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Sample records for frontal midline theta

  1. Validity and reliability of electroencephalographic frontal alpha asymmetry and frontal midline theta as biomarkers for depression.

    PubMed

    Gold, Christian; Fachner, Jörg; Erkkilä, Jaakko

    2013-04-01

    Electroencephalographic (EEG) frontal alpha asymmetry (FAA) and frontal midline (FM) theta have been suggested as biomarkers for depression and anxiety, but have mostly been assessed in small and non-clinical studies. In a clinical sample of 79 adults with depression (ICD-10: F32), resting EEG and scales of depression (MADRS) and anxiety (HADS-A) were measured at intake and after 3 months. FAA and FM theta values were referenced to a normative population database. Internal consistency, test-retest reliability, and correlations with psychiatric tests were examined. Reliability was sufficient. However, FAA and FM theta values were close to the general population, and correlations with psychiatric tests were mostly small and non-significant, with the exception of FAA on F7-F8 z-scores and HADS-A. We conclude that the validity of FAA and FM theta and therefore their potential as biomarkers for depression and anxiety remain unclear. PMID:23278257

  2. Frontal Midline Theta Reflects Anxiety and Cognitive Control: Meta-Analytic Evidence

    PubMed Central

    Cavanagh, James F.; Shackman, Alexander J.

    2014-01-01

    Evidence from imaging and anatomical studies suggests that the midcingulate cortex (MCC) is a dynamic hub lying at the interface of affect and cognition. In particular, this neural system appears to integrate information about conflict and punishment in order to optimize behavior in the face of action-outcome uncertainty. In a series of meta-analyses, we show how recent human electrophysiological research provides compelling evidence that frontal-midline theta signals reflecting MCC activity are moderated by anxiety and predict adaptive behavioral adjustments. These findings underscore the importance of frontal theta activity to a broad spectrum of control operations. We argue that frontal-midline theta provides a neurophysiologically plausible mechanism for optimally adjusting behavior to uncertainty, a hallmark of situations that elicit anxiety and demand cognitive control. These observations compel a new perspective on the mechanisms guiding motivated learning and behavior and provide a framework for understanding the role of the MCC in temperament and psychopathology. PMID:24787485

  3. Frontal midline theta reflects anxiety and cognitive control: meta-analytic evidence.

    PubMed

    Cavanagh, James F; Shackman, Alexander J

    2015-01-01

    Evidence from imaging and anatomical studies suggests that the midcingulate cortex (MCC) is a dynamic hub lying at the interface of affect and cognition. In particular, this neural system appears to integrate information about conflict and punishment in order to optimize behavior in the face of action-outcome uncertainty. In a series of meta-analyses, we show how recent human electrophysiological research provides compelling evidence that frontal-midline theta signals reflecting MCC activity are moderated by anxiety and predict adaptive behavioral adjustments. These findings underscore the importance of frontal theta activity to a broad spectrum of control operations. We argue that frontal-midline theta provides a neurophysiologically plausible mechanism for optimally adjusting behavior to uncertainty, a hallmark of situations that elicit anxiety and demand cognitive control. These observations compel a new perspective on the mechanisms guiding motivated learning and behavior and provide a framework for understanding the role of the MCC in temperament and psychopathology. PMID:24787485

  4. Event-related desynchronization of frontal-midline theta rhythm during preconscious auditory oddball processing.

    PubMed

    Kawamata, Masaru; Kirino, Eiji; Inoue, Reiichi; Arai, Heii

    2007-10-01

    The goal of this study was to explore the frontal-midline theta rhythm (Fm theta) generation mechanism employing event-related desynchronization/synchronization (ERD/ERS) analysis in relation to task-irrelevant external stimuli. A dual paradigm was employed: a videogame and the simultaneous presentation of passive auditory oddball stimuli. We analyzed the data concerning ERD/ERS using both Fast Fourier Transformation (FFT) and wavelet transform (WT). In the FFT data, during the periods with appearance of Fm theta, apparent ERD of the theta band was observed at Fz and Cz. ERD when Fm theta was present was much more prominent than when Fm theta was absent. In the WT data, as in the FFT data, ERD was seen again, but in this case the ERD was preceded by ERS during both the periods with and without Fm theta. Furthermore, the WT analysis indicated that ERD was followed by ERS during the periods without Fm theta. However, during Fm theta, no apparent ERS following ERD was seen. In our study, Fm theta was desynchronized by the auditory stimuli that were independent of the video game task used to evoke the Fm theta. The ERD of Fm theta might be reflecting the mechanism of "positive suppression" to process external auditory stimuli automatically and preventing attentional resources from being unnecessarily allocated to those stimuli. Another possibility is that Fm theta induced by our dual paradigm may reflect information processing modeled by multi-item working memory requirements for playing the videogame and the simultaneous auditory processing using a memory trace. ERS in the WT data without Fm theta might indicate further processing of the auditory information free from "positive suppression" control reflected by Fm theta. PMID:17993201

  5. Self-regulation of frontal-midline theta facilitates memory updating and mental set shifting

    PubMed Central

    Enriquez-Geppert, Stefanie; Huster, René J.; Figge, Christian; Herrmann, Christoph S.

    2014-01-01

    Frontal-midline (fm) theta oscillations as measured via the electroencephalogram (EEG) have been suggested as neural “working language” of executive functioning. Their power has been shown to increase when cognitive processing or task performance is enhanced. Thus, the question arises whether learning to increase fm-theta amplitudes would functionally impact the behavioral performance in tasks probing executive functions (EFs). Here, the effects of neurofeedback (NF), a learning method to self-up-regulate fm-theta over fm electrodes, on the four most representative EFs, memory updating, set shifting, conflict monitoring, and motor inhibition are presented. Before beginning and after completing an individualized, eight-session gap-spaced NF intervention, the three-back, letter/number task-switching, Stroop, and stop-signal tasks were tested while measuring the EEG. Self-determined up-regulation of fm-theta and its putative role for executive functioning were compared to an active control group, the so-called pseudo-neurofeedback group. Task-related fm-theta activity after training differed significantly between groups. More importantly, though, after NF significantly enhanced behavioral performance was observed. The training group showed higher accuracy scores in the three-back task and reduced mixing and shifting costs in letter/number task-switching. However, this specific protocol type did not affect performance in tasks probing conflict monitoring and motor inhibition. Thus, our results suggest a modulation of proactive but not reactive mechanisms of cognitive control. Furthermore, task-related EEG changes show a distinct pattern for fm-theta after training between the NF and the pseudo-neurofeedback group, which indicates that NF training indeed tackles EFs-networks. In sum, the modulation of fm-theta via NF may serve as potent treatment approach for executive dysfunctions. PMID:25538585

  6. Frontal midline theta reflects individual task performance in a working memory task.

    PubMed

    Maurer, Urs; Brem, Silvia; Liechti, Martina; Maurizio, Stefano; Michels, Lars; Brandeis, Daniel

    2015-01-01

    Frontal midline (fm-)theta activity has been related to working memory (WM) processes, as it typically increases with WM load. The robustness of this effect, however, varies across studies and subjects, putting limits to its interpretation. We hypothesized that variation in the fm-theta effect may reflect individual differences in task difficulty with increasing WM load as indicated by behavioural responses. We further tested whether effects in the alpha range are robust markers of WM load. We recorded 64-channel EEG from 24 healthy adults while they memorized either 2 or 4 unfamiliar symbols (low vs. high WM load) in a modified Sternberg task. The last 2 s of the retention phase were analyzed for WM load-related changes in the theta (5-7 Hz) and alpha range (lower: 8-10 Hz, upper: 10.5-12.5 Hz). Higher WM load led to less accurate and slower responses. The increase of fm-theta with WM load was most pronounced at fm electrodes, localized to anterior cingulate regions, and correlated with the participants' decrease in accuracy due to higher WM load. Alpha peak frequency increased in the high compared to the low WM load condition, corresponding to a decrease in lower alpha range across all channels. The results demonstrate that previously reported variation in fm-theta workload effects can partly be explained by variation in task difficulty indexed by individual task accuracy. Moreover, the results also demonstrate that alpha WM load effects are prominent when separating upper and lower alpha. PMID:24687327

  7. Frontal midline theta as a neurophysiological correlate for deficits of attentional orienting in children with developmental coordination disorder.

    PubMed

    Wang, Chun-Hao; Lo, Yu-Hui; Pan, Chien-Yu; Chen, Fu-Chen; Liang, Wei-Kuang; Tsai, Chia-Liang

    2015-06-01

    Children with developmental coordination disorder (DCD) have been demonstrated to show attentional orienting deficits. The neural mechanism, however, has thus far remained elusive. Here, we measure oscillations in the EEG associated with attentional orienting to address this issue. The EEG was recorded from DCD children and typical developing (TD) controls during an eye-gaze cueing paradigm. DCD group responded more slowly than TD group across all conditions. Additionally, TD group showed higher frontal midline theta activities in both valid and invalid conditions relative to a neutral condition, with such an effect absent in the DCD group. Theta oscillations might reflect attentional processing in relation to the cues being performed in TD group, with the lessened modulation of theta in DCD group possibly reflecting a deficit in attentional orienting. Possible explanations for the DCD-TD differences in theta oscillation and attentional orienting are discussed. PMID:25529042

  8. tACS Phase Locking of Frontal Midline Theta Oscillations Disrupts Working Memory Performance

    PubMed Central

    Chander, Bankim S.; Witkowski, Matthias; Braun, Christoph; Robinson, Stephen E.; Born, Jan; Cohen, Leonardo G.; Birbaumer, Niels; Soekadar, Surjo R.

    2016-01-01

    Background: Frontal midline theta (FMT) oscillations (4–8 Hz) are strongly related to cognitive and executive control during mental tasks such as memory processing, arithmetic problem solving or sustained attention. While maintenance of temporal order information during a working memory (WM) task was recently linked to FMT phase, a positive correlation between FMT power, WM demand and WM performance was shown. However, the relationship between these measures is not well understood, and it is unknown whether purposeful FMT phase manipulation during a WM task impacts FMT power and WM performance. Here we present evidence that FMT phase manipulation mediated by transcranial alternating current stimulation (tACS) can block WM demand-related FMT power increase (FMTΔpower) and disrupt normal WM performance. Methods: Twenty healthy volunteers were assigned to one of two groups (group A, group B) and performed a 2-back task across a baseline block (block 1) and an intervention block (block 2) while 275-sensor magnetoencephalography (MEG) was recorded. After no stimulation was applied during block 1, participants in group A received tACS oscillating at their individual FMT frequency over the prefrontal cortex (PFC) while group B received sham stimulation during block 2. After assessing and mapping phase locking values (PLV) between the tACS signal and brain oscillatory activity across the whole brain, FMT power and WM performance were assessed and compared between blocks and groups. Results: During block 2 of group A but not B, FMT oscillations showed increased PLV across task-related cortical areas underneath the frontal tACS electrode. While WM task-related FMTΔpower and WM performance were comparable across groups in block 1, tACS resulted in lower FMTΔpower and WM performance compared to sham stimulation in block 2. Conclusion: tACS-related manipulation of FMT phase can disrupt WM performance and influence WM task-related FMTΔpower. This finding may have important

  9. [Effect of the TRH analog DN-1417 on the appearance of frontal midline theta activity (Fm0)].

    PubMed

    Nakamura, J; Mukasa, H; Hashimoto, M; Inanaga, K

    1987-06-01

    The distinct 0 rhythm which appears in the frontal midline area during the performance of mental tasks is called Fm0. The appearance of Fm0 shows individual differences and a close relationship to the personality traits of the subject. It is also reported that administration of diazepam or alcohol brings about an increase of Fm0 along with lowering of the anxiety level. In the present study, the TRH analog DN-1417 (80 mg) was administered to 8 healthy male students for 15 days. They were all extrovert in nature and had no great neurotic tendencies as measured by the Maudsley Personality Inventory (MPI). EEG recording, determination of the blood concentration of DN-1417, and Spielberger's State-Trait Anxiety Inventory-I (STAI-I) were carried out before, during, and after drug administration. The appearance of Fm0 showed significant increase during and just after drug administration. As to anxiety, the STAI-I score showed no significant change. There was no correlation between blood concentration and Fm0. From these results, we considered that the change of appearance of Fm0 due to drug administration was not necessarily associated with change of the anxiety level, and that DN-1417, a DA releaser, increased the appearance of Fm0. PMID:2891228

  10. Frontal-posterior theta oscillations reflect memory retrieval during sentence comprehension.

    PubMed

    Meyer, Lars; Grigutsch, Maren; Schmuck, Noura; Gaston, Phoebe; Friederici, Angela D

    2015-10-01

    Successful working-memory retrieval requires that items be retained as distinct units. At the neural level, it has been shown that theta-band oscillatory power increases with the number of to-be-distinguished items during working-memory retrieval. Here we hypothesized that during sentence comprehension, verbal-working-memory retrieval demands lead to increased theta power over frontal cortex, supposedly supporting the distinction amongst stored items during verbal-working-memory retrieval. Also, synchronicity may increase between the frontal cortex and the posterior cortex, with the latter supposedly supporting item retention. We operationalized retrieval by using pronouns, which refer to and trigger the retrieval of antecedent nouns from a preceding sentence part. Retrieval demand was systematically varied by changing the pronoun antecedent: Either, it was non-embedded in the preceding main clause, and thus easy-to-retrieve across a single clause boundary, or embedded in the preceding subordinate clause, and thus hard-to-retrieve across a double clause boundary. We combined electroencephalography (EEG), scalp-level time-frequency analysis, source localization, and source-level coherence analysis, observing a frontal-midline and broad left-hemispheric theta-power increase for embedded-antecedent compared to non-embedded-antecedent retrieval. Sources were localized to left-frontal, left-parietal, and bilateral-inferior-temporal cortices. Coherence analyses suggested synchronicity between left-frontal and left-parietal and between left-frontal and right-inferior-temporal cortices. Activity of an array of left-frontal, left-parietal, and bilateral-inferior-temporal cortices may thus assist retrieval during sentence comprehension, potentially indexing the orchestration of item distinction, verbal working memory, and long-term memory. Our results extend prior findings by mapping prior knowledge on the functional role of theta oscillations onto processes genuine to human

  11. Frontal theta as a mechanism for cognitive control

    PubMed Central

    Cavanagh, James F.; Frank, Michael J.

    2014-01-01

    Recent advancements in cognitive neuroscience have afforded a description of neural responses in terms of latent algorithmic operations. However, the adoption of this approach to human scalp EEG has been more limited, despite the ability of this methodology to quantify canonical neuronal processes. Here we provide evidence that theta band activities over the mid-frontal cortex appear to reflect a common computation used for realizing the need for cognitive control. Moreover, by virtue of inherent properties of field oscillations, these theta band processes may be used to communicate this need and subsequently implement such control across disparate brain regions. Frontal theta is thus a compelling candidate mechanism by which emergent processes such as ‘cognitive control’ may be biophysically realized. PMID:24835663

  12. Automatic Detection of Frontal Face Midline by Chain-coded Merlin-Farber Hough Trasform

    NASA Astrophysics Data System (ADS)

    Okamoto, Daichi; Ohyama, Wataru; Wakabayashi, Tetsushi; Kimura, Fumitaka

    We propose a novel approach for detection of the facial midline (facial symmetry axis) from a frontal face image. The facial midline has several applications, for instance reducing computational cost required for facial feature extraction (FFE) and postoperative assessment for cosmetic or dental surgery. The proposed method detects the facial midline of a frontal face from an edge image as the symmetry axis using the Merlin-Faber Hough transformation. And a new performance improvement scheme for midline detection by MFHT is present. The main concept of the proposed scheme is suppression of redundant vote on the Hough parameter space by introducing chain code representation for the binary edge image. Experimental results on the image dataset containing 2409 images from FERET database indicate that the proposed algorithm can improve the accuracy of midline detection from 89.9% to 95.1 % for face images with different scales and rotation.

  13. Frontal predominance of a relative increase in sleep delta and theta EEG activity after sleep loss in humans

    NASA Technical Reports Server (NTRS)

    Cajochen, C.; Foy, R.; Dijk, D. J.; Czeisler, C. A. (Principal Investigator)

    1999-01-01

    The effect of sleep deprivation (40 h) on topographic and temporal aspects of electroencephalographic (EEG) activity during sleep was investigated by all night spectral analysis in six young volunteers. The sleep-deprivation-induced increase of EEG power density in the delta and theta frequencies (1-7 Hz) during nonREM sleep, assessed along the antero-posterior axis (midline: Fz, Cz, Pz, Oz), was significantly larger in the more frontal derivations (Fz, Cz) than in the more parietal derivations (Pz, Oz). This frequency-specific frontal predominance was already present in the first 30 min of recovery sleep, and dissipated in the course of the 8-h sleep episode. The data demonstrate that the enhancement of slow wave EEG activity during sleep following extended wakefulness is most pronounced in frontal cortical areas.

  14. Frontal EEG theta changes assess the training improvements of novices in flight simulation tasks.

    PubMed

    Borghini, G; Arico, P; Astolfi, L; Toppi, J; Cincotti, F; Mattia, D; Cherubino, P; Vecchiato, G; Maglione, A G; Graziani, I; Babiloni, F

    2013-01-01

    The aim of the study is to analyze the variation of the EEG power spectra in theta band when a novice starts to learn a new task. In particular, the goal is to find out the differences from the beginning of the training to the session in which the performance level is good enough for considering him/her able to complete the task without any problems. While the novices were engaged in the flight simulation tasks we recorded the brain activity by using high resolution EEG techniques as well as neurophysiologic variables such as heart rate (HR) and eye blinks rate (EBR). Results show clear changes in the EEG power spectra in theta band over the frontal brain areas, either over the left, the midline and the right side, during the learning process of the task. These results are also supported by the autonomic signals of HR and EBR, by the performances' trends and by the questionnaires for the evaluation of the perceived workload level. PMID:24111260

  15. Frontal and rostral anterior cingulate (rACC) theta EEG in depression: implications for treatment outcome?

    PubMed

    Arns, Martijn; Etkin, Amit; Hegerl, Ulrich; Williams, Leanne M; DeBattista, Charles; Palmer, Donna M; Fitzgerald, Paul B; Harris, Anthony; deBeuss, Roger; Gordon, Evian

    2015-08-01

    In major depressive disorder (MDD), elevated theta current density in the rostral anterior cingulate (rACC), as estimated by source localization of scalp-recorded electroencenphalogram (EEG), has been associated with response to antidepressant treatments, whereas elevated frontal theta has been linked to non-response. This study used source localization to attempt to integrate these apparently opposite results and test, whether antidepressant response is associated with elevated rACC theta and non-response with elevated frontal theta and whether theta activity is a differential predictor of response to different types of commonly used antidepressants. In the international Study to Predict Optimized Treatment in Depression (iSPOT-D), a multi-center, international, randomized, prospective practical trial, 1008 MDD participants were randomized to escitalopram, sertraline or venlafaxine-XR. The study also recruited 336 healthy controls. Treatment response and remission were established after eight weeks using the 17-item Hamilton Rating Scale for Depression (HRSD17). The resting-state EEG was assessed at baseline with eyes closed and source localization (eLORETA) was employed to extract theta from the rACC and frontal cortex. Patients with MDD had elevated theta in both frontal cortex and rACC, with small effect sizes. High frontal and rACC theta were associated with treatment non-response, but not with non-remission, and this effect was most pronounced in a subgroup with previous treatment failures. Low theta in frontal cortex and rACC are found in responders to antidepressant treatments with a small effect size. Future studies should investigate in more detail the role of previous treatment (failure) in the association between theta and treatment outcome. PMID:25936227

  16. Social exclusion modulates event-related frontal theta and tracks ostracism distress in children.

    PubMed

    van Noordt, Stefon J R; White, Lars O; Wu, Jia; Mayes, Linda C; Crowley, Michael J

    2015-09-01

    Social exclusion is a potent elicitor of distress. Previous studies have shown that medial frontal theta oscillations are modulated by the experience of social exclusion. Using the Cyberball paradigm, we examined event-related dynamics of theta power in the EEG at medial frontal sites while children aged 8-12 years were exposed to conditions of fair play and social exclusion. Using an event-related design, we found that medial frontal theta oscillations (4-8Hz) increase during both early (i.e., 200-400ms) and late (i.e., 400-800ms) processing of rejection events during social exclusion relative to perceptually identical "not my turn" events during inclusion. Importantly, we show that only for the later time window (400-800ms) slow-wave theta power tracks self-reported ostracism distress. Specifically, greater theta power at medial frontal sites to "rejection" events predicted higher levels of ostracism distress. Alpha and beta oscillations for rejection events were unrelated to ostracism distress at either 200-400ms or 400-800ms time windows. Our findings extend previous studies by showing that medial frontal theta oscillations for rejection events are a neural signature of social exclusion, linked to experienced distress in middle childhood. PMID:26048623

  17. Theta lingua franca: a common mid-frontal substrate for action monitoring processes.

    PubMed

    Cavanagh, James F; Zambrano-Vazquez, Laura; Allen, John J B

    2012-02-01

    We present evidence that a multitude of mid-frontal event-related potential (ERP) components partially reflect a common theta band oscillatory process. Specifically, mid-frontal ERP components in the N2 time range and error-related negativity time range are parsimoniously characterized as reflections of theta band activities. Forty participants completed three different tasks with varying stimulus-response demands. Permutation tests were used to identify the dominant time-frequency responses of stimulus- and response-locked conditions as well as the enhanced responses to novelty, conflict, punishment, and error. A dominant theta band feature was found in all conditions, and both ERP component amplitudes and theta power measures were similarly modulated by novelty, conflict, punishment, and error. The findings support the hypothesis that generic and reactive medial prefrontal cortex processes are parsimoniously reflected by theta band activities. PMID:22091878

  18. TERT promoter mutated WHO grades II and III gliomas are located preferentially in the frontal lobe and avoid the midline

    PubMed Central

    Sun, Ze-Lin; Chan, Aden Ka-Yin; Chen, Ling-Chao; Tang, Chao; Zhang, Zhen-Yu; Ding, Xiao-Jie; Wang, Yang; Sun, Chong-Ran; Ng, Ho-Keung; Yao, Yu; Zhou, Liang-Fu

    2015-01-01

    The promoter region of telomerase reverse transcriptase (TERTp) and isocitrate dehydrogenase (IDH) have been regarded as biomarkers with distinct clinical and phenotypic features. Investigated the possible correlations between tumor location and genetic alterations would enhance our understanding of gliomagenesis and heterogeneity of glioma. We examined mutations of TERTp and IDH by direct sequencing and fluorescence in-situ hybridization in a cohort of 225 grades II and III diffuse gliomas. Correlation analysis between molecular markers and tumor locations was performed by Chi-square tests/Fisher’s exact test and multivariate logistic regression analysis. We found gliomas in frontal lobe showed higher frequency of TERTp mutation (P=0.0337) and simultaneously mutations of IDH and TERTp (IDH mut-TERTpmut) (P=0.0281) than frequency of biomarkers mutation of tumors in no-Frontal lobes, while lower frequency of TERTp mutation (P<0.0001) and simultaneously wild type of IDH and TERTp (IDH wt-TERTpwt) (P<0.0001) in midline than no-midline lobes. Logistic regression analysis indicated that locations of tumors associated with TERTp mutation (OR=0.540, 95% CI 0.324-0.900, P=0.018) and status of combinations of IDH and TERTp (IDH mut-TERTp mut vs. IDH wt-TERTp wt OR=0.162, 95% CI 0.075-0.350, P<0.001). In conclusion, grades II and III gliomas harboring TERTp mutation were located preferentially in the frontal lobe and rarely in midline. Association of IDH-TERTp status and tumor location suggests their potential values in molecular classification of grades II and III gliomas. PMID:26617880

  19. A Comparison of Frontal Theta Activity During Shooting among Biathletes and Cross-Country Skiers before and after Vigorous Exercise

    PubMed Central

    Luchsinger, Harri; Sandbakk, Øyvind; Schubert, Michael; Ettema, Gertjan; Baumeister, Jochen

    2016-01-01

    Background Previous studies using electroencephalography (EEG) to monitor brain activity have linked higher frontal theta activity to more focused attention and superior performance in goal-directed precision tasks. In biathlon, shooting performance requires focused attention after high-intensity cross-country skiing. Purpose To compare biathletes (serving as experts) and cross-country skiers (novices) and examine the effect of vigorous exercise on frontal theta activity during shooting. Methods EEG frontal theta (4–7 Hz) activity was compared between nine biathletes and eight cross-country skiers at comparable skiing performance levels who fired 100 shots on a 5-m indoor shooting range in quiescent condition followed by 20 shots after each of five 6-min high-intensity roller skiing sessions in the skating technique on a treadmill. Results Biathletes hit 80±14% and 81±10% before and after the roller skiing sessions, respectively. For the cross-country skiers these values were significantly lower than for the biathletes and amounted to 39±13% and 44±11% (p<0.01). Biathletes had on average 6% higher frontal theta activity during shooting as compared to cross-country skiers (F1,15 = 4.82, p = 0.044), but no significant effect of vigorous exercise on frontal theta activity in either of the two groups were found (F1,15 = 0.14, p = 0.72). Conclusions Biathletes had significantly higher frontal theta activity than cross-country skiers during shooting, indicating higher focused attention in biathletes. Vigorous exercise did not decrease shooting performance or frontal theta activity during shooting in biathletes and cross-country skiers. PMID:26981639

  20. Frontal and parietal theta burst TMS impairs working memory for visual-spatial conjunctions.

    PubMed

    Morgan, Helen M; Jackson, Margaret C; van Koningsbruggen, Martijn G; Shapiro, Kimron L; Linden, David E J

    2013-03-01

    In tasks that selectively probe visual or spatial working memory (WM) frontal and posterior cortical areas show a segregation, with dorsal areas preferentially involved in spatial (e.g. location) WM and ventral areas in visual (e.g. object identity) WM. In a previous fMRI study [1], we showed that right parietal cortex (PC) was more active during WM for orientation, whereas left inferior frontal gyrus (IFG) was more active during colour WM. During WM for colour-orientation conjunctions, activity in these areas was intermediate to the level of activity for the single task preferred and non-preferred information. To examine whether these specialised areas play a critical role in coordinating visual and spatial WM to perform a conjunction task, we used theta burst transcranial magnetic stimulation (TMS) to induce a functional deficit. Compared to sham stimulation, TMS to right PC or left IFG selectively impaired WM for conjunctions but not single features. This is consistent with findings from visual search paradigms, in which frontal and parietal TMS selectively affects search for conjunctions compared to single features, and with combined TMS and functional imaging work suggesting that parietal and frontal regions are functionally coupled in tasks requiring integration of visual and spatial information. Our results thus elucidate mechanisms by which the brain coordinates spatially segregated processing streams and have implications beyond the field of working memory. PMID:22483548

  1. Morning nutrition and executive function processes in preadolescents: gender variations in phasic modulation of frontal eeg theta activity during a go/ no-go task

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Frontal EEG theta activity has been related to executive functions (i.e., goal-directed behavior such as inhibition and flexibility of action). We studied the effects of morning nutritional status on frontal theta-executive function relationships using stimulus-locked responses [event-related increa...

  2. Auditory Conflict Resolution Correlates with Medial–Lateral Frontal Theta/Alpha Phase Synchrony

    PubMed Central

    Huang, Samantha; Rossi, Stephanie; Hämäläinen, Matti; Ahveninen, Jyrki

    2014-01-01

    When multiple persons speak simultaneously, it may be difficult for the listener to direct attention to correct sound objects among conflicting ones. This could occur, for example, in an emergency situation in which one hears conflicting instructions and the loudest, instead of the wisest, voice prevails. Here, we used cortically-constrained oscillatory MEG/EEG estimates to examine how different brain regions, including caudal anterior cingulate (cACC) and dorsolateral prefrontal cortices (DLPFC), work together to resolve these kinds of auditory conflicts. During an auditory flanker interference task, subjects were presented with sound patterns consisting of three different voices, from three different directions (45° left, straight ahead, 45° right), sounding out either the letters “A” or “O”. They were asked to discriminate which sound was presented centrally and ignore the flanking distracters that were phonetically either congruent (50%) or incongruent (50%) with the target. Our cortical MEG/EEG oscillatory estimates demonstrated a direct relationship between performance and brain activity, showing that efficient conflict resolution, as measured with reduced conflict-induced RT lags, is predicted by theta/alpha phase coupling between cACC and right lateral frontal cortex regions intersecting the right frontal eye fields (FEF) and DLPFC, as well as by increased pre-stimulus gamma (60–110 Hz) power in the left inferior fontal cortex. Notably, cACC connectivity patterns that correlated with behavioral conflict-resolution measures were found during both the pre-stimulus and the pre-response periods. Our data provide evidence that, instead of being only transiently activated upon conflict detection, cACC is involved in sustained engagement of attentional resources required for effective sound object selection performance. PMID:25343503

  3. Resting posterior versus frontal delta/theta EEG activity is associated with extraversion and the COMT VAL(158)MET polymorphism.

    PubMed

    Wacker, Jan; Gatt, Justine Megan

    2010-07-01

    Recent studies suggest that resting posterior versus frontal EEG delta/theta activity (delta/theta Pz-Fz) is both sensitive to pharmacological manipulations of neural dopamine and associated with the agency facet of extraversion (i.e., a motivational disposition comprising enthusiasm, energy, assertiveness, achievement striving and social dominance). These observations suggest that posterior versus frontal resting EEG delta/theta activity may represent a useful marker for investigating the molecular genetic basis of extraversion. The present study aimed to test the novel hypothesis of an association between delta/theta Pz-Fz and a functional polymorphism of the enzyme catechol-O-methyltransferase (COMT VAL(158)MET) involved in dopamine catabolism. This was conducted in a large EEG data set from the Brain Resource International Database (BRID; resting EEG from N=1093 healthy individuals, 382 of which also genotyped for COMT VAL(158)MET). In summary, we (1) showed for the first time that the VAL allele is associated with increased delta/theta Pz-Fz; (2) replicated the association between extraversion and delta/theta Pz-Fz in a large, heterogeneous sample including both genders; and (3) documented that the VAL allele of the COMT VAL(158)MET is associated with increased extraversion scores, as previously reported for an overlapping BRID sample. This coherent pattern of findings adds further support to the suggestion that the posterior-anterior distribution of resting EEG slow wave activity in the delta/theta range represents a useful tool for probing the dopaminergic basis of extraversion. PMID:20450956

  4. Neural mechanisms of infant learning: differences in frontal theta activity during object exploration modulate subsequent object recognition.

    PubMed

    Begus, Katarina; Southgate, Victoria; Gliga, Teodora

    2015-05-01

    Investigating learning mechanisms in infancy relies largely on behavioural measures like visual attention, which often fail to predict whether stimuli would be encoded successfully. This study explored EEG activity in the theta frequency band, previously shown to predict successful learning in adults, to directly study infants' cognitive engagement, beyond visual attention. We tested 11-month-old infants (N = 23) and demonstrated that differences in frontal theta-band oscillations, recorded during infants' object exploration, predicted differential subsequent recognition of these objects in a preferential-looking test. Given that theta activity is modulated by motivation to learn in adults, these findings set the ground for future investigation into the drivers of infant learning. PMID:26018832

  5. Neural mechanisms of infant learning: differences in frontal theta activity during object exploration modulate subsequent object recognition

    PubMed Central

    Begus, Katarina; Southgate, Victoria; Gliga, Teodora

    2015-01-01

    Investigating learning mechanisms in infancy relies largely on behavioural measures like visual attention, which often fail to predict whether stimuli would be encoded successfully. This study explored EEG activity in the theta frequency band, previously shown to predict successful learning in adults, to directly study infants' cognitive engagement, beyond visual attention. We tested 11-month-old infants (N = 23) and demonstrated that differences in frontal theta-band oscillations, recorded during infants' object exploration, predicted differential subsequent recognition of these objects in a preferential-looking test. Given that theta activity is modulated by motivation to learn in adults, these findings set the ground for future investigation into the drivers of infant learning. PMID:26018832

  6. EEG Theta Dynamics within Frontal and Parietal Cortices for Error Processing during Reaching Movements in a Prism Adaptation Study Altering Visuo-Motor Predictive Planning

    PubMed Central

    Bonfiglio, Luca; Minichilli, Fabrizio; Cantore, Nicoletta; Carboncini, Maria Chiara; Piccotti, Emily; Rossi, Bruno

    2016-01-01

    Modulation of frontal midline theta (fmθ) is observed during error commission, but little is known about the role of theta oscillations in correcting motor behaviours. We investigate EEG activity of healthy partipants executing a reaching task under variable degrees of prism-induced visuo-motor distortion and visual occlusion of the initial arm trajectory. This task introduces directional errors of different magnitudes. The discrepancy between predicted and actual movement directions (i.e. the error), at the time when visual feedback (hand appearance) became available, elicits a signal that triggers on-line movement correction. Analysis were performed on 25 EEG channels. For each participant, the median value of the angular error of all reaching trials was used to partition the EEG epochs into high- and low-error conditions. We computed event-related spectral perturbations (ERSP) time-locked either to visual feedback or to the onset of movement correction. ERSP time-locked to the onset of visual feedback showed that fmθ increased in the high- but not in the low-error condition with an approximate time lag of 200 ms. Moreover, when single epochs were sorted by the degree of motor error, fmθ started to increase when a certain level of error was exceeded and, then, scaled with error magnitude. When ERSP were time-locked to the onset of movement correction, the fmθ increase anticipated this event with an approximate time lead of 50 ms. During successive trials, an error reduction was observed which was associated with indices of adaptations (i.e., aftereffects) suggesting the need to explore if theta oscillations may facilitate learning. To our knowledge this is the first study where the EEG signal recorded during reaching movements was time-locked to the onset of the error visual feedback. This allowed us to conclude that theta oscillations putatively generated by anterior cingulate cortex activation are implicated in error processing in semi-naturalistic motor

  7. Posterior versus frontal theta activity indexes approach motivation during affective autobiographical memories.

    PubMed

    Walden, K; Pornpattananangkul, N; Curlee, A; McAdams, D P; Nusslock, R

    2015-03-01

    Research has recently identified a promising neurophysiological marker of approach motivation involving posterior versus frontal (Pz - Fz) electroencephalographic (EEG) theta activity PFTA; Wacker, Chavanon, & Stemmler (Journal of Personality and Social Psychology 91:171-187, 2006). Preliminary evidence indicated that PFTA is modulated by dopaminergic activity, thought to underlie appetitive tendencies, and that it indexes self-reported behavioral activation system (BAS) sensitivity. To date, research has largely relied on resting indices of PFTA and has yet to examine the relationship between PFTA and specific approach-related affective states generated by emotionally salient laboratory tasks. Accordingly, the present study evaluated PFTA both at rest and during an ecologically valid autobiographical memory task in which participants recalled personal life experiences involving a goal-striving, an anxious apprehension, a low-point (i.e., difficult), and a neutral memory while EEG data were recorded. In line with prediction, elevated PFTA was observed during both goal-striving and anxious apprehension autobiographical memories. PFTA was particularly elevated during anxious apprehension memories coded as being high on approach-related tendencies. Elevated PFTA during anxious apprehension is consistent with a growing literature indicating that anxious apprehension is associated with elevated approach- and reward-related brain function. Lastly, elevated resting PFTA was positively correlated with self-reported trait anger, a negatively valenced emotion characterized by approach-related tendencies. These results have implications for (a) enhancing our understanding of the neurophysiology of approach-related emotions, (b) establishing PFTA as an index of appetitive motivational states, and (c) clarifying our understanding of the neurophysiology and approach-related tendencies associated with both anxious apprehension and anger. PMID:25245178

  8. Emotional conflict processing induce boosted theta oscillation.

    PubMed

    Ma, Jianling; Liu, Chang; Chen, Xu

    2015-05-19

    Although previous studies have reported the neural correlates and dynamics of emotional conflict processing, the neural oscillatory features of such processing remain unclear. The present study uses time-frequency analysis to determine the event-related spectral perturbation (ERSP) characteristics underlying emotional conflict processing. Our behavioral results replicate previous findings of shorter response times and fewer response errors under the congruent condition relative to the incongruent condition, indicating a robust interference effect. Theta oscillatory activity was larger for the incongruent than for the congruent condition over frontal and frontal-central midline areas, reflecting a greater need for control under conditions of conflict. Moreover, the theta power difference was negatively associated with the RT difference, indicating that greater theta power leads to better behavioral performance. The present findings provide evidence that the theta oscillation is necessary for the control of emotional conflict. PMID:25863173

  9. Timing Tasks Synchronize Cerebellar and Frontal Ramping Activity and Theta Oscillations: Implications for Cerebellar Stimulation in Diseases of Impaired Cognition

    PubMed Central

    Parker, Krystal L.

    2016-01-01

    Timing is a fundamental and highly conserved mammalian capability, yet the underlying neural mechanisms are widely debated. Ramping activity of single neurons that gradually increase or decrease activity to encode the passage of time has been speculated to predict a behaviorally relevant temporal event. Cue-evoked low-frequency activity has also been implicated in temporal processing. Ramping activity and low-frequency oscillations occur throughout the brain and could indicate a network-based approach to timing. Temporal processing requires cognitive mechanisms of working memory, attention, and reasoning, which are dysfunctional in neuropsychiatric disease. Therefore, timing tasks could be used to probe cognition in animals with disease phenotypes. The medial frontal cortex and cerebellum are involved in cognition. Cerebellar stimulation has been shown to influence medial frontal activity and improve cognition in schizophrenia. However, the mechanism underlying the efficacy of cerebellar stimulation is unknown. Here, we discuss how timing tasks can be used to probe cerebellar interactions with the frontal cortex and the therapeutic potential of cerebellar stimulation. The goal of this theory and hypothesis manuscript is threefold. First, we will summarize evidence indicating that in addition to motor learning, timing tasks involve cognitive processes that are present within both the cerebellum and medial frontal cortex. Second, we propose methodologies to investigate the connections between these areas in patients with Parkinson’s disease, autism, and schizophrenia. Lastly, we hypothesize that cerebellar transcranial stimulation may rescue medial frontal ramping activity, theta oscillations, and timing abnormalities, thereby restoring executive function in diseases of impaired cognition. This hypothesis could inspire the use of timing tasks as biomarkers for neuronal and cognitive abnormalities in neuropsychiatric disease and promote the therapeutic potential of

  10. (No) time for control: Frontal theta dynamics reveal the cost of temporally guided conflict anticipation.

    PubMed

    van Driel, Joram; Swart, Jennifer C; Egner, Tobias; Ridderinkhof, K Richard; Cohen, Michael X

    2015-12-01

    During situations of response conflict, cognitive control is characterized by prefrontal theta-band (3- to 8-Hz) activity. It has been shown that cognitive control can be triggered proactively by contextual cues that predict conflict. Here, we investigated whether a pretrial preparation interval could serve as such a cue. This would show that the temporal contingencies embedded in the task can be used to anticipate upcoming conflict. To this end, we recorded electroencephalography (EEG) from 30 human subjects while they performed a version of a Simon task in which the duration of a fixation cross between trials predicted whether the next trial would contain response conflict. Both their behavior and EEG activity showed a consistent but unexpected pattern of results: The conflict effect (increased reaction times and decreased accuracy on conflict as compared to nonconflict trials) was stronger when conflict was cued, and this was associated with stronger conflict-related midfrontal theta activity and functional connectivity. Interestingly, intervals that predicted conflict did show a pretarget increase in midfrontal theta power. These findings suggest that temporally guided expectations of conflict do heighten conflict anticipation, but also lead to less efficiently applied reactive control. We further explored this post-hoc interpretation by means of three behavioral follow-up experiments, in which we used nontemporal cues, semantically informative cues, and neutral cues. Together, this body of results suggests that the counterintuitive cost of conflict cueing may not be uniquely related to the temporal domain, but may instead be related to the implicitness and validity of the cue. PMID:26111755

  11. Human brain EEG indices of emotions: delineating responses to affective vocalizations by measuring frontal theta event-related synchronization.

    PubMed

    Bekkedal, Marni Y V; Rossi, John; Panksepp, Jaak

    2011-10-01

    At present there is no direct brain measure of basic emotional dynamics from the human brain. EEG provides non-invasive approaches for monitoring brain electrical activity to emotional stimuli. Event-related desynchronization/synchronization (ERD/ERS) analysis, based on power shifts in specific frequency bands, has some potential as a method for differentiating responses to basic emotions as measured during brief presentations of affective stimuli. Although there appears to be fairly consistent theta ERS in frontal regions of the brain during the earliest phases of processing affective auditory stimuli, the patterns do not readily distinguish between specific emotions. To date it has not been possible to consistently differentiate brain responses to emotion-specific affective states or stimuli, and some evidence to suggests the theta ERS more likely measures general arousal processes rather than yielding veridical indices of specific emotional states. Perhaps cortical EEG patterns will never be able to be used to distinguish discrete emotional states from the surface of the brain. The implications and limitations of such approaches for understanding human emotions are discussed. PMID:21596060

  12. Reward feedback processing in children and adolescents: Medial frontal theta oscillations

    PubMed Central

    Crowley, Michael J.; van Noordt, Stefon J.R.; Wu, Jia; Hommer, Rebecca E.; South, Mikle; Fearon, R. M. P.; Mayes, Linda C.

    2014-01-01

    We examined event-related electroencephalography (EEG) oscillations, including event-related spectral perturbations (ERSP) and intertrial coherence (ITC), to compare feedback processing during a chance-based reward vs. non-reward task in groups of 10-12-year-old (n = 42), 13-14-year-old (n = 34) and 15-17-year-olds (n = 32). Because few, if any studies have applied these analytic methods to examine feedback processing in children or adolescents, we used a fine-grained approach that explored one half hertz by 16 ms increments during feedback (no win vs. win events) in the theta (4-8 Hz) frequency band. Complex wavelet frequency decomposition revealed that no win feedback was associated with enhanced theta power and phase coherence. We observed condition and age-based differences for both ERSP and ITC, with stronger effects for ITC. The transition from childhood to early adolescence (13-14 yrs.) was a point of increased differentiation of ITC favoring no win vs. wins feedback and also compared to children or older adolescents, a point of heightened ITC for no win feedback (quadratic effect). PMID:24360036

  13. Morning nutrition and executive function processes in preadolescents: modulation of frontal event-related theta, beta and gamma EEG oscillations during a go/ no-go task

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Executive functions (i.e., goal-directed behavior such as inhibition and flexibility of action) have been linked to frontal brain regions and to covariations in oscillatory brain activity, e.g., theta and gamma activity. We studied the effects of morning nutritional status on executive function rel...

  14. Short theta burst stimulation to left frontal cortex prior to encoding enhances subsequent recognition memory.

    PubMed

    Demeter, Elise; Mirdamadi, Jasmine L; Meehan, Sean K; Taylor, Stephan F

    2016-08-01

    Deep semantic encoding of verbal stimuli can aid in later successful retrieval of those stimuli from long-term episodic memory. Evidence from numerous neuropsychological and neuroimaging experiments demonstrate regions in left prefrontal cortex, including left dorsolateral prefrontal cortex (DLPFC), are important for processes related to encoding. Here, we investigated the relationship between left DLPFC activity during encoding and successful subsequent memory with transcranial magnetic stimulation (TMS). In a pair of experiments using a 2-session within-subjects design, we stimulated either left DLPFC or a control region (Vertex) with a single 2-s train of short theta burst stimulation (sTBS) during a semantic encoding task and then gave participants a recognition memory test. We found that subsequent memory was enhanced on the day left DLPFC was stimulated, relative to the day Vertex was stimulated, and that DLPFC stimulation also increased participants' confidence in their decisions during the recognition task. We also explored the time course of how long the effects of sTBS persisted. Our data suggest 2 s of sTBS to left DLPFC is capable of enhancing subsequent memory for items encoded up to 15 s following stimulation. Collectively, these data demonstrate sTBS is capable of enhancing long-term memory and provide evidence that TBS protocols are a potentially powerful tool for modulating cognitive function. PMID:27098772

  15. Successful memory encoding is associated with increased cross-frequency coupling between frontal theta and posterior gamma oscillations in human scalp-recorded EEG.

    PubMed

    Friese, Uwe; Köster, Moritz; Hassler, Uwe; Martens, Ulla; Trujillo-Barreto, Nelson; Gruber, Thomas

    2013-02-01

    Although previous studies have established that successful memory encoding is associated with increased synchronization of theta-band and gamma-band oscillations, it is unclear if there is a functional relationship between oscillations in these frequency bands. Using scalp-recorded EEG in healthy human participants, we demonstrate that cross-frequency coupling between frontal theta phase and posterior gamma power is enhanced during the encoding of visual stimuli which participants later on remember versus items which participants subsequently forget ("subsequent memory effect," SME). Conventional wavelet analyses and source localizations revealed SMEs in spectral power of theta-, alpha-, and gamma-band. Successful compared to unsuccessful encoding was reflected in increased theta-band activity in right frontal cortex as well as increased gamma-band activity in parietal-occipital regions. Moreover, decreased alpha-band activity in prefrontal and occipital cortex was also related to successful encoding. Overall, these findings support the idea that during the formation of new memories frontal cortex regions interact with cortical representations in posterior areas. PMID:23142278

  16. Human subthalamic nucleus-medial frontal cortex theta phase coherence is involved in conflict and error related cortical monitoring.

    PubMed

    Zavala, Baltazar; Tan, Huiling; Ashkan, Keyoumars; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Zaghloul, Kareem; Brown, Peter

    2016-08-15

    The medial prefrontal cortex (mPFC) is thought to control the shift from automatic to controlled action selection when conflict is present or when mistakes have been recently committed. Growing evidence suggests that this process involves frequency specific communication in the theta (4-8Hz) band between the mPFC and the subthalamic nucleus (STN), which is the main target of deep brain stimulation (DBS) for Parkinson's disease. Key in this hypothesis is the finding that DBS can lead to impulsivity by disrupting the correlation between higher mPFC oscillations and slower reaction times during conflict. In order to test whether theta band coherence between the mPFC and the STN underlies adjustments to conflict and to errors, we simultaneously recorded mPFC and STN electrophysiological activity while DBS patients performed an arrowed flanker task. These recordings revealed higher theta phase coherence between the two sites during the high conflict trials relative to the low conflict trials. These differences were observed soon after conflicting arrows were displayed, but before a response was executed. Furthermore, trials that occurred after an error was committed showed higher phase coherence relative to trials that followed a correct trial, suggesting that mPFC-STN connectivity may also play a role in error related adjustments in behavior. Interestingly, the phase coherence we observed occurred before increases in theta power, implying that the theta phase and power may influence behavior at separate times during cortical monitoring. Finally, we showed that pre-stimulus differences in STN theta power were related to the reaction time on a given trial, which may help adjust behavior based on the probability of observing conflict during a task. PMID:27181763

  17. Effects of thienodiazepine derivatives, etizolam and clotiazepam on the appearance of Fm theta.

    PubMed

    Nakamura, J; Mukasa, H

    1992-12-01

    The effects of new thienodiazepine anxiolytics, etizolam and clotiazepam, on the appearance of frontal midline theta activity (Fm theta) were studied by the double-blind crossover method. The results were as follows; 1) Both clotiazepam and placebo tended to increase the Fm theta appearance in all subjects, but etizolam showed no such tendency. 2) Clotiazepam significantly increased the Fm theta appearance as compared with placebo in subjects with a high neurotic tendency (N-scale of MPI above 19). 3) Clotiazepam tended to increase the Fm theta appearance as compared with placebo and etizolam in subjects with a high anxiety level (MAS score above 14). 4) Apparently more subjects complained of drowsiness after the administration of etizolam than after clotiazepam or placebo. PMID:1363923

  18. Theta oscillations during the processing of monetary loss and gain: A perspective on gender and impulsivity

    PubMed Central

    Kamarajan, Chella; Rangaswamy, Madhavi; Chorlian, David B.; Manz, Niklas; Tang, Yongqiang; Pandey, Ashwini K.; Roopesh, Bangalore N.; Stimus, Arthur T.; Porjesz, Bernice

    2008-01-01

    Event-related oscillations (EROs) have proved to be very useful in the understanding of a variety of neurocognitive processes including reward/outcome processing. In the present study, theta power (4.0–7.0 Hz) following outcome stimuli in the time window of the N2-P3 complex (200–500 ms) was analyzed in healthy normals (20 males and 20 females) while performing a gambling task that involved monetary loss and gain. The main aim was to analyze outcome processing in terms of event-related theta power in the context of valence, amount, gender, and impulsivity. The S-transform was used for the signal processing of the ERO data in terms of time-frequency-power. Results from filtered waveforms showed a partially consistent phase-alignment of the increased theta activity corresponding to N2 and P3 components following the outcome stimuli. Gain conditions produced more theta power than loss conditions. While there was anterior involvement in both gain and loss, posterior activation was stronger during gain conditions than during loss conditions. Females exhibited posterior maxima during gain conditions while males had an anterior maxima during both loss and gain conditions. The current source density of theta activity in females involved larger areas of the scalp including a bilateral frontal activity while males predominantly had a frontal midline activity. Theta power was significantly higher in females than males across all conditions. Low theta (4.0–5.5 Hz) predominantly contributed to the posterior activity during gain conditions. High theta (5.5–7.0 Hz) was more associated with impulsivity measures than low theta activity. These findings may offer valuable clues to understand outcome processing, impulsivity, and gender differences. PMID:18616934

  19. Mathematically gifted adolescents mobilize enhanced workspace configuration of theta cortical network during deductive reasoning.

    PubMed

    Zhang, L; Gan, J Q; Wang, H

    2015-03-19

    Previous studies have established the importance of the fronto-parietal brain network in the information processing of reasoning. At the level of cortical source analysis, this eletroencepalogram (EEG) study investigates the functional reorganization of the theta-band (4-8Hz) neurocognitive network of mathematically gifted adolescents during deductive reasoning. Depending on the dense increase of long-range phase synchronizations in the reasoning process, math-gifted adolescents show more significant adaptive reorganization and enhanced "workspace" configuration in the theta network as compared with average-ability control subjects. The salient areas are mainly located in the anterior cortical vertices of the fronto-parietal network. Further correlation analyses have shown that the enhanced workspace configuration with respect to the global topological metrics of the theta network in math-gifted subjects is correlated with the intensive frontal midline theta (fm theta) response that is related to strong neural effort for cognitive events. These results suggest that by investing more cognitive resources math-gifted adolescents temporally mobilize an enhanced task-related global neuronal workspace, which is manifested as a highly integrated fronto-parietal information processing network during the reasoning process. PMID:25595993

  20. Congenital midline cervical cleft.

    PubMed

    Agag, Richard; Sacks, Justin; Silver, Lester

    2007-01-01

    Congenital midline cervical cleft (CMCC) is a rare disorder of the ventral neck that is clinically evident at birth and must be differentiated from the more common thyroglossal duct cyst. The case of CMCC presented here was associated with chromosomes 13/14 de novo Robertsonian translocations as well as midline deformities including a sacral tuft and a minor tongue-tie. The case is presented as well as discussion of histopathology, embryology, and surgical treatment. PMID:17214531

  1. Positive Emotional Experience: Induced by Vibroacoustic Stimulation Using a Body Monochord in Patients with Psychosomatic Disorders: Is Associated with an Increase in EEG-Theta and a Decrease in EEG-Alpha Power.

    PubMed

    Sandler, H; Tamm, S; Fendel, U; Rose, M; Klapp, B F; Bösel, R

    2016-07-01

    Relaxation and meditation techniques are generally characterized by focusing attention, which is associated with an increase of frontal EEG Theta. Some studies on music perception suggest an activation of Frontal Midline Theta during emotionally positive attribution, others display a lateralization of electrocortical processes in the attribution of music induced emotion of different valence. The present study examined the effects of vibroacoustic stimulation using a Body Monochord and the conventional relaxation music from an audio CD on the spontaneous EEG of patients suffering from psychosomatic disorders (N = 60). Each treatment took about 20 min and was presented to the patients in random order. Subjective experience was recorded via self-rating scale. EEG power spectra of the Theta, Alpha-1 and Alpha-2 bands were analysed and compard between the two treatment conditions. There was no lateralization of electrocortical activity in terms of the emotional experience of the musical pieces. A reduction in Alpha-2 power occurred during both treatments. An emotionally positive attribution of the experience of the vibroacoustically induced relaxation state is characterized by a more pronounced release of control. In the context of focused attention this is interpreted as flow experience. The spontaneous EEG showed an increase in Theta power, particularly in the frontal medial and central medial area, and a greater reduction in Alpha-2 power. The intensity of positive emotional feelings during the CD music showed no significant effect on the increase in Theta power. PMID:26936595

  2. Congenital midline nasofrontal masses.

    PubMed

    Saettele, Megan; Alexander, Alan; Markovich, Brian; Morelli, John; Lowe, Lisa H

    2012-09-01

    Congenital midline nasal masses are uncommon anomalies including nasal dermoids/epidermoids, nasal glial heterotopias and encephaloceles. These lesions can occur at the nasal bridge, extend intranasally and have intracranial extension with communication to the subarachnoid space. Therefore, accurate diagnosis of these lesions is critically important for presurgical planning and prevention of potentially fatal complications. Neuroimaging is essential in the evaluation of congenital midline nasal masses to identify the specific type of lesion, evaluate for the presence of intracranial extension and allow for appropriate presurgical planning. PMID:22648391

  3. Congenital Midline Cervical Cleft

    PubMed Central

    Villanueva-Meyer, Javier; Glastonbury, Christine; Marcovici, Peter

    2015-01-01

    Congenital midline cervical cleft is a rare anomaly that typically presents in the neonatal period as a thin suprasternal vertical band of erythematous skin with a nipple-like projection superiorly, which may exude fluid. We present the clinical and pathophysiologic features and the imaging findings of this uncommon, and rarely described entity in a newborn girl. PMID:25926928

  4. Midline thalamic neurons are differentially engaged during hippocampus network oscillations.

    PubMed

    Lara-Vásquez, Ariel; Espinosa, Nelson; Durán, Ernesto; Stockle, Marcelo; Fuentealba, Pablo

    2016-01-01

    The midline thalamus is reciprocally connected with the medial temporal lobe, where neural circuitry essential for spatial navigation and memory formation resides. Yet, little information is available on the dynamic relationship between activity patterns in the midline thalamus and medial temporal lobe. Here, we report on the functional heterogeneity of anatomically-identified thalamic neurons and the differential modulation of their activity with respect to dorsal hippocampal rhythms in the anesthetized mouse. Midline thalamic neurons expressing the calcium-binding protein calretinin, irrespective of their selective co-expression of calbindin, discharged at overall low levels, did not increase their activity during hippocampal theta oscillations, and their firing rates were inhibited during hippocampal sharp wave-ripples. Conversely, thalamic neurons lacking calretinin discharged at higher rates, increased their activity during hippocampal theta waves, but remained unaffected during sharp wave-ripples. Our results indicate that the midline thalamic system comprises at least two different classes of thalamic projection neuron, which can be partly defined by their differential engagement by hippocampal pathways during specific network oscillations that accompany distinct behavioral contexts. Thus, different midline thalamic neuronal populations might be selectively recruited to support distinct stages of memory processing, consistent with the thalamus being pivotal in the dialogue of cortical circuits. PMID:27411890

  5. Midline thalamic neurons are differentially engaged during hippocampus network oscillations

    PubMed Central

    Lara-Vásquez, Ariel; Espinosa, Nelson; Durán, Ernesto; Stockle, Marcelo; Fuentealba, Pablo

    2016-01-01

    The midline thalamus is reciprocally connected with the medial temporal lobe, where neural circuitry essential for spatial navigation and memory formation resides. Yet, little information is available on the dynamic relationship between activity patterns in the midline thalamus and medial temporal lobe. Here, we report on the functional heterogeneity of anatomically-identified thalamic neurons and the differential modulation of their activity with respect to dorsal hippocampal rhythms in the anesthetized mouse. Midline thalamic neurons expressing the calcium-binding protein calretinin, irrespective of their selective co-expression of calbindin, discharged at overall low levels, did not increase their activity during hippocampal theta oscillations, and their firing rates were inhibited during hippocampal sharp wave-ripples. Conversely, thalamic neurons lacking calretinin discharged at higher rates, increased their activity during hippocampal theta waves, but remained unaffected during sharp wave-ripples. Our results indicate that the midline thalamic system comprises at least two different classes of thalamic projection neuron, which can be partly defined by their differential engagement by hippocampal pathways during specific network oscillations that accompany distinct behavioral contexts. Thus, different midline thalamic neuronal populations might be selectively recruited to support distinct stages of memory processing, consistent with the thalamus being pivotal in the dialogue of cortical circuits. PMID:27411890

  6. Prefrontal and midline interactions mediating behavioural control

    PubMed Central

    Fassbender, Catherine; Hester, Robert; Murphy, Kevin; Foxe, John J.; Foxe, Deirdre M.; Garavan, Hugh

    2011-01-01

    Top-down control processes are thought to interact with bottom-up stimulus-driven task demands to facilitate the smooth execution of behaviour. Frontal and midline areas are believed to subserve these control processes but their distinct roles and the interactions between them remain to be fully elucidated. In this fMRI study, we utilised a GO/NO-GO task with cued and uncued inhibitory events to investigate the effect of cue-induced levels of top-down control on NO-GO trial response conflict. We found that on a within-subjects, trial-for-trial basis, high levels of top-down control, as indexed by left dorsolateral prefrontal activation prior to the NO-GO, resulted in lower levels of activation on the NO-GO trial in the pre-supplementary motor area. These results suggest that prefrontal and midline regions work together to implement cognitive control and reveal that intra-subject variability is reflected in these lateral and midline interactions. PMID:19120444

  7. Pediatric frontal mucocele secondary to a bifid frontal sinus septum.

    PubMed

    Plikaitis, Christina M; Purzycki, Adam R; Couture, Daniel; David, Lisa R

    2010-09-01

    A mucocele is a mucus-containing sac lined with epithelium that arises within a sinus when its drainage is compromised. The frontal sinus is the most common location, with frontal mucocele development occurring when the nasofrontal duct becomes obstructed because of polyps, bone tumors, prior surgery, sinusitis, trauma, or anatomic variation. We report an unusual case of a sterile pediatric frontal mucocele presenting as a slowly enlarging forehead mass due to a bifid frontal sinus septum. A 9-year-old girl presented to the craniofacial clinic for evaluation of a right frontal mass that had been slowly growing over the past year. She was otherwise healthy and had no history of previous trauma or sinus infections. Computed tomography (CT) scan results revealed a localized frontal fluid collection with protrusion and thinning of the anterior frontal bone between 2 midline bony septii. Surgical cranialization of the frontal sinus was performed. The anatomy of her lesion seen both on CT scan and intraoperatively likely explains this unusual case presentation. Instead of the usual inciting event of an intact frontal sinus drainage system becoming blocked, this patient seemed to have a primary developmental lack of any drainage system that led to her mucocele. During formation of her frontal sinus, she developed a bifid septum within the midline that excluded a portion of her frontal sinus from the lateral nasofrontal ducts. With mucus-producing epithelium trapped within these bony confines, pressure began to mount with expansion and thinning of the bone both anteriorly and posteriorly. The lack of any infectious symptoms and sterile culture results may support that this space developed primarily and was never in continuity with the external drainage system. Only 4 other patients have been reported with asymptomatic forehead swelling as the only presenting symptom, with the age ranging from 33 to 79 years. This patient represents the first clinical report of a congenital

  8. Management of Midline Facial Clefts.

    PubMed

    Mishra, Sobhan; Sabhlok, Samrat; Panda, Pankaj Kumar; Khatri, Isha

    2015-12-01

    Median or midline facial clefts are rare anomalies of developmental origin, etiology of whose occurrence is still unknown precisely. The most basic presentation of midline facial clefts is in the form of a Median cleft lip which is defined as any congenital vertical cleft through the centre of the upper lip. First described by Bechard in 1823, it is the most common amongst all atypical clefts reported. The incidence is about 1:10,00,000 births. This may occur as a sporadic event or as a part of an inherited sequence of anomalies. It arises embryologically from incomplete fusion of the medial nasal prominences. The authors present a series of eight cases with varying degrees of midline facial clefts. This review article aims to give a broad idea on the various classifications used for further understanding of midline facial clefts and a brief idea about the various surgical management techniques used in the repair of these facial clefts. PMID:26604459

  9. Theta and Alpha Band Modulations Reflect Error-Related Adjustments in the Auditory Condensation Task

    PubMed Central

    Novikov, Nikita A.; Bryzgalov, Dmitri V.; Chernyshev, Boris V.

    2015-01-01

    Error commission leads to adaptive adjustments in a number of brain networks that subserve goal-directed behavior, resulting in either enhanced stimulus processing or increased motor threshold depending on the nature of errors committed. Here, we studied these adjustments by analyzing post-error modulations of alpha and theta band activity in the auditory version of the two-choice condensation task, which is highly demanding for sustained attention while involves no inhibition of prepotent responses. Errors were followed by increased frontal midline theta (FMT) activity, as well as by enhanced alpha band suppression in the parietal and the left central regions; parietal alpha suppression correlated with the task performance, left central alpha suppression correlated with the post-error slowing, and FMT increase correlated with both behavioral measures. On post-error correct trials, left-central alpha band suppression started earlier before the response, and the response was followed by weaker FMT activity, as well as by enhanced alpha band suppression distributed over the entire scalp. These findings indicate that several separate neuronal networks are involved in post-error adjustments, including the midfrontal performance monitoring network, the parietal attentional network, and the sensorimotor network. Supposedly, activity within these networks is rapidly modulated after errors, resulting in optimization of their functional state on the subsequent trials, with corresponding changes in behavioral measures. PMID:26733266

  10. Middle interhemispheric variant of holoprosencephaly: A rare midline malformation

    PubMed Central

    Rajalakshmi, P. Prathiba; Gadodia, Ankur; Priyatharshini, P.

    2015-01-01

    Middle interhemispheric variant (MIH) of holoprosencephaly (HPE) or syntelencephaly is a rare variant of HPE characterized by abnormal midline union of the posterior frontal and parietal lobes with variable fusion of thalami. It varies from classic HPE in embryopathogenesis, severity of fusion of brain structures, associated craniofacial anomalies and clinical presentation. We report a case of MIH in a 5-year-old girl, who presented with severe developmental delay and discuss the features differentiating it from other more common forms of HPE. PMID:26557166

  11. Middle interhemispheric variant of holoprosencephaly: A rare midline malformation.

    PubMed

    Rajalakshmi, P Prathiba; Gadodia, Ankur; Priyatharshini, P

    2015-01-01

    Middle interhemispheric variant (MIH) of holoprosencephaly (HPE) or syntelencephaly is a rare variant of HPE characterized by abnormal midline union of the posterior frontal and parietal lobes with variable fusion of thalami. It varies from classic HPE in embryopathogenesis, severity of fusion of brain structures, associated craniofacial anomalies and clinical presentation. We report a case of MIH in a 5-year-old girl, who presented with severe developmental delay and discuss the features differentiating it from other more common forms of HPE. PMID:26557166

  12. Age-related oscillatory theta modulation of multisensory integration in frontocentral regions.

    PubMed

    Yan, Tianyi; Bi, Xiaoshan; Zhang, Mengmeng; Wang, Wenhui; Yao, Zhiqi; Yang, Weiping; Wu, Jinglong

    2016-08-01

    This study used electroencephalogram measurements to investigate the effects of aging on oscillatory theta modulation during an audiovisual discrimination task. By a wavelet-based time-frequency analysis, age-related theta oscillation response differences were observed within a relatively restricted time range (0-500 ms) over frontal-central regions. Older adults showed stronger theta spectral power during visual and audiovisual stimuli in the left frontal regions; however, young adults showed stronger theta spectral power during auditory and audiovisual stimuli in the central regions. These findings suggest that multisensory oscillatory theta responses differ according to age, which further proves that the left frontal regions play an important role in audiovisual integration. PMID:27272690

  13. Frontal Oscillatory Dynamics Predict Feedback Learning and Action Adjustment

    ERIC Educational Resources Information Center

    van de Vijver, Irene; Ridderinkhof, K. Richard; Cohen, Michael X.

    2011-01-01

    Frontal oscillatory dynamics in the theta (4-8 Hz) and beta (20-30 Hz) frequency bands have been implicated in cognitive control processes. Here we investigated the changes in coordinated activity within and between frontal brain areas during feedback-based response learning. In a time estimation task, participants learned to press a button after…

  14. Self-Related Processing and Deactivation of Cortical Midline Regions in Disorders of Consciousness

    PubMed Central

    Crone, Julia Sophia; Höller, Yvonne; Bergmann, Jürgen; Golaszewski, Stefan; Trinka, Eugen; Kronbichler, Martin

    2013-01-01

    Self-related stimuli activate anterior parts of cortical midline regions, which normally show task-induced deactivation. Deactivation in medial posterior and frontal regions is associated with the ability to focus attention on the demands of the task, and therefore, with consciousness. Studies investigating patients with impaired consciousness, that is, patients in minimally conscious state and patients with unresponsive wakefulness syndrome (formerly vegetative state), demonstrate that these patients show responses to self-related content in the anterior cingulate cortex. However, it remains unclear if these responses are an indication for conscious processing of stimuli or are due to automatic processing. To shed further light on this issue, we investigated responses of cortical midline regions to the own and another name in 27 patients with a disorder of consciousness and compared them to task-induced deactivation. While almost all of the control subjects responding to the own name demonstrated higher activation due to the self-related content in anterior midline regions and additional deactivation, none of the responding patients did so. Differences between groups showed a similar pattern of findings. Despite the relation between behavioral responsiveness in patients and activation in response to the own name, the findings of this study do not provide evidence for a direct association of activation in anterior midline regions and conscious processing. The deficits in processing of self-referential content in anterior midline regions may rather be due to general impairments in cognitive processing and not particularly linked to impaired consciousness. PMID:23986685

  15. Resting state theta band source distribution and functional connectivity in remitted schizophrenia.

    PubMed

    Shreekantiah Umesh, D; Tikka, Sai Krishna; Goyal, Nishant; Nizamie, S Haque; Sinha, Vinod Kumar

    2016-09-01

    Increased resting theta activity is one consistent observation occurring during all the phases of schizophrenia. However, the resting theta oscillations during the remission phase are yet unclear. We studied resting theta current source density and functional connectivity in remitted schizophrenia and compared with healthy controls. Significantly increased current source density was found in the dominant anterior cingulate cortex. Increased connectivity between the inferior parietal lobe bilaterally and between the left inferior parietal lobe and right middle frontal gyrus was also found. It may be concluded that schizophrenia patients have aberrant regional theta band current source density and functional connectivity even during remission. PMID:27484634

  16. Limbic circuitry of the midline thalamus.

    PubMed

    Vertes, Robert P; Linley, Stephanie B; Hoover, Walter B

    2015-07-01

    The thalamus was subdivided into three major groups: sensorimotor nuclei (or principal/relay nuclei), limbic nuclei and nuclei bridging these two domains. Limbic nuclei of thalamus (or 'limbic thalamus') consist of the anterior nuclei, midline nuclei, medial division of the mediodorsal nucleus (MDm) and central medial nucleus (CM) of the intralaminar complex. The midline nuclei include the paraventricular (PV) and paratenial (PT) nuclei, dorsally, and the reuniens (RE) and rhomboid (RH) nuclei, ventrally. The 'limbic' thalamic nuclei predominantly connect with limbic-related structures and serve a direct role in limbic-associated functions. Regarding the midline nuclei, RE/RH mainly target limbic cortical structures, particularly the hippocampus and the medial prefrontal cortex. Accordingly, RE/RH participate in functions involving interactions of the HF and mPFC. By contrast, PV/PT mainly project to limbic subcortical structures, particularly the amygdala and nucleus accumbens, and hence are critically involved in affective behaviors such as stress/anxiety, feeding behavior, and drug seeking activities. The anatomical/functional characteristics of MDm and CM are very similar to those of the midline nuclei and hence the collection of nuclei extending dorsoventrally along the midline/paramidline of the thalamus constitute the core of the 'limbic thalamus'. PMID:25616182

  17. LIMBIC CIRCUITRY OF THE MIDLINE THALAMUS

    PubMed Central

    Vertes, Robert P.; Linley, Stephanie B.; Hoover, Walter B.

    2016-01-01

    The thalamus was subdivided into three major groups: sensorimotor nuclei (or principal/relay nuclei), limbic nuclei and nuclei bridging these two domains. Limbic nuclei of thalamus (or ‘limbic thalamus’) consist of the anterior nuclei, midline nuclei, medial division of the mediodorsal nucleus (MDm) and central medial nucleus (CM) of the intralaminar complex. The midline nuclei include the paraventricular (PV) and paratenial (PT) nuclei, dorsally, and the reuniens (RE) and rhomboid (RH) nuclei, ventrally. The ‘limbic’ thalamic nuclei predominantly connect with limbic-related structures and serve a direct role in limbic–associated functions. Regarding the midline nuclei, RE/RH mainly target limbic cortical structures, particularly the hippocampus and the medial prefrontal cortex. Accordingly, RE/RH participate in functions involving interactions of the HF and mPFC. By contrast, PV/PT mainly project to limbic subcortical structures, particularly the amygdala and nucleus accumbens, and hence are critically involved in affective behaviors such as stress/anxiety, feeding behavior, and drug seeking activities. The anatomical/functional characteristics of MDm and CM are very similar to those of the midline nuclei and hence the collection of nuclei extending dorsoventrally along the midline/paramidline of the thalamus constitute the core of the ‘limbic thalamus’. PMID:25616182

  18. Revisiting the Factors Underlying Maxillary Midline Diastema

    PubMed Central

    Jaija, Abdullah M. Zakria; El-Beialy, Amr Ragab; Mostafa, Yehya A.

    2016-01-01

    Aim. The aim of this study is to analyze the etiological factors underlying the presence of maxillary midline diastema in a sample of orthodontic patients. Materials and Methods. One hundred patients who fulfill the inclusion criteria were selected from 1355 patients seeking orthodontic treatment. The pretreatment orthodontic records were analyzed. The width of the maxillary midline diastema was measured clinically with a digital caliper at two levels: the mesioincisal angles of the central incisors and five millimeters from the incisal edge. The two measurements were averaged, and patients with diastema of more than 0.5 millimeter in width were enrolled. Results. Diastema is a multifactorial clinical finding with more than one underlying etiological cause. The interrelationship between the familial pattern of midline diastema and the microdontia, macroglossia, labial frenum, and alveolar cleft conforms was clear. The effect of a mesiodens and the upper lateral incisor whether bilaterally missing, unerupted, or peg shaped was minimal. Conclusion. Etiological factors underlying maxillary midline diastema are interconnected. Using a checklist as a guide during handling maxillary midline diastema is important in the different stages of treatment. PMID:27239374

  19. Revisiting the Factors Underlying Maxillary Midline Diastema.

    PubMed

    Jaija, Abdullah M Zakria; El-Beialy, Amr Ragab; Mostafa, Yehya A

    2016-01-01

    Aim. The aim of this study is to analyze the etiological factors underlying the presence of maxillary midline diastema in a sample of orthodontic patients. Materials and Methods. One hundred patients who fulfill the inclusion criteria were selected from 1355 patients seeking orthodontic treatment. The pretreatment orthodontic records were analyzed. The width of the maxillary midline diastema was measured clinically with a digital caliper at two levels: the mesioincisal angles of the central incisors and five millimeters from the incisal edge. The two measurements were averaged, and patients with diastema of more than 0.5 millimeter in width were enrolled. Results. Diastema is a multifactorial clinical finding with more than one underlying etiological cause. The interrelationship between the familial pattern of midline diastema and the microdontia, macroglossia, labial frenum, and alveolar cleft conforms was clear. The effect of a mesiodens and the upper lateral incisor whether bilaterally missing, unerupted, or peg shaped was minimal. Conclusion. Etiological factors underlying maxillary midline diastema are interconnected. Using a checklist as a guide during handling maxillary midline diastema is important in the different stages of treatment. PMID:27239374

  20. Midline lateralization thyroplasty for adductor spasmodic dysphonia.

    PubMed

    Isshiki, N; Tsuji, D H; Yamamoto, Y; Iizuka, Y

    2000-02-01

    Midline lateralization thyroplasty was successfully performed on a patient with adductor spasmodic dysphonia. The thyroid cartilage was incised at the midline, and a 3 x 2-mm perforation was made at the anterior commissure to widen it. The perforation was closed with a free composite graft taken from the upper edge of the thyroid ala, and the incised thyroid cartilage edges were kept separated 4 mm apart with silicone wedges. A part of the sternohyoid muscle was rotated to seal any leak from the perforation. The postoperative course was uneventful. The voice has been restored to normal, and there is no sign of recurrence of the symptom so far, as of 1 year 5 months postoperative. Although a longer follow-up is needed, this case indicates that midline type II thyroplasty could be a useful treatment for adductor spasmodic dysphonia. PMID:10685572

  1. In vitro thermosensitivity of the midline thalamus

    NASA Technical Reports Server (NTRS)

    Travis, Kathleen A.; Bockholt, H. Jeremy; Zardetto-Smith, Andrea M.

