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Sample records for cerebeller cortex key

  1. Severe cerebellitis following methadone poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Fionnghuala; MacLennan, Suzanna C.; Devile, Catherine J.; Saunders, Dawn E. [Great Ormond Street Hospital, Department of Paediatric Neurology, London (United Kingdom)

    2008-02-15

    We report a 3-year-old girl with an unusual presentation of cerebellitis following ingestion of methadone. CT showed diffuse symmetrical swelling and oedema of the cerebellum resulting in compression of the fourth ventricle and hydrocephalus. The changes were confirmed on MRI with the addition of watershed injuries. These findings represent a toxic encephalopathy and have been reported in previous cases of heroin intoxication by inhalation, but rarely following opioid ingestion. The aetiology of the watershed infarcts is discussed. (orig.)

  2. Severe cerebellitis following methadone poisoning

    International Nuclear Information System (INIS)

    We report a 3-year-old girl with an unusual presentation of cerebellitis following ingestion of methadone. CT showed diffuse symmetrical swelling and oedema of the cerebellum resulting in compression of the fourth ventricle and hydrocephalus. The changes were confirmed on MRI with the addition of watershed injuries. These findings represent a toxic encephalopathy and have been reported in previous cases of heroin intoxication by inhalation, but rarely following opioid ingestion. The aetiology of the watershed infarcts is discussed. (orig.)

  3. MR imaging of acute disseminated encephalomyelitis, cerebellitis and myelitis in infancy: likely topographic variant of a single process; Imagen en RM de encefalomielitis aguda diseminada, cerebelitis y mielitis en la infancia: probables variantes topograficas de un mismo proceso

    Energy Technology Data Exchange (ETDEWEB)

    Fortuno, J. R.; Menor, F.; Esteban, M. J.; Pamies, J. [Hospital Universitario Infantil La Fe (Spain); Gomez-Gosalvez, F. A. [Hospital Verge dels Liris de Alcoi (Spain); Jover, J. [Hospital General de Elda (Spain)

    2003-07-01

    To describe MR images of acute disseminated encephalomyelitis (ADE) in a paediatric group, particularly focused on its likely topographic variants, cerebellitis and myelitis, its evolution, and the differential diagnosis between it an an initial outbreak of multiple sclerosis. Initial and follow-up cranial MR images were retrospectively reviewed for 14 paediatric patients diagnosed with either ADE, cerebellitis or myelitis. In 9 patients, a spinal cord monitoring was included. Three topographic variants have been considered: ADE (7 patients). In the case of ADE, the supratentorial white matter was always affected, the brain stem in five (71%) and the cerebellum in two (28,5%). Basal ganglionic lesions were detected in 5 patients (71%) and cortical lesions in one (14%). Associated spinal cord abnormality was found in five of the six cases in which this study was included (83%). ADE lesions tended to be nodular and poorly differentiated whereas in cerebellitis and myelitis the predominant pattern was one of diffuse damage. Evolution of the lesions was toward reduction/resolution. Follow-up using MR in the medium-term in 6 patients (four ADE and two cerebellitis) did not detect any new lesions. Clinical follow-up of the patients did not show any neurological recurrences in any of them. ADE, cerebillits and myelitis could be topographic variants of a single process with a common pathogeny. As the spinal cord often seems to play a role in ADE, spinal cord monitoring would be recommended, even in the absence of the above-mentioned symptoms. This spinal cord abnormality, which is usually diffuse, plus deep gray matter damage, as well as the disease of monophase course, corroborated by a sequential MR follow-up, is all helpful in the differential diagnosis with multiple sclerosis. Nonetheless, the differential diagnosis between a recurring form of ADE and an encephalomyelitis is practically impossible to make. (Author) 33 refs.

  4. MR imaging of acute disseminated encephalomyelitis, cerebellitis and myelitis in infancy: likely topographic variant of a single process

    International Nuclear Information System (INIS)

    To describe MR images of acute disseminated encephalomyelitis (ADE) in a paediatric group, particularly focused on its likely topographic variants, cerebellitis and myelitis, its evolution, and the differential diagnosis between it an an initial outbreak of multiple sclerosis. Initial and follow-up cranial MR images were retrospectively reviewed for 14 paediatric patients diagnosed with either ADE, cerebellitis or myelitis. In 9 patients, a spinal cord monitoring was included. Three topographic variants have been considered: ADE (7 patients). In the case of ADE, the supratentorial white matter was always affected, the brain stem in five (71%) and the cerebellum in two (28,5%). Basal ganglionic lesions were detected in 5 patients (71%) and cortical lesions in one (14%). Associated spinal cord abnormality was found in five of the six cases in which this study was included (83%). ADE lesions tended to be nodular and poorly differentiated whereas in cerebellitis and myelitis the predominant pattern was one of diffuse damage. Evolution of the lesions was toward reduction/resolution. Follow-up using MR in the medium-term in 6 patients (four ADE and two cerebellitis) did not detect any new lesions. Clinical follow-up of the patients did not show any neurological recurrences in any of them. ADE, cerebillits and myelitis could be topographic variants of a single process with a common pathogeny. As the spinal cord often seems to play a role in ADE, spinal cord monitoring would be recommended, even in the absence of the above-mentioned symptoms. This spinal cord abnormality, which is usually diffuse, plus deep gray matter damage, as well as the disease of monophase course, corroborated by a sequential MR follow-up, is all helpful in the differential diagnosis with multiple sclerosis. Nonetheless, the differential diagnosis between a recurring form of ADE and an encephalomyelitis is practically impossible to make. (Author) 33 refs

  5. Epstein-Barr virus co-infection in a patient with dengue fever presenting with post-infectious cerebellitis: a case report

    Directory of Open Access Journals (Sweden)

    Karunarathne Suneth

    2012-01-01

    Full Text Available Abstract Introduction Post-infectious cerebellitis is an acute form of inflammatory encephalitis mainly limited to the cerebellum. It is commonly found in children, especially after viral infections such as Epstein-Barr virus. Post-infectious cerebellitis presents with acute onset dysarthria and ataxia. To the best of our knowledge, this is the first case report of post-infectious cerebellitis in a patient with both dengue and Epstein-Barr viral infection confirmed on serology. Case presentation A 43-year-old Sri Lankan Sinhala man presented with an acute febrile illness associated with thrombocytopenia. While being managed as uncomplicated dengue fever, our patient developed dysarthria, ataxia and cerebellar signs. Our patient's infectious disease screen was positive for both dengue and Epstein-Barr specific immunoglobulin M. A cerebrospinal fluid analysis was suggestive of viral meningoencephalitis while cerebrospinal fluid serology was positive for dengue immunoglobulin G. T2-weighted magnetic resonance images were consistent with post-viral cerebellitis. The patient was given full supportive care and he made an uneventful complete recovery. Conclusion There have been no previously reported cases of post-infectious cerebellitis associated with both Epstein-Barr and dengue viral infections confirmed by serology. Our patient's clinical features and findings on the imaging studies were consistent with post-viral cerebellitis. This report highlights the need to screen for other possible more common etiologies of a particular presentation before coming to a specific diagnosis based on initial findings. Uncomplicated cases of cerebellitis can be successfully managed with appropriate supportive measures with good prognosis, as in this case.

  6. A key region in the human parietal cortex for processing proprioceptive hand feedback during reaching movements

    DEFF Research Database (Denmark)

    Reichenbach, Alexandra; Thielscher, Axel; Peer, Angelika;

    2014-01-01

    neuroimaging studies have focused mainly on identifying the parts of the posterior parietal cortex (PPC) that contribute to visually guided movements. We used event-related TMS and force perturbations of the reaching hand to test whether the same sub-regions of the left PPC contribute to the processing of...... proprioceptive-only and of multi-sensory information about hand position when reaching for a visual target. TMS over two distinct stimulation sites elicited differential effects: TMS applied over the posterior part of the medial intraparietal sulcus (mIPS) compromised reaching accuracy when proprioception was...... the only sensory information available for correcting the reaching error. When visual feedback of the hand was available, TMS over the anterior intraparietal sulcus (aIPS) prolonged reaching time. Our results show for the first time the causal involvement of the posterior mIPS in processing...

  7. Herniation to foramen magnum in the course of cerebellitis in a 4-year-old boy, as shown by CT and MRI - case report

    International Nuclear Information System (INIS)

    Background: Acute cerebellitis is an uncommon but dangerous complication of infectious diseases. Besides neurological examination, neuroimaging (especially MR imaging) is very useful for diagnosing cerebellitis. Case Report: A 4-year-old boy was admitted to the hospital with a 1-week history of fever, vomiting and headache. His past medical history was unremarkable. The physical examination revealed disturbance of consciousness and truncal ataxia. He underwent urgent CT and MRI examinations which demonstrated isolated swelling of the cerebellar hemispheres and the vermis, with increased signal intensity in T2-weighted, FLAIR, and DWI sequence and a significant mass effect associated with tonsillar herniation. An emergent life-saving suboccipital craniectomy was performed with removal of the C1 vertebral arch. There was a gradual clinical improvement, and a follow-up brain MRI revealed disappearance of cerebellar swelling and of mass effect. Conclusions: Magnetic resonance (MR), including diffusion-weighted imaging (DWI) sequence, plays an important role in the diagnostic work-up of cerebellitis in children. This imaging method is very useful for detecting cerebellitis, evaluating its severity and monitoring the disease. (authors)

  8. Brain banks as key part of biochemical and molecular studies on cerebral cortex involvement in Parkinson's disease.

    Science.gov (United States)

    Ravid, Rivka; Ferrer, Isidro

    2012-04-01

    Exciting developments in basic and clinical neuroscience and recent progress in the field of Parkinson's disease (PD) are partly a result of the availability of human specimens obtained through brain banks. These banks have optimized the methodological, managerial and organizational procedures; standard operating procedures; and ethical, legal and social issues, including the code of conduct for 21st Century brain banking and novel protocols. The present minireview focuses on current brain banking organization and management, as well as the likely future direction of the brain banking field. We emphasize the potentials and pitfalls when using high-quality specimens of the human central nervous system for advancing PD research. PD is a generalized disease in which α-synuclein is not a unique component but, instead, is only one of the players accounting for the complex impairment of biochemical/molecular processes involved in metabolic pathways. This is particularly important in the cerebral cortex, where altered cognition has a complex neurochemical substrate. Mitochondria and energy metabolism impairment, abnormal RNA, microRNA, protein synthesis, post-translational protein modifications and alterations in the lipid composition of membranes and lipid rafts are part of these complementary factors. We have to be alert to the possible pitfalls of each specimen and its suitability for a particular study. Not all samples qualify for the study of DNA, RNA, proteins, post-translational modifications, lipids and metabolomes, although the use of carefully selected samples and appropriate methods minimizes pitfalls and errors and guarantees high-quality reserach. PMID:22313511

  9. Acute cerebellitis successfully managed with temporary cerebrospinal fluid diversion using a long tunnel external ventricular drain: a long-term radiological follow-up of two cases.

    Science.gov (United States)

    Waqas, Muhammad; Hadi, Yousaf Bashir; Sheikh, Sadaf; Shamim, Shahzad M

    2016-01-01

    Acute cerebellitis (AC) is a rare inflammatory childhood disorder. Although there is no consensus on standard treatment for cerebellitis, its outcome is usually favourable. We report two cases of AC in the paediatric age group, successfully managed with long tunnel external ventricular drain (EVD). The first patient was an 8-year-old boy with a history of fever and headache. Sequential MRI showed diffuse cerebellar swelling with tonsillar herniation and resulting hydrocephalus. The second patient was a 6-month-old boy who presented with high-grade fever associated with chills. CT scan of the head showed triventricular hydrocephalus with obliteration of cerebrospinal fluid spaces and cisterns. Both patients underwent immediate emergency right-sided long tunnel EVD insertion. The EVD was removed on the 9th day in the first patient and the 10th day in the second patient; the patients showed no neurological deficits at a follow-up of 2 years and 1 year, respectively. PMID:27166004

  10. Cerebelite aguda causada por vírus Epstein-Barr: relato de caso Acute cerebellitis caused by Epstein-Barr virus: case report

    Directory of Open Access Journals (Sweden)

    Hélio A.G. Teive

    2001-09-01

    Full Text Available A cerebelite aguda pode ocorrer em associação a infecção pelo vírus da varicela-zoster, enterovirus, caxumba, micoplasma e outros agentes infecciosos. A cerebelite aguda é uma complicação rara da infecção pelo vírus Epstein-Barr (EBV. Relatamos o caso de uma mulher de 21 anos com história de 12 dias de evolução com náuseas, vômitos, ataxia de marcha e membros, tremor cefálico e de membros, opsoclono, mioclonias e rash cutâneo. Sorologia para EBV foi positiva. A infecção pelo EBV, com complicações neurológicas, pode não se apresentar com os sinais e sintomas clássicos da mononucleose infeciosa.Acute cerebellitis can occur in association with varicella-zoster virus, enterovirus, mumps, mycoplasma, and other infective organisms. Acute cerebellitis is a rare complication of Epstein-Barr virus (EBV infection. We report the case of a 21-year-old woman with a 12-day history of nausea and vomiting, gait and limbs ataxia, myoclonus, tremor of head and all four limbs, opsoclonus and cutaneous rash. Anti-EBV IgG and IgM antibodies against antiviral capsid were positive and anti-EBV against virus-associated nuclear antigen was also positive. EBV infection in association with neurological findings can occur without the classic signs and symptoms of infectious mononucleosis.

  11. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

    DEFF Research Database (Denmark)

    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe;

    2013-01-01

    Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalog...... evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex....

  12. Addiction and the adrenal cortex

    OpenAIRE

    Vinson, Gavin P; Brennan, Caroline H.

    2013-01-01

    Substantial evidence shows that the hypophyseal–pituitary–adrenal (HPA) axis and corticosteroids are involved in the process of addiction to a variety of agents, and the adrenal cortex has a key role. In general, plasma concentrations of cortisol (or corticosterone in rats or mice) increase on drug withdrawal in a manner that suggests correlation with the behavioural and symptomatic sequelae both in man and in experimental animals. Corticosteroid levels fall back to normal values in resumptio...

  13. Key; key ring

    International Nuclear Information System (INIS)

    Key and/or key ring is provided with illuminating means which do not require a source of electrical power. The key shown comprises a shank and a head, the head being moulded from a luminous plastic material which glows in the dark. To improve keying together of shank and head there is a pair of holes in the head of the shank. Alternatively the key may be coated in illuminating material or provided with sheath or cover of illuminating material. The key may be provided with company logo. The key ring has attached thereto a hollow plastics container whose interior is coated with a phosphor and which is filled with tritium gas. (author)

  14. Regulating prefrontal cortex activation

    DEFF Research Database (Denmark)

    Aznar, Susana; Klein, Anders Bue

    2013-01-01

    The prefrontal cortex (PFC) is involved in mediating important higher-order cognitive processes such as decision making, prompting thereby our actions. At the same time, PFC activation is strongly influenced by emotional reactions through its functional interaction with the amygdala and the stria...

  15. Cognition without Cortex.

    Science.gov (United States)

    Güntürkün, Onur; Bugnyar, Thomas

    2016-04-01

    Assumptions on the neural basis of cognition usually focus on cortical mechanisms. Birds have no cortex, but recent studies in parrots and corvids show that their cognitive skills are on par with primates. These cognitive findings are accompanied by neurobiological discoveries that reveal avian and mammalian forebrains are homologous, and show similarities in connectivity and function down to the cellular level. But because birds have a large pallium, but no cortex, a specific cortical architecture cannot be a requirement for advanced cognitive skills. During the long parallel evolution of mammals and birds, several neural mechanisms for cognition and complex behaviors may have converged despite an overall forebrain organization that is otherwise vastly different. PMID:26944218

  16. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  17. The orbitofrontal cortex and beyond: from affect to decision-making.

    Science.gov (United States)

    Rolls, Edmund T; Grabenhorst, Fabian

    2008-11-01

    The orbitofrontal cortex represents the reward or affective value of primary reinforcers including taste, touch, texture, and face expression. It learns to associate other stimuli with these to produce representations of the expected reward value for visual, auditory, and abstract stimuli including monetary reward value. The orbitofrontal cortex thus plays a key role in emotion, by representing the goals for action. The learning process is stimulus-reinforcer association learning. Negative reward prediction error neurons are related to this affective learning. Activations in the orbitofrontal cortex correlate with the subjective emotional experience of affective stimuli, and damage to the orbitofrontal cortex impairs emotion-related learning, emotional behaviour, and subjective affective state. With an origin from beyond the orbitofrontal cortex, top-down attention to affect modulates orbitofrontal cortex representations, and attention to intensity modulates representations in earlier cortical areas of the physical properties of stimuli. Top-down word-level cognitive inputs can bias affective representations in the orbitofrontal cortex, providing a mechanism for cognition to influence emotion. Whereas the orbitofrontal cortex provides a representation of reward or affective value on a continuous scale, areas beyond the orbitofrontal cortex such as the medial prefrontal cortex area 10 are involved in binary decision-making when a choice must be made. For this decision-making, the orbitofrontal cortex provides a representation of each specific reward in a common currency. PMID:18824074

  18. Aberrant functional connectivity differentiates retrosplenial cortex from posterior cingulate cortex in prodromal Alzheimer's disease.

    Science.gov (United States)

    Dillen, Kim N H; Jacobs, Heidi I L; Kukolja, Juraj; von Reutern, Boris; Richter, Nils; Onur, Özgür A; Dronse, Julian; Langen, Karl-Josef; Fink, Gereon R

    2016-08-01

    The posterior cingulate cortex (PCC) is a key hub of the default mode network, a resting-state network involved in episodic memory, showing functional connectivity (FC) changes in Alzheimer's disease (AD). However, PCC is a cytoarchitectonically heterogeneous region. Specifically, the retrosplenial cortex (RSC), often subsumed under the PCC, is an area functionally and microanatomically distinct from PCC. To investigate FC patterns of RSC and PCC separately, we used resting-state functional magnetic resonance imaging in healthy aging participants, patients with subjective cognitive impairment, and prodromal AD. Compared to the other 2 groups, we found higher FC from RSC to frontal cortex in subjective cognitive impairment but higher FC to occipital cortex in prodromal AD. Conversely, FC from PCC to the lingual gyrus was higher in prodromal AD. Furthermore, data indicate that RSC and PCC are characterized by differential FC patterns represented by hub-specific interactions with memory and attentions scores in prodromal AD compared to cognitively normal individuals, possibly reflecting compensatory mechanisms for RSC and neurodegenerative processes for PCC. Data thus confirm and extend previous studies suggesting that the RSC is functionally distinct from PCC. PMID:27318139

  19. Cerebral cortex modulation of pain

    Institute of Scientific and Technical Information of China (English)

    Yu-feng XIE; Fu-quan HUO; Jing-shi TANG

    2009-01-01

    Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional com-ponents mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SⅠ) and secondary somatosensory (SⅡ) cortices, the ventrolateral orbital cortex and the motor cortex. These corti-cal structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaque-ductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be in-volved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.

  20. MRI volumetry of prefrontal cortex

    Science.gov (United States)

    Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.

    1995-05-01

    Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was depression and schizophrenia can be efficiently assessed using this method.

  1. Chemosensory Learning in the Cortex

    Directory of Open Access Journals (Sweden)

    Edmund eRolls

    2011-09-01

    Full Text Available Taste is a primary reinforcer. Olfactory-taste and visual-taste association learning takes place in the primate including human orbitofrontal cortex to build representations of flavour. Rapid reversal of this learning can occur using a rule-based learning system that can be reset when an expected taste or flavour reward is not obtained, that is by negative reward prediction error, to which a population of neurons in the orbitofrontal cortex responds. The representation in the orbitofrontal cortex but not the primary taste or olfactory cortex is of the reward value of the visual / olfactory / taste / input as shown by devaluation experiments in which food is fed to satiety, and by correlations with the activations with subjective pleasantness ratings in humans. Sensory-specific satiety for taste, olfactory, visual, and oral somatosensory inputs produced by feeding a particular food to satiety are implemented it is proposed by medium-term synaptic adaptation in the orbitofrontal cortex. Cognitive factors, including word-level descriptions, modulate the representation of the reward value of food in the orbitofrontal cortex, and this effect is learned it is proposed by associative modification of top-down synapses onto neurons activated by bottom-up taste and olfactory inputs when both are active in the orbitofrontal cortex. A similar associative synaptic learning process is proposed to be part of the mechanism for the top-down attentional control to the reward value vs the sensory properties such as intensity of taste and olfactory inputs in the orbitofrontal cortex, as part of a biased activation theory of selective attention.

  2. Activation of cannabinoid system in anterior cingulate cortex and orbitofrontal cortex modulates cost-benefit decision making

    OpenAIRE

    Khani, Abbas; Kermani, Mojtaba; Hesam, 6Soghra; Haghparast, Abbas; Enrike G Argandoña; Rainer, Gregor

    2015-01-01

    Despite the evidence for altered decision making in cannabis abusers, the role of the cannabinoid system in decision-making circuits has not been studied. Here, we examined the effects of cannabinoid modulation during cost-benefit decision making in the anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC), key brain areas involved in decision making. We trained different groups of rats in a delay-based and an effort-based form of cost-benefit T-maze decision-making task. During test...

  3. Canonical computations of cerebral cortex.

    Science.gov (United States)

    Miller, Kenneth D

    2016-04-01

    The idea that there is a fundamental cortical circuit that performs canonical computations remains compelling though far from proven. Here we review evidence for two canonical operations within sensory cortical areas: a feedforward computation of selectivity; and a recurrent computation of gain in which, given sufficiently strong external input, perhaps from multiple sources, intracortical input largely, but not completely, cancels this external input. This operation leads to many characteristic cortical nonlinearities in integrating multiple stimuli. The cortical computation must combine such local processing with hierarchical processing across areas. We point to important changes in moving from sensory cortex to motor and frontal cortex and the possibility of substantial differences between cortex in rodents vs. species with columnar organization of selectivity. PMID:26868041

  4. The dorsolateral prefrontal cortex, schizophrenia and PET

    International Nuclear Information System (INIS)

    Central neurophysiology can be measured with PET. These measurements are providing insights into the regional abnormalities associated with schizophrenia. Cohorts of schizophrenic subjects have been studied cross-sectionally in attempts to identify common regional deficits. More recently the advent of fast dynamic measurements of regional cerebral blood flow have allowed rapid serial measurements in the same subject in different brain states (activation studies). These complementary approaches are based upon, and are interpreted with reference to, a number of methodological considerations and underlying hypotheses. The key hypotheses underpining cross-sectional and activation studies are discussed within the framework of the lesion model and functional anatomy models of brain function. This brief review of some assumptions, ideas and methodological constraints is illustrated with empirical data implicating the dorsolateral prefrontal cortex in schizophrenic symptoms. (author)

  5. Food related processes in the insular cortex

    OpenAIRE

    Frank, Sabine; Kullmann, Stephanie; Veit, Ralf

    2013-01-01

    The insular cortex is a multimodal brain region with regional cytoarchitectonic differences indicating various functional specializations. As a multisensory neural node, the insular cortex integrates perception, emotion, interoceptive awareness, cognition, and gustation. Regarding the latter, predominantly the anterior part of the insular cortex is regarded as the primary taste cortex. In this review, we will specifically focus on the involvement of the insula in food processing and on multim...

  6. Food related processes in the insular cortex

    OpenAIRE

    Sabine eFrank; Stephanie eKullmann; Ralf eVeit

    2013-01-01

    The insular cortex is a multimodal brain region with regional cytoarchitectonic differences indicating various functional specializations. As a multisensory neural node, the insular cortex integrates perception, emotion, interoceptive awareness, cognition, and gustation. Regarding the latter, predominantly the anterior part of the insular cortex is regarded as the primary taste cortex.In this review, we will specifically focus on the involvement of the insula in food processing and on multimo...

  7. Parcellation in Left Lateral Parietal Cortex Is Similar in Adults and Children

    OpenAIRE

    Barnes, Kelly Anne; Nelson, Steven M.; Cohen, Alexander L.; Power, Jonathan D.; Coalson, Rebecca S.; Miezin, Francis M.; Vogel, Alecia C.; Dubis, Joseph W.; Church, Jessica A.; Petersen, Steven E.; Schlaggar, Bradley L.

    2011-01-01

    A key question in developmental neuroscience involves understanding how and when the cerebral cortex is partitioned into distinct functional areas. The present study used functional connectivity MRI mapping and graph theory to identify putative cortical areas and generate a parcellation scheme of left lateral parietal cortex (LLPC) in 7 to 10-year-old children and adults. Results indicated that a majority of putative LLPC areas could be matched across groups (mean distance between matched are...

  8. GluA1 Phosphorylation Contributes to Postsynaptic Amplification of Neuropathic Pain in the Insular Cortex

    OpenAIRE

    Qiu, Shuang; Zhang, Ming; Yan LIU; Guo, Yanyan; Zhao, Huan; Song, Qian; Zhao, Minggao; Huganir, Richard L.; Luo, Jianhong; Xu, Hui; Zhuo, Min

    2014-01-01

    Long-term potentiation of glutamatergic transmission has been observed after physiological learning or pathological injuries in different brain regions, including the spinal cord, hippocampus, amygdala, and cortices. The insular cortex is a key cortical region that plays important roles in aversive learning and neuropathic pain. However, little is known about whether excitatory transmission in the insular cortex undergoes plastic changes after peripheral nerve injury. Here, we found that peri...

  9. Eight open questions in the computational modeling of higher sensory cortex.

    Science.gov (United States)

    Yamins, Daniel Lk; DiCarlo, James J

    2016-04-01

    Propelled by advances in biologically inspired computer vision and artificial intelligence, the past five years have seen significant progress in using deep neural networks to model response patterns of neurons in visual cortex. In this paper, we briefly review this progress and then discuss eight key 'open questions' that we believe will drive research in computational models of sensory systems over the next five years, both in visual cortex and beyond. PMID:26921828

  10. Motor cortex guides selection of predictable movement targets

    Science.gov (United States)

    Woodgate, Philip J.W.; Strauss, Soeren; Sami, Saber A.; Heinke, Dietmar

    2016-01-01

    The present paper asks whether the motor cortex contributes to prediction-based guidance of target selection. This question was inspired by recent evidence that suggests (i) recurrent connections from the motor system into the attentional system may extract movement-relevant perceptual information and (ii) that the motor cortex cannot only generate predictions of the sensory consequences of movements but may also operate as predictor of perceptual events in general. To test this idea we employed a choice reaching task requiring participants to rapidly reach and touch a predictable or unpredictable colour target. Motor cortex activity was modulated via transcranial direct current stimulation (tDCS). In Experiment 1 target colour repetitions were predictable. Under such conditions anodal tDCS facilitated selection versus sham and cathodal tDCS. This improvement was apparent for trajectory curvature but not movement initiation. Conversely, where no predictability of colour was embedded reach performance was unaffected by tDCS. Finally, the results of a key-press experiment suggested that motor cortex involvement is restricted to tasks where the predictable target colour is movement-relevant. The outcomes are interpreted as evidence that the motor system contributes to the top-down guidance of selective attention to movement targets. PMID:25835319

  11. Disease: H00060 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available AG repeat expansion) [HSA:1822] [KO:K05626] Disease class: polyglutamine disease Affected region: cerebell...um, cerebral cortex, basal ganglia, Luys body Microscopic lesion: neuronal and glia

  12. Subplate in the developing cortex of mouse and human

    DEFF Research Database (Denmark)

    Wang, Wei Zhi; Hoerder-Suabedissen, Anna; Oeschger, Franziska M;

    2010-01-01

    Abstract The subplate is a largely transient zone containing precocious neurons involved in several key steps of cortical development. The majority of subplate neurons form a compact layer in mouse, but are dispersed throughout a much larger zone in the human. In rodent, subplate neurons are among...... the earliest born neocortical cells, whereas in primate, neurons are added to the subplate throughout cortical neurogenesis. Magnetic resonance imaging and histochemical studies show that the human subplate grows in size until the end of the second trimester. Previous microarray experiments in mice...... have shown several genes that are specifically expressed in the subplate layer of the rodent dorsal cortex. Here we examined the human subplate for some of these markers. In the human dorsal cortex, connective tissue growth factor-positive neurons can be seen in the ventricular zone at 15...

  13. Virtual reality and the role of the prefrontal cortex in adults and children.

    Directory of Open Access Journals (Sweden)

    Lutz Jäncke

    2009-05-01

    Full Text Available In this review the neural underpinnings of the experience of presence are outlined. Firstly, it will be shown that presence is associated with an activation of a distributed network including the dorsal and ventral visual stream, the parietal cortex, the premotor cortex, mesial temporal areas, the brainstem and the thalamus. Second, the dorsolateral prefrontal cortex (DLPFC is identified as a key node of this network in that it modulates the activity of this network and the associated experience of presence. Third, because of their unmatured frontal cortex, children lack the strong modulatory influence of the DLPFC on this network. Fourth, it is shown that by manipulating the activation in the DLPFC using transcranial direct current stimulation (tDCS while participants are exposed to the virtual roller coaster ride presence-related measures are influenced. Finally, these findings are discussed in the context of current models explaining the experience of presence, the rubber hand illusion, and out of body experiences.

