WorldWideScience

Sample records for human medial temporal

  1. Medial temporal lobe roles in human path integration.

    Directory of Open Access Journals (Sweden)

    Naohide Yamamoto

    Full Text Available Path integration is a process in which observers derive their location by integrating self-motion signals along their locomotion trajectory. Although the medial temporal lobe (MTL is thought to take part in path integration, the scope of its role for path integration remains unclear. To address this issue, we administered a variety of tasks involving path integration and other related processes to a group of neurosurgical patients whose MTL was unilaterally resected as therapy for epilepsy. These patients were unimpaired relative to neurologically intact controls in many tasks that required integration of various kinds of sensory self-motion information. However, the same patients (especially those who had lesions in the right hemisphere walked farther than the controls when attempting to walk without vision to a previewed target. Importantly, this task was unique in our test battery in that it allowed participants to form a mental representation of the target location and anticipate their upcoming walking trajectory before they began moving. Thus, these results put forth a new idea that the role of MTL structures for human path integration may stem from their participation in predicting the consequences of one's locomotor actions. The strengths of this new theoretical viewpoint are discussed.

  2. Medial temporal lobe

    International Nuclear Information System (INIS)

    Silver, A.J.; Cross, D.T.; Friedman, D.P.; Bello, J.A.; Hilal, S.K.

    1989-01-01

    To better define the MR appearance of hippocampal sclerosis, the authors have reviewed over 500 MR coronal images of the temporal lobes. Many cysts were noted that analysis showed were of choroid-fissure (arachnoid) origin. Their association with seizures was low. A few nontumorous, static, medial temporal lesions, noted on T2-weighted coronal images, were poorly visualized on T1-weighted images and did not enhance with gadolinium. The margins were irregular, involved the hippocampus, and were often associated with focal atrophy. The lesions usually were associated with seizure disorders and specific electroencephalographic changes, and the authors believe they represented hippocampal sclerosis

  3. Parametric fMRI analysis of visual encoding in the human medial temporal lobe.

    Science.gov (United States)

    Rombouts, S A; Scheltens, P; Machielson, W C; Barkhof, F; Hoogenraad, F G; Veltman, D J; Valk, J; Witter, M P

    1999-01-01

    A number of functional brain imaging studies indicate that the medial temporal lobe system is crucially involved in encoding new information into memory. However, most studies were based on differences in brain activity between encoding of familiar vs. novel stimuli. To further study the underlying cognitive processes, we applied a parametric design of encoding. Seven healthy subjects were instructed to encode complex color pictures into memory. Stimuli were presented in a parametric fashion at different rates, thus representing different loads of encoding. Functional magnetic resonance imaging (fMRI) was used to assess changes in brain activation. To determine the number of pictures successfully stored into memory, recognition scores were determined afterwards. During encoding, brain activation occurred in the medial temporal lobe, comparable to the results obtained by others. Increasing the encoding load resulted in an increase in the number of successfully stored items. This was reflected in a significant increase in brain activation in the left lingual gyrus, in the left and right parahippocampal gyrus, and in the right inferior frontal gyrus. This study shows that fMRI can detect changes in brain activation during variation of one aspect of higher cognitive tasks. Further, it strongly supports the notion that the human medial temporal lobe is involved in encoding novel visual information into memory.

  4. Peripheral inflammation acutely impairs human spatial memory via actions on medial temporal lobe glucose metabolism.

    Science.gov (United States)

    Harrison, Neil A; Doeller, Christian F; Voon, Valerie; Burgess, Neil; Critchley, Hugo D

    2014-10-01

    Inflammation impairs cognitive performance and is implicated in the progression of neurodegenerative disorders. Rodent studies demonstrated key roles for inflammatory mediators in many processes critical to memory, including long-term potentiation, synaptic plasticity, and neurogenesis. They also demonstrated functional impairment of medial temporal lobe (MTL) structures by systemic inflammation. However, human data to support this position are limited. Sequential fluorodeoxyglucose positron emission tomography together with experimentally induced inflammation was used to investigate effects of a systemic inflammatory challenge on human MTL function. Fluorodeoxyglucose positron emission tomography scanning was performed in 20 healthy participants before and after typhoid vaccination and saline control injection. After each scanning session, participants performed a virtual reality spatial memory task analogous to the Morris water maze and a mirror-tracing procedural memory control task. Fluorodeoxyglucose positron emission tomography data demonstrated an acute reduction in human MTL glucose metabolism after inflammation. The inflammatory challenge also selectively compromised human spatial, but not procedural, memory; this effect that was independent of actions on motivation or psychomotor response. Effects of inflammation on parahippocampal and rhinal glucose metabolism directly mediated actions of inflammation on spatial memory. These data demonstrate acute sensitivity of human MTL to mild peripheral inflammation, giving rise to associated functional impairment in the form of reduced spatial memory performance. Our findings suggest a mechanism for the observed epidemiologic link between inflammation and risk of age-related cognitive decline and progression of neurodegenerative disorders including Alzheimer's disease. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. Regional activation of the human medial temporal lobe during intentional encoding of objects and positions

    DEFF Research Database (Denmark)

    Ramsøy, Thomas Z.; Liptrot, Matthew G.; Skimminge, Arnold

    2009-01-01

    The medial temporal lobe (MTL) consists of several regions thought to be involved in learning and memory. However, the degree of functional specialization among these regions remains unclear. Previous studies have demonstrated effects of both content and processing stage, but findings have been i...

  6. Human amnesia and the medial temporal lobe illuminated by neuropsychological and neurohistological findings for patient E.P.

    Science.gov (United States)

    Insausti, Ricardo; Annese, Jacopo; Amaral, David G.; Squire, Larry R.

    2013-01-01

    We present neurohistological information for a case of bilateral, symmetrical damage to the medial temporal lobe and well-documented memory impairment. E.P. developed profound memory impairment at age 70 y and then was studied for 14 y He had no capacity for learning facts and events and had retrograde amnesia covering several decades. He also had a modest impairment of semantic knowledge. Neurohistological analysis revealed bilaterally symmetrical lesions of the medial temporal lobe that eliminated the temporal pole, the amygdala, the entorhinal cortex, the hippocampus, the perirhinal cortex, and rostral parahippocampal cortex. The lesion also extended laterally to involve the fusiform gyrus substantially. Last, the superior, inferior, and middle temporal gyri were atrophic, and subjacent white matter was gliotic. Several considerations indicate that E.P.’s severe memory impairment was caused by his medial temporal lesions, whereas his impaired semantic knowledge was caused by lateral temporal damage. His lateral temporal damage also may have contributed to his extensive retrograde amnesia. The findings illuminate the anatomical relationship between memory, perception, and semantic knowledge. PMID:23620517

  7. Single-neuron correlates of subjective vision in the human medial temporal lobe

    OpenAIRE

    Kreiman, Gabriel; Fried, Itzhak; Koch, Christof

    2002-01-01

    Visual information from the environment is transformed into perceptual sensations through several stages of neuronal processing. Flash suppression constitutes a striking example in which the same retinal input can give rise to two different conscious visual percepts. We directly recorded the responses of individual neurons during flash suppression in the human amygdala, entorhinal cortex, hippocampus, and parahippocampal gyrus, allowing us to explore the neuronal responses in untrained subjec...

  8. Episodic reinstatement in the medial temporal lobe.

    Science.gov (United States)

    Staresina, Bernhard P; Henson, Richard N A; Kriegeskorte, Nikolaus; Alink, Arjen

    2012-12-12

    The essence of episodic memory is our ability to reexperience past events in great detail, even in the absence of external stimulus cues. Does the phenomenological reinstatement of past experiences go along with reinstating unique neural representations in the brain? And if so, how is this accomplished by the medial temporal lobe (MTL), a brain region intimately linked to episodic memory? Computational models suggest that such reinstatement (also termed "pattern completion") in cortical regions is mediated by the hippocampus, a key region of the MTL. Although recent functional magnetic resonance imaging studies demonstrated reinstatement of coarse item properties like stimulus category or task context across different brain regions, it has not yet been shown whether reinstatement can be observed at the level of individual, discrete events-arguably the defining feature of episodic memory-nor whether MTL structures like the hippocampus support this "true episodic" reinstatement. Here we show that neural activity patterns for unique word-scene combinations encountered during encoding are reinstated in human parahippocampal cortex (PhC) during retrieval. Critically, this reinstatement occurs when word-scene combinations are successfully recollected (even though the original scene is not visually presented) and does not encompass other stimulus domains (such as word-color associations). Finally, the degree of PhC reinstatement across retrieval events correlated with hippocampal activity, consistent with a role of the hippocampus in coordinating pattern completion in cortical regions.

  9. Altered medial temporal activation related to local glutamate levels in subjects with prodromal signs of psychosis.

    OpenAIRE

    Valli, I; Stone, J; Mechelli, A; Bhattacharyya, S; Raffin, M; Allen, P; Fusar-Poli, P; Lythgoe, D; O'Gorman, R; Seal, M; McGuire, P

    2011-01-01

    In individuals at high risk of psychosis, medial temporal dysfunction seemed related to a loss of the normal relationship with local glutamate levels. This study provides the first evidence that links medial temporal dysfunction with the central glutamate system in humans and is consistent with evidence that drugs that modulate glutamatergic transmission might be useful in the treatment of psychosis.

  10. Altered medial temporal activation related to local glutamate levels in subjects with prodromal signs of psychosis.

    Science.gov (United States)

    Valli, Isabel; Stone, James; Mechelli, Andrea; Bhattacharyya, Sagnik; Raffin, Marie; Allen, Paul; Fusar-Poli, Paolo; Lythgoe, David; O'Gorman, Ruth; Seal, Marc; McGuire, Philip

    2011-01-01

    Both medial temporal cortical dysfunction and perturbed glutamatergic neurotransmission are regarded as fundamental pathophysiological features of psychosis. However, although animal models of psychosis suggest that these two abnormalities are interrelated, their relationship in humans has yet to be investigated. We used a combination of functional magnetic resonance imaging and magnetic resonance spectroscopy to investigate the relationship between medial temporal activation during an episodic memory task and local glutamate levels in 22 individuals with an at-risk mental state for psychosis and 14 healthy volunteers. We observed a significant between-group difference in the coupling of medial temporal activation with local glutamate levels. In control subjects, medial temporal activation during episodic encoding was positively associated with medial temporal glutamate. However, in the clinical population, medial temporal activation was reduced, and the relationship with glutamate was absent. In individuals at high risk of psychosis, medial temporal dysfunction seemed related to a loss of the normal relationship with local glutamate levels. This study provides the first evidence that links medial temporal dysfunction with the central glutamate system in humans and is consistent with evidence that drugs that modulate glutamatergic transmission might be useful in the treatment of psychosis. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  11. Medial temporal lobe damage impairs representation of simple stimuli

    Directory of Open Access Journals (Sweden)

    David E Warren

    2010-05-01

    Full Text Available Medial temporal lobe damage in humans is typically thought to produce a circumscribed impairment in the acquisition of new enduring memories, but recent reports have documented deficits even in short-term maintenance. We examined possible maintenance deficits in a population of medial temporal lobe amnesics, with the goal of characterizing their impairments as either representational drift or outright loss of representation over time. Patients and healthy comparisons performed a visual search task in which the similarity of various lures to a target was varied parametrically. Stimuli were simple shapes varying along one of several visual dimensions. The task was performed in two conditions, one presenting a sample target simultaneously with the search array and the other imposing a delay between sample and array. Eye-movement data collected during search revealed that the duration of fixations to items varied with lure-target similarity for all participants, i.e., fixations were longer for items more similar to the target. In the simultaneous condition, patients and comparisons exhibited an equivalent effect of similarity on fixation durations. However, imposing a delay modulated the effect differently for the two groups: in comparisons, fixation duration to similar items was exaggerated; in patients, the original effect was diminished. These findings indicate that medial temporal lobe lesions subtly impair short-term maintenance of even simple stimuli, with performance reflecting not the complete loss of the maintained representation but rather a degradation or progressive drift of the representation over time.

  12. Default network connectivity in medial temporal lobe amnesia.

    Science.gov (United States)

    Hayes, Scott M; Salat, David H; Verfaellie, Mieke

    2012-10-17

    There is substantial overlap between the brain regions supporting episodic memory and the default network. However, in humans, the impact of bilateral medial temporal lobe (MTL) damage on a large-scale neural network such as the default mode network is unknown. To examine this issue, resting fMRI was performed with amnesic patients and control participants. Seed-based functional connectivity analyses revealed robust default network connectivity in amnesia in cortical default network regions such as medial prefrontal cortex, posterior medial cortex, and lateral parietal cortex, as well as evidence of connectivity to residual MTL tissue. Relative to control participants, decreased posterior cingulate cortex connectivity to MTL and increased connectivity to cortical default network regions including lateral parietal and medial prefrontal cortex were observed in amnesic patients. In contrast, somatomotor network connectivity was intact in amnesic patients, indicating that bilateral MTL lesions may selectively impact the default network. Changes in default network connectivity in amnesia were largely restricted to the MTL subsystem, providing preliminary support from MTL amnesic patients that the default network can be fractionated into functionally and structurally distinct components. To our knowledge, this is the first examination of the default network in amnesia.

  13. MRI parcellation of ex vivo medial temporal lobe.

    Science.gov (United States)

    Augustinack, Jean C; Magnain, Caroline; Reuter, Martin; van der Kouwe, André J W; Boas, David; Fischl, Bruce

    2014-06-01

    Recent advancements in radio frequency coils, field strength and sophisticated pulse sequences have propelled modern brain mapping and have made validation to biological standards - histology and pathology - possible. The medial temporal lobe has long been established as a pivotal brain region for connectivity, function and unique structure in the human brain, and reveals disconnection in mild Alzheimer's disease. Specific brain mapping of mesocortical areas affected with neurofibrillary tangle pathology early in disease progression provides not only an accurate description for location of these areas but also supplies spherical coordinates that allow comparison between other ex vivo cases and larger in vivo datasets. We have identified several cytoarchitectonic features in the medial temporal lobe with high resolution ex vivo MRI, including gray matter structures such as the entorhinal layer II 'islands', perirhinal layer II-III columns, presubicular 'clouds', granule cell layer of the dentate gyrus as well as lamina of the hippocampus. Localization of Brodmann areas 28 and 35 (entorhinal and perirhinal, respectively) demonstrates MRI based area boundaries validated with multiple methods and histological stains. Based on our findings, both myelin and Nissl staining relate to contrast in ex vivo MRI. Precise brain mapping serves to create modern atlases for cortical areas, allowing accurate localization with important applications to detecting early disease processes. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Effect of propofol on the medial temporal lobe emotional memory system: a functional magnetic resonance imaging study in human subjects.

    Science.gov (United States)

    Pryor, K O; Root, J C; Mehta, M; Stern, E; Pan, H; Veselis, R A; Silbersweig, D A

    2015-07-01

    Subclinical doses of propofol produce anterograde amnesia, characterized by an early failure of memory consolidation. It is unknown how propofol affects the amygdala-dependent emotional memory system, which modulates consolidation in the hippocampus in response to emotional arousal and neurohumoral stress. We present an event-related functional magnetic resonance imaging study of the effects of propofol on the emotional memory system in human subjects. Thirty-five healthy subjects were randomized to receive propofol, at an estimated brain concentration of 0.90 μg ml(-1), or placebo. During drug infusion, emotionally arousing and neutral images were presented in a continuous recognition task, while blood-oxygen-level-dependent activation responses were acquired. After a drug-free interval of 2 h, subsequent memory for successfully encoded items was assessed. Imaging analysis was performed using statistical parametric mapping and behavioural analysis using signal detection models. Propofol had no effect on the stereotypical amygdalar response to emotional arousal, but caused marked suppression of the hippocampal response. Propofol caused memory performance to become uncoupled from amygdalar activation, but it remained correlated with activation in the posterior hippocampus, which decreased in proportion to amnesia. Propofol is relatively ineffective at suppressing amygdalar activation at sedative doses, but abolishes emotional modulation and causes amnesia via mechanisms that commonly involve hyporesponsiveness of the hippocampus. These findings raise the possibility that amygdala-dependent fear systems may remain intact even when a patient has diminished memory of events. This may be of clinical importance in the perioperative development of fear-based psychopathologies, such as post-traumatic stress disorder. NCT00504894. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions

  15. Integrating what and when across the primate medial temporal lobe.

    Science.gov (United States)

    Naya, Yuji; Suzuki, Wendy A

    2011-08-05

    Episodic memory or memory for the detailed events in our lives is critically dependent on structures of the medial temporal lobe (MTL). A fundamental component of episodic memory is memory for the temporal order of items within an episode. To understand the contribution of individual MTL structures to temporal-order memory, we recorded single-unit activity and local field potential from three MTL areas (hippocampus and entorhinal and perirhinal cortex) and visual area TE as monkeys performed a temporal-order memory task. Hippocampus provided incremental timing signals from one item presentation to the next, whereas perirhinal cortex signaled the conjunction of items and their relative temporal order. Thus, perirhinal cortex appeared to integrate timing information from hippocampus with item information from visual sensory area TE.

  16. Visual working memory capacity and the medial temporal lobe.

    Science.gov (United States)

    Jeneson, Annette; Wixted, John T; Hopkins, Ramona O; Squire, Larry R

    2012-03-07

    Patients with medial temporal lobe (MTL) damage are sometimes impaired at remembering visual information across delays as short as a few seconds. Such impairments could reflect either impaired visual working memory capacity or impaired long-term memory (because attention has been diverted or because working memory capacity has been exceeded). Using a standard change-detection task, we asked whether visual working memory capacity is intact or impaired after MTL damage. Five patients with hippocampal lesions and one patient with large MTL lesions saw an array of 1, 2, 3, 4, or 6 colored squares, followed after 3, 4, or 8 s by a second array where one of the colored squares was cued. The task was to decide whether the cued square had the same color as the corresponding square in the first array or a different color. At the 1 s delay typically used to assess working memory capacity, patients performed as well as controls at all array sizes. At the longer delays, patients performed as well as controls at small array sizes, thought to be within the capacity limit, and worse than controls at large array sizes, thought to exceed the capacity limit. The findings suggest that visual working memory capacity in humans is intact after damage to the MTL structures and that damage to these structures impairs performance only when visual working memory is insufficient to support performance.

  17. Testing the importance of the Medial Temporal Lobes in human interoception: Does it matter if there is a memory component to the task?

    Science.gov (United States)

    Berriman, Joanne; Stevenson, Richard J; Thayer, Zoe C; Thompson, Elizabeth; Mohamed, Armin; Watson, John D G; Miller, Laurie A

    2016-10-01

    Interoception is the ability to consciously perceive internal bodily states. Neuroimaging suggests that the insula (IC) and anterior cingulate cortex (ACC) mediate interoception, while studies involving patients/animals with brain lesions suggest the medial temporal lobe (MTL) is particularly important. One reason for these contrasting conclusions may lie in the types of interoceptive task used by these different approaches. Some tasks probably require integration of current physiological state with mnemonic information (e.g., how much one last ate), and these may be especially reliant upon MTL processing. We compared one task that probably requires integration - a water load task - with one that likely does not - a heart-rate tracking task - in two individuals with selective MTL damage (and with intact IC and ACC). A group of matched healthy individuals served as controls. The main finding was that individuals with MTL damage, relative to controls, were equally and significantly impaired on both types of interoception task. This suggests that MTL structures are involved in mediating interoception even when using a task (heart rate tracking) that does not seemingly require memory and that in neuroimaging studies activates the IC and ACC. The reasons for this apparent inconsistency with neuroimaging findings and the functional role of the MTL in interoception are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Radiosurgery for Medial Temporal Lobe Epilepsy Resulting from Mesial Temporal Sclerosis.

    Science.gov (United States)

    Gianaris, Thomas; Witt, Thomas; Barbaro, Nicholas M

    2016-01-01

    Medial temporal lobe epilepsy associated with mesial temporal sclerosis (MTS) is perhaps the most well-defined epilepsy syndrome that is responsive to structural interventions such as surgery. Several minimally invasive techniques have arisen that provide additional options for the treatment of MTS while potentially avoiding many of open surgery's associated risks. By evading these risks, they also open up treatment options to patients who otherwise are poor surgical candidates. Radiosurgery is one of the most intensively studied of these alternatives and has found a growing role in the treatment of medial temporal lobe epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Working memory for conjunctions relies on the medial temporal lobe.

    Science.gov (United States)

    Olson, Ingrid R; Page, Katie; Moore, Katherine Sledge; Chatterjee, Anjan; Verfaellie, Mieke

    2006-04-26

    A prominent theory of hippocampal function proposes that the hippocampus is importantly involved in relating or binding together separate pieces of information to form an episodic representation. This hypothesis has only been applied to studies of long-term memory because the paradigmatic view of the hippocampus is that it is not critical for short-term forms of memory. However, relational processing is important in many working memory tasks, especially tasks using visual stimuli. Here, we test the hypothesis that the medial temporal lobes are important for relational memory even over short delays. The task required patients with medial temporal lobe amnesia and controls to remember three objects, locations, or object-location conjunctions over 1 or 8 s delays. The results show that working memory for objects and locations was at normal levels, but that memory for conjunctions was severely impaired at 8 s delays. Additional analyses suggest that the hippocampus per se is critical for accurate conjunction working memory. We propose that the hippocampus is critically involved in memory for conjunctions at both short and long delays.

  20. Early seizure propagation from the occipital lobe to medial temporal structures and its surgical implication.

    Science.gov (United States)

    Usui, Naotaka; Mihara, Tadahiro; Baba, Koichi; Matsuda, Kazumi; Tottori, Takayasu; Umeoka, Shuichi; Nakamura, Fumihiro; Terada, Kiyohito; Usui, Keiko; Inoue, Yushi

    2008-12-01

    Intracranial EEG documentation of seizure propagation from the occipital lobe to medial temporal structures is relatively rare. We retrospectively analyzed intracranial EEG recorded with electrodes implanted in the medial temporal lobe in patients who underwent occipital lobe surgery. Four patients with occipital lesions, who underwent intracranial EEG monitoring with intracerebral electrodes implanted in the medial temporal lobe prior to occipital lobe surgery, were studied. Subdural electrodes were placed over the occipital lobe and adjacent areas. Intracerebral electrodes were implanted into bilateral hippocampi and the amygdala in three patients, and in the hippocampus and amygdala ipsilateral to the lesion in one. In light of the intracranial EEG findings, the occipital lobe was resected but the medial temporal lobe was spared in all patients. The follow-up period ranged from six to 16 years, and seizure outcome was Engel Class I in all patients. Sixty six seizures were analyzed. The majority of the seizures originated from the occipital lobe. In complex partial seizures, ictal discharges propagated to the medial temporal lobe. No seizures originating from the temporal lobe were documented. In some seizures, the ictal-onset zone could not be identified. In these seizures, very early propagation to the medial temporal lobe was observed. Interictal spikes were recorded in the medial temporal lobe in all cases. Intracranial EEG revealed very early involvement of the medial temporal lobe in some seizures. Seizure control was achieved without resection of the medial temporal structures.

  1. Contributions of Medial Temporal Lobe and Striatal Memory Systems to Learning and Retrieving Overlapping Spatial Memories

    Science.gov (United States)

    Brown, Thackery I.; Stern, Chantal E.

    2014-01-01

    Many life experiences share information with other memories. In order to make decisions based on overlapping memories, we need to distinguish between experiences to determine the appropriate behavior for the current situation. Previous work suggests that the medial temporal lobe (MTL) and medial caudate interact to support the retrieval of overlapping navigational memories in different contexts. The present study used functional magnetic resonance imaging (fMRI) in humans to test the prediction that the MTL and medial caudate play complementary roles in learning novel mazes that cross paths with, and must be distinguished from, previously learned routes. During fMRI scanning, participants navigated virtual routes that were well learned from prior training while also learning new mazes. Critically, some routes learned during scanning shared hallways with those learned during pre-scan training. Overlap between mazes required participants to use contextual cues to select between alternative behaviors. Results demonstrated parahippocampal cortex activity specific for novel spatial cues that distinguish between overlapping routes. The hippocampus and medial caudate were active for learning overlapping spatial memories, and increased their activity for previously learned routes when they became context dependent. Our findings provide novel evidence that the MTL and medial caudate play complementary roles in the learning, updating, and execution of context-dependent navigational behaviors. PMID:23448868

  2. Differential roles for medial prefrontal and medial temporal cortices in schema-dependent encoding: From congruent to incongruent

    OpenAIRE

    Kesteren, M.T.R. van; Beul, S.F.; Takashima, A.; Henson, R.N.; Ruiter, D.J.

    2013-01-01

    Information that is congruent with prior knowledge is generally remembered better than incongruent information. This effect of congruency on memory has been attributed to a facilitatory influence of activated schemas on memory encoding and consolidation processes, and hypothesised to reflect a shift between processing in medial temporal lobes (MTL) towards processing in medial prefrontal cortex (mPFC). To investigate this shift, we used functional magnetic resonance imaging (fMRI) to compare ...

  3. Enhancement of Neocortical-Medial Temporal EEG Correlations during Non-REM Sleep

    Directory of Open Access Journals (Sweden)

    Nikolai Axmacher

    2008-01-01

    Full Text Available Interregional interactions of oscillatory activity are crucial for the integrated processing of multiple brain regions. However, while the EEG in virtually all brain structures passes through substantial modifications during sleep, it is still an open question whether interactions between neocortical and medial temporal EEG oscillations also depend on the state of alertness. Several previous studies in animals and humans suggest that hippocampal-neocortical interactions crucially depend on the state of alertness (i.e., waking state or sleep. Here, we analyzed scalp and intracranial EEG recordings during sleep and waking state in epilepsy patients undergoing presurgical evaluation. We found that the amplitudes of oscillations within the medial temporal lobe and the neocortex were more closely correlated during sleep, in particular during non-REM sleep, than during waking state. Possibly, the encoding of novel sensory inputs, which mainly occurs during waking state, requires that medial temporal dynamics are rather independent from neocortical dynamics, while the consolidation of memories during sleep may demand closer interactions between MTL and neocortex.

  4. Feasibility of the Medial Temporal lobe Atrophy index (MTAi and derived methods for measuring atrophy of the medial temporal lobe

    Directory of Open Access Journals (Sweden)

    Francisco eConejo Bayón

    2014-11-01

    Full Text Available Introduction: the Medial Temporal-lobe Atrophy index (MTAi, 2D-Medial Temporal Atrophy (2D-MTA, yearly rate of MTA (yrRMTA and yearly rate of relative MTA (yrRMTA are simple protocols for measuring the relative extent of atrophy in the MTL in relation to the global brain atrophy. Albeit preliminary studies showed interest of these methods in the diagnosis of AD, FTLD and correlation with cognitive impairment in PD, formal feasibility and validity studies remained pending. As a first step, we aimed to assess the feasibility. Mainly, we aimed to assess the reproducibility of measuring the areas needed to compute these indices. We also aimed to assess the efforts needed to start using these methods correctly. Methods: a series of 290 1.5T-MRI studies from 230 subjects ranging 65-85 years old who had been studied for cognitive impairment were used in this study. Six inexperienced tracers (IT plus one experienced tracer (ET traced the three areas needed to compute the indices. Finally, tracers underwent a short survey on their experience learning to compute the MTAi and experience of usage, including items relative to training time needed to understand and apply the MTAi, time to perform a study after training and overall satisfaction. Results: learning to trace the areas needed to compute the MTAi and derived methods is quick and easy. Results indicate very good intrarater ICC for the MTAi, good intrarater ICC for the 2D-MTA, yrMTA and yrRMTA and also good interrater ICC for the MTAi, 2D-MTA, yrMTA and yrRMTA.Conclusion: our data support that MTAi and derived methods (2D-MTA, yrMTA and yrRTMA have good to very good intrarater and interrater reproducibility and may be easily implemented in clinical practice even if new users have no experience tracing the area of regions of interest.

  5. Autonoetic Consciousness in Autobiographical Memories after Medial Temporal Lobe Resection

    Directory of Open Access Journals (Sweden)

    M. Noulhiane

    2008-01-01

    Full Text Available This study aims to investigate autonoetic consciousness associated with episodic autobiographical memory in patients who had undergone unilateral medial temporal lobe resection for intractable epilepsy. Autonoetic consciousness, defined as the conscious feeling of mentally travelling back in time to relive a specific event, was assessed using the Remember/Know (R/K paradigm across different time periods as proposed in the autobiographical memory task developed by Piolino et al. (TEMPau task. Results revealed that the two patient groups (left and right temporal resection gave reduced sense of reliving (R responses and more familiarity (K responses than healthy controls. This poor autonoetic consciousness was highlighted when patients were asked to justify their Remember responses by recalling sensory-perceptive, affective or spatiotemporal specific details across all life periods. These results support the bilateral MTL contribution to episodic autobiographical memory covering the entire lifespan, which is consistent with the multiple trace theory of MTL function [7,9]. This study also demonstrates the bilateral involvement of MTL structures in recalling specific details of personal events characterized by autonoetic consciousness.

  6. Autonoetic Consciousness in Autobiographical Memories after Medial Temporal Lobe Resection

    Science.gov (United States)

    Noulhiane, M.; Piolino, P.; Hasboun, D.; Clemenceau, S.; Baulac, M.; Samson, S.

    2008-01-01

    This study aims to investigate autonoetic consciousness associated with episodic autobiographical memory in patients who had undergone unilateral medial temporal lobe resection for intractable epilepsy. Autonoetic consciousness, defined as the conscious feeling of mentally travelling back in time to relive a specific event, was assessed using the Remember/Know (R/K) paradigm across different time periods as proposed in the autobiographical memory task developed by Piolino et al. (TEMPau task). Results revealed that the two patient groups (left and right temporal resection) gave reduced sense of reliving (R) responses and more familiarity (K) responses than healthy controls. This poor autonoetic consciousness was highlighted when patients were asked to justify their Remember responses by recalling sensory-perceptive, affective or spatiotemporal specific details across all life periods. These results support the bilateral MTL contribution to episodic autobiographical memory covering the entire lifespan, which is consistent with the multiple trace theory of MTL function [7,9]. This study also demonstrates the bilateral involvement of MTL structures in recalling specific details of personal events characterized by autonoetic consciousness. PMID:18413911

  7. Anatomical pathways for auditory memory II: Information from rostral superior temporal gyrus to dorsolateral temporal pole and medial temporal cortex.

    Directory of Open Access Journals (Sweden)

    Monica eMunoz-Lopez

    2015-05-01

    Full Text Available Auditory recognition memory in non-human primates differs from recognition memory in other sensory systems. Monkeys learn the rule for visual and tactile delayed matching-to-sample within a few sessions, and then show one-trial recognition memory lasting 10-20 minutes. In contrast, monkeys require hundreds of sessions to master the rule for auditory recognition, and then show retention lasting no longer than 30-40 seconds. Moreover, unlike the severe effects of rhinal lesions on visual memory, such lesions have no effect on the monkeys’ auditory memory performance. It is possible, therefore, that the anatomical pathways differ. Long-term visual recognition memory requires anatomical connections from the visual association area TE with areas 35 and 36 of the perirhinal cortex (PRC. We examined whether there is a similar anatomical route for auditory processing, or that poor auditory recognition memory may reflect the lack of such a pathway. Our hypothesis is that an auditory pathway for recognition memory originates in the higher order processing areas of the rostral superior temporal gyrus (rSTG, and then connects via the dorsolateral temporal pole to access the rhinal cortex of the medial temporal lobe. To test this, we placed retrograde (3% FB and 2% DY and anterograde (10% BDA 10,000 MW tracer injections in rSTG and the dorsolateral area 38DL of the temporal pole. Results showed that area 38DL receives dense projections from auditory association areas Ts1, TAa, TPO of the rSTG, from the rostral parabelt and, to a lesser extent, from areas Ts2-3 and PGa. In turn, area 38DL projects densely to area 35 of PRC, entorhinal cortex, and to areas TH/TF of the posterior parahippocampal cortex. Significantly, this projection avoids most of area 36r/c of PRC. This anatomical arrangement may contribute to our understanding of the poor auditory memory of rhesus monkeys.

  8. Anatomical pathways for auditory memory II: information from rostral superior temporal gyrus to dorsolateral temporal pole and medial temporal cortex.

    Science.gov (United States)

    Muñoz-López, M; Insausti, R; Mohedano-Moriano, A; Mishkin, M; Saunders, R C

    2015-01-01

    Auditory recognition memory in non-human primates differs from recognition memory in other sensory systems. Monkeys learn the rule for visual and tactile delayed matching-to-sample within a few sessions, and then show one-trial recognition memory lasting 10-20 min. In contrast, monkeys require hundreds of sessions to master the rule for auditory recognition, and then show retention lasting no longer than 30-40 s. Moreover, unlike the severe effects of rhinal lesions on visual memory, such lesions have no effect on the monkeys' auditory memory performance. The anatomical pathways for auditory memory may differ from those in vision. Long-term visual recognition memory requires anatomical connections from the visual association area TE with areas 35 and 36 of the perirhinal cortex (PRC). We examined whether there is a similar anatomical route for auditory processing, or that poor auditory recognition memory may reflect the lack of such a pathway. Our hypothesis is that an auditory pathway for recognition memory originates in the higher order processing areas of the rostral superior temporal gyrus (rSTG), and then connects via the dorsolateral temporal pole to access the rhinal cortex of the medial temporal lobe. To test this, we placed retrograde (3% FB and 2% DY) and anterograde (10% BDA 10,000 mW) tracer injections in rSTG and the dorsolateral area 38 DL of the temporal pole. Results showed that area 38DL receives dense projections from auditory association areas Ts1, TAa, TPO of the rSTG, from the rostral parabelt and, to a lesser extent, from areas Ts2-3 and PGa. In turn, area 38DL projects densely to area 35 of PRC, entorhinal cortex (EC), and to areas TH/TF of the posterior parahippocampal cortex. Significantly, this projection avoids most of area 36r/c of PRC. This anatomical arrangement may contribute to our understanding of the poor auditory memory of rhesus monkeys.

  9. Asymmetry of medial and lateral temporal regional glucose metabolism in temporal lobe epilepsy by F-18-FDG PET

    International Nuclear Information System (INIS)

    Lee, Dong Soo; Yeo, Jeong Seok; Song, Ho Cheon; Lee, Sang Kun; Kim, Hyun Jip; Chung, June Key; Lee, Myung Chul

    1999-01-01

    We investigated the difference of glucose metabolism of medial and lateral temporal lobes of patients with temporal lobe epilepsy (TLE) utilizing quantitative comparison of regional metabolic activities using asymmetric index. We studied 19 pathologically proven mesial TLE and 25 lateral TLE patients. Lateral TLE patients were either normal on magnetic resonance imaging (cryptogenic: n=14) or had structural lesions (lesional: n=11). Asymmetric index (ASI) was calculated as [(ipsilateral contralateral)/(ipsilateral + contralateral )]x200. ASI of medial and lateral lobes of mesial TLE was decreased (-16.4±8.3 and -12.7± 5.5, respectively). In cryptogenic lateral TLE, ASI of lateral temporal lobe was decreased (-11.8± 4.7), whereas that of medial temporal lobe was not decreased (-4.6±6.3). ASI of medial lobe of lesional lateral TLE was -7.3±9.1, which was significantly different from that of mesial TLE (p<0.05). Patients with lesional lateral TLE had evident metabolic defects or decrease (ASI: -22±10.5) in lateral temporal lobe. While we could not find the difference of metabolic activity in lateral temporal lobes between cryptogenic lateral TLE and mesial TLE patients, the difference of metabolic activity was significant in medial temporal lobes which was revealed by ASI quantitation. Asymmetric decrease of metabolic activity in both medial and lateral temporal lobes indicates medial temporal epilepsy. Symmetry of metabolic activity in medial temporal lobe combined with asymmetry of that in lateral temporal lobe may give hints that the epileptogenic zone is lateral

  10. Temporal and extra-temporal hypoperfusion in medial temporal lobe epilepsy evaluated by arterial-spin-labeling based MRI

    International Nuclear Information System (INIS)

    Shen Lianfang; Zhang Zhiqiang; Lu Guangming; Yuan Cuiping; Wang Zhengge; Wang Haoxue; Huang Wei; Wei Fangyuan; Chen Guanghui; Tan Qifu

    2012-01-01

    Objective: To evaluate the feasibility of the lateralization of unilateral medial temporal lobe epilepsy (mTLE) by using arterial-spin-labeling (ASL) based perfusion MR imaging and investigate the changes of perfusion in the regions related to mTLE network and the relationship between the perfusion and the clinical status. Methods: Twenty-five patients with left-sided and 23 with right-sided mTLE were enrolled, and 30 healthy volunteers were recruited. The cerebral blood flow (CBF) of related region was measured based on pulsed-ASL sequence on Siemens 3 T scanner. The CBF of the mTLE group were compared with that in the controls by using ANOVA analysis. The asymmetric indices of CBF in the medial temporal lobe were calculated as the lesion side compared with the normal side in matched region in mTLE group. Results: Compared with the volunteers, the patients with mTLE showed the decrease of CBF in the bilateral medial and lateral temporal, the frontal and parietal regions relating to the default-mode network and more serious in lesion side. The CBF values of the medial temporal lobe were negatively correlated with the epilepsy duration (r=-0.51, P<0.01). The asymmetric index of CBF as-0.01 has a 76.0% (19/25) sensitivity and a 78.3% (18/23) specificity to distinguish the lesion side. Conclusions: The decrease of CBF in the temporal and extra-temporal region by ASL-based MRI suggests the functional abnormalities in the network involved by mTLE. The ASL technique is a useful tool for lateralizing the unilateral mTLE. (authors)

  11. Dynamic imaging in mild traumatic brain injury: support for the theory of medial temporal vulnerability.

    Science.gov (United States)

    Umile, Eric M; Sandel, M Elizabeth; Alavi, Abass; Terry, Charles M; Plotkin, Rosette C

    2002-11-01

    To determine whether patients with mild traumatic brain injury (TBI) and persistent postconcussive symptoms have evidence of temporal lobe injury on dynamic imaging. Case series. An academic medical center. Twenty patients with a clinical diagnosis of mild TBI and persistent postconcussive symptoms were referred for neuropsychologic evaluation and dynamic imaging. Fifteen (75%) had normal magnetic resonance imaging (MRI) and/or computed tomography (CT) scans at the time of injury. Neuropsychologic testing, positron-emission tomography (PET), and single-photon emission-computed tomography (SPECT). Temporal lobe findings on static imaging (MRI, CT) and dynamic imaging (PET, SPECT); neuropsychologic test findings on measures of verbal and visual memory. Testing documented neurobehavioral deficits in 19 patients (95%). Dynamic imaging documented abnormal findings in 18 patients (90%). Fifteen patients (75%) had temporal lobe abnormalities on PET and SPECT (primarily in medial temporal regions); abnormal findings were bilateral in 10 patients (50%) and unilateral in 5 (25%). Six patients (30%) had frontal abnormalities, and 8 (40%) had nonfrontotemporal abnormalities. Correlations between neuropsychologic testing and dynamic imaging could be established but not consistently across the whole group. Patients with mild TBI and persistent postconcussive symptoms have a high incidence of temporal lobe injury (presumably involving the hippocampus and related structures), which may explain the frequent finding of memory disorders in this population. The abnormal temporal lobe findings on PET and SPECT in humans may be analogous to the neuropathologic evidence of medial temporal injury provided by animal studies after mild TBI. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

  12. Non-invasive examinations successfully select patients with medial temporal lobe epilepsy for anterior temporal lobectomy

    Energy Technology Data Exchange (ETDEWEB)

    Morioka, Takato; Nishio, Shunji; Kawamura, Tadao; Fukui, Kimiko; Sasaki, Masayuki; Fukui, Masashi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences

    2001-06-01

    We retrospectively analyzed 8 patients with intractable medial temporal lobe epilepsy (MTLE) who underwent the anterior temporal lobectomy with hippocampectomy (ATL) without invasive examinations such as chronic subdural electrode recording. Five patients had a history of febrile convulsion. While all 8 patients had oral automatism, automatism of ipsilateral limbs with dystonic posture of contralateral limbs was demonstrated in 2 patients. Bilateral temporal paroxysmal activities on interictal EEG was observed in 4 patients and all patients had clear ictal onset zone on unilateral anterior temporal region. MRI demonstrated unilateral hippocampal sclerosis in 5 cases. Interictal FDG-PET depicted hypometabolism of the unilateral temporal lobe in all cases, however, ECD-SPECT failed to reveal the hypoperfusion of the unilateral temporal lobe in a case. Postoperatively, 7 cases became seizure free, and one had rare seizure. Non-invasive examinations, especially ictal EEG and concordant FDG-PET findings, in patients with oral automatism in seizure semiology, successfully select patients with MTLE for ATL. (author)

  13. Non-invasive examinations successfully select patients with medial temporal lobe epilepsy for anterior temporal lobectomy

    International Nuclear Information System (INIS)

    Morioka, Takato; Nishio, Shunji; Kawamura, Tadao; Fukui, Kimiko; Sasaki, Masayuki; Fukui, Masashi

    2001-01-01

    We retrospectively analyzed 8 patients with intractable medial temporal lobe epilepsy (MTLE) who underwent the anterior temporal lobectomy with hippocampectomy (ATL) without invasive examinations such as chronic subdural electrode recording. Five patients had a history of febrile convulsion. While all 8 patients had oral automatism, automatism of ipsilateral limbs with dystonic posture of contralateral limbs was demonstrated in 2 patients. Bilateral temporal paroxysmal activities on interictal EEG was observed in 4 patients and all patients had clear ictal onset zone on unilateral anterior temporal region. MRI demonstrated unilateral hippocampal sclerosis in 5 cases. Interictal FDG-PET depicted hypometabolism of the unilateral temporal lobe in all cases, however, ECD-SPECT failed to reveal the hypoperfusion of the unilateral temporal lobe in a case. Postoperatively, 7 cases became seizure free, and one had rare seizure. Non-invasive examinations, especially ictal EEG and concordant FDG-PET findings, in patients with oral automatism in seizure semiology, successfully select patients with MTLE for ATL. (author)

  14. Neural activity in the medial temporal lobe reveals the fidelity of mental time travel.

    Science.gov (United States)

    Kragel, James E; Morton, Neal W; Polyn, Sean M

    2015-02-18

    Neural circuitry in the medial temporal lobe (MTL) is critically involved in mental time travel, which involves the vivid retrieval of the details of past experience. Neuroscientific theories propose that the MTL supports memory of the past by retrieving previously encoded episodic information, as well as by reactivating a temporal code specifying the position of a particular event within an episode. However, the neural computations supporting these abilities are underspecified. To test hypotheses regarding the computational mechanisms supported by different MTL subregions during mental time travel, we developed a computational model that linked a blood oxygenation level-dependent signal to cognitive operations, allowing us to predict human performance in a memory search task. Activity in the posterior MTL, including parahippocampal cortex, reflected how strongly one reactivates the temporal context of a retrieved memory, allowing the model to predict whether the next memory will correspond to a nearby moment in the study episode. A signal in the anterior MTL, including perirhinal cortex, indicated the successful retrieval of list items, without providing information regarding temporal organization. A hippocampal signal reflected both processes, consistent with theories that this region binds item and context information together to form episodic memories. These findings provide evidence for modern theories that describe complementary roles of the hippocampus and surrounding parahippocampal and perirhinal cortices during the retrieval of episodic memories, shaping how humans revisit the past. Copyright © 2015 the authors 0270-6474/15/352914-13$15.00/0.

  15. Episodic memory and the medial temporal lobe: not all it seems. Evidence from the temporal variants of frontotemporal dementia

    NARCIS (Netherlands)

    Pleizier, C.M.; van der Vlies, A.E.; Koedam, E.L.G.E.; Koene, T.; Barkhof, F.; van der Flier, W.M.; Scheltens, P.; Pijnenburg, Y.A.L.

    2012-01-01

    Background: Disproportionate medial temporal lobe atrophy (MTA) is an early finding in Alzheimer's disease (AD). Episodic memory impairment in AD is associated with the degree of MTA. Episodic memory impairment and MTA are also found in semantic dementia (SD) and in right temporal lobe atrophy

  16. The relationship of medial temporal lobe epilepsy with the declarative memory system

    Directory of Open Access Journals (Sweden)

    Halász Péter

    2016-12-01

    Full Text Available Introduction. Medial temporal lobe of epilepsy (MTLE is considered as local/regional epilepsy. However, as was discussed in Part I of this review (Halász, 2016a there is more evidence regarding the involvement of both temporal lobes so as to consider MTLE as one of the typical bilateral system epilepsies.

  17. Electrophysiological evidence during episodic prospection implicates medial prefrontal and bilateral middle temporal gyrus.

    Science.gov (United States)

    Hsu, Chia-Fen; Sonuga-Barke, Edmund J S

    2016-08-01

    fMRI studies have implicated the medial prefrontal cortex and medial temporal lobe, components of the default mode network (DMN), in episodic prospection. This study compared quantitative EEG localized to these DMN regions during prospection and during resting and while waiting for rewards. EEG was recorded in twenty-two adults while they were asked to (i) envision future monetary episodes; (ii) wait for rewards and (iii) rest. Activation sources were localized to core DMN regions. EEG power and phase coherence were compared across conditions. Prospection, compared to resting and waiting, was associated with reduced power in the medial prefrontal gyrus and increased power in the bilateral medial temporal gyrus across frequency bands as well as greater phase synchrony between these regions in the delta band. The current quantitative EEG analysis confirms prior fMRI research suggesting that medial prefrontal and medial temporal gyrus interactions are central to the capacity for episodic prospection. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Associative learning beyond the medial temporal lobe: many actors on the memory stage

    Directory of Open Access Journals (Sweden)

    Giulio ePergola

    2013-11-01

    Full Text Available Decades of research have established a model that includes the medial temporal lobe, and particularly the hippocampus, as a critical node for episodic memory. Neuroimaging and clinical studies have shown the involvement of additional cortical and subcortical regions. Among these areas, the thalamus, the retrosplenial cortex and the prefrontal cortices have been consistently related to episodic memory performance.This article provides evidences that these areas are in different forms and degrees critical for human memory function rather than playing only an ancillary role. First we briefly summarize findings on the involvement of the hippocampus and the medial temporal lobe in recognition memory and recall. We then focus on the clinical and neuroimaging evidence available on thalamo-frontal and thalamo-retrosplenial networks. The role of these networks in episodic memory has been considered secondary, partly because disruption of these areas does not always lead to severe impairments; to account for this evidence, we discuss methodological issues related to the investigation of these regions. We propose that these networks contribute differently to recognition memory and recall, and also that the memory stage of their contribution shows specificity to encoding or retrieval in recall tasks. We note that the same mechanisms may be in force when humans perform non-episodic tasks, e.g., semantic retrieval and mental time travel. Functional disturbance of these networks is related to cognitive impairments not only in neurological disorders, but also in psychiatric medical conditions, such as schizophrenia. Finally we discuss possible mechanisms for the contribution of these areas to memory, including regulation of oscillatory rhythms and long-term potentiation. We conclude that integrity of the thalamo-frontal and the thalamo-retrosplenial networks is necessary for the manifold features of episodic memory.

  19. Theta oscillations orchestrate medial temporal lobe and neocortex in remembering autobiographical memories.

    Science.gov (United States)

    Fuentemilla, L; Barnes, G R; Düzel, E; Levine, B

    2014-01-15

    Remembering autobiographical events can be associated with detailed visual imagery. The medial temporal lobe (MTL), precuneus and prefrontal cortex are held to jointly enable such vivid retrieval, but how these regions are orchestrated remains unclear. An influential prediction from animal physiology is that neural oscillations in theta frequency may be important. In this experiment, participants prospectively collected audio recordings describing personal autobiographical episodes or semantic knowledge over 2 to 7 months. These were replayed as memory retrieval cues while recording brain activity with magnetoencephalography (MEG). We identified a peak of theta power within a left MTL region of interest during both autobiographical and General Semantic retrieval. This MTL region was selectively phase-synchronized with theta oscillations in precuneus and medial prefrontal cortex, and this synchrony was higher during autobiographical as compared to General Semantic knowledge retrieval. Higher synchrony also predicted more detailed visual imagery during retrieval. Thus, theta phase-synchrony orchestrates in humans the MTL with a distributed neocortical memory network when vividly remembering autobiographical experiences. © 2013.

  20. Fornix and medial temporal lobe lesions lead to comparable deficits in complex visual perception.

    Science.gov (United States)

    Lech, Robert K; Koch, Benno; Schwarz, Michael; Suchan, Boris

    2016-05-04

    Recent research dealing with the structures of the medial temporal lobe (MTL) has shifted away from exclusively investigating memory-related processes and has repeatedly incorporated the investigation of complex visual perception. Several studies have demonstrated that higher level visual tasks can recruit structures like the hippocampus and perirhinal cortex in order to successfully perform complex visual discriminations, leading to a perceptual-mnemonic or representational view of the medial temporal lobe. The current study employed a complex visual discrimination paradigm in two patients suffering from brain lesions with differing locations and origin. Both patients, one with extensive medial temporal lobe lesions (VG) and one with a small lesion of the anterior fornix (HJK), were impaired in complex discriminations while showing otherwise mostly intact cognitive functions. The current data confirmed previous results while also extending the perceptual-mnemonic theory of the MTL to the main output structure of the hippocampus, the fornix. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Automatic interpretation of F-18-FDG brain PET using artificial neural network: discrimination of medial and lateral temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Sung; Lee, Dong Soo; Kim, Seok Ki; Park, Kwang Suk; Lee, Sang Kun; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2004-06-01

    We developed a computer-aided classifier using artificial neural network (ANN) to discriminate the cerebral metabolic pattern of medial and lateral temporal lobe epilepsy (TLE). We studied brain F-18-FDG PET images of 113 epilepsy patients surgically and pathologically proven as medial TLE (left 41, right 42) or lateral TLE (left 14, right 16). PET images were spatially transformed onto a standard template and normalized to the mean counts of cortical regions. Asymmetry indices for predefined 17 mirrored regions to hemispheric midline and those for medial and lateral temporal lobes were used as input features for ANN. ANN classifier was composed of 3 independent multi-layered perceptions (1 for left/right lateralization and 2 for medial/lateral discrimination) and trained to interpret metabolic patterns and produce one of 4 diagnoses (L/R medial TLE or L/R lateral TLE). Randomly selected 8 images from each group were used to train the ANN classifier and remaining 81 images were used as test sets. The accuracy of the diagnosis with ANN was estimated by averaging the agreement rates of independent 50 trials and compared to that of nuclear medicine experts. The accuracy in lateralization was 89% by the human experts and 90% by the ANN classifier. Overall accuracy in localization of epileptogenic zones by the ANN classifier was 69%, which was comparable to that by the human experts (72%). We conclude that ANN classifier performed as well as human experts and could be potentially useful supporting tool for the differential diagnosis of TLE.

  2. Automatic interpretation of F-18-FDG brain PET using artificial neural network: discrimination of medial and lateral temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Lee, Jae Sung; Lee, Dong Soo; Kim, Seok Ki; Park, Kwang Suk; Lee, Sang Kun; Chung, June Key; Lee, Myung Chul

    2004-01-01

    We developed a computer-aided classifier using artificial neural network (ANN) to discriminate the cerebral metabolic pattern of medial and lateral temporal lobe epilepsy (TLE). We studied brain F-18-FDG PET images of 113 epilepsy patients surgically and pathologically proven as medial TLE (left 41, right 42) or lateral TLE (left 14, right 16). PET images were spatially transformed onto a standard template and normalized to the mean counts of cortical regions. Asymmetry indices for predefined 17 mirrored regions to hemispheric midline and those for medial and lateral temporal lobes were used as input features for ANN. ANN classifier was composed of 3 independent multi-layered perceptions (1 for left/right lateralization and 2 for medial/lateral discrimination) and trained to interpret metabolic patterns and produce one of 4 diagnoses (L/R medial TLE or L/R lateral TLE). Randomly selected 8 images from each group were used to train the ANN classifier and remaining 81 images were used as test sets. The accuracy of the diagnosis with ANN was estimated by averaging the agreement rates of independent 50 trials and compared to that of nuclear medicine experts. The accuracy in lateralization was 89% by the human experts and 90% by the ANN classifier. Overall accuracy in localization of epileptogenic zones by the ANN classifier was 69%, which was comparable to that by the human experts (72%). We conclude that ANN classifier performed as well as human experts and could be potentially useful supporting tool for the differential diagnosis of TLE

  3. High gamma oscillations in medial temporal lobe during overt production of speech and gestures.

    Science.gov (United States)

    Marstaller, Lars; Burianová, Hana; Sowman, Paul F

    2014-01-01

    The study of the production of co-speech gestures (CSGs), i.e., meaningful hand movements that often accompany speech during everyday discourse, provides an important opportunity to investigate the integration of language, action, and memory because of the semantic overlap between gesture movements and speech content. Behavioral studies of CSGs and speech suggest that they have a common base in memory and predict that overt production of both speech and CSGs would be preceded by neural activity related to memory processes. However, to date the neural correlates and timing of CSG production are still largely unknown. In the current study, we addressed these questions with magnetoencephalography and a semantic association paradigm in which participants overtly produced speech or gesture responses that were either meaningfully related to a stimulus or not. Using spectral and beamforming analyses to investigate the neural activity preceding the responses, we found a desynchronization in the beta band (15-25 Hz), which originated 900 ms prior to the onset of speech and was localized to motor and somatosensory regions in the cortex and cerebellum, as well as right inferior frontal gyrus. Beta desynchronization is often seen as an indicator of motor processing and thus reflects motor activity related to the hand movements that gestures add to speech. Furthermore, our results show oscillations in the high gamma band (50-90 Hz), which originated 400 ms prior to speech onset and were localized to the left medial temporal lobe. High gamma oscillations have previously been found to be involved in memory processes and we thus interpret them to be related to contextual association of semantic information in memory. The results of our study show that high gamma oscillations in medial temporal cortex play an important role in the binding of information in human memory during speech and CSG production.

  4. High gamma oscillations in medial temporal lobe during overt production of speech and gestures.

    Directory of Open Access Journals (Sweden)

    Lars Marstaller

    Full Text Available The study of the production of co-speech gestures (CSGs, i.e., meaningful hand movements that often accompany speech during everyday discourse, provides an important opportunity to investigate the integration of language, action, and memory because of the semantic overlap between gesture movements and speech content. Behavioral studies of CSGs and speech suggest that they have a common base in memory and predict that overt production of both speech and CSGs would be preceded by neural activity related to memory processes. However, to date the neural correlates and timing of CSG production are still largely unknown. In the current study, we addressed these questions with magnetoencephalography and a semantic association paradigm in which participants overtly produced speech or gesture responses that were either meaningfully related to a stimulus or not. Using spectral and beamforming analyses to investigate the neural activity preceding the responses, we found a desynchronization in the beta band (15-25 Hz, which originated 900 ms prior to the onset of speech and was localized to motor and somatosensory regions in the cortex and cerebellum, as well as right inferior frontal gyrus. Beta desynchronization is often seen as an indicator of motor processing and thus reflects motor activity related to the hand movements that gestures add to speech. Furthermore, our results show oscillations in the high gamma band (50-90 Hz, which originated 400 ms prior to speech onset and were localized to the left medial temporal lobe. High gamma oscillations have previously been found to be involved in memory processes and we thus interpret them to be related to contextual association of semantic information in memory. The results of our study show that high gamma oscillations in medial temporal cortex play an important role in the binding of information in human memory during speech and CSG production.

  5. Going beyond LTM in the MTL: A Synthesis of Neuropsychological and Neuroimaging Findings on the Role of the Medial Temporal Lobe in Memory and Perception

    Science.gov (United States)

    Graham, Kim S.; Barense, Morgan D.; Lee, Andy C. H.

    2010-01-01

    Studies in rats and non-human primates suggest that medial temporal lobe (MTL) structures play a role in perceptual processing, with the hippocampus necessary for spatial discrimination, and the perirhinal cortex for object discrimination. Until recently, there was little convergent evidence for analogous functional specialisation in humans, or…

  6. Distinct medial temporal networks encode surprise during motivation by reward versus punishment

    Science.gov (United States)

    Murty, Vishnu P.; LaBar, Kevin S.; Adcock, R. Alison

    2016-01-01

    Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also impacts neural and mnemonic encoding of surprising events. During functional magnetic resonance imaging (fMRI), participants encountered perceptually unexpected events either during the pursuit of rewards or avoidance of punishments. Despite similar levels of motivation across groups, reward and punishment facilitated the processing of surprising events in different medial temporal lobe regions. Whereas during reward motivation, perceptual surprises enhanced activation in the hippocampus, during punishment motivation surprises instead enhanced activation in parahippocampal cortex. Further, we found that reward motivation facilitated hippocampal coupling with ventromedial PFC, whereas punishment motivation facilitated parahippocampal cortical coupling with orbitofrontal cortex. Behaviorally, post-scan testing revealed that reward, but not punishment, motivation resulted in greater memory selectivity for surprising events encountered during goal pursuit. Together these findings demonstrate that neuromodulatory systems engaged by anticipation of reward and punishment target separate components of the medial temporal lobe, modulating medial temporal lobe sensitivity and connectivity. Thus, reward and punishment motivation yield distinct neural contexts for learning, with distinct consequences for how surprises are incorporated into predictive mnemonic models of the environment. PMID:26854903

  7. Adaptation to Cognitive Context and Item Information in the Medial Temporal Lobes

    Science.gov (United States)

    Diana, Rachel A.; Yonelinas, Andrew P.; Ranganath, Charan

    2012-01-01

    The medial temporal lobes (MTL) play an essential role in episodic memory, and accumulating evidence indicates that two MTL subregions--the perirhinal (PRc) and parahippocampal (PHc) cortices--might have different functions. According to the binding of item and context theory ( [16] and [21]), PRc is involved in processing item information, the…

  8. Working Memory, Long-Term Memory, and Medial Temporal Lobe Function

    Science.gov (United States)

    Jeneson, Annette; Squire, Larry R.

    2012-01-01

    Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance…

  9. Network Alterations Supporting Word Retrieval in Patients with Medial Temporal Lobe Epilepsy

    Science.gov (United States)

    Protzner, Andrea B.; McAndrews, Mary Pat

    2011-01-01

    Although the hippocampus is not considered a key structure in semantic memory, patients with medial-temporal lobe epilepsy (mTLE) have deficits in semantic access on some word retrieval tasks. We hypothesized that these deficits reflect the negative impact of focal epilepsy on remote cerebral structures. Thus, we expected that the networks that…

  10. Recollection of episodic memory within the medial temporal lobe: behavioural dissociations from other types of memory.

    Science.gov (United States)

    Easton, Alexander; Eacott, Madeline J

    2010-12-31

    In recent years there has been significant debate about whether there is a single medial temporal lobe memory system or dissociable systems for episodic and other types of declarative memory. In addition there has been a similar debate over the dissociability of recollection and familiarity based processes in recognition memory. Here we present evidence from recent work using episodic memory tasks in animals that allows us to explore these issues in more depth. We review studies that demonstrate triple dissociations within the medial temporal lobe, with only the hippocampal system being necessary for episodic memory. Similarly we review behavioural evidence for a dissociation in a task of episodic memory in rats where animals with lesions of the fornix are only impaired at recollection of the episodic memory, not recognition within the same trial. This work, then, supports recent models of dissociable neural systems within the medial temporal lobe but also raises questions for future investigation about the interactions of these medial temporal lobe memory systems with other structures. Copyright © 2009 Elsevier B.V. All rights reserved.

  11. Medial Temporal Lobe Activity during Source Retrieval Reflects Information Type, Not Memory Strength

    Science.gov (United States)

    Diana, Rachel A.; Yonelinas, Andrew P.; Ranganath, Charan

    2010-01-01

    The medial temporal lobes (MTLs) are critical for episodic memory but the functions of MTL subregions are controversial. According to memory strength theory, MTL subregions collectively support declarative memory in a graded manner. In contrast, other theories assert that MTL subregions support functionally distinct processes. For instance, one…

  12. Distinct medial temporal networks encode surprise during motivation by reward versus punishment.

    Science.gov (United States)

    Murty, Vishnu P; LaBar, Kevin S; Adcock, R Alison

    2016-10-01

    Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also impacts neural and mnemonic encoding of surprising events. During functional magnetic resonance imaging (fMRI), participants encountered perceptually unexpected events either during the pursuit of rewards or avoidance of punishments. Despite similar levels of motivation across groups, reward and punishment facilitated the processing of surprising events in different medial temporal lobe regions. Whereas during reward motivation, perceptual surprises enhanced activation in the hippocampus, during punishment motivation surprises instead enhanced activation in parahippocampal cortex. Further, we found that reward motivation facilitated hippocampal coupling with ventromedial PFC, whereas punishment motivation facilitated parahippocampal cortical coupling with orbitofrontal cortex. Behaviorally, post-scan testing revealed that reward, but not punishment, motivation resulted in greater memory selectivity for surprising events encountered during goal pursuit. Together these findings demonstrate that neuromodulatory systems engaged by anticipation of reward and punishment target separate components of the medial temporal lobe, modulating medial temporal lobe sensitivity and connectivity. Thus, reward and punishment motivation yield distinct neural contexts for learning, with distinct consequences for how surprises are incorporated into predictive mnemonic models of the environment. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Dissociating basal forebrain and medial temporal amnesic syndromes: insights from classical conditioning.

    Science.gov (United States)

    Myer, Catherine E; Bryant, Deborah; DeLuca, John; Gluck, Mark A

    2002-01-01

    In humans, anterograde amnesia can result from damage to the medial temporal (MT) lobes (including hippocampus), as well as to other brain areas such as basal forebrain. Results from animal classical conditioning studies suggest that there may be qualitative differences in the memory impairment following MT vs. basal forebrain damage. Specifically, delay eyeblink conditioning is spared after MT damage in animals and humans, but impaired in animals with basal forebrain damage. Recently, we have likewise shown delay eyeblink conditioning impairment in humans with amnesia following anterior communicating artery (ACoA) aneurysm rupture, which damages the basal forebrain. Another associative learning task, a computer-based concurrent visual discrimination, also appears to be spared in MT amnesia while ACoA amnesics are slower to learn the discriminations. Conversely, animal and computational models suggest that, even though MT amnesics may learn quickly, they may learn qualitatively differently from controls, and these differences may result in impaired transfer when familiar information is presented in novel combinations. Our initial data suggests such a two-phase learning and transfer task may provide a double dissociation between MT amnesics (spared initial learning but impaired transfer) and ACoA amnesics (slow initial learning but spared transfer). Together, these emerging data suggest that there are subtle but dissociable differences in the amnesic syndrome following damage to the MT lobes vs. basal forebrain, and that these differences may be most visible in non-declarative tasks such as eyeblink classical conditioning and simple associative learning.

  14. Morphometry of medial gaps of human brain artery branches.

    Science.gov (United States)

    Canham, Peter B; Finlay, Helen M

    2004-05-01

    The bifurcation regions of the major human cerebral arteries are vulnerable to the formation of saccular aneurysms. A consistent feature of these bifurcations is a discontinuity of the tunica media at the apex of the flow divider. The objective was to measure the 3-dimensional geometry of these medial gaps or "medial defects." Nineteen bifurcations and 2 junctions of human cerebral arteries branches (from 4 male and 2 female subjects) were formalin-fixed at physiological pressure and processed for longitudinal serial sectioning. The apex and adjacent regions were examined and measurements were made from high-magnification photomicrographs, or projection microscope images, of the gap dimensions at multiple levels through the bifurcation. Plots were made of the width of the media as a function of distance from the apex. The media at each edge of the medial gap widened over a short distance, reaching the full width of the media of the contiguous daughter vessel. Medial gap dimensions were compared with the planar angle of the bifurcation, and a strong negative correlation was found, ie, the acute angled branches have the more prominent medial gaps. A discontinuity of the media at the apex was seen in all the bifurcations examined and was also found in the junction regions of brain arteries. We determined that the gap width is continuous with well-defined dimensions throughout its length and average length-to-width ratio of 6.9. The gaps were generally centered on the prominence of the apical ridge.

  15. Anatomical segmentation of the human medial prefrontal cortex

    NARCIS (Netherlands)

    Corcoles-Parada, M.; Müller, N.C.J.; Ubero, M.; Serrano-Del-Pueblo, V.M.; Mansilla, F.; Marcos-Rabal, P.; Artacho-Perula, E.; Dresler, M.; Insausti, R.; Fernandez, G.; Munoz-Lopez, M.

    2017-01-01

    The medial prefrontal areas 32, 24, 14, and 25 (mPFC) form part of the limbic memory system, but little is known about their functional specialization in humans. To add anatomical precision to structural and functional magnetic resonance imaging (MRI) data, we aimed to identify these mPFC subareas

  16. Differential roles for medial prefrontal and medial temporal cortices in schema-dependent encoding: from congruent to incongruent.

    Science.gov (United States)

    van Kesteren, Marlieke T R; Beul, Sarah F; Takashima, Atsuko; Henson, Richard N; Ruiter, Dirk J; Fernández, Guillén

    2013-10-01

    Information that is congruent with prior knowledge is generally remembered better than incongruent information. This effect of congruency on memory has been attributed to a facilitatory influence of activated schemas on memory encoding and consolidation processes, and hypothesised to reflect a shift between processing in medial temporal lobes (MTL) towards processing in medial prefrontal cortex (mPFC). To investigate this shift, we used functional magnetic resonance imaging (fMRI) to compare brain activity during paired-associate encoding across three levels of subjective congruency of the association with prior knowledge. Participants indicated how congruent they found an object-scene pair during scanning, and were tested on item and associative recognition memory for these associations one day later. Behaviourally, we found a monotonic increase in memory performance with increasing congruency for both item and associative memory. Moreover, as hypothesised, encoding-related activity in mPFC increased linearly with increasing congruency, whereas MTL showed the opposite pattern of increasing encoding-related activity with decreasing congruency. Additionally, mPFC showed increased functional connectivity with a region in the ventral visual stream, presumably related to the binding of visual representations. These results support predictions made by a recent neuroscientific framework concerning the effects of schema on memory. Specifically, our findings show that enhanced memory for more congruent information is mediated by the mPFC, which is hypothesised to guide integration of new information into a pre-existing schema represented in cortical areas, while memory for more incongruent information relies instead on automatic encoding of arbitrary associations by the MTL. © 2013 Elsevier Ltd. All rights reserved.

  17. Dopamine in the medial amygdala network mediates human bonding.

    Science.gov (United States)

    Atzil, Shir; Touroutoglou, Alexandra; Rudy, Tali; Salcedo, Stephanie; Feldman, Ruth; Hooker, Jacob M; Dickerson, Bradford C; Catana, Ciprian; Barrett, Lisa Feldman

    2017-02-28

    Research in humans and nonhuman animals indicates that social affiliation, and particularly maternal bonding, depends on reward circuitry. Although numerous mechanistic studies in rodents demonstrated that maternal bonding depends on striatal dopamine transmission, the neurochemistry supporting maternal behavior in humans has not been described so far. In this study, we tested the role of central dopamine in human bonding. We applied a combined functional MRI-PET scanner to simultaneously probe mothers' dopamine responses to their infants and the connectivity between the nucleus accumbens (NAcc), the amygdala, and the medial prefrontal cortex (mPFC), which form an intrinsic network (referred to as the "medial amygdala network") that supports social functioning. We also measured the mothers' behavioral synchrony with their infants and plasma oxytocin. The results of this study suggest that synchronous maternal behavior is associated with increased dopamine responses to the mother's infant and stronger intrinsic connectivity within the medial amygdala network. Moreover, stronger network connectivity is associated with increased dopamine responses within the network and decreased plasma oxytocin. Together, these data indicate that dopamine is involved in human bonding. Compared with other mammals, humans have an unusually complex social life. The complexity of human bonding cannot be fully captured in nonhuman animal models, particularly in pathological bonding, such as that in autistic spectrum disorder or postpartum depression. Thus, investigations of the neurochemistry of social bonding in humans, for which this study provides initial evidence, are warranted.

  18. Visual perception and memory systems: from cortex to medial temporal lobe.

    Science.gov (United States)

    Khan, Zafar U; Martín-Montañez, Elisa; Baxter, Mark G

    2011-05-01

    Visual perception and memory are the most important components of vision processing in the brain. It was thought that the perceptual aspect of a visual stimulus occurs in visual cortical areas and that this serves as the substrate for the formation of visual memory in a distinct part of the brain called the medial temporal lobe. However, current evidence indicates that there is no functional separation of areas. Entire visual cortical pathways and connecting medial temporal lobe are important for both perception and visual memory. Though some aspects of this view are debated, evidence from both sides will be explored here. In this review, we will discuss the anatomical and functional architecture of the entire system and the implications of these structures in visual perception and memory.

  19. SPHENOID SINUS (SS ANTERIOR MEDIAL TEMPORAL LOBE ENCEPHALOCELE (AMTLE WITH SPONTANEOUS CSF RHINORRHOEA : A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Laveena

    2015-09-01

    Full Text Available Cranial encephaloceles are the herniation of intracranial meninges and brain tissue through a defect in the cranium or skull base. These are rare conditions with an incidence of approximately 1 in 35,000 people, and are more common in the anterior cranial fossa than those in the middle one . 1,2 Temporal lobe herniation through a mid dle fossa defect into the lateral recess of the Sphenoid Sinus is even rarer than its medial representation. Intrasphenoidal encephaloceles are extremely rare findings 3 . Spontaneous, or primary, CSF fistula is a separate entity with no underlying cause of the CSF leak. Spontaneous CSF leaks are usually associated with a co - existing encephalocele of variable size 4 . We present a case of spontaneous CSF rhinorrhoea in a sphenoid sinus Anterior Medial Temporal lobe encephalocele herniating through a clinically silent lateral Craniopharyngeal canal.

  20. Diabetes mellitus, hypertension and medial temporal lobe atrophy: the LADIS study

    DEFF Research Database (Denmark)

    Korf, E S C; van Straaten, E C W; de Leeuw, F-E

    2007-01-01

    HYPOTHESIS: Based on recent findings on the association between vascular risk factors and hippocampal atrophy, we hypothesized that hypertension and diabetes mellitus (DM) are associated with medial temporal lobe atrophy (MTA) in subjects without disability, independent of the severity of white...... matter hyperintensities. METHODS: In the Leukoaraiosis And DISability in the elderly (LADIS) study, we investigated the relationships between DM, hypertension, blood pressure and MTA in 582 subjects, stratified by white matter hyperintensity severity, using multinomial logistic regression. MTA...... was visually scored for the left and right medial temporal lobe (score 0-4), and meaned. RESULTS: Mean age was 73.5 years (sd 5.1), 54% was female. Of the subjects, 15% had DM, and 70% had a history of hypertension. The likelihood of having MTA score 3 was significantly higher in subjects with DM (OR 2.9; 95...

  1. Threat of punishment motivates memory encoding via amygdala, not midbrain, interactions with the medial temporal lobe.

    Science.gov (United States)

    Murty, Vishnu P; Labar, Kevin S; Adcock, R Alison

    2012-06-27

    Neural circuits associated with motivated declarative encoding and active threat avoidance have both been described, but the relative contribution of these systems to punishment-motivated encoding remains unknown. The current study used functional magnetic resonance imaging in humans to examine mechanisms of declarative memory enhancement when subjects were motivated to avoid punishments that were contingent on forgetting. A motivational cue on each trial informed participants whether they would be punished or not for forgetting an upcoming scene image. Items associated with the threat of shock were better recognized 24 h later. Punishment-motivated enhancements in subsequent memory were associated with anticipatory activation of right amygdala and increases in its functional connectivity with parahippocampal and orbitofrontal cortices. On a trial-by-trial basis, right amygdala activation during the motivational cue predicted hippocampal activation during encoding of the subsequent scene; across participants, the strength of this interaction predicted memory advantages due to motivation. Of note, punishment-motivated learning was not associated with activation of dopaminergic midbrain, as would be predicted by valence-independent models of motivation to learn. These data are consistent with the view that motivation by punishment activates the amygdala, which in turn prepares the medial temporal lobe for memory formation. The findings further suggest a brain system for declarative learning motivated by punishment that is distinct from that for learning motivated by reward.

