hoeft, Fumiko

    2009-02-01

    Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are two noninvasive brain stimulation techniques that can modulate activity in specific regions of the cortex. At this point, their use in brain stimulation is primarily investigational; however, there is clear evidence that these tools can reduce pain and modify neurophysiologic correlates of the pain experience. TMS has also been used to predict response to surgically implanted stimulation for the treatment of chronic pain. Furthermore, TMS and tDCS can be applied with other techniques, such as event-related potentials and pharmacologic manipulation, to illuminate the underlying physiologic mechanisms of normal and pathological pain. This review presents a description and overview of the uses of two major brain stimulation techniques and a listing of useful references for further study.

  3. Mimicking muscle activity with electrical stimulation

    Science.gov (United States)

    Johnson, Lise A.; Fuglevand, Andrew J.

    2011-02-01

    Functional electrical stimulation is a rehabilitation technology that can restore some degree of motor function in individuals who have sustained a spinal cord injury or stroke. One way to identify the spatio-temporal patterns of muscle stimulation needed to elicit complex upper limb movements is to use electromyographic (EMG) activity recorded from able-bodied subjects as a template for electrical stimulation. However, this requires a transfer function to convert the recorded (or predicted) EMG signals into an appropriate pattern of electrical stimulation. Here we develop a generalized transfer function that maps EMG activity into a stimulation pattern that modulates muscle output by varying both the pulse frequency and the pulse amplitude. We show that the stimulation patterns produced by this transfer function mimic the active state measured by EMG insofar as they reproduce with good fidelity the complex patterns of joint torque and joint displacement.

  4. Analysis of Facial Expression by Taste Stimulation

    Science.gov (United States)

    Tobitani, Kensuke; Kato, Kunihito; Yamamoto, Kazuhiko

    In this study, we focused on the basic taste stimulation for the analysis of real facial expressions. We considered that the expressions caused by taste stimulation were unaffected by individuality or emotion, that is, such expressions were involuntary. We analyzed the movement of facial muscles by taste stimulation and compared real expressions with artificial expressions. From the result, we identified an obvious difference between real and artificial expressions. Thus, our method would be a new approach for facial expression recognition.

  5. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    A literature search on reservoir and/or well stimulation techniques suitable for application in geothermal fields is presented. The literature on stimulation techniques in oil and gas field applications was also searched and evaluated as to its relevancy to geothermal operations. The equivalent low-temperature work documented in the open literature is cited, and an attempt is made to evaluate the relevance of this information as far as high-temperature stimulation work is concerned. Clays play an important role in any stimulation work. Therefore, special emphasis has been placed on clay behavior anticipated in geothermal operations. (MHR)

  6. Stimulant ADHD Medications -- Methylphenidate and Amphetamines

    Science.gov (United States)

    ... prescription stimulants? dextroamphetamine (Dexedrine ® ) dextroamphetamine/amphetamine combination product (Adderall ® ) methylphenidate (Ritalin ® , Concerta ® ). Popular slang terms for prescription ...

  7. Cognitive stimulation in healthy older adults: a cognitive stimulation program using leisure activities compared to a conventional cognitive stimulation program.

    Science.gov (United States)

    Grimaud, Élisabeth; Taconnat, Laurence; Clarys, David

    2017-06-01

    The aim of this study was to compare two methods of cognitive stimulation for the cognitive functions. The first method used an usual approach, the second used leisure activities in order to assess their benefits on cognitive functions (speed of processing; working memory capacity and executive functions) and psychoaffective measures (memory span and self esteem). 67 participants over 60 years old took part in the experiment. They were divided into three groups: 1 group followed a program of conventional cognitive stimulation, 1 group a program of cognitive stimulation using leisure activities and 1 control group. The different measures have been evaluated before and after the training program. Results show that the cognitive stimulation program using leisure activities is as effective on memory span, updating and memory self-perception as the program using conventional cognitive stimulation, and more effective on self-esteem than the conventional program. There is no difference between the two stimulated groups and the control group on speed of processing. Neither of the two cognitive stimulation programs provides a benefit over shifting and inhibition. These results indicate that it seems to be possible to enhance working memory and to observe far transfer benefits over self-perception (self-esteem and memory self-perception) when using leisure activities as a tool for cognitive stimulation.

  8. Current density in radiation stimulated superconductors

    International Nuclear Information System (INIS)

    Wafelbakker, C.K.

    1977-01-01

    Eliashberg's theory of stimulated superconductivity is reviewed and discussed within the BCS-Mattis formalism for impure superconductors. Stimulation by microwaves as well as by acoustical fields is considered. Eliashberg's results are completed by obtaining the nonequilibrium current response to an applied transverse vector potential. The resulting expression may be used to obtain the critical current of small specimens. (Auth.)

  9. Are Prescription Stimulants “Smart Pills”?

    Science.gov (United States)

    Smith, M. Elizabeth; Farah, Martha J.

    2013-01-01

    Use of prescription stimulants by normal healthy individuals to enhance cognition is said to be on the rise. Who is using these medications for cognitive enhancement, and how prevalent is this practice? Do prescription stimulants in fact enhance cognition for normal healthy people? We review the epidemiological and cognitive neuroscience literatures in search of answers to these questions. Epidemiological issues addressed include the prevalence of nonmedical stimulant use, user demographics, methods by which users obtain prescription stimulants, and motivations for use. Cognitive neuroscience issues addressed include the effects of prescription stimulants on learning and executive function, as well as the task and individual variables associated with these effects. Little is known about the prevalence of prescription stimulant use for cognitive enhancement outside of student populations. Among college students, estimates of use vary widely but, taken together, suggest that the practice is commonplace. The cognitive effects of stimulants on normal healthy people cannot yet be characterized definitively, despite the volume of research that has been carried out on these issues. Published evidence suggests that declarative memory can be improved by stimulants, with some evidence consistent with enhanced consolidation of memories. Effects on the executive functions of working memory and cognitive control are less reliable but have been found for at least some individuals on some tasks. In closing, we enumerate the many outstanding questions that remain to be addressed by future research and also identify obstacles facing this research. PMID:21859174

  10. Kinetics of infrared stimulated luminescence from feldspars

    DEFF Research Database (Denmark)

    Jain, Mayank; Sohbati, Reza; Guralnik, Benny

    2015-01-01

    thermal and optical, of the infrared stimulated luminescence signal from feldspar. Based on the application of this model, it is concluded that different infra-red stimulated luminescence emissions (UV, blue, yellow and far-red) follow the same kinetics, and, therefore, involve participation of the same...... in feldspar. © 2015 Elsevier Ltd. All rights reserved....

  11. Swelling of rat hepatocytes stimulates glycogen synthesis

    NARCIS (Netherlands)

    Baquet, A.; Hue, L.; Meijer, A. J.; van Woerkom, G. M.; Plomp, P. J.

    1990-01-01

    In hepatocytes from fasted rats, several amino acids are known to stimulate glycogen synthesis via activation of glycogen synthase. The hypothesis that an increase in cell volume resulting from amino acid uptake may be involved in the stimulation of glycogen synthesis is supported by the following

  12. Thyroid stimulating hormone and subclinical thyroid dysfunction

    International Nuclear Information System (INIS)

    Guo Yongtie

    2008-01-01

    Subclinical thyroid dysfunction has mild clinical symptoms. It is nonspecific and not so noticeable. It performs only for thyroid stimulating hormone rise and decline. The value of early diagnosis and treatment of thyroid stimulating hormone in subclinical thyroid dysfunction were reviewed. (authors)

  13. Stimulation of seeds by low dose irradiation

    International Nuclear Information System (INIS)

    Lawson, Helen

    1976-05-01

    The first section of the bibliography lists materials on the stimulation of seeds by low dose irradiation, with particular reference to stimulation of germination and yield. The second section contains a small number of selected references on seed irradiation facilities. (author)

  14. Inhibition of Lipopolysaccharide-Stimulated Neuro- Inflammatory ...

    African Journals Online (AJOL)

    Purpose: To investigate the in vitro antioxidant and anti-neuroinflammatory effects of Tetragonia tetragonoides (Pall.) Kuntze extract (TKE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Methods: To evaluate the effects of TKE, LPS-stimulated BV microglia were used and the expression and production of ...

  15. Anal sphincter responses after perianal electrical stimulation

    DEFF Research Database (Denmark)

    Pedersen, Ejnar; Klemar, B; Schrøder, H D

    1982-01-01

    not fatigued by repeated stimulation, were most dependent on placement of stimulating and recording electrodes, and always had a higher threshold than the third response. The third response was constantly present in normal subjects. It had the longest EMG response and the latency decreased with increasing...

  16. Selective brain stimulation using conditioning pulses

    NARCIS (Netherlands)

    Holsheimer, J.

    2005-01-01

    A system and method is described for preferentially stimulating dorsal column fibers while avoiding stimulation of dorsal root fibers. The invention applies hyperpolarizing (anodic) pre-pulses (HPP) and depolarizing (cathodic) pre-pulses (DPP) to neural tissue, such as spinal cord tissue, through a

  17. Violet stimulated luminescence: geo- or thermochronometer?

    DEFF Research Database (Denmark)

    Ankjærgaard, Christina; Guralnik, Benny; Porat, N.

    2015-01-01

    The method of quartz optically stimulated luminescence (OSL) dating is widely used, but generally limited to the past ~0.1 million years (Ma) due to early saturation of the desired signal. Violet stimulated luminescence (VSL) of quartz has previously been shown as a promising alternative...

  18. Motor cortex stimulation: role of computer modeling

    NARCIS (Netherlands)

    Manola, L.; Holsheimer, J.; Sakas, D.E.; Simpson, B.A

    Motor cortex stimulation (MCS) is a promising clinical technique used to treat chronic, otherwise intractable pain. However, the mechanisms by which the neural elements that are stimulated during MCS induce pain relief are not understood. Neither is it known which neural elements (fibers (parallel

  19. Twiddler's syndrome in spinal cord stimulation.

    Science.gov (United States)

    Al-Mahfoudh, Rafid; Chan, Yuen; Chong, Hsu Pheen; Farah, Jibril Osman

    2016-01-01

    The aims are to present a case series of Twiddler's syndrome in spinal cord stimulators with analysis of the possible mechanism of this syndrome and discuss how this phenomenon can be prevented. Data were collected retrospectively between 2007 and 2013 for all patients presenting with failure of spinal cord stimulators. The diagnostic criterion for Twiddler's syndrome is radiological evidence of twisting of wires in the presence of failure of spinal cord stimulation. Our unit implants on average 110 spinal cord stimulators a year. Over the 5-year study period, all consecutive cases of spinal cord stimulation failure were studied. Three patients with Twiddler's syndrome were identified. Presentation ranged from 4 to 228 weeks after implantation. Imaging revealed repeated rotations and twisting of the wires of the spinal cord stimulators leading to hardware failure. To the best of our knowledge this is the first reported series of Twiddler's syndrome with implantable pulse generators (IPGs) for spinal cord stimulation. Hardware failure is not uncommon in spinal cord stimulation. Awareness and identification of Twiddler's syndrome may help prevent its occurrence and further revisions. This may be achieved by implanting the IPG in the lumbar region subcutaneously above the belt line. Psychological intervention may have a preventative role for those who are deemed at high risk of Twiddler's syndrome from initial psychological screening.

  20. Transcranial magnetic stimulation in children.

    Science.gov (United States)

    Garvey, Marjorie A; Mall, Volker

    2008-05-01

    Developmental disabilities (e.g. attention deficit disorder; cerebral palsy) are frequently associated with deviations of the typical pattern of motor skill maturation. Neurophysiologic tools, such as transcranial magnetic stimulation (TMS), which probe motor cortex function, can potentially provide insights into both typical neuromotor maturation and the mechanisms underlying the motor skill deficits in children with developmental disabilities. These insights may set the stage for finding effective interventions for these disorders. We review the literature pertaining to the use of TMS in pediatrics. Most TMS-evoked parameters show age-related changes in typically developing children and some of these are abnormal in a number of childhood-onset neurological disorders. Although no TMS-evoked parameters are diagnostic for any disorder, changes in certain parameters appear to reflect disease burden or may provide a measure of treatment-related improvement. Furthermore, TMS may be especially useful when combined with other neurophysiologic modalities (e.g. fMRI). However, much work remains to be done to determine if TMS-evoked parameters can be used as valid and reliable biomarkers for disease burden, the natural history of neurological injury and repair, and the efficacy of pharmacological and rehabilitation interventions.

  1. Digital electronic bone growth stimulator

    Energy Technology Data Exchange (ETDEWEB)

    Kronberg, J.W.

    1993-01-01

    The present invention relates to the electrical treatment of biological tissue. In particular, the present invention discloses a device that produces discrete electrical pulse trains for treating osteoporosis and accelerating bone growth. According to its major aspects and broadly stated, the present invention consists of an electrical circuit configuration capable of generating Bassett-type waveforms shown with alternative signals provide for the treatment of either fractured bones or osteoporosis. The signal generator comprises a quartz clock, an oscillator circuit, a binary divider chain, and a plurality of simple, digital logic gates. Signals are delivered efficiently, with little or no distortion, and uniformly distributed throughout the area of injury. Perferably, power is furnished by widely available and inexpensive radio batteries, needing replacement only once in several days. The present invention can be affixed to a medical cast without a great increase in either weight or bulk. Also, the disclosed stimulator can be used to treat osteoporosis or to strengthen a healing bone after the cast has been removed by attaching the device to the patient`s skin or clothing.

  2. Hyperthermia stimulates HIV-1 replication.

    Directory of Open Access Journals (Sweden)

    Ferdinand Roesch

    Full Text Available HIV-infected individuals may experience fever episodes. Fever is an elevation of the body temperature accompanied by inflammation. It is usually beneficial for the host through enhancement of immunological defenses. In cultures, transient non-physiological heat shock (42-45°C and Heat Shock Proteins (HSPs modulate HIV-1 replication, through poorly defined mechanisms. The effect of physiological hyperthermia (38-40°C on HIV-1 infection has not been extensively investigated. Here, we show that culturing primary CD4+ T lymphocytes and cell lines at a fever-like temperature (39.5°C increased the efficiency of HIV-1 replication by 2 to 7 fold. Hyperthermia did not facilitate viral entry nor reverse transcription, but increased Tat transactivation of the LTR viral promoter. Hyperthermia also boosted HIV-1 reactivation in a model of latently-infected cells. By imaging HIV-1 transcription, we further show that Hsp90 co-localized with actively transcribing provirus, and this phenomenon was enhanced at 39.5°C. The Hsp90 inhibitor 17-AAG abrogated the increase of HIV-1 replication in hyperthermic cells. Altogether, our results indicate that fever may directly stimulate HIV-1 replication, in a process involving Hsp90 and facilitation of Tat-mediated LTR activity.

  3. Transdermal optogenetic peripheral nerve stimulation

    Science.gov (United States)

    Maimon, Benjamin E.; Zorzos, Anthony N.; Bendell, Rhys; Harding, Alexander; Fahmi, Mina; Srinivasan, Shriya; Calvaresi, Peter; Herr, Hugh M.

    2017-06-01

    Objective: A fundamental limitation in both the scientific utility and clinical translation of peripheral nerve optogenetic technologies is the optical inaccessibility of the target nerve due to the significant scattering and absorption of light in biological tissues. To date, illuminating deep nerve targets has required implantable optical sources, including fiber-optic and LED-based systems, both of which have significant drawbacks. Approach: Here we report an alternative approach involving transdermal illumination. Utilizing an intramuscular injection of ultra-high concentration AAV6-hSyn-ChR2-EYFP in rats. Main results: We demonstrate transdermal stimulation of motor nerves at 4.4 mm and 1.9 mm depth with an incident laser power of 160 mW and 10 mW, respectively. Furthermore, we employ this technique to accurately control ankle position by modulating laser power or position on the skin surface. Significance: These results have the potential to enable future scientific optogenetic studies of pathologies implicated in the peripheral nervous system for awake, freely-moving animals, as well as a basis for future clinical studies.

  4. Spatially selective photoconductive stimulation of live neurons

    Directory of Open Access Journals (Sweden)

    Jacob eCampbell

    2014-05-01

    Full Text Available Synaptic activity is intimately linked to neuronal structure and function. Stimulation of live cultured primary neurons, coupled with fluorescent indicator imaging, is a powerful technique to assess the impact of synaptic activity on neuronal protein trafficking and function. Current technology for neuronal stimulation in culture include chemical techniques or microelectrode or optogenetic based techniques. While technically powerful, chemical stimulation has limited spatial resolution and microelectrode and optogenetic techniques require specialized equipment and expertise. We report an optimized and improved technique for laser based photoconductive stimulation of live neurons using an inverted confocal microscope that overcomes these limitations. The advantages of this approach include its non-invasive nature and adaptability to temporal and spatial manipulation. We demonstrate that the technique can be manipulated to achieve spatially selective stimulation of live neurons. Coupled with live imaging of fluorescent indicators, this simple and efficient technique should allow for significant advances in neuronal cell biology.

  5. Adaptive deep brain stimulation in Parkinson's disease.

    Science.gov (United States)

    Beudel, M; Brown, P

    2016-01-01

    Although Deep Brain Stimulation (DBS) is an established treatment for Parkinson's disease (PD), there are still limitations in terms of effectivity, side-effects and battery consumption. One of the reasons for this may be that not only pathological but also physiological neural activity can be suppressed whilst stimulating. For this reason, adaptive DBS (aDBS), where stimulation is applied according to the level of pathological activity, might be advantageous. Initial studies of aDBS demonstrate effectiveness in PD, but there are still many questions to be answered before aDBS can be applied clinically. Here we discuss the feedback signals and stimulation algorithms involved in adaptive stimulation in PD and sketch a potential road-map towards clinical application. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Nanotechnology for Stimulating Osteoprogenitor Differentiation

    Science.gov (United States)

    Ibrahim, A.; Bulstrode, N.W.; Whitaker, I.S.; Eastwood, D.M.; Dunaway, D.; Ferretti, P.

    2016-01-01

    Background: Bone is the second most transplanted tissue and due to its complex structure, metabolic demands and various functions, current reconstructive options such as foreign body implants and autologous tissue transfer are limited in their ability to restore defects. Most tissue engineering approaches target osteoinduction of osteoprogenitor cells by modifying the extracellular environment, using scaffolds or targeting intracellular signaling mechanisms or commonly a combination of all of these. Whilst there is no consensus as to what is the optimal cell type or approach, nanotechnology has been proposed as a powerful tool to manipulate the biomolecular and physical environment to direct osteoprogenitor cells to induce bone formation. Methods: Review of the published literature was undertaken to provide an overview of the use of nanotechnology to control osteoprogenitor differentiation and discuss the most recent developments, limitations and future directions. Results: Nanotechnology can be used to stimulate osteoprogenitor differentiation in a variety of way. We have principally classified research into nanotechnology for bone tissue engineering as generating biomimetic scaffolds, a vector to deliver genes or growth factors to cells or to alter the biophysical environment. A number of studies have shown promising results with regards to directing ostroprogenitor cell differentiation although limitations include a lack of in vivo data and incomplete characterization of engineered bone. Conclusion: There is increasing evidence that nanotechnology can be used to direct the fate of osteoprogenitor and promote bone formation. Further analysis of the functional properties and long term survival in animal models is required to assess the maturity and clinical potential of this. PMID:28217210

  7. Cranial electrotherapy stimulation and fibromyalgia.

    Science.gov (United States)

    Gilula, Marshall F

    2007-07-01

    Cranial electrotherapy stimulation (CES) is a well-documented neuroelectrical modality that has been proven effective in some good studies of fibromyalgia (FM) patients. CES is no panacea but, for some FM patients, the modality can be valuable. This article discusses aspects of both CES and FM and how they relate to the individual with the condition. FM frequently has many comorbidities such as anxiety, depression, insomnia and a great variety of different rheumatologic and neurological symptoms that often resemble multiple sclerosis, dysautonomias, chronic fatigue syndrome and others. However, despite long-standing criteria from the American College of Rheumatology for FM, some physicians believe there is probably no single homogeneous condition that can be labeled as FM. Whether it is a disease, a syndrome or something else, sufferers feel like they are living one disaster after another. Active self-involvement in care usually enhances the therapeutic results of various treatments and also improves the patient's sense of being in control of the condition. D-ribose supplementation may prove to significantly enhance energy, sleep, mental clarity, pain control and well-being in FM patients. A form of evoked potential biofeedback, the EPFX, is a powerful stress reduction technique which assesses the chief stressors and risk factors for illness that can impede the FM patient's built-in healing abilities. Future healthcare will likely expand the diagnostic criteria of FM and/or illuminate a group of related conditions and the ways in which the conditions relate to each other. Future medicine for FM and related conditions may increasingly involve multimodality treatment that features CES as one significant part of the therapeutic regimen. Future medicine may also include CES as an invaluable, cost-effective add-on to many facets of clinical pharmacology and medical therapeutics.

  8. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation.

    Science.gov (United States)

    Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

    2015-07-16

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

  9. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    2015-07-01

    Full Text Available Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

  10. Surface-distributed low-frequency asynchronous stimulation delays fatigue of stimulated muscles.

    Science.gov (United States)

    Maneski, Lana Z Popović; Malešević, Nebojša M; Savić, Andrej M; Keller, Thierry; Popović, Dejan B

    2013-12-01

    One important reason why functional electrical stimulation (FES) has not gained widespread clinical use is the limitation imposed by rapid muscle fatigue due to non-physiological activation of the stimulated muscles. We aimed to show that asynchronous low-pulse-rate (LPR) electrical stimulation applied by multipad surface electrodes greatly postpones the occurrence of muscle fatigue compared with conventional stimulation (high pulse rate, HPR). We compared the produced force vs. time of the forearm muscles responsible for finger flexion in 2 stimulation protocols, LPR (fL = 10 Hz) and HPR (fH = 40 Hz). Surface-distributed low-frequency asynchronous stimulation (sDLFAS) doubles the time interval before the onset of fatigue (104 ± 80%) compared with conventional synchronous stimulation. Combining the performance of multipad electrodes (increased selectivity and facilitated positioning) with sDLFAS (decreased fatigue) can improve many FES applications in both the lower and upper extremities. Copyright © 2013 Wiley Periodicals, Inc.

  11. Smart control for functional electrical stimulation with optimal pulse intensity

    Directory of Open Access Journals (Sweden)

    Reinert Aljoscha

    2016-09-01

    Full Text Available Transcutaneous electrical stimulation is a common treatment option for patients suffering from spinal cord injury or stroke. Two major difficulties arise when employing electrical stimulation in patients: Accurate stimulation electrode placement and configuration of optimal stimulation parameters. Optimizing the stimulation parameters has the advantage to reduce muscle fatigue after repetitive stimulation. Here we present a newly developed system which is able to automatically find the optimal individual stimulation intensity by varying the pulse length. The effectiveness is measured with flex sensors. By adapting the stimulation parameters, the effect of muscle fatigue can be compensated, allowing for a more stable movement upon stimulation over time.

  12. Electrical stimulation to accelerate wound healing

    Science.gov (United States)

    Thakral, Gaurav; LaFontaine, Javier; Najafi, Bijan; Talal, Talal K.; Kim, Paul; Lavery, Lawrence A.

    2013-01-01

    Background There are several applications of electrical stimulation described in medical literature to accelerate wound healing and improve cutaneous perfusion. This is a simple technique that could be incorporated as an adjunctive therapy in plastic surgery. The objective of this review was to evaluate the results of randomized clinical trials that use electrical stimulation for wound healing. Method We identified 21 randomized clinical trials that used electrical stimulation for wound healing. We did not include five studies with treatment groups with less than eight subjects. Results Electrical stimulation was associated with faster wound area reduction or a higher proportion of wounds that healed in 14 out of 16 wound randomized clinical trials. The type of electrical stimulation, waveform, and duration of therapy vary in the literature. Conclusion Electrical stimulation has been shown to accelerate wound healing and increase cutaneous perfusion in human studies. Electrical stimulation is an adjunctive therapy that is underutilized in plastic surgery and could improve flap and graft survival, accelerate postoperative recovery, and decrease necrosis following foot reconstruction. PMID:24049559

  13. Transcranial magnetic stimulation intensities in cognitive paradigms.

    Directory of Open Access Journals (Sweden)

    Jakob A Kaminski

    Full Text Available BACKGROUND: Transcranial magnetic stimulation (TMS has become an important experimental tool for exploring the brain's functional anatomy. As TMS interferes with neural activity, the hypothetical function of the stimulated area can thus be tested. One unresolved methodological issue in TMS experiments is the question of how to adequately calibrate stimulation intensities. The motor threshold (MT is often taken as a reference for individually adapted stimulation intensities in TMS experiments, even if they do not involve the motor system. The aim of the present study was to evaluate whether it is reasonable to adjust stimulation intensities in each subject to the individual MT if prefrontal regions are stimulated prior to the performance of a cognitive paradigm. METHODS AND FINDINGS: Repetitive TMS (rTMS was applied prior to a working memory task, either at the 'fixed' intensity of 40% maximum stimulator output (MSO, or individually adapted at 90% of the subject's MT. Stimulation was applied to a target region in the left posterior middle frontal gyrus (pMFG, as indicated by a functional magnetic resonance imaging (fMRI localizer acquired beforehand, or to a control site (vertex. Results show that MT predicted the effect size after stimulating subjects with the fixed intensity (i.e., subjects with a low MT showed a greater behavioral effect. Nevertheless, the individual adaptation of intensities did not lead to stable effects. CONCLUSION: Therefore, we suggest assessing MT and account for it as a measure for general cortical TMS susceptibility, even if TMS is applied outside the motor domain.

  14. Mucus-stimulating factor in tears.

    Science.gov (United States)

    Franklin, R M; Bang, B G

    1980-04-01

    Mechanisms responsible for regulation of tear film mucus are poorly understood. Humoral factors responsible for stimulation of mucus secretion can be studied in vitro by using the free-swimming urn cell, a normal component of the coelomic fluid of the marine invertebrate Sipunculus nudus. With this system, a tear mucus-stimulating factor was found in normal human tears but was markedly decreased in patients with dry eye syndromes. It is suggested that a mucus-stimulating factor exists in normal human tears and that a decrease in this substance may be instrumental in the pathophysiology of certain dry eye syndromes.

  15. Stimulation Technologies for Deep Well Completions

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Wolhart

    2005-06-30

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies conducted a study to evaluate the stimulation of deep wells. The objective of the project was to review U.S. deep well drilling and stimulation activity, review rock mechanics and fracture growth in deep, high-pressure/temperature wells and evaluate stimulation technology in several key deep plays. This report documents results from this project.

  16. Controlling illegal stimulants: a regulated market model

    Directory of Open Access Journals (Sweden)

    Haden Mark

    2008-01-01

    Full Text Available Abstract Prohibition of illegal drugs is a failed social policy and new models of regulation of these substances are needed. This paper explores a proposal for a post-prohibition, public health based model for the regulation of the most problematic drugs, the smokable and injectable stimulants. The literature on stimulant maintenance is explored. Seven foundational principles are suggested that could support this regulatory model of drug control that would reduce both health and social problems related to illegal stimulants. Some details of this model are examined and the paper concludes that drug policies need to be subject to research and based on evidence.

  17. Innovations in deep brain stimulation methodology.

    Science.gov (United States)

    Kühn, Andrea A; Volkmann, Jens

    2017-01-01

    Deep brain stimulation is a powerful clinical method for movement disorders that no longer respond satisfactorily to pharmacological management, but its progress has been hampered by stagnation in technological procedure solutions and device development. Recently, the combined research efforts of bioengineers, neuroscientists, and clinicians have helped to better understand the mechanisms of deep brain stimulation, and solutions for the translational roadblock are emerging. Here, we define the needs for methodological advances in deep brain stimulation from a neurophysiological perspective and describe technological solutions that are currently evaluated for near-term clinical application. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  18. Anal sphincter responses after perianal electrical stimulation

    DEFF Research Database (Denmark)

    Pedersen, Ejnar; Klemar, B; Schrøder, H D

    1982-01-01

    not fatigued by repeated stimulation, were most dependent on placement of stimulating and recording electrodes, and always had a higher threshold than the third response. The third response was constantly present in normal subjects. It had the longest EMG response and the latency decreased with increasing......By perianal electrical stimulation and EMG recording from the external anal sphincter three responses were found with latencies of 2-8, 13-18 and 30-60 ms, respectively. The two first responses were recorded in most cases. They were characterised by constant latency and uniform pattern, were...

  19. Computational analysis of transcranial magnetic stimulation in the presence of deep brain stimulation probes

    Science.gov (United States)

    Syeda, F.; Holloway, K.; El-Gendy, A. A.; Hadimani, R. L.

    2017-05-01

    Transcranial Magnetic Stimulation is an emerging non-invasive treatment for depression, Parkinson's disease, and a variety of other neurological disorders. Many Parkinson's patients receive the treatment known as Deep Brain Stimulation, but often require additional therapy for speech and swallowing impairment. Transcranial Magnetic Stimulation has been explored as a possible treatment by stimulating the mouth motor area of the brain. We have calculated induced electric field, magnetic field, and temperature distributions in the brain using finite element analysis and anatomically realistic heterogeneous head models fitted with Deep Brain Stimulation leads. A Figure of 8 coil, current of 5000 A, and frequency of 2.5 kHz are used as simulation parameters. Results suggest that Deep Brain Stimulation leads cause surrounding tissues to experience slightly increased E-field (Δ Emax =30 V/m), but not exceeding the nominal values induced in brain tissue by Transcranial Magnetic Stimulation without leads (215 V/m). The maximum temperature in the brain tissues surrounding leads did not change significantly from the normal human body temperature of 37 °C. Therefore, we ascertain that Transcranial Magnetic Stimulation in the mouth motor area may stimulate brain tissue surrounding Deep Brain Stimulation leads, but will not cause tissue damage.

  20. Towards a Switched-Capacitor Based Stimulator for Efficient Deep-Brain Stimulation

    Science.gov (United States)

    Vidal, Jose; Ghovanloo, Maysam

    2013-01-01

    We have developed a novel 4-channel prototype stimulation circuit for implantable neurological stimulators (INS). This Switched-Capacitor based Stimulator (SCS) aims to utilize charge storage and charge injection techniques to take advantage of both the efficiency of conventional voltage-controlled stimulators (VCS) and the safety and controllability of current-controlled stimulators (CCS). The discrete SCS prototype offers fine control over stimulation parameters such as voltage, current, pulse width, frequency, and active electrode channel via a LabVIEW graphical user interface (GUI) when connected to a PC through USB. Furthermore, the prototype utilizes a floating current sensor to provide charge-balanced biphasic stimulation and ensure safety. The stimulator was analyzed using an electrode-electrolyte interface (EEI) model as well as with a pair of pacing electrodes in saline. The primary motivation of this research is to test the feasibility and functionality of a safe, effective, and power-efficient switched-capacitor based stimulator for use in Deep Brain Stimulation. PMID:21095987

  1. Dyslexia Treated by Hemisphere Stimulation Technic

    OpenAIRE

    J Gordon Millichap

    1997-01-01

    Results of treatment of severe dyslexia in 80 children, ages 6 to 15 years, using hemisphere stimulation technics, are reported from the outpatient Department for Dyslexia, Child Psychiatric Center, Paedological Institute, Amsterdam, The Netherlands.

  2. Neural adaptations to electrical stimulation strength training

    NARCIS (Netherlands)

    Hortobagyi, Tibor; Maffiuletti, Nicola A.

    2011-01-01

    This review provides evidence for the hypothesis that electrostimulation strength training (EST) increases the force of a maximal voluntary contraction (MVC) through neural adaptations in healthy skeletal muscle. Although electrical stimulation and voluntary effort activate muscle differently, there

  3. Rewiring neural interactions by micro-stimulation

    Directory of Open Access Journals (Sweden)

    James M Rebesco

    2010-08-01

    Full Text Available Plasticity is a crucial component of normal brain function and a critical mechanism for recovery from injury. In vitro, associative pairing of presynaptic spiking and stimulus-induced postsynaptic depolarization causes changes in the synaptic efficacy of the presynaptic neuron, when activated by extrinsic stimulation. In vivo, such paradigms can alter the responses of whole groups of neurons to stimulation. Here, we used in vivo spike-triggered stimulation to drive plastic changes in rat forelimb sensorimotor cortex, which we monitored using a statistical measure of functional connectivity inferred from the spiking statistics of the neurons during normal, spontaneous behavior. These induced plastic changes in inferred functional connectivity depended on the latency between trigger spike and stimulation, and appear to reflect a robust reorganization of the network. Such targeted connectivity changes might provide a tool for rerouting the flow of information through a network, with implications for both rehabilitation and brain-machine interface applications.

  4. Imbibition well stimulation via neural network design

    Science.gov (United States)

    Weiss, William

    2007-08-14

    A method for stimulation of hydrocarbon production via imbibition by utilization of surfactants. The method includes use of fuzzy logic and neural network architecture constructs to determine surfactant use.

  5. Stimulation Technologies for Deep Well Completions

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-09-30

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a study to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. An assessment of historical deep gas well drilling activity and forecast of future trends was completed during the first six months of the project; this segment of the project was covered in Technical Project Report No. 1. The second progress report covers the next six months of the project during which efforts were primarily split between summarizing rock mechanics and fracture growth in deep reservoirs and contacting operators about case studies of deep gas well stimulation.

  6. Transient effects on stimulated Brillouin scattering

    International Nuclear Information System (INIS)

    Faris, G.W.; Dyer, M.J.; Hickman, A.P.

    1992-01-01

    We present a detailed comparison of theory and experiment for transient stimulated Brillouin scattering for a pump pulse with Gaussian temporal profile. A new approach for measuring Brillouin linewidths is demonstrated, and an unexplained asymmetry is observed

  7. Treatment Pulse Application for Magnetic Stimulation

    Directory of Open Access Journals (Sweden)

    Sun-Seob Choi

    2011-01-01

    Full Text Available Treatment and diagnosis can be made in difficult areas simply by changing the output pulse form of the magnetic stimulation device. However, there is a limitation in the range of treatments and diagnoses of a conventional sinusoidal stimulation treatment pulse because the intensity, width, and form of the pulse must be changed according to the lesion type. This paper reports a multidischarge method, where the stimulation coils were driven in sequence via multiple switching control. The limitation of the existing simple sinusoidal pulse form could be overcome by changing the intensity, width, and form of the pulse. In this study, a new sequential discharge method was proposed to freely alter the pulse width. The output characteristics of the stimulation treatment pulse were examined according to the trigger signal delay applied to the switch at each stage by applying a range of superposition pulses to the magnetic simulation device, which is widely used in industry and medicine.

  8. Ethical issues in deep brain stimulation

    NARCIS (Netherlands)

    M.H.N. Schermer (Maartje)

    2011-01-01

    textabstractDeep brain stimulation (DBS) is currently used to treat neurological disorders like Parkinson's disease, essential tremor, and dystonia, and is explored as an experimental treatment for psychiatric disorders like major depression and obsessive compulsive disorder. This mini review

  9. Transcranial magnetic stimulation and the human brain

    Science.gov (United States)

    Hallett, Mark

    2000-07-01

    Transcranial magnetic stimulation (TMS) is rapidly developing as a powerful, non-invasive tool for studying the human brain. A pulsed magnetic field creates current flow in the brain and can temporarily excite or inhibit specific areas. TMS of motor cortex can produce a muscle twitch or block movement; TMS of occipital cortex can produce visual phosphenes or scotomas. TMS can also alter the functioning of the brain beyond the time of stimulation, offering potential for therapy.

  10. [Novel functional electrical stimulation for neurorehabilitation].

    Science.gov (United States)

    Hara, Yukihiro

    2010-02-01

    Our understanding of motor learning, neuroplasticity, and functional recovery after the occurrence of brain lesions has increased considerably. New findings in basic neuroscience have provided an impetus for research in motor rehabilitation. Several prospective studies have shown that repeated motor practice and motor activity in a real world environment have a favorable effect on motor recovery in stroke patients. Electrical stimulation can be applied in a variety of ways to the hemiparetic upper extremity following a stroke. In particular, electromyography (EMG)-triggered electrical muscle stimulation improves the motor function of the hemiparetic arm and hand. Triggered electrical stimulation is reported to be more effective than non-triggered electrical stimulation in facilitating upper extremity motor recovery after stroke. Power-assisted functional electrical stimulation (FES) induces greater muscle contraction by electrical stimulation that is in proportion to voluntary integrated EMG signals. Daily power-assisted FES home-program therapy with novel equipment has been shown to effectively improve wrist, finger extension, and shoulder flexion. Combined modulation of voluntary movement, proprioceptive sensory feedback, and electrical stimulation might play an important role in improving impaired sensory-motor integration by power-assisted FES therapy. A multi-channel near-infrared spectroscopy (NIRS) studies in which the hemoglobin levels in the brain were non-invasively and dynamically measured during functional activity found that the cerebral blood flow in the injured sensory-motor cortex area is greater during a power-assisted FES session than during simple active movement or simple electrical stimulation. A novel power-assisted FES sleeve (Cyberhand) has been developed for the rehabilitation of hemiplegic upper extremities.

  11. Brain stimulation methods to treat tobacco addiction.

    Science.gov (United States)

    Wing, Victoria C; Barr, Mera S; Wass, Caroline E; Lipsman, Nir; Lozano, Andres M; Daskalakis, Zafiris J; George, Tony P

    2013-05-01

    Tobacco smoking is the leading cause of preventable deaths worldwide, but many smokers are simply unable to quit. Psychosocial and pharmaceutical treatments have shown modest results on smoking cessation rates, but there is an urgent need to develop treatments with greater efficacy. Brain stimulation methods are gaining increasing interest as possible addiction therapeutics. The purpose of this paper is to review the studies that have evaluated brain stimulation techniques on tobacco addiction, and discuss future directions for research in this novel area of addiction interventions. Electronic and manual literature searches identified fifteen studies that administered repetitive transcranial magnetic stimulation (rTMS), cranial electrostimulation (CES), transcranial direct current stimulation (tDCS) or deep brain stimulation (DBS). rTMS was found to be the most well studied method with respect to tobacco addiction. Results indicate that rTMS and tDCS targeted to the dorsolateral prefrontal cortex (DLPFC) were the most efficacious in reducing tobacco cravings, an effect that may be mediated through the brain reward system involved in tobacco addiction. While rTMS was shown to reduce consumption of cigarettes, as yet no brain stimulation technique has been shown to significantly increase abstinence rates. It is possible that the therapeutic effects of rTMS and tDCS may be improved by optimization of stimulation parameters and increasing the duration of treatment. Although further studies are needed to confirm the ability of brain stimulation methods to treat tobacco addiction, this review indicates that rTMS and tDCS both represent potentially novel treatment modalities. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Unidirectional ephaptic stimulation between two myelinated axons.

    Science.gov (United States)

    Capllonch-Juan, Miguel; Kolbl, Florian; Sepulveda, Francisco

    2017-07-01

    Providing realistic sensory feedback for prosthetic devices strongly relies on an accurate modelling of machine-nerve interfaces. Models of these interfaces in the peripheral nervous system usually neglect the effects that ephaptic coupling can have on the selectivity of stimulating electrodes. In this contribution, we study the ephaptic stimulation between myelinated axons and show its relation with the separation between fibers and the conductivity of the medium that surrounds them.

  13. Considering optogenetic stimulation for cochlear implants.

    Science.gov (United States)

    Jeschke, Marcus; Moser, Tobias

    2015-04-01

    Electrical cochlear implants are by far the most successful neuroprostheses and have been implanted in over 300,000 people worldwide. Cochlear implants enable open speech comprehension in most patients but are limited in providing music appreciation and speech understanding in noisy environments. This is generally considered to be due to low frequency resolution as a consequence of wide current spread from stimulation contacts. Accordingly, the number of independently usable stimulation channels is limited to less than a dozen. As light can be conveniently focused, optical stimulation might provide an alternative approach to cochlear implants with increased number of independent stimulation channels. Here, we focus on summarizing recent work on optogenetic stimulation as one way to develop optical cochlear implants. We conclude that proof of principle has been presented for optogenetic stimulation of the cochlea and central auditory neurons in rodents as well as for the technical realization of flexible μLED-based multichannel cochlear implants. Still, much remains to be done in order to advance the technique for auditory research and even more for eventual clinical translation. This article is part of a Special Issue entitled . Copyright © 2015. Published by Elsevier B.V.

  14. [Prenatal stimulation: results in the peripartum period].

    Science.gov (United States)

    Aguilar Cordero, M J; Vieite Ravelo, M; Padilla López, C A; Mur Villar, N; Rizo Baeza, M; Gómez García, C I

    2012-01-01

    During pregnancy, the prolonged stress and worry felt by mothers can alter the development and function of the right brain hemisphere. For this reason, importance is given to prenatal stimulation programs for pregnant women. To determine the perinatal results in the moment of childbirth in mothers who had participated in prenatal stimulation programs. An experimental study was conducted in five health districts in the town of Cienfuegos (Cuba) with a view to identifying the perinatal results at the moment of childbirth in women that had participated in prenatal stimulation programs. The study consisted of an intentional sampling of all of the subjects (n = 200 women who were 20-28 weeks pregnant). The variables studied were the following: duration of labor, baby's birth weight, Apgar score at birth, type of childbirth, and opinion of the subjects about the prenatal stimulation program. Of the population sample, 36% of the subjects gave birth in less than six hours; 67.5% had babies weighing 2,500-3,000 grams; and 96.5% had babies whose Apgar scores were between 8 and 9. Finally, 68.5% of the subjects had natural childbirths and 96% were satisfied with the prenatal stimulation program. The results obtained showed that these new prenatal stimulation programs were well received by the subjects in this study.

  15. Some Motivational Properties of Sensory Stimulation in Psychotic Children

    Science.gov (United States)

    Rincover, Arnold; And Others

    1977-01-01

    This experiment assessed the reinforcing properties of sensory stimulation for autistic children using three different types of sensory stimulation: music, visual flickering, and visual movement. (SB)

  16. Initial activation state, stimulation intensity and timing of stimulation interact in producing behavioral effects of TMS

    OpenAIRE

    Silvanto, Juha; Bona, Silvia; Cattaneo, Zaira

    2017-01-01

    Behavioral effects of transcranial magnetic stimulation (TMS) have been shown to depend on various factors, such as neural activation state, stimulation intensity, and timing of stimulation. Here we examined whether these factors interact, by applying TMS at either sub- or suprathreshold intensity (relative to phosphene threshold, PT) and at different time points during a state-dependent TMS paradigm. The state manipulation involved a behavioral task in which a visual prime (color grating) wa...

  17. The Codacs™ direct acoustic cochlear implant actuator: exploring alternative stimulation sites and their stimulation efficiency.

    Directory of Open Access Journals (Sweden)

    Martin Grossöhmichen

    Full Text Available This work assesses the efficiency of the Codacs system actuator (Cochlear Ltd., Sydney Australia in different inner ear stimulation modalities. Originally the actuator was intended for direct perilymph stimulation after stapedotomy using a piston prosthesis. A possible alternative application is the stimulation of middle ear structures or the round window (RW. Here the perilymph stimulation with a K-piston through a stapes footplate (SFP fenestration (N = 10 as well as stimulation of the stapes head (SH with a Bell prosthesis (N = 9, SFP stimulation with an Omega/Aerial prosthesis (N = 8 and reverse RW stimulation (N = 10 were performed in cadaveric human temporal bones (TBs. Codacs actuator output is expressed as equivalent sound pressure level (eq. SPL using RW and SFP displacement responses, measured by Laser Doppler velocimetry as reference. The axial actuator coupling force in stimulation of stapes and RW was adjusted to ~5 mN. The Bell prosthesis and Omega/Aerial prosthesis stimulation generated similar mean eq. SPLs (Bell: 127.5-141.8 eq. dB SPL; Omega/Aerial: 123.6-143.9 eq. dB SPL, being significantly more efficient than K-piston perilymph stimulation (108.6-131.6 eq. dB SPL and RW stimulation (108.3-128.2 eq. dB SPL. Our results demonstrate that SH, SFP and RW are adequate alternative stimulation sites for the Codacs actuator using coupling prostheses and an axial coupling force of ~5 mN. Based on the eq. SPLs, all investigated methods were adequate for in vivo hearing aid applications, provided that experimental conditions including constant coupling force will be implemented.