  14. Layer II/III of the prefrontal cortex: inhibition by the serotonin 5-HT1A receptor in development and stress

    OpenAIRE

    Goodfellow, Nathalie M.; Benekareddy, Madhurima; Vaidya, Vidita A.; Lambe, Evelyn K.

    2009-01-01

    The modulation of the prefrontal cortex by the neurotransmitter serotonin (5-HT) is thought to play a key role in determining adult anxiety levels. Layer II/III of the prefrontal cortex, which mediates communication across cortical regions, displays a of high level 5-HT1A receptor binding in normal individuals and a significantly lower level in patients with mood and anxiety disorders. Here, we examine how serotonin modulates pyramidal neurons in layer II/III of the rat prefrontal cortex thro...

  15. Mapping Prefrontal Cortex Functions in Human Infancy

    Science.gov (United States)

    Grossmann, Tobias

    2013-01-01

    It has long been thought that the prefrontal cortex, as the seat of most higher brain functions, is functionally silent during most of infancy. This review highlights recent work concerned with the precise mapping (localization) of brain activation in human infants, providing evidence that prefrontal cortex exhibits functional activation much…

  16. Prefrontal cortex and social cognition in mouse and man

    Directory of Open Access Journals (Sweden)

    Lucy King Bicks

    2015-11-01

    Full Text Available Social cognition is a complex process that requires the integration of a wide variety of behaviors, including salience, reward-seeking, motivation, knowledge of self and others, and flexibly adjusting behavior in social groups. Not surprisingly, social cognition represents a sensitive domain commonly disrupted in the pathology of a variety of psychiatric disorders including Autism Spectrum Disorder (ASD and Schizophrenia (SCZ. Here, we discuss convergent research from animal models to human disease that implicates the prefrontal cortex (PFC as a key regulator in social cognition, suggesting that disruptions in prefrontal microcircuitry play an essential role in the pathophysiology of psychiatric disorders with shared social deficits. We take a translational perspective of social cognition, and review three key behaviors that are essential to normal social processing in rodents and humans, including social motivation, social recognition, and dominance hierarchy. A shared prefrontal circuitry may underlie these behaviors. Social cognition deficits in animal models of neurodevelopmental disorders like ASD and SCZ have been linked to an altered balance of excitation and inhibition (E/I ratio within the cortex generally, and PFC specifically. A clear picture of the mechanisms by which altered E/I ratio in the PFC might lead to disruptions of social cognition across a variety of behaviors is not well understood. Future studies should explore how disrupted developmental trajectory of prefrontal microcircuitry could lead to altered E/I balance and subsequent deficits in the social domain

  17. Group key management

    Energy Technology Data Exchange (ETDEWEB)

    Dunigan, T.; Cao, C.

    1997-08-01

    This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.

  18. Modular Connector Keying Concept

    Science.gov (United States)

    Ishman, Scott; Dukes, Scott; Warnica, Gary; Conrad, Guy; Senigla, Steven

    2013-01-01

    For panel-mount-type connectors, keying is usually "built-in" to the connector body, necessitating different part numbers for each key arrangement. This is costly for jobs that require small quantities. This invention was driven to provide a cost savings and to reduce documentation of individual parts. The keys are removable and configurable in up to 16 combinations. Since the key parts are separate from the connector body, a common design can be used for the plug, receptacle, and key parts. The keying can then be set at the next higher assembly.

  19. The Piriform Cortex and Human Focal Epilepsy

    OpenAIRE

    Vaughan, David N.; Graeme D. Jackson

    2014-01-01

    It is surprising that the piriform cortex, when compared to the hippocampus, has been given relatively little significance in human epilepsy. Like the hippocampus, it has a phylogenetically preserved three-layered cortex that is vulnerable to excitotoxic injury, has broad connections to both limbic and cortical areas, and is highly epileptogenic – being critical to the kindling process. The well-known phenomenon of early olfactory auras in temporal lobe epilepsy highlights its clinical releva...

  20. Food related processes in the insular cortex

    Directory of Open Access Journals (Sweden)

    Sabine eFrank

    2013-08-01

    Full Text Available The insular cortex is a multimodal brain region with regional cytoarchitectonic differences indicating various functional specializations. As a multisensory neural node, the insular cortex integrates perception, emotion, interoceptive awareness, cognition, and gustation. Regarding the latter, predominantly the anterior part of the insular cortex is regarded as the primary taste cortex.In this review, we will specifically focus on the involvement of the insula in food processing and on multimodal integration of food-related items. Influencing factors of insular activation elicited by various foods range from calorie-content to the internal physiologic state, body mass index or eating behavior. Sensory perception of food-related stimuli including seeing, smelling, and tasting elicits increased activation in the anterior and mid-dorsal part of the insular cortex. Apart from the pure sensory gustatory processing, there is also a strong association with the rewarding/hedonic aspects of food items, which is reflected in higher insular activity and stronger connections to other reward-related areas. Interestingly, the processing of food items has been found to elicit different insular activation in lean compared to obese subjects and in patients suffering from an eating disorder (anorexia nervosa, bulimia nervosa. The knowledge of functional differences in the insular cortex opens up the opportunity for possible noninvasive treatment approaches for obesity and eating disorders. To target brain functions directly, real-time functional magnetic resonance imaging neurofeedback offers a state-of-the-art tool to learn to control the anterior insular cortex activity voluntarily. First evidence indicates that obese adults have an enhanced ability to regulate the anterior insular cortex.

  1. Biometry, the safe key

    OpenAIRE

    María Fraile-Hurtado; Miguel Herrero-Langreo; Pilar Menéndez-Miguel; Valerio Delgado-Villanueva

    2010-01-01

    Biometry is the next step in authentication, why do not we take this stepforward in our communication security systems? Keys are the main disadvantage in the cryptography, what if we were our own key?

  2. Key Management Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides a secure environment to research and develop advanced electronic key management and networked key distribution technologies for the Navy and DoD....

  3. Financial Key Ratios

    OpenAIRE

    Tănase Alin-Eliodor

    2014-01-01

    This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

  4. Public Key Cryptography.

    Science.gov (United States)

    Tapson, Frank

    1996-01-01

    Describes public key cryptography, also known as RSA, which is a system using two keys, one used to put a message into cipher and another used to decipher the message. Presents examples using small prime numbers. (MKR)

  5. In the Rat Cerebellar Cortex

    Directory of Open Access Journals (Sweden)

    Gokhan Ordek

    2014-10-01

    Full Text Available The changes of excitability in affected neural networks can be used as a marker to study the temporal course of traumatic brain injury (TBI. The cerebellum is an ideal platform to study brain injury mechanisms at the network level using the electrophysiological methods. Within its crystalline morphology, the cerebellar cortex contains highly organized topographical subunits that are defined by two main inputs, the climbing and mossy fibers. Here we demonstrate the use of cerebellar evoked potentials (EPs mediated through these afferent systems for monitoring the injury progression in a rat model of fluid percussion injury (FPI. A mechanical tap on the dorsal hand was used as a stimulus, and EPs were recorded from the paramedian lobule (PML of the posterior cerebellum via multi-electrode arrays (MEA. Post-injury evoked response amplitudes (EPAs were analyzed on a daily basis for one week and compared with pre-injury values. We found a trend of consistently decreasing EPAs in all nine animals, losing as much as 72±4% of baseline amplitudes measured before the injury. Notably, our results highlighted two particular time windows; the first 24 hours of injury in the acute period and day-3 to day-7 in the delayed period where the largest drops (~50% and 24% were observed in the EPAs. In addition, cross-correlations of spontaneous signals between electrode pairs declined (from 0.47±0.1 to 0.35±0.04, p<0.001 along with the EPAs throughout the week of injury. In support of the electrophysiological findings, immunohistochemical analysis at day-7 post-injury showed detectable Purkinje cell loss at low FPI pressures and more with the largest pressures used. Our results suggest that sensory evoked potentials recorded from the cerebellar surface can be a useful technique to monitor the course of cerebellar injury and identify the phases of injury progression even at mild levels.

  6. Megabits secure key rate quantum key distribution

    International Nuclear Information System (INIS)

    Quantum cryptography can provide unconditional secure communication between two authorized parties based on the basic principles of quantum mechanics. However, imperfect practical conditions limit its transmission distance and communication speed. Here, we implemented the differential phase shift (DPS) quantum key distribution (QKD) with an up-conversion-assisted hybrid photon detector (HPD) and achieved a 1.3 Mbits per second secure key rate over a 10 km fiber, which is tolerant against photon number splitting (PNS) attack, general collective attacks on individual photons and any other known sequential unambiguous state discrimination (USD) attacks.

  7. The Key Lake project

    International Nuclear Information System (INIS)

    Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included

  8. LOCKS AND KEYS SERVICE

    CERN Multimedia

    Locks and Keys Service

    2002-01-01

    The Locks and Keys service (ST/FM) will move from building 55 to building 570 from the 2nd August to the 9th August 2002 included. During this period the service will be closed. Only in case of extreme urgency please call the 164550. Starting from Monday, 12th August, the Locks and Keys Service will continue to follow the activities related to office keys (keys and locks) and will provide the keys for furniture. The service is open from 8h30 to 12h00 and from 13h00 to 17h30. We remind you that your divisional correspondents can help you in the execution of the procedures. We thank you for your comprehension and we remain at your service to help you in solving all the matters related to keys for offices and furniture. Locks and Keys Service - ST Division - FM Group

  9. Auditory Connections and Functions of Prefrontal Cortex

    Directory of Open Access Journals (Sweden)

    BethanyPlakke

    2014-07-01

    Full Text Available The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC. In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition.

  10. Intelligent card access keys

    International Nuclear Information System (INIS)

    A newly developed access control technology allows information about users to be stored on key-like EEPROM devices. The keys store encrypted information about the user and his or her authorized access activity. Specially developed key readers scan, decrypt, and process the key data, and make the decision whether entry should be granted or denied. The key readers can function as complete, stand-alone facility management systems, incorporating access control, security monitoring, and remote control. In this configuration, the key readers provide anti-passback protection and other special features without requiring any data lines between readers. The key readers also feature sophisticated algorithmic processing for performing complex operations such as two-man control or cross zoned security annunciation. Key readers can also be interconnected with an MCM-1000 Multiples Monitoring System to form a distributed processing local area network. In such a configuration, changes in key reader status can be uploaded to the MCM-1000, and programming changes and operator commands can be downloaded to the key readers

  11. How does the cortex get its folds? The role of tension-based morphogenesis

    Science.gov (United States)

    van Essen, David

    The cerebral cortex is a sheet-like structure that is convoluted to varying degrees in different species and, for human cortex, shows remarkable variability across individuals - even in identical twins. This talk will discuss key biological events and physical forces involved in how the cortex gets its folds. The early stages of cortical morphogenesis are established by exquisitely regulated patterns of cellular proliferation and migration that place the right numbers of cells in an appropriate starting configuration. A major focus will be on the proposed role of mechanical tension in the next stages of morphogenesis. Does tension along apical dendrites of cortical pyramidal cells help make the cortex a sheet? Does tension along long-distance axons cause the cortex to fold? These are attractive but controversial ideas. I will suggest ways in which physicists can contribute critical models and analyses that may help distinguish the relative contributions of several mechanisms (differential proliferation, buckling of the cortical sheet, and tension-based cortical folding). Physicists can also help in evaluating the degree to which cortical circuits reflect principles of compact wiring and the putative role of tension-based morphogenesis in wiring length minimization.

  12. 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.

  13. A disinhibitory microcircuit initiates critical period plasticity in visual cortex

    Science.gov (United States)

    Kuhlman, Sandra J.; Olivas, Nicholas D.; Tring, Elaine; Ikrar, Taruna; Xu, Xiangmin; Trachtenberg, Joshua T.

    2014-01-01

    Early sensory experience instructs the maturation of neural circuitry in cortex 1,2. This has been extensively studied in the primary visual cortex where loss of vision to one eye permanently degrades cortical responsiveness to that eye 3,4, a phenomenon known as ocular dominance plasticity (ODP). Cortical inhibition mediates this process 4-6, but the precise role of specific classes of inhibitory neurons in ODP is controversial. Here we report that evoked firing rates of binocular excitatory neurons in primary visual cortex immediately drop by half when vision is restricted to one eye, but gradually return to normal over the following 24 hours, despite the fact that vision remains restricted to one eye. This restoration of binocular-like excitatory firing rates following monocular deprivation results from a rapid, though transient reduction in the firing rates of fast-spiking, parvalbumin-positive (PV) interneurons, which in turn can be attributed to a decrease in local excitatory circuit input onto PV interneurons. This reduction in PV cell evoked responses following monocular lid suture is restricted to the critical period for ODP and appears to be necessary for subsequent shifts in excitatory ODP. Pharmacologically enhancing inhibition at the time of sight deprivation blocks ODP and, conversely, pharmaco-genetic reduction of PV cell firing rates can extend the critical period for ODP. These findings define the microcircuit changes initiating competitive plasticity during critical periods of cortical development. Moreover, they show that the restoration of evoked firing rates of L2/3 pyramidal neurons by PV-specific disinhibition is a key step in the progression of ocular dominance plasticity. PMID:23975100

  14. Motor cortex neuroplasticity following brachial plexus transfer

    Directory of Open Access Journals (Sweden)

    Michael Biggs

    2013-08-01

    Full Text Available In the past decade, research has demonstrated that cortical plasticity, once thought only to exist in the early stages of life, does indeed continue on into adulthood. Brain plasticity is now acknowledged as a core principle of brain function and describes the ability of the central nervous system to adapt and modify its structural organization and function as an adaptive response to functional demand. In this clinical case study we describe how we used neuroimaging techniques to observe the functional topographical expansion of a patch of cortex along the sensorimotor cortex of a 27 year-old woman following brachial plexus transfer surgery to re-innervate her left arm. We found bilateral activations present in the thalamus, caudate, insula as well as across the sensorimotor cortex during an elbow flex motor task. In contrast we found less activity in the sensorimotor cortex for a finger tap motor task in addition to activations lateralised to the left inferior frontal gyrus and thalamus and bilaterally for the insula. From a pain perspective the patient who had experienced extensive phantom limb pain before surgery found these sensations were markedly reduced following transfer of the right brachial plexus to the intact left arm. Within the context of this clinical case the results suggest that functional improvements in limb mobility are associated with increased activation in the sensorimotor cortex as well as reduced phantom limb pain.

  15. The Homomorphic Key Agreement

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    There are various challenges that are faced in group communication, so it is necessary to ensure session key. Key agreement is the fundamental cryptographic primitive for establishing a secure communication. It is a process of computing a shared secret contributed by two or more entities such that no single node can predetermine the resulting value. An authenticated key agreement is attained by combining the key agreement protocol with digital signatures. After a brief introduction to existing key agreement in group communication, Making use of the additive-multiplicative homomorphism in the integer ring defined by Sander and Tschudin: A new protocols, called the homomorphism key agreement, was designed, which can be self-contributory, robust, scalable and applicable in group communication.

  16. Mega Key Authentication Mechanism

    OpenAIRE

    Kloss, Guy

    2016-01-01

    For secure communication it is not just sufficient to use strong cryptography with good and strong keys, but to actually have the assurance, that the keys in use for it are authentic and from the contact one is expecting to communicate with. Without that, it is possible to be subject to impersonation or man-in-the-middle (MitM) attacks. Mega meets this problem by providing a hierarchical authentication mechanism for contacts and their keys. To avoid any hassle when using multiple types of key...

  17. Cortex commands the performance of skilled movement.

    Science.gov (United States)

    Guo, Jian-Zhong; Graves, Austin R; Guo, Wendy W; Zheng, Jihong; Lee, Allen; Rodríguez-González, Juan; Li, Nuo; Macklin, John J; Phillips, James W; Mensh, Brett D; Branson, Kristin; Hantman, Adam W

    2015-01-01

    Mammalian cerebral cortex is accepted as being critical for voluntary motor control, but what functions depend on cortex is still unclear. Here we used rapid, reversible optogenetic inhibition to test the role of cortex during a head-fixed task in which mice reach, grab, and eat a food pellet. Sudden cortical inhibition blocked initiation or froze execution of this skilled prehension behavior, but left untrained forelimb movements unaffected. Unexpectedly, kinematically normal prehension occurred immediately after cortical inhibition, even during rest periods lacking cue and pellet. This 'rebound' prehension was only evoked in trained and food-deprived animals, suggesting that a motivation-gated motor engram sufficient to evoke prehension is activated at inhibition's end. These results demonstrate the necessity and sufficiency of cortical activity for enacting a learned skill. PMID:26633811

  18. The Age of Human Cerebral Cortex Neurons

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, R D; Curtis, M A; Spalding, K L; Buchholz, B A; Fink, D; Bjork-Eriksson, T; Nordborg, C; Gage, F H; Druid, H; Eriksson, P S; Frisen, J

    2006-04-06

    The traditional static view of the adult mammalian brain has been challenged by the realization of continuous generation of neurons from stem cells. Based mainly on studies in experimental animals, adult neurogenesis may contribute to recovery after brain insults and decreased neurogenesis has been implicated in the pathogenesis of neurological and psychiatric diseases in man. The extent of neurogenesis in the adult human brain has, however, been difficult to establish. We have taken advantage of the integration of {sup 14}C, generated by nuclear bomb tests during the Cold War, in DNA to establish the age of neurons in the major areas of the human cerebral cortex. Together with the analysis of the cortex from patients who received BrdU, which integrates in the DNA of dividing cells, our results demonstrate that whereas non-neuronal cells turn over, neurons in the human cerebral cortex are not generated postnatally at detectable levels, but are as old as the individual.

  19. Olfactory consciousness and gamma oscillation couplings across the olfactory bulb, olfactory cortex and orbitofrontal cortex

    Directory of Open Access Journals (Sweden)

    KensakuMori

    2013-10-01

    Full Text Available The orbitofrontal cortex receives multi-modality sensory inputs, including olfactory input, and is thought to be involved in conscious perception of the olfactory image of objects. Generation of olfactory consciousness requires neuronal circuit mechanisms for the ‘binding’ of distributed neuronal activities, with each constituent neuron representing a specific component of an olfactory percept. The shortest neuronal pathway for odor signals to reach the orbitofrontal cortex is olfactory sensory neuron – olfactory bulb – olfactory cortex – orbitofrontal cortex, but other pathways exist, including transthalamic pathways. Here, we review studies on the structural organization and functional properties of the shortest pathway, and propose a model of neuronal circuit mechanisms underlying the temporal bindings of distributed neuronal activities in the olfactory cortex. We describe a hypothesis that suggests functional roles of gamma oscillations in the bindings. This hypothesis proposes that two types of projection neurons in the olfactory bulb, tufted cells and mitral cells, play distinct functional roles in bindings at neuronal circuits in the olfactory cortex: tufted cells provide specificity-projecting circuits which send odor information with early-onset fast gamma synchronization, while mitral cells give rise to dispersedly-projecting feed-forward binding circuits which transmit the response synchronization timing with later-onset slow gamma synchronization. This hypothesis also suggests a sequence of bindings in the olfactory cortex: a small-scale binding by the early-phase fast gamma synchrony of tufted cell inputs followed by a larger-scale binding due to the later-onset slow gamma synchrony of mitral cell inputs. We discuss that behavioral state, including wakefulness and sleep, regulates gamma oscillation couplings across the olfactory bulb, olfactory cortex, and orbitofrontal cortex.

  20. Postictal inhibition of the somatosensory cortex

    DEFF Research Database (Denmark)

    Beniczky, Sándor; Jovanovic, Marina; Atkins, Mary Doreen;

    2011-01-01

    Transient suppression of the motor cortex and of the speech areas cause well-described postictal phenomena following seizures involving the respective cortical areas. Pain is a rare symptom in epileptic seizures. We present a patient with painful tonic seizures in the left leg. The amplitude of t...

  1. Functional genomics of early cortex patterning

    OpenAIRE

    Chambers, David; Fishell, Gord

    2006-01-01

    Several lines of evidence have illuminated the fundamental developmental principles involved in establishing and implementing pattern formation in the mammalian neocortex. A recent study has sought to unravel the underlying genetic control of cortex patterning by elucidating the transcriptional profile of discrete neocortical regions.

  2. The insular cortex: a comparative perspective.

    Science.gov (United States)

    Butti, Camilla; Hof, Patrick R

    2010-06-01

    The human insular cortex is involved in a variety of viscerosensory, visceromotor, and interoceptive functions, and plays a role in complex processes such as emotions, music, and language. Across mammals, the insula has considerable morphologic variability. We review the structure and connectivity of the insula in laboratory animals (mouse, domestic cat, macaque monkey), and we present original data on the morphology and cytoarchitecture of insular cortex in less common species including a large carnivore (the Atlantic walrus, Odobenus rosmarus), two artiodactyls (the pigmy hippopotamus, Hexaprotodon liberiensis, and the Western bongo, Tragelaphus eurycerus), two cetaceans (the beluga whale, Delphinapterus leucas, and the minke whale, Balaenoptera acutorostrata), and a sirenian (the Florida manatee, Trichechus manatus latirostris). The insula shows substantial variability in shape, extent, and gyral and sulcal patterns, as well as differences in laminar organization, cellular specialization, and structural association with the claustrum. Our observations reveal that the insular cortex is extremely variable among mammals. These differences could be related to the role exerted by specific and selective pressures on cortical structure during evolution. We conclude that it is not possible to identify a general model of organization for the mammalian insular cortex. PMID:20512368

  3. Molecular Components and Functions of the Endocannabinoid System in Mouse Prefrontal Cortex

    OpenAIRE

    Mathieu Lafourcade; Izaskun Elezgarai; Susana Mato; Yamina Bakiri; Pedro Grandes; Manzoni, Olivier J.

    2007-01-01

    BACKGROUND: Cannabinoids have deleterious effects on prefrontal cortex (PFC)-mediated functions and multiple evidences link the endogenous cannabinoid (endocannabinoid) system, cannabis use and schizophrenia, a disease in which PFC functions are altered. Nonetheless, the molecular composition and the physiological functions of the endocannabinoid system in the PFC are unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here, using electron microscopy we found that key proteins involved in endocannabinoi...

  4. Dysfunction of the prefrontal cortex in addiction: neuroimaging findings and clinical implications

    OpenAIRE

    Goldstein, Rita Z.; Volkow, Nora D

    2011-01-01

    The loss of control over drug intake that occurs in addiction was initially believed to result from disruption of subcortical reward circuits. However, imaging studies in addictive behaviours have identified a key involvement of the prefrontal cortex (PFC) both through its regulation of limbic reward regions and its involvement in higher-order executive function (for example, self-control, salience attribution and awareness). This Review focuses on functional neuroimaging studies conducted in...

  5. Microcircuits of excitatory and inhibitory neurons in layer 2/3 of mouse barrel cortex

    OpenAIRE

    Avermann, Michael; Tomm, Christian; Mateo, Celine; Gerstner, Wulfram; Petersen, Carl C. H.

    2012-01-01

    Avermann M, Tomm C, Mateo C, Gerstner W, Petersen CC. Microcircuits of excitatory and inhibitory neurons in layer 2/3 of mouse barrel cortex. J Neurophysiol 107: 3116-3134, 2012. First published March 7, 2012; doi:10.1152/jn.00917.2011.-Synaptic interactions between nearby excitatory and inhibitory neurons in the neocortex are thought to play fundamental roles in sensory processing. Here, we have combined optogenetic stimulation, whole cell recordings, and computational modeling to define key...

  6. Key concepts in energy

    CERN Document Server

    Madureira, Nuno Luis

    2014-01-01

    Highlights how key energy concepts surfaced, tracing their evolution throughout history to encompasses four economic concepts and four technological-engineering concepts developed through their history to conclude with current economic and environmental sciences Considers the process of energy-substitutions through complementary usages, hybridization and technological mixes Combines a conceptual approach with key theoretical concepts from engineering, geological and economic sciences providing cross disciplinary overview of energy fundamentals in a short and focused reading

  7. Secret Key Crypto Implementations

    Science.gov (United States)

    Bertoni, Guido Marco; Melzani, Filippo

    This chapter presents the algorithm selected in 2001 as the Advanced Encryption Standard. This algorithm is the base for implementing security and privacy based on symmetric key solutions in almost all new applications. Secret key algorithms are used in combination with modes of operation to provide different security properties. The most used modes of operation are presented in this chapter. Finally an overview of the different techniques of software and hardware implementations is given.

  8. Lock and key colloids.

    Science.gov (United States)

    Sacanna, S; Irvine, W T M; Chaikin, P M; Pine, D J

    2010-03-25

    New functional materials can in principle be created using colloids that self-assemble into a desired structure by means of a programmable recognition and binding scheme. This idea has been explored by attaching 'programmed' DNA strands to nanometre- and micrometre- sized particles and then using DNA hybridization to direct the placement of the particles in the final assembly. Here we demonstrate an alternative recognition mechanism for directing the assembly of composite structures, based on particles with complementary shapes. Our system, which uses Fischer's lock-and-key principle, employs colloidal spheres as keys and monodisperse colloidal particles with a spherical cavity as locks that bind spontaneously and reversibly via the depletion interaction. The lock-and-key binding is specific because it is controlled by how closely the size of a spherical colloidal key particle matches the radius of the spherical cavity of the lock particle. The strength of the binding can be further tuned by adjusting the solution composition or temperature. The composite assemblies have the unique feature of having flexible bonds, allowing us to produce flexible dimeric, trimeric and tetrameric colloidal molecules as well as more complex colloidal polymers. We expect that this lock-and-key recognition mechanism will find wider use as a means of programming and directing colloidal self-assembly. PMID:20336142

  9. Key World Energy Statistics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The IEA produced its first handy, pocket-sized summary of key energy data in 1997. This new edition responds to the enormously positive reaction to the book since then. Key World Energy Statistics produced by the IEA contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts. It exists in different formats to suit our readers' requirements.

  10. Learning to smell danger: acquired associative representation of threat in the olfactory cortex.

    Science.gov (United States)

    Li, Wen

    2014-01-01

    Neuroscience research over the past few decades has reached a strong consensus that the amygdala plays a key role in emotion processing. However, many questions remain unanswered, especially concerning emotion perception. Based on mnemonic theories of olfactory perception and in light of the highly associative nature of olfactory cortical processing, here I propose a sensory cortical model of olfactory threat perception (i.e., sensory-cortex-based threat perception): the olfactory cortex stores threat codes as acquired associative representations (AARs) formed via aversive life experiences, thereby enabling encoding of threat cues during sensory processing. Rodent and human research in olfactory aversive conditioning was reviewed, indicating learning-induced plasticity in the amygdala and the olfactory piriform cortex. In addition, as aversive learning becomes consolidated in the amygdala, the associative olfactory (piriform) cortex may undergo (long-term) plastic changes, resulting in modified neural response patterns that underpin threat AARs. This proposal thus brings forward a sensory cortical pathway to threat processing (in addition to amygdala-based processes), potentially accounting for an alternative mechanism underlying the pathophysiology of anxiety and depression. PMID:24778610

  11. Determining physical properties of the cell cortex

    CERN Document Server

    Saha, A; Behrndt, M; Heisenberg, C -P; Jülicher, F; Grill, S W

    2015-01-01

    Actin and myosin assemble into a thin layer of a highly dynamic network underneath the membrane of eukaryotic cells. This network generates the forces that drive cell and tissue-scale morphogenetic processes. The effective material properties of this active network determine large-scale deformations and other morphogenetic events. For example,the characteristic time of stress relaxation (the Maxwell time)in the actomyosin sets the time scale of large-scale deformation of the cortex. Similarly, the characteristic length of stress propagation (the hydrodynamic length) sets the length scale of slow deformations, and a large hydrodynamic length is a prerequisite for long-ranged cortical flows. Here we introduce a method to determine physical parameters of the actomyosin cortical layer (in vivo). For this we investigate the relaxation dynamics of the cortex in response to laser ablation in the one-cell-stage {\\it C. elegans} embryo and in the gastrulating zebrafish embryo. These responses can be interpreted using ...

  12. Uptake of trimethoprim by renal cortex.

    Science.gov (United States)

    Cacini, W; Myre, S A

    1985-10-01

    The purpose of this study was to examine the mechanisms involved in the uptake of the urinary antibacterial drug trimethoprim by incubated slices of rat renal cortex. Concentration-dependent studies of the uptake process demonstrated that a saturable component was involved. The results of inhibitor studies as well as the time-course pattern support the conclusion that at least two processes are involved in the uptake of trimethoprim. These include active transport via the organic cation system, accounting for about 40% of the total uptake, and a second component that continues to operate under conditions of inhibited cellular metabolism. Chromatographic examination of post-incubation bathing medium and slice extracts failed to demonstrate renal cortex metabolism of trimethoprim. PMID:4052093

  13. Encoding frequency contrast in primate auditory cortex

    OpenAIRE

    Malone, Brian J.; Scott, Brian H.; Semple, Malcolm N.