  2. Functional neuroimaging studies of episodic memory. Functional dissociation in the medial temporal lobe structures

    International Nuclear Information System (INIS)

    Tsukiura, Takashi

    2008-01-01

    Previous functional neuroimaging studies have demonstrated the critical role of the medial temporal lobe (MTL) regions in the encoding and retrieval of episodic memory. It has also been shown that an emotional factor in human memory enhances episodic encoding and retrieval. However, there is little evidence regarding the specific contribution of each MTL region to the relational, contextual, and emotional processes of episodic memory. The goal of this review article is to identify differential activation patterns of the processes between MTL regions. Results from functional neuroimaging studies of episodic memory show that the hippocampus is involved in encoding the relation between memory items, whereas the entorhinal and perirhinal cortices (anterior parahippocampal gyrus) contribute to the encoding of a single item. Additionally, the parahippocampal cortex (posterior parahippocampal gyrus) is selectively activated during the processing of contextual information of episodic memory. A similar pattern of functional dissociation is found in episodic memory retrieval. Functional neuroimaging has also shown that emotional information of episodic memory enhances amygdala-MTL correlations and that this enhancement is observed during both the encoding and retrieval of emotional memories. These findings from pervious neuroimaging studies suggest that different MTL regions could organize memory for personally experienced episodes via the 'relation' and 'context' factors of episodic memory, and that the emotional factor of episodes could modulate the functional organization in the MTL regions. (author)

  3. Role of the medial temporal lobes in relational memory: Neuropsychological evidence from a cued recognition paradigm

    OpenAIRE

    Kan, Irene P.; Giovanello, Kelly S.; Schnyer, David M.; Makris, Nikos; Verfaellie, Mieke

    2007-01-01

    In this study, we examined the role of the hippocampus in relational memory by comparing item recognition performance in amnesic patients with medial temporal lobe (MTL) damage and their matched controls. Specifically, we investigated the contribution of associative memory to item recognition using a cued recognition paradigm. Control subjects studied cue-target pairs once, whereas amnesic patients studied cue-target pairs six times. Following study, subjects made recognition judgments about ...

  4. Distinct medial temporal networks encode surprise during motivation by reward versus punishment

    OpenAIRE

    Murty, Vishnu P.; LaBar, Kevin S.; Adcock, R. Alison

    2016-01-01

    Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also...

  5. Correlation between hippocampal volumes and medial temporal lobe atrophy in patients with Alzheimer's disease

    OpenAIRE

    Dhikav, Vikas; Duraiswamy, Sharmila; Anand, Kuljeet Singh

    2017-01-01

    Introduction: Hippocampus undergoes atrophy in patients with Alzheimer's disease (AD). Calculation of hippocampal volumes can be done by a variety of methods using T1-weighted images of magnetic resonance imaging (MRI) of the brain. Medial temporal lobes atrophy (MTL) can be rated visually using T1-weighted MRI brain images. The present study was done to see if any correlation existed between hippocampal volumes and visual rating scores of the MTL using Scheltens Visual Rating Method. Materia...

  6. Losing sight of the future: Impaired semantic prospection following medial temporal lobe lesions

    Science.gov (United States)

    Race, Elizabeth; Keane, Margaret M.; Verfaellie, Mieke

    2012-01-01

    The ability to imagine the future (prospection) relies on many of the same brain regions that support memory for the past. To date, scientific research has primarily focused on the neural substrates of episodic forms of prospection (mental simulation of spatiotemporally specific future events) whereas little is known about the neural substrates of semantic prospection (mental simulation of future nonpersonal facts). Of particular interest is the role of the medial temporal lobes, and specifically the hippocampus. While the hippocampus has been proposed to play a key role in episodic prospection, recent evidence suggests that it may not play a similar role in semantic prospection. To examine this possibility, amnesic patients with medial temporal lobe (MTL) lesions were asked to imagine future issues occurring in the public domain. The results showed that patients could list general semantic facts about the future, but when probed to elaborate, patients produced impoverished descriptions that lacked semantic detail. This impairment occurred despite intact performance on standard neuropsychological tests of semantic processing, and did not simply reflect deficits in narrative construction. The performance of a patient with damage limited to the hippocampus was similar to that of the remaining MTL patients and amnesic patients’ impaired elaboration of the semantic future correlated with their impaired elaboration of the semantic past. Together, these results provide novel evidence from MTL amnesia that memory and prospection are linked in the semantic domain and reveal that the medial temporal lobes play a critical role in the construction of detailed, multi-element semantic simulations. PMID:23197413

  7. Effects of Level of Retrieval Success on Recall-Related Frontal and Medial Temporal Lobe Activations

    Directory of Open Access Journals (Sweden)

    Daniela Montaldi

    2002-01-01

    Full Text Available Brain dedicated single photon emission computed tomography (SPECT was used to compare the neuroactivation produced by the cued recall of response words in a set of studied word pairs with that produced by the cued retrieval of words semantically related to unstudied stimulus words. Six of the 12 subjects scanned were extensively trained so as to have good memory of the studied pairs and the remaining six were minimally trained so as to have poor memory. When comparing episodic with semantic retrieval, the well-trained subjects showed significant left medial temporal lobe activation, which was also significantly greater than that shown by the poorly trained subjects, who failed to show significant medial temporal lobe activation. In contrast, the poorly trained subjects showed significant bilateral frontal lobe activation, which was significantly greater than that shown by the well-trained subjects who failed to show significant frontal lobe activation. The frontal activations occurred mainly in the dorsolateral region, but extended into the ventrolateral and, to a lesser extent, the frontal polar regions. It is argued that whereas the medial temporal lobe activation increased as the proportion of response words successfully recalled increased, the bilateral frontal lobe activation increased in proportion to retrieval effort, which was greater when learning had been less good.

  8. Segregation of the human medial prefrontal cortex in social cognition

    Directory of Open Access Journals (Sweden)

    Danilo eBzdok

    2013-05-01

    Full Text Available While the human medial prefrontal cortex (mPFC is widely believed to be a key node of neural networks relevant for socio-emotional processing, its functional subspecialization is still poorly understood. We thus revisited the often assumed differentiation of the mPFC in social cognition along its ventral-dorsal axis. Our neuroinformatic analysis was based on a neuroimaging meta-analysis of perspective-taking that yielded two separate clusters in the ventral and dorsal mPFC, respectively. We determined each seed region’s brain-wide interaction pattern by two complementary measures of functional connectivity: co-activation across a wide range of neuroimaging studies archived in the BrainMap database and correlated signal fluctuations during unconstrained (resting cognition. Furthermore, we characterized the functions associated with these two regions using the BrainMap database. Across methods, the ventral mPFC was more strongly connected with the nucleus accumbens, hippocampus, posterior cingulate cortex, and retrosplenial cortex, while the dorsal mPFC was more strongly connected with the inferior frontal gyrus, temporo-parietal junction, and middle temporal gyrus. Further, the ventral mPFC was selectively associated with action execution, olfaction, and reward related tasks, while the dorsal mPFC was selectively associated with perspective-taking and episodic memory retrieval. The ventral mPFC is therefore predominantly involved in sensory-driven, approach/avoidance-modulating, and evaluation-related processing, whereas the dorsal mPFC is predominantly involved in internally driven, memory-informed, and metacognition-related processing in social cognition.

  9. Usefulness of StereoEEG-based tailored surgery for medial temporal lobe epilepsy. Preliminary results in 11 patients.

    Science.gov (United States)

    Kubota, Yuichi; Ochiai, Taku; Hori, Tomokatsu; Kawamata, Takakazu

    2017-07-01

    Surgical options for medial temporal lobe epilepsy (MTLE) include anterior temporal lobectomy (ATL) and selective amygdalohippocampectomy (SAH). Optimal criteria for choosing the appropriate surgical approach remain uncertain. This article reports 11 consecutive cases in which electrophysiological findings of stereoelectroencephalography (SEEG) were used to determine the optimal surgical approach. Eleven consecutive patients with MTLE underwent SEEG evaluation and were placed in either the medial or the medial+lateral group based on the findings. Patients in the medial group underwent SAH using the subtemporal approach, and patients in the medial+lateral group underwent SEEG-guided anterior temporal lobectomy. SEEG findings were also compared with other examinations including flumazenil (FMZ)-positron emission tomography (PET), fluorine-18 labeled fluorodeoxyglucose (FDG)-PET, and magnetoencephalography (MEG). Results were evaluated to determine which examinations most consistently identified the epileptogenic zone. Of the 11 cases, 4 patients were placed in the medial group, and 7 patients in the medial+lateral group. Of patients, 90.9% were classified in class I of the Engel Epilepsy Surgery Outcome Scale, while 72.7% were classified in class I by the International League Against Epilepsy (ILAE) system. Analyzed by group, 100% of the medial group experienced an Engel class I outcome in the medial group, compared to 85.7% in the medial+lateral group. SEEG findings were comparable with FDG-PET results (10 of 11, 91%). Tailored surgery guided by SEEG is an electrophysiologically feasible treatment for MTLE that can result in favorable outcomes. Although seizures are thought to originate in the medial temporal lobe in MTLE, it is important for involvement of the lateral temporal cortex to be also considered in some cases. Copyright © 2017. Published by Elsevier B.V.

  10. Age-related functional changes in domain-specific medial temporal lobe pathways.

    Science.gov (United States)

    Berron, David; Neumann, Katja; Maass, Anne; Schütze, Hartmut; Fliessbach, Klaus; Kiven, Verena; Jessen, Frank; Sauvage, Magdalena; Kumaran, Dharshan; Düzel, Emrah

    2018-05-01

    There is now converging evidence from studies in animals and humans that the medial temporal lobes (MTLs) harbor anatomically distinct processing pathways for object and scene information. Recent functional magnetic resonance imaging studies in humans suggest that this domain-specific organization may be associated with a functional preference of the anterior-lateral part of the entorhinal cortex (alErC) for objects and the posterior-medial entorhinal cortex (pmErC) for scenes. As MTL subregions are differentially affected by aging and neurodegenerative diseases, the question was raised whether aging may affect the 2 pathways differentially. To address this possibility, we developed a paradigm that allows the investigation of object memory and scene memory in a mnemonic discrimination task. A group of young (n = 43) and healthy older subjects (n = 44) underwent functional magnetic resonance imaging recordings during this novel task, while they were asked to discriminate exact repetitions of object and scene stimuli from novel stimuli that were similar but modified versions of the original stimuli ("lures"). We used structural magnetic resonance images to manually segment anatomical components of the MTL including alErC and pmErC and used these segmented regions to analyze domain specificity of functional activity. Across the entire sample, object processing was associated with activation of the perirhinal cortex (PrC) and alErC, whereas for scene processing, activation was more predominant in the parahippocampal cortex and pmErC. Functional activity related to mnemonic discrimination of object and scene lures from exact repetitions was found to overlap between processing pathways and suggests that while the PrC-alErC pathway was more involved in object discrimination, both pathways were involved in the discrimination of similar scenes. Older adults were behaviorally less accurate than young adults in discriminating similar lures from exact repetitions, but this

  11. Two-population model for medial temporal lobe neurons: The vast majority are almost silent.

    Science.gov (United States)

    Magyar, Andrew; Collins, John

    2015-07-01

    Recordings in the human medial temporal lobe have found many neurons that respond to pictures (and related stimuli) of just one particular person of those presented. It has been proposed that these are concept cells, responding to just a single concept. However, a direct experimental test of the concept cell idea appears impossible, because it would need the measurement of the response of each cell to enormous numbers of other stimuli. Here we propose a new statistical method for analysis of the data that gives a more powerful way to analyze how close data are to the concept-cell idea. Central to the model is the neuronal sparsity, defined as the total fraction of stimuli that elicit an above-threshold response in the neuron. The model exploits the large number of sampled neurons to give sensitivity to situations where the average response sparsity is much less than one response for the number of presented stimuli. We show that a conventional model where a single sparsity is postulated for all neurons gives an extremely poor fit to the data. In contrast, a model with two dramatically different populations gives an excellent fit to data from the hippocampus and entorhinal cortex. In the hippocampus, one population has 7% of the cells with a 2.6% sparsity. But a much larger fraction (93%) respond to only 0.1% of the stimuli. This can result in an extreme bias in the responsiveness of reported neurons compared with a typical neuron. Finally, we show how to allow for the fact that some identified units correspond to multiple neurons and find that our conclusions at the neural level are quantitatively changed but strengthened, with an even stronger difference between the two populations.

  12. MR volumetric measurement of medial temporal lobe in differentiating Alzheimer disease and subcortical ischemic vascular dementia

    International Nuclear Information System (INIS)

    Wang Liang; Li Kuncheng; Liu Shuliang

    2003-01-01

    Objective: To evaluate the value of measurement of medial temporal structure by MR imaging volumetry in the differential diagnosis for patients with Alzheimer's disease (AD) and subcortical ischemic vascular dementia (SIVD). Methods: Thirty-three probable patients of AD, 33 normal controls, and 17 patients suspected with SIVD had been scanned by MRI, and volumetric measurements of amygdala (AMY), hippocampal formations (HF), entorhinal cortices (EC), parahippocampal gyri (PHG), and temporal horn of lateral ventricle (TH) were done on a serial reconstructed MR images. Results: Both atrophy of HF and dilatation of TH were significant (P<0.05) in SIVD group compared with that in control group. All the measurements with the exception of TH were atrophied significantly (P<0.001) in AD group compared with that in SIVD group and could significantly discriminate the two group. Among these indexes, the left EC provided the best discrimination with the specificity of 82.4%, sensitivity of 87.9%, and accuracy of 86.0%, respectively, and the average accuracy of bilateral EC in discrimination was 85%. Conclusion: The MR imaging volumetric measurements of medial temporal structure could offer useful information in discriminating individuals with AD from that with SIVD. Meanwhile, it should be understood that the AD-type pathological changes could also be induced by cerebrovascular disease

  13. Aberrant Wnt signaling pathway in medial temporal lobe structures of Alzheimer's disease

    DEFF Research Database (Denmark)

    Riise, Jesper; Plath, Niels; Pakkenberg, Bente

    2015-01-01

    alterations of the intracellular Wnt pathway signaling components β-catenin, Gsk3β and Tcf7l1/Tcf3 and the phosphorylation state of β-catenin and Gsk3β in the hippocampus suggestive of a link between AD and aberrant canonical activity. Alterations in Gsk3β co-appeared with hippocampal kinase...... on isolated Wnt pathway components. Here, we provide the first comprehensive pathway-focused evaluation of the Wnt pathway in the entorhinal cortex and hippocampus of AD brains. Our data demonstrate altered Wnt pathway gene expression at all levels of the pathway in both medial temporal lobe regions...

  14. Towards a functional organization of episodic memory in the medial temporal lobe.

    Science.gov (United States)

    Eichenbaum, Howard; Sauvage, Magdalena; Fortin, Norbert; Komorowski, Robert; Lipton, Paul

    2012-08-01

    Here we describe a model of medial temporal lobe organization in which parallel "what" and "where" processing streams converge within the hippocampus to represent events in the spatio-temporal context in which they occurred; this circuitry also mediates the retrieval of context from event cues and vice versa, which are prototypes of episodic recall. Evidence from studies in animals are reviewed in support of this model, including experiments that distinguish characteristics of episodic recollection from familiarity, neuropsychological and recording studies that have identified a key role for the hippocampus in recollection and in associating events with the context in which they occurred, and distinct roles for parahippocampal region areas in separate "what" and "where" information processing that contributes to recollective and episodic memory. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Whole-brain voxel-based morphometry of white matter in medial temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Yu Aihong [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China); Li Kuncheng [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China)], E-mail: Likuncheng@vip.sina.com; Li Lin; Shan Baoci [Institute of High Energy Physics, Chinese Academy of Sciences (China); Wang Yuping; Xue Sufang [Department of Neurology, Xuanwu Hospital, Capital University of Medical Sciences (China)

    2008-01-15

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in medial temporal lobe epilepsy (MTLE). Materials and methods: We studied 23 patients with MTLE and 13 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The seizure focus was right sided in 11 patients and left sided in 12. The data were collected on a 1.5 T MR system and analyzed by SPM 99 to generate white matter density maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MTLE prominently including bilateral frontal lobes, bilateral temporal lobes and corpus callosum. White matter reduction was also found in the bilateral cerebellar hemispheres in the left MTLE group. Conclusion: VBM is a simple and automated approach that is able to identify diffuse whole-brain white matter reduction in MTLE.

  16. Whole-brain voxel-based morphometry of white matter in medial temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Yu Aihong; Li Kuncheng; Li Lin; Shan Baoci; Wang Yuping; Xue Sufang

    2008-01-01

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in medial temporal lobe epilepsy (MTLE). Materials and methods: We studied 23 patients with MTLE and 13 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The seizure focus was right sided in 11 patients and left sided in 12. The data were collected on a 1.5 T MR system and analyzed by SPM 99 to generate white matter density maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MTLE prominently including bilateral frontal lobes, bilateral temporal lobes and corpus callosum. White matter reduction was also found in the bilateral cerebellar hemispheres in the left MTLE group. Conclusion: VBM is a simple and automated approach that is able to identify diffuse whole-brain white matter reduction in MTLE

  17. The Medial Temporal Lobe – Conduit of Parallel Connectivity: A model for Attention, Memory, and Perception.

    Directory of Open Access Journals (Sweden)

    Brian B. Mozaffari

    2014-11-01

    Full Text Available Based on the notion that the brain is equipped with a hierarchical organization, which embodies environmental contingencies across many time scales, this paper suggests that the medial temporal lobe (MTL – located deep in the hierarchy – serves as a bridge connecting supra to infra – MTL levels. Bridging the upper and lower regions of the hierarchy provides a parallel architecture that optimizes information flow between upper and lower regions to aid attention, encoding, and processing of quick complex visual phenomenon. Bypassing intermediate hierarchy levels, information conveyed through the MTL ‘bridge’ allows upper levels to make educated predictions about the prevailing context and accordingly select lower representations to increase the efficiency of predictive coding throughout the hierarchy. This selection or activation/deactivation is associated with endogenous attention. In the event that these ‘bridge’ predictions are inaccurate, this architecture enables the rapid encoding of novel contingencies. A review of hierarchical models in relation to memory is provided along with a new theory, Medial-temporal-lobe Conduit for Parallel Connectivity (MCPC. In this scheme, consolidation is considered as a secondary process, occurring after a MTL-bridged connection, which eventually allows upper and lower levels to access each other directly. With repeated reactivations, as contingencies become consolidated, less MTL activity is predicted. Finally, MTL bridging may aid processing transient but structured perceptual events, by allowing communication between upper and lower levels without calling on intermediate levels of representation.

  18. Medial temporal lobe contributions to cued retrieval of items and contexts.

    Science.gov (United States)

    Hannula, Deborah E; Libby, Laura A; Yonelinas, Andrew P; Ranganath, Charan

    2013-10-01

    Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model-namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Insulin Resistance Predicts Medial Temporal Hypermetabolism in Mild Cognitive Impairment Conversion to Alzheimer Disease

    Science.gov (United States)

    Willette, Auriel A.; Modanlo, Nina

    2015-01-01

    Alzheimer disease (AD) is characterized by progressive hypometabolism on [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) scans. Peripheral insulin resistance (IR) increases AD risk. No studies have examined associations between FDG metabolism and IR in mild cognitive impairment (MCI) and AD, as well as MCI conversion to AD. We studied 26 cognitively normal (CN), 194 MCI (39 MCI-progressors, 148 MCI-stable, 2 years after baseline), and 60 AD subjects with baseline FDG-PET from the Alzheimer’s Disease Neuroimaging Initiative. Mean FDG metabolism was derived for AD-vulnerable regions of interest (ROIs), including lateral parietal and posteromedial cortices, medial temporal lobe (MTL), hippocampus, and ventral prefrontal cortices (vPFC), as well as postcentral gyrus and global cerebrum control regions. The homeostasis model assessment of IR (HOMA-IR) was used to measure IR. For AD, higher HOMA-IR predicted lower FDG in all ROIs. For MCI-progressors, higher HOMA-IR predicted higher FDG in the MTL and hippocampus. Control regions showed no associations. Higher HOMA-IR predicted hypermetabolism in MCI-progressors and hypometabolism in AD in medial temporal regions. Future longitudinal studies should examine the pathophysiologic significance of the shift from MTL hyper- to hypometabolism associated with IR. PMID:25576061

  20. Medial Temporal Lobe Contributions to Cued Retrieval of Items and Contexts

    Science.gov (United States)

    Hannula, Deborah E.; Libby, Laura A.; Yonelinas, Andrew P.; Ranganath, Charan

    2013-01-01

    Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model – namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. PMID:23466350

  1. Close but no cigar: Spatial precision deficits following medial temporal lobe lesions provide novel insight into theoretical models of navigation and memory.

    Science.gov (United States)

    Kolarik, Branden S; Baer, Trevor; Shahlaie, Kiarash; Yonelinas, Andrew P; Ekstrom, Arne D

    2018-01-01

    Increasing evidence suggests that the human hippocampus contributes to a range of different behaviors, including episodic memory, language, short-term memory, and navigation. A novel theoretical framework, the Precision and Binding Model, accounts for these phenomenon by describing a role for the hippocampus in high-resolution, complex binding. Other theories like Cognitive Map Theory, in contrast, predict a specific role for the hippocampus in allocentric navigation, while Declarative Memory Theory predicts a specific role in delay-dependent conscious memory. Navigation provides a unique venue for testing these predictions, with past results from research with humans providing inconsistent findings regarding the role of the human hippocampus in spatial navigation. Here, we tested five patients with lesions primarily restricted to the hippocampus and those extending out into the surrounding medial temporal lobe cortex on a virtual water maze task. Consistent with the Precision and Binding Model, we found partially intact allocentric memory in all patients, with impairments in the spatial precision of their searches for a hidden target. We found similar impairments at both immediate and delayed testing. Our findings are consistent with the Precision and Binding Model of hippocampal function, arguing for its role across domains in high-resolution, complex binding. Remembering goal locations in one's environment is a critical skill for survival. How this information is represented in the brain is still not fully understood, but is believed to rely in some capacity on structures in the medial temporal lobe. Contradictory findings from studies of both humans and animals have been difficult to reconcile with regard to the role of the MTL, specifically the hippocampus. By assessing impairments observed during navigation to a goal in patients with medial temporal lobe damage we can better understand the role these structures play in such behavior. Utilizing virtual reality

  2. Tau and β-Amyloid Are Associated with Medial Temporal Lobe Structure, Function, and Memory Encoding in Normal Aging

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Shawn M. [Univ. of California, Berkeley, CA (United States). Helen Wills Neuroscience Inst.; Lockhart, Samuel N. [Univ. of California, Berkeley, CA (United States). Helen Wills Neuroscience Inst.; Baker, Suzanne L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Biophysics and Integrated Bioimaging; Jagust, William J. [Univ. of California, Berkeley, CA (United States). Helen Wills Neuroscience Inst.; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Biophysics and Integrated Bioimaging

    2017-03-22

    Normal aging is associated with a decline in episodic memory and also with aggregation of the β-amyloid (Aβ) and tau proteins and atrophy of medial temporal lobe (MTL) structures crucial to memory formation. Although some evidence suggests that Aβ is associated with aberrant neural activity, the relationships among these two aggregated proteins, neural function, and brain structure are poorly understood. Using in vivo human Aβ and tau imaging, we demonstrate that increased Aβ and tau are both associated with aberrant fMRI activity in the MTL during memory encoding in cognitively normal older adults. This pathological neural activity was in turn associated with worse memory performance and atrophy within the MTL. A mediation analysis revealed that the relationship with regional atrophy was explained by MTL tau. These findings broaden the concept of cognitive aging to include evidence of Alzheimer’s disease-related protein aggregation as an underlying mechanism of age-related memory impairment.

  3. Medial frontal cortex and response conflict: Evidence from human intracranial EEG and medial frontal cortex lesion

    NARCIS (Netherlands)

    Cohen, M.X.; Ridderinkhof, K.R.; Haupt, S.; Elger, C.E.; Fell, J.

    2008-01-01

    The medial frontal cortex (MFC) has been implicated in the monitoring and selection of actions in the face of competing alternatives, but much remains unknown about its functional properties, including electrophysiological oscillations, during response conflict tasks. Here, we recorded intracranial

  4. Preservation of episodic memory in semantic dementia: The importance of regions beyond the medial temporal lobes.

    Science.gov (United States)

    Irish, Muireann; Bunk, Steffie; Tu, Sicong; Kamminga, Jody; Hodges, John R; Hornberger, Michael; Piguet, Olivier

    2016-01-29

    Episodic memory impairment represents one of the hallmark clinical features of patients with Alzheimer's disease (AD) attributable to the degeneration of medial temporal and parietal regions of the brain. In contrast, a somewhat paradoxical profile of relatively intact episodic memory, particularly for non-verbal material, is observed in semantic dementia (SD), despite marked atrophy of the hippocampus. This retrospective study investigated the neural substrates of episodic memory retrieval in 20 patients with a diagnosis of SD and 21 disease-matched cases of AD and compared their performance to that of 35 age- and education-matched healthy older Controls. Participants completed the Rey Complex Figure and the memory subscale of the Addenbrooke's Cognitive Examination-Revised as indices of visual and verbal episodic recall, respectively. Relative to Controls, AD patients showed compromised memory performance on both visual and verbal memory tasks. In contrast, memory deficits in SD were modality-specific occurring exclusively on the verbal task. Controlling for semantic processing ameliorated these deficits in SD, while memory impairments persisted in AD. Voxel-based morphometry analyses revealed significant overlap in the neural correlates of verbal episodic memory in AD and SD with predominantly anteromedial regions, including the bilateral hippocampus, strongly implicated. Controlling for semantic processing negated this effect in SD, however, a distributed network of frontal, medial temporal, and parietal regions was implicated in AD. Our study corroborates the view that episodic memory deficits in SD arise very largely as a consequence of the conceptual loading of traditional tasks. We propose that the functional integrity of frontal and parietal regions enables new learning to occur in SD in the face of significant hippocampal and anteromedial temporal lobe pathology, underscoring the inherent complexity of the episodic memory circuitry. Copyright © 2015

  5. Deep processing activates the medial temporal lobe in young but not in old adults.

    Science.gov (United States)

    Daselaar, Sander M; Veltman, Dick J; Rombouts, Serge A R B; Raaijmakers, Jeroen G W; Jonker, Cees

    2003-11-01

    Age-related impairments in episodic memory have been related to a deficiency in semantic processing, based on the finding that elderly adults typically benefit less than young adults from deep, semantic as opposed to shallow, nonsemantic processing of study items. In the present study, we tested the hypothesis that elderly adults are not able to perform certain cognitive operations under deep processing conditions. We further hypothesised that this inability does not involve regions commonly associated with lexical/semantic retrieval processes, but rather involves a dysfunction of the medial temporal lobe (MTL) memory system. To this end, we used functional MRI on rather extensive groups of young and elderly adults to compare brain activity patterns obtained during a deep (living/nonliving) and a shallow (uppercase/lowercase) classification task. Common activity in relation to semantic classification was observed in regions that have been previously related to semantic retrieval, including mainly left-lateralised activity in the inferior prefrontal, middle temporal, and middle frontal/anterior cingulate gyrus. Although the young adults showed more activity in some of these areas, the finding of mainly overlapping activation patterns during semantic classification supports the idea that lexical/semantic retrieval processes are still intact in elderly adults. This received further support by the finding that both groups showed similar behavioural performances as well on the deep and shallow classification tasks. Importantly, though, the young revealed significantly more activity than the elderly adults in the left anterior hippocampus during deep relative to shallow classification. This finding is in line with the idea that age-related impairments in episodic encoding are, at least partly, due to an under-recruitment of the medial temporal lobe memory system.

  6. A protocol for manual segmentation of medial temporal lobe subregions in 7 Tesla MRI

    Directory of Open Access Journals (Sweden)

    D. Berron

    2017-01-01

    Full Text Available Recent advances in MRI and increasing knowledge on the characterization and anatomical variability of medial temporal lobe (MTL anatomy have paved the way for more specific subdivisions of the MTL in humans. In addition, recent studies suggest that early changes in many neurodegenerative and neuropsychiatric diseases are better detected in smaller subregions of the MTL rather than with whole structure analyses. Here, we developed a new protocol using 7 Tesla (T MRI incorporating novel anatomical findings for the manual segmentation of entorhinal cortex (ErC, perirhinal cortex (PrC; divided into area 35 and 36, parahippocampal cortex (PhC, and hippocampus; which includes the subfields subiculum (Sub, CA1, CA2, as well as CA3 and dentate gyrus (DG which are separated by the endfolial pathway covering most of the long axis of the hippocampus. We provide detailed instructions alongside slice-by-slice segmentations to ease learning for the untrained but also more experienced raters. Twenty-two subjects were scanned (19–32 yrs, mean age = 26 years, 12 females with a turbo spin echo (TSE T2-weighted MRI sequence with high-resolution oblique coronal slices oriented orthogonal to the long axis of the hippocampus (in-plane resolution 0.44×0.44 mm2 and 1.0 mm slice thickness. The scans were manually delineated by two experienced raters, to assess intra- and inter-rater reliability. The Dice Similarity Index (DSI was above 0.78 for all regions and the Intraclass Correlation Coefficients (ICC were between 0.76 to 0.99 both for intra- and inter-rater reliability. In conclusion, this study presents a fine-grained and comprehensive segmentation protocol for MTL structures at 7 T MRI that closely follows recent knowledge from anatomical studies. More specific subdivisions (e.g. area 35 and 36 in PrC, and the separation of DG and CA3 may pave the way for more precise delineations thereby enabling the detection of early volumetric changes in dementia and

  7. Medial temporal and neocortical contributions to remote memory for semantic narratives: evidence from amnesia.

    Science.gov (United States)

    Verfaellie, Mieke; Bousquet, Kathryn; Keane, Margaret M

    2014-08-01

    Studies of remote memory for semantic facts and concepts suggest that hippocampal lesions lead to a temporally graded impairment that extends no more than ten years prior to the onset of amnesia. Such findings have led to the notion that once consolidated, semantic memories are represented neocortically and are no longer dependent on the hippocampus. Here, we examined the fate of well-established semantic narratives following medial temporal lobe (MTL) lesions. Seven amnesic patients, five with lesions restricted to the MTL and two with lesions extending into lateral temporal cortex (MTL+), were asked to recount fairy tales and bible stories that they rated as familiar. Narratives were scored for number and type of details, number of main thematic elements, and order in which the main thematic elements were recounted. In comparison to controls, patients with MTL lesions produced fewer details, but the number and order of main thematic elements generated was intact. By contrast, patients with MTL+ lesions showed a pervasive impairment, affecting not only the generation of details, but also the generation and ordering of main steps. These findings challenge the notion that, once consolidated, semantic memories are no longer dependent on the hippocampus for retrieval. Possible hippocampal contributions to the retrieval of detailed semantic narratives are discussed. Published by Elsevier Ltd.

  8. Pathology-Based Approach to Seizure Outcome After Surgery for Pharmacoresistant Medial Temporal Lobe Epilepsy.

    Science.gov (United States)

    Martinoni, Matteo; Berti, Pier Paolo; Marucci, Gianluca; Rubboli, Guido; Volpi, Lilia; Riguzzi, Patrizia; Marliani, Federica; Toni, Francesco; Bisulli, Francesca; Tinuper, Paolo; Michelucci, Roberto; Baruzzi, Agostino; Giulioni, Marco

    2016-06-01

    Hippocampal sclerosis (HS) is the most common cause of drug-resistant medial temporal lobe epilepsy (MTLE). Structural abnormalities such as HS, granule cell pathology (GCP), and focal cortical dysplasia (FCD) have been classified histopathologically, possibly allowing a more accurate assessment of prognostic seizure and neuropsychologic outcomes. We correlated seizure outcome with comprehensive temporal lobe pathologic findings, identified according to the most recent classification systems of HS, GCP, and FCD. All the 83 patients who underwent anterior temporal lobectomy (ATL) for drug-resistant MTLE and with a proven diagnosis of HS between April 2001 and May 2014 were collected. Patients were divided in 2 main groups: 1) isolated HS with/without GCP (HS +/- GCP); and 2) HS associated with FCD with/without GCP (HS+FCD +/- GCP). Patients were followed up at least 1 year, and seizure outcome was reported in accordance with Engel classification. Group I: HS +/- GCP: Statistical analysis confirmed a better outcome in HS + GCP patients than in HS-no GCP (P epilepsy surgery might improve the interpretation of the results, could predict which cases will enjoy a better seizure outcome, and could help to the comprehension of the causes of failures. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. A functional MRI study of language networks in left medial temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Yu Aihong; Wang Xiaoyi; Xu Guoqing; Li Yongjie; Qin Wen; Li Kuncheng; Wang, Yuping

    2011-01-01

    Purpose: The purpose of this study was to investigate the abnormality of language networks in left medial temporal lobe epilepsy (MTLE) using fMRI. Materials and methods: Eight patients with left MTLE and 15 healthy subjects were evaluated. An auditory semantic judgment (AJ) paradigm was used. The fMRI data were collected on a 3T MR system and analyzed by AFNI (analysis of functional neuroimages) to generate the activation map. Results: Behavioral data showed that the reaction time of the left MTLE patients was significantly longer than that of controls on the AJ task (t = -3.396, P < 0.05). The left MTLE patients also exhibited diffusively decreased activation in the AJ task. Right hemisphere dominance of Broca's and Wernicke's areas was demonstrated in left MTLE patients. Conclusions: Long-term activation of spikes in left MTLE patients results in language impairment, which is associated with an abnormality of the brain neural network.

  10. Physical activity level and medial temporal health in youth at ultra high-risk for psychosis.

    Science.gov (United States)

    Mittal, Vijay A; Gupta, Tina; Orr, Joseph M; Pelletier-Baldelli, Andrea; Dean, Derek J; Lunsford-Avery, Jessica R; Smith, Ashley K; Robustelli, Briana L; Leopold, Daniel R; Millman, Zachary B

    2013-11-01

    A growing body of evidence suggests that moderate to vigorous activity levels can affect quality of life, cognition, and brain structure in patients diagnosed with schizophrenia. However, physical activity has not been systematically studied during the period immediately preceding the onset of psychosis. Given reports of exercise-based neurogenesis in schizophrenia, understanding naturalistic physical activity levels in the prodrome may provide valuable information for early intervention efforts. The present study examined 29 ultra high-risk (UHR) and 27 matched controls to determine relationships between physical activity level, brain structure (hippocampus and parahippocampal gyrus), and symptoms. Participants were assessed with actigraphy for a 5-day period, MRI, and structured clinical interviews. UHR participants showed a greater percentage of time in sedentary behavior while healthy controls spent more time engaged in light to vigorous activity. There was a strong trend to suggest the UHR group showed less total physical activity. The UHR group exhibited smaller medial temporal volumes when compared with healthy controls. Total level of physical activity in the UHR group was moderately correlated with parahippocampal gyri bilaterally (right: r = .44, left: r = .55) and with occupational functioning (r = -.36; of negative symptom domain), but not positive symptomatology. Results suggest that inactivity is associated with medial temporal lobe health. Future studies are needed to determine if symptoms are driving inactivity, which in turn may be affecting the health of the parahippocampal structure and progression of illness. Although causality cannot be determined from the present design, these findings hold important implications for etiological conceptions and suggest promise for an experimental trial. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  11. The Medial Temporal Lobe and the Left Inferior Prefrontal Cortex Jointly Support Interference Resolution in Verbal Working Memory

    Science.gov (United States)

    Oztekin, Ilke; Curtis, Clayton E.; McElree, Brian

    2009-01-01

    During working memory retrieval, proactive interference (PI) can be induced by semantic similarity and episodic familiarity. Here, we used fMRI to test hypotheses about the role of the left inferior frontal gyrus (LIFG) and the medial temporal lobe (MTL) regions in successful resolution of PI. Participants studied six-word lists and responded to a…

  12. The Role of Medial Temporal Lobe Regions in Incidental and Intentional Retrieval of Item and Relational Information in Aging.

    Science.gov (United States)

    Wang, Wei-Chun; Giovanello, Kelly S

    2016-06-01

    Considerable neuropsychological and neuroimaging work indicates that the medial temporal lobes are critical for both item and relational memory retrieval. However, there remain outstanding issues in the literature, namely the extent to which medial temporal lobe regions are differentially recruited during incidental and intentional retrieval of item and relational information, and the extent to which aging may affect these neural substrates. The current fMRI study sought to address these questions; participants incidentally encoded word pairs embedded in sentences and incidental item and relational retrieval were assessed through speeded reading of intact, rearranged, and new word-pair sentences, while intentional item and relational retrieval were assessed through old/new associative recognition of a separate set of intact, rearranged, and new word pairs. Results indicated that, in both younger and older adults, anterior hippocampus and perirhinal cortex indexed incidental and intentional item retrieval in the same manner. In contrast, posterior hippocampus supported incidental and intentional relational retrieval in both age groups and an adjacent cluster in posterior hippocampus was recruited during both forms of relational retrieval for older, but not younger, adults. Our findings suggest that while medial temporal lobe regions do not differentiate between incidental and intentional forms of retrieval, there are distinct roles for anterior and posterior medial temporal lobe regions during retrieval of item and relational information, respectively, and further indicate that posterior regions may, under certain conditions, be over-recruited in healthy aging. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. A Pencil Rescues Impaired Performance on a Visual Discrimination Task in Patients with Medial Temporal Lobe Lesions

    Science.gov (United States)

    Knutson, Ashley R.; Hopkins, Ramona O.; Squire, Larry R.

    2013-01-01

    We tested proposals that medial temporal lobe (MTL) structures support not just memory but certain kinds of visual perception as well. Patients with hippocampal lesions or larger MTL lesions attempted to identify the unique object among twin pairs of objects that had a high degree of feature overlap. Patients were markedly impaired under the more…

  14. Altered Medial Frontal and Superior Temporal Response to Implicit Processing of Emotions in Autism.

    Science.gov (United States)

    Kana, Rajesh K; Patriquin, Michelle A; Black, Briley S; Channell, Marie M; Wicker, Bruno

    2016-01-01

    Interpreting emotional expressions appropriately poses a challenge for individuals with autism spectrum disorder (ASD). In particular, difficulties with emotional processing in ASD are more pronounced in contexts where emotional expressions are subtle, automatic, and reflexive-that is, implicit. In contrast, explicit emotional processing, which requires the cognitive evaluation of an emotional experience, appears to be relatively intact in individuals with ASD. In the present study, we examined the brain activation and functional connectivity differences underlying explicit and implicit emotional processing in age- and IQ-matched adults with (n = 17) and without (n = 15) ASD. Results indicated: (1) significantly reduced levels of brain activation in participants with ASD in medial prefrontal cortex (MPFC) and superior temporal gyrus (STG) during implicit emotion processing; (2) significantly weaker functional connectivity in the ASD group in connections of the MPFC with the amygdala, temporal lobe, parietal lobe, and fusiform gyrus; (3) No group difference in performance accuracy or reaction time; and (4) Significant positive relationship between empathizing ability and STG activity in ASD but not in typically developing participants. These findings suggest that the neural mechanisms underlying implicit, but not explicit, emotion processing may be altered at multiple levels in individuals with ASD. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  15. Familiarity and recollection vs representational models of medial temporal lobe structures: A single-case study.

    Science.gov (United States)

    Lacot, Emilie; Vautier, Stéphane; Kőhler, Stefan; Pariente, Jérémie; Martin, Chris B; Puel, Michèle; Lotterie, Jean-Albert; Barbeau, Emmanuel J

    2017-09-01

    Although it is known that medial temporal lobe (MTL) structures support declarative memory, the fact these structures have different architectonics and circuitry suggests they may also play different functional roles. Selective lesions of MTL structures offer an opportunity to understand these roles. We report, in this study, on JMG, a patient who presents highly unusual lesions that completely affected all MTL structures except for the right hippocampus and parts of neighbouring medial parahippocampal cortex. We first demonstrate that JMG shows preserved recall for visual material on 5 experimental tasks. This finding suggests that his right hippocampus is functional, even though it appears largely disconnected from most of its MTL afferents. In contrast, JMG performed very poorly, as compared to control subjects, on 7 tasks of visual recognition memory for single items. Although he sometimes performed above chance, neither familiarity nor recollection appeared fully preserved. These results indicate that extrahippocampal structures, damaged bilaterally in JMG, perform critical operations for item recognition; and that the hippocampus cannot take over that role, including recollection, when these structures are largely damaged. Finally, in a set of 3 recognition memory tasks with scenes as stimuli, JMG performed at the level of control participants and obtained normal indices of familiarity and recollection. Overall, our findings suggest that the right hippocampus and remnants of parahippocampal cortex can support recognition memory for scenes in the absence of preserved item-recognition memory. The patterns of dissociations, which we report in the present study, provide support for a representational account of the functional organization of MTL structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. [Pathological neocortical findings in patients with medication-resistant medial temporal lobe epilepsy submitted to surgery].

    Science.gov (United States)

    Estupiñán-Díaz, B; Morales-Chacón, L M; Lorigados-Pedre, L; García-Maeso, I; Bender-del Busto, J E; Trápaga-Quincoses, O; Hidalgo-Portal, L; García-Navarro, M E; Sánchez-Coroneaux, A; Orozco-Suárez, S

    The dual pathology consisting of hippocampal sclerosis plus focal cortical dysplasia (FCD) is often reported in patients with medication-resistant medial temporal lobe epilepsy (MTLE). To determine the histopathological changes that take place in the neocortex of patients with medication-resistant MTLE submitted to surgery and to evaluate the relation between the histopathological changes, pathological background and the clinical course of patients who had received surgical treatment. Tissue obtained by en bloc resection from the neocortex of 18 patients with MTLE refractory to medical treatment was processed histologically and a tailored temporal lobectomy was performed with electrocorticography. Dual pathology was diagnosed in 13 patients (72.2%). Imaging studies confirmed the existence of mesial sclerosis of the temporal in 100% of cases and there was no evidence of neocortical lesions. Histologically, 46.15% and 38.46% of the patients were diagnosed as belonging to FCD type 1a and FCD type 1b, respectively. Only one patient presented FCD type 2a. A statistically significant relation was found between the presence of dual pathology and the existence of an early precipitating injury (p = 0.04). One year after surgery, 72.7% (8/11) patients with dual pathology were classified as belonging to Engel class I. In patients with MTLE there are microscopic FCD-type alterations in the neocortex. There is an association between these alterations and the existence of an initial precipitating injury. Complete resection of the epileptogenic area, which is guaranteed by the lobectomy tailored by electrocorticography, allows patients to enjoy a favourable post-surgical progression one year after surgery.

  17. Differential contributions of the anterior temporal and medial temporal lobe to the retrieval of memory for person identity information.

    Science.gov (United States)

    Tsukiura, Takashi; Suzuki, Chisato; Shigemune, Yayoi; Mochizuki-Kawai, Hiroko

    2008-12-01

    Although previous studies have suggested the importance of the bilateral anterior temporal (ATL) and medial temporal lobes (MTL) in the retrieval of person identity information, there is little evidence concerning how these regions differentially contribute to the process. Here we investigated this question using functional magnetic resonance imaging (fMRI). Before scanning, subjects learned associations among faces (F), names (N), and job titles (as a form of person-related semantics, S). During retrieval with fMRI, subjects were presented with previously learned and new S stimuli, and judged whether the stimuli were old or new. Successful retrieval (H) trials were divided into three conditions: retrieval of S and associated F and N (HSFN); retrieval of S and associated F (HSF); and retrieval of S only (HS). The left ATL was significantly activated in HSFN, compared to HSF or HS, whereas the right ATL and MTL were significantly activated in HSFN and HSF relative to HS. In addition, activity in bilateral ATL was significantly correlated with reaction time for HSFN, whereas we found no significant correlation between activity in the right MTL and reaction time in any condition. The present findings suggest that the left ATL may mediate associations between names and person-related semantic information, whereas the right ATL mediates the association between faces and person-related semantic information in memory for person identity information. In addition, activation of the right MTL region implies that this area may contribute to a more general relational processing of associative components, including memory for person identity information. Copyright 2007 Wiley-Liss, Inc.

  18. 99mTc-HMPAO SPECT in dementia of the Alzheimer type. Hypoperfusion in the medial temporal region

    International Nuclear Information System (INIS)

    Nakamura, Yu; Kawakatsu, Shinobu; Shinohara, Masao; Nadaoka, Toshihide; Totsuka, Shiro; Komatani, Akio

    1995-01-01

    This study examined regional cerebral blood flow (rCBF) by single photon emission computed tomography (SPECT) using technetium 99m-hexamethyl-propyleneamineoxime and correlated the results with neuropsychological findings in 30 patients with dementia of the Alzheimer type (AT dementia). Ten healthy persons served as controls. The group of mild AT dementia exhibited a significant decrease in rCBF in the lower part of the right lateral frontal lobe and in the right parietal lobe. In the group of moderate AT dementia, the significant decrease in rCBF was noted in the lower part of the bilateral frontal lobes, the parietal part of the temporal lobe, the parietal lobe, and the medial temporal lobe. Factor analysis for neuropsychological test revealed three factors involved in rCBF. There was a significantly positive correlation between the factor responsible for memory and recall and rCBF in the left frontal lobe, the anterior part of the lateral temporal lobe, and the medial temporal lobe. These findings suggested that disturbance of the memory circuit may exist in the medial temporal lobe and others as pathophysiology of AT dementia. (N.K.)

  19. Resection of the medial temporal lobe disconnects the rostral superior temporal gyrus from some of its projection targets in the frontal lobe and thalamus.

    Science.gov (United States)

    Muñoz, Monica; Mishkin, Mortimer; Saunders, Richard C

    2009-09-01

    Auditory memory in the monkey does not appear to extend beyond the limits of working memory. It is therefore surprising that this ability is impaired by medial temporal lobe (MTL) resections, because such lesions spare working memory in other sensory modalities. To determine whether MTL ablations might have caused the auditory deficit through inadvertent transection of superior temporal gyrus (STG) projections to its downstream targets, and, if so, which targets might have been compromised, we injected anterograde tracer (biotinylated dextran amine) in the STG of both the normal and MTL-lesioned hemispheres of split-brain monkeys. Interhemispheric comparison of label failed to show any effect of the MTL ablation on efferents from caudal STG, which projects to the inferior prefrontal convexity. However, the ablation did consistently interrupt the normally dense projections from rostral STG to both the ventral medial prefrontal cortex and medial thalamic nuclei. The findings support the possibility that the auditory working memory deficit after MTL ablation is due to transection of downstream auditory projections, and indicate that the candidate structures for mediating auditory working memory are the ventral medial prefrontal cortical areas, the medial thalamus, or both.

  20. Stress as a mnemonic filter: Interactions between medial temporal lobe encoding processes and post-encoding stress.

    Science.gov (United States)

    Ritchey, Maureen; McCullough, Andrew M; Ranganath, Charan; Yonelinas, Andrew P

    2017-01-01

    Acute stress has been shown to modulate memory for recently learned information, an effect attributed to the influence of stress hormones on medial temporal lobe (MTL) consolidation processes. However, little is known about which memories will be affected when stress follows encoding. One possibility is that stress interacts with encoding processes to selectively protect memories that had elicited responses in the hippocampus and amygdala, two MTL structures important for memory formation. There is limited evidence for interactions between encoding processes and consolidation effects in humans, but recent studies of consolidation in rodents have emphasized the importance of encoding "tags" for determining the impact of consolidation manipulations on memory. Here, we used functional magnetic resonance imaging in humans to test the hypothesis that the effects of post-encoding stress depend on MTL processes observed during encoding. We found that changes in stress hormone levels were associated with an increase in the contingency of memory outcomes on hippocampal and amygdala encoding responses. That is, for participants showing high cortisol reactivity, memories became more dependent on MTL activity observed during encoding, thereby shifting the distribution of recollected events toward those that had elicited relatively high activation. Surprisingly, this effect was generally larger for neutral, compared to emotionally negative, memories. The results suggest that stress does not uniformly enhance memory, but instead selectively preserves memories tagged during encoding, effectively acting as mnemonic filter. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Frontal, Striatal, and Medial Temporal Sensitivity to Value Distinguishes Risk-Taking from Risk-Aversive Older Adults during Decision Making.

    Science.gov (United States)

    Goh, Joshua O S; Su, Yu-Shiang; Tang, Yong-Jheng; McCarrey, Anna C; Tereshchenko, Alexander; Elkins, Wendy; Resnick, Susan M

    2016-12-07

    Aging compromises the frontal, striatal, and medial temporal areas of the reward system, impeding accurate value representation and feedback processing critical for decision making. However, substantial variability characterizes age-related effects on the brain so that some older individuals evince clear neurocognitive declines whereas others are spared. Moreover, the functional correlates of normative individual differences in older-adult value-based decision making remain unclear. We performed a functional magnetic resonance imaging study in 173 human older adults during a lottery choice task in which costly to more desirable stakes were depicted using low to high expected values (EVs) of points. Across trials that varied in EVs, participants decided to accept or decline the offered stakes to maximize total accumulated points. We found that greater age was associated with less optimal decisions, accepting stakes when losses were likely and declining stakes when gains were likely, and was associated with increased frontal activity for costlier stakes. Critically, risk preferences varied substantially across older adults and neural sensitivity to EVs in the frontal, striatal, and medial temporal areas dissociated risk-aversive from risk-taking individuals. Specifically, risk-averters increased neural responses to increasing EVs as stakes became more desirable, whereas risk-takers increased neural responses with decreasing EV as stakes became more costly. Risk preference also modulated striatal responses during feedback with risk-takers showing more positive responses to gains compared with risk-averters. Our findings highlight the frontal, striatal, and medial temporal areas as key neural loci in which individual differences differentially affect value-based decision-making ability in older adults. Frontal, striatal, and medial temporal functions implicated in value-based decision processing of rewards and costs undergo substantial age-related changes. However, age

  2. Human medial frontal cortex activity predicts learning from errors.

    Science.gov (United States)

    Hester, Robert; Barre, Natalie; Murphy, Kevin; Silk, Tim J; Mattingley, Jason B

    2008-08-01

    Learning from errors is a critical feature of human cognition. It underlies our ability to adapt to changing environmental demands and to tune behavior for optimal performance. The posterior medial frontal cortex (pMFC) has been implicated in the evaluation of errors to control behavior, although it has not previously been shown that activity in this region predicts learning from errors. Using functional magnetic resonance imaging, we examined activity in the pMFC during an associative learning task in which participants had to recall the spatial locations of 2-digit targets and were provided with immediate feedback regarding accuracy. Activity within the pMFC was significantly greater for errors that were subsequently corrected than for errors that were repeated. Moreover, pMFC activity during recall errors predicted future responses (correct vs. incorrect), despite a sizeable interval (on average 70 s) between an error and the next presentation of the same recall probe. Activity within the hippocampus also predicted future performance and correlated with error-feedback-related pMFC activity. A relationship between performance expectations and pMFC activity, in the absence of differing reinforcement value for errors, is consistent with the idea that error-related pMFC activity reflects the extent to which an outcome is "worse than expected."

  3. Medial temporal lobe contributions to short-term memory for faces

    Science.gov (United States)

    Race, Elizabeth; LaRocque, Karen F.; Keane, Margaret M.; Verfaellie, Mieke

    2015-01-01

    The role of the medial temporal lobes (MTL) in short-term memory (STM) remains a matter of debate. While imaging studies commonly show hippocampal activation during short-delay memory tasks, evidence from amnesic patients with MTL lesions is mixed. It has been argued that apparent STM impairments in amnesia may reflect long-term memory (LTM) contributions to performance. We challenge this conclusion by demonstrating that MTL amnesic patients show impaired delayed matching-to-sample (DMS) for faces in a task that meets both a traditional delay-based and a recently proposed distractor-based criterion for classification as a STM task. In Experiment 1, we demonstrate that our face DMS task meets the proposed distractor-based criterion for STM classification, in that extensive processing of delay-period distractor stimuli disrupts performance of healthy individuals. In Experiment 2, MTL amnesic patients with lesions extending into anterior subhippocampal cortex, but not patients with lesions limited to the hippocampus, show impaired performance on this task without distraction at delays as short as 8s, within temporal range of delay-based STM classification, in the context of intact perceptual matching performance. Experiment 3 provides support for the hypothesis that STM for faces relies on configural processing by showing that the extent to which healthy participants’ performance is disrupted by interference depends on the configural demands of the distractor task. Together, these findings are consistent with the notion that the amnesic impairment in STM for faces reflects a deficit in configural processing associated with subhippocampal cortices and provide novel evidence that the MTL supports cognition beyond the LTM domain. PMID:23937185

  4. Medial temporal lobe contributions to short-term memory for faces.

    Science.gov (United States)

    Race, Elizabeth; LaRocque, Karen F; Keane, Margaret M; Verfaellie, Mieke

    2013-11-01

    The role of the medial temporal lobes (MTL) in short-term memory (STM) remains a matter of debate. Whereas imaging studies commonly show hippocampal activation during short-delay memory tasks, evidence from amnesic patients with MTL lesions is mixed. It has been argued that apparent STM impairments in amnesia may reflect long-term memory (LTM) contributions to performance. We challenge this conclusion by demonstrating that MTL amnesic patients show impaired delayed matching-to-sample (DMS) for faces in a task that meets both a traditional delay-based and a recently proposed distractor-based criterion for classification as an STM task. In Experiment 1, we demonstrate that our face DMS task meets the proposed distractor-based criterion for STM classification, in that extensive processing of delay-period distractor stimuli disrupts performance of healthy individuals. In Experiment 2, MTL amnesic patients with lesions extending into anterior subhippocampal cortex, but not patients with lesions limited to the hippocampus, show impaired performance on this task without distraction at delays as short as 8 s, within temporal range of delay-based STM classification, in the context of intact perceptual matching performance. Experiment 3 provides support for the hypothesis that STM for faces relies on configural processing by showing that the extent to which healthy participants' performance is disrupted by interference depends on the configural demands of the distractor task. Together, these findings are consistent with the notion that the amnesic impairment in STM for faces reflects a deficit in configural processing associated with subhippocampal cortices and provide novel evidence that the MTL supports cognition beyond the LTM domain. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  5. Long-term effects of neonatal medial temporal ablations on socioemotional behavior in monkeys

    Science.gov (United States)

    Málková, Ludise; Mishkin, Mortimer; Suomi, Stephen J.; Bachevalier, Jocelyne

    2010-01-01

    Socioemotional abnormalities, including low levels of social interaction and high levels of self-directed activity, were reported when rhesus monkeys with neonatal ablations of either the medial temporal lobe (AH) or the inferior temporal cortex (TE) were paired with unoperated peers at two and six months of age, though these abnormalities were more severe in the AH group (Bachevalier et al., 2001). As they reached adulthood (Experiment 1), the same monkeys were re-evaluated in the same dyads and their reactivity to novel toys, social status, and reactions to separation from age-matched peers were also assessed. Group TE now showed few if any of the abnormal behaviors observed when they were infants. By contrast, Group AH continued to display low levels of social interaction, high levels of self-directed activity and submissive behavior, and reduced responses to separation, although they reacted normally to novel toys. To determine whether this degree of socioemotional impairment was less severe than that produced by the same damage in adulthood, we assessed dyadic social interactions of monkeys raised until adulthood in laboratory conditions similar to those of the earlier groups and then given the AH ablation (Experiment 2). Two months postoperatively these adult-lesioned monkeys showed a small reduction in social interactions that became more pronounced six months postoperatively, yet remained less severe than that seen in the infant-lesioned monkeys. Also, except for an increase in food and water consumption throughout this 6-month period, they showed no other socioemotional effects. The finding that neonatal AH lesions produce more severe socioemotional disturbances than the same lesion in adulthood is the reverse of the effect commonly reported for other cognitive functions after cerebral damage. PMID:21133531

  6. New learning of music after bilateral medial temporal lobe damage: evidence from an amnesic patient.

    Science.gov (United States)

    Valtonen, Jussi; Gregory, Emma; Landau, Barbara; McCloskey, Michael

    2014-01-01

    Damage to the hippocampus impairs the ability to acquire new declarative memories, but not the ability to learn simple motor tasks. An unresolved question is whether hippocampal damage affects learning for music performance, which requires motor processes, but in a cognitively complex context. We studied learning of novel musical pieces by sight-reading in a newly identified amnesic, LSJ, who was a skilled amateur violist prior to contracting herpes simplex encephalitis. LSJ has suffered virtually complete destruction of the hippocampus bilaterally, as well as extensive damage to other medial temporal lobe structures and the left anterior temporal lobe. Because of LSJ's rare combination of musical training and near-complete hippocampal destruction, her case provides a unique opportunity to investigate the role of the hippocampus for complex motor learning processes specifically related to music performance. Three novel pieces of viola music were composed and closely matched for factors contributing to a piece's musical complexity. LSJ practiced playing two of the pieces, one in each of the two sessions during the same day. Relative to a third unpracticed control piece, LSJ showed significant pre- to post-training improvement for the two practiced pieces. Learning effects were observed both with detailed analyses of correctly played notes, and with subjective whole-piece performance evaluations by string instrument players. The learning effects were evident immediately after practice and 14 days later. The observed learning stands in sharp contrast to LSJ's complete lack of awareness that the same pieces were being presented repeatedly, and to the profound impairments she exhibits in other learning tasks. Although learning in simple motor tasks has been previously observed in amnesic patients, our results demonstrate that non-hippocampal structures can support complex learning of novel musical sequences for music performance.

  7. Phosphorus-31 and proton magnetic resonance spectroscopy of the medial temporal region in schizophrenic patients

    International Nuclear Information System (INIS)

    Yamada, Koichiro

    1996-01-01

    Phosphorus-31 magnetic resonance spectroscopy (MRS) was performed 22 schizophrenic patients and in 22 healthy volunteers. Psychiatric symptoms were estimated on the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS). The spectra were quantified for phosphomonoesters (PME), inorganic orthophosphate (Pi), phosphodiesters (PDE), phosphocreatine (Pcr) and the γ, α and β phosphates of 5'-adenosine triphosphate (ATP) by peak area measurements. Proton MRS was performed in 15 schizophrenic patients and in 15 healthy volunteers. Psychiatric symptoms were estimated on the Positive and Negative Syndrome Scale (PANSS) and the SANS. The spectra of N-acetylates (NA), choline-containing compounds (Cho) and creatine-phosphocreatine (Cr) were quantified. The patients showed an increase in the % PDE and a decrease in the % β-ATP in the left temporal region. Positive correlations were found between the % PDE and the subscale of positive symptoms on the BPRS and the total score of SAPS. The % β-ATP correlated negatively with the total score on SAPS. The NA/Cho and NA/Cr ratios were significantly lower in patients than in normal subjects. The Cho/Cr ratio was higher in the patient group. The age at onset of illness correlated positively with the NA/Cho and NA/Cr ratios. No significant correlations were observed between the ratios of metabolites and the scores of PANSS and SANS. There were no significant associations between the mole percentages and the ratios and the daily doses of neuroleptics and anticholinergics. These findings suggest that the disturbed membrane phospholipid and high-energy phosphate metabolism in the left medial temporal region may be one of the pathophysiologies of neuroleptic-resistant positive symptoms in schizophrenia and these abnormalities may be related to neuronal loss and/or neuronal dysfunction in this region. (H.O.)

  8. New Learning of Music after Bilateral Medial Temporal Lobe Damage: Evidence from an Amnesic Patient

    Science.gov (United States)

    Valtonen, Jussi; Gregory, Emma; Landau, Barbara; McCloskey, Michael

    2014-01-01

    Damage to the hippocampus impairs the ability to acquire new declarative memories, but not the ability to learn simple motor tasks. An unresolved question is whether hippocampal damage affects learning for music performance, which requires motor processes, but in a cognitively complex context. We studied learning of novel musical pieces by sight-reading in a newly identified amnesic, LSJ, who was a skilled amateur violist prior to contracting herpes simplex encephalitis. LSJ has suffered virtually complete destruction of the hippocampus bilaterally, as well as extensive damage to other medial temporal lobe structures and the left anterior temporal lobe. Because of LSJ’s rare combination of musical training and near-complete hippocampal destruction, her case provides a unique opportunity to investigate the role of the hippocampus for complex motor learning processes specifically related to music performance. Three novel pieces of viola music were composed and closely matched for factors contributing to a piece’s musical complexity. LSJ practiced playing two of the pieces, one in each of the two sessions during the same day. Relative to a third unpracticed control piece, LSJ showed significant pre- to post-training improvement for the two practiced pieces. Learning effects were observed both with detailed analyses of correctly played notes, and with subjective whole-piece performance evaluations by string instrument players. The learning effects were evident immediately after practice and 14 days later. The observed learning stands in sharp contrast to LSJ’s complete lack of awareness that the same pieces were being presented repeatedly, and to the profound impairments she exhibits in other learning tasks. Although learning in simple motor tasks has been previously observed in amnesic patients, our results demonstrate that non-hippocampal structures can support complex learning of novel musical sequences for music performance. PMID:25232312

  9. New Learning of Music after Bilateral Medial Temporal Lobe Damage: Evidence from an Amnesic Patient

    Directory of Open Access Journals (Sweden)

    Jussi eValtonen

    2014-09-01

    Full Text Available Damage to the hippocampus impairs the ability to acquire new declarative memories, but not the ability to learn simple motor tasks. An unresolved question is whether hippocampal damage affects learning for music performance, which requires motor processes, but in a cognitively complex context. We studied learning of novel musical pieces by sight-reading in a newly-identified amnesic, LSJ, who was a skilled amateur violist prior to contracting herpes simplex encephalitis. LSJ has suffered virtually complete destruction of the hippocampus bilaterally, as well as extensive damage to other medial temporal lobe structures and the left anterior temporal lobe. Because of LSJ’s rare combination of musical training and near-complete hippocampal destruction, her case provides a unique opportunity to investigate the role of the hippocampus for complex motor learning processes specifically related to music performance. Three novel pieces of viola music were composed, closely matched for factors contributing to a piece’s musical complexity. LSJ practiced playing two of the pieces, one in each of two sessions during the same day. Relative to a third unpracticed control piece, LSJ showed significant pre- to post-training improvement for the two practiced pieces. Learning effects were observed both with detailed analyses of correctly played notes, and with subjective whole-piece performance evaluations by string instrument players. The learning effects were evident immediately after practice and 14 days later. The observed learning stands in sharp contrast to LSJ’s complete lack of awareness that the same pieces were being presented repeatedly, and to the profound impairments she exhibits in other learning tasks. Although learning in simple motor tasks has been previously observed in amnesic patients, our results demonstrate that non-hippocampal structures can support complex learning of novel musical sequences for music performance.

  10. A functional MRI study of language networks in left medial temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Yu Aihong, E-mail: yuaihong163@tom.com [Department of Radiology, the 4th Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China); Wang Xiaoyi; Xu Guoqing [Beijing Normal University, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing 100875 (China); Li Yongjie [Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China); Qin Wen; Li Kuncheng [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences (China); Wang, Yuping [Department of Neurology, Xuanwu Hospital, Capital University of Medical Sciences (China)

    2011-11-15

    Purpose: The purpose of this study was to investigate the abnormality of language networks in left medial temporal lobe epilepsy (MTLE) using fMRI. Materials and methods: Eight patients with left MTLE and 15 healthy subjects were evaluated. An auditory semantic judgment (AJ) paradigm was used. The fMRI data were collected on a 3T MR system and analyzed by AFNI (analysis of functional neuroimages) to generate the activation map. Results: Behavioral data showed that the reaction time of the left MTLE patients was significantly longer than that of controls on the AJ task (t = -3.396, P < 0.05). The left MTLE patients also exhibited diffusively decreased activation in the AJ task. Right hemisphere dominance of Broca's and Wernicke's areas was demonstrated in left MTLE patients. Conclusions: Long-term activation of spikes in left MTLE patients results in language impairment, which is associated with an abnormality of the brain neural network.

  11. Medial Temporal Lobe Contributions to Future Thinking: Evidence from Neuroimaging and Amnesia

    Directory of Open Access Journals (Sweden)

    Mieke Verfaellie

    2012-09-01

    Full Text Available Following early amnesic case reports, there is now considerable evidence suggesting a link between remembering the past and envisioning the future. This link is evident in the overlap in neural substrates as well as cognitive processes involved in both kinds of tasks. While constructing a future narrative requires multiple processes, neuroimaging and lesion data converge on a critical role for the medial temporal lobes (MTL in retrieving and recombining details from memory in the service of novel simulations. Deficient detail retrieval and recombination may lead to impairments not only in episodic, but also in semantic prospection. MTL contributions to scene construction and mental time travel may further compound impairments in amnesia on tasks that pose additional demands on these processes, but are unlikely to form the core deficit underlying amnesics' cross-domain future thinking impairment. Future studies exploring the role of episodic memory in other forms of self-projection or future-oriented behaviour may elucidate further the adaptive role of memory.

  12. Memory for relations in the short term and the long term after medial temporal lobe damage.

    Science.gov (United States)

    Squire, Larry R

    2017-05-01

    A central idea about the organization of declarative memory and the function of the hippocampus is that the hippocampus provides for the coding of relationships between items. A question arises whether this idea refers to the process of forming long-term memory or whether, as some studies have suggested, memory for relations might depend on the hippocampus even at short retention intervals and even when the task falls within the province of short-term (working) memory. The latter formulation appears to place the operation of relational memory into conflict with the idea that working memory is independent of medial temporal lobe (MTL) structures. In this report, the concepts of relational memory and working memory are discussed in the light of a simple demonstration experiment. Patients with MTL lesions successfully learned and recalled two word pairs when tested directly after learning but failed altogether when tested after a delay. The results do not contradict the idea that the hippocampus has a fundamental role in relational memory. However, there is a need for further elaboration and specification of the idea in order to explain why patients with MTL lesions can establish relational memory in the short term but not in long-term memory. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Domain-specific impairment of source memory following a right posterior medial temporal lobe lesion.

    Science.gov (United States)

    Peters, Jan; Koch, Benno; Schwarz, Michael; Daum, Irene

    2007-01-01

    This single case analysis of memory performance in a patient with an ischemic lesion affecting posterior but not anterior right medial temporal lobe (MTL) indicates that source memory can be disrupted in a domain-specific manner. The patient showed normal recognition memory for gray-scale photos of objects (visual condition) and spoken words (auditory condition). While memory for visual source (texture/color of the background against which pictures appeared) was within the normal range, auditory source memory (male/female speaker voice) was at chance level, a performance pattern significantly different from the control group. This dissociation is consistent with recent fMRI evidence of anterior/posterior MTL dissociations depending upon the nature of source information (visual texture/color vs. auditory speaker voice). The findings are in good agreement with the view of dissociable memory processing by the perirhinal cortex (anterior MTL) and parahippocampal cortex (posterior MTL), depending upon the neocortical input that these regions receive. (c) 2007 Wiley-Liss, Inc.

  14. Scene complexity: influence on perception, memory, and development in the medial temporal lobe

    Directory of Open Access Journals (Sweden)

    Xiaoqian J Chai

    2010-03-01

    Full Text Available Regions in the medial temporal lobe (MTL and prefrontal cortex (PFC are involved in memory formation for scenes in both children and adults. The development in children and adolescents of successful memory encoding for scenes has been associated with increased activation in PFC, but not MTL, regions. However, evidence suggests that a functional subregion of the MTL that supports scene perception, located in the parahippocampal gyrus (PHG, goes through a prolonged maturation process. Here we tested the hypothesis that maturation of scene perception supports the development of memory for complex scenes. Scenes were characterized by their levels of complexity defined by the number of unique object categories depicted in the scene. Recognition memory improved with age, in participants ages 8-24, for high, but not low, complexity scenes. High-complexity compared to low-complexity scenes activated a network of regions including the posterior PHG. The difference in activations for high- versus low- complexity scenes increased with age in the right posterior PHG. Finally, activations in right posterior PHG were associated with age-related increases in successful memory formation for high-, but not low-, complexity scenes. These results suggest that functional maturation of the right posterior PHG plays a critical role in the development of enduring long-term recollection for high-complexity scenes.

  15. Memory for fearful faces across development: specialization of amygdala nuclei and medial temporal lobe structures.

    Science.gov (United States)

    Pinabiaux, Charlotte; Hertz-Pannier, Lucie; Chiron, Catherine; Rodrigo, Sébastian; Jambaqué, Isabelle; Noulhiane, Marion

    2013-01-01

    Enhanced memory for emotional faces is a significant component of adaptive social interactions, but little is known on its neural developmental correlates. We explored the role of amygdaloid complex (AC) and medial temporal lobe (MTL) in emotional memory recognition across development, by comparing fMRI activations of successful memory encoding of fearful and neutral faces in children (n = 12; 8-12 years) and adolescents (n = 12; 13-17 years). Memory for fearful faces was enhanced compared with neutral ones in adolescents, as opposed to children. In adolescents, activations associated with successful encoding of fearful faces were centered on baso-lateral AC nuclei, hippocampus, enthorhinal and parahippocampal cortices. In children, successful encoding of fearful faces relied on activations of centro-mesial AC nuclei, which was not accompanied by functional activation of MTL memory structures. Successful encoding of neutral faces depended on activations in anterior MTL region (hippocampal head and body) in adolescents, but more posterior ones (hippocampal tail and parahippocampal cortex) in children. In conclusion, two distinct functional specializations emerge from childhood to adolescence and result in the enhancement of memory for these particular stimuli: the specialization of baso-lateral AC nuclei, which is associated with the expertise in processing emotional facial expression, and which is intimately related to the specialization of MTL memory network. How the interplay between specialization of AC nuclei and of MTL memory structures is fundamental for the edification of social interactions remains to be elucidated.

  16. Memory for fearful faces across development: specialization of amygdala nuclei and medial temporal lobe structures

    Directory of Open Access Journals (Sweden)

    Charlotte ePinabiaux

    2013-12-01

    Full Text Available Enhanced memory for emotional faces is a significant component of adaptive social interactions, but little is known on its neural developmental correlates. We explored the role of amygdaloid complex (AC and medial temporal lobe (MTL in emotional memory recognition across development, by comparing fMRI activations of successful memory encoding of fearful and neutral faces in children (n=12; 8-12 years and adolescents (n=12; 13-17 years. Memory for fearful faces was enhanced compared with neutral ones in adolescents, as opposed to children. In adolescents, activations associated with successful encoding of fearful faces were centered on baso-lateral AC nuclei, hippocampus, enthorhinal and parahippocampal cortices. In children, successful encoding of fearful faces relied on activations of centro-mesial AC nuclei, which was not accompanied by functional activation of MTL memory structures. Successful encoding of neutral faces depended on activations in anterior MTL region (hippocampal head and body in adolescents, but more posterior ones (hippocampal tail and parahippocampal cortex in children. In conclusion, two distinct functional specializations emerge from childhood to adolescence and result in the enhancement of memory for these particular stimuli: the specialization of baso-lateral AC nuclei, which is associated with the expertise in processing emotional facial expression, and which is intimately related to the specialization of MTL memory network. How the interplay between specialization of AC nuclei and of MTL memory structures is fundamental for the edification of social interactions remains to be elucidated.

  17. White Matter Tracts Connected to the Medial Temporal Lobe Support the Development of Mnemonic Control.

    Science.gov (United States)

    Wendelken, Carter; Lee, Joshua K; Pospisil, Jacqueline; Sastre, Marcos; Ross, Julia M; Bunge, Silvia A; Ghetti, Simona

    2015-09-01

    One of the most important factors driving the development of memory during childhood is mnemonic control, or the capacity to initiate and maintain the processes that guide encoding and retrieval operations. The ability to selectively attend to and encode relevant stimuli is a particularly useful form of mnemonic control, and is one that undergoes marked improvement over childhood. We hypothesized that structural integrity of white matter tracts, in particular those connecting medial temporal lobe memory regions to other cortical areas, and/or those connecting frontal and parietal control regions, should contribute to successful mnemonic control. To test this hypothesis, we examined the relationship between structural integrity of selected white matter tracts and an experimental measure of mnemonic control, involving enhancement of memory by attention at encoding, in 116 children aged 7-11 and 25 young adults. We observed a positive relationship between integrity of uncinate fasciculus and mnemonic enhancement across age groups. In adults, but not in children, we also observed an association between mnemonic enhancement and integrity of ventral cingulum bundle and ventral fornix/fimbria. Integrity of fronto-parietal tracts, including dorsal cingulum and superior longitudinal fasciculus, was unrelated to mnemonic enhancement. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Cognitive impairment and medial temporal lobe structure in young adults with a depressive episode.