  18. Stimulating at the right time: phase-specific deep brain stimulation.

    Science.gov (United States)

    Cagnan, Hayriye; Pedrosa, David; Little, Simon; Pogosyan, Alek; Cheeran, Binith; Aziz, Tipu; Green, Alexander; Fitzgerald, James; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Friston, Karl J; Denison, Timothy; Brown, Peter

    2017-01-01

    SEE MOLL AND ENGEL DOI101093/AWW308 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Brain regions dynamically engage and disengage with one another to execute everyday actions from movement to decision making. Pathologies such as Parkinson's disease and tremor emerge when brain regions controlling movement cannot readily decouple, compromising motor function. Here, we propose a novel stimulation strategy that selectively regulates neural synchrony through phase-specific stimulation. We demonstrate for the first time the therapeutic potential of such a stimulation strategy for the treatment of patients with pathological tremor. Symptom suppression is achieved by delivering stimulation to the ventrolateral thalamus, timed according to the patient's tremor rhythm. Sustained locking of deep brain stimulation to a particular phase of tremor afforded clinically significant tremor relief (up to 87% tremor suppression) in selected patients with essential tremor despite delivering less than half the energy of conventional high frequency stimulation. Phase-specific stimulation efficacy depended on the resonant characteristics of the underlying tremor network. Selective regulation of neural synchrony through phase-locked stimulation has the potential to both increase the efficiency of therapy and to minimize stimulation-induced side effects. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

  19. Brain stimulation in posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Vladan Novakovic

    2011-10-01

    Full Text Available Posttraumatic stress disorder (PTSD is a complex, heterogeneous disorder that develops following trauma and often includes perceptual, cognitive, affective, physiological, and psychological features. PTSD is characterized by hyperarousal, intrusive thoughts, exaggerated startle response, flashbacks, nightmares, sleep disturbances, emotional numbness, and persistent avoidance of trauma-associated stimuli. The efficacy of available treatments for PTSD may result in part from relief of associated depressive and anxiety-related symptoms in addition to treatment of core symptoms that derive from reexperiencing, numbing, and hyperarousal. Diverse, heterogeneous mechanisms of action and the ability to act broadly or very locally may enable brain stimulation devices to address PTSD core symptoms in more targeted ways. To achieve this goal, specific theoretical bases derived from novel, well-designed research protocols will be necessary. Brain stimulation devices include both long-used and new electrical and magnetic devices. Electroconvulsive therapy (ECT and Cranial electrotherapy stimulation (CES have both been in use for decades; transcranial magnetic stimulation (TMS, magnetic seizure therapy (MST, deep brain stimulation (DBS, transcranial Direct Current Stimulation (tDCS, and vagus nerve stimulation (VNS have been developed recently, over approximately the past twenty years. The efficacy of brain stimulation has been demonstrated as a treatment for psychiatric and neurological disorders such as anxiety (CES, depression (ECT, CES, rTMS, VNS, DBS, obsessive-compulsive disorder (OCD (DBS, essential tremor, dystonia (DBS, epilepsy (DBS, VNS, Parkinson Disease (DBS, pain (CES, and insomnia (CES. To date, limited data on brain stimulation for PTSD offer only modest guidance. ECT has shown some efficacy in reducing comorbid depression in PTSD patients but has not been demonstrated to improve most core PTSD symptoms. CES and VNS have shown some efficacy in

  20. Mechanism of adrenergic stimulation of hepatic ketogenesis.

    Science.gov (United States)

    Kosugi, K; Harano, Y; Nakano, T; Suzuki, M; Kashiwagi, A; Shigeta, Y

    1983-11-01

    The effects of alpha- and beta-adrenergic stimulation on ketogenesis were examined in freshly isolated rat hepatocytes in order to determine which alpha- or beta-adrenergic stimulation is involved in the enhancement of ketogenesis. In the presence of 0.3 mmol/L (U-14C)-palmitate, epinephrine, norepinephrine, and phenylephrine at 500 ng/mL increased ketogenesis by 25% (16.0 +/- 0.17 v 12.8 +/- 0.13 nmol/mg protein per hour), 20% (15.3 +/- 0.28) and 20% (15.4 +/- 0.36), respectively. However, isoproterenol even at 1 microgram/mL did not stimulate ketogenesis. Phentolamine (5 micrograms/mL) almost completely abolished the effect of epinephrine on ketogenesis (13.7 +/- 0.30 v 16.0 +/- 0.17) but propranolol did not inhibit the stimulation by epinephrine (15.6 +/- 0.38 v 16.0 +/- 0.17). Trifluoperazine (10 mumol/L), presumably an inhibitor of calcium-dependent protein kinase, abolished the effect of epinephrine (13.6 +/- 0.22 v 16.0 +/- 0.17). These results indicate that catecholamines increase ketogenesis predominantly through the alpha-adrenergic system independent of cyclic AMP, and calcium-dependent protein kinase is thought to be involved in the activation of ketogenesis. On the other hand, glucagon stimulated ketogenesis with an increase of cyclic AMP, which was not inhibited by alpha- and beta-adrenergic antagonists. Alpha-adrenergic stimulation increased hepatic glycogenolysis much more at much lower concentrations when compared with ketogenesis. Stimulation of ketogenesis by catecholamines seemed to be less sensitive and responsive compared with hepatic glycogenolysis.

  1. Vagus nerve stimulation improves working memory performance.

    Science.gov (United States)

    Sun, Lihua; Peräkylä, Jari; Holm, Katri; Haapasalo, Joonas; Lehtimäki, Kai; Ogawa, Keith H; Peltola, Jukka; Hartikainen, Kaisa M

    2017-12-01

    Vagus nerve stimulation (VNS) is used for treating refractory epilepsy and major depression. While the impact of this treatment on seizures has been established, its impact on human cognition remains equivocal. The goal of this study is to elucidate the immediate effects of vagus nerve stimulation on attention, cognition, and emotional reactivity in patients with epilepsy. Twenty patients (12 male and 8 female; 45 ± 13 years old) treated with VNS due to refractory epilepsy participated in the study. Subjects performed a computer-based test of executive functions embedded with emotional distractors while their brain activity was recorded with electroencephalography. Subjects' cognitive performance, early visual event-related potential N1, and frontal alpha asymmetry were studied when cyclic vagus nerve stimulation was on and when it was off. We found that vagus nerve stimulation improved working memory performance as seen in reduced errors on a subtask that relied on working memory, odds ratio (OR) = 0.63 (95% confidence interval, CI [0.47, 0.85]) and increased N1 amplitude, F(1, 15) = 10.17, p = .006. In addition, vagus nerve stimulation resulted in longer reaction time, F(1, 16) = 8.23, p = .019, and greater frontal alpha asymmetry, F(1, 16) = 11.79, p = .003, in response to threat-related distractors. This is the first study to show immediate improvement in working memory performance in humans with clinically relevant vagus nerve stimulation. Furthermore, vagus nerve stimulation had immediate effects on emotional reactivity evidenced in behavior and brain physiology.

  2. Stimulation of Cl(-) secretion by chlorzoxazone.

    Science.gov (United States)

    Singh, A K; Devor, D C; Gerlach, A C; Gondor, M; Pilewski, J M; Bridges, R J

    2000-02-01

    We previously demonstrated that 1-ethyl-2-benzimidazolone (1-EBIO) directly activates basolateral membrane calcium-activated K(+) channels (K(Ca)), thereby stimulating Cl(-) secretion across several epithelia. In our pursuit to identify potent modulators of Cl(-) secretion that may be useful to overcome the Cl(-) secretory defect in cystic fibrosis (CF), we have identified chlorzoxazone [5-chloro-2(3H)-benzoxazolone], a clinically used centrally acting muscle relaxant, as a stimulator of Cl(-) secretion in several epithelial cell types, including T84, Calu-3, and human bronchial epithelium. The Cl(-) secretory response induced by chlorzoxazone was blocked by charybdotoxin (CTX), a known blocker of K(Ca). In nystatin-permeabilized monolayers, chlorzoxazone stimulated a basolateral membrane I(K), which was inhibited by CTX and also stimulated an apical I(Cl) that was inhibited by glibenclamide, indicating that the G(Cl) responsible for this I(Cl) may be cystic fibrosis transmembrane conductance regulator (CFTR). In membrane vesicles prepared from T84 cells, chlorzoxazone stimulated (86)Rb(+) uptake in a CTX-sensitive manner. In excised, inside-out patches, chlorzoxazone activated an inwardly-rectifying K(+) channel, which was inhibited by CTX. 6-Hydroxychlorzoxazone, the major metabolite of chlorzoxazone, did not activate K(Ca), whereas zoxazolamine (2-amino-5-chlorzoxazole) showed a similar response profile as chlorzoxazone. In normal human nasal epithelium, chlorzoxazone elicited hyperpolarization of the potential difference that was similar in magnitude to isoproterenol. However, in the nasal epithelium of CF patients with the DeltaF508 mutation of CFTR, there was no detectable Cl(-) secretory response to chlorzoxazone. These studies demonstrate that chlorzoxazone stimulates transepithelial Cl(-) secretion in normal airway epithelium in vitro and in vivo, and suggest that stimulation requires functional CFTR in the epithelia.

  3. In vitro magnetic stimulation: a simple stimulation device to deliver defined low intensity electromagnetic fields

    Directory of Open Access Journals (Sweden)

    Stephanie Grehl

    2016-11-01

    Full Text Available Non-invasive electromagnetic field brain stimulation (NIBS appears to benefit human neurological and psychiatric conditions, although the optimal stimulation parameters and underlying mechanisms remain unclear. Although in vitro studies have begun to elucidate cellular mechanisms, stimulation is delivered by a range of coils (from commercially available human stimulation coils to laboratory-built circuits so that the electromagnetic fields induced within the tissue to produce the reported effects are ill-defined.Here we develop a simple in vitro stimulation device with plug-and-play features that allow delivery of a range of stimulation parameters. We chose to test low intensity repetitive magnetic stimulation (LI-rMS delivered at 3 frequencies to hindbrain explant cultures containing the olivocerebellar pathway. We used computational modelling to define the parameters of a stimulation circuit and coil that deliver a unidirectional homogeneous magnetic field of known intensity and direction, and therefore a predictable electric field, to the target. We built the coil to be compatible with culture requirements: stimulation within an incubator; a flat surface allowing consistent position and magnetic field direction; location outside the culture plate to maintain sterility and no heating or vibration. Measurements at the explant confirmed the induced magnetic field was homogenous and matched the simulation results. To validate our system we investigated biological effects following LI-rMS at 1 Hz, 10 Hz and biomimetic high frequency (BHFS, which we have previously shown induces neural circuit reorganisation. We found that gene expression was modified by LI-rMS in a frequency-related manner. Four hours after a single 10-minute stimulation session, the number of c-fos positive cells increased, indicating that our stimulation activated the tissue. Also, after 14 days of LI-rMS, the expression of genes normally present in the tissue was differentially

  4. Adjacent stimulation and measurement patterns considered harmful

    International Nuclear Information System (INIS)

    Adler, Andy; Maimaitijiang, Yasheng; Gaggero, Pascal Olivier

    2011-01-01

    We characterize the ability of electrical impedance tomography (EIT) to distinguish changes in internal conductivity distributions, and analyze it as a function of stimulation and measurement patterns. A distinguishability measure, z, is proposed which is related to the signal-to-noise ratio of a medium and to the probability of detection of conductivity changes in a region of interest. z is a function of the number of electrodes, the EIT stimulation and measurement protocol, the stimulation amplitude, the measurement noise, and the size and location of the contrasts. Using this measure we analyze various choices of stimulation and measurement patterns under the constraint of medical electrical safety limits (maximum current into the body). Analysis is performed for a planar placement of 16 electrodes for simulated 3D tank and chest shapes, and measurements in a saline tank. Results show that the traditional (and still most common) adjacent stimulation and measurement patterns have by far the poorest performance (by 6.9 ×). Good results are obtained for trigonometric patterns and for pair drive and measurement patterns separated by over 90°. Since the possible improvement over adjacent patterns is so large, we present this result as a call to action: adjacent patterns are harmful, and should be abandoned. We recommend using pair drive and measurement patterns separated by one electrode less than 180°. We describe an approach to modify an adjacent pattern EIT system by adjusting electrode placement

  5. Stimulants for the control of hedonic appetite

    Directory of Open Access Journals (Sweden)

    Alison Sally Poulton

    2016-04-01

    Full Text Available The focus of this paper is treatment of obesity in relation to the management of hedonic appetite. Obesity is a complex condition which may be potentiated by excessive reward seeking in combination with executive functioning deficits that impair cognitive control of behaviour. Stimulant medications address both reward deficiency and enhance motivation, as well as suppressing appetite. They have long been recognised to be effective for treating obesity. However, stimulants can be abused for their euphoric effect. They induce euphoria via the same neural pathway that underlies their therapeutic effect in obesity. For this reason they have generally not been endorsed for use in obesity. Among the stimulants, only phentermine (either alone or in combination with topiramate and bupropion (which has stimulant-like properties and is used in combination with naltrexone, are approved by the United States Food and Drug Administration (FDA for obesity, although dexamphetamine and methylpenidate are approved and widely used for treating attention deficit hyperactivity disorder (ADHD in adults and children. Experience gained over many years in the treatment of ADHD demonstrates that with careful dose titration, stimulants can be used safely. In obesity, improvement in mood and executive functioning could assist with the lifestyle changes necessary for weight control, acting synergistically with appetite suppression. The obesity crisis has reached the stage that strong consideration should be given to adequate utilisation of this effective and inexpensive class of drug.

  6. Vestibular stimulation for management of premenstrual syndrome.

    Science.gov (United States)

    Johny, Minu; Kumar, Sai Sailesh; Rajagopalan, Archana; Mukkadan, Joseph Kurien

    2017-01-01

    The present study was undertaken to observe the effectiveness of vestibular stimulation in the management of premenstrual syndrome (PMS). The present study was an experimental study; twenty female participants of age group 18-30 years were recruited in the present study. Conventional swing was used to administer vestibular stimulation. Variables were recorded before and after vestibular stimulation and compared. Depression and stress scores are significantly decreased after 2 months of intervention. Anxiety scores decreased followed by vestibular stimulation. However, it is no statistically significant. Serum cortisol levels significantly decreased after 2 months of intervention. WHOQOL-BREF-transformed scores were not significantly changed followed by the intervention. However, psychological domain score (T2) and social relationships domain score (T3) were increased followed by intervention. Systolic blood pressure was significantly decreased after 2 months of intervention. No significant change was observed in diastolic pressure and pulse rate. Pain score was significantly decreased after 2 months of intervention. Mini mental status examination scores and spatial and verbal memory score were significantly improved followed by intervention. The present study provides preliminary evidence for implementing vestibular stimulation for management of PMS as a nonpharmacological therapy. Hence, we recommend further well-controlled, detailed studies in this area with higher sample size.

  7. Stimulant and sedative effects of alcohol.

    Science.gov (United States)

    Hendler, Reuben A; Ramchandani, Vijay A; Gilman, Jodi; Hommer, Daniel W

    2013-01-01

    Alcohol produces both stimulant and sedating effects in humans. These two seemingly opposite effects are central to the understanding of much of the literature on alcohol use and misuse. In this chapter we review studies that describe and attempt to measure various aspects of alcohol's subjective, autonomic, motor, cognitive and behavioral effects from the perspective of stimulation and sedation. Although subjective sedative and stimulatory effects can be measured, it is not entirely clear if all motor, cognitive and behavioral effects can be unambiguously assigned to either one or the other category. Increased heart rate and aggression seem strongly associated with stimulation, but motor slowing and cognitive impairment can also show a similar time course to stimulation, making their relation to sedation problematic. There is good agreement that alcohol's ability to induce striatal dopamine release is the mechanism underlying alcohol's stimulatory effects; however, the change in brain function underlying sedation is less well understood. In general, stimulatory effects are thought to be more rewarding than sedative effects, but this may not be true for anxiolytic effects which seem more closely related to sedation than stimulation. The two major theories of how response to alcohol predicts risk for alcoholism both postulate that individuals at high risk for alcohol use disorders have a reduced sedative response to alcohol compared to individuals not at high risk. In addition one theory proposes that alcoholism risk is also associated with a larger stimulatory response to alcohol.

  8. Stimulation of suicidal erythrocyte death by sulforaphane.

    Science.gov (United States)

    Alzoubi, Kousi; Calabrò, Salvatrice; Faggio, Caterina; Lang, Florian

    2015-03-01

    Sulforaphane, an isothiocyanate from cruciferous vegetable, counteracts malignancy. The effect is at least in part due to the stimulation of suicidal death or apoptosis of tumour cells. Mechanisms invoked in sulforaphane-induced apoptosis include mitochondrial depolarization and altered gene expression. Despite the lack of mitochondria and nuclei, erythrocytes may, similar to apoptosis of nucleated cells, enter eryptosis, a suicidal cell death characterized by cell shrinkage and phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca(2+)-activity ([Ca(2+)]i). This study explored whether sulforaphane stimulates eryptosis. Cell volume was estimated from forward scatter, phosphatidylserine exposure at the cell surface from annexin V binding and [Ca(2+)]i from Fluo-3 fluorescence. A 48-hr treatment of human erythrocytes with sulforaphane (50-100 μM) significantly decreased forward scatter, significantly increased the percentage of annexin V binding cells and significantly increased [Ca(2+)]i. The effect of sulforaphane (100 μM) on annexin V binding was significantly blunted but not abrogated by the removal of extracellular Ca(2+). Sulforaphane (100 μM) significantly increased ceramide formation. In conclusion, sulforaphane stimulates suicidal erythrocyte death or eryptosis, an effect at least partially, but not exclusively, due to the stimulation of Ca(2+) entry and ceramide formation. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  9. Technological Advances in Deep Brain Stimulation.

    Science.gov (United States)

    Ughratdar, Ismail; Samuel, Michael; Ashkan, Keyoumars

    2015-01-01

    Functional and stereotactic neurosurgery has always been regarded as a subspecialty based on and driven by technological advances. However until recently, the fundamentals of deep brain stimulation (DBS) hardware and software design had largely remained stagnant since its inception almost three decades ago. Recent improved understanding of disease processes in movement disorders as well clinician and patient demands has resulted in new avenues of development for DBS technology. This review describes new advances both related to hardware and software for neuromodulation. New electrode designs with segmented contacts now enable sophisticated shaping and sculpting of the field of stimulation, potentially allowing multi-target stimulation and avoidance of side effects. To avoid lengthy programming sessions utilising multiple lead contacts, new user-friendly software allows for computational modelling and individualised directed programming. Therapy delivery is being improved with the next generation of smaller profile, longer-lasting, re-chargeable implantable pulse generators (IPGs). These include IPGs capable of delivering constant current stimulation or personalised closed-loop adaptive stimulation. Post-implantation Magnetic Resonance Imaging (MRI) has long been an issue which has been partially overcome with 'MRI conditional devices' and has enabled verification of DBS lead location. Surgical technique is considering a shift from frame-based to frameless stereotaxy or greater role for robot assisted implantation. The challenge for these contemporary techniques however, will be in demonstrating equivalent safety and accuracy to conventional methods. We also discuss potential future direction utilising wireless technology allowing for miniaturisation of hardware.

  10. Deep brain stimulation: how does it work?

    Science.gov (United States)

    Agnesi, Filippo; Johnson, Matthew D; Vitek, Jerrold L

    2013-01-01

    Chronic deep brain stimulation (DBS) has become a widely accepted surgical treatment for medication-refractory movement disorders and is under evaluation for a variety of neurological disorders. In order to create opportunities to improve treatment efficacy, streamline parameter selection, and foster new potential applications, it is important to have a clear and comprehensive understanding of how DBS works. Although early hypothesis proposed that high-frequency electrical stimulation inhibited neuronal activity proximal to the active electrode, recent studies have suggested that the output of the stimulated nuclei is paradoxically activated by DBS. Such regular, time-locked output is thought to override the transmission of pathological bursting and oscillatory activity through the stimulated nuclei, as well as inducing synaptic plasticity and network reorganization. This chapter reviews electrophysiological experiments, biochemical analyses, computer modeling and imaging studies positing that, although general principles exist, the therapeutic mechanism(s) of action depend both on the site of stimulation and on the disorder being treated. © 2013 Elsevier B.V. All rights reserved.

  11. Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead

    NARCIS (Netherlands)

    van Dijk, Kees J.; Verhagen, Rens; Bour, Lo J.; Heida, Ciska; Veltink, Peter H.

    2017-01-01

    Objective: Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of

  12. Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead

    NARCIS (Netherlands)

    van Dijk, Kees J.; Verhagen, Rens; Bour, Lo J.; Heida, Ciska; Veltink, Peter H.

    2017-01-01

    Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of this study

  13. 21 CFR 862.1690 - Thyroid stimulating hormone test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Thyroid stimulating hormone test system. 862.1690... Systems § 862.1690 Thyroid stimulating hormone test system. (a) Identification. A thyroid stimulating hormone test system is a device intended to measure thyroid stimulating hormone, also known as...

  14. 21 CFR 882.5860 - Implanted neuromuscular stimulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted neuromuscular stimulator. 882.5860... neuromuscular stimulator. (a) Identification. An implanted neuromuscular stimulator is a device that provides... Administration on or before July 13, 1999 for any implanted neuromuscular stimulator that was in commercial...

  15. 21 CFR 882.5820 - Implanted cerebellar stimulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted cerebellar stimulator. 882.5820 Section... (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5820 Implanted cerebellar stimulator. (a) Identification. An implanted cerebellar stimulator is a device used to stimulate...

  16. An Implantable Mixed Analog/Digital Neural Stimulator Circuit

    DEFF Research Database (Denmark)

    Gudnason, Gunnar; Bruun, Erik; Haugland, Morten

    1999-01-01

    This paper describes a chip for a multichannel neural stimulator for functional electrical stimulation. The chip performs all the signal processing required in an implanted neural stimulator. The power and signal transmission to the stimulator is carried out via an inductive link. From the signal...

  17. Early experiences with tachycardia-triggered vagus nerve stimulation using the AspireSR stimulator.

    Science.gov (United States)

    El Tahry, Riëm; Hirsch, Martin; Van Rijckevorsel, Kenou; Santos, Susana Ferrao; de Tourtchaninoff, Marianne; Rooijakkers, Herbert; Coenen, Volker; Schulze-Bonhage, Andreas

    2016-06-01

    Many epilepsy patients treated with vagus nerve stimulation additionally use an "on-demand" function, triggering an extra stimulation to terminate a seizure or diminish its severity. Nevertheless, a substantial number of patients are not able to actively trigger stimulations by use of a magnet, due to the absence of an aura or inability for voluntary actions in the early phase of a seizure. To address this need, a novel implantable pulse generator, the AspireSR VNS system, was developed to provide automated ictal stimulation triggered by a seizure-detecting algorithm. We report our experience with three patients in assessing the functionality of ictal stimulation, illustrating the detection system in practice. Detection of ictal tachycardia and variable additional detections of physiological tachycardia depended on the individual seizure-detecting algorithm settings.

  18. Thermally stimulated currents in gamma irradiated polymer

    International Nuclear Information System (INIS)

    Chu, S.S.

    1982-01-01

    Thermally stimulated currents of polymers have some properties as radiation dosimetry, especially polymer could be made as a good dosimeter in biological fields because of tissue equivlent material. We experimented the radiation response of polymers and attempted to apply it in clinical use. Polymers have properties of thermoluminescence and thermally stimulated currents which are due to several kinds of charged particles such as dipoles, electronic trapped charges and mobile ions. Several peaks are detected in the thermally stimulated currents in polyethylene under vias field V, by heating from room temperature to 100degC shortly after irradiation. As V increases, both the peak temperature Tsub(m) and the activation energy H decreases, while the peak current Isub(m) increases. We plotted the Tsub(m)-V and Isub(m)-V curves and calculated the electron trap depth with the recombination operative TSC theory and compared the peak TSC with radiation doses. (Author)

  19. Evaluation of Galvanic Vestibular Stimulation System

    Science.gov (United States)

    Kofman, I. S.; Warren, E.; DeSoto, R.; Moroney, G.; Chastain, J.; De Dios, Y. E.; Gadd, N.; Taylor, L.; Peters, B. T.; Allen, E.; hide

    2017-01-01

    Microgravity exposure results in an adaptive central reinterpretation of information from multiple sensory sources to produce a sensorimotor state appropriate for motor actions in this unique environment, but this new adaptive state is no longer appropriate for the 1-g gravitational environment on Earth. During these gravitational transitions, astronauts experience deficits in both perceptual and motor functions including impaired postural control, disruption in spatial orientation, impaired control of locomotion that include alterations in muscle activation variability, modified lower limb kinematics, alterations in head-trunk coordination as well as reduced dynamic visual acuity. Post-flight changes in postural and locomotor control might have adverse consequences if a rapid egress was required following a long-duration mission, where support personnel may not be available to aid crewmembers. The act of emergency egress includes, but is not limited to standing, walking, climbing a ladder, jumping down, monitoring displays, actuating discrete controls, operating auxiliary equipment, and communicating with Mission Control and recovery teams while maintaining spatial orientation, mobility and postural stability in order to escape safely. The average time to recover impaired postural control and functional mobility to preflight levels of performance has been shown to be approximately two weeks after long-duration spaceflight. The postflight alterations are due in part to central reinterpretation of vestibular information caused by exposure to microgravity. In this study we will use a commonly used technique of transcutaneous electrical stimulation applied across the vestibular end organs (galvanic vestibular stimulation, GVS) to disrupt vestibular function as a simulation of post-flight disturbances. The goal of this project is an engineering human-in-the-loop evaluation of a device that can degrade performance of functional tasks (e.g. to maintain upright balance

  20. Gender and injuries predict stimulant medication

    DEFF Research Database (Denmark)

    Dalsgaard, Søren; Leckman, James F.; Nielsen, Helena Skyt

    2014-01-01

    Objective: The purpose of this article was to examine whether injuries in early childhood and gender predict prescriptions of stimulant medication in three groups of children: With attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and other psychiatric disorders (OPD...... follow-up of all cases. We found that the number of injuries prior to diagnosis was associated with initiation of stimulant treatment in all three groups of patients. In addition, male gender predicted treatment with ADHD medications. Our results suggest that the number of injuries early in life prior......). Methods: This was a population-based study with prospective and complete follow-up of children with ADHD (n=11,553), ASD (n=9698), and OPD (n=48,468), of whom 61%, 16%, and 3%, respectively, were treated with stimulants. For all 69,719 individual children data on psychiatric diagnoses, injuries, and drug...

  1. Magnetic fields in noninvasive brain stimulation.

    Science.gov (United States)

    Vidal-Dourado, Marcos; Conforto, Adriana Bastos; Caboclo, Luis Otávio Sales Ferreira; Scaff, Milberto; Guilhoto, Laura Maria de Figueiredo Ferreira; Yacubian, Elza Márcia Targas

    2014-04-01

    The idea that magnetic fields could be used therapeutically arose 2000 years ago. These therapeutic possibilities were expanded after the discovery of electromagnetic induction by the Englishman Michael Faraday and the American Joseph Henry. In 1896, Arsène d'Arsonval reported his experience with noninvasive brain magnetic stimulation to the scientific French community. In the second half of the 20th century, changing magnetic fields emerged as a noninvasive tool to study the nervous system and to modulate neural function. In 1985, Barker, Jalinous, and Freeston presented transcranial magnetic stimulation, a relatively focal and painless technique. Transcranial magnetic stimulation has been proposed as a clinical neurophysiology tool and as a potential adjuvant treatment for psychiatric and neurologic conditions. This article aims to contextualize the progress of use of magnetic fields in the history of neuroscience and medical sciences, until 1985.

  2. Pathways of translation: deep brain stimulation.

    Science.gov (United States)

    Gionfriddo, Michael R; Greenberg, Alexandra J; Wahegaonkar, Abhijeet L; Lee, Kendall H

    2013-12-01

    Electrical stimulation of the brain has a 2000 year history. Deep brain stimulation (DBS), one form of neurostimulation, is a functional neurosurgical approach in which a high-frequency electrical current stimulates targeted brain structures for therapeutic benefit. It is an effective treatment for certain neuropathologic movement disorders and an emerging therapy for psychiatric conditions and epilepsy. Its translational journey did not follow the typical bench-to-bedside path, but rather reversed the process. The shift from ancient and medieval folkloric remedy to accepted medical practice began with independent discoveries about electricity during the 19th century and was fostered by technological advances of the 20th. In this paper, we review that journey and discuss how the quest to expand its applications and improve outcomes is taking DBS from the bedside back to the bench. © 2013 Wiley Periodicals, Inc.

  3. Lubiprostone stimulates small intestinal mucin release

    Directory of Open Access Journals (Sweden)

    De Lisle Robert C

    2012-11-01

    Full Text Available Abstract Background Lubiprostone is a synthetic bicyclic fatty acid derivative of prostaglandin E1 (PGE1 used for chronic constipation. The best known action of lubiprostone is simulation of Cl- dependent fluid secretion. In a mouse model of the genetic disease cystic fibrosis, we previously showed that in vivo administration of lubiprostone resulted in greater mucus accumulation in the small intestine. The aim of this study was to directly test whether lubiprostone stimulates intestinal mucin release. Methods Mucin release was measured by mounting segments (4-5 cm of mouse proximal-mid small intestine in an organ bath, allowing access to the perfusate (luminal and the bath (serosal solutions. Nifedipine (10-6 M and indomethacin (10-5 M were included in all solutions to inhibit smooth muscle activity and endogenous prostaglandin production, respectively. The tissue was equilibrated under flow for 30 min, using the perfusate collected during the final 10 min of the equilibration period to measure unstimulated release rate. Stimulus was then added to either the perfusate or the bath and the perfusate was collected for another 30 min to measure the stimulated mucin release rate. Mucin in perfusates was quantified by periodic acid-Schiff's base dot-blot assay, using purified pig gastric mucin as a standard. Results When applied luminally at 1 μM lubiprostone was ineffective at stimulating mucin release. When added to the serosal solution, 1 μM lubiprostone stimulated mucin release to ~300% of the unstimulated rate. As a positive control, serosal 1 μM prostaglandin E2 increased mucin release to ~400% of the unstimulated rate. Conclusions These results support the idea that lubiprostone has prostaglandin-like actions on the intestine, which includes stimulation of mucin release. Stimulation of mucin release by lubiprostone may be protective in gastrointestinal conditions where loss of mucus is believed to contribute to pathogenesis. Thus, in

  4. Stimulation of Managers in Regional Enterprises

    Directory of Open Access Journals (Sweden)

    Vladimir Nikiforovich Belkin

    2018-03-01

    Full Text Available Most of the principles related to top managers work incentives were inherited from the planned economy that produces demotivation and opportunistic behaviour. Remuneration is a commercial secret and shall not be disclosed. The system of top managers’ stimulation is unbalanced and does not motivate them to achieve medium- and long-term goals of the company. The study pays great attention to the development of managers’ stimulation policies, the transparency of remuneration, correlation between pay and performance. We provide practical examples of foreign and national experience, showing the ability to ensure the transparency of remuneration of managers, and the relation between compensation and performance. These examples show that managers’ remuneration amount does not always correspond to the efficiency of enterprises and return on capital. To solve these problems, we offer to develop philosophy and policy for the stimulation of managers in enterprises. It will allow to find a balance between the interests of shareholders and managers. Furthermore, this philosophy will have a positive impact on the competitiveness of enterprises in a region. The policy of stimulating managers should include certain key areas. Firstly, it should ensure the competitiveness of managers’ remuneration. Secondly, it implies studying the motives of managers’ work and the integration of these motives in the development of incentive system for the managers. Thirdly, it should include an optimal combination of elements to stimulate labour: base salary, material and social remuneration, short and long-term remuneration, etc. And last, it should consider the indicators and norms of enterprise’s effectiveness as well as the assessment of working results of managers. The results of this research can be used for further study of the stimulation of managers’ work in Russian companies. They can also be used in practice for the analysis of labour incentives of

  5. Investigating Tactile Stimulation in Symbiotic Systems

    DEFF Research Database (Denmark)

    Orso, Valeria; Mazza, Renato; Gamberini, Luciano

    2017-01-01

    The core characteristics of tactile stimuli, i.e., recognition reliability and tolerance to ambient interference, make them an ideal candidate to be integrated into a symbiotic system. The selection of the appropriate stimulation is indeed important in order not to hinder the interaction from...... the user’s perspective. Here we present the process of selecting the most adequate tactile stimulation delivered by a tactile vest while users were engaged in an absorbing activity, namely playing a video-game. A total of 20 participants (mean age 24.78; SD= 1.57) were involved. Among the eight tactile...

  6. Consensus paper: combining transcranial stimulation with neuroimaging

    DEFF Research Database (Denmark)

    Siebner, Hartwig R; Bergmann, Til O; Bestmann, Sven

    2009-01-01

    to be taken into account when using TMS in the context of neuroimaging. We then discuss the use of specific brain mapping techniques in conjunction with TMS. We emphasize that the various neuroimaging techniques offer complementary information and have different methodologic strengths and weaknesses....... information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need...

  7. Stimulation-induced cerebral glycolytic glucose metabolism

    International Nuclear Information System (INIS)

    Ackermann, R.F.; Lear, J.L.

    1989-01-01

    The authors have developed a method to estimate the relative amounts of cerebral oxidative and glycolytic glucose metabolism with sequentially administered radiolabeled fluorode-oxyglucose (FDG) and 6-glucose (GLU). Cerebral FDG metabolite concentration was found to reflect total glucose metabolism. Cerebral GLU metabolite concentration, however, was found to reflect mainly oxidative metabolism, because of significant fraction of the radiolabel was lost through lactate production and diffusion from the brain with glycolysis. The authors applied the method to normal rats, to seizing rats, and to optically stimulated rats. Normal cerebral glucose metabolism was primarily oxidative, but stimulation caused profound increases in glycolysis in activated brain regions

  8. Fetal intermediate lobe is stimulated by parturition.

    Science.gov (United States)

    Facchinetti, F; Lanzani, A; Genazzani, A R

    1989-11-01

    The fetal pituitary gland secretes beta-endorphin in blood in response to delivery. However, other forms of endorphin have recently been observed in the fetal pituitary, such as N-acetyl-beta-endorphin, which is devoid of opiate activity, and a desacetylated form of alpha-melanocyte-stimulating hormone. Both endorphins originate in the pituitary intermediate lobe. The sensitivity of this lobe to labor stress was assessed by the evaluation of beta-endorphin, N-acetyl-beta-endorphin, melanocyte-stimulating hormone, and desacetylated alpha-melanocyte-stimulating hormone in maternal plasma and cord blood in 11 cases of vaginal delivery and 10 cases of elective cesarean section without labor. Plasma peptide levels were determined by specific radioimmunoassays after extraction on Sep-Pak C-18 cartridges and high-performance liquid chromatography fractionation. Cord blood samples of infants delivered vaginally showed higher beta-endorphin (8.5 +/- 1.6 pmol/L, mean +/- SE) and desacetylated alpha-melanocyte-stimulating hormone (13.6 +/- 3.2 pmol/L) levels than those delivered by elective cesarean section (3.7 +/- 0.8 and 4.2 +/- 1.1 pmol/L, for beta-endorphin and desacetylated alpha-melanocyte-stimulating hormone, respectively). N-acetyl-beta-endorphin and alpha-melanocyte-stimulating hormone levels do not differ in relation to the mode of delivery. In maternal circulation beta-endorphin levels were higher in those delivered vaginally (5.2 pm 1) than in women who had cesarean sections (2.5 +/- 0.5 pmol/L), whereas no changes were found for the other peptides. In vaginal deliveries, the level of desacetylated alpha-melanocyte-stimulating hormone was higher in cord blood (13.6 +/- 3.2 pmol/L) than in maternal plasma (6.5 +/- 3 pmol/L); there were no significant differences with regard to the other peptides. Fetal and maternal levels of all the peptides were similar in cases of cesarean section. We conclude that parturition activates proopiomelanocortin peptide release from

  9. A novel dual-wavelength laser stimulator to elicit transient and tonic nociceptive stimulation.

    Science.gov (United States)

    Dong, Xiaoxi; Liu, Tianjun; Wang, Han; Yang, Jichun; Chen, Zhuying; Hu, Yong; Li, Yingxin

    2017-07-01

    This study aimed to develop a new laser stimulator to elicit both transient and sustained heat stimulation with a dual-wavelength laser system as a tool for the investigation of both transient and tonic experimental models of pain. The laser stimulator used a 980-nm pulsed laser to generate transient heat stimulation and a 1940-nm continuous-wave (CW) laser to provide sustained heat stimulation. The laser with 980-nm wavelength can elicit transient pain with less thermal injury, while the 1940-nm CW laser can effectively stimulate both superficial and deep nociceptors to elicit tonic pain. A proportional integral-derivative (PID) temperature feedback control system was implemented to ensure constancy of temperature during heat stimulation. The performance of this stimulator was evaluated by in vitro and in vivo animal experiments. In vitro experiments on totally 120 specimens fresh pig skin included transient heat stimulation by 980-nm laser (1.5 J, 10 ms), sustained heat stimulation by 1940-nm laser (50-55 °C temperature control mode or 1.5 W, 5 min continuous power supply), and the combination of transient/sustained heat stimulation by dual lasers (1.5 J, 10 ms, 980-nm pulse laser, and 1940-nm laser with 50-55 °C temperature control mode). Hemoglobin brushing and wind-cooling methods were tested to find better stimulation model. A classic tail-flick latency (TFL) experiment with 20 Wistar rats was used to evaluate the in vivo efficacy of transient and tonic pain stimulation with 15 J, 100 ms 980-nm single laser pulse, and 1.5 W constant 1940-nm laser power. Ideal stimulation parameters to generate transient pain were found to be a 26.6 °C peak temperature rise and 0.67 s pain duration. In our model of tonic pain, 5 min of tonic stimulation produced a temperature change of 53.7 ± 1.3 °C with 1.6 ± 0.2% variation. When the transient and tonic stimulation protocols were combined, no significant difference was observed depending on the order

  10. Higher-order power harmonics of pulsed electrical stimulation modulates corticospinal contribution of peripheral nerve stimulation.

    Science.gov (United States)

    Chen, Chiun-Fan; Bikson, Marom; Chou, Li-Wei; Shan, Chunlei; Khadka, Niranjan; Chen, Wen-Shiang; Fregni, Felipe

    2017-03-03

    It is well established that electrical-stimulation frequency is crucial to determining the scale of induced neuromodulation, particularly when attempting to modulate corticospinal excitability. However, the modulatory effects of stimulation frequency are not only determined by its absolute value but also by other parameters such as power at harmonics. The stimulus pulse shape further influences parameters such as excitation threshold and fiber selectivity. The explicit role of the power in these harmonics in determining the outcome of stimulation has not previously been analyzed. In this study, we adopted an animal model of peripheral electrical stimulation that includes an amplitude-adapted pulse train which induces force enhancements with a corticospinal contribution. We report that the electrical-stimulation-induced force enhancements were correlated with the amplitude of stimulation power harmonics during the amplitude-adapted pulse train. In an exploratory analysis, different levels of correlation were observed between force enhancement and power harmonics of 20-80 Hz (r = 0.4247, p = 0.0243), 100-180 Hz (r = 0.5894, p = 0.0001), 200-280 Hz (r = 0.7002, p harmonics. This is a pilot, but important first demonstration that power at high order harmonics in the frequency spectrum of electrical stimulation pulses may contribute to neuromodulation, thus warrant explicit attention in therapy design and analysis.

  11. Light stimulation of iris tyrosinase in vivo

    International Nuclear Information System (INIS)

    Dryja, T.P.; Kimball, G.P.; Albert, D.M.

    1980-01-01

    This paper presents evidence that light stimulates tyrosinase activity in iris melanocytes in rabbits. Levels of iris tyrosinase were found to be greater in eyes of rabbits exposed to light for 6 weeks than in eyes of rabbits maintained in darkness. Despite increasing tyrosinase levels, exposure to light produced no clinically observable change in iris color

  12. Modeling of thermally stimulated depolarization current (TSDC ...

    Indian Academy of Sciences (India)

    Keywords. Dipole–dipole interaction; relaxation; modeling; TSDC; activation energy; PVC; ABS. Abstract. The study of thermally stimulated depolarization current (TSDC) using the dipole–dipole interaction model is described in this work. The dipole–dipole interactionmodel (DDIM) determines the TSDC peak successfully ...

  13. Thermally stimulated discharge conductivity in polymer composite ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. This paper describes the results of thermally stimulated discharge conductivity study of activated charcoal–polyvinyl chloride (PVC) thin film thermoelectrets. TSDC has been carried out in the temperature range 308–400°K and at four different polarizing fields. Results are discussed on the basis of mobility of acti-.

  14. Thermally stimulated discharge conductivity in polymer composite ...

    Indian Academy of Sciences (India)

    This paper describes the results of thermally stimulated discharge conductivity study of activated charcoal–polyvinyl chloride (PVC) thin film thermoelectrets. TSDC has been carried out in the temperature range 308–400°K and at four different polarizing fields. Results are discussed on the basis of mobility of activated ...

  15. Nonlinear electrodynamics in microwave-stimulated superconductivity

    International Nuclear Information System (INIS)

    Mooij, J.E.; Klapwijk, T.M.

    1983-01-01

    In practical experiments on microwave-stimulated superconductivity the current source character of the microwave coupling leads to a strong dependence of the field strength on the value of the gap. Various consequences are pointed out, in particular, for a quantitative comparison between critical current and gap or order-parameter enhancement

  16. Transcutaneous Electrical Nerve Stimulation: Research Update.

    Science.gov (United States)

    Johns, Florene Carnicelli

    Currently, research is being performed in the area of nonsurgical and nonchemical means for influencing the body's threshold for pain. Today, transcutaneous electrical nerve stimulation (TENS) is being widely used for this purpose. Application of this treatment can be confusing, however, because determining such things as selection of the proper…

  17. Thermally stimulated luminescence studies in combustion ...

    Indian Academy of Sciences (India)

    Wintec

    resonance, photoacoustic studies/optical absorption etc in order to understand the TSL mechanism leading to gene- ration and trapping of defect centres due to ionizing radiation and light emission in aluminum oxide during thermal stimulation. Figure 3 shows the variation of TSL intensity with γ- ray dose in combustion ...

  18. Stimulated secondary emission from semiconductor microcavities

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Mizeikis, V.; Langbein, Wolfgang Werner

    2001-01-01

    We find strong influence of final-state stimulation on the time-resolved light emission dynamics from semiconductor microcavities after pulsed excitation allowing angle-resonant polariton-polariton scattering on the lower-polariton branch. The polariton dynamics can be controlled by injection...

  19. Causal Measurement Models: Can Criticism Stimulate Clarification?

    Science.gov (United States)

    Markus, Keith A.

    2016-01-01

    In their 2016 work, Aguirre-Urreta et al. provided a contribution to the literature on causal measurement models that enhances clarity and stimulates further thinking. Aguirre-Urreta et al. presented a form of statistical identity involving mapping onto the portion of the parameter space involving the nomological net, relationships between the…

  20. Ultrasound stimulation of mandibular bone defect healing

    NARCIS (Netherlands)

    Schortinghuis, Jurjen

    2004-01-01

    The conclusions of the experimental work presented in this thesis are: 1. Low intensity pulsed ultrasound is not effective in stimulating bone growth into a rat mandibular defect, either with or without the use of osteoconductive membranes. 2. Low intensity pulsed ultrasound does not seem to have an

  1. Investigating Tactile Stimulation in Symbiotic Systems

    DEFF Research Database (Denmark)

    Orso, Valeria; Mazza, Renato; Gamberini, Luciano

    2017-01-01

    the user’s perspective. Here we present the process of selecting the most adequate tactile stimulation delivered by a tactile vest while users were engaged in an absorbing activity, namely playing a video-game. A total of 20 participants (mean age 24.78; SD= 1.57) were involved. Among the eight tactile...

  2. Gastric applications of electrical field stimulation.

    LENUS (Irish Health Repository)

    Hogan, Aisling M

    2012-02-01

    Advances in clinical applications of electricity have been vast since the launch of Hayman\\'s first cardiac pacemaker more than 70 years ago. Gastric electrical stimulation devices have been recently licensed for treatment of gastroparesis and preliminary studies examining their potential for use in refractory obesity yield promising results.

  3. Conducting Polymers in Neural Stimulation Applications

    Science.gov (United States)

    Zhou, David D.; Cui, X. Tracy; Hines, Amy; Greenberg, Robert J.

    With advances in neural prostheses, the demand for high-resolution and site-specific stimulation is driving microelectrode research to develop electrodes that are much smaller in area and longer in lifetime. For such arrays, the choice of electrode material has become increasingly important. Currently, most neural stimulation devices use platinum, iridium oxide, or titanium nitride electrodes. Although those metal electrodes have low electrode impedance, high charge injection capability, and high corrosion resistance, the neural interface between solid metal and soft tissue has undesilable characteristics. Recently, several conducting polymers, also known as inherently conducting polymers (ICPs), have been explored as new electrode materials for neural interfaces. Polypyrrole (PPy), polyaniline (PANi), and poly(3,4-ethylenedioxythiophene) (PEDOT) polymers may offer the organic, improved bionic interface that is necessary to promote biocompatibility in neural stimulation applications. While conducting polymers hold much promise in biomedical applications, more research is needed to further understand the properties of these materials. Factors such as electrode impedance, polymer volume changes under electrical stimulation, charge injection capability, biocompatibility, and long-term stability are of significant importance and may pose as challenges in the future success of conducting polymers in biomedical applications.

  4. Stimulation of Erythrocyte Death by Phloretin

    Directory of Open Access Journals (Sweden)

    Rosi Bissinger

    2014-12-01

    Full Text Available Background: Phloretin, a natural component of apples, pears and strawberries, has previously been shown to stimulate apoptosis of nucleated cells. Erythrocytes may similarly enter suicidal death or eryptosis, which is characterized by cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i, ceramide, ATP depletion, and activation of protein kinase C (PKC as well as p38 mitogen activated protein kinase (p38 kinase. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, and ceramide abundance from binding of specific antibodies. Results: A 48 h exposure of human erythrocytes to phloretin significantly increased the percentage of annexin-V-binding cells (≥100 µM without significantly influencing forward scatter. Phloretin did not significantly modify [Ca2+]i and the stimulation of annexin-V-binding by phloretin (300 µM did not require presence of extracellular Ca2+. Phloretin did not significantly modify erythrocyte ATP levels, and the effect of phloretin on annexin-V-binding was not significantly altered by PKC inhibitor staurosporine (1 µM or p38 kinase inhibitor SB2203580 (2 µM. However, phloretin significantly increased the ceramide abundance at the cell surface. Conclusions: Phloretin stimulates phospholipid scrambling of the erythrocyte cell membrane, an effect at least partially due to up-regulation of ceramide abundance.