    2014-01-01

    Changes in amplitude and frequency jointly determine much of the communicative significance of complex acoustic signals, including human speech. We have previously described responses of neurons in the core auditory cortex of awake rhesus macaques to sinusoidal amplitude modulation (SAM) signals. Here we report a complementary study of sinusoidal frequency modulation (SFM) in the same neurons. Responses to SFM were analogous to SAM responses in that changes in multiple parameters defining SFM...

  14. Inhibition in the Human Auditory Cortex

    OpenAIRE

    Koji Inui; Kei Nakagawa; Makoto Nishihara; Eishi Motomura; Ryusuke Kakigi

    2016-01-01

    Despite their indispensable roles in sensory processing, little is known about inhibitory interneurons in humans. Inhibitory postsynaptic potentials cannot be recorded non-invasively, at least in a pure form, in humans. We herein sought to clarify whether prepulse inhibition (PPI) in the auditory cortex reflected inhibition via interneurons using magnetoencephalography. An abrupt increase in sound pressure by 10 dB in a continuous sound was used to evoke the test response, and PPI was observe...

  15. Dopamine gates sensory representations in cortex

    OpenAIRE

    Eshel, Neir; Tian, Ju

    2014-01-01

    The prefrontal cortex (PFC) maintains information about relevant sensory stimuli, in a process thought to rely on dopamine release. In a recent paper, Jacob et al. (J Neurosci 33: 13724–13734, 2013) demonstrated one way in which dopamine might facilitate this process. The authors recorded from PFC neurons in monkeys during local application of dopamine. They found that dopamine increases the gain of sensory-evoked responses in putative pyramidal neurons in PFC, potentially by inhibiting local...

  16. Odorant Category Profile Selectivity of Olfactory Cortex

    OpenAIRE

    Yoshida, Ikue; Mori, Kensaku

    2007-01-01

    The olfactory cortex receives converging axonal inputs from many mitral and tufted cells in the olfactory bulb. Recent studies indicate that single cortical neurons integrate signals from diverse odorants. However, there remains a basic question, namely, the signals from which kinds of odorants are integrated by the individual cortical neurons? The present study examined the possibility that some cortical neurons integrate signals from distinct component odorants of natural foods because indi...

  17. Color contrast processing in human striate cortex

    OpenAIRE

    Kentridge, R. W.; Heywood, C. A.; Weiskrantz, L.

    2007-01-01

    Color constancy refers to the unchanging nature of the perceived color of an object despite considerable variation in the wavelength composition of the light illuminating it. The color contrasts between objects and their backgrounds play a crucial role in color constancy. We tested a patient whose right striate cortex had been removed and demonstrated that he made no use of color contrast in judging color appearance but instead made judgments based simply on wavelength comparison. This was sh...

  18. Five Keys to Success

    Science.gov (United States)

    Peddy, Walter J.

    2009-01-01

    The first year as a principal is filled with self-doubt. As one already knows, there is no book or guide that can fully prepare someone for what the principal's position entails. All first-year principals have to learn by doing. In this article, the author discusses five keys to success that will guide and help first-year principals with the…

  19. Key Competencies. Second Edition.

    Science.gov (United States)

    Haworth, David; Browne, Geoff

    Key competencies (or generic skills) have been specified in four sources: Further Education Unit (FEU), United Kingdom (1987); Finn Report (1991) and Mayer Committee (1992), Australia; U.S. Labor Secretary's Commission on Achieving Necessary Skills (SCANS) (June 1991); and Butterworth and Lovell (1983), New South Wales. A comparison of the four…

  20. Cryptographic Key Management System

    Energy Technology Data Exchange (ETDEWEB)

    No, author

    2014-02-21

    This report summarizes the outcome of U.S. Department of Energy (DOE) contract DE-OE0000543, requesting the design of a Cryptographic Key Management System (CKMS) for the secure management of cryptographic keys for the energy sector infrastructure. Prime contractor Sypris Electronics, in collaboration with Oak Ridge National Laboratories (ORNL), Electric Power Research Institute (EPRI), Valicore Technologies, and Purdue University's Center for Education and Research in Information Assurance and Security (CERIAS) and Smart Meter Integration Laboratory (SMIL), has designed, developed and evaluated the CKMS solution. We provide an overview of the project in Section 3, review the core contributions of all contractors in Section 4, and discuss bene ts to the DOE in Section 5. In Section 6 we describe the technical construction of the CKMS solution, and review its key contributions in Section 6.9. Section 7 describes the evaluation and demonstration of the CKMS solution in different environments. We summarize the key project objectives in Section 8, list publications resulting from the project in Section 9, and conclude with a discussion on commercialization in Section 10 and future work in Section 11.

  1. Locks and Keys Service

    CERN Multimedia

    Claude Ducastel

    The GS-LS-SEM section is pleased to inform you that as from Monday 30 November 2009, the opening hours of the Locks and Keys service will be the following: 08h30 - 12h30 / 13h30 - 16:30, Mondays to Fridays. GS-SEM-LS 73333

  2. Turn key contracts

    International Nuclear Information System (INIS)

    The aim of this summary is to point out some specific areas which have to be covered in a turn-key contract and which are of primarily interest to the buyer of a nuclear plant. It will be assumed that the buyer is utility company in a developing country and a plant supplier a company in an industrial country. (orig./FW)

  3. Keyed shear joints

    DEFF Research Database (Denmark)

    Hansen, Klaus

    This report gives a summary of the present information on the behaviour of vertical keyed shear joints in large panel structures. An attemp is made to outline the implications which this information might have on the analysis and design of a complete wall. The publications also gives a short...

  4. Binocular form deprivation influences the visual cortex

    Institute of Scientific and Technical Information of China (English)

    Mingming Liu; Chuanhuang Weng; Hanping Xie; Wei Qin

    2012-01-01

    1a-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors are considered to play a crucial role in synaptic plasticity in the developing visual cortex. In this study, we established a rat model of binocular form deprivation by suturing the rat binocular eyelids before eye-opening at postnatal day 14. During development, the decay time of excitatory postsynaptic currents mediated by 1a-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid receptors of normal rats became longer after eyeopening; however, the decay time did not change significantly in binocular form deprivation rats. The peak value in the normal group became gradually larger with age, but there was no significant change in the binocular form deprivation group. These findings indicate that binocular form deprivation influences the properties of excitatory postsynaptic currents mediated by β-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid receptors in the rat visual cortex around the end of the critical period, indicating that form stimulation is associated with the experience-dependent modification of neuronal synapses in the visual cortex.

  5. Activity of the motor cortex during scratching.

    Science.gov (United States)

    Sirota, Mikhail G; Pavlova, Galina A; Beloozerova, Irina N

    2006-02-01

    In awake cats sitting with the head restrained, scratching was evoked using stimulation of the ear. Cats scratched the shoulder area, consistently failing to reach the ear. Kinematics of the hind limb movements and the activity of ankle muscles, however, were similar to those reported earlier in unrestrained cats. The activity of single neurons in the hind limb representation of the motor cortex, including pyramidal tract neurons (PTNs), was examined. During the protraction stage of the scratch response, the activity in 35% of the neurons increased and in 50% decreased compared with rest. During the rhythmic stage, the motor cortex population activity was approximately two times higher compared with rest, because the activity of 53% of neurons increased and that of 33% decreased in this stage. The activity of 61% of neurons was modulated in the scratching rhythm. The average depth of frequency modulation was 12.1 +/- 5.3%, similar to that reported earlier for locomotion. The phases of activity of different neurons were approximately evenly distributed over the scratch cycle. There was no simple correlation between resting receptive field properties and the activity of neurons during the scratch response. We conclude that the motor cortex participates in both the protraction and the rhythmic stages of the scratch response. PMID:16236789

  6. Contextual Learning Induces Dendritic Spine Clustering in Retrosplenial Cortex

    Directory of Open Access Journals (Sweden)

    Adam C Frank

    2014-03-01

    Full Text Available Molecular and electrophysiological studies find convergent evidence suggesting that plasticity within a dendritic tree is not randomly dispersed, but rather clustered into functional groups. Further, results from in silico neuronal modeling show that clustered plasticity is able to increase storage capacity 45 times compared to dispersed plasticity. Recent in vivo work utilizing chronic 2-photon microscopy tested the clustering hypothesis and showed that repetitive motor learning is able to induce clustered addition of new dendritic spines on apical dendrites of L5 neurons in primary motor cortex; moreover, clustered spines were found to be more stable than non-clustered spines, suggesting a physiological role for spine clustering. To further test this hypothesis we used in vivo 2-photon imaging in Thy1-YFP-H mice to chronically examine dendritic spine dynamics in retrosplenial cortex (RSC during spatial learning. RSC is a key component of an extended spatial learning and memory circuit that includes hippocampus and entorhinal cortex. Importantly, RSC is known from both lesion and immediate early gene studies to be critically involved in spatial learning and more specifically in contextual fear conditioning. We utilized a modified contextual fear conditioning protocol wherein animals received a mild foot shock each day for five days; this protocol induces gradual increases in context freezing over several days before the animals reach a behavioral plateau. We coupled behavioral training with four separate in vivo imaging sessions, two before training begins, one early in training, and a final session after training is complete. This allowed us to image spine dynamics before training as well as early in learning and after animals had reached behavioral asymptote. We find that this contextual learning protocol induces a statistically significant increase in the formation of clusters of new dendritic spines in trained animals when compared to home

  7. Using image key as cipher key in AES

    OpenAIRE

    Razi Hosseinkhani; Hamid Haj Seyyed Javadi

    2012-01-01

    This paper describes how cipher key can be generated from image. We use image to generate cipher key for AES algorithm. After this step , cipher key watermarked in image. S-Box generated by this key which it called Key-dependant S-box. These steps make AES algorithm more robust and more reliable.

  8. Key Changes [Book Review

    OpenAIRE

    Kousser, J. Morgan

    1981-01-01

    The notion that electoral history may be divided into long periods of stability broken periodically by major shocks has been the central organizing motif of American political history for a generation. Drawing on the simple empirical observation that the balance of electoral support for the major American political parties across geographic units remained roughly the same for a sequence of contests, and then shifted rather suddenly into a new and lasting pattern, V. 0. Key, Jr., Lee Benson, W...

  9. Developing Key Account Managers

    OpenAIRE

    Millman, T; Wilson, K

    1995-01-01

    Key account management (KAM) in industrial and business-to-business markets has its roots in sales management where it has long been recognised that customers of strategic importance require special treatment. More recently, growing interest among academics and practitioners in relationship marketing has forced KAM centre stage as one of the few seemingly tried/tested approaches to customer retention and development. This trend, however, has exposed three inter-related problems for the adopti...

  10. Public-Key Cryptography

    OpenAIRE

    Lint, van, JH

    2003-01-01

    Part I: Theory Provable security is an important goal in the design of public-key cryptosystems. For most security properties, it is computational security that has to be considered: an attack scenario describes how adversaries interact with the cryptosystem, trying to attack it; the system can be called secure if adversaries with reasonably bounded computational means have negligible prospects of success. The lack of computational problems that are guaranteed to be hard in an appropriate sen...

  11. Differential expression of molecular motors in the motor cortex of sporadic ALS.

    Science.gov (United States)

    Pantelidou, Maria; Zographos, Spyros E; Lederer, Carsten W; Kyriakides, Theodore; Pfaffl, Michael W; Santama, Niovi

    2007-06-01

    The molecular mechanisms underlying the selective neurodegeneration of motor neurons in amyotrophic lateral sclerosis (ALS) are inadequately understood. Recent breakthroughs have implicated impaired axonal transport, mediated by molecular motors, as a key element for disease onset and progression. The current work identifies the expression of 15 kinesin-like motors in healthy human motor cortex, including three novel isoforms. Our comprehensive quantitative mRNA analysis in control and sporadic ALS (SALS) motor cortex specimens detects SALS-specific down-regulation of KIF1Bbeta and novel KIF3Abeta, two isoforms we show to be enriched in the brain, and also of SOD1, a key enzyme linked to familial ALS. This is accompanied by a marked reduction of KIF3Abeta protein levels. In the motor cortex KIF3Abeta localizes in cholinergic neurons, including upper motor neurons. No mutations causing splicing defects or altering protein-coding sequences were identified in the genes of the three proteins. The present study implicates two motor proteins as possible candidates in SALS pathology. PMID:17418584

  12. Activation of cannabinoid system in anterior cingulate cortex and orbitofrontal cortex modulates cost-benefit decision making.

    Science.gov (United States)

    Khani, Abbas; Kermani, Mojtaba; Hesam, Soghra; Haghparast, Abbas; Argandoña, Enrike G; Rainer, Gregor

    2015-06-01

    Despite the evidence for altered decision making in cannabis abusers, the role of the cannabinoid system in decision-making circuits has not been studied. Here, we examined the effects of cannabinoid modulation during cost-benefit decision making in the anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC), key brain areas involved in decision making. We trained different groups of rats in a delay-based and an effort-based form of cost-benefit T-maze decision-making task. During test days, the rats received local injections of either vehicle or ACEA, a cannabinoid type-1 receptor (CB1R) agonist in the ACC or OFC. We measured spontaneous locomotor activity following the same treatments and characterized CB1Rs localization on different neuronal populations within these regions using immunohistochemistry. We showed that CB1R activation in the ACC impaired decision making such that rats were less willing to invest physical effort to gain high reward. Similarly, CB1R activation in the OFC induced impulsive pattern of choice such that rats preferred small immediate rewards to large delayed rewards. Control tasks ensured that the effects were specific for differential cost-benefit tasks. Furthermore, we characterized widespread colocalizations of CB1Rs on GABAergic axonal ends but few colocalizations on glutamatergic, dopaminergic, and serotonergic neuronal ends. These results provide first direct evidence that the cannabinoid system plays a critical role in regulating cost-benefit decision making in the ACC and OFC and implicate cannabinoid modulation of synaptic ends of predominantly interneurons and to a lesser degree other neuronal populations in these two frontal regions. PMID:25529106

  13. NAGRADATA. Code key. Geology

    International Nuclear Information System (INIS)

    This reference manual provides users of the NAGRADATA system with comprehensive keys to the coding/decoding of geological and technical information to be stored in or retreaved from the databank. Emphasis has been placed on input data coding. When data is retreaved the translation into plain language of stored coded information is done automatically by computer. Three keys each, list the complete set of currently defined codes for the NAGRADATA system, namely codes with appropriate definitions, arranged: 1. according to subject matter (thematically) 2. the codes listed alphabetically and 3. the definitions listed alphabetically. Additional explanation is provided for the proper application of the codes and the logic behind the creation of new codes to be used within the NAGRADATA system. NAGRADATA makes use of codes instead of plain language for data storage; this offers the following advantages: speed of data processing, mainly data retrieval, economies of storage memory requirements, the standardisation of terminology. The nature of this thesaurian type 'key to codes' makes it impossible to either establish a final form or to cover the entire spectrum of requirements. Therefore, this first issue of codes to NAGRADATA must be considered to represent the current state of progress of a living system and future editions will be issued in a loose leave ringbook system which can be updated by an organised (updating) service. (author)

  14. Altered SPECT (123)I-iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa.

    Science.gov (United States)

    Nagamitsu, Shinichiro; Sakurai, Rieko; Matsuoka, Michiko; Chiba, Hiromi; Ozono, Shuichi; Tanigawa, Hitoshi; Yamashita, Yushiro; Kaida, Hayato; Ishibashi, Masatoshi; Kakuma, Tatsuki; Croarkin, Paul E; Matsuishi, Toyojiro

    2016-01-01

    Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN) in children. The purpose of this study was to examine cortical GABA(A)-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single-photon emission computed tomography (SPECT) measurements using (123)I-iomazenil, which binds to GABA(A)-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26) and the short form of the Profile of Mood States (POMS). Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil-binding activity in cortical regions of interest and psychometric profiles and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil-binding activity in the anterior and posterior cingulate cortex. Higher POMS subscale scores were significantly associated with lower iomazenil-binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC). "Depression-Dejection" and "Confusion" POMS subscale scores, and total POMS score showed interaction effects with brain regions in iomazenil-binding activity. Decreased binding in the anterior cingulate cortex and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered in

  15. Developmental changes in GABAergic mechanisms in human visual cortex across the lifespan

    Directory of Open Access Journals (Sweden)

    Joshua G A Pinto

    2010-06-01

    Full Text Available Functional maturation of visual cortex is linked with dynamic changes in synaptic expression of GABAergic mechanisms. These include setting the excitation-inhibition balance required for experience-dependent plasticity, as well as, intracortical inhibition underlying development and aging of receptive field properties. Animal studies have shown developmental regulation of GABAergic mechanisms in visual cortex. In this study, we show for the first time how these mechanisms develop in the human visual cortex across the lifespan. We used Western blot analysis of postmortem tissue from human primary visual cortex (n=30, range: 20 days to 80 years to quantify expression of 8 pre- and post-synaptic GABAergic markers. We quantified the inhibitory modulating cannabinoid receptor (CB1, GABA vesicular transporter (VGAT, GABA synthesizing enzymes (GAD65/GAD67, GABAA receptor anchoring protein (Gephyrin, and GABAA receptor subunits (GABAA∝1, GABAA∝2, GABAA∝3. We found a complex pattern of changes, many of which were prolonged and continued well into into the teen, young adult, and even older adult years. These included a monotonic increase or decrease (GABAA∝1, GABAA∝2, a biphasic increase then decrease (GAD65, Gephyrin, or multiple increases and decreases (VGAT, CB1 across the lifespan. Comparing the balances between the pre- and post-synaptic markers we found 3 main transitions (early childhood, early teen years, aging when there were rapid switches in the composition of the GABAergic signaling system, indicating that functioning of the GABAergic system must change as the visual cortex develops and ages. Furthermore, these results provide key information for translating therapies developed in animal models into effective treatments for amblyopia in humans.

  16. Altered SPECT 123I-iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

    Science.gov (United States)

    Nagamitsu, Shinichiro; Sakurai, Rieko; Matsuoka, Michiko; Chiba, Hiromi; Ozono, Shuichi; Tanigawa, Hitoshi; Yamashita, Yushiro; Kaida, Hayato; Ishibashi, Masatoshi; Kakuma, Tatsuki; Croarkin, Paul E.; Matsuishi, Toyojiro

    2016-01-01

    Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN) in children. The purpose of this study was to examine cortical GABA(A)-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single-photon emission computed tomography (SPECT) measurements using 123I-iomazenil, which binds to GABA(A)-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26) and the short form of the Profile of Mood States (POMS). Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil-binding activity in cortical regions of interest and psychometric profiles and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil-binding activity in the anterior and posterior cingulate cortex. Higher POMS subscale scores were significantly associated with lower iomazenil-binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC). “Depression–Dejection” and “Confusion” POMS subscale scores, and total POMS score showed interaction effects with brain regions in iomazenil-binding activity. Decreased binding in the anterior cingulate cortex and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered

  17. Identification key to Quivira milkweeds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a key to milkweed identification at Quivira National Wildlife Refuge. It contains a dichotomous key as well as a picture key. Milkweeds found on...

  18. Connectivity changes underlying neurofeedback training of visual cortex activity.

    Directory of Open Access Journals (Sweden)

    Frank Scharnowski

    Full Text Available Neurofeedback based on real-time functional magnetic resonance imaging (fMRI is a new approach that allows training of voluntary control over regionally specific brain activity. However, the neural basis of successful neurofeedback learning remains poorly understood. Here, we assessed changes in effective brain connectivity associated with neurofeedback training of visual cortex activity. Using dynamic causal modeling (DCM, we found that training participants to increase visual cortex activity was associated with increased effective connectivity between the visual cortex and the superior parietal lobe. Specifically, participants who learned to control activity in their visual cortex showed increased top-down control of the superior parietal lobe over the visual cortex, and at the same time reduced bottom-up processing. These results are consistent with efficient employment of top-down visual attention and imagery, which were the cognitive strategies used by participants to increase their visual cortex activity.

  19. Magnetic Resonance and adrenal cortex pathology

    International Nuclear Information System (INIS)

    M.R.I. allows a good delineation of adrenals, due to the high contrast with fat and to the use of frontal planes. On post operative adrenal lesions samples the lipid percentages, high in normal and hyperplasic glands, was still high in most benign adenomas, and very low (under 5 %) in adrenal carcinomas. MRI, with Dixon sequence, allows to evaluate this lipid percentage in adrenal lesions. Post-operative controls show a good agreement between in vivo and in vitro measurements. This simple technique should allow to discriminate between malignant and benign adrenal cortex lesions

  20. What does spatial alternation tell us about retrosplenial cortex function?

    OpenAIRE

    Andrew John Dudley Nelson

    2015-01-01

    The retrosplenial cortex supports navigation, but there are good reasons to suppose that the retrosplenial cortex has a very different role in spatial memory from that of the hippocampus and anterior thalamic nuclei. For example, retrosplenial lesions appear to have little or no effect on standard tests of spatial alternation. To examine these differences, the current study sought to determine whether the retrosplenial cortex is important for just one spatial cue type (e.g. allocentric, direc...

  1. What does spatial alternation tell us about retrosplenial cortex function?

    OpenAIRE

    Nelson, Andrew J.D.; Powell, Anna L.; Holmes, Joshua D.; Vann, Seralynne D.; Aggleton, John. P.

    2015-01-01

    The retrosplenial cortex supports navigation, but there are good reasons to suppose that the retrosplenial cortex has a very different role in spatial memory from that of the hippocampus and anterior thalamic nuclei. For example, retrosplenial lesions appear to have little or no effect on standard tests of spatial alternation. To examine these differences, the current study sought to determine whether the retrosplenial cortex is important for just one spatial cue type (e.g., allocentric, dire...

  2. Complementary sensory and associative microcircuitry in primary olfactory cortex

    OpenAIRE

    Wiegand, H.F.; Beed, P.; Bendels, M.H.; Leibold, C.; Schmitz, D; Johenning, F.W.

    2011-01-01

    The three-layered primary olfactory (piriform) cortex is the largest component of the olfactory cortex. Sensory and intracortical inputs converge on principal cells in the anterior piriform cortex (aPC). We characterize organization principles of the sensory and intracortical microcircuitry of layer II and III principal cells in acute slices of rat aPC using laser-scanning photostimulation and fast two-photon population Ca(2+) imaging. Layer II and III principal cells are set up on a superfic...

  3. Quantum Key Distribution Protocol with Private-Public Key

    OpenAIRE

    Serna, Eduin H.

    2009-01-01

    A quantum cryptographic protocol based in public key cryptography combinations and private key cryptography is presented. Unlike the BB84 protocol [1] and its many variants [2,3] two quantum channels are used. The present research does not make reconciliation mechanisms of information to derive the key. A three related system of key distribution are described.

  4. Measurements of evoked electroencephalograph by transcranial magnetic stimulation applied to motor cortex and posterior parietal cortex

    Science.gov (United States)

    Iwahashi, Masakuni; Koyama, Yohei; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo; Iramina, Keiji

    2009-04-01

    To investigate the functional connectivity, the evoked potentials by stimulating at the motor cortex, the posterior parietal cortex, and the cerebellum by transcranial magnetic stimulation (TMS) were measured. It is difficult to measure the evoked electroencephalograph (EEG) by the magnetic stimulation because of the large artifact induced by the magnetic pulse. We used an EEG measurement system with sample-and-hold circuit and an independent component analysis to eliminate the electromagnetic interaction emitted from TMS. It was possible to measure EEG signals from all electrodes over the head within 10 ms after applying the TMS. When the motor area was stimulated by TMS, the spread of evoked electrical activity to the contralateral hemisphere was observed at 20 ms after stimulation. However, when the posterior parietal cortex was stimulated, the evoked electrical activity to the contralateral hemisphere was not observed. When the cerebellum was stimulated, the cortical activity propagated from the stimulated point to the frontal area and the contralateral hemisphere at around 20 ms after stimulation. These results suggest that the motor area has a strong interhemispheric connection and the posterior parietal cortex has no interhemispheric connection.

  5. Premotor cortex modulates somatosensory cortex during voluntary movements without proprioceptive feedback

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Lundbye-Jensen, Jesper; Geertsen, Svend Sparre;

    2007-01-01

    Movement perception relies on sensory feedback, but the involvement of efference copies remains unclear. We investigated movements without proprioceptive feedback using ischemic nerve block during fMRI in healthy humans, and found preserved activation of the primary somatosensory cortex. This...

  6. Frequency specific modulation of human somatosensory cortex

    Directory of Open Access Journals (Sweden)

    Matteo eFeurra

    2011-02-01

    Full Text Available Oscillatory neuronal activities are commonly observed in response to sensory stimulation. However, their functional roles are still the subject of debate. One way to probe the roles of oscillatory neural activities is to deliver alternating current to the cortex at biologically relevant frequencies and examine whether such stimulation influences perception and cognition. In this study, we tested whether transcranial alternating current stimulation (tACS over the primary somatosensory cortex (SI could elicit tactile sensations in humans in a frequency dependent manner. We tested the effectiveness of tACS over SI at frequency bands ranging from 2 to 70 Hz. Our results show that stimulation in alpha (10-14 Hz and high gamma (52-70 Hz frequency range produces a tactile sensation in the contralateral hand. A weaker effect was also observed for beta (16-20 Hz stimulation. These findings highlight the frequency-dependency of effective tACS over SI with the effective frequencies corresponding to those observed in previous EEG/MEG studies of tactile perception. Our present study suggests that tACS could be used as a powerful online stimulation technique to reveal the causal roles of oscillatory brain activities.

  7. Conceptual size representation in ventral visual cortex.

    Science.gov (United States)

    Gabay, Shai; Kalanthroff, Eyal; Henik, Avishai; Gronau, Nurit

    2016-01-29

    Recent findings suggest that visual objects may be mapped along the ventral occipitotemporal cortex according to their real-world size (Konkle and Oliva, 2012). It has been argued that such mapping does not reflect an abstract, conceptual size representation, but rather the visual or functional properties associated with small versus big real-world objects. To determine whether a more abstract conceptual size representation may affect visual cortical activation we used meaningless geometrical shapes, devoid of semantic or functional associations, which were associated with specific size representations by virtue of extensive training. Following training, participants underwent functional magnetic resonance imaging (fMRI) scanning while performing a conceptual size comparison task on the geometrical shapes. In addition, a size comparison task was conducted for numeral digits denoting small and big numbers. A region-of-interest analysis revealed larger blood oxygenation level dependent (BOLD) responses for conceptually 'big' than for conceptually 'small' shapes, as well as for big versus small numbers, within medial (parahippocampal place area, PPA) and lateral (occipital place area, OPA) place-selective regions. Processing of the 'big' visual shapes further elicited enhanced activation in early visual cortex, possibly reflecting top-down projections from PPA. By using arbitrary shapes and numbers we minimized visual, categorical, or functional influences on fMRI measurement, providing evidence for a possible neural mechanism underlying the representation of abstract conceptual size within the ventral visual stream. PMID:26731198

  8. ABSTRACTS AND KEY WORDS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Determination of the Estrogen Alkylphenols and Bisphenol A in Marine Sediments by Gas Chromatography-Mass Spectrometry Deng Xu-xiu et al. (1) Abstract Octylphenol, nonylphenol and bisphenol A are recognized environmental endocrine disruptors. A quantitative method was established for the simultaneous determination of octylphenol, nonylphenol and bisphenol A in marine sediments by gas chromatography-mass spectrometry. The test sample was extracted by methanol with ultrasonic technique, purified with copper powder and carbon solid phase extraction column, and derived with heptafluorobutyric anhydride. Then the analytes were separated on HP-5ms column and determined by gas chromatography-mass. The recovery of the method was between 84.3% and 94.5%, and the LOQ of 4-N- octylphenol, nonylphenol and bisphenol A was 0.25 g/kg, 0.15 g/kg and 0.15 g/kg. Key words octylphenol; nonylphenol; bisphenol A; gas chromatography-mass spectrometry

  9. Key figures. Year 2005

    International Nuclear Information System (INIS)

    This document summarizes in a series of tables the key data of the petroleum industry and of the other energies for the year 2005. Data of the two previous years are given for comparison: 1 - petroleum, France: exploration, reserves, production, transports (tankers, pipelines, crude and refined products), storage capacities, status of resources and uses, foreign trade (imports, prices, exports), refining (capacities, facilities), evolution of supplies, automotive fuels consumption; 2 - energies, France: production, consumption and trade data for coal, natural gas, electricity; total production and consumption of primary energy; consumption per sector of use; 3 - petroleum, world: crude production and reserves per geographical area, OPEC production, imports/exports and refining/consumption per geographical area, international quotation for crudes and refined products; 4 - energies, world: reserves, production and consumption data for coal, natural gas and electricity; uranium production and resources; total primary energy production and consumption per energy source and geographical area. (J.S.)