    Science.gov (United States)

    Donix, Markus; Haussmann, Robert; Helling, Franziska; Zweiniger, Anne; Lange, Jan; Werner, Annett; Donix, Katharina L; Brandt, Moritz D; Linn, Jennifer; Bauer, Michael; Buthut, Maria

    2018-09-01

    Cognitive deficits are common in patients with a depressive episode although the predictors for their development and severity remain elusive. We investigated whether subjective and objective cognitive impairment in young depressed adults would be associated with cortical thinning in medial temporal subregions. High-resolution magnetic resonance imaging, cortical unfolding data analysis, and comprehensive assessments of subjective and objective cognitive abilities were performed on 27 young patients with a depressive episode (mean age: 29.0 ± 5.8 years) and 23 older participants without a history of a depressive disorder but amnestic mild cognitive impairment (68.5 ± 6.6 years) or normal cognition (65.2 ± 8.7 years). Thickness reductions in parahippocampal, perirhinal and fusiform cortices were associated with subjective memory deficits only among young patients with a depressive episode and a measurable cognitive impairment. Long-term longitudinal data would be desirable to determine the trajectories of cognitive impairment associated with depression in patients with or without cortical structure changes. The presence of clinically significant cognitive deficits in young people with a depressive episode may identify a patient population with extrahippocampal cortical thinning. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Medial Temporal Lobe Contributions to Episodic Future Thinking: Scene Construction or Future Projection?

    Science.gov (United States)

    Palombo, D J; Hayes, S M; Peterson, K M; Keane, M M; Verfaellie, M

    2018-02-01

    Previous research has shown that the medial temporal lobes (MTL) are more strongly engaged when individuals think about the future than about the present, leading to the suggestion that future projection drives MTL engagement. However, future thinking tasks often involve scene processing, leaving open the alternative possibility that scene-construction demands, rather than future projection, are responsible for the MTL differences observed in prior work. This study explores this alternative account. Using functional magnetic resonance imaging, we directly contrasted MTL activity in 1) high scene-construction and low scene-construction imagination conditions matched in future thinking demands and 2) future-oriented and present-oriented imagination conditions matched in scene-construction demands. Consistent with the alternative account, the MTL was more active for the high versus low scene-construction condition. By contrast, MTL differences were not observed when comparing the future versus present conditions. Moreover, the magnitude of MTL activation was associated with the extent to which participants imagined a scene but was not associated with the extent to which participants thought about the future. These findings help disambiguate which component processes of imagination specifically involve the MTL. Published by Oxford University Press 2016.

  20. Differentiation of medial or lateral temporal lobe epilepsy by F-18-fluorodeoxyglucose positron emission tomography: comparative study with magnetic resonance imaging in 113 surgically and pathologically proven patients

    International Nuclear Information System (INIS)

    Lee, Dong Soo; Lee, Sang Kun; Chang, Ki Hyun; Chung, Chun Kee; Choi, Ki Young; Chung, June Key; Lee, Myung Chul

    1999-01-01

    As mesial temporal lobe epilepsy (TLE) shows hypometabolism of medial and lateral temporal lobe, we investigated whether symmetric uptake of F-18-FDG in medial temporal lobes can differentiate mesial from lateral TLE. In 113 patients (83 mesial TLE, 30 lateral TLE) who underwent anterior temporal lobectomy and/or corticectomy with good surgical outcome, we performed F-18-FDG PET and compared F-18-FDG uptake of medial and lateral temporal lobes. All the patients with mesial TLE had hippocampal sclerosis except one congenital abnormal hippocampus. Patients with lateral TLE revealed cerebromalacia, microdysgenesis, arteriovenous malformation, old contusion, and cortical dysplasia. Sensitivity of F-18-FDG PET and MR for mesial TLE was 84% (70/83) and 73% (62/83), respectively. Sensitivity of F-18-FDG PET and MR for lateral TLE was 90% (27/30) and 66% (20/30), respectively. Twelve patients were normal on F-18-FDG PET. 101 patients had hypometabolism of lateral temporal lobe. Among 88 patients who showed hypometabolism of medial temporal lobe as well as lateral temporal lobe, 70 were mesial TLE patients and 18 were lateral TLE on pathologic examination. Positive predictive value of medial temporal hypometabolism for mesial TLE was 80%. Among 13 patients who showed hypometabolism of only lateral temporal lobe, 4 were mesial TLE and 9 were lateral TLE. Positive predictive value of hypometabolism of lateral temporal lobe for the diagnosis of lateral TLE was 69% (9/ 13). Normal MR findings stood against medial TLE, whose negative predictive value was 66%. Lateral temporal lobe epilepsy should be suspected when there is decreased F-18-FDG uptake in lateral temporal lobe with normal uptake in medial temporal lobe

  1. Dorso-medial and ventro-lateral functional specialization of the human retrosplenial complex in spatial updating and orienting.

    Science.gov (United States)

    Burles, Ford; Slone, Edward; Iaria, Giuseppe

    2017-04-01

    The retrosplenial complex is a region within the posterior cingulate cortex implicated in spatial navigation. Here, we investigated the functional specialization of this large and anatomically heterogeneous region using fMRI and resting-state functional connectivity combined with a spatial task with distinct phases of spatial 'updating' (i.e., integrating and maintaining object locations in memory during spatial displacement) and 'orienting' (i.e., recalling unseen locations from current position in space). Both spatial 'updating' and 'orienting' produced bilateral activity in the retrosplenial complex, among other areas. However, spatial 'updating' produced slightly greater activity in ventro-lateral portions, of the retrosplenial complex, whereas spatial 'orienting' produced greater activity in a more dorsal and medial portion of it (both regions localized along the parieto-occipital fissure). At rest, both ventro-lateral and dorso-medial subregions of the retrosplenial complex were functionally connected to the hippocampus and parahippocampus, regions both involved in spatial orientation and navigation. However, the ventro-lateral subregion of the retrosplenial complex displayed more positive functional connectivity with ventral occipital and temporal object recognition regions, whereas the dorso-medial subregion activity was more correlated to dorsal activity and frontal activity, as well as negatively correlated with more ventral parietal structures. These findings provide evidence for a dorso-medial to ventro-lateral functional specialization within the human retrosplenial complex that may shed more light on the complex neural mechanisms underlying spatial orientation and navigation in humans.

  2. Linking DMN connectivity to episodic memory capacity: What can we learn from patients with medial temporal lobe damage?

    Directory of Open Access Journals (Sweden)

    Cornelia McCormick

    2014-01-01

    Full Text Available Computational models predict that focal damage to the Default Mode Network (DMN causes widespread decreases and increases of functional DMN connectivity. How such alterations impact functioning in a specific cognitive domain such as episodic memory remains relatively unexplored. Here, we show in patients with unilateral medial temporal lobe epilepsy (mTLE that focal structural damage leads indeed to specific patterns of DMN functional connectivity alterations, specifically decreased connectivity between both medial temporal lobes (MTLs and the posterior part of the DMN and increased intrahemispheric anterior–posterior connectivity. Importantly, these patterns were associated with better and worse episodic memory capacity, respectively. These distinct patterns, shown here for the first time, suggest that a close dialogue between both MTLs and the posterior components of the DMN is required to fully express the extensive repertoire of episodic memory abilities.

  3. Medial temporal lobe damage causes deficits in episodic memory and episodic future thinking not attributable to deficits in narrative construction.

    Science.gov (United States)

    Race, Elizabeth; Keane, Margaret M; Verfaellie, Mieke

    2011-07-13

    The medial temporal lobe (MTL) makes critical contributions to episodic memory, but its contributions to episodic future thinking remain a matter of debate. By one view, imagining future events relies on MTL mechanisms that also support memory for past events. Alternatively, it has recently been suggested that future thinking is independent of MTL-mediated processes and can be supported by regions outside the MTL. The current study investigated the nature and necessity of MTL involvement in imagining the future and tested the novel hypothesis that the MTL contributes to future thinking by supporting online binding processes related to narrative construction. Human amnesic patients with well characterized MTL damage and healthy controls constructed narratives about (1) future events, (2) past events, and (3) visually presented pictures. While all three tasks place similar demands on narrative construction, only the past and future conditions require memory/future thinking to mentally generate relevant narrative information. Patients produced impoverished descriptions of both past and future events but were unimpaired at producing detailed picture narratives. In addition, future-thinking performance positively correlated with episodic memory performance but did not correlate with picture narrative performance. Finally, future-thinking impairments were present when MTL lesions were restricted to the hippocampus and did not depend on the presence of neural damage outside the MTL. These results indicate that the ability to generate and maintain a detailed narrative is preserved in amnesia and suggest that a common MTL mechanism supports both episodic memory and episodic future thinking.

  4. Medial Temporal Lobe Damage Causes Deficits in Episodic Memory and Episodic Future Thinking Not Attributable to Deficits in Narrative Construction

    Science.gov (United States)

    Race, Elizabeth; Keane, Margaret M.; Verfaellie, Mieke

    2015-01-01

    The medial temporal lobe (MTL) makes critical contributions to episodic memory, but its contributions to episodic future thinking remain a matter of debate. By one view, imagining future events relies on MTL mechanisms that also support memory for past events. Alternatively, it has recently been suggested that future thinking is independent of MTL-mediated processes and can be supported by regions outside the MTL. The current study investigated the nature and necessity of MTL involvement in imagining the future and tested the novel hypothesis that the MTL contributes to future thinking by supporting online binding processes related to narrative construction. Human amnesic patients with well-characterized MTL damage and healthy controls constructed narratives about (a) future events, (b) past events, and (c) visually-presented pictures. While all three tasks place similar demands on narrative construction, only the past and future conditions require memory/future thinking to mentally generate relevant narrative information. Patients produced impoverished descriptions of both past and future events but were unimpaired at producing detailed picture narratives. In addition, future-thinking performance positively correlated with episodic memory performance but did not correlate with picture narrative performance. Finally, future-thinking impairments were present when MTL lesions were restricted to the hippocampus and did not depend on the presence of neural damage outside the MTL. These results indicate that the ability to generate and maintain a detailed narrative is preserved in amnesia and suggest that a common MTL mechanism supports both episodic memory and episodic future thinking. PMID:21753003

  5. Quantitative Evaluation of Medial Temporal Lobe Morphology in Children with Febrile Status Epilepticus: Results of the FEBSTAT Study.

    Science.gov (United States)

    McClelland, A C; Gomes, W A; Shinnar, S; Hesdorffer, D C; Bagiella, E; Lewis, D V; Bello, J A; Chan, S; MacFall, J; Chen, M; Pellock, J M; Nordli, D R; Frank, L M; Moshé, S L; Shinnar, R C; Sun, S

    2016-12-01

    The pathogenesis of febrile status epilepticus is poorly understood, but prior studies have suggested an association with temporal lobe abnormalities, including hippocampal malrotation. We used a quantitative morphometric method to assess the association between temporal lobe morphology and febrile status epilepticus. Brain MR imaging was performed in children presenting with febrile status epilepticus and control subjects as part of the Consequences of Prolonged Febrile Seizures in Childhood study. Medial temporal lobe morphologic parameters were measured manually, including the distance of the hippocampus from the midline, hippocampal height:width ratio, hippocampal angle, collateral sulcus angle, and width of the temporal horn. Temporal lobe morphologic parameters were correlated with the presence of visual hippocampal malrotation; the strongest association was with left temporal horn width (P status epilepticus, encompassing both the right and left sides. This association was statistically strongest in the right temporal lobe, whereas hippocampal malrotation was almost exclusively left-sided in this cohort. The association between temporal lobe measurements and febrile status epilepticus persisted when the analysis was restricted to cases with visually normal imaging findings without hippocampal malrotation or other visually apparent abnormalities. Several component morphologic features of hippocampal malrotation are independently associated with febrile status epilepticus, even when complete hippocampal malrotation is absent. Unexpectedly, this association predominantly involves the right temporal lobe. These findings suggest that a spectrum of bilateral temporal lobe anomalies are associated with febrile status epilepticus in children. Hippocampal malrotation may represent a visually apparent subset of this spectrum. © 2016 by American Journal of Neuroradiology.

  6. Working memory, long-term memory, and medial temporal lobe function

    Science.gov (United States)

    Jeneson, Annette; Squire, Larry R.

    2012-01-01

    Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have been interpreted to mean that the MTL is sometimes needed for working memory and possibly even for visual perception itself. We present a reappraisal of this interpretation. Our main conclusion is that, if the material to be learned exceeds working memory capacity, if the material is difficult to rehearse, or if attention is diverted, performance depends on long-term memory even when the retention interval is brief. This fundamental notion is better captured by the terms subspan memory and supraspan memory than by the terms short-term memory and long-term memory. We propose methods for determining when performance on short-delay tasks must depend on long-term (supraspan) memory and suggest that MTL lesions impair performance only when immediate memory and working memory are insufficient to support performance. In neuroimaging studies, MTL activity during encoding is influenced by the memory load and correlates positively with long-term retention of the material that was presented. The most parsimonious and consistent interpretation of all the data is that subspan memoranda are supported by immediate memory and working memory and are independent of the MTL. PMID:22180053

  7. The medial temporal lobe supports sensing-based visual working memory.

    Science.gov (United States)

    Goodrich, Robin I; Yonelinas, Andrew P

    2016-08-01

    It is well established that the medial temporal lobe (MTL), including the hippocampus, is essential for long-term memory. In addition, recent studies suggest that the MTL may also support visual working memory (VWM), but the conditions under which the MTL plays a critical role are not yet clear. To address this issue, we used a color change detection paradigm to examine the effects of MTL damage on VWM by analyzing the receiver operating characteristics of patients with MTL damage and healthy age- and education-matched controls. Compared to controls, patients with MTL damage demonstrated significant reductions in VWM accuracy. Importantly, the patients were not impaired at making accurate high-confidence judgments that a change had occurred; however, they were impaired when making low-confidence responses indicating that they sensed whether or not there had been a visual change. Moreover, these impairments were observed under conditions that emphasized the retrieval of complex bindings or the retrieval of high-resolution bindings. That is, patients with MTL damage exhibited VWM impairments when they were required to remember either a larger number of low-resolution bindings (i.e., set size of 5 and obvious color changes) or a smaller number of high-resolution bindings (i.e., set size of 3 and subtle color changes). The results indicate that only some VWM processes are dependent on the MTL, and are consistent with the proposal that the MTL plays a critical role in forming complex, high-resolution bindings. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Volumetric analysis of medial temporal lobe structures in brain development from childhood to adolescence.

    Science.gov (United States)

    Hu, Shiyan; Pruessner, Jens C; Coupé, Pierrick; Collins, D Louis

    2013-07-01

    Puberty is an important stage of development as a child's sexual and physical characteristics mature because of hormonal changes. To better understand puberty-related effects on brain development, we investigated the magnetic resonance imaging (MRI) data of 306 subjects from 4 to 18 years of age. Subjects were grouped into before and during puberty groups according to their sexual maturity levels measured by the puberty scores. An appearance model-based automatic segmentation method with patch-based local refinement was employed to segment the MRI data and extract the volumes of medial temporal lobe (MTL) structures including the amygdala (AG), the hippocampus (HC), the entorhinal/perirhinal cortex (EPC), and the parahippocampal cortex (PHC). Our analysis showed age-related volumetric changes for the AG, HC, right EPC, and left PHC but only before puberty. After onset of puberty, these volumetric changes then correlate more with sexual maturity level, as measured by the puberty score. When normalized for brain volume, the volumes of the right HC decrease for boys; the volumes of the left HC increase for girls; and the volumes of the left and right PHC decrease for boys. These findings suggest that the rising levels of testosterone in boys and estrogen in girls might have opposite effects, especially for the HC and the PHC. Our findings on sex-specific and sexual maturity-related volumes may be useful in better understanding the MTL developmental differences and related learning, memory, and emotion differences between boys and girls during puberty. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Hippocampal subfield and medial temporal cortical persistent activity during working memory reflects ongoing encoding

    Directory of Open Access Journals (Sweden)

    Rachel K Nauer

    2015-03-01

    Full Text Available Previous neuroimaging studies support a role for the medial temporal lobes (MTL in maintaining novel stimuli over brief working memory (WM delays, and suggest delay period activity predicts subsequent memory. Additionally, slice recording studies have demonstrated neuronal persistent spiking in entorhinal cortex (EC, perirhinal cortex (PrC, and hippocampus (CA1, CA3, subiculum. These data have led to computational models that suggest persistent spiking in parahippocampal regions could sustain neuronal representations of sensory information over many seconds. This mechanism may support both WM maintenance and encoding of information into long term episodic memory. The goal of the current study was to use high-resolution fMRI to elucidate the contributions of the MTL cortices and hippocampal subfields to WM maintenance as it relates to later episodic recognition memory. We scanned participants while they performed a delayed match to sample task with novel scene stimuli, and assessed their memory for these scenes post-scan. We hypothesized stimulus-driven activation that persists into the delay period—a putative correlate of persistent spiking—would predict later recognition memory. Our results suggest sample and delay period activation in the parahippocampal cortex (PHC, PrC, and subiculum (extending into DG/CA3 and CA1 was linearly related to increases in subsequent memory strength. These data extend previous neuroimaging studies that have constrained their analysis to either the sample or delay period by modeling these together as one continuous ongoing encoding process, and support computational frameworks that predict persistent activity underlies both WM and episodic encoding.

  10. Medial temporal lobe reinstatement of content-specific details predicts source memory

    Science.gov (United States)

    Liang, Jackson C.; Preston, Alison R.

    2016-01-01

    Leading theories propose that when remembering past events, medial temporal lobe (MTL) structures reinstate the neural patterns that were active when those events were initially encoded. Accurate reinstatement is hypothesized to support detailed recollection of memories, including their source. While several studies have linked cortical reinstatement to successful retrieval, indexing reinstatement within the MTL network and its relationship to memory performance has proved challenging. Here, we addressed this gap in knowledge by having participants perform an incidental encoding task, during which they visualized people, places, and objects in response to adjective cues. During a surprise memory test, participants saw studied and novel adjectives and indicated the imagery task they performed for each adjective. A multivariate pattern classifier was trained to discriminate the imagery tasks based on functional magnetic resonance imaging (fMRI) responses from hippocampus and MTL cortex at encoding. The classifier was then tested on MTL patterns during the source memory task. We found that MTL encoding patterns were reinstated during successful source retrieval. Moreover, when participants made source misattributions, errors were predicted by reinstatement of incorrect source content in MTL cortex. We further observed a gradient of content-specific reinstatement along the anterior-posterior axis of hippocampus and MTL cortex. Within anterior hippocampus, we found that reinstatement of person content was related to source memory accuracy, whereas reinstatement of place information across the entire hippocampal axis predicted correct source judgments. Content-specific reinstatement was also graded across MTL cortex, with PRc patterns evincing reactivation of people and more posterior regions, including PHc, showing evidence for reinstatement of places and objects. Collectively, these findings provide key evidence that source recollection relies on reinstatement of past

  11. Voxel-based morphometry (VBM) based assessment of gray matter loss in medial temporal lobe epilepsy; comparison with FDG PET

    International Nuclear Information System (INIS)

    Kang, Hye Jin; Lee, Ho Young; Lee, Jae Sung; Kang, Eun Joo; Lee, Sang Gun; Chang, Kee Hyun; Lee, Dong Soo

    2004-01-01

    The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron emission tomography (FDG PET). MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was performed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones

  12. Voxel-based morphometry (VBM) based assessment of gray matter loss in medial temporal lobe epilepsy; comparison with FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hye Jin; Lee, Ho Young; Lee, Jae Sung; Kang, Eun Joo; Lee, Sang Gun; Chang, Kee Hyun; Lee, Dong Soo [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2004-02-01

    The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron emission tomography (FDG PET). MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was performed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones.

  13. Effects of neonatal inferior prefrontal and medial temporal lesions on learning the rule for delayed nonmatching-to-sample.

    Science.gov (United States)

    Málková, L; Bachevalier, J; Webster, M; Mishkin, M

    2000-01-01

    The ability of rhesus monkeys to master the rule for delayed nonmatching-to-sample (DNMS) has a protracted ontogenetic development, reaching adult levels of proficiency around 4 to 5 years of age (Bachevalier, 1990). To test the possibility that this slow development could be due, at least in part, to immaturity of the prefrontal component of a temporo-prefrontal circuit important for DNMS rule learning (Kowalska, Bachevalier, & Mishkin, 1991; Weinstein, Saunders, & Mishkin, 1988), monkeys with neonatal lesions of the inferior prefrontal convexity were compared on DNMS with both normal controls and animals given neonatal lesions of the medial temporal lobe. Consistent with our previous results (Bachevalier & Mishkin, 1994; Málková, Mishkin, & Bachevalier, 1995), the neonatal medial temporal lesions led to marked impairment in rule learning (as well as in recognition memory with long delays and list lengths) at both 3 months and 2 years of age. By contrast, the neonatal inferior convexity lesions yielded no impairment in rule-learning at 3 months and only a mild impairment at 2 years, a finding that also contrasts sharply with the marked effects of the same lesion made in adulthood. This pattern of sparing closely resembles the one found earlier after neonatal lesions to the cortical visual area TE (Bachevalier & Mishkin, 1994; Málková et al., 1995). The functional sparing at 3 months probably reflects the fact that the temporo-prefrontal circuit is nonfunctional at this early age, resulting in a total dependency on medial temporal contributions to rule learning. With further development, however, this circuit begins to provide a supplementary route for learning.

  14. The timing of associative memory formation: frontal lobe and anterior medial temporal lobe activity at associative binding predicts memory

    Science.gov (United States)

    Hales, J. B.

    2011-01-01

    The process of associating items encountered over time and across variable time delays is fundamental for creating memories in daily life, such as for stories and episodes. Forming associative memory for temporally discontiguous items involves medial temporal lobe structures and additional neocortical processing regions, including prefrontal cortex, parietal lobe, and lateral occipital regions. However, most prior memory studies, using concurrently presented stimuli, have failed to examine the temporal aspect of successful associative memory formation to identify when activity in these brain regions is predictive of associative memory formation. In the current study, functional MRI data were acquired while subjects were shown pairs of sequentially presented visual images with a fixed interitem delay within pairs. This design allowed the entire time course of the trial to be analyzed, starting from onset of the first item, across the 5.5-s delay period, and through offset of the second item. Subjects then completed a postscan recognition test for the items and associations they encoded during the scan and their confidence for each. After controlling for item-memory strength, we isolated brain regions selectively involved in associative encoding. Consistent with prior findings, increased regional activity predicting subsequent associative memory success was found in anterior medial temporal lobe regions of left perirhinal and entorhinal cortices and in left prefrontal cortex and lateral occipital regions. The temporal separation within each pair, however, allowed extension of these findings by isolating the timing of regional involvement, showing that increased response in these regions occurs during binding but not during maintenance. PMID:21248058

  15. A High-Resolution Study of Hippocampal and Medial Temporal Lobe Correlates of Spatial Context and Prospective Overlapping Route Memory

    Science.gov (United States)

    Brown, Thackery I.; Hasselmo, Michael E.; Stern, Chantal E.

    2015-01-01

    When navigating our world we often first plan or retrieve an ideal route to our goal, avoiding alternative paths that lead to other destinations. The medial temporal lobe (MTL) has been implicated in processing contextual information, sequence memory, and uniquely retrieving routes that overlap or “cross paths.” However, the identity of subregions of the hippocampus and neighboring cortex that support these functions in humans remains unclear. The present study used high-resolution functional magnetic resonance imaging (hr-fMRI) in humans to test whether the CA3/DG hippocampal subfield and para-hippocampal cortex are important for processing spatial context and route retrieval, and whether the CA1 subfield facilitates prospective planning of mazes that must be distinguished from alternative overlapping routes. During hr-fMRI scanning, participants navigated virtual mazes that were well-learned from prior training while also learning new mazes. Some routes learned during scanning shared hallways with those learned during pre-scan training, requiring participants to select between alternative paths. Critically, each maze began with a distinct spatial contextual Cue period. Our analysis targeted activity from the Cue period, during which participants identified the current navigational episode, facilitating retrieval of upcoming route components and distinguishing mazes that overlap. Results demonstrated that multiple MTL regions were predominantly active for the contextual Cue period of the task, with specific regions of CA3/DG, parahippocampal cortex, and perirhinal cortex being consistently recruited across trials for Cue periods of both novel and familiar mazes. During early trials of the task, both CA3/DG and CA1 were more active for overlapping than non-overlapping Cue periods. Trial-by-trial Cue period responses in CA1 tracked subsequent overlapping maze performance across runs. Together, our findings provide novel insight into the contributions of MTL

  16. Effects of medial temporal lobe degeneration on brain perfusion in amnestic MCI of AD type: deafferentation and functional compensation?

    International Nuclear Information System (INIS)

    Guedj, Eric; Barbeau, Emmanuel J.; Didic, Mira; Poncet, Michel; Ceccaldi, Mathieu; Felician, Olivier; Laforte, Catherine de; Mundler, Olivier; Ranjeva, Jean-Philippe; Cozzone, Patrick J.

    2009-01-01

    Cortical atrophy is correlated with the progression of neuropathological lesions within the medial temporal lobes (MTL) in Alzheimer's disease (AD). Our aim was to determine which local and remote functional changes result from MTL volume loss at the predementia stage. We studied the relationship between entorhinal and hippocampal MR volumes and whole-brain SPECT perfusion via a voxel-based correlative analysis in 19 patients with amnestic mild cognitive impairment with a memory profile suggestive of early AD. Right MTL volumes were positively correlated with remote posterior perfusion of the posterior cingulate cortex, and negatively correlated with remote anterior perfusion of the right medial and dorsolateral prefrontal cortex. There was no local correlation between volumes and perfusion within the MTL. These findings provide further insight into functional changes that result from MTL volume loss during the predementia stage of AD. The positive correlation between MTL volumes and posterior cingulate perfusion may reflect the deafferentation of a temporocingulate network due to mediotemporal degeneration. The paradoxical negative correlation between MTL volumes and prefrontal perfusion may result from recruitment of an alternative anterior temporofrontal network. It remains to be investigated how the ''net sum'' of this perfusion modulation affects memory and other cognitive domains through a possible compensatory perspective. (orig.)

  17. Effects of medial temporal lobe degeneration on brain perfusion in amnestic MCI of AD type: deafferentation and functional compensation?

    Energy Technology Data Exchange (ETDEWEB)

    Guedj, Eric [Centre Hospitalo-Universitaire de la Timone, Service Central de Biophysique et de Medecine Nucleaire, Marseille Cedex 5 (France); Universite de la Mediterranee Aix-Marseille II, Laboratoire de Neurophysiologie et Neuropsychologie, Inserm U751, Faculte de Medecine, Marseille (France); Universite de la Mediterranee Aix-Marseille II, Centre de Resonance Magnetique Biologique et Medicale (CRMBM), UMR CNRS 6612, Faculte de Medecine, Marseille (France); Barbeau, Emmanuel J. [CNRS - Universite Paul Sabatier Toulouse 3, Centre de Recherche Cerveau et Cognition, UMR-5549, Toulouse (France); Didic, Mira; Poncet, Michel; Ceccaldi, Mathieu [CHU Timone, Service de Neurologie et de Neuropsychologie, Marseille (France); Universite de la Mediterranee Aix-Marseille II, Laboratoire de Neurophysiologie et Neuropsychologie, Inserm U751, Faculte de Medecine, Marseille (France); Felician, Olivier [CHU Timone, Service de Neurologie et de Neuropsychologie, Marseille (France); Universite de la Mediterranee Aix-Marseille II, Laboratoire de Neurophysiologie et Neuropsychologie, Inserm U751, Faculte de Medecine, Marseille (France); Centre Saint-Charles, Laboratoire de Neurobiologie Integrative et Adaptative, UMR CNRS 6149, Marseille (France); Laforte, Catherine de; Mundler, Olivier [Centre Hospitalo-Universitaire de la Timone, Service Central de Biophysique et de Medecine Nucleaire, Marseille Cedex 5 (France); Ranjeva, Jean-Philippe; Cozzone, Patrick J. [Universite de la Mediterranee Aix-Marseille II, Centre de Resonance Magnetique Biologique et Medicale (CRMBM), UMR CNRS 6612, Faculte de Medecine, Marseille (France)

    2009-07-15

    Cortical atrophy is correlated with the progression of neuropathological lesions within the medial temporal lobes (MTL) in Alzheimer's disease (AD). Our aim was to determine which local and remote functional changes result from MTL volume loss at the predementia stage. We studied the relationship between entorhinal and hippocampal MR volumes and whole-brain SPECT perfusion via a voxel-based correlative analysis in 19 patients with amnestic mild cognitive impairment with a memory profile suggestive of early AD. Right MTL volumes were positively correlated with remote posterior perfusion of the posterior cingulate cortex, and negatively correlated with remote anterior perfusion of the right medial and dorsolateral prefrontal cortex. There was no local correlation between volumes and perfusion within the MTL. These findings provide further insight into functional changes that result from MTL volume loss during the predementia stage of AD. The positive correlation between MTL volumes and posterior cingulate perfusion may reflect the deafferentation of a temporocingulate network due to mediotemporal degeneration. The paradoxical negative correlation between MTL volumes and prefrontal perfusion may result from recruitment of an alternative anterior temporofrontal network. It remains to be investigated how the ''net sum'' of this perfusion modulation affects memory and other cognitive domains through a possible compensatory perspective. (orig.)

  18. Thalamo-Cortical Disruption Contributes to Short-Term Memory Deficits in Patients with Medial Temporal Lobe Damage.

    Science.gov (United States)

    Voets, Natalie L; Menke, Ricarda A L; Jbabdi, Saad; Husain, Masud; Stacey, Richard; Carpenter, Katherine; Adcock, Jane E

    2015-11-01

    Short-term (STM) and long-term memory (LTM) have largely been considered as separate brain systems reflecting fronto-parietal and medial temporal lobe (MTL) functions, respectively. This functional dichotomy has been called into question by evidence of deficits on aspects of working memory in patients with MTL damage, suggesting a potentially direct hippocampal contribution to STM. As the hippocampus has direct anatomical connections with the thalamus, we tested the hypothesis that damage to thalamic nuclei regulating cortico-cortical interactions may contribute to STM deficits in patients with hippocampal dysfunction. We used diffusion-weighted magnetic resonance imaging-based tractography to identify anatomical subdivisions in patients with MTL epilepsy. From these, we measured resting-state functional connectivity with detailed cortical divisions of the frontal, temporal, and parietal lobes. Whereas thalamo-temporal functional connectivity reflected LTM performance, thalamo-prefrontal functional connectivity specifically predicted STM performance. Notably, patients with hippocampal volume loss showed thalamic volume loss, most prominent in the pulvinar region, not detected in patients with normal hippocampal volumes. Aberrant thalamo-cortical connectivity in the epileptic hemisphere was mirrored in a loss of behavioral association with STM performance specifically in patients with hippocampal atrophy. These findings identify thalamo-cortical disruption as a potential mechanism contributing to STM deficits in the context of MTL damage. © The Author 2015. Published by Oxford University Press.

  19. Medial temporal lobe structure and cognition in individuals with schizophrenia and in their non-psychotic siblings.

    Science.gov (United States)

    Karnik-Henry, Meghana S; Wang, Lei; Barch, Deanna M; Harms, Michael P; Campanella, Carolina; Csernansky, John G

    2012-07-01

    Medial temporal lobe (MTL) structures play a central role in episodic memory. Prior studies suggest that individuals with schizophrenia have deficits in episodic memory as well as structural abnormalities of the medial temporal lobe (MTL). While correlations have been reported between MTL volume loss and episodic memory deficits in such individuals, it is not clear whether such correlations reflect the influence of the disease state or of underlying genetic influences that might contribute to risk. We used high resolution magnetic resonance imaging and probabilistic algorithms for image analysis to determine whether MTL structure, episodic memory performance and the relationship between the two differed among groups of 47 healthy control subjects, 50 control siblings, 39 schizophrenia subjects, and 33 siblings of schizophrenia subjects. High-dimensional large deformation brain mapping was used to obtain volume measures of the hippocampus. Cortical distance mapping was used to obtain volume and thickness measures of the parahippocampal gyrus (PHG) and its substructures: the entorhinal cortex (ERC), the perirhinal cortex (PRC), and the parahippocampal cortex (PHC). Neuropsychological data was used to establish an episodic memory domain score for each subject. Both schizophrenia subjects and their siblings displayed abnormalities in episodic memory performance. Siblings of individuals with schizophrenia, and to a lesser extent, individuals with schizophrenia themselves, displayed abnormalities in measures of MTL structure (volume loss or cortical thinning) as compared to control groups. Further, we observed correlations between structural measures and memory performance in both schizophrenia subjects and their siblings, but not in their respective control groups. These findings suggest that disease-specific genetic factors present in both patients and their relatives may be responsible for correlated abnormalities of MTL structure and memory impairment. The observed

  20. Manual Planimetry of the Medial Temporal Lobe Versus Automated Volumetry of the Hippocampus in the Diagnosis of Alzheimer's Disease.

    Science.gov (United States)

    Menéndez González, Manuel; Suárez-Sanmartin, Esther; García, Ciara; Martínez-Camblor, Pablo; Westman, Eric; Simmons, Andy

    2016-03-26

    Though a disproportionate rate of atrophy in the medial temporal lobe (MTA) represents a reliable marker of Alzheimer's disease (AD) pathology, measurement of the MTA is not currently widely used in daily clinical practice. This is mainly because the methods available to date are sophisticated and difficult to implement in clinical practice (volumetric methods), are poorly explored (linear and planimetric methods), or lack objectivity (visual rating). Here, we aimed to compare the results of a manual planimetric measure (the yearly rate of absolute atrophy of the medial temporal lobe, 2D-yrA-MTL) with the results of an automated volumetric measure (the yearly rate of atrophy of the hippocampus, 3D-yrA-H). A series of 1.5T MRI studies on 290 subjects in the age range of 65-85 years, including patients with AD (n = 100), mild cognitive impairment (MCI) (n = 100), and matched controls (n = 90) from the AddNeuroMed study, were examined by two independent subgroups of researchers: one in charge of volumetric measures and the other in charge of planimetric measures. The means of both methods were significantly different between AD and the other two diagnostic groups. In the differential diagnosis of AD against controls, 3D-yrA-H performed significantly better than 2D-yrA-MTL while differences were not statistically significant in the differential diagnosis of AD against MCI. Automated volumetry of the hippocampus is superior to manual planimetry of the MTL in the diagnosis of AD. Nevertheless, the 2D-yrAMTL is a simpler method that could be easily implemented in clinical practice when volumetry is not available.

  1. New MRI Markers for Alzheimer's Disease: A Meta-Analysis of Diffusion Tensor Imaging and a Comparison with Medial Temporal Lobe Measurements

    NARCIS (Netherlands)

    Clerx, L.; Visser, P.J.; Verhey, F.; Aalten, P.

    2012-01-01

    The aim of the present study is to evaluate the diagnostic value of diffusion tensor imaging (DTI) for early Alzheimer's disease (AD) in comparison to widely accepted medial temporal lobe (MTL) atrophy measurements. A systematic literature research was performed into DTI and MTL atrophy in AD and

  2. The medial temporal lobes distinguish between within-item and item-context relations during autobiographical memory retrieval.

    Science.gov (United States)

    Sheldon, Signy; Levine, Brian

    2015-12-01

    During autobiographical memory retrieval, the medial temporal lobes (MTL) relate together multiple event elements, including object (within-item relations) and context (item-context relations) information, to create a cohesive memory. There is consistent support for a functional specialization within the MTL according to these relational processes, much of which comes from recognition memory experiments. In this study, we compared brain activation patterns associated with retrieving within-item relations (i.e., associating conceptual and sensory-perceptual object features) and item-context relations (i.e., spatial relations among objects) with respect to naturalistic autobiographical retrieval. We developed a novel paradigm that cued participants to retrieve information about past autobiographical events, non-episodic within-item relations, and non-episodic item-context relations with the perceptuomotor aspects of retrieval equated across these conditions. We used multivariate analysis techniques to extract common and distinct patterns of activity among these conditions within the MTL and across the whole brain, both in terms of spatial and temporal patterns of activity. The anterior MTL (perirhinal cortex and anterior hippocampus) was preferentially recruited for generating within-item relations later in retrieval whereas the posterior MTL (posterior parahippocampal cortex and posterior hippocampus) was preferentially recruited for generating item-context relations across the retrieval phase. These findings provide novel evidence for functional specialization within the MTL with respect to naturalistic memory retrieval. © 2015 Wiley Periodicals, Inc.

  3. The temporal structure of resting-state brain activity in the medial prefrontal cortex predicts self-consciousness.

    Science.gov (United States)

    Huang, Zirui; Obara, Natsuho; Davis, Henry Hap; Pokorny, Johanna; Northoff, Georg

    2016-02-01

    Recent studies have demonstrated an overlap between the neural substrate of resting-state activity and self-related processing in the cortical midline structures (CMS). However, the neural and psychological mechanisms mediating this so-called "rest-self overlap" remain unclear. To investigate the neural mechanisms, we estimated the temporal structure of spontaneous/resting-state activity, e.g. its long-range temporal correlations or self-affinity across time as indexed by the power-law exponent (PLE). The PLE was obtained in resting-state activity in the medial prefrontal cortex (MPFC) and the posterior cingulate cortex (PCC) in 47 healthy subjects by functional magnetic resonance imaging (fMRI). We performed correlation analyses of the PLE and Revised Self-Consciousness Scale (SCSR) scores, which enabled us to access different dimensions of self-consciousness and specified rest-self overlap in a psychological regard. The PLE in the MPFC's resting-state activity correlated with private self-consciousness scores from the SCSR. Conversely, we found no correlation between the PLE and the other subscales of the SCSR (public, social) or between other resting-state measures, including functional connectivity, and the SCSR subscales. This is the first evidence for the association between the scale-free dynamics of resting-state activity in the CMS and the private dimension of self-consciousness. This finding implies the relationship of especially the private dimension of self with the temporal structure of resting-state activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H215O PET

    International Nuclear Information System (INIS)

    Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

    2002-01-01

    The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H 2 15 O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period

  5. Raman spectroscopy imaging reveals interplay between atherosclerosis and medial calcification in the human aorta

    Science.gov (United States)

    You, Amanda Y. F.; Bergholt, Mads S.; St-Pierre, Jean-Philippe; Kit-Anan, Worrapong; Pence, Isaac J.; Chester, Adrian H.; Yacoub, Magdi H.; Bertazzo, Sergio; Stevens, Molly M.

    2017-01-01

    Medial calcification in the human aorta accumulates during aging and is known to be aggravated in several diseases. Atherosclerosis, another major cause of cardiovascular calcification, shares some common aggravators. However, the mechanisms of cardiovascular calcification remain poorly understood. To elucidate the relationship between medial aortic calcification and atherosclerosis, we characterized the cross-sectional distributions of the predominant minerals in aortic tissue, apatite and whitlockite, and the associated extracellular matrix. We also compared the cellular changes between atherosclerotic and nonatherosclerotic human aortic tissues. This was achieved through the development of Raman spectroscopy imaging methods that adapted algorithms to distinguish between the major biomolecules present within these tissues. We present a relationship between apatite, cholesterol, and triglyceride in atherosclerosis, with the relative amount of all molecules concurrently increased in the atherosclerotic plaque. Further, the increase in apatite was disproportionately large in relation to whitlockite in the aortic media directly underlying a plaque, indicating that apatite is more pathologically significant in atherosclerosis-aggravated medial calcification. We also discovered a reduction of β-carotene in the whole aortic intima, including a plaque in atherosclerotic aortic tissues compared to nonatherosclerotic tissues. This unprecedented biomolecular characterization of the aortic tissue furthers our understanding of pathological and physiological cardiovascular calcification events in humans. PMID:29226241

  6. The role of the medial temporal limbic system in processing emotions in voice and music.

    Science.gov (United States)

    Frühholz, Sascha; Trost, Wiebke; Grandjean, Didier

    2014-12-01

    Subcortical brain structures of the limbic system, such as the amygdala, are thought to decode the emotional value of sensory information. Recent neuroimaging studies, as well as lesion studies in patients, have shown that the amygdala is sensitive to emotions in voice and music. Similarly, the hippocampus, another part of the temporal limbic system (TLS), is responsive to vocal and musical emotions, but its specific roles in emotional processing from music and especially from voices have been largely neglected. Here we review recent research on vocal and musical emotions, and outline commonalities and differences in the neural processing of emotions in the TLS in terms of emotional valence, emotional intensity and arousal, as well as in terms of acoustic and structural features of voices and music. We summarize the findings in a neural framework including several subcortical and cortical functional pathways between the auditory system and the TLS. This framework proposes that some vocal expressions might already receive a fast emotional evaluation via a subcortical pathway to the amygdala, whereas cortical pathways to the TLS are thought to be equally used for vocal and musical emotions. While the amygdala might be specifically involved in a coarse decoding of the emotional value of voices and music, the hippocampus might process more complex vocal and musical emotions, and might have an important role especially for the decoding of musical emotions by providing memory-based and contextual associations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Decoding Overlapping Memories in the Medial Temporal Lobes Using High-Resolution fMRI

    Science.gov (United States)

    Chadwick, Martin J.; Hassabis, Demis; Maguire, Eleanor A.

    2011-01-01

    The hippocampus is proposed to process overlapping episodes as discrete memory traces, although direct evidence for this in human episodic memory is scarce. Using green-screen technology we created four highly overlapping movies of everyday events. Participants were scanned using high-resolution fMRI while recalling the movies. Multivariate…

  8. Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

    Science.gov (United States)

    Brown, Thackery I; Rissman, Jesse; Chow, Tiffany E; Uncapher, Melina R; Wagner, Anthony D

    2018-04-18

    Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory.

  9. The role of medial temporal lobe in retrieving spatial and nonspatial relations from episodic and semantic memory.

    Science.gov (United States)

    Ryan, Lee; Lin, Chun-Yu; Ketcham, Katie; Nadel, Lynn

    2010-01-01

    This study examined the involvement of medial temporal lobe, especially the hippocampus, in processing spatial and nonspatial relations using episodic and semantic versions of a relational judgment task. Participants studied object arrays and were tested on different types of relations between pairs of objects. Three prevalent views of hippocampal function were considered. Cognitive map theory (O'Keefe and Nadel (1978) The Hippocampus as a Cognitive Map. USA: Oxford University Press) emphasizes hippocampal involvement in spatial relational tasks. Multiple trace theory (Nadel and Moscovitch (1997) Memory consolidation, retrograde amnesia and the hippocampal complex Curr Opin Neurobiol 7:217-227) emphasizes hippocampal involvement in episodic tasks. Eichenbaum and Cohen's ((2001) From Conditioning to Conscious Recollection: Memory Systems of the Brain. USA: Oxford University Press) relational theory predicts equivalent hippocampal involvement in all relational tasks within both semantic and episodic memory. The fMRI results provided partial support for all three theories, though none of them fit the data perfectly. We observed hippocampal activation during all relational tasks, with increased activation for spatial compared to nonspatial relations, and for episodic compared to semantic relations. The placement of activation along the anterior-posterior axis of the hippocampus also differentiated the conditions. We suggest a view of hippocampal function in memory that incorporates aspects of all three theories. Copyright 2009 Wiley-Liss, Inc.

  10. A multicenter reproducibility study of single-voxel {sup 1}H-MRS of the medial temporal lobe

    Energy Technology Data Exchange (ETDEWEB)

    Traeber, Frank; Block, Wolfgang; Guer, Okan; Schild, Hans H. [University of Bonn, Department of Radiology, Bonn (Germany); Freymann, Nikolaus; Heun, Reinhard; Jessen, Frank [University of Bonn, Department of Psychiatry, Bonn (Germany); Kucinski, Thomas [University of Hamburg, Department of Neuroradiology, Hamburg (Germany); Hammen, Thilo [University of Erlangen, Department of Psychiatry, Erlangen (Germany); Ende, Gabriele [Central Institute of Mental Health, NMR Research in Psychiatry, Mannheim (Germany); Pilatus, Ulrich [University of Frankfurt, Department of Neuroradiology, Frankfurt (Germany); Hampel, Harald [University of Munich, Department of Psychiatry, Munich (Germany)

    2006-05-15

    Proton magnetic resonance spectroscopy ({sup 1}H-MRS) has provided evidence for a reduction of N-acetyl-aspartate (NAA) in the medial temporal lobe (MTL) in cerebral disorders such as Alzheimer's Disease. Within the {sup 1}H-MRS study of the German Research Network on Dementia, we determined the multicenter reproducibility of single-voxel {sup 1}H-MRS of the MTL. At five sites with 1.5T MR systems, single-voxel {sup 1}H spectra from the MTL of an identical healthy subject were measured. The same subject was also examined at one of the sites five times to assess intracenter stability. The protocol included water-suppressed spectra with TE 272 ms and TE 30 ms and unsuppressed spectra for absolute quantification of metabolite concentrations. The intracenter reproducibility of absolute NAA concentration, expressed as coefficient of variation (CV), was 1.8%. CV for the concentrations of creatine (Cr), choline (Cho), and myoinositol (MI) and for the ratios NAA/Cr, NAA/Cho, and MI/NAA varied by 11-16%. Intercenter CV was 3.9% for NAA and were below 10% for all other metabolites and metabolic ratios. Our study demonstrates that quantitative assessment of NAA with single-voxel MRS can be performed with high intercenter reproducibility. This is the basis for applying {sup 1}H-MRS in large-scale early recognition and treatment studies in MTL affecting disorders. (orig.)

  11. Visual rating of medial temporal lobe metabolism in mild cognitive impairment and Alzheimer's disease using FDG-PET

    International Nuclear Information System (INIS)

    Mosconi, Lisa; Santi, Susan De; Li, Yi; Li, Juan; Zhan, Jiong; Boppana, Madhu; Tsui, Wai Hon; Leon, Mony J. de; Pupi, Alberto

    2006-01-01

    This study was designed to examine the utility of visual inspection of medial temporal lobe (MTL) metabolism in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD) using FDG-PET scans. Seventy-five subjects [27 normal controls (NL), 26 MCI, and 22 AD] with FDG-PET and MRI scans were included in this study. We developed a four-point visual rating scale to evaluate the presence and severity of MTL hypometabolism on FDG-PET scans. The visual MTL ratings were compared with quantitative glucose metabolic rate (MR glc ) data extracted using regions of interest (ROIs) from the MRI-coregistered PET scans of all subjects. A standard rating evaluation of neocortical hypometabolism was also completed. Logistic regressions were used to determine and compare the diagnostic accuracy of the MTL and cortical ratings. For both MTL and cortical ratings, high intra- and inter-rater reliabilities were found (p values glc measures (p values <0.001). The combination of MTL and cortical ratings significantly improved the diagnostic accuracy over the cortical rating alone, with 100% of AD, 77% of MCI, and 85% of NL cases being correctly identified. This study shows that the visual rating of MTL hypometabolism on PET is reliable, yields a diagnostic accuracy equal to the quantitative ROI measures, and is clinically useful and more sensitive than cortical ratings for patients with MCI. We suggest this method be further evaluated for its potential in the early diagnosis of AD. (orig.)

  12. Medial temporal lobe-dependent repetition suppression and enhancement due to implicit versus explicit processing of individual repeated search displays

    Directory of Open Access Journals (Sweden)

    Thomas eGeyer

    2012-10-01

    Full Text Available Using visual search, functional magnetic resonance imaging (fMRI and patient studies have demonstrated that medial temporal lobe (MTL structures differentiate repeated from novel displays – even when observers are unaware of display repetitions. This suggests a role for MTL in both explicit and, importantly, implicit learning of repeated sensory information (Greene et al., 2007. However, recent behavioral studies suggest, by examining visual search and recognition performance concurrently, that observers have explicit knowledge of at least some of the repeated displays (Geyer et al., 2010. The aim of the present fMRI study was thus to contribute new evidence regarding the contribution of MTL structures to explicit versus implicit learning in visual search. It was found that MTL activation was increased for explicit and, respectively, decreased for implicit relative to baseline displays. These activation differences were most pronounced in left anterior parahippocampal cortex, especially when observers were highly trained on the repeated displays. The data are taken to suggest that explicit and implicit memory processes are linked within MTL structures, but expressed via functionally separable mechanisms (repetition enhancement vs. -suppression. They further show that repetition effects in visual search would have to be investigated at the display level.

  13. Reactivation of medial temporal lobe and occipital lobe during the retrieval of color information: A positron emission tomography study.

    Science.gov (United States)

    Ueno, Aya; Abe, Nobuhito; Suzuki, Maki; Hirayama, Kazumi; Mori, Etsuro; Tashiro, Manabu; Itoh, Masatoshi; Fujii, Toshikatsu

    2007-02-01

    It is widely accepted that memory traces of an event include various types of information about the content of the event and about the circumstances in which the individual experienced it. However, how these various types of information are stored and later retrieved is poorly understood. One hypothesis postulates that the retrieval of specific event information reactivates regions that were active during the encoding of this information, with the aid of binding functions of the medial temporal lobe (MTL) structures. We used positron emission tomography to identify the brain regions related to the encoding and retrieval of color information. Specifically, we assessed whether overlapping activity was found in both the MTL structures and color-related cortical regions during the encoding and retrieval of color information attached with meaningless shapes. During the study, subjects were asked to encode colored (red or green) and achromatic random shapes. At subsequent testing, subjects were presented with only achromatic shapes, which had been presented with or without colors during encoding, and were engaged in retrieval tasks of shapes and colors. Overlapping activity was found in the MTL and occipital lobe (the lingual and inferior occipital gyri) in the right hemisphere during the encoding and retrieval of meaningless shapes with color information compared with those without color information. Although there are some limitations to be considered, the present findings seem to support the view that the retrieval of specific event information is associated with reactivation of both the MTL structures and the regions involved during encoding of the information.

  14. A multicenter reproducibility study of single-voxel 1H-MRS of the medial temporal lobe

    International Nuclear Information System (INIS)

    Traeber, Frank; Block, Wolfgang; Guer, Okan; Schild, Hans H.; Freymann, Nikolaus; Heun, Reinhard; Jessen, Frank; Kucinski, Thomas; Hammen, Thilo; Ende, Gabriele; Pilatus, Ulrich; Hampel, Harald

    2006-01-01

    Proton magnetic resonance spectroscopy ( 1 H-MRS) has provided evidence for a reduction of N-acetyl-aspartate (NAA) in the medial temporal lobe (MTL) in cerebral disorders such as Alzheimer's Disease. Within the 1 H-MRS study of the German Research Network on Dementia, we determined the multicenter reproducibility of single-voxel 1 H-MRS of the MTL. At five sites with 1.5T MR systems, single-voxel 1 H spectra from the MTL of an identical healthy subject were measured. The same subject was also examined at one of the sites five times to assess intracenter stability. The protocol included water-suppressed spectra with TE 272 ms and TE 30 ms and unsuppressed spectra for absolute quantification of metabolite concentrations. The intracenter reproducibility of absolute NAA concentration, expressed as coefficient of variation (CV), was 1.8%. CV for the concentrations of creatine (Cr), choline (Cho), and myoinositol (MI) and for the ratios NAA/Cr, NAA/Cho, and MI/NAA varied by 11-16%. Intercenter CV was 3.9% for NAA and were below 10% for all other metabolites and metabolic ratios. Our study demonstrates that quantitative assessment of NAA with single-voxel MRS can be performed with high intercenter reproducibility. This is the basis for applying 1 H-MRS in large-scale early recognition and treatment studies in MTL affecting disorders. (orig.)

  15. Quasi-linear viscoelastic properties of the human medial patello-femoral ligament.

    Science.gov (United States)

    Criscenti, G; De Maria, C; Sebastiani, E; Tei, M; Placella, G; Speziali, A; Vozzi, G; Cerulli, G

    2015-12-16

    The evaluation of viscoelastic properties of human medial patello-femoral ligament is fundamental to understand its physiological function and contribution as stabilizer for the selection of the methods of repair and reconstruction and for the development of scaffolds with adequate mechanical properties. In this work, 12 human specimens were tested to evaluate the time- and history-dependent non linear viscoelastic properties of human medial patello-femoral ligament using the quasi-linear viscoelastic (QLV) theory formulated by Fung et al. (1972) and modified by Abramowitch and Woo (2004). The five constant of the QLV theory, used to describe the instantaneous elastic response and the reduced relaxation function on stress relaxation experiments, were successfully evaluated. It was found that the constant A was 1.21±0.96MPa and the dimensionless constant B was 26.03±4.16. The magnitude of viscous response, the constant C, was 0.11±0.02 and the initial and late relaxation time constants τ1 and τ2 were 6.32±1.76s and 903.47±504.73s respectively. The total stress relaxation was 32.7±4.7%. To validate our results, the obtained constants were used to evaluate peak stresses from a cyclic stress relaxation test on three different specimens. The theoretically predicted values fit the experimental ones demonstrating that the QLV theory could be used to evaluate the viscoelastic properties of the human medial patello-femoral ligament. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Quantification of beta A4 protein deposition in the medial temporal lobe: a comparison of Alzheimer's disease and senile dementia of the Lewy body type.

    Science.gov (United States)

    Gentleman, S M; Williams, B; Royston, M C; Jagoe, R; Clinton, J; Perry, R H; Ince, P G; Allsop, D; Polak, J M; Roberts, G W

    1992-08-03

    The distribution of beta-amyloid protein (beta A4) was examined in the medial temporal lobes from cases of Alzheimer's disease (AD) (n = 13), senile dementia of Lewy body type (SDLT) (n = 12) and age matched controls (n = 9). Using a previously described image analysis technique the extent of beta A4 pathology was determined in ten distinct anatomical sites within the medial temporal lobe. AD and SDLT cases contained very similar amounts of beta A4 in the areas sampled and both contained significantly more beta A4 than the age matched controls, particularly in the dentate and parahippocampal gyri. The similarity of the beta A4 load in the two conditions is in contrast to reported differences in the number of neurofibrillary tangles which can be observed. It is suggested that AD and SDLT represent a spectrum of pathology which centres around the aberrant processing of the beta A4 precursor protein.

  17. Human Plague Risk: Spatial-Temporal Models

    Science.gov (United States)

    Pinzon, Jorge E.

    2010-01-01

    This chpater reviews the use of spatial-temporal models in identifying potential risks of plague outbreaks into the human population. Using earth observations by satellites remote sensing there has been a systematic analysis and mapping of the close coupling between the vectors of the disease and climate variability. The overall result is that incidence of plague is correlated to positive El Nino/Southem Oscillation (ENSO).

  18. Visual short-term memory for high resolution associations is impaired in patients with medial temporal lobe damage.

    Science.gov (United States)

    Koen, Joshua D; Borders, Alyssa A; Petzold, Michael T; Yonelinas, Andrew P

    2017-02-01

    The medial temporal lobe (MTL) plays a critical role in episodic long-term memory, but whether the MTL is necessary for visual short-term memory is controversial. Some studies have indicated that MTL damage disrupts visual short-term memory performance whereas other studies have failed to find such evidence. To account for these mixed results, it has been proposed that the hippocampus is critical in supporting short-term memory for high resolution complex bindings, while the cortex is sufficient to support simple, low resolution bindings. This hypothesis was tested in the current study by assessing visual short-term memory in patients with damage to the MTL and controls for high resolution and low resolution object-location and object-color associations. In the location tests, participants encoded sets of two or four objects in different locations on the screen. After each set, participants performed a two-alternative forced-choice task in which they were required to discriminate the object in the target location from the object in a high or low resolution lure location (i.e., the object locations were very close or far away from the target location, respectively). Similarly, in the color tests, participants were presented with sets of two or four objects in a different color and, after each set, were required to discriminate the object in the target color from the object in a high or low resolution lure color (i.e., the lure color was very similar or very different, respectively, to the studied color). The patients were significantly impaired in visual short-term memory, but importantly, they were more impaired for high resolution object-location and object-color bindings. The results are consistent with the proposal that the hippocampus plays a critical role in forming and maintaining complex, high resolution bindings. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Usefulness of medial temporal lobe atrophy visual rating scale in detecting Alzheimer′s disease: Preliminary study

    Directory of Open Access Journals (Sweden)

    Jae-Hyeok Heo

    2013-01-01

    Full Text Available Background: The Korean version of Mini-Mental Status Examination (K-MMSE and the Korean version of Addenbrooke Cognitive Examination (K-ACE have been validated as quick neuropsychological tests for screening dementia in various clinical settings. Medial temporal atrophy (MTA is an early pathological characteristic of Alzheimer′s disease (AD. We aimed to assess the diagnostic validity of the fusion of the neuropsychological test and visual rating scale (VRS of MTA in AD. Materials and Methods: A total of fifty subjects (25 AD, 25 controls were included. The neuropsychological tests used were the K-MMSE and the K-ACE. T1 axial imaging visual rating scale (VRS was applied for assessing the grade of MTA. We calculated the fusion score with the difference of neuropsychological test and VRS of MTA. The receiver operating characteristics (ROC curve was used to determine optimal cut-off score, sensitivity and specificity of the fusion scores in screening AD. Results: No significant differences in age, gender and education were found between AD and control group. The values of K-MMSE, K-ACE, CDR, VRS and cognitive function test minus VRS were significantly lower in the AD group than control group. The AUC (Area under the curve, sensitivity and specificity for K-MMSE minus VRS were 0.857, 84% and 80% and for K-ACE minus VRS were 0.884, 80% and 88%, respectively. Those for K-MMSE only were 0.842, 76% and 72% and for K-ACE only were 0.868, 80% and 88%, respectively. Conclusions: The fusion of the neuropsychological test and VRS suggested clinical usefulness in their easy and superiority over neuropsychological test only. However, this study failed to find any difference. This may be because of small numbers in the study or because there is no true difference.

  20. Working memory retrieval differences between medial temporal lobe epilepsy patients and controls: a three memory layer approach.

    Science.gov (United States)

    López-Frutos, José María; Poch, Claudia; García-Morales, Irene; Ruiz-Vargas, José María; Campo, Pablo

    2014-02-01

    Multi-store models of working memory (WM) have given way to more dynamic approaches that conceive WM as an activated subset of long-term memory (LTM). The resulting framework considers that memory representations are governed by a hierarchy of accessibility. The activated part of LTM holds representations in a heightened state of activation, some of which can reach a state of immediate accessibility according to task demands. Recent neuroimaging studies have studied the neural basis of retrieval information with different states of accessibility. It was found that the medial temporal lobe (MTL) was involved in retrieving information within immediate access store and outside this privileged zone. In the current study we further explored the contribution of MTL to WM retrieval by analyzing the consequences of MTL damage to this process considering the state of accessibility of memory representations. The performance of a group of epilepsy patients with left hippocampal sclerosis in a 12-item recognition task was compared with that of a healthy control group. We adopted an embedded model of WM that distinguishes three components: the activated LTM, the region of direct access, and a single-item focus of attention. Groups did not differ when retrieving information from single-item focus, but patients were less accurate retrieving information outside focal attention, either items from LTM or items expected to be in the WM range. Analyses focused on items held in the direct access buffer showed that consequences of MTL damage were modulated by the level of accessibility of memory representations, producing a reduced capacity. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Automated Volumetry and Regional Thickness Analysis of Hippocampal Subfields and Medial Temporal Cortical Structures in Mild Cognitive Impairment

    Science.gov (United States)

    Yushkevich, Paul A.; Pluta, John B.; Wang, Hongzhi; Xie, Long; Ding, Song-Lin; Gertje, E. C.; Mancuso, Lauren; Kliot, Daria; Das, Sandhitsu R.; Wolk, David A.

    2014-01-01

    We evaluate a fully automatic technique for labeling hippocampal subfields and cortical subregions in the medial temporal lobe (MTL) in in vivo 3 Tesla MRI. The method performs segmentation on a T2-weighted MRI scan with 0.4 × 0.4 × 2.0 mm3 resolution, partial brain coverage, and oblique orientation. Hippocampal subfields, entorhinal cortex, and perirhinal cortex are labeled using a pipeline that combines multi-atlas label fusion and learning-based error correction. In contrast to earlier work on automatic subfield segmentation in T2-weighted MRI (Yushkevich et al., 2010), our approach requires no manual initialization, labels hippocampal subfields over a greater anterior-posterior extent, and labels the perirhinal cortex, which is further subdivided into Brodmann areas 35 and 36. The accuracy of the automatic segmentation relative to manual segmentation is measured using cross-validation in 29 subjects from a study of amnestic Mild Cognitive Impairment (aMCI), and is highest for the dentate gyrus (Dice coefficient is 0.823), CA1 (0.803), perirhinal cortex (0.797) and entorhinal cortex (0.786) labels. A larger cohort of 83 subjects is used to examine the effects of aMCI in the hippocampal region using both subfield volume and regional subfield thickness maps. Most significant differences between aMCI and healthy aging are observed bilaterally in the CA1 subfield and in the left Brodmann area 35. Thickness analysis results are consistent with volumetry, but provide additional regional specificity and suggest non-uniformity in the effects of aMCI on hippocampal subfields and MTL cortical subregions. PMID:25181316

  2. Is there a medial nucleus of the trapezoid body in humans?

    DEFF Research Database (Denmark)

    Richter, Erik; Norris, B E; Fullerton, B C

    1983-01-01

    The medial nucleus of the trapezoid body (MNTB) appears to be a prominent auditory structure in many mammals. However, the presence of an MNTB in the human brain has not been clearly established. One of the most characteristic features of the cat MNTB is the presence of large somatic endings...... with multiple synaptic sites, the calyces of Held. We examined adult human brains at both light and electron microscopic levels and found neurons with unusually large endings in a location that is similar to that for the MNTB in other animals. Moreover, the sizes and shapes of some cells in this area...... are similar to the principal cells of the cat MNTB. These observations support the idea that humans have cells that resemble MNTB neurons in other species. It has been suggested that the cat MNTB may be involved in the generation of wave 3 of its brainstem auditory evoked potentials, so the presence...

  3. More consistently altered connectivity patterns for cerebellum and medial temporal lobes than for amygdala and striatum in schizophrenia

    Directory of Open Access Journals (Sweden)

    Henning ePeters

    2016-02-01

    Full Text Available Background: Brain architecture can be divided into a cortico-thalamic system and modulatory ‘subcortical-cerebellar’ systems containing key structures such as striatum, medial temporal lobes (MTLs, amygdala, and cerebellum. Subcortical-cerebellar systems are known to be altered in schizophrenia. In particular, intrinsic functional brain connectivity (iFC between these systems has been consistently demonstrated in patients. While altered connectivity is known for each subcortical-cerebellar system separately, it is unknown whether subcortical-cerebellar systems’ connectivity patterns with the cortico-thalamic system are comparably altered across systems, i.e., if separate subcortical-cerebellar systems’ connectivity patterns are consistent across patients. Methods: To investigate this question, 18 patients with schizophrenia (3 unmedicated, 15 medicated with atypical antipsychotics and 18 healthy controls were assessed by resting-state functional magnetic resonance imaging (fMRI. Independent component analysis of fMRI data revealed cortical intrinsic brain networks (NWs with time courses representing proxies for cortico-thalamic system activity. Subcortical-cerebellar systems’ activity was represented by fMRI-based time courses of selected regions-of-interest (ROIs (i.e., striatum, MTL, amygdala, cerebellum. Correlation analysis among ROI- and NWs-time courses yielded individual connectivity matrices (i.e. connectivity between NW and ROIs (allROIs-NW, separateROI-NW, only NWs (NWs-NWs, and only ROIs (allROIs-allROIs as main outcome measures, which were classified by support-vector-machine-based leave-one-out cross-validation. Differences in classification accuracy were statistically evaluated for consistency across subjects and systems. Results: Correlation matrices based on allROIs-NWs yielded 91% classification accuracy, which was significantly superior to allROIs-allROIs and NWs-NWs (56% and 74%, respectively. Considering separate

  4. Tissue Expressions of Soluble Human Epoxide Hydrolase-2 Enzyme in Patients with Temporal Lobe Epilepsy.

    Science.gov (United States)

    Ahmedov, Merdin Lyutviev; Kemerdere, Rahsan; Baran, Oguz; Inal, Berrin Bercik; Gumus, Alper; Coskun, Cihan; Yeni, Seher Naz; Eren, Bulent; Uzan, Mustafa; Tanriverdi, Taner

    2017-10-01

    We sought to simply demonstrate how levels of soluble human epoxide hydrolase-2 show changes in both temporal the cortex and hippocampal complex in patients with temporal lobe epilepsy. A total of 20 patients underwent anterior temporal lobe resection due to temporal lobe epilepsy. The control group comprised 15 people who died in traffic accidents or by falling from a height, and their autopsy findings were included. Adequately sized temporal cortex and hippocampal samples were removed from each patient during surgery, and the same anatomic structures were removed from the control subjects during the autopsy procedures. Each sample was stored at -80°C as rapidly as possible until the enzyme assay. The temporal cortex in the epilepsy patients had a significantly higher enzyme level than did the temporal cortex of the control group (P = 0.03). Correlation analysis showed that as the enzyme level increases in the temporal cortex, it also increases in the hippocampal complex (r 2  = 0.06, P = 0.00001). More important, enzyme tissue levels showed positive correlations with seizure frequency in both the temporal cortex and hippocampal complex in patients (r 2  = 0.7, P = 0.00001 and r 2  = 0.4, P = 0.003, respectively). The duration of epilepsy was also positively correlated with the hippocampal enzyme level (r 2  = 0.06, P = 0.00001). Soluble human epoxy hydrolase enzyme-2 is increased in both lateral and medial temporal tissues in temporal lobe epilepsy. Further studies should be conducted as inhibition of this enzyme has resulted in a significant decrease in or stopping of seizures and attenuated neuroinflammation in experimental epilepsy models in the current literature. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Correlación entre la memoria subjetiva y objetiva episódica en pacientes con epilepsia del lóbulo temporal medial intratable

    OpenAIRE

    Marilyn Zaldivar Bermúdez; Lilia María Morales Chacón; Otto Trápaga Quincoses; María García Navarro; Abel Sánchez Curuneaux

    2013-01-01

    Introducción. En la literatura científica revisada prevalece una discordancia en las investigaciones sobre la relación entre la memoria subjetiva y objetiva en pacientes con Epilepsia del Lóbulo Temporal medial intratable (ELTmi). Objetivo. Identificar la existencia o no de relación entre la memoria subjetiva y objetiva episódica en pacientes con ELTmi. Metodología. Se estudiaron 32 pacientes, con edades entre 15 y 60 años, empleándose el método clínico. Se aplicó una entrevista semiestructur...

  6. Motor units in the human medial gastrocnemius muscle are not spatially localized or functionally grouped.

    Science.gov (United States)

    Héroux, Martin E; Brown, Harrison J; Inglis, J Timothy; Siegmund, Gunter P; Blouin, Jean-Sébastien

    2015-08-15

    Human medial gastrocnemius (MG) motor units (MUs) are thought to occupy small muscle territories or regions, with low-threshold units preferentially located distally. We used intramuscular recordings to measure the territory of muscle fibres from MG MUs and determine whether these MUs are grouped by recruitment threshold or joint action (ankle plantar flexion and knee flexion). The territory of MUs from the MG muscle varied from somewhat localized to highly distributed, with approximately half the MUs spanning at least half the length and width of the muscle. There was also no evidence of regional muscle activity based on MU recruitment thresholds or joint action. The CNS does not have the means to selectively activate regions of the MG muscle based on task requirements. Human medial gastrocnemius (MG) motor units (MUs) are thought to occupy small muscle territories, with low-threshold units preferentially located distally. In this study, subjects (n = 8) performed ramped and sustained isometric contractions (ankle plantar flexion and knee flexion; range: ∼1-40% maximal voluntary contraction) and we measured MU territory size with spike-triggered averages from fine-wire electrodes inserted along the length (seven electrodes) or across the width (five electrodes) of the MG muscle. Of 69 MUs identified along the length of the muscle, 32 spanned at least half the muscle length (≥ 6.9 cm), 11 of which spanned all recording sites (13.6-17.9 cm). Distal fibres had smaller pennation angles (P recruitment threshold or contraction type, nor was there a relationship between MU territory size and recruitment threshold (Spearman's rho = -0.20 and 0.13, P > 0.18). MUs in the human MG have larger territories than previously reported and are not localized based on recruitment threshold or joint action. This indicates that the CNS does not have the means to selectively activate regions of the MG muscle based on task requirements. © 2015 The Authors. The Journal of

  7. Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometrics

    Science.gov (United States)

    Lockwood, Charles A; Lynch, John M; Kimbel, William H

    2002-01-01

    The hominid temporal bone offers a complex array of morphology that is linked to several different functional systems. Its frequent preservation in the fossil record gives the temporal bone added significance in the study of human evolution, but its morphology has proven difficult to quantify. In this study we use techniques of 3D geometric morphometrics to quantify differences among humans and great apes and discuss the results in a phylogenetic context. Twenty-three landmarks on the ectocranial surface of the temporal bone provide a high level of anatomical detail. Generalized Procrustes analysis (GPA) is used to register (adjust for position, orientation and scale) landmark data from 405 adults representing Homo, Pan, Gorilla and Pongo. Principal components analysis of residuals from the GPA shows that the major source of variation is between humans and apes. Human characteristics such as a coronally orientated petrous axis, a deep mandibular fossa, a projecting mastoid process, and reduced lateral extension of the tympanic element strongly impact the analysis. In phenetic cluster analyses, gorillas and orangutans group together with respect to chimpanzees, and all apes group together with respect to humans. Thus, the analysis contradicts depictions of African apes as a single morphotype. Gorillas and orangutans lack the extensive preglenoid surface of chimpanzees, and their mastoid processes are less medially inflected. These and other characters shared by gorillas and orangutans are probably primitive for the African hominid clade. PMID:12489757

  8. A comparative perspective on the human temporal lobe

    NARCIS (Netherlands)

    Bryant, K.L.; Preuss, T.M.; Bruner, E.; Ogihara, N.; Tanabe, H.

    2018-01-01

    The temporal lobe is a morphological specialization of primates resulting from an expansion of higher-order visual cortex that is a hallmark of the primate brain. Among primates, humans possess a temporal lobe that has significantly expanded. Several uniquely human cognitive abilities, including

  9. Neuropsychiatric effects of neurodegeneration of the medial vs. lateral ventral prefrontal cortex in humans

    OpenAIRE

    Huey, Edward D.; Lee, Seonjoo; Brickman, Adam M.; Manoochehri, Masood; Griffith, Erica; Devanand, D.P.; Stern, Yaakov; Grafman, Jordan

    2015-01-01

    Animal evidence suggests that a brain network involving the medial and rostral ventral prefrontal cortex (PFC) is central for threat response and arousal and a network involving the lateral and caudal PFC plays an important role in reward learning and behavioral control. In this study, we contrasted the neuropsychiatric effects of degeneration of the medial versus lateral PFC in 43 patients with Frontotemporal dementia and 11 patients with Corticobasal Syndrome using MRI, the Neuropsychiatric...

  10. Asymmetry and sexual dimorphism of the medial frontal gyrus visible surface in humans

    Directory of Open Access Journals (Sweden)

    Spasojević Goran

    2010-01-01

    Full Text Available Background/Aim. Studies of visible (extrasulcal surface of the brain hemispheres are not feasible for measurements of the brain size, but are valuable for analysis and quantification of sexual dimorphism and/or asymmetries of the human brain. Morphological and morphometric investigations of the brain may contribute in genetic studies of the human nervous system. The aim of this study was to determine and to quantify sexual dimorphism and the right/left morphological asymmetry of the visible surface of medial frontal gyrus (gyrus frontalis medialis - GFM. Methods. Measurements and analysis of the visible surface of GFM were done on 84 hemispheres (42 brains from the persons of both sexes: 26 males and 16 females, 20-65 years of age. After fixation in 10% formalin and dissection, digital morphometric measurements were performed. We studied these in relation to the side of the hemisphere and the person's sex. Standardized digital AutoCAD planimetry of the visible surface of GFM was enabled by the use of coordinate system of intercommissural line. Results. In the whole sample, the visible surface of the right GFM (21.39 cm2 was statistically significantly greater (p < 0.05 than the left GFM (18.35 cm2 indicating the right/left asymmetry of the visible surface of GFM. Also, the visible surface of the right GFM in the males (22.66 cm2 was significantly greater (p < 0.05 than in the females (19.35 cm2, while the difference in size of the left GFM between the males and the females was not significant (p > 0.05. Conclusion. Morphological analysis of visible surface of GFM performed by digital planimetry showed sexual dimorphism of the visible surface and the presence of right/left asymmetry of GFM.