  5. Ipsilateral masking between acoustic and electric stimulations.

    Science.gov (United States)

    Lin, Payton; Turner, Christopher W; Gantz, Bruce J; Djalilian, Hamid R; Zeng, Fan-Gang

    2011-08-01

    Residual acoustic hearing can be preserved in the same ear following cochlear implantation with minimally traumatic surgical techniques and short-electrode arrays. The combined electric-acoustic stimulation significantly improves cochlear implant performance, particularly speech recognition in noise. The present study measures simultaneous masking by electric pulses on acoustic pure tones, or vice versa, to investigate electric-acoustic interactions and their underlying psychophysical mechanisms. Six subjects, with acoustic hearing preserved at low frequencies in their implanted ear, participated in the study. One subject had a fully inserted 24 mm Nucleus Freedom array and five subjects had Iowa/Nucleus hybrid implants that were only 10 mm in length. Electric masking data of the long-electrode subject showed that stimulation from the most apical electrodes produced threshold elevations over 10 dB for 500, 625, and 750 Hz probe tones, but no elevation for 125 and 250 Hz tones. On the contrary, electric stimulation did not produce any electric masking in the short-electrode subjects. In the acoustic masking experiment, 125-750 Hz pure tones were used to acoustically mask electric stimulation. The acoustic masking results showed that, independent of pure tone frequency, both long- and short-electrode subjects showed threshold elevations at apical and basal electrodes. The present results can be interpreted in terms of underlying physiological mechanisms related to either place-dependent peripheral masking or place-independent central masking.

  6. Optically stimulated luminescence techniques in retrospective dosimetry

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Murray, A.S.

    2001-01-01

    windows, and detection sensitivity, (ii) experience with various stimulation light sources, including filtered incandescent lamps (420-550 nm) and high intensity light emitting diodes (470 nm) and laser diodes (830-850 nm). We also discuss recently developed high-precision single-aliquot measurement...

  7. Prenatal music stimulation facilitates the postnatal functional ...

    Indian Academy of Sciences (India)

    We wanted to evaluate the effects of prenatal repetitive music stimulation on the remodelling of the auditory cortex and visual Wulst in chicks. Fertilized eggs (0 day) of white leghorn chicken (Gallus domesticus) during incubation were exposed either to music or no sound from embryonic day 10 until hatching. Auditory and ...

  8. Three-beam double stimulated Raman scatterings

    Science.gov (United States)

    Cho, Minhaeng

    2018-01-01

    Two-beam stimulated Raman scattering with pump and Stokes beams is manifest in both the Raman loss of the pump beam and the Raman gain of the Stokes beam, and it has been used in various label-free bioimaging applications. Here, a three-beam stimulated Raman scattering that involves pump, Stokes, and depletion beams is considered, where two stimulated Raman gain-loss processes are deliberately made to compete with each other. It is shown that the three-beam Raman scattering process can be described by coupled differential equations for the increased numbers of Stokes and depletion beam photons. From approximate solutions of the coupled differential equations and numerical calculation results, it is shown that a highly efficient suppression of the Stokes Raman gain is possible by using an intense depletion beam whose frequency difference from that of the pump beam is identical to another acceptor Raman mode frequency. I anticipate that the present work will provide a theoretical framework for super-resolution stimulated Raman scattering microscopy.

  9. Stimulated Deep Neural Network for Speech Recognition

    Science.gov (United States)

    2016-09-08

    approaches yield state-of-the-art performance in a range of tasks, including speech recognition . However, the parameters of the network are hard to analyze...advantage of the smoothness con- straints that stimulated training offers. The approaches are eval- uated on two large vocabulary speech recognition

  10. Computer Games Functioning as Motivation Stimulants

    Science.gov (United States)

    Lin, Grace Hui Chin; Tsai, Tony Kung Wan; Chien, Paul Shih Chieh

    2011-01-01

    Numerous scholars have recommended computer games can function as influential motivation stimulants of English learning, showing benefits as learning tools (Clarke and Dede, 2007; Dede, 2009; Klopfer and Squire, 2009; Liu and Chu, 2010; Mitchell, Dede & Dunleavy, 2009). This study aimed to further test and verify the above suggestion,…

  11. Stimulating Interest in Science and Mathematics.

    Science.gov (United States)

    Hoffman, Albert C.

    1988-01-01

    Two programs were designed at Millersville University (Pennsylvania) to stimulate interest in science and mathematics: (1) academically talented students from grades 4-11 attend science lectures/demonstrations and participate in a science knowledge competition, and (2) secondary teachers and students in grades 8-11 participate in hands-on…

  12. Stimulating Economic Development Through the Capital Market ...

    African Journals Online (AJOL)

    Stimulating Economic Development Through the Capital Market: The Nigerian Experience. ... Journal of Research in National Development ... The explanatory variables were Market capitalization, All shares index Value of transactions, Volume of transactions and Number of listed companies for each of the models.

  13. Seismic stimulation for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pride, S.R.; Flekkoy, E.G.; Aursjo, O.

    2008-07-22

    The pore-scale effects of seismic stimulation on two-phase flow are modeled numerically in random 2D grain0pack geometries. Seismic stimulation aims to enhance oil production by sending seismic waves across a reservoir to liberate immobile patches of oil. For seismic amplitudes above a well-defined (analytically expressed) dimensionless criterion, the force perturbation associated with the waves indeed can liberate oil trapped on capillary barriers and get it flowing again under the background pressure gradient. Subsequent coalescence of the freed oil droplets acts to enhance oil movement further because longer bubbles overcome capillary barriers more efficiently than shorter bubbles do. Poroelasticity theory defines the effective force that a seismic wave adds to the background fluid-pressure gradient. The lattice-Boltzmann model in two dimensions is used to perform pore-scale numerical simulations. Dimensionless numbers (groups of material and force parameters) involved in seismic stimulation are defined carefully so that numerical simulations can be applied to field-scale conditions. Using the analytical criteria defined in the paper, there is a significant range of reservoir conditions over which seismic stimulation can be expected to enhance oil production.

  14. Optically stimulated luminescence dating of rock surfaces

    DEFF Research Database (Denmark)

    Sohbati, Reza

    There are many examples of rock surfaces, rock art and stone structures whose ages are of great importance to the understanding of various phenomena in geology, climatology and archaeology. Optically stimulated luminescence (OSL) dating is a well-established chronological tool that has successful...

  15. Human transient response under local thermal stimulation

    Directory of Open Access Journals (Sweden)

    Wang Lijuan

    2017-01-01

    Full Text Available Human body can operate physiological thermoregulation system when it is exposed to cold or hot environment. Whether it can do the same work when a local part of body is stimulated by different temperatures? The objective of this paper is to prove it. Twelve subjects are recruited to participate in this experiment. After stabilizing in a comfort environment, their palms are stimulated by a pouch of 39, 36, 33, 30, and 27°C. Subject’s skin temperature, heart rate, heat flux of skin, and thermal sensation are recorded. The results indicate that when local part is suffering from harsh temperature, the whole body is doing physiological thermoregulation. Besides, when the local part is stimulated by high temperature and its thermal sensation is warm, the thermal sensation of whole body can be neutral. What is more, human body is more sensitive to cool stimulation than to warm one. The conclusions are significant to reveal and make full use of physiological thermoregulation.

  16. Social Early Stimulation of Trisomy-21 Babies

    Science.gov (United States)

    Aparicio, Maria Teresa Sanz; Balana, Javier Menendez

    2003-01-01

    This study was initiated with twenty Down's syndrome babies to verify whether subjects undergoing social early stimulation would benefit from this type of treatment. An experimental study was designed with two training groups: visual or written instructions. The analyses of the results established statistically significant differences in the…

  17. Does civic participation stimulate political activity?

    NARCIS (Netherlands)

    van Stekelenburg, J.; Klandermans, P.G.; Akkerman, A.

    2016-01-01

    Activists are the engines of social movements. What spurs their activism? This article scrutinizes the role of civic participation in stimulating political action. We examine how the type of voluntary organization, scope of involvement and intensity of activity relate to political activity. Contrary

  18. STIMULATION TECHNOLOGIES FOR DEEP WELL COMPLETIONS

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Wolhart

    2003-06-01

    The Department of Energy (DOE) is sponsoring a Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a project to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. Phase 1 was recently completed and consisted of assessing deep gas well drilling activity (1995-2007) and an industry survey on deep gas well stimulation practices by region. Of the 29,000 oil, gas and dry holes drilled in 2002, about 300 were drilled in the deep well; 25% were dry, 50% were high temperature/high pressure completions and 25% were simply deep completions. South Texas has about 30% of these wells, Oklahoma 20%, Gulf of Mexico Shelf 15% and the Gulf Coast about 15%. The Rockies represent only 2% of deep drilling. Of the 60 operators who drill deep and HTHP wells, the top 20 drill almost 80% of the wells. Six operators drill half the U.S. deep wells. Deep drilling peaked at 425 wells in 1998 and fell to 250 in 1999. Drilling is expected to rise through 2004 after which drilling should cycle down as overall drilling declines.

  19. Progesterone stimulates pancreatic cell proliferation in vivo

    NARCIS (Netherlands)

    Nieuwenhuizen, AG; Schuiling, GA; Liem, SMS; Moes, H; Koiter, TR; Uilenbroek, JTJ

    Treatment of cyclic and pregnant rats with progesterone stimulates cell proliferation within the islets of Langerhans. It was investigated whether this effect of progesterone depends on sex and/or the presence of the gonads or the presence of oestradiol, For this purpose, Silastic tubes containing

  20. Galvanic vestibular stimulation speeds visual memory recall.

    Science.gov (United States)

    Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

    2008-08-01

    The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement.

  1. Thermally stimulated discharge current (TSDC) and dielectric ...

    Indian Academy of Sciences (India)

    Unknown

    2001-10-09

    Oct 9, 2001 ... current (TSDC) peak above room temperature. Hong and Day (1979) applied the techniques of thermally stimulated polarization and depolarization current for studying alkaline ion motion in glasses of sodium silicate and lead silicate. The peaks observed are discussed on the basis of d.c. conductivity and ...

  2. Prenatal music stimulation facilitates the postnatal functional ...

    Indian Academy of Sciences (India)

    2014-01-27

    Jan 27, 2014 ... Rhythmic sound or music is known to improve cognition in animals and humans. We wanted to evaluate the effects of prenatal repetitive music stimulation on the remodelling of the auditory cortex and visual Wulst in chicks. Fertilized eggs (0 day) of white leghorn chicken (Gallus domesticus) during ...

  3. Optically stimulated luminescence dating of young sediments

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, Andrew S.

    2009-01-01

    Optically stimulated luminescence (OSL) dating of young (... of OSL dating, outlines the problems specific to the dating of young material, and then uses recent applications to young sediments to illustrate the greatly increased scope and potential of the method in geomorphology and the geology of recent deposits. The overall reliability of this new generation...

  4. Motor Cortex Stimulation in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Marisa De Rose

    2012-01-01

    Full Text Available Motor Cortex Stimulation (MCS is less efficacious than Deep Brain Stimulation (DBS in Parkinson's disease. However, it might be proposed to patients excluded from DBS or unresponsive to DBS. Ten patients with advanced PD underwent unilateral MCS contralaterally to the worst clinical side. A plate electrode was positioned over the motor cortex in the epidural space through single burr hole after identification of the area with neuronavigation and neurophysiological tests. Clinical assessment was performed by total UPDRS, UPDRS III total, UPDRS III-items 27–31, UPDRS IV, and UPDRS II before implantation in off-medication and on-medication states and after surgery at 1, 3, 6, 12, 18, 24, and 36 months in on-medication/on-stimulation and off-medication/on-stimulation states. We assessed changes of quality of life, throughout the Parkinson's disease quality of life scale (PDQoL-39, and the dose of anti-Parkinson's disease medications, throughout the Ldopa equivalent daily dose (LEDD. During off-medication state, we observed moderate and transitory reduction of total UPDRS and UPDRS total scores and significant and long-lasting improvement in UPDRS III items 27–31 score for axial symptoms. There was marked reduction of UPDRS IV score and LEDD. PDQL-39 improvement was also significant. No important complications and adverse events occurred.

  5. A level stimulator programmed for audiometry

    International Nuclear Information System (INIS)

    Fayart, Gerard

    1976-02-01

    This stimulator has been designed for automated audiometric experiments on lemurians. The variations of the transmission level are programmed on punched tape whose reading is controlled by an audiofrequency attenuator. The positive answers of the animal are stored in a seven-counter memory and the results are read by display [fr

  6. Stimulating Strategically Aligned Behaviour among Employees

    NARCIS (Netherlands)

    C.B.M. van Riel (Cees); G.A.J.M. Berens (Guido); M. Dijkstra (Majorie)

    2008-01-01

    textabstractStrategically aligned behaviour (SAB), i.e., employee action that is consistent with the company’s strategy, is of vital importance to companies. This study provides insights into the way managers can promote such behaviour among employees by stimulating employee motivation and by

  7. Transgalactooligosaccharides stimulate calcium absorption in postmenopausal women

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Schoterman, M.H.C.; Muijs, T.

    2000-01-01

    The aim of this study was to investigate whether a product rich in transgalactooligosaccharides (TOS, Elix'or) stimulates true Ca absorption in postmenopausal women. The study was a double-blind, randomized crossover study, consisting of two 9-d treatment periods separated by a 19-d washout period.

  8. Improving the luteal phase after ovarian stimulation

    DEFF Research Database (Denmark)

    Andersen, Claus Yding; Vilbour Andersen, K

    2014-01-01

    The human chorionic gonadotrophin (HCG) trigger used for final follicular maturation in connection with assisted reproduction treatment combines ovulation induction and early luteal-phase stimulation of the corpora lutea. The use of a gonadotrophin-releasing hormone agonist (GnRHa) for final...

  9. Tissue damage thresholds during therapeutic electrical stimulation

    Science.gov (United States)

    Cogan, Stuart F.; Ludwig, Kip A.; Welle, Cristin G.; Takmakov, Pavel

    2016-04-01

    Objective. Recent initiatives in bioelectronic modulation of the nervous system by the NIH (SPARC), DARPA (ElectRx, SUBNETS) and the GlaxoSmithKline Bioelectronic Medicines effort are ushering in a new era of therapeutic electrical stimulation. These novel therapies are prompting a re-evaluation of established electrical thresholds for stimulation-induced tissue damage. Approach. In this review, we explore what is known and unknown in published literature regarding tissue damage from electrical stimulation. Main results. For macroelectrodes, the potential for tissue damage is often assessed by comparing the intensity of stimulation, characterized by the charge density and charge per phase of a stimulus pulse, with a damage threshold identified through histological evidence from in vivo experiments as described by the Shannon equation. While the Shannon equation has proved useful in assessing the likely occurrence of tissue damage, the analysis is limited by the experimental parameters of the original studies. Tissue damage is influenced by factors not explicitly incorporated into the Shannon equation, including pulse frequency, duty cycle, current density, and electrode size. Microelectrodes in particular do not follow the charge per phase and charge density co-dependence reflected in the Shannon equation. The relevance of these factors to tissue damage is framed in the context of available reports from modeling and in vivo studies. Significance. It is apparent that emerging applications, especially with microelectrodes, will require clinical charge densities that exceed traditional damage thresholds. Experimental data show that stimulation at higher charge densities can be achieved without causing tissue damage, suggesting that safety parameters for microelectrodes might be distinct from those defined for macroelectrodes. However, these increased charge densities may need to be justified by bench, non-clinical or clinical testing to provide evidence of device

  10. Proinflammatory mediators stimulate neutrophil-directed angiogenesis.

    LENUS (Irish Health Repository)

    McCourt, M

    2012-02-03

    BACKGROUND: Vascular endothelial growth factor (VEGF; vascular permeability factor) is one of the most potent proangiogenic cytokines, and it plays a central role in mediating the process of angiogenesis or new blood vessel formation. Neutrophils (PMNs) recently have been shown to produce VEGF. HYPOTHESIS: The acute inflammatory response is a potent stimulus for PMN-directed angiogenesis. METHODS: Neutrophils were isolated from healthy volunteers and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and anti-human Fas monoclonal antibody. Culture supernatants were assayed for VEGF using enzyme-linked immunosorbent assays. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs were then added to human umbilical vein endothelial cells and human microvessel endothelial cells and assessed for endothelial cell proliferation using 5-bromodeoxyuridine labeling. Tubule formation was also assessed on MATRIGEL basement membrane matrix. Neutrophils were lysed to measure total VEGF release, and VEGF expression was detected using Western blot analysis. RESULTS: Lipopolysaccharide and TNF-alpha stimulation resulted in significantly increased release of PMN VEGF (532+\\/-49 and 484+\\/-80 pg\\/mL, respectively; for all, presented as mean +\\/- SEM) compared with control experiments (32+\\/-4 pg\\/mL). Interleukin 6 and Fas had no effect. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs also resulted in significant increases (P<.005) in macrovascular and microvascular endothelial cell proliferation and tubule formation. Adding anti-human VEGF-neutralizing polyclonal antibody to stimulated PMN supernatant inhibited these effects. Total VEGF release following cell lysis and Western blot analysis suggests that the VEGF is released from an intracellular store. CONCLUSION: Activated human PMNs are directly angiogenic by releasing VEGF, and this has important implications for inflammation, capillary leak syndrome

  11. Theory of multichannel magnetic stimulation: toward functional neuromuscular rehabilitation.

    Science.gov (United States)

    Ruohonen, J; Ravazzani, P; Grandori, F; Ilmoniemi, R J

    1999-06-01

    Human excitable cells can be stimulated noninvasively with externally applied time-varying electromagnetic fields. The stimulation can be achieved either by directly driving current into the tissue (electrical stimulation) or by means of electro-magnetic induction (magnetic stimulation). While the electrical stimulation of the peripheral neuromuscular system has many beneficial applications, peripheral magnetic stimulation has so far only a few. This paper analyzes theoretically the use of multiple magnetic stimulation coils to better control the excitation and also to eventually mimic electrical stimulation. Multiple coils allow electronic spatial adjustment of the shape and location of the stimulus without moving the coils. The new properties may enable unforeseen uses for peripheral magnetic stimulation, e.g., in rehabilitation of patients with neuromuscular impairment.

  12. Immediate effect of laryngeal surface electrical stimulation on swallowing performance.

    Science.gov (United States)

    Takahashi, Keizo; Hori, Kazuhiro; Hayashi, Hirokazu; Fujiu-Kurachi, Masako; Ono, Takahiro; Tsujimura, Takanori; Magara, Jin; Inoue, Makoto

    2018-01-01

    Surface electrical stimulation of the laryngeal region is used to improve swallowing in dysphagic patients. However, little is known about how electrical stimulation affects tongue movements and related functions. We investigated the effect of electrical stimulation on tongue pressure and hyoid movement, as well as suprahyoid and infrahyoid muscle activity, in 18 healthy young participants. Electrical stimulation (0.2-ms duration, 80 Hz, 80% of each participant's maximal tolerance) of the laryngeal region was applied. Each subject swallowed 5 ml of barium sulfate liquid 36 times at 10-s intervals. During the middle 2 min, electrical stimulation was delivered. Tongue pressure, electromyographic activity of the suprahyoid and infrahyoid muscles, and videofluorographic images were simultaneously recorded. Tongue pressure during stimulation was significantly lower than before or after stimulation and was significantly greater after stimulation than at baseline. Suprahyoid activity after stimulation was larger than at baseline, while infrahyoid muscle activity did not change. During stimulation, the position of the hyoid at rest was descended, the highest hyoid position was significantly inferior, and the vertical movement was greater than before or after stimulation. After stimulation, the positions of the hyoid at rest and at the maximum elevation were more superior than before stimulation. The deviation of the highest positions of the hyoid before and after stimulation corresponded to the differences in tongue pressures at those times. These results suggest that surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. NEW & NOTEWORTHY Surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. Tongue muscles may contribute to overshot recovery

  13. A new brain stimulation method: Noninvasive transcranial magneto–acoustical stimulation

    International Nuclear Information System (INIS)

    Yuan Yi; Chen Yu-Dong; Li Xiao-Li

    2016-01-01

    We investigate transcranial magneto–acoustical stimulation (TMAS) for noninvasive brain neuromodulation in vivo. TMAS as a novel technique uses an ultrasound wave to induce an electric current in the brain tissue in the static magnetic field. It has the advantage of high spatial resolution and penetration depth. The mechanism of TMAS onto a neuron is analyzed by combining the TMAS principle and Hodgkin–Huxley neuron model. The anesthetized rats are stimulated by TMAS, resulting in the local field potentials which are recorded and analyzed. The simulation results show that TMAS can induce neuronal action potential. The experimental results indicate that TMAS can not only increase the amplitude of local field potentials but also enhance the effect of focused ultrasound stimulation on the neuromodulation. In summary, TMAS can accomplish brain neuromodulation, suggesting a potentially powerful noninvasive stimulation method to interfere with brain rhythms for diagnostic and therapeutic purposes. (paper)

  14. Electrical stimulation of the upper extremity in stroke: cyclic versus EMG-triggered stimulation

    NARCIS (Netherlands)

    de Kroon, Joke R.; IJzerman, Maarten Joost

    2008-01-01

    Objective: To compare the effect of cyclic and electromyography (EMG)-triggered electrical stimulation on motor impairment and function of the affected upper extremity in chronic stroke. Design: Randomized controlled trial. Setting: Outpatient clinic of a rehabilitation centre. Subjects and

  15. In vivo charge injection limits increased after 'unsafe' stimulation

    DEFF Research Database (Denmark)

    Meijs, Suzan; Sørensen, Søren; Rechendorff, Kristian

    2015-01-01

    The effect of unsafe stimulation on charge injection limits (Qinj) and pulsing capacitance (Cpulse) was investigated. Four stimulation protocols were applied: 20 mA – 200 and 400 Hz, 50 mA – 200 and 400 Hz. Increasing Qinj and Cpulse were observed for all stimulation protocols. Corrosion was not ......The effect of unsafe stimulation on charge injection limits (Qinj) and pulsing capacitance (Cpulse) was investigated. Four stimulation protocols were applied: 20 mA – 200 and 400 Hz, 50 mA – 200 and 400 Hz. Increasing Qinj and Cpulse were observed for all stimulation protocols. Corrosion...

  16. Non-invasive brain stimulation in early rehabilitation after stroke.

    Science.gov (United States)

    Blesneag, A V; Popa, L; Stan, A D

    2015-01-01

    The new tendency in rehabilitation involves non-invasive tools that, if applied early after stroke, promote neurorecovery. Repetitive transcranial magnetic stimulation and transcranial direct current stimulation may correct the disruption of cortical excitability and effectively contribute to the restoration of movement and speech. The present paper analyses the results of non-invasive brain stimulation (NIBS) trials, highlighting different aspects related to the repetitive transcranial magnetic stimulation frequency, transcranial direct current stimulation polarity, the period and stimulation places in acute and subacute ischemic strokes. The risk of adverse events, the association with motor or language recovery specific training, and the cumulative positive effect evaluation are also discussed.

  17. The safety of transcranial magnetic stimulation with deep brain stimulation instruments

    OpenAIRE

    Shimojima, Yoshio; Morita, Hiroshi; Nishikawa, Noriko; Kodaira, Minori; Hashimoto, Takao; Ikeda, Shu-ichi

    2010-01-01

    Objectives: Transcranial magnetic stimulation (TMS) has been employed in patients with an implanted deep brain Stimulation (DBS) device. We investigated the safety of TMS using Simulation models with an implanted DBS device. Methods: The DBS lead was inserted into plastic phantoms filled with dilute gelatin showing impedance similar to that of human brain. TMS was performed with three different types of magnetic coil. During TMS (I) electrode movement, (2) temperature change around the lead, ...

  18. Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead.

    Science.gov (United States)

    van Dijk, Kees J; Verhagen, Rens; Bour, Lo J; Heida, Ciska; Veltink, Peter H

    2017-10-15

    Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of this study is to assess the performances of a new eight channel steering-DBS lead and compare this with a conventional cylindrical contact (CC) lead. The two leads were evaluated in a finite element electric field model combined with multicompartment neuron and axon models, representing the internal capsule (IC) fibers and subthalamic nucleus (STN) cells. We defined the optimal stimulation setting as the configuration that activated the highest percentage of STN cells, without activating any IC fibers. With this criterion, we compared monopolar stimulation using a single contact of the steering-DBS lead and CC lead, on three locations and four orientations of the lead. In addition, we performed a current steering test case by dividing the current over two contacts with the steering-DBS lead in its worst-case orientation. In most cases, the steering-DBS lead is able to stimulate a significantly higher percentage of STN cells compared to the CC lead using single contact stimulation or using a two contact current steering protocol when there is approximately a 1 mm displacement of the CC lead. The results also show that correct placement and orientation of the lead in the target remains an important aspect in achieving the optimal stimulation outcome. Currently, clinical trials are set up in Europe with a similar design as the steering-DBS lead. Our results illustrate the importance of the orientation of the new steering-DBS lead in avoiding side effects induced by stimulation of IC fibers. Therefore, in clinical trials sufficient attention should be paid to implanting the steering DBS-lead in the most effective orientation. © 2017 International Neuromodulation Society.

  19. Computational electromagnetic methods for transcranial magnetic stimulation

    Science.gov (United States)

    Gomez, Luis J.

    Transcranial magnetic stimulation (TMS) is a noninvasive technique used both as a research tool for cognitive neuroscience and as a FDA approved treatment for depression. During TMS, coils positioned near the scalp generate electric fields and activate targeted brain regions. In this thesis, several computational electromagnetics methods that improve the analysis, design, and uncertainty quantification of TMS systems were developed. Analysis: A new fast direct technique for solving the large and sparse linear system of equations (LSEs) arising from the finite difference (FD) discretization of Maxwell's quasi-static equations was developed. Following a factorization step, the solver permits computation of TMS fields inside realistic brain models in seconds, allowing for patient-specific real-time usage during TMS. The solver is an alternative to iterative methods for solving FD LSEs, often requiring run-times of minutes. A new integral equation (IE) method for analyzing TMS fields was developed. The human head is highly-heterogeneous and characterized by high-relative permittivities (107). IE techniques for analyzing electromagnetic interactions with such media suffer from high-contrast and low-frequency breakdowns. The novel high-permittivity and low-frequency stable internally combined volume-surface IE method developed. The method not only applies to the analysis of high-permittivity objects, but it is also the first IE tool that is stable when analyzing highly-inhomogeneous negative permittivity plasmas. Design: TMS applications call for electric fields to be sharply focused on regions that lie deep inside the brain. Unfortunately, fields generated by present-day Figure-8 coils stimulate relatively large regions near the brain surface. An optimization method for designing single feed TMS coil-arrays capable of producing more localized and deeper stimulation was developed. Results show that the coil-arrays stimulate 2.4 cm into the head while stimulating 3

  20. Can the human lumbar posterior columns be stimulated by transcutaneous spinal cord stimulation? A modeling study.

    Science.gov (United States)

    Danner, Simon M; Hofstoetter, Ursula S; Ladenbauer, Josef; Rattay, Frank; Minassian, Karen

    2011-03-01

    Stimulation of different spinal cord segments in humans is a widely developed clinical practice for modification of pain, altered sensation, and movement. The human lumbar cord has become a target for modification of motor control by epidural and, more recently, by transcutaneous spinal cord stimulation. Posterior columns of the lumbar spinal cord represent a vertical system of axons and when activated can add other inputs to the motor control of the spinal cord than stimulated posterior roots. We used a detailed three-dimensional volume conductor model of the torso and the McIntyre-Richard-Grill axon model to calculate the thresholds of axons within the posterior columns in response to transcutaneous lumbar spinal cord stimulation. Superficially located large-diameter posterior column fibers with multiple collaterals have a threshold of 45.4 V, three times higher than posterior root fibers (14.1 V). With the stimulation strength needed to activate posterior column axons, posterior root fibers of large and small diameters as well as anterior root fibers are coactivated. The reported results inform on these threshold differences, when stimulation is applied to the posterior structures of the lumbar cord at intensities above the threshold of large-diameter posterior root fibers. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  1. On the possible role of stimulation duration for after-effects of transcranial alternating current stimulation

    Directory of Open Access Journals (Sweden)

    Daniel eStrüber

    2015-08-01

    Full Text Available Transcranial alternating current stimulation is a novel method that allows application of sinusoidal currents to modulate brain oscillations and cognitive processes. Studies in humans have demonstrated tACS after-effects following stimulation durations in the range of minutes. However, such after-effects are absent in animal studies using much shorter stimulation protocols in the range of seconds. Thus, stimulation duration might be a critical parameter for after-effects to occur. To test this hypothesis, we repeated a recent human tACS experiment with a short duration. We applied alpha tACS intermittently for one second duration while keeping other parameters identical. The results demonstrate that this very short intermittent protocol did not produce after-effects on amplitude or phase of the electroencephalogram. Since synaptic plasticity has been suggested as a possible mechanism for after-effects, our results indicate that a stimulation duration of one second is too short to induce synaptic plasticity. Future studies in animals are required that use extended stimulation durations to reveal the neuronal underpinnings. A better understanding of the mechanisms of tACS after-effects is crucial for potential clinical applications.

  2. Field modeling for transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Thielscher, Axel; Antunes, Andre; Saturnino, Guilherme B

    2015-01-01

    ) improving the usability of the tools for field calculation to the level that they can be easily used by non-experts. We then introduce a new version of our pipeline for field calculations (www.simnibs.org) that substantially simplifies setting up and running TMS and tDCS simulations based on Finite......Electric field calculations based on numerical methods and increasingly realistic head models are more and more used in research on Transcranial Magnetic Stimulation (TMS). However, they are still far from being established as standard tools for the planning and analysis in practical applications...... of TMS. Here, we start by delineating three main challenges that need to be addressed to unravel their full potential. This comprises (i) identifying and dealing with the model uncertainties, (ii) establishing a clear link between the induced fields and the physiological stimulation effects, and (iii...

  3. Stimulation of bone healing with interferential therapy.

    Science.gov (United States)

    Ganne, J M

    1988-01-01

    Methods of electrical stimulation of bone are reviewed for a comparison with the use of interference currents and for a consideration of the possible merits of various methods. A summary is given of results of treatment of 38 patients with delayed or non-union and predisposition to non-union, and the technique used with Interferential Therapy is described in detail. Results are also given of a study of the effects of stimulation on 11 patients with acute fractures of the tibial shaft, compared with 11 closely matched patients with similar acute fractures who did not receive Interferential Therapy. The advantages of surgically non-invasive techniques are emphasised and recommendations are made for the use of interference currents prophylactically in specific cases. Copyright © 1988 Australian Physiotherapy Association. Published by . All rights reserved.

  4. Deep brain stimulation for cluster headache

    DEFF Research Database (Denmark)

    Grover, Patrick J; Pereira, Erlick A C; Green, Alexander L

    2009-01-01

    Cluster headache is a severely debilitating disorder that can remain unrelieved by current pharmacotherapy. Alongside ablative neurosurgical procedures, neuromodulatory treatments of deep brain stimulation (DBS) and occipital nerve simulation have emerged in the last few years as effective...... treatments for medically refractory cluster headaches. Pioneers in the field have sought to publish guidelines for neurosurgical treatment; however, only small case series with limited long-term follow-up have been published. Controversy remains over which surgical treatments are best and in which...... circumstances to intervene. Here we review current data on neurosurgical interventions for chronic cluster headache focusing upon DBS and occipital nerve stimulation, and discuss the indications for and putative mechanisms of DBS including translational insights from functional neuroimaging, diffusion weighted...

  5. New method of stimulation of gastric peristalsis

    International Nuclear Information System (INIS)

    Ilyasova, E.B.; Dmitriev, Yu.Ya.

    1986-01-01

    Diadynamic currents were first used in an X-ray study for the stimulation of gastric peristalsis in cancer, a SNIM-1 apparatus serving as a source. It was based on a number of experimental studies indicating a possibility of using diadynamic currents, a variety of direct current, in cancer patients. Altogether 283 stomach cancer patients were examined. A method of peristalsis stimulation with diadynamic currents made it possible to significantly raise the accuracy of standard X-ray examination in establishing the anatomical form of the growth of stomach cancer, its intraorganic extension, the level of proximal and distal limits. The proposed method is simple to perform, the equipment is available in physiotherapeutic units

  6. PRESYNAPTIC DOPAMINE MODULATION BY STIMULANT SELF ADMINISTRATION

    Science.gov (United States)

    España, Rodrigo A.; Jones, Sara R.

    2013-01-01

    The mesolimbic dopamine system is an essential participant in the initiation and modulation of various forms of goal-directed behavior, including drug reinforcement and addiction processes. Dopamine neurotransmission is increased by acute administration of all drugs of abuse, including the stimulants cocaine and amphetamine. Chronic exposure to these drugs via voluntary self-administration provides a model of stimulant abuse that is useful in evaluating potential behavioral and neurochemical adaptations that occur during addiction. This review describes commonly used methodologies to measure dopamine and baseline parameters of presynaptic dopamine regulation, including exocytotic release and reuptake through the dopamine transporter in the nucleus accumbens core, as well as dramatic adaptations in dopamine neurotransmission and drug sensitivity that occur with acute non-contingent and chronic, contingent self-administration of cocaine and amphetamine. PMID:23277050

  7. Stimulated recall interviews for describing pragmatic epistemology

    Science.gov (United States)

    Shubert, Christopher W.; Meredith, Dawn C.

    2015-12-01

    Students' epistemologies affect how and what they learn: do they believe physics is a list of equations, or a coherent and sensible description of the physical world? In order to study these epistemologies as part of curricular assessment, we adopt the resources framework, which posits that students have many productive epistemological resources that can be brought to bear as they learn physics. In previous studies, these epistemologies have been either inferred from behavior in learning contexts or probed through surveys or interviews outside of the learning context. We argue that stimulated recall interviews provide a contextually and interpretively valid method to access students' epistemologies that complement existing methods. We develop a stimulated recall interview methodology to assess a curricular intervention and find evidence that epistemological resources aptly describe student epistemologies.

  8. Plasmonic Nanoprobes for Stimulated Emission Depletion Nanoscopy.

    Science.gov (United States)

    Cortés, Emiliano; Huidobro, Paloma A; Sinclair, Hugo G; Guldbrand, Stina; Peveler, William J; Davies, Timothy; Parrinello, Simona; Görlitz, Frederik; Dunsby, Chris; Neil, Mark A A; Sivan, Yonatan; Parkin, Ivan P; French, Paul M W; Maier, Stefan A

    2016-11-22

    Plasmonic nanoparticles influence the absorption and emission processes of nearby emitters due to local enhancements of the illuminating radiation and the photonic density of states. Here, we use the plasmon resonance of metal nanoparticles in order to enhance the stimulated depletion of excited molecules for super-resolved nanoscopy. We demonstrate stimulated emission depletion (STED) nanoscopy with gold nanorods with a long axis of only 26 nm and a width of 8 nm. These particles provide an enhancement of up to 50% of the resolution compared to fluorescent-only probes without plasmonic components irradiated with the same depletion power. The nanoparticle-assisted STED probes reported here represent a ∼2 × 10 3 reduction in probe volume compared to previously used nanoparticles. Finally, we demonstrate their application toward plasmon-assisted STED cellular imaging at low-depletion powers, and we also discuss their current limitations.

  9. Spinal cord stimulation: Background and clinical application

    DEFF Research Database (Denmark)

    Meier, Kaare

    2014-01-01

    Background Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain refractory to conventional treatment. SCS treatment consists of one or more leads implanted in the epidural space of the spinal canal, connected to an implantable pulse generator (IPG). Each lead carries...... a number of contacts capable of delivering a weak electrical current to the spinal cord, evoking a feeling of peripheral paresthesia. With correct indication and if implanted by an experienced implanter, success rates generally are in the range of about 50–75%. Common indications include complex regional...... is described in detail and illustrated with a series of intraoperative pictures. Finally, indications for SCS are discussed along with some of the controversies surrounding the therapy. Implications The reader is presented with a broad overview of spinal cord stimulation, including the historical...

  10. Stimulated Brillouin processes in crystals and glasses

    International Nuclear Information System (INIS)

    Faris, G.W.; Hickman, A.P.

    1992-02-01

    The basic physics and material properties needed to describe and predict the Brillouin gain for a variety of materials have been investigated. Lawrence Livermore National Laboratory (LLNL) has identified transverse stimulated Brillouin scattering (SBS) as an important limiting mechanism in high power laser fusion systems. At sufficiently high laser intensities, SBS drives acoustic vibrations that can damage optical components. SRI has performed measurements and developed the corresponding theory for stimulated Brillouin gain spectroscopy in anisotropic crystals. Absolute Brillouin steady-state gain coefficients, linewidths, and frequency shifts have been determined at 532 nm for a number of optical materials of interest to LLNL. This knowledge can be used to select optical materials and devise suppression schemes that will allow much higher laser fluences to be used in laser fusion

  11. The transition process: Stimulating free entrepreneurship

    Directory of Open Access Journals (Sweden)

    Stojanović Božo J.

    2003-01-01

    Full Text Available The text consists of two parts. In the first we expound the thesis that transition is actually a process of creation of institutional preconditions for development of private entrepreneurship at a given moment and under the inherited circumstances. To create an environment that stimulates free entrepreneurship and enables a successful transition requires a lot of knowledge, creativity and pragmatism (there is no general model. The rest remains on the entrepreneurs. In the second part we analyse the experience of FRY before and after the change of regime. During the former regime FRY was an example of degenerative connection between politics and economy geared to prevent reforms. The task of the new government is to make a radical break with the earlier practice. If the reform is not radical and not aiming to create an institutional environment that fully stimulates competition and private entrepreneurship (which has not been the case so far, it has no good prospects to succeed.

  12. Enhancement stimulants: perceived motivational and cognitive advantages

    Directory of Open Access Journals (Sweden)

    Irena P. Ilieva

    2013-10-01

    Full Text Available Psychostimulants like Adderall and Ritalin are widely used for cognitive enhancement by people without ADHD, although the empirical literature has shown little conclusive evidence for effectiveness in this population. This paper explores one potential explanation of this discrepancy: the possibility that the benefit from enhancement stimulants is at least in part motivational, rather than purely cognitive. We review relevant laboratory, survey and interview research and present the results of a new survey of enhancement users with the goal of comparing perceived cognitive and motivational effects. These users perceived stimulant effects on motivationally-related factors, especially energy and motivation, and reported motivational effects to be at least as pronounced as cognitive effects, including effects on "attention."

  13. Enhancement stimulants: perceived motivational and cognitive advantages.

    Science.gov (United States)

    Ilieva, Irena P; Farah, Martha J

    2013-01-01

    Psychostimulants like Adderall and Ritalin are widely used for cognitive enhancement by people without ADHD, although the empirical literature has shown little conclusive evidence for effectiveness in this population. This paper explores one potential explanation of this discrepancy: the possibility that the benefit from enhancement stimulants is at least in part motivational, rather than purely cognitive. We review relevant laboratory, survey, and interview research and present the results of a new survey of enhancement users with the goal of comparing perceived cognitive and motivational effects. These users perceived stimulant effects on motivationally-related factors, especially "energy" and "motivation," and reported motivational effects to be at least as pronounced as cognitive effects, including the effects on "attention."

  14. Neutron stimulated emission computed tomography: Background corrections

    International Nuclear Information System (INIS)

    Floyd, Carey E.; Sharma, Amy C.; Bender, Janelle E.; Kapadia, Anuj J.; Xia, Jessie Q.; Harrawood, Brian P.; Tourassi, Georgia D.; Lo, Joseph Y.; Kiser, Matthew R.; Crowell, Alexander S.; Pedroni, Ronald S.; Macri, Robert A.; Tajima, Shigeyuki; Howell, Calvin R.

    2007-01-01

    Neutron stimulated emission computed tomography (NSECT) is an imaging technique that provides an in-vivo tomographic spectroscopic image of the distribution of elements in a body. To achieve this, a neutron beam illuminates the body. Nuclei in the body along the path of the beam are stimulated by inelastic scattering of the neutrons in the beam and emit characteristic gamma photons whose unique energy identifies the element. The emitted gammas are collected in a spectrometer and form a projection intensity for each spectral line at the projection orientation of the neutron beam. Rotating and translating either the body or the beam will allow a tomographic projection set to be acquired. Images are reconstructed to represent the spatial distribution of elements in the body. Critical to this process is the appropriate removal of background gamma events from the spectrum. Here we demonstrate the equivalence of two background correction techniques and discuss the appropriate application of each

  15. Deep brain stimulation surgery for alcohol addiction.

    Science.gov (United States)

    Voges, Juergen; Müller, Ulf; Bogerts, Bernhard; Münte, Thomas; Heinze, Hans-Jochen

    2013-01-01

    The consequences of chronic alcohol dependence cause important health and economic burdens worldwide. Relapse rates after standard treatment (medication and psychotherapy) are high. There is evidence from in vivo investigations and from studies in patients that the brain's reward system is critically involved in the development and maintenance of addictive behavior, suggesting that modification of this system could significantly improve the prognosis of addictive patients. Motivated by an accidental observation, we used the nucleus accumbens (NAc), which has a central position in the dopaminergic reward system for deep brain stimulation (DBS) of alcohol addiction. We report our first experiences with NAc DBS for alcohol dependence and review the literature addressing the mechanisms leading to addiction. Five patients were treated off-label with bilateral NAc DBS for severe alcohol addiction (average follow-up 38 months). All patients experienced significant and ongoing improvement of craving. Two patients remained completely abstinent for more than 4 years. NAc stimulation was tolerated without permanent side effects. Simultaneous recording of local field potentials from the target area and surface electroencephalography while patients performed neuropsychological tasks gave a hint on the pivotal role of the NAc in processing alcohol-related cues. To our knowledge, the data presented here reflect the first attempt to treat alcohol-addicted patients with NAc DBS. Electrical NAc stimulation probably counterbalances the effect of drug-related stimuli triggering involuntarily drug-seeking behavior. Meanwhile, two prospective clinical studies using randomized, double-blind, and crossover stimulation protocols for DBS are underway to corroborate these preliminary results. Published by Elsevier Inc.

  16. Bubble nonlinear dynamics and stimulated scattering process

    Science.gov (United States)

    Jie, Shi; De-Sen, Yang; Sheng-Guo, Shi; Bo, Hu; Hao-Yang, Zhang; Shi-Yong, Hu

    2016-02-01

    A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller-Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. Project supported by the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT1228) and the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 11204050 and 11204049).

  17. Mechanism of stimulated radiation by charged particles

    International Nuclear Information System (INIS)

    Zachary, W.W.

    1979-01-01

    We have studied the mechanism for radiation by charged particles called stimulated electromagnetic shock radiation (SESR) by Schneider and Spitzer caused by the interaction between a relativistic charged particle and an externally applied electromagnetic plane wave in a dielectric. The present theory predicts that the SESR effect is large when the frequency of the plane wave lies in the microwave region but is small at higher frequencies for plane-wave field strengths smaller than the breakdown field of the dielectric

  18. Anesthesia for Pediatric Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Joseph Sebeo

    2010-01-01

    Full Text Available In patients refractory to medical therapy, deep brain stimulations (DBSs have emerged as the treatment of movement disorders particularly Parkinson's disease. Their use has also been extended in pediatric and adult patients to treat epileptogenic foci. We here performed a retrospective chart review of anesthesia records from 28 pediatric cases of patients who underwent DBS implantation for dystonia using combinations of dexmedetomidine and propofol-based anesthesia. Complications with anesthetic techniques including airway and cardiovascular difficulties were analyzed.

  19. Reconstitution of catecholamine-stimulated guanosinetriphosphatase activity.

    Science.gov (United States)

    Brandt, D R; Asano, T; Pedersen, S E; Ross, E M

    1983-09-13

    beta-Adrenergic receptors were partially purified from turkey erythrocyte membranes by alprenolol-agarose chromatography to 0.25-2 nmol/mg of protein, and the stimulatory guanosine 5'-triphosphate (GTP) binding protein of adenylate cyclase (Gs) was purified from rabbit liver. These proteins were reconstituted into phospholipid vesicles by addition of phospholipids and removal of detergent by gel filtration. This preparation hydrolyzes GTP to guanosine 5'-diphosphate (GDP) plus inorganic phosphate (Pi) in response to beta-adrenergic agonists. The initial rate of isoproterenol-stimulated hydrolysis is approximately 1 mol of GTP hydrolyzed min-1 X mol-1 of Gs. This low rate may be limited by the hormone-stimulated binding of substrate, since it is roughly equal to the rate of binding of the GTP analogue guanosine 5'-O-(3-[35S] thiotriphosphate) [( 35S]GTP gamma S) to Gs in the vesicles. Activity in the absence of agonist, or in the presence of agonist plus a beta-adrenergic antagonist, is 8-25% of the hormone-stimulated activity. Guanosinetriphosphatase (GTPase) is not saturated at 10 microM GTP, and the response to GTP is formally consistent either with the existence of multiple Km's or of a separate stimulatory site for GTP. The GTPase activity of Gs in vesicles is also stimulated by 50 mM MgCl2 in the presence or absence of receptor. Significant GTPase activity is not observed with Lubrol-solubilized Gs, although [35S]-GTP gamma S binding is increased by Lubrol solubilization.

  20. Hippocampal correlates of aversive mibdrain stimulation.

    Science.gov (United States)

    Routtenberg, A; Kramis, R C

    1968-06-21

    Hippocampal synchronization during aversive dorsal midbrain stimulation was observed in rats both in a conditioning procedure and under d-tubo-curarine paralysis. The results restrict the generality of previous reports which correlated hippocampal synchronization and desynchronization with approach and withdrawal behavior, respectively. Relative to the condition of free movement, curarization reduced the frequency of both "spontaneous" and dorsal midbrain-evoked synchronization, thus suggesting possible direct and indirect effects of d-tubocurarine on subcortical structures.

  1. Concurrent electrical cervicomedullary stimulation and cervical transcutaneous spinal direct current stimulation result in a stimulus interaction.