  10. Key figures. Year 2006

    International Nuclear Information System (INIS)

    This document summarizes in a series of tables the key data of the petroleum industry and of the other energies for the year 2006. Data of the two previous years are given for comparison: 1 - petroleum, France: exploration, reserves, production, transports (tankers, pipelines, crude and refined products), storage capacities, status of resources and uses, foreign trade (imports, prices, exports), refining (capacities, facilities), evolution of supplies, automotive fuels consumption; 2 - energies, France: production, consumption and trade data for coal, natural gas, electricity; total production and consumption of primary energy; consumption per sector of use; 3 - petroleum, world: crude production and reserves per geographical area, OPEC production, imports/exports and refining/consumption per geographical area, international quotation for crudes and refined products; 4 - energies, world: reserves, production and consumption data for coal, natural gas and electricity; uranium production and resources; total primary energy production and consumption per energy source and geographical area. (J.S.)

  11. ABSTRACTS AND KEY WORDS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Comparative Study on Adhesion Effect Among Different Materials of Sepia esculenta Wang Xue-mei et al. (1) Abstract PE Harness, mesh, sea cucumber seedling box attached, sorghum bar, tamarix (fresh, and old), artemisia annua (fresh, and old) and artificial egg-based subsidiary were used as spawning substrates of Sepia esculenta for comparative study on adhesion effect during artificial breeding. The results showed that the best was artificial egg-based subsidiary produced by the process of invention in this study. The second was old artemisia annua and tamarix. PE Harness, mesh, sea cucumber seedling box attached, sorghum bar were unsatisfactory for using as spawning substrates of Sepia esculenta. Key words Sepia esculenta; adhesion effect; different materials

  12. Effects of the Bee Venom Herbal Acupuncture on the Neurotransmitters of the Rat Brain Cortex

    Directory of Open Access Journals (Sweden)

    Hyoung-Seok Yun

    2001-02-01

    Full Text Available In order to study the effects of bee venom Herbal Acupuncture on neurotransmitters in the rat brain cortex, herbal acupuncture with bee venom group and normal saline group was performed at LI4 bilaterally of the rat. the average optical density of neurotransmitters from the cerebral cortex was analysed 30 minutes after the herbal aqupuncture, by the immunohistochemistry. The results were as follows: 1. The density of NADPH-diaphorase in bee venom group was increased significantly at the motor cortex, visual cortex, auditory cortex, cingulate cortex, retrosplenial cortex and perirhinal cortex compared to the normal saline group. 2. The average optical density of vasoactive intestinal peptide in bee venom group had significant changes at the insular cortex, retrosplenial cortex and perirhinal cortex, compared to the normal saline group. 3. The average optical density of neuropeptide-Y in bee venom group increased significantly at the visual cortex and cingulate cortex, compared to the normal saline group.

  13. Creating Concepts from Converging Features in Human Cortex.

    Science.gov (United States)

    Coutanche, Marc N; Thompson-Schill, Sharon L

    2015-09-01

    To make sense of the world around us, our brain must remember the overlapping features of millions of objects. Crucially, it must also represent each object's unique feature-convergence. Some theories propose that an integration area (or "convergence zone") binds together separate features. We report an investigation of our knowledge of objects' features and identity, and the link between them. We used functional magnetic resonance imaging to record neural activity, as humans attempted to detect a cued fruit or vegetable in visual noise. Crucially, we analyzed brain activity before a fruit or vegetable was present, allowing us to interrogate top-down activity. We found that pattern-classification algorithms could be used to decode the detection target's identity in the left anterior temporal lobe (ATL), its shape in lateral occipital cortex, and its color in right V4. A novel decoding-dependency analysis revealed that identity information in left ATL was specifically predicted by the temporal convergence of shape and color codes in early visual regions. People with stronger feature-and-identity dependencies had more similar top-down and bottom-up activity patterns. These results fulfill three key requirements for a neural convergence zone: a convergence result (object identity), ingredients (color and shape), and the link between them. PMID:24692512

  14. Key data. Energy

    International Nuclear Information System (INIS)

    Energy actors and economical energy context are changing: the world extension and the opening of markets calls for reliable and convenient indicators to understand the energy choices and stakes of France with respect to European and world data. The examination of this 2001 issue of the key energy data will help the reader in his understanding of the French energy policy which is mainly based on: the imperative security of energy supplies, the limitation of CO2 emissions and the respect of the environment, the growth of economic competitiveness, the keeping of public utilities, and the employment. The energy data are presented in tables, graphs, curves and charts. The production, consumption, and foreign market data of France and of the rest of the world are presented successively for: the overall energy sources, petroleum, natural gas, coal and electricity. Renewable energy data are presented for Europe and France (consumption, production, wind energy, solar energy, heat distribution networks, bio-fuels, biogas, biomass). A chapter concerns the rational use of energy in the industry, in transports and in the residential and tertiary sectors. The emissions of pollutants (CH4, CO, CO2, VOCs, N2O, NOx, SO2) are given for France and compared to the worldwide CO2 emissions. (J.S.)

  15. Anodic or cathodic motor cortex stimulation for pain?

    NARCIS (Netherlands)

    Holsheimer, J.; Manola, L.

    2006-01-01

    Objective. In motor cortex stimulation (MCS) for central and trigeminal pain Resume leads are placed epidurally over the motor and sensory cortex. Several bipolar combinations are used to identify the cortical target corresponding to the painful body segment. The cathode giving the largest motor r

  16. Ventromedial prefrontal cortex mediates visual attention during facial emotion recognition

    OpenAIRE

    Wolf, Richard C.; Philippi, Carissa L.; Motzkin, Julian C.; Baskaya, Mustafa K.; Koenigs, Michael

    2014-01-01

    The ventromedial prefrontal cortex plays a crucial role in regulating emotion and social behavior, yet the precise mechanisms underlying this function remain unclear. Using eye-tracking in patients with brain lesions, Wolf et al. show that ventromedial prefrontal cortex is critical for directing visual attention during facial emotion recognition.

  17. Olfactocentric Paralimbic Cortex Morphology in Adolescents with Bipolar Disorder

    Science.gov (United States)

    Wang, Fei; Kalmar, Jessica H.; Womer, Fay Y.; Edmiston, Erin E.; Chepenik, Lara G.; Chen, Rachel; Spencer, Linda; Blumberg, Hilary P.

    2011-01-01

    The olfactocentric paralimbic cortex plays a critical role in the regulation of emotional and neurovegetative functions that are disrupted in core features of bipolar disorder. Adolescence is thought to be a critical period in both the maturation of the olfactocentric paralimbic cortex and in the emergence of bipolar disorder pathology. Together,…

  18. An approach to visual cortex operation: optical neuron model

    OpenAIRE

    Martín Pereda, José Antonio; González Marcos, Ana

    1994-01-01

    Several works have been published in the last years concerning the modelling and implementation of the visual cortex operation. Most of them present simple neurons with just two different responses, namely inhibitory and excitatory. Some of the different types of visual cortex cells are simulated in these configurations.

  19. Metaphorically Feeling: Comprehending Textural Metaphors Activates Somatosensory Cortex

    Science.gov (United States)

    Lacey, Simon; Stilla, Randall; Sathian, K.

    2012-01-01

    Conceptual metaphor theory suggests that knowledge is structured around metaphorical mappings derived from physical experience. Segregated processing of object properties in sensory cortex allows testing of the hypothesis that metaphor processing recruits activity in domain-specific sensory cortex. Using functional magnetic resonance imaging…

  20. Anodal transcranial direct current stimulation reduces psychophysically measured surround suppression in the human visual cortex.

    Directory of Open Access Journals (Sweden)

    Daniel P Spiegel

    Full Text Available Transcranial direct current stimulation (tDCS is a safe, non-invasive technique for transiently modulating the balance of excitation and inhibition within the human brain. It has been reported that anodal tDCS can reduce both GABA mediated inhibition and GABA concentration within the human motor cortex. As GABA mediated inhibition is thought to be a key modulator of plasticity within the adult brain, these findings have broad implications for the future use of tDCS. It is important, therefore, to establish whether tDCS can exert similar effects within non-motor brain areas. The aim of this study was to assess whether anodal tDCS could reduce inhibitory interactions within the human visual cortex. Psychophysical measures of surround suppression were used as an index of inhibition within V1. Overlay suppression, which is thought to originate within the lateral geniculate nucleus (LGN, was also measured as a control. Anodal stimulation of the occipital poles significantly reduced psychophysical surround suppression, but had no effect on overlay suppression. This effect was specific to anodal stimulation as cathodal stimulation had no effect on either measure. These psychophysical results provide the first evidence for tDCS-induced reductions of intracortical inhibition within the human visual cortex.

  1. RTTN Mutations Link Primary Cilia Function to Organization of the Human Cerebral Cortex

    Science.gov (United States)

    Kheradmand Kia, Sima; Verbeek, Elly; Engelen, Erik; Schot, Rachel; Poot, Raymond A.; de Coo, Irenaeus F.M.; Lequin, Maarten H.; Poulton, Cathryn J.; Pourfarzad, Farzin; Grosveld, Frank G.; Brehm, António; de Wit, Marie Claire Y.; Oegema, Renske; Dobyns, William B.; Verheijen, Frans W.; Mancini, Grazia M.S.

    2012-01-01

    Polymicrogyria is a malformation of the developing cerebral cortex caused by abnormal organization and characterized by many small gyri and fusion of the outer molecular layer. We have identified autosomal-recessive mutations in RTTN, encoding Rotatin, in individuals with bilateral diffuse polymicrogyria from two separate families. Rotatin determines early embryonic axial rotation, as well as anteroposterior and dorsoventral patterning in the mouse. Human Rotatin has recently been identified as a centrosome-associated protein. The Drosophila melanogaster homolog of Rotatin, Ana3, is needed for structural integrity of centrioles and basal bodies and maintenance of sensory neurons. We show that Rotatin colocalizes with the basal bodies at the primary cilium. Cultured fibroblasts from affected individuals have structural abnormalities of the cilia and exhibit downregulation of BMP4, WNT5A, and WNT2B, which are key regulators of cortical patterning and are expressed at the cortical hem, the cortex-organizing center that gives rise to Cajal-Retzius (CR) neurons. Interestingly, we have shown that in mouse embryos, Rotatin colocalizes with CR neurons at the subpial marginal zone. Knockdown experiments in human fibroblasts and neural stem cells confirm a role for RTTN in cilia structure and function. RTTN mutations therefore link aberrant ciliary function to abnormal development and organization of the cortex in human individuals. PMID:22939636

  2. Mindful attention to breath regulates emotions via increased amygdala-prefrontal cortex connectivity.

    Science.gov (United States)

    Doll, Anselm; Hölzel, Britta K; Mulej Bratec, Satja; Boucard, Christine C; Xie, Xiyao; Wohlschläger, Afra M; Sorg, Christian

    2016-07-01

    Mindfulness practice is beneficial for emotion regulation; however, the neural mechanisms underlying this effect are poorly understood. The current study focuses on effects of attention-to-breath (ATB) as a basic mindfulness practice on aversive emotions at behavioral and brain levels. A key finding across different emotion regulation strategies is the modulation of amygdala and prefrontal activity. It is unclear how ATB relevant brain areas in the prefrontal cortex integrate with amygdala activation during emotional stimulation. We proposed that, during emotional stimulation, ATB down-regulates activation in the amygdala and increases its integration with prefrontal regions. To address this hypothesis, 26 healthy controls were trained in mindfulness-based attention-to-breath meditation for two weeks and then stimulated with aversive pictures during both attention-to-breath and passive viewing while undergoing fMRI. Data were controlled for breathing frequency. Results indicate that (1) ATB was effective in regulating aversive emotions. (2) Left dorso-medial prefrontal cortex was associated with ATB in general. (3) A fronto-parietal network was additionally recruited during emotional stimulation. (4) ATB down regulated amygdala activation and increased amygdala-prefrontal integration, with such increased integration being associated with mindfulness ability. Results suggest amygdala-dorsal prefrontal cortex integration as a potential neural pathway of emotion regulation by mindfulness practice. PMID:27033686

  3. Reduced frontal cortex thickness and cortical volume associated with pathological narcissism.

    Science.gov (United States)

    Mao, Yu; Sang, Na; Wang, Yongchao; Hou, Xin; Huang, Hui; Wei, Dongtao; Zhang, Jinfu; Qiu, Jiang

    2016-07-22

    Pathological narcissism is often characterized by arrogant behavior, a lack of empathy, and willingness to exploit other individuals. Generally, individuals with high levels of narcissism are more likely to suffer mental disorders. However, the brain structural basis of individual pathological narcissism trait among healthy people has not yet been investigated with surface-based morphometry. Thus, in this study, we investigated the relationship between cortical thickness (CT), cortical volume (CV), and individual pathological narcissism in a large healthy sample of 176 college students. Multiple regression was used to analyze the correlation between regional CT, CV, and the total Pathological Narcissism Inventory (PNI) score, adjusting for age, sex, and total intracranial volume. The results showed that the PNI score was significantly negatively associated with CT and CV in the right dorsolateral prefrontal cortex (DLPFC, key region of the central executive network, CEN), which might be associated with impaired emotion regulation processes. Furthermore, the PNI score showed significant negative associations with CV in the right postcentral gyrus, left medial prefrontal cortex (MPFC), and the CT in the right inferior frontal cortex (IFG, overlap with social brain network), which may be related to impairments in social cognition. Together, these findings suggest a unique structural basis for individual differences in pathological narcissism, distributed across different gray matter regions of the social brain network and CEN. PMID:27129440

  4. The gene cortex controls mimicry and crypsis in butterflies and moths.

    Science.gov (United States)

    Nadeau, Nicola J; Pardo-Diaz, Carolina; Whibley, Annabel; Supple, Megan A; Saenko, Suzanne V; Wallbank, Richard W R; Wu, Grace C; Maroja, Luana; Ferguson, Laura; Hanly, Joseph J; Hines, Heather; Salazar, Camilo; Merrill, Richard M; Dowling, Andrea J; ffrench-Constant, Richard H; Llaurens, Violaine; Joron, Mathieu; McMillan, W Owen; Jiggins, Chris D

    2016-06-01

    The wing patterns of butterflies and moths (Lepidoptera) are diverse and striking examples of evolutionary diversification by natural selection. Lepidopteran wing colour patterns are a key innovation, consisting of arrays of coloured scales. We still lack a general understanding of how these patterns are controlled and whether this control shows any commonality across the 160,000 moth and 17,000 butterfly species. Here, we use fine-scale mapping with population genomics and gene expression analyses to identify a gene, cortex, that regulates pattern switches in multiple species across the mimetic radiation in Heliconius butterflies. cortex belongs to a fast-evolving subfamily of the otherwise highly conserved fizzy family of cell-cycle regulators, suggesting that it probably regulates pigmentation patterning by regulating scale cell development. In parallel with findings in the peppered moth (Biston betularia), our results suggest that this mechanism is common within Lepidoptera and that cortex has become a major target for natural selection acting on colour and pattern variation in this group of insects. PMID:27251285

  5. Patterning the cerebral cortex: traveling with morphogens.

    Science.gov (United States)

    Borello, Ugo; Pierani, Alessandra

    2010-08-01

    The neocortex represents the brain structure that has been subjected to a major expansion in its relative size during the course of mammalian evolution. An exquisite coordination of appropriate growth of competent territories along multiple axes and their spatial patterning is required for regionalization of the cortical primordium and the formation of functional areas. The achievement of such a highly complex architecture relies on a precise orchestration of the proliferation of progenitors, onset of neurogenesis, spatio-temporal generation of distinct cell types and control of their migration. We will review recent work on alternative molecular mechanisms that, via the migration of signaling cells/structures, participate in coordinating growth and spatial patterning in the developing cerebral cortex. By integrating temporal and spatial parameters as well as absolute levels of signaling this novel strategy might represent a general mechanism for long-range patterning in large structures, in addition to the passive diffusion of morphogens. PMID:20542680

  6. Spindle Bursts in Neonatal Rat Cerebral Cortex.

    Science.gov (United States)

    Yang, Jenq-Wei; Reyes-Puerta, Vicente; Kilb, Werner; Luhmann, Heiko J

    2016-01-01

    Spontaneous and sensory evoked spindle bursts represent a functional hallmark of the developing cerebral cortex in vitro and in vivo. They have been observed in various neocortical areas of numerous species, including newborn rodents and preterm human infants. Spindle bursts are generated in complex neocortical-subcortical circuits involving in many cases the participation of motor brain regions. Together with early gamma oscillations, spindle bursts synchronize the activity of a local neuronal network organized in a cortical column. Disturbances in spindle burst activity during corticogenesis may contribute to disorders in cortical architecture and in the activity-dependent control of programmed cell death. In this review we discuss (i) the functional properties of spindle bursts, (ii) the mechanisms underlying their generation, (iii) the synchronous patterns and cortical networks associated with spindle bursts, and (iv) the physiological and pathophysiological role of spindle bursts during early cortical development. PMID:27034844

  7. Early GABAergic circuitry in the cerebral cortex.

    Science.gov (United States)

    Luhmann, Heiko J; Kirischuk, Sergei; Sinning, Anne; Kilb, Werner

    2014-06-01

    In the cerebral cortex GABAergic signaling plays an important role in regulating early developmental processes, for example, neurogenesis, migration and differentiation. Transient cell populations, namely Cajal-Retzius in the marginal zone and thalamic input receiving subplate neurons, are integrated as active elements in transitory GABAergic circuits. Although immature pyramidal neurons receive GABAergic synaptic inputs already at fetal stages, they are integrated into functional GABAergic circuits only several days later. In consequence, GABAergic synaptic transmission has only a minor influence on spontaneous network activity during early corticogenesis. Concurrent with the gradual developmental shift of GABA action from excitatory to inhibitory and the maturation of cortical synaptic connections, GABA becomes more important in synchronizing neuronal network activity. PMID:24434608

  8. Anodal Transcranial Direct Current Stimulation Reduces Psychophysically Measured Surround Suppression in the Human Visual Cortex

    OpenAIRE

    Daniel P. Spiegel; Hansen, Bruce C.; Byblow, Winston D.; Benjamin Thompson

    2012-01-01

    Transcranial direct current stimulation (tDCS) is a safe, non-invasive technique for transiently modulating the balance of excitation and inhibition within the human brain. It has been reported that anodal tDCS can reduce both GABA mediated inhibition and GABA concentration within the human motor cortex. As GABA mediated inhibition is thought to be a key modulator of plasticity within the adult brain, these findings have broad implications for the future use of tDCS. It is important, therefor...

  9. A threshold key escrow scheme based on public key cryptosystem

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In key escrow field it is important to solve the problem thatuser's secret key completely depends on the trusted escrow agency. In 1995, some methods of solving the problem were presented. But these methods are no better than that of directly using threshold cryptography. In this paper, we present a common pattern of threshold key escrow scheme based on public key cryptosystem, and a detailed design based on the improved RSA algorithm is given. The above problem is solved by this scheme.

  10. Representation of Maximally Regular Textures in Human Visual Cortex.

    Science.gov (United States)

    Kohler, Peter J; Clarke, Alasdair; Yakovleva, Alexandra; Liu, Yanxi; Norcia, Anthony M

    2016-01-20

    Naturalistic textures with an intermediate degree of statistical regularity can capture key structural features of natural images (Freeman and Simoncelli, 2011). V2 and later visual areas are sensitive to these features, while primary visual cortex is not (Freeman et al., 2013). Here we expand on this work by investigating a class of textures that have maximal formal regularity, the 17 crystallographic wallpaper groups (Fedorov, 1891). We used texture stimuli from four of the groups that differ in the maximum order of rotation symmetry they contain, and measured neural responses in human participants using functional MRI and high-density EEG. We found that cortical area V3 has a parametric representation of the rotation symmetries in the textures that is not present in either V1 or V2, the first discovery of a stimulus property that differentiates processing in V3 from that of lower-level areas. Parametric responses were also seen in higher-order ventral stream areas V4, VO1, and lateral occipital complex (LOC), but not in dorsal stream areas. The parametric response pattern was replicated in the EEG data, and source localization indicated that responses in V3 and V4 lead responses in LOC, which is consistent with a feedforward mechanism. Finally, we presented our stimuli to four well developed feedforward models and found that none of them were able to account for our results. Our results highlight structural regularity as an important stimulus dimension for distinguishing the early stages of visual processing, and suggest a previously unrecognized role for V3 in the visual form-processing hierarchy. Significance statement: Hierarchical processing is a fundamental organizing principle in visual neuroscience, with each successive processing stage being sensitive to increasingly complex stimulus properties. Here, we probe the encoding hierarchy in human visual cortex using a class of visual textures--wallpaper patterns--that are maximally regular. Through a

  11. Double Cortex Syndrome (Subcortical Band Heterotopia: A Case Report

    Directory of Open Access Journals (Sweden)

    Ali Akbar MOMEN

    2015-06-01

    Full Text Available AbstractObjectiveApproximately 5–10% of preschool age children are considered developmentally disabled. Brain Magnetic Resonance Imaging (MRI plays a key role in the diagnostic evaluation in these children. Many congenital or acquired brain anomalies are revealed with MRIs. Although the majority of these abnormalities are sporadic but patients with subcortical band heterotopia or double cortex syndrome have sex-linked inheritance. We are going to present the first case in Iran from Ahvaz city, which was presented with status epilepticus associated with developmental delay and finally diagnosed as double cortex syndrome, because band heterotopia cases especially for continuous or generalized form is rare.A 4.5-year-old developmentally delayed girl was admitted for generalized tonic clonic seizure attack of 1 hr, upward gaze, locked mouth, and urinary incontinence (status epilepticus in the child neurology ward. She had a history of recurrent seizures that started as febrile seizures since she was 12 months of age and had frequent admissions for having recurrent seizure attacks. She was the only child of consanguineous parents with negative family history of any neurologic problems. She was a product of uneventful term pregnancy, vaginal delivery with a low Apgar score at birth who was admitted for six days in the neonatal ward for hypotonia and cyanosis. At 4.5 years of age, she had HC: 45cm (<3% Length: 102 cm (25–75%, and BW: 18kg (75%.She was able to sit, walk with support, speak a few words, and communicate with others. A physical exam was unremarkable. Lab data including CBC, blood biochemical, and urinalysis results were all within normal limits, but the electroencephalography (EEG revealed generalized poly spike-wave discharges. A brain MRI showed corpus callosal dysplasia, generalized band heterotopia, and polymicrogyria. She was discharged home with oral valproate and regular outpatient follow-ups.In the diagnostic evaluation of

  12. Determining Physical Properties of the Cell Cortex.

    Science.gov (United States)

    Saha, Arnab; Nishikawa, Masatoshi; Behrndt, Martin; Heisenberg, Carl-Philipp; Jülicher, Frank; Grill, Stephan W

    2016-03-29

    Actin and myosin assemble into a thin layer of a highly dynamic network underneath the membrane of eukaryotic cells. This network generates the forces that drive cell- and tissue-scale morphogenetic processes. The effective material properties of this active network determine large-scale deformations and other morphogenetic events. For example, the characteristic time of stress relaxation (the Maxwell time τM) in the actomyosin sets the timescale of large-scale deformation of the cortex. Similarly, the characteristic length of stress propagation (the hydrodynamic length λ) sets the length scale of slow deformations, and a large hydrodynamic length is a prerequisite for long-ranged cortical flows. Here we introduce a method to determine physical parameters of the actomyosin cortical layer in vivo directly from laser ablation experiments. For this we investigate the cortical response to laser ablation in the one-cell-stage Caenorhabditis elegans embryo and in the gastrulating zebrafish embryo. These responses can be interpreted using a coarse-grained physical description of the cortex in terms of a two-dimensional thin film of an active viscoelastic gel. To determine the Maxwell time τM, the hydrodynamic length λ, the ratio of active stress ζΔμ, and per-area friction γ, we evaluated the response to laser ablation in two different ways: by quantifying flow and density fields as a function of space and time, and by determining the time evolution of the shape of the ablated region. Importantly, both methods provide best-fit physical parameters that are in close agreement with each other and that are similar to previous estimates in the two systems. Our method provides an accurate and robust means for measuring physical parameters of the actomyosin cortical layer. It can be useful for investigations of actomyosin mechanics at the cellular-scale, but also for providing insights into the active mechanics processes that govern tissue-scale morphogenesis. PMID

  13. Preferential Encoding of Visual Categories in Parietal Cortex Compared to Prefrontal Cortex

    OpenAIRE

    Swaminathan, Sruthi K.; Freedman, David J

    2012-01-01

    The ability to recognize the behavioral significance, or category membership, of sensory stimuli is critical for interpreting the meaning of events in our environment. Prior neurophysiological studies of visual categorization found categorical representations of stimuli in prefrontal cortex (PFC), an area closely associated with cognitive and executive functions. Recent studies have also identified neuronal category signals in parietal areas typically associated with visual-spatial processing...

  14. Increased Amygdala and Visual Cortex Activity and Functional Connectivity towards Stimulus Novelty Is Associated with State Anxiety

    OpenAIRE

    Ousdal, Olga T; Andreassen, Ole A; Server, Andres; Jensen, Jimmy

    2014-01-01

    Novel stimuli often require a rapid reallocation of sensory processing resources to determine the significance of the event, and the appropriate behavioral response. Both the amygdala and the visual cortex are central elements of the neural circuitry responding to novelty, demonstrating increased activity to new as compared to highly familiarized stimuli. Further, these brain areas are intimately connected, and thus the amygdala may be a key region for directing sensory processing resources t...

  15. Increased amygdala and visual cortex activity and functional connectivity towards stimulus novelty is associated with state anxiety

    OpenAIRE

    2014-01-01

    Novel stimuli often require a rapid reallocation of sensory processing resources to determine the significance of the event, and the appropriate behavioral response. Both the amygdala and the visual cortex are central elements of the neural circuitry responding to novelty, demonstrating increased activity to new as compared to highly familiarized stimuli. Further, these brain areas are intimately connected, and thus the amygdala may be a key region for directing sensory processing resources t...

  16. Anatomical and functional overlap within the insula and anterior cingulate cortex during interoception and phobic symptom provocation

    OpenAIRE

    Caseras, Xavier; Murphy, Kevin; Mataix-Cols, David; López-Sola, Marina; Soriano-Mas, Carles; Ortiz Valencia, Héctor; Pujol, Jesus; Torrubia, Rafael

    2011-01-01

    The anterior insula and the dorsal anterior cingulate cortex (ACC) are regarded as key brain structures associated with the integration of perceived phobic characteristics of external stimuli and the perception of ones own body responses that leads to emotional feelings. To test to what extent the activity in these two brain structures anatomically and functionally overlap during phobic reactions and interoception, we submitted the same group of phobic participants (n = 29; either spider or b...

  17. Characterization of the Fiber Connectivity Profile of the Cerebral Cortex in Schizotypal Personality Disorder: A Pilot Study.

    Science.gov (United States)

    Liu, Kai; Zhang, Teng; Zhang, Qing; Sun, Yueji; Wu, Jianlin; Lei, Yi; Chu, Winnie C W; Mok, Vincent C T; Wang, Defeng; Shi, Lin

    2016-01-01

    Schizotypal personality disorder (SPD) is considered one of the classic disconnection syndromes. However, the specific cortical disconnectivity pattern has not been fully investigated. In this study, we aimed to explore significant alterations in whole-cortex structural connectivity in SPD individuals (SPDs) by combining the techniques of brain surface morphometry and white matter tractography. Diffusion and structural MR data were collected from 20 subjects with SPD (all males; age, 19.7 ± 0.9 years) and 18 healthy controls (all males; age, 20.3 ± 1.0 years). To measure the structural connectivity for a given unit area of the cortex, the fiber connectivity density (FiCD) value was proposed and calculated as the sum of the fractional anisotropy of all the fibers connecting to that unit area in tractography. Then, the resultant whole-cortex FiCD maps were compared in a vertex-wise manner between SPDs and controls. Compared with normal controls, SPDs showed significantly decreased FiCD in the rostral middle frontal gyrus (crossing BA 9 and BA 10) and significantly increased FiCD in the anterior part of the fusiform/inferior temporal cortex (P < 0.05, Monte Carlo simulation corrected). Moreover, the gray matter volume extracted from the left rostral middle frontal cluster was observed to be significantly greater in the SPD group (P = 0.02). Overall, this study identifies a decrease in connectivity in the left middle frontal cortex as a key neural deficit at the whole-cortex level in SPD, thus providing insight into its neuropathological basis. PMID:27303358

  18. Characterization of the fiber connectivity profile of the cerebral cortex in schizotypal personality disorder: A pilot study

    Directory of Open Access Journals (Sweden)

    Kai eLiu

    2016-05-01

    Full Text Available Schizotypal personality disorder (SPD is considered one of the classic disconnection syndromes. However, the specific cortical disconnectivity pattern has not been fully investigated. In this study, we aimed to explore significant alterations in whole-cortex structural connectivity in SPD individuals (SPDs by combining the techniques of brain surface morphometry and white matter (WM tractography. Diffusion and structural MR data were collected from twenty subjects with SPD (all males; age, 19.7 ± 0.9 yrs and eighteen healthy controls (all males; age, 20.3 ± 1.0 yrs. To measure the structural connectivity for a given unit area of the cortex, the fiber connectivity density (FiCD value was proposed and calculated as the sum of the fractional anisotropy of all the fibers connecting to that unit area in tractography. Then, the resultant whole-cortex FiCD maps were compared in a vertex-wise manner between SPDs and controls. Compared with normal controls, SPDs showed significantly decreased FiCD in the rostral middle frontal gyrus (crossing BA9 and BA10 and significantly increased FiCD in the anterior part of the fusiform/inferior temporal cortex (P < 0.05, Monte Carlo simulation corrected. Moreover, the gray matter volume extracted from the left rostral middle frontal cluster was observed to be significantly greater in the SPD group (P = 0.02. Overall, this study identifies a decrease in connectivity in the left middle frontal cortex as a key neural deficit at the whole-cortex level in SPD, thus providing insight into its neuropathological basis.