    1995-01-01

    This study compared the thermosensitivity and spontaneous activity of thatamic midline neurons with those of neurons in areas widely regarded to be involved in thermoregulation (preoptic/anterior hypothalamus and posterior hypothalamus). In vitro single unit recordings were made from neurons within the thalamic midline nuclei, the preoptic/anterior hypothalamus and posterior hypothalamus prior to and during a temperature change 3-7 C above and below 37 C. There were no significant differences in the degree of thermosensitivity or the proportion of thermosensitive neurons in the three areas. In each area examined, the thermosensitive neurons had a spontaneous activity which was significantly greater than that of the temperature-insensitive neurons. The results suggest that structures of the midline thalamus may play a role similar to that of the preoptic/anterior hypothalamus and posterior hypothalamus in the processing of temperature related information.

  2. Understanding the theta aurora

    NASA Astrophysics Data System (ADS)

    Fear, Robert; Milan, Steve; Carter, Jennifer; Maggiolo, Romain; Fazakerley, Andrew; Dandouras, Iannis; Mende, Stephen

    2015-04-01

    The theta aurora, first observed by Dynamics Explorer in the 1980s, is a configuration of the Earth's aurora in which auroral emissions extend into and across the polar cap in the form of a transpolar arc. It is well established that the theta aurora occurs predominantly when the interplanetary magnetic field has a northward component, but over the last thirty years various mechanisms have been put forward to explain this intriguing phenomenon. In the last couple of years, a range of evidence has accumulated which strongly suggests that the transpolar arc is formed as proposed by Milan et al. (2005): magnetotail reconnection occurs during intervals of northward IMF, which results in a local "wedge" of closed magnetospheric flux that remains trapped in the magnetotail. Precipitation on these closed field lines results in the transpolar arc analogously to the formation of the aurora in the main oval. Evidence for magnetotail reconnection as the cause of the theta aurora includes the timescales necessary to influence the location at which the transpolar arc forms, and the presence of characteristic ionospheric flows which are excited by magnetotail reconnection and which are statistically associated with transpolar arcs (Fear & Milan, 2012a,b). Most recently, direct observation has been made of a localised wedge of closed magnetic flux, "trapped" in the lobe, which was observed to move back and forth in a manner which (to our knowledge) can only be explained by the magnetotail reconnection mechanism (Fear et al., 2014). In this talk, we summarise the evidence for the formation of the theta aurora by magnetotail reconnection, and discuss the remaining challenges in obtaining a comprehensive understanding of this spectacular phenomenon.

  3. Evidence for the "midline" hypothesis in associated defects of laterality formation and multiple midline anomalies.

    PubMed

    Gilbert-Barness, E; Debich-Spicer, D; Cohen, M M; Opitz, J M

    2001-07-15

    A male infant was liveborn at 38 weeks of gestation to a G4P1AB2, 22-year-old, mother. Polyhydramnios and multiple congenital anomalies were noted by ultrasonography; the infant died 5 min after birth. At autopsy, the infant had multiple defects of blastogenesis including midline anomalies with asplenia and abnormalities of laterality formation. The laterality defects were unusual in that they combined asplenia with hypoplastic, symmetrically unilobate lungs and bilateral hyparterial bronchi more consistent with polysplenia, abdominal situs inversus with midline stomach, symmetric liver, and left gallbladder. No intracardiac abnormalities were present, but there was azygous continuation of the inferior vena cava. Additional multiple midline defects included bronchoesophageal fistula, duodenal atresia, absence of posterior leaf of diaphragm; horseshoe adrenal gland; microcephaly; Dandy-Walker anomaly with agenesis of cerebellar vermis and occipital encephalocele; holoprosencephaly with orbital encephalocele, midline defect of the orbital plate of the skull, bilateral anophthalmia, double proboscis with bilateral choanal atresia, midline upper lip and palatal cleft; single-lobed thyroid; hypoplastic external genitalia with midline cleft of scrotum, long tapering fingers, and defects of the cranium at the sites of orbital and occipital encephaloceles. Defects of laterality frequently are associated with other complex midline anomalies, which both result from a disturbance of pattern formation during blastogenesis, i.e., the induction of the progenitor fields. The latter are the result of the establishment of upstream expression domains of growth and transcription factors and other morphogens. Many of these and other genetic systems, expressed asymmetrically around the midline, are responsible for laterality formation and are the result of upstream and subsequent downstream gene expression cascades through the expression of genes such as HOX genes; bFGF; transforming

  4. Pre-stimulus thalamic theta power predicts human memory formation.

    PubMed

    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    Pre-stimulus theta (4-8Hz) power in the hippocampus and neocortex predicts whether a memory for a subsequent event will be formed. Anatomical studies reveal thalamus-hippocampal connectivity, and lesion, neuroimaging, and electrophysiological studies show that memory processing involves the dorsomedial (DMTN) and anterior thalamic nuclei (ATN). The small size and deep location of these nuclei have limited real-time study of their activity, however, and it is unknown whether pre-stimulus theta power predictive of successful memory formation is also found in these subcortical structures. We recorded human electrophysiological data from the DMTN and ATN of 7 patients receiving deep brain stimulation for refractory epilepsy. We found that greater pre-stimulus theta power in the right DMTN was associated with successful memory encoding, predicting both behavioral outcome and post-stimulus correlates of successful memory formation. In particular, significant correlations were observed between right DMTN theta power and both frontal theta and right ATN gamma (32-50Hz) phase alignment, and frontal-ATN theta-gamma cross-frequency coupling. We draw the following primary conclusions. Our results provide direct electrophysiological evidence in humans of a role for the DMTN as well as the ATN in memory formation. Furthermore, prediction of subsequent memory performance by pre-stimulus thalamic oscillations provides evidence that post-stimulus differences in thalamic activity that index successful and unsuccessful encoding reflect brain processes specifically underpinning memory formation. Finally, the findings broaden the understanding of brain states that facilitate memory encoding to include subcortical as well as cortical structures. PMID:27208861

  5. Ramanujan's mock theta functions.

    PubMed

    Griffin, Michael; Ono, Ken; Rolen, Larry

    2013-04-01

    In his famous deathbed letter, Ramanujan introduced the notion of a mock theta function, and he offered some alleged examples. Recent work by Zwegers [Zwegers S (2001) Contemp Math 291:268-277 and Zwegers S (2002) PhD thesis (Univ of Utrecht, Utrecht, The Netherlands)] has elucidated the theory encompassing these examples. They are holomorphic parts of special harmonic weak Maass forms. Despite this understanding, little attention has been given to Ramanujan's original definition. Here, we prove that Ramanujan's examples do indeed satisfy his original definition. PMID:23536292

  6. The theta aurora

    NASA Technical Reports Server (NTRS)

    Frank, L. A.; Craven, J. D.; Gurnett, D. A.; Shawhan, S. D.; Burch, J. L.; Winningham, J. D.; Chappell, C. R.; Waite, J. H.; Maynard, N. C.; Sugiura, M.

    1986-01-01

    A comprehensive review is presented of the characteristics of theta aurora as revealed from four imaging efforts with the DE 1 and 2 satellites. The theta aurora consists of an auroral oval with a sun-aligned arc extending from the dayside to the nightside sectors of the oval. The DE 1 spacecraft provided high altitude simultaneous measurements of the electric and magnetic fields and plasma and the DE 2 collected equivalent low altitude data on the four events. The plasma was found to convect sunward when the transpolar arc appeared, while the convection was antisunward in other regions over the polar cap. The arc plasmas featured field-aligned electron acceleration into the polar atmosphere and field-aligned current sheets, both of which were sparse over the rest of the polar cap. The ions originated in the ionosphere and the solar wind; ions over the rest of the polar cap mainly arrived from the magnetosphere. Further discussions are provided of the dominant electrons and ions and the associated flow directions into and out of the various regions of the pole, similarities between the transpolar arc and the auroral oval, and interactions between the ionosphere and the auroral phenomena.

  7. Midline Prostatic Cyst Marsupialization Using Holmium Laser.

    PubMed

    Kilinc, Mehmet; Goger, Yunus Emre; Piskin, Mesut; Balasar, Mehmet; Kandemir, Abdulkadir

    2015-01-01

    Many of the prostatic cysts are asymptomatic and only 5% are symptomatic (Hamper et al., 1990; Higashi et al., 1990). These symptoms include pelvic pain, hematospermia, infertility, voiding dysfunction, prostatitis-like syndrome, and painful ejaculation. Treatment of prostatic cysts includes TRUSG guided drainage, endoscopic transurethral resection, and in some cases even open surgery. In the literature, endoscopic interventions use marsupialization of the midline prostatic cyst with transurethral resection (TUR) or transurethral incision with endoscopic urethrotomy (Dik et al., 1996; Terris, 1995). Holmium: YAG laser was employed for the marsupialization of the cyst wall in midline prostatic cyst treatment for the first time in the present study. Symptoms, treatment, and follow-up are presented in this paper. PMID:26101688

  8. Midline Prostatic Cyst Marsupialization Using Holmium Laser

    PubMed Central

    Kilinc, Mehmet; Goger, Yunus Emre; Piskin, Mesut; Balasar, Mehmet; Kandemir, Abdulkadir

    2015-01-01

    Many of the prostatic cysts are asymptomatic and only 5% are symptomatic (Hamper et al., 1990; Higashi et al., 1990). These symptoms include pelvic pain, hematospermia, infertility, voiding dysfunction, prostatitis-like syndrome, and painful ejaculation. Treatment of prostatic cysts includes TRUSG guided drainage, endoscopic transurethral resection, and in some cases even open surgery. In the literature, endoscopic interventions use marsupialization of the midline prostatic cyst with transurethral resection (TUR) or transurethral incision with endoscopic urethrotomy (Dik et al., 1996; Terris, 1995). Holmium: YAG laser was employed for the marsupialization of the cyst wall in midline prostatic cyst treatment for the first time in the present study. Symptoms, treatment, and follow-up are presented in this paper. PMID:26101688

  9. TMS-induced theta phase synchrony reveals a bottom-up network in working memory.

    PubMed

    Miyauchi, Eri; Kitajo, Keiichi; Kawasaki, Masahiro

    2016-05-27

    Global theta phase synchronization between the frontal and sensory areas has been suggested to connect the relevant areas for executive processes of working memory (WM). However, little is known regarding network directionality (i.e. top-down or bottom-up) of this interaction. To address the issue, the present study conducted transcranial magnetic stimulation (TMS)-electroencephalography (EEG) experiment during WM tasks. Results showed that TMS-induced increases in theta phase synchronization were observed only when TMS was delivered to the sensory areas but not the frontal area. These findings suggest that network directionality represented in WM is bottom-up rather than top-down. PMID:27063284

  10. Theta vocabulary II. Multidimensional case

    NASA Astrophysics Data System (ADS)

    Kharchev, S.; Zabrodin, A.

    2016-06-01

    It is shown that the Jacobi and Riemann identities of degree four for the multidimensional theta functions as well as the Weierstrass identities emerge as algebraic consequences of the fundamental multidimensional binary identities connecting the theta functions with Riemann matrices τ and 2 τ.

  11. Modulation of induced frontocentral theta (Fm-θ) event-related (de-)synchronisation dynamics following mindfulness-based cognitive therapy in Major Depressive Disorder.

    PubMed

    Schoenberg, Poppy L A; Speckens, Anne E M

    2014-10-01

    Depressive severity has been associated with attenuated neocortical frontal midline theta (Fm-θ) power/evoked activity. Mindfulness-Based Cognitive Therapy (MBCT) has shown to be a successful novel intervention for Major Depressive Disorder (MDD), albeit precise working mechanisms remain elusive. We examined the hypothesis that MBCT would have modulating effects upon evoked Fm-θ power, in addition to investigating possible mediation of induced event-related de/synchronisation (ERD/ERS) dynamics. Fifty one patients with a primary diagnosis of MDD (26 exposed to MBCT vs. 25 wait-list/WL controls) undertook a Go/NoGo task consisting of positive, negative and neutral words, further stratified into abstract versus trait adjective matrices. Depressive symptom severity and rumination were also examined. A pattern of enhanced induced Fm-θ synchronisation during the latter 400-800 ms temporal-window pre-to-post MBCT was observed; the contrary in the WL. Modulated ERD/ERS dynamics correlated to amelioration in depressive and rumination symptoms in the MBCT group. We propose the primary action pathway alluded to a neural disengagement mechanism enacting upon tonic neuronal assemblies implicated in emotional and self-related processing. Due to the complexity and presently undiscovered complete unified scientific understanding of neuro-oscillatory-dynamics, and associated clinical interplays; we hypothesise that the electro-cortical and connected clinical working pathways of MBCT in depression are multi-levelled constituting nonlinear and interdependent mechanisms, represented by mediated EEG synchronisation dynamics. PMID:25206931

  12. Theta responses are abnormal in mild cognitive impairment: evidence from analysis of theta event-related synchronization during a temporal expectancy task.

    PubMed

    Caravaglios, Giuseppe; Muscoso, Emma Gabriella; Di Maria, Giulia; Costanzo, Erminio

    2013-07-01

    We examined the hypothesis that the attention/executive deficits in mild cognitive impairment (MCI) due to Alzheimer's disease is associated to an abnormal cortical activation, revealed by the method of event-related synchronization/desynchronization (ERS/ERD) in the theta band during a paradigm of temporal orienting of attention. MCI patients (n = 25) and healthy elderly (HE) matched controls (n = 15) performed a task in which periodically omitted tones had to be predicted and their virtual onset time had to be marked by pressing a button. Single-trial theta responses were measured, respectively, before and after the motor response. Then, theta responses were compared to theta power during eyes closed resting state (ERD/ERS method).The temporal course of the task was characterized by two different behavioural conditions: (1) a pre-event epoch, in which the subject awaited the virtual onset of the omitted tone, (2) a post-event (after button pressing) epoch, in which the subject was in a post-motor response condition. The most important findings are summarized as follows: (1) in both groups, the pre-event epoch was characterized by theta ERS on temporal electrodes, but HE had a greater theta ERS compared to that of MCI group; (2) in both groups, during the post-motor condition, there was a theta ERS on prefrontal regions, and, also in this case, HE showed a greater theta enhancement compared to that of MCI patients; (3) HE showed evidence of lateralization: during the waiting epoch, theta ERS was dominant on the right posterior temporal lead (T6), whilst, during the post-motor epoch, theta ERS was greater on the left, as well as the midline prefrontal leads. Compared to the traditional neuropsychological measures for the episodic memory, these theta ERS indicators were less accurate in differentiating MCI patients from healthy elderly. The clinical relevance of these findings is that the weaker theta reactivity in MCI would indicate an early impairment in the

  13. Decrease of theta response in euthymic bipolar patients during an oddball paradigm.

    PubMed

    Atagün, M İ; Güntekin, B; Ozerdem, A; Tülay, E; Başar, E

    2013-06-01

    Theta oscillations are related to cognitive functions and reflect functional integration of frontal and medial temporal structures into coherent neurocognitive networks. This study assessed event-related theta oscillations in medication-free, euthymic patients with bipolar disorder upon auditory oddball paradigm. Twenty-two DSM-IV euthymic bipolar I (n = 19) and II (n = 3) patients and twenty-two healthy subjects were included. Patients were euthymic for at least 6 months, and psychotropic-free for at least 2 weeks. EEG was recorded at 30 electrode sites. Auditory oddball paradigm and sensory stimuli were used. Event-related Oscillations were analyzed using adaptive filtering in two different theta frequency bands (4-6 Hz, 6-8 Hz). In healthy subjects, slow theta (4-6 Hz) responses were significantly higher than those of euthymic patients upon target, non-target and sensory stimuli (p < 0.05). Fast theta (6-8 Hz) responses of healthy subjects were significantly higher than those of euthymic patients upon target-only stimuli (p < 0.05). Reduced theta oscillations during auditory processing provide strong quantitative evidence of activation deficits in related networks in bipolar disorder. Fast theta responses are related to cognitive functions, whereas slow theta responses are related to sensory processes more than cognitive processes. PMID:24427202

  14. Resonances, and mechanisms of Theta-production

    SciTech Connect

    Ya.I. Azimov; I.I. Strakovsky

    2004-09-01

    After explaining necessity of exotic hadrons, we discuss mechanisms which could determine production of the exotic Theta-baryon. A possible important role of resonances (producing the Theta in real or virtual decays) is emphasized for various processes. Several experimental directions for studies of such resonances, and the Theta itself, are suggested. We briefly discuss also recent negative results on the Theta-baryon.

  15. Treatment of giant congenital cysts of the midline in adults: Report of two cases and review of the literature

    PubMed Central

    Lauretti, Liverana; Mattogno, Pier Paolo; Bianchi, Federico; Pallini, Roberto; Fernandez, Eduardo; Doglietto, Francesco

    2015-01-01

    Background: Giant cysts of the midline, not associated to a tumor, are exceptional finding in the brain of adults. Here we present two cases of symptomatic giant cerebral cysts of the midline occurred in an elderly and in a young adult patients both treated with mini-invasive unilateral neuroendoscopic procedure. In the recent literature (since 1999) similar cases have not been reported. Beside the clinical report, review of literature and major anatomical features of the region are described. Case Description: These two adults (82 and 41 years old respectively) had a slow progressive development of headache, gait disturbances, memory impairment and urinary incontinence. Magnetic resonance imaging showed giant cyst of the midline and hydrocephalus. Surgery with the endoscopic procedure, through a right frontal burr hole, was followed by clinical and radiological improvement. Conclusion: Giant cerebral cysts of the midline in adults can be successfully treated through a neuroendoscopic monolateral approach that comprehends multiple openings, diffuse coagulation of the capsule, and careful releasing of capsule-ependyma adherences. Knowledge of major anatomical and developmental details of the septal region is necessary to avoid complication in a mini-invasive surgical procedure. PMID:26421217

  16. Pathology of 'non-healing (midline) granuloma'.

    PubMed Central

    Michaels, L; Gregory, M M

    1977-01-01

    In a histological study of biopsy and postmortem material from 30 cases of nasal disease in which a clinical diagnosis of 'midline granuloma' or Wegener's granuloma had been given, we selected 10 cases on the basis of the presence of widespread coagulative necrosis and atypical cells. Evidence is provided that such changes represent a malignant neoplasm of histiocytic lymphoma type. Local invasion and spread to cervical and more distant lymph nodes, spleen, liver, and kidney were seen in some of the cases. Erythrophagocytic activity was marked in the spleen in three cases and histiocytic infiltration of the bone marrow in two cases, indicating a more generalised activity of histiocytic cells. Terms such as 'malignant granuloma' should be abandoned. In obstructive and ulcerating conditions of the nose efforts should be concentrated on making an accurate histological diagnosis. Images PMID:323295

  17. Midline diastema and its aetiology--a review.

    PubMed

    Abraham, Reji; Kamath, Geetha

    2014-06-01

    Maxillary midline diastema is a common aesthetic complaint of patients. Treating the midline diastema is a matter of concern for practitioners, as many different aetiologies are reported to be associated with it. The appearance of midline diastema as part of the normal dental development makes it difficult for practitioners to decide whether to intervene or not at an early stage. The aim of this article is to review the possible aetiology and management options which will help the clinician to diagnose, intercept and to take effective action to correct the midline diastema. The available data shows that an early intervention is desirable in cases with large diastemas. Treatment modality, timing and retention protocol depends on the aetiology of the diastema. Therefore, priority needs to be given to diagnosing the aetiology before making any treatment decisions. Clinical Relevance: This article aims to determine and evaluate the aetiology and possible treatment options of midline diastema. PMID:25073229

  18. Association between theta power in 6-month old infants at rest and maternal PTSD severity: A pilot study.

    PubMed

    Sanjuan, Pilar M; Poremba, Carly; Flynn, Lucinda R; Savich, Renate; Annett, Robert D; Stephen, Julia

    2016-09-01

    Compared to infants born to mothers without PTSD, infants born to mothers with active PTSD develop poorer behavioral reactivity and emotional regulation. However, the association between perinatal maternal PTSD and infant neural activation remains largely unknown. This pilot study (N=14) examined the association between perinatal PTSD severity and infant frontal neural activity, as measured by MEG theta power during rest. Results indicated that resting left anterior temporal/frontal theta power was correlated with perinatal PTSD severity (p=0.004). These findings suggest delayed cortical maturation in infants whose mothers had higher perinatal PTSD severity and generate questions regarding perinatal PTSD severity and infant neurophysiological consequences. PMID:27473944

  19. The effects of theta transcranial alternating current stimulation (tACS) on fluid intelligence.

    PubMed

    Pahor, Anja; Jaušovec, Norbert

    2014-09-01

    The objective of the study was to explore the influence of transcranial alternating current stimulation (tACS) on resting brain activity and on measures of fluid intelligence. Theta tACS was applied to the left parietal and left frontal brain areas of healthy participants after which resting electroencephalogram (EEG) data was recorded. Following sham/active stimulation, the participants solved two tests of fluid intelligence while their EEG was recorded. The results showed that active theta tACS affected spectral power in theta and alpha frequency bands. In addition, active theta tACS improved performance on tests of fluid intelligence. This influence was more pronounced in the group of participants that received stimulation to the left parietal area than in the group of participants that received stimulation to the left frontal area. Left parietal tACS increased performance on the difficult test items of both tests (RAPM and PF&C) whereas left frontal tACS increased performance only on the easy test items of one test (RAPM). The observed behavioral tACS influences were also accompanied by changes in neuroelectric activity. The behavioral and neuroelectric data tentatively support the P-FIT neurobiological model of intelligence. PMID:24998643

  20. Coherent theta-band EEG activity predicts item-context binding during encoding.

    PubMed

    Summerfield, Christopher; Mangels, Jennifer A

    2005-02-01

    Episodic memories consist of semantic information coupled with a rich array of contextual detail. Here, we investigate the neural processes by which information about the sensory context of a learning event is "bound" to the semantic representation of the to-be-encoded item. We present evidence that item-context binding during encoding is mediated by frontoposterior electroencephalographic (EEG) phase locking within and between hemispheres in the theta (4-8 Hz) band. During a task in which subjects encoded words in different font colors, later memory for the word was associated with sustained frontal theta activity and frontoposterior theta-band coherence, primarily within the left hemisphere. When the word-color association was later successfully retrieved, however, neurons synchronized their theta-band responses bilaterally in a more sustained fashion, particularly during the latter part of the stimulus epoch (>800 ms). Our results confirm the importance of functional coupling between frontal and posterior regions for successful encoding. One interpretation of these data is hemispheric contributions to item and context encoding may be asymmetric, with left hemisphere coherence facilitating semantic processing of an item and right hemisphere coherence facilitating processing of sensory context. Theta-band coherence may be an important mechanism by which brain networks exchange information during learning. PMID:15652304

  1. Modulation of theta phase synchronization in the human electroencephalogram during a recognition memory task.

    PubMed

    Kim, Sung-Phil; Kang, Jae-Hwan; Choe, Seong-Hyun; Jeong, Ji Woon; Kim, Hyun Taek; Yun, Kyongsik; Jeong, Jaeseung; Lee, Seung-Hwan

    2012-08-01

    To the extent that recognition memory relies on interactions among widely distributed neural assemblies across the brain, phase synchronization between brain rhythms may play an important role in meditating those interactions. As the theta rhythm is known to modulate in power during the recognition memory process, we aimed to determine how the phase synchronization of the theta rhythms across the brain changes with recognition memory. Fourteen human participants performed a visual object recognition task in a virtual reality environment. Electroencephalograms were recorded from the scalp of the participants while they either recognized objects that had been presented previously or identified new objects. From the electroencephalogram recordings, we analyzed the phase-locking value of the theta rhythms, which indicates the degree of phase synchronization. We found that the overall phase-locking value recorded during the recognition of previously viewed objects was greater than that recorded during the identification of new objects. Specifically, the theta rhythms became strongly synchronized between the frontal and the left parietal areas during the recognition of previously viewed objects. These results suggest that the recognition memory process may involve an interaction between the frontal and the left parietal cortical regions mediated by theta phase synchronization. PMID:22610314

  2. Simultaneous correction of functional posterior cross bite and midline shift

    PubMed Central

    Arvinth, R.; Rana, Shailendra Singh; Duggal, Ritu; Kharbanda, Om Prakash

    2016-01-01

    The most frequent cause of functional posterior crossbite is the reduction in width of the maxillary dental arch. This posterior crossbite is associated with anterior crowding which is presented as an infrapositioned canine or a palatally positioned lateral incisor on one side; this leads to an upper midline shift toward the crowded side. The present case report shows the management of posterior crossbite with functional shift and upper midline shift simultaneously without adverse side effects. In this case, rapid maxillary expansion along with fixed appliance is used to correct posterior crossbite with the upper dental midline shift using reciprocal action of elastic transseptal fibers.

  3. Comparative drug screening in NUT midline carcinoma

    PubMed Central

    Beesley, A H; Stirnweiss, A; Ferrari, E; Endersby, R; Howlett, M; Failes, T W; Arndt, G M; Charles, A K; Cole, C H; Kees, U R

    2014-01-01

    Background: The NUT midline carcinoma (NMC) is a rare but fatal cancer for which systematic testing of therapy options has never been performed. Methods: On the basis of disease biology, we compared the efficacy of the CDK9 inhibitor flavopiridol (FP) with a panel of anticancer agents in NMC cell lines and mouse xenografts. Results: In vitro anthracyclines, topoisomerase inhibitors, and microtubule poisons were among the most cytotoxic drug classes for NMC cells, while efficacy of the bromodomain inhibitor JQ1 varied considerably between lines carrying different BRD4 (bromodomain-containing protein 4)–NUT (nuclear protein in testis) translocations. Efficacy of FP was comparable to vincristine and doxorubicin, drugs that have been previously used in NMC patients. All three compounds showed significantly better activity than etoposide and vorinostat, agents that have also been used in NMC patients. Statins and antimetabolites demonstrated intermediate single-agent efficacy. In vivo, vincristine significantly inhibited tumour growth in two different NMC xenografts. Flavopiridol in vivo was significantly effective in one of the two NMC xenograft lines, demonstrating the biological heterogeneity of this disease. Conclusions: These results demonstrate that FP may be of benefit to a subset of patients with NMC, and warrant a continued emphasis on microtubule inhibitors, anthracyclines, and topoisomerase inhibitors as effective drug classes in this disease. PMID:24518598

  4. Midline Anterior Craniofacial Approach for Malignancy

    PubMed Central

    Wellman, Bryan John; Traynelis, Vincent C.; McCulloch, Timothy M.; Funk, Gerry F.; Menezes, Arnold H.; Hoffman, Henry T.

    1999-01-01

    Thirty consecutive cases of midline anterior craniofacial procedures for the treatment of malignant neoplasms arising from the paranasal sinuses were reviewed. Posterior and lateral base craniofacial procedures were specifically excluded. This review compares the results, in terms of survival and major complication rate, between en bloc and piecemeal resections. The average follow-up was 4 years and 3 months. Sixteen patients were treated with an en bloc resection. The major complication rate was 31%. One-year survival rate was 94% for the en bloc resection group, 67% for patients with positive margins, and 100% for patients with clear margins. Three-year survival for en bloc resection dropped to 56, 33, and 67%, respectively. Fourteen patients were treated with piecemeal resections. The major complication rate was 21%. One-year survival rate was 83% for the piecemeal resection group, 60% for patients with positive margins, and 100% for patients with clear margins. Three-year survival dropped to 70, 60, and 80%, respectively. Although it is considered desirable to obtain an en bloc resection in some craniofacial procedures, we conclude that a piecemeal resection is a viable alternative in situations where an en bloc procedure is difficult to obtain safely. ImagesFigure 1p43-bFigure 2p44-b PMID:17171080

  5. Regional and inter-regional theta oscillation during episodic novelty processing.

    PubMed

    Lee, Gwan-Taek; Lee, Chany; Kim, Kyung Hwan; Jung, Ki-Young

    2014-10-01

    Recent event-related potential (ERP) and functional magnetic resonance imaging (fMRI) studies suggest that novelty processing may be involved in processes that recognize the meaning of a novel sound, during which widespread cortical regions including the right prefrontal cortex are engaged. However, it remains unclear how those cortical regions are functionally integrated during novelty processing. Because theta oscillation has been assumed to have a crucial role in memory operations, we examined local and inter-regional neural synchrony of theta band activity during novelty processing. Fifteen right-handed healthy university students participated in this study. Subjects performed an auditory novelty oddball task that consisted of the random sequence of three types of stimuli such as a target (1000Hz pure tone), novel (familiar environmental sounds such as dog bark, buzz, car crashing sound and so on), and standard sounds (950Hz pure tone). Event-related spectra perturbation (ERSP) and the phase-locking value (PLV) were measured from human scalp EEG during task. Non-parametric statistical tests were applied to test for significant differences between stimulus novelty and stimulus targets in ERSP and PLV. The novelty P3 showed significant higher amplitude and shorter latency compared with target P3 in frontocentral regions. Overall, theta activity was significantly higher in the novel stimuli compared with the target stimuli. Specifically, the difference in theta power between novel and target stimuli was most significant in the right frontal region. This right frontal theta activity was accompanied by phase synchronization with the left temporal region. Our results imply that theta phase synchronization between right frontal and left temporal regions underlie the retrieval of memory traces for unexpected but familiar sounds from long term memory in addition to working memory retrieval or novelty encoding. PMID:25014407

  6. Midline Body Actions and Leftward Spatial "Aiming" in Patients with Spatial Neglect.

    PubMed

    Chaudhari, Amit; Pigott, Kara; Barrett, A M

    2015-01-01

    Spatial motor-intentional "Aiming" bias is a dysfunction in initiation/execution of motor-intentional behavior, resulting in hypokinetic and hypometric leftward movements. Aiming bias may contribute to posture, balance, and movement problems and uniquely account for disability in post-stroke spatial neglect. Body movement may modify and even worsen Aiming errors, but therapy techniques, such as visual scanning training, do not take this into account. Here, we evaluated (1) whether instructing neglect patients to move midline body parts improves their ability to explore left space and (2) whether this has a different impact on different patients. A 68-year-old woman with spatial neglect after a right basal ganglia infarct had difficulty orienting to and identifying left-sided objects. She was prompted with four instructions: "look to the left," "point with your nose to the left," "point with your [right] hand to the left," and "stick out your tongue and point it to the left." She oriented leftward dramatically better when pointing with the tongue/nose, than she did when pointing with the hand. We then tested nine more consecutive patients with spatial neglect using the same instructions. Only four of them made any orienting errors. Only one patient made >50% errors when pointing with the hand, and she did not benefit from pointing with the tongue/nose. We observed that pointing with the tongue could facilitate left-sided orientation in a stroke survivor with spatial neglect. If midline structures are represented more bilaterally, they may be less affected by Aiming bias. Alternatively, moving the body midline may be more permissive for leftward orienting than moving right body parts. We were not able to replicate this effect in another patient; we suspect that the magnitude of this effect may depend upon the degree to which patients have directional akinesia, spatial Where deficits, or cerebellar/frontal cortical lesions. Future research could examine these

  7. Conservation of arthropod midline netrin accumulation revealed with a cross-reactive antibody provides evidence for midline cell homology

    PubMed Central

    Simanton, Wendy; Clark, Stephanie; Clemons, Anthony; Jacowski, Caitlin; Farrell-VanZomeren, Adrienne; Beach, Paul; Browne, William E.; Duman-Scheel, Molly

    2009-01-01

    SUMMARY Although many similarities in arthropod CNS development exist, differences in axonogenesis and the formation of midline cells, which regulate axon growth, have been observed. For example, axon growth patterns in the ventral nerve cord of Artemia franciscana differ from that of Drosophila melanogaster. Despite such differences, conserved molecular marker expression at the midline of several arthropod species indicates that midline cells may be homologous in distantly related arthropods. However, data from additional species are needed to test this hypothesis. In this investigation, nerve cord formation and the putative homology of midline cells were examined in distantly related arthropods, including: long- and short-germ insects (D. melanogaster, Aedes aeygypti, and Tribolium castaneum), branchiopod crustaceans (A. franciscana and Triops longicauditus), and malacostracan crustaceans (Porcellio laevis and Parhyale hawaiensis). These comparative analyses were aided by a cross-reactive antibody generated against the Netrin (Net) protein, a midline cell marker and regulator of axonogenesis. The mechanism of nerve cord formation observed in Artemia is found in Triops, another branchiopod, but is not found in the other arthropods examined. Despite divergent mechanisms of midline cell formation and nerve cord development, Net accumulation is detected in a well-conserved subset of midline cells in branchiopod crustaceans, malacostracan crustaceans, and insects. Notably, the Net accumulation pattern is also conserved at the midline of the amphipod P. hawaiensis, which undergoes split germ-band development. Conserved Net accumulation patterns indicate that arthropod midline cells are homologous, and that Nets function to regulate commissure formation during CNS development of Tetraconata. PMID:19469853

  8. Oscillatory dynamics coordinating human frontal networks in support of goal maintenance.

    PubMed

    Voytek, Bradley; Kayser, Andrew S; Badre, David; Fegen, David; Chang, Edward F; Crone, Nathan E; Parvizi, Josef; Knight, Robert T; D'Esposito, Mark

    2015-09-01

    Humans have a capacity for hierarchical cognitive control-the ability to simultaneously control immediate actions while holding more abstract goals in mind. Neuropsychological and neuroimaging evidence suggests that hierarchical cognitive control emerges from a frontal architecture whereby prefrontal cortex coordinates neural activity in the motor cortices when abstract rules are needed to govern motor outcomes. We utilized the improved temporal resolution of human intracranial electrocorticography to investigate the mechanisms by which frontal cortical oscillatory networks communicate in support of hierarchical cognitive control. Responding according to progressively more abstract rules resulted in greater frontal network theta phase encoding (4-8 Hz) and increased prefrontal local neuronal population activity (high gamma amplitude, 80-150 Hz), which predicts trial-by-trial response times. Theta phase encoding coupled with high gamma amplitude during inter-regional information encoding, suggesting that inter-regional phase encoding is a mechanism for the dynamic instantiation of complex cognitive functions by frontal cortical subnetworks. PMID:26214371

  9. On Ramanujan's definition of mock theta function.

    PubMed

    Rhoades, Robert C

    2013-05-01

    In his famous "deathbed" letter, Ramanujan "defined" the notion of a mock theta function and offered some examples of functions he believed satisfied his definition. Very recently, Griffin et al. established for the first time that Ramanujan's mock theta functions actually satisfy his own definition. On the other hand, Zwegers' 2002 doctoral thesis [Zwegers S (2002) Mock theta functions. PhD thesis (Univ Utrecht, Utrecht, The Netherlands)] showed that all of Ramanujan's examples are holomorphic parts of harmonic Maass forms. This has led to an alternate definition of a mock theta function. This paper shows that Ramanujan's definition of mock theta function is not equivalent to the modern definition. PMID:23625007

  10. Genetic variability in the human cannabinoid receptor 1 is associated with resting state EEG theta power in humans.

    PubMed

    Heitland, I; Kenemans, J L; Böcker, K B E; Baas, J M P

    2014-11-01

    It has long been postulated that exogenous cannabinoids have a profound effect on human cognitive functioning. These cannabinoid effects are thought to depend, at least in parts, on alterations of phase-locking of local field potential neuronal firing. The latter can be measured as activity in the theta frequency band (4-7Hz) by electroencephalogram. Theta oscillations are supposed to serve as a mechanism in neural representations of behaviorally relevant information. However, it remains unknown whether variability in endogenous cannabinoid activity is involved in theta rhythms and therefore, may serve as an individual differences index of human cognitive functioning. To clarify this issue, we recorded resting state EEG activity in 164 healthy human subjects and extracted EEG power across frequency bands (δ, θ, α, and β). To assess variability in the endocannabinoid system, two genetic polymorphisms (rs1049353, rs2180619) within the cannabinoid receptor 1 (CB1) were determined in all participants. As expected, we observed significant effects of rs1049353 on EEG power in the theta band at frontal, central and parietal electrode regions. Crucially, these effects were specific for the theta band, with no effects on activity in the other frequency bands. Rs2180619 showed no significant associations with theta power after Bonferroni correction. Taken together, we provide novel evidence in humans showing that genetic variability in the cannabinoid receptor 1 is associated with resting state EEG power in the theta frequency band. This extends prior findings of exogenous cannabinoid effects on theta power to the endogenous cannabinoid system. PMID:25116250

  11. EEG theta and Mu oscillations during perception of human and robot actions.

    PubMed

    Urgen, Burcu A; Plank, Markus; Ishiguro, Hiroshi; Poizner, Howard; Saygin, Ayse P

    2013-01-01

    The perception of others' actions supports important skills such as communication, intention understanding, and empathy. Are mechanisms of action processing in the human brain specifically tuned to process biological agents? Humanoid robots can perform recognizable actions, but can look and move differently from humans, and as such, can be used in experiments to address such questions. Here, we recorded EEG as participants viewed actions performed by three agents. In the Human condition, the agent had biological appearance and motion. The other two conditions featured a state-of-the-art robot in two different appearances: Android, which had biological appearance but mechanical motion, and Robot, which had mechanical appearance and motion. We explored whether sensorimotor mu (8-13 Hz) and frontal theta (4-8 Hz) activity exhibited selectivity for biological entities, in particular for whether the visual appearance and/or the motion of the observed agent was biological. Sensorimotor mu suppression has been linked to the motor simulation aspect of action processing (and the human mirror neuron system, MNS), and frontal theta to semantic and memory-related aspects. For all three agents, action observation induced significant attenuation in the power of mu oscillations, with no difference between agents. Thus, mu suppression, considered an index of MNS activity, does not appear to be selective for biological agents. Observation of the Robot resulted in greater frontal theta activity compared to the Android and the Human, whereas the latter two did not differ from each other. Frontal theta thus appears to be sensitive to visual appearance, suggesting agents that are not sufficiently biological in appearance may result in greater memory processing demands for the observer. Studies combining robotics and neuroscience such as this one can allow us to explore neural basis of action processing on the one hand, and inform the design of social robots on the other. PMID:24348375

  12. EEG theta and Mu oscillations during perception of human and robot actions

    PubMed Central

    Urgen, Burcu A.; Plank, Markus; Ishiguro, Hiroshi; Poizner, Howard; Saygin, Ayse P.

    2013-01-01

    The perception of others’ actions supports important skills such as communication, intention understanding, and empathy. Are mechanisms of action processing in the human brain specifically tuned to process biological agents? Humanoid robots can perform recognizable actions, but can look and move differently from humans, and as such, can be used in experiments to address such questions. Here, we recorded EEG as participants viewed actions performed by three agents. In the Human condition, the agent had biological appearance and motion. The other two conditions featured a state-of-the-art robot in two different appearances: Android, which had biological appearance but mechanical motion, and Robot, which had mechanical appearance and motion. We explored whether sensorimotor mu (8–13 Hz) and frontal theta (4–8 Hz) activity exhibited selectivity for biological entities, in particular for whether the visual appearance and/or the motion of the observed agent was biological. Sensorimotor mu suppression has been linked to the motor simulation aspect of action processing (and the human mirror neuron system, MNS), and frontal theta to semantic and memory-related aspects. For all three agents, action observation induced significant attenuation in the power of mu oscillations, with no difference between agents. Thus, mu suppression, considered an index of MNS activity, does not appear to be selective for biological agents. Observation of the Robot resulted in greater frontal theta activity compared to the Android and the Human, whereas the latter two did not differ from each other. Frontal theta thus appears to be sensitive to visual appearance, suggesting agents that are not sufficiently biological in appearance may result in greater memory processing demands for the observer. Studies combining robotics and neuroscience such as this one can allow us to explore neural basis of action processing on the one hand, and inform the design of social robots on the other. PMID

  13. Tensile Properties of the Murine Ventral Vertical Midline Incision

    PubMed Central

    Carlson, Mark A.; Chakkalakal, Dennis

    2011-01-01

    Background In clinical surgery, the vertical midline abdominal incision is popular but associated with healing failures. A murine model of the ventral vertical midline incision was developed in order to study the healing of this incision type. Methodology/Principal Findings The strength of the wild type murine ventral abdominal wall in the midline was contained within the dermis; the linea alba made a negligible contribution. Unwounded abdominal wall had a downward trend (nonsignificant) in maximal tension between 12 and 29 weeks of age. The incision attained 50% of its final strength by postoperative day 40. The maximal tension of the ventral vertical midline incision was nearly that of unwounded abdominal wall by postwounding day 60; there was no difference in unwounded vs. wounded maximal tension at postwounding day 120. Conclusions/Significance After 120 days of healing, the ventral vertical midline incision in the wild type mouse was not significantly different from age-matched nonwounded controls. About half of the final incisional strength was attained after 6 weeks of healing. The significance of this work was to establish the kinetics of wild type incisional healing in a model for which numerous genotypes and genetic tools would be available for subsequent study. PMID:21915298

  14. Uncovertebral Anatomic Midline Targeting for Cervical Disc Arthroplasty

    PubMed Central

    Bednar, Drew A.

    2012-01-01

    Study Design Prospective observational cohort. Objective To document the accuracy of uncovertebral anatomic targeting in positioning cervical disc arthroplasty. Summary of Background Data Disc arthroplasty implants depend on midline placement for optimum mechanical function. Fluoroscopy is used to delineate the midline. Anatomic targeting from the uncovertebral joints in the neck may be adequate. We have investigated the efficacy of uncovertebral anatomic targeting for cervical disc arthroplasty. Methods Anatomic uncovertebral midline targeting for disc arthroplasty insertion was performed in 18 male (mean age 51 years, range 27 to 67) and 22 female (mean age 50, range 35 to 70) patients receiving a total of 59 implants over a 5-year period. Device insertion was under only lateral imaging control. Postinsertion operative fluoroscopy with optimized centering was used to record implant position in the anteroposterior plane, and centerline analysis was performed using cursor measurement technology from the GE PACS™ imaging system (GE Medical Systems, Mt. Prospect, IL). Results Analysis found a mean deviation from the ideal midline placement of only 0.7 mm (range, 0 to 2.9 mm). Only three devices were more than 2 mm off the anatomic midline. Conclusion This anatomic technique is effective, safely minimizing imaging resource needs and X-ray exposure to the patient and operating team. PMID:24353946

  15. A midline for oxaliplatin infusion: the myth of safety devices

    PubMed Central

    Masters, Ben; Hickish, Tamas; Uña Cidon, Esther

    2014-01-01

    Oxaliplatin is a platinum compound mainly used in the treatment of colorectal cancer. According to its manufacturer it is not considered vesicant agent though it has been shown to cause severe tissue damage if extravasation occurs in large doses. Several cases of extravasation have been reported; most of them from incorrectly placed peripheral cannula or incorrect use of central venous access devices. To reduce these risks, peripherally inserted central catheters and midline catheters have been increasingly used and are especially helpful if poor peripheral venous access. Midlines are mainly used for patients not receiving vesicant drugs, and are generally inserted without radiological guidance. They are believed to be safe, but we present the first ever-documented oxaliplatin extravasation injury from a midline catheter. PMID:24903726

  16. Traveling Theta Waves in the Human Hippocampus.

    PubMed

    Zhang, Honghui; Jacobs, Joshua

    2015-09-01

    The hippocampal theta oscillation is strongly correlated with behaviors such as memory and spatial navigation, but we do not understand its specific functional role. One hint of theta's function came from the discovery in rodents that theta oscillations are traveling waves that allow parts of the hippocampus to simultaneously exhibit separate oscillatory phases. Because hippocampal theta oscillations in humans have different properties compared with rodents, we examined these signals directly using multielectrode recordings from neurosurgical patients. Our findings confirm that human hippocampal theta oscillations are traveling waves, but also show that these oscillations appear at a broader range of frequencies compared with rodents. Human traveling waves showed a distinctive pattern of spatial propagation such that there is a consistent phase spread across the hippocampus regardless of the oscillations' frequency. This suggests that traveling theta oscillations are important functionally in humans because they coordinate phase coding throughout the hippocampus in a consistent manner. Significance statement: We show for the first time in humans that hippocampal theta oscillations are traveling waves, moving along the length of the hippocampus in a posterior-anterior direction. The existence of these traveling theta waves is important for understanding hippocampal neural coding because they cause neurons at separate positions in the hippocampus to experience different theta phases simultaneously. The theta phase that a neuron measures is a key factor in how that cell represents behavioral information. Therefore, the existence of traveling theta waves indicates that, to fully understand how a hippocampal neuron represents information, it is vital to also account for that cell's location in addition to conventional measures of neural activity. PMID:26354915

  17. Numerical experiments on the theta pinch

    NASA Technical Reports Server (NTRS)

    Volosevich, P. P.; Zukakishyili, G. G.

    1979-01-01

    Numerical calculation of theta pinch problems are presented. Physical processes in theta pinch systems are considered in a one dimensional, two temperature magnetohydrodynamic, approximation with allowance for end losses by longitudinal heat conductivity. The numerical calculations are compared with results of earlier experiments.

  18. Midline Body Actions and Leftward Spatial “Aiming” in Patients with Spatial Neglect

    PubMed Central

    Chaudhari, Amit; Pigott, Kara; Barrett, A. M.

    2015-01-01

    Spatial motor–intentional “Aiming” bias is a dysfunction in initiation/execution of motor–intentional behavior, resulting in hypokinetic and hypometric leftward movements. Aiming bias may contribute to posture, balance, and movement problems and uniquely account for disability in post-stroke spatial neglect. Body movement may modify and even worsen Aiming errors, but therapy techniques, such as visual scanning training, do not take this into account. Here, we evaluated (1) whether instructing neglect patients to move midline body parts improves their ability to explore left space and (2) whether this has a different impact on different patients. A 68-year-old woman with spatial neglect after a right basal ganglia infarct had difficulty orienting to and identifying left-sided objects. She was prompted with four instructions: “look to the left,” “point with your nose to the left,” “point with your [right] hand to the left,” and “stick out your tongue and point it to the left.” She oriented leftward dramatically better when pointing with the tongue/nose, than she did when pointing with the hand. We then tested nine more consecutive patients with spatial neglect using the same instructions. Only four of them made any orienting errors. Only one patient made >50% errors when pointing with the hand, and she did not benefit from pointing with the tongue/nose. We observed that pointing with the tongue could facilitate left-sided orientation in a stroke survivor with spatial neglect. If midline structures are represented more bilaterally, they may be less affected by Aiming bias. Alternatively, moving the body midline may be more permissive for leftward orienting than moving right body parts. We were not able to replicate this effect in another patient; we suspect that the magnitude of this effect may depend upon the degree to which patients have directional akinesia, spatial Where deficits, or cerebellar/frontal cortical lesions. Future research

  19. Frontal Fibrosing Alopecia.

    PubMed

    Holmes, S

    2016-07-01

    Frontal fibrosing alopecia, described just over 20 years ago, has become one of the most frequently seen causes of scarring alopecia at many specialist hair clinics. Considered a clinical variant of lichen planopilaris (LPP), it has distinctive features and associations which distinguish it from LPP. Although largely affecting postmenopausal women, a small but increasing number of men and premenopausal women are affected. The spectrum of the disease has expanded from involvement of the frontal hairline and eyebrows, to potentially affecting the entire hairline, facial and body hair. Genetic and environmental factors have been implicated but the aetiology remains uncertain. A range of treatments have been used in management of the condition, but clinical trials are required to establish effectiveness. PMID:27388531

  20. Frontal Polymerization in Microgravity

    NASA Technical Reports Server (NTRS)

    Pojman, John A.

    1999-01-01

    Frontal polymerization systems, with their inherent large thermal and compositional gradients, are greatly affected by buoyancy-driven convection. Sounding rocket experiments allowed the preparation of benchmark materials and demonstrated that methods to suppress the Rayleigh-Taylor instability in ground-based research did not significantly affect the molecular weight of the polymer. Experiments under weightlessness show clearly that bubbles produced during the reaction interact very differently than under 1 g.

  1. [Frontal mucocele: open surgery].

    PubMed

    Pia, F; Aluffi, P; Borello, G

    1999-06-01

    This work presents 13 cases of frontal mucoceles, 9 with endo-orbital extension. All were treated with 'open surgery': 11 using a fronto-orbital approach, 2 with a bicoronal Cairns-Unterberger approach. Four patients had recurrent mucoceles 1-20 years after the previous surgery. In one case there was an association with frontal osteoma. In 10 cases, conservative treatment was applied through repermeabilization of the infundibular region through an external, endonasal pathway and positioning of a nasal sinus drainage tube (kept in place for 4 weeks). In the remaining 3 cases, the sinus cavity was obliterated with autologous abdominal fat. This choice was made because of the presence of osteomyelitic foci, in one case mucopioceles, or by the widespread dural exposure encountered during the course of surgery. Two cases of post-operative sinus reinfection were encountered: one underwent surgical revision, the other was an orbital site recurrence arising 7 years after previous surgical obliteration of the frontal sinus. The esthetic result was unsatisfactory in 2 patients treated with a trans-facial approach. Ten patients were disease free after an average 56 months of follow-up. Although functional endoscopic surgery undoubtedly makes it possible to achieve excellent results in the treatment of most sinus mucoceles, open surgery remains a valid procedure in frontal mucoceles with orbital and/or endocranial extension and in cases where the district anatomy is unfavorable for a purely endonasal approach. The indications and limitations of open surgery are critically discussed in the light of personal experience and current literature. PMID:10546373

  2. Lower theta inter-trial phase coherence during performance monitoring is related to higher reaction time variability: a lifespan study.

    PubMed

    Papenberg, Goran; Hämmerer, Dorothea; Müller, Viktor; Lindenberger, Ulman; Li, Shu-Chen

    2013-12-01

    Trial-to-trial reaction time (RT) variability is consistently higher in children and older adults than in younger adults. Converging evidence also indicates that higher RT variability is (a) associated with lower behavioral performance on complex cognitive tasks, (b) distinguishes patients with neurological deficits from healthy individuals, and also (c) predicts longitudinal cognitive decline in older adults. However, so far the processes underlying increased RT variability are poorly understood. Previous evidence suggests that control signals in the medial frontal cortex (MFC) are reflected in theta band activity and may implicate the coordination of distinct brain areas during performance monitoring. We hypothesized that greater trial-to-trial variability in theta power during performance monitoring may be associated with greater behavioral variability in response latencies. We analyzed event-related theta oscillations assessed during a cued-Go/NoGo task in a lifespan sample covering the age range from middle childhood to old age. Our results show that theta inter-trial coherence during NoGo trials increases from childhood to early adulthood, and decreases from early adulthood to old age. Moreover, in all age groups, individuals with higher variability in medial frontal stimulus-locked theta oscillations showed higher trial-to-trial RT variability behaviorally. Importantly, this effect was strongest at high performance monitoring demands and independent of motor response execution as well as theta power. Taken together, our findings reveal that lower theta inter-trial coherence is related to greater behavioral variability within and across age groups. These results hint at the possibility that more variable MFC control may be associated with greater performance fluctuations. PMID:23876249

  3. Concurrent working memory task decreases the Stroop interference effect as indexed by the decreased theta oscillations.

    PubMed

    Zhao, Y; Tang, D; Hu, L; Zhang, L; Hitchman, G; Wang, L; Chen, A

    2014-03-14

    Working memory (WM) tasks may increase or decrease the interference effect of concurrently performed cognitive control tasks. However, the neural oscillatory correlates of this modulation effect of WM on the Stroop task are still largely unknown. In the present study, behavioral and electroencephalographic (EEG) data were recorded from 32 healthy participants during their performance of the single Stroop task and the same task with a concurrent WM task. We observed that the Stroop interference effect represented in both response times (RTs) and theta-band event-related spectral perturbation (ERSP) magnitude reduced under the dual-task condition compared with the single-task condition. The reduction of interference in theta-band ERSP was further positively correlated with interference reduction in RTs, and was mainly explained by the source in the left middle frontal gyrus. In conclusion, the present study suggests that the effect of concurrent WM tasks on the reduction of the Stroop interference effect can be indexed by EEG oscillations in theta-band rhythm in the centro-frontal regions and this modulation was mediated by the reduced cognitive control under the concurrent WM task. PMID:24406438

  4. Midline (Central) Fluid Percussion Model of Traumatic Brain Injury.

    PubMed

    Rowe, Rachel K; Griffiths, Daniel R; Lifshitz, Jonathan

    2016-01-01

    Research models of traumatic brain injury (TBI) hold significant validity towards the human condition, with each model replicating a subset of clinical features and symptoms. After 30 years of characterization and implementation, fluid percussion injury (FPI) is firmly recognized as a clinically relevant model of TBI, encompassing concussion through severe injury. The midline variation of FPI may best represent mild and diffuse clinical brain injury, because of the acute behavioral deficits, the late onset of subtle behavioral morbidities, and the absence of gross histopathology. This chapter outlines the procedures for midline (diffuse) FPI in adult male rats and mice. With these procedures, it becomes possible to generate brain-injured laboratory animals for studies of injury-induced pathophysiology and behavioral deficits, for which rational therapeutic interventions can be implemented. PMID:27604721

  5. The midline metathoracic ear of the praying mantis, Mantis religiosa.

    PubMed

    Yager, D D; Hoy, R R

    1987-12-01

    The praying mantis, Mantis religiosa, is unique in possessing a single, tympanal auditory organ located in the ventral midline of its body between the metathoracic coxae. The ear is in a deep groove and consists of two tympana facing each other and backed by large air sacs. Neural transduction takes place in a structure at the anterior end of the groove. This tympanal organ contains 32 chordotonal sensilla organized into three groups, two of which are 180 degrees out of line with the one attaching directly to the tympanum. Innervation is provided by Nerve root 7 from the metathoracic ganglion. Cobalt backfills show that the auditory neuropile is a series of finger-like projections terminating ipsilaterally near the midline, primarily near DC III and SMC. The auditory neuropile thus differs from the pattern common to all other insects previously studied. PMID:3690633

  6. Individual differences in EEG theta and alpha dynamics during working memory correlate with fMRI responses across subjects

    PubMed Central

    Meltzer, Jed A.; Negishi, Michiro; Mayes, Linda C.; Constable, R. Todd

    2007-01-01

    Objective Theta and alpha range EEG oscillations are commonly induced in cognitive tasks, but their possible relationship to the BOLD signal of fMRI is not well understood, and individual variability is high. We explored individual differences in EEG reactivity to determine whether it is positively or negatively correlated with BOLD across subjects. Methods A Sternberg working memory task with 2, 4, or 6 digits was administered to 18 subjects in separate fMRI and EEG sessions. Memory load dependent theta and alpha reactivity was quantified and used as a regressor to reveal brain areas exhibiting EEG-fMRI correlation across subjects. Results Theta increases localized to medial prefrontal cortex, and correlated negatively with BOLD in that region and in other “default mode” areas. Alpha modulation localized to parietal-occipital midline cortex and also correlated negatively with BOLD. Conclusions Individual tendencies to exhibit memory-load dependent oscillations are associated with negative BOLD responses certain brain regions. Significance Positive BOLD responses and increased EEG oscillations do not necessarily arise in the same regions. Negative BOLD responses may also relate to cognitive activity, as traditionally indexed by increased EEG power in the theta band. PMID:17900976

  7. Closure of large midline diastema by a "HIV-Spring".

    PubMed

    Harikrishnan, Pandurangan

    2015-01-01

    Midline diastema is a common orthodontic problem in mixed dentition caused by various factors like genetic, supernumery teeth, abnormal frenum attachment, habits and microdontia etc. Large diastemas need closure for the eruption of adjacent teeth. I present here a newly designed customized self active HIV-Spring (Hari Inverted 'V' Spring) for closing a large diastema with minimum orthodontic materials and less activation visits. The spring can be modfied for the three dimensional movement of central incisors. PMID:25881378

  8. Robotic Anterior and Midline Skull Base Surgery: Preclinical Investigations

    SciTech Connect

    O'Malley, Bert W. Weinstein, Gregory S.

    2007-10-01

    Purpose: To develop a minimally invasive surgical technique to access the midline and anterior skull base using the optical and technical advantages of robotic surgical instrumentation. Methods and Materials: Ten experimental procedures focusing on approaches to the nasopharynx, clivus, sphenoid, pituitary sella, and suprasellar regions were performed on one cadaver and one live mongrel dog. Both the cadaver and canine procedures were performed in an approved training facility using the da Vinci Surgical Robot. For the canine experiments, a transoral robotic surgery (TORS) approach was used, and for the cadaver a newly developed combined cervical-transoral robotic surgery (C-TORS) approach was investigated and compared with standard TORS. The ability to access and dissect tissues within the various areas of the midline and anterior skull base were evaluated, and techniques to enhance visualization and instrumentation were developed. Results: Standard TORS approaches did not provide adequate access to the midline and anterior skull base; however, the newly developed C-TORS approach was successful in providing the surgical access to these regions of the skull base. Conclusion: Robotic surgery is an exciting minimally invasive approach to the skull base that warrants continued preclinical investigation and development.

  9. Note on trigonometric expansions of theta functions

    NASA Astrophysics Data System (ADS)

    Chouikha, A. Raouf

    2003-04-01

    We are interested in properties of coefficients of certain expansions of the classical theta functions. We show that they are solutions of a differential system derived from the heat equation. We plan to explicitly give expressions of these coefficients.

  10. Human hippocampal theta activity during virtual navigation.

    PubMed

    Ekstrom, Arne D; Caplan, Jeremy B; Ho, Emily; Shattuck, Kirk; Fried, Itzhak; Kahana, Michael J

    2005-01-01

    This study examines whether 4-8-Hz theta oscillations can be seen in the human hippocampus, and whether these oscillations increase during virtual movement and searching, as they do in rodents. Recordings from both hippocampal and neocortical depth electrodes were analyzed while six epileptic patients played a virtual taxi-driver game. During the game, the patients alternated between searching for passengers, whose locations were random, and delivering them to stores, whose locations remained constant. In both hippocampus and neocortex, theta increased during virtual movement in all phases of the game. Hippocampal and neocortical theta activity were also significantly correlated with each other, but this correlation did not differ between neocortex and hippocampus and within disparate neocortical electrodes. Our findings demonstrate the existence of movement-related theta oscillations in human hippocampus, and suggest that both cortical and hippocampal oscillations play a role in attention and sensorimotor integration. PMID:16114040

  11. Sensory and spinal inhibitory dorsal midline crossing is independent of Robo3

    PubMed Central

    Comer, John D.; Pan, Fong Cheng; Willet, Spencer G.; Haldipur, Parthiv; Millen, Kathleen J.; Wright, Christopher V. E.; Kaltschmidt, Julia A.

    2015-01-01

    Commissural neurons project across the midline at all levels of the central nervous system (CNS), providing bilateral communication critical for the coordination of motor activity and sensory perception. Midline crossing at the spinal ventral midline has been extensively studied and has revealed that multiple developmental lineages contribute to this commissural neuron population. Ventral midline crossing occurs in a manner dependent on Robo3 regulation of Robo/Slit signaling and the ventral commissure is absent in the spinal cord and hindbrain of Robo3 mutants. Midline crossing in the spinal cord is not limited to the ventral midline, however. While prior anatomical studies provide evidence that commissural axons also cross the midline dorsally, little is known of the genetic and molecular properties of dorsally-crossing neurons or of the mechanisms that regulate dorsal midline crossing. In this study, we describe a commissural neuron population that crosses the spinal dorsal midline during the last quarter of embryogenesis in discrete fiber bundles present throughout the rostrocaudal extent of the spinal cord. Using immunohistochemistry, neurotracing, and mouse genetics, we show that this commissural neuron population includes spinal inhibitory neurons and sensory nociceptors. While the floor plate and roof plate are dispensable for dorsal midline crossing, we show that this population depends on Robo/Slit signaling yet crosses the dorsal midline in a Robo3-independent manner. The dorsally-crossing commissural neuron population we describe suggests a substrate circuitry for pain processing in the dorsal spinal cord. PMID:26257608

  12. Sensory and spinal inhibitory dorsal midline crossing is independent of Robo3.

    PubMed

    Comer, John D; Pan, Fong Cheng; Willet, Spencer G; Haldipur, Parthiv; Millen, Kathleen J; Wright, Christopher V E; Kaltschmidt, Julia A

    2015-01-01

    Commissural neurons project across the midline at all levels of the central nervous system (CNS), providing bilateral communication critical for the coordination of motor activity and sensory perception. Midline crossing at the spinal ventral midline has been extensively studied and has revealed that multiple developmental lineages contribute to this commissural neuron population. Ventral midline crossing occurs in a manner dependent on Robo3 regulation of Robo/Slit signaling and the ventral commissure is absent in the spinal cord and hindbrain of Robo3 mutants. Midline crossing in the spinal cord is not limited to the ventral midline, however. While prior anatomical studies provide evidence that commissural axons also cross the midline dorsally, little is known of the genetic and molecular properties of dorsally-crossing neurons or of the mechanisms that regulate dorsal midline crossing. In this study, we describe a commissural neuron population that crosses the spinal dorsal midline during the last quarter of embryogenesis in discrete fiber bundles present throughout the rostrocaudal extent of the spinal cord. Using immunohistochemistry, neurotracing, and mouse genetics, we show that this commissural neuron population includes spinal inhibitory neurons and sensory nociceptors. While the floor plate and roof plate are dispensable for dorsal midline crossing, we show that this population depends on Robo/Slit signaling yet crosses the dorsal midline in a Robo3-independent manner. The dorsally-crossing commissural neuron population we describe suggests a substrate circuitry for pain processing in the dorsal spinal cord. PMID:26257608

  13. Family-based genome-wide association study of frontal θ oscillations identifies potassium channel gene KCNJ6.

    PubMed

    Kang, S J; Rangaswamy, M; Manz, N; Wang, J-C; Wetherill, L; Hinrichs, T; Almasy, L; Brooks, A; Chorlian, D B; Dick, D; Hesselbrock, V; Kramer, J; Kuperman, S; Nurnberger, J; Rice, J; Schuckit, M; Tischfield, J; Bierut, L J; Edenberg, H J; Goate, A; Foroud, T; Porjesz, B

    2012-08-01

    Event-related oscillations (EROs) represent highly heritable neuroelectric correlates of cognitive processes that manifest deficits in alcoholics and in offspring at high risk to develop alcoholism. Theta ERO to targets in the visual oddball task has been shown to be an endophenotype for alcoholism. A family-based genome-wide association study was performed for the frontal theta ERO phenotype using 634 583 autosomal single nucleotide polymorphisms (SNPs) genotyped in 1560 family members from 117 families densely affected by alcohol use disorders, recruited in the Collaborative Study on the Genetics of Alcoholism. Genome-wide significant association was found with several SNPs on chromosome 21 in KCNJ6 (a potassium inward rectifier channel; KIR3.2/GIRK2), with the most significant SNP at P = 4.7 × 10(-10)). The same SNPs were also associated with EROs from central and parietal electrodes, but with less significance, suggesting that the association is frontally focused. One imputed synonymous SNP in exon four, highly correlated with our top three SNPs, was significantly associated with the frontal theta ERO phenotype. These results suggest KCNJ6 or its product GIRK2 account for some of the variations in frontal theta band oscillations. GIRK2 receptor activation contributes to slow inhibitory postsynaptic potentials that modulate neuronal excitability, and therefore influence neuronal networks. PMID:22554406

  14. An Alpha and Theta Intensive and Short Neurofeedback Protocol for Healthy Aging Working-Memory Training

    PubMed Central

    Reis, Joana; Portugal, Ana Maria; Fernandes, Luís; Afonso, Nuno; Pereira, Mariana; Sousa, Nuno; Dias, Nuno S.

    2016-01-01

    The present study tested the effects of an intensive and short alpha and theta neurofeedback (NF) protocol in working memory (WM) performance in a healthy elder population and explored the effects of a multimodal approach, by supplementing NF with cognitive tasks. Participants were allocated to four groups: NF (N = 9); neurofeedback supplemented with cognitive training (NFCT) (N = 8); cognitive training (CT) (N = 7) and sham neurofeedback (Sham-NF) (N = 6). The intervention consisted in 30-min sessions for 8 days. The NF group presented post intervention increases of alpha and theta relative power as well as performance in the matrix rotation task. In addition, a successful up training of frontal theta showed positive correlation with an improvement of post-training alpha and a better performance in the matrix rotation task. The results presented herein suggest that an intensive and short NF protocol enables elders to learn alpha and theta self-modulation and already presents moderate improvements in cognition and basal EEG. Also, CT group showed moderate performance gains on the cognitive tasks used during the training sessions but no clear improvements on neurophysiology and behavioral measurements were observed. This study represents a first attempt to study the effects of an intensive and short NF protocol in WM performance of elders. The evidence presented here suggests that an intensive and short NF intervention could be a valid alternative for introduction of older populations to NF methodologies. PMID:27458369

  15. An Alpha and Theta Intensive and Short Neurofeedback Protocol for Healthy Aging Working-Memory Training.

    PubMed

    Reis, Joana; Portugal, Ana Maria; Fernandes, Luís; Afonso, Nuno; Pereira, Mariana; Sousa, Nuno; Dias, Nuno S

    2016-01-01

    The present study tested the effects of an intensive and short alpha and theta neurofeedback (NF) protocol in working memory (WM) performance in a healthy elder population and explored the effects of a multimodal approach, by supplementing NF with cognitive tasks. Participants were allocated to four groups: NF (N = 9); neurofeedback supplemented with cognitive training (NFCT) (N = 8); cognitive training (CT) (N = 7) and sham neurofeedback (Sham-NF) (N = 6). The intervention consisted in 30-min sessions for 8 days. The NF group presented post intervention increases of alpha and theta relative power as well as performance in the matrix rotation task. In addition, a successful up training of frontal theta showed positive correlation with an improvement of post-training alpha and a better performance in the matrix rotation task. The results presented herein suggest that an intensive and short NF protocol enables elders to learn alpha and theta self-modulation and already presents moderate improvements in cognition and basal EEG. Also, CT group showed moderate performance gains on the cognitive tasks used during the training sessions but no clear improvements on neurophysiology and behavioral measurements were observed. This study represents a first attempt to study the effects of an intensive and short NF protocol in WM performance of elders. The evidence presented here suggests that an intensive and short NF intervention could be a valid alternative for introduction of older populations to NF methodologies. PMID:27458369

  16. Instrumentation in Frontal Sinus Surgery.

    PubMed

    Tajudeen, Bobby A; Adappa, Nithin D

    2016-08-01

    Frontal recess dissection proposes many challenges to the surgeon. These challenges stem from its highly variable nature, small caliber, difficult visualization, and proximity to vital structures such as the skull base and orbit. As such, delicate mucosal-sparing dissection of the frontal recess with proper instrumentation is paramount to minimize scar formation and ensure patency. Here, the article explores key instrumentation in frontal recess surgery with an emphasis on hand instruments and adjunctive technologies. PMID:27329980

  17. Corticostriatal Field Potentials Are Modulated at Delta and Theta Frequencies during Interval-Timing Task in Rodents

    PubMed Central

    Emmons, Eric B.; Ruggiero, Rafael N.; Kelley, Ryan M.; Parker, Krystal L.; Narayanan, Nandakumar S.

    2016-01-01

    Organizing movements in time is a critical and highly conserved feature of mammalian behavior. Temporal control of action requires corticostriatal networks. We investigate these networks in rodents using a two-interval timing task while recording LFPs in medial frontal cortex (MFC) or dorsomedial striatum. Consistent with prior work, we found cue-triggered delta (1–4 Hz) and theta activity (4–8 Hz) primarily in rodent MFC. We observed delta activity across temporal intervals in MFC and dorsomedial striatum. Rewarded responses were associated with increased delta activity in MFC. Activity in theta bands in MFC and delta bands in the striatum was linked with the timing of responses. These data suggest both delta and theta activity in frontostriatal networks are modulated during interval timing and that activity in these bands may be involved in the temporal control of action. PMID:27092091

  18. Interhemispheric Asymmetries and Theta Activity in the Rostral Anterior Cingulate Cortex as EEG Signature of HIV-Related Depression: Gender Matters.

    PubMed

    Kremer, Heidemarie; Lutz, Franz P C; McIntosh, Roger C; Dévieux, Jessy G; Ironson, Gail

    2016-04-01

    Resting EEGs of 40 people living with HIV (PLWH) on long-term antiretroviral treatment were examined for z-scored deviations from a healthy control (normative database) to examine the main and interaction effects of depression and gender. Regions of interest were frontal (alpha) and central (all bands) for interhemispheric asymmetries in quantitative EEGs and theta in the rostral anterior cingulate cortex (rACC) in low-resolution electromagnetic tomography (LORETA). Z-scored normed deviations of depressed PLWH, compared with nondepressed, showed right-dominant interhemispheric asymmetries in all regions. However, after adjusting for multiple testing, significance remained only central for theta, alpha, and beta. Reversed (left-dominant) frontal alpha asymmetry is a potential EEG marker of depression in the HIV negative population that was not reversed in depressive PLWH; however, corresponding with extant literature, gender had an effect on the size of frontal alpha asymmetry. The LORETA analysis revealed a trending interactional effect of depression and gender on theta activity in the rACC in Brodmann area 32. We found that compared to men, women had greater right-dominant frontal alpha-asymmetry and elevated theta activity in voxels of the rACC, which may indicate less likelihood of depression and a higher likelihood of response to antidepressants. In conclusion, subtle EEG deviations, such as right-dominant central theta, alpha, and beta asymmetries and theta activity in the rACC may mark HIV-related depressive symptoms and may predict the likelihood of response to antidepressants but gender effects need to be taken into account. Although this study introduced the use of LORETA to examine the neurophysiological correlates of negative affect in PLWH, further research is needed to assess the utility of this tool in diagnostics and treatment monitoring of depression in PLWH. PMID:25568149

  19. Intrinsic properties and neuropharmacology of midline paraventricular thalamic nucleus neurons

    PubMed Central

    Kolaj, Miloslav; Zhang, Li; Hermes, Michael L. H. J.

    2014-01-01

    Neurons in the midline and intralaminar thalamic nuclei are components of an interconnected brainstem, limbic and prefrontal cortex neural network that is engaged during arousal, vigilance, motivated and addictive behaviors, and stress. To better understand the cellular mechanisms underlying these functions, here we review some of the recently characterized electrophysiological and neuropharmacological properties of neurons in the paraventricular thalamic nucleus (PVT), derived from whole cell patch clamp recordings in acute rat brain slice preparations. PVT neurons display firing patterns and ionic conductances (IT and IH) that exhibit significant diurnal change. Their resting membrane potential (RMP) is maintained by various ionic conductances that include inward rectifier (Kir), hyperpolarization-activated nonselective cation (HCN) and TWIK-related acid sensitive (TASK) K+ channels. Firing patterns are regulated by high voltage-activated (HVA) and low voltage-activated (LVA) Ca2+ conductances. Moreover, transient receptor potential (TRP)-like nonselective cation channels together with Ca2+- and Na+-activated K+ conductances (KCa; KNa) contribute to unique slow afterhyperpolarizing potentials (sAHPs) that are generally not detectable in lateral thalamic or reticular thalamic nucleus neurons. The excitability of PVT neurons is also modulated by activation of neurotransmitter receptors associated with afferent pathways to PVT and other thalamic midline nuclei. We report on receptor-mediated actions of GABA, glutamate, monoamines and several neuropeptides: arginine vasopressin, gastrin-releasing peptide, thyrotropin releasing hormone and the orexins (hypocretins). This review represents an initial survey of intrinsic and transmitter-sensitive ionic conductances that are deemed to be unique to this population of midline thalamic neurons, information that is fundamental to an appreciation of the role these thalamic neurons may play in normal central nervous system

  20. Analysis of matrix cracking and local delamination in (O/theta/-theta)sub s graphite epoxy laminates under tension load

    NASA Technical Reports Server (NTRS)

    Salpekar, S. A.; O'Brien, T. K.

    1991-01-01

    Several 3D finite element analyses of (O/theta/-theta)sub s graphite epoxy laminates, where theta = 15, 20, 25, 30, and 45 deg, subjected to axial tension load were performed. The interlaminar stresses in the theta/-theta interface were calculated with and without a matrix crack in the central -theta plies. The interlaminar normal stress changes from a small compressive stress when no matrix crack is present to a high tensile stress at the intersection of the matrix crack and free edge. The analysis of local delamination from the -theta matrix crack indicates a high strain energy release rate and a localized mode I component near the free edge, within one ply distance from the matrix crack. In order to examine the stress state causing the matrix cracking the maximum principal normal stress in a plane perpendicular to the fiber direction in the -theta ply was calculated in an uncracked laminate. The corresponding shear stress parallel to the fiber was also calculated. The principal normal stress at the laminate edge increases through the ply thickness and reached a very high tensile value at the theta/-theta interface indicating that the crack in the -theta ply may initiate at the theta/-theta interface. Crack profiles on the laminate edge in the -theta ply were constructed from the principal stress directions. The cracks were found to be more curved for layups with smaller theta angles, which is consistent with experimental observations in the literature.

  1. Analysis of matrix cracking and local delamination in (0/theta/-theta)sub s graphite epoxy laminates under tension load

    NASA Technical Reports Server (NTRS)

    Salpekar, S. A.; Obrien, T. K.