  11. Medial temporal lobe involvement in an implicit memory task: evidence of collaborating implicit and explicit memory systems from FMRI and Alzheimer's disease.

    Science.gov (United States)

    Koenig, Phyllis; Smith, Edward E; Troiani, Vanessa; Anderson, Chivon; Moore, Peachie; Grossman, Murray

    2008-12-01

    We used a prototype extraction task to assess implicit learning of a meaningful novel visual category. Cortical activation was monitored in young adults with functional magnetic resonance imaging. We observed occipital deactivation at test consistent with perceptually based implicit learning, and lateral temporal cortex deactivation reflecting implicit acquisition of the category's semantic nature. Medial temporal lobe (MTL) activation during exposure and test suggested involvement of explicit memory as well. Behavioral performance of Alzheimer's disease (AD) patients and healthy seniors was also assessed, and AD performance was correlated with gray matter volume using voxel-based morphometry. AD patients showed learning, consistent with preserved implicit memory, and confirming that AD patients' implicit memory is not limited to abstract patterns. However, patients were somewhat impaired relative to healthy seniors. Occipital and lateral temporal cortical volume correlated with successful AD patient performance, and thus overlapped with young adults' areas of deactivation. Patients' severe MTL atrophy precluded involvement of this region. AD patients thus appear to engage a cortically based implicit memory mechanism, whereas their relative deficit on this task may reflect their MTL disease. These findings suggest that implicit and explicit memory systems collaborate in neurologically intact individuals performing an ostensibly implicit memory task.

  12. What, if anything, is the medial temporal lobe, and how can the amygdala be part of it if there is no such thing?

    Science.gov (United States)

    Murray, Elisabeth A; Wise, Steven P

    2004-11-01

    Should the medial temporal lobe (MTL) of primates--which includes allocortical structures such as the hippocampus, neocortical structures such as the parahippocampal cortex, and nuclear structures such as the basolateral amygdala--be considered a single "thing"? According to the prevailing view, here termed the reification theory, the answer is yes. According to this theory, the MTL functions as an amalgamated entity that provides the neuronal mechanisms for declarative memory; the greater the damage to the MTL or any of its components, the greater the deleterious effects on declarative memory. A countervailing view, here called the balkanization theory, holds that the various components of the MTL process and store different kinds of information. According to this theory, damage to each part of the MTL causes a unique set of behavioral deficits-some involving memory, others involving perception, and yet others involving response selection. The empirical neuropsychological evidence favors the balkanization theory, as do some new concepts in theoretical neuroanatomy.

  13. Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward

    Science.gov (United States)

    Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios

    2014-01-01

    To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. PMID:25008408

  14. Pseudohypacusis in childhood and adolescence is associated with increased gray matter volume in the medial frontal gyrus and superior temporal gyrus.

    Science.gov (United States)

    Tomoda, Akemi; Kinoshita, Sumihito; Korenaga, Yuki; Mabe, Hiroyo

    2012-04-01

    Pseudohypacusis is a somatoform disorder characterized by hearing loss with discrepancies between pure-tone audiometry and auditory brainstem response (ABR), but the underlying neuronal mechanisms remain unclear. Using voxel-based morphometry (VBM) with magnetic resonance (MR) imaging for 14 unmedicated, right-handed patients and 35 healthy control subjects, we investigated whether functional hearing loss was associated with discernible changes of brain morphology. Group differences in gray matter volume (GMV) were assessed using high-resolution, T1-weighted, volumetric MR imaging datasets (3T Trio scanner; Siemens AG) and analyzed with covariant factors of age, sex, socioeconomic status (SES), and total GMV, which was increased by 27.9% in the left medial frontal gyrus (MFG) (Brodmann area 10) (p=.001, corrected cluster level) and by 14.4% in the right superior temporal gyrus (STG) and the adjacent middle temporal gyrus (MTG) (BA42 to 21) (p=.009, corrected cluster level) in patients with pseudohypacusis. The GMV in the right STG (BA42) and verbal intelligence quotient (IQ) were correlated significantly with the Wechsler Intelligence Scale for Children - Third Edition (WISC-III) (ß=-.57, p<.0001) and level of SES (ß=-.55, p<.0001). The present findings suggest that the development of the auditory association cortex involved in language processing is affected, causing insufficient pruning during brain development. We therefore assert that differences in the neuroanatomical substrate of pseudohypacusis subjects result from a developmental disorder in auditory processing. Copyright © 2010 Elsevier Srl. All rights reserved.

  15. Spatial and Temporal Episodic Memory Retrieval Recruit Dissociable Functional Networks in the Human Brain

    Science.gov (United States)

    Ekstrom, Arne D.; Bookheimer, Susan Y.

    2007-01-01

    Imaging, electrophysiological studies, and lesion work have shown that the medial temporal lobe (MTL) is important for episodic memory; however, it is unclear whether different MTL regions support the spatial, temporal, and item elements of episodic memory. In this study we used fMRI to examine retrieval performance emphasizing different aspects…

  16. Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward.

    Science.gov (United States)

    Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios; Musallam, Sam

    2014-10-01

    To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. Copyright © 2014 the American Physiological Society.

  17. Characteristics of spectro-temporal modulation frequency selectivity in humans.

    Science.gov (United States)

    Oetjen, Arne; Verhey, Jesko L

    2017-03-01

    There is increasing evidence that the auditory system shows frequency selectivity for spectro-temporal modulations. A recent study of the authors has shown spectro-temporal modulation masking patterns that were in agreement with the hypothesis of spectro-temporal modulation filters in the human auditory system [Oetjen and Verhey (2015). J. Acoust. Soc. Am. 137(2), 714-723]. In the present study, that experimental data and additional data were used to model this spectro-temporal frequency selectivity. The additional data were collected to investigate to what extent the spectro-temporal modulation-frequency selectivity results from a combination of a purely temporal amplitude-modulation filter and a purely spectral amplitude-modulation filter. In contrast to the previous study, thresholds were measured for masker and target modulations with opposite directions, i.e., an upward pointing target modulation and a downward pointing masker modulation. The comparison of this data set with previous corresponding data with the same direction from target and masker modulations indicate that a specific spectro-temporal modulation filter is required to simulate all aspects of spectro-temporal modulation frequency selectivity. A model using a modified Gabor filter with a purely temporal and a purely spectral filter predicts the spectro-temporal modulation masking data.

  18. Time and temporality: linguistic distribution in human life-games

    DEFF Research Database (Denmark)

    Cowley, Stephen

    2014-01-01

    culture, individuals developed a knack of using linguistic distribution to link metabolism with collective ways of assessing and managing experience. Of human temporal management, the best known case is the mental time travel enabled by, among other functions, autobiographical memory. One contribution......While clock-time can be used to clarify facts, all living systems construct their own temporalities. Having illustrated the claim for foxtail grasses, it is argued that, with motility and brains, organisms came to use temporalities that build flexibility into behavior. With the rise of human...

  19. Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H{sub 2}{sup 15}O PET

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2002-06-01

    The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H{sub 2}{sup 15}O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period.

  20. Healthy aging attenuates task-related specialization in the human medial temporal lobe

    DEFF Research Database (Denmark)

    Ramsøy, Thomas Z.; Liptrot, Matthew George; Skimminge, Arnold Jesper Møller

    2012-01-01

    conflicting findings. Using functional magnetic resonance imaging (fMRI), we have recently shown that young healthy individuals show a stronger activation of the MTL during encoding of objects as compared with encoding of positions. Using the same encoding task, the present study addressed the question...

  1. Application of own computer program for assessment of brain-fluid index in the medial temporal lobe portions in patients with drug-resistant temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Boguslawska, R.; Skrobowska, E.; Rysz, A.

    2009-01-01

    Background: Epilepsy resistant to pharmacological treatment still remains one of the main problems in contemporary epileptology. The problem most frequently concerns patients with focal epilepsy, with the seizure focus possible to localize. In case of drug-resistant epilepsy, both morphological imaging methods (MR) and manual measurements or volumetry are used. Also functional studies, such as MRS (magnetic resonance spectroscopy), fMRI (functional magnetic resonance), SPECT (single photon emission tomography) and PET (positron emission tomography) are performed. Material/Methods: The study presents application of own computer program based on the method of segmentation of the cerebrospinal fluid (CSF) and the brain tissue. The program calculates automatically the brain-fluin index in the hippocampal region. The material comprises the brain-fluin index results calculated with the presented program in comparison with the method of manual delineation in a group of 50 patients with drug-resistant temporal lobe epilepsy. The program is easy to use, it reads the MR data recorded in DICOM installed on a PC. Results: The brain-fluin index result (expressed as a decimal fraction) is calculated on the basis of 4 consecutive layers examined by MR (evaluating hippocampal structures) performed using SE sequence, and T2-weighted imaging in the frontal plane perpendicular to the long axis of the temporal lobes. The results obtained in epilepsy patients were compared with 24 control subjects. Conclusions: Detailed analysis of the obtained data allowed to conclude that precise hippocampal volume assessment can be obtained by combination of both methods, i.e. manual delineation and automatic calculation of brain-fluin index taking into consideration the total volume of cerebral structures. (authors)

  2. Timed Up and Go test, atrophy of medial temporal areas and cognitive functions in community-dwelling older adults with normal cognition and mild cognitive impairment.

    Science.gov (United States)

    Kose, Yujiro; Ikenaga, Masahiro; Yamada, Yosuke; Morimura, Kazuhiro; Takeda, Noriko; Ouma, Shinji; Tsuboi, Yoshio; Yamada, Tatsuo; Kimura, Misaka; Kiyonaga, Akira; Higaki, Yasuki; Tanaka, Hiroaki

    2016-12-01

    This study aimed to ascertain if performance on the Timed Up and Go (TUG) test is associated with indicators of brain volume and cognitive functions among community-dwelling older adults with normal cognition or mild cognitive impairment. Participants were 80 community-dwelling older adults aged 65-89years (44 men, 36 women), including 20 with mild cognitive impairment. Participants completed the TUG and a battery of cognitive assessments, including the Mini-Mental State Examination (MMSE), the Logical Memory I and II (LM-I, LM-II) subtests of the Wechsler Memory Scale-Revised; and the Trail Making Test A and B (TMT-A, TMT-B). Bilateral, right- and left-side medial temporal area atrophy as well as whole gray and white matter indices were determined with the Voxel-based Specific Regional Analysis System for Alzheimer's Disease. We divided participants into three groups based on TUG performance: "better" (≤6.9s); "normal" (7-10s); and "poor" (≥10.1s). Worse TMT-A and TMT-B performance showed significant independent associations with worse TUG performance (Pareas were significantly independently associated with worse TUG performance (Parea atrophy in community-dwelling older adults. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Practical use of visual medial temporal lobe atrophy cut-off scores in Alzheimer's disease: Validation in a large memory clinic population

    International Nuclear Information System (INIS)

    Claus, Jules J.; Holl, Dana C.; Roorda, Jelmen J.; Staekenborg, Salka S.; Schuur, Jacqueline; Koster, Pieter; Tielkes, Caroline E.M.; Scheltens, Philip

    2017-01-01

    To provide age-specific medial temporal lobe atrophy (MTA) cut-off scores for routine clinical practice as marker for Alzheimer's disease (AD). Patients with AD (n = 832, mean age 81.8 years) were compared with patients with subjective cognitive impairment (n = 333, mean age 71.8 years) in a large single-centre memory clinic. Mean of right and left MTA scores was determined with visual rating (Scheltens scale) using CT (0, no atrophy to 4, severe atrophy). Relationships between age and MTA scores were analysed with regression analysis. For various MTA cut-off scores, decade-specific sensitivity and specificity and area under the curve (AUC) values, computed with receiver operator characteristic curves, were determined. MTA strongly increased with age in both groups to a similar degree. Optimal MTA cut-off values for the age ranges <65, 65-74, 75-84 and ≥85 were: ≥1.0, ≥1.5, ≥ 2.0 and ≥2.0. Corresponding values of sensitivity and specificity were 83.3% and 86.4%; 73.7% and 84.6%; 73.7% and 76.2%; and 84.0% and 62.5%. From this large unique memory clinic cohort we suggest decade-specific MTA cut-off scores for clinical use. After age 85 years, however, the practical usefulness of the MTA cut-off is limited. (orig.)

  4. Practical use of visual medial temporal lobe atrophy cut-off scores in Alzheimer's disease: Validation in a large memory clinic population

    Energy Technology Data Exchange (ETDEWEB)

    Claus, Jules J.; Holl, Dana C.; Roorda, Jelmen J. [Tergooi Hospital, Department of Neurology, Blaricum (Netherlands); Staekenborg, Salka S. [Tergooi Hospital, Department of Neurology, Blaricum (Netherlands); VU University Medical Center, Department of Neurology, Alzheimer Center, Amsterdam (Netherlands); Schuur, Jacqueline [Tergooi Hospital, Department of Geriatrics, Blaricum (Netherlands); Koster, Pieter [Tergooi Hospital, Department of Radiology, Blaricum (Netherlands); Tielkes, Caroline E.M. [Tergooi Hospital, Department of Medical Psychology, Blaricum (Netherlands); Scheltens, Philip [VU University Medical Center, Department of Neurology, Alzheimer Center, Amsterdam (Netherlands)

    2017-08-15

    To provide age-specific medial temporal lobe atrophy (MTA) cut-off scores for routine clinical practice as marker for Alzheimer's disease (AD). Patients with AD (n = 832, mean age 81.8 years) were compared with patients with subjective cognitive impairment (n = 333, mean age 71.8 years) in a large single-centre memory clinic. Mean of right and left MTA scores was determined with visual rating (Scheltens scale) using CT (0, no atrophy to 4, severe atrophy). Relationships between age and MTA scores were analysed with regression analysis. For various MTA cut-off scores, decade-specific sensitivity and specificity and area under the curve (AUC) values, computed with receiver operator characteristic curves, were determined. MTA strongly increased with age in both groups to a similar degree. Optimal MTA cut-off values for the age ranges <65, 65-74, 75-84 and ≥85 were: ≥1.0, ≥1.5, ≥ 2.0 and ≥2.0. Corresponding values of sensitivity and specificity were 83.3% and 86.4%; 73.7% and 84.6%; 73.7% and 76.2%; and 84.0% and 62.5%. From this large unique memory clinic cohort we suggest decade-specific MTA cut-off scores for clinical use. After age 85 years, however, the practical usefulness of the MTA cut-off is limited. (orig.)

  5. Temporal stability in human interaction networks

    Science.gov (United States)

    Fabbri, Renato; Fabbri, Ricardo; Antunes, Deborah Christina; Pisani, Marilia Mello; de Oliveira, Osvaldo Novais

    2017-11-01

    This paper reports on stable (or invariant) properties of human interaction networks, with benchmarks derived from public email lists. Activity, recognized through messages sent, along time and topology were observed in snapshots in a timeline, and at different scales. Our analysis shows that activity is practically the same for all networks across timescales ranging from seconds to months. The principal components of the participants in the topological metrics space remain practically unchanged as different sets of messages are considered. The activity of participants follows the expected scale-free trace, thus yielding the hub, intermediary and peripheral classes of vertices by comparison against the Erdös-Rényi model. The relative sizes of these three sectors are essentially the same for all email lists and the same along time. Typically, 45% are peripheral vertices. Similar results for the distribution of participants in the three sectors and for the relative importance of the topological metrics were obtained for 12 additional networks from Facebook, Twitter and ParticipaBR. These properties are consistent with the literature and may be general for human interaction networks, which has important implications for establishing a typology of participants based on quantitative criteria.

  6. The role of temporal structure in human vision.

    Science.gov (United States)

    Blake, Randolph; Lee, Sang-Hun

    2005-03-01

    Gestalt psychologists identified several stimulus properties thought to underlie visual grouping and figure/ground segmentation, and among those properties was common fate: the tendency to group together individual objects that move together in the same direction at the same speed. Recent years have witnessed an upsurge of interest in visual grouping based on other time-dependent sources of visual information, including synchronized changes in luminance, in motion direction, and in figure/ ground relations. These various sources of temporal grouping information can be subsumed under the rubric temporal structure. In this article, the authors review evidence bearing on the effectiveness of temporal structure in visual grouping. They start with an overview of evidence bearing on temporal acuity of human vision, covering studies dealing with temporal integration and temporal differentiation. They then summarize psychophysical studies dealing with figure/ground segregation based on temporal phase differences in deterministic and stochastic events. The authors conclude with a brief discussion of neurophysiological implications of these results.

  7. Low pre-existing gray matter volume in the medial temporal lobe and white matter lesions are associated with postoperative cognitive dysfunction after cardiac surgery.

    Directory of Open Access Journals (Sweden)

    Kengo Maekawa

    Full Text Available OBJECTIVES: Postoperative cognitive dysfunction (POCD is recognized as a complication in the elderly after cardiac surgery. Imaging of the brain provides evidence of neurodegeneration in elderly patients; however, abnormalities in brain structure and their relation to POCD are uncertain. This pilot study investigated whether loss of gray matter in the bilateral medial temporal lobe (MTL, seen in preoperative MRI, was associated with POCD. METHODS: Data were collected prospectively on 28 elderly patients scheduled for elective cardiac surgery. MRI of the brains of all patients were assessed for prior cerebral infarctions, and carotid and intracranial arterial stenosis. Patients also completed six neuropsychological tests of memory, attention and executive function before and after surgery. POCD was defined as an individual decrease in more than two tests of at least 1 standard deviation from the group baseline mean for that test. The degree of gray matter loss in the MTL of each patient was calculated using voxel-based morphometry with three-dimensional, T1-weighted MRI. This represented the degree of gray matter change as a Z score. RESULTS: Postoperative cognitive dysfunction was identified in 8 of the 28 patients (29%. Patients with POCD had significantly more white matter lesions on MRI, and greater loss of gray matter in the bilateral MTL (average Z score 2.0±0.9 than patients without POCD. An analysis by stepwise logistic regression identified gray matter loss in the MTL and cerebral infarctions on MRI as independent predictors of POCD. CONCLUSIONS: These preliminary findings suggested that reduced gray matter in the bilateral MTL and white matter lesions existed in brains of elderly cardiac surgery patients who experienced POCD. Additional studies with larger sample sizes are needed to confirm these findings.

  8. Visual rating of medial temporal lobe metabolism in mild cognitive impairment and Alzheimer's disease using FDG-PET

    Energy Technology Data Exchange (ETDEWEB)

    Mosconi, Lisa [New York University School of Medicine, Department of Psychiatry, New York, NY (United States); University of Florence, Department of Clinical Pathophysiology, Nuclear Medicine Unit, Florence (Italy); New York University School of Medicine, Center for Brain Health, New York, NY (United States); Santi, Susan De; Li, Yi; Li, Juan; Zhan, Jiong; Boppana, Madhu [New York University School of Medicine, Department of Psychiatry, New York, NY (United States); Tsui, Wai Hon; Leon, Mony J. de [New York University School of Medicine, Department of Psychiatry, New York, NY (United States); Nathan Kline Institute, Orangeburg, NY (United States); Pupi, Alberto [University of Florence, Department of Clinical Pathophysiology, Nuclear Medicine Unit, Florence (Italy)

    2006-02-01

    This study was designed to examine the utility of visual inspection of medial temporal lobe (MTL) metabolism in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD) using FDG-PET scans. Seventy-five subjects [27 normal controls (NL), 26 MCI, and 22 AD] with FDG-PET and MRI scans were included in this study. We developed a four-point visual rating scale to evaluate the presence and severity of MTL hypometabolism on FDG-PET scans. The visual MTL ratings were compared with quantitative glucose metabolic rate (MR{sub glc}) data extracted using regions of interest (ROIs) from the MRI-coregistered PET scans of all subjects. A standard rating evaluation of neocortical hypometabolism was also completed. Logistic regressions were used to determine and compare the diagnostic accuracy of the MTL and cortical ratings. For both MTL and cortical ratings, high intra- and inter-rater reliabilities were found (p values <0.001). The MTL rating was highly correlated with and yielded a diagnostic accuracy equivalent to the ROI MR{sub glc} measures (p values <0.001). The combination of MTL and cortical ratings significantly improved the diagnostic accuracy over the cortical rating alone, with 100% of AD, 77% of MCI, and 85% of NL cases being correctly identified. This study shows that the visual rating of MTL hypometabolism on PET is reliable, yields a diagnostic accuracy equal to the quantitative ROI measures, and is clinically useful and more sensitive than cortical ratings for patients with MCI. We suggest this method be further evaluated for its potential in the early diagnosis of AD. (orig.)

  9. A case of double depressor palsy followed by pursuit deficit due to sequential infarction in bilateral thalamus and right medial superior temporal area.

    Science.gov (United States)

    Kim, Su Jin; Yeom, Myeong In; Lee, Seung Uk

    2017-12-01

    We present a unique case of a patient who suffered two rare events affecting the supranuclear control, first of the vertical and second of the horizontal eye movements. The first event involved bilateral thalamic infarcts that resulted in double depressor palsy. The second event occurred 1 year later and it involved supranuclear control of horizontal eye movements creating pursuit deficit. A 47-year-old male presented with complaints of diplopia upon awakening. He had atrial fibrillation, mitral valve regurgitation, aortic valve regurgitation, and a history of spleen infarction 1 year ago. His right eye was hypertrophic and right eye downgaze was limited unilaterally of equal degree in adduction and abduction. The patient was diagnosed with double depressor palsy of the right eye. Magnetic resonance imaging (MRI) of the brain showed an old infarction of the left thalamus, and diffusion MRI showed acute infarction of the right thalamus. The patient's daily warfarin dose was 2 mg and it was increased to 5 mg with cilostazol 75 mg twice a day. Seven weeks later, the patient's ocular movement revealed near normal muscle action, and subjectively, the patient was diplopia free. At follow-up 12 months later, the patient revisited the hospital because of sudden onset of blurred vision on right gaze. He was observed to have smooth pursuit deficit to the right side, and orthophoric position of the eyes in primary gaze. MRI of the brain showed an acute infarction in the right medial superior temporal area. The patient experienced very rare abnormal eyeball movements twice. This case highlights the importance of evaluating vertical movement of the eyes and vascular supplies when patients present with depressor deficit and supports the theory of a supranuclear function in patients who present with pursuit deficit.

  10. Hierarchical Aligned Cluster Analysis for Temporal Clustering of Human Motion.

    Science.gov (United States)

    Zhou, Feng; De la Torre, Fernando; Hodgins, Jessica K

    2013-03-01

    Temporal segmentation of human motion into plausible motion primitives is central to understanding and building computational models of human motion. Several issues contribute to the challenge of discovering motion primitives: the exponential nature of all possible movement combinations, the variability in the temporal scale of human actions, and the complexity of representing articulated motion. We pose the problem of learning motion primitives as one of temporal clustering, and derive an unsupervised hierarchical bottom-up framework called hierarchical aligned cluster analysis (HACA). HACA finds a partition of a given multidimensional time series into m disjoint segments such that each segment belongs to one of k clusters. HACA combines kernel k-means with the generalized dynamic time alignment kernel to cluster time series data. Moreover, it provides a natural framework to find a low-dimensional embedding for time series. HACA is efficiently optimized with a coordinate descent strategy and dynamic programming. Experimental results on motion capture and video data demonstrate the effectiveness of HACA for segmenting complex motions and as a visualization tool. We also compare the performance of HACA to state-of-the-art algorithms for temporal clustering on data of a honey bee dance. The HACA code is available online.

  11. The research of morphological variations and sexual dimorphism of primary grooves on the medial side of brain hemispheres in humans

    Directory of Open Access Journals (Sweden)

    Spasojević Goran

    2012-01-01

    Full Text Available Morphological studies of the various parts of the brain show certain morphological and morphometric differences in correlation with sex, so-called sexual dimorphism of the brain. Our research has been done on the cerebral hemispheres, taken from cadavers of both sexes and different age without pathological processes in the brain. The sample comprised 26 male brains and 16 female brains. We studied three primary grooves (sulcus cinguli, sulcus parietooccipitalis and sulcus calcarinus of the medial surface of the human cerebral hemispheres. We conducted morphological typology of grooves and morphometric measurements of primary brain grooves length in relation to sex and side of hemisphere. The results showed a statistically significant sex difference in the cingulate sulcus length (p0,05. Determined morphometric sexual dimorphism in cingulate sulcus length is significant because it implies the correlation between morphology and function of the explored areas of the cerebral cortex.

  12. Passive Muscle-Tendon Unit Gearing is Joint Dependent in Human Medial Gastrocnemius

    Directory of Open Access Journals (Sweden)

    Emma F Hodson-Tole

    2016-03-01

    Full Text Available Skeletal muscles change length and develop force both passively and actively. Gearing allows muscle fibre length changes to be uncoupled from those of the whole muscle-tendon unit. During active contractions this process allows muscles to operate at mechanically favorable conditions for power or economical force production. Here we ask whether gearing is constant in passive muscle; determining the relationship between fascicle and muscle-tendon unit length change in the bi-articular medial gastrocnemius and investigating the influence of whether motion occurs at the knee or ankle joint. Specifically, the same muscle-tendon unit length changes were elicited by rotating either the ankle or knee joint whilst simultaneously measuring fascicle lengths in proximal and distal muscle regions using B-mode ultrasound. In both the proximal and distal muscle region, passive gearing values differed depending on whether ankle or knee motion occurred. Fascicle length changes were greater with ankle motion, likely reflecting anatomical differences in proximal and distal passive tendinous tissues, as well as shape changes of the adjacent mono-articular soleus. This suggests that there is joint-dependent dissociation between the mechanical behaviour of muscle fibres and the muscle-tendon unit during passive joint motions that may be important to consider when developing accurate models of bi-articular muscles.

  13. Astrocyte uncoupling as a cause of human temporal lobe epilepsy.

    Science.gov (United States)

    Bedner, Peter; Dupper, Alexander; Hüttmann, Kerstin; Müller, Julia; Herde, Michel K; Dublin, Pavel; Deshpande, Tushar; Schramm, Johannes; Häussler, Ute; Haas, Carola A; Henneberger, Christian; Theis, Martin; Steinhäuser, Christian

    2015-05-01

    Glial cells are now recognized as active communication partners in the central nervous system, and this new perspective has rekindled the question of their role in pathology. In the present study we analysed functional properties of astrocytes in hippocampal specimens from patients with mesial temporal lobe epilepsy without (n = 44) and with sclerosis (n = 75) combining patch clamp recording, K(+) concentration analysis, electroencephalography/video-monitoring, and fate mapping analysis. We found that the hippocampus of patients with mesial temporal lobe epilepsy with sclerosis is completely devoid of bona fide astrocytes and gap junction coupling, whereas coupled astrocytes were abundantly present in non-sclerotic specimens. To decide whether these glial changes represent cause or effect of mesial temporal lobe epilepsy with sclerosis, we developed a mouse model that reproduced key features of human mesial temporal lobe epilepsy with sclerosis. In this model, uncoupling impaired K(+) buffering and temporally preceded apoptotic neuronal death and the generation of spontaneous seizures. Uncoupling was induced through intraperitoneal injection of lipopolysaccharide, prevented in Toll-like receptor4 knockout mice and reproduced in situ through acute cytokine or lipopolysaccharide incubation. Fate mapping confirmed that in the course of mesial temporal lobe epilepsy with sclerosis, astrocytes acquire an atypical functional phenotype and lose coupling. These data suggest that astrocyte dysfunction might be a prime cause of mesial temporal lobe epilepsy with sclerosis and identify novel targets for anti-epileptogenic therapeutic intervention. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Temporal dynamics of figure-ground segregation in human vision.

    Science.gov (United States)

    Neri, Peter; Levi, Dennis M

    2007-01-01

    The segregation of figure from ground is arguably one of the most fundamental operations in human vision. Neural signals reflecting this operation appear in cortex as early as 50 ms and as late as 300 ms after presentation of a visual stimulus, but it is not known when these signals are used by the brain to construct the percepts of figure and ground. We used psychophysical reverse correlation to identify the temporal window for figure-ground signals in human perception and found it to lie within the range of 100-160 ms. Figure enhancement within this narrow temporal window was transient rather than sustained as may be expected from measurements in single neurons. These psychophysical results prompt and guide further electrophysiological studies.

  15. Encoding model of temporal processing in human visual cortex.

    Science.gov (United States)

    Stigliani, Anthony; Jeska, Brianna; Grill-Spector, Kalanit

    2017-12-19

    How is temporal information processed in human visual cortex? Visual input is relayed to V1 through segregated transient and sustained channels in the retina and lateral geniculate nucleus (LGN). However, there is intense debate as to how sustained and transient temporal channels contribute to visual processing beyond V1. The prevailing view associates transient processing predominately with motion-sensitive regions and sustained processing with ventral stream regions, while the opposing view suggests that both temporal channels contribute to neural processing beyond V1. Using fMRI, we measured cortical responses to time-varying stimuli and then implemented a two temporal channel-encoding model to evaluate the contributions of each channel. Different from the general linear model of fMRI that predicts responses directly from the stimulus, the encoding approach first models neural responses to the stimulus from which fMRI responses are derived. This encoding approach not only predicts cortical responses to time-varying stimuli from milliseconds to seconds but also, reveals differential contributions of temporal channels across visual cortex. Consistent with the prevailing view, motion-sensitive regions and adjacent lateral occipitotemporal regions are dominated by transient responses. However, ventral occipitotemporal regions are driven by both sustained and transient channels, with transient responses exceeding the sustained. These findings propose a rethinking of temporal processing in the ventral stream and suggest that transient processing may contribute to rapid extraction of the content of the visual input. Importantly, our encoding approach has vast implications, because it can be applied with fMRI to decipher neural computations in millisecond resolution in any part of the brain. Copyright © 2017 the Author(s). Published by PNAS.

  16. Temporal trends in human vulnerability to excessive heat

    Science.gov (United States)

    Sheridan, Scott C.; Allen, Michael J.

    2018-04-01

    Over recent decades, studies have examined various morbidity and mortality outcomes associated with heat exposure. This review explores the collective knowledge of the temporal trends of heat on human health, with regard to the hypothesis that humans are less vulnerable to heat events presently than in the past. Using Web of Science and Scopus, the authors identified all peer-reviewed articles that contained keywords on human impact (e.g. mortality, morbidity) and meteorological component (e.g. heat, heatwave). After sorting, a total of 71 articles, both case studies and epidemiological studies, contained explicit assessments of temporal trends in human vulnerability, and thus were used in this review. Most of the studies utilized mortality data, focused on the developed world, and showed a general decrease in heat sensitivity. Factors such as the implementation of a heat warning system, increased awareness, and improved quality of life were cited as contributing factors that led to the decreased impact of heat. Despite the overall recent decreases in heat vulnerability, spatial variability was shown, and differences with respect to health outcomes were also discussed. Several papers noted increases in heat’s impact on human health, particularly when unprecedented conditions occurred. Further, many populations, from outdoor workers to rural residents, in addition to the populations in much of the developing world, have been significantly underrepresented in research to date, and temporal changes in their vulnerability should be assessed in future studies. Moreover, continued monitoring and improvement of heat intervention is needed; with projected changes in the frequency, duration, and intensity of heat events combined with shifts in demographics, heat will remain a major public health issue moving forward.

  17. Lateralization for dynamic facial expressions in human superior temporal sulcus.

    Science.gov (United States)

    De Winter, François-Laurent; Zhu, Qi; Van den Stock, Jan; Nelissen, Koen; Peeters, Ronald; de Gelder, Beatrice; Vanduffel, Wim; Vandenbulcke, Mathieu

    2015-02-01

    Most face processing studies in humans show stronger activation in the right compared to the left hemisphere. Evidence is largely based on studies with static stimuli focusing on the fusiform face area (FFA). Hence, the pattern of lateralization for dynamic faces is less clear. Furthermore, it is unclear whether this property is common to human and non-human primates due to predisposing processing strategies in the right hemisphere or that alternatively left sided specialization for language in humans could be the driving force behind this phenomenon. We aimed to address both issues by studying lateralization for dynamic facial expressions in monkeys and humans. Therefore, we conducted an event-related fMRI experiment in three macaques and twenty right handed humans. We presented human and monkey dynamic facial expressions (chewing and fear) as well as scrambled versions to both species. We studied lateralization in independently defined face-responsive and face-selective regions by calculating a weighted lateralization index (LIwm) using a bootstrapping method. In order to examine if lateralization in humans is related to language, we performed a separate fMRI experiment in ten human volunteers including a 'speech' expression (one syllable non-word) and its scrambled version. Both within face-responsive and selective regions, we found consistent lateralization for dynamic faces (chewing and fear) versus scrambled versions in the right human posterior superior temporal sulcus (pSTS), but not in FFA nor in ventral temporal cortex. Conversely, in monkeys no consistent pattern of lateralization for dynamic facial expressions was observed. Finally, LIwms based on the contrast between different types of dynamic facial expressions (relative to scrambled versions) revealed left-sided lateralization in human pSTS for speech-related expressions compared to chewing and emotional expressions. To conclude, we found consistent laterality effects in human posterior STS but not

  18. Glutamate concentration in the medial prefrontal cortex predicts resting-state cortical-subcortical functional connectivity in humans.

    Directory of Open Access Journals (Sweden)

    Niall W Duncan

    Full Text Available Communication between cortical and subcortical regions is integral to a wide range of psychological processes and has been implicated in a number of psychiatric conditions. Studies in animals have provided insight into the biochemical and connectivity processes underlying such communication. However, to date no experiments that link these factors in humans in vivo have been carried out. To investigate the role of glutamate in individual differences in communication between the cortex--specifically the medial prefrontal cortex (mPFC--and subcortical regions in humans, a combination of resting-state fMRI, DTI and MRS was performed. The subcortical target regions were the nucleus accumbens (NAc, dorsomedial thalamus (DMT, and periaqueductal grey (PAG. It was found that functional connectivity between the mPFC and each of the NAc and DMT was positively correlated with mPFC glutamate concentrations, whilst functional connectivity between the mPFC and PAG was negatively correlated with glutamate concentration. The correlations involving mPFC glutamate and FC between the mPFC and each of the DMT and PAG were mirrored by correlations with structural connectivity, providing evidence that the glutamatergic relationship may, in part, be due to direct connectivity. These results are in agreement with existing results from animal studies and may have relevance for MDD and schizophrenia.

  19. The increase in medial prefrontal glutamate/glutamine concentration during memory encoding is associated with better memory performance and stronger functional connectivity in the human medial prefrontal-thalamus-hippocampus network.

    Science.gov (United States)

    Thielen, Jan-Willem; Hong, Donghyun; Rohani Rankouhi, Seyedmorteza; Wiltfang, Jens; Fernández, Guillén; Norris, David G; Tendolkar, Indira

    2018-06-01

    The classical model of the declarative memory system describes the hippocampus and its interactions with representational brain areas in posterior neocortex as being essential for the formation of long-term episodic memories. However, new evidence suggests an extension of this classical model by assigning the medial prefrontal cortex (mPFC) a specific, yet not fully defined role in episodic memory. In this study, we utilized 1H magnetic resonance spectroscopy (MRS) and psychophysiological interaction (PPI) analysis to lend further support for the idea of a mnemonic role of the mPFC in humans. By using MRS, we measured mPFC γ-aminobutyric acid (GABA) and glutamate/glutamine (GLx) concentrations before and after volunteers memorized face-name association. We demonstrate that mPFC GLx but not GABA levels increased during the memory task, which appeared to be related to memory performance. Regarding functional connectivity, we used the subsequent memory paradigm and found that the GLx increase was associated with stronger mPFC connectivity to thalamus and hippocampus for associations subsequently recognized with high confidence as opposed to subsequently recognized with low confidence/forgotten. Taken together, we provide new evidence for an mPFC involvement in episodic memory by showing a memory-related increase in mPFC excitatory neurotransmitter levels that was associated with better memory and stronger memory-related functional connectivity in a medial prefrontal-thalamus-hippocampus network. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  20. Internally generated preactivation of single neurons in human medial frontal cortex predicts volition

    OpenAIRE

    Fried, Itzhak; Mukamel, Roy; Kreiman, Gabriel

    2011-01-01

    Understanding how self-initiated behavior is encoded by neuronal circuits in the human brain remains elusive. We recorded the activity of 1019 neurons while twelve subjects performed self-initiated finger movement. We report progressive neuronal recruitment over ∼1500 ms before subjects report making the decision to move. We observed progressive increase or decrease in neuronal firing rate, particularly in the supplementary motor area (SMA), as the reported time of decision was approached. A ...

  1. Quantitative Measurement of Dissection Resistance in Intimal and Medial Layers of Human Coronary Arteries

    Science.gov (United States)

    Wang, Ying; Johnson, John A.; Spinale, Francis G.; Sutton, Michael A.; Lessner, Susan M.

    2014-01-01

    The left anterior descending (LAD) coronary artery is the most frequently involved vessel in coronary artery dissection, a cause of acute coronary syndrome or sudden cardiac death. The biomechanical mechanisms underlying arterial dissection are not well understood. This study investigated the dissection properties of LAD specimens harvested from explanted hearts at the time of cardiac transplantation, from patients with primary dilated cardiomyopathy (n=12). Using a previously validated approach uniquely modified for these human LAD specimens, we quantified the local energy release rate, G, within different arterial layers during experimental dissection events (tissue tearing). Results show that the mean values of G during arterial dissection within the intima and within the media in human LADs are 20.7±16.5 J/m2 and 10.3±5.0 J/m2, respectively. The difference in dissection resistance between tearing events occurring within the intima and within the media is statistically significant. Our data fall in the same order of magnitude as most previous measurements of adhesive strength in other human arteries, with the differences in measured values of G within the layers most likely due to histologically observed differences in the structure and composition of arterial layers. PMID:24729631

  2. Temporal-spatial characteristics of phase-amplitude coupling in electrocorticogram for human temporal lobe epilepsy.

    Science.gov (United States)

    Zhang, Ruihua; Ren, Ye; Liu, Chunyan; Xu, Na; Li, Xiaoli; Cong, Fengyu; Ristaniemi, Tapani; Wang, YuPing

    2017-09-01

    Neural activity of the epileptic human brain contains low- and high-frequency oscillations in different frequency bands, some of which have been used as reliable biomarkers of the epileptogenic brain areas. However, the relationship between the low- and high-frequency oscillations in different cortical areas during the period from pre-seizure to post-seizure has not been completely clarified. We recorded electrocorticogram data from the temporal lobe and hippocampus of seven patients with temporal lobe epilepsy. The modulation index based on the Kullback-Leibler distance and the phase-amplitude coupling co-modulogram were adopted to quantify the coupling strength between the phase of low-frequency oscillations (0.2-10Hz) and the amplitude of high-frequency oscillations (11-400Hz) in different seizure epochs. The time-varying phase-amplitude modulogram was used to analyze the phase-amplitude coupling pattern during the entire period from pre-seizure to post-seizure in both the left and right temporal lobe and hippocampus. Channels with strong modulation index were compared with the seizure onset channels identified by the neurosurgeons and the resection channels in the clinical surgery. The phase-amplitude coupling strength (modulation index) increased significantly in the mid-seizure epoch and decrease significantly in seizure termination and post-seizure epochs (ptemporal cortex and hippocampus. The "fall-max" phase-amplitude modulation pattern, i.e., high-frequency amplitudes were largest in the low-frequency phase range [-π, 0], which corresponded to the falling edges of low-frequency oscillations, appeared in the middle period of the seizures at epileptic focus channels. Channels with strong modulation index appeared on the corresponding left or right temporal cortex of surgical resection and overlapped with the clinical resection zones in all patients. The "fall-max" pattern between the phase of low-frequency oscillation and amplitude of high

  3. Recruitment of motor units in the medial gastrocnemius muscle during human quiet standing: is recruitment intermittent? What triggers recruitment?

    Science.gov (United States)

    Vieira, Taian M M; Loram, Ian D; Muceli, Silvia; Merletti, Roberto; Farina, Dario

    2012-01-01

    The recruitment and the rate of discharge of motor units are determinants of muscle force. Within a motoneuron pool, recruitment and rate coding of individual motor units might be controlled independently, depending on the circumstances. In this study, we tested whether, during human quiet standing, the force of the medial gastrocnemius (MG) muscle is predominantly controlled by recruitment or rate coding. If MG control during standing was mainly due to recruitment, then we further asked what the trigger mechanism is. Is it determined internally, or is it related to body kinematics? While seven healthy subjects stood quietly, intramuscular electromyograms were recorded from the MG muscle with three pairs of wire electrodes. The number of active motor units and their mean discharge rate were compared for different sway velocities and positions. Motor unit discharges occurred more frequently when the body swayed faster and forward (Pearson R = 0.63; P motor unit potentials was explained chiefly by the recruitment of additional units. During forward body shifts, the median number of units detected increased from 3 to 11 (P motor units did not discharge continuously throughout standing. They were recruited within individual, forward sways and intermittently, with a modal rate of two recruitments per second. This modal rate is consistent with previous circumstantial evidence relating the control of standing to an intrinsic, higher level planning process.

  4. Human temporal cortical single neuron activity during working memory maintenance.

    Science.gov (United States)

    Zamora, Leona; Corina, David; Ojemann, George

    2016-06-01

    The Working Memory model of human memory, first introduced by Baddeley and Hitch (1974), has been one of the most influential psychological constructs in cognitive psychology and human neuroscience. However the neuronal correlates of core components of this model have yet to be fully elucidated. Here we present data from two studies where human temporal cortical single neuron activity was recorded during tasks differentially affecting the maintenance component of verbal working memory. In Study One we vary the presence or absence of distracting items for the entire period of memory storage. In Study Two we vary the duration of storage so that distractors filled all, or only one-third of the time the memory was stored. Extracellular single neuron recordings were obtained from 36 subjects undergoing awake temporal lobe resections for epilepsy, 25 in Study one, 11 in Study two. Recordings were obtained from a total of 166 lateral temporal cortex neurons during performance of one of these two tasks, 86 study one, 80 study two. Significant changes in activity with distractor manipulation were present in 74 of these neurons (45%), 38 Study one, 36 Study two. In 48 (65%) of those there was increased activity during the period when distracting items were absent, 26 Study One, 22 Study Two. The magnitude of this increase was greater for Study One, 47.6%, than Study Two, 8.1%, paralleling the reduction in memory errors in the absence of distracters, for Study One of 70.3%, Study Two 26.3% These findings establish that human lateral temporal cortex is part of the neural system for working memory, with activity during maintenance of that memory that parallels performance, suggesting it represents active rehearsal. In 31 of these neurons (65%) this activity was an extension of that during working memory encoding that differed significantly from the neural processes recorded during overt and silent language tasks without a recent memory component, 17 Study one, 14 Study two

  5. Human Temporal Cortical Single Neuron Activity During Working Memory Maintenance

    Science.gov (United States)

    Zamora, Leona; Corina, David; Ojemann, George

    2016-01-01

    The Working Memory model of human memory, first introduced by Baddeley and Hitch (1974), has been one of the most influential psychological constructs in cognitive psychology and human neuroscience. However the neuronal correlates of core components of this model have yet to be fully elucidated. Here we present data from two studies where human temporal cortical single neuron activity was recorded during tasks differentially affecting the maintenance component of verbal working memory. In Study One we vary the presence or absence of distracting items for the entire period of memory storage. In Study Two we vary the duration of storage so that distractors filled all, or only one-third of the time the memory was stored. Extracellular single neuron recordings were obtained from 36 subjects undergoing awake temporal lobe resections for epilepsy, 25 in Study one, 11 in Study two. Recordings were obtained from a total of 166 lateral temporal cortex neurons during performance of one of these two tasks, 86 study one, 80 study two. Significant changes in activity with distractor manipulation were present in 74 of these neurons (45%), 38 Study one, 36 Study two. In 48 (65%) of those there was increased activity during the period when distracting items were absent, 26 Study One, 22 Study Two. The magnitude of this increase was greater for Study One, 47.6%, than Study Two, 8.1%, paralleling the reduction in memory errors in the absence of distracters, for Study One of 70.3%, Study Two 26.3% These findings establish that human lateral temporal cortex is part of the neural system for working memory, with activity during maintenance of that memory that parallels performance, suggesting it represents active rehearsal. In 31 of these neurons (65%) this activity was an extension of that during working memory encoding that differed significantly from the neural processes recorded during overt and silent language tasks without a recent memory component, 17 Study one, 14 Study two

  6. Internally generated preactivation of single neurons in human medial frontal cortex predicts volition

    Science.gov (United States)

    Fried, Itzhak; Mukamel, Roy; Kreiman, Gabriel

    2011-01-01

    Understanding how self-initiated behavior is encoded by neuronal circuits in the human brain remains elusive. We recorded the activity of 1019 neurons while twelve subjects performed self-initiated finger movement. We report progressive neuronal recruitment over ~1500 ms before subjects report making the decision to move. We observed progressive increase or decrease in neuronal firing rate, particularly in the supplementary motor area (SMA), as the reported time of decision was approached. A population of 256 SMA neurons is sufficient to predict in single trials the impending decision to move with accuracy greater than 80% already 700 ms prior to subjects’ awareness. Furthermore, we predict, with a precision of a few hundred ms, the actual time point of this voluntary decision to move. We implement a computational model whereby volition emerges once a change in internally generated firing rate of neuronal assemblies crosses a threshold. PMID:21315264

  7. Filtering the reality: functional dissociation of lateral and medial pain systems during sleep in humans.

    Science.gov (United States)

    Bastuji, Hélène; Mazza, Stéphanie; Perchet, Caroline; Frot, Maud; Mauguière, François; Magnin, Michel; Garcia-Larrea, Luis

    2012-11-01

    Behavioral reactions to sensory stimuli during sleep are scarce despite preservation of sizeable cortical responses. To further understand such dissociation, we recorded intracortical field potentials to painful laser pulses in humans during waking and all-night sleep. Recordings were obtained from the three cortical structures receiving 95% of the spinothalamic cortical input in primates, namely the parietal operculum, posterior insula, and mid-anterior cingulate cortex. The dynamics of responses during sleep differed among cortical sites. In sleep Stage 2, evoked potential amplitudes were similarly attenuated relative to waking in all three cortical regions. During paradoxical, or rapid eye movements (REM), sleep, opercular and insular potentials remained stable in comparison with Stage 2, whereas the responses from mid-anterior cingulate abated drastically, and decreasing below background noise in half of the subjects. Thus, while the lateral operculo-insular system subserving sensory analysis of somatic stimuli remained active during paradoxical-REM sleep, mid-anterior cingulate processes related to orienting and avoidance behavior were suppressed. Dissociation between sensory and orienting-motor networks might explain why nociceptive stimuli can be either neglected or incorporated into dreams without awakening the subject. Copyright © 2011 Wiley Periodicals, Inc.

  8. [Human interaction, social cognition, and the superior temporal sulcus].

    Science.gov (United States)

    Brunelle, Francis; Saitovitch, Anna; Boddaert, Nathalie; Grevent, David; Cambier, Jean; Lelord, Gilbert; Samson, Yves; Zilbovicius, Monica

    2013-01-01

    Human beings are social animals. This ability to live together is ensured by cognitive functions, the neuroanatomical bases of which are starting to be unraveled by MRI-based studies. The regions and network engaged in this process are known as the "social brain ". The core of this network is the superior temporal sulcus (STS), which integrates sensory and emotional inputs. Modeling studies of healthy volunteers have shown the role of the STS.in recognizing others as biological beings, as well as facial and eye-gaze recognition, intentionality and emotions. This cognitive capacity has been described as the "theory of mind ". Pathological models such as autism, in which the main clinical abnormality is altered social abilities and communication, have confirmed the role of the STS in the social brain. Conceptualisation of this empathic capacity has been described as "meta cognition ", which forms the basis of human social organizationand culture.

  9. Prediction of Human Activity by Discovering Temporal Sequence Patterns.

    Science.gov (United States)

    Li, Kang; Fu, Yun

    2014-08-01

    Early prediction of ongoing human activity has become more valuable in a large variety of time-critical applications. To build an effective representation for prediction, human activities can be characterized by a complex temporal composition of constituent simple actions and interacting objects. Different from early detection on short-duration simple actions, we propose a novel framework for long -duration complex activity prediction by discovering three key aspects of activity: Causality, Context-cue, and Predictability. The major contributions of our work include: (1) a general framework is proposed to systematically address the problem of complex activity prediction by mining temporal sequence patterns; (2) probabilistic suffix tree (PST) is introduced to model causal relationships between constituent actions, where both large and small order Markov dependencies between action units are captured; (3) the context-cue, especially interactive objects information, is modeled through sequential pattern mining (SPM), where a series of action and object co-occurrence are encoded as a complex symbolic sequence; (4) we also present a predictive accumulative function (PAF) to depict the predictability of each kind of activity. The effectiveness of our approach is evaluated on two experimental scenarios with two data sets for each: action-only prediction and context-aware prediction. Our method achieves superior performance for predicting global activity classes and local action units.

  10. Association of 5' end neuregulin-1 (NRG1) gene variation with subcortical medial frontal microstructure in humans.

    Science.gov (United States)

    Winterer, Georg; Konrad, Andreas; Vucurevic, Goran; Musso, Francesco; Stoeter, Peter; Dahmen, Norbert

    2008-04-01

    ., Lemke, G., Sainz, J., Johannesson, G., Andresson, T., Gudbjartsson, D., Manolescu, A., Frigge, M.L., Gurney, M.E., Kong, A., Gulcher, J.R., Petursson, H., Stefansson, K. 2002. Neuregulin-1 and susceptibility to schizophrenia. Am. J. Hum. Genet. 71, 877-892). As predicted, we found medial frontal FA to be significantly associated with this NRG1 gene variation. Using voxel-based morphometry (VBM), we could largely exclude the possibility that this genotype effect is indirectly caused by genotype-dependent effects on brain volume. This is the first demonstration that SNP8NRG221533 of the NRG1 gene affects medial frontal white matter microstructure in humans. As the degree of neuronal myelination contributes to structural integrity, our finding further supports a potential role of NRG1 in neuronal myelination in the human brain. By extension, our findings suggest that SNP8NRG221533 may contribute to the risk for the complex polygenic illness schizophrenia via its impact on myelination in frontal lobe white matter.

  11. Differential Intracochlear Sound Pressure Measurements in Normal Human Temporal Bones

    Science.gov (United States)

    Nakajima, Hideko Heidi; Dong, Wei; Olson, Elizabeth S.; Merchant, Saumil N.; Ravicz, Michael E.; Rosowski, John J.

    2009-02-01

    We present the first simultaneous sound pressure measurements in scala vestibuli and scala tympani of the cochlea in human cadaveric temporal bones. Micro-scale fiberoptic pressure sensors enabled the study of differential sound pressure at the cochlear base. This differential pressure is the input to the cochlear partition, driving cochlear waves and auditory transduction. Results showed that: pressure of scala vestibuli was much greater than scala tympani except at low and high frequencies where scala tympani pressure affects the input to the cochlea; the differential pressure proved to be an excellent measure of normal ossicular transduction of sound (shown to decrease 30-50 dB with ossicular disarticulation, whereas the individual scala pressures were significantly affected by non-ossicular conduction of sound at high frequencies); the middle-ear gain and differential pressure were generally bandpass in frequency dependence; and the middle-ear delay in the human was over twice that of the gerbil. Concurrent stapes velocity measurements allowed determination of the differential impedance across the partition and round-window impedance. The differential impedance was generally resistive, while the round-window impedance was consistent with a compliance in conjunction with distributed inertia and damping. Our techniques can be used to study inner-ear conductive pathologies (e.g., semicircular dehiscence), as well as non-ossicular cochlear stimulation (e.g., round-window stimulation) - situations that cannot be completely quantified by measurements of stapes velocity or scala-vestibuli pressure by themselves.

  12. Temporal morphologic changes in human colorectal carcinomas following xenografting.

    Science.gov (United States)

    Barkla, D H; Tutton, P J

    1983-03-01

    The temporal morphologic changes of human colorectal carcinomas following xenografting into immunosuppressed mice were investigated by the use of light and transmission electron microscopy. The results show that colorectal carcinomas undergo a series of morphologic changes during the initial 30-day period following transplantation. During the initial 1-5-day period the majority of tumor cells die, and during the following 5-10-day period the necrotic debris created during the 1-5-day period is removed by host-supplied inflammatory cells. Only small groups of peripherally placed tumor cells survived at the end of the first 10 days. During the 10-20-day period the tumor cell populations of xenografts were reestablished by a morphologically heterogeneous population of tumor cells, and during the 20-30 day period consolidation of this process continued and some xenografts showed macroscopic evidence of growth. The authors hypothesize that human colorectal carcinomas, like the antecedent epithelium, contain subpopulations of undifferentiated cells that give rise to populations of more-differentiated cells.

  13. Dynamic encoding of speech sequence probability in human temporal cortex.

    Science.gov (United States)

    Leonard, Matthew K; Bouchard, Kristofer E; Tang, Claire; Chang, Edward F

    2015-05-06

    Sensory processing involves identification of stimulus features, but also integration with the surrounding sensory and cognitive context. Previous work in animals and humans has shown fine-scale sensitivity to context in the form of learned knowledge about the statistics of the sensory environment, including relative probabilities of discrete units in a stream of sequential auditory input. These statistics are a defining characteristic of one of the most important sequential signals humans encounter: speech. For speech, extensive exposure to a language tunes listeners to the statistics of sound sequences. To address how speech sequence statistics are neurally encoded, we used high-resolution direct cortical recordings from human lateral superior temporal cortex as subjects listened to words and nonwords with varying transition probabilities between sound segments. In addition to their sensitivity to acoustic features (including contextual features, such as coarticulation), we found that neural responses dynamically encoded the language-level probability of both preceding and upcoming speech sounds. Transition probability first negatively modulated neural responses, followed by positive modulation of neural responses, consistent with coordinated predictive and retrospective recognition processes, respectively. Furthermore, transition probability encoding was different for real English words compared with nonwords, providing evidence for online interactions with high-order linguistic knowledge. These results demonstrate that sensory processing of deeply learned stimuli involves integrating physical stimulus features with their contextual sequential structure. Despite not being consciously aware of phoneme sequence statistics, listeners use this information to process spoken input and to link low-level acoustic representations with linguistic information about word identity and meaning. Copyright © 2015 the authors 0270-6474/15/357203-12$15.00/0.

  14. New total ossicular replacement prostheses with a resilient joint: experimental data from human temporal bones.

    Science.gov (United States)

    Arechvo, Irina; Bornitz, Matthias; Lasurashvili, Nikoloz; Zahnert, Thomas; Beleites, Thomas

    2012-01-01

    New flexible total ossicular prostheses with an integrated microjoint can compensate for large static displacements in the reconstructed ossicular chain. When properly designed, they can mimic the function of the joints of the intact chain and ensure good vibration transfer in both straight and bent conditions. Prosthesis dislocations and extrusions are frequently observed after middle ear surgery. They are mainly related to the altered distance between the coupling points because of large static eardrum displacements. The new prostheses consist of 2 titanium shafts, which are incorporated into a silicone body. The sound transfer function and stapes footplate displacement at static loads were evaluated in human temporal bones after ossicular reconstruction using prostheses with 2 different silicones with different hardness values. The stiffness and bending characteristics of the prostheses were investigated with a quasi-static load. The sound transfer properties of the middle ears with the prostheses inserted under uncompressed conditions were comparable with those of ears with intact ossicular chains. The implant with the soft silicone had improved acoustic transfer characteristics over the implant with the hard silicone in a compressed state. In the quasi-static experiments, the minimum medial footplate displacement was found with the same implant. The bending characteristics depended on the silicone stiffness and correlated closely with the point and angle of the load incidence. The titanium prostheses with a resilient joint that were investigated in this study had good sound transfer characteristics under optimal conditions as well as in a compressed state. As a result of joint bending, the implants compensate for the small changes in length of the ossicular chain that occur under varying middle ear pressure. The implants require a stable support at the stapes footplate to function properly.

  15. Quantifying interictal metabolic activity in human temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Henry, T.R.; Mazziotta, J.C.; Engel, J. Jr.; Christenson, P.D.; Zhang, J.X.; Phelps, M.E.; Kuhl, D.E.

    1990-01-01

    The majority of patients with complex partial seizures of unilateral temporal lobe origin have interictal temporal hypometabolism on [18F]fluorodeoxyglucose positron emission tomography (FDG PET) studies. Often, this hypometabolism extends to ipsilateral extratemporal sites. The use of accurately quantified metabolic data has been limited by the absence of an equally reliable method of anatomical analysis of PET images. We developed a standardized method for visual placement of anatomically configured regions of interest on FDG PET studies, which is particularly adapted to the widespread, asymmetric, and often severe interictal metabolic alterations of temporal lobe epilepsy. This method was applied by a single investigator, who was blind to the identity of subjects, to 10 normal control and 25 interictal temporal lobe epilepsy studies. All subjects had normal brain anatomical volumes on structural neuroimaging studies. The results demonstrate ipsilateral thalamic and temporal lobe involvement in the interictal hypometabolism of unilateral temporal lobe epilepsy. Ipsilateral frontal, parietal, and basal ganglial metabolism is also reduced, although not as markedly as is temporal and thalamic metabolism

  16. Temporal and spatial variation of the human microbiota during pregnancy.

    Science.gov (United States)

    DiGiulio, Daniel B; Callahan, Benjamin J; McMurdie, Paul J; Costello, Elizabeth K; Lyell, Deirdre J; Robaczewska, Anna; Sun, Christine L; Goltsman, Daniela S A; Wong, Ronald J; Shaw, Gary; Stevenson, David K; Holmes, Susan P; Relman, David A

    2015-09-01

    Despite the critical role of the human microbiota in health, our understanding of microbiota compositional dynamics during and after pregnancy is incomplete. We conducted a case-control study of 49 pregnant women, 15 of whom delivered preterm. From 40 of these women, we analyzed bacterial taxonomic composition of 3,767 specimens collected prospectively and weekly during gestation and monthly after delivery from the vagina, distal gut, saliva, and tooth/gum. Linear mixed-effects modeling, medoid-based clustering, and Markov chain modeling were used to analyze community temporal trends, community structure, and vaginal community state transitions. Microbiota community taxonomic composition and diversity remained remarkably stable at all four body sites during pregnancy (P > 0.05 for trends over time). Prevalence of a Lactobacillus-poor vaginal community state type (CST 4) was inversely correlated with gestational age at delivery (P = 0.0039). Risk for preterm birth was more pronounced for subjects with CST 4 accompanied by elevated Gardnerella or Ureaplasma abundances. This finding was validated with a set of 246 vaginal specimens from nine women (four of whom delivered preterm). Most women experienced a postdelivery disturbance in the vaginal community characterized by a decrease in Lactobacillus species and an increase in diverse anaerobes such as Peptoniphilus, Prevotella, and Anaerococcus species. This disturbance was unrelated to gestational age at delivery and persisted for up to 1 y. These findings have important implications for predicting premature labor, a major global health problem, and for understanding the potential impact of a persistent, altered postpartum microbiota on maternal health, including outcomes of pregnancies following short interpregnancy intervals.

  17. Temporal and Spatial Categorization in Human and Non-Human Primates

    Directory of Open Access Journals (Sweden)

    Juan Carlos eMendez

    2011-09-01

    Full Text Available It has been proposed that a functional overlap exists in the brain for temporal and spatial information processing. To test this, we designed two relative categorization tasks in which human subjects and a Rhesus monkey had to assign time intervals or distances to a ‘short’ or ‘long’ category according to varying prototypes. The performance of both species was analyzed using psychometric techniques that showed that they may have similar perceptual, memory and/or decision mechanisms, specially for the estimation of time intervals. We also did a correlation analysis with human subjects’ psychometric thresholds and the results imply that indeed, temporal and spatial information categorization share neural substrates. However, not all of the tested distances and intervals correlated with each other, suggesting the existence of sub-circuits that process restricted ranges of distances and intervals. A different analysis was done on the monkey data, in which the influence of the previous categorical prototypes was measured on the task currently being performed. Again, we found a significant interaction between previous and current interval and distance categorization. Overall, the present paper points towards common or at least partially overlapped neural circuits for temporal and spatial categorization in primates.

  18. Tuning for temporal interval in human apparent motion detection.

    Science.gov (United States)

    Bours, Roger J E; Stuur, Sanne; Lankheet, Martin J M

    2007-01-08

    Detection of apparent motion in random dot patterns requires correlation across time and space. It has been difficult to study the temporal requirements for the correlation step because motion detection also depends on temporal filtering preceding correlation and on integration at the next levels. To specifically study tuning for temporal interval in the correlation step, we performed an experiment in which prefiltering and postintegration were held constant and in which we used a motion stimulus containing coherent motion for a single interval value only. The stimulus consisted of a sparse random dot pattern in which each dot was presented in two frames only, separated by a specified interval. On each frame, half of the dots were refreshed and the other half was a displaced reincarnation of the pattern generated one or several frames earlier. Motion energy statistics in such a stimulus do not vary from frame to frame, and the directional bias in spatiotemporal correlations is similar for different interval settings. We measured coherence thresholds for left-right direction discrimination by varying motion coherence levels in a Quest staircase procedure, as a function of both step size and interval. Results show that highest sensitivity was found for an interval of 17-42 ms, irrespective of viewing distance. The falloff at longer intervals was much sharper than previously described. Tuning for temporal interval was largely, but not completely, independent of step size. The optimal temporal interval slightly decreased with increasing step size. Similarly, the optimal step size decreased with increasing temporal interval.

  19. The anatomy of the human medial forebrain bundle: Ventral tegmental area connections to reward-associated subcortical and frontal lobe regions

    Directory of Open Access Journals (Sweden)

    Volker Arnd Coenen

    Full Text Available Introduction: Despite their importance in reward, motivation, and learning there is only sparse anatomical knowledge about the human medial forebrain bundle (MFB and the connectivity of the ventral tegmental area (VTA. A thorough anatomical and microstructural description of the reward related PFC/OFC regions and their connection to the VTA - the superolateral branch of the MFB (slMFB - is however mandatory to enable an interpretation of distinct therapeutic effects from different interventional treatment modalities in neuropsychiatric disorders (DBS, TMS etc.. This work aims at a normative description of the human MFB (and more detailed the slMFB anatomy with respect to distant prefrontal connections and microstructural features. Methods and material: Healthy subjects (n = 55; mean age ± SD, 40 ± 10 years; 32 females underwent high resolution anatomical magnetic resonance imaging including diffusion tensor imaging. Connectivity of the VTA and the resulting slMFB were investigated on the group level using a global tractography approach. The Desikan/Killiany parceling (8 segments of the prefrontal cortex was used to describe sub-segments of the MFB. A qualitative overlap with Brodmann areas was additionally described. Additionally, a pure visual analysis was performed comparing local and global tracking approaches for their ability to fully visualize the slMFB. Results: The MFB could be robustly described both in the present sample as well as in additional control analyses in data from the human connectome project. Most VTA- connections reached the superior frontal gyrus, the middel frontal gyrus and the lateral orbitofrontal region corresponding to Brodmann areas 10, 9, 8, 11, and 11m. The projections to these regions comprised 97% (right and 98% (left of the total relative fiber counts of the slMFB. Discussion: The anatomical description of the human MFB shows far reaching connectivity of VTA to reward-related subcortical and

  20. Modeling the Temporal Nature of Human Behavior for Demographics Prediction

    DEFF Research Database (Denmark)

    Felbo, Bjarke; Sundsøy, Pål; Pentland, Alex

    2017-01-01

    Mobile phone metadata is increasingly used for humanitarian purposes in developing countries as traditional data is scarce. Basic demographic information is however often absent from mobile phone datasets, limiting the operational impact of the datasets. For these reasons, there has been a growing...... interest in predicting demographic information from mobile phone metadata. Previous work focused on creating increasingly advanced features to be modeled with standard machine learning algorithms. We here instead model the raw mobile phone metadata directly using deep learning, exploiting the temporal...... on both age and gender prediction using only the temporal modality in mobile metadata. We finally validate our method on low activity users and evaluate the modeling assumptions....

  1. Motor unit recruitment and firing rate in medial gastrocnemius muscles during external perturbations in standing in humans.

    Science.gov (United States)

    Pollock, C L; Ivanova, T D; Hunt, M A; Garland, S J

    2014-10-01

    There is limited investigation of the interaction between motor unit recruitment and rate coding for modulating force during standing or responding to external perturbations. Fifty-seven motor units were recorded from the medial gastrocnemius muscle with intramuscular electrodes in response to external perturbations in standing. Anteriorly directed perturbations were generated by applying loads in 0.45-kg increments at the pelvis every 25-40 s until 2.25 kg was maintained. Motor unit firing rate was calculated for the initial recruitment load and all subsequent loads during two epochs: 1) dynamic response to perturbation directly following each load drop and 2) maintenance of steady state between perturbations. Joint kinematics and surface electromyography (EMG) from lower extremities and force platform measurements were assessed. Application of the external loads resulted in a significant forward progression of the anterior-posterior center of pressure (AP COP) that was accompanied by modest changes in joint angles (recruitment, motor unit firing rate immediately after the load drop was significantly lower than during subsequent load drops or during the steady state at the same load. There was a modest increase in motor unit firing rate immediately after the load drop on subsequent load drops associated with regaining balance. There was no effect of maintaining balance with increased load and forward progression of the AP COP on steady-state motor unit firing rate. The medial gastrocnemius utilized primarily motor unit recruitment to achieve the increased levels of activation necessary to maintain standing in the presence of external loads. Copyright © 2014 the American Physiological Society.

  2. Maturation of Cortico-Subcortical Structural Networks-Segregation and Overlap of Medial Temporal and Fronto-Striatal Systems in Development.

    Science.gov (United States)

    Walhovd, Kristine B; Tamnes, Christian K; Bjørnerud, Atle; Due-Tønnessen, Paulina; Holland, Dominic; Dale, Anders M; Fjell, Anders M

    2015-07-01

    The brain consists of partly segregated neural circuits within which structural convergence and functional integration occurs during development. The relationship of structural cortical and subcortical maturation is largely unknown. We aimed to study volumetric development of the hippocampus and basal ganglia (caudate, putamen, pallidum, accumbens) in relation to volume changes throughout the cortex. Longitudinal MRI data were obtained across a mean interval of 2.6 years in 85 participants with an age range of 8-19 years at study start. Left and right subcortical changes were related to cortical change vertex-wise in the ipsilateral hemisphere with general linear models with age, sex, interval between scans, and mean cortical volume change as covariates. Hippocampal-cortical change relationships centered on parts of the Papez circuit, including entorhinal, parahippocampal, and isthmus cingulate areas, and lateral temporal, insular, and orbitofrontal cortices in the left hemisphere. Basal ganglia-cortical change relationships were observed in mostly nonoverlapping and more anterior cortical areas, all including the anterior cingulate. Other patterns were unique to specific basal ganglia structures, including pre-, post-, and paracentral patterns relating to putamen change. In conclusion, patterns of cortico-subcortical development as assessed by morphometric analyses in part map out segregated neural circuits at the macrostructural level. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Contributions of Feature Binding During Encoding and Functional Connectivity of the Medial Temporal Lobe Structures to Episodic Memory Deficits Across the Prodromal and First-Episode Phases of Schizophrenia.

    Science.gov (United States)

    Haut, Kristen M; van Erp, Theo G M; Knowlton, Barbara; Bearden, Carrie E; Subotnik, Kenneth; Ventura, Joseph; Nuechterlein, Keith H; Cannon, Tyrone D

    2015-03-01

    Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia ( n = 27) and high psychosis risk ( n = 28) compared with control participants ( n = 22 and n = 20, respectively) underwent functional MRI during a remember-know memory task. Psychophysiological interaction analyses, using medial temporal lobe (MTL) structures as regions of interest, were conducted to measure functional connectivity patterns supporting successful episodic memory. During encoding, patients with first-episode schizophrenia demonstrated reduced functional coupling between MTL regions and regions involved in stimulus representations, stimulus selection, and cognitive control. Relative to control participants and patients with high psychosis risk who did not convert to psychosis, patients with high psychosis risk who later converted to psychosis also demonstrated reduced connectivity between MTL regions and auditory-verbal and visual-association regions. These results suggest that episodic memory deficits in schizophrenia are related to inefficient recruitment of cortical connections involved in associative memory formation; such deficits precede the onset of psychosis among those individuals at high clinical risk.

  4. MODELING SPECTRAL AND TEMPORAL MASKING IN THE HUMAN AUDITORY SYSTEM

    DEFF Research Database (Denmark)

    Dau, Torsten; Jepsen, Morten Løve; Ewert, Stephan D.

    2007-01-01

    An auditory signal processing model is presented that simulates psychoacoustical data from a large variety of experimental conditions related to spectral and temporal masking. The model is based on the modulation filterbank model by Dau et al. [J. Acoust. Soc. Am. 102, 2892-2905 (1997)] but inclu......An auditory signal processing model is presented that simulates psychoacoustical data from a large variety of experimental conditions related to spectral and temporal masking. The model is based on the modulation filterbank model by Dau et al. [J. Acoust. Soc. Am. 102, 2892-2905 (1997...... was tested in conditions of tone-in-noise masking, intensity discrimination, spectral masking with tones and narrowband noises, forward masking with (on- and off-frequency) noise- and pure-tone maskers, and amplitude modulation detection using different noise carrier bandwidths. One of the key properties...

  5. Multi-scale spatio-temporal analysis of human mobility

    DEFF Research Database (Denmark)

    Alessandretti, Laura; Sapiezynski, Piotr; Jørgensen, Sune Lehmann

    2017-01-01

    The recent availability of digital traces generated by phone calls and online logins has significantly increased the scientific understanding of human mobility. Until now, however, limited data resolution and coverage have hindered a coherent description of human displacements across different...

  6. Temporal summation of heat pain in humans: Evidence supporting thalamocortical modulation.

    Science.gov (United States)

    Tran, Tuan D; Wang, Heng; Tandon, Animesh; Hernandez-Garcia, Luis; Casey, Kenneth L

    2010-07-01

    Noxious cutaneous contact heat stimuli (48 degrees C) are perceived as increasingly painful when the stimulus duration is extended from 5 to 10s, reflecting the temporal summation of central neuronal activity mediating heat pain. However, the sensation of increasing heat pain disappears, reaching a plateau as stimulus duration increases from 10 to 20s. We used functional magnetic resonance imaging (fMRI) in 10 healthy subjects to determine if active central mechanisms could contribute to this psychophysical plateau. During heat pain durations ranging from 5 to 20s, activation intensities in the bilateral orbitofrontal cortices and the activation volume in the left primary (S1) somatosensory cortex correlated only with perceived stimulus intensity and not with stimulus duration. Activation volumes increased with both stimulus duration and perceived intensity in the left lateral thalamus, posterior insula, inferior parietal cortex, and hippocampus. In contrast, during the psychophysical plateau, both the intensity and volume of thalamic and cortical activations in the right medial thalamus, right posterior insula, and left secondary (S2) somatosensory cortex continued to increase with stimulus duration but not with perceived stimulus intensity. Activation volumes in the left medial and right lateral thalamus, and the bilateral mid-anterior cingulate, left orbitofrontal, and right S2 cortices also increased only with stimulus duration. The increased activity of specific thalamic and cortical structures as stimulus duration, but not perceived intensity, increases is consistent with the recruitment of a thalamocortical mechanism that participates in the modulation of pain-related cortical responses and the temporal summation of heat pain. Published by Elsevier B.V.

  7. Comparison of Urban Human Movements Inferring from Multi-Source Spatial-Temporal Data

    Science.gov (United States)

    Cao, Rui; Tu, Wei; Cao, Jinzhou; Li, Qingquan

    2016-06-01

    The quantification of human movements is very hard because of the sparsity of traditional data and the labour intensive of the data collecting process. Recently, much spatial-temporal data give us an opportunity to observe human movement. This research investigates the relationship of city-wide human movements inferring from two types of spatial-temporal data at traffic analysis zone (TAZ) level. The first type of human movement is inferred from long-time smart card transaction data recording the boarding actions. The second type of human movement is extracted from citywide time sequenced mobile phone data with 30 minutes interval. Travel volume, travel distance and travel time are used to measure aggregated human movements in the city. To further examine the relationship between the two types of inferred movements, the linear correlation analysis is conducted on the hourly travel volume. The obtained results show that human movements inferred from smart card data and mobile phone data have a correlation of 0.635. However, there are still some non-ignorable differences in some special areas. This research not only reveals the citywide spatial-temporal human dynamic but also benefits the understanding of the reliability of the inference of human movements with big spatial-temporal data.