  19. Characterization of the Fiber Connectivity Profile of the Cerebral Cortex in Schizotypal Personality Disorder: A Pilot Study

    Science.gov (United States)

    Liu, Kai; Zhang, Teng; Zhang, Qing; Sun, Yueji; Wu, Jianlin; Lei, Yi; Chu, Winnie C. W.; Mok, Vincent C. T.; Wang, Defeng; Shi, Lin

    2016-01-01

    Schizotypal personality disorder (SPD) is considered one of the classic disconnection syndromes. However, the specific cortical disconnectivity pattern has not been fully investigated. In this study, we aimed to explore significant alterations in whole-cortex structural connectivity in SPD individuals (SPDs) by combining the techniques of brain surface morphometry and white matter tractography. Diffusion and structural MR data were collected from 20 subjects with SPD (all males; age, 19.7 ± 0.9 years) and 18 healthy controls (all males; age, 20.3 ± 1.0 years). To measure the structural connectivity for a given unit area of the cortex, the fiber connectivity density (FiCD) value was proposed and calculated as the sum of the fractional anisotropy of all the fibers connecting to that unit area in tractography. Then, the resultant whole-cortex FiCD maps were compared in a vertex-wise manner between SPDs and controls. Compared with normal controls, SPDs showed significantly decreased FiCD in the rostral middle frontal gyrus (crossing BA 9 and BA 10) and significantly increased FiCD in the anterior part of the fusiform/inferior temporal cortex (P < 0.05, Monte Carlo simulation corrected). Moreover, the gray matter volume extracted from the left rostral middle frontal cluster was observed to be significantly greater in the SPD group (P = 0.02). Overall, this study identifies a decrease in connectivity in the left middle frontal cortex as a key neural deficit at the whole-cortex level in SPD, thus providing insight into its neuropathological basis. PMID:27303358

  20. Altered SPECT 123I iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

    Directory of Open Access Journals (Sweden)

    Shinichiro eNagamitsu

    2016-02-01

    Full Text Available Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN in children. The purpose of this study was to examine cortical GABA(A-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single photon emission computed tomography (SPECT measurements using 123I iomazenil, which binds to GABA(A-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26 and the short form of the Profile of Mood States (POMS. Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil binding activity in cortical regions of interest (ROIs and psychometric profiles, and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil binding activity in the anterior posterior cingulate cortex (ACC. Higher POMS subscale scores were significantly associated with lower iomazenil binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC. Depression-Dejection, and Confusion POMS subscale scores, and total POMS score, showed interaction effects with brain regions in iomazenil binding activity. Decreased binding in the ACC and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered in children

  1. Key Concepts in Informatics: Algorithm

    Science.gov (United States)

    Szlávi, Péter; Zsakó, László

    2014-01-01

    "The system of key concepts contains the most important key concepts related to the development tasks of knowledge areas and their vertical hierarchy as well as the links of basic key concepts of different knowledge areas." (Vass 2011) One of the most important of these concepts is the algorithm. In everyday life, when learning or…

  2. Forelimb training drives transient map reorganization in ipsilateral motor cortex.

    Science.gov (United States)

    Pruitt, David T; Schmid, Ariel N; Danaphongse, Tanya T; Flanagan, Kate E; Morrison, Robert A; Kilgard, Michael P; Rennaker, Robert L; Hays, Seth A

    2016-10-15

    Skilled motor training results in reorganization of contralateral motor cortex movement representations. The ipsilateral motor cortex is believed to play a role in skilled motor control, but little is known about how training influences reorganization of ipsilateral motor representations of the trained limb. To determine whether training results in reorganization of ipsilateral motor cortex maps, rats were trained to perform the isometric pull task, an automated motor task that requires skilled forelimb use. After either 3 or 6 months of training, intracortical microstimulation (ICMS) mapping was performed to document motor representations of the trained forelimb in the hemisphere ipsilateral to that limb. Motor training for 3 months resulted in a robust expansion of right forelimb representation in the right motor cortex, demonstrating that skilled motor training drives map plasticity ipsilateral to the trained limb. After 6 months of training, the right forelimb representation in the right motor cortex was significantly smaller than the representation observed in rats trained for 3 months and similar to untrained controls, consistent with a normalization of motor cortex maps. Forelimb map area was not correlated with performance on the trained task, suggesting that task performance is maintained despite normalization of cortical maps. This study provides new insights into how the ipsilateral cortex changes in response to skilled learning and may inform rehabilitative strategies to enhance cortical plasticity to support recovery after brain injury. PMID:27392641

  3. On Compression of Cryptographic Keys

    CERN Document Server

    Chan, Aldar C-F

    2007-01-01

    Any secured system can be modeled as a capability-based access control system in which each user is given a set of secret keys of the resources he is granted access to. In some large systems with resource-constrained devices, such as sensor networks and RFID systems, the design is sensitive to memory or key storage cost. With a goal to minimize the maximum users' key storage, key compression based on key linking, that is, deriving one key from another without compromising security, is studied. A lower bound on key storage needed for a general access structure with key derivation is derived. This bound demonstrates the theoretic limit of any systems which do not trade off security and can be treated as a negative result to provide ground for designs with security tradeoff. A concrete, provably secure key linking scheme based on pseudorandom functions is given. Using the key linking framework, a number of key pre-distribution schemes in the literature are analyzed.

  4. Secure key storage and distribution

    Science.gov (United States)

    Agrawal, Punit

    2015-06-02

    This disclosure describes a distributed, fault-tolerant security system that enables the secure storage and distribution of private keys. In one implementation, the security system includes a plurality of computing resources that independently store private keys provided by publishers and encrypted using a single security system public key. To protect against malicious activity, the security system private key necessary to decrypt the publication private keys is not stored at any of the computing resources. Rather portions, or shares of the security system private key are stored at each of the computing resources within the security system and multiple security systems must communicate and share partial decryptions in order to decrypt the stored private key.

  5. Limitations on quantum key repeaters.

    Science.gov (United States)

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-01-01

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol. PMID:25903096

  6. Local production of astrocytes in the cerebral cortex.

    Science.gov (United States)

    Ge, W-P; Jia, J-M

    2016-05-26

    Astrocytes are the largest glial population in the mammalian brain. Astrocytes in the cerebral cortex are reportedly generated from four sources, namely radial glia, progenitors in the subventricular zone (SVZ progenitors), locally proliferating glia, and NG2 glia; it remains an open question, however, as to what extent these four cell types contribute to the substantial increase in astrocytes that occurs postnatally in the cerebral cortex. Here we summarize all possible sources of astrocytes and discuss their roles in this postnatal increase. In particular, we focus on astrocytes derived from local proliferation within the cortex. PMID:26343293

  7. Parietal cortex and representation of the mental Self

    DEFF Research Database (Denmark)

    Lou, Hans C; Luber, Bruce; Crupain, Michael;

    2004-01-01

    Oneself, Best Friend, and the Danish Queen, activation increased in the left lateral temporal cortex and decreased in the right inferior parietal region with decreasing self-reference. Functionally, the former region was preferentially connected to medial prefrontal cortex, the latter to medial parietal....... The medial parietal region may, then, be conceived of as a nodal structure in self-representation, functionally connected to both the right parietal and the medial prefrontal cortices. To determine whether medial parietal cortex in this network is essential for episodic memory retrieval with self...

  8. The prefrontal cortex shows context-specific changes in effective connectivity to motor or visual cortex during the selection of action or colour

    DEFF Research Database (Denmark)

    Rowe, James B.; Stephan, Klaas E.; Friston, Karl;

    2005-01-01

    used functional magnetic imaging (fMRI) to study the free selection of actions and colours. Control conditions used externally specified actions and colours. The prefrontal cortex was activated during free selection, regardless of modality, in contrast to modality-specific activations outside...... prefrontal cortex. Structural equation modelling (SEM) of fMRI data was used to test the hypothesis that although the same regions of prefrontal cortex may be active in tasks within different domains, there is task-dependent effective connectivity between prefrontal cortex and non-prefrontal cortex. The SEM...... included high-order interactions between modality, selection and regional activity. There was greater coupling between prefrontal cortex and motor cortex during free selection and action tasks, and between prefrontal cortex and visual cortex during free selection of colours. The results suggest that the...

  9. Concentric scheme of monkey auditory cortex

    Science.gov (United States)

    Kosaki, Hiroko; Saunders, Richard C.; Mishkin, Mortimer

    2003-04-01

    The cytoarchitecture of the rhesus monkey's auditory cortex was examined using immunocytochemical staining with parvalbumin, calbindin-D28K, and SMI32, as well as staining for cytochrome oxidase (CO). The results suggest that Kaas and Hackett's scheme of the auditory cortices can be extended to include five concentric rings surrounding an inner core. The inner core, containing areas A1 and R, is the most densely stained with parvalbumin and CO and can be separated on the basis of laminar patterns of SMI32 staining into lateral and medial subdivisions. From the inner core to the fifth (outermost) ring, parvalbumin staining gradually decreases and calbindin staining gradually increases. The first ring corresponds to Kaas and Hackett's auditory belt, and the second, to their parabelt. SMI32 staining revealed a clear border between these two. Rings 2 through 5 extend laterally into the dorsal bank of the superior temporal sulcus. The results also suggest that the rostral tip of the outermost ring adjoins the rostroventral part of the insula (area Pro) and the temporal pole, while the caudal tip adjoins the ventral part of area 7a.

  10. Lateralization of auditory-cortex functions.

    Science.gov (United States)

    Tervaniemi, Mari; Hugdahl, Kenneth

    2003-12-01

    In the present review, we summarize the most recent findings and current views about the structural and functional basis of human brain lateralization in the auditory modality. Main emphasis is given to hemodynamic and electromagnetic data of healthy adult participants with regard to music- vs. speech-sound encoding. Moreover, a selective set of behavioral dichotic-listening (DL) results and clinical findings (e.g., schizophrenia, dyslexia) are included. It is shown that human brain has a strong predisposition to process speech sounds in the left and music sounds in the right auditory cortex in the temporal lobe. Up to great extent, an auditory area located at the posterior end of the temporal lobe (called planum temporale [PT]) underlies this functional asymmetry. However, the predisposition is not bound to informational sound content but to rapid temporal information more common in speech than in music sounds. Finally, we obtain evidence for the vulnerability of the functional specialization of sound processing. These altered forms of lateralization may be caused by top-down and bottom-up effects inter- and intraindividually In other words, relatively small changes in acoustic sound features or in their familiarity may modify the degree in which the left vs. right auditory areas contribute to sound encoding. PMID:14629926

  11. Does the orbitofrontal cortex signal value?

    Science.gov (United States)

    Schoenbaum, Geoffrey; Takahashi, Yuji; Liu, Tzu-Lan; McDannald, Michael A

    2011-12-01

    The orbitofrontal cortex (OFC) has long been implicated in associative learning. Early work by Mishkin and Rolls showed that the OFC was critical for rapid changes in learned behavior, a role that was reflected in the encoding of associative information by orbitofrontal neurons. Over the years, new data-particularly neurophysiological data-have increasingly emphasized the OFC in signaling actual value. These signals have been reported to vary according to internal preferences and judgments and to even be completely independent of the sensory qualities of predictive cues, the actual rewards, and the responses required to obtain them. At the same time, increasingly sophisticated behavioral studies have shown that the OFC is often unnecessary for simple value-based behavior and instead seems critical when information about specific outcomes must be used to guide behavior and learning. Here, we review these data and suggest a theory that potentially reconciles these two ideas, value versus specific outcomes, and bodies of work on the OFC. PMID:22145878

  12. Inhibition in the Human Auditory Cortex.

    Directory of Open Access Journals (Sweden)

    Koji Inui

    Full Text Available Despite their indispensable roles in sensory processing, little is known about inhibitory interneurons in humans. Inhibitory postsynaptic potentials cannot be recorded non-invasively, at least in a pure form, in humans. We herein sought to clarify whether prepulse inhibition (PPI in the auditory cortex reflected inhibition via interneurons using magnetoencephalography. An abrupt increase in sound pressure by 10 dB in a continuous sound was used to evoke the test response, and PPI was observed by inserting a weak (5 dB increase for 1 ms prepulse. The time course of the inhibition evaluated by prepulses presented at 10-800 ms before the test stimulus showed at least two temporally distinct inhibitions peaking at approximately 20-60 and 600 ms that presumably reflected IPSPs by fast spiking, parvalbumin-positive cells and somatostatin-positive, Martinotti cells, respectively. In another experiment, we confirmed that the degree of the inhibition depended on the strength of the prepulse, but not on the amplitude of the prepulse-evoked cortical response, indicating that the prepulse-evoked excitatory response and prepulse-evoked inhibition reflected activation in two different pathways. Although many diseases such as schizophrenia may involve deficits in the inhibitory system, we do not have appropriate methods to evaluate them; therefore, the easy and non-invasive method described herein may be clinically useful.

  13. CREB Regulates Experience-Dependent Spine Formation and Enlargement in Mouse Barrel Cortex

    Directory of Open Access Journals (Sweden)

    Annabella Pignataro

    2015-01-01

    Full Text Available Experience modifies synaptic connectivity through processes that involve dendritic spine rearrangements in neuronal circuits. Although cAMP response element binding protein (CREB has a key function in spines changes, its role in activity-dependent rearrangements in brain regions of rodents interacting with the surrounding environment has received little attention so far. Here we studied the effects of vibrissae trimming, a widely used model of sensory deprivation-induced cortical plasticity, on processes associated with dendritic spine rearrangements in the barrel cortex of a transgenic mouse model of CREB downregulation (mCREB mice. We found that sensory deprivation through prolonged whisker trimming leads to an increased number of thin spines in the layer V of related barrel cortex (Contra in wild type but not mCREB mice. In the barrel field controlling spared whiskers (Ipsi, the same trimming protocol results in a CREB-dependent enlargement of dendritic spines. Last, we demonstrated that CREB regulates structural rearrangements of synapses that associate with dynamic changes of dendritic spines. Our findings suggest that CREB plays a key role in dendritic spine dynamics and synaptic circuits rearrangements that account for new brain connectivity in response to changes in the environment.

  14. Effects of decreased inhibition on synaptic plasticity and dendritic morphology in the juvenile prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Xanthippi Konstantoudaki

    2014-03-01

    Full Text Available Excitation-inhibition balance is critical for maintaining proper functioning of the cerebral cortex, as evident from electrophysiological and modeling studies, and it is also important for animal behavior (Yizhar et al., 2011. In the cerebral cortex, excitation is provided by glutamate release from pyramidal neurons, while inhibition is provided by GABA release from several types of interneurons. Many neuropsychiatric disorders, such as epilepsy, anxiety, schizophrenia and autism exhibit an imbalance between the excitatory and inhibitory mechanisms of cortical circuits within key brain regions as prefrontal cortex or hippocampus, primarily through dysfunctions in the inhibitory system (Lewis, Volk, & Hashimoto, 2003; Marín, 2012 Given the significant role of GABAergic inhibition in shaping proper function of the cerebral cortex, we used a mouse model of developmentally decreased GABAergic inhibition in order to examine its effects in network properties, namely basal synaptic transmission, synaptic plasticity and dendritic morphology of pyramidal neurons. For our study, we used mice (postnatal day 20-30 in which the Rac1 protein was deleted from Nkx2.1-expressing neurons (Vidaki et al., 2012, (Rac1fl/flNkx2.1 +/cre referred as Rac1 KO mice, and heterozygous (Rac1+/flNkx2.1 +/cre or control (Rac1+/flNkx2.1 +/+ mice. The specific ablation of Rac1 protein from NKx2.1-expressing MGE-derived progenitors leads to a perturbation of their cell cycle exit resulting in decreased number of interneurons in the cortex(Vidaki et al, 2012. We prepared brain slices from the prefrontal cortex and recorded field excitatory postsynaptic potentials (fEPSPs from layer II neurons while stimulating axons in layer II. We find that the evoked fEPSPs are decreased in Rac1 KO mice compared to Rac1 heterozygous or control mice. This could suggest that the decreased GABAergic inhibition causes network alterations that result in reduced glutamatergic function. Furthermore

  15. Reservoir Computing Properties of Neural Dynamics in Prefrontal Cortex

    Science.gov (United States)

    Procyk, Emmanuel; Dominey, Peter Ford

    2016-01-01

    Primates display a remarkable ability to adapt to novel situations. Determining what is most pertinent in these situations is not always possible based only on the current sensory inputs, and often also depends on recent inputs and behavioral outputs that contribute to internal states. Thus, one can ask how cortical dynamics generate representations of these complex situations. It has been observed that mixed selectivity in cortical neurons contributes to represent diverse situations defined by a combination of the current stimuli, and that mixed selectivity is readily obtained in randomly connected recurrent networks. In this context, these reservoir networks reproduce the highly recurrent nature of local cortical connectivity. Recombining present and past inputs, random recurrent networks from the reservoir computing framework generate mixed selectivity which provides pre-coded representations of an essentially universal set of contexts. These representations can then be selectively amplified through learning to solve the task at hand. We thus explored their representational power and dynamical properties after training a reservoir to perform a complex cognitive task initially developed for monkeys. The reservoir model inherently displayed a dynamic form of mixed selectivity, key to the representation of the behavioral context over time. The pre-coded representation of context was amplified by training a feedback neuron to explicitly represent this context, thereby reproducing the effect of learning and allowing the model to perform more robustly. This second version of the model demonstrates how a hybrid dynamical regime combining spatio-temporal processing of reservoirs, and input driven attracting dynamics generated by the feedback neuron, can be used to solve a complex cognitive task. We compared reservoir activity to neural activity of dorsal anterior cingulate cortex of monkeys which revealed similar network dynamics. We argue that reservoir computing is a

  16. Identifying tier one key suppliers.

    Science.gov (United States)

    Wicks, Steve

    2013-01-01

    In today's global marketplace, businesses are becoming increasingly reliant on suppliers for the provision of key processes, activities, products and services in support of their strategic business goals. The result is that now, more than ever, the failure of a key supplier has potential to damage reputation, productivity, compliance and financial performance seriously. Yet despite this, there is no recognised standard or guidance for identifying a tier one key supplier base and, up to now, there has been little or no research on how to do so effectively. This paper outlines the key findings of a BCI-sponsored research project to investigate good practice in identifying tier one key suppliers, and suggests a scalable framework process model and risk matrix tool to help businesses effectively identify their tier one key supplier base. PMID:23615061

  17. Monocular Visual Deprivation Suppresses Excitability in Adult Human Visual Cortex

    DEFF Research Database (Denmark)

    Lou, Astrid Rosenstand; Madsen, Kristoffer Hougaard; Paulson, Olaf Bjarne;

    2011-01-01

    The adult visual cortex maintains a substantial potential for plasticity in response to a change in visual input. For instance, transcranial magnetic stimulation (TMS) studies have shown that binocular deprivation (BD) increases the cortical excitability for inducing phosphenes with TMS. Here, we...... employed TMS to trace plastic changes in adult visual cortex before, during, and after 48 h of monocular deprivation (MD) of the right dominant eye. In healthy adult volunteers, MD-induced changes in visual cortex excitability were probed with paired-pulse TMS applied to the left and right occipital cortex....... Stimulus–response curves were constructed by recording the intensity of the reported phosphenes evoked in the contralateral visual field at range of TMS intensities. Phosphene measurements revealed that MD produced a rapid and robust decrease in cortical excitability relative to a control condition without...

  18. Effects of entorhinal cortex lesions on memory in different tasks

    Directory of Open Access Journals (Sweden)

    G.P. Gutierrez-Figueroa

    1997-06-01

    Full Text Available Lesions of the entorhinal cortex produce retrograde memory impairment in both animals and humans. Here we report the effects of bilateral entorhinal cortex lesions caused by the stereotaxic infusion of N-methyl-D-aspartate (NMDA in rats at two different moments, before or after the training session, on memory of different tasks: two-way shuttle avoidance, inhibitory avoidance and habituation to an open field. Pre- or post-training entorhinal cortex lesions caused an impairment of performance in the shuttle avoidance task, which agrees with the previously described role of this area in the processing of memories acquired in successive sessions. In the inhibitory avoidance task, only the post-training lesions had an effect (amnesia. No effect was observed on the open field task. The findings suggest that the role of the entorhinal cortex in memory processing is task-dependent, perhaps related to the complexity of each task

  19. Altered functional connectivity of prefrontal cortex in chronic heroin abusers

    Institute of Scientific and Technical Information of China (English)

    Yinbao Qi; Xianming Fu; Ruobing Qian; Chaoshi Niu; Xiangpin Wei

    2011-01-01

    In this study, we investigated alterations in the resting-state functional connectivity of the pre-frontal cortex in chronic heroin abusers using functional magnetic resonance imaging. We found that, compared with normal controls, in heroin abusers the left prefrontal cortex showed decreased functional connectivity with the left hippocampus, right anterior cingulate, left middle frontal gyrus, right middle frontal gyrus and right precuneus. However, the right prefrontal cortex showed decreased functional connectivity with the left orbital frontal cortex and the left middle frontal gyrus in chronic heroin abusers. These alterations of resting-state functional connectivity in the prefrontal cortices of heroin abusers suggest that their frontal executive neural network may be impaired, and that this may contribute to their continued heroin abuse and relapse after withdrawal.

  20. Human primary visual cortex topography imaged via positron tomography

    International Nuclear Information System (INIS)

    The visuotopic structure of primary visual cortex was studied in a group of 7 human volunteers using positron emission transaxial tomography (PETT) and 18F-labeled 2-deoxy-2-fluoro-D-glucose ([18F]DG). A computer animation was constructed with a spatial structure which was matched to estimates of human cortical magnification factor and to striate cortex stimulus preferences. A lateralized cortical 'checker-board' pattern of [18F]DG was stimulated in primary visual cortex by having subjects view this computer animation following i.v. injection of [18F]DG. The spatial structure of the stimulus was designed to produce an easily recognizable 'signature' in a series of 9 serial PETT scans obtained from each of a group of 7 volunteers. The predicted lateralized topographic 'signature' was observed in 6 of 7 subjects. Applications of this method for further PETT studies of human visual cortex are discussed. (Auth.)

  1. Reorganization of the Human Somatosensory Cortex in Hand Dystonia

    Directory of Open Access Journals (Sweden)

    Maria Jose Catalan

    2012-05-01

    Full Text Available Background and Purpose: Abnormalities of finger representations in the somatosensory cortex have been identified in patients with focal hand dystonia. Measuring blood flow with positron emission tomography (PET can be use to demonstrate functional localization of receptive fields. Methods: A vibratory stimulus was applied to the right thumb and little finger of six healthy volunteers and six patients with focal hand dystonia to map their receptive fields using H215O PET. Results: The cortical finger representations in the primary somatosensory cortex were closer to each other in patients than in normal subjects. No abnormalities were found in secondary somatosensory cortex, but the somatotopy there is less well distinguished. Conclusions: These data confirm prior electrophysiological and functional neuroimaging observations showing abnormalities of finger representations in somatosensory cortex of patients with focal hand dystonia.

  2. Cortex Matures Faster in Youths With Highest IQ

    Science.gov (United States)

    ... NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table of Contents For ... on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast the thinking part ...

  3. Public Key Infrastructure: A Survey

    OpenAIRE

    Aysha Albarqi; Ethar Alzaid; Fatimah Al Ghamdi; Somaya Asiri; Jayaprakash Kar

    2014-01-01

    As security is essential in communications through electronic networks, development of structures providing high levels of security is needed. Public Key Infrastructure (PKI) is a way of providing security measures by implementing the means of key pairs among users. In this paper, an overview of the public key infrastructure is discussed that includes various components and operation, some well known PKIs and their comparisons. Also we discuss current implementations, risk and challenges of P...

  4. An Internet Key Exchange Protocol Based on Public Key Infrastructure

    Institute of Scientific and Technical Information of China (English)

    朱建明; 马建峰

    2004-01-01

    Internet key exchange (IKE) is an automated key exchange mechanism that is used to facilitate the transfer of IPSec security associations (SAs). Public key infrastructure (PKI) is considered as a key element for providing security to new distributed communication networks and services. In this paper, we concentrate on the properties of the protocol of Phase 1 IKE. After investigating IKE protocol and PKI technology, we combine IKE protocol and PKI and present an implementation scheme of the IKE based on PKI. Then, we give a logic analysis of the proposed protocol with the BAN-logic and discuss the security of the protocol. The result indicates that the protocol is correct and satisfies the security requirements of Internet key exchange.

  5. Changing microcircuits in the subplate of the developing cortex

    OpenAIRE

    Viswanathan, Sarada; Bandyopadhyay, Sharba; Kao, Joseph P.Y.; Kanold, Patrick O.

    2012-01-01

    Subplate neurons (SPNs) are a population of neurons in the mammalian cerebral cortex that exist predominantly in the prenatal and early postnatal period. Loss of SPNs prevents the functional maturation of the cerebral cortex. SPNs receive subcortical input from the thalamus and relay this information to the developing cortical plate and thereby can influence cortical activity in a feed-forward manner. Little is known about potential feedback projections from the cortical plate to SPNs. Thus, ...

  6. Laminar circuit organization and response modulation in mouse visual cortex

    OpenAIRE

    Victor Quintanar-Zilinskas; Xiangmin Xu

    2012-01-01

    The mouse has become an increasingly important animal model for visual system studies, but few studies have investigated local functional circuit organization of mouse visual cortex. Here we used our newly developed mapping technique combining laser scanning photostimulation (LSPS) with fast voltage-sensitive dye (VSD) imaging to examine the spatial organization and temporal dynamics of laminar circuit responses in living slice preparations of mouse primary visual cortex (V1). During experi...

  7. Auditory Cortex Basal Activity Modulates Cochlear Responses in Chinchillas

    OpenAIRE

    León, Alex; Elgueda, Diego; Silva, María A.; Hamamé, Carlos M.; Delano, Paul H.

    2012-01-01

    Background The auditory efferent system has unique neuroanatomical pathways that connect the cerebral cortex with sensory receptor cells. Pyramidal neurons located in layers V and VI of the primary auditory cortex constitute descending projections to the thalamus, inferior colliculus, and even directly to the superior olivary complex and to the cochlear nucleus. Efferent pathways are connected to the cochlear receptor by the olivocochlear system, which innervates outer hair cells and auditory...

  8. Mapping the structural core of human cerebral cortex.

    OpenAIRE

    Hagmann, Patric; Cammoun, Leila; Gigandet, Xavier; Meuli, Reto; Honey, Christopher J.; Sporns, Olaf; Wedeen, Van Jay

    2008-01-01

    Author Summary In the human brain, neural activation patterns are shaped by the underlying structural connections that form a dense network of fiber pathways linking all regions of the cerebral cortex. Using diffusion imaging techniques, which allow the noninvasive mapping of fiber pathways, we constructed connection maps covering the entire cortical surface. Computational analyses of the resulting complex brain network reveal regions of cortex that are highly connected and highly central, fo...

  9. Connectivity Changes Underlying Neurofeedback Training of Visual Cortex Activity

    OpenAIRE

    Frank Scharnowski; Maria Joao Rosa; Narly Golestani; Chloe Hutton; Oliver Josephs; Nikolaus Weiskopf; Geraint Rees

    2014-01-01

    Neurofeedback based on real-time functional magnetic resonance imaging (fMRI) is a new approach that allows training of voluntary control over regionally specific brain activity. However, the neural basis of successful neurofeedback learning remains poorly understood. Here, we assessed changes in effective brain connectivity associated with neurofeedback training of visual cortex activity. Using dynamic causal modeling (DCM), we found that training participants to increase visual cortex activ...