    1991-01-01

    Several 3D finite element analyses of (0/theta/-theta)sub s graphite epoxy laminates, where theta=15, 20, 25, 30, and 45 deg, subjected to axial tension load were performed. The interlaminar stresses in the theta/-theta interface were calculated with and without a matrix crack in the central -theta plies. The interlaminar normal stress changes from a small compressive stress when no matrix crack is present to a high tensile stress at the intersection of the matrix crack and free edge. The analysis of local delamination from the -theta matrix crack indicates a high strain energy release rate and a localized mode I component near the free edge, within one ply distance from the matrix crack. In order to examine the stress state causing the matrix cracking the maximum principal normal stress in a plane perpendicular to the fiber direction in the -theta ply was calculated in an uncracked laminate. The corresponding shear stress parallel to the fiber was also calculated. The principal normal stress at the laminate edge increases through the ply thickness and reached a very high tensile value at the theta/-theta interface indicating that the crack in the -theta ply may initiate at the theta/-theta interface. Crack profiles on the laminate edge in the -theta ply were constructed from the principal stress directions. The cracks were found to be more curved for layups with smaller theta angles, which is consistent with experimental observations in the literature.

  2. Measuring Theta_13 at Daya Bay

    SciTech Connect

    Lau, Kwong

    2014-03-14

    We measured the neutrino mixing angle, theta13, presumably related to the preponderance of matter over antimatter in our universe with high precision. We determined theta13 by measuring the disappearance of neutrinos from a group of six nuclear reactors. The target, located inside a mountain at about 2 km from the reactors, is 80 tons of liquid scintillator doped with trace amount of Gadolinium to increase its neutron detection efficiency. The neutrino flux is measured by the inverse beta-decay reaction where the final-state particles are detected by the liquid scintillator. The measured value of theta13, based on data collected over 3 years, is large, around 8 degrees, rendering the measurement of the parameter related to matter-antimatter asymmetry in future long baseline neutrino experiments easier.

  3. Directed Communication between Nucleus Accumbens and Neocortex in Humans Is Differentially Supported by Synchronization in the Theta and Alpha Band

    PubMed Central

    Horschig, Jörn M.; Smolders, Ruud; Bonnefond, Mathilde; Schoffelen, Jan-Mathijs; van den Munckhof, Pepijn; Schuurman, P. Richard; Cools, Roshan; Denys, Damiaan; Jensen, Ole

    2015-01-01

    Here, we report evidence for oscillatory bi-directional interactions between the nucleus accumbens and the neocortex in humans. Six patients performed a demanding covert visual attention task while we simultaneously recorded brain activity from deep-brain electrodes implanted in the nucleus accumbens and the surface electroencephalogram (EEG). Both theta and alpha oscillations were strongly coherent with the frontal and parietal EEG during the task. Theta-band coherence increased during processing of the visual stimuli. Granger causality analysis revealed that the nucleus accumbens was communicating with the neocortex primarily in the theta-band, while the cortex was communicating the nucleus accumbens in the alpha-band. These data are consistent with a model, in which theta- and alpha-band oscillations serve dissociable roles: Prior to stimulus processing, the cortex might suppress ongoing processing in the nucleus accumbens by modulating alpha-band activity. Subsequently, upon stimulus presentation, theta oscillations might facilitate the active exchange of stimulus information from the nucleus accumbens to the cortex. PMID:26394404

  4. Midline Cervical Cleft: Review of an Uncommon Entity

    PubMed Central

    Puscas, Liana

    2015-01-01

    Introduction. Midline cervical cleft is a rare congenital malformation which nonetheless has a classic presentation. This study presents one of the largest single series of new patients with MCC and provides an exhaustive review and catalogue of publications from the international literature. Materials and Methods. Retrospective chart review performed in two academic medical centers and literature review performed with primary verification of all quoted references. Results. Ten patients with MCC were identified (8 boys and 2 girls). All patients presented with the classic findings of this congenital anomaly, and the length of the skin defect correlated with an increase in the patient's age. Surgical excision was complete in all cases. Thorough international literature review yielded only 195 verifiable previously reported cases. Conclusions. This is one of the largest series of new patients with midline cervical cleft presented in the world literature. Although rare (with less than 200 cases published to date) this entity does have a reliable presentation that should lead to rapid and accurate diagnosis. Complete surgical excision at an early age is appropriate since the anomaly increases in length commensurate with the patient's age. PMID:25983756

  5. Deficient Event-Related Theta Oscillations in Individuals at Risk for Alcoholism: A Study of Reward Processing and Impulsivity Features

    PubMed Central

    Kamarajan, Chella; Pandey, Ashwini K.; Chorlian, David B.; Manz, Niklas; Stimus, Arthur T.; Anokhin, Andrey P.; Bauer, Lance O.; Kuperman, Samuel; Kramer, John; Bucholz, Kathleen K.; Schuckit, Marc A.; Hesselbrock, Victor M.; Porjesz, Bernice

    2015-01-01

    Background Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. Event-related oscillations (EROs) have been used to effectively measure brain (dys)function during cognitive tasks in individuals with alcoholism and related disorders and in those at risk to develop these disorders. The current study examines ERO theta power during reward processing as well as impulsivity in adolescent and young adult subjects at high risk for alcoholism. Methods EROs were recorded during a monetary gambling task (MGT) in 12–25 years old participants (N = 1821; males = 48%) from high risk alcoholic families (HR, N = 1534) and comparison low risk community families (LR, N = 287) from the Collaborative Study on the Genetics of Alcoholism (COGA). Impulsivity scores and prevalence of externalizing diagnoses were also compared between LR and HR groups. Results HR offspring showed lower theta power and decreased current source density (CSD) activity than LR offspring during loss and gain conditions. Younger males had higher theta power than younger females in both groups, while the older HR females showed more theta power than older HR males. Younger subjects showed higher theta power than older subjects in each comparison. Differences in topography (i.e., frontalization) between groups were also observed. Further, HR subjects across gender had higher impulsivity scores and increased prevalence of externalizing disorders compared to LR subjects. Conclusions As theta power during reward processing is found to be lower not only in alcoholics, but also in HR subjects, it is proposed that reduced reward-related theta power, in addition to impulsivity and externalizing features, may be related in a predisposition to develop alcoholism and related disorders. PMID:26580209

  6. Analysis of matrix cracking and local delamination in (0/theta/-theta)s graphite epoxy laminates under tensile load

    NASA Technical Reports Server (NTRS)

    Salpekar, S. A.; O'Brien, T. K.

    1993-01-01

    Three-dimensional element analyses of (0/theta/-theta)s graphite epoxy laminates, where theta = 15, 20, 25, 30, and 45 deg, subjected to axial tensile load, were performed. The interlaminar stresses in the theta/-theta interface were calculated with and without a matrix crack in the central -theta plies. The interlaminar normal stress changes from a small compressive stress when no matrix crack is present to a high tensile stress at the intersection of the matrix crack and the free edge. The analysis of local delamination from the -theta matrix crack indicates a high strain energy release rate and a localized Mode I component near the free edge, within one-ply distance from the matrix crack. To examine the stress state causing the matrix cracking, the maximum principal normal stress in a plane perpendicular to the fiber direction in the -theta ply was calculated in an uncracked laminate. The corresponding shear stress parallel to the fiber was also calculated. The principal normal stress at the laminate edge increased through the ply thickness and reached a very high tensile value at the theta/-theta interface indicating that the crack in the -theta ply may initiate at the theta/-theta interface.

  7. Hippocampal theta, gamma, and theta-gamma coupling: effects of aging, environmental change, and cholinergic activation

    PubMed Central

    Jacobson, Tara K.; Howe, Matthew D.; Schmidt, Brandy; Hinman, James R.; Escabí, Monty A.

    2013-01-01

    Hippocampal theta and gamma oscillations coordinate the timing of multiple inputs to hippocampal neurons and have been linked to information processing and the dynamics of encoding and retrieval. One major influence on hippocampal rhythmicity is from cholinergic afferents. In both humans and rodents, aging is linked to impairments in hippocampus-dependent function along with degradation of cholinergic function. Cholinomimetics can reverse some age-related memory impairments and modulate oscillations in the hippocampus. Therefore, one would expect corresponding changes in these oscillations and possible rescue with the cholinomimetic physostigmine. Hippocampal activity was recorded while animals explored a familiar or a novel maze configuration. Reexposure to a familiar situation resulted in minimal aging effects or changes in theta or gamma oscillations. In contrast, exploration of a novel maze configuration increased theta power; this was greater in adult than old animals, although the deficit was reversed with physostigmine. In contrast to the theta results, the effects of novelty, age, and/or physostigmine on gamma were relatively weak. Unrelated to the behavioral situation were an age-related decrease in the degree of theta-gamma coupling and the fact that physostigmine lowered the frequency of theta in both adult and old animals. The results indicate that age-related changes in gamma and theta modulation of gamma, while reflecting aging changes in hippocampal circuitry, seem less related to aging changes in information processing. In contrast, the data support a role for theta and the cholinergic system in encoding and that hippocampal aging is related to impaired encoding of new information. PMID:23303862

  8. Rapid memory stabilization by transient theta coherence in the human medial temporal lobe.

    PubMed

    Thézé, Raphaël; Guggisberg, Adrian G; Nahum, Louis; Schnider, Armin

    2016-04-01

    Presenting stimuli again after presentation of intervening stimuli improves their retention, an effect known as the spacing effect. However, using event-related potentials (ERPs), we had observed that immediate, in comparison to spaced, repetition of pictures induced a positive frontal potential at 200-300 ms. This potential appeared to emanate from the left medial temporal lobe (MTL), a structure critical for memory consolidation. In this study, we tested the behavioral relevance of this signal and explored functional connectivity changes during picture repetition. We obtained high-density electroencephalographic recordings from 14 healthy subjects performing a continuous recognition task where pictures were either repeated immediately or after 9 intervening items. Conventional ERP analysis replicated the positive frontal potential emanating from the left MTL at 250-350 ms in response to immediately repeated stimuli. Connectivity analysis showed that this ERP was associated with increased coherence in the MTL region-left more that right-in the theta-band (3.5-7 Hz) 200-400 ms following immediate, but not spaced, repetition. This increase was stronger in subjects who better recognized immediately repeated stimuli after 30 min. These findings indicate that transient theta-band synchronization between the MTL and the rest of the brain at 200-400 ms reflects a memory stabilizing signal. © 2015 Wiley Periodicals, Inc. PMID:26386180

  9. Upper and Lower Extremity Midline Crossing Effects upon Adults with Mild to Moderate Mental Retardation.

    ERIC Educational Resources Information Center

    Woodard, Rebecca J.; Surburg, Paul R.; Lewis, Colleen A.

    1998-01-01

    This study examined whether midline crossing inhibition (MCI) was present in 13 adults with mild to moderate mental retardation when crossing the midline of the body with both the upper and lower extremities. Results indicated that participants exhibited MCI with both the upper and lower extremities. (Author/CR)

  10. Human Hippocampal Theta Oscillations during Movement without Visual Cues.

    PubMed

    Qasim, Salman E; Jacobs, Joshua

    2016-03-16

    The hippocampus exhibits theta oscillations when animals navigate. Vass et al. (2016) discovered that theta oscillations are also present when humans are moved through a virtual environment without sensory feedback, indicating that theta oscillations have a general role in spatial cognition beyond sensorimotor processing. PMID:26985718

  11. Frontal and Parietal Cortices Show Different Spatiotemporal Dynamics across Problem-solving Stages.

    PubMed

    Tschentscher, Nadja; Hauk, Olaf

    2016-08-01

    Arithmetic problem-solving can be conceptualized as a multistage process ranging from task encoding over rule and strategy selection to step-wise task execution. Previous fMRI research suggested a frontal-parietal network involved in the execution of complex numerical and nonnumerical tasks, but evidence is lacking on the particular contributions of frontal and parietal cortices across time. In an arithmetic task paradigm, we evaluated individual participants' "retrieval" and "multistep procedural" strategies on a trial-by-trial basis and contrasted those in time-resolved analyses using combined EEG and MEG. Retrieval strategies relied on direct retrieval of arithmetic facts (e.g., 2 + 3 = 5). Procedural strategies required multiple solution steps (e.g., 12 + 23 = 12 + 20 + 3 or 23 + 10 + 2). Evoked source analyses revealed independent activation dynamics within the first second of problem-solving in brain areas previously described as one network, such as the frontal-parietal cognitive control network: The right frontal cortex showed earliest effects of strategy selection for multistep procedural strategies around 300 msec, before parietal cortex activated around 700 msec. In time-frequency source power analyses, memory retrieval and multistep procedural strategies were differentially reflected in theta, alpha, and beta frequencies: Stronger beta and alpha desynchronizations emerged for procedural strategies in right frontal, parietal, and temporal regions as function of executive demands. Arithmetic fact retrieval was reflected in right prefrontal increases in theta power. Our results demonstrate differential brain dynamics within frontal-parietal networks across the time course of a problem-solving process, and analyses of different frequency bands allowed us to disentangle cortical regions supporting the underlying memory and executive functions. PMID:27027542

  12. Lateral Ventricle Volume Asymmetry Predicts Midline Shift in Severe Traumatic Brain Injury.

    PubMed

    Tóth, Arnold; Schmalfuss, Ilona; Heaton, Shelley C; Gabrielli, Andrea; Hannay, H Julia; Papa, Linda; Brophy, Gretchen M; Wang, Kevin K W; Büki, András; Schwarcz, Attila; Hayes, Ronald L; Robertson, Claudia S; Robicsek, Steven A

    2015-09-01

    Midline shift following severe traumatic brain injury (sTBI) detected on computed tomography (CT) scans is an established predictor of poor outcome. We hypothesized that lateral ventricular volume (LVV) asymmetry is an earlier sign of developing asymmetric intracranial pathology than midline shift. This retrospective analysis was performed on data from 84 adults with blunt sTBI requiring a ventriculostomy who presented to a Level I trauma center. Seventy-six patients underwent serial CTs within 3 h and an average of three scans within the first 10 d of sTBI. Left and right LVVs were quantified by computer-assisted manual volumetric measurements. LVV ratios (LVR) were determined on the admission CT to evaluate ventricular asymmetry. The relationship between the admission LVR value and subsequent midline shift development was tested using receiver operating characteristic (ROC) analysis, and odds ratio (OR) and relative risk tests. Sixty patients had no >5 mm midline shift on the initial admission scan. Of these, 15 patients developed it subsequently (16 patients already had >5 mm midline shift on admission scans). For >5 mm midline shift development, admission LVR of >1.67 was shown to have a sensitivity of 73.3% and a specificity of 73.3% (area under the curve=0.782; p<0.0001). LVR of >1.67 as exposure yielded an OR of 7.56 (p<0.01), and a risk ratio of 4.42 (p<0.01) for midline shift development as unfavorable outcome. We propose that LVR captures LVV asymmetry and is not only related to, but also predicts the development of midline shift already at admission CT examination. Lateral ventricles may have a higher "compliance" than midline structures to developing asymmetric brain pathology. LVR analysis is simple, rapidly accomplished and may allow earlier interventions to attenuate midline shift and potentially improve ultimate outcomes. PMID:25752227

  13. Electromagnetic theta gun and tubular projectiles

    SciTech Connect

    Burgess, T.J.; Cnare, E.C.; Oberkampf, W.L.; Beard, S.G.; Cowan, M.

    1980-12-01

    Unlike the better known rail gun, the theta gun applies the propelling force along the length of its projectile. This is shown to allow much greater acceleration of high fineness ratio projectiles for a given barrel pressure, allowing much shorter barrels for military applications. A computer code which simulates performance of the theta gun is described and experimental results from a few simple, low energy experiments show close agreement with code predictions. Trajectories and aerodynamic heating for three candidate military projectiles are calculated for vertical and horizontal atmospheric launches where initial velocity is as high as 3 km/s. The calculations indicate that in some cases a thin layer of heatshield (ablator) will be required to control projectile heating.

  14. Management of Frontal Sinus Tumors.

    PubMed

    Selleck, Anne Morgan; Desai, Dipan; Thorp, Brian D; Ebert, Charles S; Zanation, Adam M

    2016-08-01

    The most common primary tumors of the frontal sinus are osteomas and inverted papillomas, although a variety of other tumors involving this space have been reported. With the advent of new surgical techniques and instrumentation, an endoscopic approach to this region has become feasible. The preoperative assessment and decision making must take into account the complexity of frontal sinus anatomy, tumor type, tumor location, and associated attachments. These procedures allow adequate visualization, tumor removal, and postoperative monitoring, and preserve fairly normal sinus function. Open techniques may also be required and should be in the surgeon's armamentarium. PMID:27450620

  15. Progressive Fracture of [0/90/ + or - Theta]s Composite Structure Under Uniform Pressure Load

    NASA Technical Reports Server (NTRS)

    Gotsis, Pascalis K.; Chamis, Christos C.; Gotsis, Christos K.; Mouratidis, Ericos

    2007-01-01

    S-Glass/epoxy [0/90/plus or minus theta]s for theta =45 deg., 60 deg., and 75 deg. laminated fiber-reinforced composite stiffened plate was simulated to investigated for damage and fracture progression under uniform pressure. An integrated computer code was augmented for the simulation of the damage initiation, growth, accumulation, and propagation to fracture and to structural collapse. Results show in detail the damage progression sequence and structural fracture resistance during different degradation stages. Damage through the thickness of the laminate initiated first at [0/90/plus or minus 45]s at 15.168 MPa (2200 psi), followed by [0/90/plus or minus 60]s at 16.96 MPa (2460 psi) and finally by [0/90/plus or minus 75]s at 19.3 MPa (2800 psi). After damage initiation happened the cracks propagate rapidly to structural fracture.

  16. When the Midline Diastema Is Not Characteristic of the "Ugly Duckling" Stage.

    PubMed

    Tanaka, Orlando Motohiro; Morino, Alessandro Yuske Kusano; Machuca, Oscar Fernando; Schneider, Neblyssa Ágatha

    2015-01-01

    This case report presents the interceptive orthodontic treatment of a 9-year, 5-month-old boy with class I malocclusion, a 9.0-mm maxillary midline diastema, and deviation from the midline. The treatment goals were to decrease the magnitude of the diastema and to simulate the characteristics of the "ugly duckling" stage. Braces were placed on the first molars and the maxillary central incisors. The biomechanics of the anchors on the first molars elicited substantial mesial movement of the left central incisor to match the midline. A flat wire segment was bonded onto the palatal surface of the central incisors for retention. PMID:26345220

  17. When the Midline Diastema Is Not Characteristic of the “Ugly Duckling” Stage

    PubMed Central

    Tanaka, Orlando Motohiro; Morino, Alessandro Yuske Kusano; Machuca, Oscar Fernando; Schneider, Neblyssa Ágatha

    2015-01-01

    This case report presents the interceptive orthodontic treatment of a 9-year, 5-month-old boy with class I malocclusion, a 9.0-mm maxillary midline diastema, and deviation from the midline. The treatment goals were to decrease the magnitude of the diastema and to simulate the characteristics of the “ugly duckling” stage. Braces were placed on the first molars and the maxillary central incisors. The biomechanics of the anchors on the first molars elicited substantial mesial movement of the left central incisor to match the midline. A flat wire segment was bonded onto the palatal surface of the central incisors for retention. PMID:26345220

  18. Conceptual Models of Frontal Cyclones.

    ERIC Educational Resources Information Center

    Eagleman, Joe R.

    1981-01-01

    This discussion of weather models uses maps to illustrate the differences among three types of frontal cyclones (long wave, short wave, and troughs). Awareness of these cyclones can provide clues to atmospheric conditions which can lead toward accurate weather forecasting. (AM)

  19. Collaborative Writing: Online versus Frontal

    ERIC Educational Resources Information Center

    Passig, David; Schwartz, Gali

    2007-01-01

    Students in higher education, most frequently, use the frontal approach while being asked to collaborate on a writing assignment. However, the difficulty in collaborative writing using conventional technologies such as pen and paper, board or computer is the limited ability to view the work of your peers during the process (Baeker, Glass,…

  20. [Diagnostic dyspraxia and frontal syndrome].

    PubMed

    Donnet, A; Schmitt, A; Poncet, M

    1998-05-01

    A 27-year-old ambidexter woman experienced a clinical and psychometric frontal syndrome associated with a partial callosal syndrome following transcallosal surgery for an intraventricular neurocytoma. She also complained of difficulties with her left hand which realized a particular form of diagnostic dyspraxia: there were specific features of an isolated dysfunction of the control of the realization of a program. PMID:9773062

  1. Clinical evaluation of a securement device used on midline catheters.

    PubMed

    Ventura, Roy; O'Loughlin, Chris; Vavrik, Boris

    2016-07-28

    Since the introduction of sutureless securement products for vascular access devices (VADs), there has been a great deal of discussion of their advantages and disadvantages in comparison with sutures. This includes questions related to VAD securement, patients' comfort, infection control, user-friendliness and potential complications of using the device. The literature review of the available evidence indicates the superiority of the novel sutureless devices in the aforementioned aspects. The authors collected data to further contribute in the analysis of the attributes of these products, namely Statlock™ and Grip-Lok™ (current devices). The authors then trialled, collected and analysed data from relevant healthcare practitioners on their perception of a novel sutureless 3M™ Tegaderm™ PICC/CVC Securement Device + Tegaderm™ I.V. Advanced Securement Dressing (trialled device) for midline VADs. Evaluation forms have been provided and filled in by the practitioners. The results showed that the trialled product is perceived as user-and patient-friendly, resulting in increased security of VAD and easier handling compared to the current devices. Overall, 70% of the evaluators stated that the trialled product has better or much better overall performance. The remaining 30% characterised the overall performance comparable with the current devices. PMID:27467651

  2. Appearance can be deceptive: Dentigerous cyst crossing the midline.

    PubMed

    Paul, Rahul; Paul, Geeta; Prasad, Ruchika K; Singh, Shilpa; Agarwal, Nitin; Sinha, Abhishek

    2013-01-01

    Dentigerous cyst is a developmental odontogenic cyst, which develops by accumulation of fluid between reduced enamel epithelium and the tooth crown of an unerupted tooth. Dentigerous cysts are usually solitary, slow growing, asymptomatic lesions that are incidentally found during routine radiographs They most frequently involve the mandibular third molar followed in order of frequency by the maxillary canine, mandibular second pre-molar and maxillary third molar. Occasionally, these cysts become painful when infected causing swelling and erythema. The cyst is usually small, however, when large, results in the expansion and thinning of the cortex leading to pathological fracture. Radiographic features are specific to the lesion characterized by a well-defined radiolucency circumscribed by a sclerotic border, associated with the crown of an impacted or unerupted tooth. Dentigerous cysts are treated most commonly by enucleation, Marsupialization and decompression of cyst by fenestration. The criteria for selecting the treatment modality is based on the age, size, location, stage of root development, position of the involved tooth and relation of the lesion to the adjacent tooth and vital structure. The prognosis is an excellent when the cyst is enucleated and recurrence is rare. In this article, we present a case of a Dentigerous cyst in an 80-year-old man in the anterior aspect of the mandible enveloping an impacted canine and crossing the midline but with no clinical expansion or discomfort. PMID:24163563

  3. Differentiation of NUT Midline Carcinoma by Epigenomic Reprogramming

    PubMed Central

    Schwartz, Brian E.; Hofer, Matthias D.; Lemieux, Madeleine E.; Bauer, Daniel E.; Cameron, Michael J.; West, Nathan H.; Agoston, Elin S.; Reynoird, Nicolas; Khochbin, Saadi; Ince, Tan A.; Christie, Amanda; Janeway, Katherine A.; Vargas, Sara O.; Perez-Atayde, Antonio R.; Aster, Jon C.; Sallan, Stephen E.; Kung, Andrew L.; Bradner, James E.; French, Christopher A.

    2011-01-01

    NUT midline carcinoma (NMC) is a lethal pediatric tumor defined by the presence of BRD-NUT fusion proteins that arrest differentiation. Here we explore the mechanisms underlying the ability of BRD4-NUT to prevent squamous differentiation. In both gain-of and loss-of-expression assays we find that expression of BRD4-NUT is associated with globally decreased histone acetylation and transcriptional repression. Bulk chromatin acetylation can be restored by treatment of NMC cells with histone deacetylase inhibitors (HDACi), engaging a program of squamous differentiation and arrested growth in vitro that closely mimics the effects of siRNA mediated attenuation of BRD4-NUT expression. The potential therapeutic utility of HDACi differentiation therapy was established in three different NMC xenograft models, where it produced significant growth inhibition and a survival benefit. Based on these results and translational studies performed with patient-derived primary tumor cells, a child with NMC was treated with the FDA-approved HDAC inhibitor, vorinostat. An objective response was obtained after five weeks of therapy, as determined by positron emission tomography. These findings provide preclinical support for trials of HDACi in patients with NMC. PMID:21447744

  4. Network mechanisms of responsiveness to continuous theta-burst stimulation.

    PubMed

    Rizk, Sviatlana; Ptak, Radek; Nyffeler, Thomas; Schnider, Armin; Guggisberg, Adrian G

    2013-10-01

    Continuous theta-burst stimulation (cTBS) can modify behavior, but effects are inconsistent and their mechanisms insufficiently understood. As coherence in resting-state networks influences human behavior, we hypothesized that cTBS may act via modulation of neural oscillation coherence. This study used electroencephalography (EEG) to investigate whether behavioral effects of cTBS on visuospatial attention are associated with coherence changes in the attention network. In healthy human subjects, cTBS of the right posterior parietal cortex (PPC) and the right frontal eye field was compared with sham stimulation. Effects on visuospatial attention were quantified with a visual exploration task, and network effects were assessed from surface EEG with inverse solutions and source coherence analyses. Before stimulation, left visual exploration was linearly correlated with alpha-band coherence between the right temporo-parietal cortex and the rest of the brain. Posterior parietal cortex stimulation induced neglect-like visual exploration behavior in the majority, but not all, subjects. It reduced alpha-band coherence between the stimulation site and the rest of the brain but also enhanced it between the contralateral left parietal cortex and the rest of the brain. The contralateral increase correlated with the induced reduction in left visual attention. The behavioral response of individual participants to cTBS could be predicted by coherence in the right temporo-parietal junction before stimulation. Behavioral effects of cTBS therefore depend on network states before stimulation and are linearly associated with changes in network interactions. In particular, cTBS modulates an interhemispheric competition in alpha-band coherence. EEG network imaging might help to optimize therapeutic cTBS in the future. PMID:23941616

  5. Frontal Monitoring and Parietal Evidence: Mechanisms of Error Correction.

    PubMed

    Navarro-Cebrian, Ana; Knight, Robert T; Kayser, Andrew S

    2016-08-01

    When we respond to a stimulus, our decisions are based not only on external stimuli but also on our ongoing performance. If the response deviates from our goals, monitoring and decision-making brain areas interact so that future behavior may change. By taking advantage of natural variation in error salience, as measured by the RT taken to correct an error (RTEC), here we argue that an evidence accumulation framework provides a potential underlying mechanism for this variable process of error identification and correction, as evidenced by covariation of frontal monitoring and parietal decision-making processes. We study two early EEG signals linked to monitoring within medial PFC-the error-related negativity (ERN) and frontocentral theta activity-and a third EEG signal, the error positivity (Pe), that is thought to share the same parietal substrates as a signal (the P3b) proposed to reflect evidence accumulation. As predicted, our data show that on slow RTEC trials, frontal monitoring resources are less strongly employed, and the latency of the Pe is longer. Critically, the speed of the RTEC also covaries with the magnitude of subsequent neural (intertrial alpha power) and behavioral (post-error slowing) adjustments following the correction. These results are synthesized to describe a timing diagram for adaptive decision-making after errors and support a potential evidence accumulation mechanism in which error signaling is followed by rapid behavioral adjustments. PMID:27027420

  6. Nuclear Protein of the Testis Midline Carcinoma Masquerading as a Primary Mediastinal Seminoma

    PubMed Central

    Sayapina, Maria S.; Savelov, Nikita A.; Karseladze, Apollon I.; Bulanov, Anatoly A.; Tryakin, Alexey A.; Nosov, Dmitry A.; Garin, Avgust M.; Tjulandin, Sergey A.

    2016-01-01

    Nuclear protein of the testis (NUT) midline carcinomas are rare aggressive carcinomas characterized by chromosomal rearrangements that involve the gene encoding the NUT. This article reviews the clinicopathologic features and the differential diagnosis of these malignancies. PMID:27441078

  7. Tobacco Smoking and the Resting Maternal Brain: A Preliminary Study of Frontal EEG

    PubMed Central

    Wilbanks, Haley E.; Von Mohr, Mariana; Potenza, Marc N.; Mayes, Linda C.; Rutherford, Helena J.V.

    2016-01-01

    Tobacco smoking has been attributed to a wide range of detrimental health consequences for both women and their children. In addition to its known physical health effects, smoking may also impact maternal neural responses and subsequent caregiving behavior. To begin investigating this issue, we employed electroencephalography (EEG) to examine resting neural oscillations of tobacco-smoking mothers (n = 35) and non-smoking mothers (n = 35). We examined seven EEG frequency bands recorded from frontal electrode sites (delta, theta, alpha, alpha1, alpha2, beta, and gamma). While no between-group differences were present in high-frequency bands (alpha2, beta, gamma), smokers showed greater spectral power in low-frequency bands (delta, theta, alpha, alpha1) compared to non-smokers. This increased power in low-frequency bands of tobacco-smoking mothers is consistent with a less aroused state and may be one mechanism through which smoking might affect the maternal brain and caregiving behavior. PMID:27354838

  8. Perinatal midline astrocyte development is impaired in fibroblast growth factor 8 hypomorphic mice.

    PubMed

    Stewart, Courtney E; Corella, Kristina M; Samberg, Brittany D; Jones, Paula T; Linscott, Megan L; Chung, Wilson C J

    2016-09-01

    Our previous studies showed that Fgf8 mutations can cause Kallmann syndrome (KS), a form of congenital hypogonadotropic hypogonadism, in which patients do not undergo puberty and are infertile. Interestingly, some KS patients also have agenesis of the corpus callosum (ACC) suggesting that KS pathology is not limited to reproductive function. Here, we asked whether FGF8 dysfunction is the underlying cause of ACC in some KS patients. Indeed, early studies in transgenic mice with Fgf8 mutations reported the presence of failed or incomplete corpus callosum formation. Additional studies in transgenic mice showed that FGF8 function most likely prevents the prenatal elimination of glial fibrillary acidic protein (GFAP)-immunoreactive (IR) glial cells in the indusium griseum (IG) and midline zipper (MZ), two anterior-dorsal midline regions required for corpus callosum formation (i.e., between embryonic days (E) 15.5-18.5). Here, we tested the hypothesis that FGF8 function is critical for the survival of the GFAP-IR midline glial cells. First, we measured the incidence of apoptosis in the anterior-dorsal midline region in Fgf8 hypomorphic mice during embryonic corpus callosum formation. Second, we quantified the GFAP expression in the anterior-dorsal midbrain region during pre- and postnatal development, in order to study: 1) how Fgf8 hypomorphy disrupts prenatal GFAP-IR midline glial cell development, and 2) whether Fgf8 hypomorphy continues to disrupt postnatal GFAP-IR midline glial cell development. Our results indicate that perinatal FGF8 signaling is important for the timing of the onset of anterior-dorsal Gfap expression in midline glial cells suggesting that FGF8 function regulates midline GFAP-IR glial cell development, which when disrupted by Fgf8 deficiency prevents the formation of the corpus callosum. These studies provide an experimentally-based mechanistic explanation as to why corpus callosum formation may fail in KS patients with deficits in FGF signaling

  9. Primary Pulmonary NUT Midline Carcinoma: Clinical, Radiographic, and Pathologic Characterizations.

    PubMed

    Sholl, Lynette M; Nishino, Mizuki; Pokharel, Saraswati; Mino-Kenudson, Mari; French, Christopher A; Janne, Pasi A; Lathan, Christopher

    2015-06-01

    NUT midline carcinoma (NMC) is a poorly differentiated tumor typically driven by a t(15;19) rearrangement leading to a NUT fusion event. This rare and uniformly fatal tumor arises in multiple organ sites; however the clinical, radiographic, and pathologic characteristics of primary pulmonary NMC are poorly defined. We identified eight cases of primary pulmonary NMC in our consult practice over 4 years and, using a NUT immunohistochemistry screen, retrospectively identified one additional case from 166 (0.6%) consecutive in-house biopsies of lung carcinomas lacking glandular differentiation. Eight cases had available clinical and radiographic data and shared a remarkable degree of similarity. The median age at presentation was 30 (range 21-68). Six patients had little or no smoking history. All complained of 1 to 3 months of cough at presentation. Computed tomography scans showed a large, centrally located primary mass with confluent involvement of mediastinal lymph nodes, pleural disease, and sparing of the contralateral lung. Lytic bone metastases were common but brain metastases were absent in all cases. Pathologically, all cases showed primitive-appearing round to epitheloid cells growing in nests and sheets. All tumors expressed keratin, p63 or p40, and NUT protein. Eight cases had a fluorescence in situ hybridization-proven BRD4-NUT or BRD3-NUT rearrangement; one case was presumed to have a NUT-variant fusion event. Median overall survival was 2.2 months. Despite the rarity of primary pulmonary NMC, it is important to recognize this entity to counsel patients regarding outcome and to identify candidates for targeted BRD inhibitors currently in clinical trials. PMID:26001144

  10. Historical evolution of the frontal lobe syndrome.

    PubMed

    Krudop, Welmoed A; Pijnenburg, Yolande A L

    2015-01-01

    The function of the frontal lobes and the related frontal lobe syndrome have not been described in detail until relatively late in history. Slowly, the combination of knowledge from animal models, the detailed examination of symptoms after traumatic frontal lobe injuries, and the rise and fall of psychosurgery has led to increasing insight into frontal lobe function. The frontosubcortical circuits have been described and increasingly related to clinical syndromes, confirmed by the latest developments in functional connectivity networks. PMID:25997476

  11. Extracardiac anomalies in the heterotaxy syndromes with focus on anomalies of midline-associated structures.

    PubMed

    Ticho, B S; Goldstein, A M; Van Praagh, R

    2000-03-15

    The extracardiac defects in patients with heterotaxy have not been examined as extensively as cardiac defects. We found a high incidence of midline-associated defects in 160 autopsied cases of heterotaxy (asplenia, polysplenia, or single right-sided spleen). Fifty-two percent of patients with left-sided polysplenia had a midline-associated defect, as did 45% of those with asplenia. Most common were musculoskeletal or genitourinary anomalies, as well as cleft palate. Fused adrenal glands and anal stenosis or atresia occurred exclusively among patients with asplenia. A midline anomaly was twice as likely to be detected on complete autopsy than from clinical findings alone. Linkage studies should take into account that affected subjects may have isolated subclinical midline defects. The high incidence of midline-associated defects supports the theory that the midline plays a critical role in establishing left-right asymmetry in the body. Comparison of these defects with mouse models of laterality defects suggests that mutations that disrupt the transforming growth factor beta pathway may result in heterotaxy. PMID:12000048

  12. Mushroom body defect is required in parallel to Netrin for midline axon guidance in Drosophila

    PubMed Central

    Cate, Marie-Sophie; Gajendra, Sangeetha; Alsbury, Samantha; Raabe, Thomas; Tear, Guy; Mitchell, Kevin J.

    2016-01-01

    The outgrowth of many neurons within the central nervous system is initially directed towards or away from the cells lying at the midline. Recent genetic evidence suggests that a simple model of differential sensitivity to the conserved Netrin attractants and Slit repellents is insufficient to explain the guidance of all axons at the midline. In the Drosophila embryonic ventral nerve cord, many axons still cross the midline in the absence of the Netrin genes (NetA and NetB) or their receptor frazzled. Here we show that mutation of mushroom body defect (mud) dramatically enhances the phenotype of Netrin or frazzled mutants, resulting in many more axons failing to cross the midline, although mutations in mud alone have little effect. This suggests that mud, which encodes a microtubule-binding coiled-coil protein homologous to NuMA and LIN-5, is an essential component of a Netrin-independent pathway that acts in parallel to promote midline crossing. We demonstrate that this novel role of Mud in axon guidance is independent of its previously described role in neural precursor development. These studies identify a parallel pathway controlling midline guidance in Drosophila and highlight a novel role for Mud potentially acting downstream of Frizzled to aid axon guidance. PMID:26893348

  13. Mushroom body defect is required in parallel to Netrin for midline axon guidance in Drosophila.

    PubMed

    Cate, Marie-Sophie; Gajendra, Sangeetha; Alsbury, Samantha; Raabe, Thomas; Tear, Guy; Mitchell, Kevin J

    2016-03-15

    The outgrowth of many neurons within the central nervous system is initially directed towards or away from the cells lying at the midline. Recent genetic evidence suggests that a simple model of differential sensitivity to the conserved Netrin attractants and Slit repellents is insufficient to explain the guidance of all axons at the midline. In the Drosophila embryonic ventral nerve cord, many axons still cross the midline in the absence of the Netrin genes (NetA and NetB) or their receptor frazzled. Here we show that mutation of mushroom body defect (mud) dramatically enhances the phenotype of Netrin or frazzled mutants, resulting in many more axons failing to cross the midline, although mutations in mud alone have little effect. This suggests that mud, which encodes a microtubule-binding coiled-coil protein homologous to NuMA and LIN-5, is an essential component of a Netrin-independent pathway that acts in parallel to promote midline crossing. We demonstrate that this novel role of Mud in axon guidance is independent of its previously described role in neural precursor development. These studies identify a parallel pathway controlling midline guidance in Drosophila and highlight a novel role for Mud potentially acting downstream of Frizzled to aid axon guidance. PMID:26893348

  14. Psychophysical properties of line bisection and body midline perception in unilateral neglect.

    PubMed

    Pizzamiglio, L; Committeri, G; Galati, G; Patria, F

    2000-09-01

    Past research associated unilateral neglect with a systematic ipsilesional shift of the perceived position of the body midline; however, this was not confirmed by recent experiments. We used the constant stimuli method to control for potential artifacts intrinsic to the techniques used in previous studies. Body midline perception was measured in the visual and proprioceptive modalities in ten patients with left unilateral neglect, ten control patients and ten normal subjects and compared with a visual line bisection task, also using the constant stimuli method. Neglect patients showed a significant rightward bias in the line bisection task, but no consistent directional bias either in the proprioceptive or in the visual body midline task. These results clearly counter the association between neglect and an ipsilesional shift of the body midline. However, in the body midline tasks neglect patients made more errors in judgement on both sides of their subjective midline, both with respect to the control groups and with respect to the line bisection task. This may imply that a specific impairment of body-centered representations is indeed present and manifests as a non directional increase in response variability, rather than as a systematic shift. It is suggested that body- and object-related tasks (such as line bisection) may be processed by independent cognitive computations. This interpretation is discussed with reference to a recent neuroimaging study investigating the same kinds of tasks. PMID:11059450

  15. Occurrence of midline diastema and frenum attachments amongst school children in Nairobi, Kenya.

    PubMed

    Kaimenyi, J T

    1998-01-01

    The aim of this study was to determine the prevalence of midline diastema, tongue tie and frenum attachments amongst school children in Nairobi. A total of 1802 children aged between 4 and 16 years were selected randomly using multistage sampling technique. To avoid oversampling in either sex, a proportionate sampling procedure was used. Thereafter, a thorough intra-oral examination was carried out using a mouth mirror under artificial or natural light with the children lying on a supine position. Presence or absence of midline interdental spaces unusually bigger than other interdental spaces were noted and recorded on a prepared dateacollection form. Accurate location of the origin of the frenum was done using Placek et al Morphological-functional classification of the labial frenum attachments. Data was analyzed manually by tally method. Results showed that 35% had upper and lower midline diastema. 55% were females and 45% were males. Their mean age was 7.6 years. 0.2% had a high lingual frenum. The commonest location of frenum attachment amongst children with lower midline diastema was the mucogingival junction (86%) whereas amongst those with upper midline diastema it was attached gingiva (50%). None of the children had frenum attachment on the interdental papilla. It was concluded that the maxilla had a higher prevalence of midline diastema than the mandible and that papillary penetrating frenum attachments amongst these patients were higher in the maxilla than the mandible. PMID:10530193

  16. Theta oscillations accompanying concurrent auditory stream segregation.

    PubMed

    Tóth, Brigitta; Kocsis, Zsuzsanna; Urbán, Gábor; Winkler, István

    2016-08-01

    The ability to isolate a single sound source among concurrent sources is crucial for veridical auditory perception. The present study investigated the event-related oscillations evoked by complex tones, which could be perceived as a single sound and tonal complexes with cues promoting the perception of two concurrent sounds by inharmonicity, onset asynchrony, and/or perceived source location difference of the components tones. In separate task conditions, participants performed a visual change detection task (visual control), watched a silent movie (passive listening) or reported for each tone whether they perceived one or two concurrent sounds (active listening). In two time windows, the amplitude of theta oscillation was modulated by the presence vs. absence of the cues: 60-350ms/6-8Hz (early) and 350-450ms/4-8Hz (late). The early response appeared both in the passive and the active listening conditions; it did not closely match the task performance; and it had a fronto-central scalp distribution. The late response was only elicited in the active listening condition; it closely matched the task performance; and it had a centro-parietal scalp distribution. The neural processes reflected by these responses are probably involved in the processing of concurrent sound segregation cues, in sound categorization, and response preparation and monitoring. The current results are compatible with the notion that theta oscillations mediate some of the processes involved in concurrent sound segregation. PMID:27170058

  17. Frontal photopolymerization for microfluidic applications.

    PubMed

    Cabral, João T; Hudson, Steven D; Harrison, Christopher; Douglas, Jack F

    2004-11-01

    Frontal photopolymerization (FPP) offers numerous advantages for the rapid prototyping of microfluidic devices. Quantitative utilization of this method, however, requires a control of the vertical dimensions of the patterned resist material. To address this fundamental problem, we study the ultraviolet (UV) photopolymerization of a series of multifunctional thiolene resists through a combination of experiments and analytical modeling of the polymerization fronts. We describe this nonlinear spatio-temporal growth process in terms of a "minimal" model involving an order parameter phi(x, t) characterizing the extent of monomer-to-polymer conversion, the optical attenuation T(x, t), and the solid front position h(t). The latter exhibits an induction time (or equivalent critical UV dose) characterizing the onset of frontal propagation. We also observe a novel transition between two logarithmic rates of growth, determined by the Beer-Lambert attenuation constants mu(0) and mu(infinity) of the monomer and fully polymerized material, respectively. The measured frontal kinetics and optical transmission of the thiolene resist materials are consistent with our photopolymerization model, exhibiting both "photodarkening" and "photoinvariant" polymerization. This is apparently the first observation of photodarkening reported in FPP. On the basis of these results, multilevel fluidic devices with controlled height are readily fabricated with modulated illumination. A representative two-level microfluidic device, incorporating a chaotic mixer, a T junction, and a series of controlled flow constrictions, illustrates the practical versatility of this fabrication method. PMID:15518489

  18. A theory of alpha/theta neurofeedback, creative performance enhancement, long distance functional connectivity and psychological integration.

    PubMed

    Gruzelier, John

    2009-02-01

    Professionally significant enhancement of music and dance performance and mood has followed training with an EEG-neurofeedback protocol which increases the ratio of theta to alpha waves using auditory feedback with eyes closed. While originally the protocol was designed to induce hypnogogia, a state historically associated with creativity, the outcome was psychological integration, while subsequent applications focusing on raising the theta-alpha ratio, reduced depression and anxiety in alcoholism and resolved post traumatic stress syndrome (PTSD). In optimal performance studies we confirmed associations with creativity in musical performance, but effects also included technique and communication. We extended efficacy to dance and social anxiety. Diversity of outcome has a counterpart in wide ranging associations between theta oscillations and behaviour in cognitive and affective neuroscience: in animals with sensory-motor activity in exploration, effort, working memory, learning, retention and REM sleep; in man with meditative concentration, reduced anxiety and sympathetic autonomic activation, as well as task demands in virtual spatial navigation, focussed and sustained attention, working and recognition memory, and having implications for synaptic plasticity and long term potentiation. Neuroanatomical circuitry involves the ascending mescencephalic-cortical arousal system, and limbic circuits subserving cognitive as well as affective/motivational functions. Working memory and meditative bliss, representing cognitive and affective domains, respectively, involve coupling between frontal and posterior cortices, exemplify a role for theta and alpha waves in mediating the interaction between distal and widely distributed connections. It is posited that this mediation in part underpins the integrational attributes of alpha-theta training in optimal performance and psychotherapy, creative associations in hypnogogia, and enhancement of technical, communication and

  19. Fracture of the frontal sinus in children.

    PubMed

    Weber, S C; Cohn, A M

    1977-04-01

    Two juvenile patients, ages 5 and 8, had traumatic fractures of the frontal sinus that included involvement of the nasal-frontal ducts and posterior tables. Principles of management are discussed and the techniques for the operative procedures described. While rare in occurrence in children, it is felt that traumatic involvement of the nasal-frontal ducts or posterior tables of the frontal sinus requires an osteoplastic flap--fat obliteration of the frontal sinus cavity in order to preclude subsequent mucocele development or mucosal ingrowth into the anterior fossa. PMID:849204

  20. [Frontal osteoplasty technique. Report of a case of giant frontal osteoma].

    PubMed

    García Rodríguez, M R; Cabanas López, A; Fernández Domínguez, A; García Calleja, J M; García Rodríguez, J F

    1991-01-01

    We present the case of a patient with old frontal headache, who was admitted with frontal acute sinusitis symptoms at the emergency service. The radiology study shows a compatible image with frontal osteoma, which was extirpated as being asymptomatic, by frontal osteoplastic technique. The case is described and it is made a frontal osteoma review and the surgical technique used to do it. PMID:2036264

  1. EEG theta/beta ratio as a potential biomarker for attentional control and resilience against deleterious effects of stress on attention.

    PubMed

    Putman, Peter; Verkuil, Bart; Arias-Garcia, Elsa; Pantazi, Ioanna; van Schie, Charlotte

    2014-06-01

    Anxious stress compromises cognitive executive performance. This occurs, for instance, in cognitive performance anxiety (CPA), in which anxiety about one's cognitive performance causes that performance to actually deteriorate (e.g., test anxiety). This is thought to result from a prefrontal cortically (PFC) mediated failure of top-down attentional control over stress-induced automatic processing of threat-related information. In addition, stress-induced increased catecholamine influx into the PFC may directly compromise attentional function. Previous research has suggested that the ratio between resting state electroencephalographic (EEG) low- and high-frequency power (the theta/beta ratio) is related to trait attentional control, which might moderate these effects of stress on attentional function. The goals of the present study were to test the novel prediction that theta/beta ratio moderates the deleterious effects of CPA-like anxious stress on state attentional control and to replicate a previous finding that the theta/beta ratio is related to self-reported trait attentional control. After recording of baseline frontal EEG signals, 77 participants performed a stress induction or a control procedure. Trait attentional control was assessed with the Attentional Control Scale, whereas stress-induced changes in attentional control and anxiety were measured with self-report visual analogue scales. The hypothesized moderating influence of theta/beta ratio on the effects of stress on state attentional control was confirmed. Theta/beta ratio explained 28% of the variance in stress-induced deterioration of self-reported attentional control. The negative relationship between theta/beta ratio and trait attentional control was replicated (r = -.33). The theta/beta ratio reflects, likely prefrontally mediated, attentional control, and should be a useful biomarker for the study of CPA and other anxiety-cognition interactions. PMID:24379166

  2. The neuronal mechanisms underlying improvement of impulsivity in ADHD by theta/beta neurofeedback.

    PubMed

    Bluschke, Annet; Broschwitz, Felicia; Kohl, Simon; Roessner, Veit; Beste, Christian

    2016-01-01

    Neurofeedback is increasingly recognized as an intervention to treat core symptoms of attention deficit hyperactivity disorder (ADHD). Despite the large number of studies having been carried out to evaluate its effectiveness, it is widely elusive what neuronal mechanisms related to the core symptoms of ADHD are modulated by neurofeedback. 19 children with ADHD undergoing 8 weeks of theta/beta neurofeedback and 17 waiting list controls performed a Go/Nogo task in a pre-post design. We used neurophysiological measures combining high-density EEG recording with source localization analyses using sLORETA. Compared to the waiting list ADHD control group, impulsive behaviour measured was reduced after neurofeedback treatment. The effects of neurofeedback were very specific for situations requiring inhibitory control over responses. The neurophysiological data shows that processes of perceptual gating, attentional selection and resource allocation processes were not affected by neurofeedback. Rather, neurofeedback effects seem to be based on the modulation of response inhibition processes in medial frontal cortices. The study shows that specific neuronal mechanisms underlying impulsivity are modulated by theta/beta neurofeedback in ADHD. The applied neurofeedback protocol could be particularly suitable to address inhibitory control. The study validates assumed functional neuroanatomical target regions of an established neurofeedback protocol on a neurophysiological level. PMID:27514985

  3. The neuronal mechanisms underlying improvement of impulsivity in ADHD by theta/beta neurofeedback

    PubMed Central

    Bluschke, Annet; Broschwitz, Felicia; Kohl, Simon; Roessner, Veit; Beste, Christian

    2016-01-01

    Neurofeedback is increasingly recognized as an intervention to treat core symptoms of attention deficit hyperactivity disorder (ADHD). Despite the large number of studies having been carried out to evaluate its effectiveness, it is widely elusive what neuronal mechanisms related to the core symptoms of ADHD are modulated by neurofeedback. 19 children with ADHD undergoing 8 weeks of theta/beta neurofeedback and 17 waiting list controls performed a Go/Nogo task in a pre-post design. We used neurophysiological measures combining high-density EEG recording with source localization analyses using sLORETA. Compared to the waiting list ADHD control group, impulsive behaviour measured was reduced after neurofeedback treatment. The effects of neurofeedback were very specific for situations requiring inhibitory control over responses. The neurophysiological data shows that processes of perceptual gating, attentional selection and resource allocation processes were not affected by neurofeedback. Rather, neurofeedback effects seem to be based on the modulation of response inhibition processes in medial frontal cortices. The study shows that specific neuronal mechanisms underlying impulsivity are modulated by theta/beta neurofeedback in ADHD. The applied neurofeedback protocol could be particularly suitable to address inhibitory control. The study validates assumed functional neuroanatomical target regions of an established neurofeedback protocol on a neurophysiological level. PMID:27514985

  4. Hippocampo-cerebellar theta band phase synchrony in rabbits.

    PubMed

    Wikgren, J; Nokia, M S; Penttonen, M

    2010-02-17

    Hippocampal functioning, in the form of theta band oscillation, has been shown to modulate and predict cerebellar learning of which rabbit eyeblink conditioning is perhaps the most well-known example. The contribution of hippocampal neural activity to cerebellar learning is only possible if there is a functional connection between the two structures. Here, in the context of trace eyeblink conditioning, we show (1) that, in addition to the hippocampus, prominent theta oscillation also occurs in the cerebellum, and (2) that cerebellar theta oscillation is synchronized with that in the hippocampus. Further, the degree of phase synchrony (PS) increased both as a response to the conditioning stimuli and as a function of the relative power of hippocampal theta oscillation. However, the degree of PS did not change as a function of either training or learning nor did it predict learning rate as the hippocampal theta ratio did. Nevertheless, theta band synchronization might reflect the formation of transient neural assemblies between the hippocampus and the cerebellum. These findings help us understand how hippocampal function can affect eyeblink conditioning, during which the critical plasticity occurs in the cerebellum. Future studies should examine cerebellar unit activity in relation to hippocampal theta oscillations in order to discover the detailed mechanisms of theta-paced neural activity. PMID:19945512

  5. Theta Phase Synchrony and Conscious Target Perception

    PubMed Central

    Slagter, Heleen A.; Lutz, Antoine; Greischar, Lawrence L.; Nieuwenhuis, Sander; Davidson, Richard J.

    2008-01-01

    The information processing capacity of the human mind is limited, as is evidenced by the attentional blink—a deficit in identifying the second of two targets (T1 and T2) presented in close succession. This deficit is thought to result from an overinvestment of limited resources in T1 processing. We previously reported that intensive mental training in a style of meditation aimed at reducing elaborate object processing, reduced brain resource allocation to T1, and improved T2 accuracy [Slagter, H. A., Lutz, A., Greisschar, L. L., Frances, A. D., Nieuwenhuis, S., Davis, J., et al. Mental training affects distribution of limited brain resources. PloS Biology, 5, e138, 2007]. Here we report EEG spectral analyses to examine the possibility that this reduction in elaborate T1 processing rendered the system more available to process new target information, as indexed by T2-locked phase variability. Intensive mental training was associated with decreased cross-trial variability in the phase of oscillatory theta activity after successfully detected T2s, in particular, for those individuals who showed the greatest reduction in brain resource allocation to T1. These data implicate theta phase locking in conscious target perception, and suggest that after mental training the cognitive system is more rapidly available to process new target information. Mental training was not associated with changes in the amplitude of T2-induced responses or oscillatory activity before task onset. In combination, these findings illustrate the usefulness of systematic mental training in the study of the human mind by revealing the neural mechanisms that enable the brain to successfully represent target information. PMID:18823234

  6. Biomechanics of frontal skull fracture.

    PubMed

    Delye, Hans; Verschueren, Peter; Depreitere, Bart; Verpoest, Ignaas; Berckmans, Daniel; Vander Sloten, Jos; Van Der Perre, Georges; Goffin, Jan

    2007-10-01

    The purpose of the present study was to investigate whether an energy failure level applies to the skull fracture mechanics in unembalmed post-mortem human heads under dynamic frontal loading conditions. A double-pendulum model was used to conduct frontal impact tests on specimens from 18 unembalmed post-mortem human subjects. The specimens were isolated at the occipital condyle level, and pre-test computed tomography images were obtained. The specimens were rigidly attached to an aluminum pendulum in an upside down position and obtained a single degree of freedom, allowing motion in the plane of impact. A steel pendulum delivered the impact and was fitted with a flat-surfaced, cylindrical aluminum impactor, which distributed the load to a force sensor. The relative displacement between the two pendulums was used as a measure for the deformation of the specimen in the plane of impact. Three impact velocity conditions were created: low (3.60+/-0.23 m/sec), intermediate (5.21+/-0.04 m/sec), and high (6.95+/-0.04 m/sec) velocity. Computed tomography and dissection techniques were used to detect pathology. If no fracture was detected, repeated tests on the same specimen were performed with higher impact energy until fracture occurred. Peak force, displacement and energy variables were used to describe the biomechanics. Our data suggests the existence of an energy failure level in the range of 22-24 J for dynamic frontal loading of an intact unembalmed head, allowed to move with one degree of freedom. Further experiments, however, are necessary to confirm that this is a definitive energy criterion for skull fracture following impact. PMID:17970621

  7. Neural circuits underlying the generation of theta oscillations.

    PubMed

    Pignatelli, Michele; Beyeler, Anna; Leinekugel, Xavier

    2012-01-01

    Theta oscillations represent the neural network configuration underlying active awake behavior and paradoxical sleep. This major EEG pattern has been extensively studied, from physiological to anatomical levels, for more than half a century. Nevertheless the cellular and network mechanisms accountable for the theta generation are still not fully understood. This review synthesizes the current knowledge on the circuitry involved in the generation of theta oscillations, from the hippocampus to extra hippocampal structures such as septal complex, entorhinal cortex and pedunculopontine tegmentum, a main trigger of theta state through direct and indirect projections to the septal complex. We conclude with a short overview of the perspectives offered by technical advances for deciphering more precisely the different neural components underlying the emergence of theta oscillations. PMID:21964249

  8. Regeneration and maintenance of the planarian midline is regulated by a slit orthologue.

    PubMed

    Cebrià, Francesc; Guo, Tingxia; Jopek, Jessica; Newmark, Phillip A

    2007-07-15

    Several families of evolutionarily conserved axon guidance cues orchestrate the precise wiring of the nervous system during embryonic development. The remarkable plasticity of freshwater planarians provides the opportunity to study these molecules in the context of neural regeneration and maintenance. Here we characterize a homologue of the Slit family of guidance cues from the planarian Schmidtea mediterranea. Smed-slit is expressed along the planarian midline, in both dorsal and ventral domains. RNA interference (RNAi) targeting Smed-slit results in the collapse of many newly regenerated tissues at the midline; these include the cephalic ganglia, ventral nerve cords, photoreceptors, and the posterior digestive system. Surprisingly, Smed-slit RNAi knockdown animals also develop morphologically distinguishable, ectopic neural structures near the midline in uninjured regions of intact and regenerating planarians. These results suggest that Smed-slit acts not only as a repulsive cue required for proper midline formation during regeneration but that it may also act to regulate the behavior of neural precursors at the midline in intact planarians. PMID:17553481

  9. Clinical Utilization of M Spring for the Space Closure of Midline Diastema – Clinical Case Reports

    PubMed Central

    Sankar, Hanumanth; Kommi, Pradeep Babu; Arani, Nandakumar; Keerthi, V. Naga

    2016-01-01

    People approach orthodontist mainly for aesthetic purpose, midline diastema is one of the condition which causes aesthetic compromise. The midline diastema can be caused by various reasons such as high frenal attachment, midline pathology, etc. In the field of orthodontics, relapse rate is high while treating midline diastema. This relapse can be reduced only when there is bodily movement of the incisors in mesial direction. In this article, two cases of midline diastema are selected. Both the cases were treated using “M” spring which has three coils; two at periphery and one at the center and each coil was of 3mm diameter. “M” spring was fabricated using round 0.018” AJ Wilcock wire for one case and 0.017 X 0.025 TMA for another case. For both cases the duration of treatment was for six weeks. IOPA was taken after six weeks, the case in which rectangular wire was used; there was bodily movement of the central incisor in mesial direction. Whereas in round wire technique, predominantly tipping type of tooth movement was seen. The rectangular wire has two point contacts, because of which bodily movement was obtained. This technique of using rectangular wire to fabricate “M” spring has less inventory and chair side time. PMID:27135014

  10. Clinical Utilization of M Spring for the Space Closure of Midline Diastema - Clinical Case Reports.

    PubMed

    Kanyas, S Dhivya; Sankar, Hanumanth; Kommi, Pradeep Babu; Arani, Nandakumar; Keerthi, V Naga

    2016-03-01

    People approach orthodontist mainly for aesthetic purpose, midline diastema is one of the condition which causes aesthetic compromise. The midline diastema can be caused by various reasons such as high frenal attachment, midline pathology, etc. In the field of orthodontics, relapse rate is high while treating midline diastema. This relapse can be reduced only when there is bodily movement of the incisors in mesial direction. In this article, two cases of midline diastema are selected. Both the cases were treated using "M" spring which has three coils; two at periphery and one at the center and each coil was of 3mm diameter. "M" spring was fabricated using round 0.018" AJ Wilcock wire for one case and 0.017 X 0.025 TMA for another case. For both cases the duration of treatment was for six weeks. IOPA was taken after six weeks, the case in which rectangular wire was used; there was bodily movement of the central incisor in mesial direction. Whereas in round wire technique, predominantly tipping type of tooth movement was seen. The rectangular wire has two point contacts, because of which bodily movement was obtained. This technique of using rectangular wire to fabricate "M" spring has less inventory and chair side time. PMID:27135014

  11. Slow-Theta-to-Gamma Phase-Amplitude Coupling in Human Hippocampus Supports the Formation of New Episodic Memories.

    PubMed

    Lega, Bradley; Burke, John; Jacobs, Joshua; Kahana, Michael J

    2016-01-01

    Phase-amplitude coupling (PAC) has been proposed as a neural mechanism for coordinating information processing across brain regions. Here we sought to characterize PAC in the human hippocampus, and in temporal and frontal cortices, during the formation of new episodic memories. Intracranial recordings taken as 56 neurosurgical patients studied and recalled lists of words revealed significant hippocampal PAC, with slow-theta activity (2.5-5 Hz) modulating gamma band activity (34-130 Hz). Furthermore, a significant number of hippocampal electrodes exhibited greater PAC during successful than unsuccessful encoding, with the gamma activity at these sites coupled to the trough of the slow-theta oscillation. These same conditions facilitate LTP in animal models, providing a possible mechanism of action for this effect in human memory. Uniquely in the hippocampus, phase preference during item encoding exhibited a biphasic pattern. Overall, our findings help translate between the patterns identified during basic memory tasks in animals and those present during complex human memory encoding. We discuss the unique properties of human hippocampal PAC and how our findings relate to influential theories of information processing based on theta-gamma interactions. PMID:25316340

  12. Comparative study between lag screw and miniplate fixation for straight midline mandibular osteotomy.

    PubMed

    Dediol, E; Čvrljević, I; Dobranić, M; Uglešić, V

    2014-04-01

    The mandibular swing approach is a surgical approach for the resection of malignant lesions localized in the posterior oral cavity and oropharynx. We analyzed 15 years of experience with fixation of the straight midline mandibulotomy and compared two fixation methods: lag screws and miniplates. A total of 117 patients underwent a straight midline mandibulotomy during the study period; 85 had fixation with two lag screws and 32 with two miniplates. The overall complication rate was low and there was no significant difference in complication rate regarding the fixation method (9% for miniplates vs. 7% for lag screws). The most serious complication over the whole study period was non union, which occurred in only two patients, followed by orocutaneous fistula and infection. Radiotherapy did not cause serious complications and is not regarded as hazardous in midline mandibulotomy patients. We conclude that lag screw fixation is at least as safe as miniplate fixation, but because of better fragment compression, offers faster bone healing. PMID:24100153

  13. FGF-dependent midline-derived progenitor cells in hypothalamic infundibular development.

    PubMed

    Pearson, Caroline Alayne; Ohyama, Kyoji; Manning, Liz; Aghamohammadzadeh, Soheil; Sang, Helen; Placzek, Marysia

    2011-06-01

    The infundibulum links the nervous and endocrine systems, serving as a crucial integrating centre for body homeostasis. Here we describe that the chick infundibulum derives from two subsets of anterior ventral midline cells. One set remains at the ventral midline and forms the posterior-ventral infundibulum. A second set migrates laterally, forming a collar around the midline. We show that collar cells are composed of Fgf3(+) SOX3(+) proliferating progenitors, the induction of which is SHH dependent, but the maintenance of which requires FGF signalling. Collar cells proliferate late into embryogenesis, can generate neurospheres that passage extensively, and differentiate to distinct fates, including hypothalamic neuronal fates and Fgf10(+) anterior-dorsal infundibular cells. Together, our study shows that a subset of anterior floor plate-like cells gives rise to Fgf3(+) SOX3(+) progenitor cells, demonstrates a dual origin of infundibular cells and reveals a crucial role for FGF signalling in governing extended infundibular growth. PMID:21610037

  14. FGF-dependent midline-derived progenitor cells in hypothalamic infundibular development

    PubMed Central

    Pearson, Caroline Alayne; Ohyama, Kyoji; Manning, Liz; Aghamohammadzadeh, Soheil; Sang, Helen; Placzek, Marysia

    2011-01-01

    The infundibulum links the nervous and endocrine systems, serving as a crucial integrating centre for body homeostasis. Here we describe that the chick infundibulum derives from two subsets of anterior ventral midline cells. One set remains at the ventral midline and forms the posterior-ventral infundibulum. A second set migrates laterally, forming a collar around the midline. We show that collar cells are composed of Fgf3+ SOX3+ proliferating progenitors, the induction of which is SHH dependent, but the maintenance of which requires FGF signalling. Collar cells proliferate late into embryogenesis, can generate neurospheres that passage extensively, and differentiate to distinct fates, including hypothalamic neuronal fates and Fgf10+ anterior-dorsal infundibular cells. Together, our study shows that a subset of anterior floor plate-like cells gives rise to Fgf3+ SOX3+ progenitor cells, demonstrates a dual origin of infundibular cells and reveals a crucial role for FGF signalling in governing extended infundibular growth. PMID:21610037

  15. Pleomorphic Adenoma of Base of Tongue: Is Midline Mandibulotomy Necessary for Approaching Benign Base Tongue Lesions?

    PubMed Central

    Bansal, Sandeep; Kalsotra, Gopika; Mohammed, Abdul Wadood; Bahl, Amanjit; Gupta, Ashok K.

    2012-01-01

    Objective. To report a rare presentation of pleomorphic adenoma, at base tongue, excised surgically by a transoral midline glossotomy technique without mandibulotomy. Case Report. Pleomorphic adenoma is a benign tumor of the salivary gland found rarely in the base of tongue. Surgery is the definitive treatment for this tumor, and different approaches have been mentioned in the literature. In our case we surgically excised the tumor by a transoral midline glossotomy technique without mandibulotomy where we combined the cosmetic advantage of transoral technique and the exposure advantage of a glossotomy technique. Discussion. We discuss the different approaches to oropharynx, their advantages and disadvantages. Primary transoral approach provides better cosmesis but less exposure whereas median labiomandibuloglossotomy approach provides more exposure but is cosmetically unacceptable. Conclusion. A transoral midline glossotomy approach without mandibulotomy provides wide exposure with acceptable cosmesis. PMID:22953125

  16. Anatomic Considerations in Frontal Sinus Surgery.

    PubMed

    Folbe, Adam J; Svider, Peter F; Eloy, Jean Anderson

    2016-08-01

    Comprehension of the complex anatomic variants comprising the frontal sinus outflow tract is essential for successful surgical intervention. Deviation from sound technique increases the potential for a variety of deleterious sequelae, including recurrent disease as well as catastrophic intracranial and orbital injury. Furthermore, incomplete removal of elements occluding the frontal recess can result in severe stenosis that can increase the difficulty of further interventions. This review covers anatomic considerations that should be kept in mind when performing frontal sinus surgery. PMID:27329978

  17. Theta synchronizes the activity of medial prefrontal neurons during learning.

    PubMed

    Paz, Rony; Bauer, Elizabeth P; Paré, Denis

    2008-07-01

    Memory consolidation is thought to involve the gradual transfer of transient hippocampal-dependent traces to distributed neocortical sites via the rhinal cortices. Recently, medial prefrontal (mPFC) neurons were shown to facilitate this process when their activity becomes synchronized. However, the mechanisms underlying this enhanced synchrony remain unclear. Because the hippocampus projects to the mPFC, we tested whether theta oscillations contribute to synchronize mPFC neurons during learning. Thus, we obtained field (LFP) and unit recordings from multiple mPFC sites during the acquisition of a trace-conditioning task, where a visual conditioned stimulus (CS) predicted reward delivery. In quiet waking, the activity of mPFC neurons was modulated by theta oscillations. During conditioning, CS presentation caused an increase in mPFC theta power that augmented as the CS gained predictive value for reward delivery. This increased theta power coincided with a transient theta phase locking at distributed mPFC sites, an effect that was also manifest in the timing of mPFC unit activity. Overall, these results show that theta oscillations contribute to synchronize neuronal activity at distributed mPFC sites, suggesting that the hippocampus, by generating a stronger theta source during learning, can synchronize mPFC activity, in turn facilitating rhinal transfer of its activity to the neocortex. PMID:18612069

  18. A Comparison of Midline and Tracheal Gene Regulation during Drosophila Development

    PubMed Central

    Long, Sarah K. R.; Fulkerson, Eric; Breese, Rebecca; Hernandez, Giovanna; Davis, Cara; Melton, Mark A.; Chandran, Rachana R.; Butler, Napoleon; Jiang, Lan; Estes, Patricia

    2014-01-01

    Within the Drosophila embryo, two related bHLH-PAS proteins, Single-minded and Trachealess, control development of the central nervous system midline and the trachea, respectively. These two proteins are bHLH-PAS transcription factors and independently form heterodimers with another bHLH-PAS protein, Tango. During early embryogenesis, expression of Single-minded is restricted to the midline and Trachealess to the trachea and salivary glands, whereas Tango is ubiquitously expressed. Both Single-minded/Tango and Trachealess/Tango heterodimers bind to the same DNA sequence, called the CNS midline element (CME) within cis-regulatory sequences of downstream target genes. While Single-minded/Tango and Trachealess/Tango activate some of the same genes in their respective tissues during embryogenesis, they also activate a number of different genes restricted to only certain tissues. The goal of this research is to understand how these two related heterodimers bind different enhancers to activate different genes, thereby regulating the development of functionally diverse tissues. Existing data indicates that Single-minded and Trachealess may bind to different co-factors restricted to various tissues, causing them to interact with the CME only within certain sequence contexts. This would lead to the activation of different target genes in different cell types. To understand how the context surrounding the CME is recognized by different bHLH-PAS heterodimers and their co-factors, we identified and analyzed novel enhancers that drive midline and/or tracheal expression and compared them to previously characterized enhancers. In addition, we tested expression of synthetic reporter genes containing the CME flanked by different sequences. Taken together, these experiments identify elements overrepresented within midline and tracheal enhancers and suggest that sequences immediately surrounding a CME help dictate whether a gene is expressed in the midline or trachea. PMID:24465586

  19. Overview of Frontal Sinus Pathology and Management.

    PubMed

    Vázquez, Alejandro; Baredes, Soly; Setzen, Michael; Eloy, Jean Anderson

    2016-08-01

    The frontal sinus is the most complex of all paranasal sinuses. Given its proximity to the cranial vault and orbit, frontal sinus pathology can progress to involve these structures and lead to significant morbidity, or even mortality. Surgical management of the frontal sinus is technically challenging. Various open and endoscopic surgical techniques are available to the otolaryngologist. This article presents an overview of the major disease entities that affect the frontal sinus, with a special emphasis on treatment principles and surgical management. PMID:27329984

  20. Analysis of the energetic parameters of a theta pinch

    SciTech Connect

    Cavalcanti, G. H.; Farias, E. E.

    2009-12-15

    This work is devoted to study experimentally the performance of a theta pinch when the number of capacitors and turns of magnetic coil and the diameter of the glass tube are changed. To model the theta pinch a simple RLC circuit is used and the measurement of energy transmission from the bank of capacitors to the plasma is made using few experimental resources. In this work it was analyzed more than 2500 curves with a nonlinear procedure. Our results show that it is possible to design an optimized theta pinch making the appropriated choice of energetic parameters and therefore to reduce the stress of the system.

  1. Numerical studies of frontal dynamics

    NASA Technical Reports Server (NTRS)

    Keyser, Daniel

    1986-01-01

    Efforts concentrated on the development of a two dimensional primitive equation (PE) model of frontogenesis that simultaneously incorporates the frontagenetical mechanisms of confluence and horizontal shear. Applying this model to study the effects of upper level frontogenesis, it appeared to be dominated by tilting effects associated with cross front variation of vertical motion, in which subsidence is maximized within and to the warm side of the frontal zone. Results suggest that aspects characteristic of three-dimensional baroclinic waves may be abstracted to a significant extent in a two dimensional framework. They also show that upper-level frontogenesis and tropopause folding can occur in the absence of three-dimensional curvature effects, commonly believed to be necessary for realistic upper-level frontogenesis. An implication of the dominant tilting effects is that they may have to be adequately resolved by numerical weather prediction models, thus requiring better horizontal and vertical resolution.

  2. Intrinsic Cornu Ammonis Area 1 Theta-Nested Gamma Oscillations Induced by Optogenetic Theta Frequency Stimulation

    PubMed Central

    Butler, James L.; Mendonça, Philipe R. F.; Robinson, Hugh P. C.