  8. COMPARISON OF URBAN HUMAN MOVEMENTS INFERRING FROM MULTI-SOURCE SPATIAL-TEMPORAL DATA

    Directory of Open Access Journals (Sweden)

    R. Cao

    2016-06-01

    Full Text Available The quantification of human movements is very hard because of the sparsity of traditional data and the labour intensive of the data collecting process. Recently, much spatial-temporal data give us an opportunity to observe human movement. This research investigates the relationship of city-wide human movements inferring from two types of spatial-temporal data at traffic analysis zone (TAZ level. The first type of human movement is inferred from long-time smart card transaction data recording the boarding actions. The second type of human movement is extracted from citywide time sequenced mobile phone data with 30 minutes interval. Travel volume, travel distance and travel time are used to measure aggregated human movements in the city. To further examine the relationship between the two types of inferred movements, the linear correlation analysis is conducted on the hourly travel volume. The obtained results show that human movements inferred from smart card data and mobile phone data have a correlation of 0.635. However, there are still some non-ignorable differences in some special areas. This research not only reveals the citywide spatial-temporal human dynamic but also benefits the understanding of the reliability of the inference of human movements with big spatial-temporal data.

  9. Concurrent Acoustic Activation of the Medial Olivocochlear System Modifies the After-Effects of Intense Low-Frequency Sound on the Human Inner Ear.

    Science.gov (United States)

    Kugler, Kathrin; Wiegrebe, Lutz; Gürkov, Robert; Krause, Eike; Drexl, Markus

    2015-12-01

    >Human hearing is rather insensitive for very low frequencies (i.e. below 100 Hz). Despite this insensitivity, low-frequency sound can cause oscillating changes of cochlear gain in inner ear regions processing even much higher frequencies. These alterations outlast the duration of the low-frequency stimulation by several minutes, for which the term 'bounce phenomenon' has been coined. Previously, we have shown that the bounce can be traced by monitoring frequency and level changes of spontaneous otoacoustic emissions (SOAEs) over time. It has been suggested elsewhere that large receptor potentials elicited by low-frequency stimulation produce a net Ca(2+) influx and associated gain decrease in outer hair cells. The bounce presumably reflects an underdamped, homeostatic readjustment of increased Ca(2+) concentrations and related gain changes after low-frequency sound offset. Here, we test this hypothesis by activating the medial olivocochlear efferent system during presentation of the bounce-evoking low-frequency (LF) sound. The efferent system is known to modulate outer hair cell Ca(2+) concentrations and receptor potentials, and therefore, it should modulate the characteristics of the bounce phenomenon. We show that simultaneous presentation of contralateral broadband noise (100 Hz-8 kHz, 65 and 70 dB SPL, 90 s, activating the efferent system) and ipsilateral low-frequency sound (30 Hz, 120 dB SPL, 90 s, inducing the bounce) affects the characteristics of bouncing SOAEs recorded after low-frequency sound offset. Specifically, the decay time constant of the SOAE level changes is shorter, and the transient SOAE suppression is less pronounced. Moreover, the number of new, transient SOAEs as they are seen during the bounce, are reduced. Taken together, activation of the medial olivocochlear system during induction of the bounce phenomenon with low-frequency sound results in changed characteristics of the bounce phenomenon. Thus, our data provide experimental support

  10. Spatio-Temporal Layout of Human Actions for Improved Bag-of-Words Action Detection

    NARCIS (Netherlands)

    Burghouts, G.J.; Schutte, K.

    2013-01-01

    We investigate how human action recognition can be improved by considering spatio-temporal layout of actions. From literature, we adopt a pipeline consisting of STIP features, a random forest to quantize the features into histograms, and an SVM classifier. Our goal is to detect 48 human actions,

  11. Human multipotent mesenchymal stromal cells in the treatment of postoperative temporal bone defect: an animal model

    Czech Academy of Sciences Publication Activity Database

    Školoudík, L.; Chrobok, V.; Kalfert, D.; Kočí, Zuzana; Syková, Eva; Chumak, Tetyana; Popelář, Jiří; Syka, Josef; Laco, J.; Dědková, J.; Dayanithi, Govindan; Filip, S.

    2016-01-01

    Roč. 25, č. 7 (2016), s. 1405-1414 ISSN 0963-6897 R&D Projects: GA MŠk(CZ) LO1309 Institutional support: RVO:68378041 Keywords : Human bone marrow * Human mesenchymal stromal cells (hMSCs) * Middle ear surgery * Temporal bone Subject RIV: FP - Other Medical Disciplines Impact factor: 3.006, year: 2016

  12. A method based on temporal concept analysis for detecting and profiling human trafficking suspects

    NARCIS (Netherlands)

    Poelmans, J.; Elzinga, P.; Viaene, S.; Dedene, G.; Hamza, M.H.

    2010-01-01

    Human trafficking and forced prostitution are a serious problem for the Amsterdam-Amstelland police (the Netherlands). In this paper, we present a method based on Temporal Concept Analysis for detecting and profiling human trafficking suspects. Using traditional Formal Concept Analysis, we first

  13. Locating the scala media in the fixed human temporal bone for therapeutic access: a preliminary study.

    Science.gov (United States)

    Pau, H; Fagan, P; Oleskevich, S

    2006-11-01

    To investigate the location of the scala media in relation to the round window niche in human temporal bones. Ten human temporal bones were investigated by radical mastoidectomy and promontory drill-out. Temporal bone laboratory. The distance from the scala media to the anterior edge of the round window niche, measured by Fisch's stapedectomy measuring cylinders. The scala media was identified at the transection point of a vertical line 1.6 to 2.2 mm (mean=1.8 mm; standard deviation=0.2) anterior to the anterior edge of the round window niche and a horizontal line 0.2 mm inferior to the lower border of the oval window. This report demonstrates the point of entry into the scala media via the promontory in fixed temporal bone models, which may provide a site of entry for stem cells and gene therapy insertion.

  14. Cortical oscillations in auditory perception and speech: evidence for two temporal windows in human auditory cortex

    Directory of Open Access Journals (Sweden)

    Huan eLuo

    2012-05-01

    Full Text Available Natural sounds, including vocal communication sounds, contain critical information at multiple time scales. Two essential temporal modulation rates in speech have been argued to be in the low gamma band (~20-80 ms duration information and the theta band (~150-300 ms, corresponding to segmental and syllabic modulation rates, respectively. On one hypothesis, auditory cortex implements temporal integration using time constants closely related to these values. The neural correlates of a proposed dual temporal window mechanism in human auditory cortex remain poorly understood. We recorded MEG responses from participants listening to non-speech auditory stimuli with different temporal structures, created by concatenating frequency-modulated segments of varied segment durations. We show that these non-speech stimuli with temporal structure matching speech-relevant scales (~25 ms and ~200 ms elicit reliable phase tracking in the corresponding associated oscillatory frequencies (low gamma and theta bands. In contrast, stimuli with non-matching temporal structure do not. Furthermore, the topography of theta band phase tracking shows rightward lateralization while gamma band phase tracking occurs bilaterally. The results support the hypothesis that there exists multi-time resolution processing in cortex on discontinuous scales and provide evidence for an asymmetric organization of temporal analysis (asymmetrical sampling in time, AST. The data argue for a macroscopic-level neural mechanism underlying multi-time resolution processing: the sliding and resetting of intrinsic temporal windows on privileged time scales.

  15. Tractography-based Parcellation of the Human Middle Temporal Gyrus

    Science.gov (United States)

    Xu, Jinping; Wang, Jiaojian; Fan, Lingzhong; Li, Hai; Zhang, Wen; Hu, Qingmao; Jiang, Tianzi

    2015-01-01

    The middle temporal gyrus (MTG) participates in a variety of functions, suggesting the existence of distinct functional subregions. In order to further delineate the functions of this brain area, we parcellated the MTG based on its distinct anatomical connectivity profiles and identified four distinct subregions, including the anterior (aMTG), middle (mMTG), posterior (pMTG), and sulcus (sMTG). Both the anatomical connectivity patterns and the resting-state functional connectivity patterns revealed distinct connectivity profiles for each subregion. The aMTG was primarily involved in the default mode network, sound recognition, and semantic retrieval. The mMTG was predominantly involved in the semantic memory and semantic control networks. The pMTG seems to be a part of the traditional sensory language area. The sMTG appears to be associated with decoding gaze direction and intelligible speech. Interestingly, the functional connectivity with Brodmann’s Area (BA) 40, BA 44, and BA 45 gradually increased from the anterior to the posterior MTG, a finding which indicated functional topographical organization as well as implying that language processing is functionally segregated in the MTG. These proposed subdivisions of the MTG and its functions contribute to understanding the complex functions of the MTG at the subregional level. PMID:26689815

  16. Temporal interaction between an artificial orchestra conductor and human musicians

    NARCIS (Netherlands)

    Reidsma, Dennis; Nijholt, Antinus; Bos, Pieter

    2008-01-01

    The Virtual Conductor project concerns the development of the first properly interactive virtual orchestra conductor—a Virtual Human that can conduct a piece of music through interaction with musicians, leading and following them while they are playing. This article describes our motivation for

  17. Magnetic resonance and diffusion tensor imaging analyses indicate heterogeneous strains along human medial gastrocnemius fascicles caused by submaximal plantar-flexion activity.

    Science.gov (United States)

    Karakuzu, Agah; Pamuk, Uluç; Ozturk, Cengizhan; Acar, Burak; Yucesoy, Can A

    2017-05-24

    Sarcomere length changes are central to force production and excursion of skeletal muscle. Previous modeling indicates non-uniformity of that if mechanical interaction of muscle with its surrounding muscular and connective tissues is taken into account. Hence, quantifying length changes along the fascicles of activated human muscle in vivo is crucial, but this is lacking due to technical complexities. Combining magnetic resonance imaging deformation analyses and diffusion tensor imaging tractography, the aim was to test the hypothesis that submaximal plantar flexion activity at 15% MVC causes heterogeneous length changes along the fascicles of human medial gastrocnemius (GM) muscle. A general fascicle strain distribution pattern shown for all subjects indicates that proximal track segments are shortened, whereas distal ones are lengthened (e.g., by 13% and 29%, respectively). Mean fiber direction strains of different tracts also shows heterogeneity (for up to 57.5% of the fascicles). Inter-subject variability of amplitude and distribution of fascicle strains is notable. These findings confirm the hypothesis and are solid indicators for the functionally dependent mechanics of human muscle, in vivo. Heterogeneity of fascicle strains can be explained by epimuscular myofascial force transmission. To the best of our knowledge, this is the first study, which quantified local deformations along human skeletal muscle fascicles caused by sustained submaximal activation. The present approach and indicated fascicle strain heterogeneity has numerous implications for muscle function in health and disease to estimate the muscle's contribution to the joint moment and excursion and to evaluate mechanisms of muscle injury and several treatment techniques. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. High-Throughput Data of Circular RNA Profiles in Human Temporal Cortex Tissue Reveals Novel Insights into Temporal Lobe Epilepsy.

    Science.gov (United States)

    Li, Jiaxin; Lin, Haijun; Sun, Zhenrong; Kong, Guanyi; Yan, Xu; Wang, Yujiao; Wang, Xiaoxuan; Wen, Yanhua; Liu, Xiang; Zheng, Hongkun; Jia, Mei; Shi, Zhongfang; Xu, Rong; Yang, Shaohua; Yuan, Fang

    2018-01-01

    Circular RNAs (circRNAs) are a class of long noncoding RNAs with a closed loop structure that regulate gene expression as microRNA sponges. CircRNAs are more enriched in brain tissue, but knowledge of the role of circRNAs in temporal lobe epilepsy (TLE) has remained limited. This study is the first to identify the global expression profiles and characteristics of circRNAs in human temporal cortex tissue from TLE patients. Temporal cortices were collected from 17 TLE patients and 17 non-TLE patients. Total RNA was isolated, and high-throughput sequencing was used to profile the transcriptome of dysregulated circRNAs. Quantitative PCR was performed for the validation of changed circRNAs. In total, 78983 circRNAs, including 15.29% known and 84.71% novel circRNAs, were detected in this study. Intriguingly, 442 circRNAs were differentially expressed between the TLE and non-TLE groups (fold change≥2.0 and FDR≤0.05). Of these circRNAs, 188 were up-regulated, and 254 were down-regulated in the TLE patient group. Eight circRNAs were validated by real-time PCR. Remarkably, circ-EFCAB2 was intensely up-regulated, while circ-DROSHA expression was significantly lower in the TLE group than in the non-TLE group (P<0.05). Bioinformatic analysis revealed that circ-EFCAB2 binds to miR-485-5p to increase the expression level of the ion channel CLCN6, while circ-DROSHA interacts with miR-1252-5p to decrease the expression level of ATP1A2. The dysregulations of circRNAs may reflect the pathogenesis of TLE and circ-EFCAB2 and circ-DROSHA might be potential therapeutic targets and biomarkers in TLE patients. © 2018 The Author(s). Published by S. Karger AG, Basel.

  19. Characterization of cognitive deficits in rats overexpressing human alpha-synuclein in the ventral tegmental area and medial septum using recombinant adeno-associated viral vectors.

    Science.gov (United States)

    Hall, Hélène; Jewett, Michael; Landeck, Natalie; Nilsson, Nathalie; Schagerlöf, Ulrika; Leanza, Giampiero; Kirik, Deniz

    2013-01-01

    Intraneuronal inclusions containing alpha-synuclein (a-syn) constitute one of the pathological hallmarks of Parkinson's disease (PD) and are accompanied by severe neurodegeneration of A9 dopaminergic neurons located in the substantia nigra. Although to a lesser extent, A10 dopaminergic neurons are also affected. Neurodegeneration of other neuronal populations, such as the cholinergic, serotonergic and noradrenergic cell groups, has also been documented in PD patients. Studies in human post-mortem PD brains and in rodent models suggest that deficits in cholinergic and dopaminergic systems may be associated with the cognitive impairment seen in this disease. Here, we investigated the consequences of targeted overexpression of a-syn in the mesocorticolimbic dopaminergic and septohippocampal cholinergic pathways. Rats were injected with recombinant adeno-associated viral vectors encoding for either human wild-type a-syn or green fluorescent protein (GFP) in the ventral tegmental area and the medial septum/vertical limb of the diagonal band of Broca, two regions rich in dopaminergic and cholinergic neurons, respectively. Histopathological analysis showed widespread insoluble a-syn positive inclusions in all major projections areas of the targeted nuclei, including the hippocampus, neocortex, nucleus accumbens and anteromedial striatum. In addition, the rats overexpressing human a-syn displayed an abnormal locomotor response to apomorphine injection and exhibited spatial learning and memory deficits in the Morris water maze task, in the absence of obvious spontaneous locomotor impairment. As losses in dopaminergic and cholinergic immunoreactivity in both the GFP and a-syn expressing animals were mild-to-moderate and did not differ from each other, the behavioral impairments seen in the a-syn overexpressing animals appear to be determined by the long term persisting neuropathology in the surviving neurons rather than by neurodegeneration.

  20. Nicotinamide Phosphoribosyltransferase in Smooth Muscle Cells Maintains Genome Integrity, Resists Aortic Medial Degeneration, and Is Suppressed in Human Thoracic Aortic Aneurysm Disease.

    Science.gov (United States)

    Watson, Alanna; Nong, Zengxuan; Yin, Hao; O'Neil, Caroline; Fox, Stephanie; Balint, Brittany; Guo, Linrui; Leo, Oberdan; Chu, Michael W A; Gros, Robert; Pickering, J Geoffrey

    2017-06-09

    The thoracic aortic wall can degenerate over time with catastrophic consequences. Vascular smooth muscle cells (SMCs) can resist and repair artery damage, but their capacities decline with age and stress. Recently, cellular production of nicotinamide adenine dinucleotide (NAD + ) via nicotinamide phosphoribosyltransferase (Nampt) has emerged as a mediator of cell vitality. However, a role for Nampt in aortic SMCs in vivo is unknown. To determine whether a Nampt-NAD + control system exists within the aortic media and is required for aortic health. Ascending aortas from patients with dilated aortopathy were immunostained for NAMPT, revealing an inverse relationship between SMC NAMPT content and aortic diameter. To determine whether a Nampt-NAD + control system in SMCs impacts aortic integrity, mice with Nampt -deficient SMCs were generated. SMC- Nampt knockout mice were viable but with mildly dilated aortas that had a 43% reduction in NAD + in the media. Infusion of angiotensin II led to aortic medial hemorrhage and dissection. SMCs were not apoptotic but displayed senescence associated-ß-galactosidase activity and upregulated p16, indicating premature senescence. Furthermore, there was evidence for oxidized DNA lesions, double-strand DNA strand breaks, and pronounced susceptibility to single-strand breakage. This was linked to suppressed poly(ADP-ribose) polymerase-1 activity and was reversible on resupplying NAD + with nicotinamide riboside. Remarkably, we discovered unrepaired DNA strand breaks in SMCs within the human ascending aorta, which were specifically enriched in SMCs with low NAMPT. NAMPT promoter analysis revealed CpG hypermethylation within the dilated human thoracic aorta and in SMCs cultured from these tissues, which inversely correlated with NAMPT expression. The aortic media depends on an intrinsic NAD + fueling system to protect against DNA damage and premature SMC senescence, with relevance to human thoracic aortopathy. © 2017 American Heart

  1. Human processing of short temporal intervals as revealed by an ERP waveform analysis

    Directory of Open Access Journals (Sweden)

    Yoshitaka eNakajima

    2011-12-01

    Full Text Available To clarify the time course over which the human brain processes information about durations up to ~300 ms, we reanalyzed the data that were previously reported by Mitsudo et al. (2009 using a multivariate analysis method. Event-related potentials were recorded from 19 scalp electrodes on 11 (9 original and 2 additional participants while they judged whether two neighboring empty time intervals—called t1 and t2 and marked by three tone bursts—had equal durations. There was also a control condition in which the participants were presented the same temporal patterns but without a judgment task. In the present reanalysis, we sought to visualize how the temporal patterns were represented in the brain over time. A correlation matrix across channels was calculated for each temporal pattern. Geometric separations between the correlation matrices were calculated, and subjected to multidimensional scaling. We performed such analyses for a moving 100-ms time window after the t1 presentations. In the windows centered at < 100 ms after the t2 presentation, the analyses revealed the local maxima of categorical separation between temporal patterns of perceptually equal durations versus perceptually unequal durations, both in the judgment condition and in the control condition. Such categorization of the temporal patterns was prominent only in narrow temporal regions. The analysis indicated that the participants determined whether the two neighboring time intervals were of equal duration mostly within 100 ms after the presentation of the temporal patterns. A very fast brain activity was related to the perception of elementary temporal patterns without explicit judgments. This is consistent with the findings of Mitsudo et al., and it is in line with the processing time hypothesis proposed by Nakajima et al. (2004. The validity of the correlation matrix analyses turned out to be an effective tool to grasp the overall responses of the brain to temporal

  2. Modelling temporal networks of human face-to-face contacts with public activity and individual reachability

    Science.gov (United States)

    Zhang, Yi-Qing; Cui, Jing; Zhang, Shu-Min; Zhang, Qi; Li, Xiang

    2016-02-01

    Modelling temporal networks of human face-to-face contacts is vital both for understanding the spread of airborne pathogens and word-of-mouth spreading of information. Although many efforts have been devoted to model these temporal networks, there are still two important social features, public activity and individual reachability, have been ignored in these models. Here we present a simple model that captures these two features and other typical properties of empirical face-to-face contact networks. The model describes agents which are characterized by an attractiveness to slow down the motion of nearby people, have event-triggered active probability and perform an activity-dependent biased random walk in a square box with periodic boundary. The model quantitatively reproduces two empirical temporal networks of human face-to-face contacts which are testified by their network properties and the epidemic spread dynamics on them.

  3. The Temporal Signature of Memories: Identification of a General Mechanism for Dynamic Memory Replay in Humans

    Science.gov (United States)

    Michelmann, Sebastian; Bowman, Howard; Hanslmayr, Simon

    2016-01-01

    Reinstatement of dynamic memories requires the replay of neural patterns that unfold over time in a similar manner as during perception. However, little is known about the mechanisms that guide such a temporally structured replay in humans, because previous studies used either unsuitable methods or paradigms to address this question. Here, we overcome these limitations by developing a new analysis method to detect the replay of temporal patterns in a paradigm that requires participants to mentally replay short sound or video clips. We show that memory reinstatement is accompanied by a decrease of low-frequency (8 Hz) power, which carries a temporal phase signature of the replayed stimulus. These replay effects were evident in the visual as well as in the auditory domain and were localized to sensory-specific regions. These results suggest low-frequency phase to be a domain-general mechanism that orchestrates dynamic memory replay in humans. PMID:27494601

  4. The Temporal Signature of Memories: Identification of a General Mechanism for Dynamic Memory Replay in Humans.

    Directory of Open Access Journals (Sweden)

    Sebastian Michelmann

    2016-08-01

    Full Text Available Reinstatement of dynamic memories requires the replay of neural patterns that unfold over time in a similar manner as during perception. However, little is known about the mechanisms that guide such a temporally structured replay in humans, because previous studies used either unsuitable methods or paradigms to address this question. Here, we overcome these limitations by developing a new analysis method to detect the replay of temporal patterns in a paradigm that requires participants to mentally replay short sound or video clips. We show that memory reinstatement is accompanied by a decrease of low-frequency (8 Hz power, which carries a temporal phase signature of the replayed stimulus. These replay effects were evident in the visual as well as in the auditory domain and were localized to sensory-specific regions. These results suggest low-frequency phase to be a domain-general mechanism that orchestrates dynamic memory replay in humans.

  5. Ipsilateral Medial and Lateral Discoid Meniscus with Medial Meniscus Tear

    OpenAIRE

    Shimozaki, Kengo; Nakase, Junsuke; Ohashi, Yoshinori; Numata, Hitoaki; Oshima, Takeshi; Takata, Yasushi; Tsuchiya, Hiroyuki

    2016-01-01

    Introduction: Discoid meniscus is a well-documented knee pathology, and there are many cases of medial or lateral discoid meniscus reported in the literature. However, ipsilateral concurrent medial and lateral discoid meniscus is very rare, and only a few cases have been reported. Herein, we report a case of concurrent medial and lateral discoid meniscus. Case Report: A 27-year-old Japanese man complained of pain on medial joint space in his right knee that was diagnosed as a complete medial ...

  6. Spatial and temporal patterns of human Puumala virus (PUUV infections in Germany

    Directory of Open Access Journals (Sweden)

    Sarah Cunze

    2018-02-01

    Full Text Available Background Worldwide, the number of recorded human hantavirus infections as well as the number of affected countries is on the rise. In Europe, most human hantavirus infections are caused by the Puumala virus (PUUV, with bank voles (Myodes glareolus as reservoir hosts. Generally, infection outbreaks have been related to environmental conditions, particularly climatic conditions, food supply for the reservoir species and land use. However, although attempts have been made, the insufficient availability of environmental data is often hampering accurate temporal and spatially explicit models of human hantavirus infections. Methods In the present study, dynamics of human PUUV infections between 2001 and 2015 were explored using ArcGIS in order to identify spatio-temporal patterns. Results Percentage cover of forest area was identified as an important factor for the spatial pattern, whereas beech mast was found explaining temporal patterns of human PUUV infections in Germany. High numbers of infections were recorded in 2007, 2010 and 2012 and areas with highest records were located in Baden-Wuerttemberg (southwest Germany and North Rhine-Westphalia (western Germany. Conclusion More reliable data on reservoir host distribution, pathogen verification as well as an increased awareness of physicians are some of the factors that should improve future human infection risk assessments in Germany.

  7. Time reversibility of intracranial human EEG recordings in mesial temporal lobe epilepsy

    Science.gov (United States)

    van der Heyden, M. J.; Diks, C.; Pijn, J. P. M.; Velis, D. N.

    1996-02-01

    Intracranial electroencephalograms from patients suffering from mesial temporal lobe epilepsy were tested for time reversibility. If the recorded time series is irreversible, the input of the recording system cannot be a realisation of a linear Gaussian random process. We confirmed experimentally that the measurement equipment did not introduce irreversibility in the recorded output when the input was a realisation of a linear Gaussian random process. In general, the non-seizure recordings are reversible, whereas the seizure recordings are irreversible. These results suggest that time reversibility is a useful property for the characterisation of human intracranial EEG recordings in mesial temporal lobe epilepsy.

  8. High-field magnetic resonance imaging of the human temporal lobe

    Directory of Open Access Journals (Sweden)

    Luis M. Colon-Perez

    2015-01-01

    Conclusions: Fresh ex vivo MR imaging, along with tractography, revealed complex intra-temporal structural variation corresponding to neuronal cell body layers, dendritic fields, and axonal projection systems evident histologically. This is the first study to describe in detail the human temporal lobe structural organization using high-field MR imaging and tractography. By preserving the 3-dimensional structures of the hippocampus and surrounding structures, specific changes in anatomy may inform us about the changes that occur in TLE in relation to the disease process and structural underpinnings in epilepsy-related memory dysfunction.

  9. Towards human behavior recognition based on spatio temporal features and support vector machines

    Science.gov (United States)

    Ghabri, Sawsen; Ouarda, Wael; Alimi, Adel M.

    2017-03-01

    Security and surveillance are vital issues in today's world. The recent acts of terrorism have highlighted the urgent need for efficient surveillance. There is indeed a need for an automated system for video surveillance which can detect identity and activity of person. In this article, we propose a new paradigm to recognize an aggressive human behavior such as boxing action. Our proposed system for human activity detection includes the use of a fusion between Spatio Temporal Interest Point (STIP) and Histogram of Oriented Gradient (HoG) features. The novel feature called Spatio Temporal Histogram Oriented Gradient (STHOG). To evaluate the robustness of our proposed paradigm with a local application of HoG technique on STIP points, we made experiments on KTH human action dataset based on Multi Class Support Vector Machines classification. The proposed scheme outperforms basic descriptors like HoG and STIP to achieve 82.26% us an accuracy value of classification rate.

  10. Human Superior Temporal Gyrus Organization of Spectrotemporal Modulation Tuning Derived from Speech Stimuli.

    Science.gov (United States)

    Hullett, Patrick W; Hamilton, Liberty S; Mesgarani, Nima; Schreiner, Christoph E; Chang, Edward F

    2016-02-10

    The human superior temporal gyrus (STG) is critical for speech perception, yet the organization of spectrotemporal processing of speech within the STG is not well understood. Here, to characterize the spatial organization of spectrotemporal processing of speech across human STG, we use high-density cortical surface field potential recordings while participants listened to natural continuous speech. While synthetic broad-band stimuli did not yield sustained activation of the STG, spectrotemporal receptive fields could be reconstructed from vigorous responses to speech stimuli. We find that the human STG displays a robust anterior-posterior spatial distribution of spectrotemporal tuning in which the posterior STG is tuned for temporally fast varying speech sounds that have relatively constant energy across the frequency axis (low spectral modulation) while the anterior STG is tuned for temporally slow varying speech sounds that have a high degree of spectral variation across the frequency axis (high spectral modulation). This work illustrates organization of spectrotemporal processing in the human STG, and illuminates processing of ethologically relevant speech signals in a region of the brain specialized for speech perception. Considerable evidence has implicated the human superior temporal gyrus (STG) in speech processing. However, the gross organization of spectrotemporal processing of speech within the STG is not well characterized. Here we use natural speech stimuli and advanced receptive field characterization methods to show that spectrotemporal features within speech are well organized along the posterior-to-anterior axis of the human STG. These findings demonstrate robust functional organization based on spectrotemporal modulation content, and illustrate that much of the encoded information in the STG represents the physical acoustic properties of speech stimuli. Copyright © 2016 the authors 0270-6474/16/362014-13$15.00/0.

  11. Arthroscopic partial medial meniscectomy

    Directory of Open Access Journals (Sweden)

    Dašić Žarko

    2011-01-01

    Full Text Available Background/Aim. Meniscal injuries are common in professional or recreational sports as well as in daily activities. If meniscal lesions lead to physical impairment they usually require surgical treatment. Arthroscopic treatment of meniscal injuries is one of the most often performed orthopedic operative procedures. Methods. The study analyzed the results of arthroscopic partial medial meniscectomy in 213 patients in a 24-month period, from 2006, to 2008. Results. In our series of arthroscopically treated medial meniscus tears we noted 78 (36.62% vertical complete bucket handle lesions, 19 (8.92% vertical incomplete lesions, 18 (8.45% longitudinal tears, 35 (16.43% oblique tears, 18 (8.45% complex degenerative lesions, 17 (7.98% radial lesions and 28 (13.14% horisontal lesions. Mean preoperative International Knee Documentation Committee (IKDC score was 49.81%, 1 month after the arthroscopic partial medial meniscectomy the mean IKDC score was 84.08%, and 6 months after mean IKDC score was 90.36%. Six months after the procedure 197 (92.49% of patients had good or excellent subjective postoperative clinical outcomes, while 14 (6.57% patients subjectively did not notice a significant improvement after the intervention, and 2 (0.93% patients had no subjective improvement after the partial medial meniscectomy at all. Conclusion. Arthroscopic partial medial meniscetomy is minimally invasive diagnostic and therapeutic procedure and in well selected cases is a method of choice for treatment of medial meniscus injuries when repair techniques are not a viable option. It has small rate of complications, low morbidity and fast rehabilitation.

  12. Fetal development of deep back muscles in the human thoracic region with a focus on transversospinalis muscles and the medial branch of the spinal nerve posterior ramus

    Science.gov (United States)

    Sato, Tatsuo; Koizumi, Masahiro; Kim, Ji Hyun; Kim, Jeong Hyun; Wang, Bao Jian; Murakami, Gen; Cho, Baik Hwan

    2011-01-01

    Fetal development of human deep back muscles has not yet been fully described, possibly because of the difficulty in identifying muscle bundle directions in horizontal sections. Here, we prepared near-frontal sections along the thoracic back skin (eight fetuses) as well as horizontal sections (six fetuses) from 14 mid-term fetuses at 9–15 weeks of gestation. In the deep side of the trapezius and rhomboideus muscles, the CD34-positive thoracolumbar fascia was evident even at 9 weeks. Desmin-reactivity was strong and homogeneous in the superficial muscle fibers in contrast to the spotty expression in the deep fibers. Thus, in back muscles, formation of the myotendinous junction may start from the superficial muscles and advance to the deep muscles. The fact that developing intramuscular tendons were desmin-negative suggested little possibility of a secondary change from the muscle fibers to tendons. We found no prospective spinalis muscle or its tendinous connections with other muscles. Instead, abundant CD68-positive macrophages along the spinous process at 15 weeks suggested a change in muscle attachment, an event that may result in a later formation of the spinalis muscle. S100-positive intramuscular nerves exhibited downward courses from the multifidus longus muscle in the original segment to the rotatores brevis muscles in the inferiorly adjacent level. The medial cutaneous nerve had already reached the thoracolumbar fascia at 9 weeks, but by 15 weeks the nerve could not penetrate the trapezius muscle. Finally, we propose a folded myotomal model of the primitive transversospinalis muscle that seems to explain a fact that the roofing tile-like configuration of nerve twigs in the semispinalis muscle is reversed in the multifidus and rotatores muscles. PMID:21954879

  13. Bayesian spatio-temporal analysis and geospatial risk factors of human monocytic ehrlichiosis.

    Directory of Open Access Journals (Sweden)

    Ram K Raghavan

    Full Text Available Variations in spatio-temporal patterns of Human Monocytic Ehrlichiosis (HME infection in the state of Kansas, USA were examined and the relationship between HME relative risk and various environmental, climatic and socio-economic variables were evaluated. HME data used in the study was reported to the Kansas Department of Health and Environment between years 2005-2012, and geospatial variables representing the physical environment [National Land cover/Land use, NASA Moderate Resolution Imaging Spectroradiometer (MODIS], climate [NASA MODIS, Prediction of Worldwide Renewable Energy (POWER], and socio-economic conditions (US Census Bureau were derived from publicly available sources. Following univariate screening of candidate variables using logistic regressions, two Bayesian hierarchical models were fit; a partial spatio-temporal model with random effects and a spatio-temporal interaction term, and a second model that included additional covariate terms. The best fitting model revealed that spatio-temporal autocorrelation in Kansas increased steadily from 2005-2012, and identified poverty status, relative humidity, and an interactive factor, 'diurnal temperature range x mixed forest area' as significant county-level risk factors for HME. The identification of significant spatio-temporal pattern and new risk factors are important in the context of HME prevention, for future research in the areas of ecology and evolution of HME, and as well as climate change impacts on tick-borne diseases.

  14. High-resolution temporal and regional mapping of MAPT expression and splicing in human brain development.

    Science.gov (United States)

    Hefti, Marco M; Farrell, Kurt; Kim, SoongHo; Bowles, Kathryn R; Fowkes, Mary E; Raj, Towfique; Crary, John F

    2018-01-01

    The microtubule associated protein tau plays a critical role in the pathogenesis of neurodegenerative disease. Recent studies suggest that tau also plays a role in disorders of neuronal connectivity, including epilepsy and post-traumatic stress disorder. Animal studies have shown that the MAPT gene, which codes for the tau protein, undergoes complex pre-mRNA alternative splicing to produce multiple isoforms during brain development. Human data, particularly on temporal and regional variation in tau splicing during development are however lacking. In this study, we present the first detailed examination of the temporal and regional sequence of MAPT alternative splicing in the developing human brain. We used a novel computational analysis of large transcriptomic datasets (total n = 502 patients), quantitative polymerase chain reaction (qPCR) and western blotting to examine tau expression and splicing in post-mortem human fetal, pediatric and adult brains. We found that MAPT exons 2 and 10 undergo abrupt shifts in expression during the perinatal period that are unique in the canonical human microtubule-associated protein family, while exon 3 showed small but significant temporal variation. Tau isoform expression may be a marker of neuronal maturation, temporally correlated with the onset of axonal growth. Immature brain regions such as the ganglionic eminence and rhombic lip had very low tau expression, but within more mature regions, there was little variation in tau expression or splicing. We thus demonstrate an abrupt, evolutionarily conserved shift in tau isoform expression during the human perinatal period that may be due to tau expression in maturing neurons. Alternative splicing of the MAPT pre-mRNA may play a vital role in normal brain development across multiple species and provides a basis for future investigations into the developmental and pathological functions of the tau protein.

  15. Patterns of morphological integration between parietal and temporal areas in the human skull.

    Science.gov (United States)

    Bruner, Emiliano; Pereira-Pedro, Ana Sofia; Bastir, Markus

    2017-10-01

    Modern humans have evolved bulging parietal areas and large, projecting temporal lobes. Both changes, largely due to a longitudinal expansion of these cranial and cerebral elements, were hypothesized to be the result of brain evolution and cognitive variations. Nonetheless, the independence of these two morphological characters has not been evaluated. Because of structural and functional integration among cranial elements, changes in the position of the temporal poles can be a secondary consequence of parietal bulging and reorientation of the head axis. In this study, we use geometric morphometrics to test the correlation between parietal shape and the morphology of the endocranial base in a sample of adult modern humans. Our results suggest that parietal proportions show no correlation with the relative position of the temporal poles within the spatial organization of the endocranial base. The vault and endocranial base are likely to be involved in distinct morphogenetic processes, with scarce or no integration between these two districts. Therefore, the current evidence rejects the hypothesis of reciprocal morphological influences between parietal and temporal morphology, suggesting that evolutionary spatial changes in these two areas may have been independent. However, parietal bulging exerts a visible effect on the rotation of the cranial base, influencing head position and orientation. This change can have had a major relevance in the reorganization of the head functional axis. © 2017 Wiley Periodicals, Inc.

  16. Temporal overlap of humans and giant lizards (Varanidae; Squamata) in Pleistocene Australia

    Science.gov (United States)

    Price, Gilbert J.; Louys, Julien; Cramb, Jonathan; Feng, Yue-xing; Zhao, Jian-xin; Hocknull, Scott A.; Webb, Gregory E.; Nguyen, Ai Duc; Joannes-Boyau, Renaud

    2015-10-01

    An obvious but key prerequisite to testing hypotheses concerning the role of humans in the extinction of late Quaternary 'megafauna' is demonstrating that humans and the extinct taxa overlapped, both temporally and spatially. In many regions, a paucity of reliably dated fossil occurrences of megafauna makes it challenging, if not impossible, to test many of the leading extinction hypotheses. The giant monitor lizards of Australia are a case in point. Despite commonly being argued to have suffered extinction at the hands of the first human colonisers (who arrived by 50 ka), it has never been reliably demonstrated that giant monitors and humans temporally overlapped in Australia. Here we present the results of an integrated U-Th and 14C dating study of a late Pleistocene fossil deposit that has yielded the youngest dated remains of giant monitor lizards in Australia. The site, Colosseum Chamber, is a cave deposit in the Mt Etna region, central eastern Australia. Sixteen new dates were generated and demonstrate that the bulk of the material in the deposit accumulated since ca. 50 ka. The new monitor fossil is, minimally, 30 ky younger than the previous youngest reliably dated record for giant lizards in Australia and for the first time, demonstrates that on a continental scale, humans and giant lizards overlapped in time. The new record brings the existing geochronological dataset for Australian giant monitor lizards to seven dated occurrences. With such sparse data, we are hesitant to argue that our new date represents the time of their extinction from the continent. Rather, we suspect that future fossil collecting will yield new samples both older and younger than 50 ka. Nevertheless, we unequivocally demonstrate that humans and giant monitor lizards overlapped temporally in Australia, and thus, humans can only now be considered potential drivers for their extinction.

  17. Neutrophil Extracellular Traps and Fibrin in Otitis Media: Analysis of Human and Chinchilla Temporal Bones.

    Science.gov (United States)

    Schachern, Patricia A; Kwon, Geeyoun; Briles, David E; Ferrieri, Patricia; Juhn, Steven; Cureoglu, Sebahattin; Paparella, Michael M; Tsuprun, Vladimir

    2017-10-01

    Bacterial resistance in acute otitis can result in bacterial persistence and biofilm formation, triggering chronic and recurrent infections. To investigate the middle ear inflammatory response to bacterial infection in human and chinchilla temporal bones. Six chinchillas underwent intrabullar inoculations with 0.5 mL of 106 colony-forming units (CFUs) of Streptococcus pneumoniae, serotype 2. Two days later, we counted bacteria in middle ear effusions postmortem. One ear from each chinchilla was processed in paraffin and sectioned at 5 µm. The opposite ear was embedded in epoxy resin, sectioned at a thickness of 1 µm, and stained with toluidine blue. In addition, we examined human temporal bones from 2 deceased donors with clinical histories of otitis media (1 with acute onset otitis media, 1 with recurrent infection). Temporal bones had been previously removed at autopsy, processed, embedded in celloidin, and cut at a thickness of 20 µm. Sections of temporal bones from both chinchillas and humans were stained with hematoxylin-eosin and immunolabeled with antifibrin and antihistone H4 antibodies. Histopatological and imminohistochemical changes owing to otitis media. Bacterial counts in chinchilla middle ear effusions 2 days after inoculation were approximately 2 logs above initial inoculum counts. Both human and chinchilla middle ear effusions contained bacteria embedded in a fibrous matrix. Some fibers in the matrix showed positive staining with antifibrin antibody, others with antihistone H4 antibody. In acute and recurrent otitis media, fibrin and neutrophil extracellular traps (NETs) are part of the host inflammatory response to bacterial infection. In the early stages of otitis media the host defense system uses fibrin to entrap bacteria, and NETs function to eliminate bacteria. In chronic otitis media, fibrin and NETs appear to persist.

  18. Temporal characteristics of the influence of punishment on perceptual decision making in the human brain

    OpenAIRE

    Blank, H.; Guido, B.; Heekeren, H.R.; Philiastides, M.G.

    2013-01-01

    Perceptual decision making is the process by which information from sensory systems is combined and used to influence our behavior. In addition to the sensory input, this process can be affected by other factors, such as reward and punishment for correct and incorrect responses. To investigate the temporal dynamics of how monetary punishment influences perceptual decision making in humans, we collected electroencephalography (EEG) data during a perceptual categorization task whereby the punis...

  19. Predators or prey? Spatio-temporal discrimination of human-derived risk by brown bears.

    Science.gov (United States)

    Ordiz, Andrés; Støen, Ole-Gunnar; Delibes, Miguel; Swenson, Jon E

    2011-05-01

    Prey usually adjust anti-predator behavior to subtle variations in perceived risk. However, it is not clear whether adult large carnivores that are virtually free of natural predation adjust their behavior to subtle variations in human-derived risk, even when living in human-dominated landscapes. As a model, we studied resting-site selection by a large carnivore, the brown bear (Ursus arctos), under different spatial and temporal levels of human activity. We quantified horizontal and canopy cover at 440 bear beds and 439 random sites at different distances from human settlements, seasons, and times of the day. We hypothesized that beds would be more concealed than random sites and that beds would be more concealed in relation to human-derived risk. Although human densities in Scandinavia are the lowest within bear ranges in Western Europe, we found an effect of human activity; bears chose beds with higher horizontal and canopy cover during the day (0700-1900 hours), especially when resting closer to human settlements, than at night (2200-0600 hours). In summer/fall (the berry season), with more intensive and dispersed human activity, including hunting, bears rested further from human settlements during the day than in spring (pre-berry season). Additionally, day beds in the summer/fall were the most concealed. Large carnivores often avoid humans at a landscape scale, but total avoidance in human-dominated areas is not possible. Apparently, bears adjust their behavior to avoid human encounters, which resembles the way prey avoid their predators. Bears responded to fine-scale variations in human-derived risk, both on a seasonal and a daily basis.

  20. Does sex matter? Temporal and spatial patterns of cougar-human conflict in British Columbia.

    Science.gov (United States)

    Teichman, Kristine J; Cristescu, Bogdan; Nielsen, Scott E

    2013-01-01

    Wildlife-human conflicts occur wherever large carnivores overlap human inhabited areas. Conflict mitigation can be facilitated by understanding long-term dynamics and examining sex-structured conflict patterns. Predicting areas with high probability of conflict helps focus management strategies in order to proactively decrease carnivore mortality. We investigated the importance of cougar (Puma concolor) habitat, human landscape characteristics and the combination of habitat and human features on the temporal and spatial patterns of cougar-human conflicts in British Columbia. Conflicts (n = 1,727; 1978-2007) involved similar numbers of male and female cougars with conflict rate decreasing over the past decade. Conflicts were concentrated within the southern part of the province with the most conflicts per unit area occurring on Vancouver Island. For both sexes, the most supported spatial models for the most recent (1998-2007) conflicts contained both human and habitat variables. Conflicts were more likely to occur close to roads, at intermediate elevations and far from the northern edge of the cougar distribution range in British Columbia. Male cougar conflicts were more likely to occur in areas of intermediate human density. Unlike cougar conflicts in other regions, cattle density was not a significant predictor of conflict location. With human populations expanding, conflicts are expected to increase. Conservation tools, such as the maps predicting conflict hotspots from this study, can help focus management efforts to decrease carnivore-human conflict.

  1. Does sex matter? Temporal and spatial patterns of cougar-human conflict in British Columbia.

    Directory of Open Access Journals (Sweden)

    Kristine J Teichman

    Full Text Available Wildlife-human conflicts occur wherever large carnivores overlap human inhabited areas. Conflict mitigation can be facilitated by understanding long-term dynamics and examining sex-structured conflict patterns. Predicting areas with high probability of conflict helps focus management strategies in order to proactively decrease carnivore mortality. We investigated the importance of cougar (Puma concolor habitat, human landscape characteristics and the combination of habitat and human features on the temporal and spatial patterns of cougar-human conflicts in British Columbia. Conflicts (n = 1,727; 1978-2007 involved similar numbers of male and female cougars with conflict rate decreasing over the past decade. Conflicts were concentrated within the southern part of the province with the most conflicts per unit area occurring on Vancouver Island. For both sexes, the most supported spatial models for the most recent (1998-2007 conflicts contained both human and habitat variables. Conflicts were more likely to occur close to roads, at intermediate elevations and far from the northern edge of the cougar distribution range in British Columbia. Male cougar conflicts were more likely to occur in areas of intermediate human density. Unlike cougar conflicts in other regions, cattle density was not a significant predictor of conflict location. With human populations expanding, conflicts are expected to increase. Conservation tools, such as the maps predicting conflict hotspots from this study, can help focus management efforts to decrease carnivore-human conflict.

  2. The medial patellofemoral complex.

    Science.gov (United States)

    Loeb, Alexander E; Tanaka, Miho J

    2018-06-01

    The purpose of this review is to describe the current understanding of the medial patellofemoral complex, including recent anatomic advances, evaluation of indications for reconstruction with concomitant pathology, and surgical reconstruction techniques. Recent advances in our understanding of MPFC anatomy have found that there are fibers that insert onto the deep quadriceps tendon as well as the patella, thus earning the name "medial patellofemoral complex" to allow for the variability in its anatomy. In MPFC reconstruction, anatomic origin and insertion points and appropriate graft length are critical to prevent overconstraint of the patellofemoral joint. The MPFC is a crucial soft tissue checkrein to lateral patellar translation, and its repair or reconstruction results in good restoration of patellofemoral stability. As our understanding of MPFC anatomy evolves, further studies are needed to apply its relevance in kinematics and surgical applications to its role in maintaining patellar stability.

  3. Displacement of the medial meniscus within the passive motion characteristics of the human knee joint: an RSA study in human cadaver knees.

    NARCIS (Netherlands)

    Tienen, T. van; Buma, P.; Scholten, J.G.; Kampen, A. van; Veth, R.P.H.; Verdonschot, N.J.J.

    2005-01-01

    The objective of this study was to validate an in vitro human cadaver knee-joint model for the evaluation of the meniscal movement during knee-joint flexion. The question was whether our model showed comparable meniscal displacements to those found in earlier meniscal movement studies in vivo.

  4. Interactions between the spatial and temporal stimulus factors that influence multisensory integration in human performance.

    Science.gov (United States)

    Stevenson, Ryan A; Fister, Juliane Krueger; Barnett, Zachary P; Nidiffer, Aaron R; Wallace, Mark T

    2012-05-01

    In natural environments, human sensory systems work in a coordinated and integrated manner to perceive and respond to external events. Previous research has shown that the spatial and temporal relationships of sensory signals are paramount in determining how information is integrated across sensory modalities, but in ecologically plausible settings, these factors are not independent. In the current study, we provide a novel exploration of the impact on behavioral performance for systematic manipulations of the spatial location and temporal synchrony of a visual-auditory stimulus pair. Simple auditory and visual stimuli were presented across a range of spatial locations and stimulus onset asynchronies (SOAs), and participants performed both a spatial localization and simultaneity judgment task. Response times in localizing paired visual-auditory stimuli were slower in the periphery and at larger SOAs, but most importantly, an interaction was found between the two factors, in which the effect of SOA was greater in peripheral as opposed to central locations. Simultaneity judgments also revealed a novel interaction between space and time: individuals were more likely to judge stimuli as synchronous when occurring in the periphery at large SOAs. The results of this study provide novel insights into (a) how the speed of spatial localization of an audiovisual stimulus is affected by location and temporal coincidence and the interaction between these two factors and (b) how the location of a multisensory stimulus impacts judgments concerning the temporal relationship of the paired stimuli. These findings provide strong evidence for a complex interdependency between spatial location and temporal structure in determining the ultimate behavioral and perceptual outcome associated with a paired multisensory (i.e., visual-auditory) stimulus.

  5. Fast Temporal Activity Proposals for Efficient Detection of Human Actions in Untrimmed Videos

    KAUST Repository

    Heilbron, Fabian Caba; Niebles, Juan Carlos; Ghanem, Bernard

    2016-01-01

    In many large-scale video analysis scenarios, one is interested in localizing and recognizing human activities that occur in short temporal intervals within long untrimmed videos. Current approaches for activity detection still struggle to handle large-scale video collections and the task remains relatively unexplored. This is in part due to the computational complexity of current action recognition approaches and the lack of a method that proposes fewer intervals in the video, where activity processing can be focused. In this paper, we introduce a proposal method that aims to recover temporal segments containing actions in untrimmed videos. Building on techniques for learning sparse dictionaries, we introduce a learning framework to represent and retrieve activity proposals. We demonstrate the capabilities of our method in not only producing high quality proposals but also in its efficiency. Finally, we show the positive impact our method has on recognition performance when it is used for action detection, while running at 10FPS.

  6. Fast Temporal Activity Proposals for Efficient Detection of Human Actions in Untrimmed Videos

    KAUST Repository

    Heilbron, Fabian Caba

    2016-12-13

    In many large-scale video analysis scenarios, one is interested in localizing and recognizing human activities that occur in short temporal intervals within long untrimmed videos. Current approaches for activity detection still struggle to handle large-scale video collections and the task remains relatively unexplored. This is in part due to the computational complexity of current action recognition approaches and the lack of a method that proposes fewer intervals in the video, where activity processing can be focused. In this paper, we introduce a proposal method that aims to recover temporal segments containing actions in untrimmed videos. Building on techniques for learning sparse dictionaries, we introduce a learning framework to represent and retrieve activity proposals. We demonstrate the capabilities of our method in not only producing high quality proposals but also in its efficiency. Finally, we show the positive impact our method has on recognition performance when it is used for action detection, while running at 10FPS.

  7. Demographic and spatio-temporal variation in human plague at a persistent focus in Tanzania

    DEFF Research Database (Denmark)

    Davis, S; Makundi, R H; Machang'u, R S

    2006-01-01

    Human plague in the Western Usambara Mountains in Tanzania has been a public health problem since the first outbreak in 1980. The wildlife reservoir is unknown and eradication measures that have proved effective elsewhere in Tanzania appear to fail in this region. We use census data from 2002...... and hospital records kept since 1986 to describe the temporal, spatial and demographic variation in human plague. A seasonal peak in cases occurs from December to February with the numbers of cases during this peak varying between 0 and 1150. Variation in incidence, calculated for each village as the mean...... number of cases per thousand inhabitants per year, indicates that human plague is concentrated around a group of three neighbouring, relatively isolated, high-altitude villages; Nywelo, Madala and Gologolo. However, there was no evidence that these villages were acting as a source of infection...

  8. Temporal expression pattern of genes during the period of sex differentiation in human embryonic gonads

    DEFF Research Database (Denmark)

    Mamsen, Linn S; Ernst, Emil H; Borup, Rehannah

    2017-01-01

    The precise timing and sequence of changes in expression of key genes and proteins during human sex-differentiation and onset of steroidogenesis was evaluated by whole-genome expression in 67 first trimester human embryonic and fetal ovaries and testis and confirmed by qPCR and immunohistochemistry...... (IHC). SRY/SOX9 expression initiated in testis around day 40 pc, followed by initiation of AMH and steroidogenic genes required for androgen production at day 53 pc. In ovaries, gene expression of RSPO1, LIN28, FOXL2, WNT2B, and ETV5, were significantly higher than in testis, whereas GLI1...... was significantly higher in testis than ovaries. Gene expression was confirmed by IHC for GAGE, SOX9, AMH, CYP17A1, LIN28, WNT2B, ETV5 and GLI1. Gene expression was not associated with the maternal smoking habits. Collectively, a precise temporal determination of changes in expression of key genes involved in human...

  9. Changes in flip/flop splicing of astroglial AMPA receptors in human temporal lobe epilepsy.

    Science.gov (United States)

    Seifert, Gerald; Schröder, Wolfgang; Hinterkeuser, Stefan; Schumacher, Thekla; Schramm, Johannes; Steinhäuser, Christian

    2002-01-01

    Recent data suggested a role for glial cells in epilepsy. This study sought to identify and functionally characterize AMPA receptors expressed by astrocytes in human hippocampal tissue resected from patients with intractable temporal lobe epilepsy. Patch-clamp and fast application methods were combined to investigate astrocytes in situ and after fresh isolation from the stratum radiatum of the hippocampal CA1 subfield. Relying on presurgical and histopathologic analysis, we divided human specimens into two groups, Ammon's horn sclerosis (AHS) and lesion-associated epilepsy. Fast application of glutamate and kainate evoked receptor currents in all cells studied. Reversal-potential analysis revealed an intermediate Ca2+ permeability of the receptor channels that did not vary between the two groups of patients. However, preapplication of the AMPA receptor-specific modulator, cyclothiazide, disclosed differences in flip-flop splicing. This treatment considerably enhanced the receptor conductance, with potentiation being significantly stronger in cells from AHS specimens compared with lesion-associated cells, suggesting upregulation of AMPA receptor flip splice variants in astrocytes of the sclerotic tissue. Compelling evidence has been accumulated showing direct and rapid signaling between neurons and glial cells. Our data suggest that in AHS patients, neuronally released glutamate will lead to an enhanced and prolonged depolarization of astrocytes, which might be involved in seizure generation and spread in this particular condition of human temporal lobe epilepsy.

  10. Spatio-temporal epidemiology of human West Nile virus disease in South Dakota.

    Science.gov (United States)

    Wimberly, Michael C; Giacomo, Paolla; Kightlinger, Lon; Hildreth, Michael B

    2013-10-29

    Despite a cold temperate climate and low human population density, the Northern Great Plains has become a persistent hot spot for human West Nile virus (WNV) disease in North America. Understanding the spatial and temporal patterns of WNV can provide insights into the epidemiological and ecological factors that influence disease emergence and persistence. We analyzed the 1,962 cases of human WNV disease that occurred in South Dakota from 2002-2012 to identify the geographic distribution, seasonal cycles, and interannual variability of disease risk. The geographic and seasonal patterns of WNV have changed since the invasion and initial epidemic in 2002-2003, with cases shifting toward the eastern portion of South Dakota and occurring earlier in the transmission season in more recent years. WNV cases were temporally autocorrelated at lags of up to six weeks and early season cumulative case numbers were correlated with seasonal totals, indicating the possibility of using these data for short-term early detection of outbreaks. Epidemiological data are likely to be most effective for early warning of WNV virus outbreaks if they are integrated with entomological surveillance and environmental monitoring to leverage the strengths and minimize the weaknesses of each information source.

  11. Frequency-Selective Attention in Auditory Scenes Recruits Frequency Representations Throughout Human Superior Temporal Cortex.

    Science.gov (United States)

    Riecke, Lars; Peters, Judith C; Valente, Giancarlo; Kemper, Valentin G; Formisano, Elia; Sorger, Bettina

    2017-05-01

    A sound of interest may be tracked amid other salient sounds by focusing attention on its characteristic features including its frequency. Functional magnetic resonance imaging findings have indicated that frequency representations in human primary auditory cortex (AC) contribute to this feat. However, attentional modulations were examined at relatively low spatial and spectral resolutions, and frequency-selective contributions outside the primary AC could not be established. To address these issues, we compared blood oxygenation level-dependent (BOLD) responses in the superior temporal cortex of human listeners while they identified single frequencies versus listened selectively for various frequencies within a multifrequency scene. Using best-frequency mapping, we observed that the detailed spatial layout of attention-induced BOLD response enhancements in primary AC follows the tonotopy of stimulus-driven frequency representations-analogous to the "spotlight" of attention enhancing visuospatial representations in retinotopic visual cortex. Moreover, using an algorithm trained to discriminate stimulus-driven frequency representations, we could successfully decode the focus of frequency-selective attention from listeners' BOLD response patterns in nonprimary AC. Our results indicate that the human brain facilitates selective listening to a frequency of interest in a scene by reinforcing the fine-grained activity pattern throughout the entire superior temporal cortex that would be evoked if that frequency was present alone. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. From Brain-Environment Connections to Temporal Dynamics and Social Interaction: Principles of Human Brain Function.

    Science.gov (United States)

    Hari, Riitta

    2017-06-07

    Experimental data about brain function accumulate faster than does our understanding of how the brain works. To tackle some general principles at the grain level of behavior, I start from the omnipresent brain-environment connection that forces regularities of the physical world to shape the brain. Based on top-down processing, added by sparse sensory information, people are able to form individual "caricature worlds," which are similar enough to be shared among other people and which allow quick and purposeful reactions to abrupt changes. Temporal dynamics and social interaction in natural environments serve as further essential organizing principles of human brain function. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Ex vivo study of dentate gyrus neurogenesis in human pharmacoresistant temporal lobe epilepsy.

    Science.gov (United States)

    Paradisi, M; Fernández, M; Del Vecchio, G; Lizzo, G; Marucci, G; Giulioni, M; Pozzati, E; Antonelli, T; Lanzoni, G; Bagnara, G P; Giardino, L; Calzà, L

    2010-10-01

    Neurogenesis in adult humans occurs in at least two areas of the brain, the subventricular zone of the telencephalon and the subgranular layer of the dentate gyrus in the hippocampal formation. We studied dentate gyrus subgranular layer neurogenesis in patients subjected to tailored antero-mesial temporal resection including amygdalohippocampectomy due to pharmacoresistant temporal lobe epilepsy (TLE) using the in vitro neurosphere assay. Sixteen patients were enrolled in the study; mesial temporal sclerosis (MTS) was present in eight patients. Neurogenesis was investigated by ex vivo neurosphere expansion in the presence of mitogens (epidermal growth factor + basic fibroblast growth factor) and spontaneous differentiation after mitogen withdrawal. Growth factor synthesis was investigated by qRT-PCR in neurospheres. We demonstrate that in vitro proliferation of cells derived from dentate gyrus of TLE patients is dependent on disease duration. Moreover, the presence of MTS impairs proliferation. As long as in vitro proliferation occurs, neurogenesis is maintained, and cells expressing a mature neurone phenotype (TuJ1, MAP2, GAD) are spontaneously formed after mitogen withdrawal. Finally, formed neurospheres express mRNAs encoding for growth (vascular endothelial growth factor) as well as neurotrophic factors (brain-derived neurotrophic factor, ciliary neurotrophic factor, glial-derived neurotrophic factor, nerve growth factor). We demonstrated that residual neurogenesis in the subgranular layer of the dentate gyrus in TLE is dependent on diseases duration and absent in MTS. © 2010 The Authors. Neuropathology and Applied Neurobiology © 2010 British Neuropathological Society.

  14. Temporal coherence for pure tones in budgerigars (Melopsittacus undulatus) and humans (Homo sapiens).

    Science.gov (United States)

    Neilans, Erikson G; Dent, Micheal L

    2015-02-01

    Auditory scene analysis has been suggested as a universal process that exists across all animals. Relative to humans, however, little work has been devoted to how animals perceptually isolate different sound sources. Frequency separation of sounds is arguably the most common parameter studied in auditory streaming, but it is not the only factor contributing to how the auditory scene is perceived. Researchers have found that in humans, even at large frequency separations, synchronous tones are heard as a single auditory stream, whereas asynchronous tones with the same frequency separations are perceived as 2 distinct sounds. These findings demonstrate how both the timing and frequency separation of sounds are important for auditory scene analysis. It is unclear how animals, such as budgerigars (Melopsittacus undulatus), perceive synchronous and asynchronous sounds. In this study, budgerigars and humans (Homo sapiens) were tested on their perception of synchronous, asynchronous, and partially overlapping pure tones using the same psychophysical procedures. Species differences were found between budgerigars and humans in how partially overlapping sounds were perceived, with budgerigars more likely to segregate overlapping sounds and humans more apt to fuse the 2 sounds together. The results also illustrated that temporal cues are particularly important for stream segregation of overlapping sounds. Lastly, budgerigars were found to segregate partially overlapping sounds in a manner predicted by computational models of streaming, whereas humans were not. PsycINFO Database Record (c) 2015 APA, all rights reserved.

  15. Effects of psilocybin on time perception and temporal control of behaviour in humans.

    Science.gov (United States)

    Wittmann, Marc; Carter, Olivia; Hasler, Felix; Cahn, B Rael; Grimberg, Ulrike; Spring, Philipp; Hell, Daniel; Flohr, Hans; Vollenweider, Franz X

    2007-01-01

    Hallucinogenic psilocybin is known to alter the subjective experience of time. However, there is no study that systematically investigated objective measures of time perception under psilocybin. Therefore, we studied dose-dependent effects of the serotonin (5-HT)2A/1A receptor agonist psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine) on temporal processing, employing tasks of temporal reproduction, sensorimotor synchronization and tapping tempo. To control for cognitive and subjective changes, we assessed spatial working memory and conscious experience. Twelve healthy human volunteers were tested under placebo, medium (115 microg/kg), and high (250 microg/kg) dose conditions, in a double-blind experimental design. Psilocybin was found to significantly impair subjects' ability to (1) reproduce interval durations longer than 2.5 sec, (2) to synchronize to inter-beat intervals longer than 2 sec and (3) caused subjects to be slower in their preferred tapping rate. These objective effects on timing performance were accompanied by working-memory deficits and subjective changes in conscious state, namely increased reports of 'depersonalization' and 'derealization' phenomena including disturbances in subjective 'time sense.' Our study is the first to systematically assess the impact of psilocybin on timing performance on standardized measures of temporal processing. Results indicate that the serotonin system is selectively involved in duration processing of intervals longer than 2 to 3 seconds and in the voluntary control of the speed of movement. We speculate that psilocybin's selective disruption of longer intervals is likely to be a product of interactions with cognitive dimensions of temporal processing -presumably via 5-HT2A receptor stimulation.

  16. White matter tract recovery following medial temporal lobectomy and selective amygdalohippocampectomy for tumor resection via a ROVOT-m port-guided technique: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Srikant S. Chakravarthi

    2016-12-01

    Conclusions: To our knowledge, this is the first reported case of a temporal lobectomy and amygdalohippocampectomy using a port technique, in particular, one that demonstrates recovery of the critical (ILF and uncinate fasciculus subcortical white matter tracts. The combination of real-time, rapid, geometrically accurate 3D-planning of white matter tracts is imperative, especially in conjunction with minimally invasive approaches, thereby offering a new, safer perspective into the approach of temporal lobe lesions.

  17. Remote sensing captures varying temporal patterns of vegetation between human-altered and natural landscapes.

    Science.gov (United States)

    Leong, Misha; Roderick, George K

    2015-01-01

    Global change has led to shifts in phenology, potentially disrupting species interactions such as plant-pollinator relationships. Advances in remote sensing techniques allow one to detect vegetation phenological diversity between different land use types, but it is not clear how this translates to other communities in the ecosystem. Here, we investigated the phenological diversity of the vegetation across a human-altered landscape including urban, agricultural, and natural land use types. We found that the patterns of change in the vegetation indices (EVI and NDVI) of human-altered landscapes are out of synchronization with the phenology in neighboring natural California grassland habitat. Comparing these findings to a spatio-temporal pollinator distribution dataset, EVI and NDVI were significant predictors of total bee abundance, a relationship that improved with time lags. This evidence supports the importance of differences in temporal dynamics between land use types. These findings also highlight the potential to utilize remote sensing data to make predictions for components of biodiversity that have tight vegetation associations, such as pollinators.

  18. Differential Processing of Consonance and Dissonance within the Human Superior Temporal Gyrus

    Directory of Open Access Journals (Sweden)

    Francine eFoo

    2016-04-01

    Full Text Available The auditory cortex is well known to be critical for music perception, including the perception of consonance and dissonance. Studies on the neural correlates of consonance and dissonance perception have largely employed non-invasive electrophysiological and functional imaging techniques in humans as well as neurophysiological recordings in animals, but the fine-grained spatiotemporal dynamics within the human auditory cortex remain unknown. We recorded electrocorticographic (ECoG signals directly from the lateral surface of either the left or right temporal lobe of 8 patients undergoing neurosurgical treatment as they passively listened to highly consonant and highly dissonant musical chords. We assessed ECoG activity in the high gamma (γhigh, 70-150 Hz frequency range within the superior temporal gyrus (STG and observed two types of cortical sites of interest in both hemispheres: one type showed no significant difference in γhigh activity between consonant and dissonant chords, and another type showed increased γhigh responses to dissonant chords between 75-200ms post-stimulus onset. Furthermore, a subset of these sites exhibited additional sensitivity towards different types of dissonant chords. We also observed a distinct spatial organization of cortical sites in the right STG, with dissonant-sensitive sites located anterior to non-sensitive sites. In sum, these findings demonstrate differential processing of consonance and dissonance in bilateral STG with the right hemisphere exhibiting robust and spatially organized sensitivity towards dissonance.

  19. Non-mydriatic video ophthalmoscope to measure fast temporal changes of the human retina

    Science.gov (United States)

    Tornow, Ralf P.; Kolář, Radim; Odstrčilík, Jan

    2015-07-01

    The analysis of fast temporal changes of the human retina can be used to get insight to normal physiological behavior and to detect pathological deviations. This can be important for the early detection of glaucoma and other eye diseases. We developed a small, lightweight, USB powered video ophthalmoscope that allows taking video sequences of the human retina with at least 25 frames per second without dilating the pupil. Short sequences (about 10 s) of the optic nerve head (20° x 15°) are recorded from subjects and registered offline using two-stage process (phase correlation and Lucas-Kanade approach) to compensate for eye movements. From registered video sequences, different parameters can be calculated. Two applications are described here: measurement of (i) cardiac cycle induced pulsatile reflection changes and (ii) eye movements and fixation pattern. Cardiac cycle induced pulsatile reflection changes are caused by changing blood volume in the retina. Waveform and pulse parameters like amplitude and rise time can be measured in any selected areas within the retinal image. Fixation pattern ΔY(ΔX) can be assessed from eye movements during video acquisition. The eye movements ΔX[t], ΔY[t] are derived from image registration results with high temporal (40 ms) and spatial (1,86 arcmin) resolution. Parameters of pulsatile reflection changes and fixation pattern can be affected in beginning glaucoma and the method described here may support early detection of glaucoma and other eye disease.

  20. Functional connection between posterior superior temporal gyrus and ventrolateral prefrontal cortex in human.

    Science.gov (United States)

    Garell, P C; Bakken, H; Greenlee, J D W; Volkov, I; Reale, R A; Oya, H; Kawasaki, H; Howard, M A; Brugge, J F

    2013-10-01

    The connection between auditory fields of the temporal lobe and prefrontal cortex has been well characterized in nonhuman primates. Little is known of temporofrontal connectivity in humans, however, due largely to the fact that invasive experimental approaches used so successfully to trace anatomical pathways in laboratory animals cannot be used in humans. Instead, we used a functional tract-tracing method in 12 neurosurgical patients with multicontact electrode arrays chronically implanted over the left (n = 7) or right (n = 5) perisylvian temporal auditory cortex (area PLST) and the ventrolateral prefrontal cortex (VLPFC) of the inferior frontal gyrus (IFG) for diagnosis and treatment of medically intractable epilepsy. Area PLST was identified by the distribution of average auditory-evoked potentials obtained in response to simple and complex sounds. The same sounds evoked little if there is any activity in VLPFC. A single bipolar electrical pulse (0.2 ms, charge-balanced) applied between contacts within physiologically identified PLST resulted in polyphasic evoked potentials clustered in VLPFC, with greatest activation being in pars triangularis of the IFG. The average peak latency of the earliest negative deflection of the evoked potential on VLPFC was 13.48 ms (range: 9.0-18.5 ms), providing evidence for a rapidly conducting pathway between area PLST and VLPFC.

  1. Improving fire season definition by optimized temporal modelling of daily human-caused ignitions.

    Science.gov (United States)

    Costafreda-Aumedes, S; Vega-Garcia, C; Comas, C

    2018-07-01

    Wildfire suppression management is usually based on fast control of all ignitions, especially in highly populated countries with pervasive values-at-risk. To minimize values-at-risk loss by improving response time of suppression resources it is necessary to anticipate ignitions, which are mainly caused by people. Previous studies have found that human-ignition patterns change spatially and temporally depending on socio-economic activities, hence, the deployment of suppression resources along the year should consider these patterns. However, full suppression capacity is operational only within legally established fire seasons, driven by past events and budgets, which limits response capacity and increases damages out of them. The aim of this study was to assess the temporal definition of fire seasons from the perspective of human-ignition patterns for the case study of Spain, where people cause over 95% of fires. Humans engage in activities that use fire as a tool in certain periods within a year, and in locations linked to specific spatial factors. Geographic variables (population, infrastructures, physiography and land uses) were used as explanatory variables for human-ignition patterns. The changing influence of these geographic variables on occurrence along the year was analysed with day-by-day logistic regression models. Daily models were built for all the municipal units in the two climatic regions in Spain (Atlantic and Mediterranean Spain) from 2002 to 2014, and similar models were grouped within continuous periods, designated as ignition-based seasons. We found three ignition-based seasons in the Mediterranean region and five in the Atlantic zones, not coincidental with calendar seasons, but with a high degree of agreement with current legally designated operational fire seasons. Our results suggest that an additional late-winter-early-spring fire season in the Mediterranean area and the extension of this same season in the Atlantic zone should be re

  2. Atraumatic medial collateral ligament oedema in medial compartment knee osteoarthritis

    International Nuclear Information System (INIS)

    Bergin, D.; Keogh, C.; O'Connell, M.; Zoga, A.; Rowe, D.; Shah, B.; Eustace, S.

    2002-01-01

    Objective: To describe and determine the prevalence of atraumatic medial collateral oedema identified in patients with medial compartment osteoarthritis. Design and patients: Sixty patients, 30 patients with medial compartment knee osteoarthritis (Kellgren and Lawrence grade 2 to 4) and 30 age-matched patients with atraumatic knee pain without osteoarthritis, referred for MR imaging over a 2 year period were included in the study. In each case, severity of osteoarthritis was recorded on radiographs and correlated with the presence or absence of medial collateral ligament oedema at MR imaging. Results: Medial collateral oedema was identified in 27 of the 30 patients with osteoarthritis, of whom 14 had grade 1 oedema and 13 had grade 2 oedema compared with the presence of medial collateral ligament oedema (grade 1) in only two of the 30 control patients without osteoarthritis (P<<0.0001). Conclusion: Medial collateral oedema is common in patients with osteoarthritis in the absence of trauma. When identified, medial collateral ligament oedema should be considered to be a feature of osteoarthritis and should not be incorrectly attributed to an acute traumatic injury. (orig.)

  3. An approximation to the temporal order in endogenous circadian rhythms of genes implicated in human adipose tissue metabolism

    Science.gov (United States)

    Although it is well established that human adipose tissue (AT) shows circadian rhythmicity, published studies have been discussed as if tissues or systems showed only one or few circadian rhythms at a time. To provide an overall view of the internal temporal order of circadian rhythms in human AT in...

  4. Direct radiocarbon dating and DNA analysis of the Darra-i-Kur (Afghanistan) human temporal bone.

    Science.gov (United States)

    Douka, Katerina; Slon, Viviane; Stringer, Chris; Potts, Richard; Hübner, Alexander; Meyer, Matthias; Spoor, Fred; Pääbo, Svante; Higham, Tom

    2017-06-01

    The temporal bone discovered in the 1960s from the Darra-i-Kur cave in Afghanistan is often cited as one of the very few Pleistocene human fossils from Central Asia. Here we report the first direct radiocarbon date for the specimen and the genetic analyses of DNA extracted and sequenced from two areas of the bone. The new radiocarbon determination places the find to ∼4500 cal BP (∼2500 BCE) contradicting an assumed Palaeolithic age of ∼30,000 years, as originally suggested. The DNA retrieved from the specimen originates from a male individual who carried mitochondrial DNA of the modern human type. The petrous part yielded more endogenous ancient DNA molecules than the squamous part of the same bone. Molecular dating of the Darra-i-Kur mitochondrial DNA sequence corroborates the radiocarbon date and suggests that the specimen is younger than previously thought. Taken together, the results consolidate the fact that the human bone is not associated with the Pleistocene-age deposits of Darra-i-Kur; instead it is intrusive, possibly re-deposited from upper levels dating to much later periods (Neolithic). Despite its Holocene age, the Darra-i-Kur specimen is, so far, the first and only ancient human from Afghanistan whose DNA has been sequenced. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The use of census migration data to approximate human movement patterns across temporal scales.