    Science.gov (United States)

    Dongés, Siobhan C; Bai, Siwei; Taylor, Janet L

    2017-10-01

    What is the central question of this study? We previously showed that the motor pathway is not modified after cervical transcutaneous spinal direct current stimulation (tsDCS) applied using anterior-posterior electrodes. Here, we examine the motor pathway during stimulation. What is the main finding and its importance? We show that electrically elicited muscle responses to cervicomedullary stimulation are modified during tsDCS, whereas magnetically elicited responses are not. Modelling reveals electrical field modifications during concurrent tsDCS and electrical cervicomedullary stimulation. Changes in muscle response probably result from electrical field modifications rather than physiological changes. Care should be taken when applying electrical stimuli simultaneously. Transcutaneous spinal direct current stimulation (tsDCS) can modulate neuronal excitability within the human spinal cord; however, few studies have used tsDCS at a cervical level. This study aimed to characterize cervical tsDCS further by observing its acute effects on motor responses to transcranial magnetic stimulation and cervicomedullary stimulation. In both studies 1 and 2, participants (study 1, n = 8, four female; and study 2, n = 8, three female) received two periods of 10 min, 3 mA cervical tsDCS on the same day through electrodes placed in an anterior-posterior configuration over the neck; one period with the cathode posterior (c-tsDCS) and the other with the anode posterior (a-tsDCS). In study 1, electrically elicited cervicomedullary motor evoked potentials (eCMEPs) and transcranial magnetic stimulation-elicited motor evoked potentials (MEPs) were measured in biceps brachii and flexor carpi radialis before, during and after each tsDCS period. In study 2, eCMEPs and magnetically elicited CMEPs (mCMEPs) were measured before, during and after each tsDCS period. For study 3, computational modelling was used to observe possible interactions of cervical tsDCS and electrical

  2. A brush stimulator for functional brain imaging.

    Science.gov (United States)

    Jousmäki, V; Nishitani, N; Hari, R

    2007-12-01

    To describe a novel non-magnetic hand-held device to stimulate various parts of the skin and to evaluate its performance in magnetoencephalographic (MEG) recordings. The hand-held part of the device consists of an optic fiber bundle that forms a small brush. Half of the fibers emit modulated red light and the other half detect the reflected light from the skin so that the brush-to-skin contact is detected by means of reflectance. Light tapping of the back of the hand at the innervation area of the radial nerve elicited clear responses in all 10 subjects studied, with the main deflections peaking 40-70 ms after the stimulus. The earliest responses, obtained with a higher number of averaged trials, peaked 27-28 ms after the tap to the left hand dorsum. Source analysis of the MEG signals indicated neuronal sources at the primary somatosensory (SI) cortex, with a clear somatotopical order for face vs. hand. The device seems feasible for both MEG and functional magnetic resonance imaging experiments to address functional anatomy of the human somatosensory system with a real-life like stimulation. Non-magnetic and artefact-free tactile stimulator with a selective stimulus offers new possibilities for experimental designs to study the human mechanoreceptor system.

  3. Andrographolide Stimulates Neurogenesis in the Adult Hippocampus

    Directory of Open Access Journals (Sweden)

    Lorena Varela-Nallar

    2015-01-01

    Full Text Available Andrographolide (ANDRO is a labdane diterpenoid component of Andrographis paniculata widely used for its anti-inflammatory properties. We have recently determined that ANDRO is a competitive inhibitor of glycogen synthase kinase-3β (GSK-3β, a key enzyme of the Wnt/β-catenin signaling cascade. Since this signaling pathway regulates neurogenesis in the adult hippocampus, we evaluated whether ANDRO stimulates this process. Treatment with ANDRO increased neural progenitor cell proliferation and the number of immature neurons in the hippocampus of 2- and 10-month-old mice compared to age-matched control mice. Moreover, ANDRO stimulated neurogenesis increasing the number of newborn dentate granule neurons. Also, the effect of ANDRO was evaluated in the APPswe/PS1ΔE9 transgenic mouse model of Alzheimer’s disease. In these mice, ANDRO increased cell proliferation and the density of immature neurons in the dentate gyrus. Concomitantly with the increase in neurogenesis, ANDRO induced the activation of the Wnt signaling pathway in the hippocampus of wild-type and APPswe/PS1ΔE9 mice determined by increased levels of β-catenin, the inactive form of GSK-3β, and NeuroD1, a Wnt target gene involved in neurogenesis. Our findings indicate that ANDRO stimulates neurogenesis in the adult hippocampus suggesting that this drug could be used as a therapy in diseases in which neurogenesis is affected.

  4. Luminescence optically stimulated: theory and applications

    International Nuclear Information System (INIS)

    Rivera M, T.; Azorin N, J.

    2002-01-01

    The thermally stimulated luminescence (Tl) has occupied an important place in the Solid state physics (FES) by the flexibility of the phenomena, mainly for its applications in the fields of Radiation Physics (FR) and Medical Physics (MF). The reason of this phenomena lies in the fact of the electrons release by the action of heat. Under that same reason, it can be used the action of another stimulant agent for releasing the trapped electrons in the metastable states (EM), this agent is the light which has the same effect that the heat, giving as result the production of light photons at using light in the visible spectra, of different wavelength that the excitation light. This phenomena is called Luminescence optically stimulated (LOE). The LOE has a great impact in the Solid State Physics (FES), dating and now in the use of the phenomena as a dosimetric method, alternate to the Tl, for its use in the ionizing and non-ionizing radiations fields. (Author)

  5. Fetal stimulation by pulsed diagnostic ultrasound.

    Science.gov (United States)

    Fatemi, M; Ogburn, P L; Greenleaf, J F

    2001-08-01

    To show that pulsed ultrasound from a clinical ultrasonic imaging system can stimulate the fetus. Stimulation is defined mainly as increased fetal gross body movements in response to excitation. Fetuses of a group of 9 volunteer women (mean gestational age, 33.37 weeks; range, 25-40 weeks) were evaluated for body movement under 3 different conditions: (1) control, with no ultrasound exposure; (2) ultrasound in continuous wave Doppler mode; and (3) pulsed ultrasound in pulsed Doppler and B modes. A conventional external fetal monitor, with negligible ultrasonic output, was used to monitor fetal gross body motions. After an initial rest period of 3 minutes with 1 or no fetal motion, fetuses were monitored for an additional 3 minutes under the exposure criterion defined for each condition. Resulting fetal motions under the 3 conditions were compared using the Wilcoxon signed rank test. The test showed that fetuses moved significantly more frequently under condition 3 (mean +/- SD, 3.43 +/- 1.93 movements per minute) than under condition 1 (0.40 +/- 7.33 movements per minute) or condition 2 (0.63 +/- 7.67 movements per minute); P = .004 and .016, respectively. Fetal movements under conditions 1 and 2 did not differ significantly. Diagnostic ultrasound may stimulate fetal body motion.

  6. Measured stimulated Raman gain in methane

    International Nuclear Information System (INIS)

    Lopert, R.B.

    1983-01-01

    This report is about the stimulated Raman effect in methane due to the nu 1 vibration. For various gas pressures between 150 torr and 30 atm, the Raman lineshape function was both experimentally measured and synthesized using a computer model. The stimulated Raman gain was measured by sending a pump laser beam provided by an argon-ion laser and a weak probe beam provided by a tunable dye laser through a cell of methane gas. The stimulated Raman effect caused some of the energy from the pump beam to be transferred to the probe beam. The intensity of the pump beam was low so the gain of the probe beam was on the order of parts per million. A two detector arrangement and a differential amplifier system that had a feedback loop to balance the detectors was constructed to measure the small gains. A detailed description of this detection system that was able to measure gains as small as 0.2 parts per million is provided

  7. Action-blindsight in healthy subjects after transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Kristiansen, Lasse; Rowe, James B.

    2008-01-01

    Clinical cases of blindsight have shown that visually guided movements can be accomplished without conscious visual perception. Here, we show that blindsight can be induced in healthy subjects by using transcranial magnetic stimulation over the visual cortex. Transcranial magnetic stimulation...

  8. Peripheral nerve stimulator-induced electrostimulation at the P6 ...

    African Journals Online (AJOL)

    group B) received train-of-four electrical stimulation using the peripheral nerve stimulator (PNS) immediately prior to spinal anaesthesia until the completion of surgery. Outcome measures: The primary outcome measure was mean arterial ...

  9. Consecutive Acupuncture Stimulations Lead to Significantly Decreased Neural Responses

    NARCIS (Netherlands)

    Yeo, S.; Choe, I.H.; Noort, M.W.M.L. van den; Bosch, M.P.C.; Lim, S.

    2010-01-01

    Objective: Functional magnetic resonance imaging (fMRI), in combination with block design paradigms with consecutive acupuncture stimulations, has often been used to investigate the neural responses to acupuncture. In this study, we investigated whether previous acupuncture stimulations can affect

  10. Stimulation of artemisinin biosynthesis in Artemisia annua hairy ...

    African Journals Online (AJOL)

    , the OGA-induced reactive oxygen species (ROS) were involved in stimulating the artemisinin biosynthesis in the hairy roots. This is the first report on the stimulation of artemisinin production in hairy roots by an oligogalacturonide elicitor.

  11. Dynamics of the Alpha Peak Frequency During Flicker Stimulation

    NARCIS (Netherlands)

    Garcia Molina, G.; Milanowski ,P.

    2012-01-01

    Repetitive visual stimulation elicits specific brain responses knownas steady state visual evoked potentials (SSVEP). The SSVEP manifests as oscillatory components at the stimulation frequency or harmonics in brain signals such as the electroencephalogram (EEG) or magnetoencephalogram. Analysis of

  12. Electrical stimulation in dysphagia treatment: a justified controversy?

    NARCIS (Netherlands)

    Bogaardt, H. C. A.

    2008-01-01

    Electrical stimulation in dysphagia treatment: a justified controversy? Neuromuscular electrostimulation (LAMES) is a method for stimulating muscles with short electrical pulses. Neuromuscular electrostimulation is frequently used in physiotherapy to strengthen healthy muscles (as in sports

  13. Analysis of Postural Control Adaptation During Galvanic and Vibratory Stimulation

    National Research Council Canada - National Science Library

    Fransson, P

    2001-01-01

    The objective for this study was to investigate whether the postural control adaptation during galvanic stimulation of the vestibular nerve were similar to that found during vibration stimulation to the calf muscles...

  14. Effect of stimulation intensity on assessment of voluntary activation

    NARCIS (Netherlands)

    van Leeuwen, D.M.; de Ruiter, C.J.; de Haan, A.

    2012-01-01

    Introduction: The interpolated twitch technique is often used to assess voluntary activation (VA) of skeletal muscles. We investigated VA and the voluntary torque-superimposed torque relationship using either supramaximal nerve stimulation or better tolerated submaximal muscle stimulation, which is

  15. Effect of stimulation intensity on assessment of voluntary activation.

    NARCIS (Netherlands)

    Dr. D.M. van Leeuwen; C.J. de Ruiter; A.J. de Haan

    2012-01-01

    INTRODUCTION: The interpolated twitch technique is often used to assess voluntary activation (VA) of skeletal muscles. We investigated VA and the voluntary torque-superimposed torque relationship using either supramaximal nerve stimulation or better tolerated submaximal muscle stimulation, which is

  16. Functional Electrical Stimulation in Children and Adolescents with Cerebral Palsy

    Science.gov (United States)

    van der Linden, Marietta

    2012-01-01

    In this article, the author talks about functional electrical stimulation in children and adolescents with cerebral palsy. Functional electrical stimulation (FES) is defined as the electrical stimulation of muscles that have impaired motor control, in order to produce a contraction to obtain functionally useful movement. It was first proposed in…

  17. Medical back belt with integrated neuromuscular electrical stimulation

    NARCIS (Netherlands)

    Bottenberg, E. (Eliza); Brinks, G.J. (Ger); Hesse, J. (Jenny)

    2014-01-01

    The medical back belt with integrated neuromuscular electrical stimulation is anorthopedic device, which has two main functions. The first function is to stimulate the backmuscles by using a neuromuscular electrical stimulation device that releases regular,electrical impulses. The second function of

  18. 21 CFR 890.5860 - Ultrasound and muscle stimulator.

    Science.gov (United States)

    2010-04-01

    ..., muscle spasms, and joint contractures, but not for the treatment of malignancies. The device also passes... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasound and muscle stimulator. 890.5860 Section... Ultrasound and muscle stimulator. (a) Ultrasound and muscle stimulator for use in applying therapeutic deep...

  19. Pattern of Stimulant Use among Nigerian Undergraduate Students ...

    African Journals Online (AJOL)

    The instrument consisted of sociodemographic variables and the stimulant section of the World Health Organisation Questionnaire for Student Drug Use Survey. An item was added to determine the ... need to study without using stimulants. Keywords Pattern, stimulant, psychoactive-substance, caffeine, prevention, control ...

  20. 21 CFR 882.5800 - Cranial electrotherapy stimulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cranial electrotherapy stimulator. 882.5800 Section 882.5800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... electrotherapy stimulator. (a) Identification. A cranial electrotherapy stimulator is a device that applies...

  1. Effect of bleeding method and low voltage electrical stimulation on ...

    African Journals Online (AJOL)

    An early post mortem low voltage electrical stimulation (ES) of the carcasses also had no influence on the cooking loss, drip loss and colour of these muscles. Electrical stimulation did result in a lower pH45 in both the fillet and big drum muscles. However, after 24 h the pH of the muscles did not differ. Electrical stimulation ...

  2. Design of efficient and safe neural stimulators : A multidisciplinary approach

    NARCIS (Netherlands)

    Van Dongen, M.N.

    2015-01-01

    Neural stimulation is an established treatment methodology for an increasing number of diseases. Electrical Stimulation injects a stimulation signal through electrodes that are implanted in the target area of the central or peripheral nervous system in order to evoke a specific neuronal response

  3. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator (neuromuscular blockade monitor) is...

  4. [Subcutaneous stimulation as additional therapy to spinal cord stimulation in a post-laminectomy syndrome patient].

    Science.gov (United States)

    Akbaş, Mert; Yeğin, Mehmet Arif; Özdemir, İrem; Göksu, Ethem; Akyüz, Mahmut

    2016-01-01

    Spinal cord stimulation as treatment of chronic low back pain via neuromodulation has been frequently performed in recent years. The dorsal column is stimulated by an electrode placed at the epidural region. In the case presently described, subcutaneous lead was implanted in a patient with failed back syndrome after spinal cord stimulation was inadequate to treat back and gluteal pain. A 65-year-old male had undergone surgery to treat lumbar disc herniation, after which he received physical therapy and multiple steroid injections due to unrelieved pain. He was admitted to the pain clinic with pain radiating to right gluteal muscle and leg. Spinal cord stimulation was performed and, as pain was not relieved, subcutaneous lead was applied to the right cluneal nerve distribution. Following treatment, the patient scored 1-2 on visual analog scale. Pain had been reduced by over 80%. Octad electrode was placed between T8 and T10 vertebrae after Tuohy needle was introduced to intervertebral area between L1 and L2. Paresthesia occurred in the right extremity. Boundaries were determined by area of right gluteal region in which paresthesia did not occur. Octad electrode was placed subcutaneously after vertical line was drawn from center point. Paresthesia occurred throughout the region. Pulse wave was 390-450 msec; frequency was 10-30 Hz. Subcutaneous electrode replacement is effective additional therapy when pain is not relieved by spinal cord stimulation.

  5. Approximating transcranial magnetic stimulation with electric stimulation in mouse: a simulation study.

    Science.gov (United States)

    Barnes, Walter L; Lee, Won Hee; Peterchev, Angel V

    2014-01-01

    Rodent models are valuable for preclinical examination of novel therapeutic techniques, including transcranial magnetic stimulation (TMS). However, comparison of TMS effects in rodents and humans is confounded by inaccurate scaling of the spatial extent of the induced electric field in rodents. The electric field is substantially less focal in rodent models of TMS due to the technical restrictions of making very small coils that can handle the currents required for TMS. We examine the electric field distributions generated by various electrode configurations of electric stimulation in an inhomogeneous high-resolution finite element mouse model, and show that the electric field distributions produced by human TMS can be approximated by electric stimulation in mouse. Based on these results and the limits of magnetic stimulation in mice, we argue that the most practical and accurate way to model focal TMS in mice is electric stimulation through either cortical surface electrodes or electrodes implanted halfway through the mouse cranium. This approach could allow much more accurate approximation of the human TMS electric field focality and strength than that offered by TMS in mouse, enabling, for example, focal targeting of specific cortical regions, which is common in human TMS paradigms.

  6. Carbon Nanofiber Nanoelectrodes for Neural Stimulation and Chemical Detection: The Era of "Smart" Deep Brain Stimulation

    Science.gov (United States)

    Koehne, Jessica E.

    2016-01-01

    A sensor platform based on vertically aligned carbon nanofibers (CNFs) has been developed. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report two studies using vertically aligned CNF nanoelectrodes for biomedical applications. CNF arrays are investigated as neural stimulation and neurotransmitter recording electrodes for application in deep brain stimulation (DBS). Polypyrrole coated CNF nanoelectrodes have shown great promise as stimulating electrodes due to their large surface area, low impedance, biocompatibility and capacity for highly localized stimulation. CNFs embedded in SiO2 have been used as sensing electrodes for neurotransmitter detection. Our approach combines a multiplexed CNF electrode chip, developed at NASA Ames Research Center, with the Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS) system, developed at the Mayo Clinic. Preliminary results indicate that the CNF nanoelectrode arrays are easily integrated with WINCS for neurotransmitter detection in a multiplexed array format. In the future, combining CNF based stimulating and recording electrodes with WINCS may lay the foundation for an implantable smart therapeutic system that utilizes neurochemical feedback control while likely resulting in increased DBS application in various neuropsychiatric disorders. In total, our goal is to take advantage of the nanostructure of CNF arrays for biosensing studies requiring ultrahigh sensitivity, high-degree of miniaturization, and selective biofunctionalization.

  7. Carbon Nanofiber Nanoelectrodes for Neural Stimulation and Chemical Detection: The Era of Smart Deep Brain Stimulation

    Science.gov (United States)

    Koehne, Jessica E.

    2016-01-01

    A sensor platform based on vertically aligned carbon nanofibers (CNFs) has been developed. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report two studies using vertically aligned CNF nanoelectrodes for biomedical applications. CNF arrays are investigated as neural stimulation and neurotransmitter recording electrodes for application in deep brain stimulation (DBS). Polypyrrole coated CNF nanoelectrodes have shown great promise as stimulating electrodes due to their large surface area, low impedance, biocompatibility and capacity for highly localized stimulation. CNFs embedded in SiO2 have been used as sensing electrodes for neurotransmitter detection. Our approach combines a multiplexed CNF electrode chip, developed at NASA Ames Research Center, with the Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS) system, developed at the Mayo Clinic. Preliminary results indicate that the CNF nanoelectrode arrays are easily integrated with WINCS for neurotransmitter detection in a multiplexed array format. In the future, combining CNF based stimulating and recording electrodes with WINCS may lay the foundation for an implantable "smart" therapeutic system that utilizes neurochemical feedback control while likely resulting in increased DBS application in various neuropsychiatric disorders. In total, our goal is to take advantage of the nanostructure of CNF arrays for biosensing studies requiring ultrahigh sensitivity, high-degree of miniaturization, and selective biofunctionalization.

  8. A Stimulator ASIC Featuring Versatile Management for Vestibular Prostheses.

    Science.gov (United States)

    Dai Jiang; Demosthenous, Andreas; Perkins, Timothy; Xiao Liu; Donaldson, Nick

    2011-04-01

    This paper presents a multichannel stimulator ASIC for an implantable vestibular prosthesis. The system features versatile stimulation management which allows fine setting of the parameters for biphasic stimulation pulses. To address the problem of charge imbalance due to rounding errors, the digital processor can calculate and provide accurate charge correction. A technique to reduce the data rate to the stimulator is described. The stimulator ASIC was implemented in 0.6-μ m high-voltage CMOS technology occupying an area of 2.27 mm(2). The measured performance of the ASIC has been verified using vestibular electrodes in saline.

  9. Local and Systemic Changes in Pain Sensitivity After 4 Weeks of Calf Muscle Stretching in a Nonpainful Population

    DEFF Research Database (Denmark)

    Bartholdy, Cecilie; Zangger, Graziella; Hansen, Lisbeth

    2016-01-01

    BACKGROUND: Stretching is often used in clinical practice for a variety of purposes, including pain therapy. The possible mechanism behind the effect of stretching remains to be clarified. AIM: To investigate whether 4 weeks of unilateral stretching of the calf muscles would affect local...... and central pain sensitivity. METHOD: This study was a randomized assessor-blinded clinical study. Healthy participants (age 18 to 40) were included and randomized. Participants in the intervention group were instructed to perform 2 stretching exercises targeting the calf muscles; 3 times 30 seconds, 7 days...... intervention group/19 control group). No statistically significant group differences in the changes from baseline were found regarding PPT and TS measurements for the stretched calf, the contra-lateral calf, and the arm. CONCLUSION: Four weeks of regular stretching of the calf muscles does not affect pressure...

  10. Comparison of cortical responses to the activation of retina by visual stimulation and transcorneal electrical stimulation.

    Science.gov (United States)

    Sun, Pengcheng; Li, Heng; Lu, Zhuofan; Su, Xiaofan; Ma, Zengguang; Chen, Jianpin; Li, Liming; Zhou, Chuanqing; Chen, Yao; Chai, Xinyu

    2018-02-21

    Electrical stimulation has been widely used in many ophthalmic diseases to modulate neuronal activities or restore partial visual function. Due to the different processing pathways and mechanisms, responses to visual and electrical stimulation in the primary visual cortex and higher visual areas might be different. This differences would shed some light on the properties of cortical responses evoked by electrical stimulation. This study's goal was to directly compare the cortical responses evoked by visual and electrical stimulation and investigate the cortical processing of visual information and extrinsic electrical signal. Optical imaging of intrinsic signals (OIS) was used to probe the cortical hemodynamic responses in 11 cats. Transcorneal electrical stimulation (TES) through an ERG-jet contact lens electrode was used to activate visual cortices. Full-field and peripheral drifting gratings were used as the visual stimuli. The response latency evoked by TES was shorter than that responding to visual stimulation (VS). Cortical responses evoked by VS were retinotopically organized, which was consistent with previous studies. On the other hand, the cortical region activated by TES was preferentially located in the secondary visual cortex (Area 18), while the primary visual cortex (Area 17) was activated by a higher current intensity. Compared with the full-field VS, the cortical response in Area 18 to TES with a current intensity above 1.2 mA was significantly stronger. According to our results, we provided some evidence that the cortical processing of TES was influenced by the distribution of the electrical field in the retina and the activating threshold of different retinal ganglion cells. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Cranial electrotherapy stimulation and transcranial pulsed current stimulation: a computer based high-resolution modeling study.

    Science.gov (United States)

    Datta, Abhishek; Dmochowski, Jacek P; Guleyupoglu, Berkan; Bikson, Marom; Fregni, Felipe

    2013-01-15

    The field of non-invasive brain stimulation has developed significantly over the last two decades. Though two techniques of noninvasive brain stimulation--transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS)--are becoming established tools for research in neuroscience and for some clinical applications, related techniques that also show some promising clinical results have not been developed at the same pace. One of these related techniques is cranial electrotherapy stimulation (CES), a class of transcranial pulsed current stimulation (tPCS). In order to understand further the mechanisms of CES, we aimed to model CES using a magnetic resonance imaging (MRI)-derived finite element head model including cortical and also subcortical structures. Cortical electric field (current density) peak intensities and distributions were analyzed. We evaluated different electrode configurations of CES including in-ear and over-ear montages. Our results confirm that significant amounts of current pass the skull and reach cortical and subcortical structures. In addition, depending on the montage, induced currents at subcortical areas, such as midbrain, pons, thalamus and hypothalamus are of similar magnitude than that of cortical areas. Incremental variations of electrode position on the head surface also influence which cortical regions are modulated. The high-resolution modeling predictions suggest that details of electrode montage influence current flow through superficial and deep structures. Finally we present laptop based methods for tPCS dose design using dominant frequency and spherical models. These modeling predictions and tools are the first step to advance rational and optimized use of tPCS and CES. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Bilateral saccadic eye movements and tactile stimulation, but not auditory stimulation, enhance memory retrieval.

    Science.gov (United States)

    Nieuwenhuis, Sander; Elzinga, Bernet M; Ras, Priscilla H; Berends, Floris; Duijs, Peter; Samara, Zoe; Slagter, Heleen A

    2013-02-01

    Recent research has shown superior memory retrieval when participants make a series of horizontal saccadic eye movements between the memory encoding phase and the retrieval phase compared to participants who do not move their eyes or move their eyes vertically. It has been hypothesized that the rapidly alternating activation of the two hemispheres that is associated with the series of left-right eye movements is critical in causing the enhanced retrieval. This hypothesis predicts a beneficial effect on retrieval of alternating left-right stimulation not only of the visuomotor system, but also of the somatosensory system, both of which have a strict contralateral organization. In contrast, this hypothesis does not predict an effect, or a weaker effect, on retrieval of alternating left-right stimulation of the auditory system, which has a much less lateralized organization. Consistent with these predictions, we replicated the horizontal saccade-induced retrieval enhancement (Experiment 1) and showed that a similar retrieval enhancement occurs after alternating left-right tactile stimulation (Experiment 2). Furthermore, retrieval was not enhanced after alternating left-right auditory stimulation compared to simultaneous bilateral auditory stimulation (Experiment 3). We discuss the possibility that alternating bilateral activation of the left and right hemispheres exerts its effects on memory by increasing the functional connectivity between the two hemispheres. We also discuss the findings in the context of clinical practice, in which bilateral eye movements (EMDR) and auditory stimulation are used in the treatment of post-traumatic stress disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Repetitive transcranial magnetic stimulation in psychiatry

    Directory of Open Access Journals (Sweden)

    Biswa Ranjan Mishra

    2011-01-01

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a non-invasive and relatively painless tool that has been used to study various cognitive functions as well as to understand the brain-behavior relationship in normal individuals as well as in those with various neuropsychiatric disorders. It has also been used as a therapeutic tool in various neuropsychiatric disorders because of its ability to specifically modulate distinct brain areas. Studies have shown that repeated stimulation at low frequency produces long-lasting inhibition, which is called as long-term depression, whereas repeated high-frequency stimulation can produce excitation through long-term potentiation. This paper reviews the current status of rTMS as an investigative and therapeutic modality in various neuropsychiatric disorders. It has been used to study the cortical and subcortical functions, neural plasticity and brain mapping in normal individuals and in various neuropsychiatric disorders. rTMS has been most promising in the treatment of depression, with an overall milder adverse effect profile compared with electroconvulsive therapy. In other neuropsychiatric disorders such as schizophrenia, mania, epilepsy and substance abuse, it has been found to be useful, although further studies are required to establish therapeutic efficacy. It appears to be ineffective in the treatment of obsessive compulsive disorder. There is a paucity of studies of efficacy and safety of rTMS in pediatric and geriatric population. Although it appears safe, further research is required to optimize its efficacy and reduce the side-effects. Magnetic seizure therapy, which involves producing seizures akin to electroconvulsive therapy, appears to be of comparable efficacy in the treatment of depression with less cognitive adverse effects.

  14. Asystole Following Profound Vagal Stimulation During Hepatectomy

    Directory of Open Access Journals (Sweden)

    Preeta John

    2008-01-01

    Full Text Available Asystole in a non laparoscopic upper abdominal surgery following intense vagal stimulation is a rare event. This case report highlights the need for awareness of such a complication when a thoracic epidural anaesthetic has been given in addition to a general anaesthetic for an upper abdominal procedure. A combined thoracic epidural and general anaesthetic was given. The anterior abdominal wall was retracted forty minutes after administration of the epidural bolus. This maneuver resulted in a profound vagal response with bradycardia and asystole. The patient was resuscitated successfully with a cardiac massage, atropine and adrenaline and the surgery was resumed. Surgery lasted eleven hours and was uneventful.

  15. [B lymphocyte stimulator in systemic lupus erythematosus].

    Science.gov (United States)

    Mercado, Ulises

    2012-01-01

    The B lymphocyte stimulator (BLyS) is an essential protein for the growth and survival of B cells. BLyS is expressed on monocytes, macrophages, and dendritic cells. BLyS binds to three receptors on B cells: BAFF-R, BCMA, and TACI. BLyS overexpression in mice leads to lupus-like syndrome, but not in all, whereas BLyS deficient mice results in a block of B cell development. High serum levels of BLyS can be detected in patients with lupus and rheumatoid arthritis. BLyS antagonists are an attractive target for treating autoimmune diseases.

  16. DNA repair in PHA stimulated human lymphocytes

    International Nuclear Information System (INIS)

    Catena, C.; Mattoni, A.

    1984-01-01

    Damage an repair of radiation induced DNA strand breaks were measured by alkaline lysis and hydroxyapatite chromatography. PHA stimulated human lymphocytes show that the rejoining process is complete within the first 50 min., afterwords secondary DNA damage and chromatid aberration. DNA repair, in synchronized culture, allows to evaluate individual repair capacity and this in turn can contribute to the discovery of individual who, although they do not demonstrate apparent clinical signs, are carriers of DNA repair deficiency. Being evident that a correlation exists between DNA repair capacity and carcinogenesis, the possibility of evaluating the existent relationship between DNA repair and survival in tumor cells comes therefore into discussion

  17. Stimulated Brillouin Cavity Optomechanics in Liquid Droplets

    Science.gov (United States)

    Giorgini, A.; Avino, S.; Malara, P.; De Natale, P.; Yannai, M.; Carmon, T.; Gagliardi, G.

    2018-02-01

    Liquid droplets are ubiquitous in nature wherein surface tension shapes them into perfect spheres with atomic-scale smooth surfaces. Here, we use stable droplets that cohost equatorial acoustical and optical resonances phase matched to enable the exchange of energy and momentum between sound and light. Relying on free-space laser excitation of multiple whispering-gallery modes, we harness a triple-resonant forward Brillouin scattering to stimulate optomechanical surface waves. Nonlinear amplification of droplet vibrations in the 60-70 MHz range is realized with spectral narrowing beyond the limit of material loss, thereby activating the droplet as hypersound-laser emitter.

  18. Sodium-stimulated ATPase in Streptococcus faecalis.

    OpenAIRE

    Kinoshita, N; Unemoto, T; Kobayashi, H

    1984-01-01

    We measured Na+-stimulated ATPase activity in a mutant of Streptococcus faecalis defective in the generation of proton motive force. The activity in membrane vesicles was 62.1 +/- 5.9 nmol of phosphate produced per min per mg of protein when cells were grown on medium containing 0.12 M Na+. Activity decreased as the concentration of Na+ in the growth medium decreased. The decrease in enzyme activity corresponded to the decrease in transport activity for Na+ in both whole cells and membrane ve...

  19. Effects of Vibrotactile Stimulation During Virtual Sandboarding

    DEFF Research Database (Denmark)

    Lind, Stine; Thomsen, Lui; Egebjerg, Mie

    2016-01-01

    underneath the board. The study compared three conditions: no vibration, constant vibration and dynamic vibration. The results suggest that constant vibrotactile feedback led to significantly more compelling self-motion illusions and a higher degree of perceived realism, than the condition devoid......This poster details a within-subjects study (n=17) investigating the effects of vibrotactile stimulation on illusory self-motion, presence and perceived realism during an interactive sandboarding simulation. Vibrotactile feedback was delivered using a low frequency audio transducer mounted...

  20. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

    This book provides readers with basic principles of the electrochemistry of the electrodes used in modern, implantable neural prostheses. The authors discuss the boundaries and conditions in which the electrodes continue to function properly for long time spans, which are required when designing neural stimulator devices for long-term in vivo applications. Two kinds of electrode materials, titanium nitride and iridium are discussed extensively, both qualitatively and quantitatively. The influence of the counter electrode on the safety margins and electrode lifetime in a two electrode system is explained. Electrode modeling is handled in a final chapter.

  1. The analysis of thermally stimulated processes

    CERN Document Server

    Chen, R; Pamplin, Brian

    1981-01-01

    Thermally stimulated processes include a number of phenomena - either physical or chemical in nature - in which a certain property of a substance is measured during controlled heating from a 'low' temperature. Workers and graduate students in a wide spectrum of fields require an introduction to methods of extracting information from such measurements. This book gives an interdisciplinary approach to various methods which may be applied to analytical chemistry including radiation dosimetry and determination of archaeological and geological ages. In addition, recent advances are included, such

  2. Optically Stimulated Luminescence Fundamentals and Applications

    CERN Document Server

    McKeever, Stephen

    2011-01-01

    The book discusses advanced modern applications of optically stimulated luminescence including the appropriate fundamentals of the process. It features major chapters on the use of OSL in space radiation dosimetry, medical physics, personnel dosimetry, security, solid-state physics and other related applications. In each case, the underlying theory is discussed on an as-needed basis for a complete understanding of the phenomena, but with an emphasis of the practical applications of the technique. After an introductory chapter, Chapters 2 to 6 cover basic theory and practical aspects, personal

  3. Isoconversional kinetics of thermally stimulated processes

    CERN Document Server

    Vyazovkin, Sergey

    2015-01-01

    The use of isoconversional kinetic methods for analysis of thermogravimetric and calorimetric data on thermally stimulated processes is quickly growing in popularity. The purpose of this book is to create the first comprehensive resource on the theory and applications of isoconversional methodology. The book introduces the reader to the kinetics of physical and chemical condensed phase processes that occur as a result of changing temperature and discusses how isoconversional analysis can provide important kinetic insights into them. The book will help the readers to develop a better understanding of the methodology, and promote its efficient usage and successful development.

  4. Stimulated-emission-depletion microscopy with a multicolor stimulated-Raman-scattering light source.

    Science.gov (United States)

    Rankin, Brian R; Kellner, Robert R; Hell, Stefan W

    2008-11-01

    We describe a subdiffraction-resolution far-field fluorescence microscope employing stimulated emission depletion (STED) with a light source consisting of a microchip laser coupled into a standard single-mode fiber, which, via stimulated Raman scattering (SRS), yields a comb-like spectrum of seven discrete peaks extending from the fundamental wavelength at 532 nm to 620 nm. Each of the spectral peaks can be used as STED light for overcoming the diffraction barrier. This SRS light source enables the simple implementation of multicolor STED and provides a spectral output with multiple available wavelengths from green to red with potential for further expansion.

  5. Paired associative stimulation targeting the tibialis anterior muscle using either mono or biphasic transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Mrachacz-Kersting, Natalie; Stevenson, Andrew James Thomas

    2017-01-01

    Paired associative stimulation (PAS) protocols induce plastic changes within the motor cortex. The objectives of this study were to investigate PAS effects targeting the tibialis anterior (TA) muscle using a biphasic transcranial magnetic stimulation (TMS) pulse form and, to determine whether...... a reduced intensity of this pulse would lead to significant changes as has been reported for hand muscles using a monophasic TMS pulse. Three interventions were investigated: (1) suprathreshold PAbi-PAS (n = 11); (2) suprathreshold PAmono-PAS (n = 11) where PAS was applied using a biphasic or monophasic...

  6. Thermo-stimulated current and dielectric loss in composite materials

    International Nuclear Information System (INIS)

    Nishijima, S.; Hagihara, T.; Okada, T.

    1986-01-01

    Thermo-stimulated current and dielectric loss measurements have been performed on five kinds of commercially available composite materials in order to study the electric properties of composite materials at low temperatures. Thermo-stimulated current measurements have been made on the composite materials in which the matrix quality was changed intentionally. The changes in the matrices were introduced by gamma irradiation or different curing conditions. Thermo-stimulated current and dielectric loss measurements revealed the number and the molecular weight of dipolar molecules. The different features of thermo-stimulated current and dielectric losses were determined for different composite materials. The gamma irradiation and the curing conditions especially affect the thermo-stimulated current features. The changes in macroscopic mechanical properties reflect those of thermo-stimulated current. It was found that the change in quality and/or degradation of the composite materials could be detected by means of thermo-stimulated current and/or dielectric loss measurements

  7. Design of efficient and safe neural stimulators a multidisciplinary approach

    CERN Document Server

    van Dongen, Marijn

    2016-01-01

    This book discusses the design of neural stimulator systems which are used for the treatment of a wide variety of brain disorders such as Parkinson’s, depression and tinnitus. Whereas many existing books treating neural stimulation focus on one particular design aspect, such as the electrical design of the stimulator, this book uses a multidisciplinary approach: by combining the fields of neuroscience, electrophysiology and electrical engineering a thorough understanding of the complete neural stimulation chain is created (from the stimulation IC down to the neural cell). This multidisciplinary approach enables readers to gain new insights into stimulator design, while context is provided by presenting innovative design examples. Provides a single-source, multidisciplinary reference to the field of neural stimulation, bridging an important knowledge gap among the fields of bioelectricity, neuroscience, neuroengineering and microelectronics;Uses a top-down approach to understanding the neural activation proc...

  8. Stimulation of entorhinal cortex-dentate gyrus circuitry is antidepressive.

    Science.gov (United States)

    Yun, Sanghee; Reynolds, Ryan P; Petrof, Iraklis; White, Alicia; Rivera, Phillip D; Segev, Amir; Gibson, Adam D; Suarez, Maiko; DeSalle, Matthew J; Ito, Naoki; Mukherjee, Shibani; Richardson, Devon R; Kang, Catherine E; Ahrens-Nicklas, Rebecca C; Soler, Ivan; Chetkovich, Dane M; Kourrich, Saïd; Coulter, Douglas A; Eisch, Amelia J

    2018-04-16

    Major depressive disorder (MDD) is considered a 'circuitopathy', and brain stimulation therapies hold promise for ameliorating MDD symptoms, including hippocampal dysfunction. It is unknown whether stimulation of upstream hippocampal circuitry, such as the entorhinal cortex (Ent), is antidepressive, although Ent stimulation improves learning and memory in mice and humans. Here we show that molecular targeting (Ent-specific knockdown of a psychosocial stress-induced protein) and chemogenetic stimulation of Ent neurons induce antidepressive-like effects in mice. Mechanistically, we show that Ent-stimulation-induced antidepressive-like behavior relies on the generation of new hippocampal neurons. Thus, controlled stimulation of Ent hippocampal afferents is antidepressive via increased hippocampal neurogenesis. These findings emphasize the power and potential of Ent glutamatergic afferent stimulation-previously well-known for its ability to influence learning and memory-for MDD treatment.

  9. The Underlying Mechanism of Preventing Facial Nerve Stimulation by Triphasic Pulse Stimulation in Cochlear Implant Users Assessed With Objective Measure.

    Science.gov (United States)

    Bahmer, Andreas; Baumann, Uwe

    2016-10-01

    Triphasic pulse stimulation prevents from facial nerve stimulation (FNS) because of a different electromyographic input-output function compared with biphasic pulse stimulation. FNS is sometimes observed in cochlear implant users as an unwanted side effect of electrical stimulation of the auditory nerve. The common stimulation applied in current cochlear implant consists of biphasic pulse patterns. Two common clinical remedies to prevent unpleasant FNS caused by activation of certain electrodes are to expand their pulse phase duration or simply deactivate them. Unfortunately, in some patients these methods do not provide sufficient FNS prevention. In these patients triphasic pulse can prevent from FNS. The underlying mechanism is yet unclear. Electromyographic (EMG) recordings of muscles innervated by the facial nerve (musculi orbicularis ori and oculi) were applied to quantitatively assess the effects on FNS. Triphasic and biphasic fitting maps were compared in four subjects with severe FNS. Based on the recordings, a model is presented which intends to explain the beneficial effects of triphasic pulse application. Triphasic stimulation provided by fitting of an OPUS 2 speech processor device. For three patients, EMG was successfully recorded depending on stimulation level up to uncomfortable and intolerable FNS stimulation as upper boarder. The obtained EMG recordings demonstrated high individual variability. However, a difference between the input-output function for biphasic and triphasic pulse stimulation was visually observable. Compared with standard biphasic stimulation, triphasic pulses require higher stimulation levels to elicit an equal amount of FNS, as reflected by EMG amplitudes. In addition, we assume a steeper slope of the input-output function for biphasic pulse stimulation compared with triphasic pulse stimulation. Triphasic pulse stimulation prevents from FNS because of a smaller gradient of EMG input-output function compared with biphasic pulse

  10. PROMOTION OF ACTIVE MEASURES AND EMPLOYMENT STIMULATION

    Directory of Open Access Journals (Sweden)

    LAVINIA ELISABETA POPP

    2012-01-01

    Full Text Available Researches in the field of the labour market has allowed the identification of certain specific mechanisms for employment promotion; at present, on the Romanian labour market we find passive policies, concretised in financial aids paid to the unemployed, along with active policies, constituting the most efficient social protection activity addressed to the unemployed (they aim at counterbalancing the inefficiencies determined by the granting of financial allowances, help population to find a job by actions of information, professional training and contributing to the encouragement of the labour force mobility. The paper refers to some theoretical considerations related to the influence factors of employment stimulation, as well as to the unemployment – correlated adequate measures synapse. The applied research comprises the analysis of statistic documents; the method used is the case study, i.e. the activity of employment stimulation carried on by the County Agency for Employment Caraş-Severin, in the period 2004-2012. The conclusions highlight the impact of the activity of the institutions involved in the system of social protection and security within the labour market.

  11. Transcranial magnetic stimulation techniques in clinical investigation.

    Science.gov (United States)

    Currà, A; Modugno, N; Inghilleri, M; Manfredi, M; Hallett, M; Berardelli, A

    2002-12-24

    Transcranial magnetic stimulation (TMS) is a technique that can activate cortical motor areas and the corticospinal tract without causing the subject discomfort. Since TMS was introduced, numerous applications of the technique have been developed for the evaluation of neurologic diseases. Standard TMS applications (central motor conduction time, threshold and amplitude of motor evoked potentials) allow the evaluation of motor conduction in the CNS. Conduction studies provide specific information in neurologic conditions characterized by clinical and subclinical upper motor neuron involvement. In addition, they have proved useful in monitoring motor abnormalities and the recovery of motor function. TMS also gives information on the pathophysiology of the processes underlying the various clinical conditions. More complex TMS applications (paired-pulse stimulation, silent period, ipsilateral silent period, input-output curve, and evaluation of central fatigue) allow investigation into the mechanisms of diseases causing changes in the excitability of cortical motor areas. These techniques are also useful in monitoring the effects of neurotrophic drugs on cortical activity. TMS applications have an important place among the investigative tools to study patients with motor disorders.

  12. Electroacoustic Stimulation: Now and into the Future

    Science.gov (United States)

    Irving, S.; Gillespie, L.; Richardson, R.; Rowe, D.; Fallon, J. B.; Wise, A. K.

    2014-01-01

    Cochlear implants have provided hearing to hundreds of thousands of profoundly deaf people around the world. Recently, the eligibility criteria for cochlear implantation have been relaxed to include individuals who have some useful residual hearing. These recipients receive inputs from both electric and acoustic stimulation (EAS). Implant recipients who can combine these hearing modalities demonstrate pronounced benefit in speech perception, listening in background noise, and music appreciation over implant recipients that rely on electrical stimulation alone. The mechanisms bestowing this benefit are unknown, but it is likely that interaction of the electric and acoustic signals in the auditory pathway plays a role. Protection of residual hearing both during and following cochlear implantation is critical for EAS. A number of surgical refinements have been implemented to protect residual hearing, and the development of hearing-protective drug and gene therapies is promising for EAS recipients. This review outlines the current field of EAS, with a focus on interactions that are observed between these modalities in animal models. It also outlines current trends in EAS surgery and gives an overview of the drug and gene therapies that are clinically translatable and may one day provide protection of residual hearing for cochlear implant recipients. PMID:25276779

  13. Thermally Stimulated Currents in Nanocrystalline Titania

    Directory of Open Access Journals (Sweden)

    Mara Bruzzi

    2018-01-01

    Full Text Available A thorough study on the distribution of defect-related active energy levels has been performed on nanocrystalline TiO2. Films have been deposited on thick-alumina printed circuit boards equipped with electrical contacts, heater and temperature sensors, to carry out a detailed thermally stimulated currents analysis on a wide temperature range (5–630 K, in view to evidence contributions from shallow to deep energy levels within the gap. Data have been processed by numerically modelling electrical transport. The model considers both free and hopping contribution to conduction, a density of states characterized by an exponential tail of localized states below the conduction band and the convolution of standard Thermally Stimulated Currents (TSC emissions with gaussian distributions to take into account the variability in energy due to local perturbations in the highly disordered network. Results show that in the low temperature range, up to 200 K, hopping within the exponential band tail represents the main contribution to electrical conduction. Above room temperature, electrical conduction is dominated by free carriers contribution and by emissions from deep energy levels, with a defect density ranging within 1014–1018 cm−3, associated with physio- and chemi-sorbed water vapour, OH groups and to oxygen vacancies.

  14. Kinetics of infrared stimulated luminescence from feldspars

    International Nuclear Information System (INIS)

    Jain, M.; Sohbati, R.; Guralnik, B.; Murray, A.S.; Kook, M.; Lapp, T.; Prasad, A.K.; Thomsen, K.J.; Buylaert, J.P.

    2015-01-01

    We extend the localised transition model based on randomly varying recombination distances (Jain et al., 2012) to include Arrhenius analysis and truncated nearest neighbour distributions. The model makes important predictions regarding a) the physical understanding of the linear intercepts in the Arrhenius analysis for localised recombination systems and b) the relationship between charge depletion and shape of the luminescence decay curves; these predictions are successfully tested by experimental investigations. We demonstrate that this model successfully describes the kinetic behaviour, both thermal and optical, of the infrared stimulated luminescence signal from feldspar. Based on the application of this model, it is concluded that different infra-red stimulated luminescence emissions (UV, blue, yellow and far-red) follow the same kinetics, and, therefore, involve participation of the same electron (dosimetric) trap. The differences in thermal stabilities of the different emissions results from differences in number densities of the recombination sites. The results have implications for understanding the mechanism of the far-red emission, and the spatial distributions of recombination sites in feldspar. - Highlights: • Arrhenius analysis of IRSL based on localized transition model (Jain et al., 2012). • Kinetics of IRSL for the different emission bands. • A new analytical description for IRSL. • Demonstrating that feldspar IRSL is consistent with the predictions of the LTM.