    2016-01-01

    Gamma oscillations (30–120 Hz) are thought to be important for various cognitive functions, including perception and working memory, and disruption of these oscillations has been implicated in brain disorders, such as schizophrenia and Alzheimer's disease. The cornu ammonis area 1 (CA1) of the hippocampus receives gamma frequency inputs from upstream regions (cornu ammonis area 3 and medial entorhinal cortex) and generates itself a faster gamma oscillation. The exact nature and origin of the intrinsic CA1 gamma oscillation is still under debate. Here, we expressed channelrhodopsin-2 under the CaMKIIα promoter in mice and prepared hippocampal slices to produce a model of intrinsic CA1 gamma oscillations. Sinusoidal optical stimulation of CA1 at theta frequency was found to induce robust theta-nested gamma oscillations with a temporal and spatial profile similar to CA1 gamma in vivo. The results suggest the presence of a single gamma rhythm generator with a frequency range of 65–75 Hz at 32°C. Pharmacological analysis found that the oscillations depended on both AMPA and GABAA receptors. Cell-attached and whole-cell recordings revealed that excitatory neuron firing slightly preceded interneuron firing within each gamma cycle, suggesting that this intrinsic CA1 gamma oscillation is generated with a pyramidal–interneuron circuit mechanism. SIGNIFICANCE STATEMENT This study demonstrates that the cornu ammonis area 1 (CA1) is capable of generating intrinsic gamma oscillations in response to theta input. This gamma generator is independent of activity in the upstream regions, highlighting that CA1 can produce its own gamma oscillation in addition to inheriting activity from the upstream regions. This supports the theory that gamma oscillations predominantly function to achieve local synchrony, and that a local gamma generated in each area conducts the signal to the downstream region. PMID:27076416

  3. Hippocampal-Prefrontal Theta Oscillations Support Memory Integration.

    PubMed

    Backus, Alexander R; Schoffelen, Jan-Mathijs; Szebényi, Szabolcs; Hanslmayr, Simon; Doeller, Christian F

    2016-02-22

    Integration of separate memories forms the basis of inferential reasoning--an essential cognitive process that enables complex behavior. Considerable evidence suggests that both hippocampus and medial prefrontal cortex (mPFC) play a crucial role in memory integration. Although previous studies indicate that theta oscillations facilitate memory processes, the electrophysiological mechanisms underlying memory integration remain elusive. To bridge this gap, we recorded magnetoencephalography data while participants performed an inference task and employed novel source reconstruction techniques to estimate oscillatory signals from the hippocampus. We found that hippocampal theta power during encoding predicts subsequent memory integration. Moreover, we observed increased theta coherence between hippocampus and mPFC. Our results suggest that integrated memory representations arise through hippocampal theta oscillations, possibly reflecting dynamic switching between encoding and retrieval states, and facilitating communication with mPFC. These findings have important implications for our understanding of memory-based decision making and knowledge acquisition. PMID:26832442

  4. Reversed theta sequences of hippocampal cell assemblies during backward travel.

    PubMed

    Cei, Anne; Girardeau, Gabrielle; Drieu, Céline; Kanbi, Karim El; Zugaro, Michaël

    2014-05-01

    Hippocampal cell assemblies coding for past, present and future events form theta-timescale (~100 ms) sequences that represent spatio-temporal episodes. However, the underlying mechanisms remain largely unknown. We recorded hippocampal and entorhinal cortical activity as rats experienced backward travel on a model train. Although the firing fields of place cells remained stable, the order in which they were activated in the theta sequence was reversed during backward travel. Thus, hippocampal cell assemblies coordinated their relative timing to correctly predict the sequential traversal of place fields in reverse order. At the single-cell level, theta phase represented distance traveled through the field, even though the head of the rat was oriented opposite to travel direction and entorhinal head-direction cells maintained their preferred firing direction. Our results challenge most theoretical models of theta sequence generation in the hippocampus. PMID:24667574

  5. Simultaneous observations of a theta aurora and associated magnetotail plasmas

    SciTech Connect

    Huang, C.Y.; Craven, J.D.; Frank, L.A.

    1989-08-01

    Observations of a transpolar arc and simultaneous measurements of associated plasmas in the magnetotail lobe on March 25, 1982, are presented. The auroral imager on board Dynamics Explorer 1 observes a theta aurora in the northern polar cap for more than 2 hours, between 0502 and 0720 UT. ISEE 1 is located in the southern lobe of the geomagnetic tail at a distance of 22.2 RE during this time. The plasma and particle detectors measure intermittent bursts of particle fluxes between 0530 and 0705 UT. The observations suggest that these particle fluxes represent the high-altitude signature of a theta aurora in the southern polar cap. The relatively dense and energetic plasmas are organized into several filamentary structures. Magnetic mapping between the two polar regions indicates that the theta aurora in the southern hemisphere is a mirror reflection about the noon-midnight meridional plane of the theta aurora in the northern hemisphere.

  6. Neutrino mass hierarchy determination for theta{sub 13} = 0

    SciTech Connect

    Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Sankar, S. Uma

    2010-03-30

    We examine the possibility of determining the neutrino mass hierarchy in the limit theta{sub 13} = 0 using atmospheric neutrinos as the source. In this limit, theta{sub 13} driven matter effects are absent so independent measurements of DELTA{sub 31} and DELTA{sub 32} can, in principle, lead to hierarchy determination. Since their difference is DELTA{sub 21}, one needs an experimental arrangement where DELTA{sub 21}L/E > or approx. 1 can be achieved. This can be satisfied by atmospheric neutrinos which have a large range of L and E. Still, we find that hierarchy determination in the theta{sub 13} = 0 limit with atmospheric neutrinos is not a realistic possibility, even in conjunction with a beam experiment like T2K or NOnuA. We discuss why, and also reiterate the general conditions for hierarchy determination if theta{sub 13} = 0.

  7. Probing {theta}{sub 23} in neutrino telescopes

    SciTech Connect

    Choubey, Sandhya; Niro, Viviana; Rodejohann, Werner

    2008-06-01

    Among all neutrino mixing parameters, the atmospheric neutrino mixing angle {theta}{sub 23} introduces the strongest variation on the flux ratios of ultrahigh-energy neutrinos. We investigate the potential of these flux ratio measurements at neutrino telescopes to constrain {theta}{sub 23}. We consider astrophysical neutrinos originating from pion, muon-damped, and neutron sources and make a comparative study of their sensitivity reach to {theta}{sub 23}. It is found that neutron sources are most favorable for testing deviations from maximal {theta}{sub 23}. Using a {chi}{sup 2} analysis, we show, in particular, the power of combining (i) different flux ratios from the same type of source, and also (ii) combining flux ratios from different astrophysical sources. We include in our analysis 'impure' sources, i.e., deviations from the usually assumed initial (1 ratio 2 ratio 0), (0 ratio 1 ratio 0), or (1 ratio 0 ratio 0) flux compositions.

  8. The cos-theta coil re-re-visited

    NASA Astrophysics Data System (ADS)

    Crawford, Christopher

    2013-10-01

    Precision measurement of symmetry violating effects such the electric dipole moment (EDM) of fundamental particles requires extremely uniform fields. The cos-theta coil is the standard workhorse for generating uniform transverse magnetic fields in these experiments. Limitations in field uniformity include fringe effects (finite length), discretization (finite number of wires), and construction tolerance (finite resources). The field can be isolated from its environment by superposition of two coaxial cos-theta coils of different radii and opposite magnetic moment (double-cos-theta coil), or by shielding the coil inside a permeable or superconducting cylinder. I will discuss methods for optimizing the field uniformity of a compact cos-theta coil, and compare the ultimate limit on errors due to each source described above. Within the context of the scalar potential, I will show a straightforward generalization to non-circular coils with z- or ϕ-symmetry. Supported in part by DOE contract DE-SC0008107.

  9. Simultaneous observations of a theta aurora and associated magnetotail plasmas

    NASA Technical Reports Server (NTRS)

    Huang, C. Y.; Craven, J. D.; Frank, L. A.

    1989-01-01

    Observations of a transpolar arc and simultaneous measurements of associated plasmas in the magnetotail lobe on March 25, 1982, are presented. The auroral imager on board Dynamics Explorer 1 observes a theta aurora in the northern polar cap for more than two hours, between 0502 and 0720 UT. ISEE 1 is located in the southern lobe of the geomagnetic tail at a distance of 22.2 R(E) during this time. The plasma and particle detectors measure intermittent bursts of particle fluxes between 0530 and 0705 UT. The observations suggest that these particle fluxes represent the high-altitude signature of a theta aurora in the southern polar cap. The relatively dense and energetic plasmas are organized into several filamentary structures. Magnetic mapping between the two polar regions indicates that the theta aurora in the Southern Hemisphere is a mirror reflection about the noon-midnight meridional plane of the theta aurora in the Northern Hemisphere.

  10. Human frontal lobes are not relatively large.

    PubMed

    Barton, Robert A; Venditti, Chris

    2013-05-28

    One of the most pervasive assumptions about human brain evolution is that it involved relative enlargement of the frontal lobes. We show that this assumption is without foundation. Analysis of five independent data sets using correctly scaled measures and phylogenetic methods reveals that the size of human frontal lobes, and of specific frontal regions, is as expected relative to the size of other brain structures. Recent claims for relative enlargement of human frontal white matter volume, and for relative enlargement shared by all great apes, seem to be mistaken. Furthermore, using a recently developed method for detecting shifts in evolutionary rates, we find that the rate of change in relative frontal cortex volume along the phylogenetic branch leading to humans was unremarkable and that other branches showed significantly faster rates of change. Although absolute and proportional frontal region size increased rapidly in humans, this change was tightly correlated with corresponding size increases in other areas and whole brain size, and with decreases in frontal neuron densities. The search for the neural basis of human cognitive uniqueness should therefore focus less on the frontal lobes in isolation and more on distributed neural networks. PMID:23671074

  11. Transient global amnesia and left frontal haemorrhage.

    PubMed Central

    Jacome, D. E.; Yanez, G. F.

    1988-01-01

    A patient developed spontaneous, acute, dominant frontal lobe haemorrhage neighbouring on a zone of pre-existing post-traumatic encephalomalacia manifesting clinically as transient global amnesia. Amnesia can be secondary to disease of the frontal lobe, affecting pathways interconnecting the basal forebrain and hippocampus of the temporal lobe. Images Figure 1 PMID:3174526

  12. The surgery of frontal sinus infection.

    PubMed

    Du Preez, S F; Collard, W M; Sellars, S L

    1975-11-01

    A clinical and surgical review of 37 patients treated for acute and chronic frontal sinusitis at Groote Schuur Hospital during the 6-year period 1967-1972, is presented. The mode of clinical presentation of this disease and its complications are discussed, and the surgical management of frontal sinus disease as practised at this hospital is described. PMID:1198214

  13. Human frontal lobes are not relatively large

    PubMed Central

    Barton, Robert A.; Venditti, Chris

    2013-01-01

    One of the most pervasive assumptions about human brain evolution is that it involved relative enlargement of the frontal lobes. We show that this assumption is without foundation. Analysis of five independent data sets using correctly scaled measures and phylogenetic methods reveals that the size of human frontal lobes, and of specific frontal regions, is as expected relative to the size of other brain structures. Recent claims for relative enlargement of human frontal white matter volume, and for relative enlargement shared by all great apes, seem to be mistaken. Furthermore, using a recently developed method for detecting shifts in evolutionary rates, we find that the rate of change in relative frontal cortex volume along the phylogenetic branch leading to humans was unremarkable and that other branches showed significantly faster rates of change. Although absolute and proportional frontal region size increased rapidly in humans, this change was tightly correlated with corresponding size increases in other areas and whole brain size, and with decreases in frontal neuron densities. The search for the neural basis of human cognitive uniqueness should therefore focus less on the frontal lobes in isolation and more on distributed neural networks. PMID:23671074

  14. Midline Crossing: Developmental Trend from 3 to 10 Years of Age in a Preferential Card-Reaching Task

    ERIC Educational Resources Information Center

    Carlier, M.; Doyen, A.-L.; Lamard, C.

    2006-01-01

    We assessed 110 left-handed and 322 right-handed children aged from 3 to 10 years, using Bishop's card-reaching task. Manual body midline crossings were observed. A regular developmental trend was observed from 3 to 10 years: older children crossed the body midline more frequently when reaching for cards than did younger children. The factor age…

  15. Neonatal Stroke Causes Poor Midline Motor Behaviors and Poor Fine and Gross Motor Skills during Early Infancy

    ERIC Educational Resources Information Center

    Chen, Chao-Ying; Lo, Warren D.; Heathcock, Jill C.

    2013-01-01

    Upper extremity movements, midline behaviors, fine, and gross motor skills are frequently impaired in hemiparesis and cerebral palsy. We investigated midline toy exploration and fine and gross motor skills in infants at risk for hemiplegic cerebral palsy. Eight infants with neonatal stroke (NS) and thirteen infants with typical development (TD)…

  16. Chemogenetic silencing of the midline and intralaminar thalamus blocks amygdala-kindled seizures.

    PubMed

    Wicker, Evan; Forcelli, Patrick A

    2016-09-01

    Temporal lobe epilepsy is the most common form of medically-intractable epilepsy. While seizures in TLE originate in structures such as hippocampus, amygdala, and temporal cortex, they propagate through a crucial relay: the midline/intralaminar thalamus. Prior studies have shown that pharmacological inhibition of midline thalamus attenuates limbic seizures. Here, we examined a recently developed technology, Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), as a means of chemogenetic silencing to attenuate limbic seizures. Adult, male rats were electrically kindled from the amygdala, and injected with virus coding for inhibitory (hM4Di) DREADDs into the midline/intralaminar thalamus. When treated with the otherwise inert ligand Clozapine-N-Oxide (CNO) at doses of 2.5, 5, and 10mg/kg, electrographic and behavioral seizure manifestations were suppressed in comparison to vehicle. At higher doses, we found complete blockade of seizure activity in a subset of subjects. CNO displayed a sharp time-response profile, with significant seizure attenuation seen 20-30min post injection, in comparison to 10 and 40min post injection. Seizures in animals injected with a control vector (i.e., no DREADD) were unaffected by CNO administration. These data underscore the crucial role of the midline/intralaminar thalamus in the propagation of seizures, specifically in the amygdala kindling model, and provide validation of chemogenetic silencing of limbic seizures. PMID:27404844

  17. Maxillary Midline diastema closure after replacement of primary teeth with implant prosthesis.

    PubMed

    Al-Saqabi, Farah Y; Fenlon, Michael R; Bavisha, Kalpesh A

    2015-05-01

    This case shows an excellent esthetic treatment outcome using implant-retained crowns replacing maxillary laterals and canines in hypodontia patient with unusual incidence of spontaneous diastema closure after the placement of implants. To our knowledge, this is the first case report showing maxillary midline diastema closure after implant placement. PMID:25984308

  18. Transient Relay Function of Midline Thalamic Nuclei during Long-Term Memory Consolidation in Humans

    ERIC Educational Resources Information Center

    Thielen, Jan-Willem; Takashima, Atsuko; Rutters, Femke; Tendolkar, Indira; Fernández, Guillén

    2015-01-01

    To test the hypothesis that thalamic midline nuclei play a transient role in memory consolidation, we reanalyzed a prospective functional MRI study, contrasting recent and progressively more remote memory retrieval. We revealed a transient thalamic connectivity increase with the hippocampus, the medial prefrontal cortex (mPFC), and a…

  19. Cooperation or competition of the two hemispheres in processing characters presented at vertical midline.

    PubMed

    Verleger, Rolf; Dittmer, Marie; Smigasiewicz, Kamila

    2013-01-01

    Little is known about how the hemispheres interact in processing of stimuli presented at vertical midline. Processing might be mutually independent or cooperative. Here we measured target identification and visually evoked EEG potentials while stimulus streams containing two targets, T1 and T2, were either presented at vertical midline above and below fixation, or laterally, left and right. With left and right streams, potentials evoked by filler stimuli and by T2 were earlier at the right than the left visual cortex, and T2 was better identified left than right, confirming earlier results and suggesting better capabilities of the right hemisphere in this task. With streams above and below fixation, EEG potentials evoked by filler stimuli and by T2 were likewise earlier at the right than the left hemisphere, and T2 was generally identified as well as, but not better than left T2, in one target constellation even worse (T2 in lower stream preceded by T1 in upper stream). These results suggest right-hemisphere preference for this task even with stimuli at vertical midline, and no added value through hemispheric cooperation. Lacking asymmetry for T1 amidst asymmetries for filler stimuli and for T2 might indicate alternating access of the hemispheres to midline stimuli as one means of hemispheric division of labor. PMID:23451226

  20. gdnf activates midline repulsion by Semaphorin3B via NCAM during commissural axon guidance.

    PubMed

    Charoy, Camille; Nawabi, Homaira; Reynaud, Florie; Derrington, Edmund; Bozon, Muriel; Wright, Kevin; Falk, Julien; Helmbacher, Françoise; Kindbeiter, Karine; Castellani, Valérie

    2012-09-20

    The Neurotrophic factor gdnf plays diverse developmental roles, supporting survival and also acting as a chemoattractant for axon and cell migration. We report that in the developing spinal cord, a focal source of gdnf is present in the floor plate (FP) where commissural axons cross the midline. Gdnf has no direct guidance properties but switches on the responsiveness of crossing commissural growth cones to the midline repellent Semaphorin3B by suppressing calpain-mediated processing of the Sema3B signaling coreceptor Plexin-A1. Analysis of single and double mutant mouse models indicates that although gdnf is the principal trigger of Sema3B midline repulsion, it acts with another FP cue, NrCAM. Finally, genetic and in vitro experiments provide evidence that this gdnf effect is RET independent and mediated by NCAM/GFRα1 signaling. This study identifies a regulator of midline crossing and reveals interplays between Semaphorin and gdnf signaling during axon guidance. PMID:22998873

  1. Clinical and Imaging Features of a Congenital Midline Cervical Cleft in a Neonate: A Rare Anomaly

    PubMed Central

    Bawa, Pritish; Ibrahim, Zachary; Amodio, John

    2015-01-01

    Congenital midline cervical cleft (CMCC) is a rare congenital anomaly. CMCC and its complications and treatment have been well described in ENT, dermatology, and pediatric surgery literature. However, to our knowledge, the imaging work-up has not been reported in the literature thus far. We present a case of CMCC in a neonate with description of clinical presentation and imaging features. PMID:26078904

  2. Midline lumbar ganglion/synovial cyst mimicking an epidural tumor: case report and review of pathogenesis.

    PubMed

    Azzam, C J

    1988-08-01

    A case of a midline lumbar extradural ganglion/synovial cyst causing lumbar canal stenosis and mimicking an epidural tumor is presented. The lesion was demonstrated by a magnetic resonance imaging study, and relief of symptoms was achieved with decompressive laminectomy and total removal of the mass. The pathogenesis of lumbar ganglion/synovial cyst is reviewed. PMID:2972941

  3. Self-Referential Processing, Rumination, and Cortical Midline Structures in Major Depression

    PubMed Central

    Nejad, Ayna Baladi; Fossati, Philippe; Lemogne, Cédric

    2013-01-01

    Major depression is associated with a bias toward negative emotional processing and increased self-focus, i.e., the process by which one engages in self-referential processing. The increased self-focus in depression is suggested to be of a persistent, repetitive and self-critical nature, and is conceptualized as ruminative brooding. The role of the medial prefrontal cortex in self-referential processing has been previously emphasized in acute major depression. There is increasing evidence that self-referential processing as well as the cortical midline structures play a major role in the development, course, and treatment response of major depressive disorder. However, the links between self-referential processing, rumination, and the cortical midline structures in depression are still poorly understood. Here, we reviewed brain imaging studies in depressed patients and healthy subjects that have examined these links. Self-referential processing in major depression seems associated with abnormally increased activity of the anterior cortical midline structures. Abnormal interactions between the lateralized task-positive network, and the midline cortical structures of the default mode network, as well as the emotional response network, may underlie the pervasiveness of ruminative brooding. Furthermore, targeting this maladaptive form of rumination and its underlying neural correlates may be key for effective treatment. PMID:24124416

  4. Medial prefrontal theta phase coupling during spatial memory retrieval.

    PubMed

    Kaplan, Raphael; Bush, Daniel; Bonnefond, Mathilde; Bandettini, Peter A; Barnes, Gareth R; Doeller, Christian F; Burgess, Neil

    2014-06-01

    Memory retrieval is believed to involve a disparate network of areas, including medial prefrontal and medial temporal cortices, but the mechanisms underlying their coordination remain elusive. One suggestion is that oscillatory coherence mediates inter-regional communication, implicating theta phase and theta-gamma phase-amplitude coupling in mnemonic function across species. To examine this hypothesis, we used non-invasive whole-head magnetoencephalography (MEG) as participants retrieved the location of objects encountered within a virtual environment. We demonstrate that, when participants are cued with the image of an object whose location they must subsequently navigate to, there is a significant increase in 4-8 Hz theta power in medial prefrontal cortex (mPFC), and the phase of this oscillation is coupled both with ongoing theta phase in the medial temporal lobe (MTL) and perceptually induced 65-85 Hz gamma amplitude in medial parietal cortex. These results suggest that theta phase coupling between mPFC and MTL and theta-gamma phase-amplitude coupling between mPFC and neocortical regions may play a role in human spatial memory retrieval. PMID:24497013

  5. Analytical Insights on Theta-Gamma Coupled Neural Oscillators

    PubMed Central

    2013-01-01

    In this paper, we study the dynamics of a quadratic integrate-and-fire neuron, spiking in the gamma (30–100 Hz) range, coupled to a delta/theta frequency (1–8 Hz) neural oscillator. Using analytical and semianalytical methods, we were able to derive characteristic spiking times for the system in two distinct regimes (depending on parameter values): one regime where the gamma neuron is intrinsically oscillating in the absence of theta input, and a second one in which gamma spiking is directly gated by theta input, i.e., windows of gamma activity alternate with silence periods depending on the underlying theta phase. In the former case, we transform the equations such that the system becomes analogous to the Mathieu differential equation. By solving this equation, we can compute numerically the time to the first gamma spike, and then use singular perturbation theory to find successive spike times. On the other hand, in the excitable condition, we make direct use of singular perturbation theory to obtain an approximation of the time to first gamma spike, and then extend the result to calculate ensuing gamma spikes in a recursive fashion. We thereby give explicit formulas for the onset and offset of gamma spike burst during a theta cycle, and provide an estimation of the total number of spikes per theta cycle both for excitable and oscillator regimes. PMID:23945442

  6. Frontal sinus cholesterol granuloma: Case report

    PubMed Central

    Deep, Nicholas L.; Chaaban, Mohamad R.; Chaudhry, Ajaz L.

    2014-01-01

    A case report of a massive cholesterol granuloma (CG) of the frontal sinus in a 15-year-old male subject treated endoscopically is reported. CGs are slowly expanding, cystic lesions that are rarely observed in the frontal sinus. Frontal sinus CGs characteristically present with proptosis, diplopia, and a unilateral painless expanding mass above the orbit. Patients frequently report a history of chronic nasal obstruction or head trauma. Although the pathogenesis is unclear, it is likely multifactorial in etiology. Surgical resection via endoscopic sinus surgery has been gaining popularity because of the minimally invasive approach and lower rates of recurrence. PMID:24612824

  7. Spectral modulation of frontal EEG during motor skill acquisition: a mobile EEG study.

    PubMed

    Wong, Savio W H; Chan, Rosa H M; Mak, Joseph N

    2014-01-01

    This study investigates the modulation of frontal EEG dynamics with respect to progress in motor skill acquisition using a wireless EEG system with a single dry sensor. Participants were required to complete repeated trials of a computerized visual-motor task similar to mirror drawing while the EEG was collected. In each trial, task performance of the participants was summarized with a familiarity index which took into account the performance accuracy, completion rate and time. Our findings demonstrated that certain EEG power spectra decreased with an increase in motor task familiarity. In particular, frontal EEG activities in delta and theta bands of the whole trial and in gamma band in the middle of the trial are having a significant negative relationship with the overall familiarity level of the task. The findings suggest that frontal EEG spectra are significantly modulated during motor skill acquisition. Results of this study shed light on the possibility of simultaneous monitoring of brain activity during an unconstrained natural task with a single dry sensor mobile EEG in an everyday environment. PMID:24095979

  8. Cranialization of the Frontal Sinus for Secondary Mucocele Prevention following Open Surgery for Benign Frontal Lesions

    PubMed Central

    Horowitz, Gilad; Amit, Moran; Ben-Ari, Oded; Gil, Ziv; Abergel, Abraham; Margalit, Nevo; Cavel, Oren; Wasserzug, Oshri; Fliss, Dan M.

    2013-01-01

    Objective To compare frontal sinus cranialization to obliteration for future prevention of secondary mucocele formation following open surgery for benign lesions of the frontal sinus. Study Design Retrospective case series. Setting Tertiary academic medical center. Patients Sixty-nine patients operated for benign frontal sinus pathology between 1994 and 2011. Interventions Open excision of benign frontal sinus pathology followed by either frontal obliteration (n = 41, 59%) or frontal cranialization (n = 28, 41%). Main Outcome Measures The prevalence of post-surgical complications and secondary mucocele formation were compiled. Results Pathologies included osteoma (n = 34, 49%), mucocele (n = 27, 39%), fibrous dysplasia (n = 6, 9%), and encephalocele (n = 2, 3%). Complications included skin infections (n = 6), postoperative cutaneous fistula (n = 1), telecanthus (n = 4), diplopia (n = 3), nasal deformity (n = 2) and epiphora (n = 1). None of the patients suffered from postoperative CSF leak, meningitis or pneumocephalus. Six patients, all of whom had previously undergone frontal sinus obliteration, required revision surgery due to secondary mucocele formation. Statistical analysis using non-inferiority test reveal that cranialization of the frontal sinus is non-inferior to obliteration for preventing secondary mucocele formation (P<0.0001). Conclusion Cranialization of the frontal sinus appears to be a good option for prevention of secondary mucocele development after open excision of benign frontal sinus lesions. PMID:24376760

  9. Msxb is a core component of the genetic circuitry specifying the dorsal and ventral neurogenic midlines in the ascidian embryo.

    PubMed

    Roure, Agnès; Darras, Sébastien

    2016-01-01

    The tail ascidian larval peripheral nervous system is made up of epidermal sensory neurons distributed more or less regularly in ventral and dorsal midlines. Their formation occurs in two-steps: the ventral and dorsal midlines are induced as neurogenic territories by Fgf9/16/20 and Admp respectively. The Delta2/Notch interaction then controls the number of neurons that form. The genetic machinery acting between the inductive processes taking place before gastrulation and neuron specification at tailbud stages are largely unknown. The analysis of seven transcription factors expressed in the forming midlines revealed an unexpected complexity and dynamic of gene expression. Their systematic overexpression confirmed that these genes do not interact following a linear cascade of activation. However, the integration of our data revealed the distinct key roles of the two upstream factors Msxb and Nkx-C that are the earliest expressed genes and the only ones able to induce neurogenic midline and ESN formation. Our data suggest that Msxb would be the primary midline gene integrating inputs from the ventral and dorsal inducers and launching a pan-midline transcriptional program. Nkx-C would be involved in tail tip specification, in maintenance of the pan-midline network and in a posterior to anterior wave controlling differentiation. PMID:26592100

  10. Quantum modular forms, mock modular forms, and partial theta functions

    NASA Astrophysics Data System (ADS)

    Kimport, Susanna

    Defined by Zagier in 2010, quantum modular forms have been the subject of an explosion of recent research. Many of these results are aimed at discovering examples of these functions, which are defined on the rational numbers and have "nice" modularity properties. Though the subject is in its early stages, numerous results (including Zagier's original examples) show these objects naturally arising from many areas of mathematics as limits of other modular-like functions. One such family of examples is due to Folsom, Ono, and Rhoades, who connected these new objects to partial theta functions (introduced by Rogers in 1917) and mock modular forms (about which there is a rich theory, whose origins date back to Ramanujan in 1920). In this thesis, we build off of the work of Folsom, Ono, and Rhoades by providing an infinite family of quantum modular forms of arbitrary positive half-integral weight. Further, this family of quantum modular forms "glues" mock modular forms to partial theta functions and is constructed from a so-called "universal" mock theta function by extending a method of Eichler and Zagier (originally defined for holomorphic Jacobi forms) into a non-holomorphic setting. In addition to the infinite family, we explore the weight 1/2 and 3/2 functions in more depth. For both of these weights, we are able to explicitly write down the quantum modular form, as well as the corresponding "errors to modularity," which can be shown to be Mordell integrals of specific theta functions and, as a consequence, are real-analytic functions. Finally, we turn our attention to the partial theta functions associated with these low weight examples. Berndt and Kim provide asymptotic expansions for a certain class of partial theta functions as q approaches 1 radially within the unit disk. Here, we extend this work to not only obtain asymptotic expansions for this class of functions as q approaches any root of unity, but also for a certain class of derivatives of these functions

  11. A comparison of the Wiltse versus midline approaches in degenerative conditions of the lumbar spine.

    PubMed

    Street, John T; Andrew Glennie, R; Dea, Nicolas; DiPaola, Christian; Wang, Zhi; Boyd, Michael; Paquette, Scott J; Kwon, Brian K; Dvorak, Marcel F; Fisher, Charles G

    2016-09-01

    OBJECTIVE The objective of this study was to determine if there is a significant difference in surgical site infection (SSI) when comparing the Wiltse and midline approaches for posterior instrumented interbody fusions of the lumbar spine and, secondarily, to evaluate if the reoperation rates and specific causes for reoperation were similar for both approaches. METHODS A total of 358 patients who underwent 1- or 2-level posterior instrumented interbody fusions for degenerative lumbar spinal pathology through either a midline or Wiltse approach were prospectively followed between March 2005 and January 2011 at a single tertiary care facility. A retrospective analysis was performed primarily to evaluate the incidence of SSI and the incidence and causes for reoperation. Secondary outcome measures included intraoperative complications, blood loss, and length of stay. A matched analysis was performed using the Fisher's exact test and a logistic regression model. The matched analysis controlled for age, sex, comorbidities, number of index levels addressed surgically, number of levels fused, and the use of bone grafting. RESULTS All patients returned for follow-up at 1 year, and adverse events were followed for 2 years. The rate of SSI was greater in the midline group (8 of 103 patients; 7.8%) versus the Wiltse group (1 of 103 patients; 1.0%) (p = 0.018). Fewer additional surgical procedures were performed in the Wiltse group (p = 0.025; OR 0.47; 95% CI 0.23-0.95). Proximal adjacent segment failure requiring reoperation occurred more frequently in the midline group (15 of 103 patients; 14.6%) versus the Wiltse group (6 of 103 patients; 5.8%) (p = 0.048). Blood loss was significantly lower in the Wiltse group (436 ml) versus the midline group (703 ml); however, there was no significant difference between the 2 groups in intraoperative complications or length of stay. CONCLUSIONS The patients who underwent the Wiltse approach had a decreased risk of wound breakdown and

  12. Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning.

    PubMed

    Hoffmann, Loren C; Cicchese, Joseph J; Berry, Stephen D

    2015-01-01

    Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3-12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3-7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning. PMID:25918501

  13. Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning

    PubMed Central

    Hoffmann, Loren C.; Cicchese, Joseph J.; Berry, Stephen D.

    2015-01-01

    Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3–12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3–7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning. PMID:25918501

  14. Theta EEG neurofeedback benefits early consolidation of motor sequence learning.

    PubMed

    Rozengurt, Roman; Barnea, Anat; Uchida, Sunao; Levy, Daniel A

    2016-07-01

    Procedural learning is subject to consolidation processes believed to depend on the modulation of functional connections involved in representing the acquired skill. While sleep provides the most commonly studied framework for such consolidation processes, posttraining modulation of oscillatory brain activity may also impact on plasticity processes. Under the hypothesis that consolidation of motor learning is associated with theta band activity, we used EEG neurofeedback (NFB) to enable participants to selectively increase either theta or beta power in their EEG spectra following the acquisition phase of motor sequence learning. We tested performance on a motor task before and after training, right after the NFB session to assess immediate NFB effects, 1 day after NFB to assess interaction between NFB effects and overnight sleep-dependent stabilization, and 1 week after the initial session, to assess the effects of NFB on long-term stabilization of motor training. We also explored the extent of the influence of single-electrode NFB on EEG recorded across the scalp. Results revealed a significantly greater improvement in performance immediately after NFB in the theta group than in the beta group. This effect continued for testing up to 1 week following training. Across participants, post-NFB improvement correlated positively with theta/beta ratio change achieved during NFB. Additionally, NFB was found to cause widespread band-power modulation beyond the electrode used for feedback. Thus, upregulating postlearning theta power may yield contributions to the immediate performance and subsequent consolidation of an acquired motor skill. PMID:27080752

  15. Theta oscillations and human navigation: a magnetoencephalography study.

    PubMed

    de Araújo, Dráulio B; Baffa, Oswaldo; Wakai, Ronald T

    2002-01-01

    Magnetoencephalography (MEG) was used to study alpha and theta activity while subjects navigated through a computer-generated virtual reality town. The subjects were first allowed to explore the environment freely. They then had to navigate from a starting point to a destination, knowing that an obstruction would appear at one of several possible locations along the main route and force them to take a detour. Spatiotemporal analysis of the theta and alpha bands were performed (1) prior to the start of navigation, (2) from the start of navigation until the obstruction was encountered, (3) during the time subjects were contemplating a detour and were not navigating, and (4) from the resumption of navigation until the destination was reached. In all subjects, theta power was strongest during the two periods of navigation. The peak frequency of the oscillations was approximately 3.7 Hz. Control studies consisted of a motor task similar to that required for navigation, passive viewing of a tour through the same virtual reality town, and a mental concentration task. No consistent increases in theta power were seen in the MEG during any of the control tasks. The results suggest an association between theta rhythm and the performance of navigational tasks in humans. PMID:11798388

  16. Human Frontal Lobes and AI Planning Systems

    NASA Technical Reports Server (NTRS)

    Levinson, Richard; Lum, Henry Jr. (Technical Monitor)

    1994-01-01

    Human frontal lobes are essential for maintaining a self-regulating balance between predictive and reactive behavior. This paper describes a system that integrates prediction and reaction based on neuropsychological theories of frontal lobe function. In addition to enhancing our understanding of deliberate action in humans' the model is being used to develop and evaluate the same properties in machines. First, the paper presents some background neuropsychology in order to set a general context. The role of frontal lobes is then presented by summarizing three theories which formed the basis for this work. The components of an artificial frontal lobe are then discussed from both neuropsychological and AI perspectives. The paper concludes by discussing issues and methods for evaluating systems that integrate planning and reaction.

  17. Frontal sinus recognition for human identification

    NASA Astrophysics Data System (ADS)

    Falguera, Juan Rogelio; Falguera, Fernanda Pereira Sartori; Marana, Aparecido Nilceu

    2008-03-01

    Many methods based on biometrics such as fingerprint, face, iris, and retina have been proposed for person identification. However, for deceased individuals, such biometric measurements are not available. In such cases, parts of the human skeleton can be used for identification, such as dental records, thorax, vertebrae, shoulder, and frontal sinus. It has been established in prior investigations that the radiographic pattern of frontal sinus is highly variable and unique for every individual. This has stimulated the proposition of measurements of the frontal sinus pattern, obtained from x-ray films, for skeletal identification. This paper presents a frontal sinus recognition method for human identification based on Image Foresting Transform and shape context. Experimental results (ERR = 5,82%) have shown the effectiveness of the proposed method.

  18. Rationale for Management of Frontal Sinus Fractures

    PubMed Central

    BANICA, Bogdan; ENE, Patricia; DABU, Aurelia; ENE, Razvan; CIRSTOIU, Catalin

    2013-01-01

    ABSTRACT The optimal treatment of frontal sinus fractures remains controversial. Multiple treatment options and algorithms have been proposed by multiple specialties throughout the years; however, the optimal method of frontal sinus repair has yet to be discovered. Overwhelming complications such as meningitis, encephalitis or brain abscess are quite uncommon nowadays. Nevertheless, late development of invasive mucoceles is not a rarity and therefore long-term follow-up is mandatory. PMID:24790677

  19. Beyond the sniffer: frontal sinuses in Carnivora.

    PubMed

    Curtis, Abigail A; Van Valkenburgh, Blaire

    2014-11-01

    Paranasal sinuses are some of the most poorly understood features of mammalian cranial anatomy. They are highly variable in presence and form among species, but their function is not well understood. The best-supported explanations for the function of sinuses is that they opportunistically fill mechanically unnecessary space, but that in some cases, sinuses in combination with the configuration of the frontal bone may improve skull performance by increasing skull strength and dissipating stresses more evenly. We used CT technology to investigate patterns in frontal sinus size and shape disparity among three families of carnivores: Canidae, Felidae, and Hyaenidae. We provide some of the first quantitative data on sinus morphology for these three families, and employ a novel method to quantify the relationship between three-dimensional sinus shape and skull shape. As expected, frontal sinus size and shape were more strongly correlated with frontal bone size and shape than with the morphology of the skull as a whole. However, sinus morphology was also related to allometric differences among families that are linked to biomechanical function. Our results support the hypothesis that frontal sinuses most often opportunistically fill space that is mechanically unnecessary, and they can facilitate cranial shape changes that reduce stress during feeding. Moreover, we suggest that the ability to form frontal sinuses allows species to modify skull function without compromising the performance of more functionally constrained regions such as the nasal chamber (heat/water conservation, olfaction), and braincase (housing the brain and sensory structures). PMID:25312364

  20. Theta oscillations regulate the speed of locomotion via a hippocampus to lateral septum pathway

    PubMed Central

    Bender, Franziska; Gorbati, Maria; Cadavieco, Marta Carus; Denisova, Natalia; Gao, Xiaojie; Holman, Constance; Korotkova, Tatiana; Ponomarenko, Alexey

    2015-01-01

    Hippocampal theta oscillations support encoding of an animal's position during spatial navigation, yet longstanding questions about their impact on locomotion remain unanswered. Combining optogenetic control of hippocampal theta oscillations with electrophysiological recordings in mice, we show that hippocampal theta oscillations regulate locomotion. In particular, we demonstrate that their regularity underlies more stable and slower running speeds during exploration. More regular theta oscillations are accompanied by more regular theta-rhythmic spiking output of pyramidal cells. Theta oscillations are coordinated between the hippocampus and its main subcortical output, the lateral septum (LS). Chemo- or optogenetic inhibition of this pathway reveals its necessity for the hippocampal regulation of running speed. Moreover, theta-rhythmic stimulation of LS projections to the lateral hypothalamus replicates the reduction of running speed induced by more regular hippocampal theta oscillations. These results suggest that changes in hippocampal theta synchronization are translated into rapid adjustment of running speed via the LS. PMID:26455912

  1. Theta oscillations regulate the speed of locomotion via a hippocampus to lateral septum pathway.

    PubMed

    Bender, Franziska; Gorbati, Maria; Cadavieco, Marta Carus; Denisova, Natalia; Gao, Xiaojie; Holman, Constance; Korotkova, Tatiana; Ponomarenko, Alexey

    2015-01-01

    Hippocampal theta oscillations support encoding of an animal's position during spatial navigation, yet longstanding questions about their impact on locomotion remain unanswered. Combining optogenetic control of hippocampal theta oscillations with electrophysiological recordings in mice, we show that hippocampal theta oscillations regulate locomotion. In particular, we demonstrate that their regularity underlies more stable and slower running speeds during exploration. More regular theta oscillations are accompanied by more regular theta-rhythmic spiking output of pyramidal cells. Theta oscillations are coordinated between the hippocampus and its main subcortical output, the lateral septum (LS). Chemo- or optogenetic inhibition of this pathway reveals its necessity for the hippocampal regulation of running speed. Moreover, theta-rhythmic stimulation of LS projections to the lateral hypothalamus replicates the reduction of running speed induced by more regular hippocampal theta oscillations. These results suggest that changes in hippocampal theta synchronization are translated into rapid adjustment of running speed via the LS. PMID:26455912

  2. Segmented flow sampling with push-pull theta pipettes.

    PubMed

    Saha-Shah, Anumita; Green, Curtis M; Abraham, David H; Baker, Lane A

    2016-03-21

    We report development of a mobile and easy-to-fabricate theta pipette microfluidic device for segmented flow sampling. The theta pipettes were also used as electrospray emitters for analysis of sub-nanoliter segments, which resulted in delivery of analyte to the vacuum inlet of the mass spectrometer without multiple transfer steps. Theta pipette probes enable sample collection with high spatial resolution due to micron or smaller sized probe inlets and can be used to manipulate aqueous segments in the range of 200 pL to tens of nanoliters. Optimized conditions can enable sampling with high spatial and temporal resolution, suitable for chemical monitoring in biological samples and studies of sample heterogeneity. Intercellular heterogeneity among Allium cepa cells was studied by collecting cytoplasm from multiple cells using a single probe. Extracted cytoplasm was analyzed in a fast and high throughput manner by direct electrospray mass spectrometry of segmented sample from the probe tip. PMID:26907673

  3. Geometrical model for non-zero {theta}{sub 13}

    SciTech Connect

    Chen Junmou; Wang Bin; Li Xueqian

    2011-10-01

    Based on Friedberg and Lee's geometric picture by which the tribimaximal Pontecorvo-Maki-Nakawaga-Sakata leptonic mixing matrix is constructed, namely, corresponding mixing angles correspond to the geometric angles among the sides of a cube. We suggest that the three realistic mixing angles, which slightly deviate from the values determined for the cube, are due to a viable deformation from the perfectly cubic shape. Taking the best-fitted results of {theta}{sub 12} and {theta}{sub 23} as inputs, we determine the central value of sin{sup 2}2{theta}{sub 13} should be 0.0238, with a relatively large error tolerance; this value lies in the range of measurement precision of the Daya Bay experiment and is consistent with recent results from the T2K Collaboration.

  4. Midline extraperitoneal approach for bilateral widespread retroperitoneal abscess originating from anorectal infection

    PubMed Central

    Okuda, Koji; Oshima, Yuka; Saito, Kentaro; Uesaka, Takahiro; Terasaki, Yasunobu; Kasai, Hironori; Minagawa, Nozomi; Oshima, Takahiro; Okawa, Yumi; Misawa, Kazuhito

    2015-01-01

    Introduction Anorectal abscess is one of the most common anorectal conditions encountered in practice. However, such abscesses may rarely extend upward and cause life-threatening medical conditions. Presentation of case A 53-year-old woman presented with symptoms of anorectal abscess and evidence of severe inflammatory response and acute kidney injury. Computed tomography revealed a widespread abscess extending to the bilateral retroperitoneal spaces. Surgical drainage was performed via a totally extraperitoneal approach through a lower midline abdominal incision, and the patient had a rapid and uncomplicated recovery. Discussion Although retroperitoneal abscesses originating from the anorectal region are rare, they are life-threating events that require immediate treatment. Percutaneous abscess drainage has been recently evolved; however, surgical drainage is required sometimes that may be challenging, particularly in the case of widespread abscesses, as in our case. Conclusion The midline extraperitoneal approach reported here might be an effective surgical option for patients with bilateral widespread retroperitoneal abscesses. PMID:26701843

  5. Perfusion MRI Indexes Variability in the Functional Brain Effects of Theta-Burst Transcranial Magnetic Stimulation

    PubMed Central

    Gratton, Caterina; Lee, Taraz G.; Nomura, Emi M.; D’Esposito, Mark

    2014-01-01

    Transcranial Magnetic Stimulation (TMS) is an important tool for testing causal relationships in cognitive neuroscience research. However, the efficacy of TMS can be variable across individuals and difficult to measure. This variability is especially a challenge when TMS is applied to regions without well-characterized behavioral effects, such as in studies using TMS on multi-modal areas in intrinsic networks. Here, we examined whether perfusion fMRI recordings of Cerebral Blood Flow (CBF), a quantitative measure sensitive to slow functional changes, reliably index variability in the effects of stimulation. Twenty-seven participants each completed four combined TMS-fMRI sessions during which both resting state Blood Oxygen Level Dependent (BOLD) and perfusion Arterial Spin Labeling (ASL) scans were recorded. In each session after the first baseline day, continuous theta-burst TMS (TBS) was applied to one of three locations: left dorsolateral prefrontal cortex (L dlPFC), left anterior insula/frontal operculum (L aI/fO), or left primary somatosensory cortex (L S1). The two frontal targets are components of intrinsic networks and L S1 was used as an experimental control. CBF changes were measured both before and after TMS on each day from a series of interleaved resting state and perfusion scans. Although TBS led to weak selective increases under the coil in CBF measurements across the group, individual subjects showed wide variability in their responses. TBS-induced changes in rCBF were related to TBS-induced changes in functional connectivity of the relevant intrinsic networks measured during separate resting-state BOLD scans. This relationship was selective: CBF and functional connectivity of these networks were not related before TBS or after TBS to the experimental control region (S1). Furthermore, subject groups with different directions of CBF change after TBS showed distinct modulations in the functional interactions of targeted networks. These results suggest

  6. Differential geometry of the Fermat quartic and theta functions

    NASA Astrophysics Data System (ADS)

    Hadnot, Jason

    2012-02-01

    The universal curve over a finite cover of the moduli space of elliptic curves with level four structure is embedded in C as the Fermat quartic and is parametrized via the four Jacobi theta functions. Constructions from completely integrable systems have shown the importance of looking at the curvature of certain spaces and here we compute sectional curvatures. For our computations, we choose the ambient Fubini-Study metric of C. We also derive several theta identities which arise from the quartic's holomorphic two-form.

  7. Changes in quality of life during orthodontic correction of midline diastema

    PubMed Central

    Nagalakshmi, S.; Sathish, R.; Priya, K.; Dhayanithi, D.

    2014-01-01

    Aim: The aim of our study is to evaluate the changes in quality of life among patients treated for maxillary midline diastema by fixed orthodontic appliances. Materials and Methods: This prospective longitudinal study consists of 40 patients of age group 20-30 years who underwent orthodontic correction of midline diastema. The patient's quality of life is evaluated using 22-item orthognathic quality of life questionnaire. They were evaluated prior to appliance therapy, 1 month after appliance fixation, 4th and 8th month during treatment and 1 month after treatment. Results: Our results showed moderate improvement in quality of life as early as at the start of orthodontic therapy. The response was equal among both sexes. The quality of life experience improved only mildly during the orthodontic treatment. However, the condition specific quality of life at the end of appliance therapy improved by nearly 50% when compared with prior to treatment. Conclusion: Our study has concluded that the correction of midline diastema has improved the quality of life among young people by nearly 50%. The acceptance to orthodontic therapy and patient perception toward fixed appliance has demonstrated remarkable improvement in quality of life during the treatment. Our study calls for additional patient counseling and motivation during the course of fixed appliance therapy. PMID:25210363

  8. A midline switch of receptor processing regulates commissural axon guidance in vertebrates

    PubMed Central

    Nawabi, Homaira; Briançon-Marjollet, Anne; Clark, Christopher; Sanyas, Isabelle; Takamatsu, Hyota; Okuno, Tatsusada; Kumanogoh, Atsushi; Bozon, Muriel; Takeshima, Kaori; Yoshida, Yutaka; Moret, Frédéric; Abouzid, Karima; Castellani, Valérie

    2010-01-01

    Commissural axon guidance requires complex modulations of growth cone sensitivity to midline-derived cues, but underlying mechanisms in vertebrates remain largely unknown. By using combinations of ex vivo and in vivo approaches, we uncovered a molecular pathway controlling the gain of response to a midline repellent, Semaphorin3B (Sema3B). First, we provide evidence that Semaphorin3B/Plexin-A1 signaling participates in the guidance of commissural projections at the vertebrate ventral midline. Second, we show that, at the precrossing stage, commissural neurons synthesize the Neuropilin-2 and Plexin-A1 Semaphorin3B receptor subunits, but Plexin-A1 expression is prevented by a calpain1-mediated processing, resulting in silencing commissural responsiveness. Third, we report that, during floor plate (FP) in-growth, calpain1 activity is suppressed by local signals, allowing Plexin-A1 accumulation in the growth cone and sensitization to Sema3B. Finally, we show that the FP cue NrCAM mediates the switch of Plexin-A1 processing underlying growth cone sensitization to Sema3B. This reveals pathway-dependent modulation of guidance receptor processing as a novel mechanism for regulating guidance decisions at intermediate targets. PMID:20159958

  9. A midline switch of receptor processing regulates commissural axon guidance in vertebrates.

    PubMed

    Nawabi, Homaira; Briançon-Marjollet, Anne; Clark, Christopher; Sanyas, Isabelle; Takamatsu, Hyota; Okuno, Tatsusada; Kumanogoh, Atsushi; Bozon, Muriel; Takeshima, Kaori; Yoshida, Yutaka; Moret, Frédéric; Abouzid, Karima; Castellani, Valérie

    2010-02-15

    Commissural axon guidance requires complex modulations of growth cone sensitivity to midline-derived cues, but underlying mechanisms in vertebrates remain largely unknown. By using combinations of ex vivo and in vivo approaches, we uncovered a molecular pathway controlling the gain of response to a midline repellent, Semaphorin3B (Sema3B). First, we provide evidence that Semaphorin3B/Plexin-A1 signaling participates in the guidance of commissural projections at the vertebrate ventral midline. Second, we show that, at the precrossing stage, commissural neurons synthesize the Neuropilin-2 and Plexin-A1 Semaphorin3B receptor subunits, but Plexin-A1 expression is prevented by a calpain1-mediated processing, resulting in silencing commissural responsiveness. Third, we report that, during floor plate (FP) in-growth, calpain1 activity is suppressed by local signals, allowing Plexin-A1 accumulation in the growth cone and sensitization to Sema3B. Finally, we show that the FP cue NrCAM mediates the switch of Plexin-A1 processing underlying growth cone sensitization to Sema3B. This reveals pathway-dependent modulation of guidance receptor processing as a novel mechanism for regulating guidance decisions at intermediate targets. PMID:20159958

  10. Axonal commissures in the central nervous system: how to cross the midline?

    PubMed

    Nawabi, Homaira; Castellani, Valérie

    2011-08-01

    Organisms with bilateral symmetry elaborate patterns of neuronal projections connecting both sides of the central nervous system at all levels of the neuraxis. During development, these so-called commissural projections navigate across the midline to innervate their contralateral targets. Commissural axon pathfinding has been extensively studied over the past years and turns out to be a highly complex process, implicating modulation of axon responsiveness to the various guidance cues that instruct axon trajectories towards, within and away from the midline. Understanding the molecular mechanisms allowing these switches of response to take place at the appropriate time and place is a major challenge for current research. Recent work characterized several instructive processes controlling the spatial and temporal fine-tuning of the guidance molecular machinery. These findings illustrate the molecular strategies by which commissural axons modulate their sensitivity to guidance cues during midline crossing and show that regulation at both transcriptional and post-transcriptional levels are crucial for commissural axon guidance. PMID:21538161

  11. Treatment of Calcified Insertional Achilles Tendinopathy by the Posterior Midline Approach.

    PubMed

    Miao, Xu-Dong; Jiang, Hongfei; Wu, Yong-Ping; Tao, Hui-Min; Yang, Di-Sheng; Hu, Hang

    2016-01-01

    The present study investigated the clinical outcomes of the posterior midline approach in the treatment of 34 patients with significantly calcified insertional Achilles tendinopathy. The posterior midline approach was applied for the surgical treatment of 34 patients with chronic significantly calcified insertional Achilles tendinopathy after failed conservative treatment. Gastrocnemius recession was performed simultaneously for patients with gastrocnemius contracture. The Fowler-Philip angle and parallel pitch lines were measured before surgery, and the visual analog scale, Tegner score, and Victorian Institute of Sport tendon study group score were recorded before and after surgery. The mean follow-up period was 45.2 ± 17.7 (range 24 to 84) months. After surgery, the visual analog scale score had decreased notably, and the Tegner score and Victorian Institute of Sport tendon study group score had increased significantly. The posterior midline approach can achieve satisfactory outcomes in the treatment of significantly calcified insertional Achilles tendinopathy, and gastrocnemius recession (Strayer procedure) should be performed for patients with gastrocnemius contracture to improve the surgical outcome. PMID:26874831

  12. Midline-derived Shh regulates mesonephric tubule formation through the paraxial mesoderm

    PubMed Central

    Murashima, Aki; Akita, Hiroki; Okazawa, Mika; Kishigami, Satoshi; Nakagata, Naomi; Nishinakamura, Ryuichi; Yamada, Gen

    2014-01-01

    During organogenesis, Sonic hedgehog (Shh) possesses dual functions: Shh emanating from midline structures regulates the positioning of bilateral structures at early stages, whereas organ-specific Shh locally regulates organ morphogenesis at later stages. The mesonephros is a transient embryonic kidney in amniote, whereas it becomes definitive adult kidney in some anamniotes. Thus, elucidating the regulation of mesonephros formation has important implications for our understanding of kidney development and evolution. In Shh knockout (KO) mutant mice, the mesonephros was displaced towards the midline and ectopic mesonephric tubules (MTs) were present in the caudal mesonephros. Mesonephros-specific ablation of Shh in Hoxb7-Cre;Shhflox/− and Sall1CreERT2/+;Shhflox/− mice embryos indicated that Shh expressed in the mesonephros was not required for either the development of the mesonephros or the differentiation of the male reproductive tract. Moreover, stage-specific ablation of Shh in ShhCreERT2/flox mice showed that notochord- and/or floor plate-derived Shh were essential for the regulation of the number and position of MTs. Lineage analysis of hedgehog (Hh)-responsive cells, and analysis of gene expression in Shh KO embryos suggested that Shh regulated nephrogenic gene expression indirectly, possibly through effects on the paraxial mesoderm. These data demonstrate the essential role of midline-derived Shh in local tissue morphogenesis and differentiation. PMID:24370450

  13. Automated MRI parcellation of the frontal lobe

    PubMed Central

    Ranta, Marin E.; Chen, Min; Crocetti, Deana; Prince, Jerry L.; Subramaniam, Krish; Fischl, Bruce; Kaufmann, Walter E.; Mostofsky, Stewart H.

    2014-01-01

    Examination of associations between specific disorders and physical properties of functionally relevant frontal lobe sub-regions is a fundamental goal in neuropsychiatry. Here we present and evaluate automated methods of frontal lobe parcellation with the programs FreeSurfer(FS) and TOADS-CRUISE(T-C), based on the manual method described in Ranta et al. (2009) in which sulcal-gyral landmarks were used to manually delimit functionally relevant regions within the frontal lobe: i.e., primary motor cortex, anterior cingulate, deep white matter, premotor cortex regions (supplementary motor complex, frontal eye field and lateral premotor cortex) and prefrontal cortex (PFC) regions (medial PFC, dorsolateral PFC, inferior PFC, lateral orbitofrontal cortex (OFC) and medial OFC). Dice's coefficient, a measure of overlap, and percent volume difference were used to measure the reliability between manual and automated delineations for each frontal lobe region. For FS, mean Dice's coefficient for all regions was 0.75 and percent volume difference was 21.2%. For T-C the mean Dice's coefficient was 0.77 and the mean percent volume difference for all regions was 20.2%. These results, along with a high degree of agreement between the two automated methods (mean Dice's coefficient = 0.81, percent volume difference = 12.4%) and a proof-of-principle group difference analysis that highlights the consistency and sensitivity of the automated methods, indicate that the automated methods are valid techniques for parcellation of the frontal lobe into functionally relevant sub-regions. Thus, the methodology has the potential to increase efficiency, statistical power and reproducibility for population analyses of neuropsychiatric disorders with hypothesized frontal lobe contributions. PMID:23897577

  14. [Normal aging of frontal lobe functions].

    PubMed

    Calso, Cristina; Besnard, Jérémy; Allain, Philippe

    2016-03-01

    Normal aging in individuals is often associated with morphological, metabolic and cognitive changes, which particularly concern the cerebral frontal regions. Starting from the "frontal lobe hypothesis of cognitive aging" (West, 1996), the present review is based on the neuroanatomical model developed by Stuss (2008), introducing four categories of frontal lobe functions: executive control, behavioural and emotional self-regulation and decision-making, energization and meta-cognitive functions. The selected studies only address the changes of one at least of these functions. The results suggest a deterioration of several cognitive frontal abilities in normal aging: flexibility, inhibition, planning, verbal fluency, implicit decision-making, second-order and affective theory of mind. Normal aging seems also to be characterised by a general reduction in processing speed observed during neuropsychological assessment (Salthouse, 1996). Nevertheless many cognitive functions remain preserved such as automatic or non-conscious inhibition, specific capacities of flexibility and first-order theory of mind. Therefore normal aging doesn't seem to be associated with a global cognitive decline but rather with a selective change in some frontal systems, conclusion which should be taken into account for designing caring programs in normal aging. PMID:27005339

  15. Interhemispheric Plasticity following Intermittent Theta Burst Stimulation in Chronic Poststroke Aphasia

    PubMed Central

    Griffis, Joseph C.; Nenert, Rodolphe; Allendorfer, Jane B.; Szaflarski, Jerzy P.

    2016-01-01

    The effects of noninvasive neurostimulation on brain structure and function in chronic poststroke aphasia are poorly understood. We investigated the effects of intermittent theta burst stimulation (iTBS) applied to residual language-responsive cortex in chronic patients using functional and anatomical MRI data acquired before and after iTBS. Lateralization index (LI) analyses, along with comparisons of inferior frontal gyrus (IFG) activation and connectivity during covert verb generation, were used to assess changes in cortical language function. Voxel-based morphometry (VBM) was used to assess effects on regional grey matter (GM). LI analyses revealed a leftward shift in IFG activity after treatment. While left IFG activation increased, right IFG activation decreased. Changes in right to left IFG connectivity during covert verb generation also decreased after iTBS. Behavioral correlations revealed a negative relationship between changes in right IFG activation and improvements in fluency. While anatomical analyses did not reveal statistically significant changes in grey matter volume, the fMRI results provide evidence for changes in right and left IFG function after iTBS. The negative relationship between post-iTBS changes in right IFG activity during covert verb generation and improvements in fluency suggests that iTBS applied to residual left-hemispheric language areas may reduce contralateral responses related to language production and facilitate recruitment of residual language areas after stroke. PMID:26881111

  16. A Low energy neutrino factory for large theta(13)

    SciTech Connect

    Geer, Steve; Mena, Olga; Pascoli, Silvia; /Durham U., IPPP

    2007-01-01

    If the value of {theta}{sub 13} is within the reach of the upcoming generation of long-baseline experiments, T2K and NOvA, they show that a low-energy neutrino factory, with peak energy in the few GeV range, would provide a sensitive tool to explore CP-violation and the neutrino mass hierarchy. They consider baselines with typical length 1000-1500 km. The unique performance of the low energy neutrino factory is due to the rich neutrino oscillation pattern at energies between 1 and 4 GeV at baselines {Omicron}(1000) km. They perform both a semi-analytical study of the sensitivities and a numerical analysis to explore how well this setup can measure {theta}{sub 13}, CP-violation, and determine the type of mass hierarchy and the {theta}{sub 23} quadrant. A low energy neutrino factory provides a powerful tool to resolve ambiguities and make precise parameter determinations, for both large and fairly small values of the mixing parameter {theta}{sub 13}.

  17. Holomorphic projections and Ramanujan’s mock theta functions

    PubMed Central

    Imamoğlu, Özlem; Raum, Martin; Richter, Olav K.

    2014-01-01

    We use spectral methods of automorphic forms to establish a holomorphic projection operator for tensor products of vector-valued harmonic weak Maass forms and vector-valued modular forms. We apply this operator to discover simple recursions for Fourier series coefficients of Ramanujan’s mock theta functions. PMID:24591582

  18. Presence of state transitions in the cryptophyte alga Guillardia theta

    PubMed Central

    Cheregi, Otilia; Kotabová, Eva; Prášil, Ondřej; Schröder, Wolfgang P.; Kaňa, Radek; Funk, Christiane

    2015-01-01

    Plants and algae have developed various regulatory mechanisms for optimal delivery of excitation energy to the photosystems even during fluctuating light conditions; these include state transitions as well as non-photochemical quenching. The former process maintains the balance by redistributing antennae excitation between the photosystems, meanwhile the latter by dissipating excessive excitation inside the antennae. In the present study, these mechanisms have been analysed in the cryptophyte alga Guillardia theta. Photoprotective non-photochemical quenching was observed in cultures only after they had entered the stationary growth phase. These cells displayed a diminished overall photosynthetic efficiency, measured as CO2 assimilation rate and electron transport rate. However, in the logarithmic growth phase G. theta cells redistributed excitation energy via a mechanism similar to state transitions. These state transitions were triggered by blue light absorbed by the membrane integrated chlorophyll a/c antennae, and green light absorbed by the lumenal biliproteins was ineffective. It is proposed that state transitions in G. theta are induced by small re-arrangements of the intrinsic antennae proteins, resulting in their coupling/uncoupling to the photosystems in state 1 or state 2, respectively. G. theta therefore represents a chromalveolate algae able to perform state transitions. PMID:26254328

  19. Presence of state transitions in the cryptophyte alga Guillardia theta.

    PubMed

    Cheregi, Otilia; Kotabová, Eva; Prášil, Ondřej; Schröder, Wolfgang P; Kaňa, Radek; Funk, Christiane

    2015-10-01

    Plants and algae have developed various regulatory mechanisms for optimal delivery of excitation energy to the photosystems even during fluctuating light conditions; these include state transitions as well as non-photochemical quenching. The former process maintains the balance by redistributing antennae excitation between the photosystems, meanwhile the latter by dissipating excessive excitation inside the antennae. In the present study, these mechanisms have been analysed in the cryptophyte alga Guillardia theta. Photoprotective non-photochemical quenching was observed in cultures only after they had entered the stationary growth phase. These cells displayed a diminished overall photosynthetic efficiency, measured as CO2 assimilation rate and electron transport rate. However, in the logarithmic growth phase G. theta cells redistributed excitation energy via a mechanism similar to state transitions. These state transitions were triggered by blue light absorbed by the membrane integrated chlorophyll a/c antennae, and green light absorbed by the lumenal biliproteins was ineffective. It is proposed that state transitions in G. theta are induced by small re-arrangements of the intrinsic antennae proteins, resulting in their coupling/uncoupling to the photosystems in state 1 or state 2, respectively. G. theta therefore represents a chromalveolate algae able to perform state transitions. PMID:26254328

  20. Interindividual Differences in Alpha and Theta Power Reflect Memory Performance.

    ERIC Educational Resources Information Center

    Klimesch, W.; Vogt, F.; Doppelmayr, M.

    1999-01-01

    Tested whether tonic EEG power is related to memory performance by analyzing ongoing EEG for 60 subjects in 5 experimental conditions. Subjects with good memory performance had significantly larger upper alpha power, but less theta and lower alpha power. Also discusses findings for subjects good at calculation. (SLD)

  1. Irregular Speech Rate Dissociates Auditory Cortical Entrainment, Evoked Responses, and Frontal Alpha

    PubMed Central

    Kayser, Stephanie J.; Ince, Robin A.A.; Gross, Joachim

    2015-01-01

    The entrainment of slow rhythmic auditory cortical activity to the temporal regularities in speech is considered to be a central mechanism underlying auditory perception. Previous work has shown that entrainment is reduced when the quality of the acoustic input is degraded, but has also linked rhythmic activity at similar time scales to the encoding of temporal expectations. To understand these bottom-up and top-down contributions to rhythmic entrainment, we manipulated the temporal predictive structure of speech by parametrically altering the distribution of pauses between syllables or words, thereby rendering the local speech rate irregular while preserving intelligibility and the envelope fluctuations of the acoustic signal. Recording EEG activity in human participants, we found that this manipulation did not alter neural processes reflecting the encoding of individual sound transients, such as evoked potentials. However, the manipulation significantly reduced the fidelity of auditory delta (but not theta) band entrainment to the speech envelope. It also reduced left frontal alpha power and this alpha reduction was predictive of the reduced delta entrainment across participants. Our results show that rhythmic auditory entrainment in delta and theta bands reflect functionally distinct processes. Furthermore, they reveal that delta entrainment is under top-down control and likely reflects prefrontal processes that are sensitive to acoustical regularities rather than the bottom-up encoding of acoustic features. SIGNIFICANCE STATEMENT The entrainment of rhythmic auditory cortical activity to the speech envelope is considered to be critical for hearing. Previous work has proposed divergent views in which entrainment reflects either early evoked responses related to sound encoding or high-level processes related to expectation or cognitive selection. Using a manipulation of speech rate, we dissociated auditory entrainment at different time scales. Specifically, our

  2. Violations of parity and charge conjugation in the {theta} vacuum with imaginary chemical potential

    SciTech Connect

    Kouno, Hiroaki; Sakai, Yuji; Sasaki, Takahiro; Kashiwa, Kouji; Yahiro, Masanobu

    2011-04-01

    Charge conjugation (C) and parity (P) are exact symmetries at {theta}={pi} and {Theta}{identical_to}{mu}/(iT)={pi}, where {theta} is the parameter of the so-called {theta} vacuum, {mu} is the imaginary quark-number chemical potential and T is the temperature. Spontaneous breakings of these discrete symmetries are investigated by the Polyakov-loop extended Nambu-Jona-Lasinio model. At zero T, P symmetry is spontaneously broken while C symmetry is conserved. As T increases, P symmetry is restored just after C symmetry is spontaneously broken, so that either P or C symmetry or both the symmetries are spontaneously broken for any T. The chiral-symmetry restoration and the deconfinement transition at {theta}={Theta}=0 are remnants of the P restoration and the C breaking at {theta}={Theta}={pi}, respectively.

  3. Sexual differentiation of mammalian frontal cortex

    SciTech Connect

    Maggi, A.; Zucchi, I.

    1987-03-23

    The pattern of distribution of the progesterone binding sites was examined in selected nuclei of the brain of male and female rat. In female rats the frontal cortex resulted to be the region with the highest concentration of /sup 3/H R5020 biding sites. However, in male rats the same region showed very little progestin binding activity. When female rats were androgenized via neonatal exposure to testosterone, the progestin binding activity of the frontal cortex became similar to that observed in male rats. The present investigation indicates that sexual differentiation of the rat brain may include also brain regions not clearly involved in sex related functions like the frontal cortex. 30 references, 2 figures, 1 table.

  4. Frontal-subcortical circuitry and behavior

    PubMed Central

    Bonelli, Raphael M.; Cummings, Jeffrey L.

    2007-01-01

    The neuropsychiatric manifestations of neurodegenerative diseases are closely linked to neurocircuitry defects. Frontal-subcortical circuits, in particular, are effector mechanisms that allow the organism to act on its environment In this paper, we present the three main frontal-subcortical circuits: the dorsolateral prefrontal circuit allows the organization of information to facilitate a response; the anterior cingulate circuit is required for motivated behavior; and the orbitofrontal circuit allows the integration of limbic and emotional information into behavioral responses. Impaired executive functions, apathy, and impulsivity are hallmarks of frontal-subcortical circuit dysfunction. A variety of other neuropsychiatrie disorders, such as Tourette's syndrome, Huntington's disease, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, schizophrenia, and mood disorders may result from disturbances that have a direct or indirect impact on the integrity or functioning of these loops. PMID:17726913

  5. Cephalic aura after frontal lobe resection.

    PubMed

    Kakisaka, Yosuke; Jehi, Lara; Alkawadri, Rafeed; Wang, Zhong I; Enatsu, Rei; Mosher, John C; Dubarry, Anne-Sophie; Alexopoulos, Andreas V; Burgess, Richard C

    2014-08-01

    A cephalic aura is a common sensory aura typically seen in frontal lobe epilepsy. The generation mechanism of cephalic aura is not fully understood. It is hypothesized that to generate a cephalic aura extensive cortical areas need to be excited. We report a patient who started to have cephalic aura after right frontal lobe resection. Magnetoencephalography (MEG) showed interictal spike and ictal change during cephalic aura, both of which were distributed in the right frontal region, and the latter involved much more widespread areas than the former on MEG sensors. The peculiar seizure onset pattern may indicate that surgical modification of the epileptic network was related to the appearance of cephalic aura. We hypothesize that generation of cephalic aura may be associated with more extensive cortical involvement of epileptic activity than that of interictal activity, in at least a subset of cases. PMID:24613491

  6. Frontal-thalamic circuits associated with language

    PubMed Central

    Barbas, Helen; García-Cabezas, Miguel Ángel; Zikopoulos, Basilis

    2012-01-01

    Thalamic nuclei associated with language including the ventral lateral, ventral anterior, intralaminar and mediodorsal form a hub that uniquely receives the output of the basal ganglia and cerebellum, and is connected with frontal (premotor and prefrontal) cortices through two parallel circuits: a thalamic pathway targets the middle frontal cortical layers focally, and the other innervates widely cortical layer 1, poised to recruit other cortices and thalamic nuclei for complex cognitive operations. Return frontal pathways to the thalamus originate from cortical layers 6 and 5. Information through this integrated thalamo-cortical system is gated by the inhibitory thalamic reticular nucleus and modulated by dopamine, representing a specialization in primates. The intricate dialogue of distinct thalamic nuclei with the basal ganglia, cerebellum, and specific dorsolateral prefrontal and premotor cortices associated with language, suggests synergistic roles in the complex but seemingly effortless sequential transformation of cognitive operations for speech production in humans. PMID:23211411

  7. The frontal method in hydrodynamics simulations

    USGS Publications Warehouse

    Walters, R.A.

    1980-01-01

    The frontal solution method has proven to be an effective means of solving the matrix equations resulting from the application of the finite element method to a variety of problems. In this study, several versions of the frontal method were compared in efficiency for several hydrodynamics problems. Three basic modifications were shown to be of value: 1. Elimination of equations with boundary conditions beforehand, 2. Modification of the pivoting procedures to allow dynamic management of the equation size, and 3. Storage of the eliminated equations in a vector. These modifications are sufficiently general to be applied to other classes of problems. ?? 1980.

  8. Frontal Polymerization in Microgravity Summary of Research

    NASA Technical Reports Server (NTRS)

    Pojman, John A.

    2002-01-01

    The project began with frontal polymerization (FP). We studied many aspects of FP on the ground and performed two successful weeks of flying on the KC-135. The project evolved into the current flight investigation, Transient Interfacial Phenomena in Miscible Polymer Systems (TIPMPS), as we recognized that an essential question could best be studied using a non-frontal approach. We present detailed results from our ground-based work on FP, KC-135 results and the background, justification and numerical work for the TIPMPS project.

  9. [Simple partial frontal nonconvulsive status epilepticus].

    PubMed

    Thomas, P; Mottin, Y

    1997-07-01

    Non convulsive status epilepticus (NCSE) of frontal origin is a rare cause of mental confusion. The present case of possible frontal-onset NCSE proved to have a neuropsychological examination that was suggestive either of a disruption of attentional function or a left prefrontal dysfunction, exhibiting disturbances of immediate memory and logical programmation, perseverations and affective disinhibition. Vigilance was not impaired. This case was therefore, on a nosographic point of view, more consistent with a simple partial status epilepticus with cognitive and affective symptomatology rather than with a complex partial status epilepticus of extra-temporal origin. PMID:9684010

  10. Learner Acquisition of Dialect Variation in a Study Abroad Context: The Case of the Spanish [Theta

    ERIC Educational Resources Information Center

    Ringer-Hilfinger, Kathryn

    2012-01-01

    The present study aims at analyzing the acquisition of dialect variation by native English-speaking university students who study Spanish for a semester in Spain. The selected variable is the phoneme /[theta]/ (theta). The goal is to assess learner awareness, opinion, and use of [theta]. Data were elicited through a set of oral and written tasks…

  11. Modulation of Hippocampal Theta Oscillations and Spatial Memory by Relaxin-3 Neurons of the Nucleus Incertus

    ERIC Educational Resources Information Center

    Ma, Sherie; Olucha-Bordonau, Francisco E.; Hossain, M. Akhter; Lin, Feng; Kuei, Chester; Liu, Changlu; Wade, John D.; Sutton, Steven W.; Nunez, Angel; Gundlach, Andrew L.

    2009-01-01

    Hippocampal theta rhythm is thought to underlie learning and memory, and it is well established that "pacemaker" neurons in medial septum (MS) modulate theta activity. Recent studies in the rat demonstrated that brainstem-generated theta rhythm occurs through a multisynaptic pathway via the nucleus incertus (NI), which is the primary source of the…

  12. Frontal EEG/ERP correlates of attentional processes, cortisol and motivational states in adolescents from lower and higher socioeconomic status

    PubMed Central

    D'Angiulli, Amedeo; Weinberg, Joanne; Oberlander, Tim F.; Grunau, Ruth E.; Hertzman, Clyde; Maggi, Stefania

    2012-01-01

    Event-related potentials (ERPs) and other electroencephalographic (EEG) evidence show that frontal brain areas of higher and lower socioeconomic status (SES) children are recruited differently during selective attention tasks. We assessed whether multiple variables related to self-regulation (perceived mental effort) emotional states (e.g., anxiety, stress, etc.) and motivational states (e.g., boredom, engagement, etc.) may co-occur or interact with frontal attentional processing probed in two matched-samples of fourteen lower-SES and higher-SES adolescents. ERP and EEG activation were measured during a task probing selective attention to sequences of tones. Pre- and post-task salivary cortisol and self-reported emotional states were also measured. At similar behavioural performance level, the higher-SES group showed a greater ERP differentiation between attended (relevant) and unattended (irrelevant) tones than the lower-SES group. EEG power analysis revealed a cross-over interaction, specifically, lower-SES adolescents showed significantly higher theta power when ignoring rather than attending to tones, whereas, higher-SES adolescents showed the opposite pattern. Significant theta asymmetry differences were also found at midfrontal electrodes indicating left hypo-activity in lower-SES adolescents. The attended vs. unattended difference in right midfrontal theta increased with individual SES rank, and (independently from SES) with lower cortisol task reactivity and higher boredom. Results suggest lower-SES children used additional compensatory resources to monitor/control response inhibition to distracters, perceiving also more mental effort, as compared to higher-SES counterparts. Nevertheless, stress, boredom and other task-related perceived states were unrelated to SES. Ruling out presumed confounds, this study confirms the midfrontal mechanisms responsible for the SES effects on selective attention reported previously and here reflect genuine cognitive

  13. Steel factor controls midline cell death of primordial germ cells and is essential for their normal proliferation and migration.