    Directory of Open Access Journals (Sweden)

    Amy Wesolowski

    Full Text Available Human movement plays a key role in economies and development, the delivery of services, and the spread of infectious diseases. However, it remains poorly quantified partly because reliable data are often lacking, particularly for low-income countries. The most widely available are migration data from human population censuses, which provide valuable information on relatively long timescale relocations across countries, but do not capture the shorter-scale patterns, trips less than a year, that make up the bulk of human movement. Census-derived migration data may provide valuable proxies for shorter-term movements however, as substantial migration between regions can be indicative of well connected places exhibiting high levels of movement at finer time scales, but this has never been examined in detail. Here, an extensive mobile phone usage data set for Kenya was processed to extract movements between counties in 2009 on weekly, monthly, and annual time scales and compared to data on change in residence from the national census conducted during the same time period. We find that the relative ordering across Kenyan counties for incoming, outgoing and between-county movements shows strong correlations. Moreover, the distributions of trip durations from both sources of data are similar, and a spatial interaction model fit to the data reveals the relationships of different parameters over a range of movement time scales. Significant relationships between census migration data and fine temporal scale movement patterns exist, and results suggest that census data can be used to approximate certain features of movement patterns across multiple temporal scales, extending the utility of census-derived migration data.

  6. The use of census migration data to approximate human movement patterns across temporal scales.

    Science.gov (United States)

    Wesolowski, Amy; Buckee, Caroline O; Pindolia, Deepa K; Eagle, Nathan; Smith, David L; Garcia, Andres J; Tatem, Andrew J

    2013-01-01

    Human movement plays a key role in economies and development, the delivery of services, and the spread of infectious diseases. However, it remains poorly quantified partly because reliable data are often lacking, particularly for low-income countries. The most widely available are migration data from human population censuses, which provide valuable information on relatively long timescale relocations across countries, but do not capture the shorter-scale patterns, trips less than a year, that make up the bulk of human movement. Census-derived migration data may provide valuable proxies for shorter-term movements however, as substantial migration between regions can be indicative of well connected places exhibiting high levels of movement at finer time scales, but this has never been examined in detail. Here, an extensive mobile phone usage data set for Kenya was processed to extract movements between counties in 2009 on weekly, monthly, and annual time scales and compared to data on change in residence from the national census conducted during the same time period. We find that the relative ordering across Kenyan counties for incoming, outgoing and between-county movements shows strong correlations. Moreover, the distributions of trip durations from both sources of data are similar, and a spatial interaction model fit to the data reveals the relationships of different parameters over a range of movement time scales. Significant relationships between census migration data and fine temporal scale movement patterns exist, and results suggest that census data can be used to approximate certain features of movement patterns across multiple temporal scales, extending the utility of census-derived migration data.

  7. Mouth and Voice: A Relationship between Visual and Auditory Preference in the Human Superior Temporal Sulcus.

    Science.gov (United States)

    Zhu, Lin L; Beauchamp, Michael S

    2017-03-08

    Cortex in and around the human posterior superior temporal sulcus (pSTS) is known to be critical for speech perception. The pSTS responds to both the visual modality (especially biological motion) and the auditory modality (especially human voices). Using fMRI in single subjects with no spatial smoothing, we show that visual and auditory selectivity are linked. Regions of the pSTS were identified that preferred visually presented moving mouths (presented in isolation or as part of a whole face) or moving eyes. Mouth-preferring regions responded strongly to voices and showed a significant preference for vocal compared with nonvocal sounds. In contrast, eye-preferring regions did not respond to either vocal or nonvocal sounds. The converse was also true: regions of the pSTS that showed a significant response to speech or preferred vocal to nonvocal sounds responded more strongly to visually presented mouths than eyes. These findings can be explained by environmental statistics. In natural environments, humans see visual mouth movements at the same time as they hear voices, while there is no auditory accompaniment to visual eye movements. The strength of a voxel's preference for visual mouth movements was strongly correlated with the magnitude of its auditory speech response and its preference for vocal sounds, suggesting that visual and auditory speech features are coded together in small populations of neurons within the pSTS. SIGNIFICANCE STATEMENT Humans interacting face to face make use of auditory cues from the talker's voice and visual cues from the talker's mouth to understand speech. The human posterior superior temporal sulcus (pSTS), a brain region known to be important for speech perception, is complex, with some regions responding to specific visual stimuli and others to specific auditory stimuli. Using BOLD fMRI, we show that the natural statistics of human speech, in which voices co-occur with mouth movements, are reflected in the neural architecture of

  8. Fragmented medial coronoid process

    International Nuclear Information System (INIS)

    Juhasz, Cs.; Juhasz, T.

    1997-01-01

    Fragmented medial coronoid process: (FCP) is often considered to be part of the osteochondrosis dissecans complex, but trauma and growth discrepancies between the radius and ulna are proposed as causes. There is little to clinically differentiate FCP, from osteochondrosis dissecans (OCD) of the elbow. Pain on, flexion-extension of the elbow and lateral rotation of the paw is a little more consistent in FCP. Radiographic examination of the elbow is important despite the, fact that radiographic signs of the FCP are often nonspecific. Excessive osteoarthrosis and superimposition of the radial head and coronoid process make identification of the FCP difficult. Craniocaudal, flexed mediolateral and 25 degree craniocaudal-lateromedial views are necessary for diagnosis. Osteophyte production is more dramatic with FCP than with OCD and suggests therefore the occurrence of OCP in many cases. Although the detached process may be seen on any view, the oblique projection offers the least obstructed view. Exposure of the joint is identical to that for OCD, that means a medial approach with osteotomy of the epicondyle. In most cases the process is loose enough to be readily apparent, but in some it is necessary to exert force on the process in order to find the cleavage plane. It is necessary to remove the osteophytes as well and to inspect and irrigate the joint carefully to remove cartilage fragments before closure. Confinement is advisable for 4 weeks before returning the dog to normal activity. The outlook for function is good if the FCP is removed before secondary degenerative joint disease is well established

  9. Temporal and spatial distribution of human cryptosporidiosis in the west of Ireland 2004-2007.

    LENUS (Irish Health Repository)

    Callaghan, Mary

    2009-01-01

    BACKGROUND: Cryptosporidiosis is increasingly recognised as a cause of gastrointestinal infection in Ireland and has been implicated in several outbreaks. This study aimed to investigate the spatial and temporal distribution of human cryptosporidiosis in the west of Ireland in order to identify high risk seasons and areas and to compare Classically Calculated (CC) and Empirical Bayesian (EB) incidence rates. Two spatial scales of analysis were used with a view to identifying the best one in assessing geographical patterns of infection. Global Moran\\'s I and Local Moran\\'s I tests of autocorrelation were used to test for evidence of global and local spatial clustering. RESULTS: There were statistically significant seasonal patterns of cryptosporidiosis with peaks in spring and an increasing temporal trend. Significant (p < 0.05) global spatial clustering was observed in CC rates at the Electoral Division (ED) level but not in EB rates at the same level. Despite variations in disease, ED level was found to provide the most accurate account of distribution of cryptosporidiosis in the West of Ireland but required spatial EB smoothing of cases. There were a number of areas identified with significant local clustering of cryptosporidiosis rates. CONCLUSION: This study identified spatial and temporal patterns in cryptosporidiosis distribution. The study also showed benefit in performing spatial analyses at more than one spatial scale to assess geographical patterns in disease distribution and that smoothing of disease rates for mapping in small areas enhances visualisation of spatial patterns. These findings are relevant in guiding policy decisions on disease control strategies.

  10. Temporal envelope processing in the human auditory cortex: response and interconnections of auditory cortical areas.

    Science.gov (United States)

    Gourévitch, Boris; Le Bouquin Jeannès, Régine; Faucon, Gérard; Liégeois-Chauvel, Catherine

    2008-03-01

    Temporal envelope processing in the human auditory cortex has an important role in language analysis. In this paper, depth recordings of local field potentials in response to amplitude modulated white noises were used to design maps of activation in primary, secondary and associative auditory areas and to study the propagation of the cortical activity between them. The comparison of activations between auditory areas was based on a signal-to-noise ratio associated with the response to amplitude modulation (AM). The functional connectivity between cortical areas was quantified by the directed coherence (DCOH) applied to auditory evoked potentials. This study shows the following reproducible results on twenty subjects: (1) the primary auditory cortex (PAC), the secondary cortices (secondary auditory cortex (SAC) and planum temporale (PT)), the insular gyrus, the Brodmann area (BA) 22 and the posterior part of T1 gyrus (T1Post) respond to AM in both hemispheres. (2) A stronger response to AM was observed in SAC and T1Post of the left hemisphere independent of the modulation frequency (MF), and in the left BA22 for MFs 8 and 16Hz, compared to those in the right. (3) The activation and propagation features emphasized at least four different types of temporal processing. (4) A sequential activation of PAC, SAC and BA22 areas was clearly visible at all MFs, while other auditory areas may be more involved in parallel processing upon a stream originating from primary auditory area, which thus acts as a distribution hub. These results suggest that different psychological information is carried by the temporal envelope of sounds relative to the rate of amplitude modulation.

  11. Upregulation of adenosine kinase in astrocytes in experimental and human temporal lobe epilepsy.

    Science.gov (United States)

    Aronica, Eleonora; Zurolo, Emanuele; Iyer, Anand; de Groot, Marjolein; Anink, Jasper; Carbonell, Caterina; van Vliet, Erwin A; Baayen, Johannes C; Boison, Detlev; Gorter, Jan A

    2011-09-01

    Adenosine kinase (ADK) represents the key metabolic enzyme for the regulation of extracellular adenosine levels in the brain. In adult brain, ADK is primarily present in astrocytes. Several lines of experimental evidence support a critical role of ADK in different types of brain injury associated with astrogliosis, which is also a prominent morphologic feature of temporal lobe epilepsy (TLE). We hypothesized that dysregulation of ADK is an ubiquitous pathologic hallmark of TLE. Using immunocytochemistry and Western blot analysis, we investigated ADK protein expression in a rat model of TLE during epileptogenesis and the chronic epileptic phase and compared those findings with tissue resected from TLE patients with mesial temporal sclerosis (MTS). In rat control hippocampus and cortex, a low baseline expression of ADK was found with mainly nuclear localization. One week after the electrical induction of status epilepticus (SE), prominent up-regulation of ADK became evident in astrocytes with a characteristic cytoplasmic localization. This increase in ADK persisted at least for 3-4 months after SE in rats developing a progressive form of epilepsy. In line with the findings from the rat model, expression of astrocytic ADK was also found to be increased in the hippocampus and temporal cortex of patients with TLE. In addition, in vitro experiments in human astrocyte cultures showed that ADK expression was increased by several proinflammatory molecules (interleukin-1β and lipopolysaccharide). These results suggest that dysregulation of ADK in astrocytes is a common pathologic hallmark of TLE. Moreover, in vitro data suggest the existence of an additional layer of modulatory crosstalk between the astrocyte-based adenosine cycle and inflammation. Whether this interaction also can play a role in vivo needs to be further investigated. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

  12. Method to investigate temporal dynamics of ganglion and other retinal cells in the living human eye

    Science.gov (United States)

    Kurokawa, Kazuhiro; Liu, Zhuolin; Crowell, James; Zhang, Furu; Miller, Donald T.

    2018-02-01

    The inner retina is critical for visual processing, but much remains unknown about its neural circuitry and vulnerability to disease. A major bottleneck has been our inability to observe the structure and function of the cells composing these retinal layers in the living human eye. Here, we present a noninvasive method to observe both structural and functional information. Adaptive optics optical coherence tomography (AO-OCT) is used to resolve the inner retinal cells in all three dimensions and novel post processing algorithms are applied to extract structure and physiology down to the cellular level. AO-OCT captured the 3D mosaic of individual ganglion cell somas, retinal nerve fiber bundles of micron caliber, and microglial cells, all in exquisite detail. Time correlation analysis of the AO-OCT videos revealed notable temporal differences between the principal layers of the inner retina. The GC layer was more dynamic than the nerve fiber and inner plexiform layers. At the cellular level, we applied a customized correlation method to individual GCL somas, and found a mean time constant of activity of 0.57 s and spread of +/-0.1 s suggesting a range of physiological dynamics even in the same cell type. Extending our method to slower dynamics (from minutes to one year), time-lapse imaging and temporal speckle contrast revealed appendage and soma motion of resting microglial cells at the retinal surface.

  13. Temporal components of the motor patterns expressed by the human spinal cord reflect foot kinematics.

    Science.gov (United States)

    Ivanenko, Yuri P; Grasso, Renato; Zago, Myrka; Molinari, Marco; Scivoletto, Giorgio; Castellano, Vincenzo; Macellari, Velio; Lacquaniti, Francesco

    2003-11-01

    What are the building blocks with which the human spinal cord constructs the motor patterns of locomotion? In principle, they could correspond to each individual activity pattern in dozens of different muscles. Alternatively, there could exist a small set of constituent temporal components that are common to all activation patterns and reflect global kinematic goals. To address this issue, we studied patients with spinal injury trained to step on a treadmill with body weight support. Patients learned to produce foot kinematics similar to that of healthy subjects but with activity patterns of individual muscles generally different from the control group. Hidden in the muscle patterns, we found a basic set of five temporal components, whose flexible combination accounted for the wide range of muscle patterns recorded in both controls and patients. Furthermore, two of the components were systematically related to foot kinematics across different stepping speeds and loading conditions. We suggest that the components are related to control signals output by spinal pattern generators, normally under the influence of descending and afferent inputs.

  14. Speech-specific tuning of neurons in human superior temporal gyrus.

    Science.gov (United States)

    Chan, Alexander M; Dykstra, Andrew R; Jayaram, Vinay; Leonard, Matthew K; Travis, Katherine E; Gygi, Brian; Baker, Janet M; Eskandar, Emad; Hochberg, Leigh R; Halgren, Eric; Cash, Sydney S

    2014-10-01

    How the brain extracts words from auditory signals is an unanswered question. We recorded approximately 150 single and multi-units from the left anterior superior temporal gyrus of a patient during multiple auditory experiments. Against low background activity, 45% of units robustly fired to particular spoken words with little or no response to pure tones, noise-vocoded speech, or environmental sounds. Many units were tuned to complex but specific sets of phonemes, which were influenced by local context but invariant to speaker, and suppressed during self-produced speech. The firing of several units to specific visual letters was correlated with their response to the corresponding auditory phonemes, providing the first direct neural evidence for phonological recoding during reading. Maximal decoding of individual phonemes and words identities was attained using firing rates from approximately 5 neurons within 200 ms after word onset. Thus, neurons in human superior temporal gyrus use sparse spatially organized population encoding of complex acoustic-phonetic features to help recognize auditory and visual words. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Object Representations in Human Visual Cortex Formed Through Temporal Integration of Dynamic Partial Shape Views.

    Science.gov (United States)

    Orlov, Tanya; Zohary, Ehud

    2018-01-17

    We typically recognize visual objects using the spatial layout of their parts, which are present simultaneously on the retina. Therefore, shape extraction is based on integration of the relevant retinal information over space. The lateral occipital complex (LOC) can represent shape faithfully in such conditions. However, integration over time is sometimes required to determine object shape. To study shape extraction through temporal integration of successive partial shape views, we presented human participants (both men and women) with artificial shapes that moved behind a narrow vertical or horizontal slit. Only a tiny fraction of the shape was visible at any instant at the same retinal location. However, observers perceived a coherent whole shape instead of a jumbled pattern. Using fMRI and multivoxel pattern analysis, we searched for brain regions that encode temporally integrated shape identity. We further required that the representation of shape should be invariant to changes in the slit orientation. We show that slit-invariant shape information is most accurate in the LOC. Importantly, the slit-invariant shape representations matched the conventional whole-shape representations assessed during full-image runs. Moreover, when the same slit-dependent shape slivers were shuffled, thereby preventing their spatiotemporal integration, slit-invariant shape information was reduced dramatically. The slit-invariant representation of the various shapes also mirrored the structure of shape perceptual space as assessed by perceptual similarity judgment tests. Therefore, the LOC is likely to mediate temporal integration of slit-dependent shape views, generating a slit-invariant whole-shape percept. These findings provide strong evidence for a global encoding of shape in the LOC regardless of integration processes required to generate the shape percept. SIGNIFICANCE STATEMENT Visual objects are recognized through spatial integration of features available simultaneously on

  16. Spatio-Temporal Analysis of Human Activities in Indoor Environments through Mobile Sensing

    DEFF Research Database (Denmark)

    Prentow, Thor Siiger

    with the intuition and personal experience of the planners. Lack of real-time information on task execution has made it difficult to adapt to changes in the schedules, such as delays or suddenly occurring urgent tasks. The recent advances in methods and devices for mobile sensing provides opportunities...... methods for spatio-temporal analysis of human activities in indoor environments based on mobile sensing. The methods aim to improve scheduling and facility utilization by providing information on the used route networks, transportation modes, travel times, and the flow of people through buildings....... The methods are based on large-scale real-time indoor positioning through the use of existing WiFi infrastructures, which allows for easy deployment even in very large building complexes. The methods are designed for real-time operation, which enables them to detect and adjust to changes as they occur...

  17. a Three-Step Spatial-Temporal Clustering Method for Human Activity Pattern Analysis

    Science.gov (United States)

    Huang, W.; Li, S.; Xu, S.

    2016-06-01

    How people move in cities and what they do in various locations at different times form human activity patterns. Human activity pattern plays a key role in in urban planning, traffic forecasting, public health and safety, emergency response, friend recommendation, and so on. Therefore, scholars from different fields, such as social science, geography, transportation, physics and computer science, have made great efforts in modelling and analysing human activity patterns or human mobility patterns. One of the essential tasks in such studies is to find the locations or places where individuals stay to perform some kind of activities before further activity pattern analysis. In the era of Big Data, the emerging of social media along with wearable devices enables human activity data to be collected more easily and efficiently. Furthermore, the dimension of the accessible human activity data has been extended from two to three (space or space-time) to four dimensions (space, time and semantics). More specifically, not only a location and time that people stay and spend are collected, but also what people "say" for in a location at a time can be obtained. The characteristics of these datasets shed new light on the analysis of human mobility, where some of new methodologies should be accordingly developed to handle them. Traditional methods such as neural networks, statistics and clustering have been applied to study human activity patterns using geosocial media data. Among them, clustering methods have been widely used to analyse spatiotemporal patterns. However, to our best knowledge, few of clustering algorithms are specifically developed for handling the datasets that contain spatial, temporal and semantic aspects all together. In this work, we propose a three-step human activity clustering method based on space, time and semantics to fill this gap. One-year Twitter data, posted in Toronto, Canada, is used to test the clustering-based method. The results show that the

  18. A THREE-STEP SPATIAL-TEMPORAL-SEMANTIC CLUSTERING METHOD FOR HUMAN ACTIVITY PATTERN ANALYSIS

    Directory of Open Access Journals (Sweden)

    W. Huang

    2016-06-01

    Full Text Available How people move in cities and what they do in various locations at different times form human activity patterns. Human activity pattern plays a key role in in urban planning, traffic forecasting, public health and safety, emergency response, friend recommendation, and so on. Therefore, scholars from different fields, such as social science, geography, transportation, physics and computer science, have made great efforts in modelling and analysing human activity patterns or human mobility patterns. One of the essential tasks in such studies is to find the locations or places where individuals stay to perform some kind of activities before further activity pattern analysis. In the era of Big Data, the emerging of social media along with wearable devices enables human activity data to be collected more easily and efficiently. Furthermore, the dimension of the accessible human activity data has been extended from two to three (space or space-time to four dimensions (space, time and semantics. More specifically, not only a location and time that people stay and spend are collected, but also what people “say” for in a location at a time can be obtained. The characteristics of these datasets shed new light on the analysis of human mobility, where some of new methodologies should be accordingly developed to handle them. Traditional methods such as neural networks, statistics and clustering have been applied to study human activity patterns using geosocial media data. Among them, clustering methods have been widely used to analyse spatiotemporal patterns. However, to our best knowledge, few of clustering algorithms are specifically developed for handling the datasets that contain spatial, temporal and semantic aspects all together. In this work, we propose a three-step human activity clustering method based on space, time and semantics to fill this gap. One-year Twitter data, posted in Toronto, Canada, is used to test the clustering-based method. The

  19. Gene expression analyses of the spatio-temporal relationships of human medulloblastoma subgroups during early human neurogenesis.

    Directory of Open Access Journals (Sweden)

    Cornelia M Hooper

    Full Text Available Medulloblastoma is the most common form of malignant paediatric brain tumour and is the leading cause of childhood cancer related mortality. The four molecular subgroups of medulloblastoma that have been identified - WNT, SHH, Group 3 and Group 4 - have molecular and topographical characteristics suggestive of different cells of origin. Definitive identification of the cell(s of origin of the medulloblastoma subgroups, particularly the poorer prognosis Group 3 and Group 4 medulloblastoma, is critical to understand the pathogenesis of the disease, and ultimately for the development of more effective treatment options. To address this issue, the gene expression profiles of normal human neural tissues and cell types representing a broad neuro-developmental continuum, were compared to those of two independent cohorts of primary human medulloblastoma specimens. Clustering, co-expression network, and gene expression analyses revealed that WNT and SHH medulloblastoma may be derived from distinct neural stem cell populations during early embryonic development, while the transcriptional profiles of Group 3 and Group 4 medulloblastoma resemble cerebellar granule neuron precursors at weeks 10-15 and 20-30 of embryogenesis, respectively. Our data indicate that Group 3 medulloblastoma may arise through abnormal neuronal differentiation, whereas deregulation of synaptic pruning-associated apoptosis may be driving Group 4 tumorigenesis. Overall, these data provide significant new insight into the spatio-temporal relationships and molecular pathogenesis of the human medulloblastoma subgroups, and provide an important framework for the development of more refined model systems, and ultimately improved therapeutic strategies.

  20. Centralization of extruded medial meniscus delays cartilage degeneration in rats.

    Science.gov (United States)

    Ozeki, Nobutake; Muneta, Takeshi; Kawabata, Kenichi; Koga, Hideyuki; Nakagawa, Yusuke; Saito, Ryusuke; Udo, Mio; Yanagisawa, Katsuaki; Ohara, Toshiyuki; Mochizuki, Tomoyuki; Tsuji, Kunikazu; Saito, Tomoyuki; Sekiya, Ichiro

    2017-05-01

    Meniscus extrusion often observed in knee osteoarthritis has a strong correlation with the progression of cartilage degeneration and symptom in the patients. We recently reported a novel procedure "arthroscopic centralization" in which the capsule was sutured to the edge of the tibial plateau to reduce meniscus extrusion in the human knee. However, there is no animal model to study the efficacy of this procedure. The purposes of this study were [1] to establish a model of centralization for the extruded medial meniscus in a rat model; and [2] to investigate the chondroprotective effect of this procedure. Medial meniscus extrusion was induced by the release of the anterior synovial capsule and the transection of the meniscotibial ligament. Centralization was performed by the pulled-out suture technique. Alternatively, control rats had only the medial meniscus extrusion surgery. Medial meniscus extrusion was evaluated by micro-CT and macroscopic findings. Cartilage degeneration of the medial tibial plateau was evaluated macroscopically and histologically. By micro-CT analysis, the medial meniscus extrusion was significantly improved in the centralization group in comparison to the extrusion group throughout the study. Both macroscopically and histologically, the cartilage lesion of the medial tibial plateau was prevented in the centralization group but was apparent in the control group. We developed medial meniscus extrusion in a rat model, and centralization of the extruded medial meniscus by the pull-out suture technique improved the medial meniscus extrusion and delayed cartilage degeneration, though the effect was limited. Centralization is a promising treatment to prevent the progression of osteoarthritis. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Differential Processing of Consonance and Dissonance within the Human Superior Temporal Gyrus

    Science.gov (United States)

    Foo, Francine; King-Stephens, David; Weber, Peter; Laxer, Kenneth; Parvizi, Josef; Knight, Robert T.

    2016-01-01

    The auditory cortex is well-known to be critical for music perception, including the perception of consonance and dissonance. Studies on the neural correlates of consonance and dissonance perception have largely employed non-invasive electrophysiological and functional imaging techniques in humans as well as neurophysiological recordings in animals, but the fine-grained spatiotemporal dynamics within the human auditory cortex remain unknown. We recorded electrocorticographic (ECoG) signals directly from the lateral surface of either the left or right temporal lobe of eight patients undergoing neurosurgical treatment as they passively listened to highly consonant and highly dissonant musical chords. We assessed ECoG activity in the high gamma (γhigh, 70–150 Hz) frequency range within the superior temporal gyrus (STG) and observed two types of cortical sites of interest in both hemispheres: one type showed no significant difference in γhigh activity between consonant and dissonant chords, and another type showed increased γhigh responses to dissonant chords between 75 and 200 ms post-stimulus onset. Furthermore, a subset of these sites exhibited additional sensitivity towards different types of dissonant chords, and a positive correlation between changes in γhigh power and the degree of stimulus roughness was observed in both hemispheres. We also observed a distinct spatial organization of cortical sites in the right STG, with dissonant-sensitive sites located anterior to non-sensitive sites. In sum, these findings demonstrate differential processing of consonance and dissonance in bilateral STG with the right hemisphere exhibiting robust and spatially organized sensitivity toward dissonance. PMID:27148011

  2. Geographic and temporal trends in proboscidean and human radiocarbon histories during the late Pleistocene

    Science.gov (United States)

    Ugan, Andrew; Byers, David

    2007-12-01

    The causes of large animal extinctions at the end of the Pleistocene remain a hotly debated topic focused primarily on the effects of human over hunting and climate change. Here we examine multiple, large radiocarbon data sets for humans and extinct proboscideans and explore how variation in their temporal and geographic distributions were related prior to proboscidean extinction. These data include 4532 archaeological determinations from Europe and Siberia and 1177 mammoth and mastodont determinations from Europe, Siberia, and North America. All span the period from 45,000 to 12,000 calendar years BP. We show that while the geographic ranges of dated human occupations and proboscidean remains overlap across the terminal Pleistocene of the Old World, the two groups remain largely segregated and increases in the frequency of human occupations do not coincide with declines in proboscidean remains. Prior to the Last Glacial Maximum (LGM; ca 21,000 years BP), archaeological 14C determinations increase slightly in frequency worldwide while the frequency of dated proboscidean remains varies depending on taxon and location. After the LGM, both sympatric and allopatric groups of humans and proboscideans increase sharply as climatic conditions ameliorate. Post-LGM radiocarbon frequencies among proboscideans peak at different times, also depending upon taxon and location. Woolly mammoths in Beringia reach a maximum and then decline beginning between 16,000 and 15,500 years BP, woolly mammoths in Europe and Siberia ca 14,500 and 13,500 BP, and Columbian mammoth and American mastodont only after 13,000 BP. Declines among woolly mammoths appear to coincide with the restructuring of biotic communities following the Pleistocene-Holocene transition.

  3. Differential DNA methylation profiles of coding and non-coding genes define hippocampal sclerosis in human temporal lobe epilepsy

    Science.gov (United States)

    Miller-Delaney, Suzanne F.C.; Bryan, Kenneth; Das, Sudipto; McKiernan, Ross C.; Bray, Isabella M.; Reynolds, James P.; Gwinn, Ryder; Stallings, Raymond L.

    2015-01-01

    Temporal lobe epilepsy is associated with large-scale, wide-ranging changes in gene expression in the hippocampus. Epigenetic changes to DNA are attractive mechanisms to explain the sustained hyperexcitability of chronic epilepsy. Here, through methylation analysis of all annotated C-phosphate-G islands and promoter regions in the human genome, we report a pilot study of the methylation profiles of temporal lobe epilepsy with or without hippocampal sclerosis. Furthermore, by comparative analysis of expression and promoter methylation, we identify methylation sensitive non-coding RNA in human temporal lobe epilepsy. A total of 146 protein-coding genes exhibited altered DNA methylation in temporal lobe epilepsy hippocampus (n = 9) when compared to control (n = 5), with 81.5% of the promoters of these genes displaying hypermethylation. Unique methylation profiles were evident in temporal lobe epilepsy with or without hippocampal sclerosis, in addition to a common methylation profile regardless of pathology grade. Gene ontology terms associated with development, neuron remodelling and neuron maturation were over-represented in the methylation profile of Watson Grade 1 samples (mild hippocampal sclerosis). In addition to genes associated with neuronal, neurotransmitter/synaptic transmission and cell death functions, differential hypermethylation of genes associated with transcriptional regulation was evident in temporal lobe epilepsy, but overall few genes previously associated with epilepsy were among the differentially methylated. Finally, a panel of 13, methylation-sensitive microRNA were identified in temporal lobe epilepsy including MIR27A, miR-193a-5p (MIR193A) and miR-876-3p (MIR876), and the differential methylation of long non-coding RNA documented for the first time. The present study therefore reports select, genome-wide DNA methylation changes in human temporal lobe epilepsy that may contribute to the molecular architecture of the epileptic brain. PMID

  4. Our Faces in the Dog's Brain: Functional Imaging Reveals Temporal Cortex Activation during Perception of Human Faces.

    Directory of Open Access Journals (Sweden)

    Laura V Cuaya

    Full Text Available Dogs have a rich social relationship with humans. One fundamental aspect of it is how dogs pay close attention to human faces in order to guide their behavior, for example, by recognizing their owner and his/her emotional state using visual cues. It is well known that humans have specific brain regions for the processing of other human faces, yet it is unclear how dogs' brains process human faces. For this reason, our study focuses on describing the brain correlates of perception of human faces in dogs using functional magnetic resonance imaging (fMRI. We trained seven domestic dogs to remain awake, still and unrestrained inside an MRI scanner. We used a visual stimulation paradigm with block design to compare activity elicited by human faces against everyday objects. Brain activity related to the perception of faces changed significantly in several brain regions, but mainly in the bilateral temporal cortex. The opposite contrast (i.e., everyday objects against human faces showed no significant brain activity change. The temporal cortex is part of the ventral visual pathway, and our results are consistent with reports in other species like primates and sheep, that suggest a high degree of evolutionary conservation of this pathway for face processing. This study introduces the temporal cortex as candidate to process human faces, a pillar of social cognition in dogs.

  5. HURON (HUman and Robotic Optimization Network) Multi-Agent Temporal Activity Planner/Scheduler

    Science.gov (United States)

    Hua, Hook; Mrozinski, Joseph J.; Elfes, Alberto; Adumitroaie, Virgil; Shelton, Kacie E.; Smith, Jeffrey H.; Lincoln, William P.; Weisbin, Charles R.

    2012-01-01

    HURON solves the problem of how to optimize a plan and schedule for assigning multiple agents to a temporal sequence of actions (e.g., science tasks). Developed as a generic planning and scheduling tool, HURON has been used to optimize space mission surface operations. The tool has also been used to analyze lunar architectures for a variety of surface operational scenarios in order to maximize return on investment and productivity. These scenarios include numerous science activities performed by a diverse set of agents: humans, teleoperated rovers, and autonomous rovers. Once given a set of agents, activities, resources, resource constraints, temporal constraints, and de pendencies, HURON computes an optimal schedule that meets a specified goal (e.g., maximum productivity or minimum time), subject to the constraints. HURON performs planning and scheduling optimization as a graph search in state-space with forward progression. Each node in the graph contains a state instance. Starting with the initial node, a graph is automatically constructed with new successive nodes of each new state to explore. The optimization uses a set of pre-conditions and post-conditions to create the children states. The Python language was adopted to not only enable more agile development, but to also allow the domain experts to easily define their optimization models. A graphical user interface was also developed to facilitate real-time search information feedback and interaction by the operator in the search optimization process. The HURON package has many potential uses in the fields of Operations Research and Management Science where this technology applies to many commercial domains requiring optimization to reduce costs. For example, optimizing a fleet of transportation truck routes, aircraft flight scheduling, and other route-planning scenarios involving multiple agent task optimization would all benefit by using HURON.

  6. Survival of mossy cells of the hippocampal dentate gyrus in humans with mesial temporal lobe epilepsy.

    Science.gov (United States)

    Seress, László; Abrahám, Hajnalka; Horváth, Zsolt; Dóczi, Tamás; Janszky, József; Klemm, Joyce; Byrne, Richard; Bakay, Roy A E

    2009-12-01

    Hippocampal sclerosis can be identified in most patients with mesial temporal lobe epilepsy (TLE). Surgical removal of the sclerotic hippocampus is widely performed to treat patients with drug-resistant mesial TLE. In general, both epilepsy-prone and epilepsy-resistant neurons are believed to be in the hippocampal formation. The hilar mossy cells of the hippocampal dentate gyrus are usually considered one of the most vulnerable types of neurons. The aim of this study was to clarify the fate of mossy cells in the hippocampus in epileptic humans. Of the 19 patients included in this study, 15 underwent temporal lobe resection because of drug-resistant TLE. Four patients were used as controls because they harbored tumors that had not invaded the hippocampus and they had experienced no seizures. Histological evaluation of resected hippocampal tissues was performed using immunohistochemistry. Mossy cells were identified in the control as well as the epileptic hippocampi by using cocaine- and amphetamine-regulated transcript peptide immunohistochemistry. In most cases the number of mossy cells was reduced and thorny excrescences were smaller in the epileptic hippocampi than in controls; however, there was a significant loss of pyramidal cells and a partial loss of granule cells in the same epileptic hippocampi in which mossy cell loss was apparent. The loss of mossy cells could be correlated with the extent of hippocampal sclerosis, patient age at seizure onset, duration of epilepsy, and frequency of seizures. In many cases large numbers of mossy cells were present in the hilus of the dentate gyrus when most pyramidal neurons of the CA1 and CA3 areas of the Ammon's horn were lost, suggesting that mossy cells may not be more vulnerable to epileptic seizures than the hippocampal pyramidal neurons.

  7. Retinal Vascular and Oxygen Temporal Dynamic Responses to Light Flicker in Humans.

    Science.gov (United States)

    Felder, Anthony E; Wanek, Justin; Blair, Norman P; Shahidi, Mahnaz

    2017-11-01

    To mathematically model the temporal dynamic responses of retinal vessel diameter (D), oxygen saturation (SO2), and inner retinal oxygen extraction fraction (OEF) to light flicker and to describe their responses to its cessation in humans. In 16 healthy subjects (age: 60 ± 12 years), retinal oximetry was performed before, during, and after light flicker stimulation. At each time point, five metrics were measured: retinal arterial and venous D (DA, DV) and SO2 (SO2A, SO2V), and OEF. Intra- and intersubject variability of metrics was assessed by coefficient of variation of measurements before flicker within and among subjects, respectively. Metrics during flicker were modeled by exponential functions to determine the flicker-induced steady state metric values and the time constants of changes. Metrics after the cessation of flicker were compared to those before flicker. Intra- and intersubject variability for all metrics were less than 6% and 16%, respectively. At the flicker-induced steady state, DA and DV increased by 5%, SO2V increased by 7%, and OEF decreased by 13%. The time constants of DA and DV (14, 15 seconds) were twofold smaller than those of SO2V and OEF (39, 34 seconds). Within 26 seconds after the cessation of flicker, all metrics were not significantly different from before flicker values (P ≥ 0.07). Mathematical modeling revealed considerable differences in the time courses of changes among metrics during flicker, indicating flicker duration should be considered separately for each metric. Future application of this method may be useful to elucidate alterations in temporal dynamic responses to light flicker due to retinal diseases.

  8. Vocal fold injection medialization laryngoplasty.

    Science.gov (United States)

    Modi, Vikash K

    2012-01-01

    Unilateral vocal fold paralysis (UVFP) can cause glottic insufficiency that can result in hoarseness, chronic cough, dysphagia, and/or aspiration. In rare circumstances, UVFP can cause airway obstruction necessitating a tracheostomy. The treatment options for UVFP include observation, speech therapy, vocal fold injection medialization laryngoplasty, thyroplasty, and laryngeal reinnervation. In this chapter, the author will discuss the technique of vocal fold injection for medialization of a UVFP. Copyright © 2012 S. Karger AG, Basel.

  9. Analysis of Vibrant Soundbridge placement against the round window membrane in a human cadaveric temporal bone model.

    NARCIS (Netherlands)

    Pennings, R.J.E.; Ho, A.; Brown, J.; Wijhe, R.G. van; Bance, M.

    2010-01-01

    OBJECTIVE: To evaluate optimal placement of the Floating Mass Transducer of the Vibrant Soundbridge (Med-El, Innsbruck, Austria) against the round window membrane, particularly the impact of interposed coupling fascia and of covering materials. METHOD: : Six fresh human cadaveric temporal bones were

  10. Pyramidal neurons in the septal and temporal CA1 field of the human and hedgehog tenrec hippocampus.

    Science.gov (United States)

    Liagkouras, Ioannis; Michaloudi, Helen; Batzios, Christos; Psaroulis, Dimitrios; Georgiadis, Marios; Künzle, Heinz; Papadopoulos, Georgios C

    2008-07-07

    The present study examines comparatively the cellular density of disector-counted/Nissl-stained CA1 pyramidal neurons and the morphometric characteristics (dendritic number/length, spine number/density and Sholl-counted dendritic branch points/20 microm) of the basal and apical dendritic systems of Golgi-impregnated CA1 neurons, in the septal and temporal hippocampus of the human and hedgehog tenrec brain. The obtained results indicate that in both hippocampal parts the cellular density of the CA1 pyramidal neurons is lower in human than in tenrec. However, while the human pyramidal cell density is higher in the septal hippocampal part than in the temporal one, in the tenrec the density of these cells is higher in the temporal part. The dendritic tree of the CA1 pyramidal cells, more developed in the septal than in temporal hippocampus in both species studied, is in general more complex in the human hippocampus. The basal and the apical dendritic systems exhibit species related morphometric differences, while dendrites of different orders exhibit differences in their number and length, and in their spine density. Finally, in both species, as well as hippocampal parts and dendritic systems, changes of dendritic morphometric features along ascending dendritic orders fluctuate in a similar way, as do the number of dendritic branch points in relation to the distance from the neuron soma.

  11. Spatio-temporal patterns of attacks on human and economic losses from wildlife in Chitwan National Park, Nepal

    NARCIS (Netherlands)

    Lamichhaen, B.R.; Persoon, G.A.; Leirs, H.; Poudel, S.; Subedi, N.; Pokheral, C.P.; Bhattarai, S.; Thapalia, B.P.; Iongh, de H.H.

    2018-01-01

    Wildlife attacks on humans and economic losses often result in reduced support of local communities for wildlife conservation. Information on spatial and temporal patterns of such losses in the highly affected areas contribute in designing and implementing effective mitigation measures. We analyzed

  12. Modeling the Effect of Religion on Human Empathy Based on an Adaptive Temporal-Causal Network Model

    NARCIS (Netherlands)

    van Ments, L.I.; Roelofsma, P.H.M.P.; Treur, J.

    2018-01-01

    Religion is a central aspect of many individuals’ lives around the world, and its influence on human behaviour has been extensively studied from many different perspectives. The current study integrates a number of these perspectives into one adaptive temporal-causal network model describing the

  13. Multi-view 3D human pose estimation combining single-frame recovery, temporal integration and model adaptation

    NARCIS (Netherlands)

    Hofmann, K.M.; Gavrilla, D.M.

    2009-01-01

    We present a system for the estimation of unconstrained 3D human upper body movement from multiple cameras. Its main novelty lies in the integration of three components: single frame pose recovery, temporal integration and model adaptation. Single frame pose recovery consists of a hypothesis

  14. Short-term and long-term memory in early temporal lobe dysfunction.

    Science.gov (United States)

    Hershey, T; Craft, S; Glauser, T A; Hale, S

    1998-01-01

    Following medial temporal damage, mature humans are impaired in retaining new information over long delays but not short delays. The question of whether a similar dissociation occurs in children was addressed by testing children (ages 7-16) with unilateral temporal lobe epilepsy (TLE) and controls on short- and long-term memory tasks, including a spatial delayed response task (SDR). Early-onset TLE did not affect performance on short delays on SDR, but it did impair performance at the longest delay (60 s), similar to adults with unilateral medial temporal damage. In addition, early-onset TLE affected performance on pattern recall, spatial span, and verbal span with rehearsal interference. No differences were found on story recall or on a response inhibition task.

  15. The new mid-scala electrode array: a radiologic and histologic study in human temporal bones.

    Science.gov (United States)

    Hassepass, Frederike; Bulla, Stefan; Maier, Wolfgang; Laszig, Roland; Arndt, Susan; Beck, Rainer; Traser, Lousia; Aschendorff, Antje

    2014-09-01

    To analyze the quality of insertion of the newly developed midscala (MS) electrode, which targets a midscalar electrode position to reduce the risk of trauma to the lateral wall and the modiolus. Modern cochlear implant surgery aims for a safe intracochlear placement of electrode arrays with an ongoing debate regarding cochleostomy or round window (RW) insertion and the use of lateral wall or perimodiolar electrode placement. Intracochlear trauma after insertion of different electrodes depends on insertion mode and electrode design and may result in trauma to the delicate structures of the cochlear. We performed a temporal bone (TB) trial with insertion of the MS electrode in n = 20 TB's after a mastoidectomy and posterior tympanotomy. Insertion was performed either via the RW or a cochleostomy. Electrode positioning, length of insertion, and angle of insertion were analyzed with rotational tomography (RT). TBs were histologically analyzed. Results of RT and histology were compared. Scala tympani (ST) insertion could be accomplished reliably by both RW and via a cochleostomy approach. In 20 TBs, 1 scala vestibuli insertion, 1 incomplete (ST), and 1 elevation of basilar membrane were depicted. No trauma was found in 94.7% of all ST insertions. RT allowed determination of the intracochlear electrode position, which was specified by histologic sectioning. The new MS electrode seems to fulfill reliable atraumatic intracochlear placement via RW and cochleostomy approaches. RT is available for evaluation of intracochlear electrode position, serving as a potential quality control instrument in human implantation.

  16. Interplay between the temporal dynamics of the vaginal microbiota and human papillomavirus detection.

    Science.gov (United States)

    Brotman, Rebecca M; Shardell, Michelle D; Gajer, Pawel; Tracy, J Kathleen; Zenilman, Jonathan M; Ravel, Jacques; Gravitt, Patti E

    2014-12-01

    We sought to describe the temporal relationship between vaginal microbiota and human papillomavirus (HPV) detection. Thirty-two reproductive-age women self-collected midvaginal swabs twice weekly for 16 weeks (937 samples). Vaginal bacterial communities were characterized by pyrosequencing of barcoded 16S rRNA genes and clustered into 6 community state types (CSTs). Each swab was tested for 37 HPV types. The effects of CSTs on the rate of transition between HPV-negative and HPV-positive states were assessed using continuous-time Markov models. Participants had an average of 29 samples, with HPV point prevalence between 58%-77%. CST was associated with changes in HPV status (PVaginal microbiota dominated by L. gasseri was associated with increased clearance of detectable HPV. Frequent longitudinal sampling is necessary for evaluation of the association between HPV detection and dynamic microbiota. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. Mapping human temporal and parietal neuronal population activity and functional coupling during mathematical cognition

    Science.gov (United States)

    Daitch, Amy L.; Foster, Brett L.; Schrouff, Jessica; Rangarajan, Vinitha; Kaşikçi, Itır; Gattas, Sandra; Parvizi, Josef

    2016-01-01

    Brain areas within the lateral parietal cortex (LPC) and ventral temporal cortex (VTC) have been shown to code for abstract quantity representations and for symbolic numerical representations, respectively. To explore the fast dynamics of activity within each region and the interaction between them, we used electrocorticography recordings from 16 neurosurgical subjects implanted with grids of electrodes over these two regions and tracked the activity within and between the regions as subjects performed three different numerical tasks. Although our results reconfirm the presence of math-selective hubs within the VTC and LPC, we report here a remarkable heterogeneity of neural responses within each region at both millimeter and millisecond scales. Moreover, we show that the heterogeneity of response profiles within each hub mirrors the distinct patterns of functional coupling between them. Our results support the existence of multiple bidirectional functional loops operating between discrete populations of neurons within the VTC and LPC during the visual processing of numerals and the performance of arithmetic functions. These findings reveal information about the dynamics of numerical processing in the brain and also provide insight into the fine-grained functional architecture and connectivity within the human brain. PMID:27821758

  18. Temporal characteristics of the influence of punishment on perceptual decision making in the human brain.

    Science.gov (United States)

    Blank, Helen; Biele, Guido; Heekeren, Hauke R; Philiastides, Marios G

    2013-02-27

    Perceptual decision making is the process by which information from sensory systems is combined and used to influence our behavior. In addition to the sensory input, this process can be affected by other factors, such as reward and punishment for correct and incorrect responses. To investigate the temporal dynamics of how monetary punishment influences perceptual decision making in humans, we collected electroencephalography (EEG) data during a perceptual categorization task whereby the punishment level for incorrect responses was parametrically manipulated across blocks of trials. Behaviorally, we observed improved accuracy for high relative to low punishment levels. Using multivariate linear discriminant analysis of the EEG, we identified multiple punishment-induced discriminating components with spatially distinct scalp topographies. Compared with components related to sensory evidence, components discriminating punishment levels appeared later in the trial, suggesting that punishment affects primarily late postsensory, decision-related processing. Crucially, the amplitude of these punishment components across participants was predictive of the size of the behavioral improvements induced by punishment. Finally, trial-by-trial changes in prestimulus oscillatory activity in the alpha and gamma bands were good predictors of the amplitude of these components. We discuss these findings in the context of increased motivation/attention, resulting from increases in punishment, which in turn yields improved decision-related processing.

  19. Stria vascularis and cochlear hair cell changes in syphilis: A human temporal bone study.

    Science.gov (United States)

    Hızlı, Ömer; Kaya, Serdar; Hızlı, Pelin; Paparella, Michael M; Cureoglu, Sebahattin

    2016-12-01

    To observe any changes in stria vascularis and cochlear hair cells in patients with syphilis. We examined 13 human temporal bone samples from 8 patients with syphilis (our syphilis group), as well as 12 histopathologically normal samples from 9 age-matched patients without syphilis (our control group). We compared, between the two groups, the mean area of the stria vascularis (measured with conventional light microscopy connected to a personal computer) and the mean percentage of cochlear hair cell loss (obtained from cytocochleograms). In our syphilis group, only 1 (7.7%) of the 13 samples had precipitate in the endolymphatic or perilymphatic spaces; 8 (61.5%) of the samples revealed the presence of endolymphatic hydrops (4 cochlear, 4 saccular). The mean area of the stria vascularis did not significantly differ, in any turn of the cochlea, between the 2 groups (P>0.1). However, we did find significant differences between the 2 groups in the mean percentage of outer hair cells in the apical turn (Psyphilis group, we observed either complete loss of the organ of Corti or a flattened organ of Corti without any cells in addition to the absence of both outer and inner hair cells. In this study, syphilis led either to complete loss of the organ of Corti or to significant loss of cochlear hair cells, in addition to cochleosaccular hydrops. But the area of the stria vascularis did not change. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Transient reduction in theta power caused by interictal spikes in human temporal lobe epilepsy.

    Science.gov (United States)

    Manling Ge; Jundan Guo; Yangyang Xing; Zhiguo Feng; Weide Lu; Xinxin Ma; Yuehua Geng; Xin Zhang

    2017-07-01

    The inhibitory impacts of spikes on LFP theta rhythms(4-8Hz) are investigated around sporadic spikes(SSs) based on intracerebral EEG of 4 REM sleep patients with temporal lobe epilepsy(TLE) under the pre-surgical monitoring. Sequential interictal spikes in both genesis area and extended propagation pathway are collected, that, SSs genesis only in anterior hippocampus(aH)(possible propagation pathway in Entorhinal cortex(EC)), only in EC(possible propagation pathway in aH), and in both aH and EC synchronously. Instantaneous theta power was estimated by using Gabor wavelet transform, and theta power level was estimated by averaged over time and frequency before SSs(350ms pre-spike) and after SSs(350ms post-spike). The inhibitory effect around spikes was evaluated by the ratio of theta power level difference between pre-spike and post-spike to pre-spike theta power level. The findings were that theta power level was reduced across SSs, and the effects were more sever in the case of SSs in both aH and EC synchronously than either SSs only in EC or SSs only in aH. It is concluded that interictal spikes impair LFP theta rhythms transiently and directly. The work suggests that the reduction of theta power after the interictal spike might be an evaluation indicator of damage of epilepsy to human cognitive rhythms.

  1. Differential Intracochlear Sound Pressure Measurements in Human Temporal Bones with an Off-the-Shelf Sensor

    Directory of Open Access Journals (Sweden)

    Martin Grossöhmichen

    2016-01-01

    Full Text Available The standard method to determine the output level of acoustic and mechanical stimulation to the inner ear is measurement of vibration response of the stapes in human cadaveric temporal bones (TBs by laser Doppler vibrometry. However, this method is reliable only if the intact ossicular chain is stimulated. For other stimulation modes an alternative method is needed. The differential intracochlear sound pressure between scala vestibuli (SV and scala tympani (ST is assumed to correlate with excitation. Using a custom-made pressure sensor it has been successfully measured and used to determine the output level of acoustic and mechanical stimulation. To make this method generally accessible, an off-the-shelf pressure sensor (Samba Preclin 420 LP, Samba Sensors was tested here for intracochlear sound pressure measurements. During acoustic stimulation, intracochlear sound pressures were simultaneously measurable in SV and ST between 0.1 and 8 kHz with sufficient signal-to-noise ratios with this sensor. The pressure differences were comparable to results obtained with custom-made sensors. Our results demonstrated that the pressure sensor Samba Preclin 420 LP is usable for measurements of intracochlear sound pressures in SV and ST and for the determination of differential intracochlear sound pressures.

  2. Spatio-Temporal Constrained Human Trajectory Generation from the PIR Motion Detector Sensor Network Data: A Geometric Algebra Approach.

    Science.gov (United States)

    Yu, Zhaoyuan; Yuan, Linwang; Luo, Wen; Feng, Linyao; Lv, Guonian

    2015-12-30

    Passive infrared (PIR) motion detectors, which can support long-term continuous observation, are widely used for human motion analysis. Extracting all possible trajectories from the PIR sensor networks is important. Because the PIR sensor does not log location and individual information, none of the existing methods can generate all possible human motion trajectories that satisfy various spatio-temporal constraints from the sensor activation log data. In this paper, a geometric algebra (GA)-based approach is developed to generate all possible human trajectories from the PIR sensor network data. Firstly, the representation of the geographical network, sensor activation response sequences and the human motion are represented as algebraic elements using GA. The human motion status of each sensor activation are labeled using the GA-based trajectory tracking. Then, a matrix multiplication approach is developed to dynamically generate the human trajectories according to the sensor activation log and the spatio-temporal constraints. The method is tested with the MERL motion database. Experiments show that our method can flexibly extract the major statistical pattern of the human motion. Compared with direct statistical analysis and tracklet graph method, our method can effectively extract all possible trajectories of the human motion, which makes it more accurate. Our method is also likely to provides a new way to filter other passive sensor log data in sensor networks.

  3. Spatio-Temporal Constrained Human Trajectory Generation from the PIR Motion Detector Sensor Network Data: A Geometric Algebra Approach

    Directory of Open Access Journals (Sweden)

    Zhaoyuan Yu

    2015-12-01

    Full Text Available Passive infrared (PIR motion detectors, which can support long-term continuous observation, are widely used for human motion analysis. Extracting all possible trajectories from the PIR sensor networks is important. Because the PIR sensor does not log location and individual information, none of the existing methods can generate all possible human motion trajectories that satisfy various spatio-temporal constraints from the sensor activation log data. In this paper, a geometric algebra (GA-based approach is developed to generate all possible human trajectories from the PIR sensor network data. Firstly, the representation of the geographical network, sensor activation response sequences and the human motion are represented as algebraic elements using GA. The human motion status of each sensor activation are labeled using the GA-based trajectory tracking. Then, a matrix multiplication approach is developed to dynamically generate the human trajectories according to the sensor activation log and the spatio-temporal constraints. The method is tested with the MERL motion database. Experiments show that our method can flexibly extract the major statistical pattern of the human motion. Compared with direct statistical analysis and tracklet graph method, our method can effectively extract all possible trajectories of the human motion, which makes it more accurate. Our method is also likely to provides a new way to filter other passive sensor log data in sensor networks.

  4. Temporal Dissociation of Neocortical and Hippocampal Contributions to Mental Time Travel Using Intracranial Recordings in Humans.

    Science.gov (United States)

    Schurr, Roey; Nitzan, Mor; Eliahou, Ruth; Spinelli, Laurent; Seeck, Margitta; Blanke, Olaf; Arzy, Shahar

    2018-01-01

    In mental time travel (MTT) one is "traveling" back-and-forth in time, remembering, and imagining events. Despite intensive research regarding memory processes in the hippocampus, it was only recently shown that the hippocampus plays an essential role in encoding the temporal order of events remembered, and therefore plays an important role in MTT. Does it also encode the temporal relations of these events to the remembering self? We asked patients undergoing pre-surgical evaluation with depth electrodes penetrating the temporal lobes bilaterally toward the hippocampus to project themselves in time to a past, future, or present time-point, and then make judgments regarding various events. Classification analysis of intracranial evoked potentials revealed clear temporal dissociation in the left hemisphere between lateral-temporal electrodes, activated at ~100-300 ms, and hippocampal electrodes, activated at ~400-600 ms. This dissociation may suggest a division of labor in the temporal lobe during self-projection in time, hinting toward the different roles of the lateral-temporal cortex and the hippocampus in MTT and the temporal organization of the related events with respect to the experiencing self.

  5. Assessment of spatio-temporal gait parameters from trunk accelerations during human walking

    NARCIS (Netherlands)

    Zijlstra, W; Hof, AL

    2003-01-01

    This paper studies the feasibility of an analysis of spatio-temporal gait parameters based upon accelerometry. To this purpose, acceleration patterns of the trunk and their relationships with spatio-temporal gait parameters were analysed in healthy subjects. Based on model predictions of the body's

  6. Temporal Dissociation of Neocortical and Hippocampal Contributions to Mental Time Travel Using Intracranial Recordings in Humans

    Directory of Open Access Journals (Sweden)

    Roey Schurr

    2018-02-01

    Full Text Available In mental time travel (MTT one is “traveling” back-and-forth in time, remembering, and imagining events. Despite intensive research regarding memory processes in the hippocampus, it was only recently shown that the hippocampus plays an essential role in encoding the temporal order of events remembered, and therefore plays an important role in MTT. Does it also encode the temporal relations of these events to the remembering self? We asked patients undergoing pre-surgical evaluation with depth electrodes penetrating the temporal lobes bilaterally toward the hippocampus to project themselves in time to a past, future, or present time-point, and then make judgments regarding various events. Classification analysis of intracranial evoked potentials revealed clear temporal dissociation in the left hemisphere between lateral-temporal electrodes, activated at ~100–300 ms, and hippocampal electrodes, activated at ~400–600 ms. This dissociation may suggest a division of labor in the temporal lobe during self-projection in time, hinting toward the different roles of the lateral-temporal cortex and the hippocampus in MTT and the temporal organization of the related events with respect to the experiencing self.

  7. Functional organization of the face-sensitive areas in human occipital-temporal cortex.

    Science.gov (United States)

    Shao, Hanyu; Weng, Xuchu; He, Sheng

    2017-08-15

    Human occipital-temporal cortex features several areas sensitive to faces, presumably forming the biological substrate for face perception. To date, there are piecemeal insights regarding the functional organization of these regions. They have come, however, from studies that are far from homogeneous with regard to the regions involved, the experimental design, and the data analysis approach. In order to provide an overall view of the functional organization of the face-sensitive areas, it is necessary to conduct a comprehensive study that taps into the pivotal functional properties of all the face-sensitive areas, within the context of the same experimental design, and uses multiple data analysis approaches. In this study, we identified the most robustly activated face-sensitive areas in bilateral occipital-temporal cortices (i.e., AFP, aFFA, pFFA, OFA, pcSTS, pSTS) and systemically compared their regionally averaged activation and multivoxel activation patterns to 96 images from 16 object categories, including faces and non-faces. This condition-rich and single-image analysis approach critically samples the functional properties of a brain region, allowing us to test how two basic functional properties, namely face-category selectivity and face-exemplar sensitivity are distributed among these regions. Moreover, by examining the correlational structure of neural responses to the 96 images, we characterize their interactions in the greater face-processing network. We found that (1) r-pFFA showed the highest face-category selectivity, followed by l-pFFA, bilateral aFFA and OFA, and then bilateral pcSTS. In contrast, bilateral AFP and pSTS showed low face-category selectivity; (2) l-aFFA, l-pcSTS and bilateral AFP showed evidence of face-exemplar sensitivity; (3) r-OFA showed high overall response similarities with bilateral LOC and r-pFFA, suggesting it might be a transitional stage between general and face-selective information processing; (4) r-aFFA showed high

  8. Effects of medial prefrontal cortex lesions in rats on the what-where-when memory of a fear conditioning event.

    Science.gov (United States)

    Li, Jay-Shake; Hsiao, Kun-Yuan; Chen, Wei-Min

    2011-03-17

    Previous animal studies have defined the ability to remember the details of what, where, and when of an event as an episodic-like memory to be used to model episodic memory in humans. Numerous findings indicate that the hippocampal-frontal cortical circuitry plays a major part in its neural mechanism. Researchers have intensively studied roles of diverse hippocampus sub-regions using animal models. By contrast, the impact of prefrontal cortex lesions on episodic-like memory in animals is still unknown. Here we show that Wistar rats with bilateral medial prefrontal cortex lesions failed to use the temporal-contextual information to retrieve memory of a fear-conditioning event, indicating impairments in their episodic-like memory. Subsequent experiments excluded alternative interpretations that the manipulation impaired the fear-conditioning per se, or interfered with the sensory preconditioning process. We concluded that damages in this area might impair temporal information processing, or interfere with integrating temporal and contextual elements of fear-conditioning events to form a conjunctive entity. These findings can help understand how the medial prefrontal cortex contributes to episodic-like memory. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Temporal dynamics of ocular position dependence of the initial human vestibulo-ocular reflex.

    Science.gov (United States)

    Crane, Benjamin T; Tian, Junru; Demer, Joseph L

    2006-04-01

    While an ideal vestibulo-ocular reflex (VOR) generates ocular rotations compensatory for head motion, during visually guided movements, Listing's Law (LL) constrains the eye to rotational axes lying in Listing's Plane (LP). The present study was conducted to explore the recent proposal that the VOR's rotational axis is not collinear with the head's, but rather follows a time-dependent strategy intermediate between LL and an ideal VOR. Binocular LPs were defined during visual fixation in eight normal humans. The VOR was evoked by a highly repeatable transient whole-body yaw rotation in darkness at a peak acceleration of 2800 deg/s2. Immediately before rotation, subjects regarded targets 15 or 500 cm distant located at eye level, 20 degrees up, or 20 degrees down. Eye and head responses were compared with LL predictions in the position and velocity domains. LP orientation varied both among subjects and between individual subject's eyes, and rotated temporally with convergence by 5 +/- 5 degrees (+/-SEM). In the position domain, the eye compensated for head displacement even when the head rotated out of LP. Even within the first 20 ms from onset of head rotation, the ocular velocity axis tilted relative to the head axis by 30% +/- 8% of vertical gaze position. Saccades increased this tilt. Regardless of vertical gaze position, the ocular rotation axis tilted backward 4 degrees farther in abduction than in adduction. There was also a binocular vertical eye velocity transient and lateral tilt of the ocular axis. These disconjugate, short-latency axis perturbations appear intrinsic to the VOR and may have neural or mechanical origins.

  10. Identification of photoacoustic transients during pulsed laser ablation of the human temporal bone: an experimental model.

    Science.gov (United States)

    Wong, B J; Dickinson, M R; Berns, M W; Neev, J

    1996-12-01

    Laser ablation of hard tissues during neurotologic operations has been accomplished with continuous-wave (CW) lasers in the visible and midinfrared spectrum. The mechanism of ablation at these wavelengths is secondary to photothermal-induced tissue destruction. As a result, significant thermal damage to surrounding tissue may occur. Pulsed ultraviolet (UV) lasers have been suggested as an alternative to the argon, KTP-532, and CO2 lasers currently used in clinical practice. The pulse length of Excimer lasers are considerably shorter than the thermal diffusion time of bone tissue, and as a consequence thermal injury is minimal. This makes pulsed lasers an attractive tool for tissue ablation in the ear: in essence a "cold knife." However, the short pulse width of Excimer lasers (typically 10-150 ns) can create large thermoelastic stresses in the ablation specimen. This study identifies the presence of these photoacoustic waves during the Excimer laser treatment of the cadaveric human temporal bone. A XeCl (lambda = 308 nm, tau p = 12 ns) excimer laser was used to ablate hard tissue surrounding the oval window and facial ridge with energies of 75, 45, 25, and 12 mJ/pulse. Spot size was estimated to be 0.5 mm2. Custom high-frequency polyvinyldifluoride (PVDF) piezoelectric film transducers were fabricated and attached to the promontory, round window niche, and facial ridges. The signals were amplified using a low-noise preamplifier and recorded on a digitizing oscilloscope. Photoacoustic waves were clearly identified. Notably, large acoustic waves were measured on the promontory and on both sides of the facial ridge. The implications and clinical relevance of these findings is discussed and compared to findings obtained from a model system.

  11. The relationship between chondromalacia patella, medial meniscal tear and medial periarticular bursitis in patients with osteoarthritis

    Directory of Open Access Journals (Sweden)

    Resorlu Mustafa

    2017-11-01

    Full Text Available This study investigated the presence of bursitis in the medial compartment of the knee (pes anserine, semimembranosus-tibial collateral ligament, and medial collateral ligament bursa in osteoarthritis, chondromalacia patella and medial meniscal tears.

  12. Gray and White Matter Correlates of Navigational Ability in Humans

    NARCIS (Netherlands)

    Wegman, J.B.T.; Fonteijn, H.M.; Ekert, J. van; Tyborowska, A.B.; Jansen, C.; Janzen, G.

    2014-01-01

    Humans differ widely in their navigational abilities. Studies have shown that self-reports on navigational abilities are good predictors of performance on navigation tasks in real and virtual environments. The caudate nucleus and medial temporal lobe regions have been suggested to subserve different

  13. Injerto libre braquial medial Free medial arm graft

    Directory of Open Access Journals (Sweden)

    P. Martos Díaz

    2007-12-01

    Full Text Available Introducción. Entre las reconstrucciones de defectos titulares de cabeza y cuello, el injerto libre microvascularizado braquial medial no ha adquirido mucha popularidad debido a las variaciones anatómicas que se reflejan en la vascularización de éste. Nuestro objetivo es realizar una descripción de la anatomía y técnica quirúrgica, así como una revisión de la literatura describiendo las ventajas y desventajas de este tipo de injerto. Material y método. Presentamos el caso de una paciente con carcinoma epidermoide de mucosa yugal izquierda con afectación ganglionar ipsilateral. Se procedió a su resección con márgenes más disección cervical funcional. La reconstrucción del defecto se llevó a cabo mediante un injerto libre microvascularizado braquial medial de brazo izquierdo. Discusión. Pensamos que el injerto libre braquial medial de brazo se trata de una opción más segura a la hora de la reconstrucción de defectos cervicofaciales, aportando una serie de ventajas entre las que destacan: no sacrificio de una arteria terminal, cierre primario de la zona donante, mínimo defecto estético, y poseer una piel fina, elástica y sin vello.Introduction. Free medial microvascularized arm grafts have not become very popular for the reconstruction of head and neck defects due to anatomic variations in their vascularization. Our objective was to describe the anatomy and surgical technique and to review the literature on the advantages and disadvantages of free medial arm grafts. Material and methods. We report the case of a patient with squamous cell carcinoma of the left jugal mucosa with same-side lymph node involvement. The tumor was resected with margins and a functional cervical dissection was performed. The defect was reconstructed using a free medial microvascularized graft from the left arm. Discussion. We believe that free medial arm grafts are a safer option for the reconstruction of cervicofacial defects and that they offer

  14. A MARKOV RANDOM FIELD-BASED APPROACH TO CHARACTERIZING HUMAN BRAIN DEVELOPMENT USING SPATIAL-TEMPORAL TRANSCRIPTOME DATA.

    Science.gov (United States)

    Lin, Zhixiang; Sanders, Stephan J; Li, Mingfeng; Sestan, Nenad; State, Matthew W; Zhao, Hongyu

    2015-03-01

    Human neurodevelopment is a highly regulated biological process. In this article, we study the dynamic changes of neurodevelopment through the analysis of human brain microarray data, sampled from 16 brain regions in 15 time periods of neurodevelopment. We develop a two-step inferential procedure to identify expressed and unexpressed genes and to detect differentially expressed genes between adjacent time periods. Markov Random Field (MRF) models are used to efficiently utilize the information embedded in brain region similarity and temporal dependency in our approach. We develop and implement a Monte Carlo expectation-maximization (MCEM) algorithm to estimate the model parameters. Simulation studies suggest that our approach achieves lower misclassification error and potential gain in power compared with models not incorporating spatial similarity and temporal dependency.

  15. Quantifying human exposure to air pollution - moving from static monitoring to spatio-temporally resolved personal exposure assessment

    DEFF Research Database (Denmark)

    Steinle, Susanne; Reis, Stefan; Sabel, Clive E

    2013-01-01

    exposure studies to accurately assess human health risks. ? We discuss potential and shortcomings of methods and tools with a focus on how their development influences study design. ? We propose a novel conceptual model for integrated health impact assessment of human exposure to air pollutants. ? We......Quantifying human exposure to air pollutants is a challenging task. Ambient concentrations of air pollutants at potentially harmful levels are ubiquitous in urban areas and subject to high spatial and temporal variability. At the same time, every individual has unique activity-patterns. Exposure...... results from multifaceted relationships and interactions between environmental and human systems, adding complexity to the assessment process. Traditionally, approaches to quantify human exposure have relied on pollutant concentrations from fixed air quality network sites and static population...

  16. Modeling the Effect of Religion on Human Empathy Based on an Adaptive Temporal-Causal Network Model

    OpenAIRE

    van Ments, L.I.; Roelofsma, P.H.M.P.; Treur, J.

    2018-01-01

    Religion is a central aspect of many individuals’ lives around the world, and its influence on human behaviour has been extensively studied from many different perspectives. The current study integrates a number of these perspectives into one adaptive temporal-causal network model describing the mental states involved, their mutual relations, and the adaptation of some of these relations over time due to learning. By first developing a conceptual representation of a network model based on lit...

  17. Characterization of neurons in the cortical white matter in human temporal lobe epilepsy.

    Science.gov (United States)

    Richter, Zsófia; Janszky, József; Sétáló, György; Horváth, Réka; Horváth, Zsolt; Dóczi, Tamás; Seress, László; Ábrahám, Hajnalka

    2016-10-01

    The aim of the present work was to characterize neurons in the archi- and neocortical white matter, and to investigate their distribution in mesial temporal sclerosis. Immunohistochemistry and quantification of neurons were performed on surgically resected tissue sections of patients with therapy-resistant temporal lobe epilepsy. Temporal lobe tissues of patients with tumor but without epilepsy and that from autopsy were used as controls. Neurons were identified with immunohistochemistry using antibodies against NeuN, calcium-binding proteins, transcription factor Tbr1 and neurofilaments. We found significantly higher density of neurons in the archi- and neocortical white matter of patients with temporal lobe epilepsy than in that of controls. Based on their morphology and neurochemical content, both excitatory and inhibitory cells were present among these neurons. A subset of neurons in the white matter was Tbr-1-immunoreactive and these neurons coexpressed NeuN and neurofilament marker SMI311R. No colocalization of Tbr1 was observed with the inhibitory neuronal markers, calcium-binding proteins. We suggest that a large population of white matter neurons comprises remnants of the subplate. Furthermore, we propose that a subset of white matter neurons was arrested during migration, highlighting the role of cortical maldevelopment in epilepsy associated with mesial temporal sclerosis. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  18. Project Temporalities

    DEFF Research Database (Denmark)

    Tryggestad, Kjell; Justesen, Lise; Mouritsen, Jan

    2013-01-01

    Purpose – The purpose of this paper is to explore how animals can become stakeholders in interaction with project management technologies and what happens with project temporalities when new and surprising stakeholders become part of a project and a recognized matter of concern to be taken...... into account. Design/methodology/approach – The paper is based on a qualitative case study of a project in the building industry. The authors use actor-network theory (ANT) to analyze the emergence of animal stakeholders, stakes and temporalities. Findings – The study shows how project temporalities can...... multiply in interaction with project management technologies and how conventional linear conceptions of project time may be contested with the emergence of new non-human stakeholders and temporalities. Research limitations/implications – The study draws on ANT to show how animals can become stakeholders...

  19. Medial Canthoplasty Combined with Conjunctivodacryocystorhinostomy for the Treatment of Delayed Medial Telecanthal Deformity

    Directory of Open Access Journals (Sweden)

    Hua Sun

    2017-01-01

    Conclusions: Medial canthoplasty combined with CDCR is an effective surgical method for treatment of patients with medial telecanthal deformity and lacrimal drainage system obstruction. The study indicates that medial canthoplasty combined with CDCR surgery rebuilds normal appearance of eyelid and contour of the medial canthus and successfully repairs the function of the lacrimal drainage system.

  20. Transcriptomic analysis across nasal, temporal, and macular regions of human neural retina and RPE/choroid by RNA-Seq

    Science.gov (United States)

    Whitmore, S. Scott; Wagner, Alex H.; DeLuca, Adam P.; Drack, Arlene V.; Stone, Edwin M.; Tucker, Budd A.; Zeng, Shemin; Braun, Terry A.; Mullins, Robert F.; Scheetz, Todd E.

    2014-01-01

    Proper spatial differentiation of retinal cell types is necessary for normal human vision. Many retinal diseases, such as Best disease and male germ cell associated kinase (MAK)-associated retinitis pigmentosa, preferentially affect distinct topographic regions of the retina. While much is known about the distribution of cell-types in the retina, the distribution of molecular components across the posterior pole of the eye has not been well-studied. To investigate regional difference in molecular composition of ocular tissues, we assessed differential gene expression across the temporal, macular, and nasal retina and retinal pigment epithelium (RPE)/choroid of human eyes using RNA-Seq. RNA from temporal, macular, and nasal retina and RPE/choroid from four human donor eyes was extracted, poly-A selected, fragmented, and sequenced as 100 bp read pairs. Digital read files were mapped to the human genome and analyzed for differential expression using the Tuxedo software suite. Retina and RPE/choroid samples were clearly distinguishable at the transcriptome level. Numerous transcription factors were differentially expressed between regions of the retina and RPE/choroid. Photoreceptor-specific genes were enriched in the peripheral samples, while ganglion cell and amacrine cell genes were enriched in the macula. Within the RPE/choroid, RPE-specific genes were upregulated at the periphery while endothelium associated genes were upregulated in the macula. Consistent with previous studies, BEST1 expression was lower in macular than extramacular regions. The MAK gene was expressed at lower levels in macula than in extramacular regions, but did not exhibit a significant difference between nasal and temporal retina. The regional molecular distinction is greatest between macula and periphery and decreases between different peripheral regions within a tissue. Datasets such as these can be used to prioritize candidate genes for possible involvement in retinal diseases with

  1. Transcriptomic analysis across nasal, temporal, and macular regions of human neural retina and RPE/choroid by RNA-Seq.