  10. Molecular mechanisms of experience-dependent plasticity in visual cortex

    OpenAIRE

    Tropea, Daniela; Van Wart, Audra; Sur, Mriganka

    2008-01-01

    A remarkable amount of our current knowledge of mechanisms underlying experience-dependent plasticity during cortical development comes from study of the mammalian visual cortex. Recent advances in high-resolution cellular imaging, combined with genetic manipulations in mice, novel fluorescent recombinant probes, and large-scale screens of gene expression, have revealed multiple molecular mechanisms that underlie structural and functional plasticity in visual cortex. We situate these mechanis...

  11. Occurrence of new neurons in the piriform cortex

    Directory of Open Access Journals (Sweden)

    Ti-Fei eYuan

    2015-01-01

    Full Text Available Adult neurogenesis has been well studied in hippocampus and subventricular zone; while this is much less appreciated in other brain regions, including amygdala, hypothalamus and piriform cortex. The present review aims at summarizing recent advances on the occurrence of new neurons in the piriform cortex, their potential origin and migration route from the subventricular zone. We further discuss the relevant implications in olfactory dysfunction accompanying the neuro-degenerative diseases.

  12. Medial cortex activity, self-reflection and depression

    OpenAIRE

    Johnson, Marcia K.; Nolen-Hoeksema, Susan; Mitchell, Karen J.; Levin, Yael

    2009-01-01

    Using functional magnetic resonance imaging, we investigated neural activity associated with self-reflection in depressed [current major depressive episode (MDE)] and healthy control participants, focusing on medial cortex areas previously shown to be associated with self-reflection. Both the MDE and healthy control groups showed greater activity in anterior medial cortex (medial frontal gyrus, anterior cingulate gyrus) when cued to think about hopes and aspirations compared with duties and o...

  13. Specialized cortical subnetworks differentially connect frontal cortex to parahippocampal areas.

    Science.gov (United States)

    Hirai, Yasuharu; Morishima, Mieko; Karube, Fuyuki; Kawaguchi, Yasuo

    2012-02-01

    How information is manipulated and segregated within local circuits in the frontal cortex remains mysterious, in part because of inadequate knowledge regarding the connectivity of diverse pyramidal cell subtypes. The frontal cortex participates in the formation and retrieval of declarative memories through projections to the perirhinal cortex, and in procedural learning through projections to the striatum/pontine nuclei. In rat frontal cortex, we identified two pyramidal cell subtypes selectively projecting to distinct subregions of perirhinal cortex (PRC). PRC-projecting cells in upper layer 2/3 (L2/3) of the frontal cortex projected to perirhinal area 35, while neurons in L5 innervated perirhinal area 36. L2/3 PRC-projecting cells partially overlapped with those projecting to the basolateral amygdala. L5 PRC-projecting cells partially overlapped with crossed corticostriatal cells, but were distinct from neighboring corticothalamic (CTh)/corticopontine cells. L5 PRC-projecting and CTh cells were different in their electrophysiological properties and dendritic/axonal morphologies. Within the frontal cortex, L2/3 PRC-projecting cells innervated L5 PRC-projecting and CTh cells with similar probabilities, but received feedback excitation only from PRC-projecting cells. These data suggest that specific neuron subtypes in different cortical layers are reciprocally excited via interlaminar loops. Thus, two interacting output channels send information from the frontal cortex to different hierarchical stages of the parahippocampal network, areas 35 and 36, with additional collaterals selectively targeting the amygdala or basal ganglia, respectively. Combined with the hierarchical connectivity of PRC-projecting and CTh cells, these observations demonstrate an exquisite diversification of frontal projection neurons selectively connected according to their participation in distinct memory subsystems. PMID:22302828

  14. Effects of healthy aging on human primary visual cortex

    OpenAIRE

    2012-01-01

    Aging often results in reduced visual acuity from changes in both the eye and neural circuits [1-4]. In normally aging subjects, primary visual cortex has been shown to have reduced responses to visual stimulation [5]. It is not known, however, to what extent aging affects visual field representations and population receptive sizes in human primary visual cortex. Here we use functional MRI (fMRI) and population receptive field (pRF) modeling [6] to measure angular and eccentric retinotopic re...

  15. A disinhibitory microcircuit initiates critical period plasticity in visual cortex

    OpenAIRE

    Kuhlman, Sandra J.; Olivas, Nicholas D.; Tring, Elaine; Ikrar, Taruna; Xu, Xiangmin; Trachtenberg, Joshua T.

    2013-01-01

    Early sensory experience instructs the maturation of neural circuitry in cortex 1,2 . This has been extensively studied in the primary visual cortex where loss of vision to one eye permanently degrades cortical responsiveness to that eye 3,4 , a phenomenon known as ocular dominance plasticity (ODP). Cortical inhibition mediates this process 4-6 , but the precise role of specific classes of inhibitory neurons in ODP is controversial. Here we report that evoked firing rates of binocular excitat...

  16. Audiovisual Association Learning in the Absence of Primary Visual Cortex

    OpenAIRE

    Seirafi, Mehrdad; De Weerd, Peter; Pegna, Alan J.; de Gelder, Beatrice

    2016-01-01

    Learning audiovisual associations is mediated by the primary cortical areas; however, recent animal studies suggest that such learning can take place even in the absence of the primary visual cortex. Other studies have demonstrated the involvement of extra-geniculate pathways and especially the superior colliculus (SC) in audiovisual association learning. Here, we investigated such learning in a rare human patient with complete loss of the bilateral striate cortex. We carried out an implicit ...

  17. Functional reorganization of sensorimotor cortex in early Parkinson disease.

    OpenAIRE

    Kojovic, M.; Bologna, M; Kassavetis, P.; Murase, N.; Palomar, F. J.; Berardelli, A; Rothwell, J C; Edwards, M. J.; Bhatia, K P

    2012-01-01

    OBJECTIVE: Compensatory reorganization of the nigrostriatal system is thought to delay the onset of symptoms in early Parkinson disease (PD). Here we sought evidence that compensation may be a part of a more widespread functional reorganization in sensorimotor networks, including primary motor cortex. METHODS: Several neurophysiologic measures known to be abnormal in the motor cortex (M1) of patients with advanced PD were tested on the more and less affected side of 16 newly diagnosed and dru...

  18. High membrane protein oxidation in the human cerebral cortex

    OpenAIRE

    Matthias Granold; Bernd Moosmann; Irina Staib-Lasarzik; Thomas Arendt; Adriana del Rey; Kristin Engelhard; Christian Behl; Parvana Hajieva

    2014-01-01

    Oxidative stress is thought to be one of the main mediators of neuronal damage in human neurodegenerative disease. Still, the dissection of causal relationships has turned out to be remarkably difficult. Here, we have analyzed global protein oxidation in terms of carbonylation of membrane proteins and cytoplasmic proteins in three different mammalian species: aged human cortex and cerebellum from patients with or without Alzheimer's disease, mouse cortex and cerebellum from young and old anim...

  19. Specialized Pathways from the Primate Amygdala to Posterior Orbitofrontal Cortex

    OpenAIRE

    Timbie, Clare; Barbas, Helen

    2014-01-01

    The primate amygdala sends dense projections to posterior orbitofrontal cortex (pOFC) in pathways that are critical for processing emotional content, but the synaptic mechanisms are not understood. We addressed this issue by investigating pathways in rhesus monkeys (Macaca mulatta) from the amygdala to pOFC at the level of the system and synapse. Terminations from the amygdala were denser and larger in pOFC compared with the anterior cingulate cortex, which is also strongly connected with the...

  20. The multisensory function of the human primary visual cortex.

    Science.gov (United States)

    Murray, Micah M; Thelen, Antonia; Thut, Gregor; Romei, Vincenzo; Martuzzi, Roberto; Matusz, Pawel J

    2016-03-01

    It has been nearly 10 years since Ghazanfar and Schroeder (2006) proposed that the neocortex is essentially multisensory in nature. However, it is only recently that sufficient and hard evidence that supports this proposal has accrued. We review evidence that activity within the human primary visual cortex plays an active role in multisensory processes and directly impacts behavioural outcome. This evidence emerges from a full pallet of human brain imaging and brain mapping methods with which multisensory processes are quantitatively assessed by taking advantage of particular strengths of each technique as well as advances in signal analyses. Several general conclusions about multisensory processes in primary visual cortex of humans are supported relatively solidly. First, haemodynamic methods (fMRI/PET) show that there is both convergence and integration occurring within primary visual cortex. Second, primary visual cortex is involved in multisensory processes during early post-stimulus stages (as revealed by EEG/ERP/ERFs as well as TMS). Third, multisensory effects in primary visual cortex directly impact behaviour and perception, as revealed by correlational (EEG/ERPs/ERFs) as well as more causal measures (TMS/tACS). While the provocative claim of Ghazanfar and Schroeder (2006) that the whole of neocortex is multisensory in function has yet to be demonstrated, this can now be considered established in the case of the human primary visual cortex. PMID:26275965

  1. Spatial processing in the auditory cortex of the macaque monkey

    Science.gov (United States)

    Recanzone, Gregg H.

    2000-10-01

    The patterns of cortico-cortical and cortico-thalamic connections of auditory cortical areas in the rhesus monkey have led to the hypothesis that acoustic information is processed in series and in parallel in the primate auditory cortex. Recent physiological experiments in the behaving monkey indicate that the response properties of neurons in different cortical areas are both functionally distinct from each other, which is indicative of parallel processing, and functionally similar to each other, which is indicative of serial processing. Thus, auditory cortical processing may be similar to the serial and parallel "what" and "where" processing by the primate visual cortex. If "where" information is serially processed in the primate auditory cortex, neurons in cortical areas along this pathway should have progressively better spatial tuning properties. This prediction is supported by recent experiments that have shown that neurons in the caudomedial field have better spatial tuning properties than neurons in the primary auditory cortex. Neurons in the caudomedial field are also better than primary auditory cortex neurons at predicting the sound localization ability across different stimulus frequencies and bandwidths in both azimuth and elevation. These data support the hypothesis that the primate auditory cortex processes acoustic information in a serial and parallel manner and suggest that this may be a general cortical mechanism for sensory perception.

  2. Medial cortex activity, self-reflection and depression.

    Science.gov (United States)

    Johnson, Marcia K; Nolen-Hoeksema, Susan; Mitchell, Karen J; Levin, Yael

    2009-12-01

    Using functional magnetic resonance imaging, we investigated neural activity associated with self-reflection in depressed [current major depressive episode (MDE)] and healthy control participants, focusing on medial cortex areas previously shown to be associated with self-reflection. Both the MDE and healthy control groups showed greater activity in anterior medial cortex (medial frontal gyrus, anterior cingulate gyrus) when cued to think about hopes and aspirations compared with duties and obligations, and greater activity in posterior medial cortex (precuneus, posterior cingulate) when cued to think about duties and obligations (Experiment 1). However, the MDE group showed less activity than controls in the same area of medial frontal cortex when self-referential cues were more ambiguous with respect to valence (Experiment 2), and less deactivation in a non-self-referential condition in both experiments. Furthermore, individual differences in rumination were positively correlated with activity in both anterior and posterior medial cortex during non-self-referential conditions. These results provide converging evidence for a dissociation of anterior and posterior medial cortex depending on the focus of self-relevant thought. They also provide neural evidence consistent with behavioral findings that depression is associated with disruption of positively valenced thoughts in response to ambiguous cues, and difficulty disengaging from self-reflection when it is appropriate to do so. PMID:19620180

  3. What does spatial alternation tell us about retrosplenial cortex function?

    Directory of Open Access Journals (Sweden)

    Andrew John Dudley Nelson

    2015-05-01

    Full Text Available The retrosplenial cortex supports navigation, but there are good reasons to suppose that the retrosplenial cortex has a very different role in spatial memory from that of the hippocampus and anterior thalamic nuclei. For example, retrosplenial lesions appear to have little or no effect on standard tests of spatial alternation. To examine these differences, the current study sought to determine whether the retrosplenial cortex is important for just one spatial cue type (e.g. allocentric, directional or intra-maze cues or whether the retrosplenial cortex helps the animal switch between competing spatial strategies or competing cue types. Using T-maze alternation, retrosplenial lesion rats were challenged with situations in which the available spatial information between the sample and test phases was changed, so taxing the interaction between different cue types. Clear lesion deficits emerged when intra- and extra-maze cues were placed in conflict (by rotating the maze between the sample and choice phases, or when the animals were tested in the dark in a double-maze. Finally, temporary inactivation of the retrosplenial cortex by muscimol infusions resulted in a striking deficit on standard T-maze alternation, indicating that, over time, other sites may be able to compensate for the loss of the retrosplenial cortex. This pattern of results is consistent with the impoverished use of both allocentric and directional information, exacerbated by an impaired ability to switch between different cue types.

  4. Tinnitus intensity dependent gamma oscillations of the contralateral auditory cortex.

    Directory of Open Access Journals (Sweden)

    Elsa van der Loo

    Full Text Available BACKGROUND: Non-pulsatile tinnitus is considered a subjective auditory phantom phenomenon present in 10 to 15% of the population. Tinnitus as a phantom phenomenon is related to hyperactivity and reorganization of the auditory cortex. Magnetoencephalography studies demonstrate a correlation between gamma band activity in the contralateral auditory cortex and the presence of tinnitus. The present study aims to investigate the relation between objective gamma-band activity in the contralateral auditory cortex and subjective tinnitus loudness scores. METHODS AND FINDINGS: In unilateral tinnitus patients (N = 15; 10 right, 5 left source analysis of resting state electroencephalographic gamma band oscillations shows a strong positive correlation with Visual Analogue Scale loudness scores in the contralateral auditory cortex (max r = 0.73, p<0.05. CONCLUSION: Auditory phantom percepts thus show similar sound level dependent activation of the contralateral auditory cortex as observed in normal audition. In view of recent consciousness models and tinnitus network models these results suggest tinnitus loudness is coded by gamma band activity in the contralateral auditory cortex but might not, by itself, be responsible for tinnitus perception.

  5. High membrane protein oxidation in the human cerebral cortex

    Directory of Open Access Journals (Sweden)

    Matthias Granold

    2015-04-01

    Full Text Available Oxidative stress is thought to be one of the main mediators of neuronal damage in human neurodegenerative disease. Still, the dissection of causal relationships has turned out to be remarkably difficult. Here, we have analyzed global protein oxidation in terms of carbonylation of membrane proteins and cytoplasmic proteins in three different mammalian species: aged human cortex and cerebellum from patients with or without Alzheimer's disease, mouse cortex and cerebellum from young and old animals, and adult rat hippocampus and cortex subjected or not subjected to cerebral ischemia. Most tissues showed relatively similar levels of protein oxidation. However, human cortex was affected by severe membrane protein oxidation, while exhibiting lower than average cytoplasmic protein oxidation. In contrast, ex vivo autooxidation of murine cortical tissue primarily induced aqueous protein oxidation, while in vivo biological aging or cerebral ischemia had no major effect on brain protein oxidation. The unusually high levels of membrane protein oxidation in the human cortex were also not predicted by lipid peroxidation, as the levels of isoprostane immunoreactivity in human samples were considerably lower than in rodent tissues. Our results indicate that the aged human cortex is under steady pressure from specific and potentially detrimental membrane protein oxidation. The pronounced difference between humans, mice and rats regarding the primary site of cortical oxidation might have contributed to the unresolved difficulties in translating into therapies the wealth of data describing successful antioxidant neuroprotection in rodents.

  6. Evidence of residual disease in cryopreserved ovarian cortex from female patients with leukemia

    DEFF Research Database (Denmark)

    Rosendahl, Mikkel; Andersen, Morten Tolstrup; Ralfkiær, Elisabeth; Kjeldsen, Lars; Andersen, Mette Klarskov; Andersen, Claus Yding

    2010-01-01

    To systematically search for leukemic cells in cryopreserved ovarian cortex from Danish female patients with leukemia, who had ovarian cortex cryopreserved for fertility preservation before potentially sterilizing treatment.......To systematically search for leukemic cells in cryopreserved ovarian cortex from Danish female patients with leukemia, who had ovarian cortex cryopreserved for fertility preservation before potentially sterilizing treatment....

  7. Preferential encoding of visual categories in parietal cortex compared with prefrontal cortex.

    Science.gov (United States)

    Swaminathan, Sruthi K; Freedman, David J

    2012-02-01

    The ability to recognize the behavioral relevance, or category membership, of sensory stimuli is critical for interpreting the meaning of events in our environment. Neurophysiological studies of visual categorization have found categorical representations of stimuli in prefrontal cortex (PFC), an area that is closely associated with cognitive and executive functions. Recent studies have also identified neuronal category signals in parietal areas that are typically associated with visual-spatial processing. It has been proposed that category-related signals in parietal cortex and other visual areas may result from 'top-down' feedback from PFC. We directly compared neuronal activity in the lateral intraparietal (LIP) area and PFC in monkeys performing a visual motion categorization task. We found that LIP showed stronger, more reliable and shorter latency category signals than PFC. These findings suggest that LIP is strongly involved in visual categorization and argue against the idea that parietal category signals arise as a result of feedback from PFC during this task. PMID:22246435

  8. Epileptiform synchronization in the cingulate cortex

    Science.gov (United States)

    Panuccio, Gabriella; Curia, Giulia; Colosimo, Alfredo; Cruccu, Giorgio; Avoli, Massimo

    2016-01-01

    Summary Purpose The anterior cingulate cortex (ACC)— which plays a role in pain, emotions and behavior— can generate epileptic seizures. To date, little is known on the neuronal mechanisms leading to epileptiform synchronization in this structure. Therefore, we investigated the role of excitatory and inhibitory synaptic transmission in epileptiform activity in this cortical area. In addition, since the ACC presents with a high density of opioid receptors, we studied the effect of opioid agonism on epileptiform synchronization in this brain region. Methods We used field and intracellular recordings in conjunction with pharmacological manipulations to characterize the epileptiform activity generated by the rat ACC in a brain slice preparation. Results Bath-application of the convulsant 4- aminopyridine (4AP, 50 μM) induced both brief and prolonged periods of epileptiform synchronization resembling interictal- and ictal-like discharges, respectively. Interictal events could occur more frequently before the onset of ictal activity that was contributed by N-methyl-D-aspartate (NMDA) receptors. Mu-opioid receptor activation abolished 4AP-induced ictal events and markedly reduced the occurrence of the pharmacologically isolated GABAergic synchronous potentials. Ictal discharges were replaced by interictal events during GABAergic antagonism; this GABA-independent activity was influenced by subsequent mu-opioid agonist application. Conclusions Our results indicate that both glutamatergic and GABAergic signaling contribute to epileptiform synchronization leading to the generation of electrographic ictal events in the ACC. In addition, mu-opioid receptors appear to modulate both excitatory and inhibitory mechanisms, thus influencing epileptiform synchronization in the ACC. PMID:19178556

  9. The Basal Forebrain and Motor Cortex Provide Convergent yet Distinct Movement-Related Inputs to the Auditory Cortex.

    Science.gov (United States)

    Nelson, Anders; Mooney, Richard

    2016-05-01

    Cholinergic inputs to the auditory cortex from the basal forebrain (BF) are important to auditory processing and plasticity, but little is known about the organization of these synapses onto different auditory cortical neuron types, how they influence auditory responsiveness, and their activity patterns during various behaviors. Using intersectional tracing, optogenetic circuit mapping, and in vivo calcium imaging, we found that cholinergic axons arising from the caudal BF target major excitatory and inhibitory auditory cortical cell types, rapidly modulate auditory cortical tuning, and display fast movement-related activity. Furthermore, the BF and the motor cortex-another source of movement-related activity-provide convergent input onto some of the same auditory cortical neurons. Cholinergic and motor cortical afferents to the auditory cortex display distinct activity patterns and presynaptic partners, indicating that the auditory cortex integrates bottom-up cholinergic signals related to ongoing movements and arousal with top-down information concerning impending movements and motor planning. PMID:27112494

  10. Model plant Key Measurement Points

    International Nuclear Information System (INIS)

    For IAEA safeguards a Key Measurement Point is defined as the location where nuclear material appears in such a form that it may be measured to determine material flow or inventory. This presentation describes in an introductory manner the key measurement points and associated measurements for the model plant used in this training course

  11. The effects of prefrontal cortex inactivation on object responses of single neurons in the inferotemporal cortex during visual search

    OpenAIRE

    Monosov, Ilya E.; David L Sheinberg; Thompson, Kirk G.

    2011-01-01

    Inferotemporal cortex (IT) is believed to be directly involved in object processing and necessary for accurate and efficient object recognition. The frontal eye field (FEF) is an area in the primate prefrontal cortex that is involved in visual spatial selection and is thought to guide spatial attention and eye movements. We show that object selective responses of IT neurons and behavioral performance are affected by changes in frontal eye field activity. This was found in monkeys performing a...

  12. $\\mu$Kummer: efficient hyperelliptic signatures and key exchange on microcontrollers

    OpenAIRE

    Renes, Joost; Schwabe, Peter; Smith, Benjamin; Batina, Lejla

    2016-01-01

    We describe the design and implementation of efficient signature and key-exchange schemes for the AVR ATmega and ARM Cortex M0 microcontrollers, targeting the 128-bit security level. Our algorithms are based on an efficient Montgomery ladder scalar multiplication on the Kummer surface of Gaudry and Schost's genus-2 hyperelliptic curve, combined with the Jacobian point recovery technique of Costello, Chung, and Smith. Our results are the first to show the feasibility of software-only hyperelli...

  13. Breaking chaotic shift key communication via adaptive key identification

    International Nuclear Information System (INIS)

    This paper proposes an adaptive parameter identification method for breaking chaotic shift key communication from the transmitted signal in public channel. The sensitive dependence property of chaos on parameter mismatch is used for chaos adaptive synchronization and parameter identification. An index function about the synchronization error is defined and conjugate gradient method is used to minimize the index function and to search the transmitter's parameter (key). By using proposed method, secure key is recovered from transmitted signal generated by low dimensional chaos and hyper chaos switching communication. Multi-parameters can also be identified from the transmitted signal with noise

  14. Cortico-cortical connections of the motor cortex in the brushtailed possum (Trichosurus vulpecula).

    OpenAIRE

    Joschko, M A; Sanderson, K J

    1987-01-01

    Cortico-cortical connections of motor cortex in the marsupial brushtailed possum were traced by making injections of horseradish peroxidase (HRP) into two parts of motor cortex: the rostral agranular part which does not overlap somatosensory cortex, and the caudal part which does. Following injections in motor cortex, labelled neurons were observed on the same side of the brain within somatosensory areas 1 and 2 and in parietal cortex just caudal to S1, with most neurons in cortical Layers 2-...

  15. Functional differentiation of the premotor cortex: Behavioural and brain imaging studies in humans

    OpenAIRE

    Potgieser, Adriaan Remco Ewoud

    2015-01-01

    The premotor cortex is a brain structure that is involved in the preparation of movements. It has an important role in the final integration of task-related information and to funnel this to the primary motor cortex, which subsequently causes the execution of a movement. Premotor areas can also influence motor output through their direct interactions with both the spinal cord. Within the premotor cortex, the ventral premotor cortex (PMv), dorsal premotor cortex (PMd) and supplementary motor a...

  16. Finite key analysis for symmetric attacks in quantum key distribution

    International Nuclear Information System (INIS)

    We introduce a constructive method to calculate the achievable secret key rate for a generic class of quantum key distribution protocols, when only a finite number n of signals is given. Our approach is applicable to all scenarios in which the quantum state shared by Alice and Bob is known. In particular, we consider the six state protocol with symmetric eavesdropping attacks, and show that for a small number of signals, i.e., below n∼104, the finite key rate differs significantly from the asymptotic value for n→∞. However, for larger n, a good approximation of the asymptotic value is found. We also study secret key rates for protocols using higher-dimensional quantum systems

  17. Cedar Keys Wilderness study area : Cedar Keys National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a brief report on a wilderness study area located in the Cedar Keys National Wildlife Refuge. It discusses the history of the study area, its...

  18. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    Harinarayan Tiwari; Nayan Sharma

    2015-10-01

    This paper presents fundamental outcomes from an experimental study on the hydrodynamic performance near inlet key of Piano Key Weir (PKW). Hydrodynamic performance was tested in a circulated open channel that comprised of PKW and sand bed (d50 = 0.25 mm). Instantaneous velocities were measured at 20 cross sections using Laser Doppler Velocimeter (LDV) with constant discharge and depth. Average velocity and turbulence intensities in both directions were investigated. Average longitudinal velocities are found very much consistent at every point and maximum around the midway of inlet key. In transverse direction, flow is bifurcating in two directions which are also confirmed by average transverse velocity estimation. Variation of turbulence intensity presents average 10 times higher transverse turbulence than longitudinal turbulence near inlet key of PKW.

  19. A defined network of fast-spiking interneurons in orbitofrontal cortex: responses to behavioral contingencies and ketamine administration

    Directory of Open Access Journals (Sweden)

    Michael C Quirk

    2009-11-01

    Full Text Available Orbitofrontal cortex (OFC is a region of prefrontal cortex implicated in the motivational control of behavior and in related abnormalities seen in psychosis and depression. It has been hypothesized that a critical mechanism in these disorders is the dysfunction of GABAergic interneurons that normally regulate prefrontal information processing. Here, we studied a subclass of interneurons isolated in rat OFC using extracellular waveform and spike train analysis. During performance of a goal-directed behavioral task, the firing of this class of putative fast-spiking (FS interneurons showed robust temporal correlations indicative of a functionally coherent network. FS cell activity also co-varied with behavioral response latency, a key indicator of motivational state. Systemic administration of ketamine, a drug that can mimic psychosis, preferentially inhibited this cell class. Together, these results support the idea that OFC-FS interneurons form a critical link in the regulation of motivation by prefrontal circuits during normal and abnormal brain and behavioral states.

  20. Key parameters controlling radiology departments

    International Nuclear Information System (INIS)

    For radiology departments and outstanding practises control and optimization of processes demand an efficient management based on key data. Systems of key data deliver indicators for control of medical quality, service quality and economics. For practices effectiveness (productivity), for hospitals effectiveness and efficiency are in the focus of economical optimization strategies. Task of daily key data is continuous monitoring of activities and workflow, task of weekly/monthly key data is control of data quality, process quality and achievement of objectives, task of yearly key data is determination of long term strategies (marketing) and comparison with competitors (benchmarking). Key parameters have to be defined clearly and have to be available directly. For generation, evaluation and control of key parameters suitable forms of organization and processes are necessary. Strategies for the future will be directed more to the total processes of treatment. To think in total processes and to steer and optimize with suitable parameters is the challenge for participants in the healthcare market of the future. (orig.)

  1. Cultivating the cortex in German neuroanatomy.

    Science.gov (United States)

    Hagner, M

    2001-12-01

    The cerebral localization of mental functions is one of the centerpieces of modern brain research. Though the localization paradigm in its cultural and social interwovenness has been characterized as successful in the last third of the nineteenth century by a variety of historians of the neurosciences, there is also general agreement that localization came under threat around 1900. Besides the so-called holistic protest against the localization of mental functions, the neuroanatomical approach itself was challenged by experimental psychology, psychiatric nosology, and psychoanalysis. This story underestimates the fact that anatomically-based localization remained powerful in response to these multiple challenges. This meant a neuroanatomical revision of tools, concepts, and practices. But this meant also a shift in the cultivation of the cortex from a more philosophical agenda to rather concrete political claims. More specifically, the idea of the cortext as the noblest part of man was supplemented by suggestions concerning its "Höherzüchtung." I will analyze this re-orientation and radicalization in two steps. First, I briefly discuss the anatomical and philosophical account of Theodor Meynert and then turn to Paul Flechsig who in the late nineteenth century inscribed the ability to create culture and civilization into the cortext. Second, I focus on the neuroanatomists Oskar and Cécile Vogt, who began their careers around 1900 and expanded the cultivation of the cortext. Even before World War I, they proclaimed a "cerebral hygiene." Consequently, the Vogts linked their innovative neuroanatomical researches with the rising field of genetics, racial hygiene, and eugenics. In the early Weimar Republic, the Vogts openly supported socialist ideas and were engaged in establishing an Institute for Brain Research in Soviet Moscow, where Lenin's brain was analyzed. By the end of the Weimar Republic, the rhetoric of the Vogts was bluntly authoritarian. Based on a few

  2. Key Based Random Permutation (KBRP)

    OpenAIRE

    Shakir M. Hussain; Naim M. Ajlouni

    2006-01-01

    This study introduces a method for generating a particular permutation P of a given size N out of N! permutations from a given key. This method computes a unique permutation for a specific size since it takes the same key; therefore, the same permutation can be computed each time the same key and size are applied. The name of random permutation comes from the fact that the probability of getting this permutation is 1 out of N! possible permutations. Beside that, the permutation can not be gue...