    PubMed

    Runyan, Christopher; Schaible, Kyle; Molyneaux, Kathleen; Wang, Zhuoqiao; Levin, Linda; Wylie, Christopher

    2006-12-01

    During germ-cell migration in the mouse, the dynamics of embryo growth cause many germ cells to be left outside the range of chemoattractive signals from the gonad. At E10.5, movie analysis has shown that germ cells remaining in the midline no longer migrate directionally towards the genital ridges, but instead rapidly fragment and disappear. Extragonadal germ cell tumors of infancy, one of the most common neonatal tumors, are thought to arise from midline germ cells that failed to die. This paper addresses the mechanism of midline germ cell death in the mouse. We show that at E10.5, the rate of apoptosis is nearly four-times higher in midline germ cells than those more laterally. Gene expression profiling of purified germ cells suggests this is caused by activation of the intrinsic apoptotic pathway. We then show that germ cell apoptosis in the midline is activated by down-regulation of Steel factor (kit ligand) expression in the midline between E9.5 and E10.5. This is confirmed by the fact that removal of the intrinsic pro-apoptotic protein Bax rescues the germ-cell apoptosis seen in Steel null embryos. Two interesting things are revealed by this: first, germ-cell proliferation does not take place in these embryos after E9.0; second, migration of germ cells is highly abnormal. These data show first that changing expression of Steel factor is required for normal midline germ cell death, and second, that Steel factor is required for normal proliferation and migration of germ cells. PMID:17107997

  14. Impressive Response to Dose-Dense Chemotherapy in a Patient with NUT Midline Carcinoma

    PubMed Central

    Maur, Michela; Toss, Angela; Dominici, Massimo; Frassoldati, Antonio; Corradini, Paolo; Maiorana, Antonio; Fontana, Annalisa; Conte, Pierfranco

    2015-01-01

    Patient: Male, 21 Final Diagnosis: NUT midline carcinoma Symptoms: Fatigue • fever • pain Medication: Romidepsin Clinical Procedure: Chemotherapy Specialty: Oncology Objective: Rare disease Background: NUT midline carcinoma (NMC) is a rare, highly lethal malignancy that results from a chromosome translocation and mostly arises in the midline organs. To date, no treatment has been established. Most patients receive combinations of chemotherapy regimens and radiation, and occasionally subsequent resection; nevertheless, patients have an average survival hardly exceeding 7 months. Case Report: A 21-year-old patient was admitted to our division with a large mediastinal mass with lung nodules, multiple vertebral metastases, and massive nodal involvement. In a few days, the patient developed a superior vena cava syndrome and an acute respiratory failure. Due to the rapid course of the disease, based on preliminary histology of poorly differentiated carcinoma, a dose-dense biweekly chemotherapy with paclitaxel, ifosfamide, and cisplatin was started. In the meantime, the diagnosis of NMC was confirmed. A surprising clinical benefit was obtained after the first cycle of chemotherapy, and after 6 cycles a PET-CT scan showed a very good response. At this point, radiotherapy was started but the disease progressed outside of the radiation field. The patient entered into a compassionate use protocol with Romidepsin, but a PET/CT scan after the first course showed disease progression with peritoneal and retroperitoneal carcinosis. A treatment with Pemetrexed was then started but the patient eventually died with rapid progressive disease. Conclusions: Our case history adds some interesting findings to available knowledge: NMC can be chemosensitive and radiosensitive. This opens the possibility to study more aggressive treatments, including high-dose consolidation chemotherapy and to evaluate the role of biological agents as maintenance treatments. PMID:26140332

  15. Physiological Evidence for a Midline Spatial Channel in Human Auditory Cortex.

    PubMed

    Briley, Paul M; Goman, Adele M; Summerfield, A Quentin

    2016-08-01

    Studies with humans and other mammals have provided support for a two-channel representation of horizontal ("azimuthal") space in the auditory system. In this representation, location-sensitive neurons contribute activity to one of two broadly tuned channels whose responses are compared to derive an estimate of sound-source location. One channel is maximally responsive to sounds towards the left and the other to sounds towards the right. However, recent psychophysical studies of humans, and physiological studies of other mammals, point to the presence of an additional channel, maximally responsive to the midline. In this study, we used electroencephalography to seek physiological evidence for such a midline channel in humans. We measured neural responses to probe stimuli presented from straight ahead (0 °) or towards the right (+30 ° or +90 °). Probes were preceded by adapter stimuli to temporarily suppress channel activity. Adapters came from 0 ° or alternated between left and right (-30 ° and +30 ° or -90 ° and +90 °). For the +90 ° probe, to which the right-tuned channel would respond most strongly, both accounts predict greatest adaptation when the adapters are at ±90 °. For the 0 ° probe, the two-channel account predicts greatest adaptation from the ±90 ° adapters, while the three-channel account predicts greatest adaptation when the adapters are at 0 ° because these adapters stimulate the midline-tuned channel which responds most strongly to the 0 ° probe. The results were consistent with the three-channel account. In addition, a computational implementation of the three-channel account fitted the probe response sizes well, explaining 93 % of the variance about the mean, whereas a two-channel implementation produced a poor fit and explained only 61 % of the variance. PMID:27164943

  16. Tensor analyzing powers T/sub 20/(theta) and T/sub 22/(theta) in the /sup 2/H(darrow,. gamma. ) /sup 4/He reaction

    SciTech Connect

    Seyler, R.G.; Weller, H.R.

    1985-05-01

    Reaction theory expressions are used to prove that the tensor analyzing powers T/sub 20/(theta) and T/sub 22/(theta) for the /sup 2/H(darrow,..gamma..) /sup 4/He reaction are isotropic if the reaction is pure E2 and terms quadratic in channel-spin-2 matrix elements are neglected. Experimental departures from isotropy can be expected near theta-0/sup 0/, 90/sup 0/, and 189/sup 0/.

  17. Orthodontic retreatment of a Class III patient with significant midline asymmetry and bilateral posterior crossbite

    PubMed Central

    Brunetto, Ademir R.

    2015-01-01

    Posterior crossbite might cause serious long-term functional problems if not early treated. Nevertheless, in older patients, treatment might include palatal expansion in order to correct such malocclusion. In view of the above, this article aims at reporting late correction of bilateral posterior crossbite associated with Angle Class III malocclusion, right subdivision, with consequent midline shift (good skeletal pattern). The case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), with DI equal to or greater than 10, as a requirement for the title of certified by the BBO. PMID:25741833

  18. Orthodontic retreatment of a Class III patient with significant midline asymmetry and bilateral posterior crossbite.

    PubMed

    Brunetto, Ademir R

    2015-01-01

    Posterior crossbite might cause serious long-term functional problems if not early treated. Nevertheless, in older patients, treatment might include palatal expansion in order to correct such malocclusion. In view of the above, this article aims at reporting late correction of bilateral posterior crossbite associated with Angle Class III malocclusion, right subdivision, with consequent midline shift (good skeletal pattern). The case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), with DI equal to or greater than 10, as a requirement for the title of certified by the BBO. PMID:25741833

  19. Action sequencing deficit following frontal lobe lesion.

    PubMed

    Zanini, Sergio; Rumiati, Raffaella I; Shallice, Tim

    2002-01-01

    Frontal lobe patients carried out temporal sequencing tasks related to actions that differed in terms of their abstractness using both verbal and pictorial presentations. A generalized impairment was found: neither a type of action effect nor a modality of item presentation effect was present. The patients also carried out a corresponding action production task and produced actions quickly and without errors. The frontal lobe patients were also spared in generating verbal descriptions of actions: they were as accurate as normal controls both in terms of the details reported and in maintaining the temporal sequence. It has been argued that the difficulty in processing the temporal dimensions of actions following frontal lobe lesions is due to some form of disruption of the action representation. However, no action representational deficits were present in our frontal lobe patients. Thus, they cannot account for our findings. On the contrary, we suggest that the action sequencing deficit was a consequence of the difficulties patients experienced in rejecting wrong alternatives presented by the stimulus situation. PMID:11997488

  20. Nail Involvement in Frontal Fibrosing Alopecia

    PubMed Central

    Macpherson, Melanie; Hohendorf-Ansari, Parinaz; Trüeb, Ralph Michel

    2015-01-01

    A case of frontal fibrosing alopecia with nail involvement is presented. Nail involvement provides evidence for underlying lichen planus, and that the disease represents a rather generalized than localized process. Favorable response of the scalp condition to oral dutasteride points to an inflammatory reaction on the background of androgenetic alopecia. PMID:26180450

  1. Union, States Wage Frontal Attack on NCLB

    ERIC Educational Resources Information Center

    Keller, Bess; Sack, Joetta L.

    2005-01-01

    Widespread sniping at the Bush administration's centerpiece education law escalated into a frontal attack as the nation's largest teachers' union. Several school districts sued federal officials over the measure, just a day after the Utah legislature approved a bill challenging the reach of the law. The National Education Association's suit…

  2. Infant Frontal Asymmetry Predicts Child Emotional Availability

    ERIC Educational Resources Information Center

    Licata, Maria; Paulus, Markus; Kühn-Popp, Nina; Meinhardt, Jorg; Sodian, Beate

    2015-01-01

    While factors influencing maternal emotional availability (EA) have been well investigated, little is known about the development of child EA. The present longitudinal study investigated the role of frontal brain asymmetry in young children with regard to child EA (child responsiveness and involvement) in mother-child interaction in a sample of 28…

  3. Nail Involvement in Frontal Fibrosing Alopecia.

    PubMed

    Macpherson, Melanie; Hohendorf-Ansari, Parinaz; Trüeb, Ralph Michel

    2015-01-01

    A case of frontal fibrosing alopecia with nail involvement is presented. Nail involvement provides evidence for underlying lichen planus, and that the disease represents a rather generalized than localized process. Favorable response of the scalp condition to oral dutasteride points to an inflammatory reaction on the background of androgenetic alopecia. PMID:26180450

  4. Music Shifts Frontal EEG in Depressed Adolescents.

    ERIC Educational Resources Information Center

    Field, Tiffany; Martinez, Alex; Nawrocki, Thomas; Pickens, Jeffrey; Fox, Nathan A.; Schanberg, Saul

    1998-01-01

    Fourteen chronically depressed female adolescents listened to rock music for a 23-minute session. EEG was recorded and saliva samples were collected to determine the effects of the music on stress hormone cortisol levels. No differences were reported for mood state; however, cortisol levels decreased and relative right-frontal activation was…

  5. Affective Aprosodia from a Medial Frontal Stroke

    ERIC Educational Resources Information Center

    Heilman, Kenneth M.; Leon, Susan A.; Rosenbek, John C.

    2004-01-01

    Background and objectives: Whereas injury to the left hemisphere induces aphasia, injury to the right hemisphere's perisylvian region induces an impairment of emotional speech prosody (affective aprosodia). Left-sided medial frontal lesions are associated with reduced verbal fluency with relatively intact comprehension and repetition…

  6. A novel BRD4-NUT fusion in an undifferentiated sinonasal tumor highlights alternative splicing as a contributing oncogenic factor in NUT midline carcinoma.

    PubMed

    Stirnweiss, A; McCarthy, K; Oommen, J; Crook, M L; Hardy, K; Kees, U R; Wilton, S D; Anazodo, A; Beesley, A H

    2015-01-01

    NUT midline carcinoma (NMC) is a fatal cancer that arises in various tissues along the upper midline of the body. The defining molecular feature of NMC is a chromosomal translocation that joins (in the majority of cases) the nuclear testis gene NUT (NUTM1) to the bromodomain protein family member 4 (BRD4) and thereby creating a fusion oncogene that disrupts cellular differentiation and drives the disease. In this study, we report the case of an adolescent NMC patient presenting with severe facial pain, proptosis and visual impairment due to a mass arising from the ethmoid sinus that invaded the right orbit and frontal lobe. Treatment involved radical resection, including exenteration of the affected eye with the view to consolidate treatment with radiation therapy; however, the patient experienced rapid tumor progression and passed away 79 days post resection. Molecular analysis of the tumor tissue identified a novel in-frame BRD4-NUT transcript, with BRD4 exon 15 fused to the last 124 nucleotides of NUT exon 2 (BRD4-NUT ex15:ex2Δnt1-585). The partial deletion of NUT exon 2 was attributed to a mid-exonic genomic breakpoint and the subsequent activation of a cryptic splice site further downstream within the exon. Inhibition of the canonical 3' acceptor splice site of NUT intron 1 in cell lines expressing the most common NMC fusion transcripts (PER-403, BRD4-NUT ex11:ex2; PER-624, BRD4-NUT ex15:ex2) induced alternative splicing from the same cryptic splice site as identified in the patient. Detection of low levels of an in-frame BRD4-NUT ex11:ex2Δnt1-585 transcript in PER-403 confirmed endogenous splicing from this alternative exon 2 splice site. Although further studies are necessary to assess the clinical relevance of the increasing number of variant fusions described in NMC, the findings presented in this case identify alternative splicing as a mechanism that contributes to this pathogenic complexity. PMID:26551281

  7. A novel BRD4-NUT fusion in an undifferentiated sinonasal tumor highlights alternative splicing as a contributing oncogenic factor in NUT midline carcinoma

    PubMed Central

    Stirnweiss, A; McCarthy, K; Oommen, J; Crook, M L; Hardy, K; Kees, U R; Wilton, S D; Anazodo, A; Beesley, A H

    2015-01-01

    NUT midline carcinoma (NMC) is a fatal cancer that arises in various tissues along the upper midline of the body. The defining molecular feature of NMC is a chromosomal translocation that joins (in the majority of cases) the nuclear testis gene NUT (NUTM1) to the bromodomain protein family member 4 (BRD4) and thereby creating a fusion oncogene that disrupts cellular differentiation and drives the disease. In this study, we report the case of an adolescent NMC patient presenting with severe facial pain, proptosis and visual impairment due to a mass arising from the ethmoid sinus that invaded the right orbit and frontal lobe. Treatment involved radical resection, including exenteration of the affected eye with the view to consolidate treatment with radiation therapy; however, the patient experienced rapid tumor progression and passed away 79 days post resection. Molecular analysis of the tumor tissue identified a novel in-frame BRD4-NUT transcript, with BRD4 exon 15 fused to the last 124 nucleotides of NUT exon 2 (BRD4-NUT ex15:ex2Δnt1–585). The partial deletion of NUT exon 2 was attributed to a mid-exonic genomic breakpoint and the subsequent activation of a cryptic splice site further downstream within the exon. Inhibition of the canonical 3′ acceptor splice site of NUT intron 1 in cell lines expressing the most common NMC fusion transcripts (PER-403, BRD4-NUT ex11:ex2; PER-624, BRD4-NUT ex15:ex2) induced alternative splicing from the same cryptic splice site as identified in the patient. Detection of low levels of an in-frame BRD4-NUT ex11:ex2Δnt1–585 transcript in PER-403 confirmed endogenous splicing from this alternative exon 2 splice site. Although further studies are necessary to assess the clinical relevance of the increasing number of variant fusions described in NMC, the findings presented in this case identify alternative splicing as a mechanism that contributes to this pathogenic complexity. PMID:26551281

  8. Surface Layer Turbulence During a Frontal Passage

    SciTech Connect

    Piper, M; Lundquist, J K

    2004-06-15

    Some recent investigations have begun to quantify turbulence and dissipation in frontal zones to address the question of what physical mechanism counteracts the intensification of temperature and velocity gradients across a developing front. Frank (1994) examines the turbulence structure of two fronts that passed a 200m instrumented tower near Karlsruhe, Germany. In addition to showing the mean vertical structure of the fronts as they pass the tower, Frank demonstrates that there is an order of magnitude or more increase in turbulent kinetic energy across the frontal zone. Blumen and Piper (1999) reported turbulence statistics, including dissipation rate measurements, from the MICROFRONTS field experiment, where high-frequency turbulence data were collected from tower-mounted hotwire and sonic anemometers in a cold front and in a density current. Chapman and Browning (2001) measured dissipation rate in a precipitating frontal zone with high-resolution Doppler radar. Their measurements were conducted above the surface layer, to heights of 5km. The dissipation rate values they found are comparable to those measured in Kennedy and Shapiro (1975) in an upper-level front. Here, we expand on these recent studies by depicting the behavior of the fine scales of turbulence near the surface in a frontal zone. The primary objective of this study is to quantify the levels of turbulence and dissipation occurring in a frontal zone through the calculation of kinetic energy spectra and dissipation rates. The high-resolution turbulence data used in this study are taken during the cold front that passed the MICROFRONTS site in the early evening hours of 20 March 1995. These new measurements can be used as a basis for parameterizing the effects of surface-layer turbulence in numerical models of frontogenesis. We present three techniques for calculating the dissipation rate: direct dissipation technique, inertial dissipation technique and Kolmogorov's four-fifths law. Dissipation rate

  9. Dissociable long-term cognitive deficits after frontal versus sensorimotor cortical contusions.

    PubMed

    Lindner, M D; Plone, M A; Cain, C K; Frydel, B; Francis, J M; Emerich, D F; Sutton, R L

    1998-03-01

    Cognitive deficits are the most enduring and disabling sequelae of human traumatic brain injury (TBI), but quantifying the magnitude, duration, and pattern of cognitive deficits produced by different types of TBI has received little emphasis in preclinical animal models. The objective of the present study was to use a battery of behavioral tests to determine if different impact sites produce different patterns of behavioral deficits and to determine how long behavioral deficits can be detected after TBI. Prior to surgery, rats were trained to criteria on delayed nonmatching to position, radial arm maze, and rotarod tasks. Rats received sham surgery (controls), midline frontal contusions (frontal TBI, 2.25 m/sec impact), or unilateral sensorimotor cortex contusions (lateral TBI, 3.22 m/sec impact) at 12 months of age and were tested throughout the next 12 months. Cognitive deficits were more robust and more enduring than sensorimotor deficits for both lateral TBI and frontal TBI groups. Lateral TBI rats exhibited transient deficits in the forelimb placing and in the rotarod test of motor/ambulatory function, but cognitive deficits were apparent throughout the 12-month postsurgery period on tests of spatial learning and memory including: (1)reacquisition of a working memory version of the radial arm maze 6-7 months post-TBI, (2) performance in water maze probe trials 8 months post-TBI, and (3) repeated acquisition of the Morris water maze 8 and 11 months post-TBI. Frontal TBI rats exhibited a different pattern of deficits, with the most robust deficits in tests of attention/orientation such as: (1) the delayed nonmatching to position task (even with no delays) 1-11 weeks post-TBI, (2) the repeated acquisition version of the water maze--especially on the first "information" trial 8 months post-TBI, (3) a test of sensorimotor neglect or inattention 8.5 months post-TBI, and (4) a DRL20 test of timing and/or sustained attention 11 months after surgery. These results

  10. A model code for the radiative theta pinch

    SciTech Connect

    Lee, S.; Saw, S. H.; Lee, P. C. K.; Akel, M.; Damideh, V.; Khattak, N. A. D.; Mongkolnavin, R.; Paosawatyanyong, B.

    2014-07-15

    A model for the theta pinch is presented with three modelled phases of radial inward shock phase, reflected shock phase, and a final pinch phase. The governing equations for the phases are derived incorporating thermodynamics and radiation and radiation-coupled dynamics in the pinch phase. A code is written incorporating correction for the effects of transit delay of small disturbing speeds and the effects of plasma self-absorption on the radiation. Two model parameters are incorporated into the model, the coupling coefficient f between the primary loop current and the induced plasma current and the mass swept up factor f{sub m}. These values are taken from experiments carried out in the Chulalongkorn theta pinch.

  11. Simplified scaling model for the THETA-pinch

    SciTech Connect

    Ewing, K. J.; Thomson, D. B.

    1982-02-01

    A simple ID scaling model for the fast THETA-pinch was developed and written as a code that would be flexible, inexpensive in computer time, and readily available for use with the Los Alamos explosive-driven high-magnetic-field program. The simplified model uses three successive separate stages: (1) a snowplow-like radial implosion, (2) an idealized resistive annihilation of reverse bias field, and (3) an adiabatic compression stage of a BETA = 1 plasma for which ideal pressure balance is assumed to hold. The code uses one adjustable fitting constant whose value was first determined by comparison with results from the Los Alamos Scylla III, Scyllacita, and Scylla IA THETA-pinches.

  12. Preservation of Frontal Sinus Anatomy and Outflow Tract Following Frontal Trauma with Dural Defect

    PubMed Central

    Chin, David Chao Wu; Loh, Ian Chi Yuan

    2015-01-01

    Summary: Our case report describes a young male mechanic who was hit in his face by a spring while repairing a car, resulting in traumatic injury to the frontal sinus, with fractures of both the anterior and the posterior tables with dural defect and cerebrospinal fluid leak. Current guidelines recommend that comminuted and/or displaced fractures of the posterior table of the frontal sinus with dural defects should be either cranialized or obliterated. In this patient, instead of cranializing or obliterating the frontal sinus, we managed to preserve the frontal sinus anatomy and its outflow tract using a combined open bicoronal and nasoendoscopic approach. This avoids the long-term complications associated with cranialization or obliteration including mucocele formation and frontocutaneous fistula. PMID:25750839

  13. The Incidence of Central Line–Associated Bacteremia After the Introduction of Midline Catheters in a Ventilator Unit Population

    PubMed Central

    Pathak, Rahul; Patel, Anish; Enuh, Hilary; Adekunle, Oluwaseyi; Shrisgantharajah, Vasanthy; Diaz, Keith

    2015-01-01

    Hypothesis Our objective was to evaluate whether the use of midline venous catheters in place of central line venous catheters, when appropriate, decreased the overall incidence of central line–associated bacteremia in a ventilator unit. Methods The time interval between February 2012 and February 2013 was divided into 2 periods. Group A was the first half of the year, before the introduction of midline catheters, and group B was the second half of the year, 6 months after their introduction. Central line–associated bloodstream infection (CLABSI) was calculated using the equation: (total number of CLABSI/total number of catheter days) × 1000. The Z test was used for proportions between independent groups to compare the significance in the difference in CLABSI between groups A and B. Results There was a significant decrease in the total number of catheter days on the ventilator unit in group A from 2408 catheter days in 1 year (August 1, 2011, to July 31, 2012) before the introduction of midline catheters to 1521 catheter days in group B in the following year (November 1, 2012, to October 31, 2013; P < 0.05 for both groups). Conclusions Midline catheters in place of central lines decrease the rate of CLABSI in a ventilator unit. In addition, no bloodstream infections were associated with midline catheters. PMID:25972725

  14. Cold iron cos THETA magnet option for the SSC

    SciTech Connect

    Reardon, P.

    1985-01-01

    We review first the evolution over the past several years of a cold iron, high field cos THETA magnet design option for the SSC. We note the collaborative approach pursued by BNL and LBL on the 2-in-1 option, and the culmination of this effort in the tests of the BNL 4.5 m model magnets. Next, we discuss the subsequent 1-in-1 option being pursued jointly by BNL, Fermilab and LBL.

  15. The role of REM sleep theta activity in emotional memory

    PubMed Central

    Hutchison, Isabel C.; Rathore, Shailendra

    2015-01-01

    While non-REM (NREM) sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of rapid-eye movement (REM) sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity—which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex—is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale pontine-geniculo-occipital (PGO) waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and gradual weakening of consolidated hippocampal memory traces during REM sleep. Hippocampal theta activity is also correlated with REM sleep levels of achetylcholine - which is thought to reduce hippocampal inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate feedback within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus. PMID:26483709

  16. Correlation of hippocampal theta rhythm with changes in cutaneous temperature

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    Investigation of the possibility that the hippocampus performs the function of alerting an animal to changes in cutaneous temperature, using unanesthetized, loosely restrained rabbits. The results indicate that the hippocampal theta rhythm, which appears to be evoked by changes in cutaneous temperature, can be related to a specific type of hyppocampal neuron which is, in turn, connected with other areas of the brain involved in temperature regulation.

  17. The role of REM sleep theta activity in emotional memory.

    PubMed

    Hutchison, Isabel C; Rathore, Shailendra

    2015-01-01

    While non-REM (NREM) sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of rapid-eye movement (REM) sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity-which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex-is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale pontine-geniculo-occipital (PGO) waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and gradual weakening of consolidated hippocampal memory traces during REM sleep. Hippocampal theta activity is also correlated with REM sleep levels of achetylcholine - which is thought to reduce hippocampal inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate feedback within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus. PMID:26483709

  18. Grid cells and theta as oscillatory interference: theory and predictions.

    PubMed

    Burgess, Neil

    2008-01-01

    The oscillatory interference model [Burgess et al. (2007) Hippocampus 17:801-802] of grid cell firing is reviewed as an algorithmic level description of path integration and as an implementation level description of grid cells and their inputs. New analyses concern the relationships between the variables in the model and the theta rhythm, running speed, and the intrinsic firing frequencies of grid cells. New simulations concern the implementation of velocity-controlled oscillators (VCOs) with different preferred directions in different neurons. To summarize the model, the distance traveled along a specific direction is encoded by the phase of a VCO relative to a baseline frequency. Each VCO is an intrinsic membrane potential oscillation whose frequency increases from baseline as a result of depolarization by synaptic input from speed modulated head-direction cells. Grid cell firing is driven by the VCOs whose preferred directions match the current direction of motion. VCOs are phase-reset by location-specific input from place cells to prevent accumulation of error. The baseline frequency is identified with the local average of VCO frequencies, while EEG theta frequency is identified with the global average VCO frequency and comprises two components: the frequency at zero speed and a linear response to running speed. Quantitative predictions are given for the inter-relationships between a grid cell's intrinsic firing frequency and grid scale, the two components of theta frequency, and the running speed of the animal. Qualitative predictions are given for the properties of the VCOs, and the relationship between environmental novelty, the two components of theta, grid scale and place cell remapping. PMID:19021256

  19. Cell discharge correlates of posterior hypothalamic theta rhythm. Recipe for success in recording stable field potential.

    PubMed

    Bocian, Renata; Kłos-Wojtczak, Paulina; Konopacki, Jan

    2016-09-01

    The theta rhythm discovered in the posterior hypothalamus area (PHa) differs from theta observed in the hippocampal formation. In comparison to hippocampal spontaneous theta, the theta recorded in the PHa is rarely registered, has lower amplitude, often disappears, and sometimes returns after a few minutes. These features indicate that spontaneous theta recorded in the PHa is not an appropriate experimental model to search for the correlation between PHa cell discharges and local field potential. In this paper we present standard experimental conditions necessary to record theta-related cells in the PHa in anesthetized rats. Three pharmacological agents were used in the experiments to induce PHa theta rhythm in urethanized rats: carbachol (CCH), carbenoxolone and kainic acid, which are potent enough to induce well-synchronized PHa theta. However, CCH was found to be the best pharmacological tool to induce PHa theta oscillations, due to its longest duration of action and lack of preliminary epileptogenic effects. It seems that CCH-induced theta can be the most suitable pharmacological model for experiments with the use of protocol of long-lasting recordings of PHa theta-related cell discharges. PMID:27353451

  20. A Modified Theta Projection Model for Creep Behavior of Metals and Alloys

    NASA Astrophysics Data System (ADS)

    Kumar, Manish; Singh, I. V.; Mishra, B. K.; Ahmad, S.; Venugopal Rao, A.; Kumar, Vikas

    2016-06-01

    In this work, a modified theta projection model is proposed for the constitutive modeling of creep behavior of metals and alloys. In the conventional theta projection model, strain hardening exponent is a function of time and theta, whereas in the modified theta projection model, the exponent is taken as a function of time, theta, and applied stress. The results obtained by the modified theta projection model for Al 2124 T851 alloy at constant uniaxial tensile stress are compared with the experimental results and with the predictions of the conventional theta projection method. The creep behavior of Al 7075 T651 alloy is also predicted using modified and conventional theta projection model and compared with the available experimental data. It is observed that the modified theta projection model captures the creep behavior more accurately as compared to the conventional theta projection model. The modified theta projection model can be used to predict the creep strain of pure metals and class M alloys (similar creep behavior to pure metals) for intermediate range of stress and temperature.

  1. Theta Series, Wall-Crossing and Quantum Dilogarithm Identities

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sergei; Pioline, Boris

    2016-05-01

    Motivated by mathematical structures which arise in string vacua and gauge theories with {{{N}=2}} supersymmetry, we study the properties of certain generalized theta series which appear as Fourier coefficients of functions on a twisted torus. In Calabi-Yau string vacua, such theta series encode instanton corrections from k Neveu-Schwarz five-branes. The theta series are determined by vector-valued wave-functions, and in this work we obtain the transformation of these wave-functions induced by Kontsevich-Soibelman symplectomorphisms. This effectively provides a quantum version of these transformations, where the quantization parameter is inversely proportional to the five-brane charge k. Consistency with wall-crossing implies a new five-term relation for Faddeev's quantum dilogarithm {Φ_b} at b = 1, which we prove. By allowing the torus to be non-commutative, we obtain a more general five-term relation valid for arbitrary b and k, which may be relevant for the physics of five-branes at finite chemical potential for angular momentum.

  2. Adaptive [theta]-methods for pricing American options

    NASA Astrophysics Data System (ADS)

    Khaliq, Abdul Q. M.; Voss, David A.; Kazmi, Kamran

    2008-12-01

    We develop adaptive [theta]-methods for solving the Black-Scholes PDE for American options. By adding a small, continuous term, the Black-Scholes PDE becomes an advection-diffusion-reaction equation on a fixed spatial domain. Standard implementation of [theta]-methods would require a Newton-type iterative procedure at each time step thereby increasing the computational complexity of the methods. Our linearly implicit approach avoids such complications. We establish a general framework under which [theta]-methods satisfy a discrete version of the positivity constraint characteristic of American options, and numerically demonstrate the sensitivity of the constraint. The positivity results are established for the single-asset and independent two-asset models. In addition, we have incorporated and analyzed an adaptive time-step control strategy to increase the computational efficiency. Numerical experiments are presented for one- and two-asset American options, using adaptive exponential splitting for two-asset problems. The approach is compared with an iterative solution of the two-asset problem in terms of computational efficiency.

  3. Theta Series, Wall-Crossing and Quantum Dilogarithm Identities

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sergei; Pioline, Boris

    2016-08-01

    Motivated by mathematical structures which arise in string vacua and gauge theories with N=2 supersymmetry, we study the properties of certain generalized theta series which appear as Fourier coefficients of functions on a twisted torus. In Calabi-Yau string vacua, such theta series encode instanton corrections from k Neveu-Schwarz five-branes. The theta series are determined by vector-valued wave-functions, and in this work we obtain the transformation of these wave-functions induced by Kontsevich-Soibelman symplectomorphisms. This effectively provides a quantum version of these transformations, where the quantization parameter is inversely proportional to the five-brane charge k. Consistency with wall-crossing implies a new five-term relation for Faddeev's quantum dilogarithm {Φ_b} at b = 1, which we prove. By allowing the torus to be non-commutative, we obtain a more general five-term relation valid for arbitrary b and k, which may be relevant for the physics of five-branes at finite chemical potential for angular momentum.

  4. Speech encoding by coupled cortical theta and gamma oscillations.

    PubMed

    Hyafil, Alexandre; Fontolan, Lorenzo; Kabdebon, Claire; Gutkin, Boris; Giraud, Anne-Lise

    2015-01-01

    Many environmental stimuli present a quasi-rhythmic structure at different timescales that the brain needs to decompose and integrate. Cortical oscillations have been proposed as instruments of sensory de-multiplexing, i.e., the parallel processing of different frequency streams in sensory signals. Yet their causal role in such a process has never been demonstrated. Here, we used a neural microcircuit model to address whether coupled theta-gamma oscillations, as observed in human auditory cortex, could underpin the multiscale sensory analysis of speech. We show that, in continuous speech, theta oscillations can flexibly track the syllabic rhythm and temporally organize the phoneme-level response of gamma neurons into a code that enables syllable identification. The tracking of slow speech fluctuations by theta oscillations, and its coupling to gamma-spiking activity both appeared as critical features for accurate speech encoding. These results demonstrate that cortical oscillations can be a key instrument of speech de-multiplexing, parsing, and encoding. PMID:26023831

  5. Impaired theta-gamma coupling in APP-deficient mice

    PubMed Central

    Zhang, Xiaomin; Zhong, Wewei; Brankačk, Jurij; Weyer, Sascha W.; Müller, Ulrike C.; Tort, Adriano B. L.; Draguhn, Andreas

    2016-01-01

    Amyloid precursor protein (APP) is critically involved in the pathophysiology of Alzheimer’s disease, but its physiological functions remain elusive. Importantly, APP knockout (APP-KO) mice exhibit cognitive deficits, suggesting that APP plays a role at the neuronal network level. To investigate this possibility, we recorded local field potentials (LFPs) from the posterior parietal cortex, dorsal hippocampus and lateral prefrontal cortex of freely moving APP-KO mice. Spectral analyses showed that network oscillations within the theta- and gamma-frequency bands were not different between APP-KO and wild-type mice. Surprisingly, however, while gamma amplitude coupled to theta phase in all recorded regions of wild-type animals, in APP-KO mice theta-gamma coupling was strongly diminished in recordings from the parietal cortex and hippocampus, but not in LFPs recorded from the prefrontal cortex. Thus, lack of APP reduces oscillatory coupling in LFP recordings from specific brain regions, despite not affecting the amplitude of the oscillations. Together, our findings reveal reduced cross-frequency coupling as a functional marker of APP deficiency at the network level. PMID:26905287

  6. Distinct representations and theta dynamics in dorsal and ventral hippocampus

    PubMed Central

    Royer, Sébastien; Sirota, Anton; Patel, Jagdish; Buzsáki, György

    2010-01-01

    Although anatomical, lesion and imaging studies of the hippocampus indicate qualitatively different information processing along its septo-temporal axis, physiological mechanisms supporting such distinction are missing. We found fundamental differences between the dorsal (dCA3) and the ventral-most parts (vCA3) of the hippocampus in both environmental representation and temporal dynamics. Discrete place fields of dCA3 neurons evenly covered all parts of the testing environments. In contrast, vCA3 neurons i) rarely showed continuous two-dimensional place fields, ii) differentiated open and closed arms of a radial maze, and iii) discharged similar firing patterns with respect to the goals, both on multiple arms of a radial maze and during opposite journeys in a zig-zag maze. In addition, theta power and the fraction of theta-rhythmic neurons were substantially reduced in the ventral as compared to dorsal hippocampus. We hypothesize that the spatial representation in the septo-temporal axis of the hippocampus is progressively decreased. This change is paralleled with a reduction of theta rhythm and an increased representation of non-spatial information. PMID:20130187

  7. Recurrent somatic mutations in ACVR1 in pediatric midline high-grade astrocytoma

    PubMed Central

    Fontebasso, Adam M.; Papillon-Cavanagh, Simon; Schwartzentruber, Jeremy; Nikbakht, Hamid; Gerges, Noha; Fiset, Pierre-Olivier; Bechet, Denise; Faury, Damien; De Jay, Nicolas; Ramkissoon, Lori; Corcoran, Aoife; Jones, David T W; Sturm, Dominik; Johann, Pascal; Tomita, Tadanori; Goldman, Stewart; Nagib, Mahmoud; Bendel, Anne; Goumnerova, Liliana; Bowers, Daniel C.; Leonard, Jeffrey R.; Rubin, Joshua B.; Alden, Tord; Browd, Samuel; Geyer, J. Russell; Leary, Sarah; Jallo, George; Cohen, Kenneth; Gupta, Nalin; Prados, Michael D.; Carret, Anne-Sophie; Ellezam, Benjamin; Crevier, Louis; Klekner, Almos; Bognar, Laszlo; Hauser, Peter; Garami, Miklos; Myseros, John; Dong, Zhifeng; Siegel, Peter M.; Malkin, Hayley; Ligon, Azra; Albrecht, Steffen; Pfister, Stefan M.; Ligon, Keith L.; Majewski, Jacek; Jabado, Nada; Kieran, Mark W

    2014-01-01

    Midline pediatric high-grade astrocytomas (pHGAs) are incurable with few treatment targets identified. Most tumors harbor K27M mutations on histone 3 variants. In 40 treatment-naïve midline pHGAs, 39 analyzed by whole-exome sequencing, we find additional somatic mutations specific to tumor location. Gain-of-function mutations in ACVR1 occur in tumors of the pons in conjunction with H3.1 K27M, while FGFR1 mutations/fusions occur in thalamic tumors associated with H3.3 K27M. Hyper-activation of the bone morphogenetic protein (BMP)/ACVR1 developmental pathway in pHGAs harbouring ACVR1 mutations led to increased phospho-SMAD1/5/8 expression and up-regulation of BMP downstream early response genes in tumour cells. Global DNA methylation profiles were significantly associated with the K27M mutation regardless of the mutant H3 variant and irrespective of tumor location, supporting its role in driving the epigenetic phenotype. This significantly expands the potential treatment targets and further justifies pre-treatment biopsy in pHGA as a means to orient therapeutic efforts in this disease. PMID:24705250

  8. Distinct modes of mitotic spindle orientation align cells in the dorsal midline of ascidian embryos.

    PubMed

    Negishi, Takefumi; Yasuo, Hitoyoshi

    2015-12-01

    The orientation of cell division can have important consequences on the choice of cell fates adopted by each daughter cell as well as on the architecture of the tissue within which the dividing cell resides. We have studied in detail the oriented cell divisions that take place in the dorsal midline of the ascidian embryo. The dorsal midline cells of the ascidian embryo emerge following an asymmetric cell division oriented along the animal-vegetal (A-V) axis. This division generates the NN (Notochord-Neural) cell at the margin and the E (Endoderm) cell more vegetally. Deviating from the default mode of cell division, these sister cells divide again along the A-V axis to generate a column of four cells. We describe these cell divisions in detail. We show that the NN cell mitotic spindle rotates 90° to align along the A-V axis while the E cell spindle forms directly along the axis following the asymmetric migration of its centrosomes. We combine live imaging, embryo manipulations and pharmacological modulation of cytoskeletal elements to address the mechanisms underlying these distinct subcellular behaviours. Our evidence suggests that, in E cells, aster asymmetry together with the E cell shape contribute to the asymmetric centrosome migration. In NN cells, an intrinsic cytoplasmic polarisation of the cell results in the accumulation of dynein to the animal pole side. Our data support a model in which a dynein-dependent directional cytoplasmic pulling force may be responsible for the NN cell spindle rotation. PMID:26452428

  9. The hormonal peptide Elabela guides angioblasts to the midline during vasculogenesis

    PubMed Central

    Helker, Christian SM; Schuermann, Annika; Pollmann, Cathrin; Chng, Serene C; Kiefer, Friedemann; Reversade, Bruno; Herzog, Wiebke

    2015-01-01

    A key step in the de novo formation of the embryonic vasculature is the migration of endothelial precursors, the angioblasts, to the position of the future vessels. To form the first axial vessels, angioblasts migrate towards the midline and coalesce underneath the notochord. Vascular endothelial growth factor has been proposed to serve as a chemoattractant for the angioblasts and to regulate this medial migration. Here we challenge this model and instead demonstrate that angioblasts rely on their intrinsic expression of Apelin receptors (Aplr, APJ) for their migration to the midline. We further show that during this angioblast migration Apelin receptor signaling is mainly triggered by the recently discovered ligand Elabela (Ela). As neither of the ligands Ela or Apelin (Apln) nor their receptors have previously been implicated in regulating angioblast migration, we hereby provide a novel mechanism for regulating vasculogenesis, with direct relevance to physiological and pathological angiogenesis. DOI: http://dx.doi.org/10.7554/eLife.06726.001 PMID:26017639

  10. Spontaneous intracranial hypotension manifesting as a unilateral subdural hematoma with a marked midline shift.

    PubMed

    Inamasu, Joji; Moriya, Shigeta; Shibata, Junpei; Kumai, Tadashi; Hirose, Yuichi

    2015-01-01

    Spontaneous intracranial hypotension (SIH) is a syndrome in which hypovolemia of the cerebrospinal fluid (CSF) results in various symptoms. Although its prognosis is usually benign, cases with a rapid neurologic deterioration resulting in an altered mental status have been reported. One of the characteristic radiographic findings in such cases is the presence of bilateral accumulation of subdural fluid (hematoma/hygroma). When SIH-related subdural hematoma is present only unilaterally with a concomitant midline shift, making an accurate diagnosis may be challenging, and inadvertent hematoma evacuation may result in further neurologic deterioration. We report a 58-year-old woman with an altered mental status who had visited a local hospital and in whom a brain CT showed a unilateral subdural hematoma with a marked midline shift. She was referred to our department because of her neurologic deterioration after hematoma evacuation. A CT myelography revealed a massive CSF leakage in the entire thoracic epidural space. She made a full neurologic recovery following blood patch therapy. Our case is unique and educational because the suspicion for SIH as an underlying cause of subdural hematoma is warranted in nongeriatric patients not only with bilateral but also unilateral lesions. An immediate search for CSF leakage may be important in cases with failed hematoma evacuation surgery. PMID:25969682

  11. Spontaneous Intracranial Hypotension Manifesting as a Unilateral Subdural Hematoma with a Marked Midline Shift

    PubMed Central

    Inamasu, Joji; Moriya, Shigeta; Shibata, Junpei; Kumai, Tadashi; Hirose, Yuichi

    2015-01-01

    Spontaneous intracranial hypotension (SIH) is a syndrome in which hypovolemia of the cerebrospinal fluid (CSF) results in various symptoms. Although its prognosis is usually benign, cases with a rapid neurologic deterioration resulting in an altered mental status have been reported. One of the characteristic radiographic findings in such cases is the presence of bilateral accumulation of subdural fluid (hematoma/hygroma). When SIH-related subdural hematoma is present only unilaterally with a concomitant midline shift, making an accurate diagnosis may be challenging, and inadvertent hematoma evacuation may result in further neurologic deterioration. We report a 58-year-old woman with an altered mental status who had visited a local hospital and in whom a brain CT showed a unilateral subdural hematoma with a marked midline shift. She was referred to our department because of her neurologic deterioration after hematoma evacuation. A CT myelography revealed a massive CSF leakage in the entire thoracic epidural space. She made a full neurologic recovery following blood patch therapy. Our case is unique and educational because the suspicion for SIH as an underlying cause of subdural hematoma is warranted in nongeriatric patients not only with bilateral but also unilateral lesions. An immediate search for CSF leakage may be important in cases with failed hematoma evacuation surgery. PMID:25969682

  12. A role for midline and intralaminar thalamus in the associative blocking of Pavlovian fear conditioning

    PubMed Central

    Sengupta, Auntora; McNally, Gavan P.

    2014-01-01

    Fear learning occurs in response to positive prediction error, when the expected outcome of a conditioning trial exceeds that predicted by the conditioned stimuli present. This role for error in Pavlovian association formation is best exemplified by the phenomenon of associative blocking, whereby prior fear conditioning of conditioned stimulus (CS) A is able to prevent learning to CSB when they are conditioned in compound. The midline and intralaminar thalamic nuclei (MIT) are well-placed to contribute to fear prediction error because they receive extensive projections from the midbrain periaqueductal gray—which has a key role in fear prediction error—and project extensively to prefrontal cortex and amygdala. Here we used an associative blocking design to study the role of MIT in fear learning. In Stage I rats were trained to fear CSA via pairings with shock. In Stage II rats received compound fear conditioning of CSAB paired with shock. On test, rats that received Stage I training expressed less fear to CSB relative to control rats that did not receive this training. Microinjection of bupivacaine into MIT prior to Stage II training had no effect on the expression of fear during Stage II and had no effect on fear learning in controls, but prevented associative blocking and so enabled fear learning to CSB. These results show an important role for MIT in predictive fear learning and are discussed with reference to previous findings implicating the midline and posterior intralaminar thalamus in fear learning and fear responding. PMID:24822042

  13. Direct Midline Diastema Closure with Composite Layering Technique: A One-Year Follow-Up

    PubMed Central

    Korkut, Bora; Yanikoglu, Funda; Tagtekin, Dilek

    2016-01-01

    Objective. Maxillary anterior spacing is a common aesthetic complaint of patients. Midline diastema has a multifactorial etiology such as labial frenulum, microdontia, mesiodens, peg-shaped lateral incisors, agenesis, cysts, habits such as finger sucking, tongue thrusting, or lip sucking, dental malformations, genetics, proclinations, dental-skeletal discrepancies, and imperfect coalescence of interdental septum. Appropriate technique and material for effective treatment are based on time, physical, psychological, and economical limitations. Direct composite resins in diastema cases allow dentist and patient complete control of these limitations and formation of natural smile. Clinical Considerations. In this case report a maxillary midline diastema was closed with direct composite resin restorations in one appointment without any preparation. One bottle total etch adhesive was used and translucent/opaque composite resin shades were layered on mesial surfaces of the teeth that were isolated with rubber dam and Teflon bands. Finishing and polishing procedures were achieved by using polishing discs. Patient was informed for recalls for every 6 months. Conclusions. At one-year recall no sensitivities, discolorations, or fractures were detected on teeth and restorations. Direct composite resins seemed to be highly aesthetic and durable restorations that can satisfy patients as under the conditions of case presented. PMID:26881147

  14. Midline 1 controls polarization and migration of murine cytotoxic T cells

    PubMed Central

    Boding, Lasse; Hansen, Ann K; Nielsen, Morten M; Meroni, Germana; Braunstein, Thomas H; Woetmann, Anders; Ødum, Niels; Bonefeld, Charlotte M; Geisler, Carsten

    2014-01-01

    Midline 1 (MID1) is a microtubule-associated ubiquitin ligase that regulates protein phosphatase 2 A levels. Loss-of-function mutations in MID1 lead to the human X-linked Opitz G/BBB (OS) syndrome characterized by defective midline development during embryogenesis. We have recently shown that MID1 is strongly up-regulated in murine cytotoxic T lymphocytes (CTLs), and that it has a significant impact on exocytosis of lytic granules and the killing capacity of CTLs. The aims of the present study were to determine the localization of MID1 in migrating CTLs, and to investigate whether MID1 affects CTL polarization and migration. We found that MID1 mainly localizes to the uropod of migrating CTLs and that it has a substantial impact on CTL polarization and migration in vitro. Furthermore, analysis of contact hypersensitivity responses supported that MID1 controls effector functions of CTLs in hapten-challenged skin in vivo. These results provide significant new knowledge on the role of MID1 in CTL biology. PMID:25866633

  15. A reliable approach to the closure of large acquired midline defects of the back

    SciTech Connect

    Casas, L.A.; Lewis, V.L. Jr. )

    1989-10-01

    A systematic regionalized approach for the reconstruction of acquired thoracic and lumbar midline defects of the back is described. Twenty-three patients with wounds resulting from pressure necrosis, radiation injury, and postoperative wound infection and dehiscence were successfully reconstructed. The latissimus dorsi, trapezius, gluteus maximus, and paraspinous muscles are utilized individually or in combination as advancement, rotation, island, unipedicle, turnover, or bipedicle flaps. All flaps are designed so that their vascular pedicles are out of the field of injury. After thorough debridement, large, deep wounds are closed with two layers of muscle, while smaller, more superficial wounds are reconstructed with one layer. The trapezius muscle is utilized in the high thoracic area for the deep wound layer, while the paraspinous muscle is used for this layer in the thoracic and lumbar regions. Superficial layer and small wounds in the high thoracic area are reconstructed with either latissimus dorsi or trapezius muscle. Corresponding wounds in the thoracic and lumbar areas are closed with latissimus dorsi muscle alone or in combination with gluteus maximus muscle. The rationale for systematic regionalized reconstruction of acquired midline back wounds is described.

  16. Clinical evaluation of direct composite restoration done for midline diastema closure – long-term study

    PubMed Central

    Prabhu, R.; Bhaskaran, S.; Geetha Prabhu, K. R.; Eswaran, M. A.; Phanikrishna, G.; Deepthi, B.

    2015-01-01

    Purpose of the Study: The aim of this study was to evaluate clinically the performance of composite resin used to restore midline diastema between the maxillary and mandibular central incisors. Methodology: Direct composite restorations were done for 45 patients with midline diastema between the maxillary and mandibular central incisors. Standard protocols were followed for the placement of composite resin for the diastema closure, and recall visits were made for every 6 months for a period of 60 months for evaluation of the success of these restorations made. Qualified dental personnel examined the restorations made. Results: Clinical evaluations were done after the restorations had been in place for an average of 6 months. Results indicate that none of the restorations were totally lost, and resulting in a 91% overall retention rate for the period of 60 months. About 62% of the restorations made had no noticeable color difference with that of the adjacent tooth, and gingival health indicated 73% of the sample was without any signs of inflammation. Conclusions: Composites restored for diastemas exhibit satisfactory survival rates placed with recommended placement protocols and without occlusal loading. PMID:26538917

  17. Direct Midline Diastema Closure with Composite Layering Technique: A One-Year Follow-Up.

    PubMed

    Korkut, Bora; Yanikoglu, Funda; Tagtekin, Dilek

    2016-01-01

    Objective. Maxillary anterior spacing is a common aesthetic complaint of patients. Midline diastema has a multifactorial etiology such as labial frenulum, microdontia, mesiodens, peg-shaped lateral incisors, agenesis, cysts, habits such as finger sucking, tongue thrusting, or lip sucking, dental malformations, genetics, proclinations, dental-skeletal discrepancies, and imperfect coalescence of interdental septum. Appropriate technique and material for effective treatment are based on time, physical, psychological, and economical limitations. Direct composite resins in diastema cases allow dentist and patient complete control of these limitations and formation of natural smile. Clinical Considerations. In this case report a maxillary midline diastema was closed with direct composite resin restorations in one appointment without any preparation. One bottle total etch adhesive was used and translucent/opaque composite resin shades were layered on mesial surfaces of the teeth that were isolated with rubber dam and Teflon bands. Finishing and polishing procedures were achieved by using polishing discs. Patient was informed for recalls for every 6 months. Conclusions. At one-year recall no sensitivities, discolorations, or fractures were detected on teeth and restorations. Direct composite resins seemed to be highly aesthetic and durable restorations that can satisfy patients as under the conditions of case presented. PMID:26881147

  18. Dysfunction of a Cortical Midline Network During Emotional Appraisals in Schizophrenia

    PubMed Central

    Holt, Daphne. J.; Lakshmanan, Balaji; Freudenreich, Oliver; Goff, Donald C.; Rauch, Scott L.; Kuperberg, Gina R.

    2011-01-01

    A cardinal feature of schizophrenia is the poor comprehension, or misinterpretation, of the emotional meaning of social interactions and events, which can sometimes take the form of a persecutory delusion. It has been shown that the comprehension of the emotional meaning of the social world involves a midline paralimbic cortical network. However, the function of this network during emotional appraisals in patients with schizophrenia is not well understood. In this study, hemodynamic responses were measured in 14 patients with schizophrenia and 18 healthy subjects during the evaluation of descriptions of social situations with negative, positive, and neutral affective valence. The healthy and schizophrenia groups displayed opposite patterns of responses to emotional and neutral social situations within the medial prefrontal and posterior cingulate cortices—healthy participants showed greater activity to the emotional compared to the neutral situations, while patients exhibited greater responses to the neutral compared to the emotional situations. Moreover, the magnitude of the response within bilateral cingulate gyri to the neutral social stimuli predicted delusion severity in the patients with schizophrenia. These findings suggest that impaired functioning of cortical midline structures in schizophrenia may underlie faulty interpretations of social events, contributing to delusion formation. PMID:19605517

  19. Early results with the Mutaf technique: a novel off-midline approach in pilonidal sinus surgery

    PubMed Central

    Zorlu, Musa; Zobacı, Ethem; Kocak, Cem; Yastı, Ahmet Çınar; Dolapçı, Mete

    2016-01-01

    Purpose The objective of the present study was to compare different off-midline techniques in terms of their advantages and disadvantages. Methods A total of 81 patients were included in this prospective, controlled, randomized study. Patients in group 1 were treated with the Limberg flap, and patients in group 2 were treated with Mutaf technique. Patients were followed up for 9 months postsurgically and assessed at regular intervals. Results A total of 41 and 40 patients received surgical treatment with Limberg or Mutaf techniques, respectively. The 2 groups were similar in terms of age, gender, body mass index, and Tezel pilonidal sinus classification. Also, the 2 groups were comparable with regard to the frequency of preoperative discharge from the wound site, history of abscess formation, and the resultant antibiotic use. Early results showed similar recurrence rates and surgical-site complications between the 2 groups. Although a lower visual analogue scale score was found in group 2 at postoperative day 1, seroma persistence, time to withdrawal of surgical drains, and wound healing were more prolonged. Conclusion In this study, Mutaf technique was comparable to Limberg flap in the treatment of pilonidal sinus. Therefore, Mutaf technique may be offered as a viable surgical therapeutic option among off-midline closure approaches. PMID:27186571

  20. Outcomes and Complications of the Midline Anterior Approach 3 Years after Lumbar Spine Surgery

    PubMed Central

    Braaksma, Brian; Weinreb, Jeffrey H.; Nalbandian, Matthew; Spivak, Jeffrey M.; Petrizzo, Anthony

    2014-01-01

    Objective. The purpose of this study was to evaluate a new questionnaire to assess outcomes related to the midline anterior lumbar approach and to identify risk factors for negative patient responses. Methods. A retrospective review of 58 patients who underwent anterior lumbar surgery at a single institution for either degenerative disc disease or spondylolisthesis in 2009 was performed. The outcome measures included our newly developed Anterior Lumbar Surgery Questionnaire (ALSQ), ODI, and EQ-5D. Results. There were 58 patients available for followup, 27 women and 31 men. The average age at surgery was 50.8 years, with an average followup of 2.92 years. The average change in ODI was 34.94 (22.7) and EQ-5D was 0.28 (0.29). The rate of complications with the anterior approach was 10.3% and there was one male patient (3.2%) with retrograde ejaculation. Determination of the effectiveness of the new ALSQ revealed that it significantly correlated to the EQ-5D and ODI (P < 0.05). Smoking was associated with a negative response on thirteen questions. BMP use was not associated with a negative response on any sexual function questions. Conclusions. Our new Anterior Lumbar Surgery Questionnaire determines patient perceived complications related to the midline anterior lumbar surgical approach. PMID:25610657

  1. The Transconjunctival Transorbital Approach: A Keyhole Approach to the Midline Anterior Skull Base

    PubMed Central

    Raza, Shaan M.; Quinones-Hinojosa, Alfredo; Lim, Michael; Owusu Boahene, Kofi D.

    2015-01-01

    OBJECTIVE To report an initial experience with a medial transorbital approach to the midline skull base performed via a transconjunctival incision. METHODS The authors retrospectively reviewed their clinical experience with this approach in the management of benign cranial base pathology. Preoperative imaging, intraoperative records, hospitalization charts, and postoperative records were reviewed for relevant data. RESULTS During the period 2009–2011, six patients underwent a transconjunctival craniotomy performed by a neurosurgeon and otolaryngologist–head and neck surgeon working together. The indications for surgery were esthesioneuroblastoma in one patient, juvenile angiofibroma in one patient, Paget disease in one patient, and recalcitrant cerebrospinal fluid leaks in three patients. Three patients had prior cranial base surgery (either open craniotomy or an endonasal approach) done at another institution. The mean length of stay was 3.8 days; mean follow-up was 6 months. Surgery was considered successful in all cases (negative margins or no leak recurrence); diplopia was noted in one patient postoperatively. CONCLUSIONS The transconjunctival medial orbital craniectomy provides a minimally invasive keyhole approach to lesions located anteriorly along the anterior cranial fossa that are in the midline with lateral extension over the orbital roof. Based on our initial experience with this technique, the working space afforded limits complex surgical dissection; this approach is primarily well suited for less extensive pathology. PMID:22722037

  2. Medullary raphe midline is involved in production of expulsive expirations in anesthetized rabbits.

    PubMed

    Poliacek, I; Jakus, J; Knocikova, J; Barani, H; Halasova, E; Visnovcova, N

    2008-12-01

    Effects of kainic acid lesions in the medullary raphe midline on reflex expirations induced mechanically from the trachea were examined. Spontaneously breathing rabbits were anesthetized by ketamine and xylazine i.m., followed by pentobarbitone i.v. Excitatory neurotoxin kainic acid (2 mg/ml in artificial CSF, total volume of 55-100 nl) was pressure microinjected into the medullary midline, rostral to the obex (2 microinjections at 2 different depths). The lesion (mostly affected the obscurus and magnus raphe nuclei) reduced the number of reflex expirations by 80% and expiratory amplitudes of esophageal pressure, abdominal EMG moving averages, and abdominal EMG powers by 71%, 62%, and 57%, respectively (in all cases P<0.05). The duration of abdominal activity in post-lesion responses was not altered. Control microinjections of artificial CSF had no effect on the reflex responses. We conclude that in rabbits, the medullary raphe nuclei participate in the control of expiratory expulsions originating from the trachea. PMID:19218686

  3. Sinonasal NUT-Midline Carcinoma – A Multimodality Approach to Diagnosis, Staging and Post-Surgical Restaging

    PubMed Central

    Pagedar, Nitin; Awan, Omer; McNeely, Parren

    2015-01-01

    Nuclear protein testis (NUT) midline carcinoma is a rare malignancy involving predominantly the midline structures of the body. It is characterized by its genotypic feature of BRD4-NUT translocation, which is in contrast with other malignant processes that are usually categorized based on their histologic/phenotypic features. As these tumors may vary in their histologic presentation, they can be misdiagnosed as poorly differentiated carcinomas. Moreover, they are often very aggressive and associated with high mortality. Therefore, it is extremely important to diagnose them early using computed tomography (CT) and magnetic resonance imaging (MRI) and perform staging and restaging using 18-fluorodeoxyglucose positron emission tomography/computed tomography (18-FDG PET/CT), in addition to accurately identifying them at a microscopic and molecular level. We report a unique case of a sinonasal NUT midline carcinoma that was diagnosed with CT, staged with PET/CT, and restaged using PET/CT and MRI. PMID:26244120

  4. Criminal Responsibility of the Frontal Lobe Syndrome

    PubMed Central

    Sener, Mustafa Talip; Ozcan, Halil; Sahingoz, Sadik; Ogul4, Hayri

    2015-01-01

    Neurological and/or psychiatric symptoms might be detected due to damage of frontal lobes as detected in damages of many brain regions. Frontal lobe syndrome (FLS) occurs as a result of damage in prefrontal region due to various causes. Symptoms due to prefrontal region damage, varies according to the size and location of the lesion. In most of the cases; executive dysfunctions, attention deficits, inconsistencies in social life, impulse control problems, obsessive behaviors and violence behaviors are common clinical signs. Behavioral symptoms seen in FLS can be confused with personality disorders and negative symptoms of schizophrenia. FLS is a neuropsychiatric disorder rarely assessed in forensic psychiatry and in terms of detection of criminal responsibility. In this case report, criminal responsibility in FLS was assessed through a FLS case in which an offense of “threat” was committed and investigated in terms of criminal responsibility. PMID:26644774

  5. Criminal Responsibility of the Frontal Lobe Syndrome.

    PubMed

    Sener, Mustafa Talip; Ozcan, Halil; Sahingoz, Sadik; Ogul, Hayri

    2015-10-01

    Neurological and/or psychiatric symptoms might be detected due to damage of frontal lobes as detected in damages of many brain regions. Frontal lobe syndrome (FLS) occurs as a result of damage in prefrontal region due to various causes. Symptoms due to prefrontal region damage, varies according to the size and location of the lesion. In most of the cases; executive dysfunctions, attention deficits, inconsistencies in social life, impulse control problems, obsessive behaviors and violence behaviors are common clinical signs. Behavioral symptoms seen in FLS can be confused with personality disorders and negative symptoms of schizophrenia. FLS is a neuropsychiatric disorder rarely assessed in forensic psychiatry and in terms of detection of criminal responsibility. In this case report, criminal responsibility in FLS was assessed through a FLS case in which an offense of "threat" was committed and investigated in terms of criminal responsibility. PMID:26644774

  6. Systematic Review and Meta-Regression of Factors Affecting Midline Incisional Hernia Rates: Analysis of 14 618 Patients

    PubMed Central

    Bosanquet, David C.; Ansell, James; Abdelrahman, Tarig; Cornish, Julie; Harries, Rhiannon; Stimpson, Amy; Davies, Llion; Glasbey, James C. D.; Frewer, Kathryn A.; Frewer, Natasha C.; Russell, Daphne; Russell, Ian; Torkington, Jared

    2015-01-01

    Background The incidence of incisional hernias (IHs) following midline abdominal incisions is difficult to estimate. Furthermore recent analyses have reported inconsistent findings on the superiority of absorbable versus non-absorbable sutures. Objective To estimate the mean IH rate following midline laparotomy from the published literature, to identify variables that predict IH rates and to analyse whether the type of suture (absorbable versus non-absorbable) affects IH rates. Methods We undertook a systematic review according to PRISMA guidelines. We sought randomised trials and observational studies including patients undergoing midline incisions with standard suture closure. Papers describing two or more arms suitable for inclusion had data abstracted independently for each arm. Results Fifty-six papers, describing 83 separate groups comprising 14 618 patients, met the inclusion criteria. The prevalence of IHs after midline incision was 12.8% (range: 0 to 35.6%) at a weighted mean of 23.7 months. The estimated risk of undergoing IH repair after midline laparotomy was 5.2%. Two meta-regression analyses (A and B) each identified seven characteristics associated with increased IH rate: one patient variable (higher age), two surgical variables (surgery for AAA and either surgery for obesity surgery (model A) or using an upper midline incision (model B)), two inclusion criteria (including patients with previous laparotomies and those with previous IHs), and two circumstantial variables (later year of publication and specifying an exact significance level). There was no significant difference in IH rate between absorbable and non-absorbable sutures either alone or in conjunction with either regression analysis. Conclusions The IH rate estimated by pooling the published literature is 12.8% after about two years. Seven factors account for the large variation in IH rates across groups. However there is no evidence that suture type has an intrinsic effect on IH rates

  7. "No Longer Gage": Frontal Lobe Dysfunction and Emotional Changes.

    ERIC Educational Resources Information Center

    Stuss, Donald T.; And Others

    1992-01-01

    Reviews changes in emotional response and personality occurring after damage to frontal systems, proposes operational definitions, and analyzes reports according to these definitions. Summarizes neurological causes of frontal lobe damage and associations of frontal dysfunction with psychiatric disturbances. Proposes that primary change after…

  8. Comparison of numerical techniques for the evaluation of the Doppler broadening functions psi(x,theta) and chi(x,theta)

    NASA Technical Reports Server (NTRS)

    Canright, R. B., Jr.; Semler, T. T.

    1972-01-01

    Several approximations to the Doppler broadening functions psi(x, theta) and chi(x, theta) are compared with respect to accuracy and speed of evaluation. A technique, due to A. M. Turning (1943), is shown to be at least as accurate as direct numerical quadrature and somewhat faster than Gaussian quadrature. FORTRAN 4 listings are included.

  9. Frontal lobe astrocytoma following radiotherapy for medulloblastoma

    SciTech Connect

    Cohen, M.S.; Kushner, M.J.; Dell, S.

    1981-05-01

    A young woman had a frontal lobe astrocytoma 14 years after successful treatment of a posterior fossa medulloblastoma by surgery and whole-neuraxis irradiation. The association of these two tumors is rare, and it is unlikely that the second tumor was the result of metastasis and differentiation of residual or recurrent medulloblastoma. We review the evidence supporting this view and also the likelihood that the astrocytoma was induced by the prior radiation.

  10. Frontal Sinus Fractures: A Conservative Shift

    PubMed Central

    Weathers, William M.; Wolfswinkel, Erik M.; Hatef, Daniel A.; Lee, Edward I.; Brown, Rodger H.; Hollier, Larry H.

    2013-01-01

    This article reflects on the changing management of frontal sinus fractures. Severity of these injuries has decreased tremendously since the universal adoption of seat belts and air bags. Recently, there has been a shift from aggressive surgical management to more conservative management strategies, some forgoing surgery all together. New technologies, such as bioabsorbable plates and endoscopic sinus surgery, are leading the way in improved surgical management strategies and offer promising alternatives to the more traditional approaches. PMID:24436753

  11. Developmental consequences of childhood frontal lobe damage.

    PubMed

    Eslinger, P J; Grattan, L M; Damasio, H; Damasio, A R

    1992-07-01

    A 33-year-old woman underwent neurologic and neuropsychological studies 26 years after she sustained damage to the frontal lobe. The findings of the neurologic examination were normal, and magnetic resonance imaging revealed a lesion in left prefrontal cortex and deep white matter. Cerebral blood flow studies showed an abnormal pattern in both left and right frontal regions. The patient exhibited striking neuropsychological defects in higher cognition, most notably in self-regulation of emotion and affect and in social behavior. Analysis of her behavioral development failed to yield a pattern of abrupt onset of defect immediately after the lesion occurred. On the contrary, there was a delayed onset of defects, followed by a period of seeming progression, and finally an arrest of development in adolescence. We suggest that this peculiar pattern is the natural consequence of the varied changes that occurred in brain development and social cognition during the patient's formative years. While certain long-term neuropsychological deficits in our case are similar to those following frontal damage in adults, the delayed onset and progression of deficits are different. PMID:1497505

  12. Cervical spine response in frontal crash.

    PubMed

    Panzer, Matthew B; Fice, Jason B; Cronin, Duane S

    2011-11-01

    Predicting neck response and injury resulting from motor vehicle accidents is essential to improving occupant protection. A detailed human cervical spine finite element model has been developed, with material properties and geometry determined a priori of any validation, for the evaluation of global kinematics and tissue-level response. Model validation was based on flexion/extension response at the segment level, tension response of the whole ligamentous cervical spine, head kinematic response from volunteer frontal impacts, and soft tissue response from cadaveric whole cervical spine frontal impacts. The validation responses were rated as 0.79, assessed using advanced cross-correlation analysis, indicating the model exhibits good biofidelity. The model was then used to evaluate soft tissue response in frontal impact scenarios ranging from 8G to 22G in severity. Disc strains were highest in the C4-C5-C6 segments, and ligament strains were greatest in the ISL and LF ligaments. Both ligament and disc fiber strain levels exceeded the failure tolerances in the 22G case, in agreement with existing data. This study demonstrated that a cervical spine model can be developed at the tissue level and provide accurate biofidelic kinematic and local tissue response, leading to injury prediction in automotive crash scenarios. PMID:21665513

  13. Frontal lobe function in temporal lobe epilepsy

    PubMed Central

    Stretton, J.; Thompson, P.J.

    2012-01-01

    Summary Temporal lobe epilepsy (TLE) is typically associated with long-term memory dysfunction. The frontal lobes support high-level cognition comprising executive skills and working memory that is vital for daily life functioning. Deficits in these functions have been increasingly reported in TLE. Evidence from both the neuropsychological and neuroimaging literature suggests both executive function and working memory are compromised in the presence of TLE. In relation to executive impairment, particular focus has been paid to set shifting as measured by the Wisconsin Card Sorting Task. Other discrete executive functions such as decision-making and theory of mind also appear vulnerable but have received little attention. With regard to working memory, the medial temporal lobe structures appear have a more critical role, but with emerging evidence of hippocampal dependent and independent processes. The relative role of underlying pathology and seizure spread is likely to have considerable bearing upon the cognitive phenotype and trajectory in TLE. The identification of the nature of frontal lobe dysfunction in TLE thus has important clinical implications for prognosis and surgical management. Longitudinal neuropsychological and neuroimaging studies assessing frontal lobe function in TLE patients pre- and postoperatively will improve our understanding further. PMID:22100147

  14. Role of Frontal Alpha Oscillations in Creativity

    PubMed Central

    Lustenberger, Caroline; Boyle, Michael R.; Foulser, A. Alban; Mellin, Juliann M.; Fröhlich, Flavio

    2015-01-01

    Creativity, the ability to produce innovative ideas, is a key higher-order cognitive function that is poorly understood. At the level of macroscopic cortical network dynamics, recent EEG data suggests that cortical oscillations in the alpha frequency band (8 – 12 Hz) are correlated with creative thinking. However, whether alpha oscillations play a fundamental role in creativity has remained unknown. Here we show that creativity is increased by enhancing alpha power using 10 Hz transcranial alternating current stimulation (10Hz-tACS) of the frontal cortex. In a study of 20 healthy participants with a randomized, balanced cross-over design, we found a significant improvement of 7.4% in the Creativity Index measured by the Torrance Test of Creative Thinking, a comprehensive and most frequently used assay of creative potential and strengths. In a second similar study with 20 subjects, 40Hz-tACS was used in instead of 10Hz-tACS to rule out a general “electrical stimulation” effect. No significant change in the Creativity Index was found for such frontal gamma stimulation. Our results suggest that alpha activity in frontal brain areas is selectively involved in creativity; this enhancement represents the first demonstration of specific neuronal dynamics that drive creativity and can be modulated by non-invasive brain stimulation. Our findings agree with the model that alpha recruitment increases with internal processing demands and is involved in inhibitory top-down control, which is an important requirement for creative ideation. PMID:25913062

  15. Peak frequency in the theta and alpha bands correlates with human working memory capacity.

    PubMed

    Moran, Rosalyn J; Campo, Pablo; Maestu, Fernando; Reilly, Richard B; Dolan, Raymond J; Strange, Bryan A

    2010-01-01

    Theta oscillations in the local field potential of neural ensembles are considered key mediators of human working memory. Theoretical accounts arising from animal hippocampal recordings propose that the phase of theta oscillations serves to instantiate sequential neuronal firing to form discrete representations of items held online. Human evidence of phase relationships in visual working memory has enhanced this theory, implicating long theta cycles in supporting greater memory capacity. Here we use human magnetoencephalographic recordings to examine a novel, alternative principle of theta functionality. The principle we hypothesize is derived from information theory and predicts that rather than long (low frequency) theta cycles, short (high frequency) theta cycles are best suited to support high information capacity. From oscillatory activity recorded during the maintenance period of a visual working memory task we show that a network of brain regions displays an increase in peak 4-12 Hz frequency with increasing memory load. Source localization techniques reveal that this network comprises bilateral prefrontal and right parietal cortices. Further, the peak of oscillation along this theta-alpha frequency axis is significantly higher in high capacity individuals compared to low capacity individuals. Importantly while we observe the adherence of cortical neuronal oscillations to our novel principle of theta functioning, we also observe the traditional inverse effect of low frequency theta maintaining high loads, where critically this was located in medial temporal regions suggesting parallel, dissociable hippocampal-centric, and prefrontal-centric theta mechanisms. PMID:21206531

  16. Sex differences in human EEG theta oscillations during spatial navigation in virtual reality.

    PubMed

    Kober, Silvia Erika; Neuper, Christa

    2011-03-01

    The present study examines theta oscillations (electroencephalographic (EEG) activity with a frequency of 4-8 Hz) in male and female young adults during spatial navigation in virtual environments. Twenty-seven participants (13 males and 14 females) performed a spatial navigation task in a virtual maze where they had to find the shortest ways between landmarks. Absolute theta band power and event-related desynchronisation/synchronisation (ERD/ERS) in the theta frequency band was used to analyze the EEG data. Processing of spatial cues or landmarks induced cortical theta activity compared to a baseline condition, confirming the hypothesis that theta oscillations reflect sensorimotor integration. The sensorimotor integration hypothesis proposes that theta oscillations coordinate sensory information with a motor plan to direct wayfinding behaviour to known goal locations. No sex differences were found in spatial performance. However, female participants showed a stronger increase in theta oscillations during processing of landmarks as navigational aids compared to a baseline condition than men. Additionally, a higher theta power was associated with an increased navigation performance in women, whereas an increase in theta power was associated with a decreased navigation performance in men. These results might indicate a stronger sensorimotor integration in females than in males. Possible explanations for the emerged sex differences in cortical theta activity are discussed. PMID:21146566

  17. The effects of botulinum toxin A on survival of rat TRAM flap with vertical midline scar.

    PubMed

    Park, Tae Hwan; Rah, Dong Kyun; Chong, Yosep; Kim, June-kyu

    2015-01-01

    The transverse rectus abdominis musculocutaneous (TRAM) flap has been widely used in various reconstructive surgeries. Recently, there have been reports regarding the positive effect of botulinum toxin A (BoTA) on flap survival. We hypothesized that pretreatment with BoTA could augment the survival of pedicled TRAM flaps with a vertical midline scar. Twenty-four Sprague-Dawley rats were randomly divided into 2 groups, namely, control group and BoTA group. Five days after a vertical midline incision, the BoTA group was pretreated with BoTA, whereas the control group was pretreated with normal saline. Ten days after the initial incision, the TRAM flap was harvested. We evaluated the gross flap survival and analyzed the overall histologic change, lumen area of pedicle, and microvessel density with immunohistochemistry. Reverse transcription polymerase chain reaction was performed for the evaluation of angiogenesis-related factors. In the BoTA group, the gross flap survival rate was significantly higher than that in the control group on both ipsilateral and contralateral sides (P < 0.001). In the BoTA group, a significant increase in pedicle lumen area was observed (P < 0.001). In the control group, mild to moderate epidermal necrosis was seen; microvessels were relatively small compared with those of the BoTA group. According to immunohistochemistry, the number of CD31 positively stained vessels was significantly higher on the contralateral side in the control group compared to that in the BoTA group (P < 0.001). The relative messenger RNA (mRNA) expression of CD31 was significantly lower in the BoTA group than that in the control group on both ipsilateral and contralateral sides (P < 0.001). Meanwhile, the relative mRNA expression of VEGF was significantly higher in the BoTA group than in the control group on both ipsilateral and contralateral sides (P < 0.001).We believe that preoperative BoTA therapy is a feasible method to improve circulation of the rat TRAM flap

  18. Aged rats show dominant modulation of lower frequency hippocampal theta rhythm during running.

    PubMed

    Li, Jia-Yi; Kuo, Terry B J; Yang, Cheryl C H

    2016-10-01

    Aging causes considerable decline in both physiological and mental functions, particularly cognitive function. The hippocampal theta rhythm (4-12Hz) is related to both cognition and locomotion. Aging-related findings of the frequency and amplitude of hippocampal theta oscillations are inconsistent and occasionally contradictory. This inconsistency may be due to the effects of the sleep/wake state and different frequency subbands being overlooked. We assumed that aged rats have lower responses of the hippocampal theta rhythm during running, which is mainly due to the dominant modulation of theta frequency subbands related to cognition. By simultaneously recording electroencephalography, physical activity (PA), and the heart rate (HR), this experiment explored the theta oscillations before, during, and after treadmill running at a constant speed in 8-week-old (adult) and 60-week-old (middle-aged) rats. Compared with adult rats, the middle-aged rats exhibited lower theta activity in all frequency ranges before running. Running increased the theta frequency (Frq, 4-12Hz), total activity of the whole theta band (total power, TP), activity of the middle theta frequency (MT, 6.5-9.5Hz), and PA in both age groups. However, the middle-aged rats still showed fewer changes in these parameters during the whole running process. After the waking baseline values were substracted, middle-aged rats showed significantly fewer differences in ΔFrq, ΔTP, and ΔMT but significantly more differences in low-frequency theta activity (4.0-6.5Hz) and HR than the adult rats did. Therefore, the decreasing activity and response of the whole theta band in the middle-aged rats resulted in dominant modulation of the middle to lower frequency (4.0-9.5Hz) theta rhythm. The different alterations in the theta rhythm during treadmill running in the two groups may reflect that learning decline with age. PMID:27496645

  19. The Impact of Frontal and Non-Frontal Brain Tumor Lesions on Wisconsin Card Sorting Test Performance

    ERIC Educational Resources Information Center

    Goldstein, B.; Obrzut, J. E.; John, C.; Ledakis, G.; Armstrong, C. L.