    Science.gov (United States)

    Whitmore, S Scott; Wagner, Alex H; DeLuca, Adam P; Drack, Arlene V; Stone, Edwin M; Tucker, Budd A; Zeng, Shemin; Braun, Terry A; Mullins, Robert F; Scheetz, Todd E

    2014-12-01

    Proper spatial differentiation of retinal cell types is necessary for normal human vision. Many retinal diseases, such as Best disease and male germ cell associated kinase (MAK)-associated retinitis pigmentosa, preferentially affect distinct topographic regions of the retina. While much is known about the distribution of cell types in the retina, the distribution of molecular components across the posterior pole of the eye has not been well-studied. To investigate regional difference in molecular composition of ocular tissues, we assessed differential gene expression across the temporal, macular, and nasal retina and retinal pigment epithelium (RPE)/choroid of human eyes using RNA-Seq. RNA from temporal, macular, and nasal retina and RPE/choroid from four human donor eyes was extracted, poly-A selected, fragmented, and sequenced as 100 bp read pairs. Digital read files were mapped to the human genome and analyzed for differential expression using the Tuxedo software suite. Retina and RPE/choroid samples were clearly distinguishable at the transcriptome level. Numerous transcription factors were differentially expressed between regions of the retina and RPE/choroid. Photoreceptor-specific genes were enriched in the peripheral samples, while ganglion cell and amacrine cell genes were enriched in the macula. Within the RPE/choroid, RPE-specific genes were upregulated at the periphery while endothelium associated genes were upregulated in the macula. Consistent with previous studies, BEST1 expression was lower in macular than extramacular regions. The MAK gene was expressed at lower levels in macula than in extramacular regions, but did not exhibit a significant difference between nasal and temporal retina. The regional molecular distinction is greatest between macula and periphery and decreases between different peripheral regions within a tissue. Datasets such as these can be used to prioritize candidate genes for possible involvement in retinal diseases with

  2. Medial tibial “spackling” to lessen chronic medial tibial soft tissue irritation

    Directory of Open Access Journals (Sweden)

    J. Ryan Martin, MD

    2016-09-01

    Full Text Available We describe a unique, utilitarian reconstructive treatment option known as tibial “spackling” for chronic, localized medial joint line pain corresponding with progressive radiographic peripheral medial tibial bone loss beneath a well-fixed revision total knee arthroplasty tibial baseplate. It is believed that this localized pain is due to chronic irritation of the medial capsule and collateral ligament from the prominent medial edge of the tibial component. In the setting of failed nonoperative treatment, our experience with utilizing bone cement to reconstruct the medial tibial bone defect and create a smooth medial tibial surface has been successful in eliminating chronic medial soft tissue irritation.

  3. T-pattern analysis for the study of temporal structure of animal and human behavior: a comprehensive review.

    Science.gov (United States)

    Casarrubea, M; Jonsson, G K; Faulisi, F; Sorbera, F; Di Giovanni, G; Benigno, A; Crescimanno, G; Magnusson, M S

    2015-01-15

    A basic tenet in the realm of modern behavioral sciences is that behavior consists of patterns in time. For this reason, investigations of behavior deal with sequences that are not easily perceivable by the unaided observer. This problem calls for improved means of detection, data handling and analysis. This review focuses on the analysis of the temporal structure of behavior carried out by means of a multivariate approach known as T-pattern analysis. Using this technique, recurring sequences of behavioral events, usually hard to detect, can be unveiled and carefully described. T-pattern analysis has been successfully applied in the study of various aspects of human or animal behavior such as behavioral modifications in neuro-psychiatric diseases, route-tracing stereotypy in mice, interaction between human subjects and animal or artificial agents, hormonal-behavioral interactions, patterns of behavior associated with emesis and, in our laboratories, exploration and anxiety-related behaviors in rodents. After describing the theory and concepts of T-pattern analysis, this review will focus on the application of the analysis to the study of the temporal characteristics of behavior in different species from rodents to human beings. This work could represent a useful background for researchers who intend to employ such a refined multivariate approach to the study of behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Epidemiological features and risk factors associated with the spatial and temporal distribution of human brucellosis in China

    Science.gov (United States)

    2013-01-01

    Background Human brucellosis incidence in China has been increasing dramatically since 1999. However, epidemiological features and potential factors underlying the re-emergence of the disease remain less understood. Methods Data on human and animal brucellosis cases at the county scale were collected for the year 2004 to 2010. Also collected were environmental and socioeconomic variables. Epidemiological features including spatial and temporal patterns of the disease were characterized, and the potential factors related to the spatial heterogeneity and the temporal trend of were analysed using Poisson regression analysis, Granger causality analysis, and autoregressive distributed lag (ADL) models, respectively. Results The epidemic showed a significantly higher spatial correlation with the number of sheep and goats than swine and cattle. The disease was most prevalent in grassland areas with elevation between 800–1,600 meters. The ADL models revealed that local epidemics were correlated with comparatively lower temperatures and less sunshine in winter and spring, with a 1–7 month lag before the epidemic peak in May. Conclusions Our findings indicate that human brucellosis tended to occur most commonly in grasslands at moderate elevation where sheep and goats were the predominant livestock, and in years with cooler winter and spring or less sunshine. PMID:24238301

  5. Spatio-temporal re-organization of replication foci accompanies replication domain consolidation during human pluripotent stem cell lineage specification

    Science.gov (United States)

    Wilson, Korey A.; Elefanty, Andrew G.; Stanley, Edouard G.; Gilbert, David M.

    2016-01-01

    ABSTRACT Lineage specification of both mouse and human pluripotent stem cells (PSCs) is accompanied by spatial consolidation of chromosome domains and temporal consolidation of their replication timing. Replication timing and chromatin organization are both established during G1 phase at the timing decision point (TDP). Here, we have developed live cell imaging tools to track spatio-temporal replication domain consolidation during differentiation. First, we demonstrate that the fluorescence ubiquitination cell cycle indicator (Fucci) system is incapable of demarcating G1/S or G2/M cell cycle transitions. Instead, we employ a combination of fluorescent PCNA to monitor S phase progression, cytokinesis to demarcate mitosis, and fluorescent nucleotides to label early and late replication foci and track their 3D organization into sub-nuclear chromatin compartments throughout all cell cycle transitions. We find that, as human PSCs differentiate, the length of S phase devoted to replication of spatially clustered replication foci increases, coincident with global compartmentalization of domains into temporally clustered blocks of chromatin. Importantly, re-localization and anchorage of domains was completed prior to the onset of S phase, even in the context of an abbreviated PSC G1 phase. This approach can also be employed to investigate cell fate transitions in single PSCs, which could be seen to differentiate preferentially from G1 phase. Together, our results establish real-time, live-cell imaging methods for tracking cell cycle transitions during human PSC differentiation that can be applied to study chromosome domain consolidation and other aspects of lineage specification. PMID:27433885

  6. A Postmortem Study of Frontal and Temporal Gyri Thickness and Cell Number in Human Obesity.

    Science.gov (United States)

    Gómez-Apo, Erick; García-Sierra, Adrián; Silva-Pereyra, Juan; Soto-Abraham, Virgilia; Mondragón-Maya, Alejandra; Velasco-Vales, Verónica; Pescatello, Linda S

    2018-01-01

    This study aimed to compare cortex thickness and neuronal cell density in postmortem brain tissue from people with overweight or obesity and normal weight. The cortex thickness and neuron density of eight donors with overweight or obesity (mean = 31.6 kg/m 2 ; SD = 4.35; n = 8; 6 male) and eight donors with normal weight (mean = 21.8 kg/m 2 ; SD = 1.5; n = 8; 5 male) were compared. All participants were Mexican and lived in Mexico City. Randomly selected thickness measures of different cortex areas from the frontal and temporal lobes were analyzed based on high-resolution real-size photographs. A histological analysis of systematic-random fields was used to quantify the number of neurons in postmortem left and right of the first, second, and third gyri of frontal and temporal lobe brain samples. No statistical difference was found in cortical thickness between donors with overweight or obesity and individuals with normal weight. A smaller number of neurons was found among the donors with overweight or obesity than the donors with normal weight at different frontal and temporal areas. A lower density of neurons is associated with overweight or obesity. The morphological basis for structural brain changes in obesity requires further investigation. © 2017 The Obesity Society.

  7. Hippocampus, Perirhinal Cortex, and Complex Visual Discriminations in Rats and Humans

    Science.gov (United States)

    Hales, Jena B.; Broadbent, Nicola J.; Velu, Priya D.; Squire, Larry R.; Clark, Robert E.

    2015-01-01

    Structures in the medial temporal lobe, including the hippocampus and perirhinal cortex, are known to be essential for the formation of long-term memory. Recent animal and human studies have investigated whether perirhinal cortex might also be important for visual perception. In our study, using a simultaneous oddity discrimination task, rats with…

  8. Temporal and Spatial Impact of Human Cadaver Decomposition on Soil Bacterial and Arthropod Community Structure and Function

    Science.gov (United States)

    Singh, Baneshwar; Minick, Kevan J.; Strickland, Michael S.; Wickings, Kyle G.; Crippen, Tawni L.; Tarone, Aaron M.; Benbow, M. Eric; Sufrin, Ness; Tomberlin, Jeffery K.; Pechal, Jennifer L.

    2018-01-01

    As vertebrate carrion decomposes, there is a release of nutrient-rich fluids into the underlying soil, which can impact associated biological community structure and function. How these changes alter soil biogeochemical cycles is relatively unknown and may prove useful in the identification of carrion decomposition islands that have long lasting, focal ecological effects. This study investigated the spatial (0, 1, and 5 m) and temporal (3–732 days) dynamics of human cadaver decomposition on soil bacterial and arthropod community structure and microbial function. We observed strong evidence of a predictable response to cadaver decomposition that varies over space for soil bacterial and arthropod community structure, carbon (C) mineralization and microbial substrate utilization patterns. In the presence of a cadaver (i.e., 0 m samples), the relative abundance of Bacteroidetes and Firmicutes was greater, while the relative abundance of Acidobacteria, Chloroflexi, Gemmatimonadetes, and Verrucomicrobia was lower when compared to samples at 1 and 5 m. Micro-arthropods were more abundant (15 to 17-fold) in soils collected at 0 m compared to either 1 or 5 m, but overall, micro-arthropod community composition was unrelated to either bacterial community composition or function. Bacterial community structure and microbial function also exhibited temporal relationships, whereas arthropod community structure did not. Cumulative precipitation was more effective in predicting temporal variations in bacterial abundance and microbial activity than accumulated degree days. In the presence of the cadaver (i.e., 0 m samples), the relative abundance of Actinobacteria increased significantly with cumulative precipitation. Furthermore, soil bacterial communities and C mineralization were sensitive to the introduction of human cadavers as they diverged from baseline levels and did not recover completely in approximately 2 years. These data are valuable for understanding ecosystem

  9. Temporal and Spatial Impact of Human Cadaver Decomposition on Soil Bacterial and Arthropod Community Structure and Function

    Directory of Open Access Journals (Sweden)

    Baneshwar Singh

    2018-01-01

    Full Text Available As vertebrate carrion decomposes, there is a release of nutrient-rich fluids into the underlying soil, which can impact associated biological community structure and function. How these changes alter soil biogeochemical cycles is relatively unknown and may prove useful in the identification of carrion decomposition islands that have long lasting, focal ecological effects. This study investigated the spatial (0, 1, and 5 m and temporal (3–732 days dynamics of human cadaver decomposition on soil bacterial and arthropod community structure and microbial function. We observed strong evidence of a predictable response to cadaver decomposition that varies over space for soil bacterial and arthropod community structure, carbon (C mineralization and microbial substrate utilization patterns. In the presence of a cadaver (i.e., 0 m samples, the relative abundance of Bacteroidetes and Firmicutes was greater, while the relative abundance of Acidobacteria, Chloroflexi, Gemmatimonadetes, and Verrucomicrobia was lower when compared to samples at 1 and 5 m. Micro-arthropods were more abundant (15 to 17-fold in soils collected at 0 m compared to either 1 or 5 m, but overall, micro-arthropod community composition was unrelated to either bacterial community composition or function. Bacterial community structure and microbial function also exhibited temporal relationships, whereas arthropod community structure did not. Cumulative precipitation was more effective in predicting temporal variations in bacterial abundance and microbial activity than accumulated degree days. In the presence of the cadaver (i.e., 0 m samples, the relative abundance of Actinobacteria increased significantly with cumulative precipitation. Furthermore, soil bacterial communities and C mineralization were sensitive to the introduction of human cadavers as they diverged from baseline levels and did not recover completely in approximately 2 years. These data are valuable for understanding

  10. Temporal aspects of DNA and RNA synthesis during human immunodeficiency virus infection: Evidence for differential gene expression

    International Nuclear Information System (INIS)

    Kim, Sunyoung; Baltimore, D.; Byrn, R.; Groopman, J.

    1989-01-01

    The kinetics of retroviral DNA and RNA synthesis are parameters vital to understanding viral growth, especially for human immunodeficiency virus (HIV), which encodes several of its own regulatory genes. The authors have established a single-cycle growth condition for HIV in H9 cells, a human CD4 + lymphocyte line. The full-length viral linear DNA is first detectable by 4 h postinfection. During a one-step growth of HIV, amounts of viral DNA gradually increase until 8 to 12 h postinfection and then decrease. The copy number of unintegrated viral DNA is not extraordinarily high even at its peak. Most strikingly, there is a temporal program of RNA accumulation: the earliest RNA is greatly enriched in the 2-kilobase subgenomic mRNA species, while the level of 9.2-kilobase RNA which is both genomic RNA and mRNA remains low until after 24 h of infection. Virus production begins at about 24 h postinfection. Thus, viral DNA synthesis is as rapid as for other retroviruses, but viral RNA synthesis involves temporal alteration in the species that accumulate, presumably as a consequence of viral regulatory genes

  11. Quantifying human exposure to air pollution--moving from static monitoring to spatio-temporally resolved personal exposure assessment.

    Science.gov (United States)

    Steinle, Susanne; Reis, Stefan; Sabel, Clive Eric

    2013-01-15

    Quantifying human exposure to air pollutants is a challenging task. Ambient concentrations of air pollutants at potentially harmful levels are ubiquitous in urban areas and subject to high spatial and temporal variability. At the same time, every individual has unique activity-patterns. Exposure results from multifaceted relationships and interactions between environmental and human systems, adding complexity to the assessment process. Traditionally, approaches to quantify human exposure have relied on pollutant concentrations from fixed air quality network sites and static population distributions. New developments in sensor technology now enable us to monitor personal exposure to air pollutants directly while people are moving through their activity spaces and varying concentration fields. The literature review on which this paper is based on reflects recent developments in the assessment of human exposure to air pollution. This includes the discussion of methodologies and concepts, and the elaboration of approaches and study designs applied in the field. We identify shortcomings of current approaches and discuss future research needs. We close by proposing a novel conceptual model for the integrated assessment of human exposure to air pollutants taking into account latest technological capabilities and contextual information. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Acute Medial Plantar Fascia Tear.

    Science.gov (United States)

    Pascoe, Stephanie C; Mazzola, Timothy J

    2016-06-01

    A 32-year-old man who participated in competitive soccer came to physical therapy via direct access for a chief complaint of plantar foot pain. The clinical examination findings and mechanism of injury raised a concern for a plantar fascia tear, so the patient was referred to the physician and magnetic resonance imaging was obtained. The magnetic resonance image confirmed a high-grade, partial-thickness, proximal plantar fascia tear with localized edema at the location of the medial band. J Orthop Sports Phys Ther 2016;46(6):495. doi:10.2519/jospt.2016.0409.

  13. Using Temporal Covariance of Motion and Geometric Features via Boosting for Human Fall Detection.

    Science.gov (United States)

    Ali, Syed Farooq; Khan, Reamsha; Mahmood, Arif; Hassan, Malik Tahir; Jeon, And Moongu

    2018-06-12

    Fall induced damages are serious incidences for aged as well as young persons. A real-time automatic and accurate fall detection system can play a vital role in timely medication care which will ultimately help to decrease the damages and complications. In this paper, we propose a fast and more accurate real-time system which can detect people falling in videos captured by surveillance cameras. Novel temporal and spatial variance-based features are proposed which comprise the discriminatory motion, geometric orientation and location of the person. These features are used along with ensemble learning strategy of boosting with J48 and Adaboost classifiers. Experiments have been conducted on publicly available standard datasets including Multiple Cameras Fall ( with 2 classes and 3 classes ) and UR Fall Detection achieving percentage accuracies of 99.2, 99.25 and 99.0, respectively. Comparisons with nine state-of-the-art methods demonstrate the effectiveness of the proposed approach on both datasets.

  14. An Approximation to the Temporal Order in Endogenous Circadian Rhythms of Genes Implicated in Human Adipose Tissue Metabolism

    Science.gov (United States)

    GARAULET, MARTA; ORDOVÁS, JOSÉ M.; GÓMEZ-ABELLÁN, PURIFICACIÓN; MARTÍNEZ, JOSE A.; MADRID, JUAN A.

    2015-01-01

    Although it is well established that human adipose tissue (AT) shows circadian rhythmicity, published studies have been discussed as if tissues or systems showed only one or few circadian rhythms at a time. To provide an overall view of the internal temporal order of circadian rhythms in human AT including genes implicated in metabolic processes such as energy intake and expenditure, insulin resistance, adipocyte differentiation, dyslipidemia, and body fat distribution. Visceral and subcutaneous abdominal AT biopsies (n = 6) were obtained from morbid obese women (BMI ≥ 40 kg/m2). To investigate rhythmic expression pattern, AT explants were cultured during 24-h and gene expression was analyzed at the following times: 08:00, 14:00, 20:00, 02:00 h using quantitative real-time PCR. Clock genes, glucocorticoid metabolism-related genes, leptin, adiponectin and their receptors were studied. Significant differences were found both in achrophases and relative-amplitude among genes (P 30%). When interpreting the phase map of gene expression in both depots, data indicated that circadian rhythmicity of the genes studied followed a predictable physiological pattern, particularly for subcutaneous AT. Interesting are the relationships between adiponectin, leptin, and glucocorticoid metabolism-related genes circadian profiles. Their metabolic significance is discussed. Visceral AT behaved in a different way than subcutaneous for most of the genes studied. For every gene, protein mRNA levels fluctuated during the day in synchrony with its receptors. We have provided an overall view of the internal temporal order of circadian rhythms in human adipose tissue. PMID:21520059

  15. Snapping Knee Caused by Medial Meniscal Cyst

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Ohishi

    2014-01-01

    Full Text Available Snapping phenomenon around the medial aspect of the knee is rare. We present this case of snapping knee caused by the sartorius muscle over a large medial meniscal cyst in a 66-year-old female. Magnetic resonance images demonstrated a large medial meniscal cyst with a horizontal tear of the medial meniscus. Arthroscopic cyst decompression with limited meniscectomy resulted in the disappearance of snapping, and no recurrence of the cyst was observed during a 2-year follow-up period.

  16. The 'temporal effect' in hominids: Reinvestigating the nature of support for a chimp-human clade in bone morphology.

    Science.gov (United States)

    Pearson, Alannah; Groves, Colin; Cardini, Andrea

    2015-11-01

    In 2004, an analysis by Lockwood and colleagues of hard-tissue morphology, using geometric morphometrics on the temporal bone, succeeded in recovering the correct phylogeny of living hominids without resorting to potentially problematic methods for transforming continuous shape variables into meristic characters. That work has increased hope that by using modern analytical methods and phylogenetically informative anatomical data we might one day be able to accurately infer the relationships of hominins, including the closest extinct relatives of modern humans. In the present study, using 3D virtually generated models of the hominid temporal bone and a larger suite of geometric morphometric and comparative techniques, we have re-examined the evidence for a Pan-Homo clade. Despite differences in samples, as well as the type of raw data, the effect of measurement error (and especially landmark digitization by a different operator), but also a broader perspective brought in by our diverse set of approaches, our reanalysis largely supports Lockwood and colleagues' original results. However, by focusing not only mainly on shape (as in the original 2004 analysis) but also on size and 'size-corrected' (non-allometric) shape, we demonstrate that the strong phylogenetic signal in the temporal bone is largely related to similarities in size. Thus, with this study, we are not suggesting the use of a single 'character', such as size, for phylogenetic inference, but we do challenge the common view that shape, with its highly complex and multivariate nature, is necessarily more phylogenetically informative than size and that actually size and size-related shape variation (i.e., allometry) confound phylogenetic inference based on morphology. This perspective may in fact be less generalizable than often believed. Thus, while we confirm the original findings by Lockwood et al., we provide a deep reinterpretation of their nature and potential implications for hominid phylogenetics

  17. Burying dogs in ancient Cis-Baikal, Siberia: temporal trends and relationships with human diet and subsistence practices.

    Directory of Open Access Journals (Sweden)

    Robert J Losey

    Full Text Available The first objective of this study is to examine temporal patterns in ancient dog burials in the Lake Baikal region of Eastern Siberia. The second objective is to determine if the practice of dog burial here can be correlated with patterns in human subsistence practices, in particular a reliance on terrestrial mammals. Direct radiocarbon dating of a suite of the region's dog remains indicates that these animals were given burial only during periods in which human burials were common. Dog burials of any kind were most common during the Early Neolithic (∼7-8000 B.P., and rare during all other time periods. Further, only foraging groups seem to have buried canids in this region, as pastoralist habitation sites and cemeteries generally lack dog interments, with the exception of sacrificed animals. Stable carbon and nitrogen isotope data indicate that dogs were only buried where and when human diets were relatively rich in aquatic foods, which here most likely included river and lake fish and Baikal seal (Phoca sibirica. Generally, human and dog diets appear to have been similar across the study subregions, and this is important for interpreting their radiocarbon dates, and comparing them to those obtained on the region's human remains, both of which likely carry a freshwater old carbon bias. Slight offsets were observed in the isotope values of dogs and humans in our samples, particularly where both have diets rich in aquatic fauna. This may result from dietary differences between people and their dogs, perhaps due to consuming fish of different sizes, or even different tissues from the same aquatic fauna. This paper also provides a first glimpse of the DNA of ancient canids in Northeast Asia.

  18. Burying dogs in ancient Cis-Baikal, Siberia: temporal trends and relationships with human diet and subsistence practices.

    Science.gov (United States)

    Losey, Robert J; Garvie-Lok, Sandra; Leonard, Jennifer A; Katzenberg, M Anne; Germonpré, Mietje; Nomokonova, Tatiana; Sablin, Mikhail V; Goriunova, Olga I; Berdnikova, Natalia E; Savel'ev, Nikolai A

    2013-01-01

    The first objective of this study is to examine temporal patterns in ancient dog burials in the Lake Baikal region of Eastern Siberia. The second objective is to determine if the practice of dog burial here can be correlated with patterns in human subsistence practices, in particular a reliance on terrestrial mammals. Direct radiocarbon dating of a suite of the region's dog remains indicates that these animals were given burial only during periods in which human burials were common. Dog burials of any kind were most common during the Early Neolithic (∼7-8000 B.P.), and rare during all other time periods. Further, only foraging groups seem to have buried canids in this region, as pastoralist habitation sites and cemeteries generally lack dog interments, with the exception of sacrificed animals. Stable carbon and nitrogen isotope data indicate that dogs were only buried where and when human diets were relatively rich in aquatic foods, which here most likely included river and lake fish and Baikal seal (Phoca sibirica). Generally, human and dog diets appear to have been similar across the study subregions, and this is important for interpreting their radiocarbon dates, and comparing them to those obtained on the region's human remains, both of which likely carry a freshwater old carbon bias. Slight offsets were observed in the isotope values of dogs and humans in our samples, particularly where both have diets rich in aquatic fauna. This may result from dietary differences between people and their dogs, perhaps due to consuming fish of different sizes, or even different tissues from the same aquatic fauna. This paper also provides a first glimpse of the DNA of ancient canids in Northeast Asia.

  19. Spatio-temporal patterns of attacks on human and economic losses from wildlife in Chitwan National Park, Nepal.

    Science.gov (United States)

    Lamichhane, Babu Ram; Persoon, Gerard A; Leirs, Herwig; Poudel, Shashank; Subedi, Naresh; Pokheral, Chiranjibi Prasad; Bhattarai, Santosh; Thapaliya, Bishnu Prasad; de Iongh, Hans H

    2018-01-01

    Wildlife attacks on humans and economic losses often result in reduced support of local communities for wildlife conservation. Information on spatial and temporal patterns of such losses in the highly affected areas contribute in designing and implementing effective mitigation measures. We analyzed the loss of humans, livestock and property caused by wildlife during 1998 to 2016, using victim family's reports to Chitwan National Park authorities and Buffer Zone User Committees. A total of 4,014 incidents were recorded including attacks on humans, livestock depredation, property damage and crop raiding caused by 12 wildlife species. In total >400,000 US dollar was paid to the victim families as a relief over the whole period. Most of the attacks on humans were caused by rhino, sloth bear, tiger, elephant, wild boar and leopard. A significantly higher number of conflict incidents caused by rhino and elephant were observed during full moon periods. An increase in the wildlife population did not coincide with an equal rise in conflict incidents reported. Underprivileged ethnic communities were attacked by wildlife more frequently than expected. Number of attacks on humans by carnivores and herbivores did not differ significantly. An insignificant decreasing trend of wildlife attacks on humans and livestock was observed with significant variation over the years. Tiger and leopard caused >90% of livestock depredation. Tigers killed both large (cattle and buffalo) and medium sized (goat, sheep, pig) livestock but leopard mostly killed medium sized livestock. Most (87%) of the livestock killing during 2012-2016 occurred within the stall but close (conflict mitigation measures (electric and mesh wire fences) have contributed to keep the conflict incidents in control. Strengthening mitigation measures like construction of electric or mesh wire fences and predator-proof livestock corrals along with educating local communities about wildlife behavior and timely management of

  20. Temporal differentiation across a West-European Y-chromosomal cline: genealogy as a tool in human population genetics.

    Science.gov (United States)

    Larmuseau, Maarten H D; Ottoni, Claudio; Raeymaekers, Joost A M; Vanderheyden, Nancy; Larmuseau, Hendrik F M; Decorte, Ronny

    2012-04-01

    The pattern of population genetic variation and allele frequencies within a species are unstable and are changing over time according to different evolutionary factors. For humans, it is possible to combine detailed patrilineal genealogical records with deep Y-chromosome (Y-chr) genotyping to disentangle signals of historical population genetic structures because of the exponential increase in genetic genealogical data. To test this approach, we studied the temporal pattern of the 'autochthonous' micro-geographical genetic structure in the region of Brabant in Belgium and the Netherlands (Northwest Europe). Genealogical data of 881 individuals from Northwest Europe were collected, from which 634 family trees showed a residence within Brabant for at least one generation. The Y-chr genetic variation of the 634 participants was investigated using 110 Y-SNPs and 38 Y-STRs and linked to particular locations within Brabant on specific time periods based on genealogical records. Significant temporal variation in the Y-chr distribution was detected through a north-south gradient in the frequencies distribution of sub-haplogroup R1b1b2a1 (R-U106), next to an opposite trend for R1b1b2a2g (R-U152). The gradient on R-U106 faded in time and even became totally invisible during the Industrial Revolution in the first half of the nineteenth century. Therefore, genealogical data for at least 200 years are required to study small-scale 'autochthonous' population structure in Western Europe.

  1. Temporally coordinated spiking activity of human induced pluripotent stem cell-derived neurons co-cultured with astrocytes.

    Science.gov (United States)

    Kayama, Tasuku; Suzuki, Ikuro; Odawara, Aoi; Sasaki, Takuya; Ikegaya, Yuji

    2018-01-01

    In culture conditions, human induced-pluripotent stem cells (hiPSC)-derived neurons form synaptic connections with other cells and establish neuronal networks, which are expected to be an in vitro model system for drug discovery screening and toxicity testing. While early studies demonstrated effects of co-culture of hiPSC-derived neurons with astroglial cells on survival and maturation of hiPSC-derived neurons, the population spiking patterns of such hiPSC-derived neurons have not been fully characterized. In this study, we analyzed temporal spiking patterns of hiPSC-derived neurons recorded by a multi-electrode array system. We discovered that specific sets of hiPSC-derived neurons co-cultured with astrocytes showed more frequent and highly coherent non-random synchronized spike trains and more dynamic changes in overall spike patterns over time. These temporally coordinated spiking patterns are physiological signs of organized circuits of hiPSC-derived neurons and suggest benefits of co-culture of hiPSC-derived neurons with astrocytes. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Ocular-following responses to white noise stimuli in humans reveal a novel nonlinearity that results from temporal sampling.

    Science.gov (United States)

    Sheliga, Boris M; Quaia, Christian; FitzGibbon, Edmond J; Cumming, Bruce G

    2016-01-01

    White noise stimuli are frequently used to study the visual processing of broadband images in the laboratory. A common goal is to describe how responses are derived from Fourier components in the image. We investigated this issue by recording the ocular-following responses (OFRs) to white noise stimuli in human subjects. For a given speed we compared OFRs to unfiltered white noise with those to noise filtered with band-pass filters and notch filters. Removing components with low spatial frequency (SF) reduced OFR magnitudes, and the SF associated with the greatest reduction matched the SF that produced the maximal response when presented alone. This reduction declined rapidly with SF, compatible with a winner-take-all operation. Removing higher SF components increased OFR magnitudes. For higher speeds this effect became larger and propagated toward lower SFs. All of these effects were quantitatively well described by a model that combined two factors: (a) an excitatory drive that reflected the OFRs to individual Fourier components and (b) a suppression by higher SF channels where the temporal sampling of the display led to flicker. This nonlinear interaction has an important practical implication: Even with high refresh rates (150 Hz), the temporal sampling introduced by visual displays has a significant impact on visual processing. For instance, we show that this distorts speed tuning curves, shifting the peak to lower speeds. Careful attention to spectral content, in the light of this nonlinearity, is necessary to minimize the resulting artifact when using white noise patterns undergoing apparent motion.

  3. Attention to emotion modulates fMRI activity in human right superior temporal sulcus.

    Science.gov (United States)

    Narumoto, J; Okada, T; Sadato, N; Fukui, K; Yonekura, Y

    2001-10-01

    A parallel neural network has been proposed for processing various types of information conveyed by faces including emotion. Using functional magnetic resonance imaging (fMRI), we tested the effect of the explicit attention to the emotional expression of the faces on the neuronal activity of the face-responsive regions. Delayed match to sample procedure was adopted. Subjects were required to match the visually presented pictures with regard to the contour of the face pictures, facial identity, and emotional expressions by valence (happy and fearful expressions) and arousal (fearful and sad expressions). Contour matching of the non-face scrambled pictures was used as a control condition. The face-responsive regions that responded more to faces than to non-face stimuli were the bilateral lateral fusiform gyrus (LFG), the right superior temporal sulcus (STS), and the bilateral intraparietal sulcus (IPS). In these regions, general attention to the face enhanced the activities of the bilateral LFG, the right STS, and the left IPS compared with attention to the contour of the facial image. Selective attention to facial emotion specifically enhanced the activity of the right STS compared with attention to the face per se. The results suggest that the right STS region plays a special role in facial emotion recognition within distributed face-processing systems. This finding may support the notion that the STS is involved in social perception.

  4. Temporal integration of sequential auditory events: silent period in sound pattern activates human planum temporale.

    Science.gov (United States)

    Mustovic, Henrietta; Scheffler, Klaus; Di Salle, Francesco; Esposito, Fabrizio; Neuhoff, John G; Hennig, Jürgen; Seifritz, Erich

    2003-09-01

    Temporal integration is a fundamental process that the brain carries out to construct coherent percepts from serial sensory events. This process critically depends on the formation of memory traces reconciling past with present events and is particularly important in the auditory domain where sensory information is received both serially and in parallel. It has been suggested that buffers for transient auditory memory traces reside in the auditory cortex. However, previous studies investigating "echoic memory" did not distinguish between brain response to novel auditory stimulus characteristics on the level of basic sound processing and a higher level involving matching of present with stored information. Here we used functional magnetic resonance imaging in combination with a regular pattern of sounds repeated every 100 ms and deviant interspersed stimuli of 100-ms duration, which were either brief presentations of louder sounds or brief periods of silence, to probe the formation of auditory memory traces. To avoid interaction with scanner noise, the auditory stimulation sequence was implemented into the image acquisition scheme. Compared to increased loudness events, silent periods produced specific neural activation in the right planum temporale and temporoparietal junction. Our findings suggest that this area posterior to the auditory cortex plays a critical role in integrating sequential auditory events and is involved in the formation of short-term auditory memory traces. This function of the planum temporale appears to be fundamental in the segregation of simultaneous sound sources.

  5. Shedding Light on the Controversy Surrounding the Temporal Decline in Human Sperm Counts: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Marcello Cocuzza

    2014-01-01

    Full Text Available We systematically examined the evidence of declining sperm counts and the hypothesis that an increased exposure to environmental pollutants is responsible for such decline. Search engines, including PUBMED, MEDLINE, EMBASE, BIOSIS, and Cochrane library, were used to identify epidemiologic studies published from 1985 to 2013. We concluded that there is no enough evidence to confirm a worldwide decline in sperm counts. Also, there seems to be no scientific truth of a causative role for endocrine disruptors in the temporal decline of sperm production. Such assumptions are based on few meta-analyses and retrospective studies, while other well-conducted researches could not confirm these findings. We acknowledge that difficult-to-control confounding factors in the highly variable nature of semen, selection criteria, and comparability of populations from different time periods in secular-trend studies, the quality of laboratory methods for counting sperm, and apparently geographic variations in semen quality are the main issues that complicate the interpretation of the available evidence. Owing to the importance of this subject and the uncertainties still prevailing, there is a need not only for continuing monitoring of semen quality, reproductive hormones, and xenobiotics, but also for a better definition of fecundity.

  6. Cue competition affects temporal dynamics of edge-assignment in human visual cortex.

    Science.gov (United States)

    Brooks, Joseph L; Palmer, Stephen E

    2011-03-01

    Edge-assignment determines the perception of relative depth across an edge and the shape of the closer side. Many cues determine edge-assignment, but relatively little is known about the neural mechanisms involved in combining these cues. Here, we manipulated extremal edge and attention cues to bias edge-assignment such that these two cues either cooperated or competed. To index their neural representations, we flickered figure and ground regions at different frequencies and measured the corresponding steady-state visual-evoked potentials (SSVEPs). Figural regions had stronger SSVEP responses than ground regions, independent of whether they were attended or unattended. In addition, competition and cooperation between the two edge-assignment cues significantly affected the temporal dynamics of edge-assignment processes. The figural SSVEP response peaked earlier when the cues causing it cooperated than when they competed, but sustained edge-assignment effects were equivalent for cooperating and competing cues, consistent with a winner-take-all outcome. These results provide physiological evidence that figure-ground organization involves competitive processes that can affect the latency of figural assignment.

  7. Temporal coding of brain patterns for direct limb control in humans

    Directory of Open Access Journals (Sweden)

    Gernot Mueller-Putz

    2010-06-01

    Full Text Available For individuals with a high spinal cord injury (SCI not only the lower limbs, but also the upper extremities are paralyzed. A neuroprosthesis can be used to restore the lost hand and arm function in those tetraplegics. The main problem for this group of individuals, however, is the reduced ability to voluntarily operate device controllers. A Brain-Computer Interface provides a non-manual alternative to conventional input devices by translating brain activity patterns into control commands. We show that the temporal coding of individual mental imagery pattern can be used to control two independent degrees of freedom – grasp and elbow function - of an artificial robotic arm by utilizing a minimum number of EEG scalp electrodes. We describe the procedure from the initial screening to the final application. From eight naïve subjects participating on-line feedback experiments, four were able to voluntarily control an artificial arm by inducing one motor imagery pattern derived from one EEG derivation only.

  8. Global spatio-temporal patterns in human migration: a complex network perspective.

    Science.gov (United States)

    Davis, Kyle F; D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2013-01-01

    Migration is a powerful adaptive strategy for humans to navigate hardship and pursue a better quality of life. As a universal vehicle facilitating exchanges of ideas, culture, money and goods, international migration is a major contributor to globalization. Consisting of countries linked by multiple connections of human movements, global migration constitutes a network. Despite the important role of human migration in connecting various communities in different parts of the world, the topology and behavior of the international migration network and its changes through time remain poorly understood. Here we show that the global human migration network became more interconnected during the latter half of the twentieth century and that migrant destination choice partly reflects colonial and postcolonial histories, language, religion, and distances. From 1960 to 2000 we found a steady increase in network transitivity (i.e. connectivity between nodes connected to the same node), a decrease in average path length and an upward shift in degree distribution, all of which strengthened the 'small-world' behavior of the migration network. Furthermore, we found that distinct groups of countries preferentially interact to form migration communities based largely on historical, cultural and economic factors.

  9. Global spatio-temporal patterns in human migration: a complex network perspective.

    Directory of Open Access Journals (Sweden)

    Kyle F Davis

    Full Text Available Migration is a powerful adaptive strategy for humans to navigate hardship and pursue a better quality of life. As a universal vehicle facilitating exchanges of ideas, culture, money and goods, international migration is a major contributor to globalization. Consisting of countries linked by multiple connections of human movements, global migration constitutes a network. Despite the important role of human migration in connecting various communities in different parts of the world, the topology and behavior of the international migration network and its changes through time remain poorly understood. Here we show that the global human migration network became more interconnected during the latter half of the twentieth century and that migrant destination choice partly reflects colonial and postcolonial histories, language, religion, and distances. From 1960 to 2000 we found a steady increase in network transitivity (i.e. connectivity between nodes connected to the same node, a decrease in average path length and an upward shift in degree distribution, all of which strengthened the 'small-world' behavior of the migration network. Furthermore, we found that distinct groups of countries preferentially interact to form migration communities based largely on historical, cultural and economic factors.

  10. Mapping auditory core, lateral belt, and parabelt cortices in the human superior temporal gyrus

    DEFF Research Database (Denmark)

    Sweet, Robert A; Dorph-Petersen, Karl-Anton; Lewis, David A

    2005-01-01

    The goal of the present study was to determine whether the architectonic criteria used to identify the core, lateral belt, and parabelt auditory cortices in macaque monkeys (Macaca fascicularis) could be used to identify homologous regions in humans (Homo sapiens). Current evidence indicates...

  11. Brain activity related to working memory for temporal order and object information.

    Science.gov (United States)

    Roberts, Brooke M; Libby, Laura A; Inhoff, Marika C; Ranganath, Charan

    2017-06-08

    Maintaining items in an appropriate sequence is important for many daily activities; however, remarkably little is known about the neural basis of human temporal working memory. Prior work suggests that the prefrontal cortex (PFC) and medial temporal lobe (MTL), including the hippocampus, play a role in representing information about temporal order. The involvement of these areas in successful temporal working memory, however, is less clear. Additionally, it is unknown whether regions in the PFC and MTL support temporal working memory across different timescales, or at coarse or fine levels of temporal detail. To address these questions, participants were scanned while completing 3 working memory task conditions (Group, Position and Item) that were matched in terms of difficulty and the number of items to be actively maintained. Group and Position trials probed temporal working memory processes, requiring the maintenance of hierarchically organized coarse and fine temporal information, respectively. To isolate activation related to temporal working memory, Group and Position trials were contrasted against Item trials, which required detailed working memory maintenance of visual objects. Results revealed that working memory encoding and maintenance of temporal information relative to visual information was associated with increased activation in dorsolateral PFC (DLPFC), and perirhinal cortex (PRC). In contrast, maintenance of visual details relative to temporal information was characterized by greater activation of parahippocampal cortex (PHC), medial and anterior PFC, and retrosplenial cortex. In the hippocampus, a dissociation along the longitudinal axis was observed such that the anterior hippocampus was more active for working memory encoding and maintenance of visual detail information relative to temporal information, whereas the posterior hippocampus displayed the opposite effect. Posterior parietal cortex was the only region to show sensitivity to temporal

  12. The relationship between employees' perceptions of human resource systems and organizational performance: examining mediating mechanisms and temporal dynamics.

    Science.gov (United States)

    Piening, Erk P; Baluch, Alina M; Salge, Torsten Oliver

    2013-11-01

    Given the limited understanding of temporal issues in extant theorizing about the link between human resource management (HRM) and performance, in this study we aim to shed light on how, when, and why HR interventions affect organizational performance. On the basis of longitudinal, multi-informant and multisource data from public hospital services in England, we provide new insights into the complex interplay between employees' perceptions of HR systems, job satisfaction, and performance outcomes over time. The dynamic panel data analyses provide support for changes in employees' experience of an HR system being related to subsequent changes in customer satisfaction, as mediated by changes in job satisfaction, albeit these effects decrease over time. Moreover, our longitudinal analyses highlight the importance of feedback effects in the HRM-performance chain, which otherwise appears to evolve in a cyclical manner. (c) 2013 APA, all rights reserved.

  13. Accidental hazardous material releases with human impacts in the United States: exploration of geographical distribution and temporal trends.

    Science.gov (United States)

    Sengul, Hatice; Santella, Nicholas; Steinberg, Laura J; Chermak, Christina

    2010-09-01

    To investigate the circumstances and geographic and temporal distributions of hazardous material releases and resulting human impacts in the United States. Releases with fatalities, injuries, and evacuations were identified from reports to the National Response Center between 1990 and 2008, correcting for data quality issues identified in previous studies. From more than 550,000 reports, 861 deaths, 16,348 injuries and 741,427 evacuations were identified. Injuries from releases of chemicals at fixed facilities and natural gas from pipelines have decreased whereas evacuations from petroleum releases at fixed facilities have increased. Results confirm recent advances in chemical and pipeline safety and suggest directions for further improvement including targeted training and inspections and adoption of inherently safer design principles.

  14. Temporal Profiling and Pulsed SILAC Labeling Identify Novel Secreted Proteins during ex vivo Osteoblast Differentiation of Human Stromal Stem Cells

    DEFF Research Database (Denmark)

    Kristensen, Lars P; Chen, Li; Nielsen, Maria Overbeck

    2012-01-01

    , is not fully established. To address these questions, we quantified the temporal dynamics of the human stromal (mesenchymal, skeletal) stem cell (hMSC) secretome during ex vivo OB differentiation using stable isotope labeling by amino acids in cell culture (SILAC). In addition, we employed pulsed SILAC...... the identification of novel factors produced by hMSC with potential role in OB differentiation. Our study demonstrates that the secretome of osteoblastic cells is more complex than previously reported and supports the emerging evidence that osteoblastic cells secrete proteins with endocrine functions and regulate...... regulators of OB differentiation. Furthermore, we studied the biological effects of one of these proteins, the hormone stanniocalcin 2 (STC2) and demonstrated its autocrine effects in enhancing osteoblastic differentiation of hMSC. In conclusion, combining complete and pulsed SILAC labeling facilitated...

  15. The postnatal development of the temporal part of the human temporomandibular joint. A quantitative study on skulls.

    Science.gov (United States)

    Dibbets, J M; Dijkman, G E

    1997-12-01

    The morphology of the temporal part of the human temporomandibular joint (TMJ) changes drastically during postnatal development. The glenoid fossa will acquire its characteristic S shape and a tubercle will develop. The combined results of the literature and of this study allow a reconstruction of the actual growth processes. The roof of the glenoid fossa appears to enlarge forward by remodeling while sagittal and vertical growth is mainly achieved by deposition at the top of the tubercle. These latter changes result in a steeper slope of the eminence and take place in 3 phases, parallelling the eruption of the first incisors, the permanent first molars and the permanent second molars. While the zygomatic arch thickens by deposition at all surfaces, it also remodels downward relative to the external meatus. As a result, the neonate anulus occupies a lower position relative to this arch than does the adult meatus.

  16. Rhythm and Time in Music Epitomize the Temporal Dynamics of Human Communicative Behavior: The Broad Implications of London's Trinity

    Directory of Open Access Journals (Sweden)

    Peter E. Keller

    2012-09-01

    Full Text Available Three key issues about rhythm and timing in music are drawn to the attention of linguists in a paper by London (2012. In this commentary, I argue that these issues are relevant not only to linguists, but also to those in any field dealing with the temporal dynamics of human communicative behavior. Thus, the distinction between endogenously and exogenously driven mechanisms of perceptual organization, the active nature of perception, and the presence of multiple time scales are topics that also concern experimental psychologists and cognitive neuroscientists. London’s argument that these three issues play a crucial role in the perception of rhythm and timing implies that they should be considered collectively when attempting to understand diverse communicative acts.

  17. Spatio-temporal pattern analysis for evaluation of the spread of human infections with avian influenza A(H7N9) virus in China, 2013-2014.

    Science.gov (United States)

    Dong, Wen; Yang, Kun; Xu, Quanli; Liu, Lin; Chen, Juan

    2017-10-24

    A large number (n = 460) of A(H7N9) human infections have been reported in China from March 2013 through December 2014, and H7N9 outbreaks in humans became an emerging issue for China health, which have caused numerous disease outbreaks in domestic poultry and wild bird populations, and threatened human health severely. The aims of this study were to investigate the directional trend of the epidemic and to identify the significant presence of spatial-temporal clustering of influenza A(H7N9) human cases between March 2013 and December 2014. Three distinct epidemic phases of A(H7N9) human infections were identified in this study. In each phase, standard deviational ellipse analysis was conducted to examine the directional trend of disease spreading, and retrospective space-time permutation scan statistic was then used to identify the spatio-temporal cluster patterns of H7N9 outbreaks in humans. The ever-changing location and the increasing size of the three identified standard deviational ellipses showed that the epidemic moved from east to southeast coast, and hence to some central regions, with a future epidemiological trend of continue dispersing to more central regions of China, and a few new human cases might also appear in parts of the western China. Furthermore, A(H7N9) human infections were clustering in space and time in the first two phases with five significant spatio-temporal clusters (p < 0.05), but there was no significant cluster identified in phase III. There was a new epidemiologic pattern that the decrease in significant spatio-temporal cluster of A(H7N9) human infections was accompanied with an obvious spatial expansion of the outbreaks during the study period, and identification of the spatio-temporal patterns of the epidemic can provide valuable insights for better understanding the spreading dynamics of the disease in China.

  18. Medial subtalar dislocation: Case report

    Directory of Open Access Journals (Sweden)

    Manojlović Radovan

    2010-01-01

    Full Text Available Introduction. Subtalar dislocation (SI is a term that refers to an injury in which there is dislocation of the talonavicular and talocalcanear joint, although the tibiotalar joint is intact. Case Outline. A case of medial subtalar dislocation as a result of basketball injury, so-called 'basketball foot', is presented. Closed reposition in i.v. anaesthesia was performed with the patient in supine position and a knee flexed at 90 degrees. Longitudinal manual traction in line of deformity was carried out in plantar flexion. The reposition continued with abduction and eversion simultaneously increasing dorsiflexion. It was made in the first attempt and completed instantly. Rehabilitation was initiated after 5 weeks of immobilization. One year after the injury, the functional outcome was excellent with full range of motion and the patient was symptom-free. For better interpretation of roentgenogram, bone model of subtalar dislocation was made using the cadaver bone. Conclusion. Although the treatment of such injury is usually successful, diagnosis can be difficult because it is a rare injury, and moreover, X-ray of the injury can be confusing due to superposition of bones. Radiograms revealed superposition of the calcaneus, tarsal and metatarsal bones which was radiographically visualized in the anterior-posterior projection as one osseous block inward from the talus, and on the lateral view as in an osteal block below the tibial bone. Prompt recognition of these injuries followed by proper, delicately closed reduction under anaesthesia is crucial for achieving a good functional result in case of medial subtalar dislocation.

  19. Intrinsic neurophysiological properties of hilar ectopic and normotopic dentate granule cells in human temporal lobe epilepsy and a rat model.

    Science.gov (United States)

    Althaus, A L; Sagher, O; Parent, J M; Murphy, G G

    2015-02-15

    Hilar ectopic dentate granule cells (DGCs) are a salient feature of aberrant plasticity in human temporal lobe epilepsy (TLE) and most rodent models of the disease. Recent evidence from rodent TLE models suggests that hilar ectopic DGCs contribute to hyperexcitability within the epileptic hippocampal network. Here we investigate the intrinsic excitability of DGCs from humans with TLE and the rat pilocarpine TLE model with the objective of comparing the neurophysiology of hilar ectopic DGCs to their normotopic counterparts in the granule cell layer (GCL). We recorded from 36 GCL and 7 hilar DGCs from human TLE tissue. Compared with GCL DGCs, hilar DGCs in patient tissue exhibited lower action potential (AP) firing rates, more depolarized AP threshold, and differed in single AP waveform, consistent with an overall decrease in excitability. To evaluate the intrinsic neurophysiology of hilar ectopic DGCs, we made recordings from retrovirus-birthdated, adult-born DGCs 2-4 mo after pilocarpine-induced status epilepticus or sham treatment in rats. Hilar DGCs from epileptic rats exhibited higher AP firing rates than normotopic DGCs from epileptic or control animals. They also displayed more depolarized resting membrane potential and wider AP waveforms, indicating an overall increase in excitability. The contrasting findings between disease and disease model may reflect differences between the late-stage disease tissue available from human surgical specimens and the earlier disease stage examined in the rat TLE model. These data represent the first neurophysiological characterization of ectopic DGCs from human hippocampus and prospectively birthdated ectopic DGCs in a rodent TLE model. Copyright © 2015 the American Physiological Society.

  20. Dendrimer-driven neurotrophin expression differs in temporal patterns between rodent and human stem cells.

    Science.gov (United States)

    Shakhbazau, Antos; Shcharbin, Dzmitry; Seviaryn, Ihar; Goncharova, Natalya; Kosmacheva, Svetlana; Potapnev, Mihail; Bryszewska, Maria; Kumar, Ranjan; Biernaskie, Jeffrey; Midha, Rajiv

    2012-05-07

    This study reports the use of a nonviral expression system based on polyamidoamine dendrimers for time-restricted neurotrophin overproduction in mesenchymal stem cells and skin precursor-derived Schwann cells. The dendrimers were used to deliver plasmids for brain-derived neurotrophic factor (BDNF) or neurotrophin-3 (NT-3) expression in both rodent and human stem cells, and the timelines of expression were studied. We have found that, despite the fact that transfection efficiencies and protein expression levels were comparable, dendrimer-driven expression in human mesenchymal stem cells was characterized by a more rapid decline compared to rodent cells. Transient expression systems can be beneficial for some neurotrophins, which were earlier reported to cause unwanted side effects in virus-based long-term expression models. Nonviral neurotrophin expression is a biologically safe and accessible alternative to increase the therapeutic potential of autologous adult stem cells and stem cell-derived functional differentiated cells.

  1. Spatial and temporal changes in cumulative human impacts on the world's ocean.

    Science.gov (United States)

    Halpern, Benjamin S; Frazier, Melanie; Potapenko, John; Casey, Kenneth S; Koenig, Kellee; Longo, Catherine; Lowndes, Julia Stewart; Rockwood, R Cotton; Selig, Elizabeth R; Selkoe, Kimberly A; Walbridge, Shaun

    2015-07-14

    Human pressures on the ocean are thought to be increasing globally, yet we know little about their patterns of cumulative change, which pressures are most responsible for change, and which places are experiencing the greatest increases. Managers and policymakers require such information to make strategic decisions and monitor progress towards management objectives. Here we calculate and map recent change over 5 years in cumulative impacts to marine ecosystems globally from fishing, climate change, and ocean- and land-based stressors. Nearly 66% of the ocean and 77% of national jurisdictions show increased human impact, driven mostly by climate change pressures. Five percent of the ocean is heavily impacted with increasing pressures, requiring management attention. Ten percent has very low impact with decreasing pressures. Our results provide large-scale guidance about where to prioritize management efforts and affirm the importance of addressing climate change to maintain and improve the condition of marine ecosystems.

  2. Temporal and spatial performance of vector velocity imaging in the human fetal heart.

    Science.gov (United States)

    Matsui, H; Germanakis, I; Kulinskaya, E; Gardiner, H M

    2011-02-01

    To assess the spatial and temporal performance of fetal myocardial speckle tracking, using high-frame-rate (HFR) storing and Lagrangian strain analysis. Dummy electrocardiographic signaling permitted DICOM HFR in 124 normal fetuses and paired low-frame-rate (LFR) video storing at 25 Hz in 93 of them. Vector velocity imaging (VVI) tracking co-ordinates were used to compare time and spatial domain measures. We compared tracking success, Lagrangian strain, peak diastolic velocity and positive strain rate values in HFR vs. LFR video storing. Further comparisons within an HFR subset included Lagrangian vs. natural strain, VVI vs. M-mode annular displacement, and VVI vs. pulsed-wave tissue Doppler imaging (TDI) peak velocities. HFR (average 79.4 Hz) tracking was more successful than LFR (86 vs. 76%, P = 0.024). Lagrangian and natural HFR strain correlated highly (left ventricle (LV): r = 0.883, P < 0.001; right ventricle (RV): r = 0.792, P < 0.001) but natural strain gave 20% lower values, suggesting reduced reliability of measurement. Lagrangian HFR strain was similar in LV and RV and decreased with gestation (P = 0.015 and P < 0.001, respectively). LV Lagrangian LFR strain was significantly lower than the values for the RV (P < 0.001) and those using paired LV-HFR recordings (P = 0.007). Annular displacement methods correlated highly (LV = 1.046, r = 0.90, P < 0.001; RV = 1.170, r = 0.88, P < 0.001). Early diastolic waves were visible in 95% of TDI, but in only 26% of HFR and 0% of LFR recordings, and HFR-VVI velocities were significantly lower than those for TDI (P < 0.001). Doppler estimation of velocities remains superior to VVI but image gating and use of original co-ordinates should improve offline VVI assessment of fetal myocardial function. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.

  3. A Temporal White Noise Analysis for Extracting the Impulse Response Function of the Human Electroretinogram.

    Science.gov (United States)

    Zele, Andrew J; Feigl, Beatrix; Kambhampati, Pradeep K; Aher, Avinash; McKeefry, Declan; Parry, Neil; Maguire, John; Murray, Ian; Kremers, Jan

    2017-11-01

    We introduce a method for determining the impulse response function (IRF) of the ERG derived from responses to temporal white noise (TWN) stimuli. This white noise ERG (wnERG) was recorded in participants with normal trichromatic vision to full-field (Ganzfeld) and 39.3° diameter focal stimuli at mesopic and photopic mean luminances and at different TWN contrasts. The IRF was obtained by cross-correlating the TWN stimulus with the wnERG. We show that wnERG recordings are highly repeatable, with good signal-to-noise ratio, and do not lead to blink artifacts. The wnERG resembles a flash ERG waveform with an initial negativity (N1) followed by a positivity (P1), with amplitudes that are linearly related to stimulus contrast. These N1 and N1-P1 components showed commonalties in implicit times with the a- and b-waves of flash ERGs. There was a clear transition from rod- to cone-driven wnERGs at ∼1 photopic cd.m -2 . We infer that oscillatory potentials found with the flash ERG, but not the wnERG, may reflect retinal nonlinearities due to the compression of energy into a short time period during a stimulus flash. The wnERG provides a new approach to study the physiology of the retina using a stimulation method with adaptation and contrast conditions similar to natural scenes to allow for independent variation of stimulus strength and mean luminance, which is not possible with the conventional flash ERG. The white noise ERG methodology will be of benefit for clinical studies and animal models in the evaluation of hypotheses related to cellular redundancy to understand the effects of disease on specific visual pathways.

  4. Temporal and spatial dispersion of human body temperature during deep hypothermia.

    Science.gov (United States)

    Opatz, O; Trippel, T; Lochner, A; Werner, A; Stahn, A; Steinach, M; Lenk, J; Kuppe, H; Gunga, H C

    2013-11-01

    Clinical temperature management remains challenging. Choosing the right sensor location to determine the core body temperature is a particular matter of academic and clinical debate. This study aimed to investigate the relationship of measured temperatures at different sites during surgery in deep hypothermic patients. In this prospective single-centre study, we studied 24 patients undergoing cardiothoracic surgery: 12 in normothermia, 3 in mild, and 9 in deep hypothermia. Temperature recordings of a non-invasive heat flux sensor at the forehead were compared with the arterial outlet temperature of a heart-lung machine, with the temperature on a conventional vesical bladder thermistor and, for patients undergoing deep hypothermia, with oesophageal temperature. Using a linear model for sensor comparison, the arterial outlet sensor showed a difference among the other sensor positions between -0.54 and -1.12°C. The 95% confidence interval ranged between 7.06 and 8.82°C for the upper limit and -8.14 and -10.62°C for the lower limit. Because of the hysteretic shape, the curves were divided into phases and fitted into a non-linear model according to time and placement of the sensors. During cooling and warming phases, a quadratic relationship could be observed among arterial, oesophageal, vesical, and cranial temperature recordings, with coefficients of determination ranging between 0.95 and 0.98 (standard errors of the estimate 0.69-1.12°C). We suggest that measured surrogate temperatures as indices of the cerebral temperature (e.g. vesical bladder temperature) should be interpreted with respect to the temporal and spatial dispersion during cooling and rewarming phases.

  5. Spatial and temporal changes in cumulative human impacts on the world's ocean

    OpenAIRE

    Halpern, Benjamin S.; Frazier, Melanie; Potapenko, John; Casey, Kenneth S.; Koenig, Kellee; Longo, Catherine; Lowndes, Julia Stewart; Rockwood, R. Cotton; Selig, Elizabeth R.; Selkoe, Kimberly A.; Walbridge, Shaun

    2015-01-01

    Human pressures on the ocean are thought to be increasing globally, yet we know little about their patterns of cumulative change, which pressures are most responsible for change, and which places are experiencing the greatest increases. Managers and policymakers require such information to make strategic decisions and monitor progress towards management objectives. Here we calculate and map recent change over 5 years in cumulative impacts to marine ecosystems globally from fishing, climate ch...

  6. Analysis of temporal variation in human masticatory cycles during gum chewing.

    Science.gov (United States)

    Crane, Elizabeth A; Rothman, Edward D; Childers, David; Gerstner, Geoffrey E

    2013-10-01

    The study investigated modulation of fast and slow opening (FO, SO) and closing (FC, SC) chewing cycle phases using gum-chewing sequences in humans. Twenty-two healthy adult subjects participated by chewing gum for at least 20s on the right side and at least 20s on the left side while jaw movements were tracked with a 3D motion analysis system. Jaw movement data were digitized, and chewing cycle phases were identified and analysed for all chewing cycles in a complete sequence. All four chewing cycle phase durations were more variant than total cycle durations, a result found in other non-human primates. Significant negative correlations existed between the opening phases, SO and FO, and between the closing phases, SC and FC; however, there was less consistency in terms of which phases were negatively correlated both between subjects, and between chewing sides within subjects, compared with results reported in other species. The coordination of intra-cycle phases appears to be flexible and to follow complex rules during gum-chewing in humans. Alternatively, the observed intra-cycle phase relationships could simply reflect: (1) variation in jaw kinematics due to variation in how gum was handled by the tongue on a chew-by-chew basis in our experimental design or (2) by variation due to data sampling noise and/or how phases were defined and identified. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Outside-In Deep Medial Collateral Ligament Release During Arthroscopic Medial Meniscus Surgery.

    Science.gov (United States)

    Todor, Adrian; Caterev, Sergiu; Nistor, Dan Viorel

    2016-08-01

    Arthroscopic partial medial meniscectomy is a very common orthopaedic procedure performed for symptomatic, irreparable meniscus tears. It is usually associated with a very good outcome and minimal complications. In some patients with tight medial compartment, the posterior horn of the medial meniscus can be difficult to visualize, and access in this area with instruments may be challenging. To increase the opening of the medial compartment, after valgus-extension stress position of the knee, different techniques of deep medial collateral ligament release have been described. The outside-in pie-crusting technique shown in this technical note has documented effectiveness and good outcomes with minimal or no morbidity.

  8. Human-induced C erosion and burial across spatial and temporal scales. (Invited)

    Science.gov (United States)

    van oost, K.

    2013-12-01

    Anthropogenic land cover change and soil erosion are tightly coupled: accelerated erosion and deposition of soil are inevitable consequences of the removal of vegetative cover and increased exposure of the soil surface to erosion. A significant portion of the earth surface has now been disturbed and this has locally accelerated erosion 10- to 100-fold. Although there is now growing awareness that the erosion-induced C flux may be an important factor determining global and regional net terrestrial ecosystem C balances, the significance of this disturbance for the past, present and future C cycle remains uncertain. In this paper, we argue that the significance for both past and present C budgets remains poorly quantified due to uncertainty about the contribution of biotic versus erosion-induced C fluxes because of their intrinsically different space and time scales. Carbon erosion research in agro-ecosystems has traditionally focused on short-term processes, i.e. single events to a few decades and longer-term observations of C and sediment dynamics are therefore rare. Likewise, C cycling is typically studied at the profile-scale while erosion processes operate over various spatial scales and whole-watershed approaches are therefore needed. We address this issue here by synthesizing 3 case studies where we report results of a measurement campaign to characterize the erosional control on vertical carbon fluxes from degraded land. First, using signatures in soil sedimentary archives, we integrate the effects of accelerated C erosion across point, hillslope and catchment scale for a temperate river catchment over the period of agriculture to demonstrate that accounting for the non-steady-state C dynamics in geomorphic active systems is pertinent to understand both past and future anthropogenic global change. Secondly, we report year-round soil respiration measurements with high temporal resolution along an erosion gradient on cultivated sloping land in the Chinese Loess

  9. Time-frequency analysis with temporal and spectral resolution as the human auditory system

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.

    1992-01-01

    The human perception of sound is a suitable area for the application of a simultaneous time-frequency analysis, since the ear is selective in both domains. A perfect reconstruction filter bank with bandwidths approximating the critical bands is presented. The orthogonality of the filter makes...... it possible to examine the masking effect with realistic signals. The tree structure of the filter bank makes it difficult to obtain well-attenuated stop-bands. The use of filters of different length solves this problem...

  10. No evidence of parvovirus B19, Chlamydia pneumoniae or human herpes virus infection in temporal artery biopsies in patients with giant cell arteritis

    DEFF Research Database (Denmark)

    Helweg-Larsen, J; Tarp, B; Obel, N

    2002-01-01

    conditions. DNA was extracted from frozen biopsies and PCR was used to amplify genes from Chlamydia pneumoniae, parvovirus B19 and each of the eight human herpes viruses: herpes simplex viruses HSV-1 and 2, Epstein-Barr virus, cytomegalovirus, varicella zoster virus and human herpes viruses HHV-6, -7 and -8......OBJECTIVES: Recent studies have suggested that infective agents may be involved in the pathogenesis of giant cell arteritis (GCA), in particular Chlamydia pneumoniae and parvovirus B19. We investigated temporal arteries from patients with GCA for these infections as well as human herpes viruses....... RESULTS: In all 30 biopsies, PCR was negative for DNAs of parvovirus B19, each of the eight human herpes viruses and C. pneumoniae. CONCLUSIONS: We found no evidence of DNA from parvovirus B19, human herpes virus or C. pneumoniae in any of the temporal arteries. These agents do not seem to play a unique...

  11. Temporal, Diagnostic, and Tissue-Specific Regulation of NRG3 Isoform Expression in Human Brain Development and Affective Disorders

    Science.gov (United States)

    Paterson, Clare; Wang, Yanhong; Hyde, Thomas M.; Weinberger, Daniel R.; Kleinman, Joel E.; Law, Amanda J.

    2018-01-01

    Objective Genes implicated in schizophrenia are enriched in networks differentially regulated during human CNS development. Neuregulin 3 (NRG3), a brain-enriched neurotrophin, undergoes alternative splicing and is implicated in several neurological disorders with developmental origins. Isoform-specific increases in NRG3 are observed in schizophrenia and associated with rs10748842, a NRG3 risk polymorphism, suggesting NRG3 transcriptional dysregulation as a molecular mechanism of risk. The authors quantitatively mapped the temporal trajectories of NRG3 isoforms (classes I–IV) in the neocortex throughout the human lifespan, examined whether tissue-specific regulation of NRG3 occurs in humans, and determined if abnormalities in NRG3 transcriptomics occur in mood disorders and are genetically determined. Method NRG3 isoform classes I–IV were quantified using quantitative real-time polymerase chain reaction in human postmortem dorsolateral prefrontal cortex from 286 nonpsychiatric control individuals, from gestational week 14 to 85 years old, and individuals diagnosed with either bipolar disorder (N=34) or major depressive disorder (N=69). Tissue-specific mapping was investigated in several human tissues. rs10748842 was genotyped in individuals with mood disorders, and association with NRG3 isoform expression examined. Results NRG3 classes displayed individually specific expression trajectories across human neocortical development and aging; classes I, II, and IV were significantly associated with developmental stage. NRG3 class I was increased in bipolar and major depressive disorder, consistent with observations in schizophrenia. NRG3 class II was increased in bipolar disorder, and class III was increased in major depression. The rs10748842 risk genotype predicted elevated class II and III expression, consistent with previous reports in the brain, with tissue-specific analyses suggesting that classes II and III are brain-specific isoforms of NRG3. Conclusions

  12. Temporal parameter change of human postural control ability during upright swing using recursive least square method

    Science.gov (United States)

    Goto, Akifumi; Ishida, Mizuri; Sagawa, Koichi

    2010-01-01

    The purpose of this study is to derive quantitative assessment indicators of the human postural control ability. An inverted pendulum is applied to standing human body and is controlled by ankle joint torque according to PD control method in sagittal plane. Torque control parameters (KP: proportional gain, KD: derivative gain) and pole placements of postural control system are estimated with time from inclination angle variation using fixed trace method as recursive least square method. Eight young healthy volunteers are participated in the experiment, in which volunteers are asked to incline forward as far as and as fast as possible 10 times over 10 [s] stationary intervals with their neck joint, hip joint and knee joint fixed, and then return to initial upright posture. The inclination angle is measured by an optical motion capture system. Three conditions are introduced to simulate unstable standing posture; 1) eyes-opened posture for healthy condition, 2) eyes-closed posture for visual impaired and 3) one-legged posture for lower-extremity muscle weakness. The estimated parameters Kp, KD and pole placements are applied to multiple comparison test among all stability conditions. The test results indicate that Kp, KD and real pole reflect effect of lower-extremity muscle weakness and KD also represents effect of visual impairment. It is suggested that the proposed method is valid for quantitative assessment of standing postural control ability.

  13. Semi-manual mastoidectomy assisted by human-robot collaborative control - A temporal bone replica study.

    Science.gov (United States)

    Lim, Hoon; Matsumoto, Nozomu; Cho, Byunghyun; Hong, Jaesung; Yamashita, Makoto; Hashizume, Makoto; Yi, Byung-Ju

    2016-04-01

    To develop an otological robot that can protect important organs from being injured. We developed a five degree-of-freedom robot for otological surgery. Unlike the other robots that were reported previously, our robot does not replace surgeon's procedures, but instead utilizes human-robot collaborative control. The robot basically releases all of the actuators so that the surgeon can manipulate the drill within the robot's working area with minimal restriction. When the drill reaches a forbidden area, the surgeon feels as if the drill hits a wall. When an engineer performed mastoidectomy using the robot for assistance, the facial nerve in the segmented region was always protected with a more than 2.5mm margin, which was almost the same as the pre-set safety margin of 3mm. Semi-manual drilling using human-robot collaborative control was feasible, and may hold a realistic prospect of clinical use in the near future. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Intralaminar and medial thalamic influence on cortical synchrony, information transmission and cognition

    Directory of Open Access Journals (Sweden)

    Yuri B Saalmann

    2014-05-01

    Full Text Available The intralaminar and medial thalamic nuclei are part of the higher-order thalamus, which receives little sensory input, and instead forms extensive cortico-thalamo-cortical pathways. The large mediodorsal thalamic nucleus predominantly connects with the prefrontal cortex, the adjacent intralaminar nuclei connect with fronto-parietal cortex, and the midline thalamic nuclei connect with medial prefrontal cortex and medial temporal lobe. Taking into account this connectivity pattern, it is not surprising that the intralaminar and medial thalamus has been implicated in a variety of cognitive functions, including memory processing, attention and orienting, as well as reward-based behavior. This review addresses how the intralaminar and medial thalamus may regulate information transmission in cortical circuits. A key neural mechanism may involve intralaminar and medial thalamic neurons modulating the degree of synchrony between different groups of cortical neurons according to behavioral demands. Such a thalamic-mediated synchronization mechanism may give rise to large-scale integration of information across multiple cortical circuits, consequently influencing the level of arousal and consciousness. Overall, the growing evidence supports a general role for the higher-order thalamus in the control of cortical information transmission and cognitive processing.

  15. System-wide temporal characterization of the proteome and phosphoproteome of human embryonic stem cell differentiation

    DEFF Research Database (Denmark)

    Rigbolt, Kristoffer T.G.; Prokhorova, Tatyana; Akimov, Vyacheslav

    2011-01-01

    by feeder cells. We profiled 6521 proteins and 23,522 phosphorylation sites, of which almost 50% displayed dynamic changes in phosphorylation status during 24 hours of differentiation. These data are a resource for studies of the events associated with the maintenance of hESC pluripotency and those...... of the matching sequence motif. In addition to identifying previously unknown phosphorylation sites on factors associated with differentiation, such as kinases and transcription factors, we observed dynamic phosphorylation of DNA methyltransferases (DNMTs). We found a specific interaction of DNMTs during early......To elucidate cellular events underlying the pluripotency of human embryonic stem cells (hESCs), we performed parallel quantitative proteomic and phosphoproteomic analyses of hESCs during differentiation initiated by a diacylglycerol analog or transfer to media that had not been conditioned...

  16. Temporal Evolution of Design Principles in Engineering Systems: Analogies with Human Evolution

    DEFF Research Database (Denmark)

    Deb, Kalyanmoy; Bandaru, Sunith; Tutum, Cem Celal

    2012-01-01

    constructed later during optimization. Interestingly, there exists a simile between evolution of design principles with that of human evolution. Such information about the hierarchy of key design principles should enable designers to have a deeper understanding of their problems.......Optimization of an engineering system or component makes a series of changes in the initial random solution(s) iteratively to form the final optimal shape. When multiple conflicting objectives are considered, recent studies on innovization revealed the fact that the set of Pareto-optimal solutions...... portray certain common design principles. In this paper, we consider a 14-variable bi-objective design optimization of a MEMS device and identify a number of such common design principles through a recently proposed automated innovization procedure. Although these design principles are found to exist...

  17. The temporal expression of estrogen receptor alpha-36 and runx2 in human bone marrow derived stromal cells during osteogenesis

    International Nuclear Information System (INIS)

    Francis, W.R.; Owens, S.E.; Wilde, C.; Pallister, I.; Kanamarlapudi, V.; Zou, W.; Xia, Z.

    2014-01-01

    Highlights: • ERα36 is the predominant ERα isoform involved in bone regulation in human BMSC. • ERα36 mRNA is significantly upregulated during the process of osteogenesis. • The pattern of ERα36 and runx2 mRNA expression is similar during osteogenesis. • ERα36 appears to be co-localised with runx2 during osteogenesis. - Abstract: During bone maintenance in vivo, estrogen signals through estrogen receptor (ER)-α. The objectives of this study were to investigate the temporal expression of ERα36 and ascertain its functional relevance during osteogenesis in human bone marrow derived stromal cells (BMSC). This was assessed in relation to runt-related transcription factor-2 (runx2), a main modulatory protein involved in bone formation. ERα36 and runx2 subcellular localisation was assessed using immunocytochemistry, and their mRNA expression levels by real time PCR throughout the process of osteogenesis. The osteogenically induced BMSCs demonstrated a rise in ERα36 mRNA during proliferation followed by a decline in expression at day 10, which represents a change in dynamics within the culture between the proliferative stage and the differentiative stage. The mRNA expression profile of runx2 mirrored that of ERα36 and showed a degree subcellular co-localisation with ERα36. This study suggests that ERα36 is involved in the process of osteogenesis in BMSCs, which has implications in estrogen deficient environments

  18. Modelling the effect of religion on human empathy based on an adaptive temporal-causal network model.

    Science.gov (United States)

    van Ments, Laila; Roelofsma, Peter; Treur, Jan

    2018-01-01

    Religion is a central aspect of many individuals' lives around the world, and its influence on human behaviour has been extensively studied from many different perspectives. The current study integrates a number of these perspectives into one adaptive temporal-causal network model describing the mental states involved, their mutual relations, and the adaptation of some of these relations over time due to learning. By first developing a conceptual representation of a network model based on the literature, and then formalizing this model into a numerical representation, simulations can be done for almost any kind of religion and person, showing different behaviours for persons with different religious backgrounds and characters. The focus was mainly on the influence of religion on human empathy and dis-empathy, a topic very relevant today. The developed model could be valuable for many uses, involving support for a better understanding, and even prediction, of the behaviour of religious individuals. It is illustrated for a number of different scenarios based on different characteristics of the persons and of the religion.

  19. Multimedia human brain database system for surgical candidacy determination in temporal lobe epilepsy with content-based image retrieval

    Science.gov (United States)

    Siadat, Mohammad-Reza; Soltanian-Zadeh, Hamid; Fotouhi, Farshad A.; Elisevich, Kost

    2003-01-01

    This paper presents the development of a human brain multimedia database for surgical candidacy determination in temporal lobe epilepsy. The focus of the paper is on content-based image management, navigation and retrieval. Several medical image-processing methods including our newly developed segmentation method are utilized for information extraction/correlation and indexing. The input data includes T1-, T2-Weighted MRI and FLAIR MRI and ictal and interictal SPECT modalities with associated clinical data and EEG data analysis. The database can answer queries regarding issues such as the correlation between the attribute X of the entity Y and the outcome of a temporal lobe epilepsy surgery. The entity Y can be a brain anatomical structure such as the hippocampus. The attribute X can be either a functionality feature of the anatomical structure Y, calculated with SPECT modalities, such as signal average, or a volumetric/morphological feature of the entity Y such as volume or average curvature. The outcome of the surgery can be any surgery assessment such as memory quotient. A determination is made regarding surgical candidacy by analysis of both textual and image data. The current database system suggests a surgical determination for the cases with relatively small hippocampus and high signal intensity average on FLAIR images within the hippocampus. This indication pretty much fits with the surgeons" expectations/observations. Moreover, as the database gets more populated with patient profiles and individual surgical outcomes, using data mining methods one may discover partially invisible correlations between the contents of different modalities of data and the outcome of the surgery.