  3. Smartphones Could Make Keys Obsolete

    Institute of Scientific and Technical Information of China (English)

    Matt Richtel

    2011-01-01

    @@ Front pockets and purses are slowly being emptied of one of civilization's most basic and enduring tools: the key.It's being swallowed by the cellphone.New technology lets smartphones unlock hotel, office and house doors and open garages and even car doors. It's a not-too-distant cousin of the technology that allows key fobs to remotely unlock automobiles or key cards to be waved beside electronic pads at office entrances.What's new is that it is on the device more people are using as the Swiss Army knife of electronics, in equal parts phone, memo pad, stereo, map, GPS unit, and camera and game machine.

  4. Functional and structural remodeling of glutamate synapses in prefrontal and frontal cortex induced by behavioral stress

    Directory of Open Access Journals (Sweden)

    Laura eMusazzi

    2015-04-01

    Full Text Available Increasing evidence has shown that the pathophysiology of neuropsychiatric disorders, including mood disorders, is associated with abnormal function and regulation of the glutamatergic system. Consistently, preclinical studies on stress-based animal models of pathology showed that glucocorticoids and stress exert crucial effects on neuronal excitability and function, especially in cortical and limbic areas. In prefrontal and frontal cortex, acute stress was shown to induce enhancement of glutamate release/transmission dependent on activation of corticosterone receptors. Although the mechanisms whereby stress affects glutamate transmission have not yet been fully understood, it was shown that synaptic, non-genomic action of corticosterone is required to increase the readily releasable pool of glutamate vesicles but is not sufficient to enhance transmission in prefrontal and frontal cortex. Slower, partly genomic mechanisms are probably necessary for the enhancement of glutamate transmission induced by stress.Combined evidence has suggested that the changes in glutamate release and transmission are responsible for the dendritic remodeling and morphological changes induced by stress and it has been argued that sustained alterations of glutamate transmission may play a key role in the long-term structural/functional changes associated with mood disorders in patients. Intriguingly, modifications of the glutamatergic system induced by stress in the prefrontal cortex seem to be biphasic. Indeed, while the fast response to stress suggests an enhancement in the number of excitatory synapses, synaptic transmission and working memory, long-term adaptive changes -including those consequent to chronic stress- induce opposite effects. Better knowledge of the cellular effectors involved in this biphasic effect of stress may be useful to understand the pathophysiology of stress-related disorders, and open new paths for the development of therapeutic approaches.

  5. Secret Key Generation From Mobility

    CERN Document Server

    Gungor, Onur; Koksal, C Emre

    2011-01-01

    We consider secret key generation from relative localization information of a pair of nodes in a mobile wireless network in the presence of a mobile eavesdropper. Our scheme consists of two phases: in the first phase, legitimate node pair exchanges beacon signals to establish localization information based on noisy observations of these beacons; in the second phase, nodes generate secret key bits via a public discussion. Our problem can be categorized under the source models of information theoretic secrecy, where the distance between the legitimate nodes acts as the observed common randomness. We characterize the achievable secret key bit rate in terms of the observation noise variance at the legitimate nodes and the eavesdropper. This work provides a framework that combines information theoretic secrecy and wireless localization, and proves that the localization information provides a significant additional resource for secret key generation in mobile wireless networks.

  6. Key Injury and Violence Data

    Science.gov (United States)

    ... Traumatic Brain Injury Violence Prevention Key Injury and Violence Data Recommend on Facebook Tweet Share Compartir Injuries ... of death among persons 1-44. Injury- and violence-related deaths are only part of the problem ...

  7. Frame Based Symmetric Key Cryptography

    Directory of Open Access Journals (Sweden)

    Uttam Kr. Mondal

    2011-01-01

    Full Text Available There are huge numbers of algorithms available in symmetry key block cipher. All these algorithms have been used either complicated keys to produce cipher text from plain text or a complicated algorithms for it. The level of security of all algorithms is dependent on either number of iterations or length of keys. In this paper, a symmetry key block cipher algorithm has been proposed to encrypt plain text into cipher text or vice versa using a frame set. A comparative study have been made with RSA, DES, IDEA, BAM and other algorithms with Chi-square value, frequency distribution, bit ratio to check the security level of proposed algorithm. Finally, a comparison has been made for time complexity for encryption of plain text and decryption from cipher text with the well-known existing algorithms.

  8. Key Statistics for Thyroid Cancer

    Science.gov (United States)

    ... cancer? Next Topic Thyroid cancer risk factors Key statistics for thyroid cancer How common is thyroid cancer? ... remains very low compared with most other cancers. Statistics on survival rates for thyroid cancer are discussed ...

  9. Changes in Cerebral Cortex of Children Treated for Medulloblastoma

    International Nuclear Information System (INIS)

    Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from a larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications

  10. Development of the cerebellar cortex in the mouse

    Institute of Scientific and Technical Information of China (English)

    Xiangshu Cheng; Jin Du; Dongming Yu; Qiying Jiang; Yanqiu Hu; Lei Wang; Mingshan Li; Jinbo Deng

    2011-01-01

    The cerebellum is a highly conserved structure in the central nervous system of vertebrates, and is involved in the coordination of voluntary motor behavior. Supporting this function, the cerebellar cortex presents a layered structure which requires precise spatial and temporal coordination of proliferation, migration, differentiation, and apoptosis events. The formation of the layered structure in the developing cerebellum remains unclear. The present study investigated the development of the cerebellar cortex. The results demonstrate that the primordium of the cerebellum comprises the ependymal, mantle, and marginal layers at embryonic day 12 (E12). Subsequently, the laminated cerebellar cortex undergoes cell proliferation, differentiation, and migration, and at about postnatal day 0 (P0), the cerebellar cortex presents an external granular layer, a molecular layer, a Purkinje layer, and an internal granular layer. The external granular layer is thickest at P6/7 and disappears at P20. From P0 to P30, the internal granular cells and the Purkinje cells gradually differentiate and develop until maturity. Apoptotic neurons are evident in the layered structure in the developing cerebellar cortex. The external granular layer disappears gradually because of cell migration and apoptosis. The cells of the other layers primarily undergo differentiation, development, and apoptosis.

  11. The orbitofrontal cortex: novelty, deviation from expectation, and memory.

    Science.gov (United States)

    Petrides, Michael

    2007-12-01

    The orbitofrontal cortex is strongly connected with limbic areas of the medial temporal lobe that are critically involved in the establishment of declarative memories (entorhinal and perirhinal cortex and the hippocampal region) as well as the amygdala and the hypothalamus that are involved in emotional and motivational states. The present article reviews evidence regarding the role of the orbitofrontal cortex in the processing of novel information, breaches of expectation, and memory. Functional neuroimaging evidence is provided that there is a difference between the anterior and posterior orbitofrontal cortex in such processing. Exposure to novel information gives rise to a selective increase of activity in the granular anterior part of the orbitofrontal cortex (area 11) and this activity increases when subjects attempt to encode this information in memory. If the stimuli violate expectations (e.g., inspection of graffiti-like stimuli in the context of other regular stimuli) or are unpleasant (i.e., exposure to the sounds of car crashes), there is increased response in the posteromedial agranular/dysgranular area 13 of the orbitofrontal region. The anatomic data provide a framework within which to understand these functional neuroimaging findings. PMID:17872393

  12. Responses of primate frontal cortex neurons during natural vocal communication.

    Science.gov (United States)

    Miller, Cory T; Thomas, A Wren; Nummela, Samuel U; de la Mothe, Lisa A

    2015-08-01

    The role of primate frontal cortex in vocal communication and its significance in language evolution have a controversial history. While evidence indicates that vocalization processing occurs in ventrolateral prefrontal cortex neurons, vocal-motor activity has been conjectured to be primarily subcortical and suggestive of a distinctly different neural architecture from humans. Direct evidence of neural activity during natural vocal communication is limited, as previous studies were performed in chair-restrained animals. Here we recorded the activity of single neurons across multiple regions of prefrontal and premotor cortex while freely moving marmosets engaged in a natural vocal behavior known as antiphonal calling. Our aim was to test whether neurons in marmoset frontal cortex exhibited responses during vocal-signal processing and/or vocal-motor production in the context of active, natural communication. We observed motor-related changes in single neuron activity during vocal production, but relatively weak sensory responses for vocalization processing during this natural behavior. Vocal-motor responses occurred both prior to and during call production and were typically coupled to the timing of each vocalization pulse. Despite the relatively weak sensory responses a population classifier was able to distinguish between neural activity that occurred during presentations of vocalization stimuli that elicited an antiphonal response and those that did not. These findings are suggestive of the role that nonhuman primate frontal cortex neurons play in natural communication and provide an important foundation for more explicit tests of the functional contributions of these neocortical areas during vocal behaviors. PMID:26084912

  13. Posterior parietal cortex dynamically ranks topographic signals via cholinergic influence

    Directory of Open Access Journals (Sweden)

    John Broussard

    2012-06-01

    Full Text Available The hypothesis to be discussed in this review is that posterior parietal cortex is directly involved in selecting relevant stimuli and filtering irrelevant distractors. The posterior parietal cortex receives input from several sensory modalities and integrates them in part to direct the allocation of resources to optimize gains. In conjunction with prefrontal cortex, nucleus accumbens, and basal forebrain cholinergic nuclei, it comprises a network mediating sustained attentional performance. Numerous anatomical, neurophysiological, and lesion studies have substantiated the notion that the basic functions of the posterior parietal cortex are conserved from rodents to humans. One such function is the detection and selection of relevant stimuli necessary for making optimal choices or responses. The issues to be addressed here are how behaviorally relevant targets recruit oscillatory potentials and spiking activity of posterior parietal neurons compared to similar yet irrelevant stimuli. Further, the influence of cortical cholinergic input to posterior parietal cortex in learning and decision-making is also discussed. I propose that these neurophysiological correlates of attention are transmitted to frontal cortical areas contributing to the top down selection of stimuli in a timely manner.

  14. Can lesions to the motor cortex induce amyotrophic lateral sclerosis?

    Science.gov (United States)

    Rosenbohm, Angela; Kassubek, Jan; Weydt, Patrick; Marroquin, Nicolai; Volk, Alexander E; Kubisch, Christian; Huppertz, Hans-Jürgen; Weber, Markus; Andersen, Peter M; Weishaupt, Jochen H; Ludolph, Albert C

    2014-02-01

    A recent staging effort for amyotrophic lateral sclerosis (ALS) has demonstrated that the TDP-43 neuropathology may initiate focally in the motor cortex in the majority of patients. We searched our data bank for patients with lesions of the motor cortex which preceded disease onset. We performed a search of our patient- and MRI-data bank and screened 1,835 patients with amyotrophic lateral sclerosis for frontal lobe/motor cortex lesions. We found 18 patients with definite ALS who had documented and defined lesions of the motor cortex, which preceded the initial ALS symptoms by 8-42 years. In the vast majority (15/18) of the patients, the onset of ALS was closely related to the focal lesion since it started in a body region reflecting the damaged cortical area. The findings suggest that initial lesions to the motor cortex may be a contributing initiating factor in some patients with ALS or determine the site of onset in individuals pre-disposed to ALS. PMID:24253481

  15. Finite-key security analysis for multilevel quantum key distribution

    Science.gov (United States)

    Brádler, Kamil; Mirhosseini, Mohammad; Fickler, Robert; Broadbent, Anne; Boyd, Robert

    2016-07-01

    We present a detailed security analysis of a d-dimensional quantum key distribution protocol based on two and three mutually unbiased bases (MUBs) both in an asymptotic and finite-key-length scenario. The finite secret key rates (in bits per detected photon) are calculated as a function of the length of the sifted key by (i) generalizing the uncertainly relation-based insight from BB84 to any d-level 2-MUB QKD protocol and (ii) by adopting recent advances in the second-order asymptotics for finite block length quantum coding (for both d-level 2- and 3-MUB QKD protocols). Since the finite and asymptotic secret key rates increase with d and the number of MUBs (together with the tolerable threshold) such QKD schemes could in principle offer an important advantage over BB84. We discuss the possibility of an experimental realization of the 3-MUB QKD protocol with the orbital angular momentum degrees of freedom of photons.

  16. Posterior Parietal Cortex Drives Inferotemporal Activations During Three-Dimensional Object Vision.

    Science.gov (United States)

    Van Dromme, Ilse C; Premereur, Elsie; Verhoef, Bram-Ernst; Vanduffel, Wim; Janssen, Peter

    2016-04-01

    The primate visual system consists of a ventral stream, specialized for object recognition, and a dorsal visual stream, which is crucial for spatial vision and actions. However, little is known about the interactions and information flow between these two streams. We investigated these interactions within the network processing three-dimensional (3D) object information, comprising both the dorsal and ventral stream. Reversible inactivation of the macaque caudal intraparietal area (CIP) during functional magnetic resonance imaging (fMRI) reduced fMRI activations in posterior parietal cortex in the dorsal stream and, surprisingly, also in the inferotemporal cortex (ITC) in the ventral visual stream. Moreover, CIP inactivation caused a perceptual deficit in a depth-structure categorization task. CIP-microstimulation during fMRI further suggests that CIP projects via posterior parietal areas to the ITC in the ventral stream. To our knowledge, these results provide the first causal evidence for the flow of visual 3D information from the dorsal stream to the ventral stream, and identify CIP as a key area for depth-structure processing. Thus, combining reversible inactivation and electrical microstimulation during fMRI provides a detailed view of the functional interactions between the two visual processing streams. PMID:27082854

  17. Acute phencyclidine treatment induces extensive and distinct protein phosphorylation in rat frontal cortex.

    Science.gov (United States)

    Palmowski, Pawel; Rogowska-Wrzesinska, Adelina; Williamson, James; Beck, Hans C; Mikkelsen, Jens D; Hansen, Henrik H; Jensen, Ole N

    2014-03-01

    Phencyclidine (PCP), a noncompetitive N-methyl-D-aspartate receptor antagonist, induces psychotomimetic effects in humans and animals. Administration of PCP to rodents is used as a preclinical model for schizophrenia; however, the molecular mechanisms underlying the symptoms remain largely unknown. Acute PCP treatment rapidly induces behavioral and cognitive deficits; therefore, post-translational regulation of protein activity is expected to play a role at early time points. We performed mass-spectrometry-driven quantitative analysis of rat frontal cortex 15, 30, or 240 min after the administration of PCP (10 mg/kg). We identified and quantified 23,548 peptides, including 4749 phosphopeptides, corresponding to 2604 proteins. A total of 352 proteins exhibited altered phosphorylation levels, indicating that protein phosphorylation is involved in the acute response to PCP. Computational assessment of the regulated proteins biological function revealed that PCP perturbs key processes in the frontal cortex including calcium homeostasis, organization of cytoskeleton, endo/exocytosis, and energy metabolism. This study on acute PCP treatment provides the largest proteomics and phosphoproteomics data sets to date of a preclinical model of schizophrenia. Our findings contribute to the understanding of alterations in glutamatergic neurotransmission in schizophrenia and provide a foundation for discovery of novel targets for pharmacological intervention. PMID:24564430

  18. Variability and information content in auditory cortex spike trains during an interval-discrimination task.

    Science.gov (United States)

    Abolafia, Juan M; Martinez-Garcia, M; Deco, G; Sanchez-Vives, M V

    2013-11-01

    Processing of temporal information is key in auditory processing. In this study, we recorded single-unit activity from rat auditory cortex while they performed an interval-discrimination task. The animals had to decide whether two auditory stimuli were separated by either 150 or 300 ms and nose-poke to the left or to the right accordingly. The spike firing of single neurons in the auditory cortex was then compared in engaged vs. idle brain states. We found that spike firing variability measured with the Fano factor was markedly reduced, not only during stimulation, but also in between stimuli in engaged trials. We next explored if this decrease in variability was associated with an increased information encoding. Our information theory analysis revealed increased information content in auditory responses during engagement compared with idle states, in particular in the responses to task-relevant stimuli. Altogether, we demonstrate that task-engagement significantly modulates coding properties of auditory cortical neurons during an interval-discrimination task. PMID:23945780

  19. Microglia recapitulate a hematopoietic master regulator network in the aging human frontal cortex.

    Science.gov (United States)

    Wehrspaun, Claudia C; Haerty, Wilfried; Ponting, Chris P

    2015-08-01

    Microglia form the immune system of the brain. Previous studies in cell cultures and animal models suggest altered activation states and cellular senescence in the aged brain. Instead, we analyzed 3 transcriptome data sets from the postmortem frontal cortex of 381 control individuals to show that microglia gene markers assemble into a transcriptional module in a gene coexpression network. These markers predominantly represented M1 and M1/M2b activation phenotypes. Expression of genes in this module generally declines over the adult life span. This decrease was more pronounced in microglia surface receptors for microglia and/or neuron crosstalk than in markers for activation state phenotypes. In addition to these receptors for exogenous signals, microglia are controlled by brain-expressed regulatory factors. We identified a subnetwork of transcription factors, including RUNX1, IRF8, PU.1, and TAL1, which are master regulators (MRs) for the age-dependent microglia module. The causal contributions of these MRs on the microglia module were verified using publicly available ChIP-Seq data. Interactions of these key MRs were preserved in a protein-protein interaction network. Importantly, these MRs appear to be essential for regulating microglia homeostasis in the adult human frontal cortex in addition to their crucial roles in hematopoiesis and myeloid cell-fate decisions during embryogenesis. PMID:26002684

  20. Microbiota-driven transcriptional changes in prefrontal cortex override genetic differences in social behavior.

    Science.gov (United States)

    Gacias, Mar; Gaspari, Sevasti; Santos, Patricia-Mae G; Tamburini, Sabrina; Andrade, Monica; Zhang, Fan; Shen, Nan; Tolstikov, Vladimir; Kiebish, Michael A; Dupree, Jeffrey L; Zachariou, Venetia; Clemente, Jose C; Casaccia, Patrizia

    2016-01-01

    Gene-environment interactions impact the development of neuropsychiatric disorders, but the relative contributions are unclear. Here, we identify gut microbiota as sufficient to induce depressive-like behaviors in genetically distinct mouse strains. Daily gavage of vehicle (dH2O) in nonobese diabetic (NOD) mice induced a social avoidance behavior that was not observed in C57BL/6 mice. This was not observed in NOD animals with depleted microbiota via oral administration of antibiotics. Transfer of intestinal microbiota, including members of the Clostridiales, Lachnospiraceae and Ruminococcaceae, from vehicle-gavaged NOD donors to microbiota-depleted C57BL/6 recipients was sufficient to induce social avoidance and change gene expression and myelination in the prefrontal cortex. Metabolomic analysis identified increased cresol levels in these mice, and exposure of cultured oligodendrocytes to this metabolite prevented myelin gene expression and differentiation. Our results thus demonstrate that the gut microbiota modifies the synthesis of key metabolites affecting gene expression in the prefrontal cortex, thereby modulating social behavior. PMID:27097105

  1. Posterior Parietal Cortex Drives Inferotemporal Activations During Three-Dimensional Object Vision.

    Directory of Open Access Journals (Sweden)

    Ilse C Van Dromme

    2016-04-01

    Full Text Available The primate visual system consists of a ventral stream, specialized for object recognition, and a dorsal visual stream, which is crucial for spatial vision and actions. However, little is known about the interactions and information flow between these two streams. We investigated these interactions within the network processing three-dimensional (3D object information, comprising both the dorsal and ventral stream. Reversible inactivation of the macaque caudal intraparietal area (CIP during functional magnetic resonance imaging (fMRI reduced fMRI activations in posterior parietal cortex in the dorsal stream and, surprisingly, also in the inferotemporal cortex (ITC in the ventral visual stream. Moreover, CIP inactivation caused a perceptual deficit in a depth-structure categorization task. CIP-microstimulation during fMRI further suggests that CIP projects via posterior parietal areas to the ITC in the ventral stream. To our knowledge, these results provide the first causal evidence for the flow of visual 3D information from the dorsal stream to the ventral stream, and identify CIP as a key area for depth-structure processing. Thus, combining reversible inactivation and electrical microstimulation during fMRI provides a detailed view of the functional interactions between the two visual processing streams.

  2. An increase in tobacco craving is associated with enhanced medial prefrontal cortex network coupling.

    Directory of Open Access Journals (Sweden)

    Amy C Janes

    Full Text Available Craving is a key aspect of drug dependence that is thought to motivate continued drug use. Numerous brain regions have been associated with craving, suggesting that craving is mediated by a distributed brain network. Whether an increase in subjective craving is associated with enhanced interactions among brain regions was evaluated using resting state functional magnetic imaging (fMRI in nicotine dependent participants. We focused on craving-related changes in the orbital and medial prefrontal cortex (OMPFC network, which also included the subgenual anterior cingulate cortex (sgACC extending into the ventral striatum. Brain regions in the OMPFC network are not only implicated in addiction and reward, but, due to their rich anatomic interconnections, may serve as the site of integration across craving-related brain regions. Subjective craving and resting state fMRI were evaluated twice with an ∼1 hour delay between the scans. Cigarette craving was significantly increased at the end, relative to the beginning of the scan session. Enhanced craving was associated with heightened coupling between the OMPFC network and other cortical, limbic, striatal, and visceromotor brain regions that are both anatomically interconnected with the OMPFC, and have been implicated in addiction and craving. This is the first demonstration confirming that an increase in craving is associated with enhanced brain region interactions, which may play a role in the experience of craving.

  3. What makes the dorsomedial frontal cortex active during reading the mental states of others?

    Directory of Open Access Journals (Sweden)

    Masaki eIsoda

    2013-12-01

    Full Text Available The dorsomedial frontal part of the cerebral cortex is consistently activated when people read the mental states of others, such as their beliefs, desires, and intentions, the ability known as having a theory of mind (ToM or mentalizing. This ubiquitous finding has led many researchers to conclude that the dorsomedial frontal cortex (DMFC constitutes a core component in mentalizing networks. Despite this, it remains unclear why the DMFC becomes active during ToM tasks. We argue that key psychological and behavioral aspects in mentalizing are closely associated with DMFC functions. These include executive inhibition, distinction between self and others, prediction under uncertainty, and perception of intentions, all of which are important for predicting others’ intention and behavior. We review the literature supporting this claim, ranging in fields from developmental psychology to human neuroimaging and macaque electrophysiology. Because perceiving intentions in others’ actions initiates mentalizing and forms the basis of virtually all types of social interaction, the fundamental issue in social neuroscience is to determine the aspects of physical entities that make an observer perceive that they are intentional beings and to clarify the neurobiological underpinnings of the perception of intentionality in others’ actions.

  4. What makes the dorsomedial frontal cortex active during reading the mental states of others?

    Science.gov (United States)

    Isoda, Masaki; Noritake, Atsushi

    2013-01-01

    The dorsomedial frontal part of the cerebral cortex is consistently activated when people read the mental states of others, such as their beliefs, desires, and intentions, the ability known as having a theory of mind (ToM) or mentalizing. This ubiquitous finding has led many researchers to conclude that the dorsomedial frontal cortex (DMFC) constitutes a core component in mentalizing networks. Despite this, it remains unclear why the DMFC becomes active during ToM tasks. We argue that key psychological and behavioral aspects in mentalizing are closely associated with DMFC functions. These include executive inhibition, distinction between self and others, prediction under uncertainty, and perception of intentions, all of which are important for predicting others' intention and behavior. We review the literature supporting this claim, ranging in fields from developmental psychology to human neuroimaging and macaque electrophysiology. Because perceiving intentions in others' actions initiates mentalizing and forms the basis of virtually all types of social interaction, the fundamental issue in social neuroscience is to determine the aspects of physical entities that make an observer perceive that they are intentional beings and to clarify the neurobiological underpinnings of the perception of intentionality in others' actions. PMID:24367287

  5. Excitotoxic lesion of the perirhinal cortex impairs spatial working memory in a delayed-alternation task.

    Science.gov (United States)

    Maioli, Silvia; Gangarossa, Giuseppe; Locchi, Federica; Andrioli, Anna; Bertini, Giuseppe; Rimondini, Roberto

    2012-05-01

    The perirhinal cortex (PRh) is strategically located between the neocortex and memory-related structures such as the entorhinal cortex and the hippocampal formation. The pattern of strong reciprocal connections between these areas, together with experimental evidence that PRh damage induces specific memory deficits, has placed this cortical region at the center of a growing interest for its role in learning and memory mechanisms. The aim of the present study is to clarify the involvement of PRh in learning and retention in a novel experimental model of spatial working memory, the water T-maze. The data show that pre-acquisition neurotoxic PRh lesions caused task-learning deficits. This impairment was observed during the acquisition phase as well as the retrieval phase. On the other hand, a post-acquisition PRh neurotoxic lesion failed to impair the acquisition and the retrieval of the water T-maze task performed 32 day after lesion. These results suggest a possible key role of PRh in the acquisition but not in the retention of a working memory task. Furthermore, these results show that the water T-maze may be a suitable learning paradigm to study different components of learning and memory. PMID:22391121

  6. Cues, context, and long-term memory: the role of the retrosplenial cortex in spatial cognition

    Directory of Open Access Journals (Sweden)

    Adam M P Miller

    2014-08-01

    Full Text Available Spatial navigation requires representations of landmarks and other navigation cues. The retrosplenial cortex (RSC is anatomically positioned between limbic areas important for memory formation, such as the hippocampus and the anterior thalamus, and cortical regions along the dorsal stream known to contribute importantly to long-term spatial representation, such as the posterior parietal cortex. Damage to the RSC severely impairs allocentric representations of the environment, including the ability to derive navigational information from landmarks. The specific deficits seen in tests of human and rodent navigation suggest that the RSC supports allocentric representation by processing the stable features of the environment and the spatial relationships among them. In addition to spatial cognition, the RSC plays a key role in contextual and episodic memory. The RSC also contributes importantly to the acquisition and consolidation of long-term spatial and contextual memory through its interactions with the hippocampus. Within this framework, the RSC plays a dual role as part of the feedforward network providing sensory and mnemonic input to the hippocampus and as a target of the hippocampal-dependent systems consolidation of long-term memory.

  7. Distinct Subthreshold Mechanisms Underlying Rate-Coding Principles in Primate Auditory Cortex.

    Science.gov (United States)

    Gao, Lixia; Kostlan, Kevin; Wang, Yunyan; Wang, Xiaoqin

    2016-08-17

    A key computational principle for encoding time-varying signals in auditory and somatosensory cortices of monkeys is the opponent model of rate coding by two distinct populations of neurons. However, the subthreshold mechanisms that give rise to this computation have not been revealed. Because the rate-coding neurons are only observed in awake conditions, it is especially challenging to probe their underlying cellular mechanisms. Using a novel intracellular recording technique that we developed in awake marmosets, we found that the two types of rate-coding neurons in auditory cortex exhibited distinct subthreshold responses. While the positive-monotonic neurons (monotonically increasing firing rate with increasing stimulus repetition frequency) displayed sustained depolarization at high repetition frequency, the negative-monotonic neurons (opposite trend) instead exhibited hyperpolarization at high repetition frequency but sustained depolarization at low repetition frequency. The combination of excitatory and inhibitory subthreshold events allows the cortex to represent time-varying signals through these two opponent neuronal populations. PMID:27478016

  8. Direction-dependent activation of the insular cortex during vertical and horizontal hand movements.

    Science.gov (United States)

    Rousseau, C; Fautrelle, L; Papaxanthis, C; Fadiga, L; Pozzo, T; White, O

    2016-06-14

    The planning of any motor action requires a complex multisensory processing by the brain. Gravity - immutable on Earth - has been shown to be a key input to these mechanisms. Seminal fMRI studies performed during visual perception of falling objects and self-motion demonstrated that humans represent the action of gravity in parts of the cortical vestibular system; in particular, the insular cortex and the cerebellum. However, little is known as to whether a specific neural network is engaged when processing non-visual signals relevant to gravity. We asked participants to perform vertical and horizontal hand movements without visual control, while lying in a 3T-MRI scanner. We highlighted brain regions activated in the processing of vertical movements, for which the effects of gravity changed during execution. Precisely, the left insula was activated in vertical movements and not in horizontal movements. Moreover, the network identified by contrasting vertical and horizontal movements overlapped with neural correlates previously associated to the processing of simulated self-motion and visual perception of the vertical direction. Interestingly, we found that the insular cortex activity is direction-dependent which suggests that this brain region processes the effects of gravity on the moving limbs through non-visual signals. PMID:27001175

  9. Characterization of auditory synaptic inputs to gerbil perirhinal cortex

    Directory of Open Access Journals (Sweden)

    Vibhakar C Kotak

    2015-08-01

    Full Text Available The representation of acoustic cues involves regions downstream from the auditory cortex (ACx. One such area, the perirhinal cortex (PRh, processes sensory signals containing mnemonic information. Therefore, our goal was to assess whether PRh receives auditory inputs from the auditory thalamus (MG and ACx in an auditory thalamocortical brain slice preparation and characterize these afferent-driven synaptic properties. When the MG or ACx was electrically stimulated, synaptic responses were recorded from the PRh neurons. Blockade of GABA-A receptors dramatically increased the amplitude of evoked excitatory potentials. Stimulation of the MG or ACx also evoked calcium transients in most PRh neurons. Separately, when fluoro ruby was injected in ACx in vivo, anterogradely labeled axons and terminals were observed in the PRh. Collectively, these data show that the PRh integrates auditory information from the MG and ACx and that auditory driven inhibition dominates the postsynaptic responses in a non-sensory cortical region downstream from the auditory cortex.