    2004-01-01

    Several lesion and imaging studies have suggested that the Wisconsin Card Sorting Test (WCST) is a measure of executive dysfunction. However, some studies have reported that this measure has poor anatomical specificity because patients with either frontal or non-frontal focal lesions exhibit similar performance. This study examined 25 frontal, 20…

  20. Frontal osteomyelitis presenting as upper eyelid ectropion: A cautionary tale

    PubMed Central

    Bandyopadhyay, Rakhi; Chatterjee, Arkendu; Banerjee, Sambit; Bandyopadhyay, Samir Kumar; Mondol, Anup

    2015-01-01

    Frontal osteomyelitis is a rare clinical entity that can occur as sequelae to frontal sinusitis, head trauma, as a postoperative complication following sinus surgery or due to haematogenous spread. It usually presents with a soft, fluctuant forehead swelling with pain and fever. Cicatricial ectropion is an extremely rare feature of frontal osteomyelitis. We present a young male patient presenting with cicatricial ectropion that occurred as the sole manifestation of an underlying frontal osteomyelitis. Extensive Medline search did not find any such reported case. We feel that frontal osteomyelitis should be kept in mind as a possible etiology when considering the differential diagnosis of cicatricial ectropion. PMID:26155088

  1. Impairments in proverb interpretation following focal frontal lobe lesions.

    PubMed

    Murphy, Patrick; Shallice, Tim; Robinson, Gail; MacPherson, Sarah E; Turner, Martha; Woollett, Katherine; Bozzali, Marco; Cipolotti, Lisa

    2013-09-01

    The proverb interpretation task (PIT) is often used in clinical settings to evaluate frontal "executive" dysfunction. However, only a relatively small number of studies have investigated the relationship between frontal lobe lesions and performance on the PIT. We compared 52 patients with unselected focal frontal lobe lesions with 52 closely matched healthy controls on a proverb interpretation task. Participants also completed a battery of neuropsychological tests, including a fluid intelligence task (Raven's Advanced Progressive Matrices). Lesions were firstly analysed according to a standard left/right sub-division. Secondly, a finer-grained analysis compared the performance of patients with medial, left lateral and right lateral lesions with healthy controls. Thirdly, a contrast of specific frontal subgroups compared the performance of patients with medial lesions with patients with lateral frontal lesions. The results showed that patients with left frontal lesions were significantly impaired on the PIT, while in patients with right frontal lesions the impairments approached significance. Medial frontal patients were the only frontal subgroup impaired on the PIT, relative to healthy controls and lateral frontal patients. Interestingly, an error analysis indicated that a significantly higher number of concrete responses were found in the left lateral subgroup compared to healthy controls. We found no correlation between scores on the PIT and on the fluid intelligence task. Overall our results suggest that specific regions of the frontal lobes contribute to the performance on the PIT. PMID:23850600

  2. Atypical Case of Congenital Maxillomandibular Fusion with Duplication of the Craniofacial Midline

    PubMed Central

    Martín, Lorena Pingarrón; Pérez, Mercedes Martín; García, Elena Gómez; Martín-Moro, Javier González; González, Jose Ignacio Rodríguez; García, Miguel Burgueño

    2011-01-01

    We report the first case of syngnathia with hypophyseal duplication and describe the central nervous system (CNS) and craniofacial anomalies associated with hypophyseal duplication in the reported autopsy case. We studied clinical reports, scanner images, and autopsy results of a 2-months-old female baby. The propositus had frontonasal dysmorphism, retrognathia, and bifid tongue. She also presented maxillomandibular bony fusion (syngnathia) and an intraoral hairy polyp. In the cranium, the sella turcica was broadened, with two complete hypophyses and two infundibulums. The CNS had both olfactory bulbs and corpus callosum agenesis. There are 27 previous cases of maxillomandibular fusion and seven previous autopsy cases of hypophyseal duplication associated with other frontonasal malformations. As far as the authors know, this is the first case reported in the literature that associates syngnathia with duplication of the craniofacial midline including hypophyseal duplication. PMID:22655122

  3. Meningioma arising in the hypoglossal canal: the midline suboccipital subtonsillar approach

    PubMed Central

    Dobrowolski, Samuel; Lepski, Guilherme; Tatagiba, Marcos

    2016-01-01

    Hypoglossal canal meningiomas (HCMs) are extremely rare, and a consensus has yet to be reached regarding the most appropriate treatment approach for these types of tumors. Surgical procedures to the hypoglossal canal are often complex and lengthy, and are often associated with high rates of morbidity. Several approaches have been used to remove such lesions. Most of these approaches have been adapted from methods used for jugular foramen surgery. Our goal is to present an approach that improves visualization of the hypoglossal canal, thus reducing this pathology's risk of morbidity. In this report, we describe one case of HCM in which the tumor was safely and effectively removed by the midline subtonsillar approach, which allows for a direct primary intradural visualization of the hypoglossal canal. There was no postoperative complication in the patient. The length of follow-up was 73 months, and there has been no recurrence of the tumor. PMID:27451423

  4. Meningioma arising in the hypoglossal canal: the midline suboccipital subtonsillar approach.

    PubMed

    Dobrowolski, Samuel; Lepski, Guilherme; Tatagiba, Marcos

    2016-01-01

    Hypoglossal canal meningiomas (HCMs) are extremely rare, and a consensus has yet to be reached regarding the most appropriate treatment approach for these types of tumors. Surgical procedures to the hypoglossal canal are often complex and lengthy, and are often associated with high rates of morbidity. Several approaches have been used to remove such lesions. Most of these approaches have been adapted from methods used for jugular foramen surgery. Our goal is to present an approach that improves visualization of the hypoglossal canal, thus reducing this pathology's risk of morbidity. In this report, we describe one case of HCM in which the tumor was safely and effectively removed by the midline subtonsillar approach, which allows for a direct primary intradural visualization of the hypoglossal canal. There was no postoperative complication in the patient. The length of follow-up was 73 months, and there has been no recurrence of the tumor. PMID:27451423

  5. EphB2 guides axons at the midline and is necessary for normal vestibular function

    NASA Technical Reports Server (NTRS)

    Cowan, C. A.; Yokoyama, N.; Bianchi, L. M.; Henkemeyer, M.; Fritzsch, B.

    2000-01-01

    Mice lacking the EphB2 receptor tyrosine kinase display a cell-autonomous, strain-specific circling behavior that is associated with vestibular phenotypes. In mutant embryos, the contralateral inner ear efferent growth cones exhibit inappropriate pathway selection at the midline, while in mutant adults, the endolymph-filled lumen of the semicircular canals is severely reduced. EphB2 is expressed in the endolymph-producing dark cells in the inner ear epithelium, and these cells show ultrastructural defects in the mutants. A molecular link to fluid regulation is provided by demonstrating that PDZ domain-containing proteins that bind the C termini of EphB2 and B-ephrins can also recognize the cytoplasmic tails of anion exchangers and aquaporins. This suggests EphB2 may regulate ionic homeostasis and endolymph fluid production through macromolecular associations with membrane channels that transport chloride, bicarbonate, and water.

  6. Self, cortical midline structures and the resting state: Implications for Alzheimer's disease.

    PubMed

    Weiler, Marina; Northoff, Georg; Damasceno, Benito Pereira; Balthazar, Marcio Luiz Figueredo

    2016-09-01

    Different aspects of the self have been reported to be affected in many neurological or psychiatric diseases such as Alzheimer's disease (AD), including mainly higher-level cognitive self-unawareness. This higher sense of self-awareness is most likely related to and dependent on episodic memory, due to the proper integration of ourselves in time, with a permanent conservation of ourselves (i.e., sense of continuity across time). Reviewing studies in this field, our objective is thus to raise possible explanations, especially with the help of neuroimaging studies, for where such self-awareness deficits originate in AD patients. We describe not only episodic (and autobiographical memory) impairment in patients, but also the important role of cortical midline structures, the Default Mode Network, and the resting state (intrinsic brain activity) for the processing of self-related information. PMID:27235083

  7. Theta brain rhythms index perceptual narrowing in infant speech perception

    PubMed Central

    Bosseler, Alexis N.; Taulu, Samu; Pihko, Elina; Mäkelä, Jyrki P.; Imada, Toshiaki; Ahonen, Antti; Kuhl, Patricia K.

    2013-01-01

    The development of speech perception shows a dramatic transition between infancy and adulthood. Between 6 and 12 months, infants' initial ability to discriminate all phonetic units across the world's languages narrows—native discrimination increases while non-native discrimination shows a steep decline. We used magnetoencephalography (MEG) to examine whether brain oscillations in the theta band (4–8 Hz), reflecting increases in attention and cognitive effort, would provide a neural measure of the perceptual narrowing phenomenon in speech. Using an oddball paradigm, we varied speech stimuli in two dimensions, stimulus frequency (frequent vs. infrequent) and language (native vs. non-native speech syllables) and tested 6-month-old infants, 12-month-old infants, and adults. We hypothesized that 6-month-old infants would show increased relative theta power (RTP) for frequent syllables, regardless of their status as native or non-native syllables, reflecting young infants' attention and cognitive effort in response to highly frequent stimuli (“statistical learning”). In adults, we hypothesized increased RTP for non-native stimuli, regardless of their presentation frequency, reflecting increased cognitive effort for non-native phonetic categories. The 12-month-old infants were expected to show a pattern in transition, but one more similar to adults than to 6-month-old infants. The MEG brain rhythm results supported these hypotheses. We suggest that perceptual narrowing in speech perception is governed by an implicit learning process. This learning process involves an implicit shift in attention from frequent events (infants) to learned categories (adults). Theta brain oscillatory activity may provide an index of perceptual narrowing beyond speech, and would offer a test of whether the early speech learning process is governed by domain-general or domain-specific processes. PMID:24130536

  8. Theta-Pinch Thruster for Piloted Deep Space Exploration

    NASA Technical Reports Server (NTRS)

    LaPointe, Mike R.; Reddy, Dhanireddy (Technical Monitor)

    2000-01-01

    A new high-power propulsion concept that combines a rapidly pulsed theta-pinch discharge with upstream particle reflection by a magnetic mirror was evaluated under a Phase 1 grant awarded through the NASA Institute for Advanced Concepts. Analytic and numerical models were developed to predict the performance of a theta-pinch thruster operated over a wide range of initial gas pressures and discharge periods. The models indicate that a 1 m radius, 10 m long thruster operated with hydrogen propellant could provide impulse-bits ranging from 1 N-s to 330 N-s with specific impulse values of 7,500 s to 2,500 s, respectively. A pulsed magnetic field strength of 2 T is required to compress and heat the preionized hydrogen over a 10(exp -3) second discharge period, with about 60% of the heated plasma exiting the chamber each period to produce thrust. The unoptimized thruster efficiency is low, peaking at approximately 16% for an initial hydrogen chamber pressure of 100 Torr. The specific impulse and impulse-bit at this operating condition are 3,500 s and 90 N-s, respectively, and the required discharge energy is approximately 9x10(exp 6) J. For a pulse repetition rate of 10 Hz, the engine would produce an average thrust of 900 N at 3,500 s specific impulse. Combined with the electrodeless nature of the device, these performance parameters indicate that theta-pinch thrusters could provide unique, long-life propulsion systems for piloted deep space mission applications.

  9. Effect of Painful and Non-Painful Sensorimotor Manipulations on Subjective Body Midline

    PubMed Central

    Bouffard, Jason; Gagné, Martin; Mercier, Catherine

    2013-01-01

    Patients with chronic pain often show disturbances in their body perception. Understanding the exact role played by pain is however complex, as confounding factors can contribute to the observed deficits in these clinical populations. To address this question, acute experimental pain was used to test the effect of lateralized pain on body perception in healthy subjects. Subjects were asked to indicate the position of their body midline (subjective body midline, SBM) by stopping a moving luminescent dot projected on a screen placed in front of them, in a completely dark environment. The effect of other non-painful sensorimotor manipulations was also tested to assess the potential unspecific attentional effects of stimulating one side of the body. SBM judgment was made in 17 volunteers under control and three experimental conditions: (1) painful (heat) stimulation; (2) non-painful vibrotactile stimulation; and (3) muscle contraction. The effects of the stimulated side and the type of trial (control vs. experimental condition), were tested separately for each condition with a 2 × 2 repeated measures ANOVA. The analyses revealed a significant interaction in both pain (p = 0.05) and vibration conditions (p = 0.04). Post hoc tests showed opposite effects of pain and vibration. Pain applied on the right arm deviated the SBM toward the right (stimulated) side (p = 0.03) while vibration applied on the left arm deviated the SBM toward the right (not stimulated) side (p = 0.01). These opposite patterns suggest that the shift in SBM is likely to be specifically linked to the stimulation modality. It is concluded that acute experimental pain can induce an SBM shift toward the stimulated side, which might be functionally beneficial to protect the painful area of the body. Interestingly, it appears to be easier to bias SBM toward the right side, regardless of the modality and of the stimulated side. PMID:23504448

  10. Pulmonary function after transverse or midline incision in patients with obstructive pulmonary disease.

    PubMed

    Becquemin, J P; Piquet, J; Becquemin, M H; Melliere, D; Harf, A

    1985-01-01

    Atelectasis and bronchopneumonia occur frequently in patients undergoing aorto-iliac reconstructive surgery. Transverse (T) incisions in upper abdominal surgery are thought to be followed by fewer pulmonary complications than midline incisions (M) but reports remain controversial. We studied the incidence of postoperative pulmonary complications and lung dysfunction after T and M incisions for aorto-iliac surgery in 13 patients with chronic obstructive pulmonary disease (COPD) and 13 control patients with normal lungs (C). For all subjects, we evaluated (1) postoperative clinical or radiological pulmonary events; (2) preoperatively and on postoperative days 2 (D2), 5 (D5), 9 (D9) and 12 (D12) - the forced expiratory volume in 1 s (FEV1), vital capacity (VC), alveolar-arterial oxygen difference (AaPO2), and (3) convenience for the surgeon. Operatively, aortic exposure was excellent with both incisions. Bronchopneumonia occurred only after M in five patients (1 C, 4 COPD). In contrast with the control patients in whom no difference was found between T and M incisions, the FEV1 of COPD patients was significantly less impaired with T than with M incisions (p less than 0.005 on D2 and p less than 0.05 on D5). VC decreased similarly with both incisions on D2 but on D5 the improvement was less with M (p less than 0.005). Changes in AaPO2 were more marked on D2 and D5 for the COPD patients with M incisions. We conclude that (1) in patients with chronic obstructive pulmonary disease, laparotomy with a transverse incision was associated with better postoperative lung function and fewer pulmonary complications; (2) in patients without pulmonary disease, midline and transverse incisions were equivalent. PMID:2933436

  11. The effective chiral Lagrangian from the theta term

    SciTech Connect

    Mereghetti, E.; Hockings, W.H.; Kolck, U. van

    2010-11-15

    We construct the effective chiral Lagrangian involving hadronic and electromagnetic interactions originating from the QCD {theta}-bar term. We impose vacuum alignment at both quark and hadronic levels, including field redefinitions to eliminate pion tadpoles. We show that leading time-reversal-violating (TV) hadronic interactions are related to isospin-violating interactions that can in principle be determined from charge-symmetry-breaking experiments. We discuss the complications that arise from TV electromagnetic interactions. Some implications of the expected sizes of various pion-nucleon TV interactions are presented, and the pion-nucleon form factor is used as an example.

  12. Chiral symmetry breaking and {theta} vacuum structure in QCD

    SciTech Connect

    Morchio, G. Strocchi, F.

    2009-10-15

    The solution of the axial U(1) problem, the role of the topology of the gauge group in forcing the breaking of axial symmetry in any irreducible representation of the observable algebra and the {theta} vacua structure are revisited in the temporal gauge with attention to the mathematical consistency of the derivations. Both realizations with strong and weak Gauss law are discussed; the control of the general mechanisms and structures is obtained on the basis of the localization of the (large) gauge transformations and the local generation of the chiral symmetry. The Schwinger model in the temporal gauge exactly reproduces the general results.

  13. Associative Memory Storage and Retrieval: Involvement of Theta Oscillations in Hippocampal Information Processing

    PubMed Central

    Stella, Federico; Treves, Alessandro

    2011-01-01

    Theta oscillations are thought to play a critical role in neuronal information processing, especially in the hippocampal region, where their presence is particularly salient. A detailed description of theta dynamics in this region has revealed not only a consortium of layer-specific theta dipoles, but also within-layer differences in the expression of theta. This complex and articulated arrangement of current flows is reflected in the way neuronal firing is modulated in time. Several models have proposed that these different theta modulators flexibly coordinate hippocampal regions, to support associative memory formation and retrieval. Here, we summarily review different approaches related to this issue and we describe a mechanism, based on experimental and simulation results, for memory retrieval in CA3 involving theta modulation. PMID:21961072

  14. Breast reconstruction with single-pedicle TRAM flap in breast cancer patients with low midline abdominal scar

    PubMed Central

    Wu, Jun-Dong; Huang, Wen-He; Qiu, Si-Qi; He, Li-Fang; Guo, Cui-Ping; Zhang, Yong-Qu; Zhang, Fan; Zhang, Guo-Jun

    2016-01-01

    Breast reconstruction with transverse rectus abdominis myocutaneous (TRAM) flap is challenging in patients with low midline abdominal scar. In this study, we aimed to investigate the clinical feasibility of immediate breast reconstruction using single-pedicle TRAM (SP-TRAM) flaps in patients with low midline abdominal scar. There were 4 strict selection criteria: 1) presence at least 3 perforators on the pedicle side; 2) perforators with regional average flow velocity of >20 cm/s; 3) upper edge of the abdominal scar at least 4 cm from the umbilicus; and 4) scar age >1 year. Eight breast cancer patients with low midline abdominal scar (scar group) and 20 without (control group) underwent immediate breast reconstruction with SP-TRAM flaps consisting of zone I and III and zone II tissues. Flap complications, donor-site complications, and cosmetic results were compared between the two groups. All flaps survived and both groups presented similar flap and donor site complications, including fat necrosis, seroma, hematoma, infection, delayed wound healing, and abdominal hernia, and patients in both groups had similar aesthetic results (p > 0.05). Thus, the study demonstrated that breast reconstruction using SP-TRAM flap was a safe approach in carefully selected patients with low midline abdominal scar. PMID:27406872

  15. A forkhead Transcription Factor Is Wound-Induced at the Planarian Midline and Required for Anterior Pole Regeneration

    PubMed Central

    Scimone, M. Lucila; Lapan, Sylvain W.; Reddien, Peter W.

    2014-01-01

    Planarian regeneration requires positional information to specify the identity of tissues to be replaced as well as pluripotent neoblasts capable of differentiating into new cell types. We found that wounding elicits rapid expression of a gene encoding a Forkhead-family transcription factor, FoxD. Wound-induced FoxD expression is specific to the ventral midline, is regulated by Hedgehog signaling, and is neoblast-independent. FoxD is subsequently expressed within a medial subpopulation of neoblasts at wounds involving head regeneration. Ultimately, FoxD is co-expressed with multiple anterior markers at the anterior pole. Inhibition of FoxD with RNA interference (RNAi) results in the failure to specify neoblasts expressing anterior markers (notum and prep) and in anterior pole formation defects. FoxD(RNAi) animals fail to regenerate a new midline and to properly pattern the anterior blastema, consistent with a role for the anterior pole in organizing pattern of the regenerating head. Our results suggest that wound signaling activates a forkhead transcription factor at the midline and, if the head is absent, FoxD promotes specification of neoblasts at the prior midline for anterior pole regeneration. PMID:24415944

  16. Theta and gamma coherence across the septotemporal axis during distinct behavioral states.

    PubMed

    Penley, Stephanie C; Hinman, James R; Sabolek, Helen R; Escabí, Monty A; Markus, Etan J; Chrobak, James J

    2012-05-01

    Theta (4-12 Hz) and gamma (40-100 Hz) field potentials represent the interaction of synchronized synaptic input onto distinct neuronal populations within the hippocampal formation. Theta is quite prominent during exploratory activity, locomotion, and REM sleep. Although it is generally acknowledged that theta is coherent throughout most of the hippocampus, there is significant variability in theta, as well as gamma, coherence across lamina at any particular septotemporal level of the hippocampus. Larger differences in theta coherence are observed across the septotemporal (long) axis. We have reported that during REM sleep there is a decrease in theta coherence across the long axis that varies with the topography of CA3/mossy cell input rather than the topography of the prominent entorhinal input. On the basis of differences in the rat's behavior as well as the activity of neuromodulatory inputs (e.g., noradrenergic and serotonergic), we hypothesized that theta coherence across the long axis would be greater during locomotion than REM sleep and exhibit a pattern more consistent with the topography of entorhinal inputs. We examined theta and gamma coherence indices at different septotemporal and laminar sites during distinct theta states: locomotion during maze running, REM sleep, following acute treatment with a θ-inducing cholinomimetic (physostigmine) and for comparison during slow-wave sleep. The results demonstrate a generally consistent pattern of theta and gamma coherence across the septotemporal axis of the hippocampus that is quite indifferent to sensory input and overt behavior. These results are discussed with regards to the neurobiological mechanisms that generate theta and gamma and the growing body of evidence linking theta and gamma indices to memory and other cognitive functions. PMID:21748821

  17. Correlation of the Hippocampal theta rhythm to changes in hypothalamic temperature

    NASA Technical Reports Server (NTRS)

    Saleh, M. A.; Horowitz, J. M.; Hsieh, A. C. L.

    1974-01-01

    Warming and cooling the preoptic anterior hypothalamic area in awake, loosely restrained rabbits was found to evoke theta rhythm. This is consistent with previous studies indicating that theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Several studies have correlated theta rhythm with alertness. A neural pathway involving the hypothalamus, the hippocampus, the septal area, and the reticular formation is proposed. Thus, a role of this pathway may be to alert the animal to changes in its body temperature.

  18. Light-front description for the theta dependence of meson masses in the massive Schwinger model

    SciTech Connect

    Burkardt, M.; Harada, K.

    1998-05-01

    We present a continuum formulation for {theta} vacua in the massive Schwinger model on the light front, where {theta} enters as a background electric field. The effective coupling of the external field is partially screened due to vacuum polarization processes. For small fermion masses and small {theta}, we calculate the mass of the meson and find agreement with results from bosonization. {copyright} {ital 1998} {ital The American Physical Society}

  19. Pentaquark {Theta}{sup +} production from the reaction {gamma}p {yields} {pi}{sup +} K{sup -} {Theta}{sup +}

    SciTech Connect

    W. Liu; C. M. Ko; V. Kubarovsky

    2004-02-01

    The cross section for {Theta}{sup +} production from the reaction {gamma}p {yields} {pi}{sup +} K{sup -} {Theta}{sup +}, which was observed in the CLAS experiment at the Jefferson National Laboratory, is evaluated in a hadronic model that includes couplings of {Theta}{sup +} to both KN and K*N. With their coupling constants determined from the empirical {pi} NN(1710) and {rho} NN(1710) coupling constants using the SU(3) symmetry, the cross section for this reaction has been evaluated by taking {Theta}{sup +} to have spin 1/2 and isospin 0 but either positive or negative parity. We find that the cross section is 10-15 nb if {Theta}{sup +} has positive parity as predicted by the chiral soliton model. The cross section is reduced by more than a factor of 10 if {Theta}{sup +} has negative parity as given by lattice QCD studies. For both parities, the differential distribution peaks at small negative four momentum transfer as expected from the dominating t-channel kaon-exchange diagram that involves only the coupling of {Theta}{sup +} to KN.

  20. Automatic estimation of midline shift in patients with cerebral glioma based on enhanced voigt model and local symmetry.

    PubMed

    Chen, Mingyang; Elazab, Ahmed; Jia, Fucang; Wu, Jianhuang; Li, Guanglin; Li, Xiaodong; Hu, Qingmao

    2015-12-01

    Cerebral glioma is one of the most aggressive space-occupying diseases, which will exhibit midline shift (MLS) due to mass effect. MLS has been used as an important feature for evaluating the pathological severity and patients' survival possibility. Automatic quantification of MLS is challenging due to deformation, complex shape and complex grayscale distribution. An automatic method is proposed and validated to estimate MLS in patients with gliomas diagnosed using magnetic resonance imaging (MRI). The deformed midline is approximated by combining mechanical model and local symmetry. An enhanced Voigt model which takes into account the size and spatial information of lesion is devised to predict the deformed midline. A composite local symmetry combining local intensity symmetry and local intensity gradient symmetry is proposed to refine the predicted midline within a local window whose size is determined according to the pinhole camera model. To enhance the MLS accuracy, the axial slice with maximum MSL from each volumetric data has been interpolated from a spatial resolution of 1 mm to 0.33 mm. The proposed method has been validated on 30 publicly available clinical head MRI scans presenting with MLS. It delineates the deformed midline with maximum MLS and yields a mean difference of 0.61 ± 0.27 mm, and average maximum difference of 1.89 ± 1.18 mm from the ground truth. Experiments show that the proposed method will yield better accuracy with the geometric center of pathology being the geometric center of tumor and the pathological region being the whole lesion. It has also been shown that the proposed composite local symmetry achieves significantly higher accuracy than the traditional local intensity symmetry and the local intensity gradient symmetry. To the best of our knowledge, for delineation of deformed midline, this is the first report on both quantification of gliomas and from MRI, which hopefully will provide valuable information for diagnosis

  1. The use of cubic Nd-Ba-Cu-O seeds to create {theta}[100], 90{degree}-{theta}[100], and {theta}[001] tilt Y-Ba-Cu-O grain boundaries.

    SciTech Connect

    Field, M. B.

    1998-10-20

    Using seeding techniques to control the orientation of grains, we have been able to create a wide variety of YBa{sub 2}Cu{sub 3}O{sub 6+x}, grain boundaries. In addition to five domain samples with 90{degree}[100] twist and tilt grain boundaries, we have now developed a method to produce grain boundaries in the same sample that have the misorientations {theta}[001] tilt, {theta}[100] tilt, and 90{degree} {approximately} {theta}[100], where the disorientation angle {theta} is fully controllable. We will demonstrate how these boundaries can be synthesized, give experimental evidence via polarized light microscopy and electron backscatter patterns (EBSP) that the intended grain boundaries were indeed formed, and discuss the importance of these boundaries in future grain boundary studies.

  2. Thoracolumbar Spine Fractures in Frontal Impact Crashes

    PubMed Central

    Pintar, Frank A.; Yoganandan, Narayan; Maiman, Dennis J.; Scarboro, Mark; Rudd, Rodney W.

    2012-01-01

    There is currently no injury assessment for thoracic or lumbar spine fractures in the motor vehicle crash standards throughout the world. Compression-related thoracolumbar fractures are occurring in frontal impacts and yet the mechanism of injury is poorly understood. The objective of this investigation was to characterize these injuries using real world crash data from the US-DOT-NHTSA NASS-CDS and CIREN databases. Thoracic and lumbar AIS vertebral body fracture codes were searched for in the two databases. The NASS database was used to characterize population trends as a function of crash year and vehicle model year. The CIREN database was used to examine a case series in more detail. From the NASS database there were 2000–4000 occupants in frontal impacts with thoracic and lumbar vertebral body fractures per crash year. There was an increasing trend in incidence rate of thoracolumbar fractures in frontal impact crashes as a function of vehicle model year from 1986 to 2008; this was not the case for other crash types. From the CIREN database, the thoracolumbar spine was most commonly fractured at either the T12 or L1 level. Major, burst type fractures occurred predominantly at T12, L1 or L5; wedge fractures were most common at L1. Most CIREN occupants were belted; there were slightly more females involved; they were almost all in bucket seats; impact location occurred approximately half the time on the road and half off the road. The type of object struck also seemed to have some influence on fractured spine level, suggesting that the crash deceleration pulse may be influential in the type of compression vector that migrates up the spinal column. Future biomechanical studies are required to define mechanistically how these fractures are influenced by these many factors. PMID:23169137

  3. Frontal lobe neurology and the creative mind

    PubMed Central

    de Souza, Leonardo C.; Guimarães, Henrique C.; Teixeira, Antônio L.; Caramelli, Paulo; Levy, Richard; Dubois, Bruno; Volle, Emmanuelle

    2014-01-01

    Concepts from cognitive neuroscience strongly suggest that the prefrontal cortex (PFC) plays a crucial role in the cognitive functions necessary for creative thinking. Functional imaging studies have repeatedly demonstrated the involvement of PFC in creativity tasks. Patient studies have demonstrated that frontal damage due to focal lesions or neurodegenerative diseases are associated with impairments in various creativity tasks. However, against all odds, a series of clinical observations has reported the facilitation of artistic production in patients with neurodegenerative diseases affecting PFC, such as frontotemporal dementia (FTD). An exacerbation of creativity in frontal diseases would challenge neuroimaging findings in controls and patients, as well as the theoretical role of prefrontal functions in creativity processes. To explore this paradox, we reported the history of a FTD patient who exhibited the emergence of visual artistic productions during the course of the disease. The patient produced a large amount of drawings, which have been evaluated by a group of professional artists who were blind to the diagnosis. We also reviewed the published clinical cases reporting a change in the artistic abilities in patients with neurological diseases. We attempted to reconcile these clinical observations to previous experimental findings by addressing several questions raised by our review. For instance, to what extent can the cognitive, conative, and affective changes following frontal damage explain changes in artistic abilities? Does artistic exacerbation truly reflect increased creative capacities? These considerations could help to clarify the place of creativity—as it has been defined and explored by cognitive neuroscience—in artistic creation and may provide leads for future lesion studies. PMID:25101029

  4. Cholinergic Blockade Reduces Theta-Gamma Phase Amplitude Coupling and Speed Modulation of Theta Frequency Consistent with Behavioral Effects on Encoding

    PubMed Central

    Gillet, Shea N.; Climer, Jason R.; Hasselmo, Michael E.

    2013-01-01

    Large-scale neural activation dynamics in the hippocampal-entorhinal circuit local field potential, observable as theta and gamma rhythms and coupling between these rhythms, is predictive of encoding success. Behavioral studies show that systemic administration of muscarinic acetylcholine receptor antagonists selectively impairs encoding, suggesting that they may also disrupt the coupling between the theta and gamma bands. Here, we tested the hypothesis that muscarinic antagonists selectively disrupt coupling between theta and gamma. Specifically, we characterized the effects of systemically administered scopolamine on movement-induced theta and gamma rhythms recorded in the superficial layers of the medial entorhinal cortex (MEC) of freely moving rats. We report the novel result that gamma power at the peak of theta was most reduced following muscarinic blockade, significantly shifting the phase of maximal gamma power to occur at later phases of theta. We also characterize the existence of multiple distinct gamma bands in the superficial layers of the MEC. Further, we observed that theta frequency was significantly less modulated by movement speed following muscarinic blockade. Finally, the slope relating speed to theta frequency, a correlate of familiarity with a testing enclosure, increased significantly less between the preinjection and recovery trials when scopolamine was administered during the intervening injection session than when saline was administered, suggesting that scopolamine reduced encoding of the testing enclosure. These data are consistent with computational models suggesting that encoding and retrieval occur during the peak and trough of theta, respectively, and support the theory that acetylcholine regulates the balance between encoding versus retrieval. PMID:24336727

  5. MR imaging appearance of frontal sinus barotrauma.

    PubMed

    Segev, Yoram; Landsberg, Roee; Fliss, Dan M

    2003-03-01

    We present the case of a flight passenger who experienced acute and severe headache during landing. MR imaging was performed because the patient had a history of vascular malformation and revealed an incidental venous angioma. A mass lesion in the frontal sinus, consistent with submucosal hematoma secondary to barotrauma, was thought to be the cause of the headache. To our knowledge, this is the first case of sinus barotrauma described in the radiologic literature and the first to describe the associated MR imaging findings. PMID:12637280

  6. Theta variation and spatiotemporal scaling along the septotemporal axis of the hippocampus

    PubMed Central

    Long, Lauren L.; Bunce, Jamie G.; Chrobak, James J.

    2015-01-01

    Hippocampal theta has been related to locomotor speed, attention, anxiety, sensorimotor integration and memory among other emergent phenomena. One difficulty in understanding the function of theta is that the hippocampus (HPC) modulates voluntary behavior at the same time that it processes sensory input. Both functions are correlated with characteristic changes in theta indices. The current review highlights a series of studies examining theta local field potential (LFP) signals across the septotemporal or longitudinal axis of the HPC. While the theta signal is coherent throughout the entirety of the HPC, the amplitude, but not the frequency, of theta varies significantly across its three-dimensional expanse. We suggest that the theta signal offers a rich vein of information about how distributed neuronal ensembles support emergent function. Further, we speculate that emergent function across the long axis varies with respect to spatiotemporal scale. Thus, septal HPC processes details of the proximal spatiotemporal environment while more temporal aspects process larger spaces and wider time-scales. The degree to which emergent functions are supported by the synchronization of theta across the septotemporal axis is an open question. Our working model is that theta synchrony serves to bind ensembles representing varying resolutions of spatiotemporal information at interdependent septotemporal areas of the HPC. Such synchrony and cooperative interactions along the septotemporal axis likely support memory formation and subsequent consolidation and retrieval. PMID:25852496

  7. Free focus radiography with miniaturized dental x-ray machines: a comparison of ''midline'' and ''lateral'' techniques

    SciTech Connect

    Jensen, T.W.

    1983-08-01

    The use of free focus radiography (FFR) employing miniaturized dental x-ray machines with radiation probes has never been generally accepted in dentistry despite its recognized radiographic potential. The present investigation studied ways to improve imaging and lower radiation burdens in dental free focus radiography. Relatively high air exposures ranging from 42,050 mR per film for high-resolution images to 3,214 mR per film for lower-resolution images using a current midline radiographic technique for panoramic FFR were found. In a proposed lateral FFR panoramic technique, reduced exposures ranged from 420 mR per film for high-resolution images to 14 mR per film for lower-resolution images. In each technique the lower exposure was obtained with a rare earth imaging system. A proposed modification of the current midline FFR technique using a rare earth imaging system and heavy added copper filtration was found to produce exposures in the range normally used in dentistry (207 mr), and the resultant image was high in contrast with relatively low detail. A comparison of essential characteristics of midline and lateral FFR techniques failed to identify specific advantages for the midline technique in current use. Lateral exposure modes in dental FFR should receive increased attention in the interest of good imaging and radiation control. It was noted that existing miniaturized dental x-ray machines may have been designed specifically for use of the midline FFR exposure technique, and modification of this equipment to support reliable lateral exposure modes was recommended.

  8. Dual role for Drosophila lethal of scute in CNS midline precursor formation and dopaminergic neuron and motoneuron cell fate.

    PubMed

    Stagg, Stephanie B; Guardiola, Amaris R; Crews, Stephen T

    2011-06-01

    Dopaminergic neurons play important behavioral roles in locomotion, reward and aggression. The Drosophila H-cell is a dopaminergic neuron that resides at the midline of the ventral nerve cord. Both the H-cell and the glutamatergic H-cell sib are the asymmetric progeny of the MP3 midline precursor cell. H-cell sib cell fate is dependent on Notch signaling, whereas H-cell fate is Notch independent. Genetic analysis of genes that could potentially regulate H-cell fate revealed that the lethal of scute [l(1)sc], tailup and SoxNeuro transcription factor genes act together to control H-cell gene expression. The l(1)sc bHLH gene is required for all H-cell-specific gene transcription, whereas tailup acts in parallel to l(1)sc and controls genes involved in dopamine metabolism. SoxNeuro functions downstream of l(1)sc and controls expression of a peptide neurotransmitter receptor gene. The role of l(1)sc may be more widespread, as a l(1)sc mutant shows reductions in gene expression in non-midline dopaminergic neurons. In addition, l(1)sc mutant embryos possess defects in the formation of MP4-6 midline precursor and the median neuroblast stem cell, revealing a proneural role for l(1)sc in midline cells. The Notch-dependent progeny of MP4-6 are the mVUM motoneurons, and these cells also require l(1)sc for mVUM-specific gene expression. Thus, l(1)sc plays an important regulatory role in both neurogenesis and specifying dopaminergic neuron and motoneuron identities. PMID:21558367

  9. Increased oscillatory theta activation evoked by violent digital game events.

    PubMed

    Salminen, Mikko; Ravaja, Niklas

    2008-04-11

    The authors examined electroencephalographic (EEG) oscillatory responses to two violent events, the player character wounding and killing an opponent character with a gun, in the digital game James Bond 007: NightFire. EEG was recorded from 25 (16 male) right-handed healthy young adults. EEG data were segmented into one 1-s baseline epoch before each event and two 1-s epochs after event onset. Power estimates (microV(2)) were derived with the fast Fourier transform (FFT) for each artefact free event. Both of the studied events evoked increased occipital theta (4-6Hz) responses as compared to the pre-event baseline. The wounding event evoked also increased occipital high theta (6-8Hz) response and the killing event evoked low alpha (8-10Hz) asymmetry over the central electrodes, both relative to the pre-event baseline. The results are discussed in light of facial electromyographic and electrodermal activity responses evoked by these same events, and it is suggested that the reported EEG responses may be attributable to affective processes related to these violent game events. PMID:18325669

  10. D3-instantons, mock theta series and twistors

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2013-04-01

    The D-instanton corrected hypermultiplet moduli space of type II string theory compactified on a Calabi-Yau threefold is known in the type IIA picture to be determined in terms of the generalized Donaldson-Thomas invariants, through a twistorial construction. At the same time, in the mirror type IIB picture, and in the limit where only D3-D1-D(-1)-instanton corrections are retained, it should carry an isometric action of the S-duality group SL(2, {Z} ). We prove that this is the case in the one-instanton approximation, by constructing a holomorphic action of SL(2, {Z} ) on the linearized twistor space. Using the modular invariance of the D4-D2-D0 black hole partition function, we show that the standard Darboux coordinates in twistor space have modular anomalies controlled by period integrals of a Siegel-Narain theta series, which can be canceled by a contact transformation generated by a holomorphic mock theta series.

  11. Speech encoding by coupled cortical theta and gamma oscillations

    PubMed Central

    Hyafil, Alexandre; Fontolan, Lorenzo; Kabdebon, Claire; Gutkin, Boris; Giraud, Anne-Lise

    2015-01-01

    Many environmental stimuli present a quasi-rhythmic structure at different timescales that the brain needs to decompose and integrate. Cortical oscillations have been proposed as instruments of sensory de-multiplexing, i.e., the parallel processing of different frequency streams in sensory signals. Yet their causal role in such a process has never been demonstrated. Here, we used a neural microcircuit model to address whether coupled theta–gamma oscillations, as observed in human auditory cortex, could underpin the multiscale sensory analysis of speech. We show that, in continuous speech, theta oscillations can flexibly track the syllabic rhythm and temporally organize the phoneme-level response of gamma neurons into a code that enables syllable identification. The tracking of slow speech fluctuations by theta oscillations, and its coupling to gamma-spiking activity both appeared as critical features for accurate speech encoding. These results demonstrate that cortical oscillations can be a key instrument of speech de-multiplexing, parsing, and encoding. DOI: http://dx.doi.org/10.7554/eLife.06213.001 PMID:26023831

  12. Frontal dysfunction and frontal cortical synapse loss in alcoholism--the main cause of alcohol dementia?

    PubMed

    Brun, A; Andersson, J

    2001-01-01

    Alcoholics often develop personality and behavioural changes, social and personal neglect, confabulation, lack of insight, empathy and emotional control. Such symptoms would increase the risk of engagement in and exposure to acts of violence and criminal activities carrying a risk of physical damage including head trauma and violent death. This was the case in at least 4 of the studied cases. A structural basis for such frontal lobe symptoms was looked for in a forensic material of 18 alcoholics, compared with an age-matched control group with regard to liver disease, brain changes of the Wernicke-Korsakoff type and cortical, especially frontal cortical changes. The salient finding was a consistent pattern of synapse loss in the superior laminae of the frontal cortical area 10 of Brodman in heavy drinkers, not related to liver disease or possible previous mental disease. The synapse loss is more likely related to alcohol, possibly mediated through vitamin B deficiency. Brain stem lesions as a source of additional symptoms cannot be dismissed. This pattern of synapse loss in alcoholism has not been described previously. The cortical changes are closely similar to those found in frontotemporal dementia, and seem to be a plausible main cause of the alcoholic frontal symptomatology and alcoholic dementia. PMID:11351140

  13. Appropriate frontal barrier tests for belted occupants.

    PubMed

    Hill, J R; Frampton, R J; Mackay, M

    1995-12-01

    Vehicle damage from frontal impacts was classified and investigated together with injuries sustained by belted front seat occupants. The sample consisted of 1872 frontal crashes from the Midlands of England. Analysis focused on impacts with broad objects that might conceivably be simulated by a barrier test. Two asymmetrical front-end damage patterns were commonly identified, and these gave the greatest rates of non-minor (Abbreviated Injury Scale (AIS) > or = 2) injuries in a range of Estimated Test Speeds from 35 to 52km/h which is the regime of current legislative crash tests. The most injurious type involved oblique damage caused by a substantial overlap of the struck object. The other type was from a small overlap. Objects struck and passenger compartment intrusions were compared. Appropriate asymmetrical and deformable barrier concepts were discussed. Other findings were connected with the future role of full face barriers as used in current tests such as Federal Motor Vehicle Safety Standard 208. Fuller overlaps (> 50%) tended to give more torso injuries rated > or = AIS 2 caused by seat belt loads and, at high speeds (53-79km/h), caused the most fatalities. Full overlaps (100%) rarely resulted in symmetrical intrusion into the passenger compartment. PMID:8749284

  14. A Case of Orbital Emphysema Associated with Frontal Sinus Pneumocele

    PubMed Central

    Sasaki, Takahiro; Yamoto, Toshikazu; Fujita, Koji; Nakao, Naoyuki

    2013-01-01

    Orbital emphysema is usually caused by trauma and fracture of an orbital bone, allowing air to pass from the sinuses into the orbit. Orbital emphysema without any significant trauma is rare. We present a case of a 67-year-old-woman who complained of left exophthalmos without any history of trauma, sneezing, or sinus surgery. Computed tomography scanning showed left orbital emphysema protruding the eyeball forward. The left frontal sinus was remarkably enlarged associated with a partial defect of the orbital roof, allowing air entry into the orbit. In addition, the frontal sinus ostium was occluded with the mucocele that served as a one-way valve between the frontal and the ethmoidal sinuses. We performed frontal craniotomy and removed the mucocele and the inner table of frontal bone to communicate the frontal sinus with the nasal cavity. After operation, her exophthalmos was improved. PMID:23943722

  15. A case of orbital emphysema associated with frontal sinus pneumocele.

    PubMed

    Sasaki, Takahiro; Yamoto, Toshikazu; Fujita, Koji; Nakao, Naoyuki

    2013-06-01

    Orbital emphysema is usually caused by trauma and fracture of an orbital bone, allowing air to pass from the sinuses into the orbit. Orbital emphysema without any significant trauma is rare. We present a case of a 67-year-old-woman who complained of left exophthalmos without any history of trauma, sneezing, or sinus surgery. Computed tomography scanning showed left orbital emphysema protruding the eyeball forward. The left frontal sinus was remarkably enlarged associated with a partial defect of the orbital roof, allowing air entry into the orbit. In addition, the frontal sinus ostium was occluded with the mucocele that served as a one-way valve between the frontal and the ethmoidal sinuses. We performed frontal craniotomy and removed the mucocele and the inner table of frontal bone to communicate the frontal sinus with the nasal cavity. After operation, her exophthalmos was improved. PMID:23943722

  16. Jealousy increased by induced relative left frontal cortical activity.

    PubMed

    Kelley, Nicholas J; Eastwick, Paul W; Harmon-Jones, Eddie; Schmeichel, Brandon J

    2015-10-01

    Asymmetric frontal cortical activity may be one key to the process linking social exclusion to jealous feelings. The current research examined the causal role of asymmetric frontal brain activity in modulating jealousy in response to social exclusion. Transcranial direct-current stimulation (tDCS) over the frontal cortex to manipulate asymmetric frontal cortical activity was combined with a modified version of the Cyberball paradigm designed to induce jealousy. After receiving 15 min of tDCS, participants were excluded by a desired partner and reported how jealous they felt. Among individuals who were excluded, tDCS to increase relative left frontal cortical activity caused greater levels of self-reported jealousy compared to tDCS to increase relative right frontal cortical activity or sham stimulation. Limitations concerning the specificity of this effect and implications for the role of the asymmetric prefrontal cortical activity in motivated behaviors are discussed. PMID:25844975

  17. Dissociations in Hippocampal and Frontal Contributions to Episodic Memory Performance

    PubMed Central

    Kramer, Joel H.; Rosen, Howard J.; Du, An-Tao; Schuff, Norbert; Hollnagel, Caroline; Weiner, Michael W.; Miller, Bruce L.; Delis, Dean C.

    2007-01-01

    The hippocampus and frontal lobes both contribute to episodic memory performance. In the present study, the authors evaluated the relative contributions of hippocampus, frontal lobes, anterior temporal cortex, and posterior cortex to memory performance in neurodegenerative patients and normal older controls. Subjects (n = 42) were studied with structural MRI and a memory paradigm that measured delayed recall, semantic clustering during recall, recognition discriminability, and recognition response bias. Data were analyzed with multiple regression. Consistent with the authors’ hypotheses, hippocampal volumes were the best predictor of delayed recall and recognition discriminability, whereas frontal volumes were the best predictor of semantic clustering and response bias. Smaller frontal volumes were associated with less semantic clustering during recall and a more liberal response bias. Results indicate that hippocampal and frontal contributions to episodic memory can be dissociated, with the hippocampus more important for memory accuracy, and frontal structures more important for strategic processing and decision making. PMID:16351355

  18. Monte Carlo evaluation of RapidArc™ oropharynx treatment planning strategies for sparing of midline structures

    NASA Astrophysics Data System (ADS)

    Bush, K.; Zavgorodni, S.; Gagne, I.; Townson, R.; Ansbacher, W.; Beckham, W.

    2010-08-01

    The aim of the study was to perform the Monte Carlo (MC) evaluation of RapidArc™ (Varian Medical Systems, Palo Alto, CA) dose calculations for four oropharynx midline sparing planning strategies. Six patients with squamous cell cancer of the oropharynx were each planned with four RapidArc head and neck treatment strategies consisting of single and double photon arcs. In each case, RTOG0522 protocol objectives were used during planning optimization. Dose calculations performed with the analytical anisotropic algorithm (AAA) are compared against BEAMnrc/DOSXYZnrc dose calculations for the 24-plan dataset. Mean dose and dose-to-98%-of-structure-volume (D98%) were used as metrics in the evaluation of dose to planning target volumes (PTVs). Mean dose and dose-to-2%-of-structure-volume (D2%) were used to evaluate dose differences within organs at risk (OAR). Differences in the conformity index (CI) and the homogeneity index (HI) as well as 3D dose distributions were also observed. AAA calculated PTV mean dose, D98%, and HIs showed very good agreement with MC dose calculations within the 0.8% MC (statistical) calculation uncertainty. Regional node volume (PTV-80%) mean dose and D98% were found to be overestimated (1.3%, σ = 0.8% and 2.3%, σ = 0.8%, respectively) by the AAA with respect to MC calculations. Mean dose and D2% to OAR were also observed to be consistently overestimated by the AAA. Increasing dose calculation differences were found in planning strategies exhibiting a higher overall fluence modulation. From the plan dataset, the largest local dose differences were observed in heavily shielded regions and within the esophageal and sinus cavities. AAA dose calculations as implemented in RapidArc™ demonstrate excellent agreement with MC calculations in unshielded regions containing moderate inhomogeneities. Acceptable agreement is achieved in regions of increased MLC shielding. Differences in dose are attributed to inaccuracies in the AAA-modulated fluence

  19. The effect of age on cognitive performance of frontal patients

    PubMed Central

    Cipolotti, Lisa; Healy, Colm; Chan, Edgar; MacPherson, Sarah E.; White, Mark; Woollett, Katherine; Turner, Martha; Robinson, Gail; Spanò, Barbara; Bozzali, Marco; Shallice, Tim

    2015-01-01

    Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanced Progressive Matrices, RAPM and the Stroop test) but not on nominal (Graded Naming Test, GNT) or perceptual (Incomplete Letters) task. In our non-frontal patients, age did not predict the magnitude of their impairment on the RAPM and GNT. Furthermore, the exacerbated executive impairment observed in our frontal patients manifested itself from middle age. We found that only age consistently predicted the exacerbated executive impairment. Lesions to specific frontal areas, or an increase in global brain atrophy or white matter abnormalities were not associated with this impairment. Our results are in line with the notion that the frontal cortex plays a critical role in aging to counteract cognitive and neuronal decline. We suggest that the combined effect of aging and frontal lesions impairs the frontal cortical systems by causing its computational power to fall below the threshold needed to complete executive tasks successfully. PMID:26102190

  20. Inhibitory attentional control in patients with frontal lobe damage

    PubMed Central

    Dimitrov, Mariana; Nakic, Marina; Elpern-Waxman, Jordan; Granetz, Joy; O'Grady, Joy; Phipps, Michael; Milne, Elizabeth; Logan, Gordon D.; Hasher, Lynn; Grafman, Jordan

    2006-01-01

    The performance of a group of frontal lobe lesion and a group of frontal lobe dementia patients was compared with the performance of their respective matched normal control groups on two tests of inhibitory attentional control—the stop-signal reaction time task and a negative priming task. Both patient groups responded significantly slower than their respective normal control groups, but they showed only marginally significant selective impairments on the measures of inhibition. The data suggest that the specific inhibitory processes evaluated by these two tests are, in general, spared in patients with focal frontal lobe lesions or frontal lobe degeneration. PMID:12821109

  1. Outcomes After Frontal Sinus Surgery: An Evidence-Based Review.

    PubMed

    DeConde, Adam S; Smith, Timothy L

    2016-08-01

    Endoscopic sinus surgery is an effective intervention at improving quality of life for patients with medically refractory chronic rhinosinusitis. The evidence supporting frontal sinusotomy is limited to single institution case series. However, the data for Draf IIa frontal sinusotomy do demonstrate that most patients experience lasting frontal sinus patency on postoperative endoscopic examination and improvements in quality of life. Salvage endoscopic frontal sinus surgery via a Draf III shows high rates of neo-ostium patency and subjective improvements in symptoms at a 2-year time point in case series. PMID:27450618

  2. The effect of age on cognitive performance of frontal patients.

    PubMed

    Cipolotti, Lisa; Healy, Colm; Chan, Edgar; MacPherson, Sarah E; White, Mark; Woollett, Katherine; Turner, Martha; Robinson, Gail; Spanò, Barbara; Bozzali, Marco; Shallice, Tim

    2015-08-01

    Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanced Progressive Matrices, RAPM and the Stroop test) but not on nominal (Graded Naming Test, GNT) or perceptual (Incomplete Letters) task. In our non-frontal patients, age did not predict the magnitude of their impairment on the RAPM and GNT. Furthermore, the exacerbated executive impairment observed in our frontal patients manifested itself from middle age. We found that only age consistently predicted the exacerbated executive impairment. Lesions to specific frontal areas, or an increase in global brain atrophy or white matter abnormalities were not associated with this impairment. Our results are in line with the notion that the frontal cortex plays a critical role in aging to counteract cognitive and neuronal decline. We suggest that the combined effect of aging and frontal lesions impairs the frontal cortical systems by causing its computational power to fall below the threshold needed to complete executive tasks successfully. PMID:26102190

  3. Evaluation and Decision Making in Frontal Sinus Surgery.

    PubMed

    Saini, Alok T; Govindaraj, Satish

    2016-08-01

    Management of frontal sinusitis can be challenging for even the most experienced otolaryngologists. A thorough understanding of the anatomy and pathophysiology of the frontal sinus is essential to properly manage disease affecting the frontal sinus. Being able to distinguish acute viral from acute bacterial and acute from chronic sinusitis is crucial because these distinctions guide appropriate management. Nasal endoscopy can confirm diagnosis, and radiologic imaging, including computed tomography and MRI, is often a necessary adjunct that aids in determining appropriate therapeutic decisions. One must be aware of the many procedures used in the surgical treatment of frontal sinusitis. PMID:27450615

  4. Electrical stimulation of the frontal cortex enhances slow-frequency EEG activity and sleepiness.

    PubMed

    D'Atri, A; De Simoni, E; Gorgoni, M; Ferrara, M; Ferlazzo, F; Rossini, P M; De Gennaro, L

    2016-06-01

    Our aim was to enhance the spontaneous slow-frequency EEG activity during the resting state using oscillating transcranial direct currents (tDCS) with a stimulation frequency that resembles the spontaneous oscillations of sleep onset. Accordingly, in this preliminary study, we assessed EEG after-effects of a frontal oscillatory tDCS with different frequency (0.8 vs. 5Hz) and polarity (anodal, cathodal, and sham). Two single-blind experiments compared the after effects on the resting EEG of oscillatory tDCS [Exp. 1=0.8Hz, 10 subjects (26.2±2.5years); Exp. 2=5Hz, 10 subjects (27.4±2.4years)] by manipulating its polarity. EEG signals recorded (28 scalp derivations) before and after stimulation [slow oscillations (0.5-1Hz), delta (1-4Hz), theta (5-7Hz), alpha (8-12Hz), beta 1 (13-15Hz) and beta 2 (16-24Hz)] were compared between conditions as a function of polarity (anodal vs. cathodal vs. sham) and frequency of stimulation (0.8 vs. 5Hz). We found a significant relative enhancement of the delta activity after the anodal tDCS at 5Hz compared to that at 0.8Hz. This increase, even though not reaching the statistical significance compared to sham, is concomitant to a significant increase of subjective sleepiness, as assessed by a visual analog scale. These two phenomena are linearly related with a regional specificity, correlations being restricted to cortical areas perifocal to the stimulation site. We have shown that a frontal oscillating anodal tDCS at 5Hz results in an effective change of both subjective sleepiness and spontaneous slow-frequency EEG activity. These changes are critically associated to both stimulation polarity (anodal) and frequency (5Hz). However, evidence of frequency-dependence seems more unequivocal than evidence of polarity-dependence. PMID:26964682

  5. The synchronous activity of lateral habenular neurons is essential for regulating hippocampal theta oscillation.

    PubMed

    Aizawa, Hidenori; Yanagihara, Shin; Kobayashi, Megumi; Niisato, Kazue; Takekawa, Takashi; Harukuni, Rie; McHugh, Thomas J; Fukai, Tomoki; Isomura, Yoshikazu; Okamoto, Hitoshi

    2013-05-15

    Lateral habenula (LHb) has attracted growing interest as a regulator of serotonergic and dopaminergic neurons in the CNS. However, it remains unclear how the LHb modulates brain states in animals. To identify the neural substrates that are under the influence of LHb regulation, we examined the effects of rat LHb lesions on the hippocampal oscillatory activity associated with the transition of brain states. Our results showed that the LHb lesion shortened the theta activity duration both in anesthetized and sleeping rats. Furthermore, this inhibitory effect of LHb lesion on theta maintenance depended upon an intact serotonergic median raphe, suggesting that LHb activity plays an essential role in maintaining hippocampal theta oscillation via the serotonergic raphe. Multiunit recording of sleeping rats further revealed that firing of LHb neurons showed significant phase-locking activity at each theta oscillation cycle in the hippocampus. LHb neurons showing activity that was coordinated with that of the hippocampal theta were localized in the medial LHb division, which receives afferents from the diagonal band of Broca (DBB), a pacemaker region for the hippocampal theta oscillation. Thus, our findings indicate that the DBB may pace not only the hippocampus, but also the LHb, during rapid eye movement sleep. Since serotonin is known to negatively regulate theta oscillation in the hippocampus, phase-locking activity of the LHb neurons may act, under the influence of the DBB, to maintain the hippocampal theta oscillation by modulating the activity of serotonergic neurons. PMID:23678132

  6. Ketamine disrupts theta modulation of gamma in a computer model of hippocampus

    PubMed Central

    Neymotin, Samuel A.; Lazarewicz, Maciej T.; Sherif, Mohamed; Contreras, Diego; Finkel, Leif H.; Lytton, William W.

    2011-01-01

    Abnormalities in oscillations have been suggested to play a role in schizophrenia. We studied theta-modulated gamma oscillations in a computer model of hippocampal CA3 in vivo with and without simulated application of ketamine, an NMDA receptor antagonist and psychotomimetic. Networks of 1200 multi-compartment neurons (pyramidal, basket and oriens-lacunosum moleculare, OLM, cells) generated theta and gamma oscillations from intrinsic network dynamics: basket cells primarily generated gamma and amplified theta, while OLM cells strongly contributed to theta. Extrinsic medial septal inputs paced theta and amplified both theta and gamma oscillations. Exploration of NMDA receptor reduction across all location combinations demonstrated that the experimentally-observed ketamine effect occurred only with isolated reduction of NMDA receptors on OLMs. In the ketamine simulations, lower OLM activity reduced theta power and disinhibited pyramidal cells, resulting in increased basket cell activation and gamma power. Our simulations predict: ketamine increases firing rates;oscillations can be generated by intrinsic hippocampal circuits;medial septum inputs pace and augment oscillations;pyramidal cells lead basket cells at the gamma peak but lag at trough;basket cells amplify theta rhythms;ketamine alters oscillations due to primary blockade at OLM NMDA receptors;ketamine alters phase relationships of cell firing;ketamine reduces network responsivity to the environmentketamine effect could be reversed by providing a continuous inward current to OLM cells. We suggest that this last prediction has implications for a possible novel treatment for cognitive deficits of schizophrenia by targeting OLM cells. PMID:21832203

  7. Axial laser heating of three meter theta pinch plasma columns

    NASA Astrophysics Data System (ADS)

    Hoffman, A. L.; Lowenthal, D. D.

    1980-10-01

    A 3-m long plasma column formed and confined by a fast rising solenoidal field was irradiated from one end by a powerful pulsed CO2 laser. It was found that beam trapping density minima could be maintained for the length of the laser pulse if the plasma diameter exceeded about 1.5 cm. The erosion of the density minimum was governed by classical diffusion processes. Three meter long plasmas in 2.6 cm bore plasma tubes could be fairly uniformly heated by 3.0 kJ of CO2 laser irradiation. Best results were obtained when heating began before or during the theta pinch implosion phase and the plasma fill pressure exceeded 1.0 torr H2. Plasma line energies of about 1 kJ/m could be obtained in a magnetic field rising to 6 T in 4.7 microseconds.

  8. Spike-timing error backpropagation in theta neuron networks.

    PubMed

    McKennoch, Sam; Voegtlin, Thomas; Bushnell, Linda

    2009-01-01

    The main contribution of this letter is the derivation of a steepest gradient descent learning rule for a multilayer network of theta neurons, a one-dimensional nonlinear neuron model. Central to our model is the assumption that the intrinsic neuron dynamics are sufficient to achieve consistent time coding, with no need to involve the precise shape of postsynaptic currents; this assumption departs from other related models such as SpikeProp and Tempotron learning. Our results clearly show that it is possible to perform complex computations by applying supervised learning techniques to the spike times and time response properties of nonlinear integrate and fire neurons. Networks trained with our multilayer training rule are shown to have similar generalization abilities for spike latency pattern classification as Tempotron learning. The rule is also able to train networks to perform complex regression tasks that neither SpikeProp or Tempotron learning appears to be capable of. PMID:19431278

  9. Medial frontal ∼4-Hz activity in humans and rodents is attenuated in PD patients and in rodents with cortical dopamine depletion

    PubMed Central

    Parker, Krystal L.; Chen, Kuan-Hua; Kingyon, Johnathan R.; Cavanagh, James F.

    2015-01-01

    The temporal control of action is a highly conserved and critical mammalian behavior. Here, we investigate the neuronal basis of this process using an interval timing task. In rats and humans, instructional timing cues triggered spectral power across delta and theta bands (2–6 Hz) from the medial frontal cortex (MFC). Humans and rodents with dysfunctional dopamine have impaired interval timing, and we found that both humans with Parkinson's disease (PD) and rodents with local MFC dopamine depletion had attenuated delta and theta activity. In rodents, spectral activity in this range could functionally couple single MFC neurons involved in temporal processing. Without MFC dopamine, these neurons had less functional coupling with delta/theta activity and less temporal processing. Finally, in humans this 2- to 6-Hz activity was correlated with executive function in matched controls but not in PD patients. Collectively, these findings suggest that cue-evoked low-frequency rhythms could be a clinically important biomarker of PD that is translatable to rodent models, facilitating mechanistic inquiry and the development of neurophysiological biomarkers for human disease. PMID:26133799

  10. Public Kepler Data on the Bright Star Theta Cygni

    NASA Astrophysics Data System (ADS)

    Haas, Michael Robert; Bryson, S. T.; Rowe, J. F.; Still, M. D.

    2011-01-01

    The bright star Theta Cygni (Kepler ID 11918630) has been observed by Kepler in both short (59 sec) and long (29.4 min) cadence for a period of approximately 50 days starting on MJD 55410. These observations were made at the request of the Kepler Guest Observer Office and are intended for immediate public release. The purpose is to demonstrate Kepler's exquisite photometric precision on bright, highly saturated targets. Theta Cygni is a F3V/M3V binary with a visual magnitude of 4.9/13.0. The short-cadence data show evidence of granulation (i.e., convection) out to about 1 mHz ( 100 c/d) and clear detection of numerous p-modes with a peak near 1.8 mHz ( 150 c/d). The high-frequency noise floor has a 3-sigma upper envelope of 0.4 ppm. The amplitude of the p-modes agrees with the stellar effective temperature, indicating that the star has a thin convective layer. Since a custom aperture was employed, the light curves will be constructed manually and placed on the Guest Observer website (http://keplergo.arc.nasa.gov/). The corresponding pixel-level data will be available from the Kepler archive (http://archive.stsci.edu/kepler/). The Kepler mission can accommodate a small number of such bright targets every quarter. Observing proposals can be submitted annually to the peer-reviewed Guest Observer Program, or much less formally on a quarterly basis for Director's Discretionary Time (see http://keplergo.arc.nasa.gov/GOprogramDDT.shtml). Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by NASA, Science Mission Directorate.

  11. Performance Monitoring in Monkey Frontal Eye Field

    PubMed Central

    Yu, Dian; Ferrera, Vincent P.

    2014-01-01

    The frontal eye fields (FEF) are thought to mediate response selection during oculomotor decision tasks. In addition, many FEF neurons have robust postsaccadic responses, but their role in postchoice evaluative processes (online performance monitoring) is only beginning to become apparent. Here we report error-related neural activity in FEF while monkeys performed a biased speed-categorization task that enticed the animals to make impulsive errors. Twenty-three percent of cells in macaque FEF coded an internally generated error-related signal, and many of the same cells also coded task difficulty. The observed responses are primarily consistent with three related concepts that have been associated with performance monitoring: (1) response conflict; (2) uncertainty; and (3) reward prediction. Overall, our findings suggest a novel role for the FEF as part of the neural network that evaluates the preceding choice to optimize behavior in the future. PMID:24478349

  12. Predictability of Frontal Waves and Cyclones

    NASA Astrophysics Data System (ADS)

    Frame, Thomas; Methven, John; Roberts, Nigel; Titley, Helen

    2016-04-01

    The practical limit of predictability of the occurrence extra-tropical cyclonic features (frontal waves and cyclones) is estimated using the Brier Skill of "strike probability" from the fifteen-day Met Office Global and Regional Ensemble Prediction System (MOGREPS-15). An upper limit of 14 days is found for the prediction of the occurrence of the centres of strong cyclonic features (vorticity above the 90th percentile) within a region of about 1000km radius. However when weaker cyclonic features are considered skill is lost within 8 days. The statistics of features in the model show some systematic biases relative to the analysis climatology, in particular a reduction in the number features with increasing lead time and a sensitivity of the number of cyclonic features to the presence (or not) of stochastics physics, meaning that the actual limit of predictability is quite possibly longer than our estimate.

  13. Theta-phase gamma-amplitude coupling as a neurophysiological marker of attention deficit/hyperactivity disorder in children.

    PubMed

    Kim, Jun Won; Lee, Jaewon; Kim, Bung-Nyun; Kang, Taewoong; Min, Kyung Joon; Han, Doug Hyun; Lee, Young Sik

    2015-08-31

    Theta-phase gamma-amplitude coupling (TGC) between slow and fast oscillations is considered to represent cortico-subcortical interactions. The purpose of this electroencephalographic (EEG) study was to evaluate the diagnostic utility of TGC by comparing the power spectra and TGC at rest between ADHD and control children. Nineteen-channel EEGs were recorded from 97 volunteers (including 53 subjects with ADHD attending a camp for hyperactive children). The EEG power spectra and TGC data were analyzed. Analysis of covariance (ANCOVA) was conducted on the quantitative EEG results between the groups to adjust for sex. Receiver operator characteristic (ROC) analysis was conducted to examine the discriminating ability of each parameter for ADHD diagnosis. The ADHD group exhibited significantly decreased TGC in multiple areas, including frontal (Fp1, F3, F7, F6), temporal (T3), and occipital (O2) areas, compared with the control group. The ROC analysis performed on the TGC data generated the most accurate result among the EEG measures, with an overall classification accuracy of 71.7%. TGC, which reflects the degree of neuronal interactions between functional systems, provides information about an individual's attentional network. Therefore, resting-state TGC is a promising neurophysiological marker of ADHD in children. PMID:26170246

  14. Can induced theta vacua be created in heavy-Ion collisions?

    PubMed

    Buckley; Fugleberg; Zhitnitsky

    2000-05-22

    We discuss a phenomenon important to the development of the early Universe which may be experimentally testable in heavy-ion collisions. An arbitrary induced straight theta vacuum state should be created in heavy-ion collisions, similar to the creation of the disoriented chiral condensate. It should be a large domain with a wrong straight theta(ind) not equal0 orientation which will mimic the physics of the early Universe when it is believed that the fundamental parameter straight theta(fund) not equal0. We test this idea numerically in a simple model where we study the evolution of the phases of the chiral condensates in QCD with two quark flavors with nonzero straight theta(ind) parameter. We see the formation of a nonzero straight theta(ind) vacuum on a time scale of 10(-23) s. PMID:10990805

  15. Loss of hippocampal theta rhythm results in spatial memory deficit in the rat.

    PubMed

    Winson, J

    1978-07-14

    Rats learned, using distal room cues, to run to a goal on an elevated, circular track starting from any position on the track. The goal was one of eight equidistant, recessed cups set around the track, the goal cup being distinguished from the others solely by its position in the room. After learning, electrolytic lesions were made in the medial septal nucleus eliminating hippocampal theta rhythm in some animals but not in others. Rats without theta rhythm were no longer able to perform the spatial task, whereas rats with undisturbed theta rhythm retrained normal performance. Although rats without theta rhythm could not find their way directly to the goal, they recognized its location when they came upon it by chance. This type of spatial deficit appears similar to that shown by hippocampally lesioned patient H.M. Subsequent tests demonstrated that rats deprived of theta rhythm before training could nevertheless learn the task. PMID:663646

  16. Radiative generation of {theta}{sub 13} with the seesaw threshold effect

    SciTech Connect

    Mei Jianwei; Xing Zhizhong

    2004-09-01

    We examine whether an appreciable value of the lepton flavor mixing angle {theta}{sub 13} at the electroweak scale {lambda}{sub EW} can be radiatively generated from {theta}{sub 13}=0 deg. at the grand unified theory (GUT) scale {lambda}{sub GUT}. It is found that the renormalization-group running and seesaw threshold effects may lead to {theta}{sub 13}{approx}5 deg. at low energies for two simple large-maximal mixing patterns of the Maki-Nakagawa-Sakata matrix in the minimal supersymmetric standard model. If {theta}{sub 12} is sufficiently large at {lambda}{sub GUT}, it will be possible to radiatively produce {theta}{sub 13}{approx}5 deg. at {lambda}{sub EW} both in the standard model and in its supersymmetric extensions. The mass spectrum of three heavy right-handed Majorana neutrinos and the cosmological baryon number asymmetry via leptogenesis are also calculated.

  17. ACTIVITY IN CORTICAL MIDLINE STRUCTURES IS MODULATED BY SELF-CONSTRUAL CHANGES DURING ACCULTURATION

    PubMed Central

    Chen, Pin-Hao A.; Wagner, Dylan D.; Kelley, William M.; Heatherton, Todd F.

    2015-01-01

    Recent immigrants to another culture generally experience a period of acculturation during which they show self-construal changes. Here, we examine how this acculturation period alters brain activity associated with self-referential cognition. Twenty-seven native Chinese-speaking recent immigrants completed a trait-judgment task in which they judged whether a series of psychological traits applied to themselves and, separately, whether these traits applied to their mothers. Participants were scanned at two intervals: within the first two months of their arrival in the United States (Time 1), and also six months after the initial scan (Time 2). Results already revealed a significant self-vs.-mother differentiation at Time 1 in the medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC). However, at time 2, this pattern diverged depending on whether immigrants became more or less like their original culture. That is to say, for immigrants who became less like Easterners, the self vs. mother difference remained, whereas for participants who became even more like Easterners, the self vs. mother difference in cortical midline structures disappeared. These findings support the notion that self-construal changes during the process of acculturation are reflected in the relative engagement of brain structures implicated in self-referential processing (i.e., MPFC and PCC) when judging traits with reference to oneself or a close other. PMID:26236572

  18. Influence of the cortical midline structures on moral emotion and motivation in moral decision-making.

    PubMed

    Han, Hyemin; Chen, Jingyuan; Jeong, Changwoo; Glover, Gary H

    2016-04-01

    The present study aims to examine the relationship between the cortical midline structures (CMS), which have been regarded to be associated with selfhood, and moral decision making processes at the neural level. Traditional moral psychological studies have suggested the role of moral self as the moderator of moral cognition, so activity of moral self would present at the neural level. The present study examined the interaction between the CMS and other moral-related regions by conducting psycho-physiological interaction analysis of functional images acquired while 16 subjects were solving moral dilemmas. Furthermore, we performed Granger causality analysis to demonstrate the direction of influences between activities in the regions in moral decision-making. We first demonstrate there are significant positive interactions between two central CMS seed regions-i.e., the medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC)-and brain regions associated with moral functioning including the cerebellum, brainstem, midbrain, dorsolateral prefrontal cortex, orbitofrontal cortex and anterior insula (AI); on the other hand, the posterior insula (PI) showed significant negative interaction with the seed regions. Second, several significant Granger causality was found from CMS to insula regions particularly under the moral-personal condition. Furthermore, significant dominant influence from the AI to PI was reported. Moral psychological implications of these findings are discussed. The present study demonstrated the significant interaction and influence between the CMS and morality-related regions while subject were solving moral dilemmas. Given that, activity in the CMS is significantly involved in human moral functioning. PMID:26772629

  19. Self-reflection across time: cortical midline structures differentiate between present and past selves

    PubMed Central

    Feyers, Dorothée; Majerus, Steve; Collette, Fabienne; Van der Linden, Martial; Maquet, Pierre; Salmon, Eric

    2008-01-01

    The processing of personal changes across time and the ability to differentiate between representations of present and past selves are crucial for developing a mature sense of identity. In this study, we explored the neural correlates of self-reflection across time using functional magnetic resonance imaging (fMRI). College undergraduates were asked to reflect on their own psychological characteristics and those of an intimate other, for both the present time period (i.e. at college) and a past time period (i.e. high school years) that involved significant personal changes. Cortical midline structures (CMS) were commonly recruited by the four reflective tasks (reflecting on the present self, past self, present other and past other), relative to a control condition (making valence judgments). More importantly, however, the degree of activity in CMS also varied significantly according to the target of reflection, with the ventral and dorsal medial prefrontal cortex and the posterior cingulate cortex being more recruited when reflecting on the present self than when reflecting on the past self or when reflecting on the other person. These findings suggest that CMS may contribute to differentiate between representations of present and past selves. PMID:19015116

  20. Modified transversal sagittal maxillary expander for correction of upper midline deviation associated with maxillary arch deficiency.