  15. Spontaneous and stimulated emission from quasifree electrons

    Science.gov (United States)

    Friedman, A.; Gover, A.; Kurizki, G.; Ruschin, S.; Yariv, A.

    1988-04-01

    This article presents a unified formulation and review of an extensive class of radiation effects and devices based on free or quasifree electrons. The effects and devices reviewed include slow-wave radiators [such as Čerenkov, Smith-Purcell, and TWT (traveling-wave tube) effects and devices], periodic bremsstrahlung radiators [such as undulator radiation, magnetic bremsstrahlung FEL's (free-electron lasers), and coherent bremsstrahlung in the crystal lattice], and transverse-binding radiators [such as the CRM (cyclotron resonance maser) and channeling radiation]. Starting from a general quantum-electrodynamic model, both quantum and classical effects and operating regimes of these radiation devices are described. The article provides a unified physical description of the interaction kinematics, and presents equations for the characterization of spontaneous and stimulated radiative emission in these various effects and devices. Universal relations between the spontaneous and stimulated emission parameters are revealed and shown to be related (in the quantum limit) to Einstein relations for atomic radiators and (in the classical limit) to the relations derived by Madey for magnetic bremsstrahlung FEL for on-axis radiative emission. Examples for the application of the formulation are given, estimating the feasibility of channeling radiation x-ray laser and optical regime Smith-Purcell FEL, and deriving the gain equations of magnetic bremsstrahlung FEL and CRM for arbitrary electron propagation direction, structure (wiggler) axis, and radiative emission angle.

  16. Deep Brain Stimulation, Authenticity and Value.

    Science.gov (United States)

    Pugh, Jonathan; Maslen, Hannah; Savulescu, Julian

    2017-10-01

    Deep brain stimulation has been of considerable interest to bioethicists, in large part because of the effects that the intervention can occasionally have on central features of the recipient's personality. These effects raise questions regarding the philosophical concept of authenticity. In this article, we expand on our earlier work on the concept of authenticity in the context of deep brain stimulation by developing a diachronic, value-based account of authenticity. Our account draws on both existentialist and essentialist approaches to authenticity, and Laura Waddell Ekstrom's coherentist approach to personal autonomy. In developing our account, we respond to Sven Nyholm and Elizabeth O'Neill's synchronic approach to authenticity, and explain how the diachronic approach we defend can have practical utility, contrary to Alexandre Erler and Tony Hope's criticism of autonomy-based approaches to authenticity. Having drawn a distinction between the authenticity of an individual's traits and the authenticity of that person's values, we consider how our conception of authenticity applies to the context of anorexia nervosa in comparison to other prominent accounts of authenticity. We conclude with some reflections on the prudential value of authenticity, and by highlighting how the language of authenticity can be invoked to justify covert forms of paternalism that run contrary to the value of individuality that seems to be at the heart of authenticity.

  17. Origin and evolution of deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Vittorio Alessandro eSironi

    2011-08-01

    Full Text Available This paper briefly describes how the electrical stimulation, used since antiquity to modulate the nervous system, has been a fundamental tool of neurophysiologic investigation in the second half of the 18th century and was subsequently used by the early 20th century, even for therapeutic purposes. In mid-20th century the advent of stereotactic procedures has allowed the drift from lesional to stimulating technique of deep nuclei of the brain for therapeutic purposes. In this way, DBS was born, that, over the last two decades, has led to positive results for the treatment of medically refractory Parkinson's disease, essential tremor and dystonia. In recent years, the indications for therapeutic use of DBS have been extended to epilepsy, Tourette's syndrome, psychiatric diseases (depression, obsessive-compulsive disorder, some kinds of headache, eating disorders and the minimally conscious state. The potentials of the DBS for therapeutic use are fascinating, but there are still many unresolved technical and ethical problems, concerning the identification of the targets for each disease, the selection of the patients and the evaluation of the results.

  18. Surface electrical stimulation to evoke referred sensation.

    Science.gov (United States)

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

    2015-01-01

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

  19. Sodium-stimulated ATPase in Streptococcus faecalis.

    Science.gov (United States)

    Kinoshita, N; Unemoto, T; Kobayashi, H

    1984-06-01

    We measured Na+-stimulated ATPase activity in a mutant of Streptococcus faecalis defective in the generation of proton motive force. The activity in membrane vesicles was 62.1 +/- 5.9 nmol of phosphate produced per min per mg of protein when cells were grown on medium containing 0.12 M Na+. Activity decreased as the concentration of Na+ in the growth medium decreased. The decrease in enzyme activity corresponded to the decrease in transport activity for Na+ in both whole cells and membrane vesicles. The effects of pH on both activities were identical. Thus, it is suggested that Na+ movement is mediated by this enzyme. Sodium extrusion and ATPase activity in the wild-type strain were markedly lower than those observed in the mutant strain. Elevated activities of both Na+ extrusion and Na+-stimulated ATPase could be detected in the wild-type strain when cells were grown in the absence of proton motive force. Thus, we propose that the level of ATPase is increased by dissipation of the proton motive force.

  20. Nonlinear cyclotron absorption and stimulated scattering

    International Nuclear Information System (INIS)

    Chung, T.H.

    1986-01-01

    In electron cyclotron resonance heating (ECRH), wave sources heating a plasma linearly with respect to intensity; but as the intensity of ECRH gets larger, there might appear nonlinear effects that would result in cutoff of net absorption. This thesis uses quantum mechanical theory to derive a threshold microwave intensity for nonlinear absorption. The quantum mechanical theory estimates that the threshold microwave intensity for nonlinear absorption is about 10 5 watts/cm 2 for a microwave heating experiment (T/sub e/ = 100 ev, λ = 3,783 cm, B = 2.5 kG). This value seems large considering the present power capabilities of microwave sources (10 2 ∼ 10 3 watts/cm 2 ), but for a low temperature plasma, this threshold will go down. There is another nonlinear phenomenon called stimulated cyclotron scattering that enhances photon scattering by electrons gyrating in a magnetic field. This is expected to prevent incoming photons from arriving at the central region of the fusion plasma, where absorption mainly takes place. Theory based on a photon transport model predicts that the threshold intensity for the stimulated cyclotron scattering is about 10 4 watts/cm 2 for the plasma parameters mentioned above. This value seems large also, but a longer wavelength of microwaves and a larger magnitude magnetic field, which will be the case in reactor type facilities, will lower the threshold intensity to levels comparable with the currently developed microwave sources

  1. Network effects of deep brain stimulation.

    Science.gov (United States)

    Alhourani, Ahmad; McDowell, Michael M; Randazzo, Michael J; Wozny, Thomas A; Kondylis, Efstathios D; Lipski, Witold J; Beck, Sarah; Karp, Jordan F; Ghuman, Avniel S; Richardson, R Mark

    2015-10-01

    The ability to differentially alter specific brain functions via deep brain stimulation (DBS) represents a monumental advance in clinical neuroscience, as well as within medicine as a whole. Despite the efficacy of DBS in the treatment of movement disorders, for which it is often the gold-standard therapy when medical management becomes inadequate, the mechanisms through which DBS in various brain targets produces therapeutic effects is still not well understood. This limited knowledge is a barrier to improving efficacy and reducing side effects in clinical brain stimulation. A field of study related to assessing the network effects of DBS is gradually emerging that promises to reveal aspects of the underlying pathophysiology of various brain disorders and their response to DBS that will be critical to advancing the field. This review summarizes the nascent literature related to network effects of DBS measured by cerebral blood flow and metabolic imaging, functional imaging, and electrophysiology (scalp and intracranial electroencephalography and magnetoencephalography) in order to establish a framework for future studies. Copyright © 2015 the American Physiological Society.

  2. Network effects of deep brain stimulation

    Science.gov (United States)

    Alhourani, Ahmad; McDowell, Michael M.; Randazzo, Michael J.; Wozny, Thomas A.; Kondylis, Efstathios D.; Lipski, Witold J.; Beck, Sarah; Karp, Jordan F.; Ghuman, Avniel S.

    2015-01-01

    The ability to differentially alter specific brain functions via deep brain stimulation (DBS) represents a monumental advance in clinical neuroscience, as well as within medicine as a whole. Despite the efficacy of DBS in the treatment of movement disorders, for which it is often the gold-standard therapy when medical management becomes inadequate, the mechanisms through which DBS in various brain targets produces therapeutic effects is still not well understood. This limited knowledge is a barrier to improving efficacy and reducing side effects in clinical brain stimulation. A field of study related to assessing the network effects of DBS is gradually emerging that promises to reveal aspects of the underlying pathophysiology of various brain disorders and their response to DBS that will be critical to advancing the field. This review summarizes the nascent literature related to network effects of DBS measured by cerebral blood flow and metabolic imaging, functional imaging, and electrophysiology (scalp and intracranial electroencephalography and magnetoencephalography) in order to establish a framework for future studies. PMID:26269552

  3. [Effect of cognitive stimulation in elderly community].

    Science.gov (United States)

    Apóstolo, João Luís Alves; Cardoso, Daniela Filipa Batista; Paúl, Constança; Rodrigues, Manuel Alves; Macedo, Marinha Sofia

    2016-01-01

    To demonstrate that the implementation of the Cognitive Stimulation (CS) program 'Making a Difference' (MD) improves cognition and depressive symptoms in retired community elders. This was a multicenter quasi-experimental study of 45 community dwelling elders (38 women and 7 men), with a mean age of 75.29, from 3 day-care centers in rural, semi-rural and urban environments in the central region of Portugal. Participants attended 14 sessions twice a week over seven weeks. The Montreal Cognitive Assessment (MoCA) and the Geriatric Depression Scale (GDS-15) were administered at the following three time points: baseline, post-test, and follow-up. From baseline to post-test, there is a statistically significant difference in depressive symptoms (F=7.494; P=.010) explaining 21% of the variance (partial eta squared [ηp(2)]=.21), power=.75, but there is no statistically significant difference in cognition. From post-test to follow-up, there is no difference in both cognition and depression outcomes. Our results showed improvement in elders' depressive symptoms after a seven weeks intervention program but it did not have a protective effect after the three months follow-up. No evidence was found for its efficacy in improving cognition. Cognitive stimulation may be a useful in preventing elder's depressive symptoms when included in their health promotion care plan. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  4. Repetitive transcranial magnetic stimulation and drug addiction.

    Science.gov (United States)

    Barr, Mera S; Farzan, Faranak; Wing, Victoria C; George, Tony P; Fitzgerald, Paul B; Daskalakis, Zafiris J

    2011-10-01

    Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that is now being tested for its ability to treat addiction. This review discusses current research approaches and results of studies which measured the therapeutic use of rTMS to treat tobacco, alcohol and illicit drug addiction. The research in this area is limited and therefore all studies evaluating the therapeutic use of rTMS in tobacco, alcohol or illicit drug addiction were retained including case studies through NCBI PubMed ( http://www.ncbi.nlm.nih.gov ) and manual searches. A total of eight studies were identified that examined the ability of rTMS to treat tobacco, alcohol and cocaine addiction. The results of this review indicate that rTMS is effective in reducing the level of cravings for smoking, alcohol, and cocaine when applied at high frequencies to the dorsolateral prefrontal cortex (DLPFC). Furthermore, these studies suggest that repeated sessions of high frequency rTMS over the DLPFC may be most effective in reducing the level of smoking and alcohol consumption. Although work in this area is limited, this review indicates that rTMS is a promising modality for treating drug addiction.

  5. The inhibitory effects of pudendal nerve stimulation on bladder overactivity in spinal cord injury dogs: is early stimulation necessary?

    Science.gov (United States)

    Chen, Guoqing; Liao, Limin; Dong, Qian; Ju, Yanhe

    2012-01-01

    To determine the inhibitory effects of pudendal nerve stimulation (5 Hz) on bladder overactivity at early and late stages of spinal cord injury in dogs. The study was performed in eight dogs with chronic spinal cord transection at the T9-T10 level. Group 1 (four dogs) underwent electrical stimulation of pudendal nerve one month after spinal cord transection. Group 2 (four dogs) underwent stimulation six months after spinal cord transection. The bladders were removed for histological examination of fibrosis after the stimulation. The bladder capacity and the compliance were significantly increased (p stimulation in group 1, but not in group 2. The nonvoiding contractions were inhibited in both groups by electrical stimulation. Collagen fiber was increased, while elastic fiber was significantly decreased (p stimulation can increase the bladder capacity and compliance only during the early period before the bladder wall becomes fibrosit and can inhibit the nonvoiding contraction during two stages. © 2012 International Neuromodulation Society.

  6. Urinary bladder control by electrical stimulation: review of electrical stimulation techniques in spinal cord injury

    NARCIS (Netherlands)

    Rijkhoff, N. J.; Wijkstra, H.; van Kerrebroeck, P. E.; Debruyne, F. M.

    1997-01-01

    Evacuation of urine in paraplegics without the need for catheters would be possible when voiding could be induced by eliciting a bladder contraction. A challenging option to obtain detrusor contraction is electrical stimulation of the detrusor muscle or its motor nerves. This article reviews the 4

  7. Determination of stimulation focality in heterogeneous head models during transcranial magnetic stimulation (TMS)

    Science.gov (United States)

    Lee, Erik; Hadimani, Ravi; Jiles, David

    2015-03-01

    Transcranial Magnetic Stimulation (TMS) is an increasingly popular tool used by both the scientific and medical community to understand and treat the brain. TMS has the potential to help people with a wide range of diseases such as Parkinson's, Alzheimer's, and PTSD, while currently being used to treat people with chronic, drug-resistant depression. Through computer simulations, we are able to see the electric field that TMS induces in anatomical human models, but there is no measure to quantify this electric field in a way that relates to a specific patient undergoing TMS therapy. We propose a way to quantify the focality of the induced electric field in a heterogeneous head model during TMS by relating the surface area of the brain being stimulated to the total volume of the brain being stimulated. This figure would be obtained by conducting finite element analysis (FEA) simulations of TMS therapy on a patient specific head model. Using this figure to assist in TMS therapy will allow clinicians and researchers to more accurately stimulate the desired region of a patient's brain and be more equipped to do comparative studies on the effects of TMS across different patients. This work was funded by the Carver Charitable Trust.

  8. Concerning infrared-stimulated luminescence from K-feldspars: evidence from heating before stimulating

    CERN Document Server

    Galloway, R B

    1999-01-01

    Repeated heating and stimulation by infrared of feldspar samples causes a reduction in the luminescence signal. Two feldspars were investigated, one microcline and one orthoclase. Empirically the fraction of luminescence signal f(n) remaining after the nth cycle of heating and stimulation is given by f(n)=1-a ln(n) for laboratory dosed samples of both microcline and orthoclase feldspars, for heating temperatures of 150 deg. C, 180 deg. C and 220 deg. C, for heating durations per cycle ranging from 20 s to 2400 s and with the study covering 10 cycles of heating and stimulation. Logarithmic decay of luminescence with time has been explained previously, in other contexts, as due either to quantum tunnelling or to a continuous distribution of states being involved but it is shown that these explanations do not fit the present data. The measured data on f(n) were corrected for the loss of luminescence due to infrared stimulation to ensure that this did not account for the differences between the data and the expec...

  9. Using Transcranial Direct Current Stimulation to Enhance Creative Cognition: Interactions between Task, Polarity, and Stimulation Site

    Directory of Open Access Journals (Sweden)

    Adam B. Weinberger

    2017-05-01

    Full Text Available Creative cognition is frequently described as involving two primary processes, idea generation and idea selection. A growing body of research has used transcranial direct current stimulation (tDCS to examine the neural mechanisms implicated in each of these processes. This literature has yielded a diverse set of findings that vary depending on the location and type (anodal, cathodal, or both of electrical stimulation employed, as well as the task’s reliance on idea generation or idea selection. As a result, understanding the interactions between stimulation site, polarity and task demands is required to evaluate the potential of tDCS to enhance creative performance. Here, we review tDCS designs that have elicited reliable and dissociable enhancements for creative cognition. Cathodal stimulation over the left inferior frontotemporal cortex has been associated with improvements on tasks that rely primarily on idea generation, whereas anodal tDCS over left dorsolateral prefrontal cortex (DLPFC and frontopolar cortex has been shown to augment performance on tasks that impose high demands on creative idea selection. These results highlight the functional selectivity of tDCS for different components of creative thinking and confirm the dissociable contributions of left dorsal and inferior lateral frontotemporal cortex for different creativity tasks. We discuss promising avenues for future research that can advance our understanding of the effectiveness of tDCS as a method to enhance creative cognition.

  10. Vibrotactile stimulation of the upper leg : Effects of location, stimulation method and habituation

    NARCIS (Netherlands)

    Wentink, E.C.; Mulder, A.; Rietman, Johan Swanik; Veltink, Petrus H.

    In this study vibrotactile stimulation of the upper leg and its usability for feedback was tested. Three experiments were performed on ten healthy subjects using pager motors. The first experiment was to test the perception of the vibration at different frequencies and at different locations of the

  11. Prescription Stimulants Are "A Okay": Applying Neutralization Theory to College Students' Nonmedical Prescription Stimulant Use

    Science.gov (United States)

    Cutler, Kristin A.

    2014-01-01

    Objective: National college health data indicate that prescription stimulants are the most widely misused prescription drugs among college students, with 9% admitting to nonmedical use within the past year. Although motivations for the nonmedical use of these drugs have been explored, scant attention has been paid to justifications for nonmedical…

  12. Selectively stimulating neural populations in the subthalamic region using a novel deep brain stimulation lead design

    NARCIS (Netherlands)

    van Dijk, Kees Joab; Verhagen, R.; Bour, L.J.; Heida, Tjitske

    2013-01-01

    Deep brain stimulation (DBS) of the Subthalamic Nucleus (STN) is widely used in advanced stages of Parkinson's disease(PD) and has proven to be an effective treatment of the various motor symptoms. The therapy involves implanting a lead consisting of multiple electrodes in the STN through which

  13. Low temperature stimulates alpha-melanophore-stimulating hormone secretion and inhibits background adaptation in Xenopus laevis.

    NARCIS (Netherlands)

    Tonosaki, Y; Cruijsen, P.M.; Nishiyama, K; Yaginuma, H; Roubos, E.W.

    2004-01-01

    It is well-known that alpha-melanophore-stimulating hormone (alpha-MSH) release from the amphibian pars intermedia (PI) depends on the light condition of the animal's background, permitting the animal to adapt the colour of its skin to background light intensity. In the present study, we carried out

  14. Beryllium-stimulated apoptosis in macrophage cell lines.

    Science.gov (United States)

    Sawyer, R T; Fadok, V A; Kittle, L A; Maier, L A; Newman, L S

    2000-08-21

    In vitro stimulation of bronchoalveolar lavage cells from patients with chronic beryllium disease (CBD) induces the production of TNF-alpha. We tested the hypothesis that beryllium (Be)-stimulated TNF-alpha might induce apoptosis in mouse and human macrophage cell lines. These cell lines were selected because they produce a range of Be-stimulated TNF-alpha. The mouse macrophage cell line H36.12j produces high levels of Be-stimulated TNF-alpha. The mouse macrophage cell line P388D.1 produces low, constitutive, levels of TNF-alpha and does not up-regulate Be-stimulated TNF-alpha production. The DEOHS-1 human CBD macrophage cell line does not produce constitutive or Be-stimulated TNF-alpha. Apoptosis was determined by microscopic observation of propidium iodide stained fragmented nuclei in unstimulated and BeSO(4)-stimulated macrophage cell lines. BeSO(4) induced apoptosis in all macrophage cell lines tested. Beryllium-stimulated apoptosis was dose-responsive and maximal after 24 h of exposure to 100 microM BeSO(4). In contrast, unstimulated and Al(2)(SO(4))(3)-stimulated macrophage cell lines did not undergo apoptosis. The general caspase inhibitor BD-fmk inhibited Be-stimulated macrophage cell line apoptosis at concentrations above 50 microM. Our data show that Be-stimulated macrophage cell line apoptosis was caspase-dependent and not solely dependent on Be-stimulated TNF-alpha levels. We speculate that the release of Be-antigen from apoptotic macrophages may serve to re-introduce Be material back into the lung microenvironment, make it available for uptake by new macrophages, and thereby amplify Be-stimulated cytokine production, promoting ongoing inflammation and granuloma maintenance in CBD.

  15. Vagus nerve stimulation: indications and limitations.

    Science.gov (United States)

    Ansari, S; Chaudhri, K; Al Moutaery, K A

    2007-01-01

    Vagus nerve stimulation (VNS) is an established treatment for selected patients with medically refractory seizures. Recent studies suggest that VNS could be potentially useful in the treatment of resistant depressive disorder. Although a surgical procedure is required in order to implant the VNS device, the possibility of a long-term benefit largely free of severe side effects could give VNS a privileged place in the management of resistant depression. In addition, VNS appears to affect pain perception in depressed adults; a possible role of VNS in the treatment of severe refractory headache, intractable chronic migraine and cluster headache has also been suggested. VNS is currently investigated in clinical studies, as a potential treatment for essential tremor, cognitive deficits in Alzheimer's disease, anxiety disorders, and bulimia. Finally, other studies explore the potential use of VNS in the treatment of resistant obesity, addictions, sleep disorders, narcolepsy, coma and memory and learning deficits.

  16. Transcranial Magnetic Stimulation and Aphasia Rehabilitation

    Science.gov (United States)

    Naeser, Margaret A.; Martin, Paula I; Ho, Michael; Treglia, Ethan; Kaplan, Elina; Bhashir, Shahid; Pascual-Leone, Alvaro

    2013-01-01

    Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005. In Part 1, we review the rationale for applying slow, 1 Hz, rTMS to the undamaged right hemisphere in chronic nonfluent aphasia patients following a left hemisphere stroke; and present a TMS protocol used with these patients that is associated with long-term, improved naming post- TMS. In Part, 2 we present results from a case study with chronic nonfluent aphasia where TMS treatments were followed immediately by speech therapy (constraint-induced language therapy). In Part 3, some possible mechanisms associated with improvement following a series of TMS treatments in stroke patients with aphasia are discussed. PMID:22202188

  17. Caloric vestibular stimulation in aphasic syndrome

    Directory of Open Access Journals (Sweden)

    David eWilkinson

    2013-12-01

    Full Text Available Caloric vestibular stimulation (CVS is commonly used to diagnose brainstem disorder but its therapeutic application is much less established. Based on the finding that CVS increases blood flow to brain structures associated with language and communication, we assessed whether the procedure has potential to relieve symptoms of post-stroke aphasia. Three participants, each presenting with chronic, unilateral lesions to the left hemisphere, were administered daily CVS for 4 consecutive weeks. Relative to their pre-treatment baseline scores, two of the three participants showed significant improvement on both picture and responsive naming at immediate and one-week follow-up. One of these participants also showed improved sentence repetition, and another showed improved auditory word discrimination. No adverse reactions were reported. These data provide the first, albeit tentative, evidence that CVS may relieve expressive and receptive symptoms of aphasia. A larger, sham-controlled study is now needed to further assess efficacy.

  18. Dosimetry of typical transcranial magnetic stimulation devices

    Science.gov (United States)

    Lu, Mai; Ueno, Shoogo

    2010-05-01

    The therapeutic staff using transcranial magnetic stimulation (TMS) devices could be exposed to magnetic pulses. In this paper, dependence of induced currents in real human man model on different coil shapes, distance between the coil and man model as well as the rotation of the coil in space have been investigated by employing impedance method. It was found that the figure-of-eight coil has less leakage magnetic field and low current density induced in the body compared with the round coil. The TMS power supply cables play an important role in the induced current density in human body. The induced current density in TMS operator decreased as the coil rotates from parallel position to perpendicular position. Our present study shows that TMS operator should stand at least 110 cm apart from the coil.

  19. Nanoparticles: a challenging vehicle for neural stimulation

    Directory of Open Access Journals (Sweden)

    Elisabetta eColombo

    2016-03-01

    Full Text Available Neurostimulation represents a powerful and well-established tool for the treatment of several diseases affecting the central nervous system. Although effective in reducing the symptoms or the progression of brain disorders, the poor accessibility of the deepest areas of the brain currently hampers the possibility of a more specific and controlled therapeutic stimulation, depending on invasive surgical approaches and long-term stability and biocompatibility issues. The massive research of the last decades on nanomaterials and nanoscale devices favored the development of new tools to address the limitations of the available neurostimulation approaches. This mini-review focuses on the employment of nanoparticles for the modulation of the electrophysiological activity of neuronal networks and the related transduction mechanisms underlying the nanostructure-neuron interfaces.

  20. Mapping of electrical muscle stimulation using MRI

    Science.gov (United States)

    Adams, Gregory R.; Harris, Robert T.; Woodard, Daniel; Dudley, Gary A.

    1993-01-01

    The pattern of muscle contractile activity elicited by electromyostimulation (EMS) was mapped and compared to the contractile-activity pattern produced by voluntary effort. This was done by examining the patterns and the extent of contrast shift, as indicated by T2 values, im magnetic resonance (MR) images after isometric activity of the left m. quadriceps of human subjects was elicited by EMS (1-sec train of 500-microsec sine wave pulses at 50 Hz) or voluntary effort. The results suggest that, whereas EMS stimulates the same fibers repeatedly, thereby increasing the metabolic demand and T2 values, the voluntary efforts are performed by more diffuse asynchronous activation of skeletal muscle even at forces up to 75 percent of maximal to maintain performance.

  1. FACTORS THAT STIMULATE THE ECOSYSTEM ROMANIAN ENTREPRENEURIAL

    Directory of Open Access Journals (Sweden)

    ENEA CONSTANŢA

    2017-12-01

    Full Text Available Entrepreneurship has begun to grapple with the global economic and financial crisis, and entrepreneurs have become "heroes" capable of delivering impetus to fragile economies. Small and innovative companies account for 99% of all Europe's active companies and offer 66% of available jobs. In the context of a worrying unemployment rate that persists in many countries of the world, entrepreneurship has become a viable solution to economic problems. Entrepreneurship can not be defined precisely, and the multidimensionality and homogeneity of the concept makes it very difficult to generalize the conclusions of studies for regions other than those for which they were originally developed. The objective of the present study is to carry out a comprehensive analysis of the Romanian entrepreneurial ecosystem and the factors that have the power to stimulate it, thus allowing the design of efficient policies for the development of Romanian entrepreneurship.

  2. Deep brain stimulation to reduce sexual drive.

    Science.gov (United States)

    Fuss, Johannes; Auer, Matthias K; Biedermann, Sarah V; Briken, Peer; Hacke, Werner

    2015-11-01

    To date there are few treatment options to reduce high sexual drive or sexual urges in paraphilic patients with a risk for sexual offending. Pharmacological therapy aims to reduce sexual drive by lowering testosterone at the cost of severe side effects. We hypothesize that high sexual drive could also be reduced with deep brain stimulation (DBS) of circuits that generate sexual drive. This approach would help to avoid systemic side effects of antiandrogenic drug therapies. So far the best investigated target to reduce sexual drive is the ventromedial hypothalamus, which was lesioned unilaterally and bilaterally by stereotaxic interventions in paraphilic patients in the 1970s. Here, we discuss DBS as a treatment strategy in patients with severe paraphilic disorders with a serious risk of sexual offending. There are profound ethical and practical issues associated with DBS treatment of paraphilic patients that must be solved before considering such a treatment approach.

  3. Stimulated Raman backscattering at high laser intensities

    Energy Technology Data Exchange (ETDEWEB)

    Skoric, M.M. [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Tajima, Toshiki; Sasaki, Akira; Maluckov, A.; Jovanovic, M.

    1998-03-01

    Signatures of Stimulated Raman backscattering of a short-pulse high-intensity laser interacting with an underdense plasma are discussed. We introduce a nonlinear three-wave interaction model that accounts for laser pump depletion and relativistic detuning. A mechanism is revealed based on a generic route to chaos, that predicts a progressive increase of the backscatter complexity with a growing laser intensity. Importance of kinetic effects is outlined and demonstrated in fluid-hybrid and particle simulations. As an application, we show that spectral anomalies of the backscatter, predicted by the above model, are consistent with recent sub-picosecond, high-intensity laser gas-target measurements at Livermore and elsewhere. Finally, a recently proposed scheme for generation of ultra-short, low-prepulse laser pulses by Raman backscattering in a thin foil target, is shown. (author)

  4. Temperature Gradient Driven Lasing and Stimulated Cooling

    Science.gov (United States)

    Sandner, K.; Ritsch, H.

    2012-11-01

    A laser can be understood as a thermodynamic engine converting heat to a coherent single mode field close to Carnot efficiency. To achieve lasing, spectral shaping of the excitation light is used to generate a higher effective temperature on the pump than on the gain transition. Here, using a toy model of a quantum well structure with two suitably designed tunnel-coupled wells kept at different temperatures, we predict that lasing can also occur on an actual spatial temperature gradient between the pump and gain regions. Gain and narrow band laser emission require a sufficiently large temperature gradient and resonator quality. Lasing appears concurrent with amplified heat flow between the reservoirs and points to a new form of stimulated solid state cooling. In addition, such a mechanism could reduce intrinsic heating and thus extend the operating regime of quantum cascade lasers by substituting phonon emission driven injection by a phonon absorption step.

  5. Employees' Stimulation for the Perception of Innovations

    Directory of Open Access Journals (Sweden)

    Tаtiana V. Peregudova

    2013-01-01

    Full Text Available The article justifies the approach to the encouragement of employees of the organization to the perception of innovative activity products. At the core of this process there is an estimation of their activity regarding contribution to this process by group examination with point scoring of each employee on the selected criteria.The principles of formation and distribution of the bonus fund, which it is proposed to establish on the basis of proportion of the sum of average scores which the employee received in total, are given. 20% of employees with the low rates are not paid the bonus.Such approach to the stimulation of innovation implementation in the organization will create a positive institutional environment and reduce implementation time.

  6. Temporal evolution of stimulated Brillouin backscatter

    International Nuclear Information System (INIS)

    Hinkel, D.E.; Williams, E.A.; Berger, R.L.

    1994-01-01

    A qualitative understanding of the time dependence of stimulated Brillouin scattering (SBS) provides estimates of the amount of temporal growth that occurs in current inertial confinement fusion and short laser pulse interaction experiments when the growth is limited by the length of the experiment or by motion of the ''hot spots'' of the laser intensity pattern induced by beam smoothing. In the weak coupling limit, the instantaneous growth rate depends upon the plasma initial conditions early in time, is proportional to t -1/2 later in time, and asymptotically approaches the absolute growth rate (in the absence of damping). When the instability is strongly coupled, the growth rate depends upon the plasma initial conditions early in time but is proportional to t -1/3 later in time. When the growth rate drops to a value comparable to that of the ion acoustic frequency, the instability becomes effectively weakly coupled. The effects of damping are also discussed

  7. Improving the luteal phase after ovarian stimulation

    DEFF Research Database (Denmark)

    Andersen, Claus Yding; Vilbour Andersen, K

    2014-01-01

    The human chorionic gonadotrophin (HCG) trigger used for final follicular maturation in connection with assisted reproduction treatment combines ovulation induction and early luteal-phase stimulation of the corpora lutea. The use of a gonadotrophin-releasing hormone agonist (GnRHa) for final...... follicular maturation has, however, for the first time allowed a separation of the ovulatory signal from the early luteal-phase support. This has generated new information that may improve the currently employed luteal-phase support. Thus, combined results from a number of randomized controlled trials using...... the GnRHa trigger suggest an association between the reproductive outcome after IVF treatment and the mid-luteal-phase serum progesterone concentration. It appears that a minimum mid-luteal progesterone threshold of approximately 80-100 nmol/l exists, which, when surpassed, results in reduced early...

  8. Acupuncture stimulation induces neurogenesis in adult brain.

    Science.gov (United States)

    Nam, Min-Ho; Ahn, Kwang Seok; Choi, Seung-Hoon

    2013-01-01

    The discovery of adult neurogenesis was a turning point in the field of neuroscience. Adult neurogenesis offers an enormous possibility to open a new therapeutic paradigm of neurodegenerative diseases and stroke. Recently, several studies suggested that acupuncture may enhance adult neurogenesis. Acupuncture has long been an important treatment for brain diseases in the East Asia. The scientific mechanisms of acupuncture treatment for the diseases, such as Alzheimer's disease, Parkinson's disease, and stroke, have not been clarified yet; however, the neurogenic effect of acupuncture can be a possible reason. Here, we have reviewed the studies on the effect of stimulation at various acupoints for neurogenesis, such as ST36 and GV20. The suggested mechanisms are also discussed including upregulation of brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, basic fibroblast growth factor and neuropeptide Y, and activation of the function of primo vascular system. © 2013 Elsevier Inc. All rights reserved.

  9. Luminescent solar concentrators utilizing stimulated emission.

    Science.gov (United States)

    Kaysir, Md Rejvi; Fleming, Simon; MacQueen, Rowan W; Schmidt, Timothy W; Argyros, Alexander

    2016-03-21

    Luminescent solar concentrators (LSCs) are an emerging technology that aims primarily to reduce the cost of solar energy, with great potential for building integrated photovoltaic (PV) structures. However, realizing LSCs with commercially viable efficiency is currently hindered by reabsorption losses. Here, we introduce an approach to reducing reabsorption as well as improving directional emission in LSCs by using stimulated emission. Light from a seed laser (potentially an inexpensive laser diode) passes through the entire area of the LSC panel, modifying the emission spectrum of excited dye molecules such that it is spectrally narrower, at wavelengths that minimize reabsorption to allow net gain in the system, and directed towards a small PV cell. A mathematical model, taking into account thermodynamic considerations, of such a system is presented which identifies key parameters and allows evaluation in terms of net effective output power.

  10. Pressure Stimulated Currents (PSCin marble samples

    Directory of Open Access Journals (Sweden)

    F. Vallianatos

    2004-06-01

    Full Text Available The electrical behaviour of marble samples from Penteli Mountain was studied while they were subjected to uniaxial stress. The application of consecutive impulsive variations of uniaxial stress to thirty connatural samples produced Pressure Stimulated Currents (PSC. The linear relationship between the recorded PSC and the applied variation rate was investigated. The main results are the following: as far as the samples were under pressure corresponding to their elastic region, the maximum PSC value obeyed a linear law with respect to pressure variation. In the plastic region deviations were observed which were due to variations of Young s modulus. Furthermore, a special burst form of PSC recordings during failure is presented. The latter is emitted when irregular longitudinal splitting is observed during failure.

  11. Emdogain stimulates matrix degradation by osteoblasts.

    Science.gov (United States)

    Goda, S; Inoue, H; Kaneshita, Y; Nagano, Y; Ikeo, T; Ikeo, Y T; Iida, J; Domae, N

    2008-08-01

    Emdogain has been used clinically for periodontal regeneration, although the underlying molecular mechanisms are not clear at present. In this study, we hypothesized that Emdogain stimulated degradation of type I collagen via osteoblasts. We showed that Emdogain enhanced cell-mediated degradation of type I collagen in an MMP-dependent manner. Although MG-63 cells spontaneously produced a zymogen form of MMP-1, treatment with Emdogain significantly induced the generation of the active form of this enzyme. We demonstrated that MMP-3 was produced from MG63 cells in response to Emdogain in a MEK1/2-dependent manner. Concomitantly, blocking of MEK1/2 activation by U0126 significantly inhibited the generation of the active form of MMP-1 without affecting the total production of this collagenase. These results suggest that Emdogain facilitates tissue regeneration through the activation of the collagenase, MMP-1, that degrades matrix proteins in bone tissue microenvironments.

  12. Impact of optokinetic stimulation on mental arithmetic.

    Science.gov (United States)

    Masson, Nicolas; Pesenti, Mauro; Dormal, Valérie

    2017-07-01

    Solving arithmetic problems has been shown to induce shifts of spatial attention, subtraction problems orienting attention to the left side, and addition problems to the right side of space. At the neurofunctional level, the activations elicited by the solving of arithmetical problems resemble those elicited by horizontal eye movements. Whether overt orientation of attention (i.e., eye movements) can be linked to the solving procedure is, however, still under debate. In the present study, we used optokinetic stimulation (OKS) to trigger automatic eye movements to orient participants' overt attention to the right or to the left of their visual field while they were solving addition or subtraction problems. The results show that, in comparison to leftward OKS and a control condition, rightward OKS facilitates the solving of addition problems that necessitate a carrying procedure. Subtraction solving was unaffected by leftward or rightward OKS. These results converge with previous findings to show that attentional shifts are functionally related to mental arithmetic processing.

  13. Novel applications of deep brain stimulation

    Science.gov (United States)

    Sankar, Tejas; Tierney, Travis S.; Hamani, Clement

    2012-01-01

    The success of deep brain stimulation (DBS) surgery in treating medically refractory symptoms of some movement disorders has inspired further investigation into a wide variety of other treatment-resistant conditions. These range from disorders of gait, mood, and memory to problems as diverse as obesity, consciousness, and addiction. We review the emerging indications, rationale, and outcomes for some of the most promising new applications of DBS in the treatment of postural instability associated with Parkinson's disease, depression, obsessive–compulsive disorder, obesity, substance abuse, epilepsy, Alzheimer′s-type dementia, and traumatic brain injury. These studies reveal some of the excitement in a field at the edge of a rapidly expanding frontier. Much work still remains to be done on basic mechanism of DBS, optimal target and patient selection, and long-term durability of this technology in treating new indications. PMID:22826807

  14. The effect of static force on round window stimulation with the direct acoustic cochlea stimulator.

    Science.gov (United States)

    Maier, Hannes; Salcher, Rolf; Schwab, Burkard; Lenarz, Thomas

    2013-07-01

    The Direct Acoustic Cochlea Stimulator Partial Implant (DACS PI, Phonak Acoustic Implants SA, Switzerland) is intended to stimulate the cochlea by a conventional stapedotomy piston that is crimped onto the DACS PI artificial incus. An alternative approach to the round window (RW) is successfully done with other devices, having the advantage of being also independent of the existence of middle ear structure (e.g. ossicles). Here the possibility of stimulating the RW with the DACS actuator is investigated including the impact of static force on sound transmission to the cochlea. The maximum equivalent sound pressure output with RW stimulation was determined experimentally in fresh human temporal bones. Experiments were performed in analogy to the ASTM standard (F2504.24930-1) method for the output determination of implantable middle ear hearing devices (IMEHDs) in human cadaveric temporal bones (TBs). ASTM compliant temporal bones were stimulated with a prosthesis having a spherical tip (∅0.5 mm) attached to the actuator. The stimulation was performed perpendicular to the round window membrane (RWM) at varying position relative to the RW and the resulting static force on the RW membrane was determined. At each position the displacement output of the DACS PI actuator and the stapes footplate (SFP) vibration in response to actuator stimulation was measured with a Laser Doppler Velocimeter (LDV). By comparison of the achieved output at the stapes footplate in response to sound and transducer stimulation the equivalent sound pressure level at the tympanic membrane at 1Vrms input voltage was calculated assuming that the SFP displacement in both conditions is a measure of perceived loudness, as it is done in the ASTM standard. Ten TB preparations within the acceptance range of the ASTM standard were used for analysis. The actuator driven stapes footplate displacement amplitude as well as the resulting equivalent sound pressure level was highly dependent on the static

  15. Wireless distributed functional electrical stimulation system.

    Science.gov (United States)

    Jovičić, Nenad S; Saranovac, Lazar V; Popović, Dejan B

    2012-08-09

    The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype's software. The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers). One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

  16. Optimal stimulation settings for CMAP scan registrations

    Directory of Open Access Journals (Sweden)

    Maathuis Ellen M

    2012-06-01

    Full Text Available Abstract Background The CMAP (Compound Muscle Action Potential scan is a non-invasive electrodiagnostic tool, which provides a quick and visual assessment of motor unit potentials as electrophysiological components that together constitute the CMAP. The CMAP scan records the electrical activity of the muscle (CMAP in response to transcutaneous stimulation of the motor nerve with gradual changes in stimulus intensity. Large MUs, including those that result from collateral reinnervation, appear in the CMAP scan as so-called steps, i.e., clearly visible jumps in CMAP amplitude. The CMAP scan also provides information on nerve excitability. This study aims to evaluate the influence of the stimulation protocol used on the CMAP scan and its quantification. Methods The stimulus frequency (1, 2 and 3 Hz, duration (0.05, 0.1 and 0.3 ms, or number (300, 500 and 1000 stimuli in CMAP scans of 23 subjects was systematically varied while the other two parameters were kept constant. Pain was measured by means of a visual analogue scale (VAS. Non-parametric paired tests were used to assess significant differences in excitability and step variables and VAS scores between the different stimulus parameter settings. Results We found no effect of stimulus frequency on CMAP scan variables or VAS scores. Stimulus duration affected excitability variables significantly, with higher stimulus intensity values for shorter stimulus durations. Step variables showed a clear trend towards increasing values with decreasing stimulus number. Conclusions A protocol delivering 500 stimuli at a frequency of 2 Hz with a 0.1 ms pulse duration optimized CMAP scan quantification with a minimum of subject discomfort, artefact and duration of the recording. CMAP scan variables were influenced by stimulus duration and number; hence, these need to be standardized in future studies.

  17. Monitoring hydraulic stimulation using telluric sounding

    Science.gov (United States)

    Rees, Nigel; Heinson, Graham; Conway, Dennis

    2018-01-01

    The telluric sounding (TS) method is introduced as a potential tool for monitoring hydraulic fracturing at depth. The advantage of this technique is that it requires only the measurement of electric fields, which are cheap and easy when compared with magnetotelluric measurements. Additionally, the transfer function between electric fields from two locations is essentially the identity matrix for a 1D Earth no matter what the vertical structure. Therefore, changes in the earth resulting from the introduction of conductive bodies underneath one of these sites can be associated with deviations away from the identity matrix, with static shift appearing as a galvanic multiplier at all periods. Singular value decomposition and eigenvalue analysis can reduce the complexity of the resulting telluric distortion matrix to simpler parameters that can be visualised in the form of Mohr circles. This technique would be useful in constraining the lateral extent of resistivity changes. We test the viability of utilising the TS method for monitoring on both a synthetic dataset and for a hydraulic stimulation of an enhanced geothermal system case study conducted in Paralana, South Australia. The synthetic data example shows small but consistent changes in the transfer functions associated with hydraulic stimulation, with grids of Mohr circles introduced as a useful diagnostic tool for visualising the extent of fluid movement. The Paralana electric field data were relatively noisy and affected by the dead band making the analysis of transfer functions difficult. However, changes in the order of 5% were observed from 5 s to longer periods. We conclude that deep monitoring using the TS method is marginal at depths in the order of 4 km and that in order to have meaningful interpretations, electric field data need to be of a high quality with low levels of site noise.[Figure not available: see fulltext.

  18. Wireless distributed functional electrical stimulation system

    Directory of Open Access Journals (Sweden)

    Jovičić Nenad S

    2012-08-01

    Full Text Available Abstract Background The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. Methods The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype’s software. Results The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers. One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. Conclusions The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

  19. Violet stimulated luminescence: geo- or thermochronometer?

    International Nuclear Information System (INIS)

    Ankjærgaard, C.; Guralnik, B.; Porat, N.; Heimann, A.; Jain, M.; Wallinga, J.

    2015-01-01

    The method of quartz optically stimulated luminescence (OSL) dating is widely used, but generally limited to the past ∼0.1 million years (Ma) due to early saturation of the desired signal. Violet stimulated luminescence (VSL) of quartz has previously been shown as a promising alternative, with a dose saturation level ∼20 times higher compared to that of OSL, excellent thermal stability on the 10 11 year time scale, and agreement between VSL and OSL ages up to ∼0.3 Ma. Here we explore the usability of the VSL signal to date older quartz samples from palaeosols, whose ages are bracketed by K–Ar ages and palaeomagnetic data of the interbedded basalts, emplaced between 1.6 and 0.7 Ma. VSL ages from three palaeosols largely underestimate the independent ages of their overlying basalts. This can be explained either by a low-temperature thermal anomaly resetting the VSL signal in nature, and/or by an insufficient measurement protocol, unable to correctly translate the natural signal into the equivalent laboratory dose. - Highlights: • We investigate the potential of VSL to date quartz from early Quaternary palaeosols (1.6 - 0.7 Ma old). • The VSL signals show good reproducibility, dose response, thermal stability, and dose recovery. • VSL ages from three palaeosols underestimate the independent K-Ar ages by 50% or more. • It is possible that the VSL ages are correct, but have been reset by thermal anomalies. • Further investigation of the natural VSL signal is needed to confirm these underestimating ages.

  20. An implantable wireless optogenetic stimulation system for peripheral nerve control.

    Science.gov (United States)

    Kang-Il Song; Park, Sunghee E; Myoung-Soo Kim; Chulmin Joo; Yong-Jun Kim; Suh, Jun-Kyo F; Dosik Hwang; Inchan Youn

    2015-08-01

    An implantable wireless optogenetic stimulation system with an LED-based optical stimulation cuff electrode was developed for peripheral nerve control. The proposed system consisted of a battery-powered optical cuff electrode, optical stimulation controller, and wireless communication system. The optical cuff electrode had a polydimethylsiloxane (PDMS) structure was designed to illuminate the entire sciatic nerve. The wireless communication system was designed to comply with medical implant communication service (MICS) regulations. To evaluate the proposed system, optogenetic stimulation was performed in optogenetic transgenic mice (Thy1::ChR2). The optical cuff electrode was implanted on the sciatic nerve, and movement was elicited during optical stimulation. The experimental results show that ankle movement can be generated wirelessly using optical stimulation pulse parameters.