  20. Human middle longitudinal fascicle: segregation and behavioral-clinical implications of two distinct fiber connections linking temporal pole and superior temporal gyrus with the angular gyrus or superior parietal lobule using multi-tensor tractography.

    Science.gov (United States)

    Makris, N; Preti, M G; Wassermann, D; Rathi, Y; Papadimitriou, G M; Yergatian, C; Dickerson, B C; Shenton, M E; Kubicki, M

    2013-09-01

    The middle longitudinal fascicle (MdLF) is a major fiber connection running principally between the superior temporal gyrus and the parietal lobe, neocortical regions of great biological and clinical interest. Although one of the most prominent cerebral association fiber tracts, it has only recently been discovered in humans. In this high angular resolution diffusion imaging (HARDI) MRI study, we delineated the two major fiber connections of the human MdLF, by examining morphology, topography, cortical connections, biophysical measures, volume and length in seventy-four brains. These two fiber connections course together through the dorsal temporal pole and the superior temporal gyrus maintaining a characteristic topographic relationship in the mediolateral and ventrodorsal dimensions. As these pathways course towards the parietal lobe, they split to form separate fiber pathways, one following a ventrolateral trajectory and connecting with the angular gyrus and the other following a dorsomedial route and connecting with the superior parietal lobule. Based on the functions of their cortical affiliations, we suggest that the superior temporal-angular connection of the MdLF, i.e., STG(MdLF)AG plays a role in language and attention, whereas the superior temporal-superior parietal connection of the MdLF, i.e., STG(MdLF)SPL is involved in visuospatial and integrative audiovisual functions. Furthermore, the MdLF may have clinical implications in neurodegenerative disorders such as primary progressive aphasia, frontotemporal dementia, posterior cortical atrophy, corticobulbar degeneration and Alzheimer's disease as well as attention-deficit/hyperactivity disorder and schizophrenia.

  1. Sonic hedgehog expressing and responding cells generate neuronal diversity in the medial amygdala

    Directory of Open Access Journals (Sweden)

    Machold Robert P

    2010-05-01

    Full Text Available Abstract Background The mammalian amygdala is composed of two primary functional subdivisions, classified according to whether the major output projection of each nucleus is excitatory or inhibitory. The posterior dorsal and ventral subdivisions of the medial amygdala, which primarily contain inhibitory output neurons, modulate specific aspects of innate socio-sexual and aggressive behaviors. However, the development of the neuronal diversity of this complex and important structure remains to be fully elucidated. Results Using a combination of genetic fate-mapping and loss-of-function analyses, we examined the contribution and function of Sonic hedgehog (Shh-expressing and Shh-responsive (Nkx2-1+ and Gli1+ neurons in the medial amygdala. Specifically, we found that Shh- and Nkx2-1-lineage cells contribute differentially to the dorsal and ventral subdivisions of the postnatal medial amygdala. These Shh- and Nkx2-1-lineage neurons express overlapping and non-overlapping inhibitory neuronal markers, such as Calbindin, FoxP2, nNOS and Somatostatin, revealing diverse fate contributions in discrete medial amygdala nuclear subdivisions. Electrophysiological analysis of the Shh-derived neurons additionally reveals an important functional diversity within this lineage in the medial amygdala. Moreover, inducible Gli1CreER(T2 temporal fate mapping shows that early-generated progenitors that respond to Shh signaling also contribute to medial amygdala neuronal diversity. Lastly, analysis of Nkx2-1 mutant mice demonstrates a genetic requirement for Nkx2-1 in inhibitory neuronal specification in the medial amygdala distinct from the requirement for Nkx2-1 in cerebral cortical development. Conclusions Taken together, these data reveal a differential contribution of Shh-expressing and Shh-responding cells to medial amygdala neuronal diversity as well as the function of Nkx2-1 in the development of this important limbic system structure.

  2. The gap-startle paradigm to assess auditory temporal processing: Bridging animal and human research.

    Science.gov (United States)

    Fournier, Philippe; Hébert, Sylvie

    2016-05-01

    The gap-prepulse inhibition of the acoustic startle (GPIAS) paradigm is the primary test used in animal research to identify gap detection thresholds and impairment. When a silent gap is presented shortly before a loud startling stimulus, the startle reflex is inhibited and the extent of inhibition is assumed to reflect detection. Here, we applied the same paradigm in humans. One hundred and fifty-seven normal-hearing participants were tested using one of five gap durations (5, 25, 50, 100, 200 ms) in one of the following two paradigms-gap-embedded in or gap-following-the continuous background noise. The duration-inhibition relationship was observable for both conditions but followed different patterns. In the gap-embedded paradigm, GPIAS increased significantly with gap duration up to 50 ms and then more slowly up to 200 ms (trend only). In contrast, in the gap-following paradigm, significant inhibition-different from 0--was observable only at gap durations from 50 to 200 ms. The finding that different patterns are found depending on gap position within the background noise is compatible with distinct mechanisms underlying each of the two paradigms. © 2016 Society for Psychophysiological Research.

  3. Development of surgical skill with singular neurectomy using human cadaveric temporal bones.

    Science.gov (United States)

    Feigl, Georg; Kos, Izabel; Anderhuber, Friedrich; Guyot, Jean Phillippe; Fasel, Jean

    2008-01-01

    Profound anatomical knowledge and surgical experience are essential for safe otological surgery. The surgeon's learning curve is evaluated in performing Gacek's singular neurectomy on cadaveric specimens. One otological surgeon performed Gacek's approach on 96 halves of human heads embalmed according to Thiel's method, divided into four groups (24 halves per group) and evaluated them concurrent to the evaluation of an anatomist after a first surgical attempt. Successful operations were subdivided into "direct hits" of the osseous canal of the posterior ampullary nerve also known as the singular nerve and "indirect hits" with access to the posterior ampullary recess. Unsuccessful operations showed "no hit" of the nerve without lesion of the membranous labyrinth. "Indirect" or "no hits" were reinvestigated in a second attempt to evaluate possible reclassifications due to a learning process of the surgeon. The order of dissection, the rate of success and the changes of results in correlation with the numbers of dissected specimens were documented. The success rate significantly increased from 54.2% direct hits after the first group to 87.36% in the fourth group after the first attempt. Successful operations were performed in 86.5% after completion of the first attempt and 97.9% after the second attempt. The number of new allocations decreased from 11 cases in the first group of dissected specimens to zero in the fourth group. This paper strengthens the value of cadaveric training for surgeons and the crucial role of dissection of a large number of specimens in improvement of the surgeon's experience and success rate.

  4. Endoscopic medial maxillectomy breaking new frontiers.

    Science.gov (United States)

    Mohanty, Sanjeev; Gopinath, M

    2013-07-01

    Endoscopy has changed the perspective of rhinologist towards the nose. It has revolutionised the surgical management of sinonasal disorders. Sinus surgeries were the first to get the benefit of endoscope. Gradually the domain of endoscopic surgery extended to the management of sino nasal tumours. Traditionally medial maxillectomy was performed through lateral rhinotomy or mid facial degloving approach. Endoscopic medial maxillectomy has been advocated by a number of authors in the management of benign sino-nasal tumours. We present our experience of endoscopic medial maxillectomy in the management of sinonasal pathologies.

  5. Complex Medial Meniscus Tears Are Associated With a Biconcave Medial Tibial Plateau.

    Science.gov (United States)

    Barber, F Alan; Getelman, Mark H; Berry, Kathy L

    2017-04-01

    To determine whether an association exists between a biconcave medial tibial plateau and complex medial meniscus tears. A consecutive series of stable knees undergoing arthroscopy were evaluated retrospectively with the use of preoperative magnetic resonance imaging (MRI), radiographs, and arthroscopy documented by intraoperative videos. Investigators independently performed blinded reviews of the MRI or videos. Based on the arthroscopy findings, medial tibial plateaus were classified as either biconcave or not biconcave. A transverse coronal plane ridge, separating the front of the tibial plateau from the back near the inner margin of the posterior body of the medial meniscus, was defined as biconcave. The medial plateau slope was calculated with MRI sagittal views. General demographic information, body mass index, and arthroscopically confirmed knee pathology were recorded. A total of 179 consecutive knees were studied from July 2014 through August 2015; 49 (27.2%) biconcave medial tibial plateaus and 130 (72.8%) controls were identified at arthroscopy. Complex medial meniscus tears were found in 103. Patients with a biconcave medial tibial plateau were found to have more complex medial meniscus tears (69.4%) than those without a biconcavity (53.1%) (P = .049) despite having lower body mass index (P = .020). No difference in medial tibial plateau slope was observed for biconcavities involving both cartilage and bone, bone only, or an indeterminate group (P = .47). Biconcave medial tibial plateaus were present in 27.4% of a consecutive series of patients undergoing knee arthroscopy. A biconcave medial tibial plateau was more frequently associated with a complex medial meniscus tear. Level III, case-control study. Copyright © 2016 Arthroscopy Association of North America. All rights reserved.

  6. The medial prefrontal cortex: coordinator of autonomic, neuroendocrine and behavioural responses to stress.

    Science.gov (United States)

    McKlveen, J M; Myers, B; Herman, J P

    2015-06-01

    Responding to real or potential threats in the environment requires the coordination of autonomic, neuroendocrine and behavioural processes to promote adaptation and survival. These diverging systems necessitate input from the limbic forebrain to integrate and modulate functional output in accordance with contextual demand. In the present review, we discuss the potential role of the medial prefrontal cortex (mPFC) as a coordinator of behavioural and physiological stress responses across multiple temporal and contextual domains. Furthermore, we highlight converging evidence from rodent and human research indicating the necessity of the mPFC for modulating physiological energetic systems to mobilise or limit energetic resources as needed to ultimately promote behavioural adaptation in the face of stress. We review the literature indicating that glucocorticoids act as one of the primary messengers in the reallocation of energetic resources having profound effects locally within the mPFC, as well as shaping how the mPFC acts within a network of brain structures to modulate responses to stress. Finally, we discuss how both rodent and human studies point toward a critical role of the mPFC in the coordination of anticipatory responses to stress and why this distinction is an important one to make in stress neurobiology. © 2015 British Society for Neuroendocrinology.

  7. [Tibial periostitis ("medial tibial stress syndrome")].

    Science.gov (United States)

    Fournier, Pierre-Etienne

    2003-06-01

    Medial tibial stress syndrome is characterised by complaints along the posteromedial tibia. Runners and athletes involved in jumping activities may develop this syndrome. Increased stress to stabilize the foot especially when excessive pronation is present explain the occurrence this lesion.

  8. Transcortical selective amygdalohippocampectomy technique through the middle temporal gyrus revisited: An anatomical study laboratory investigation.

    Science.gov (United States)

    Bozkurt, Baran; da Silva Centeno, Ricardo; Chaddad-Neto, Feres; da Costa, Marcos Devanir Silva; Goiri, Marcelo Augusto Acosta; Karadag, Ali; Tugcu, Bekir; Ovalioglu, Talat Cem; Tanriover, Necmettin; Kaya, Serdar; Yagmurlu, Kaan; Grande, Andrew

    2016-12-01

    The anterior temporal lobectomy (ATL) and selective amygdalohippocampectomy (SelAH) have been used for surgical treatment of mesial temporal lobe epilepsy. We examined the comprehensive white matter tract anatomy of the temporal lobe to gain an insight into the trans-middle temporal gyrus, a lateral approach which has been commonly used. The transmiddle temporal gyrus approach was performed in a stepwise manner on cadaveric human heads to examine the traversing white matter pathways through it and the structures located in the temporal horn. We reviewed the literature to compare the trans-middle temporal gyrus approach with other SelAH techniques based on surgical outcomes. There does not appear to be a significant difference in seizure outcome between SelAH and ATL. However, the SelAH provides a better neuropsychological outcomes than the ATL in selected patients. Each SelAH approach has individual advantages and disadvantages. Based on our anatomical study, in the transcortical amygdalohippocampectomy technique through the middle temporal gyrus the white matter pathways to be encountered. In the temporal horn, the collateral eminence, hippocampus, lateral ventricular sulcus, choroidal fissure, inferior choroidal point, choroid plexus, fimbria of the fornix, and amygdala are exposed. The subpial dissection is performed along the lateral ventricular sulcus from the collateral eminence on lateral side and from the choroidal fissure on medial side by microdissector for en bloc resection of the hippocampus proper. The trans-middle temporal gyrus approach is commonly used in treatment of mesial temporal lobe epilepsy patients. A better anatomical and functional understanding of the structures of the temporal lobe is crucial for safer and more accurate surgery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Endoscopic Medial Maxillectomy Breaking New Frontiers

    OpenAIRE

    Mohanty, Sanjeev; Gopinath, M.

    2011-01-01

    Endoscopy has changed the perspective of rhinologist towards the nose. It has revolutionised the surgical management of sinonasal disorders. Sinus surgeries were the first to get the benefit of endoscope. Gradually the domain of endoscopic surgery extended to the management of sino nasal tumours. Traditionally medial maxillectomy was performed through lateral rhinotomy or mid facial degloving approach. Endoscopic medial maxillectomy has been advocated by a number of authors in the management ...

  10. The relationship between chondromalacia patella, medial meniscal tear and medial periarticular bursitis in patients with osteoarthritis

    OpenAIRE

    Resorlu Mustafa; Doner Davut; Karatag Ozan; Toprak Canan Akgun

    2017-01-01

    Abstract Background This study investigated the presence of bursitis in the medial compartment of the knee (pes anserine, semimembranosus-tibial collateral ligament, and medial collateral ligament bursa) in osteoarthritis, chondromalacia patella and medial meniscal tears. Patients and methods Radiological findings of 100 patients undergoing magnetic resonance imaging with a preliminary diagnosis of knee pain were retrospectively evaluated by two radiologists. The first radiologist assessed al...

  11. Temporal-pattern similarity analysis reveals the beneficial and detrimental effects of context reinstatement on human memory.

    Science.gov (United States)

    Staudigl, Tobias; Vollmar, Christian; Noachtar, Soheyl; Hanslmayr, Simon

    2015-04-01

    A powerful force in human memory is the context in which memories are encoded (Tulving and Thomson, 1973). Several studies suggest that the reinstatement of neural encoding patterns is beneficial for memory retrieval (Manning et al., 2011; Staresina et al., 2012; Jafarpour et al., 2014). However, reinstatement of the original encoding context is not always helpful, for instance, when retrieving a memory in a different contextual situation (Smith and Vela, 2001). It is an open question whether such context-dependent memory effects can be captured by the reinstatement of neural patterns. We investigated this question by applying temporal and spatial pattern similarity analysis in MEG and intracranial EEG in a context-match paradigm. Items (words) were tagged by individual dynamic context stimuli (movies). The results show that beta oscillatory phase in visual regions and the parahippocampal cortex tracks the incidental reinstatement of individual context trajectories on a single-trial level. Crucially, memory benefitted from reinstatement when the encoding and retrieval contexts matched but suffered from reinstatement when the contexts did not match. Copyright © 2015 the authors 0270-6474/15/355373-12$15.00/0.

  12. Neural correlates of auditory temporal predictions during sensorimotor synchronization

    Directory of Open Access Journals (Sweden)

    Nadine ePecenka

    2013-08-01

    Full Text Available Musical ensemble performance requires temporally precise interpersonal action coordination. To play in synchrony, ensemble musicians presumably rely on anticipatory mechanisms that enable them to predict the timing of sounds produced by co-performers. Previous studies have shown that individuals differ in their ability to predict upcoming tempo changes in paced finger-tapping tasks (indexed by cross-correlations between tap timing and pacing events and that the degree of such prediction influences the accuracy of sensorimotor synchronization (SMS and interpersonal coordination in dyadic tapping tasks. The current functional magnetic resonance imaging study investigated the neural correlates of auditory temporal predictions during SMS in a within-subject design. Hemodynamic responses were recorded from 18 musicians while they tapped in synchrony with auditory sequences containing gradual tempo changes under conditions of varying cognitive load (achieved by a simultaneous visual n-back working-memory task comprising three levels of difficulty: observation only, 1-back, and 2-back object comparisons. Prediction ability during SMS decreased with increasing cognitive load. Results of a parametric analysis revealed that the generation of auditory temporal predictions during SMS recruits (1 a distributed network in cortico-cerebellar motor-related brain areas (left dorsal premotor and motor cortex, right lateral cerebellum, SMA proper and bilateral inferior parietal cortex and (2 medial cortical areas (medial prefrontal cortex, posterior cingulate cortex. While the first network is presumably involved in basic sensory prediction, sensorimotor integration, motor timing, and temporal adaptation, activation in the second set of areas may be related to higher-level social-cognitive processes elicited during action coordination with auditory signals that resemble music performed by human agents.

  13. Human biting activity, spatial-temporal distribution and malaria vector role of Anopheles calderoni in the southwest of Colombia.

    Science.gov (United States)

    Orjuela, Lorena I; Ahumada, Martha L; Avila, Ivonni; Herrera, Sócrates; Beier, John C; Quiñones, Martha L

    2015-06-24

    Anopheles calderoni was first recognized in Colombia in 2010 as this species had been misidentified as Anopheles punctimacula due to morphological similarities. An. calderoni is considered a malaria vector in Peru and has been found naturally infected with Plasmodium falciparum in Colombia. However, its biting behaviour, population dynamics and epidemiological importance have not been well described for Colombia. To assess the contribution of An. calderoni to malaria transmission and its human biting behaviour and spatial/temporal distribution in the southwest of Colombia, human landing catches (HLC) and larval collections were carried out in a cross-sectional, entomological study in 22 localities between 2011 and 2012, and a longitudinal study was performed in the Boca de Prieta locality in Olaya Herrera municipality between July 2012 and June 2013. All mosquitoes determined as An. calderoni were tested by ELISA to establish infection with Plasmodium spp. Larvae of An. calderoni were found in four localities in 12 out of 244 breeding sites inspected. An. calderoni adults were collected in 14 out of 22 localities during the cross-sectional study and represented 41.3% (459 of 1,111) of the collected adult specimens. Other species found were Anopheles albimanus (54.7%), Anopheles apicimacula (2.1%), Anopheles neivai (1.7%), and Anopheles argyritarsis (0.2%). In the localities that reported the highest malaria Annual Parasite Index (>10/1,000 inhabitants) during the year of sampling, An. calderoni was the predominant species (>90% of the specimens collected). In the longitudinal study, 1,528 An. calderoni were collected by HLC with highest biting rates in February, May and June 2013, periods of high precipitation. In general, the species showed a preference to bite outdoors (p Colombia. Its observed preference for outdoor biting is a major challenge for malaria control.

  14. UMAPRM: Uniformly sampling the medial axis

    KAUST Repository

    Yeh, Hsin-Yi Cindy

    2014-05-01

    © 2014 IEEE. Maintaining clearance, or distance from obstacles, is a vital component of successful motion planning algorithms. Maintaining high clearance often creates safer paths for robots. Contemporary sampling-based planning algorithms That utilize The medial axis, or The set of all points equidistant To Two or more obstacles, produce higher clearance paths. However, They are biased heavily Toward certain portions of The medial axis, sometimes ignoring parts critical To planning, e.g., specific Types of narrow passages. We introduce Uniform Medial Axis Probabilistic RoadMap (UMAPRM), a novel planning variant That generates samples uniformly on The medial axis of The free portion of Cspace. We Theoretically analyze The distribution generated by UMAPRM and show its uniformity. Our results show That UMAPRM\\'s distribution of samples along The medial axis is not only uniform but also preferable To other medial axis samplers in certain planning problems. We demonstrate That UMAPRM has negligible computational overhead over other sampling Techniques and can solve problems The others could not, e.g., a bug Trap. Finally, we demonstrate UMAPRM successfully generates higher clearance paths in The examples.

  15. Negligent and intentional fires in Portugal: the role of human and biophysical drivers on the temporal distribution

    Science.gov (United States)

    Parente, Joana; Pereira, Mário; Amraoui, Malik; Tedim, Fantina

    2017-04-01

    Portugal is the European country with higher number of fires (NF) and burnt area (BA) per unit of land area. The annual number of fires for which the cause of fire is known is not constant and relatively small (typically less than 50% of annual number of records). Nevertheless, the analysis of the fire causes reveals that the vast majority (99%) of the fires in Portugal are of human origin and only a small fraction are of natural origin (1% caused by lightning). The study period will be the recent years of 2012 - 2014, when fire recording procedures are more reliable and the cause of ignition was assessed for more than 50% (19376) of the fires. The fires with approximately seventy different causes of fire defined/recognized by the Portuguese Forest Service (ICNF) were grouped into negligent, intentional and natural fires. For this study the authors proposes the use of the Nomenclature of Territorial Units for Statistics level II, which divides Portugal in 5 basic economic regions, namely Norte, Centro, Área Metropolitana de Lisboa, Alentejo, and Algarve. Most of the fires (54%) occur in the so-called critical period defined between July and September, but high wildfire activity may also occur in few periods of the remaining months (especially in February and March). The intentional fires represent 40% of total NF but accounts for 53% of total BA during the study period. The temporal distribution are described and interpreted in terms of the climate, fire weather, land use land cover (LULC), distance to communication routes (roads and railways) and topographic variables (altitude, slope) using statistical analysis and GIS techniques. Results points to: a) higher number of negligent than intentional fires; b) higher BA on critical period in years 2012 and 2013; c) decrease in time and decrease from critical period to non-critical period of the number of fires, in all regions; and d) the dominant role of fire weather in the observed temporal patterns. We strongly

  16. The Cognitive Neuroscience of Human Memory Since H.M

    OpenAIRE

    Squire, Larry R.; Wixted, John T.

    2011-01-01

    Work with patient H.M., beginning in the 1950s, established key principles about the organization of memory that inspired decades of experimental work. Since H.M., the study of human memory and its disorders has continued to yield new insights and to improve understanding of the structure and organization of memory. Here we review this work with emphasis on the neuroanatomy of medial temporal lobe and diencephalic structures important for memory, multiple memory systems, visual perception, im...

  17. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    Science.gov (United States)

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  18. The Effect of Scala Tympani Morphology on Basilar Membrane Contact With a Straight Electrode Array: A Human Temporal Bone Study.

    Science.gov (United States)

    Verberne, Juul; Risi, Frank; Campbell, Luke; Chambers, Scott; O'Leary, Stephen

    2017-01-01

    Scala tympani morphology influences the insertion dynamics and intra-scalar position of straight electrode arrays. Hearing preservation is the goal of cochlear implantation with current thin straight electrode arrays. These hug the lateral wall, facilitating full, atraumatic insertions. However, most studies still report some postoperative hearing loss. This study explores the influence of scala tympani morphology on array position relative to the basilar membrane and its possible contribution to postoperative hearing loss. Twenty-six fresh-frozen human temporal bones implanted with a straight electrode array were three-dimensionally reconstructed from micro-photographic histological sections. Insertion depth and the proximity between the array and basilar membrane were recorded. Lateral wall shape was quantified as a curvature ratio. Insertion depths ranged from 233 to 470 degrees. The mean first point of contact between the array and basilar membrane was 185 degrees; arrays tended to remain in contact with the membrane after first contacting it. Eighty-nine and 93% of arrays that reached the upper basal (>240-360 degrees) and second (>360-720 degrees) turns respectively contacted the basilar membrane in these regions. Scalar wall curvature ratio decreased significantly (the wall became steeper) from the basal to second turns. This shift correlated with a reduced distance between the array and basilar membrane. Scala tympani morphology influences the insertion dynamics and intra-scalar position of a straight electrode array. In addition to gross trauma of cochlear structures, contact between the array and basilar membrane and how this impacts membrane function should be considered in hearing preservation cases.

  19. Temporal Profiling and Pulsed SILAC Labeling Identify Novel Secreted Proteins During Ex Vivo Osteoblast Differentiation of Human Stromal Stem Cells*

    Science.gov (United States)

    Kristensen, Lars P.; Chen, Li; Nielsen, Maria Overbeck; Qanie, Diyako W.; Kratchmarova, Irina; Kassem, Moustapha; Andersen, Jens S.

    2012-01-01

    It is well established that bone forming cells (osteoblasts) secrete proteins with autocrine, paracrine, and endocrine function. However, the identity and functional role for the majority of these secreted and differentially expressed proteins during the osteoblast (OB) differentiation process, is not fully established. To address these questions, we quantified the temporal dynamics of the human stromal (mesenchymal, skeletal) stem cell (hMSC) secretome during ex vivo OB differentiation using stable isotope labeling by amino acids in cell culture (SILAC). In addition, we employed pulsed SILAC labeling to distinguish genuine secreted proteins from intracellular contaminants. We identified 466 potentially secreted proteins that were quantified at 5 time-points during 14-days ex vivo OB differentiation including 41 proteins known to be involved in OB functions. Among these, 315 proteins exhibited more than 2-fold up or down-regulation. The pulsed SILAC method revealed a strong correlation between the fraction of isotope labeling and the subset of proteins known to be secreted and involved in OB differentiation. We verified SILAC data using qRT-PCR analysis of 9 identified potential novel regulators of OB differentiation. Furthermore, we studied the biological effects of one of these proteins, the hormone stanniocalcin 2 (STC2) and demonstrated its autocrine effects in enhancing osteoblastic differentiation of hMSC. In conclusion, combining complete and pulsed SILAC labeling facilitated the identification of novel factors produced by hMSC with potential role in OB differentiation. Our study demonstrates that the secretome of osteoblastic cells is more complex than previously reported and supports the emerging evidence that osteoblastic cells secrete proteins with endocrine functions and regulate cellular processes beyond bone formation. PMID:22801418

  20. GABAA receptor subunit expression changes in the human Alzheimer's disease hippocampus, subiculum, entorhinal cortex and superior temporal gyrus.

    Science.gov (United States)

    Kwakowsky, Andrea; Calvo-Flores Guzmán, Beatriz; Pandya, Madhavi; Turner, Clinton; Waldvogel, Henry J; Faull, Richard L

    2018-02-27

    Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. GABA type A receptors (GABA A Rs) are severely affected in Alzheimer's disease (AD). However, the distribution and subunit composition of GABA A Rs in the AD brain are not well understood. This is the first comprehensive study to show brain region- and cell layer-specific alterations in the expression of the GABA A R subunits α1-3, α5, β1-3 and γ2 in the human AD hippocampus, entorhinal cortex and superior temporal gyrus (STG). In late-stage AD tissue samples using immunohistochemistry we found significant alteration of all investigated GABA A Rs subunits except for α3 and β1 that were well preserved. The most prominent changes include an increase in GABA A R α1 expression associated with AD in all layers of the CA3 region, in the stratum (str.) granulare and hilus of the dentate gyrus (DG). We found a significant increase in GABA A R α2 expression in the str. oriens of the CA1-3, str. radiatum of the CA2,3 and decrease in the str. pyramidale of the CA1 region in AD cases. In AD there was a significant increase in GABA A R α5 subunit expression in str. pyramidale, str. oriens of the CA1 region and decrease in the STG. We also found a significant decrease in the GABA A R β3 subunit immunoreactivity in the str. oriens of the CA2, str. granulare and str. moleculare of the DG. In conclusion, these findings indicate that the expression of the GABA A R subunits shows brain region- and layer-specific alterations in AD, and these changes could significantly influence and alter GABA A R function in the disease. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. Unbiased Stereologic Estimation of the Spatial Distribution of Paget’s Disease in the Human Temporal Bone

    DEFF Research Database (Denmark)

    Bloch, Sune Land; Sørensen, Mads Sølvsten

    2014-01-01

    remodeling around the inner ear space and to compare it with that of otosclerosis in a contemporary context of temporal bone dynamics. MATERIALS AND METHODS: From the temporal bone collection of Massachusetts Eye and Ear Infirmary, 15 of 29 temporal bones with Paget's disease were selected to obtain...... an independent sample. All volume distributions were obtained along the normal axis of capsular bone remodeling activity by the use of vector-based stereology. RESULTS: Pagetic bone remodeling was distributed centrifugally around the inner ear space at the individual and the general level. This pattern...

  2. Temporal overlaps of feral cats with prey and competitors in primary and human-altered habitats on Bohol Island, Philippines.

    Science.gov (United States)

    Bogdan, Vlastimil; Jůnek, Tomáš; Jůnková Vymyslická, Pavla

    2016-01-01

    The vertebrate fauna of the Philippines, known for its diversity and high proportion of endemic species, comprises mainly small- to medium-sized forms with a few large exceptions. As with other tropical ecosystems, the major threats to wildlife are habitat loss, hunting and invasive species, of which the feral cat (Felis catus) is considered the most damaging. Our camera-trapping study focused on a terrestrial vertebrate species inventory on Bohol Island and tempo-spatial co-occurrences of feral cats with their prey and competitors. The survey took place in the Rajah Sikatuna Protected Landscape, and we examined the primary rainforest, its border with agricultural land, and rural areas in the vicinity of villages. Altogether, over 2,885 trap days we captured 30 species of vertebrates-10 mammals (including Sus philippensis), 19 birds and one reptile, Varanus cumingi. We trapped 81.8% of expected vertebrates. Based on the number of events, the most frequent native species was the barred rail (Gallirallus torquatus). The highest overlap in diel activity between cats and potential prey was recorded with rodents in rural areas (Δ = 0.62); the lowest was in the same habitat with ground-dwelling birds (Δ = 0.40). Cat activity was not recorded inside the rainforest; in other habitats their diel activity pattern differed. The cats' activity declined in daylight in the proximity of humans, while it peaked at the transition zone between rainforest and fields. Both rodents and ground-dwelling birds exhibited a shift in activity levels between sites where cats were present or absent. Rodents tend to become active by day in cat-free habitats. No cats' temporal response to co-occurrences of civets (Paradoxurus hermaphroditus and Viverra tangalunga) was found but cats in diel activity avoided domestic dogs (Canis lupus familiaris). Our first insight into the ecology of this invasive predator in the Philippines revealed an avoidance of homogeneous primary rainforest and a

  3. Temporal overlaps of feral cats with prey and competitors in primary and human-altered habitats on Bohol Island, Philippines

    Directory of Open Access Journals (Sweden)

    Vlastimil Bogdan

    2016-08-01

    Full Text Available The vertebrate fauna of the Philippines, known for its diversity and high proportion of endemic species, comprises mainly small- to medium-sized forms with a few large exceptions. As with other tropical ecosystems, the major threats to wildlife are habitat loss, hunting and invasive species, of which the feral cat (Felis catus is considered the most damaging. Our camera-trapping study focused on a terrestrial vertebrate species inventory on Bohol Island and tempo-spatial co-occurrences of feral cats with their prey and competitors. The survey took place in the Rajah Sikatuna Protected Landscape, and we examined the primary rainforest, its border with agricultural land, and rural areas in the vicinity of villages. Altogether, over 2,885 trap days we captured 30 species of vertebrates–10 mammals (including Sus philippensis, 19 birds and one reptile, Varanus cumingi. We trapped 81.8% of expected vertebrates. Based on the number of events, the most frequent native species was the barred rail (Gallirallus torquatus. The highest overlap in diel activity between cats and potential prey was recorded with rodents in rural areas (Δ = 0.62; the lowest was in the same habitat with ground-dwelling birds (Δ = 0.40. Cat activity was not recorded inside the rainforest; in other habitats their diel activity pattern differed. The cats’ activity declined in daylight in the proximity of humans, while it peaked at the transition zone between rainforest and fields. Both rodents and ground-dwelling birds exhibited a shift in activity levels between sites where cats were present or absent. Rodents tend to become active by day in cat-free habitats. No cats’ temporal response to co-occurrences of civets (Paradoxurus hermaphroditus and Viverra tangalunga was found but cats in diel activity avoided domestic dogs (Canis lupus familiaris. Our first insight into the ecology of this invasive predator in the Philippines revealed an avoidance of homogeneous primary

  4. Different Temporal Effects of Ebola Virus VP35 and VP24 Proteins on Global Gene Expression in Human Dendritic Cells.

    Science.gov (United States)

    Ilinykh, Philipp A; Lubaki, Ndongala M; Widen, Steven G; Renn, Lynnsey A; Theisen, Terence C; Rabin, Ronald L; Wood, Thomas G; Bukreyev, Alexander

    2015-08-01

    Ebola virus (EBOV) causes a severe hemorrhagic fever with a deficient immune response, lymphopenia, and lymphocyte apoptosis. Dendritic cells (DC), which trigger the adaptive response, do not mature despite EBOV infection. We recently demonstrated that DC maturation is unblocked by disabling the innate response antagonizing domains (IRADs) in EBOV VP35 and VP24 by the mutations R312A and K142A, respectively. Here we analyzed the effects of VP35 and VP24 with the IRADs disabled on global gene expression in human DC. Human monocyte-derived DC were infected by wild-type (wt) EBOV or EBOVs carrying the mutation in VP35 (EBOV/VP35m), VP24 (EBOV/VP24m), or both (EBOV/VP35m/VP24m). Global gene expression at 8 and 24 h was analyzed by deep sequencing, and the expression of interferon (IFN) subtypes up to 5 days postinfection was analyzed by quantitative reverse transcription-PCR (qRT-PCR). wt EBOV induced a weak global gene expression response, including markers of DC maturation, cytokines, chemokines, chemokine receptors, and multiple IFNs. The VP35 mutation unblocked the expression, resulting in a dramatic increase in expression of these transcripts at 8 and 24 h. Surprisingly, DC infected with EBOV/VP24m expressed lower levels of many of these transcripts at 8 h after infection, compared to wt EBOV. In contrast, at 24 h, expression of the transcripts increased in DC infected with any of the three mutants, compared to wt EBOV. Moreover, sets of genes affected by the two mutations only partially overlapped. Pathway analysis demonstrated that the VP35 mutation unblocked pathways involved in antigen processing and presentation and IFN signaling. These data suggest that EBOV IRADs have profound effects on the host adaptive immune response through massive transcriptional downregulation of DC. This study shows that infection of DC with EBOV, but not its mutant forms with the VP35 IRAD and/or VP24 IRAD disabled, causes a global block in expression of host genes. The temporal

  5. fMR-adaptation indicates selectivity to audiovisual content congruency in distributed clusters in human superior temporal cortex

    NARCIS (Netherlands)

    van Atteveldt, Nienke M; Blau, Vera C; Blomert, Leo; Goebel, Rainer

    2010-01-01

    BACKGROUND: Efficient multisensory integration is of vital importance for adequate interaction with the environment. In addition to basic binding cues like temporal and spatial coherence, meaningful multisensory information is also bound together by content-based associations. Many functional

  6. The JCR:LA-cp rat: a novel rodent model of cystic medial necrosis.

    Science.gov (United States)

    Pung, Yuh Fen; Chilian, William M; Bennett, Martin R; Figg, Nichola; Kamarulzaman, Mohd Hamzah

    2017-03-01

    Although there are multiple rodent models of the metabolic syndrome, very few develop vascular complications. In contrast, the JCR:LA-cp rat develops both metabolic syndrome and early atherosclerosis in predisposed areas. However, the pathology of the normal vessel wall has not been described. We examined JCR:LA control (+/+) or cp/cp rats fed normal chow diet for 6 or 18 mo. JCR:LA-cp rats developed multiple features of advanced cystic medial necrosis including "cysts," increased collagen formation and proteoglycan deposition around cysts, apoptosis of vascular smooth muscle cells, and spotty medial calcification. These appearances began within 6 mo and were extensive by 18 mo. JCR:LA-cp rats had reduced medial cellularity, increased medial thickness, and vessel hypoxia that was most marked in the adventitia. In conclusion, the normal chow-fed JCR:LA-cp rat represents a novel rodent model of cystic medial necrosis, associated with multiple metabolic abnormalities, vascular smooth muscle cell apoptosis, and vessel hypoxia. NEW & NOTEWORTHY Triggers for cystic medial necrosis (CMN) have been difficult to study due to lack of animal models to recapitulate the pathologies seen in humans. Our study is the first description of CMN in the rat. Thus the JCR:LA-cp rat represents a useful model to investigate the underlying molecular changes leading to the development of CMN. Copyright © 2017 the American Physiological Society.

  7. The Relationship between Chondromalacia Patella, Medial Meniscal Tear and Medial Periarticular Bursitis in Patients with Osteoarthritis.

    Science.gov (United States)

    Resorlu, Mustafa; Doner, Davut; Karatag, Ozan; Toprak, Canan Akgun

    2017-12-01

    This study investigated the presence of bursitis in the medial compartment of the knee (pes anserine, semimembranosus-tibial collateral ligament, and medial collateral ligament bursa) in osteoarthritis, chondromalacia patella and medial meniscal tears. Radiological findings of 100 patients undergoing magnetic resonance imaging with a preliminary diagnosis of knee pain were retrospectively evaluated by two radiologists. The first radiologist assessed all patients in terms of osteoarthritis, chondromalacia patella and medial meniscal tear. The second radiologist was blinded to these results and assessed the presence of bursitis in all patients. Mild osteoarthritis (grade I and II) was determined in 55 patients and severe osteoarthritis (grade III and IV) in 45 cases. At retropatellar cartilage evaluation, 25 patients were assessed as normal, while 29 patients were diagnosed with mild chondromalacia patella (grade I and II) and 46 with severe chondromalacia patella (grade III and IV). Medial meniscus tear was determined in 51 patients. Severe osteoarthritis and chondromalacia patella were positively correlated with meniscal tear (p chondromalacia patella (p = 0.023 and p = 0.479, respectively). Evaluation of lateral compartment bursae revealed lateral collateral ligament bursitis in 2 patients and iliotibial bursitis in 5 patients. We observed a greater prevalence of bursitis in the medial compartment of the knee in patients with severe osteoarthritis and medial meniscus tear.

  8. The Relationship between Chondromalacia Patella, Medial Meniscal Tear and Medial Periarticular Bursitis in Patients with Osteoarthritis

    Science.gov (United States)

    Doner, Davut; Karatag, Ozan; Toprak, Canan Akgun

    2017-01-01

    Abstract Background This study investigated the presence of bursitis in the medial compartment of the knee (pes anserine, semimembranosus-tibial collateral ligament, and medial collateral ligament bursa) in osteoarthritis, chondromalacia patella and medial meniscal tears. Patients and methods Radiological findings of 100 patients undergoing magnetic resonance imaging with a preliminary diagnosis of knee pain were retrospectively evaluated by two radiologists. The first radiologist assessed all patients in terms of osteoarthritis, chondromalacia patella and medial meniscal tear. The second radiologist was blinded to these results and assessed the presence of bursitis in all patients. Results Mild osteoarthritis (grade I and II) was determined in 55 patients and severe osteoarthritis (grade III and IV) in 45 cases. At retropatellar cartilage evaluation, 25 patients were assessed as normal, while 29 patients were diagnosed with mild chondromalacia patella (grade I and II) and 46 with severe chondromalacia patella (grade III and IV). Medial meniscus tear was determined in 51 patients. Severe osteoarthritis and chondromalacia patella were positively correlated with meniscal tear (p chondromalacia patella (p = 0.023 and p = 0.479, respectively). Evaluation of lateral compartment bursae revealed lateral collateral ligament bursitis in 2 patients and iliotibial bursitis in 5 patients. Conclusions We observed a greater prevalence of bursitis in the medial compartment of the knee in patients with severe osteoarthritis and medial meniscus tear. PMID:29333118

  9. MicroRNA and mesial temporal lobe epilepsy with hippocampal sclerosis: Whole miRNome profiling of human hippocampus.

    Science.gov (United States)

    Bencurova, Petra; Baloun, Jiri; Musilova, Katerina; Radova, Lenka; Tichy, Boris; Pail, Martin; Zeman, Martin; Brichtova, Eva; Hermanova, Marketa; Pospisilova, Sarka; Mraz, Marek; Brazdil, Milan

    2017-10-01

    Mesial temporal lobe epilepsy (mTLE) is a severe neurological disorder characterized by recurrent seizures. mTLE is frequently accompanied by neurodegeneration in the hippocampus resulting in hippocampal sclerosis (HS), the most common morphological correlate of drug resistance in mTLE patients. Incomplete knowledge of pathological changes in mTLE+HS complicates its therapy. The pathological mechanism underlying mTLE+HS may involve abnormal gene expression regulation, including posttranscriptional networks involving microRNAs (miRNAs). miRNA expression deregulation has been reported in various disorders, including epilepsy. However, the miRNA profile of mTLE+HS is not completely known and needs to be addressed. Here, we have focused on hippocampal miRNA profiling in 33 mTLE+HS patients and nine postmortem controls to reveal abnormally expressed miRNAs. In this study, we significantly reduced technology-related bias (the most common source of false positivity in miRNA profiling data) by combining two different miRNA profiling methods, namely next generation sequencing and miRNA-specific quantitative real-time polymerase chain reaction. These methods combined have identified and validated 20 miRNAs with altered expression in the human epileptic hippocampus; 19 miRNAs were up-regulated and one down-regulated in mTLE+HS patients. Nine of these miRNAs have not been previously associated with epilepsy, and 19 aberrantly expressed miRNAs potentially regulate the targets and pathways linked with epilepsy (such as potassium channels, γ-aminobutyric acid, neurotrophin signaling, and axon guidance). This study extends current knowledge of miRNA-mediated gene expression regulation in mTLE+HS by identifying miRNAs with altered expression in mTLE+HS, including nine novel abnormally expressed miRNAs and their putative targets. These observations further encourage the potential of microRNA-based biomarkers or therapies. Wiley Periodicals, Inc. © 2017 International League Against

  10. The Cognitive Neuroscience of Human Memory Since H.M

    Science.gov (United States)

    Squire, Larry R.; Wixted, John T.

    2011-01-01

    Work with patient H.M., beginning in the 1950s, established key principles about the organization of memory that inspired decades of experimental work. Since H.M., the study of human memory and its disorders has continued to yield new insights and to improve understanding of the structure and organization of memory. Here we review this work with emphasis on the neuroanatomy of medial temporal lobe and diencephalic structures important for memory, multiple memory systems, visual perception, immediate memory, memory consolidation, the locus of long-term memory storage, the concepts of recollection and familiarity, and the question of how different medial temporal lobe structures may contribute differently to memory functions. PMID:21456960

  11. Medial structure generation for registration of anatomical structures

    DEFF Research Database (Denmark)

    Vera, Sergio; Gil, Debora; Kjer, Hans Martin

    2017-01-01

    structures. Methods for generation of medial structures, however, are prone to the generation of medial artifacts (spurious branches) that traditionally need to be pruned before the medial structure can be used for further computations. The act of pruning can affect main sections of the medial surface......Medial structures (skeletons and medial manifolds) have shown capacity to describe shape in a compact way. In the field of medical imaging, they have been employed to enrich the description of organ anatomy, to improve segmentation, or to describe the organ position in relation to surrounding...

  12. Presbycusis: a human temporal bone study of individuals with flat audiometric patterns of hearing loss using a new method to quantify stria vascularis volume.

    Science.gov (United States)

    Nelson, Erik G; Hinojosa, Raul

    2003-10-01

    The purpose of this study was to determine the prevalence of stria vascularis atrophy in individuals with presbycusis and flat audiometric patterns of hearing loss. Individuals with presbycusis have historically been categorized by the shape of their audiograms, and flat audiometric thresholds have been reported to be associated with atrophy of the stria vascularis. Stria vascularis volume was not measured in these studies. Retrospective case review. Archival human temporal bones from individuals with presbycusis were selected on the basis of strict audiometric criteria for flat audiometric thresholds. Six temporal bones that met these criteria were identified and compared with 10 temporal bones in individuals with normal hearing. A unique quantitative method was developed to measure the stria vascularis volume in these temporal bones. The hair cell and spiral ganglion cell populations also were quantitatively evaluated. Only one of the six individuals with presbycusis and flat audiometric thresholds had significant atrophy of the stria vascularis. This individual with stria vascularis atrophy also had reduced inner hair cell, outer hair cell, and ganglion cell populations. Three of the individuals with presbycusis had spiral ganglion cell loss, three individuals had inner hair cell loss, and all six individuals had outer hair cell loss. The results of this investigation suggest that individuals with presbycusis and flat audiometric patterns of hearing loss infrequently have stria vascularis atrophy. Outer hair cell loss alone or in combination with inner hair cell or ganglion cell loss may be the cause of flat audiometric thresholds in individuals with presbycusis.

  13. RNA analysis of inner ear cells from formalin fixed paraffin embedded (FFPE) archival human temporal bone section using laser microdissection--a technical report.

    Science.gov (United States)

    Kimura, Yurika; Kubo, Sachiho; Koda, Hiroko; Shigemoto, Kazuhiro; Sawabe, Motoji; Kitamura, Ken

    2013-08-01

    Molecular analysis using archival human inner ear specimens is challenging because of the anatomical complexity, long-term fixation, and decalcification. However, this method may provide great benefit for elucidation of otological diseases. Here, we extracted mRNA for RT-PCR from tissues dissected from archival FFPE human inner ears by laser microdissection. Three human temporal bones obtained at autopsy were fixed in formalin, decalcified by EDTA, and embedded in paraffin. The samples were isolated into spiral ligaments, outer hair cells, spiral ganglion cells, and stria vascularis by laser microdissection. RNA was extracted and heat-treated in 10 mM citrate buffer to remove the formalin-derived modification. To identify the sites where COCH and SLC26A5 mRNA were expressed, semi-nested RT-PCR was performed. We also examined how long COCH mRNA could be amplified by semi-nested RT-PCR in archival temporal bone. COCH was expressed in the spiral ligament and stria vascularis. However, SLC26A5 was expressed only in outer hair cells. The maximum base length of COCH mRNA amplified by RT-PCR was 98 bp in 1 case and 123 bp in 2 cases. We detected COCH and SLC26A5 mRNA in specific structures and cells of the inner ear from archival human temporal bone. Our innovative method using laser microdissection and semi-nested RT-PCR should advance future RNA study of human inner ear diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Temporal Glare

    DEFF Research Database (Denmark)

    Ritschel, Tobias; Ihrke, Matthias; Frisvad, Jeppe Revall

    2009-01-01

    Glare is a consequence of light scattered within the human eye when looking at bright light sources. This effect can be exploited for tone mapping since adding glare to the depiction of high-dynamic range (HDR) imagery on a low-dynamic range (LDR) medium can dramatically increase perceived contra...... to initially static HDR images. By conducting psychophysical studies, we validate that our method improves perceived brightness and that dynamic glare-renderings are often perceived as more attractive depending on the chosen scene.......Glare is a consequence of light scattered within the human eye when looking at bright light sources. This effect can be exploited for tone mapping since adding glare to the depiction of high-dynamic range (HDR) imagery on a low-dynamic range (LDR) medium can dramatically increase perceived contrast....... Even though most, if not all, subjects report perceiving glare as a bright pattern that fluctuates in time, up to now it has only been modeled as a static phenomenon. We argue that the temporal properties of glare are a strong means to increase perceived brightness and to produce realistic...

  15. Medial branch neurotomy in low back pain

    Energy Technology Data Exchange (ETDEWEB)

    Masala, Salvatore; Mammucari, Matteo; Simonetti, Giovanni [Interventional Radiology and Radiotherapy University ' ' Tor Vergata' ' , Department of Diagnostic and Molecular Imaging, Rome (Italy); Nano, Giovanni [Interventional Radiology and Radiotherapy University ' ' Tor Vergata' ' , Department of Diagnostic and Molecular Imaging, Rome (Italy); University ' ' Tor Vergata' ' , Department of Radiology, Rome (Italy); Marcia, Stefano [S. Giovanni di Dio Hospital, Department of Diagnostic and Molecular Imaging, Cagliari (Italy)

    2012-07-15

    This study aimed to assess the effectiveness of pulsed radiofrequency medial branch dorsal ramus neurotomy in patients with facet joint syndrome. From January 2008 to April 2010, 92 patients with facet joint syndrome diagnosed by strict inclusion criteria and controlled diagnostic blocks undergone medial branch neurotomy. We did not exclude patients with failed back surgery syndrome (FBSS). Electrodes (20G) with 5-mm active tip were placed under fluoroscopy guide parallel to medial branch. Patients were followed up by physical examination and by Visual Analog Scale and Oswestry Disability Index at 1, 6, and 12 months. In all cases, pain improvement was statistically significant and so quality of life. Three non-FBSS patients had to undergo a second neurotomy because of non-satisfactory pain decrease. Complications were reported in no case. Medial branch radiofrequency neurotomy has confirmed its well-established effectiveness in pain and quality of life improvement as long as strict inclusion criteria be fulfilled and nerve ablation be accomplished by parallel electrode positioning. This statement can be extended also to FBSS patients. (orig.)

  16. Medial branch neurotomy in low back pain

    International Nuclear Information System (INIS)

    Masala, Salvatore; Mammucari, Matteo; Simonetti, Giovanni; Nano, Giovanni; Marcia, Stefano

    2012-01-01

    This study aimed to assess the effectiveness of pulsed radiofrequency medial branch dorsal ramus neurotomy in patients with facet joint syndrome. From January 2008 to April 2010, 92 patients with facet joint syndrome diagnosed by strict inclusion criteria and controlled diagnostic blocks undergone medial branch neurotomy. We did not exclude patients with failed back surgery syndrome (FBSS). Electrodes (20G) with 5-mm active tip were placed under fluoroscopy guide parallel to medial branch. Patients were followed up by physical examination and by Visual Analog Scale and Oswestry Disability Index at 1, 6, and 12 months. In all cases, pain improvement was statistically significant and so quality of life. Three non-FBSS patients had to undergo a second neurotomy because of non-satisfactory pain decrease. Complications were reported in no case. Medial branch radiofrequency neurotomy has confirmed its well-established effectiveness in pain and quality of life improvement as long as strict inclusion criteria be fulfilled and nerve ablation be accomplished by parallel electrode positioning. This statement can be extended also to FBSS patients. (orig.)

  17. Medial tibial stress syndrome: a critical review

    NARCIS (Netherlands)

    Moen, Maarten H.; Tol, Johannes L.; Weir, Adam; Steunebrink, Miriam; de Winter, Theodorus C.

    2009-01-01

    Medial tibial stress syndrome (MTSS) is one of the most common leg injuries in athletes and soldiers. The incidence of MTSS is reported as being between 4% and 35% in military personnel and athletes. The name given to this condition refers to pain on the posteromedial tibial border during exercise,

  18. Acute compartment syndrome after medial gastrocnemius tear.

    Science.gov (United States)

    Sit, Yan Kit; Lui, Tun Hing

    2015-02-01

    Acute compartment syndrome after medial gastrocnemius tear is very rare. It can involve the superficial posterior compartment alone or progress to involve all the 4 compartments of the lower legs. Those patients with high pain tolerance and minor trauma can lead to delayed presentation. Immediate fasciotomy is the treatment of choice. Therapeutic Level IV, Case Study. © 2014 The Author(s).

  19. Rheo: Japanese Sound Art Interrogating Digital Mediality

    DEFF Research Database (Denmark)

    Vandsø, Anette

    2014-01-01

    THe article asks in what way the Japanese sound artist Ryoichi Kurokawa's audiovisual installation Rheo 5 Horisonz (2010) is 'digital'. Using Professor Lars Elleströms concept of 'mediality, the main claim in this article is that Rheo no only uses digital tehcnology, but also interrogates digital...

  20. Medial prefrontal aberrations in major depressive disorder revealed by cytoarchitectonically informed voxel-based morphometry

    Science.gov (United States)

    Bludau, Sebastian; Bzdok, Danilo; Gruber, Oliver; Kohn, Nils; Riedl, Valentin; Sorg, Christian; Palomero-Gallagher, Nicola; Müller, Veronika I.; Hoffstaedter, Felix; Amunts, Katrin; Eickhoff, Simon B.

    2017-01-01

    Objective The heterogeneous human frontal pole has been identified as a node in the dysfunctional network of major depressive disorder. The contribution of the medial (socio-affective) versus lateral (cognitive) frontal pole to major depression pathogenesis is currently unclear. The present study performs morphometric comparison of the microstructurally informed subdivisions of human frontal pole between depressed patients and controls using both uni- and multivariate statistics. Methods Multi-site voxel- and region-based morphometric MRI analysis of 73 depressed patients and 73 matched controls without psychiatric history. Frontal pole volume was first compared between depressed patients and controls by subdivision-wise classical morphometric analysis. In a second approach, frontal pole volume was compared by subdivision-naive multivariate searchlight analysis based on support vector machines. Results Subdivision-wise morphometric analysis found a significantly smaller medial frontal pole in depressed patients with a negative correlation of disease severity and duration. Histologically uninformed multivariate voxel-wise statistics provided converging evidence for structural aberrations specific to the microstructurally defined medial area of the frontal pole in depressed patients. Conclusions Across disparate methods, we demonstrated subregion specificity in the left medial frontal pole volume in depressed patients. Indeed, the frontal pole was shown to structurally and functionally connect to other key regions in major depression pathology like the anterior cingulate cortex and the amygdala via the uncinate fasciculus. Present and previous findings consolidate the left medial portion of the frontal pole as particularly altered in major depression. PMID:26621569

  1. Toward a clinic of temporality?

    Science.gov (United States)

    Rivasseau Jonveaux, Thérèse; Batt, Martine; Trognon, Alain

    2017-12-01

    The discovery of time cells has expanded our knowledge in the field of spatial and temporal information coding and the key role of the hippocampus. The internal clock model complemented with the attentional gate model allows a more in-depth understanding of the perception of time. The motor representation of duration is ensured by the basal ganglia, while the cerebellum synchronizes short duration for the movement. The right prefrontal cortex seemingly intervenes in the handling of temporal information in working memory. The temporal lobe ensures the comparison of durations, especially the right lobe for the reference durations and the medial lobe for the reproduction of durations in episodic memory. During normal aging, the hypothesis of slowing of the temporal processor is evoked when noting the perception of the acceleration of the passage of time that seemingly occurs with advancing age. The various studies pertaining specifically to time cognition, albeit heterogeneous in terms of methodology, attest to the wide-ranging disturbances of this cognitive field during the course of numerous disorders, whether psychiatric - depression and schizophrenia notably - or neurological. Hence, perturbations in temporality are observed in focal brain lesions and in subcortical disorders, such as Parkinson's disease or Huntington's chorea. Alzheimer's disease represents a particularly fertile field of exploration with regard to time cognition and temporality. The objectified deconstruction of temporal experience provides insights into the very processes of temporality and their nature: episodic, semantic and procedural. In addition to exploration based on elementary stimuli, one should also consider the time lived, i.e. that of the subject, to better understand cognition as it relates to time. While the temporal dimension permeates the whole cognitive field, it remains largely neglected: integration of a genuine time cognition and temporality clinic in daily practice remains

  2. Stimulation of the medial amygdala enhances medial preoptic dopamine release: implications for male rat sexual behavior.

    Science.gov (United States)

    Dominguez, J M; Hull, E M

    2001-11-02

    Increased dopamine (DA) in the medial preoptic area (MPOA) facilitates male sexual behavior. A major source of innervation to the MPOA is the medial amygdala (MeA). We now report that chemical stimulation of the MeA enhanced levels of extracellular MPOA DA in anesthetized male rats. These results suggest that DA activity in the MPOA can be regulated by input from the MeA to the MPOA.

  3. fMR-adaptation indicates selectivity to audiovisual content congruency in distributed clusters in human superior temporal cortex.

    Science.gov (United States)

    van Atteveldt, Nienke M; Blau, Vera C; Blomert, Leo; Goebel, Rainer

    2010-02-02

    Efficient multisensory integration is of vital importance for adequate interaction with the environment. In addition to basic binding cues like temporal and spatial coherence, meaningful multisensory information is also bound together by content-based associations. Many functional Magnetic Resonance Imaging (fMRI) studies propose the (posterior) superior temporal cortex (STC) as the key structure for integrating meaningful multisensory information. However, a still unanswered question is how superior temporal cortex encodes content-based associations, especially in light of inconsistent results from studies comparing brain activation to semantically matching (congruent) versus nonmatching (incongruent) multisensory inputs. Here, we used fMR-adaptation (fMR-A) in order to circumvent potential problems with standard fMRI approaches, including spatial averaging and amplitude saturation confounds. We presented repetitions of audiovisual stimuli (letter-speech sound pairs) and manipulated the associative relation between the auditory and visual inputs (congruent/incongruent pairs). We predicted that if multisensory neuronal populations exist in STC and encode audiovisual content relatedness, adaptation should be affected by the manipulated audiovisual relation. The results revealed an occipital-temporal network that adapted independently of the audiovisual relation. Interestingly, several smaller clusters distributed over superior temporal cortex within that network, adapted stronger to congruent than to incongruent audiovisual repetitions, indicating sensitivity to content congruency. These results suggest that the revealed clusters contain multisensory neuronal populations that encode content relatedness by selectively responding to congruent audiovisual inputs, since unisensory neuronal populations are assumed to be insensitive to the audiovisual relation. These findings extend our previously revealed mechanism for the integration of letters and speech sounds and

  4. fMR-adaptation indicates selectivity to audiovisual content congruency in distributed clusters in human superior temporal cortex

    Directory of Open Access Journals (Sweden)

    Blomert Leo

    2010-02-01

    Full Text Available Abstract Background Efficient multisensory integration is of vital importance for adequate interaction with the environment. In addition to basic binding cues like temporal and spatial coherence, meaningful multisensory information is also bound together by content-based associations. Many functional Magnetic Resonance Imaging (fMRI studies propose the (posterior superior temporal cortex (STC as the key structure for integrating meaningful multisensory information. However, a still unanswered question is how superior temporal cortex encodes content-based associations, especially in light of inconsistent results from studies comparing brain activation to semantically matching (congruent versus nonmatching (incongruent multisensory inputs. Here, we used fMR-adaptation (fMR-A in order to circumvent potential problems with standard fMRI approaches, including spatial averaging and amplitude saturation confounds. We presented repetitions of audiovisual stimuli (letter-speech sound pairs and manipulated the associative relation between the auditory and visual inputs (congruent/incongruent pairs. We predicted that if multisensory neuronal populations exist in STC and encode audiovisual content relatedness, adaptation should be affected by the manipulated audiovisual relation. Results The results revealed an occipital-temporal network that adapted independently of the audiovisual relation. Interestingly, several smaller clusters distributed over superior temporal cortex within that network, adapted stronger to congruent than to incongruent audiovisual repetitions, indicating sensitivity to content congruency. Conclusions These results suggest that the revealed clusters contain multisensory neuronal populations that encode content relatedness by selectively responding to congruent audiovisual inputs, since unisensory neuronal populations are assumed to be insensitive to the audiovisual relation. These findings extend our previously revealed mechanism for

  5. Modulating Phonation Through Alteration of Vocal Fold Medial Surface Contour

    Science.gov (United States)

    Mau, Ted; Muhlestein, Joseph; Callahan, Sean; Chan, Roger W.

    2012-01-01

    Objectives 1. To test whether alteration of the vocal fold medial surface contour can improve phonation. 2. To demonstrate that implant material properties affect vibration even when implant is deep to the vocal fold lamina propria. Study Design Induced phonation of excised human larynges. Methods Thirteen larynges were harvested within 24 hours post-mortem. Phonation threshold pressure (PTP) and flow (PTF) were measured before and after vocal fold injections using either calcium hydroxylapatite (CaHA) or hyaluronic acid (HA). Small-volume injections (median 0.0625 mL) were targeted to the infero-medial aspect of the thyroarytenoid (TA) muscle. Implant locations were assessed histologically. Results The effect of implantation on PTP was material-dependent. CaHA tended to increase PTP, whereas HA tended to decrease PTP (Wilcoxon test P = 0.00013 for onset). In contrast, the effect of implantation on PTF was similar, with both materials tending to decrease PTF (P = 0.16 for onset). Histology confirmed implant presence in the inferior half of the vocal fold vertical thickness. Conclusions Taken together, these data suggested the implants may have altered the vocal fold medial surface contour, potentially resulting in a less convergent or more rectangular glottal geometry as a means to improve phonation. An implant with a closer viscoelastic match to vocal fold cover is desirable for this purpose, as material properties can affect vibration even when the implant is not placed within the lamina propria. This result is consistent with theoretical predictions and implies greater need for surgical precision in implant placement and care in material selection. PMID:22865592

  6. Natural history of medial clavicle fractures.

    Science.gov (United States)

    Salipas, Andrew; Kimmel, Lara A; Edwards, Elton R; Rakhra, Sandeep; Moaveni, Afshin Kamali

    2016-10-01

    Fractures of the medial third of the clavicle comprise less than 3% of all clavicle fractures. The natural history and optimal management of these rare injuries are unknown. The aim of our study is to describe the demographics, management and outcomes of patients with medial clavicle fractures treated at a Level 1 Trauma Centre. A retrospective review was conducted of patients presenting to our institution between January 2008 and March 2013 with a medial third clavicle fracture. Clinical and radiographic data were recorded including mechanism of injury, fracture pattern and displacement, associated injuries, management and complications. Functional outcomes were assessed using the Glasgow Outcome Scale Extended (GOS-E) scores from the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Shoulder outcomes were assessed using two patient reported outcomes scores, the American Shoulder and Elbow Society Score (ASES) and the Subjective Shoulder Value (SSV). Sixty eight medial clavicle fractures in 68 patients were evaluated. The majority of patients were male (n=53), with a median age of 53.5 years (interquartile range (IQR) 37.5-74.5 years). The most common mechanism of injury was motor vehicle accident (n=28). The in-hospital mortality rate was 4.4%. The fracture pattern was almost equally distributed between extra articular (n=35) and intra-articular (n=33). Fifty-five fractures (80.9%) had minimal or no displacement. Associated injuries were predominantly thoracic (n=31). All fractures were initially managed non-operatively, with a broad arm sling. Delayed operative fixation was performed for painful atrophic delayed union in two patients (2.9%). Both patients were under 65 years of age and had a severely displaced fracture of the medial clavicle. One intra-operative vascular complication was seen, with no adverse long-term outcome. Follow-up was obtained in 85.0% of the surviving cohort at an average of three years post injury (range 1-6 years). The mean ASES

  7. SHEEP TEMPORAL BONE

    Directory of Open Access Journals (Sweden)

    Kesavan

    2016-03-01

    Full Text Available INTRODUCTION Human temporal bones are difficult to procure now a days due to various ethical issues. Sheep temporal bone is a good alternative due to morphological similarities, easy to procure and less cost. Many middle ear exercises can be done easily and handling of instruments is done in the procedures like myringoplasty, tympanoplasty, stapedotomy, facial nerve dissection and some middle ear implants. This is useful for resident training programme.

  8. Otosclerosis: Temporal Bone Pathology.

    Science.gov (United States)

    Quesnel, Alicia M; Ishai, Reuven; McKenna, Michael J

    2018-04-01

    Otosclerosis is pathologically characterized by abnormal bony remodeling, which includes bone resorption, new bone deposition, and vascular proliferation in the temporal bone. Sensorineural hearing loss in otosclerosis is associated with extension of otosclerosis to the cochlear endosteum and deposition of collagen throughout the spiral ligament. Persistent or recurrent conductive hearing loss after stapedectomy has been associated with incomplete footplate fenestration, poor incus-prosthesis connection, and incus resorption in temporal bone specimens. Human temporal bone pathology has helped to define the role of computed tomography imaging for otosclerosis, confirming that computed tomography is highly sensitive for diagnosis, yet limited in assessing cochlear endosteal involvement. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Impaired expression of GABA transporters in the human Alzheimer's disease hippocampus, subiculum, entorhinal cortex and superior temporal gyrus.

    Science.gov (United States)

    Fuhrer, Tessa E; Palpagama, Thulani H; Waldvogel, Henry J; Synek, Beth J L; Turner, Clinton; Faull, Richard L; Kwakowsky, Andrea

    2017-05-20

    Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain and plays an important role in regulating neuronal excitability. GABA reuptake from the synapse is dependent on specific transporters - mainly GAT-1, GAT-3 and BGT-1 (GATs). This study is the first to show alterations in the expression of the GATs in the Alzheimer's disease (AD) hippocampus, entorhinal cortex and superior temporal gyrus. We found a significant increase in BGT-1 expression associated with AD in all layers of the dentate gyrus, in the stratum oriens of the CA2 and CA3 and the superior temporal gyrus. In AD there was a significant decrease in GAT-1 expression in the entorhinal cortex and superior temporal gyrus. We also found a significant decrease in GAT-3 immunoreactivity in the stratum pyramidale of the CA1 and CA3, the subiculum and entorhinal cortex. These observations indicate that the expression of the GATs shows brain-region- and layer-specific alterations in AD, suggesting a complex activation pattern of different GATs during the course of the disease. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Aberrant expression of miR-218 and miR-204 in human mesial temporal lobe epilepsy and hippocampal sclerosis-Convergence on axonal guidance

    DEFF Research Database (Denmark)

    Kaalund, Sanne S; Venø, Morten T; Bak, Mads

    2014-01-01

    OBJECTIVE: Mesial temporal lobe epilepsy (MTLE) is one of the most common types of the intractable epilepsies and is most often associated with hippocampal sclerosis (HS), which is characterized by pronounced loss of hippocampal pyramidal neurons. microRNAs (miRNAs) have been shown...... to be dysregulated in epilepsy and neurodegenerative diseases, and we hypothesized that miRNAs could be involved in the pathogenesis of MTLE and HS. METHODS: miRNA expression was quantified in hippocampal specimens from human patients using miRNA microarray and quantitative real-time polymerase chain reaction RT...

  11. Pediatric Glial Heterotopia in the Medial Canthus.

    Science.gov (United States)

    Kim, Soung Min; Amponsah, Emmanuel Kofi; Eo, Mi Young; Cho, Yun Ju; Lee, Suk Keun

    2017-11-01

    Glial heterotopias are rare, benign, congenital, midline, and nonteratomatous extracranial glial tissue. They may be confused as encephalocele or dermoid cysts and are mostly present in the nose.An 8-month-old African female child presented with a slow growing paranasal mass. The mass had been present at the left upper medial canthus since birth and had slowly and progressively enlarged. There was no communication between the mass and the cranial cavity during the operational procedure. The mass was immunohistochemically positive for S-100 protein as well as for glial fibrillary acidic protein, but negative for proliferating cell nuclear antigen. This suggested that the mass was composed of benign glial tissues with many astrocytes.The purpose of this report is to demonstrate the first patient with pediatric glial heterotopic tissue in the medial canthus and to report the clinical importance of its immunohistochemical findings.

  12. Neuromuscular Exercise Post Partial Medial Meniscectomy

    DEFF Research Database (Denmark)

    Hall, Michelle; Hinman, Rana S; Wrigley, Tim V

    2015-01-01

    PURPOSE: To evaluate the effects of a 12-week, home-based, physiotherapist-guided neuromuscular exercise program on the knee adduction moment (an indicator of mediolateral knee load distribution) in people with a medial arthroscopic partial meniscectomy within the past 3-12 months. METHODS......: An assessor-blinded, randomised controlled trial including people aged 30-50 years with no to mild pain following medial arthroscopic partial meniscectomy was conducted. Participants were randomly allocated to either a 12-week neuromuscular exercise program that targeted neutral lower limb alignment...... or a control group with no exercise. The exercise program included eight individual sessions with one of seven physiotherapists in private clinics, together with home exercises. Primary outcomes were the peak external knee adduction moment during normal pace walking and during a one-leg sit-to-stand. Secondary...

  13. [SECOT consensus on medial femorotibial osteoarthritis].

    Science.gov (United States)

    Moreno, A; Silvestre, A; Carpintero, P

    2013-01-01

    A consensus, prepared by SECOT, is presented on the management of medial knee compartment osteoarthritis, in order to establish clinical criteria and recommendations directed at unifying the criteria in its management, dealing with the factors involved in the pathogenesis of medial femorotibial knee osteoarthritis, the usefulness of diagnostic imaging techniques, and the usefulness of arthroscopy. Conservative and surgical treatments are also analysed. The experts consulted showed a consensus (agreed or disagreed) in 65.8% of the items considered, leaving 14items where no consensus was found, which included the aetiopathogenesis of the osteoarthritis, the value of NMR in degenerative disease, the usefulness of COX-2 and the chondroprotective drugs, as well as on the ideal valgus tibial osteotomy technique. © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  14. Foot medial longitudinal-arch deformation during quiet standing and gait in subjects with medial tibial stress syndrome

    DEFF Research Database (Denmark)

    Bandholm, Thomas Quaade; Boysen, Lisbeth; Haugaard, Stine

    2008-01-01

    The objective of this study was to investigate (1) if subjects with medial tibial stress syndrome demonstrate increased navicular drop and medial longitudinal-arch deformation during quiet standing and gait compared with healthy subjects, and (2) the relationship between medial longitudinal-arch ...

  15. Differential roles for medial prefrontal and medial temporal cortices in schema-dependent encoding : from congruent to incongruent

    NARCIS (Netherlands)

    van Kesteren, Marlieke T R; Beul, Sarah F; Takashima, Atsuko; Henson, Richard N; Ruiter, Dirk J; Fernández, Guillén

    2013-01-01

    Information that is congruent with prior knowledge is generally remembered better than incongruent information. This effect of congruency on memory has been attributed to a facilitatory influence of activated schemas on memory encoding and consolidation processes, and hypothesised to reflect a shift

  16. Rapid detection of new and expanding human settlements in the Limpopo province of South Africa using a spatio-temporal change detection method

    Science.gov (United States)

    Kleynhans, W.; Salmon, B. P.; Wessels, K. J.; Olivier, J. C.

    2015-08-01

    Recent development has identified the benefits of using hyper-temporal satellite time series data for land cover change detection and classification in South Africa. In particular, the monitoring of human settlement expansion in the Limpopo province is of relevance as it is the one of the most pervasive forms of land-cover change in this province which covers an area of roughly 125 000 km2. In this paper, a spatio-temporal autocorrelation change detection (STACD) method is developed to improve the performance of a pixel based temporal Autocorrelation change detection (TACD) method previously proposed. The objective is to apply the algorithm to large areas to detect the conversion of natural vegetation to settlement which is then validated by an operator using additional data (such as high resolution imagery). Importantly, as the objective of the method is to indicate areas of potential change to operators for further analysis, a low false alarm rate is required while achieving an acceptable probability of detection. Results indicate that detection accuracies of 70% of new settlement instances are achievable at a false alarm rate of less than 1% with the STACD method, an improvement of up to 17% compared to the original TACD formulation.

  17. Unicameral Bone Cyst of the Medial Cuneiform.

    Science.gov (United States)

    Schick, Faith A; Daniel, Joseph N; Miller, Juliane S

    2016-09-02

    A unicameral bone cyst is a relatively uncommon, benign bone tumor found in the metaphysis of long bones, such as the humerus and the femur, in skeletally immature persons. In the foot, these benign, fluid-filled cavities are most commonly found within the os calcis. We present a case report of a 10-year-old female with a unicameral bone cyst of the medial cuneiform.

  18. Osteoligamentous injuries of the medial ankle joint.

    Science.gov (United States)

    Lötscher, P; Lang, T H; Zwicky, L; Hintermann, B; Knupp, M

    2015-12-01

    Injuries of the ankle joint have a high incidence in daily life and sports, thus, playing an important socioeconomic role. Therefore, proper diagnosis and adequate treatment are mandatory. While most of the ligament injuries around the ankle joint are treated conservatively, great controversy exists on how to treat deltoid ligament injuries in ankle fractures. Missed injuries and inadequate treatment of the medial ankle lead to inferior outcome with instability, progressive deformity, and ankle joint osteoarthritis.

  19. Medial-lateral organization of the orbitofrontal cortex.

    Science.gov (United States)

    Rich, Erin L; Wallis, Jonathan D

    2014-07-01

    Emerging evidence suggests that specific cognitive functions localize to different subregions of OFC, but the nature of these functional distinctions remains unclear. One prominent theory, derived from human neuroima