    PubMed

    Maspero, C; Giannini, L; Galbiati, G; Farronato, G

    2015-04-01

    The transversal sagittal maxillary expander (TSME) is a fixed device designed to develop arch form in patients with constricted dental arches. The present article describes a modified TSME appliance, the activation method, the therapeutic benefits as well as clinical advantages. The appliance has two molar bands, a Hyrax-type transverse expansion screw, one 0.045-inch wire extending from the molar band to the palatal surface of the central incisor in the emiarch crossbite and an 8 mm-Hyrax-type screw attached to this wire between the molar band and the incisor. A buccal arm with a terminal loop is welded to the band in the emiarch and it is extended to the labial surface on the central incisor on the side opposite to the crossbite and the maxillary midline deviation. The modified TSME appliance described in this paper are specifically designed for anteroposterior and transverse development. It has a sagittal effect on the maxillary alveolar process and at the same time allow to restore the correct transverse maxillary diameters. PMID:25747426

  1. Sharing self-related information is associated with intrinsic functional connectivity of cortical midline brain regions.

    PubMed

    Meshi, Dar; Mamerow, Loreen; Kirilina, Evgeniya; Morawetz, Carmen; Margulies, Daniel S; Heekeren, Hauke R

    2016-01-01

    Human beings are social animals and they vary in the degree to which they share information about themselves with others. Although brain networks involved in self-related cognition have been identified, especially via the use of resting-state experiments, the neural circuitry underlying individual differences in the sharing of self-related information is currently unknown. Therefore, we investigated the intrinsic functional organization of the brain with respect to participants' degree of self-related information sharing using resting state functional magnetic resonance imaging and self-reported social media use. We conducted seed-based correlation analyses in cortical midline regions previously shown in meta-analyses to be involved in self-referential cognition: the medial prefrontal cortex (MPFC), central precuneus (CP), and caudal anterior cingulate cortex (CACC). We examined whether and how functional connectivity between these regions and the rest of the brain was associated with participants' degree of self-related information sharing. Analyses revealed associations between the MPFC and right dorsolateral prefrontal cortex (DLPFC), as well as the CP with the right DLPFC, the left lateral orbitofrontal cortex and left anterior temporal pole. These findings extend our present knowledge of functional brain connectivity, specifically demonstrating how the brain's intrinsic functional organization relates to individual differences in the sharing of self-related information. PMID:26948055

  2. Sharing self-related information is associated with intrinsic functional connectivity of cortical midline brain regions

    PubMed Central

    Meshi, Dar; Mamerow, Loreen; Kirilina, Evgeniya; Morawetz, Carmen; Margulies, Daniel S.; Heekeren, Hauke R.

    2016-01-01

    Human beings are social animals and they vary in the degree to which they share information about themselves with others. Although brain networks involved in self-related cognition have been identified, especially via the use of resting-state experiments, the neural circuitry underlying individual differences in the sharing of self-related information is currently unknown. Therefore, we investigated the intrinsic functional organization of the brain with respect to participants’ degree of self-related information sharing using resting state functional magnetic resonance imaging and self-reported social media use. We conducted seed-based correlation analyses in cortical midline regions previously shown in meta-analyses to be involved in self-referential cognition: the medial prefrontal cortex (MPFC), central precuneus (CP), and caudal anterior cingulate cortex (CACC). We examined whether and how functional connectivity between these regions and the rest of the brain was associated with participants’ degree of self-related information sharing. Analyses revealed associations between the MPFC and right dorsolateral prefrontal cortex (DLPFC), as well as the CP with the right DLPFC, the left lateral orbitofrontal cortex and left anterior temporal pole. These findings extend our present knowledge of functional brain connectivity, specifically demonstrating how the brain’s intrinsic functional organization relates to individual differences in the sharing of self-related information. PMID:26948055

  3. THE ROLE OF VENTRAL MIDLINE THALAMUS IN CHOLINERGIC-BASED RECOVERY IN THE AMNESTIC RAT

    PubMed Central

    Bobal, Michael G.; Savage, Lisa M.

    2014-01-01

    The thalamus is a critical node for several pathways involved in learning and memory. Damage to the thalamus by trauma, disease or malnourishment can impact the effectiveness of the prefrontal cortex (PFC) and hippocampus (HPC) and lead to a profound amnesia state. Using the pyrithiamine-induced thiamine deficiency (PTD) rat model of human Wernicke-Korsakoff syndrome, we tested the hypothesis that co-infusion of the acetylcholinesterase inhibitor physostigmine across the PFC and HPC would recover spatial alternation performance in PTD rats. When cholinergic tone was increased by dual injections across the PFC-HPC, spontaneous alternation performance in PTD rats was recovered. In addition, we tested a second hypothesis that two ventral midline thalamic nuclei, the rhomboid nucleus and nucleus reuniens (Rh-Re), form a critical node needed for the recovery of function observed when cholinergic tone was increased across the PFC and HPC. By using the GABAA agonist muscimol to temporarily deactivate the Rh-Re the recovery of alternation behavior obtained in the PTD model by cholinergic stimulation across the PFC-HPC was blocked. In control pair-fed (PF) rats, inactivation of the Rh-Re impaired spontaneous alternation. However, when inactivation of the Rh-Re co-occurred with physostigmine infusions across the PFC-HPC, PF rats had normal performance. These results further demonstrate that the Rh-Re is critical in facilitating interactions between the HPC and PFC, but other redundant pathways also exist. PMID:25446352

  4. The role of ventral midline thalamus in cholinergic-based recovery in the amnestic rat.

    PubMed

    Bobal, M G; Savage, L M

    2015-01-29

    The thalamus is a critical node for several pathways involved in learning and memory. Damage to the thalamus by trauma, disease or malnourishment can impact the effectiveness of the prefrontal cortex (PFC) and hippocampus (HPC) and lead to a profound amnesia state. Using the pyrithiamine-induced thiamine deficiency (PTD) rat model of human Wernicke-Korsakoff syndrome, we tested the hypothesis that co-infusion of the acetylcholinesterase inhibitor physostigmine across the PFC and HPC would recover spatial alternation performance in PTD rats. When cholinergic tone was increased by dual injections across the PFC-HPC, spontaneous alternation performance in PTD rats was recovered. In addition, we tested a second hypothesis that two ventral midline thalamic nuclei, the rhomboid nucleus and nucleus reuniens (Rh-Re), form a critical node needed for the recovery of function observed when cholinergic tone was increased across the PFC and HPC. By using the GABAA agonist muscimol to temporarily deactivate the Rh-Re the recovery of alternation behavior obtained in the PTD model by cholinergic stimulation across the PFC-HPC was blocked. In control pair-fed (PF) rats, inactivation of the Rh-Re impaired spontaneous alternation. However, when inactivation of the Rh-Re co-occurred with physostigmine infusions across the PFC-HPC, PF rats had normal performance. These results further demonstrate that the Rh-Re is critical in facilitating interactions between the HPC and PFC, but other redundant pathways also exist. PMID:25446352

  5. Cortical Midline Structures and Autobiographical-Self Processes: An Activation-Likelihood Estimation Meta-Analysis

    PubMed Central

    Araujo, Helder F.; Kaplan, Jonas; Damasio, Antonio

    2013-01-01

    The autobiographical-self refers to a mental state derived from the retrieval and assembly of memories regarding one’s biography. The process of retrieval and assembly, which can focus on biographical facts or personality traits or some combination thereof, is likely to vary according to the domain chosen for an experiment. To date, the investigation of the neural basis of this process has largely focused on the domain of personality traits using paradigms that contrasted the evaluation of one’s traits (self-traits) with those of another person’s (other-traits). This has led to the suggestion that cortical midline structures (CMSs) are specifically related to self states. Here, with the goal of testing this suggestion, we conducted activation-likelihood estimation (ALE) meta-analyses based on data from 28 neuroimaging studies. The ALE results show that both self-traits and other-traits engage CMSs; however, the engagement of medial prefrontal cortex is greater for self-traits than for other-traits, while the posteromedial cortex is more engaged for other-traits than for self-traits. These findings suggest that the involvement CMSs is not specific to the evaluation of one’s own traits, but also occurs during the evaluation of another person’s traits. PMID:24027520

  6. The presence of pacemaker HCN channels identifies theta rhythmic GABAergic neurons in the medial septum

    PubMed Central

    Varga, Viktor; Hangya, Balázs; Kránitz, Kinga; Ludányi, Anikó; Zemankovics, Rita; Katona, István; Shigemoto, Ryuichi; Freund, Tamás F; Borhegyi, Zsolt

    2008-01-01

    The medial septum (MS) is an indispensable component of the subcortical network which synchronizes the hippocampus at theta frequency during specific stages of information processing. GABAergic neurons exhibiting highly regular firing coupled to the hippocampal theta rhythm are thought to form the core of the MS rhythm-generating network. In recent studies the hyperpolarization-activated, cyclic nucleotide-gated non-selective cation (HCN) channel was shown to participate in theta synchronization of the medial septum. Here, we tested the hypothesis that HCN channel expression correlates with theta modulated firing behaviour of MS neurons by a combined anatomical and electrophysiological approach. HCN-expressing neurons represented a subpopulation of GABAergic cells in the MS partly overlapping with parvalbumin (PV)-containing neurons. Rhythmic firing in the theta frequency range was characteristic of all HCN-expressing neurons. In contrast, only a minority of HCN-negative cells displayed theta related activity. All HCN cells had tight phase coupling to hippocampal theta waves. As a group, PV-expressing HCN neurons had a marked bimodal phase distribution, whereas PV-immunonegative HCN neurons did not show group-level phase preference despite significant individual phase coupling. Microiontophoretic blockade of HCN channels resulted in the reduction of discharge frequency, but theta rhythmic firing was perturbed only in a few cases. Our data imply that HCN-expressing GABAergic neurons provide rhythmic drive in all phases of the hippocampal theta activity. In most MS theta cells rhythm genesis is apparently determined by interactions at the level of the network rather than by the pacemaking property of HCN channels alone. PMID:18565991

  7. Movement-Related Theta Rhythm in Humans: Coordinating Self-Directed Hippocampal Learning

    PubMed Central

    Kaplan, Raphael; Doeller, Christian F.; Barnes, Gareth R.; Litvak, Vladimir; Düzel, Emrah; Bandettini, Peter A.; Burgess, Neil

    2012-01-01

    The hippocampus is crucial for episodic or declarative memory and the theta rhythm has been implicated in mnemonic processing, but the functional contribution of theta to memory remains the subject of intense speculation. Recent evidence suggests that the hippocampus might function as a network hub for volitional learning. In contrast to human experiments, electrophysiological recordings in the hippocampus of behaving rodents are dominated by theta oscillations reflecting volitional movement, which has been linked to spatial exploration and encoding. This literature makes the surprising cross-species prediction that the human hippocampal theta rhythm supports memory by coordinating exploratory movements in the service of self-directed learning. We examined the links between theta, spatial exploration, and memory encoding by designing an interactive human spatial navigation paradigm combined with multimodal neuroimaging. We used both non-invasive whole-head Magnetoencephalography (MEG) to look at theta oscillations and Functional Magnetic Resonance Imaging (fMRI) to look at brain regions associated with volitional movement and learning. We found that theta power increases during the self-initiation of virtual movement, additionally correlating with subsequent memory performance and environmental familiarity. Performance-related hippocampal theta increases were observed during a static pre-navigation retrieval phase, where planning for subsequent navigation occurred. Furthermore, periods of the task showing movement-related theta increases showed decreased fMRI activity in the parahippocampus and increased activity in the hippocampus and other brain regions that strikingly overlap with the previously observed volitional learning network (the reverse pattern was seen for stationary periods). These fMRI changes also correlated with participant's performance. Our findings suggest that the human hippocampal theta rhythm supports memory by coordinating exploratory

  8. Experimental search for radiative decays of the pentaquark baryon {Theta}{sup +}(1540)

    SciTech Connect

    Barmin, V. V.; Asratyan, A. E.; Borisov, V. S.; Curceanu, C.; Davidenko, G. V.; Dolgolenko, A. G.; Guaraldo, C.; Kubantsev, M. A.; Larin, I. F.; Matveev, V. A.; Shebanov, V. A.; Shishov, N. N.; Sokolov, L. I.; Tumanov, G. K.; Verebryusov, V. S.

    2010-07-15

    The data on the reactions K{sup +}Xe {sup {yields}}K{sup 0{gamma}}X and K{sup +}Xe {sup {yields}}K{sup +{gamma}}X, obtained with the bubble chamber DIANA, have been analyzed for possible radiative decays of the {Theta}{sup +}(1540) baryon: {Theta}{sup +} {sup {yields}}K{sup 0}p{gamma} and {Theta}{sup +} {sup {yields}}K{sup +}n{gamma}. No signals have been observed, and we derive the upper limits {Gamma}({Theta}{sup +} {sup {yields}}K{sup 0}p{gamma})/{Gamma}({Theta}{sup +} {sup {yields}}K{sup 0}p) < 0.032 and {Gamma}({Theta}{sup +} {sup {yields}}K{sup +}n{gamma})/{Gamma}({Theta}{sup +} {sup {yields}}K{sup +}n{gamma}) < 0.041 which, using our previous measurement of {Gamma}({Theta}{sup +} {sup {yields}}KN) = 0.39 {+-} 0.10 MeV, translate to {Gamma}({Theta}{sup +} {sup {yields}}K{sup 0}p{gamma}) < 8 keV and {Gamma}({Theta}{sup +} {sup {yields}}K{sup +}n{gamma}) < 11 keV at 90% confidence level. We have also measured the cross sections of K{sup +}-induced reactions involving emission of a neutral pion: {sigma}(K{sup +}n {sup {yields}}K{sup 0}p{pi}{sup 0}) = 68 {+-} 18 {mu}b and {sigma}(K{sup +}N {sup {yields}}K{sup +}N{pi}{sup 0}) = 30 {+-} 8 {mu}b for incident K{sup +} momentum of 640 MeV.

  9. Evidence that the recently discovered theta 1-globin gene is functional in higher primates.

    PubMed

    Shaw, J P; Marks, J; Shen, C K

    A new subfamily of the alpha-globin-like family has recently been identified in higher primates, rabbit, galago and possibly the horse. One member of this subfamily, theta 1, is downstream from the adult alpha 1-globin gene. In orang-utan, but not in rabbit or galago, the theta 1-gene appears to be structurally intact, suggesting that it may be functional in this species. The orang-utan theta 1-gene possesses initiation and termination codons, and the predicted polypeptide differs from the orang-utan alpha 1-globin by 55 amino acids. The upstream promoter boxes CCAAT and ATA are present, although approximately 150 base pairs (bp) farther upstream than in the alpha 1-gene. This structural difference in the promoter between the orang-utan theta 1- and alpha 1-genes has led Proudfoot to speculate that the theta 1-gene may be inactive. We have now cloned the theta 1- and alpha 1-globin genes from the olive baboon, and have compared their sequences with those of orang-utan. The unique promoter structure of the orang-utan theta 1-gene is highly conserved in baboon, although the orang-utan and baboon diverged nearly 30 million years ago. The coding sequences of the two theta 1-genes differ by only 6.3% with 22 out of 27 nucleotide substitutions being codon third position silent changes. These data support the view that the theta 1-gene has been functional in the baboon, orang-utan, and by implication, in man. We also estimate that the duplication event generating the theta 1- and alpha-globin-like subfamilies may have occurred as much as 260 million years ago. PMID:3561513

  10. What makes a frontal area of primate brain the frontal eye field?

    PubMed Central

    Percheron, Gérard; François, Chantal; Pouget, Pierre

    2015-01-01

    The frontal eye field region (FEF) of the oculomotor pathways has been intensely studied. The primary goal of this review is to illustrate the phylogenetic displacement of the FEF locus in primate species. The locus is arrayed along the arcuate sulcus in monkeys and abuts into the primary motor strip region in humans. The strengths and limitations of the various functional, anatomical and histological methodologies used to identify such regions are also discussed. PMID:26042006

  11. Lateral supracerebellar infratentorial approach for microsurgical resection of large midline pineal region tumors: techniques to expand the operative corridor.

    PubMed

    Kulwin, Charles; Matsushima, Ken; Malekpour, Mahdi; Cohen-Gadol, Aaron A

    2016-01-01

    Pineal region tumors pose certain challenges in regard to their resection: a deep surgical field, associated critical surrounding neurovascular structures, and narrow operative working corridor due to obstruction by the apex of the culmen. The authors describe a lateral supracerebellar infratentorial approach that was successfully used in the treatment of 10 large (> 3 cm) midline pineal region tumors. The patients were placed in a modified lateral decubitus position. A small lateral suboccipital craniotomy exposed the transverse sinus. Tentorial retraction sutures were used to gently rotate and elevate the transverse sinus to expand the lateral supracerebellar operative corridor. This approach placed only unilateral normal structures at risk and minimized vermian venous sacrifice. The surgeon achieved generous exposure of the caudal midline mesencephalon through a "cross-court" oblique trajectory, while avoiding excessive retraction on the culmen. All patients underwent the lateral approach with no approach-related complication. The final pathological diagnoses were consistent with meningioma in 3 cases, pilocytic astrocytoma in 3 cases, intermediate grade pineal region tumor in 2 cases, and pineoblastoma in 2 cases. The entire extent of these tumors was readily reachable through the lateral supracerebellar route. Gross-total resection was achieved in 8 (80%) of the 10 cases; in 2 cases (20%) near-total resection was performed due to adherence of these tumors to deep diencephalic veins. Large midline pineal region tumors can be removed through a unilateral paramedian suboccipital craniotomy. This approach is simple, may spare some of the midline vermian bridging veins, and may be potentially less invasive and more efficient. PMID:26275000

  12. Ephrin-B reverse signaling controls septation events at the embryonic midline through separate tyrosine phosphorylation-independent signaling avenues

    PubMed Central

    Dravis, Christopher; Henkemeyer, Mark

    2011-01-01

    We report that the disruption of bidirectional signaling between ephrin-B2 and EphB receptors impairs morphogenetic cell-cell septation and closure events during development of the embryonic midline. A novel role for reverse signaling is identified in tracheoesophageal foregut septation, as animals lacking the cytoplasmic domain of ephrin-B2 present with laryngotracheoesophageal cleft (LTEC), while both EphB2/EphB3 forward signaling and ephrin-B2 reverse signaling are shown to be required for midline fusion of the palate. In a third midline event, EphB2/EphB3 are shown to mediate ventral abdominal wall closure by acting principally as ligands to stimulate ephrin-B reverse signaling. Analysis of new ephrin-B26YFΔV and ephrin-B2ΔV mutants that specifically ablate ephrin-B2 tyrosine phosphorylation- and/or PDZ domain-mediated signaling indicate there are at least two distinct phosphorylation-independent components of reverse signaling. These involve both PDZ domain interactions and a non-canonical SH2/PDZ-independent form of reverse signaling that may utilize associations with claudin family tetraspan molecules, as EphB2 and activated ephrin-B2 molecules are specifically co-localized with claudins in epithelia at the point of septation. Finally, the developmental phenotypes described here mirror common human midline birth defects found with the VACTERL association, suggesting a molecular link to bidirectional signaling through B-subclass Ephs and ephrins. PMID:21539827

  13. Frontal lobe syndrome reassessed: comparison of patients with lateral or medial frontal brain damage.

    PubMed

    Paradiso, S; Chemerinski, E; Yazici, K M; Tartaro, A; Robinson, R G

    1999-11-01

    Examination of mood and behaviour changes after frontal damage may contribute to understanding the functional role of distinct prefrontal areas in depression and anxiety. Depression and anxiety disorders, symptoms, and behaviour were compared in eight patients with single lateral and eight patients with single medial frontal lesions matched for age, sex, race, education, socioeconomic status, side, and aetiology of lesion 2 weeks and 3 months after brain injury. DSM IV major depressive and generalised anxiety disorders were more frequent in patients with lateral compared with medial lesions at 2 weeks but not at 3 months. At 3 months, however, patients with lateral damage showed greater severity of depressive symptoms, and greater impairment in both activities of daily living and social functioning. At initial evaluation depressed mood and slowness were more frequent, whereas at 3 months slowness, lack of energy, and social unease were more frequent in the lateral than the medial group. Patients with lateral lesions showed greater reduction of emotion and motivation (apathy) during both examinations. Medial frontal injury may fail to produce emotional dysregulation or may inhibit experience of mood changes, anxiety, or apathy. Lateral prefrontal damage may disrupt mood regulation and drive while leaving intact the ability to experience (negative) emotions. PMID:10519877

  14. The Human Frontal Lobes and Frontal Network Systems: An Evolutionary, Clinical, and Treatment Perspective

    PubMed Central

    Hoffmann, Michael

    2013-01-01

    Frontal lobe syndromes, better termed as frontal network systems, are relatively unique in that they may manifest from almost any brain region, due to their widespread connectivity. The understandings of the manifold expressions seen clinically are helped by considering evolutionary origins, the contribution of the state-dependent ascending monoaminergic neurotransmitter systems, and cerebral connectivity. Hence, the so-called networktopathies may be a better term for the syndromes encountered clinically. An increasing array of metric tests are becoming available that complement that long standing history of qualitative bedside assessments pioneered by Alexander Luria, for example. An understanding of the vast panoply of frontal systems' syndromes has been pivotal in understanding and diagnosing the most common dementia syndrome under the age of 60, for example, frontotemporal lobe degeneration. New treatment options are also progressively becoming available, with recent evidence of dopaminergic augmentation, for example, being helpful in traumatic brain injury. The latter include not only psychopharmacological options but also device-based therapies including mirror visual feedback therapy. PMID:23577266

  15. Post-Traumatic Pneumocele of the Frontal Sinus

    PubMed Central

    Calisir, Cuneyt; Adapinar, Baki

    2008-01-01

    A pneumocele is an abnormal dilatation of a paranasal sinus, most commonly affecting the frontal sinus. Although the etiology of pneumocele is not entirely known, several causative factors have been suggested including trauma, surgery, tumor and infection. We report here a case of post-traumatic pneumocele of the frontal sinus following a head trauma. PMID:18682678

  16. An Alternative to Impedance Screening: Unoccluded Frontal Bone Conduction Screening.

    ERIC Educational Resources Information Center

    Square, Regina; And Others

    1985-01-01

    A bone conduction hearing screening test using frontal bone oscillator placement was compared with pure-tone air-conduction screening and impedance audiometry with 114 preschoolers. Unoccluded frontal bone conduction testing produced screening results not significantly different from results obtained by impedance audiometry. (CL)!

  17. Plasticity and Functions of the Orbital Frontal Cortex

    ERIC Educational Resources Information Center

    Kolb, Bryan; Pellis, Sergio; Robinson, Terry E.

    2004-01-01

    We compare the effects of psychoactive drugs such as morphine and amphetamine on the synaptic organization of neurons in the orbital frontal (OFC) and medial frontal (mPFC) regions in the rat. Both regions are altered chronically by exposure to intermittent doses of either drug but the effects are area-dependent. For example, whereas morphine…

  18. Lhx1 functions together with Otx2, Foxa2, and Ldb1 to govern anterior mesendoderm, node, and midline development

    PubMed Central

    Costello, Ita; Nowotschin, Sonja; Sun, Xin; Mould, Arne W.; Hadjantonakis, Anna-Katerina; Bikoff, Elizabeth K.; Robertson, Elizabeth J.

    2015-01-01

    Gene regulatory networks controlling functional activities of spatially and temporally distinct endodermal cell populations in the early mouse embryo remain ill defined. The T-box transcription factor Eomes, acting downstream from Nodal/Smad signals, directly activates the LIM domain homeobox transcription factor Lhx1 in the visceral endoderm. Here we demonstrate Smad4/Eomes-dependent Lhx1 expression in the epiblast marks the entire definitive endoderm lineage, the anterior mesendoderm, and midline progenitors. Conditional inactivation of Lhx1 disrupts anterior definitive endoderm development and impedes node and midline morphogenesis in part due to severe disturbances in visceral endoderm displacement. Transcriptional profiling and ChIP-seq (chromatin immunoprecipitation [ChIP] followed by high-throughput sequencing) experiments identified Lhx1 target genes, including numerous anterior definitive endoderm markers and components of the Wnt signaling pathway. Interestingly, Lhx1-binding sites were enriched at enhancers, including the Nodal-proximal epiblast enhancer element and enhancer regions controlling Otx2 and Foxa2 expression. Moreover, in proteomic experiments, we characterized a complex comprised of Lhx1, Otx2, and Foxa2 as well as the chromatin-looping protein Ldb1. These partnerships cooperatively regulate development of the anterior mesendoderm, node, and midline cell populations responsible for establishment of the left–right body axis and head formation. PMID:26494787

  19. Treatment of Schatzker Type V and VI Tibial Plateau Fractures Using a Midline Longitudinal Incision and Dual Plating

    PubMed Central

    Cho, Kye-Youl; Oh, Hyun-Sup; Yoo, Jae-Ho; Kim, Duk-Hyun; Cho, Young-Joo

    2013-01-01

    Purpose The purpose of this study was to evaluate the results of the treatment of Schatzker type V and VI tibial plateau fractures using a midline longitudinal incision and dual-plate fixation. Materials and Methods Ten patients with Schatzker type V and VI tibial plateau fractures treated with a midline longitudinal incision and dual plating were analyzed. The patients were followed for a minimum of one year. Clinical outcomes were evaluated using range of motion, visual analogue scale (VAS) and Knee Society Score. Radiological outcomes were evaluated using the bony union time, medial proximal tibial angle (MPTA) and posterior proximal tibial angle (PPTA). Results The mean VAS score was 2.2 points, and the mean Knee Society function score was 85 points at the final follow-up. The mean flexion contracture was 2.5° and the mean further flexion was 125°. It took an average of 4 months until bony union occurred. The mean MPTA and PPTA were 90.5° and 4.4°, respectively. There was one case of delayed wound healing, but no other complications were observed. Conclusions The treatment of Schatzker type V and VI tibial plateau fractures with a midline longitudinal incision and dual-plate fixation resulted in satisfactory clinical and radiological outcomes. This can be an option when treating Schatzker type V and VI tibial plateau fractures. PMID:23741703

  20. Syk kinases are required for spinal commissural axon repulsion at the midline via the ephrin/Eph pathway.

    PubMed

    Noraz, Nelly; Jaaoini, Iness; Charoy, Camille; Watrin, Chantal; Chounlamountri, Naura; Benon, Aurélien; Malleval, Céline; Boudin, Hélène; Honnorat, Jérôme; Castellani, Valérie; Pellier-Monnin, Véronique

    2016-06-15

    In the hematopoietic system, Syk family tyrosine kinases are essential components of immunoreceptor ITAM-based signaling. While there is increasing data indicating the involvement of immunoreceptors in neural functions, the contribution of Syk kinases remains obscure. Previously, we identified phosphorylated forms of Syk kinases in specialized populations of migrating neurons or projecting axons. Moreover, we identified ephrin/Eph as guidance molecules utilizing the ITAM-bearing CD3zeta (Cd247) and associated Syk kinases for the growth cone collapse response induced in vitro Here, we show that in the developing spinal cord, Syk is phosphorylated in navigating commissural axons. By analyzing axon trajectories in open-book preparations of Syk(-/-); Zap70(-/-) mouse embryos, we show that Syk kinases are dispensable for attraction towards the midline but confer growth cone responsiveness to repulsive signals that expel commissural axons from the midline. Known to serve a repulsive function at the midline, ephrin B3/EphB2 are obvious candidates for driving the Syk-dependent repulsive response. Indeed, Syk kinases were found to be required for ephrin B3-induced growth cone collapse in cultured commissural neurons. In fragments of commissural neuron-enriched tissues, Syk is in a constitutively phosphorylated state and ephrin B3 decreased its level of phosphorylation. Direct pharmacological inhibition of Syk kinase activity was sufficient to induce growth cone collapse. In conclusion, Syk kinases act as a molecular switch of growth cone adhesive and repulsive responses. PMID:27122172

  1. Causal evidence for frontal cortex organization for perceptual decision making.

    PubMed

    Rahnev, Dobromir; Nee, Derek Evan; Riddle, Justin; Larson, Alina Sue; D'Esposito, Mark

    2016-05-24

    Although recent research has shown that the frontal cortex has a critical role in perceptual decision making, an overarching theory of frontal functional organization for perception has yet to emerge. Perceptual decision making is temporally organized such that it requires the processes of selection, criterion setting, and evaluation. We hypothesized that exploring this temporal structure would reveal a large-scale frontal organization for perception. A causal intervention with transcranial magnetic stimulation revealed clear specialization along the rostrocaudal axis such that the control of successive stages of perceptual decision making was selectively affected by perturbation of successively rostral areas. Simulations with a dynamic model of decision making suggested distinct computational contributions of each region. Finally, the emergent frontal gradient was further corroborated by functional MRI. These causal results provide an organizational principle for the role of frontal cortex in the control of perceptual decision making and suggest specific mechanistic contributions for its different subregions. PMID:27162349

  2. Causal evidence for frontal cortex organization for perceptual decision making

    PubMed Central

    Nee, Derek Evan; Riddle, Justin; Larson, Alina Sue; D’Esposito, Mark

    2016-01-01

    Although recent research has shown that the frontal cortex has a critical role in perceptual decision making, an overarching theory of frontal functional organization for perception has yet to emerge. Perceptual decision making is temporally organized such that it requires the processes of selection, criterion setting, and evaluation. We hypothesized that exploring this temporal structure would reveal a large-scale frontal organization for perception. A causal intervention with transcranial magnetic stimulation revealed clear specialization along the rostrocaudal axis such that the control of successive stages of perceptual decision making was selectively affected by perturbation of successively rostral areas. Simulations with a dynamic model of decision making suggested distinct computational contributions of each region. Finally, the emergent frontal gradient was further corroborated by functional MRI. These causal results provide an organizational principle for the role of frontal cortex in the control of perceptual decision making and suggest specific mechanistic contributions for its different subregions. PMID:27162349

  3. Kolmogorov and trigonometric widths of the Besov classes B^r_{p,\\theta} of multivariate periodic functions

    NASA Astrophysics Data System (ADS)

    Romanyuk, A. S.

    2006-02-01

    Precise (in order) estimates of the Kolmogorov widths in the space L_q, 1, of the classes B^r_{1,\\theta} and B^r_{\\infty,\\theta} and also of the trigonometric widths of the classes B^r_{p,\\theta} in L_q for p and q satisfying certain relations are obtained.

  4. The Organization of Dorsal Frontal Cortex in Humans and Macaques

    PubMed Central

    Mars, Rogier B.; Noonan, MaryAnn P.; Neubert, Franz-Xaver; Jbabdi, Saad; O'Reilly, Jill X.; Filippini, Nicola; Thomas, Adam G.; Rushworth, Matthew F.

    2013-01-01

    The human dorsal frontal cortex has been associated with the most sophisticated aspects of cognition, including those that are thought to be especially refined in humans. Here we used diffusion-weighted magnetic resonance imaging (DW-MRI) and functional MRI (fMRI) in humans and macaques to infer and compare the organization of dorsal frontal cortex in the two species. Using DW-MRI tractography-based parcellation, we identified 10 dorsal frontal regions lying between the human inferior frontal sulcus and cingulate cortex. Patterns of functional coupling between each area and the rest of the brain were then estimated with fMRI and compared with functional coupling patterns in macaques. Areas in human medial frontal cortex, including areas associated with high-level social cognitive processes such as theory of mind, showed a surprising degree of similarity in their functional coupling patterns with the frontal pole, medial prefrontal, and dorsal prefrontal convexity in the macaque. We failed to find evidence for “new” regions in human medial frontal cortex. On the lateral surface, comparison of functional coupling patterns suggested correspondences in anatomical organization distinct from those that are widely assumed. A human region sometimes referred to as lateral frontal pole more closely resembled area 46, rather than the frontal pole, of the macaque. Overall the pattern of results suggest important similarities in frontal cortex organization in humans and other primates, even in the case of regions thought to carry out uniquely human functions. The patterns of interspecies correspondences are not, however, always those that are widely assumed. PMID:23884933

  5. Spin asymmetries in {gamma} N {yields} {bar K}* {Theta}{sup +}

    SciTech Connect

    Yongseok Oh; Hungchong Kim; Su Houng Lee

    2004-11-01

    The photoproduction processes of the exotic {Theta}{sup +}(1540) baryon and the K* meson from the nucleon targets, i.e., {gamma}n {yields} K*{sup -} {Theta}{sup +} and {gamma}p {yields} {bar K}*{sup 0}{Theta}{sup +} are investigated in a hadronic model. We consider K and K* exchanges as well as the s and u channel nucleon and {Theta} terms. Various spin asymmetries together with cross sections are first computed in order to study the production mechanisms and the parity of the {Theta}{sup +}(1540) baryon. Within the uncertainties arising from the model-dependence of the production mechanisms and several coupling constants, we find that some target-recoil double spin asymmetries, C{sub xx{prime}}{sup TR} and C{sub xx{prime}}{sup TR} are sensitive to the parity of {Theta}{sup +}. In addition, the parity asymmetry of this reaction on the neutron target, which can be obtained by analyzing K* decay distribution, is found to be useful to estimate the K* N{Theta} coupling.

  6. Someone has to give in: theta oscillations correlate with adaptive behavior in social bargaining

    PubMed Central

    Zamorano, Francisco; López, Tamara; Rodriguez, Carlos; Cosmelli, Diego; Aboitiz, Francisco

    2014-01-01

    During social bargain, one has to both figure out the others’ intentions and behave strategically in such a way that the others’ behaviors will be consistent with one’s expectations. To understand the neurobiological mechanisms underlying these behaviors, we used electroencephalography while subjects played as proposers in a repeated ultimatum game. We found that subjects adapted their offers to obtain more acceptances in the last round and that this adaptation correlated negatively with prefrontal theta oscillations. People with higher prefrontal theta activity related to a rejection did not adapt their offers along the game to maximize their earning. Moreover, between-subject variation in posterior theta oscillations correlated positively with how individual theta activity influenced the change of offer after a rejection, reflecting a process of behavioral adaptation to the others’ demands. Interestingly, people adapted better their offers when they knew that they where playing against a computer, although the behavioral adaptation did not correlate with prefrontal theta oscillation. Behavioral changes between human and computer games correlated with prefrontal theta activity, suggesting that low adaptation in human games could be a strategy. Taken together, these results provide evidence for specific roles of prefrontal and posterior theta oscillations in social bargaining. PMID:24493841

  7. Photoproduction of the \\Theta^+ resonance on the nucleon in a Regge model

    SciTech Connect

    H. Kwee; M. Guidal; M. Polyakov; M. Vanderhaeghen

    2005-09-15

    We estimate the reaction mechanisms for the photoproduction of the {Theta}{sup +}(1540) resonance on the nucleon, through K and K* Regge exchanges. We compare the size of the cross sections for the {gamma}n {yields} K{sup -} {Theta}{sup +} and {gamma}p {yields} {bar K}{sup 0} {Theta}{sup +} reactions, and investigate their sensitivity to the spin-parity assignments J{sup P} = (1/2){sup {+-}}, (3/2){sup {+-}} for the {Theta}{sup +} resonance. The model allows to estimate the cross sections corresponding with a given upper bound on the width of the {Theta}{sup +}. Within this model, the cross sections on the neutron are found to be around a factor 5 larger than the ones on the proton, due to the presence of charged K exchange for the reaction on a neutron target. Furthermore, the photon asymmetry is found to display a pronounced sensitivity to the parity of the {Theta}{sup +}, making it a very promising observable to help determining the quantum numbers of the {Theta}{sup +} resonance.

  8. Developmental change in EEG theta activity in the medial prefrontal cortex during response control.

    PubMed

    Liu, Zhong-Xu; Woltering, Steven; Lewis, Marc D

    2014-01-15

    Cognitive control functions continue to improve from infancy until early adulthood, allowing flexible adaptation to a complex environment. However, it remains controversial how this development in cognitive capabilities is mediated by changes in cortical activity: both age-related increases and decreases of mediofrontal neural activity have been observed and interpreted as neural underpinnings of this functional development. To better understand this developmental process, we examined EEG theta activity in the mediofrontal region using a Go/No-go response control task. We found that both pre-stimulus baseline theta-power and theta-power during the response control task, without baseline-correction, decreased with age. Conversely, when task-related theta-power was baseline corrected (using a ratio method), it exhibited a positive developmental trajectory. The age-related theta-power increase was source-localized to the anterior cingulate cortex. This increase in theta activity also partially mediated age-related improvements in response control and was greatest in a condition that demanded greater effort. Theta activity in older children also showed greater temporal reliability across trials as measured by inter-trial phase-coherence. Interestingly, directly subtracting baseline activity from task-related activity did not yield significant developmental effects, which highlights the necessity of separating and contrasting the pre-stimulus baseline with task-related processing in the understanding of neurodevelopmental changes. PMID:24007804

  9. The expression of the T-box selector gene midline in the leg imaginal disc is controlled by both transcriptional regulation and cell lineage

    PubMed Central

    Svendsen, Pia C.; Ryu, Jae-Ryeon; Brook, William J.

    2015-01-01

    ABSTRACT The Drosophila Tbx20 homologs midline and H15 act as selector genes for ventral fate in Drosophila legs. midline and H15 expression defines the ventral domain of the leg and the two genes are necessary and sufficient for the development of ventral fate. Ventral-specific expression of midline and H15 is activated by Wingless (Wg) and repressed by Decapentaplegic (Dpp). Here we identify VLE, a 5 kb enhancer that drives ventral specific expression in the leg disc that is very similar to midline expression. Subdivision of VLE identifies two regions that mediate both activation and repression and third region that only mediates repression. Loss- and gain-of-function genetic mosaic analysis shows that the activating and repressing regions respond to Wg and Dpp signaling respectively. All three repression regions depend on the activity of Mothers-against-decapentaplegic, a Drosophila r-Smad that mediates Dpp signaling, and respond to ectopic expression of the Dpp target genes optomoter-blind and Dorsocross 3. However, only one repression region is responsive to loss of schnurri, a co-repressor required for direct repression by Dpp-signaling. Thus, Dpp signaling restricts midline expression through both direct repression and through the activation of downstream repressors. We also find that midline and H15 expression are both subject to cross-repression and feedback inhibition. Finally, a lineage analysis indicates that ventral midline-expressing cells and dorsal omb-expressing cells do not mix during development. Together this data indicates that the ventral-specific expression of midline results from both transcriptional regulation and from a lack of cell-mixing between dorsal and ventral cells. PMID:26581591

  10. Frontal delta event-related oscillations relate to frontal volume in mild cognitive impairment and healthy controls.

    PubMed

    Yener, Görsev G; Emek-Savaş, Derya Durusu; Lizio, Roberta; Çavuşoğlu, Berrin; Carducci, Filippo; Ada, Emel; Güntekin, Bahar; Babiloni, Claudio C; Başar, Erol

    2016-05-01

    Amnesic mild cognitive impairment (MCI) represents a risk of developing Alzheimer's disease (AD), but not all MCI subjects progress to dementia of AD type. Magnetic resonance imaging (MRI) of cortical and hippocampal atrophy supports early diagnosis of AD in MCI subjects, while frontal event-related oscillations (EROs) at delta frequencies (<4Hz) are appealing markers for this purpose, as they are both cost-effective and largely available. The present study tested the hypothesis that these EROs reflect cortical frontal neurodegeneration in the continuum between normal and amnesic MCI subjects. EROs and volumetric MRI data were recorded in 28 amnesic MCI and in 28 healthy elderly controls (HCs). EROs were collected during a standard visual oddball paradigm including frequent (66.6%) and rare (33.3%; targets to be mentally counted) stimuli. Peak-to-peak amplitude of delta target EROs (<4Hz) was measured. Volume of frontal cortex was estimated from MRIs. Frontal volume was lower in MCI compared to the HC group. Furthermore, widespread delta target EROs were lower in amplitude in the former than in the latter group. Finally, there was a positive correlation between frontal volume and frontal delta target EROs in MCI and HC subjects as a whole group. These results suggest that frontal delta EROs reflect frontal neurodegeneration in the continuum between normal and amnesic MCI subjects. PMID:25660300

  11. Craniovertebral junction instability as an extension of cocaine-induced midline destructive lesions: case report.

    PubMed

    Brembilla, Carlo; Lanterna, Luigi Andrea; Risso, Andrea; Bombana, Enrico; Gritti, Paolo; Trezzi, Rosangela; Bonaldi, Giuseppe; Biroli, Francesco

    2015-08-01

    With the increasingly widespread illicit use of cocaine, a broad spectrum of clinical pathologies related to this form of drug abuse is emerging. The most frequently used method of administration of powdered cocaine is intranasal inhalation, or "snorting." Consequently, adverse effects of cocaine on the nasal tract are common. Habitual nasal insufflations of cocaine can cause mucosal lesions. If cocaine use becomes chronic and compulsive, progressive damage of the mucosa and perichondrium leads to ischemic necrosis of the septal cartilage and perforation of the nasal septum. Occasionally, cocaine-induced lesions cause extensive destruction of the osteocartilaginous structures of the nose, sinuses, and palate and can mimic other diseases such as tumors, infections, and immunological diseases. In the literature currently available, involvement of the craniovertebral junction in the cocaine-induced midline destructive lesions (CIMDLs) has never been reported. The present case concerns a 44-year-old man who presented with long-standing symptoms including nasal obstruction, epistaxis, dysphagia, nasal reflux, and severe neck pain. A diagnosis of CIMDL was made in light of the patient's history and the findings on physical and endoscopic examinations, imaging studies, and laboratory testing. Involvement of the craniovertebral junction in the destructive process was evident. For neurosurgical treatment, the authors considered the high grade of atlantoaxial instability, the poorly understood cocaine-induced lesions of the spine and their potential evolution overtime, as well as cocaine abusers' poor compliance. The patient underwent posterior craniovertebral fixation. Understanding, classifying, and treating cocaine-induced lesions involving the craniovertebral junction are a challenge. PMID:25955800

  12. Time-lapse imaging reveals stereotypical patterns of Drosophila midline glial migration.

    PubMed

    Wheeler, Scott R; Pearson, Joseph C; Crews, Stephen T

    2012-01-15

    The Drosophila CNS midline glia (MG) are multifunctional cells that ensheath and provide trophic support to commissural axons, and direct embryonic development by employing a variety of signaling molecules. These glia consist of two functionally distinct populations: the anterior MG (AMG) and posterior MG (PMG). Only the AMG ensheath axon commissures, whereas the function of the non-ensheathing PMG is unknown. The Drosophila MG have proven to be an excellent system for studying glial proliferation, cell fate, apoptosis, and axon-glial interactions. However, insight into how AMG migrate and acquire their specific positions within the axon-glial scaffold has been lacking. In this paper, we use time-lapse imaging, single-cell analysis, and embryo staining to comprehensively describe the proliferation, migration, and apoptosis of the Drosophila MG. We identified 3 groups of MG that differed in the trajectories of their initial inward migration: AMG that migrate inward and to the anterior before undergoing apoptosis, AMG that migrate inward and to the posterior to ensheath commissural axons, and PMG that migrate inward and to the anterior to contact the commissural axons before undergoing apoptosis. In a second phase of their migration, the surviving AMG stereotypically migrated posteriorly to specific positions surrounding the commissures, and their final position was correlated with their location prior to migration. Most noteworthy are AMG that migrated between the commissures from a ventral to a dorsal position. Single-cell analysis indicated that individual AMG possessed wide-ranging and elaborate membrane extensions that partially ensheathed both commissures. These results provide a strong foundation for future genetic experiments to identify mutants affecting MG development, particularly in guidance cues that may direct migration. Drosophila MG are homologous in structure and function to the glial-like cells that populate the vertebrate CNS floorplate, and study

  13. NUCLEUS REUNIENS OF THE MIDLINE THALAMUS: LINK BETWEEN THE MEDIAL PREFRONTAL CORTEX AND THE HIPPOCAMPUS

    PubMed Central

    Vertes, Robert P.; Hoover, Walter B.; Szigeti-Buck, Klara; Leranth, Csaba

    2016-01-01

    The medial prefrontal cortex and the hippocampus serve well recognized roles in memory processing. The hippocampus projects densely to, and exerts strong excitatory actions on, the medial prefrontal cortex. Interestingly, the medial prefrontal cortex, in rats and other species, has no direct return projections to the hippocampus, and few projections to parahippocampal structures including the entorhinal cortex. It is well established that the nucleus reuniens of the midline thalamus is the major source of thalamic afferents to the hippocampus. Since the medial prefrontal cortex also distributes to nucleus reuniens, we examined medial prefrontal connections with populations of nucleus reuniens neurons projecting to hippocampus. We used a combined anterograde and retrograde tracing procedure at the light and electron microscopic levels. Specifically, we made Phaseolus vulgaris-leuccoagglutinin (PHA-L) injections into the medial prefrontal cortex and Fluorogold injections into the hippocampus (CA1/subiculum) and examined termination patterns of anterogradely PHA-L labeled fibers on retrogradely FG labeled cells of nucleus reuniens. At the light microscopic level, we showed that fibers from the medial prefrontal cortex form multiple putative synaptic contacts with dendrites of hippocampally projecting neurons throughout the extent of nucleus reuniens. At ultrastructural level, we showed that medial prefrontal cortical fibers form asymmetric contacts predominantly with dendritic shafts of hippocampally projecting reuniens cells. These findings indicate that nucleus reuniens represents a critical link between the medial prefrontal cortex and the hippocampus. We discuss the possibility that nucleus reuniens gates the flow of information between the medial prefrontal cortex and hippocampus dependent upon attentive/arousal states of the organism. PMID:17292803

  14. Time-lapse Imaging Reveals Stereotypical Patterns of Drosophila Midline Glial Migration

    PubMed Central

    Wheeler, Scott R.; Pearson, Joseph C.; Crews, Stephen T.

    2011-01-01

    The Drosophila CNS midline glia (MG) are multifunctional cells that ensheath and provide trophic support to commissural axons, and direct embryonic development by employing a variety of signaling molecules. These glia consist of two functionally distinct populations: the anterior MG (AMG) and posterior MG (PMG). Only the AMG ensheath axon commissures, whereas the function of the non-ensheathing PMG is unknown. The Drosophila MG have proven to be an excellent system for studying glial proliferation, cell fate, apoptosis, and axon-glial interactions. However, insight into how AMG migrate and acquire their specific positions within the axon-glial scaffold has been lacking. In this paper, we use time-lapse imaging, single-cell analysis, and embryo staining to comprehensively describe the proliferation, migration, and apoptosis of the Drosophila MG. We identified 3 groups of MG that differed in the trajectories of their initial inward migration: AMG that migrate inward and to the anterior before undergoing apoptosis, AMG that migrate inward and to the posterior to ensheath commissural axons, and PMG that migrate inward and to the anterior to contact the commissural axons before undergoing apoptosis. In a second phase of their migration, the surviving AMG stereotypically migrated posteriorly to specific positions surrounding the commissures, and their final position was correlated with their location prior to migration. Most noteworthy are AMG that migrated between the commissures from a ventral to a dorsal position. Single-cell analysis indicated that individual AMG possessed wide-ranging and elaborate membrane extensions that partially ensheathed both commissures. These results provide a strong foundation for future genetic experiments to identify mutants affecting MG development, particularly in guidance cues that may direct migration. Drosophila MG are homologous in structure and function to the glial-like cells that populate the vertebrate CNS floorplate, and study

  15. A Philosophical Perspective on the Relation between Cortical Midline Structures and the Self

    PubMed Central

    Musholt, Kristina

    2013-01-01

    In recent years there has been increasing evidence that an area in the brain called the cortical midline structures (CMSs) is implicated in what has been termed self-related processing. This article will discuss recent evidence for the relation between CMS and self-consciousness in light of several important philosophical distinctions. First, we should distinguish between being a self (i.e., being a subject of conscious experience) and being aware of being a self (i.e., being able to think about oneself as such). While the former consists in having a first-person perspective on the world, the latter requires the ability to explicitly represent one’s own perspective as such. Further, we should distinguish between being aware of oneself “as subject” and being aware of oneself “as object.” The focus of existing studies investigating the relation between CMS and self has been predominantly on the ability to think about oneself (and in particular thinking of oneself “as object”), while the more basic aspects involved in being a self have been neglected. However, it is important to widen the scope of the cognitive neuroscience to include the latter, not least because this might have important implications for a better understanding of disorders of the self, such as those involved in schizophrenia. In order to do so, cognitive neuroscience should work together with philosophy, including phenomenology. Second, we need to distinguish between personal and subpersonal level explanations. It will be argued that although it is important to respect this distinction, in principle, some subpersonal facts can enter into constitutive conditions of personal-level phenomena. However, in order for this to be possible, one needs both careful conceptual analysis and knowledge about relevant cognitive mechanisms. PMID:24032013

  16. Hippocampal Non-Theta-Contingent Eyeblink Classical Conditioning: A Model System for Neurobiological Dysfunction

    PubMed Central

    Cicchese, Joseph J.; Berry, Stephen D.

    2016-01-01

    Typical information processing is thought to depend on the integrity of neurobiological oscillations that may underlie coordination and timing of cells and assemblies within and between structures. The 3–7 Hz bandwidth of hippocampal theta rhythm is associated with cognitive processes essential to learning and depends on the integrity of cholinergic, GABAergic, and glutamatergic forebrain systems. Since several significant psychiatric disorders appear to result from dysfunction of medial temporal lobe (MTL) neurochemical systems, preclinical studies on animal models may be an important step in defining and treating such syndromes. Many studies have shown that the amount of hippocampal theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning and attainment of asymptotic performance. Our lab has developed a brain–computer interface that makes eyeblink training trials contingent upon the explicit presence or absence of hippocampal theta. The behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to fourfold increase in learning speed over non-theta states. The non-theta behavioral impairment is accompanied by disruption of the amplitude and synchrony of hippocampal local field potentials, multiple-unit excitation, and single-unit response patterns dependent on theta state. Our findings indicate a significant electrophysiological and behavioral impact of the pretrial state of the hippocampus that suggests an important role for this MTL system in associative learning and a significant deleterious impact in the absence of theta. Here, we focus on the impairments in the non-theta state, integrate them into current models of psychiatric disorders, and suggest how improvement in our understanding of neurobiological oscillations is critical for theories and treatment of psychiatric

  17. A critical test of the hippocampal theta model of anxiolytic drug action.

    PubMed

    Yeung, Michelle; Treit, Dallas; Dickson, Clayton T

    2012-01-01

    Hippocampal theta rhythms have been associated with a number of behavioural processes, including learning, memory and arousal. Recently it has been argued that the suppression of hippocampal theta is a valid indicator of anxiolytic drug action. Like all such models, however, it has relied almost exclusively on the experimental effects of well-known, clinically proven anxiolytic compounds for validation. The actual predictive validity of putative models of anxiolytic drug action, however, cannot be rigorously tested with this approach alone. The present study provides a stringent test of the predictive validity of the theta suppression model, using the drug phenytoin (50 mg/kg and 10 mg/kg), and a positive comparison compound, diazepam (2 mg/kg). Phenytoin has two important properties that are advantageous for assessing the validity of the theta suppression model: 1) it is a standard antiepileptic drug with no known anxiolytic effects, and 2) its primary mechanism of action is through suppression of the persistent sodium current, an effect that should also suppress hippocampal theta. Because of the latter property, we also directly compared the effects of phenytoin in the theta suppression model with its effects in the most widely tested behavioural model of anxiolytic drug action, the elevated plus-maze. While an anxiolytic-like effect of phenytoin in the theta suppression model might be expected simply due to its suppressive effects on sodium channel currents, anxiolytic effects in both tests would provide strong support for the predictive validity of the theta suppression model. Surprisingly, phenytoin produced clear anxiolytic-like effects in both neurophysiological and behavioural models, thus providing strong evidence of the predictive validity of the theta suppression model. This article is part of a Special Issue entitled 'Anxiety and Depression'. PMID:21723303

  18. Hippocampal Non-Theta-Contingent Eyeblink Classical Conditioning: A Model System for Neurobiological Dysfunction.

    PubMed

    Cicchese, Joseph J; Berry, Stephen D

    2016-01-01

    Typical information processing is thought to depend on the integrity of neurobiological oscillations that may underlie coordination and timing of cells and assemblies within and between structures. The 3-7 Hz bandwidth of hippocampal theta rhythm is associated with cognitive processes essential to learning and depends on the integrity of cholinergic, GABAergic, and glutamatergic forebrain systems. Since several significant psychiatric disorders appear to result from dysfunction of medial temporal lobe (MTL) neurochemical systems, preclinical studies on animal models may be an important step in defining and treating such syndromes. Many studies have shown that the amount of hippocampal theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning and attainment of asymptotic performance. Our lab has developed a brain-computer interface that makes eyeblink training trials contingent upon the explicit presence or absence of hippocampal theta. The behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to fourfold increase in learning speed over non-theta states. The non-theta behavioral impairment is accompanied by disruption of the amplitude and synchrony of hippocampal local field potentials, multiple-unit excitation, and single-unit response patterns dependent on theta state. Our findings indicate a significant electrophysiological and behavioral impact of the pretrial state of the hippocampus that suggests an important role for this MTL system in associative learning and a significant deleterious impact in the absence of theta. Here, we focus on the impairments in the non-theta state, integrate them into current models of psychiatric disorders, and suggest how improvement in our understanding of neurobiological oscillations is critical for theories and treatment of psychiatric

  19. Transverse Skin Crease versus Vertical Midline Incision versus Laparoscopy for Right Hemicolectomy: A Systematic Review—Current Status of Right Hemicolectomy

    PubMed Central

    Santoro, Alberto; Gubbiotti, Francesca; Di Rocco, Giorgio

    2014-01-01

    Purpose. The right hemicolectomy may be conducted through laparoscopic or laparotomic surgery, transverse or midline incisions. The transverse laparotomy offers some advantages compared to the midline laparotomy and laparoscopy. A literature review was performed to evaluate the possible advantages of the transverse incision versus midline incision or laparoscopic right hemicolectomy. Methods. A systematic research was performed in Medline, Embase, Cochrane Central Register of Controlled Trials, CINAHL, BioMed Central, and the Science Citation Index. Results. Laparotomic right hemicolectomy with transverse incision is preferable to laparotomic hemicolectomy with midline incision. A transverse incision offers a lessened postoperative pain following physical activity, a lessened need to administer analgesic therapy during the post-operative time, better aesthetic results, and a better post-operative pulmonary function. Open surgery with transverse or midline incision ensured a shorter operative time, lower costs and a greater length of the incision compared to the laparoscopic. However, there are no differences in the oncological outcomes. Conclusions. It was not possible to identify significant differences between the open right hemicolectomy with transverse incision versus the open right hemicolectomy with midline incision or laparoscopic hemicolectomy. PMID:24605333

  20. Inhibitory control and the frontal eye fields.

    PubMed

    Muggleton, Neil G; Chen, Chiao-Yun; Tzeng, Ovid J L; Hung, Daisy L; Juan, Chi-Hung

    2010-12-01

    Inhibitory control mechanisms are important in a range of behaviors to prevent execution of motor acts which, having been planned, are no longer necessary. Ready examples of this can be seen in a range of sports, such as cricket and baseball, where the choice between execution or inhibition of a bat swing must be made in a brief time interval. The role of the FEFs, an area typically described in relation to eye movement functions but also involved in visual processes, was investigated in an inhibitory control task using transcranial magnetic stimulation (TMS). A stop signal task with manual responses was used, providing measures of impulsivity and inhibitory control. TMS over FEF had no effect on response generation (impulsivity, indexed by go signal RT) but disrupted inhibitory control (indexed by stop signal RT). This is the first demonstration of a role for FEF in this type of task in normal subjects in a task which did not require eye movements and complements previous TMS findings of roles for pre-SMA and inferior frontal gyrus (IFG) in inhibitory control. PMID:20044887

  1. Wheelchair caster loading during frontal impact.

    PubMed

    Bertocci, Gina E; van Roosmalen, Linda

    2003-01-01

    Many wheelchair users are required or choose to use their wheelchairs as a motor vehicle seat during transport. It is therefore key that the wheelchair components be designed to tolerate crash-level loading conditions. Casters are particularly prone to failure under crash loading conditions. Our study evaluated wheelchair caster loading during 20g/48 kph frontal sled impact testing using an 85-kg surrogate wheelchair base (SWCB) with casters positioned on a load-measuring platform. A Hybrid III 50th percentile male test dummy was seated in the SWCB, which simulated a power wheelchair and was secured using four-point tiedowns. Various rear securement point heights and wheelchair seating systems were used to study their effect on caster loading. Caster normal loading was found to vary from 769 to 7,209 N depending on rear securement location and integrity of the seating system. Dynamic sled impact test results showed that normal loading of the front wheelchair casters was influenced by wheelchair seating system integrity and rear wheelchair securement height. Shear loading varied from 781 to 1,589 N and did not appear to be dependent on seat integrity or rear securement height. The load/time histories measured during dynamic impact testing can be used to guide the development of transit-safe caster design. PMID:15137727

  2. Impulsivity, Frontal Lobes and Risk for Addiction

    PubMed Central

    Crews, Fulton Timm; Boettiger, Charlotte Ann

    2009-01-01

    Alcohol and substance abuse disorders involve continued use of substances despite negative consequences, i.e. loss of behavioral control of drug use. The frontal cortical areas of brain oversee behavioral control through executive functions. Executive functions include abstract thinking, motivation, planning, attention to tasks and inhibition of impulsive responses. Impulsiveness generally refers to premature, unduly risky, poorly conceived actions. Dysfunctional impulsivity includes deficits in attention, lack of reflection and/or insensitivity to consequences, all of which occur in addiction (Evenden, 1999; (de Wit, 2009). Binge drinking models indicate chronic alcohol damages corticolimbic brain regions (Crews et al., 2000) causing reversal learning deficits indicative of loss of executive function (Obernier et al., 2002b). Genetics and adolescent age are risk factors for alcoholism that coincide with sensitivity to alcohol induced neurotoxicity. Cortical degeneration from alcohol abuse may increase impulsivity contributing to the development, persistence and severity of alcohol use disorders. Interestingly, abstinence results in bursts of neurogenesis and brain regrowth (Crews and Nixon, 2009). Treatments for alcoholism, including naltrexone pharmacotherapy and psychotherapy may work through improving executive functions. This review will examine the relationships between impulsivity and executive function behaviors to changes in cortical structure during alcohol dependence and recovery. PMID:19410598

  3. Theta-rhythmic drive between medial septum and hippocampus in slow-wave sleep and microarousal: a Granger causality analysis.

    PubMed

    Kang, D; Ding, M; Topchiy, I; Shifflett, L; Kocsis, B

    2015-11-01

    Medial septum (MS) plays a critical role in controlling the electrical activity of the hippocampus (HIPP). In particular, theta-rhythmic burst firing of MS neurons is thought to drive lasting HIPP theta oscillations in rats during waking motor activity and REM sleep. Less is known about MS-HIPP interactions in nontheta states such as non-REM sleep, in which HIPP theta oscillations are absent but theta-rhythmic burst firing in subsets of MS neurons is preserved. The present study used Granger causality (GC) to examine the interaction patterns between MS and HIPP in slow-wave sleep (SWS, a nontheta state) and during its short interruptions called microarousals (a transient theta state). We found that during SWS, while GC revealed a unidirectional MS→HIPP influence over a wide frequency band (2-12 Hz, maximum: ∼8 Hz), there was no theta peak in the hippocampal power spectra, indicating a lack of theta activity in HIPP. In contrast, during microarousals, theta peaks were seen in both MS and HIPP power spectra and were accompanied by bidirectional GC with MS→HIPP and HIPP→MS theta drives being of equal magnitude. Thus GC in a nontheta state (SWS) vs. a theta state (microarousal) primarily differed in the level of HIPP→MS. The present findings suggest a modification of our understanding of the role of MS as the theta generator in two regards. First, a MS→HIPP theta drive does not necessarily induce theta field oscillations in the hippocampus, as found in SWS. Second, HIPP theta oscillations entail bidirectional theta-rhythmic interactions between MS and HIPP. PMID:26354315

  4. Effects of intermittent theta burst stimulation on spasticity after stroke.

    PubMed

    Kim, Dae Hyun; Shin, Ji Cheol; Jung, Seungsoo; Jung, Tae-Min; Kim, Deog Young

    2015-07-01

    Spasticity is a common cause of long-term disability in poststroke hemiplegic patients. We investigated whether intermittent theta burst stimulation (iTBS) could reduce upper-limb spasticity after a stroke. Fifteen hemiplegic stroke patients were recruited for a double-blind sham-controlled cross-over design study. A single session of iTBS or sham stimulation was delivered on the motor hotspot of the affected flexor carpi radialis muscle in a random and counterbalanced order with a 1-week interval. Modified Ashworth scale (MAS), modified Tardieu scale (MTS), H-wave/M-wave amplitude ratio, peak torque (PT), peak torque angle (PTA), work of affected wrist flexor, and rectified integrated electromyographic activity of the flexor carpi radialis muscle were measured before, immediately after, 30 min after, and 1 week after iTBS or sham stimulation. Repeated-measures analysis of variance showed a significant interaction between time and intervention for the MAS, MTS, PT, PTA, and rectified integrated electromyographic activity (P<0.05), indicating that these parameters were significantly improved by iTBS compared with sham stimulation. However, the H-wave/M-wave amplitude ratio and work were not affected. MAS and MTS significantly improved for at least 30 min after iTBS, but the other parameters only improved immediately after iTBS (P<0.05). In conclusion, iTBS on the affected hemisphere may help to reduce poststroke spasticity transiently. PMID:26011507

  5. Mammalian Polymerase Theta Promotes Alternative-NHEJ and Suppresses Recombination

    PubMed Central

    Mateos-Gomez, Pedro A.; Gong, Fade; Nair, Nidhi; Miller, Kyle M.; Lazzerini-Denchi, Eros; Sfeir, Agnel

    2016-01-01

    The alternative nonhomologous end-joining (alt-NHEJ) machinery facilitates a number of genomic rearrangements, some of which can lead to cellular transformation. This error-prone repair pathway is triggered upon telomere de-protection to promote the formation of deleterious chromosome end-to-end fusions1,2,3. Using next-generation sequencing technology, we found that repair by alt-NHEJ yields non-TTAGGG nucleotide insertions at fusion breakpoints of dysfunctional telomeres. Investigating the enzymatic activity responsible for the random insertions enabled us to identify Polymerase theta (Polθ; encoded by PolQ) as a critical alt-NHEJ factor in mammalian cells. PolQ inhibition suppresses alt-NHEJ at dysfunctional telomeres, and hinders chromosomal translocations at non-telomeric loci. In addition, we found that PolQ loss results in increased rates of homology directed repair (HDR), evident by recombination of dysfunctional telomeres and accumulation of Rad51 at double stranded breaks. Lastly, we show that depletion of PolQ has a synergistic impact on cell survival in the absence of BRCA genes, suggesting that the inhibition of this mutagenic polymerase represents a valid therapeutic avenue for tumors carrying mutations in HDR genes. PMID:25642960

  6. ''Theta gun,'' a multistage, coaxial, magnetic induction projectile accelerator

    SciTech Connect

    Burgess, T.J.; Duggin, B.W.; Cowan, M. Jr.

    1985-11-01

    We experimentally and theoretically studied a multistage coaxial magnetic induction projectile accelerator. We call this system a ''theta gun'' to differentiate it from other coaxial accelerator concepts such as the mass driver. We conclude that this system can theoretically attain railgun performance only for large caliber or very high injection velocity and, even then, only for long coil geometry. Our experiments with a three-stage, capactor bank-driven accelerator are described. The experiments are modeled with a 1-1/2 dimensional equivalent circuit-hydrodynamics code which is also described. We derive an expression for the conditions of coaxial accelerator-railgun ''velocity breakeven'' in the absence of ohmic and hydrodynamic effects. This, in conjunction with an expression for the magnetic coupling coefficient, defines a set of geometric relations which the coaxial system must simultaneously satisfy. Conclusions concerning both the existence and configuration of a breakeven coaxial system follow from this requirement. The relative advantages and disadvantages of the coaxial induction projectile accelerator, previously cited in the literature, are critiqued from the viewpoint of our analysis and experimental results. We find that the advantages vis-a-vis the railgun have been overstated. 13 refs., 17 figs.

  7. Modulation of EEG Theta Band Signal Complexity by Music Therapy

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Joydeep; Lee, Eun-Jeong

    The primary goal of this study was to investigate the impact of monochord (MC) sounds, a type of archaic sounds used in music therapy, on the neural complexity of EEG signals obtained from patients undergoing chemotherapy. The secondary goal was to compare the EEG signal complexity values for monochords with those for progressive muscle relaxation (PMR), an alternative therapy for relaxation. Forty cancer patients were randomly allocated to one of the two relaxation groups, MC and PMR, over a period of six months; continuous EEG signals were recorded during the first and last sessions. EEG signals were analyzed by applying signal mode complexity, a measure of complexity of neuronal oscillations. Across sessions, both groups showed a modulation of complexity of beta-2 band (20-29Hz) at midfrontal regions, but only MC group showed a modulation of complexity of theta band (3.5-7.5Hz) at posterior regions. Therefore, the neuronal complexity patterns showed different changes in EEG frequency band specific complexity resulting in two different types of interventions. Moreover, the different neural responses to listening to monochords and PMR were observed after regular relaxation interventions over a short time span.

  8. Altered serial position learning after frontal lobe lesion.

    PubMed

    Eslinger, P J; Grattan, L M

    1994-06-01

    The serial position function is a powerful and highly reliable feature of human learning, with well-described primacy and recency effects. We tested the hypothesis that frontal lobe lesions in patients would disrupt the serial position function since such patients are known to have disturbed temporal ordering, learning in the presence of interference, encoding and organizational approaches to learning. Performance was compared in patients with focal, acquired lesions of frontal and non-frontal cortices, using a standardized paradigm of verbal list learning. Results indicated a similar pattern of performance on first trial learning for the two groups. However, across learning trials, frontal lesion subjects failed to maintain significant primacy and recency effects. Non-frontal lesion subjects consistently showed the expected U-shaped serial position curve across all trials. Subjective organization in learning was particularly deficient in the dorsolateral frontal lesion subjects. We propose that serial position effects are qualitatively different after frontal lobe lesion, being transitory and prone to alteration by the cumulative effects of disturbed temporal-spatial processing across learning trials. PMID:8084427

  9. A reexamination of the small overlap frontal crash.

    PubMed

    Scullion, Paul; Morgan, Richard M; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 - 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 - 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study-following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC-suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  10. Frontal extents in virtual environments are not immune to underperception.

    PubMed

    Kelly, Jonathan W; Hammel, William; Sjolund, Lori A; Siegel, Zachary D

    2015-08-01

    Distance is commonly underperceived by up to 50 % in virtual environments (VEs), in contrast to relatively accurate real world judgments. Experiments reported by Geuss, Stefanucci, Creem-Regehr, and Thompson (Journal of Experimental Psychology: Human Perception and Performance, 38, 1242-1253, 2012) indicate that the exocentric distance separating two objects in a VE is underperceived when the objects are oriented in the sagittal plane (depth extents), but veridically perceived when oriented in a frontoparallel plane (frontal extents). The authors conclude that "distance underestimation in the [VE] generalizes to intervals in the depth plane, but not to intervals in the frontal plane." The current experiment evaluated an alternative hypothesis that the accurate judgments of frontal extents reported by Geuss et al. were due to a fortunate balance of underperception caused by the VE and overperception of frontal relative to depth extents. Participants judged frontal and depth extents in the classroom VE used by Geuss et al. and in a sparser VE containing only a grass-covered ground plane. Judgments in the classroom VE replicated findings by Geuss et al., but judgments in the grass VE show underperception of both depth and frontal extents, indicating that frontal extents are not immune to underperception in VEs. PMID:26105656

  11. A frontal attention mechanism in the visual mismatch negativity

    PubMed Central

    Hedge, Craig; Stothart, George; Todd Jones, Jenna; Rojas Frías, Priscila; Magee, Kristopher Lundy; Brooks, Jonathan C.W.