  1. Memory and convulsive stimulation: effects of stimulus waveform.

    Science.gov (United States)

    Spanis, C W; Squire, L R

    1981-09-01

    Electrical stimulation with brief pulses can produce a seizure requiring less energy than conventional sine-wave stimulation, and it has been suggested that brief-pulse stimulation might reduce the memory loss associated with electroconvulsive therapy (ECT). The authors evaluated the effects of electroconvulsive shock (ECS) on memory in mice by using various waveforms, current intensities, training-ECS intervals, pulse widths, and stimulus durations. When equated for ability to produce seizures, low-energy, brief-pulse stimulation caused as much amnesia as sine-wave stimulation and sometimes more. In the absence of comparisons of the amnesic effects of brief-pulse and sine-wave stimulation in humans, the use of brief pulses for administering ECT is unwarranted.

  2. Stimulation-Based Control of Dynamic Brain Networks.

    Directory of Open Access Journals (Sweden)

    Sarah Feldt Muldoon

    2016-09-01

    Full Text Available The ability to modulate brain states using targeted stimulation is increasingly being employed to treat neurological disorders and to enhance human performance. Despite the growing interest in brain stimulation as a form of neuromodulation, much remains unknown about the network-level impact of these focal perturbations. To study the system wide impact of regional stimulation, we employ a data-driven computational model of nonlinear brain dynamics to systematically explore the effects of targeted stimulation. Validating predictions from network control theory, we uncover the relationship between regional controllability and the focal versus global impact of stimulation, and we relate these findings to differences in the underlying network architecture. Finally, by mapping brain regions to cognitive systems, we observe that the default mode system imparts large global change despite being highly constrained by structural connectivity. This work forms an important step towards the development of personalized stimulation protocols for medical treatment or performance enhancement.

  3. Electrical stimulation for urinary incontinence in women: a systematic review.

    Science.gov (United States)

    Schreiner, Lucas; Santos, Thais Guimarães dos; Souza, Alessandra Borba Anton de; Nygaard, Christiana Campani; Silva Filho, Irenio Gomes da

    2013-01-01

    Electrical stimulation is commonly recommended to treat urinary incontinence in women. It includes several techniques that can be used to improve stress, urge, and mixed symptoms. However, the magnitude of the alleged benefits is not completely established. To determine the effects of electrical stimulation in women with symptoms or urodynamic diagnoses of stress, urge, and mixed incontinence. Our review included articles published between January 1980 and January 2012. We used the search terms ″urinary incontinence″, ″electrical stimulation ″, ″ intravaginal ″, ″ tibial nerve ″ and ″ neuromodulation ″ for studies including female patients. We evaluated randomized trials that included electrical stimulation in at least one arm of the trial, to treat women with urinary incontinence. Two reviewers independently assessed the data from the trials, for inclusion or exclusion, and methodological analysis. A total of 30 randomized clinical trials were included. Most of the trials involved intravaginal electrical stimulation. Intravaginal electrical stimulation showed effectiveness in treating urge urinary incontinence, but reported contradictory data regarding stress and mixed incontinence. Tibial-nerve stimulation showed promising results in randomized trials with a short follow-up period. Sacral-nerve stimulation yielded interesting results in refractory patients. Tibial-nerve and intravaginal stimulation have shown effectiveness in treating urge urinary incontinence. Sacral-nerve stimulation provided benefits in refractory cases. Presently available data provide no support for the use of intravaginal electrical stimulation to treat stress urinary incontinence in women. Further randomized trials are necessary to determine the magnitude of benefits, with long-term follow-up, and the effectiveness of other electrical-stimulation therapies.

  4. Diversion of ADHD Stimulants and Victimization Among Adolescents

    OpenAIRE

    Epstein-Ngo, Quyen M.; McCabe, Sean Esteban; Veliz, Philip T.; Stoddard, Sarah A.; Austic, Elizabeth A.; Boyd, Carol J.

    2015-01-01

    Objective To examine whether a recent prescription for stimulant medication is associated with peer victimization among youth with attention deficit/hyperactivity disorder (ADHD). Methods Data from 4,965 adolescents attending five public schools who completed an annual web survey over 4 years were used to examine recent stimulant medication prescription and self-reported frequent victimization. Results Adolescents with ADHD and recent stimulant prescription reported more victimization than th...

  5. IAA-glucopyranoside stimulation of corn coleoptiles elongation

    Directory of Open Access Journals (Sweden)

    Adriana Szmidt-Jaworska

    2014-01-01

    Full Text Available It has been previously suggested that 1-O-IAGIuc growth stimulation occurs as the effect of its hydrolysis into a free IAA. In present experiments castanospermine, a known β-glucosidase inhibitor, was included. 1-O-IAGluc in the presence of castanospermine stimulated growth of corn coleoptiles segments even stronger then free IAA. So, it seems that 1-O-IAGluc itself, is responsible for the observed stimulation of corn coleoptile segments elongation.

  6. Cranial electrotherapy stimulation for treatment of anxiety, depression, and insomnia.

    Science.gov (United States)

    Kirsch, Daniel L; Nichols, Francine

    2013-03-01

    Cranial electrotherapy stimulation is a prescriptive medical device that delivers a mild form of electrical stimulation to the brain for the treatment of anxiety, depression, and insomnia. It is supported by more than 40 years of research demonstrating its effectiveness in several mechanistic studies and greater than 100 clinical studies. Adverse effects are rare (electrotherapy stimulation may also be used as an adjunctive therapy. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Feedback Information and Analysis for Microprocessor Controlled Muscle Stimulation.

    Science.gov (United States)

    1981-12-01

    through surface electrodes (Milner et al., 1970). An additional method of stimulation currently used is the intramuscular electrode. All these stimulation...voltage and current than is needed to elicit stimulation with surface or intramuscular electrodes. The stimlation system developed must be able to contrl...an aluminum semicircular brace over the hips. This brace provides the mount for the leg member feedback braces. 17 40 181 The leg mber sections

  8. How students perceive teachers' activities aimed at stimulating critical thinking

    OpenAIRE

    Mirkov, Snežana; Gutvajn, Nikoleta

    2014-01-01

    Research in the field of education show that the application of modern methods and techniques of in-class learning enhance the development of critical thinking of students. We were interested in finding out the attitudes of students towards the stimulation of critical thinking, how students perceive the activities of teachers aimed at stimulating critical thinking and their relations. The questionnaire designed for a larger research on stimulating the inititative, cooperation and creativity d...

  9. Intracranial Self-Stimulation to Evaluate Abuse Potential of Drugs

    OpenAIRE

    Negus, S. Stevens; Miller, Laurence L.

    2014-01-01

    Intracranial self-stimulation (ICSS) is a behavioral procedure in which operant responding is maintained by pulses of electrical brain stimulation. In research to study abuse-related drug effects, ICSS relies on electrode placements that target the medial forebrain bundle at the level of the lateral hypothalamus, and experimental sessions manipulate frequency or amplitude of stimulation to engender a wide range of baseline response rates or response probabilities. Under these conditions, drug...

  10. Management of Elevated Therapeutic Impedances on Deep Brain Stimulation Leads

    OpenAIRE

    Wissam Deeb; Amar Patel; Michael S. Okun; Aysegul Gunduz

    2017-01-01

    Clinical Vignette: A 64-year-old male with a history of essential tremor with bilateral thalamic ventralis intermedius deep brain stimulation implants had elevated therapeutic impedance values despite normal lead integrity impedances and good response to stimulation.Clinical Dilemma: Do elevated therapeutic impedance values indicate a sign of hardware malfunction? What are the guidelines to approach deep brain stimulation hardware malfunction?Clinical Solution: Lead integrity i...

  11. Neuroethics: The Ethics and History Behind Deep Brain Stimulation

    OpenAIRE

    Simmonds, Matthew; Franck, Jannick

    2014-01-01

    In this Project we have tried to answer the Question: What is the history leading up to the development of Deep Brain Stimulation, and what are the ethical implications to the ethics of neuroscience? Has the historical background of psychosurgery affected the ethical climate now in regards to Deep Brain Stimulation, and are there any challenges to Deep Brain Stimulation’s future? We have gone through the historical background leading up to the use of Deep Brain Stimulation, and we discuss how...

  12. Effects of Navigated Repetitive Transcranial Magnetic Stimulation After Stroke.

    Science.gov (United States)

    Chervyakov, Alexander V; Poydasheva, Alexandra G; Lyukmanov, Roman H; Suponeva, Natalia A; Chernikova, Ludmila A; Piradov, Michael A; Ustinova, Ksenia I

    2018-03-01

    The purpose of this study was to test the effects of navigated repetitive transcranial magnetic stimulation, delivered in different modes, on motor impairments and functional limitations after stroke. The study sample included 42 patients (58.5 ± 10.7 years; 26 males) who experienced a single unilateral stroke (1-12 months previously) in the area of the middle cerebral artery. Patients completed a course of conventional rehabilitation, together with 10 sessions of navigated repetitive transcranial magnetic stimulation or sham stimulation. Stimulation was scheduled five times a week over two consecutive weeks in an inpatient clinical setting. Patients were randomly assigned to one of four groups and received sham stimulation (n = 10), low-frequency (1-Hz) stimulation of the nonaffected hemisphere (n = 11), high-frequency (10-Hz) stimulation of the affected hemisphere (n = 13), or sequential combination of low- and high-frequency stimulations (n = 8). Participants were evaluated before and after stimulation with clinical tests, including the arm and hand section of the Fugl-Meyer Assessment Scale, modified Ashworth Scale of Muscle Spasticity, and Barthel Index of Activities of Daily Living. Participants in the three groups receiving navigated repetitive transcranial magnetic stimulation showed improvements in arm and hand functions on the Fugl-Meyer Stroke Assessment Scale. Ashworth Scale of Muscle Spasticity and Barthel Index scores were significantly reduced in groups receiving low- or high-frequency stimulation alone. Including navigated repetitive transcranial magnetic stimulation in a conventional rehabilitation program positively influenced motor and functional recovery in study participants, demonstrating the clinical potential of the method. The results of this study will be used for designing a large-scale clinical trial.

  13. Spinal cord stimulation for neuropathic pain: current perspectives.

    Science.gov (United States)

    Wolter, Tilman

    2014-01-01

    Neuropathic pain constitutes a significant portion of chronic pain. Patients with neuropathic pain are usually more heavily burdened than patients with nociceptive pain. They suffer more often from insomnia, anxiety, and depression. Moreover, analgesic medication often has an insufficient effect on neuropathic pain. Spinal cord stimulation constitutes a therapy alternative that, to date, remains underused. In the last 10 to 15 years, it has undergone constant technical advancement. This review gives an overview of the present practice of spinal cord stimulation for chronic neuropathic pain and current developments such as high-frequency stimulation and peripheral nerve field stimulation.

  14. Design of Electrical Stimulation Bioreactors for Cardiac Tissue Engineering

    Science.gov (United States)

    Tandon, N.; Marsano, A.; Cannizzaro, C.; Voldman, J.; Vunjak-Novakovic, G.

    2009-01-01

    Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering. PMID:19163486

  15. Modulation of auditory percepts by transcutaneous electrical stimulation.

    Science.gov (United States)

    Ueberfuhr, Margarete Anna; Braun, Amalia; Wiegrebe, Lutz; Grothe, Benedikt; Drexl, Markus

    2017-07-01

    Transcutaneous, electrical stimulation with electrodes placed on the mastoid processes represents a specific way to elicit vestibular reflexes in humans without active or passive subject movements, for which the term galvanic vestibular stimulation was coined. It has been suggested that galvanic vestibular stimulation mainly affects the vestibular periphery, but whether vestibular hair cells, vestibular afferents, or a combination of both are excited, is still a matter of debate. Galvanic vestibular stimulation has been in use since the late 18th century, but despite the long-known and well-documented effects on the vestibular system, reports of the effect of electrical stimulation on the adjacent cochlea or the ascending auditory pathway are surprisingly sparse. The present study examines the effect of transcutaneous, electrical stimulation of the human auditory periphery employing evoked and spontaneous otoacoustic emissions and several psychoacoustic measures. In particular, level growth functions of distortion product otoacoustic emissions were recorded during electrical stimulation with alternating currents (2 Hz, 1-4 mA in 1 mA-steps). In addition, the level and frequency of spontaneous otoacoustic emissions were followed before, during, and after electrical stimulation (2 Hz, 1-4 mA). To explore the effect of electrical stimulation on the retrocochlear level (i.e. on the ascending auditory pathway beyond the cochlea), psychoacoustic experiments were carried out. Specifically, participants indicated whether electrical stimulation (4 Hz, 2 and 3 mA) induced amplitude modulations of the perception of a pure tone, and of auditory illusions after presentation of either an intense, low-frequency sound (Bounce tinnitus) or a faint band-stop noise (Zwicker tone). These three psychoacoustic measures revealed significant perceived amplitude modulations during electrical stimulation in the majority of participants. However, no significant changes of evoked and

  16. Pancreatic exocrine responses to parasympathetic stimulation in anaesthetized pigs.

    Science.gov (United States)

    Halfacree, Z J; Read, P A; Edwards, A V

    2001-03-23

    Pancreatic exocrine responses to stimulation of the peripheral ends of the vagus nerves intermittently have been investigated in anaesthetized pigs and compared with the effects of continuous stimulation at corresponding frequencies. At relatively low frequencies Hz in bursts or 2 Hz continuously) both the flow of pancreatic juice and the output of protein therein were potentiated by stimulating in bursts. Thus stimulation at 20 Hz in bursts produced a significantly greater flow of pancreatic juice than stimulation at 2 Hz continuously (10.9+/-0.9 compared to 4.8+/-0.7 microl min(-1) (g gland)-1 , respectively; PHz (144+/-23 microg min(-1) (g gland)-1) far exceeded that produced during continuous stimulation at 2 Hz (49+/-9 microg min(-1) (g gland)-1; PHz) and substantially reduced the output of protein during intermittent stimulation (to 27+/-7 ng min(-1) (g gland)-1; PHz in bursts). These results show that a variety of pancreatic exocrine responses can be enhanced by stimulating the parasympathetic innervation in bursts. They are also consistent with the contention that the secretion of protein from the gland, in response to parasympathetic stimulation, is dependent mainly on activation of muscarinic receptors. They confirm that the flow of pancreatic juice is due mainly to the release of VIP and show that, in the absence of atropine, this is restricted by muscarinic inhibition which may be presynaptic as elsewhere.

  17. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    Science.gov (United States)

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Pathological gambling after bilateral subthalamic nucleus stimulation in Parkinson disease.

    Science.gov (United States)

    Smeding, H M M; Goudriaan, A E; Foncke, E M J; Schuurman, P R; Speelman, J D; Schmand, B

    2007-05-01

    We describe a patient with advanced Parkinson's disease who developed pathological gambling within a month after successful bilateral subthalamic nucleus (STN) stimulation. There was no history of gambling. On neuropsychological testing, slight cognitive decline was evident 1 year after surgery. Stimulation of the most dorsal contact with and without medication induced worse performances on decision making tests compared with the more ventral contact. Pathological gambling disappeared after discontinuation of pergolide and changing the stimulation parameters. Pathological gambling does not seem to be associated with decision making but appears to be related to a combination of bilateral STN stimulation and treatment with dopamine agonists.

  19. HGF is released from buccal fibroblasts after smokeless tobacco stimulation

    DEFF Research Database (Denmark)

    Dabelsteen, S; Christensen, S; Gron, B

    2005-01-01

    To investigate the effect of smokeless tobacco (ST) on (1) HGF, KGF and GM-CSF expression by buccal fibroblasts and (2) on keratinocyte and fibroblast proliferation. Buccal fibroblasts were stimulated with different concentrations of ST extracts in a double dilution from 0.50% w/v to 0.03% w...... on exposure time and on concentration of the tobacco extract. High concentration increased production of HGF 4-fold. KGF production was doubled when high concentration of tobacco was used, low concentration did not stimulate cells. GM-CSF production was low in both stimulated and non-stimulated cells...

  20. Interferential electric stimulation applied to the neck increases swallowing frequency.

    Science.gov (United States)

    Furuta, Takayuki; Takemura, Masanori; Tsujita, Junzo; Oku, Yoshitaka

    2012-03-01

    Swallowing disorders are a common complaint among the elderly. Recently, surface electrical stimulation applied to the neck region has received increased attention as a new modality to treat pharyngeal dysphagia. Previous reports used pulsed current at a frequency range of 1-120 Hz. Kilohertz-frequency alternating currents (ACs) have not been tested for treating dysphagia. Therefore, we evaluated the effects of interferential currents (IFCs), the most popular modality of amplitude-modulated kilohertz-frequency ACs in clinical practice, on the swallowing reflex in healthy subjects. We found that IFC stimulation at the sensory threshold with 50-Hz modulation significantly increased the number of swallows without any discomfort, but pure AC stimulation at the carrier frequency did not have a significant effect. There was no statistically significant difference in the time course of the number of swallows among 1,000-, 2,000-, 4,000-, and 6,000-Hz carrier frequencies. The number of swallows remained increased during the 15-min IFC stimulation, suggesting that IFC stimulation facilitates the swallowing reflex without adaptation, at least during this stimulation period. We suggest that an IFC stimulation or a low-frequency, modulated kilohertz AC stimulation, which would be more comfortable than pulsed currents, is an alternative stimulation mode for treating pharyngeal dysphagia.

  1. Deep Brain Stimulation for Tremor: Is There a Common Structure?

    Science.gov (United States)

    Fiechter, Michael; Nowacki, Andreas; Oertel, Markus F; Fichtner, Jens; Debove, Ines; Lachenmayer, M Lenard; Wiest, Roland; Bassetti, Claudio L; Raabe, Andreas; Kaelin-Lang, Alain; Schüpbach, Michael W; Pollo, Claudio

    2017-01-01

    Subthalamic nucleus (STN) stimulation has been recognized to control resting tremor in Parkinson disease. Similarly, thalamic stimulation (ventral intermediate nucleus; VIM) has shown tremor control in Parkinson disease, essential, and intention tremors. Recently, stimulation of the posterior subthalamic area (PSA) has been associated with excellent tremor control. Thus, the optimal site of stimulation may be located in the surrounding white matter. The objective of this work was to investigate the area of stimulation by determining the contact location correlated with the best tremor control in STN/VIM patients. The mean stimulation site and related volume of tissue activated (VTA) of 25 tremor patients (STN or VIM) were projected on the Morel atlas and compared to stimulation sites from other tremor studies. All patients showed a VTA that covered ≥50% of the area superior and medial to the STN or inferior to the VIM. Our stimulation areas suggest involvement of the more lateral and superior part of the dentato-rubro-thalamic tract (DRTT), whereas targets described in other studies seem to involve the DRTT in its more medial and inferior part when it crosses the PSA. According to anatomical and diffusion tensor imaging data, the DRTT might be the common structure stimulated at different portions within the PSA/caudal zona incerta. © 2017 S. Karger AG, Basel.

  2. A prime a day keeps calories away: The effects of supraliminal priming on food consumption and the moderating role of gender and eating restraint.

    Science.gov (United States)

    Minas, Randall K; Poor, Morgan; Dennis, Alan R; Bartelt, Valerie L

    2016-10-01

    The link between intentions and action in weight control is weaker than previously thought, so recent research has called for further investigation of ways to improve weight control that bypass conscious intentions. Priming has been shown to have effects on individual behavior in a variety of contexts by influencing subconscious cognition. This paper investigates the effects of semantic priming using healthy body image, goal-oriented words on food consumption. The moderating role of both restrained eating and gender is investigated. 161 participants were involved in an experiment using a novel version of a scrambled sentence priming game. The outcome measure was the number of kilocalories consumed, examined using a between subjects ANCOVA with priming, gender, restrained eating index, self-reported BMI, and two interaction terms (primingxgender, and primingxrestrained eating index). There was no main effect of priming but there was an interaction of priming with gender. Females consumed significantly fewer kilocalories after being exposed to priming words related to a healthy body image (i.e. "slim", "fit,") compared to females receiving the neutral prime, with a medium effect size (d = 0.58). The body image prime did not significantly affect food intake for males, nor did it have a differential effect on restrained eaters. This study shows that priming can be an effective method for influencing females to reduce food intake, regardless of whether they are restrained or unrestrained eaters. Future studies could investigate whether different priming words related to a male's healthy body image goal (i.e. "buff," "muscles," etc.) would similarly reduce food intake for males. Copyright © 2016. Published by Elsevier Ltd.

  3. The stimulated social brain: effects of transcranial direct current stimulation on social cognition.

    Science.gov (United States)

    Sellaro, Roberta; Nitsche, Michael A; Colzato, Lorenza S

    2016-04-01

    Transcranial direct current stimulation (tDCS) is an increasingly popular noninvasive neuromodulatory tool in the fields of cognitive and clinical neuroscience and psychiatry. It is an inexpensive, painless, and safe brain-stimulation technique that has proven to be effective in modulating cognitive and sensory-perceptual functioning in healthy individuals and clinical populations. Importantly, recent findings have shown that tDCS may also be an effective and promising tool for probing the neural mechanisms of social cognition. In this review, we present the state-of-the-art of the field of tDCS research in social cognition. By doing so, we aim to gather knowledge of the potential of tDCS to modulate social functioning and social decision making in healthy humans, and to inspire future research investigations. © 2016 New York Academy of Sciences.

  4. Exploring consciousness in emotional face decoding: an event-related potential analysis.

    Science.gov (United States)

    Balconi, Michela

    2006-05-01

    The author analyzed the role of consciousness in emotional face comprehension. The author recorded psychophysiological measures of event-related potentials (ERPs), elicited by supraliminal and subliminal stimuli when participants viewed emotional facial expressions of 4 emotions or neutral stimuli. The author analyzed an ERP emotion-specific effect (N200 peak variation; temporal interval was 180-300 ms poststimulus) in terms of peak amplitude and latency variables. The results indicated 4 important findings. First, there was an emotional-specific ERP deflection only for emotional stimuli, not for neutral stimuli. Second, the unaware information processing was quite similar to that of aware in terms of peak morphology, but not in terms of latency. In fact, unconscious stimulation produced a more delayed peak variation than did conscious stimulation. Third, valence of facial stimulus (positive or negative) was supraliminally and subliminally decoded because it was showed by differences of peak deflection between negative high arousing (fear and anger) and low arousing (happiness, sadness, and neutral) stimuli. Finally, the author found a more posterior distribution of ERP as a function of emotional content of the stimulus. Cortical lateralization (right or left) was not correlated to conscious or unconscious stimulation. The author discussed the functional significance of her results in terms of supraliminal and subliminal conditions.

  5. Vertex Stimulation as a Control Site for Transcranial Magnetic Stimulation: A Concurrent TMS/fMRI Study

    OpenAIRE

    Jung, JeYoung; Bungert, Andreas; Bowtell, Richard; Jackson, Stephen R.

    2016-01-01

    Background A common control condition for transcranial magnetic stimulation (TMS) studies is to apply stimulation at the vertex. An assumption of vertex stimulation is that it has relatively little influence over on-going brain processes involved in most experimental tasks, however there has been little attempt to measure neural changes linked to vertex TMS. Here we directly test this assumption by using a concurrent TMS/fMRI paradigm in which we investigate fMRI blood-oxygenation-level-depen...

  6. Are Prescription Stimulants “Smart Pills”?: The Epidemiology and Cognitive Neuroscience of Prescription Stimulant Use by Normal Healthy Individuals

    OpenAIRE

    Smith, M. Elizabeth; Farah, Martha J.

    2011-01-01

    Use of prescription stimulants by normal healthy individuals to enhance cognition is said to be on the rise. Who is using these medications for cognitive enhancement, and how prevalent is this practice? Do prescription stimulants in fact enhance cognition for normal healthy people? We review the epidemiological and cognitive neuroscience literatures in search of answers to these questions. Epidemiological issues addressed include the prevalence of nonmedical stimulant use, user demographics, ...

  7. The safety of transcranial magnetic stimulation with deep brain stimulation instruments.

    Science.gov (United States)

    Shimojima, Yoshio; Morita, Hiroshi; Nishikawa, Noriko; Kodaira, Minori; Hashimoto, Takao; Ikeda, Shu-Ichi

    2010-02-01

    Transcranial magnetic stimulation (TMS) has been employed in patients with an implanted deep brain stimulation (DBS) device. We investigated the safety of TMS using simulation models with an implanted DBS device. The DBS lead was inserted into plastic phantoms filled with dilute gelatin showing impedance similar to that of human brain. TMS was performed with three different types of magnetic coil. During TMS (1) electrode movement, (2) temperature change around the lead, and (3) TMS-induced current in various situations were observed. The amplitude and area of each evoked current were measured to calculate charge density of the evoked current. There was no movement or temperature increase during 0.2 Hz repetitive TMS with 100% stimulus intensity for 1 h. The size of evoked current linearly increased with TMS intensity. The maximum charge density exceeded the safety limit of 30 muC/cm(2)/phase during stimulation above the loops of the lead with intensity over 50% using a figure-eight coil. Strong TMS on the looped DBS leads should not be administered to avoid electrical tissue injury. Subcutaneous lead position should be paid enough attention for forthcoming situations during surgery. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Effect of transcutaneous electrical nerve stimulation induced parotid stimulation on salivary flow

    Directory of Open Access Journals (Sweden)

    Sreenivasulu Pattipati

    2013-01-01

    Full Text Available Aims and Objectives: The main objective of this study was to evaluate the duration of stimulation over the parotid salivary flow following the use of transcutaneous electric nerve stimulation (TENS in different age groups. Materials and Methods: The study was carried out in three different age groups. Under group A individuals from 21 to 35 years of age, group B 36-50 years and group C above 51 years were considered. In each group 30 subjects were taken of whom 15 were males and 15 were females. The placement of pads was approximated bilaterally over the parotid glands. The working parameters of TENS unit were fixed at 50 Hz and the unit was in normal mode. Results: Subjects belonging to group B were showing statistically significant increases in the duration of stimulated parotid salivary flow following the use of TENS. Conclusion: TENS can be considered as a non-pharmacological alternative to improve salivation for longer period in xerostomia patients.

  9. Spinal cord stimulation suppresses bradycardias and atrial tachyarrhythmias induced by mediastinal nerve stimulation in dogs.

    Science.gov (United States)

    Cardinal, René; Pagé, Pierre; Vermeulen, Michel; Bouchard, Caroline; Ardell, Jeffrey L; Foreman, Robert D; Armour, J Andrew

    2006-11-01

    Spinal cord stimulation (SCS) applied to the dorsal aspect of the cranial thoracic cord imparts cardioprotection under conditions of neuronally dependent cardiac stress. This study investigated whether neuronally induced atrial arrhythmias can be modulated by SCS. In 16 anesthetized dogs with intact stellate ganglia and in five with bilateral stellectomy, trains of five electrical stimuli were delivered during the atrial refractory period to right- or left-sided mediastinal nerves for up to 20 s before and after SCS (20 min). Recordings were obtained from 191 biatrial epicardial sites. Before SCS (11 animals), mediastinal nerve stimulation initiated bradycardia alone (12 nerve sites), bradycardia followed by tachyarrhythmia/fibrillation (50 sites), as well as tachyarrhythmia/fibrillation without a preceding bradycardia (21 sites). After SCS, the number of responsive sites inducing bradycardia was reduced by 25% (62 to 47 sites), and the cycle length prolongation in residual bradycardias was reduced. The number of responsive sites inducing tachyarrhythmia was reduced by 60% (71 to 29 sites). Once elicited, residual tachyarrhythmias arose from similar epicardial foci, displaying similar dynamics (cycle length) as in control states. In the absence of SCS, bradycardias and tachyarrhythmias induced by repeat nerve stimulation were reproducible (five additional animals). After bilateral stellectomy, SCS no longer influenced neuronal induction of bradycardia and atrial tachyarrhythmias. These data indicate that SCS obtunds the induction of atrial arrhythmias resulting from excessive activation of intrinsic cardiac neurons and that such protective effects depend on the integrity of nerves coursing via the subclavian ansae and stellate ganglia.

  10. Tactile stimulation interventions: influence of stimulation parameters on sensorimotor behavior and neurophysiological correlates in healthy and clinical samples.

    Science.gov (United States)

    Parianen Lesemann, Franca H; Reuter, Eva-Maria; Godde, Ben

    2015-04-01

    The pure exposure to extensive tactile stimulation, without the requirement of attention or active training, has been revealed to enhance sensorimotor functioning presumably due to an induction of plasticity in the somatosensory cortex. The induced effects, including increased tactile acuity and manual dexterity have repeatedly been observed in basic as well as clinical research. However, results vary greatly in respect to the strength and direction of the effects on the behavioral and on the brain level. Multiple evidences show that differences in the stimulation protocols (e.g., two vs. multiple stimulation sites) and parameters (e.g., duration, frequency, and amplitude) might contribute to this variability of effects. Nevertheless, stimulation protocols have not been comprehensively compared yet. Identifying favorable parameters for tactile stimulation interventions is especially important because of its possible application as a treatment option for patients suffering from sensory loss, maladaptive plasticity, or certain forms of motor impairment. This review aims to compare the effects of different tactile stimulation protocols and to assess possible implications for tactile interventions. Our goal is to identify ways of optimizing stimulation protocols to improve sensorimotor performance. To this end, we reviewed research on tactile stimulation in the healthy population, with a focus on the effectiveness of the applied parameters regarding psychophysiological measures. We discuss the association of stimulation-induced changes on the behavioral level with alterations in neural representations and response characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Electrical Stimulation for Urinary Incontinence in Women: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Lucas Schreiner

    2013-07-01

    Full Text Available Background Electrical stimulation is commonly recommended to treat urinary incontinence in women. It includes several techniques that can be used to improve stress, urge, and mixed symptoms. However, the magnitude of the alleged benefits is not completely established. Objectives To determine the effects of electrical stimulation in women with symptoms or urodynamic diagnoses of stress, urge, and mixed incontinence. Search Strategy: Our review included articles published between January 1980 and January 2012. We used the search terms “urinary incontinence”, “electrical stimulation”, “intravaginal”, “tibial nerve” and “neuromodulation” for studies including female patients. Selection Criteria We evaluated randomized trials that included electrical stimulation in at least one arm of the trial, to treat women with urinary incontinence. Data Collection and Analysis Two reviewers independently assessed the data from the trials, for inclusion or exclusion, and methodological analysis. Main Results A total of 30 randomized clinical trials were included. Most of the trials involved intravaginal electrical stimulation. Intravaginal electrical stimulation showed effectiveness in treating urge urinary incontinence, but reported contradictory data regarding stress and mixed incontinence. Tibial-nerve stimulation showed promising results in randomized trials with a short follow-up period. Sacral-nerve stimulation yielded interesting results in refractory patients. Conclusions Tibial-nerve and intravaginal stimulation have shown effectiveness in treating urge urinary incontinence. Sacral-nerve stimulation provided benefits in refractory cases. Presently available data provide no support for the use of intravaginal electrical stimulation to treat stress urinary incontinence in women. Further randomized trials are necessary to determine the magnitude of benefits, with long-term follow-up, and the effectiveness of other electrical-stimulation

  12. Facilitating access to emotions: neural signature of EMDR stimulation.

    Science.gov (United States)

    Herkt, Deborah; Tumani, Visal; Grön, Georg; Kammer, Thomas; Hofmann, Arne; Abler, Birgit

    2014-01-01

    Eye Movement Desensitisation and Reprocessing (EMDR) is a method in psychotherapy effective in treating symptoms of posttraumatic stress disorder. The client attends to alternating bilateral visual, auditory or sensory stimulation while confronted with emotionally disturbing material. It is thought that the bilateral stimulation as a specific element of EMDR facilitates accessing and processing of negative material while presumably creating new associative links. We hypothesized that the putatively facilitated access should be reflected in increased activation of the amygdala upon bilateral EMDR stimulation even in healthy subjects. We investigated 22 healthy female university students (mean 23.5 years) with fMRI. Subjects were scanned while confronted with blocks of disgusting and neutral picture stimuli. One third of the blocks was presented without any additional stimulation, one third with bilateral simultaneous auditory stimulation, and one third with bilateral alternating auditory stimulation as used in EMDR. Contrasting disgusting vs. neutral picture stimuli confirmed the expected robust effect of amygdala activation for all auditory stimulation conditions. The interaction analysis with the type of auditory stimulation revealed a specific increase in activation of the right amygdala for the bilateral alternating auditory stimulation. Activation of the left dorsolateral prefrontal cortex showed the opposite effect with decreased activation. We demonstrate first time evidence for a putative neurobiological basis of the bilateral alternating stimulation as used in the EMDR method. The increase in limbic processing along with decreased frontal activation is in line with theoretical models of how bilateral alternating stimulation could help with therapeutic reintegration of information, and present findings may pave the way for future research on EMDR in the context of posttraumatic stress disorder.

  13. Facilitating access to emotions: neural signature of EMDR stimulation.

    Directory of Open Access Journals (Sweden)

    Deborah Herkt

    Full Text Available Eye Movement Desensitisation and Reprocessing (EMDR is a method in psychotherapy effective in treating symptoms of posttraumatic stress disorder. The client attends to alternating bilateral visual, auditory or sensory stimulation while confronted with emotionally disturbing material. It is thought that the bilateral stimulation as a specific element of EMDR facilitates accessing and processing of negative material while presumably creating new associative links. We hypothesized that the putatively facilitated access should be reflected in increased activation of the amygdala upon bilateral EMDR stimulation even in healthy subjects.We investigated 22 healthy female university students (mean 23.5 years with fMRI. Subjects were scanned while confronted with blocks of disgusting and neutral picture stimuli. One third of the blocks was presented without any additional stimulation, one third with bilateral simultaneous auditory stimulation, and one third with bilateral alternating auditory stimulation as used in EMDR.Contrasting disgusting vs. neutral picture stimuli confirmed the expected robust effect of amygdala activation for all auditory stimulation conditions. The interaction analysis with the type of auditory stimulation revealed a specific increase in activation of the right amygdala for the bilateral alternating auditory stimulation. Activation of the left dorsolateral prefrontal cortex showed the opposite effect with decreased activation.We demonstrate first time evidence for a putative neurobiological basis of the bilateral alternating stimulation as used in the EMDR method. The increase in limbic processing along with decreased frontal activation is in line with theoretical models of how bilateral alternating stimulation could help with therapeutic reintegration of information, and present findings may pave the way for future research on EMDR in the context of posttraumatic stress disorder.

  14. The Mechanism of Financial Stimulation of Investment Activity

    Directory of Open Access Journals (Sweden)

    Vasiliy Valeryevich Tarakanov

    2016-03-01

    Full Text Available Modernization of the Russian economy and creation of conditions for its economic growth demand activization of investment activity that is possible by means of its financial stimulation. Financial stimulation of investment activity defines the need of changes of the contents, the directions and ways of implementation of the financial relations between subjects of investment activity. Financial stimulation of investment activity is carried out via the mechanism in the context of which these financial relations are settled. For defining the mechanism of financial stimulation of investment activity the authors consider the very concept of financial mechanism. The conclusion is drawn that all elements of the financial mechanism are the integrated unity, they are interdependent and interconnected, and the combination of types, forms, methods of the organization of the financial relations forms “a design of the financial mechanism”. The article specifies the maintenance of the mechanism of financial stimulation of investment activity, and reveals its essence. The structure of the mechanism of financial stimulation of investment activity is presented by the following elements: subjects of financial stimulation of investment activity, the purpose of attraction of investments by them, set of financial methods and tools, sources of means of achievement of goals, standard - legal and information support of financial stimulation of investment activity. It is proved that in the mechanism of financial stimulation of investment activity the leading role is played by the state by means of forms of direct and indirect participation in attraction of investments, each of which is realized by means of specific methods and the corresponding tools. The widespread instrument of financial stimulation of investment activity is the investments which are carried out by the state institutes of development participating in the organization of the process of financial

  15. Optimising the Effect of Stimulants on Citric Acid Production from ...

    African Journals Online (AJOL)

    Additives such as low molecular weight alcohols, trace metals, phytate, lipids etc have been reported to stimulate citric acid production. Hence the objective of this study was to investigate the effect of stimulating the metabolic activity of Aspergillus niger for the purpose of improved citric acid production from cocoyam starch.

  16. Electrical muscle stimulation (EMS) training of the hamstrings ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the effects of electrical muscle stimulation (EMS) training on hamstring muscle strength. The study utilised a quantitative experimental research design. The intervention was assessed using a Humac Norm 7000 Dynamometer. A Chattanooga Intelect Mobile Combo muscle stimulator ...

  17. Prevalence of Self-Medication of Psychoactive Stimulants and ...

    African Journals Online (AJOL)

    Purpose: To evaluate the prevalence of self-medication of psychoactive stimulants and antidepressants among pharmacy students of Pakistan. Methods: A cross-sectional survey on self-medication of psychoactive stimulants and antidepressants among pharmacy students was conducted with a structured and validated ...

  18. Influence of electrical stimulation on carcass and meat quality of ...

    African Journals Online (AJOL)

    In a previous study regarding the effects of Kosher and conventional slaughter techniques on carcass and meat quality of cattle, it was speculated that electrical stimulation may have affected some of the meat qualities. Therefore, the objective of this study was to investigate the effects of electrical stimulation (ES) and ...

  19. Neuromuscular electrical stimulation for the prevention of venous thromboembolism.

    Science.gov (United States)

    Ravikumar, Raveena; Williams, Katherine J; Babber, Adarsh; Moore, Hayley M; Lane, Tristan Ra; Shalhoub, Joseph; Davies, Alun H

    2017-01-01

    Objective Venous thromboembolism, encompassing deep vein thrombosis and pulmonary embolism, is a significant cause of morbidity and mortality, affecting one in 1000 adults per year. Neuromuscular electrical stimulation is the transcutaneous application of electrical impulses to elicit muscle contraction, preventing venous stasis. This review aims to investigate the evidence underlying the use of neuromuscular electrical stimulation in thromboprophylaxis. Methods The Medline and Embase databases were systematically searched, adhering to PRISMA guidelines, for articles relating to electrical stimulation and thromboprophylaxis. Articles were screened according to a priori inclusion and exclusion criteria. Results The search strategy identified 10 randomised controlled trials, which were used in three separate meta-analyses: five trials compared neuromuscular electrical stimulation to control, favouring neuromuscular electrical stimulation (odds ratio of deep vein thrombosis 0.29, 95% confidence interval 0.13-0.65; P = .003); three trials compared neuromuscular electrical stimulation to heparin, favouring heparin (odds ratio of deep vein thrombosis 2.00, 95% confidence interval 1.13-3.52; P = .02); three trials compared neuromuscular electrical stimulation as an adjunct to heparin versus heparin only, demonstrating no significant difference (odds ratio of deep vein thrombosis 0.33, 95% confidence interval 0.10-1.14; P = .08). Conclusion Neuromuscular electrical stimulation significantly reduces the risk of deep vein thrombosis compared to no prophylaxis. It is inferior to heparin in preventing deep vein thrombosis and there is no evidence for its use as an adjunct to heparin.

  20. Neuromuscular electrical stimulation for thromboprophylaxis: A systematic review.

    Science.gov (United States)

    Hajibandeh, S; Hajibandeh, S; Antoniou, G A; Scurr, J R H; Torella, F

    2015-10-01

    To evaluate the effect of neuromuscular electrical stimulation on lower limb venous blood flow and its role in thromboprophylaxis. Systematic review of randomised and non-randomised studies evaluating neuromuscular electrical stimulation, and reporting one or more of the following outcomes: incidence of venous thromboembolism, venous blood flow and discomfort profile. Twenty-one articles were identified. Review of these articles showed that neuromuscular electrical stimulation increases venous blood flow and is generally associated with an acceptable tolerability, potentially leading to good patient compliance. Ten comparative studies reported DVT incidence, ranging from 2% to 50% with neuromuscular electrical stimulation and 6% to 47.1% in controls. There were significant differences, among included studies, in terms of patient population, neuromuscular electrical stimulation delivery, diagnosis of venous thromboembolism and blood flow measurements. Neuromuscular electrical stimulation increases venous blood flow and is well tolerated, but current evidence does not support a role for neuromuscular electrical stimulation in thromboprophylaxis. Randomised controlled trials are required to investigate the clinical utility of neuromuscular electrical stimulation in this setting. © The Author(s) 2015.

  1. Side effects of vagus nerve stimulation during physical exercise

    NARCIS (Netherlands)

    Mulders, D.M.; de Vos, Cecilia Cecilia Clementine; Vosman, I.; Driesse, M.J.; van Putten, Michel Johannes Antonius Maria

    2012-01-01

    RATIONALE: Vagus nerve stimulation (VNS) is a treatment option in the case of refractory epilepsy. However, several side effects have been reported, including dyspnea, coughing and bradycardias [JCA 2010: 22;213-222]. Although some patients experience hardly any side effects from the stimulation

  2. Modulating the brain at work using noninvasive transcranial stimulation.

    Science.gov (United States)

    McKinley, R Andy; Bridges, Nathaniel; Walters, Craig M; Nelson, Jeremy

    2012-01-02

    This paper proposes a shift in the way researchers currently view and use transcranial brain stimulation technologies. From a neuroscience perspective, the standard application of both transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) has been mainly to explore the function of various brain regions. These tools allow for noninvasive and painless modulation of cortical tissue. In the course of studying the function of an area, many studies often report enhanced performance of a task during or following the stimulation. However, little follow-up research is typically done to further explore these effects. Approaching this growing pool of cognitive neuroscience literature with a neuroergonomics mindset (i.e., studying the brain at work), the possibilities of using these stimulation techniques for more than simply investigating the function of cortical areas become evident. In this paper, we discuss how cognitive neuroscience brain stimulation studies may complement neuroergonomics research on human performance optimization. And, through this discussion, we hope to shift the mindset of viewing transcranial stimulation techniques as solely investigatory basic science tools or possible clinical therapeutic devices to viewing transcranial stimulation techniques as interventional tools to be incorporated in applied science research and systems for the augmentation and enhancement of human operator performance. Published by Elsevier Inc.

  3. Modeling and simulation of deep brain stimulation in Parkinson's disease

    NARCIS (Netherlands)

    Heida, Tjitske; Moroney, R.; Marani, Enrico; Usunoff, K.G.; Pereira, M.; Freire, M.

    2009-01-01

    Deep Brain Stimulation (DBS) is effective in the Parkinsonian state, while it seems to produce rather non-selective stimulation over an unknown volume of tissue. Despite a huge amount of anatomical and physiological data regarding the structure of the basal ganglia (BG) and their connections, the

  4. Transcranial Magnetic Stimulation-coil design with improved focality

    Science.gov (United States)

    Rastogi, P.; Lee, E. G.; Hadimani, R. L.; Jiles, D. C.

    2017-05-01

    Transcranial Magnetic Stimulation (TMS) is a technique for neuromodulation that can be used as a non-invasive therapy for various neurological disorders. In TMS, a time varying magnetic field generated from an electromagnetic coil placed on the scalp is used to induce an electric field inside the brain. TMS coil geometry plays an important role in determining the focality and depth of penetration of the induced electric field responsible for stimulation. Clinicians and basic scientists are interested in stimulating a localized area of the brain, while minimizing the stimulation of surrounding neural networks. In this paper, a novel coil has been proposed, namely Quadruple Butterfly Coil (QBC) with an improved focality over the commercial Figure-8 coil. Finite element simulations were conducted with both the QBC and the conventional Figure-8 coil. The two coil's stimulation profiles were assessed with 50 anatomically realistic MRI derived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils has been done to determine the parameters of interest-volume of stimulation, maximum electric field, location of maximum electric field and area of stimulation across all 50 head models for both coils.

  5. Responses to lumbar magnetic stimulation in newborns with spina bifida.

    NARCIS (Netherlands)

    Geerdink, N.; Pasman, J.W.; Roeleveld, N.; Rotteveel, J.J.; Mullaart, R.A.

    2006-01-01

    Searching for a tool to quantify motor impairment in spina bifida, transcranial and lumbar magnetic stimulation were applied in affected newborn infants. Lumbar magnetic stimulation resulted in motor evoked potentials in both the quadriceps muscle and the tibialis anterior muscle in most (11/13)

  6. Neuromuscular stimulation after stroke: from technology to clinical deployment

    NARCIS (Netherlands)

    IJzerman, Maarten Joost; Renzenbrink, Gerbert J.; Geurts, Alexander C.H.

    2009-01-01

    Since the early 1960s, electrical or neuromuscular electrical stimulation (NMES) has been used to support the rehabilitation of stroke patients. One of the earliest applications of NMES included the use of external muscle stimulation to correct drop-foot after stroke. During the last few decades

  7. Neuromuscular stimulation after stroke: from technology to clinical deployment.

    NARCIS (Netherlands)

    IJzerman, M.J.; Renzenbrink, G.J.; Geurts, A.C.H.

    2009-01-01

    Since the early 1960s, electrical or neuromuscular electrical stimulation (NMES) has been used to support the rehabilitation of stroke patients. One of the earliest applications of NMES included the use of external muscle stimulation to correct drop-foot after stroke. During the last few decades

  8. Stimulant use among secondary school students in Osogbo, Nigeria.

    Science.gov (United States)

    Eegunranti, B A; Fatoye, F O; Morakinyo, O

    2009-09-01

    The objectives of this study were to determine the prevalence and pattern of stimulant use and its association with 'brain fag syndrome' among secondary school students in Osogbo, Osun State. The study also aimed to determine the association of socio-demographic variables (of the students and their parents) with stimulant use. A questionnaire consisting of sociodemographic variables, the stimulant use section of the WHO Student Drug Use Questionnaire and the Brain Fag Syndrome Scale (BFSS) was administered on randomly selected students of the two Local Government Areas of Osogbo. The prevalence rates of stimulant use were calculated and the association of stimulant use with Brain Fag Syndrome (BFS) and socio-demographic variables was determined. The 30-day prevalence rate of stimulant use was 20.3%. Users engaged more in the use of common and cheap stimulants (coffee and kola nut). Majority of users started at age 13 years or below. There was a very high relationship between stimulant use and the symptoms of the BFS (pstudents. Control programmes are urgently needed to prevent student wastage.