    2015-01-01

    Automatic detection of environmental change is a core component of attention. The mismatch negativity (MMN), an electrophysiological marker of this mechanism, has been studied prominently in the auditory domain, with cortical generators identified in temporal and frontal regions. Here, we combined electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to assess whether the underlying frontal regions associated with auditory change detection also play a role in visual change detection. Twenty healthy young adults completed a visual MMN task in separate EEG and fMRI sessions. Region of interest analyses were conducted on left and right middle frontal (MFG) and inferior frontal (IFG) gyri, i.e., the frontal areas identified as potential auditory MMN generators. A significant increase in activation was observed in the left IFG and MFG in response to blocks containing deviant stimuli. These findings suggest that a frontal mechanism is involved in the detection of change in the visual MMN. Our results support the notion that frontal mechanisms underlie attention switching, as measured via MMN, across multiple modalities. PMID:26183650

  12. Frontal Sinus Surgery Anterior to the Ethmoid Bulla

    PubMed Central

    Ji, Junfeng; Zhou, Mei; Li, Zeqing; Wang, Tianyou; Cheng, You; Wang, Qiuping

    2013-01-01

    The frontal sinus surgery is difficult to perform but the ethmoid bulla is a relative, constant landmark in the middle turbinate that can improve the surgery. The purpose of this study was to evaluate the validity, security, and predominance of approaches to the frontal sinus via the route anterior to the ethmoid bulla. The data from 370 endoscopic frontal sinus surgery cases from our center were integrated and retrospectively analyzed. Three hundred twenty-nine patients underwent frontal sinus surgery via the route anterior to the ethmoid bulla. An additional 27 patients underwent frontal sinus surgery with mini-trephination, 13 patients with the Draf II procedure, and 1 patient had applied MELP (modified endoscopic Lothrop procedure). No serious complications occurred; however, there were 3 cases of eyelid ecchymosis and 1 case of anterior ethmoid artery bleeding. In all, 319 patients (86.2%) were cured, an improvement was noted in 36 of the patients (9.7%), and there was no improvement in 15 patients (4.1%). Frontal sinus surgery via the route anterior to the ethmoid bulla is valid, relatively safe, and can be applied in most cases involving frontal disease. PMID:23701151

  13. A frontal attention mechanism in the visual mismatch negativity.

    PubMed

    Hedge, Craig; Stothart, George; Todd Jones, Jenna; Rojas Frías, Priscila; Magee, Kristopher Lundy; Brooks, Jonathan C W

    2015-10-15

    Automatic detection of environmental change is a core component of attention. The mismatch negativity (MMN), an electrophysiological marker of this mechanism, has been studied prominently in the auditory domain, with cortical generators identified in temporal and frontal regions. Here, we combined electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to assess whether the underlying frontal regions associated with auditory change detection also play a role in visual change detection. Twenty healthy young adults completed a visual MMN task in separate EEG and fMRI sessions. Region of interest analyses were conducted on left and right middle frontal (MFG) and inferior frontal (IFG) gyri, i.e., the frontal areas identified as potential auditory MMN generators. A significant increase in activation was observed in the left IFG and MFG in response to blocks containing deviant stimuli. These findings suggest that a frontal mechanism is involved in the detection of change in the visual MMN. Our results support the notion that frontal mechanisms underlie attention switching, as measured via MMN, across multiple modalities. PMID:26183650

  14. Frontal sinus parameters in computed tomography and sex determination.

    PubMed

    Akhlaghi, Mitra; Bakhtavar, Khadijeh; Moarefdoost, Jhale; Kamali, Artin; Rafeifar, Shahram

    2016-03-01

    The frontal sinus is a sturdy part of the skull that is likely to be retrieved for forensic investigations. We evaluated frontal sinus parameters in paranasal sinus computed tomography (CT) images for sex determination. The study was conducted on 200 normal paranasal sinus CT images of 100 men and 100 women of Persian origin. We categorized the studied population into three age groups of 20-34, 35-49 and ⩾ 50 years. The number of partial septa in the right frontal sinus and the maximum height and width were significantly different between the two sexes. The highest precision for sex determination was for the maximum height of the left frontal sinus (61.3%). In the 20-34 years age-group, height and width of the frontal sinus were significantly different between the two sexes and the height of the left sinus had the highest precision (60.8%). In the 35-49 years age-group, right anterior-posterior diameter had a sex determination precision of 52.3%. No frontal sinus parameter reached a statistically significant level for sex determination in the ⩾ 50 years age-group. The number of septa and scallopings were not useful in sex determination. Frontal sinus parameters did not have a high precision in sex determination among Persian adults. PMID:26980249

  15. The differing roles of the frontal cortex in fluency tests

    PubMed Central

    Shallice, Tim; Bozzali, Marco; Cipolotti, Lisa

    2012-01-01

    Fluency tasks have been widely used to tap the voluntary generation of responses. The anatomical correlates of fluency tasks and their sensitivity and specificity have been hotly debated. However, investigation of the cognitive processes involved in voluntary generation of responses and whether generation is supported by a common, general process (e.g. fluid intelligence) or specific cognitive processes underpinned by particular frontal regions has rarely been addressed. This study investigates a range of verbal and non-verbal fluency tasks in patients with unselected focal frontal (n = 47) and posterior (n = 20) lesions. Patients and controls (n = 35) matched for education, age and sex were administered fluency tasks including word (phonemic/semantic), design, gesture and ideational fluency as well as background cognitive tests. Lesions were analysed by standard anterior/posterior and left/right frontal subdivisions as well as a finer-grained frontal localization method. Thus, patients with right and left lateral lesions were compared to patients with superior medial lesions. The results show that all eight fluency tasks are sensitive to frontal lobe damage although only the phonemic word and design fluency tasks were specific to the frontal region. Superior medial patients were the only group to be impaired on all eight fluency tasks, relative to controls, consistent with an energization deficit. The most marked fluency deficits for lateral patients were along material specific lines (i.e. left—phonemic and right—design). Phonemic word fluency that requires greater selection was most severely impaired following left inferior frontal damage. Overall, our results support the notion that frontal functions comprise a set of specialized cognitive processes, supported by distinct frontal regions. PMID:22669082

  16. Decreased frontal lobe function in people with Internet addiction disorder

    PubMed Central

    Liu, Jun; Esmail, Fatema; Li, Lingjiang; Kou, Zhifeng; Li, Weihui; Gao, Xueping; Wang, Zhiyuan; Tan, Changlian; Zhang, Yan; Zhou, Shunke

    2013-01-01

    In our previous studies, we showed that frontal lobe and brainstem functions were abnormal in on-line game addicts. In this study, 14 students with Internet addiction disorder and 14 matched healthy controls underwent proton-magnetic resonance spectroscopy to measure cerebral function. Results demonstrated that the ratio of N-acetylaspartate to creatine decreased, but the ratio of cho-line-containing compounds to creatine increased in the bilateral frontal lobe white matter in people with Internet addiction disorder. However, these ratios were mostly unaltered in the brainstem, suggesting that frontal lobe function decreases in people with Internet addiction disorder. PMID:25206643

  17. Management of Frontal Sinus Cerebrospinal Fluid Leaks and Encephaloceles.

    PubMed

    Illing, Elisa A; Woodworth, Bradford A

    2016-08-01

    Encephaloceles and cerebrospinal fluid (CSF) leaks of the frontal sinus may result from congenital, traumatic, spontaneous, or neoplastic causes. Paramount to success is adequate preoperative planning with accurate history, physical exam, endoscopy, imaging, and testing to confirm location of the leak and origin of the disease. Generally, frontal sinus CSF leaks may be addressed endoscopically with favorable anatomy, proper surgical technique, and appropriate equipment. Open surgical approaches (eg, osteoplastic flap) are often required for superior/lateral defects or if the surgeon is not experienced with endoscopic frontal sinus techniques. PMID:27450619

  18. Utility of Image-Guidance in Frontal Sinus Surgery.

    PubMed

    Oakley, Gretchen M; Barham, Henry P; Harvey, Richard J

    2016-08-01

    The frontal sinus can present a challenging surgical dissection for the endoscopic surgeon. Image guidance as a surgical adjunct has become widely accepted for surgeries in this area. It can help verify vital structures and manage disorienting surgical conditions, improving surgeon confidence in performing safer and more complete surgery. It is relied upon heavily for placement of limited external frontal sinusotomies for disease beyond the endoscopic reach, and for mapping the frontal sinus for osteoplastic flap bony cuts. Its use has contributed to the expanding role of endoscopic surgical approaches for paranasal sinus inflammatory and neoplastic disease. PMID:27329979

  19. Decreased frontal lobe function in people with Internet addiction disorder.

    PubMed

    Liu, Jun; Esmail, Fatema; Li, Lingjiang; Kou, Zhifeng; Li, Weihui; Gao, Xueping; Wang, Zhiyuan; Tan, Changlian; Zhang, Yan; Zhou, Shunke

    2013-12-01

    In our previous studies, we showed that frontal lobe and brainstem functions were abnormal in on-line game addicts. In this study, 14 students with Internet addiction disorder and 14 matched healthy controls underwent proton-magnetic resonance spectroscopy to measure cerebral function. Results demonstrated that the ratio of N-acetylaspartate to creatine decreased, but the ratio of cho-line-containing compounds to creatine increased in the bilateral frontal lobe white matter in people with Internet addiction disorder. However, these ratios were mostly unaltered in the brainstem, suggesting that frontal lobe function decreases in people with Internet addiction disorder. PMID:25206643

  20. Frontal cortex mediates unconsciously triggered inhibitory control.

    PubMed

    van Gaal, Simon; Ridderinkhof, K Richard; Fahrenfort, Johannes J; Scholte, H Steven; Lamme, Victor A F

    2008-08-01

    To further our understanding of the function of conscious experience we need to know which cognitive processes require awareness and which do not. Here, we show that an unconscious stimulus can trigger inhibitory control processes, commonly ascribed to conscious control mechanisms. We combined the metacontrast masking paradigm and the Go/No-Go paradigm to study whether unconscious No-Go signals can actively trigger high-level inhibitory control processes, strongly associated with the prefrontal cortex (PFC). Behaviorally, unconscious No-Go signals sometimes triggered response inhibition to the level of complete response termination and yielded a slow down in the speed of responses that were not inhibited. Electroencephalographic recordings showed that unconscious No-Go signals elicit two neural events: (1) an early occipital event and (2) a frontocentral event somewhat later in time. The first neural event represents the visual encoding of the unconscious No-Go stimulus, and is also present in a control experiment where the masked stimulus has no behavioral relevance. The second event is unique to the Go/No-Go experiment, and shows the subsequent implementation of inhibitory control in the PFC. The size of the frontal activity pattern correlated highly with the impact of unconscious No-Go signals on subsequent behavior. We conclude that unconscious stimuli can influence whether a task will be performed or interrupted, and thus exert a form of cognitive control. These findings challenge traditional views concerning the proposed relationship between awareness and cognitive control and stretch the alleged limits and depth of unconscious information processing. PMID:18685030

  1. Theta rhythm and the encoding and retrieval of space and time

    PubMed Central

    Hasselmo, Michael E.; Stern, Chantal E.

    2013-01-01

    Physiological data demonstrates theta frequency oscillations associated with memory function and spatial behavior. Modeling and data from animals provides a perspective on the functional role of theta rhythm, including correlations with behavioral performance and coding by timing of spikes relative to phase of oscillations. Data supports a theorized role of theta rhythm in setting the dynamics for encoding and retrieval within cortical circuits. Recent data also supports models showing how network and cellular theta rhythmicity allows neurons in the entorhinal cortex and hippocampus to code time and space as a possible substrate for encoding events in episodic memory. Here we discuss these models and relate them to current physiological and behavioral data. PMID:23774394

  2. Beam heated linear theta-pinch device for producing hot plasmas

    DOEpatents

    Bohachevsky, Ihor O.

    1981-01-01

    A device for producing hot plasmas comprising a single turn theta-pinch coil, a fast discharge capacitor bank connected to the coil, a fuel element disposed along the center axis of the coil, a predetermined gas disposed within the theta-pinch coil, and a high power photon, electron or ion beam generator concentrically aligned to the theta-pinch coil. Discharge of the capacitor bank generates a cylindrical plasma sheath within the theta-pinch coil which heats the outer layer of the fuel element to form a fuel element plasma layer. The beam deposits energy in either the cylindrical plasma sheath or the fuel element plasma layer to assist the implosion of the fuel element to produce a hot plasma.

  3. Status of the iota (1440) and theta (1640) as gluonium candidates

    SciTech Connect

    Lockman, W.S.

    1983-04-01

    A review of the experimental evidence for the iota (1440) and theta (1640) states is presented. The measured properties of these states are compared with various theoretical predictions. A likely interpretation is that these states contain a large gluonic admixture.

  4. Hippocampal Theta Input to the Amygdala Shapes Feedforward Inhibition to Gate Heterosynaptic Plasticity

    PubMed Central

    Bazelot, Michaël; Bocchio, Marco; Kasugai, Yu; Fischer, David; Dodson, Paul D.; Ferraguti, Francesco; Capogna, Marco

    2015-01-01

    Summary The dynamic interactions between hippocampus and amygdala are critical for emotional memory. Theta synchrony between these structures occurs during fear memory retrieval and may facilitate synaptic plasticity, but the cellular mechanisms are unknown. We report that interneurons of the mouse basal amygdala are activated during theta network activity or optogenetic stimulation of ventral CA1 pyramidal cell axons, whereas principal neurons are inhibited. Interneurons provide feedforward inhibition that transiently hyperpolarizes principal neurons. However, synaptic inhibition attenuates during theta frequency stimulation of ventral CA1 fibers, and this broadens excitatory postsynaptic potentials. These effects are mediated by GABAB receptors and change in the Cl− driving force. Pairing theta frequency stimulation of ventral CA1 fibers with coincident stimuli of the lateral amygdala induces long-term potentiation of lateral-basal amygdala excitatory synapses. Hence, feedforward inhibition, known to enforce temporal fidelity of excitatory inputs, dominates hippocampus-amygdala interactions to gate heterosynaptic plasticity. Video Abstract PMID:26402610

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  6. Geometric variation of the frontal squama in the genus homo: frontal bulging and the origin of modern human morphology.

    PubMed

    Bruner, Emiliano; Athreya, Sheela; de la Cuétara, José Manuel; Marks, Tarah

    2013-02-01

    The majority of studies of frontal bone morphology in paleoanthropology have analyzed the frontal squama and the browridge as a single unit, mixing information from different functional elements. Taking into account that the bulging of the frontal bone is often described as a species-specific trait of Homo sapiens, in this article we analyze variation in the midsagittal profile of the genus Homo, focusing on the frontal squama alone, using landmark-based superimpositions and principal components analysis. Our results demonstrate that anatomically modern humans are definitely separated from extinct human taxa on the basis of frontal bulging. However, there is minor overlap among these groups, indicating that it is necessary to exercise caution when using this trait alone to make taxonomic inferences on individual specimens. Early modern humans do not show differences with recent modern humans, and "transitional" individuals such as Jebel Irhoud 1, Maba, and Florisbad, show modern-like frontal squama morphology. The bulging of the frontal squama in modern humans may represent a structural consequence of more general cranial changes, or it could be a response to changes in the morphology of the underlying prefrontal brain elements. A subtle difference between Neandertals and the Afro-European Middle Pleistocene Homo sample is associated with flattening at bregma in the former group, a result that merits further investigation. PMID:23292748

  7. Epoetin Theta in Anaemic Cancer Patients Receiving Platinum-Based Chemotherapy: A Randomised Controlled Trial

    PubMed Central

    Tjulandin, Sergei A; Bias, Peter; Elsässer, Reiner; Gertz, Beate; Kohler, Erich; Buchner, Anton

    2010-01-01

    Introduction Recombinant human erythropoietin (r-HuEPO) is used to treat symptomatic anaemia due to chemotherapy. A new r-HuEPO, Epoetin theta (Eporatio®), was investigated and compared to placebo and Epoetin beta in a randomised, double-blind clinical trial in adult cancer patients receiving platinum-based chemotherapy, using a fixed weekly starting dose of 20,000 IU Epoetin theta. The primary efficacy endpoint was the responder rate (complete Hb response, Hb increase ≥ 2 g/dL). Research Design and Methods 223 patients were randomised to s.c. treatment for 12 weeks with either Epoetin theta (n = 76) once per week, Epoetin beta (n = 73) three times per week or placebo (n = 74). The starting dose was 20,000 IU once weekly Epoetin theta or 450 IU/kgBW per week Epoetin beta administered in 3 equal weekly doses. Results In the Epoetin theta group were significantly more responders than in the placebo group (65.8 vs. 20.3%, P < 0.0001). Epoetin beta was also more effective than placebo (71.2 vs. 20.3%, P < 0.0001). The mean weekly dose at the time of complete Hb response was lower in the Epoetin theta group (30,000 IU) than in the Epoetin beta group (42,230 IU). Epoetin theta was clearly more effective than placebo. Conclusion This small study showed, that Epoetin theta is a safe and effective treatment of symptomatic anaemia due to platinum-based chemotherapy in cancer patients. PMID:21331363

  8. Zeeman effect in the X-ray star candidates HD 77581 and theta super 2 Orionis.

    NASA Technical Reports Server (NTRS)

    Kemp, J. C.; Wolstencroft, R. D.

    1973-01-01

    The discovery of Zeeman effects is reported in HD 77581 and theta super 2 Orionis, optical candidates for the X-ray sources Vela XR-1 and 2U 0525-06, respectively. The maximum longitudinal magnetic fields recorded were -10,000 G in HD 77581 and +1500 G in theta super 2 Ori. Various polarimetric data are also given, including evidence for a variable linear polarization in HD 77581.

  9. Differentiating neutrino models on the basis of $\\theta_{13}$ and lepton flavor violation

    SciTech Connect

    Albright, Carl H.; /Northern Illinois U. /Fermilab

    2008-03-01

    The authors show how models of neutrino masses and mixings can be differentiated on the basis of their predictions for {theta}{sub 13} and lepton flavor violation in radiative charged lepton decays and {mu} - e conversion. They illustrate the lepton flavor violation results for five predictive SO(10) SUSY GUT models and point out the relative importance of their heavy right-handed neutrino mass spectra and {theta}{sub 13} predictions.

  10. Creep modeling of welded joints using the theta projection concept and finite element analysis

    SciTech Connect

    Law, M.; Payten, W.; Snowden, K.

    2000-02-01

    Modeling of welded joints under creep conditions with element analysis was undertaken using the theta projection method. The results were compared to modeling based on a simple Norton law. Theta projection data extends the accuracy and predictive capability of finite element modeling of critical structures operating at high temperature and pressure. In some cases analyzed, it was found that the results diverged from those gained using a Norton law creep model.

  11. Comments on the slip factor and the relation Delta phi = -h Delta theta

    SciTech Connect

    Ng, K.Y.; /Fermilab

    2009-09-01

    The definition of the slip factor can be obtained from the phase equation. However, a derivation using the relation {Delta}{phi} = -h{Delta}{theta} leads to a different slip-factor definition. This apparent paradox is examined in detail and resolved. Here {Delta}{phi} is the rf phase difference and {Delta}{theta} is the azimuthal phase difference around the accelerator ring between an off-momentum particle and the synchronous particle, while h is the rf harmonic.

  12. Genetics Home Reference: autosomal dominant nocturnal frontal lobe epilepsy

    MedlinePlus

    ... brain are involved in many critical functions, including reasoning, planning, judgment, and problem-solving. It is unclear ... E, Montagna P. Nocturnal frontal lobe epilepsy. A clinical and polygraphic overview of 100 consecutive cases. Brain. ...

  13. FRONTAL VIEW OF #3 GENERATOR, 6600 VOLT OIL CIRCUIT BREAKER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FRONTAL VIEW OF #3 GENERATOR, 6600 VOLT OIL CIRCUIT BREAKER, LOCATED BEHIND SLATE SWITCHBOARD. PHOTO BY JET LOWE, HAER, 1995. - Elwha River Hydroelectric System, Elwha Hydroelectric Dam & Plant, Port Angeles, Clallam County, WA

  14. FRONTAL VIEW OF SLATE SWITCHBOARD IN THE CONTROL ROOM OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FRONTAL VIEW OF SLATE SWITCHBOARD IN THE CONTROL ROOM OF ELWHA POWERHOUSE. PHOTO BY JET LOWE, HAER, 1995 - Elwha River Hydroelectric System, Elwha Hydroelectric Dam & Plant, Port Angeles, Clallam County, WA

  15. Osteoplastic frontal sinusotomy: an analysis of 250 operations.

    PubMed

    Hardy, J M; Montgomery, W W

    1976-01-01

    The operative approach and findings of 250 osteoplastic frontal sinusotomy operations performed from 1956 through 1972 at the Massachusetts Eye and Ear Infirmary are reviewed. Indications for surgery were symptomatic and/or complicated disease of the frontal sinus, including primary chronic sinusitis and osteoma or trauma with or without associated infection. Immediate postoperative complications were minor. Follow-up of at least three years was obtained in 83% of the patients, and 93% of these have no significant symptoms to date. A distressing problem of persistent postoperative frontal pain is discussed in detail. Revision surgery has been performed in 6% of patients due to recurrent frontal sinus infection. The reasons for failure are anlyzed, and recommendations are made to minimize the possibility of recurrence. PMID:949159

  16. The scaling of frontal cortex in primates and carnivores

    PubMed Central

    Bush, Eliot C.; Allman, John M.

    2004-01-01

    Size has a profound effect on the structure of the brain. Many brain structures scale allometrically, that is, their relative size changes systematically as a function of brain size. Here we use independent contrasts analysis to examine the scaling of frontal cortex in 43 species of mammals including 25 primates and 15 carnivores. We find evidence for significant differences in scaling between primates and carnivores. Primate frontal cortex hyperscales relative to the rest of neocortex and the rest of the brain. The slope of frontal cortex contrasts on rest of cortex contrasts is 1.18 (95% confidence interval, 1.06-1.30) for primates, which is significantly greater than isometric. It is also significantly greater than the carnivore value of 0.94 (95% confidence interval, 0.82-1.07). This finding supports the idea that there are substantial differences in frontal cortex structure and development between the two groups. PMID:15007170

  17. 21. DETAILED FRONTAL VIEW WEST OF FURNACE 2, SHOWING MOUTHS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. DETAILED FRONTAL VIEW WEST OF FURNACE 2, SHOWING MOUTHS WITH ROLLERS FOR MOVING TRAYS IN AND OUT OF THE OVENS. - Vulcan Crucible Steel Company, Building No. 3, 100 First Street, Aliquippa, Beaver County, PA

  18. Unsuccessful frontal balloon sinuplasty for recurrent sinus barotrauma.

    PubMed

    Andrews, Jamie N; Weitzel, Erik K; Eller, Robert; McMains, Christopher K

    2010-05-01

    The standard of care treatment for diffuse recurrent sinus barotrauma (RSB) is an endoscopic sphenoethmoidectomy with a complete frontal dissection. Successful healing leaves the RSB patient with no ethmoid sinuses and endoscopically patent frontal, sphenoid, and maxillary ostia. In persistent cases, patients with small frontal ostia will go on to require a frontal drillout. Patients presenting for surgical management of RSB generally have minimal sinus disease despite significant symptoms during flight and the prospect of extensive surgical management can be unappealing. With the advent of balloon sinuplasty, military otolaryngologists anticipated this technology would permit therapeutic dilation of sinus ostia without the extensive surgical dissection and prolonged recovery typical for standard of care management. This case report is a cautionary note to the wider flight community to recognize a mechanism for recurrence of the underlying pathology when balloon sinuplasty is used that is not possible after properly performed standard of care sinus surgery for RSB. PMID:20464821

  19. 9. FRONTAL VIEW OF MOVABLE SPANS, RAISED AND SUSPENDED IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. FRONTAL VIEW OF MOVABLE SPANS, RAISED AND SUSPENDED IN OPENING OPERATION - Mystic River Drawbridge No. 7, Spanning Mystic River at Boston & Maine Railroad Eastern Route, Somerville, Middlesex County, MA

  20. Frontal affinity chromatography (FAC): theory and basic aspects.

    PubMed

    Kasai, Ken-ichi

    2014-01-01

    Frontal affinity chromatography (FAC) is a versatile analytical tool for determining specific interactions between biomolecules and is particularly useful in the field of glycobiology. This article presents its basic aspects, merits, and theory. PMID:25117240

  1. 14. View north of Tropic wind tunnel and frontal view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. View north of Tropic wind tunnel and frontal view of main fan (typical). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  2. Enhancement of encoding and retrieval functions through theta phase-specific manipulation of hippocampus.

    PubMed

    Siegle, Joshua H; Wilson, Matthew A

    2014-01-01

    Assessing the behavioral relevance of the hippocampal theta rhythm has proven difficult, due to a shortage of experiments that selectively manipulate phase-specific information processing. Using closed-loop stimulation, we triggered inhibition of dorsal CA1 at specific phases of the endogenous theta rhythm in freely behaving mice. This intervention enhanced performance on a spatial navigation task that requires the encoding and retrieval of information related to reward location on every trial. In agreement with prior models of hippocampal function, the behavioral effects depended on both the phase of theta and the task segment at which we stimulated. Stimulation in the encoding segment enhanced performance when inhibition was triggered by the peak of theta. Conversely, stimulation in the retrieval segment enhanced performance when inhibition was triggered by the trough of theta. These results suggest that processes related to the encoding and retrieval of task-relevant information are preferentially active at distinct phases of theta.DOI: http://dx.doi.org/10.7554/eLife.03061.001. PMID:25073927

  3. Phase-locked hippocampal theta-band responses are related to discriminative eyeblink conditioned responding.

    PubMed

    Nokia, Miriam S; Wikgren, Jan

    2013-11-01

    Hippocampal electrophysiological oscillatory activity is undoubtedly related to learning and memory. The relative power of spontaneously occurring hippocampal theta (∼4-8 Hz) oscillations predicts how fast and how well an animal will learn: more theta predicts faster acquisition of the conditioned response in eyeblink conditioning in both rats and rabbits. Here, our aim was to study how hippocampal theta-band responses to conditioned stimuli elicited during very-long delay discrimination eyeblink conditioning relate to the accompanying conditioned behavior. We trained adult male New Zealand White rabbits using 1500-ms auditory stimuli as conditioned stimuli and a 100-ms airpuff as an unconditioned stimulus. The reinforced conditioned stimulus overlapped and co-terminated with the unconditioned stimulus whereas the non-reinforced conditioned stimulus was always presented alone. Consistent with previous results, hippocampal theta-band responses to the conditioned stimuli diminished in amplitude across training. Interestingly, hippocampal theta-band responses were most consistently time-locked when a well-trained animal failed to suppress behavioral learned responses to the non-reinforced conditioned stimulus. We suggest that phase-locking of hippocampal theta-band oscillations in response to external stimuli reflects retrieval of the dominant memory trace (adaptive or not) along with initiating the most prominent action scheme related to that memory trace. PMID:24029698

  4. Chemotherapy disrupts learning, neurogenesis and theta activity in the adult brain.

    PubMed

    Nokia, Miriam S; Anderson, Megan L; Shors, Tracey J

    2012-12-01

    Chemotherapy, especially if prolonged, disrupts attention, working memory and speed of processing in humans. Most cancer drugs that cross the blood-brain barrier also decrease adult neurogenesis. Because new neurons are generated in the hippocampus, this decrease may contribute to the deficits in working memory and related thought processes. The neurophysiological mechanisms that underlie these deficits are generally unknown. A possible mediator is hippocampal oscillatory activity within the theta range (3-12 Hz). Theta activity predicts and promotes efficient learning in healthy animals and humans. Here, we hypothesised that chemotherapy disrupts learning via decreases in hippocampal adult neurogenesis and theta activity. Temozolomide was administered to adult male Sprague-Dawley rats in a cyclic manner for several weeks. Treatment was followed by training with different types of eyeblink classical conditioning, a form of associative learning. Chemotherapy reduced both neurogenesis and endogenous theta activity, as well as disrupted learning and related theta-band responses to the conditioned stimulus. The detrimental effects of temozolomide only occurred after several weeks of treatment, and only on a task that requires the association of events across a temporal gap and not during training with temporally overlapping stimuli. Chemotherapy did not disrupt the memory for previously learned associations, a memory independent of (new neurons in) the hippocampus. In conclusion, prolonged systemic chemotherapy is associated with a decrease in hippocampal adult neurogenesis and theta activity that may explain the selective deficits in processes of learning that describe the 'chemobrain'. PMID:23039863

  5. Fear and safety engage competing patterns of theta-gamma coupling in the basolateral amygdala.

    PubMed

    Stujenske, Joseph M; Likhtik, Ekaterina; Topiwala, Mihir A; Gordon, Joshua A

    2014-08-20

    Theta oscillations synchronize the basolateral amygdala (BLA) with the hippocampus (HPC) and medial prefrontal cortex (mPFC) during fear expression. The role of gamma-frequency oscillations in the BLA is less well characterized. We examined gamma- and theta-frequency activity in recordings of neural activity from the BLA-HPC-mPFC circuit during fear conditioning, extinction, and exposure to an open field. In the BLA, slow (40-70 Hz) and fast (70-120 Hz) gamma oscillations were coupled to distinct phases of the theta cycle and reflected synchronous high-frequency unit activity. During periods of fear, BLA theta-fast gamma coupling was enhanced, while fast gamma power was suppressed. Periods of relative safety were associated with enhanced BLA fast gamma power, mPFC-to-BLA directionality, and strong coupling of BLA gamma to mPFC theta. These findings suggest that switches between states of fear and safety are mediated by changes in BLA gamma coupling to competitive theta frequency inputs. PMID:25144877

  6. Enhancement of encoding and retrieval functions through theta phase-specific manipulation of hippocampus

    PubMed Central

    Siegle, Joshua H; Wilson, Matthew A

    2014-01-01

    Assessing the behavioral relevance of the hippocampal theta rhythm has proven difficult, due to a shortage of experiments that selectively manipulate phase-specific information processing. Using closed-loop stimulation, we triggered inhibition of dorsal CA1 at specific phases of the endogenous theta rhythm in freely behaving mice. This intervention enhanced performance on a spatial navigation task that requires the encoding and retrieval of information related to reward location on every trial. In agreement with prior models of hippocampal function, the behavioral effects depended on both the phase of theta and the task segment at which we stimulated. Stimulation in the encoding segment enhanced performance when inhibition was triggered by the peak of theta. Conversely, stimulation in the retrieval segment enhanced performance when inhibition was triggered by the trough of theta. These results suggest that processes related to the encoding and retrieval of task-relevant information are preferentially active at distinct phases of theta. DOI: http://dx.doi.org/10.7554/eLife.03061.001 PMID:25073927

  7. Continuous theta burst stimulation of angular gyrus reduces subjective recollection.

    PubMed

    Yazar, Yasemin; Bergström, Zara M; Simons, Jon S

    2014-01-01

    The contribution of lateral parietal regions such as the angular gyrus to human episodic memory has been the subject of much debate following widespread observations of left parietal activity in healthy volunteers during functional neuroimaging studies of memory retrieval. Patients with lateral parietal lesions are not amnesic, but recent evidence indicates that their memory abilities may not be entirely preserved. Whereas recollection appears intact when objective measures such as source accuracy are used, patients often exhibit reduced subjective confidence in their accurate recollections. When asked to recall autobiographical memories, they may produce spontaneous narratives that lack richness and specificity, but can remember specific details when prompted. Two distinct theoretical accounts have been proposed to explain these results: that the patients have a deficit in the bottom-up capturing of attention by retrieval output, or that they have an impairment in the subjective experience of recollection. The present study aimed to differentiate between these accounts using continuous theta burst stimulation (cTBS) in healthy participants to disrupt function of specific left parietal subregions, including angular gyrus. Inconsistent with predictions of the attentional theory, angular gyrus cTBS did not result in greater impairment of free recall than cued recall. Supporting predictions of the subjective recollection account, temporary disruption of angular gyrus was associated with highly accurate source recollection accuracy but a selective reduction in participants' rated source confidence. The findings are consistent with a role for angular gyrus in the integration of memory features into a conscious representation that enables the subjective experience of remembering. PMID:25333985

  8. Modulatory Effects of Theta Burst Stimulation on Cerebellar Nonsomatic Functions

    PubMed Central

    Demirtas-Tatlidede, Asli; Freitas, Catarina; Pascual-Leone, Alvaro; Schmahmann, Jeremy D.

    2011-01-01

    Clinical and functional imaging studies suggest that the cerebellar vermis is involved in the regulation of a range of nonsomatic functions including cardiovascular control, thirst, feeding behavior, and primal emotions. Cerebello-hypothalamic circuits have been postulated to be a potential neuroanatomical substrate underlying this modulation. We tested this putative relationship between the cerebellar vermis and nonsomatic functions by stimulating the cerebellum noninvasively via neuronavigated transcranial magnetic stimulation. In this randomized, counter-balanced, within-subject study, intermittent theta burst stimulation (TBS) was applied on three different days to the vermis and the right and left cerebellar hemispheres of 12 right-handed normal subjects with the aim of modulating activity in the targeted cerebellar structure. TBS-associated changes were investigated via cardiovascular monitoring, a series of emotionally arousing picture stimuli, subjective analog scales for primal emotions, and the Profile of Mood States test. All 36 sessions of cerebellar stimulation were tolerated well without serious adverse events. Cardiovascular monitoring pointed to a mild but significant decrease in heart rate subsequent to vermal stimulation; no changes were detected in systolic or diastolic blood pressure measurements. Subjective ratings detected a significant increase in Thirst and a trend toward increased Appetite following vermal stimulation. These observations are consistent with existing neurophysiological and neuroimaging data indicating a role for the cerebellum in the regulation of visceral responses. In conjunction with the modulatory function of the cerebellum, our results suggest a role for the vermis in somatovisceral integration likely through cerebello-hypothalamic pathways. Further research is warranted to elucidate the potential mechanisms underlying the cerebellar modulation of nonsomatic functions. PMID:21132574

  9. Differential frontal involvement in shifts of internal and perceptual attention

    PubMed Central

    Tanoue, Ryan T.; Jones, Kevin T.; Peterson, Dwight J.; Berryhill, Marian E.

    2012-01-01

    Background Perceptual attention enhances the processing of items in the environment, whereas internal attention enhances processing of items encoded in visual working memory. In perceptual and internal attention cueing paradigms, cues indicate the to-be-probed item before (pre-cueing) or after (retro-cueing) the memory display, respectively. Pre- and retro- cues confer similar behavioral accuracy benefits (pre-: 14–19%, retro-: 11–17%) and neuroimaging data show that they activate overlapping frontoparietal networks (1). Yet reports of behavioral and neuroimaging differences suggest that pre- and retro-cueing differentially recruit frontal and parietal cortices (1). Objective/Hypothesis This study examined whether perceptual and internal attention are equally disrupted by neurostimulation to frontal and parietal cortices. We hypothesized that neurostimulation applied to frontal cortex would disrupt internal attention to a greater extent than perceptual attention. Methods Cathodal transcranial direct current stimulation (tDCS) was applied to frontal or parietal cortices. After stimulation, participants completed a change detection task coupled with either pre- or retro- cues. Results Cathodal tDCS across site (frontal, parietal) hindered performance. However, frontal tDCS had a greater negative impact on the retro-cued trials demonstrating greater frontal involvement during shifts of internal attention. Conclusions These results complement the neuroimaging data and provide further evidence suggesting that perceptual and internal attention are not identical processes. We conclude that although internal and perceptual attention are mediated by similar frontoparietal networks, the weight of contribution of these structures differs, with internal attention relying more heavily on the frontal cortex. PMID:23266133

  10. Pleomorphic adenoma of the frontal sinus masquerading as a mucocele.

    PubMed

    Chew, Yok Kuan; Brito-Mutunayagam, Sushil; Chong, Aun Wee; Prepageran, Narayanan; Chandran, Patricia Ann; Khairuzzana, Baharudin; Lingham, Omkara Rubini

    2015-12-01

    Pleomorphic adenoma is the most common type of benign salivary gland tumor. It can also be found in the larynx, ear, neck, and nasal septum. It is rarely found in the maxillary sinus, and it has never been reported in the frontal sinus. We report a case of pleomorphic adenoma of the frontal sinus that masqueraded as a mucocele. We discuss the clinical presentation, diagnosis, and treatment of this patient, and we review the literature. PMID:26670764

  11. A Serotonin Circuit Acts as an Environmental Sensor to Mediate Midline Axon Crossing through EphrinB2

    PubMed Central

    Xing, Lingyan; Son, Jong-Hyun; Stevenson, Tamara J.; Lillesaar, Christina; Bally-Cuif, Laure; Dahl, Tiffanie

    2015-01-01

    Modulation of connectivity formation in the developing brain in response to external stimuli is poorly understood. Here, we show that the raphe nucleus and its serotonergic projections regulate pathfinding of commissural axons in zebrafish. We found that the raphe neurons extend projections toward midline-crossing axons and that when serotonergic signaling is blocked by pharmacological inhibition or by raphe neuron ablation, commissural pathfinding is disrupted. We demonstrate that the serotonin receptor htr2a is expressed on these commissural axons and that genetic knock-down of htr2a disrupts crossing. We further show that knock-down of htr2a or ablation of the raphe neurons increases ephrinB2a protein levels in commissural axons. An ephrinB2a mutant can rescue midline crossing when serotonergic signaling is blocked. Furthermore, we found that regulation of serotonin expression in the raphe neurons is modulated in response to the developmental environment. Hypoxia causes the raphe to decrease serotonin levels, leading to a reduction in midline crossing. Increasing serotonin in the setting of hypoxia restored midline crossing. Our findings demonstrate an instructive role for serotonin in axon guidance acting through ephrinB2a and reveal a novel mechanism for developmental interpretation of the environmental milieu in the generation of mature neural circuitry. SIGNIFICANCE STATEMENT We show here that serotonin has a novel role in regulating connectivity in response to the developmental environment. We demonstrate that serotonergic projections from raphe neurons regulate pathfinding of crossing axons. The neurons modulate their serotonin levels, and thus alter crossing, in response to the developmental environment including hypoxia. The findings suggest that modification of the serotonergic system by early exposures may contribute to permanent CNS connectivity alterations. This has important ramifications because of the association between premature birth and

  12. Variations in Alaska tidewater glacier frontal ablation, 1985-2013

    NASA Astrophysics Data System (ADS)

    McNabb, R. W.; Hock, R.; Huss, M.

    2015-01-01

    Our incomplete knowledge of the proportion of mass loss due to frontal ablation (the sum of ice loss through calving and submarine melt) from tidewater glaciers outside of the Greenland and Antarctic ice sheets has been cited as a major hindrance to accurate predictions of global sea level rise. We present a 28 year record (1985-2013) of frontal ablation for 27 Alaska tidewater glaciers (representing 96% of the total tidewater glacier area in the region), calculated from satellite-derived ice velocities and modeled estimates of glacier ice thickness. We account for cross-sectional ice thickness variation, long-term thickness changes, mass lost between an upstream fluxgate and the terminus, and mass change due to changes in terminus position. The total mean rate of frontal ablation for these 27 glaciers over the period 1985-2013 is 15.11 ± 3.63Gta-1. Two glaciers, Hubbard and Columbia, account for approximately 50% of these losses. The regional total ablation has decreased at a rate of 0.14Gta-1 over this time period, likely due to the slowing and thinning of many of the glaciers in the study area. Frontal ablation constitutes only ˜4% of the total annual regional ablation, but roughly 20% of net mass loss. Comparing several commonly used approximations in the calculation of frontal ablation, we find that neglecting cross-sectional thickness variations severely underestimates frontal ablation.

  13. Adult clinical neuropsychology: lessons from studies of the frontal lobes.

    PubMed

    Stuss, Donald T; Levine, Brian

    2002-01-01

    Clinical neuropsychologists have adopted numerous (and sometimes conflicting) approaches to the assessment of brain-behavior relationships. We review the historical development of these approaches and we advocate an approach to clinical neuropsychology that is informed by recent findings from cognitive neuroscience. Clinical assessment of executive and emotional processes associated with the frontal lobes of the human brain has yet to incorporate the numerous experimental neuroscience findings on this topic. We review both standard and newer techniques for assessment of frontal lobe functions, including control operations involved in language, memory, attention, emotions, self-regulation, and social functioning. Clinical and experimental research has converged to indicate the fractionation of frontal subprocesses and the initial mapping of these subprocesses to discrete frontal regions. One anatomical distinction consistent in the literature is that between dorsal and ventral functions, which can be considered cognitive and affective, respectively. The frontal lobes, in particular the frontal poles, are involved in uniquely human capacities, including self-awareness and mental time travel. PMID:11752491

  14. Repeated loss of frontal sinuses in arctoid carnivorans.

    PubMed

    Curtis, Abigail A; Lai, George; Wei, Fuwen; Van Valkenburgh, Blaire

    2015-01-01

    Many mammal skulls contain air spaces inside the bones surrounding the nasal chamber including the frontal, maxilla, ethmoid, and sphenoid, all of which are called paranasal sinuses. Within the Carnivora, frontal sinuses are usually present, but vary widely in size and shape. The causes of this variation are unclear, although there are some functional associations, such as a correlation between expanded frontal sinuses and a durophagous diet in some species (e.g., hyenas) or between absent sinuses and semiaquatic lifestyle (e.g., pinnipeds). To better understand disparity in frontal sinus morphology within Carnivora, we quantified frontal sinus size in relationship to skull size and shape in 23 species within Arctoidea, a clade that is ecologically diverse including three independent invasions of aquatic habitats, by bears, otters, and pinnipeds, respectively. Our sampled species range in behavior from terrestrial (rarely or never forage in water), to semiterrestrial (forage in water and on land), to semiaquatic (forage only in water). Results show that sinuses are either lost or reduced in both semiterrestrial and semiaquatic species, and that sinus size is related to skull size and shape. Among terrestrial species, frontal sinus size was positively allometric overall, but several terrestrial species completely lacked sinuses, including two fossorial badgers, the kinkajou (a nocturnal, arboreal frugivore), and several species with small body size, indicating that factors other than aquatic habits, such as space limitations due to constraints on skull size and shape, can limit sinus size and presence. PMID:25069818

  15. Modulation of Orthographic Decoding by Frontal Cortex

    PubMed Central

    Whaley, Meagan Lee; Kadipasaoglu, Cihan Mehmet; Cox, Steven James

    2016-01-01

    Opinions are divided on whether word reading processes occur in a hierarchical, feedforward fashion or within an interactive framework. To critically evaluate these competing theories, we recorded electrocorticographic (ECoG) data from 15 human patients with intractable epilepsy during a word completion task and evaluated brain network dynamics across individuals. We used a novel technique of analyzing multihuman ECoG recordings to identify cortical regions most relevant to processing lexical information. The mid fusiform gyrus showed the strongest, earliest response after stimulus onset, whereas activity was maximal in frontal, dorsal lateral prefrontal, and sensorimotor regions toward articulation onset. To evaluate interregional functional connectivity, ECoG data from electrodes situated over specific cortical regions of interest were fit into linear multivariate autoregressive (MVAR) models. Spectral characteristics of the MVAR models were used to precisely reveal the timing and the magnitude of information flow between localized brain regions. This is the first application of MVAR for developing a comprehensive account of interregional interactions from a word reading ECoG dataset. Our comprehensive findings revealed both top-down and bottom-up influences between higher-level language areas and the mid fusiform gyrus. Our findings thus challenge strictly hierarchical, feedforward views of word reading and suggest that orthographic processes are modulated by prefrontal and sensorimotor regions via an interactive framework. SIGNIFICANCE STATEMENT Word reading is a critical part of everyday life. When the ability to read is disrupted, it can lead to learning disorders, as well as emotional and academic difficulties. The neural mechanisms underlying word reading are not well understood due to limitations in the spatial and temporal specificity of prior word reading studies. Our research analyzed data recorded from sensors implanted directly from surface of human

  16. Working Memory Performance Correlates with Prefrontal-Hippocampal Theta Interactions but not with Prefrontal Neuron Firing Rates

    PubMed Central

    Hyman, James M.; Zilli, Eric A.; Paley, Amanda M.; Hasselmo, Michael E.

    2009-01-01

    Performance of memory tasks is impaired by lesions to either the medial prefrontal cortex (mPFC) or the hippocampus (HPC); although how these two areas contribute to successful performance is not well understood. mPFC unit activity is temporally affected by hippocampal-theta oscillations, with almost half the mPFC population entrained to theta in behaving animals, pointing to theta interactions as the mechanism enabling collaborations between these two areas. mPFC neurons respond to sensory stimuli and responses in working memory tasks, though the function of these correlated firing rate changes remains unclear because similar responses are reported during mPFC dependent and independent tasks. Using a DNMS task we compared error trials vs. correct trials and found almost all mPFC cells fired at similar rates during both error and correct trials (92%), however theta-entrainment of mPFC neurons declined during error performance as only 17% of cells were theta-entrained (during correct trials 46% of the population was theta-entrained). Across the population, error and correct trials did not differ in firing rate, but theta-entrainment was impaired. Periods of theta-entrainment and firing rate changes appeared to be independent variables, and only theta-entrainment was correlated with successful performance, indicating mPFC-HPC theta-range interactions are the key to successful DNMS performance. PMID:20431726

  17. Midline Dose Verification with Diode In Vivo Dosimetry for External Photon Therapy of Head and Neck and Pelvis Cancers During Initial Large-Field Treatments

    SciTech Connect

    Tung, Chuan-Jong; Yu, Pei-Chieh; Chiu, Min-Chi; Yeh, Chi-Yuan; Lee, Chung-Chi; Chao, Tsi-Chian

    2010-01-01

    During radiotherapy treatments, quality assurance/control is essential, particularly dose delivery to patients. This study was designed to verify midline doses with diode in vivo dosimetry. Dosimetry was studied for 6-MV bilateral fields in head and neck cancer treatments and 10-MV bilateral and anteroposterior/posteroanterior (AP/PA) fields in pelvic cancer treatments. Calibrations with corrections of diodes were performed using plastic water phantoms; 190 and 100 portals were studied for head and neck and pelvis treatments, respectively. Calculations of midline doses were made using the midline transmission, arithmetic mean, and geometric mean algorithms. These midline doses were compared with the treatment planning system target doses for lateral or AP (PA) portals and paired opposed portals. For head and neck treatments, all 3 algorithms were satisfactory, although the geometric mean algorithm was less accurate and more uncertain. For pelvis treatments, the arithmetic mean algorithm seemed unacceptable, whereas the other algorithms were satisfactory. The random error was reduced by using averaged midline doses of paired opposed portals because the asymmetric effect was averaged out. Considering the simplicity of in vivo dosimetry, the arithmetic mean and geometric mean algorithm should be adopted for head/neck and pelvis treatments, respectively.

  18. Electroencephalographic changes during piano playing and related mental tasks.

    PubMed

    Katayama, S; Hori, Y; Inokuchi, S; Hirata, T; Hayashi, Y

    1992-02-01

    Theta activity in EEG was found to be augmented in the frontal midline area in 5 young women while they played classical piano pieces and during related mental tasks. This activity was considered to be a frontal midline theta rhythm with the maximal amplitude mostly in Fz and of the frequency ranging from 5 to 7.5 Hz. This theta activity was observed to increase depending on the degree of the subjects' concentration on piano playing or related tasks. In bilateral parietal derivations, increases in the power value of alpha activity were observed in some subjects while they were listening to music, suggesting that alpha activity was involved in appreciation of music. PMID:1561902

  19. Optimal point of insertion of the needle in neuraxial blockade using a midline approach: study in a geometrical model

    PubMed Central

    Vogt, Mark; van Gerwen, Dennis J; van den Dobbelsteen, John J; Hagenaars, Martin

    2016-01-01

    Performance of neuraxial blockade using a midline approach can be technically difficult. It is therefore important to optimize factors that are under the influence of the clinician performing the procedure. One of these factors might be the chosen point of insertion of the needle. Surprisingly few data exist on where between the tips of two adjacent spinous processes the needle should be introduced. A geometrical model was adopted to gain more insight into this issue. Spinous processes were represented by parallelograms. The length, the steepness relative to the skin, and the distance between the parallelograms were varied. The influence of the chosen point of insertion of the needle on the range of angles at which the epidural and subarachnoid space could be reached was studied. The optimal point of insertion was defined as the point where this range is the widest. The geometrical model clearly demonstrated, that the range of angles at which the epidural or subarachnoid space can be reached, is dependent on the point of insertion between the tips of the adjacent spinous processes. The steeper the spinous processes run, the more cranial the point of insertion should be. Assuming that the model is representative for patients, the performance of neuraxial blockade using a midline approach might be improved by choosing the optimal point of insertion. PMID:27570462

  20. Unusual clinical case: extraluminal manifestation of a tapeworm from the eviscerated midline incision in a post-surgery patient.

    PubMed

    Dural, Ahmet Cem; Celik, Muhammet Ferhat; Temizgonul, Baha; Unsal, Mustafa Gokhan; Akarsu, Cevher; Gonenc, Murat; Kalayci, Mustafa Uygar; Alis, Halil

    2015-04-01

    Taenia saginata infestation is one of the most common cestode infestations in humans, that may cause gastrointestinal tract related complications as a result of obstruction, perforation or anastomotic leakage. A 55-year-old male patient who was receiving palliative chemotherapy for stage IV gastric cancer was admitted to the emergency department for abdominal pain. A hollow viscus organ perforation was diagnosed and an emergency surgery was performed. On postoperative day 5, the patient's midline incision eviscerated and a moving taenia emerged, with abundant particulated fluid from the incision line. The patient was admitted for abdominal surgery due to suspected bowel perforation. During the abdominal exploration, a relaxed purse stitch of the feeding tube was observed and no other bowel perforations were seen. The patient underwent two planned surgery for abdominal cavity lavage after the removal of cestode. Unfortunately, the patient died sixteen days after his admission to the intensive care unit. This is the first case describing an extraluminal manifestation of a tapeworm in a midline incision from evisceration without intestinal perforation. PMID:25881535

  1. Role of hippocampal H1 receptors in radial maze performance and hippocampal theta activity in rats.

    PubMed

    Masuoka, Takayoshi; Kamei, Chiaki

    2007-07-12

    Histamine H1 antagonists impaired the spatial memory performance. On the other hand, it is well recognized that the hippocampal theta rhythm plays a critical role in spatial memory. However, little work has been done the effect of H1 antagonists on the hippocampal theta rhythm which was associated with the memory performance. We investigated the effect of pyrilamine, a selective H1 receptor antagonist, on spatial memory performance as well as hippocampal theta rhythm during the memory task in rats. Effect of pyrilamine on spatial memory was measured using eight-arm radial maze with four arms baited. Hippocampal theta rhythm during the radial maze task was recorded with a polygraph system with a telemetric technique. Intraperitoneal injection of pyrilamine resulted in impairments of both reference and working memory on the radial maze task. The working memory deficit induced by pyrilamine was antagonized by the intrahippocampal injection of histamine and 6-[2-(4-imidazolyl)ethylamino]-N-(4-trifluoromethylphenyl)heptanecarboxamide (HTMT), a histamine H1 agonist. Intraperitoneal injection of pyrilamine decreased the hippocampal theta power at a dose that impaired reference and working memory. This effect was antagonized by the intrahippocampal injection of histamine and HTMT at a dose that ameliorated the working memory deficit. Intrahippocampal injection of pyrilamine impaired working memory and simultaneously decreased the hippocampal theta power. These results suggest that: (i) the hippocampal H1 receptors play an important role in the working memory processes on the radial maze performance and (ii) the decrease in the hippocampal theta power is associated with the working memory deficit induced by the blocking of H1 receptors. PMID:17562388

  2. A Reexamination of the Small Overlap Frontal Crash

    PubMed Central

    Scullion, Paul; Morgan, Richard M.; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 – 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 – 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study—following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC—suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  3. Specialized cortical subnetworks differentially connect frontal cortex to parahippocampal areas.

    PubMed

    Hirai, Yasuharu; Morishima, Mieko; Karube, Fuyuki; Kawaguchi, Yasuo

    2012-02-01

    How information is manipulated and segregated within local circuits in the frontal cortex remains mysterious, in part because of inadequate knowledge regarding the connectivity of diverse pyramidal cell subtypes. The frontal cortex participates in the formation and retrieval of declarative memories through projections to the perirhinal cortex, and in procedural learning through projections to the striatum/pontine nuclei. In rat frontal cortex, we identified two pyramidal cell subtypes selectively projecting to distinct subregions of perirhinal cortex (PRC). PRC-projecting cells in upper layer 2/3 (L2/3) of the frontal cortex projected to perirhinal area 35, while neurons in L5 innervated perirhinal area 36. L2/3 PRC-projecting cells partially overlapped with those projecting to the basolateral amygdala. L5 PRC-projecting cells partially overlapped with crossed corticostriatal cells, but were distinct from neighboring corticothalamic (CTh)/corticopontine cells. L5 PRC-projecting and CTh cells were different in their electrophysiological properties and dendritic/axonal morphologies. Within the frontal cortex, L2/3 PRC-projecting cells innervated L5 PRC-projecting and CTh cells with similar probabilities, but received feedback excitation only from PRC-projecting cells. These data suggest that specific neuron subtypes in different cortical layers are reciprocally excited via interlaminar loops. Thus, two interacting output channels send information from the frontal cortex to different hierarchical stages of the parahippocampal network, areas 35 and 36, with additional collaterals selectively targeting the amygdala or basal ganglia, respectively. Combined with the hierarchical connectivity of PRC-projecting and CTh cells, these observations demonstrate an exquisite diversification of frontal projection neurons selectively connected according to their participation in distinct memory subsystems. PMID:22302828

  4. The "frontal syndrome" revisited: lessons from electrostimulation mapping studies.

    PubMed

    Duffau, Hugues

    2012-01-01

    For a long time, in a localizationist view of brain functioning, a combination of symptoms called "frontal syndrome" has been interpreted as the direct result of damages involving the frontal lobe(s). The goal of this review is to challenge this view, that is, to move to a hodotopical approach to lesion mapping, on the basis of new insights provided by intraoperative electrostimulation mapping investigations in patients who underwent awake surgery for cerebral tumors. These original data reported in the last decade break with the traditional dogma of a modular and fixed organization of the central nervous system, by switching to the concepts of cerebral connectivity and plasticity - i.e., a brain organization based on dynamic interrelationships between parallel distributed networks. According to this revisited model, "frontal symptoms" can be generated by tumor or electrostimulation not only of the frontal lobes, but also of cortical and subcortical (white matter pathways/deep gray nuclei) structures outside the frontal lobes: especially, stimulation of the superior longitudinal fascicle may elicit speech production disorders, syntactic disturbances, involuntary language switching or phonemic paraphasia (arcuate fascicle), stimulation of the inferior fronto-occipital fascicle can generate semantic paraphasia or deficit of cross-modal judgment, stimulation of the subcallosal fasciculus may elicit transcortical motor aphasia, while stimulation of the striatum induces preservations. On the other hand, it is also possible to perform extensive right or left frontal lobectomy in patients who continue to have a normal familial, social and professional life, without "frontal syndrome". Therefore, this provocative approach may open the door to a renewal in the modeling of brain processing as well as in its clinical applications, especially in the fields of cerebral surgery and functional rehabilitation. These findings illustrate well the need to reinforce links between

  5. Frontal Eye Fields Control Attentional Modulation of Alpha and Gamma Oscillations in Contralateral Occipitoparietal Cortex

    PubMed Central

    O'Shea, Jacinta; Jensen, Ole; Bergmann, Til O.

    2015-01-01

    Covertly directing visuospatial attention produces a frequency-specific modulation of neuronal oscillations in occipital and parietal cortices: anticipatory alpha (8–12 Hz) power decreases contralateral and increases ipsilateral to attention, whereas stimulus-induced gamma (>40 Hz) power is boosted contralaterally and attenuated ipsilaterally. These modulations must be under top-down control; however, the control mechanisms are not yet fully understood. Here we investigated the causal contribution of the human frontal eye field (FEF) by combining repetitive transcranial magnetic stimulation (TMS) with subsequent magnetoencephalography. Following inhibitory theta burst stimulation to the left FEF, right FEF, or vertex, participants performed a visual discrimination task requiring covert attention to either visual hemifield. Both left and right FEF TMS caused marked attenuation of alpha modulation in the occipitoparietal cortex. Notably, alpha modulation was consistently reduced in the hemisphere contralateral to stimulation, leaving the ipsilateral hemisphere relatively unaffected. Additionally, right FEF TMS enhanced gamma modulation in left visual cortex. Behaviorally, TMS caused a relative slowing of response times to targets contralateral to stimulation during the early task period. Our results suggest that left and right FEF are causally involved in the attentional top-down control of anticipatory alpha power in the contralateral visual system, whereas a right-hemispheric dominance seems to exist for control of stimulus-induced gamma power. These findings contrast the assumption of primarily intrahemispheric connectivity between FEF and parietal cortex, emphasizing the relevance of interhemispheric interactions. The contralaterality of effects may result from a transient functional reorganization of the dorsal attention network after inhibition of either FEF. PMID:25632139

  6. Dissociable Roles of Dorsolateral Prefrontal Cortex and Frontal Eye Fields During Saccadic Eye Movements

    PubMed Central

    Cameron, Ian G. M.; Riddle, Justin M.; D’Esposito, Mark

    2015-01-01

    The dorsolateral prefrontal cortex (DLPFC) and the frontal eye fields (FEF) have both been implicated in the executive control of saccades, yet possible dissociable roles of each region have not been established. Specifically, both establishing a “task set” as well as suppressing an inappropriate response have been linked to DLPFC and FEF activity, with behavioral outcome measures of these mechanisms mainly being the percentage of pro-saccade errors made on anti-saccade trials. We used continuous theta-burst stimulation (cTBS) to disrupt FEF or DLPFC function in humans during an anti-saccade task to assess the causal role of these regions in these executive control processes, and in programming saccades towards (pro-saccade) or away (anti-saccade) from visual targets. After right FEF cTBS, as compared to control cTBS to the right primary somatosensory cortex (rS1), anti-saccade amplitude of the first saccade decreased and the number of anti-saccades to acquire final position increased; however direction errors to the visual target were not different. In contrast, after left DLPFC cTBS, as compared to left S1 cTBS, subjects displayed greater direction errors for contralateral anti-saccades; however, there were no impairments on the number of saccades or the saccade amplitude. These results are consistent with the notion that DLPFC is necessary for executive control of saccades, whereas FEF is necessary for visuo-motor aspects of anti-saccade programming. PMID:26635572

  7. The validity of individual frontal alpha asymmetry EEG neurofeedback.

    PubMed

    Quaedflieg, C W E M; Smulders, F T Y; Meyer, T; Peeters, F; Merckelbach, H; Smeets, T

    2016-01-01

    Frontal asymmetry in alpha oscillations is assumed to be associated with psychopathology and individual differences in emotional responding. Brain-activity-based feedback is a promising tool for the modulation of cortical activity. Here, we validated a neurofeedback protocol designed to change relative frontal asymmetry based on individual alpha peak frequencies, including real-time average referencing and eye-correction. Participants (N = 60) were randomly assigned to a right, left or placebo neurofeedback group. Results show a difference in trainability between groups, with a linear change in frontal alpha asymmetry over time for the right neurofeedback group during rest. Moreover, the asymmetry changes in the right group were frequency and location specific, even though trainability did not persist at 1 week and 1 month follow-ups. On the behavioral level, subjective stress on the second test day was reduced in the left and placebo neurofeedback groups, but not in the right neurofeedback group. We found individual differences in trainability that were dependent on training group, with participants in the right neurofeedback group being more likely to change their frontal asymmetry in the desired direction. Individual differences in trainability were also reflected in the ability to change frontal asymmetry during the feedback. PMID:26163671

  8. Frontal Sinus Mucopyocele Presenting as a Subcutaneous Forehead Mass.

    PubMed

    Carmichael, Ryan A; Kang, David R

    2015-11-01

    Mucoceles of the paranasal sinuses are benign, chronic, expanding lesions that characteristically develop because of obstruction of the sinus ostium. The frontal sinus is the most common sinus to be affected by a mucocele, which usually results from trauma or inflammatory processes. Patients with these lesions frequently present with visual complaints of decreased visual acuity, visual field abnormalities, proptosis, ptosis, displacement of the globe, or restricted ocular movements secondary to erosion through the thin bone of the superior orbit and compression on the globe. Often, intracranial extension of frontal sinus mucoceles is also present from erosion through the posterior table of the frontal sinus. Very rarely, they will present as a subcutaneous forehead mass or swelling. To the best of our knowledge, only 5 cases of a frontal sinus mucocele presenting as a forehead subcutaneous mass has been previously reported. We report the case of an 80-year-old woman with a history of remote forehead trauma who presented with a frontal sinus mucopyocele manifesting as a subcutaneous forehead mass eroding through the skin. PMID:26044600

  9. Mechanisms of spatial attention control in frontal and parietal cortex.

    PubMed

    Szczepanski, Sara M; Konen, Christina S; Kastner, Sabine

    2010-01-01

    Theories of spatial attentional control have been largely based upon studies of patients suffering from visuospatial neglect, resulting from circumscribed lesions of frontal and posterior parietal cortex. In the intact brain, the control of spatial attention has been related to a distributed frontoparietal attention network. Little is known about the nature of the control mechanisms exerted by this network. Here, we used a novel region-of-interest approach to relate activations of the attention network to recently described topographic areas in frontal cortex [frontal eye field (FEF), PreCC/IFS (precentral cortex/inferior frontal sulcus)] and parietal cortex [intraparietal sulcus areas (IPS1-IPS5) and an area in the superior parietal lobule (SPL1)] to examine their spatial attention signals. We found that attention signals in most topographic areas were spatially specific, with stronger responses when attention was directed to the contralateral than to the ipsilateral visual field. Importantly, two hemispheric asymmetries were found. First, a region in only right, but not left SPL1 carried spatial attention signals. Second, left FEF and left posterior parietal cortex (IPS1/2) generated stronger contralateral biasing signals than their counterparts in the right hemisphere. These findings are the first to characterize spatial attention signals in topographic frontal and parietal cortex and provide a neural basis in support of an interhemispheric competition account of spatial attentional control. PMID:20053897

  10. [FRONTAL, AXILLARY AND TYMPANIC TEMPERATURE MEASUREMENTS IN CHILDREN].

    PubMed

    Antabak, Anko; Sisko, Jerko; Romić, Ivan; Papes, Dino; Pasini, Miran; Haluzan, Damir; Bogović, Marko; Medancić, Suzana Srsen; Cavar, Stanko; Luetić, Tomislav; Fuchs, Nino; Andabak, Matej; Prlić, Ivica; Curković, Selena

    2016-01-01

    The purpose of this study was to compare the results of body temperature measurements obtained by standard axillary thermometers with the results of infrared tympanic and frontal skin thermometry in afebrile children. This study comprises a single-center, prospective comparison trial. A total of 345 afebrile children aged 4 to 16 years hospitalized in the pediatric surgery department for elective surgery were included. One thousand axillary, tympanic and frontal measurements were obtained and compared. We used two different infrared thermometers in this study; one type measured the tympanic temperature, the other the temperature on the forehead. The axillary temperature measured with the glass thermometer was set as the standard. Each patient was exposed to a constant environmental temperature for a minimum of 10 min before simultaneous temperature measurements. The mean-frontal temperature 36.9 ± 0.38 °C was equal to the axillary temperature 36.9 ± 0.16 °C. The mean tympanic temperature was 36.3 ± 0.98 °C. The mean difference between the tympanic and axillary temperatures was -0.4 °C. The tympanic temperature had a threefold greater dispersion than frontal and a fivefold greater dispersion than axillary temperature. The results of this study suggest that the axillary temperature measured with glass thermometer has the least dispersion. Somewhat less reliable is the frontal temperature measured with infrared thermometer. The least reliable is tympanic temperature measurement. PMID:27290811

  11. Search for $\\Theta^{++}$ Pentaquarks in the Exclusive Reaction $\\gamma p\\to K^+K^-p$

    SciTech Connect

    V. Kubarovsky; Marco Battaglieri; Raffaella De Vita; John Goett; Lei Guo; Gordon Mutchler; Paul Stoler; Dennis Weygand; Pawel Ambrozewicz; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; Harutyun Avakian; H. Bagdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; V. Batourine; Ivan Bedlinski; Ivan Bedlinskiy; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Eric Clinton; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; Volker Crede; John Cummings; Rita De Masi; Daniel Dale; Enzo De Sanctis; Pavel Degtiarenko; Alexandre Deur; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Herbert Funsten; Marianna Gabrielyan; Liping Gan; Michel Garcon; Ashot Gasparian; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; Oleksandr Glamazdin; John Goetz; Evgueni Golovatch; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Rafael Hakobyan; John Hardie; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Franz Klein; Friedrich Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Ji Li; Kenneth Livingston; Hai-jiang Lu; Marion MacCormick; Nikolai Markov; Bryan McKinnon; Bernhard Mecking; Joseph Melone; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; Rory Miskimen; Vasiliy Mochalov; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Pawel Nadel-Turonski; Itaru Nakagawa; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; Kijun Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Igor Strakovski; Steffen Strauch; Mauro Taiuti; David Tedeschi; Aram Teymurazyan; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Lawrence Weinstein; Michael Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao

    2006-04-28

    The reaction {gamma}p {yields} K{sup +}K{sup -}p was studied at Jefferson Lab with photon energies from 1.8 to 3.8 GeV using a tagged photon beam. The goal was to search for a {Theta}{sup ++} pentaquark, a narrow doubly charged baryon state having strangeness S = +1 and isospin I = 1, in the pK{sup +} invariant mass spectrum. No statistically significant evidence of a {Theta}{sup ++} was found. Upper limits on the total and differential production cross section for the reaction {gamma}p {yields} K{sup -}{Theta}{sup ++} were obtained in the mass range from 1.5 to 2.0 GeV/c{sup 2}, with an upper limit of about 0.15 nb, 95% C.L. for a narrow resonance with a mass M{sub {Theta}{sup ++}} = 1.54 GeV/c{sup 2}. This result places a very stringent upper limit on the {Theta}{sup ++} width.

  12. Spatial Working Memory in Humans Depends on Theta and High Gamma Synchronization in the Prefrontal Cortex.

    PubMed

    Alekseichuk, Ivan; Turi, Zsolt; Amador de Lara, Gabriel; Antal, Andrea; Paulus, Walter

    2016-06-20

    Previous, albeit correlative, findings have shown that the neural mechanisms underlying working memory critically require cross-structural and cross-frequency coupling mechanisms between theta and gamma neural oscillations. However, the direct causality between cross-frequency coupling and working memory performance remains to be demonstrated. Here we externally modulated the interaction of theta and gamma rhythms in the prefrontal cortex using novel cross-frequency protocols of transcranial alternating current stimulation to affect spatial working memory performance in humans. Enhancement of working memory performance and increase of global neocortical connectivity were observed when bursts of high gamma oscillations (80-100 Hz) coincided with the peaks of the theta waves, whereas superimposition on the trough of the theta wave and low gamma frequency protocols were ineffective. Thus, our results demonstrate the sensitivity of working memory performance and global neocortical connectivity to the phase and rhythm of the externally driven theta-gamma cross-frequency synchronization. PMID:27238283

  13. Event-related delta and theta synchronization during explicit and implicit emotion processing.

    PubMed

    Knyazev, G G; Slobodskoj-Plusnin, J Y; Bocharov, A V

    2009-12-29

    Emotion information processing may occur in two modes which are differently represented in conscious awareness. Fast online processing involves coarse-grained analysis of salient features, and is not represented in conscious awareness; offline processing takes hundreds of milliseconds to generate fine-grained analysis, and is represented in conscious awareness. These processing modes may be studied using event-related electroencephalogram theta and delta synchronization as a marker of emotion processing. Two experiments were conducted, which differed on the mode of emotional information presentation. In the explicit mode subjects were explicitly instructed to evaluate the emotional content of presented stimuli; in the implicit mode they performed a gender discrimination task. Firstly, we show that in both experiments theta and delta synchronization is stronger upon presentation of "emotional" than "neutral" stimuli, and in subjects who are more sensitive, or experience higher emotional involvement than in less sensitive or detached subjects. Secondly, we show that in the implicit mode theta and delta synchronization is more pronounced in an early (before 250 ms post-stimulus) processing stage, whereas in the explicit mode it is more pronounced in a later processing stage. Source localization analysis showed that implicit processing of angry and happy (relative to neutral) faces is associated with higher early (before 250 ms) theta synchronization in the right parietal cortex and the right insula, respectively. Explicit processing of angry and happy faces is associated with higher late (after 250 ms) theta synchronization in the left temporal lobe and bilateral prefrontal cortex, respectively. PMID:19796666

  14. Monte Carlo simulation studies of ring polymers at athermal and theta conditions

    NASA Astrophysics Data System (ADS)

    Fuereder, Ingo; Zifferer, Gerhard

    2011-11-01

    By use of an intramolecular criterion, i.e., the direct proportionality between mean square dimension and chain length, theta conditions for linear chains and ring shaped polymers are evaluated for several types of cubic lattice chains (simple cubic, body centered cubic, and face centered cubic). The properties of the rings are evaluated for the same thermodynamic conditions under which they are prepared thus allowing for a natural amount of knots which have been identified by use of Alexander polynomials. For the limit of infinite chain lengths the same theta parameter is found for linear chains and rings. On the contrary, a significant theta point depression occurs due to an additional excluded volume effect if unknots are exclusively regarded. Parameters characteristic of the shape of rings and chains under theta conditions extrapolated to infinite chain length fairly well coincide with respective data for random walks. Mean square dimensions (characteristic of the size) of theta systems are slightly in excess as compared to nonreversal random walks due to the necessity of avoiding overlaps on a local scale. Furthermore athermal systems are studied as well for comparison; mean square dimensions are described by use of scaling relations with proper short chain corrections, shape parameters are given in the limit of infinite chain length.

  15. The effects of alpha/theta neurofeedback on personality and mood.

    PubMed

    Raymond, Joshua; Varney, Carolyn; Parkinson, Lesley A; Gruzelier, John H

    2005-05-01

    Alpha/theta neurofeedback has been shown to be successful both in treating addictions and in enhancing artistry in music students. How its effects are mediated are not yet clear. The present study aimed to test the hypothesis that alpha/theta neurofeedback works inter alia by normalising extreme personality and raising feelings of well being. 12 participants with high scores for Withdrawal (as measured by the PSQ) were given either alpha/theta neurofeedback or mock feedback and their personality and mood were assessed. Withdrawal scores on the PSQ-80 were not found to change in either group but significant effects were found for the Profile Of Mood States (POMS), with real feedback producing higher overall scores than mock feedback (P = 0.056). Real feedback caused participants to feel significantly more energetic (P < 0.01) than did mock feedback. Sessions of real feedback made participants feel more composed (P < 0.01), agreeable (P < 0.01), elevated (P < 0.01) and confident (P < 0.05), whilst sessions of mock feedback made participants feel more tired (P < 0.05), yet composed (P < 0.01). These findings suggest that, whilst 9 sessions of alpha/theta neurofeedback was insufficient to change personality, improvements in mood may provide a partial explanation for the efficacy of alpha/theta neurofeedback. PMID:15820636

  16. Hippocampal Theta Modulation of Neocortical Spike Times and Gamma Rhythm: A Biophysical Model Study

    PubMed Central

    Spaak, Eelke; Zeitler, Magteld; Gielen, Stan

    2012-01-01

    The hippocampal theta and neocortical gamma rhythms are two prominent examples of oscillatory neuronal activity. The hippocampus has often been hypothesized to influence neocortical networks by its theta rhythm, and, recently, evidence for such a direct influence has been found. We examined a possible mechanism for this influence by means of a biophysical model study using conductance-based model neurons. We found, in agreement with previous studies, that networks of fast-spiking GABA -ergic interneurons, coupled with shunting inhibition, synchronize their spike activity at a gamma frequency and are able to impose this rhythm on a network of pyramidal cells to which they are coupled. When our model was supplied with hippocampal theta-modulated input fibres, the theta rhythm biased the spike timings of both the fast-spiking and pyramidal cells. Furthermore, both the amplitude and frequency of local field potential gamma oscillations were influenced by the phase of the theta rhythm. We show that the fast-spiking cells, not pyramidal cells, are essential for this latter phenomenon, thus highlighting their crucial role in the interplay between hippocampus and neocortex. PMID:23056213

  17. Collective Dynamics for Heterogeneous Networks of Theta Neurons

    NASA Astrophysics Data System (ADS)

    Luke, Tanushree

    Collective behavior in neural networks has often been used as an indicator of communication between different brain areas. These collective synchronization and desynchronization patterns are also considered an important feature in understanding normal and abnormal brain function. To understand the emergence of these collective patterns, I create an analytic model that identifies all such macroscopic steady-states attainable by a network of Type-I neurons. This network, whose basic unit is the model "theta'' neuron, contains a mixture of excitable and spiking neurons coupled via a smooth pulse-like synapse. Applying the Ott-Antonsen reduction method in the thermodynamic limit, I obtain a low-dimensional evolution equation that describes the asymptotic dynamics of the macroscopic mean field of the network. This model can be used as the basis in understanding more complicated neuronal networks when additional dynamical features are included. From this reduced dynamical equation for the mean field, I show that the network exhibits three collective attracting steady-states. The first two are equilibrium states that both reflect partial synchronization in the network, whereas the third is a limit cycle in which the degree of network synchronization oscillates in time. In addition to a comprehensive identification of all possible attracting macro-states, this analytic model permits a complete bifurcation analysis of the collective behavior of the network with respect to three key network features: the degree of excitability of the neurons, the heterogeneity of the population, and the overall coupling strength. The network typically tends towards the two macroscopic equilibrium states when the neuron's intrinsic dynamics and the network interactions reinforce each other. In contrast, the limit cycle state, bifurcations, and multistability tend to occur when there is competition between these network features. I also outline here an extension of the above model where the

  18. What is a realistic frontal-offset test procedure?

    PubMed

    Scheunert, D; Justen, R; Herrmann, R; Zeidler, F; Decker, J; Kallina, I

    1994-06-01

    With an increasing number of vehicles satisfying the FMVSS 208 Flat Barrier Impact Test and increasing belt usage, a high reduction of occupant injuries in general and a change from acceleration-induced to intrusion-induced injury mechanisms has been observed in Europe. The significance of intrusion-induced injury mechanisms associated with offset frontal impacts is assuming greater importance. Beginning in 1978, in response to this challenge, Mercedes-Benz has emphasized front structural countermeasures that have been found to be effective in the frequent asymmetrical frontal impacts. As an internal test, an offset impact with 40% overlap against a rigid barrier was defined. The relationship between actual accident frontal-overlap damage and barrier-test overlap values is explored in the paper. The results support the view that if a test of this type and associated design countermeasures were adopted by all vehicle manufacturers, a significant reduction of injuries would take place. PMID:8011047

  19. Simulation of frontal eddies on the East Florida Shelf

    NASA Astrophysics Data System (ADS)

    Fiechter, Jerome; Mooers, Christopher N. K.

    2003-11-01

    Frontal eddies are typical features on the cyclonic side of the Florida Current (FC) along the East Florida Shelf (EFS), producing characteristic ``shingle'' patterns in sea surface temperature. Intensive observations and idealized numerical analyses have described such eddies over the past three decades. Here, simulations from a high-resolution (2 to 10 km), curvilinear coastal ocean circulation model demonstrate their structure and evolution with realistic bottom topography and FC over an extended domain including the Straits of Florida and the entire EFS. Simulations agree with observations in estimating translation speed, recurrence period, strength, characteristic length-scales, and overall circulation patterns. In addition, the simulations demonstrate the interactions between the frontal eddies and the meander crests and bottom topography as they translate along the EFS. Overall, a first level of model validation has been established that will facilitate consideration of the forecast problem for frontal eddies associated with the FC on the EFS.

  20. Rapid preparation of molecularly imprinted polymer by frontal polymerization.

    PubMed

    Zhong, Dan-Dan; Liu, Xin; Pang, Qian-Qian; Huang, Yan-Ping; Liu, Zhao-Sheng

    2013-04-01

    Frontal polymerization was successfully applied, for the first time, to obtain molecularly imprinted polymers (MIPs). The method provides a solvent-free polymerization mode, and the reaction can be completed in 30 min. By this approach, MIPs were synthesized using a mixture of levofloxacin (template), methacrylic acid, and divinylbenzene. The effect of template concentration and the amount of comonomer on the imprinting effect of the resulting MIPs was investigated. The textural and morphological parameters of the MIP particles were also characterized by mercury intrusion porosimetry, nitrogen adsorption isotherms, and scanning electron microscopy, providing evidence concerning median pore diameter, pore volumes, and pore size distributions. The levofloxacin-imprinted polymer formed in frontal polymerization mode showed high selectivity, with an imprinting factor of 5.78. The results suggest that frontal polymerization provides an alternative means to prepare MIPs that are difficult to synthesize and may open up new perspectives in the field of MIPs. PMID:23392405