  9. Inducing circular vection with tactile stimulation encircling the waist

    NARCIS (Netherlands)

    Tinga, A.M.; Jansen, C.; Smagt, M.J. van der; Nijboer, T.C.W.; Erp, J.B.F. van

    2018-01-01

    In general, moving sensory stimuli (visual and auditory) can induce illusory sensations of self-motion (i.e. vection) in the direction opposite of the sensory stimulation. The aim of the current study was to examine whether tactile stimulation encircling the waist could induce circular vection

  10. Stimulant alcohol effects prime within session drinking behavior.

    Science.gov (United States)

    Corbin, William R; Gearhardt, Ashley; Fromme, Kim

    2008-04-01

    Individual differences in subjective alcohol effects have been shown to differ by risk status (e.g., family history of alcoholism) and to predict future risk for alcohol-related problems. Presumably, individual differences in both stimulant and sedative responses affect the rewarding value of drinking which, in turn, impacts future drinking behavior. Although plausible, this theoretical model is largely untested. The current study attempted to provide experimental evidence for the impact of subjective alcohol responses on within session drinking behavior. Using a placebo-controlled between-subjects alcohol administration paradigm, experiences and evaluations of stimulant and sedative alcohol effects (after a target dose of 0.06 g%) were assessed as predictors of ad-libitum consumption in the context of anticipatory stress. Analyses indicated that an initial dose of alcohol increased experiences of both stimulation and sedation although stimulant effects were evaluated much more positively. In addition, stimulant effects after a priming dose predicted further consumption, whereas sedative effects did not. At least among moderate to heavy drinking college students, stimulant alcohol effects are more reinforcing and predict within session drinking behavior under social stress. Increased attention should be given to stimulant alcohol effects as a risk factor for excessive consumption in this population. Incorporating information about stimulant alcohol effects in prevention and intervention programs may also be important if additional research supports the current results.

  11. 21 CFR 522.1002 - Follicle stimulating hormone.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Follicle stimulating hormone. 522.1002 Section 522...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1002 Follicle stimulating hormone. (a)(1) Specifications. Each package contains 2 vials. One vial...

  12. KCl stimulation increases norepinephrine transporter function in PC12 cells.

    Science.gov (United States)

    Mandela, Prashant; Ordway, Gregory A

    2006-09-01

    The norepinephrine transporter (NET) plays a pivotal role in terminating noradrenergic signaling and conserving norepinephrine (NE) through the process of re-uptake. Recent evidence suggests a close association between NE release and regulation of NET function. The present study evaluated the relationship between release and uptake, and the cellular mechanisms that govern these processes. KCl stimulation of PC12 cells robustly increased [3H]NE uptake via the NET and simultaneously increased [3H]NE release. KCl-stimulated increases in uptake and release were dependent on Ca2+. Treatment of cells with phorbol-12-myristate-13-acetate (PMA) or okadaic acid decreased [3H]NE uptake but did not block KCl-stimulated increases in [3H]NE uptake. In contrast, PMA increased [3H]NE release and augmented KCl-stimulated release, while okadaic acid had no effects on release. Inhibition of Ca2+-activated signaling cascades with KN93 (a Ca2+ calmodulin-dependent kinase inhibitor), or ML7 and ML9 (myosin light chain kinase inhibitors), reduced [3H]NE uptake and blocked KCl-stimulated increases in uptake. In contrast, KN93, ML7 and ML9 had no effect on KCl-stimulated [3H]NE release. KCl-stimulated increases in [3H]NE uptake were independent of transporter trafficking to the plasma membrane. While increases in both NE release and uptake mediated by KCl stimulation require Ca2+, different intracellular mechanisms mediate these two events.

  13. Effects of autonomic nerve stimulation on colorectal motility in rats

    Science.gov (United States)

    Tong, Wei Dong; Ridolfi, Timothy J.; Kosinski, Lauren; Ludwig, Kirk; Takahashi, Toku

    2010-01-01

    Background Several disease processes of the colon and rectum, including constipation and incontinence, have been associated with abnormalities of the autonomic nervous system. However, the autonomic innervation to the colon and rectum are not fully understood. The aims of this study were to investigate the effect of stimulation of vagus nerves, pelvic nerves (PN) and hypogastric nerves (HGN) on colorectal motility in rats. Methods Four strain gauge transducers were implanted on the proximal colon, mid colon, distal colon and rectum to record circular muscle contractions in rats. Electrical stimulation was administered to the efferent distal ends of the cervical vagus nerve, PN and HGN. Motility index (MI) was evaluated before and during stimulation. Key Results Electrical stimulation (5–20 Hz) of the cervical vagus elicited significant contractions in the mid colon and distal colon, whereas less pronounced contractions were observed in the proximal colon. PN stimulation elicited significant contractions in the rectum as well as the mid colon and distal colon. Atropine treatment almost completely abolished the contractions induced by vagus nerve and PN stimulation. HGN stimulation caused relaxations in the rectum, mid colon and distal colon. The relaxations in response to HGN stimulation were abolished by propranolol. Conclusions & Inferences Vagal innervation extends to the distal colon, while the PN has projections in the distribution of the rectum through the mid colon. This suggests a pattern of dual parasympathetic innervation in the left colon. Parasympathetic fibers regulate colorectal contractions via muscarinic receptors. The HGN mainly regulates colorectal relaxations via beta-adrenoceptors. PMID:20067587

  14. Luminescence from potassium feldspars stimulated by infrared and green light

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.

    1993-01-01

    A series of experiments are reported which investigate stimulated luminescence from potassium feldspar. The aim is to provide a basic phenomenological description of the response of the material to stimulation by heat, infrared radiation (875 DELTA 80 nm) and a green light wavelength band from 5 15...

  15. Injury among Stimulant-Treated Youth with ADHD

    Science.gov (United States)

    Marcus, Steven C.; Wan, George J.; Zhang, Huabin F.; Olfson, Mark

    2008-01-01

    Objective: To assess risk factors for injury among children and adolescents treated with stimulants for ADHD. Method: An analysis was performed of pharmacy and service claims data from 2000-2003 California Medicaid (Medi-Cal) focusing on children and adolescents ages 6 to 17 years who initiated stimulant therapy for ADHD. Bivariate and…

  16. Stimulability: Relationships to Other Characteristics of Children's Phonological Systems

    Science.gov (United States)

    Tyler, Ann A.; Macrae, Toby

    2010-01-01

    In honour of Miccio's memory, this article revisits the topic of stimulability in children with speech sound disorders (SSD). Eighteen children with SSD, aged 3;6-5;5 (M = 4;8), were tested for their system-wide stimulability, percentage consonants correct (PCC), phonetic inventory size, and oral- and speech-motor skills. Pearson Product Moment…

  17. 21 CFR 882.5810 - External functional neuromuscular stimulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External functional neuromuscular stimulator. 882.5810 Section 882.5810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External functional neuromuscular stimulator. (a) Identification. An external functional neuromuscular...

  18. Features of electroretinogram on rat under different color stimulation

    Directory of Open Access Journals (Sweden)

    Qing-Lin Cao

    2014-04-01

    Full Text Available AIM: To research the feature of normal SD rat and retinal cone dysfunction(RCDrat electroretinogram(ERGunder different color stimulation and to explore its possible diagnostic value. METHODS: Six male SD rats and six RCD rats were used, all of which were mature rats. They were stimulated by red, white, blue and green light and the ERG was recorded. The wavelength of red, green and blue light were 625nm, 525nm and 470nm respectively and the white light was mixed by three color light.RESULTS: The response of ERG in normal SD rat under green and blue light stimulation were stronger than under red and white stimulation. The dark-adapted ERG of RCD rat responsed to color stimulation was similar to the ERG of normal SD rat, but the amplitude under each color stimulation was lower than that of normal SD rat. Light-adapted ERG response was hardly detected waveform.CONCLUSION: Rat is sensitive to blue and green light, which can be used as a suggested light stimulation in the ERG recording. The ERG of RCD rat is not specific for color stimulation, and at present we could not use color ERG as a diagnostic indicator.

  19. Selective dorsal column stimulation in SCS, using conditioning pulses

    NARCIS (Netherlands)

    Holsheimer, J.

    2004-01-01

    A system and method is described for preferentially stimulating dorsal column fibers while avoiding stimulation of dorsal root fibers. The invention applies hyperpolarizing (anodic) pre-pulses (HPP) and depolarizing (cathodic) pre-pulses (DPP) to neural tissue, such as spinal cord tissue, through a

  20. Selective dorsal column stimulation in SCS, using conditioning pulses

    NARCIS (Netherlands)

    Holsheimer, J.

    2003-01-01

    A system and method is described for preferentially stimulating dorsal column fibers while avoiding stimulation of dorsal root fibers. The invention applies hyperpolarizing pre-pulses and depolarizing pre-pulses to neural tissue, such as spinal cord tissue, through a lead placed over the spinal cord

  1. Dynamic electrical muscle stimulation (EMS) training of the ...

    African Journals Online (AJOL)

    Previous research on muscle strengthening using electrical stimulation has mainly focused on isometric training. Thus, the aim of the study was to investigate the effect of isokinetic and isotonic electrical muscle stimulation training on the strength of the quadriceps femoris muscle group. A quantitative, experimental ...

  2. Melanoma risk after ovarian stimulation for in vitro fertilization

    NARCIS (Netherlands)

    Spaan, M.; van den Belt-Dusebout, A. W.; Schaapveld, M.; Mooij, T. M.; Burger, C. W.; van Leeuwen, F. E.; Schats, R.; Lambalk, C. B.; Kortman, M.; Laven, J. S. E.; Jansen, C. A. M.; Helmerhorst, F. M.; Cohlen, B. J.; Braat, D. D. M.; Smeenk, J. M. J.; Simons, A. H. M.; van der Veen, F.; Evers, J. L. H.; van Dop, P. A.

    2015-01-01

    STUDY QUESTION: Do women treated with ovarian stimulation for IVF have an increased risk of melanoma? SUMMARY ANSWER: Ovarian stimulation for IVF does not increase risk of melanoma, even after a prolonged follow-up. WHAT IS KNOWN ALREADY: Although exposure to ultraviolet radiation is the major risk

  3. An external control unit implemented for stimulator ASIC testing ...

    African Journals Online (AJOL)

    ) for a stimulator ASIC testing purposes. The ECU consists of a graphical user interface (GUI) from the PC, a data transceiver and a power transmitter. The GUI was developed using MATLAB for stimulation data setup. The data transceiver was ...

  4. [Stimulation of skin wound contraction and epithelialization by soluble collage].

    Science.gov (United States)

    Melikiants, A G; Kut'kova, O N

    1992-04-01

    It is found that local applications of the unguent with soluble collagen, but not solution of the collagen, stimulate healing of erosions and full-thickness excision wounds in the rat skin. Not all the stages of healing were stimulated, but only two of them--contraction and epithelialization.

  5. 21 CFR 874.1800 - Air or water caloric stimulator.

    Science.gov (United States)

    2010-04-01

    ... vestibular function testing of a patient's body balance system. The vestibular stimulation of the... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Air or water caloric stimulator. 874.1800 Section 874.1800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  6. Role of sound stimulation in reprogramming brain connectivity

    Indian Academy of Sciences (India)

    2013-07-17

    Jul 17, 2013 ... Thus, it becomes imperative to examine in detail the possible ameliorating effects of prenatal sound stimulation in existing animal models of various psychiatric disorders, such as autism. [Chaudhury S, Nag TC, Jain S and Wadhwa S 2013 Role of sound stimulation in reprogramming brain connectivity.

  7. Role of sound stimulation in reprogramming brain connectivity

    Indian Academy of Sciences (India)

    The molecular mechanisms of various changes in the hippocampus following sound stimulation to effect neurogenesis, learning and memory are described. Sound stimulation can also modify neural connectivity in the early postnatal life to enhance higher cognitive function or even repair the secondary damages in various ...

  8. Deep brain stimulation in obsessive-compulsive disorder

    NARCIS (Netherlands)

    Denys, Damiaan; Mantione, Mariska

    2009-01-01

    The use of deep brain stimulation in psychiatric disorders has received great interest owing to the small risk of the operation, the reversible nature of the technique, and the possibility of optimizing treatment postoperatively. Currently, deep brain stimulation in psychiatry is investigated for

  9. Noninvasive deep brain stimulation using focused energy sources

    NARCIS (Netherlands)

    Sierra, C. V. Rizzo

    2010-01-01

    A non-invasive methodological possibility for brain stimulation through the simultaneous use of an external energy beam and an existing brain imaging system such as functional magnetic resonance imaging (fMRI) is herein proposed; the main advantage is to confine the stimulation into a single brain

  10. Beneficial Effects of Tactile Stimulation on Early Development.

    Science.gov (United States)

    Caulfield, Rick

    2000-01-01

    Reviews selected research on the beneficial effects of tactile stimulation on infants. Examines the results of studies with animals, preterm infants, cocaine- and HIV-exposed preterm infants, and normal full-term infants. Briefly discusses caregiving implications and offers suggestions on how caregivers can incorporate tactile stimulation in…

  11. Effect of Low-Level Laser Stimulation on EEG

    Directory of Open Access Journals (Sweden)

    Jih-Huah Wu

    2012-01-01

    Full Text Available Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output power 7 mW, and operation frequency 10 Hz to deliver insensible laser stimulations to the palm. EEG activities before, during, and after the laser stimulation were collected. The amplitude powers of each EEG frequency band were analyzed. We found that the low-level laser stimulation was able to increase the power of alpha rhythms and theta waves, mainly in the posterior head regions. These effects lasted at least 15 minutes after cessation of the laser stimulation. The amplitude power of beta activities in the anterior head regions decreased after laser stimulation. We thought these EEG changes comparable to those in meditation.

  12. Influence of synchronous and sequential stimulation on muscle fatigue

    NARCIS (Netherlands)

    Thomsen, M.; Thomsen, M.; Veltink, Petrus H.

    1997-01-01

    In acute experiments the sciatic nerve of the rat is electrically stimulated to induce fatigue in the medial Gastrocnemius muscle. Fatigue tests are carried out using intermittent stimulation of different compartments (sequential) or a single compartment (synchronous) of the sciatic nerve. The

  13. Effect of Parkinson's Disease in Transcranial Magnetic Stimulation Treatment

    Science.gov (United States)

    Syeda, Farheen; Magsood, Hamzah; Lee, Erik; El-Gendy, Ahmed; Jiles, David; Hadimani, Ravi

    Transcranial Magnetic Stimulation is a non-invasive clinical therapy used to treat depression and migraine, and shows further promise as treatment for Parkinson's disease, Alzheimer's disease, and other neurological disorders. However, it is yet unclear as to how anatomical differences may affect stimulation from this treatment. We use finite element analysis to model and analyze the results of Transcranial Magnetic Stimulation in various head models. A number of heterogeneous head models have been developed using MRI data of real patients, including healthy individuals as well as patients of Parkinson's disease. Simulations of Transcranial Magnetic Stimulation performed on 22 anatomically different models highlight the differences in induced stimulation. A standard Figure of 8 coil is used with frequency 2.5 kHz, placed 5 mm above the head. We compare cortical stimulation, volume of brain tissue stimulated, specificity, and maximum E-field induced in the brain for models ranging from ages 20 to 60. Results show that stimulation varies drastically between patients of the same age and health status depending upon brain-scalp distance, which is not necessarily a linear progression with age.

  14. The effect of Hegu acupoint stimulation in dental acupuncture analgesia

    Directory of Open Access Journals (Sweden)

    Fransiskus Andrianto

    2007-03-01

    Full Text Available In daily life, dental treatments are often related with oral pain sensation which needs anesthesia procedures. Sometimes local anesthetics can not be used because patients have hypersensitive reaction or systemic diseases which may lead to complications. Stimulating acupoint, such as Hegu activates hypothalamus and pituitary gland to release endogenous opioid peptide substances that reduce pain sensitivity. The aim of the study was to determine Hegu acupoint stimulation effect on the pain sensitivity reduction in maxillary central incisor gingiva. The laboratory experimental research was conducted on 12 healthy male Wistar rats (3 months old, weights 150–200 grams. All rat samples received the same treatments and adapted within 1 month. The research was done in pre and post test control group design. 40-Volt electro-stimulation was done once on the maxillary central incisor gingiva prior to the bilateral Hegu acupoint stimulation, then followed by 3 times electro-stimulation with 3 minutes intervals. The pain scores were obtained based on the samples’ contraction in each electro-stimulation. The responses were categorized into 5 pain scores and statistically analyzed using Wilcoxon Test. The results showed that Hegu acupoint stimulation lowered the pain scores significantly (p < 0.05. Hegu acupoint stimulation could reduce the pain sensitivity in maxillary central incisor gingiva. Therefore, the use of acupuncture analgesia in dental pain management can be considered in the future.

  15. Towards a computational model for stimulation of the Pedunculopontine nucleus

    NARCIS (Netherlands)

    Lourens, Marcel Antonius Johannes; Meijer, Hil Gaétan Ellart; Heida, Tjitske; van Gils, Stephanus A.

    2009-01-01

    The pedunculopontine nucleus (PPN) has recently been suggested as a new therapeutic target for deep brain stimulation (DBS) in patients suffering from Parkinson's disease, particularly those with severe gait and postural impairment [1]. Stimulation at this site is typically delivered at low

  16. Analysis of fractal electrodes for efficient neural stimulation

    Science.gov (United States)

    Golestanirad, Laleh; Elahi, Behzad; Molina, Alberto; Mosig, Juan R.; Pollo, Claudio; Chen, Robert; Graham, Simon J.

    2013-01-01

    Planar electrodes are increasingly used in therapeutic neural stimulation techniques such as functional electrical stimulation, epidural spinal cord stimulation (ESCS), and cortical stimulation. Recently, optimized electrode geometries have been shown to increase the efficiency of neural stimulation by increasing the variation of current density on the electrode surface. In the present work, a new family of modified fractal electrode geometries is developed to enhance the efficiency of neural stimulation. It is shown that a promising approach in increasing the neural activation function is to increase the “edginess” of the electrode surface, a concept that is explained and quantified by fractal mathematics. Rigorous finite element simulations were performed to compute electric potential produced by proposed modified fractal geometries. The activation of 256 model axons positioned around the electrodes was then quantified, showing that modified fractal geometries required a 22% less input power while maintaining the same level of neural activation. Preliminary in vivo experiments investigating muscle evoked potentials due to median nerve stimulation showed encouraging results, supporting the feasibility of increasing neural stimulation efficiency using modified fractal geometries. PMID:23874290

  17. Preservice School Personnel's Knowledge of Stimulant Medication and ADHD

    Science.gov (United States)

    Pindiprolu, Sekhar S.

    2014-01-01

    Attention Deficit Hyperactivity Disorder (ADHD) is one of the most commonly diagnosed disorders among children today. Stimulants are commonly prescribed to children with ADHD to improve attention span and decrease distractibility, hyperactivity, and impulsivity. Given the increased use of stimulant medication, school personnel need to be aware of…

  18. an external control unit implemented for stimulator asic

    African Journals Online (AJOL)

    pc

    2017-11-10

    Nov 10, 2017 ... external control of supply voltage adaptation validate the functionality of the designed ECU and the stimulator ASIC. ... Keywords: external control unit; data transceiver; stimulator ASIC; retinal prosthesis; epiretinal implant ...... using MATLAB Simulink and Arduino microcontroller. Journal of Applied ...

  19. Sildenafil Stimulates Aqueous Humor Turnover in Rabbits

    Science.gov (United States)

    Alvarez, Lawrence J.; Zamudio, Aldo C.; Candia, Oscar A.

    2013-01-01

    Sildenafil citrate increases ocular blood flow and accelerates the rate of anterior chamber refilling after paracentesis. The latter effect could have resulted from a reduction in outflow facility or from an increase in aqueous humor (AH) production. In this study, we used scanning ocular fluorophotometry to examine the effects of sildenafil on AH turnover, and thus, AH production in eyes of live normal rabbits. For this, the rate of aqueous humor flow (AHF) was quantified with a commercially available fluorophotometer that measured the rate of fluorescein clearance from the anterior segment, which predominantly occurs via the trabecular meshwork. After ≈ 2 hrs of control scans to determine the baseline rate of AHF, the rabbits were fed 33 mg of sildenafil and allowed ≈ 45 min for the drug to enter the systemic circulation. Thereafter, fluorescence scans were retaken for an additional 90–120 min. Sildenafil ingestion increased AHF by about 36%, from 2.31 μL/min to 3.14 μL/min (PViagra, Revatio), stimulates AHF in rabbits. Our results seem consistent with reports indicating that the drug dilates intraocular arteries and augments intraocular vascular flow. These physiological responses to the agent apparently led to increased fluid entry into the anterior chamber. As such, the drug might have utility in patients with ocular hypotony resulting from insufficient AH formation. PMID:23562660

  20. Quantifying utricular stimulation during natural behavior

    Science.gov (United States)

    Rivera, Angela R. V.; Davis, Julian; Grant, Wally; Blob, Richard W.; Peterson, Ellengene; Neiman, Alexander B.; Rowe, Michael

    2012-01-01

    The use of natural stimuli in neurophysiological studies has led to significant insights into the encoding strategies used by sensory neurons. To investigate these encoding strategies in vestibular receptors and neurons, we have developed a method for calculating the stimuli delivered to a vestibular organ, the utricle, during natural (unrestrained) behaviors, using the turtle as our experimental preparation. High-speed digital video sequences are used to calculate the dynamic gravito-inertial (GI) vector acting on the head during behavior. X-ray computed tomography (CT) scans are used to determine the orientation of the otoconial layer (OL) of the utricle within the head, and the calculated GI vectors are then rotated into the plane of the OL. Thus, the method allows us to quantify the spatio-temporal structure of stimuli to the OL during natural behaviors. In the future, these waveforms can be used as stimuli in neurophysiological experiments to understand how natural signals are encoded by vestibular receptors and neurons. We provide one example of the method which shows that turtle feeding behaviors can stimulate the utricle at frequencies higher than those typically used in vestibular studies. This method can be adapted to other species, to other vestibular end organs, and to other methods of quantifying head movements. PMID:22753360

  1. Laser-stimulated fluorescence in paleontology.

    Directory of Open Access Journals (Sweden)

    Thomas G Kaye

    Full Text Available Fluorescence using ultraviolet (UV light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

  2. Ethical issues in deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Maartje eSchermer

    2011-05-01

    Full Text Available Deep brain stimulation (DBS is currently used to treat neurological disorders like Parkinson’s disease (PD, essential tremor and dystonia, and is explored as an experimental treatment for psychiatric disorders like Major Depression (MD and Obsessive Compulsive Disorder (OCD. This mini review discusses ethical issues in DBS treatment and research, as they have been discussed in the medical and ethical literature.With regard to DBS treatment, the most important issues are balancing risks and benefits and ensuring respect for the autonomous wish of the patient. This implies special attention to patient selection, psycho-social impact of treatment, effects on personal identity, and treatment of children. Moreover, it implies a careful informed consent process in which unrealistic expectations of patients and their families are addressed and in which special attention is given to competence. In the context of research, the fundamental ethical challenge is to promote high-quality scientific research in the interest of future patients, while at the same time safeguarding the rights and interests of vulnerable research subjects. Several guidelines have been proposed to ensure this. One of the preconditions to further development of responsible and transparent research practices is the establishment of a comprehensive registry.

  3. Bibliometric profile of deep brain stimulation.

    Science.gov (United States)

    Hu, Kejia; Moses, Ziev B; Xu, Wendong; Williams, Ziv

    2017-10-01

    We aimed to identify and analyze the characteristics of the 100 most highly-cited papers in the research field of deep brain stimulation (DBS). The Web of Science was searched for highly-cited papers related to DBS research. The number of citations, countries, institutions of origin, year of publication, and research area were noted and analyzed. The 100 most highly-cited articles had a mean of 304.15 citations. These accrued an average of 25.39 citations a year. The most represented target by far was the subthalamic nucleus (STN). These articles were published in 46 high-impact journals, with Brain (n = 10) topping the list. These articles came from 11 countries, with the USA contributing the most highly-cited articles (n = 29); however, it was the University of Toronto (n = 13) in Canada that was the institution with the most highly-cited studies. This study identified the 100 most highly-cited studies and highlighted a historical perspective on the progress in the field of DBS. These findings allow for the recognition of the most influential reports and provide useful information that can indicate areas requiring further investigation.

  4. A quarter century of stimulated Raman scattering

    International Nuclear Information System (INIS)

    Bloembergen, N.

    1987-01-01

    To round out a quarter century of SRS the timing of this writing (1986) requires a look ahead of only one year into the future. The proceedings of the 10th International Conference on Raman Spectroscopy present a picture of current activity. Further progress will be made in time-resolved spectroscopy with subpicosecond resolution, in the study of hyper-Raman and other higher order effects with CARS, in extension of resonant Raman excitation in the UV region of spectrum, and in the development of Raman laser sources. During past few years extensive theoretical investigations have been made for four-wave light mixing in the case of one or more very strong light beams. The perturbation approach for those fields ceases to be valid. If only one light field is strong, the usual approach is to make a transformation to a rotating coordinate system so that the strong Hamiltonian for this light field becomes time-independent. Very recently these techniques have been extended to the case of two or more strong fields. CARS-type experiments with strong beams are likely to receive more attention. Extrapolation of the current activities instills confidence in the vitality of stimulated Raman scattering for the foreseeable future

  5. Mechanical Stimulation by Postnasal Drip Evokes Cough

    Science.gov (United States)

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

    2015-01-01

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

  6. Does simvastatin stimulate bone formation in vivo?

    Directory of Open Access Journals (Sweden)

    Chorev Michael

    2003-04-01

    Full Text Available Abstract Background Statins, potent compounds that inhibit cholesterol synthesis in the liver have been reported to induce bone formation, both in tissue culture and in rats and mice. To re-examine potential anabolic effects of statins on bone formation, we compared the activity of simvastatin (SVS to the known anabolic effects of PTH in an established model of ovariectomized (OVX Swiss-Webster mice. Methods Mice were ovariectomized at 12 weeks of age (T0, remained untreated for 5 weeks to allow development of osteopenia (T5, followed by treatment for 8 weeks (T13. Whole, trabecular and cortical femoral bone was analyzed by micro-computed tomography (micro CT. Liquid chromatography/mass spectrometry (LC/MS was used to detect the presence of SVS and its active metabolite, simvastatin β-hydroxy acid (SVS-OH in the mouse serum. Results Trabecular BV/TV at T13 was 4.2 fold higher in animals treated with PTH (80 micro-g/kg/day compared to the OVX-vehicle treated group (p in vivo study. Conclusions While PTH demonstrated the expected anabolic effect on bone, SVS failed to stimulate bone formation, despite our verification by LC/MS of the active SVS-OH metabolite in mouse serum. While statins have clear effects on bone formation in vitro, the formulation of existing 'liver-targeted' statins requires further refinement for efficacy in vivo.

  7. Harmine stimulates proliferation of human neural progenitors

    Directory of Open Access Journals (Sweden)

    Vanja Dakic

    2016-12-01

    Full Text Available Harmine is the β-carboline alkaloid with the highest concentration in the psychotropic plant decoction Ayahuasca. In rodents, classical antidepressants reverse the symptoms of depression by stimulating neuronal proliferation. It has been shown that Ayahuasca presents antidepressant effects in patients with depressive disorder. In the present study, we investigated the effects of harmine in cell cultures containing human neural progenitor cells (hNPCs, 97% nestin-positive derived from pluripotent stem cells. After 4 days of treatment, the pool of proliferating hNPCs increased by 71.5%. Harmine has been reported as a potent inhibitor of the dual specificity tyrosine-phosphorylation-regulated kinase (DYRK1A, which regulates cell proliferation and brain development. We tested the effect of analogs of harmine, an inhibitor of DYRK1A (INDY, and an irreversible selective inhibitor of monoamine oxidase (MAO but not DYRK1A (pargyline. INDY but not pargyline induced proliferation of hNPCs similarly to harmine, suggesting that inhibition of DYRK1A is a possible mechanism to explain harmine effects upon the proliferation of hNPCs. Our findings show that harmine enhances proliferation of hNPCs and suggest that inhibition of DYRK1A may explain its effects upon proliferation in vitro and antidepressant effects in vivo.

  8. Physical Variables in the Olfactory Stimulation Process

    Science.gov (United States)

    Tucker, Don

    1963-01-01

    Electrical recording from small twigs of nerve in a tortoise showed that olfactory, vomeronasal, and trigeminal receptors in the nose are responsive to various odorants. No one kind of receptor was most sensitive to all odorants. For controlled stimulation, odorant was caused to appear in a stream of gas already flowing through the nose. Of the parameters definable at the naris, temperature, relative humidity, and nature of inert gas had little effect on olfactory responses to amyl acetate, whereas odorant species, odorant concentration, and volume flow rate effectively determined the responses of all nasal chemoreceptors. An intrinsic variable of accessibility to the receptors, particularly olfactory, was demonstrated. Flow dependence of chemoreceptor responses is thought to reflect the necessity for delivery of odorant molecules to receptor sites. Since the olfactory receptors are relatively exposed, plateauing of the response with flow rate for slightly soluble odorants suggests an approach to concentration equilibrium in the overlying mucus with that in the air entering the naris. Accordingly, data for responses to amyl acetate were fitted with Beidler's (1954) taste equation for two kinds of sites being active. The requirement for finite aqueous solubility, if true, suggests substitution of aqueous solutions for gaseous solutions. A suitable medium was found and results conformed to expectations. Olfactory receptors were insensitive to variation of ionic strength, pH, and osmotic pressure. PMID:13994681

  9. Electrical stimulation counteracts muscle decline in seniors.

    Science.gov (United States)

    Kern, Helmut; Barberi, Laura; Löfler, Stefan; Sbardella, Simona; Burggraf, Samantha; Fruhmann, Hannah; Carraro, Ugo; Mosole, Simone; Sarabon, Nejc; Vogelauer, Michael; Mayr, Winfried; Krenn, Matthias; Cvecka, Jan; Romanello, Vanina; Pietrangelo, Laura; Protasi, Feliciano; Sandri, Marco; Zampieri, Sandra; Musaro, Antonio

    2014-01-01

    The loss in muscle mass coupled with a decrease in specific force and shift in fiber composition are hallmarks of aging. Training and regular exercise attenuate the signs of sarcopenia. However, pathologic conditions limit the ability to perform physical exercise. We addressed whether electrical stimulation (ES) is an alternative intervention to improve muscle recovery and defined the molecular mechanism associated with improvement in muscle structure and function. We analyzed, at functional, structural, and molecular level, the effects of ES training on healthy seniors with normal life style, without routine sport activity. ES was able to improve muscle torque and functional performances of seniors and increased the size of fast muscle fibers. At molecular level, ES induced up-regulation of IGF-1 and modulation of MuRF-1, a muscle-specific atrophy-related gene. ES also induced up-regulation of relevant markers of differentiating satellite cells and of extracellular matrix remodeling, which might guarantee shape and mechanical forces of trained skeletal muscle as well as maintenance of satellite cell function, reducing fibrosis. Our data provide evidence that ES is a safe method to counteract muscle decline associated with aging.

  10. Statistical properties of ionospheric stimulated electromagnetic emissions

    Directory of Open Access Journals (Sweden)

    R. L. Karlsson

    2006-08-01

    Full Text Available We have analysed the statistical properties of the stimulated electromagnetic emissions (SEE spectral features in the steady state, reached after a long period of continuous HF pumping of the ionosphere in experiments performed at the Sura ionospheric radio research facility in Russia. Using a digital filter bank method, we have been able to analyse complex valued signals within narrow frequency bands. Each of the SEE spectral features are thereby separated into a number of narrow spectral components. Statistical tests were performed for all these spectral components and the distributions of the spectral amplitudes and phases were evaluated. Also, a test for sinusoidal components was performed. These tests showed that all observed SEE features were indistinguishable from coloured Gaussian noise. The test results exclude that the SEE features can be the result of a single isolated coherent process, but does not rule out that there could be many statistically independent parametric wave-wave processes taking place simultaneously at various parts of the HF-pumped ionosphere, as long as the superposition from all these is incoherent. Furthermore, from the test results, we cannot exclude the possibility that the waveforms of some, or all, of the SEE features may be chaotic.

  11. [New stimulants of corneal reparative regeneration].

    Science.gov (United States)

    Egorov, E A; Kalinin, N I; Kiiasov, A P

    1999-01-01

    The efficacy of corneregel, a drug containing pantothenic acid, a component of coenzyme A, in healing of corneal wounds has been evaluated. The study was carried out on 19 rabbits (38 eyes) with standard corneal defect made with a 5-mm trephine for lamellar transplantation of the cornea, divided into 2 groups: 1) instillations of corneregel (10 eyes) and 0.25% levomycetin solution (10 eyes) and 2) 20% solcoseryl gel (9 eyes) and 0.25% levomycetin (9 eyes). Time course of changes were evaluated by biomicroscopy (fluorescent test), histologically (hematoxylin-eosin staining), and immunohistochemically after 1, 2, 4, 7, 30, and 90 days. Proliferative activity was studied by expression of the proliferating cell nuclear antigen and the migration capacity of cells by expression of alpha-smooth muscle actin. The terms of epithelialization were as follows: corneregel 10 +/- 7 h, 20% solcoseryl gel 108 +/- 10 h, levomycetin 124 +/- 6.93 h. Earlier epithelialization in the corneregel group was apparently due to increased expression of alpha-smooth muscle actin and increase in the cell migration capacity. Hence, corneregel is recommended for practical use as a stimulant of reparative regeneration of the cornea.

  12. Tactile Stimulation Reduces Fear in Fish

    Directory of Open Access Journals (Sweden)

    Annett eSchirmer

    2013-11-01

    Full Text Available Being groomed or touched can counter stress and negative affect in mammals. In two experiments we explored whether a similar phenomenon exists in non-mammals like zebrafish. In Experiment 1, we exposed zebrafish to a natural stressor, a chemical alarm signal released by injured conspecifics. Before moving them into an observation tank, one group of fish was washed and then subjected to a water current that served as the tactile stimulus. The other group was simply washed. Fish with tactile treatment demonstrated fewer fear behaviors (e.g., bottom dwelling and lower cortisol levels than fish without. In Experiment 2, we ascertained a role of somatosensation in these effects. Using a similar paradigm as in Experiment 1, we recorded fear behaviors of intact fish and fish with damaged lateral line hair cells. Relative to the former, the latter benefited less from the tactile stimulus during fear recovery. Together these findings show that tactile stimulation can calm fish and that tactile receptors, evolutionarily older than those present in mammals, contribute to this phenomenon.

  13. [Ovarian stimulation monitoring: past, present and perspectives].

    Science.gov (United States)

    Salama, S; Torre, A; Paillusson, B; Thomin, A; Ben Brahim, F; Muratorio, C; Bailly, M; Wainer, R

    2011-04-01

    Since the inception of Assisted Reproductive Technology (ART), knowing the moment of ovulation has always been a priority. Initially, the monitoring was accomplished by observing the luteinizing hormone (LH) surge just before ovulation. Currently, in all ART facilities, the monitoring of all stimulated ovulatory cycles is done by using the conventional two-dimensional (2D) ultrasound to measure follicle diameter and by drawing blood tests that measure estradiol, progesterone, and luteinizing hormone levels. These exams allow determination of the numbers and quality of growing ovarian follicles and evaluation of follicle maturity before choosing the appropriate time for ovulation triggering. The monitoring of ovulatory cycles has now become enhanced with the arrival of new software called SonoAVC. This software allows the utilization of 3D blocks to immediately calculate the total number and volume of the follicles inside the ovary. This automatic approach is faster, precise, and more efficient. It also has better reproducibility than the classical 2D diameters. Furthermore, certain ART professionals envision that by using the SonoVac technology, patients will no longer need to be monitored with regular ultrasounds and with systematic hormonal testing. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  14. Stimulating medical education research in the Netherlands.

    Science.gov (United States)

    Jaarsma, Debbie; Scherpbier, Albert; Van Der Vleuten, Cees; Ten Cate, Olle

    2013-04-01

    Since the 1970s, the Dutch have been active innovators and researchers in the medical education domain. With regards to the quantity of publications in the medical education literature, the Netherlands rank second among countries in Europe and fourth worldwide over the past years, related to the journals with highest impact factors. We attempted to analyse what made this country so productive by exploring the backgrounds of this success. An updated comparative evaluation was conducted. Nationalities of first and last authors were screened. And an indicator whether supervision is 'exported' or 'imported' was calculated. The Netherlands still rank high in number of publications and the production increases. In contrast to other countries, the Dutch are 'exporting' their supervision. The opportunity to start a new, experimental medical school from scratch in Maastricht has undoubtedly contributed significantly to this national productivity. One other factor seems the establishment of the Netherlands Association for Medical Education with its mission to stimulate research and development of education. Annual conferences, Courses on research in medical education, Chairs in medical education qualified to graduate PhD students, and a general open and critical national culture of enquiry may have added to this success.

  15. Plasmon-enhanced optically stimulated luminescence

    International Nuclear Information System (INIS)

    Guidelli, E. J.; Baffa, O.; Ramos, A. P.

    2015-10-01

    Full text: Optically Stimulated Luminescence dosimeters (OSLD) have been largely used for personal, medical, and industrial radiation dosimetry. Developing highly sensitive and small-sized radiation detectors and dosimeters is essential for improving spatial resolution and consequently diagnosis quality and treatment efficacy in the case of applications in radiodiagnosis and radiation therapy, for instance. Conventional methods to improve the OSLD sensitivity consist of doping and co-doping the host materials with atoms of other elements, thereby increasing the amount of trapping and/or luminescent centers. Our group is researching on the use of the plasmon properties of noble metal nanoparticles to increase OSL intensity. Upon incidence of a light beam with appropriate resonant wavelengths, the oscillation of the free electrons at the nanoparticle surface originates the Localized Surface Plasmons (LSP) and the consequent plasmon resonance band. The interaction between the LSP and the surrounding luminescent material leads to new optical properties largely employed for enhancing several luminescent processes. Here we will show our results regarding the use of LSP to increase OSLD sensitivity. The interaction between the traps/luminescent centers and the plasmons depends on the distance between them, on the plasmon resonance band intensity and position, as well as on the surrounding medium. Therefore, the plasmon-enhanced luminescence is a promising tool to develop more sensitive and miniaturized OSLD. (Author)

  16. Plasmon-enhanced optically stimulated luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Guidelli, E. J.; Baffa, O. [Universidade de Sao Paulo, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Departamento de Fisica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Ramos, A. P., E-mail: ederguidelli@gmail.com [Universidade de Sao Paulo, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Departamento de Quimica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2015-10-15

    Full text: Optically Stimulated Luminescence dosimeters (OSLD) have been largely used for personal, medical, and industrial radiation dosimetry. Developing highly sensitive and small-sized radiation detectors and dosimeters is essential for improving spatial resolution and consequently diagnosis quality and treatment efficacy in the case of applications in radiodiagnosis and radiation therapy, for instance. Conventional methods to improve the OSLD sensitivity consist of doping and co-doping the host materials with atoms of other elements, thereby increasing the amount of trapping and/or luminescent centers. Our group is researching on the use of the plasmon properties of noble metal nanoparticles to increase OSL intensity. Upon incidence of a light beam with appropriate resonant wavelengths, the oscillation of the free electrons at the nanoparticle surface originates the Localized Surface Plasmons (LSP) and the consequent plasmon resonance band. The interaction between the LSP and the surrounding luminescent material leads to new optical properties largely employed for enhancing several luminescent processes. Here we will show our results regarding the use of LSP to increase OSLD sensitivity. The interaction between the traps/luminescent centers and the plasmons depends on the distance between them, on the plasmon resonance band intensity and position, as well as on the surrounding medium. Therefore, the plasmon-enhanced luminescence is a promising tool to develop more sensitive and miniaturized OSLD. (Author)

  17. Spinal cord stimulation for neuropathic pain: current perspectives

    Directory of Open Access Journals (Sweden)

    Wolter T

    2014-11-01

    Full Text Available Tilman Wolter Interdisciplinary Pain Centre, University Hospital Freiburg, Freiburg, Germany Abstract: Neuropathic pain constitutes a significant portion of chronic pain. Patients with neuropathic pain are usually more heavily burdened than patients with nociceptive pain. They suffer more often from insomnia, anxiety, and depression. Moreover, analgesic medication often has an insufficient effect on neuropathic pain. Spinal cord stimulation constitutes a therapy alternative that, to date, remains underused. In the last 10 to 15 years, it has undergone constant technical advancement. This review gives an overview of the present practice of spinal cord stimulation for chronic neuropathic pain and current developments such as high-frequency stimulation and peripheral nerve field stimulation. Keywords: spinal cord stimulation, neuropathic pain, neurostimulation

  18. Cortical excitability changes following grasping exercise augmented with electrical stimulation

    DEFF Research Database (Denmark)

    Barsi, Gergely Istvan; Popovic, Dejan B.; Tarkka, Ina M.

    2008-01-01

    Rehabilitation with augmented electrical stimulation can enhance functional recovery after stroke, and cortical plasticity may play a role in this process. The purpose of this study was to compare the effects of three training paradigms on cortical excitability in healthy subjects. Cortical......) functional electrical stimulation (FES) of the finger flexors and extensors, (2) voluntary movement (VOL) with sensory stimulation, and (3) therapeutic FES (TFES) where the electrical stimulation augmented voluntary activation. TFES training produced a significant increase in MEP magnitude throughout...... excitability was evaluated by analysing the input-output relationship between transcranial magnetic stimulation intensity and motor evoked potentials (MEPs) from the flexor muscles of the fingers. The study was performed with 25 healthy volunteers who underwent 20-min simulated therapy sessions of: (1...

  19. Transient finite element modeling of functional electrical stimulation.

    Science.gov (United States)

    Filipovic, Nenad D; Peulic, Aleksandar S; Zdravkovic, Nebojsa D; Grbovic-Markovic, Vesna M; Jurisic-Skevin, Aleksandra J

    2011-03-01

    Transcutaneous functional electrical stimulation is commonly used for strengthening muscle. However, transient effects during stimulation are not yet well explored. The effect of an amplitude change of the stimulation can be described by static model, but there is no differency for different pulse duration. The aim of this study is to present the finite element (FE) model of a transient electrical stimulation on the forearm. Discrete FE equations were derived by using a standard Galerkin procedure. Different tissue conductive and dielectric properties are fitted using least square method and trial and error analysis from experimental measurement. This study showed that FE modeling of electrical stimulation can give the spatial-temporal distribution of applied current in the forearm. Three different cases were modeled with the same geometry but with different input of the current pulse, in order to fit the tissue properties by using transient FE analysis. All three cases were compared with experimental measurements of intramuscular voltage on one volunteer.

  20. Theory of feedback controlled brain stimulations for Parkinson's disease

    Science.gov (United States)

    Sanzeni, A.; Celani, A.; Tiana, G.; Vergassola, M.

    2016-01-01

    Limb tremor and other debilitating symptoms caused by the neurodegenerative Parkinson's disease are currently treated by administering drugs and by fixed-frequency deep brain stimulation. The latter interferes directly with the brain dynamics by delivering electrical impulses to neurons in the subthalamic nucleus. While deep brain stimulation has shown therapeutic benefits in many instances, its mechanism is still unclear. Since its understanding could lead to improved protocols of stimulation and feedback control, we have studied a mathematical model of the many-body neural network dynamics controlling the dynamics of the basal ganglia. On the basis of the results obtained from the model, we propose a new procedure of active stimulation, that depends on the feedback of the network and that respects the constraints imposed by existing technology. We show by numerical simulations that the new protocol outperforms the standard ones for deep brain stimulation and we suggest future experiments that could further improve the feedback procedure.

  1. Comparative Evaluation of Tactile Sensation by Electrical and Mechanical Stimulation.

    Science.gov (United States)

    Yem, Vibol; Kajimoto, Hiroyuki

    2017-01-01

    An electrotactile display is a tactile interface that provides tactile perception by passing electrical current through the surface of the skin. It is actively used instead of mechanical tactile displays for tactile feedback because of several advantages such as its small and thin size, light weight, and high responsiveness. However, the similarities and differences between these sensations is still not clear. This study directly compares the intensity sensation of electrotactile stimulation to that of mechanical stimulation, and investigates the characteristic sensation of anodic and cathodic stimulation. In the experiment, participants underwent a 30 pps electrotactile stimulus every one second to their middle finger, and were asked to match this intensity by adjusting the intensity of a mechanical tactile stimulus to an index finger. The results showed that anodic stimulation mainly produced vibration sensation, whereas cathodic sensation produced both vibration and pressure sensations. Relatively low pressure sensation was also observed for anodic stimulation but it remains low, regardless of the increasing of electrical intensity.

  2. Non-invasive brain stimulation in neglect rehabilitation: An update.

    Directory of Open Access Journals (Sweden)

    René Martin Müri

    2013-06-01

    Full Text Available Here, we review the effects of non-invasive brain stimulation (NIBS such as transcranial magnetic stimulation (TMS or transcranial direct current stimulation (tDCS in the rehabilitation of neglect. We found 12 studies including 172 patients (10 TMS studies and 2 tDCS studies fulfilling our search criteria. Activity of daily living (ADL measures such as the Barthel Index or more specifically for neglect, the Catherine Bergego Scale were the outcome measure in 3 studies. Five studies were randomized controlled trials with a follow-up time after intervention of up to 6 weeks. One TMS study fulfilled criteria for Class I and one for Class III evidence.The studies are heterogeneous concerning their methodology, outcome measures, and stimulation parameters making firm comparisons and conclusions difficult. Overall, there are however promising results for theta burst stimulation, suggesting that TMS is a powerful add-on therapy in the rehabilitation of neglect patients.

  3. Toward rational design of electrical stimulation strategies for epilepsy control

    Science.gov (United States)

    Sunderam, Sridhar; Gluckman, Bruce; Reato, Davide; Bikson, Marom

    2009-01-01

    Electrical stimulation is emerging as a viable alternative for epilepsy patients whose seizures are not alleviated by drugs or surgery. Its attractions are temporal and spatial specificity of action, flexibility of waveform parameters and timing, and the perception that its effects are reversible unlike resective surgery. However, despite significant advances in our understanding of mechanisms of neural electrical stimulation, clinical electrotherapy for seizures relies heavily on empirical tuning of parameters and protocols. We highlight concurrent treatment goals with potentially conflicting design constraints that must be resolved when formulating rational strategies for epilepsy electrotherapy: namely seizure reduction versus cognitive impairment, stimulation efficacy versus tissue safety, and mechanistic insight versus clinical pragmatism. First, treatment markers, objectives, and metrics relevant to electrical stimulation for epilepsy are discussed from a clinical perspective. Then the experimental perspective is presented, with the biophysical mechanisms and modalities of open-loop electrical stimulation, and the potential benefits of closed-loop control for epilepsy. PMID:19926525

  4. Optogenetic stimulation effectively enhances intrinsically generated network synchrony

    Directory of Open Access Journals (Sweden)

    Ahmed eEl Hady

    2013-10-01

    Full Text Available Synchronized bursting is found in many brain areas and has also been implicated in the pathophysiology of neuropsychiatric disorders such as epilepsy, Parkinson’s disease and schizophrenia. Despite extensive studies of network burst synchronization, it is insufficiently understood how this type of network wide synchronization can be strengthened, reduced or even abolished. We combined electrical recording using multi-electrode array with optical stimulation of cultured channelrhodopsin-2 transducted hippocampal neurons to study and manipulate network burst synchronization. We found low frequency photo-stimulation protocols that are sufficient to induce potentiation of network bursting, modifying bursting dynamics and increasing interneuronal synchronization. Surprisingly, slowly fading-in light stimulation, which substantially delayed and reduced light driven spiking, was at least as effective in reorganizing network dynamics as much stronger pulsed light stimulation. Our study shows that mild stimulation protocols that do not enforce particular activity patterns onto the network can be highly effective inducers of network-level plasticity.

  5. Optogenetic stimulation effectively enhances intrinsically generated network synchrony

    Science.gov (United States)

    El Hady, Ahmed; Afshar, Ghazaleh; Bröking, Kai; Schlüter, Oliver M.; Geisel, Theo; Stühmer, Walter; Wolf, Fred

    2013-01-01

    Synchronized bursting is found in many brain areas and has also been implicated in the pathophysiology of neuropsychiatric disorders such as epilepsy, Parkinson’s disease, and schizophrenia. Despite extensive studies of network burst synchronization, it is insufficiently understood how this type of network wide synchronization can be strengthened, reduced, or even abolished. We combined electrical recording using multi-electrode array with optical stimulation of cultured channelrhodopsin-2 transducted hippocampal neurons to study and manipulate network burst synchronization. We found low frequency photo-stimulation protocols that are sufficient to induce potentiation of network bursting, modifying bursting dynamics, and increasing interneuronal synchronization. Surprisingly, slowly fading-in light stimulation, which substantially delayed and reduced light-driven spiking, was at least as effective in reorganizing network dynamics as much stronger pulsed light stimulation. Our study shows that mild stimulation protocols that do not enforce particular activity patterns onto the network can be highly effective inducers of network-level plasticity. PMID:24155695

  6. Undergraduate Prescription Stimulant Misuse: The Impact of Academic Strain.

    Science.gov (United States)

    Norman, Lauren; Ford, Jason

    2018-01-09

    This study investigated the misuse of prescription stimulants among undergraduates for academic purposes. This research is important as existing literature has indicated that this type of prescription drug misuse is a growing concern, especially among college undergraduates aged 18-25. This study focused on how various types of academic strain (i.e., academic strain, grade strain, and academic impediments) influenced the misuse of prescription stimulants. Roughly 900 quantitative surveys were collected at a large Southeastern university in May 2014 that specifically addressed prescription stimulant misuse. Results from regression analyses indicated that college students are at an increased likelihood of misusing prescription stimulants for academic purposes if they experienced academic impediments and/or grade strain during the past academic year. Conclusions/Importance: It is necessary to identify how academic strain impacts undergraduates' likelihood of engaging in the misuse of prescription stimulants as this information may aid in college based educational and prevention programs.

  7. Facial nerve stimulation as a future treatment for ischemic stroke

    Directory of Open Access Journals (Sweden)

    Mark K Borsody

    2016-01-01

    Full Text Available Stimulation of the autonomic parasympathetic fibers of the facial nerve system (hereafter simply "facial nerve" rapidly dilates the cerebral arteries and increases cerebral blood flow whether that stimulation is delivered at the facial nerve trunk or at distal points such as the sphenopalatine ganglion. Facial nerve stimulation thus could be used as an emergency treatment of conditions of brain ischemia such as ischemic stroke. A rich history of scientific research has examined this property of the facial nerve, and various means of activating the facial nerve can be employed including noninvasive means. Herein, we review the anatomical and physiological research behind facial nerve stimulation and the facial nerve stimulation devices that are in development for the treatment of ischemic stroke.

  8. Effect of vagus nerve stimulation on creativity and cognitive flexibility.

    Science.gov (United States)

    Ghacibeh, Georges A; Shenker, Joel I; Shenal, Brian; Uthman, Basim M; Heilman, Kenneth M

    2006-06-01

    The purpose of this study was to determine whether vagus nerve stimulation influences cognitive flexibility and creativity. Ten subjects, in whom vagus nerve stimulators had been implanted for the treatment of intractable seizures, performed tasks that assessed cognitive flexibility (solving anagrams), creativity (Torrance Test), and memory (Hopkins Verbal Learning Test) during actual and sham vagus nerve stimulation. Vagus nerve stimulation impaired cognitive flexibility and creativity, but these results could not be explained by the induction of a general encephalopathy because VNS did not impair learning and improved retention. The means by which vagus nerve stimulation impairs cognitive flexibility and creative thinking is probably related to increased activity of the locus coeruleus-central adrenergic system that increases the signal-to-noise ratio and improves the brain's ability to attend to sensory input, but decreases its ability to recruit large-scale networks.

  9. Neuromuscular Electrical Stimulation and Anabolic Signaling in Patients with Stroke.

    Science.gov (United States)

    Mettler, Joni A; Bennett, Sydney M; Doucet, Barbara M; Magee, Dillon M

    2017-12-01

    Stroke results in limited ability to produce voluntary muscle contraction and movement on one side of the body, leading to further muscle wasting and weakness. Neuromuscular electrical stimulation is often used to facilitate involuntary muscle contraction; however, the effect of neuromuscular electrical stimulation on muscle growth and strengthening processes in hemiparetic muscle is not clear. This study examined the skeletal muscle anabolic response of an acute bout of neuromuscular electrical stimulation in individuals with chronic stroke and healthy older adults. Eleven individuals (59.8 ± 2.7 years old) were divided into a chronic stroke group (n = 5) and a healthy older adult control group (n = 6). Muscle biopsies were obtained before and after stimulation from the vastus lateralis of the hemiparetic leg for the stroke group and the right leg for the control group. The neuromuscular electrical stimulation protocol consisted of a 60-minute, intermittent stimulation train at 60 Hz. Phosphorylation of mammalian target of rapamycin and ribosomal protein S6 kinase beta-1 were analyzed by Western blot. An acute bout of neuromuscular electrical stimulation increased phosphorylation of mammalian target of rapamycin (stroke: 56.0%; control: 51.4%; P = .002) and ribosomal protein S6 kinase beta-1 (stroke: 131.2%; control: 156.3%; P = .002) from resting levels to post-neuromuscular electrical stimulation treatment, respectively. Phosphorylated protein content was similar between stroke and control groups at both time points. Findings suggest that paretic muscles of patients with chronic stroke may maintain ability to stimulate protein synthesis machinery in response to neuromuscular electrical stimulation. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  10. Vagus nerve stimulation magnet activation for seizures: a critical review.

    Science.gov (United States)

    Fisher, R S; Eggleston, K S; Wright, C W

    2015-01-01

    Some patients receiving VNS Therapy report benefit from manually activating the generator with a handheld magnet at the time of a seizure. A review of 20 studies comprising 859 subjects identified patients who reported on-demand magnet mode stimulation to be beneficial. Benefit was reported in a weighted average of 45% of patients (range 0-89%) using the magnet, with seizure cessation claimed in a weighted average of 28% (range 15-67%). In addition to seizure termination, patients sometimes reported decreased intensity or duration of seizures or the post-ictal period. One study reported an isolated instance of worsening with magnet stimulation (Arch Pediatr Adolesc Med, 157, 2003 and 560). All of the reviewed studies assessed adjunctive magnet use. No studies were designed to provide Level I evidence of efficacy of magnet-induced stimulation. Retrospective analysis of one pivotal randomized trial of VNS therapy showed significantly more seizures terminated or improved in the active stimulation group vs the control group. Prospective, controlled studies would be required to isolate the effect and benefit of magnet mode stimulation and to document that the magnet-induced stimulation is the proximate cause of seizure reduction. Manual application of the magnet to initiate stimulation is not always practical because many patients are immobilized or unaware of their seizures, asleep or not in reach of the magnet. Algorithms based on changes in heart rate at or near the onset of the seizure provide a methodology for automated responsive stimulation. Because literature indicates additional benefits from on-demand magnet mode stimulation, a potential role exists for automatic activation of stimulation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Efficacy of Electrical Pudendal Nerve Stimulation versus Transvaginal Electrical Stimulation in Treating Female Idiopathic Urgency Urinary Incontinence.

    Science.gov (United States)

    Wang, Siyou; Lv, Jianwei; Feng, Xiaoming; Lv, Tingting

    2017-06-01

    We compared the efficacy of electrical pudendal nerve stimulation vs transvaginal electrical stimulation to treat female idiopathic urgency urinary incontinence. A total of 120 female patients with idiopathic urgency urinary incontinence refractory to medication were randomized at a ratio of 2:1 to group 1 of 80 patients and group 2 of 40. Groups 1 and 2 were treated with electrical pudendal nerve stimulation and transvaginal electrical stimulation, respectively. To perform electrical pudendal nerve stimulation long acupuncture needles were deeply inserted into 4 sacrococcygeal points and electrified to stimulate pudendal nerves. Outcome measures were the 24-hour pad test and a questionnaire to measure the severity of symptoms and quality of life in women with urgency urinary incontinence. The median severity of symptoms and quality of life score on the urgency urinary incontinence questionnaire (urgency urinary incontinence total score) was 13 (range 7 to 18.75) in group 1 and 11 (range 8 to 16) in group 2 before treatment, which decreased to 2 (range 0 to 6.75) in group 1 and 6.5 (range 3.25 to 10.75) in group 2 (both p Electrical pudendal nerve stimulation is more effective than transvaginal electrical stimulation in treating drug refractory, female idiopathic urgency urinary incontinence. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  12. Are Prescription Stimulants "Smart Pills"? The Epidemiology and Cognitive Neuroscience of Prescription Stimulant Use by Normal Healthy Individuals

    Science.gov (United States)

    Smith, M. Elizabeth; Farah, Martha J.

    2011-01-01

    Use of prescription stimulants by normal healthy individuals to enhance cognition is said to be on the rise. Who is using these medications for cognitive enhancement, and how prevalent is this practice? Do prescription stimulants in fact enhance cognition for normal healthy people? We review the epidemiological and cognitive neuroscience…

  13. Sacral nerve stimulation increases activation of the primary somatosensory cortex by anal canal stimulation in an experimental model.

    LENUS (Irish Health Repository)

    Griffin, K M

    2011-08-01

    Sacral and posterior tibial nerve stimulation may be used to treat faecal incontinence; however, the mechanism of action is unknown. The aim of this study was to establish whether sensory activation of the cerebral cortex by anal canal stimulation was increased by peripheral neuromodulation.

  14. Effect of ethanol on potassium-stimulated and electrically stimulated acetylcholine release in vitro from rat cortical slices.

    Science.gov (United States)

    Sunahara, G I; Kalant, H

    1980-06-01

    The effects of ethanol (EtOH) on potassium and electrically stimulated acetylcholine (ACh) release were compared in rat cerebral cortical slices in vitro. ACh was measured by pyrolysis - gas-liquid chromatography (GLC). Paired samples were incubated with and without 0.11 M EtOH. In the potassium stimulation experiments, cortical slices were serially incubated for three 45-min periods in normal incubation medium followed by two periods in medium containing either 15 or 27 mM K+. In the electrical stimulation experiments, the cortical slices were similarly incubated for three 30-min periods without stimulation followed by two periods of electrical (10 HZ) stimulation. ACh output rose 20% at 15 mM K+ and 160% at 27 mM K+. Ethanol had no effect on spontaneous ACh release and did not influence the ACh response to high K+ stimulation. Electrical stimulation approximately doubled the ACh output but EtOH reduced electrically stimulated ACh relese by 50--80%. These findings are compatible with the view that EtOH acts primarily on Na+ influx during the action potential.

  15. Outcomes of electrically stimulated gracilis neosphincter surgery.

    Science.gov (United States)

    Tillin, T; Chambers, M; Feldman, R

    2005-07-01

    To examine patient quality of life (QoL) and long-term costs of electrically stimulated gracilis neosphincter surgery (ESGNS). Independently conducted prospective case-comparison study of patients at the Royal London Hospital (RLH), plus a cross-sectional study of outcomes of ESGNS performed at three other UK centres. Cases were patients who underwent ESGNS at the participating hospitals during a 5-year period from 1977. Comparisons were made with two groups of people with similar bowel disorders who did not undergo ESGNS. ESGNS is a procedure designed to improve bowel function for people living with severe faecal incontinence or stomas. It involves transposition of the gracilis muscle to form a neo-anal sphincter. The transposed muscle is electrically stimulated via an electronic pulse generator implanted beneath the skin of the abdomen. Clinical success and symptomatic outcomes of surgery. Generic, domain and condition specific measures of QoL. Comparative costs to the NHS of ESGNS and conventional alternatives. At 3 years after surgery approximately three-quarters of patients still had functioning neosphincters. At this stage, bowel-related QoL and continence improved by more than 20% for nearly two-thirds of RLH patients. However, ongoing bowel evacuation difficulties occurred in half of those with good continence outcomes. QoL improvements were maintained in the smaller group of RLH patients who had reached 4 and 5 years of follow-up, although at this stage the proportion with failed neosphincters had increased. The RLH findings were supported by those from the three other UK centres. No significant changes in QoL were observed in the comparison groups during the follow-up period. The mean cost of patient care at RLH, was 23,253 pounds. In the other three centres, the estimated mean cost of the intervention per patient was 11,731 pounds, reflecting fewer planned operations and repeat admissions. Costs of patient care for those with stomas who did not undergo

  16. Luteinizing hormone and follicle stimulating hormone synergy: A review of role in controlled ovarian hyper-stimulation

    Directory of Open Access Journals (Sweden)

    Gottumukkala Achyuta Rama Raju

    2013-01-01

    Full Text Available Luteinizing hormone (LH in synergy with follicle stimulating hormone (FSH stimulates normal follicular growth and ovulation. FSH is frequently used in assisted reproductive technology (ART. Recent studies have facilitated better understanding on the complementary role of the LH to FSH in regulation of the follicle; however, role of LH in stimulation of follicle, optimal dosage of LH in stimulation and its importance in advanced aged patients has been a topic of discussion among medical fraternity. Though the administration of exogenous LH with FSH is obligatory for controlled ovarian stimulation in patients with hypogonadotropic hypogonadism, there is still a paucity of information of its usage in other patient population. In this review we looked in to the multiple roles that LH plays complementary to FSH to better understand the LH requirement in patients undergoing ART.

  17. Functional electrical stimulation on paraplegic patients

    Directory of Open Access Journals (Sweden)

    Helmut Kern

    2014-07-01

    Full Text Available We report on clinical and physiological effects of 8 months Functional Electrical Stimulation (FES of quadriceps femoris muscle on 16 paraplegic patients. Each patient had muscle biopsies, CT-muscle diameter measurements, knee extension strength testing carried out before and after 8 months FES training. Skin perfusion was documented through infrared telethermography and xenon clearance, muscle perfusion was recorded through thallium scintigraphy. After 8 months FES training baseline skin perfusion showed 86 % increase, muscle perfusion was augmented by 87 %. Muscle fiber diameters showed an average increase of 59 % after 8 months FES training. Muscles in patients with spastic paresis as well as in patients with denervation showed an increase in aerob and anaerob muscle enzymes up to the normal range. Even without axonal neurotropic substances FES was able to demonstrate fiberhypertrophy, enzyme adaptation and intracellular structural benefits in denervated muscles. The increment in muscle area as visible on CT-scans of quadriceps femoris was 30 % in spastic paraplegia and 10 % in denervated patients respectively. FES induced changes were less in areas not directly underneath the surface electrodes. We strongly recommend the use of Kern`s current for FES in denervated muscles to induce tetanic muscle contractions as we formed a very critical opinion of conventional exponential current. In patients with conus-cauda-lesions FES must be integrated into modern rehabilitation to prevent extreme muscle degeneration and decubital ulcers. Using FES we are able to improve metabolism and induce positive trophic changes in our patients lower extremities. In spastic paraplegics the functions „rising and walking“ achieved through FES are much better training than FES ergometers. Larger muscle masses are activated and an increased heart rate is measured, therefore the impact on cardiovascular fitness and metabolism is much greater. This effectively

  18. CALIBRATION AND TESTING OF SONIC STIMULATION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Roger Turpening; Wayne Pennington; Christopher Schmidt; Sean Trisch

    2005-03-01

    In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are (1) a borehole test site that will remain constant and is available all the time and for any length of time, (2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and (3) a set of procedures that ensures that the amplitude and frequency parameters of a wide range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 x 10{sup -5} cm/sec and a peak to peak pressure of approx. 2.5 x 10{sup -7} microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. Igor Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.

  19. Calibration and Testing of Sonic Stimulation Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Roger M. Turpening; Wayne D.Pennington

    2005-03-31

    In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are 1) a borehole test site that will remain constant and is available all the time and for any length of time, 2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and 3) a set of procedures that ensures that the amplitude and frequency parameters of a wide range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 X 10-5 cm/sec and a peak to peak pressure of approx. 2.5 X 10-7 microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. I. Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.

  20. Stimulated transitions in resonant atom Majorana mixing

    Science.gov (United States)

    Bernabéu, José; Segarra, Alejandro

    2018-02-01

    Massive neutrinos demand to ask whether they are Dirac or Majorana particles. Majorana neutrinos are an irrefutable proof of physics beyond the Standard Model. Neutrinoless double electron capture is not a process but a virtual Δ L = 2 mixing between a parent A Z atom and a daughter A ( Z - 2) excited atom with two electron holes. As a mixing between two neutral atoms and the observable signal in terms of emitted two-hole X-rays, the strategy, experimental signature and background are different from neutrinoless double beta decay. The mixing is resonantly enhanced for almost degeneracy and, under these conditions, there is no irreducible background from the standard two-neutrino channel. We reconstruct the natural time history of a nominally stable parent atom since its production either by nature or in the laboratory. After the time periods of atom oscillations and the decay of the short-lived daughter atom, at observable times the relevant "stationary" states are the mixed metastable long-lived state and the non-orthogonal short-lived excited state, as well as the ground state of the daughter atom. We find that they have a natural population inversion which is most appropriate for exploiting the bosonic nature of the observed atomic transitions radiation. Among different observables of the atom Majorana mixing, we include the enhanced rate of stimulated X-ray emission from the long-lived metastable state by a high-intensity X-ray beam: a gain factor of 100 can be envisaged at current XFEL facilities. On the other hand, the historical population of the daughter atom ground state can be probed by exciting it with a current pulsed optical laser, showing the characteristic absorption lines: the whole population can be excited in a shorter time than typical pulse duration.

  1. Quantitative Analysis of Lateral Pinch Force in Quadriplegic Patients Using Functional Neuromuscular Stimulation with Computer Stimulation

    Directory of Open Access Journals (Sweden)

    Ali Esteki

    2004-10-01

    Full Text Available Objective: In some applications of functional neuromuscular stimulation (FNS, the distal joint of the thumb (IP in quadriplegic patients is sometimes surgically fused at zero degrees and the FPL is stimulated. This prevents hyperextension and extreme flexion of the IP joint during lateral pinch. However, IP joint fusion removes one degree of freedom from the thumb and may reduce the grip force. An alternative approach, preferably without surgical alterations, using sufficient electrical stimulation of selected muscles was investigated. A 3D model of prehensile lateral pinch was developed. Computer simulation of the model was used to find an approach providing the appropriate posture and adequate lateral grip force for quadriplegic patients using FNS. Materials & Methods: The model consists of a multi-rigid-body system connected by one or two degree(s of freedom joints acted upon by passive resistive moments, active muscle moments and moments of external contact forces. Passive resistive moments were measured at each joint, active muscle moments were computed using a simple muscle model, and moments of external force were computed based on a force-displacement relationship for finger pads. In addition to the current strategy, two possible alternatives were studied: increasing the fused joint angle and activation of multiple muscles without joint fusion. Normal component of the grip force and its angle with respect to the horizontal plane were computed and compared for the studied cases. Results: Results showed, by using the current FNS strategy, a convenient posture and a grip force of 10.1 (N are achieved which is comparable to what is measured experimentally and introduced in the literature. Increasing the joint fusion angle from 0 to 15 and 30 degrees in parallel with the activation of FPL increased the grip force from 10.1 to 10.7 and 11.2 (N, respectively, but resulted in inconvenient posture. Among all different combinations of the muscles

  2. Low temperature stimulates alpha-melanophore-stimulating hormone secretion and inhibits background adaptation in Xenopus laevis.

    Science.gov (United States)

    Tonosaki, Y; Cruijsen, P M J M; Nishiyama, K; Yaginuma, H; Roubos, E W

    2004-11-01

    It is well-known that alpha-melanophore-stimulating hormone (alpha-MSH) release from the amphibian pars intermedia (PI) depends on the light condition of the animal's background, permitting the animal to adapt the colour of its skin to background light intensity. In the present study, we carried out nine experiments on the effect of low temperature on this skin adaptation process in the toad Xenopus laevis, using the skin melanophore index (MI) bioassay and a radioimmunoassay to measure skin colour adaptation and alpha-MSH secretion, respectively. We show that temperatures below 8 degrees C stimulate alpha-MSH secretion and skin darkening, with a maximum at 5 degrees C, independent of the illumination state of the background. No significant stimulatory effect of low temperature on the MI and alpha-MSH plasma contents was noted when the experiment was repeated with toads from which the neurointermediate lobe (NIL) had been surgically extirpated. This indicates that low temperature stimulates alpha-MSH release from melanotrope cells located in the PI. An in vitro superfusion study with the NIL demonstrated that low temperature does not act directly on the PI. A possible role of the central nervous system in cold-induced alpha-MSH release from the PI was tested by studying the hypothalamic expression of c-Fos (as an indicator for neuronal activity) and the coexistence of c-Fos with the regulators of melanotrope cell activity, neuropeptide Y (NPY) and thyrotrophin-releasing hormone (TRH), using double fluorescence immunocytochemistry. Upon lowering temperature from 22 degrees C to 5 degrees C, in white-adapted animals c-Fos expression decreased in NPY-producing suprachiasmatic-melanotrope-inhibiting neurones (SMIN) in the ventrolateral area of the suprachiasmatic nucleus (SC) but increased in TRH-containing neurones of the magnocellular nucleus. TRH is known to stimulate melanotrope alpha-MSH release. We conclude that temperatures around 5 degrees C inactivate the SMIN

  3. Shared Neural Mechanisms for the Evaluation of Intense Sensory Stimulation and Economic Reward, Dependent on Stimulation-Seeking Behavior.

    Science.gov (United States)

    Norbury, Agnes; Valton, Vincent; Rees, Geraint; Roiser, Jonathan P; Husain, Masud

    2016-09-28

    Why are some people strongly motivated by intense sensory experiences? Here we investigated how people encode the value of an intense sensory experience compared with economic reward, and how this varies according to stimulation-seeking preference. Specifically, we used a novel behavioral task in combination with computational modeling to derive the value individuals assigned to the opportunity to experience an intense tactile stimulus (mild electric shock). We then examined functional imaging data recorded during task performance to see how the opportunity to experience the sensory stimulus was encoded in stimulation-seekers versus stimulation-avoiders. We found that for individuals who positively sought out this kind of sensory stimulation, there was common encoding of anticipated economic and sensory rewards in the ventromedial prefrontal cortex. Conversely, there was robust encoding of the modeled probability of receiving such stimulation in the insula only in stimulation-avoidant individuals. Finally, we found preliminary evidence that sensory prediction error signals may be positively signed for stimulation-seekers, but negatively signed for stimulation-avoiders, in the posterior cingulate cortex. These findings may help explain why high intensity sensory experiences are appetitive for some individuals, but not for others, and may have relevance for the increased vulnerability for some psychopathologies, but perhaps increased resilience for others, in high sensation-seeking individuals. People vary in their preference for intense sensory experiences. Here, we investigated how different individuals evaluate the prospect of an unusual sensory experience (electric shock), compared with the opportunity to gain a more traditional reward (money). We found that in a subset of individuals who sought out such unusual sensory stimulation, anticipation of the sensory outcome was encoded in the same way as that of monetary gain, in the ventromedial prefrontal cortex

  4. Percutaneous tibial nerve stimulation for fecal incontinence: a video demonstration.

    Science.gov (United States)

    Hotouras, Alexander; Allison, Marion; Currie, Ann; Knowles, Charles H; Chan, Christopher L; Thaha, Mohamed A

    2012-06-01

    Fecal incontinence is an increasingly common condition with significant negative impact on quality on life and health care resources. It frequently presents a therapeutic challenge to clinicians. Emerging evidence suggests that percutaneous tibial nerve stimulation is an effective treatment for fecal incontinence with the added benefit of being minimally invasive and cost effective. Pursuant to the preliminary report of our early experience of percutaneous tibial nerve stimulation in patients with fecal incontinence published in this journal in 2010, in this dynamic article, we now describe and demonstrate the actual technique that can be performed in a nurse-led clinic or outpatient or community setting. Percutaneous tibial nerve stimulation is a technically simple procedure that can potentially be performed in an outpatient or community setting. The overall early success rate of 68% following its use reported by our unit compares favorably with the success rate following other forms of neuromodulation, including sacral nerve stimulation. When completed, our long-term outcome data will provide further information on the efficacy of tibial nerve stimulation in a larger cohort of patients (n > 100). Future studies, including our currently planned randomized controlled trial of percutaneous tibial nerve stimulation vs sham stimulation, will provide controlled efficacy data and may provide information on its exact mechanism of action.

  5. Sensory adaptation to electrical stimulation of the somatosensory nerves.

    Science.gov (United States)

    Graczyk, Emily Lauren; Delhaye, Benoit; Schiefer, Matthew A; Bensmaia, Sliman J; Tyler, Dustin J

    2018-03-19

    Sensory systems adapt their sensitivity to ambient stimulation levels to improve their responsiveness to changes in stimulation. The sense of touch is also subject to adaptation, as evidenced by the desensitization produced by prolonged vibratory stimulation of the skin. Electrical stimulation of nerves elicits tactile sensations that can convey feedback for bionic limbs. In this study, we investigate whether artificial touch is also subject to adaptation, despite the fact that the peripheral mechanotransducers are bypassed. Approach: Using well-established psychophysical paradigms, we characterize the time course and magnitude of sensory adaptation caused by extended electrical stimulation of the residual somatosensory nerves in three human amputees implanted with cuff electrodes. Main results: We find that electrical stimulation of the nerve also induces perceptual adaptation that recovers after cessation of the stimulus. The time course and magnitude of electrically-induced adaptation are equivalent to their mechanically-induced counterparts. Significance: We conclude that, in natural touch, the process of mechanotransduction is not required for adaptation, and artificial touch naturally experiences adaptation-induced adjustments of the dynamic range of sensations. Further, as it does for native hands, adaptation confers to bionic hands enhanced sensitivity to changes in stimulation and thus a more natural sensory experience. . Creative Commons Attribution license.

  6. Volume conductor model of transcutaneous electrical stimulation with kilohertz signals

    Science.gov (United States)

    Medina, Leonel E.; Grill, Warren M.

    2014-12-01

    Objective. Incorporating high-frequency components in transcutaneous electrical stimulation (TES) waveforms may make it possible to stimulate deeper nerve fibers since the impedance of tissue declines with increasing frequency. However, the mechanisms of high-frequency TES remain largely unexplored. We investigated the properties of TES with frequencies beyond those typically used in neural stimulation. Approach. We implemented a multilayer volume conductor model including dispersion and capacitive effects, coupled to a cable model of a nerve fiber. We simulated voltage- and current-controlled transcutaneous stimulation, and quantified the effects of frequency on the distribution of potentials and fiber excitation. We also quantified the effects of a novel transdermal amplitude modulated signal (TAMS) consisting of a non-zero offset sinusoidal carrier modulated by a square-pulse train. Main results. The model revealed that high-frequency signals generated larger potentials at depth than did low frequencies, but this did not translate into lower stimulation thresholds. Both TAMS and conventional rectangular pulses activated more superficial fibers in addition to the deeper, target fibers, and at no frequency did we observe an inversion of the strength-distance relationship. Current regulated stimulation was more strongly influenced by fiber depth, whereas voltage regulated stimulation was more strongly influenced by skin thickness. Finally, our model reproduced the threshold-frequency relationship of experimentally measured motor thresholds. Significance. The model may be used for prediction of motor thresholds in TES, and contributes to the understanding of high-frequency TES.

  7. Some characteristics of self-stimulation behavior of dogs.

    Science.gov (United States)

    Sadowski, B; Dembińska, M

    1973-01-01

    Self-stimulation was studied in dogs chronically implanted with electrodes in different points within the basal forebrain. The animals exhibiting pure self-rewarding behavior were defined as "optimal" and "good self-stimulators", whereas those with concomitant aversive phenomena were incorporated into the third category called "self-stimulation-withdrawal". In "optimal self-stimulators" a remarkable resistance of the response to extinction was noted. A strong negative attitude toward food was found in four dogs upon stimulation of the self-rewarding loci. Penile erection accompanied self-stimulation in two animals. Sniffing at first always followed incentive brain stimulation, but later it appeared at the beginning of each experiment and/or preceded the bouts of pressing. A rise of hypothalamic temperature was noted in mast of the animals. In some cases this was equal to or exceeded 1 degree Celsius. The temperature increase was accompanied by intense panting between the bouts. Seizures appeared locally as contractions of masticatory muscles and sometimes developed into a generalized fit. Anatomically the "reward area" in the dog extends from the septum and the preoptic area to the mammillary bodies and reaches laterally to the internal capsule.

  8. The Impact of Monaural Beat Stimulation on Anxiety and Cognition

    Directory of Open Access Journals (Sweden)

    Leila Chaieb

    2017-05-01

    Full Text Available Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz, alpha (10 Hz and gamma (40 Hz beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  9. The Impact of Monaural Beat Stimulation on Anxiety and Cognition.

    Science.gov (United States)

    Chaieb, Leila; Wilpert, Elke C; Hoppe, Christian; Axmacher, Nikolai; Fell, Juergen

    2017-01-01

    Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz), alpha (10 Hz) and gamma (40 Hz) beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  10. Early stimulation and language development of economically disadvantaged young children.

    Science.gov (United States)

    Malhi, Prahbhjot; Sidhu, Manjit; Bharti, Bhavneet

    2014-04-01

    To examine the effect of home stimulation on the language functioning of young children from low income families. The language functioning of 102 children (Mean age = 3.3 y, SD = 1.3) was assessed by the communication sub-scale of the Indian Developmental Inventory (IDI). Home visits were made to assess the quality of stimulation provided by parents to children. Seven items measuring stimulation of the child were selected from the Mohite Home Environment Inventory, a scale measuring the quality of home environment. Nearly 16 % of children from economically disadvantaged homes had language delay. Children with language delay as compared to children with adequate language skills had significantly lower stimulation at home (t = 2.59, P = 0.01), specifically parents were significantly less likely to praise their child (25 % vs. 52 %, χ (2) = 4.03, P = 0.045) or provide verbal stimulation (44 % vs. 72 %, χ (2) = 4.95, P = 0.026). Multivariate stepwise regression analysis revealed that 18 % of the variance in the communication developmental quotient (DQs) of children was accounted by stimulation and age of the child (F = 10.47, P = 0.000). Programs that seek to increase early stimulation for disadvantaged children by providing cognitive-linguistic enriched learning experiences would go a long way in paving the way for improved language, cognition and school performance in young children.

  11. Cutaneous stimulation and generation of breathing in the fetus.

    Science.gov (United States)

    Scarpelli, E M; Condorelli, S; Cosmi, E V

    1977-01-01

    The generation of spontaneous regular breathing by cutaneous stimulation and by direct electrical stimulation of the sciatic nerve was examined in six previously apneic mature fetal lambs in utero. The fetuses were stable throughout the course of the experiments: PaO2 less than or equal to 27 mm Hg, PaCO2 less than 44 mm Hg, pH 7.29-7.34, blood pressure and heart rate steady and normal. It is shown that electrical stimulation of the fetal skin (66 cps, 4.0 msec, 6 V, 0.77 ma) can be as effective as direct stimulation of the sciatic nerve (66 cps, 4.0 msec, 1.5 V, 0.08 ma) when the higher voltage and current are used. Mechanical cutaneous stimulation also produced spontaneous breathing which, however, was short lived compared with that produced by electrical stimuli. The results are consonant with our concept of activation and recruitment of quiescent respiratory center neurones by somatic sensory stimulation, and they give fundamental support to the clinical observation of others that cutaneous stimulation is effective for the treatment of apnea of prematurity. Speculation Somatic sensory stimuli from the skin may be important determinants of the onset of breathing in the fetus and newborn.

  12. Role of sound stimulation in reprogramming brain connectivity.

    Science.gov (United States)

    Chaudhury, Sraboni; Nag, Tapas C; Jain, Suman; Wadhwa, Shashi

    2013-09-01

    Sensory stimulation has a critical role to play in the development of an individual. Environmental factors tend to modify the inputs received by the sensory pathway. The developing brain is most vulnerable to these alterations and interacts with the environment to modify its neural circuitry. In addition to other sensory stimuli, auditory stimulation can also act as external stimuli to provide enrichment during the perinatal period. There is evidence that suggests that enriched environment in the form of auditory stimulation can play a substantial role in modulating plasticity during the prenatal period. This review focuses on the emerging role of prenatal auditory stimulation in the development of higher brain functions such as learning and memory in birds and mammals. The molecular mechanisms of various changes in the hippocampus following sound stimulation to effect neurogenesis, learning and memory are described. Sound stimulation can also modify neural connectivity in the early postnatal life to enhance higher cognitive function or even repair the secondary damages in various neurological and psychiatric disorders. Thus, it becomes imperative to examine in detail the possible ameliorating effects of prenatal sound stimulation in existing animal models of various psychiatric disorders, such as autism.

  13. Wirelessly powered stimulator and recorder for neuronal interfaces.

    Science.gov (United States)

    Nag, Sudip; Sharma, Dinesh

    2011-01-01

    Functional Electrical Stimulation (FES) is widely adopted in neuro-engineering to partially alleviate diseased functions in the brain, retina and cochlea. We present a 32-channel wirelessly powered constant current stimulator and low power recording amplifier for FES based applications. The biphasic stimulator utilizes innovative techniques for matched positive/ negative currents and thus improves charge balance. Electrode discharging scheme is added for stimulation artifact suppression. An improved low power amplifier is incorporated for evoked response measurements. Electrical performance is characterized using simulated electrode-electrolyte impedance. Closed-loop stimulation and recording experiments have been performed. Stimulation current magnitudes of 2 μA-200 μA and up to 400 Hz rate have been realized. Theory and limitation of discharging scheme is explored while suppressing artifacts down to 3 ms. Alternate anodic-first and cathodic-first stimulation pulses are adopted for enhanced charge balancing. The low power amplifier exhibits gain of 1200 and bandwidth 350 Hz-1.02 KHz. A multiplexer/ demultiplexer is used to share the front-end among 32 electrodes. The inductively coupled wireless energy harvester works at 125 KHz-135 KHz that can remotely deliver 1.4 mW at 1cm distance to an equivalent of 10K load. The system can accommodate multielectrodes with impedance up to 100 K Ω. The entire hybrid analog-digital system consumes 360 μW quiescent power. Miniaturization makes it suitable for in-vivo applications.

  14. Improving human plateaued motor skill with somatic stimulation.

    Directory of Open Access Journals (Sweden)

    Shintaro Uehara

    Full Text Available Procedural motor learning includes a period when no substantial gain in performance improvement is obtained even with repeated, daily practice. Prompted by the potential benefit of high-frequency transcutaneous electrical stimulation, we examined if the stimulation to the hand reduces redundant motor activity that likely exists in an acquired hand motor skill, so as to further upgrade stable motor performance. Healthy participants were trained until their motor performance of continuously rotating two balls in the palm of their right hand became stable. In the series of experiments, they repeated a trial performing this cyclic rotation as many times as possible in 15 s. In trials where we applied the stimulation to the relaxed thumb before they initiated the task, most reported that their movements became smoother and they could perform the movements at a higher cycle compared to the control trials. This was not possible when the dorsal side of the wrist was stimulated. The performance improvement was associated with reduction of amplitude of finger displacement, which was consistently observed irrespective of the task demands. Importantly, this kinematic change occurred without being noticed by the participants, and their intentional changes of motor strategies (reducing amplitude of finger displacement never improved the performance. Moreover, the performance never spontaneously improved during one-week training without stimulation, whereas the improvement in association with stimulation was consistently observed across days during training on another week combined with the stimulation. The improved effect obtained in stimulation trials on one day partially carried over to the next day, thereby promoting daily improvement of plateaued performance, which could not be unlocked by the first-week intensive training. This study demonstrated the possibility of effectively improving a plateaued motor skill, and pre-movement somatic stimulation

  15. Modulation of hippocampal activity with fornix Deep Brain Stimulation.

    Science.gov (United States)

    Stypulkowski, Paul H; Stanslaski, Scott R; Giftakis, Jonathon E

    Deep Brain Stimulation (DBS) within the Papez circuit is under investigation as a treatment for epilepsy and Alzheimer's disease. We previously reported the effects of stimulation at nodes within this network (anterior thalamic nucleus and hippocampus) on hippocampal activity in a large animal model, using a chronic implantable, clinical-grade system that permits concurrent stimulation and recording. In this study we extended earlier work to compare the effects of fornix DBS on evoked potentials (EPs) and local field potential (LFP) activity within the hippocampus, and to assess closed-loop stimulation. Unilateral fornix and hippocampal DBS leads were implanted in three ovine subjects using image-guided, frameless stereotaxy. Chronic, awake recordings of EPs and LFPs in response to fornix and hippocampal stimulation were collected with the implanted device and analyzed off-line. Stimulation of the fornix produced robust, short latency hippocampal EPs. High frequency fornix stimulation generated parameter-dependent effects. At low amplitudes, short lasting inhibition of LFP activity occurred. Above a specific amplitude threshold, DBS elicited pronounced bursts of theta activity, followed by a marked state shift in hippocampal activity. These effects persisted for minutes post-DBS and were reflected as changes in LFP spectral content and phase-amplitude coupling. Real-time modulation of hippocampal activity via the implanted device was demonstrated using LFPs as the control signal for closed-loop stimulation. The current results expand earlier findings and demonstrate target-specific effects produced by DBS within this neural circuit. These changes in network activity may provide insights into stimulation targets and parameter selection for clinical investigations. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. A tripolar current-steering stimulator ASIC for field shaping in deep brain stimulation.

    Science.gov (United States)

    Valente, Virgilio; Demosthenous, Andreas; Bayford, Richard

    2012-06-01

    A significant problem with clinical deep brain stimulation (DBS) is the high variability of its efficacy and the frequency of side effects, related to the spreading of current beyond the anatomical target area. This is the result of the lack of control that current DBS systems offer on the shaping of the electric potential distribution around the electrode. This paper presents a stimulator ASIC with a tripolar current-steering output stage, aiming at achieving more selectivity and field shaping than current DBS systems. The ASIC was fabricated in a 0.35-μ m CMOS technology occupying a core area of 0.71 mm(2). It consists of three current sourcing/sinking channels. It is capable of generating square and exponential-decay biphasic current pulses with five different time constants up to 28 ms and delivering up to 1.85 mA of cathodic current, in steps of 4 μA, from a 12 V power supply. Field shaping was validated by mapping the potential distribution when injecting current pulses through a multicontact DBS electrode in saline.

  17. "Sexy stimulants": the interaction between psychomotor stimulants and sexual behavior in the female brain.

    Science.gov (United States)

    Guarraci, Fay A; Bolton, Jessica L

    2014-06-01

    Research indicates gender differences in sensitivity to psychomotor stimulants. Preclinical work investigating the interaction between drugs of abuse and sex-specific behaviors, such as sexual behavior, is critical to our understanding of such gender differences in humans. A number of behavioral paradigms can be used to model aspects of human sexual behavior in animal subjects. Although traditional assessment of the reflexive, lordosis posture of the female rat has been used to map the neuroanatomical and neurochemical systems that contribute to uniquely female copulatory behavior, the additional behavioral paradigms discussed in the current review have helped us expand our description of the appetitive and consummatory patterns of sexual behavior in the female rat. Measuring appetitive behavior is particularly important for assessing sexual motivation, the equivalent of "desire" in humans. By investigating the effects of commonly abused drugs on female sexual motivation, we are beginning to elucidate the role of dopaminergic neurotransmission, a neural system also known to be critical to the neurobiology of drug addiction, in female sexual motivation. A better understanding of the nexus of sex and drugs in the female brain will help advance our understanding of motivation in general and explain how psychomotor stimulants affect males and females differently. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Electrical Stimulation for Pressure Injuries: A Health Technology Assessment.

    Science.gov (United States)

    2017-01-01

    Pressure injuries (bedsores) are common and reduce quality of life. They are also costly and difficult to treat. This health technology assessment evaluates the effectiveness, cost-effectiveness, budget impact, and lived experience of adding electrical stimulation to standard wound care for pressure injuries. We conducted a systematic search for studies published to December 7, 2016, limited to randomized and non-randomized controlled trials examining the effectiveness of electrical stimulation plus standard wound care versus standard wound care alone for patients with pressure injuries. We assessed the quality of evidence through Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In addition, we conducted an economic literature review and a budget impact analysis to assess the cost-effectiveness and affordability of electrical stimulation for treatment of pressure ulcers in Ontario. Given uncertainties in clinical evidence and resource use, we did not conduct a primary economic evaluation. Finally, we conducted qualitative interviews with patients and caregivers about their experiences with pressure injuries, currently available treatments, and (if applicable) electrical stimulation. Nine randomized controlled trials and two non-randomized controlled trials were found from the systematic search. There was no significant difference in complete pressure injury healing between adjunct electrical stimulation and standard wound care. There was a significant difference in wound surface area reduction favouring electrical stimulation compared with standard wound care.The only study on cost-effectiveness of electrical stimulation was partially applicable to the patient population of interest. Therefore, the cost-effectiveness of electrical stimulation cannot be determined. We estimate that the cost of publicly funding electrical stimulation for pressure injuries would be $0.77 to $3.85 million yearly for the next 5 years.Patients and caregivers

  19. Ultrasound guided, painful electrical stimulation of lumbar facet joint structures

    DEFF Research Database (Denmark)

    O'Neill, Søren; Graven-Nielsen, Thomas; Manniche, Claus

    2009-01-01

    placed either side of a lumbar facet joint (right L3-4) and used to induce experimental low back pain for 10 min with continuous stimulation. Thresholds, stimulus-response relationships, distribution and quality of the electrically induced pain were recorded. Electrical facet joint stimulation induced...... low back pain and pain referral into the anterior leg, ipsilaterally, proximal to the knee, similar to what is observed clinically. Pressure pain thresholds did not change significantly before, during and after facet joint stimulation. In conclusion, we describe a novel model of acute experimental low...

  20. Electrical Stimulation for Pressure Injuries: A Health Technology Assessment

    Science.gov (United States)

    Lambrinos, Anna; Falk, Lindsey; Ali, Arshia; Holubowich, Corinne; Walter, Melissa

    2017-01-01

    Background Pressure injuries (bedsores) are common and reduce quality of life. They are also costly and difficult to treat. This health technology assessment evaluates the effectiveness, cost-effectiveness, budget impact, and lived experience of adding electrical stimulation to standard wound care for pressure injuries. Methods We conducted a systematic search for studies published to December 7, 2016, limited to randomized and non–randomized controlled trials examining the effectiveness of electrical stimulation plus standard wound care versus standard wound care alone for patients with pressure injuries. We assessed the quality of evidence through Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In addition, we conducted an economic literature review and a budget impact analysis to assess the cost-effectiveness and affordability of electrical stimulation for treatment of pressure ulcers in Ontario. Given uncertainties in clinical evidence and resource use, we did not conduct a primary economic evaluation. Finally, we conducted qualitative interviews with patients and caregivers about their experiences with pressure injuries, currently available treatments, and (if applicable) electrical stimulation. Results Nine randomized controlled trials and two non–randomized controlled trials were found from the systematic search. There was no significant difference in complete pressure injury healing between adjunct electrical stimulation and standard wound care. There was a significant difference in wound surface area reduction favouring electrical stimulation compared with standard wound care. The only study on cost-effectiveness of electrical stimulation was partially applicable to the patient population of interest. Therefore, the cost-effectiveness of electrical stimulation cannot be determined. We estimate that the cost of publicly funding electrical stimulation for pressure injuries would be $0.77 to $3.85 million yearly for the next 5