  10. Individuals' and groups' intentions in the medial prefrontal cortex.

    Science.gov (United States)

    Chaminade, Thierry; Kawato, Mitsuo; Frith, Chris

    2011-11-16

    Functional MRI signal was recorded while participants perceived stimuli presented using moving dots. In two conditions of interest, the motion of dots depicted intentions: dots representing the joints of an agent performing an action, and dots representing individual agents behaving contingently. The finding of a common cluster in the posterior part of the medial frontal cortex involved in intentional action representation validates the hypothesis that perception of these two conditions requires a similar internal representation. A cluster responding to the behaving group only is found in the anterior medial frontal cortex. These results support a division of the medial frontal cortex according to social stimuli attributes, with anterior areas responding to higher-order group behaviours integrating the action of multiple individual agents. PMID:21897305

  11. Associative Hebbian Synaptic Plasticity in Primate Visual Cortex

    Science.gov (United States)

    Huang, Shiyong; Rozas, Carlos; Treviño, Mario; Contreras, Jessica; Yang, Sunggu; Song, Lihua; Yoshioka, Takashi; Lee, Hey-Kyoung

    2014-01-01

    In primates, the functional connectivity of adult primary visual cortex is susceptible to be modified by sensory training during perceptual learning. It is widely held that this type of neural plasticity might involve mechanisms like long-term potentiation (LTP) and long-term depression (LTD). NMDAR-dependent forms of LTP and LTD are particularly attractive because in rodents they can be induced in a Hebbian manner by near coincidental presynaptic and postsynaptic firing, in a paradigm termed spike timing-dependent plasticity (STDP). These fundamental properties of LTP and LTD, Hebbian induction and NMDAR dependence, have not been examined in primate cortex. Here we demonstrate these properties in the primary visual cortex of the rhesus macaque (Macaca mulatta), and also show that, like in rodents, STDP is gated by neuromodulators. These findings indicate that the cellular principles governing cortical plasticity are conserved across mammalian species, further validating the use of rodents as a model system. PMID:24872561

  12. Adaptation to sensory input tunes visual cortex to criticality

    Science.gov (United States)

    Shew, Woodrow L.; Clawson, Wesley P.; Pobst, Jeff; Karimipanah, Yahya; Wright, Nathaniel C.; Wessel, Ralf

    2015-08-01

    A long-standing hypothesis at the interface of physics and neuroscience is that neural networks self-organize to the critical point of a phase transition, thereby optimizing aspects of sensory information processing. This idea is partially supported by strong evidence for critical dynamics observed in the cerebral cortex, but the impact of sensory input on these dynamics is largely unknown. Thus, the foundations of this hypothesis--the self-organization process and how it manifests during strong sensory input--remain unstudied experimentally. Here we show in visual cortex and in a computational model that strong sensory input initially elicits cortical network dynamics that are not critical, but adaptive changes in the network rapidly tune the system to criticality. This conclusion is based on observations of multifaceted scaling laws predicted to occur at criticality. Our findings establish sensory adaptation as a self-organizing mechanism that maintains criticality in visual cortex during sensory information processing.

  13. Altered intrinsic connectivity of the auditory cortex in congenital amusia.

    Science.gov (United States)

    Leveque, Yohana; Fauvel, Baptiste; Groussard, Mathilde; Caclin, Anne; Albouy, Philippe; Platel, Hervé; Tillmann, Barbara

    2016-07-01

    Congenital amusia, a neurodevelopmental disorder of music perception and production, has been associated with abnormal anatomical and functional connectivity in a right frontotemporal pathway. To investigate whether spontaneous connectivity in brain networks involving the auditory cortex is altered in the amusic brain, we ran a seed-based connectivity analysis, contrasting at-rest functional MRI data of amusic and matched control participants. Our results reveal reduced frontotemporal connectivity in amusia during resting state, as well as an overconnectivity between the auditory cortex and the default mode network (DMN). The findings suggest that the auditory cortex is intrinsically more engaged toward internal processes and less available to external stimuli in amusics compared with controls. Beyond amusia, our findings provide new evidence for the link between cognitive deficits in pathology and abnormalities in the connectivity between sensory areas and the DMN at rest. PMID:27009161

  14. Visual cortex controls retinal output in the rat.

    Science.gov (United States)

    Molotchnikoff, S; Tremblay, F

    1986-07-01

    The first objective of the present investigation was to shed more light on corticofugal influences on the retina by providing an analysis of the type and proportion of retinal ganglion cells that are affected by cooling the visual cortex in rats. The second question was to determine if the pretectum participates in functional cortico-retinal relationships. In urethane-anesthetized and paralyzed hooded rats, axonal activity of retinal ganglion cells was recorded with glass micropipettes at optic chiasm level. Units were classified as ON, OFF, suppressed-by-light and concentric. The visual cortex was inactivated by cooling its surface with a 4 mm2 steel probe using the Peltier effect. The pretectum was blocked with microinjections of 50 to 100 nanoliters of cobalt ions, lidocaine hydrochloride or KCl. The inactivations and recoveries at both sites were monitored by simultaneously recording evoked field potentials. Interrupting corticofugal impulses caused modifications of the evoked discharge pattern in all types of cells. The concentric type was the group least affected by cortical cooling. A common trend emerged suggesting that cooling of the visual cortex led to an enhancement of the initial evoked excitation. This was often followed by an enhanced post-excitatory inhibition. The Pearson coefficient allowed us to measure the degree of similarity between two histograms. When all data were pooled, a weak correlation between control and test histograms (r = 0.29, N = 56) was found, while the control and recovery patterns averaged a correlation of more than twice that size (r = 0.68). In a second series of experiments, the pretectum and visual cortex (VC) were simultaneously inactivated. It is shown that both sites summed their influence and acted synergistically upon the pattern of ganglion cell responses. The results strongly suggest that the visual cortex exerts a major control over the response pattern of thirty percent of retinal ganglion cells, and that the

  15. Long-term motor cortex stimulation for phantom limb pain.

    Science.gov (United States)

    Pereira, Erlick A C; Moore, Tom; Moir, Liz; Aziz, Tipu Z

    2015-04-01

    We present the long-term course of motor cortex stimulation to relieve a case of severe burning phantom arm pain after brachial plexus injury and amputation. During 16-year follow-up the device continued to provide efficacious analgesia. However, several adjustments of stimulation parameters were required, as were multiple pulse generator changes, antibiotics for infection and one electrode revision due to lead migration. Steady increases in stimulation parameters over time were required. One of the longest follow-ups of motor cortex stimulation is described; the case illustrates challenges and pitfalls in neuromodulation for chronic pain, demonstrating strategies for maintaining analgesia and overcoming tolerance. PMID:25340991

  16. Assembly language programming ARM Cortex-M3

    CERN Document Server

    Mahout, Vincent

    2013-01-01

    ARM designs the cores of microcontrollers which equip most "embedded systems" based on 32-bit processors. Cortex M3 is one of these designs, recently developed by ARM with microcontroller applications in mind. To conceive a particularly optimized piece of software (as is often the case in the world of embedded systems) it is often necessary to know how to program in an assembly language.This book explains the basics of programming in an assembly language, while being based on the architecture of Cortex M3 in detail and developing many examples.It is written for people who have never pr

  17. Three-dimensional microtomographic imaging of human brain cortex

    CERN Document Server

    Mizutania, Ryuta; Uesugi, Kentaro; Ohyama, Masami; Takekoshi, Susumu; Osamura, R Yoshiyuki; Suzuki, Yoshio

    2016-01-01

    This paper describes an x-ray microtomographic technique for imaging the three-dimensional structure of the human cerebral cortex. Neurons in the brain constitute a neural circuit as a three-dimensional network. The brain tissue is composed of light elements that give little contrast in a hard x-ray transmission image. The contrast was enhanced by staining neural cells with metal compounds. The obtained structure revealed the microarchitecture of the gray and white matter regions of the frontal cortex, which is responsible for the higher brain functions.

  18. KeyPathwayMinerWeb

    DEFF Research Database (Denmark)

    List, Markus; Alcaraz, Nicolas; Dissing-Hansen, Martin;

    2016-01-01

    We present KeyPathwayMinerWeb, the first online platform for de novo pathway enrichment analysis directly in the browser. Given a biological interaction network (e.g. protein-protein interactions) and a series of molecular profiles derived from one or multiple OMICS studies (gene expression, for...... instance), KeyPathwayMiner extracts connected sub-networks containing a high number of active or differentially regulated genes (proteins, metabolites) in the molecular profiles. The web interface at (http://keypathwayminer.compbio.sdu.dk) implements all core functionalities of the KeyPathwayMiner tool set...... such as data integration, input of background knowledge, batch runs for parameter optimization and visualization of extracted pathways. In addition to an intuitive web interface, we also implemented a RESTful API that now enables other online developers to integrate network enrichment as a web service...

  19. Key Lake spill. Final report

    International Nuclear Information System (INIS)

    On January 5, 1984 contaminated water overflowed a storage reservoir at the Key Lake uranium mill onto the ice on a neighboring lake, into a muskeg area and onto a road. Outflow continued for two days, partially undercutting a retaining dyke. This report concludes the spill was the result of poor operation by the Key Lake Mining Corp.. The environmental impact will be minimal after cleanup. Improvements can be made in the regulatory process, and it is necessary to prepare for possible future mishaps

  20. Key World Energy Statistics 2013

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-01

    The IEA produced its first handy, pocket-sized summary of key energy data in 1997 and every year since then it has been more and more successful. Key World Energy Statistics contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts.

  1. Key China Energy Statistics 2011

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-01-15

    The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). In 2008 the Group published the Seventh Edition of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.

  2. Key China Energy Statistics 2012

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). The Group has published seven editions to date of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.

  3. Key Revocation System for DNSSEC

    Directory of Open Access Journals (Sweden)

    Gilles Guette

    2008-06-01

    Full Text Available The Doma in Name System (DNS is a distributed tree-based database largely used to translate a human readable machine name into an IP address. The DNS security extensions (DNSSEC has been designed to protect the DNS protocol using public key cryptography and digital signatures. In this paper, we show how DNSSEC can be attacked using compromised keys and the consequences of such attacks. Then, we propose a new revocation scheme for DNSSEC based on two new resource records. There is currently no revocation system defined in the DNSSEC standard.

  4. Synaptic molecular imaging in spared and deprived columns of mouse barrel cortex with array tomography.

    Science.gov (United States)

    Weiler, Nicholas C; Collman, Forrest; Vogelstein, Joshua T; Burns, Randal; Smith, Stephen J

    2014-01-01

    A major question in neuroscience is how diverse subsets of synaptic connections in neural circuits are affected by experience dependent plasticity to form the basis for behavioral learning and memory. Differences in protein expression patterns at individual synapses could constitute a key to understanding both synaptic diversity and the effects of plasticity at different synapse populations. Our approach to this question leverages the immunohistochemical multiplexing capability of array tomography (ATomo) and the columnar organization of mouse barrel cortex to create a dataset comprising high resolution volumetric images of spared and deprived cortical whisker barrels stained for over a dozen synaptic molecules each. These dataset has been made available through the Open Connectome Project for interactive online viewing, and may also be downloaded for offline analysis using web, Matlab, and other interfaces. PMID:25977797

  5. High baseline activity in inferior temporal cortex improves neural and behavioral discriminability during visual categorization

    Directory of Open Access Journals (Sweden)

    Nazli eEmadi

    2014-11-01

    Full Text Available Spontaneous firing is a ubiquitous property of neural activity in the brain. Recent literature suggests that this baseline activity plays a key role in perception. However, it is not known how the baseline activity contributes to neural coding and behavior. Here, by recording from the single neurons in the inferior temporal cortex of monkeys performing a visual categorization task, we thoroughly explored the relationship between baseline activity, the evoked response, and behavior. Specifically we found that a low-frequency (< 8 Hz oscillation in the spike train, prior and phase-locked to the stimulus onset, was correlated with increased gamma power and neuronal baseline activity. This enhancement of the baseline activity was then followed by an increase in the neural selectivity and the response reliability and eventually a higher behavioral performance.

  6. A central role for the retrosplenial cortex in de novo environmental learning.

    Science.gov (United States)

    Auger, Stephen D; Zeidman, Peter; Maguire, Eleanor A

    2015-01-01

    With experience we become accustomed to the types of environments that we normally encounter as we navigate in the world. But how does this fundamental knowledge develop in the first place and what brain regions are involved? To examine de novo environmental learning, we created an 'alien' virtual reality world populated with landmarks of which participants had no prior experience. They learned about this environment by moving within it during functional MRI (fMRI) scanning while we tracked their evolving knowledge. Retrosplenial cortex (RSC) played a central and highly selective role by representing only the most stable, permanent features in this world. Subsequently, increased coupling was noted between RSC and hippocampus, with hippocampus then expressing knowledge of permanent landmark locations and overall environmental layout. Studying how environmental representations emerge from scratch provided a new window into the information processing underpinning the brain's navigation system, highlighting the key influence of the RSC. PMID:26284602

  7. Auditory sequence processing reveals evolutionarily conserved regions of frontal cortex in macaques and humans.

    Science.gov (United States)

    Wilson, Benjamin; Kikuchi, Yukiko; Sun, Li; Hunter, David; Dick, Frederic; Smith, Kenny; Thiele, Alexander; Griffiths, Timothy D; Marslen-Wilson, William D; Petkov, Christopher I

    2015-01-01

    An evolutionary account of human language as a neurobiological system must distinguish between human-unique neurocognitive processes supporting language and evolutionarily conserved, domain-general processes that can be traced back to our primate ancestors. Neuroimaging studies across species may determine whether candidate neural processes are supported by homologous, functionally conserved brain areas or by different neurobiological substrates. Here we use functional magnetic resonance imaging in Rhesus macaques and humans to examine the brain regions involved in processing the ordering relationships between auditory nonsense words in rule-based sequences. We find that key regions in the human ventral frontal and opercular cortex have functional counterparts in the monkey brain. These regions are also known to be associated with initial stages of human syntactic processing. This study raises the possibility that certain ventral frontal neural systems, which play a significant role in language function in modern humans, originally evolved to support domain-general abilities involved in sequence processing. PMID:26573340

  8. MOVING OBSTACLE DETECTION AND REMOTE VIDEO MONITORING SYSTEM USING CORTEX-A8

    Directory of Open Access Journals (Sweden)

    V.PADMAJA, KAVITHA MAMINDLA

    2013-11-01

    Full Text Available In this paper the Detection of Moving obstacle and remote video monitoring and extracting the key frames from the captured video system based on high performance SAMSUNG S5PV210 CORTEX-A8 processor core is build and expanding peripheral devices using embedded Linux as the operating system. Today monitoring systems are either webcam based or simple motion detection based. Here we have interfaced both webcam and PIR sensor to the embedded system so that the user can get an immediate alert message and can take necessary steps. This system is based on the kernel of Cortex board with the GSM module being triggered by a Pyroelectric Infrared Sensor (PIR, which senses changes in the external temperature, especially in this case when an invader enters in to remote location and send SMS to the user. At the same time, by using a smart device or a PC, the user can link to the video streaming server constructed on the embedded board via the internet and browse the webpage to monitor the surveillance area, here the UVC driver and V4L programming is used to interface USB camera to the board to capture video information and then board will do two parallel works first one is transmits the processed captured video information using wireless network, which will be collected and monitored at client side using wireless network connection through the wireless device, second one is extracts the key frames from captured video using OpenCV and served on a server, the both provides an advantage to surveillance monitoring system.

  9. Overview, conclusions, and key recommendations

    NARCIS (Netherlands)

    R. Loeber; D.P. Farrington; J.C. Howell; M. Hoeve

    2012-01-01

    Section I of this chapter summarizes the most important points of Chapters 2 to 5 and relevant portions of Chapter 10 (which concerns European issues) by addressing key findings that are relevant for juveniles’ transition of offending from adolescence (up to age 18) into adulthood. Section I focuses

  10. Grouted Connections with Shear Keys

    DEFF Research Database (Denmark)

    Pedersen, Ronnie; Jørgensen, M. B.; Damkilde, Lars;

    2012-01-01

    This paper presents a finite element model in the software package ABAQUS in which a reliable analysis of grouted pile-to-sleeve connections with shear keys is the particular purpose. The model is calibrated to experimental results and a consistent set of input parameters is estimated so that...... different structural problems can be reproduced successfully....

  11. Key to marine arthropod larvae

    Directory of Open Access Journals (Sweden)

    John A. Fornshell

    2012-03-01

    Full Text Available The scope of this key is restricted to the larvae of marine arthropods. The key is based solely on their morphology, patterns of body segmentation, numbers of appendages, and mode of locomotion. An effort has been made to treat all traditionally named larval forms, both planktonic and benthic. It is intended that this key be useful for a researcher working with archived museum specimens and therefore, does not include habitat information as a identifying trait, even though this information is usually available in the archived records. Within the phylum Arthropoda there are two sub-phyla and eleven classes having larval stages in the marineenvironment. Where feasible the original names of the various larval types have been used. Because this nomenclature is less commonly used today compared to the past, the more recent taxonomic affinities are included in parentheses after the original larval name. The key includes the following thirty-four larvae: Branchhiopoda nauplii; Cephalocarida nauplii; Mystacocarida nauplii; trilobite larva; protonymphon; hexapod larvae; Remipedia nauplii; nauplius - Y larvae; Cirripedia nauplii; Ascothoracida nauplii; Ostracoda nauplii; Euphausiacea nauplii; Penaeidea nauplii; Cyclopoida nauplii; Calanoida nauplii; Harpacticoida nauplii;Polyarthra nauplii; cypris larva; eryonecius larva; cypris-Y larva; elapthocaris larvae; mysis larvae; lucifer zoea; acetes zoea; acanthosoma larva; phyllosoma; antizoea larva; anomuran zoea; brachyuran zoea; calyptopis larvae; furcilia larva; crytopia larva; puerulus larva; alima larva.

  12. Key Elements of Social Innovation

    OpenAIRE

    Allyson Hewitt

    2008-01-01

    This article describes four key elements of social innovation: i) social technology; ii) innovation intermediaries; iii) people who drive innovation; and iv) openness. By taking experiences from social technology and examining the impact of "open everything", this article posits the value of innovation intermediaries as critical enablers of success in the emergent field of social innovation.

  13. Key World Energy Statistics 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Key World Energy Statistics contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts.

  14. Age-related changes in the attentional control of visual cortex: A selective problem in the left visual hemifield

    OpenAIRE

    Nagamatsu, Lindsay S.; Carolan, Patrick; Liu-Ambrose, Teresa Y L; Handy, Todd C

    2011-01-01

    To what extent does our visual-spatial attention change with age? In this regard, it has been previously reported that relative to young controls, seniors show delays in attention-related sensory facilitation. Given this finding, our study was designed to examine two key questions regarding age-related changes in the effect of spatial attention on sensory-evoked responses in visual cortex –– are there visual field differences in the age-related impairments in sensory processing, and do these ...

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

    OpenAIRE

    Zavala, B.; Tan, H.; Ashkan, K; Foltynie, T. (Thomas); Limousin, P. (Patricia); Zrinzo, L.; Zaghloul, K; P. Brown

    2016-01-01

    The medial prefrontal cortex (mPFC) is thought to control the shift from automatic to controlled action selection when conflict is present or when mistakes have been recently committed. Growing evidence suggests that this process involves frequency specific communication in the theta (4-8Hz) band between the mPFC and the subthalamic nucleus (STN), which is the main target of deep brain stimulation (DBS) for Parkinson's disease. Key in this hypothesis is the finding that DBS can lead to impuls...

  16. A Mediating Role of the Premotor Cortex in Phoneme Segmentation

    Science.gov (United States)

    Sato, Marc; Tremblay, Pascale; Gracco, Vincent L.

    2009-01-01

    Consistent with a functional role of the motor system in speech perception, disturbing the activity of the left ventral premotor cortex by means of repetitive transcranial magnetic stimulation (rTMS) has been shown to impair auditory identification of syllables that were masked with white noise. However, whether this region is crucial for speech…

  17. Impulsivity, the orbifrontal cortex and borderline personality disorder

    OpenAIRE

    Berlin, Heather.; Iverson, Susan.; Edmund Rolls, Susan Iverson

    2003-01-01

    Damage to the orbitofrontal cortex (OFC) has been associated with disinhibited or socially inappropriate behaviour and emotional irregularities in both humans and monkeys. Prominent characteristics of several personality disorder syndromes, in particular Borderline Personality Disorder (BPD), are impulsivity and affective instability. This investigation aimed to determine if certain aspects of the Borderline Personality syndrome, in particular impulsivity, are associated with ...

  18. Stimulus Dependence of Gamma Oscillations in Human Visual Cortex.

    Science.gov (United States)

    Hermes, D; Miller, K J; Wandell, B A; Winawer, J

    2015-09-01

    A striking feature of some field potential recordings in visual cortex is a rhythmic oscillation within the gamma band (30-80 Hz). These oscillations have been proposed to underlie computations in perception, attention, and information transmission. Recent studies of cortical field potentials, including human electrocorticography (ECoG), have emphasized another signal within the gamma band, a nonoscillatory, broadband signal, spanning 80-200 Hz. It remains unclear under what conditions gamma oscillations are elicited in visual cortex, whether they are necessary and ubiquitous in visual encoding, and what relationship they have to nonoscillatory, broadband field potentials. We demonstrate that ECoG responses in human visual cortex (V1/V2/V3) can include robust narrowband gamma oscillations, and that these oscillations are reliably elicited by some spatial contrast patterns (luminance gratings) but not by others (noise patterns and many natural images). The gamma oscillations can be conspicuous and robust, but because they are absent for many stimuli, which observers can see and recognize, the oscillations are not necessary for seeing. In contrast, all visual stimuli induced broadband spectral changes in ECoG responses. Asynchronous neural signals in visual cortex, reflected in the broadband ECoG response, can support transmission of information for perception and recognition in the absence of pronounced gamma oscillations. PMID:24855114

  19. Development of Rostral Prefrontal Cortex and Cognitive and Behavioural Disorders

    Science.gov (United States)

    Dumontheil, Iroise; Burgess, Paul W.; Blakemore, Sarah-Jayne

    2008-01-01

    Information on the development and functions of rostral prefrontal cortex (PFC), or Brodmann area 10, has been gathered from different fields, from anatomical development to functional neuroimaging in adults, and put forward in relation to three particular cognitive and behavioural disorders. Rostral PFC is larger and has a lower cell density in…

  20. Adrenal cortex glucocorticoid function at irradiated animals on mumio leading

    International Nuclear Information System (INIS)

    In this chapter author made conclusion that the leading of mumio preparation provide normalizing influence on hypophysis-cortex adrenal system not only at short-term irradiation but and at long-term irradiation that is propitious condition for normalisation exchange processes in the cells

  1. Wrinkling of a spherical lipid interface induced by actomyosin cortex

    Science.gov (United States)

    Ito, Hiroaki; Nishigami, Yukinori; Sonobe, Seiji; Ichikawa, Masatoshi

    2015-12-01

    Actomyosin actively generates contractile forces that provide the plasma membrane with the deformation stresses essential to carry out biological processes. Although the contractile property of purified actomyosin has been extensively studied, to understand the physical contribution of the actomyosin contractile force on a deformable membrane is still a challenging problem and of great interest in the field of biophysics. Here, we reconstitute a model system with a cell-sized deformable interface that exhibits anomalous curvature-dependent wrinkling caused by the actomyosin cortex underneath the spherical closed interface. Through a shape analysis of the wrinkling deformation, we find that the dominant contributor to the wrinkled shape changes from bending elasticity to stretching elasticity of the reconstituted cortex upon increasing the droplet curvature radius of the order of the cell size, i.e., tens of micrometers. The observed curvature dependence is explained by the theoretical description of the cortex elasticity and contractility. Our present results provide a fundamental insight into the deformation of a curved membrane induced by the actomyosin cortex.

  2. Functional sex differences in human primary auditory cortex

    NARCIS (Netherlands)

    Ruytjens, Liesbet; Georgiadis, Janniko R.; Holstege, Gert; Wit, Hero P.; Albers, Frans W. J.; Willemsen, Antoon T. M.

    2007-01-01

    Background We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a bas

  3. Daily rhythm of synapse turnover in mouse somatosensory cortex.

    Science.gov (United States)

    Jasinska, Malgorzata; Grzegorczyk, Anna; Jasek, Ewa; Litwin, Jan A; Kossut, Malgorzata; Barbacka-Surowiak, Grazyna; Pyza, Elzbieta

    2014-01-01

    The whisker representations in the somatosensory barrel cortex of mice are modulated by sensory inputs associated with animal motor behavior which shows circadian rhythmicity. In a C57/BL mouse strain kept under a light/dark (LD 12:12) regime, we observed daily structural changes in the barrel cortex, correlated with the locomotor activity level. Stereological analysis of serial electron microscopic sections of the barrel cortex of mice sacrificed during their active or rest period, revealed an increase in the total numerical density of synapses and in the density of excitatory synapses located on dendritic spines during the rest, as well as an increase in the density of inhibitory synapses located on double-synapse spines during the active period. This is the first report demonstrating a daily rhythm in remodeling of the mammalian somatosensory cortex, manifested by changes in the density of synapses and dendritic spines. Moreover, we have found that the excitatory and inhibitory synapses are differently regulated during the day/night cycle. PMID:24718049

  4. Anterior Cingulate Cortex in Schema Assimilation and Expression

    Science.gov (United States)

    Wang, Szu-Han; Tse, Dorothy; Morris, Richard G. M.

    2012-01-01

    In humans and in animals, mental schemas can store information within an associative framework that enables rapid and efficient assimilation of new information. Using a hippocampal-dependent paired-associate task, we now report that the anterior cingulate cortex is part of a neocortical network of schema storage with NMDA receptor-mediated…

  5. Spindle neurons of the human anterior cingulate cortex

    Science.gov (United States)

    Nimchinsky, E. A.; Vogt, B. A.; Morrison, J. H.; Hof, P. R.; Bloom, F. E. (Principal Investigator)

    1995-01-01

    The human anterior cingulate cortex is distinguished by the presence of an unusual cell type, a large spindle neuron in layer Vb. This cell has been noted numerous times in the historical literature but has not been studied with modern neuroanatomic techniques. For instance, details regarding the neuronal class to which these cells belong and regarding their precise distribution along both ventrodorsal and anteroposterior axes of the cingulate gyrus are still lacking. In the present study, morphological features and the anatomic distribution of this cell type were studied using computer-assisted mapping and immunocytochemical techniques. Spindle neurons are restricted to the subfields of the anterior cingulate cortex (Brodmann's area 24), exhibiting a greater density in anterior portions of this area than in posterior portions, and tapering off in the transition zone between anterior and posterior cingulate cortex. Furthermore, a majority of the spindle cells at any level is located in subarea 24b on the gyral surface. Immunocytochemical analysis revealed that the neurofilament protein triple was present in a large percentage of these neurons and that they did not contain calcium-binding proteins. Injections of the carbocyanine dye DiI into the cingulum bundle revealed that these cells are projection neurons. Finally, spindle cells were consistently affected in Alzheimer's disease cases, with an overall loss of about 60%. Taken together, these observations indicate that the spindle cells of the human cingulate cortex represent a morphological subpopulation of pyramidal neurons whose restricted distribution may be associated with functionally distinct areas.

  6. Androgen receptor immunoreactivity in rat occipital cortex after callosotomy

    Directory of Open Access Journals (Sweden)

    G Lepore

    2009-08-01

    Full Text Available Gonadal steroidogenesis can be influenced by direct neural links between the central nervous system and the gonads. It is known that androgen receptor (AR is expressed in many areas of the rat brain involved in neuroendocrine control of reproduction, such as the cerebral cortex. It has been recently shown that the occipital cortex exerts an inhibitory effect on testicular stereoidogenesis by a pituitary-independent neural mechanism. Moreover, the complete transection of the corpus callosum leads to an increase in testosterone (T secretion of hemigonadectomized rats. The present study was undertaken to analyze the possible corticocortical influences regulating male reproductive activities. Adult male Wistar rats were divided into 4 groups: 1 intact animals as control; 2 rats undergoing sham callosotomy; 3 posterior callosotomy; 4 gonadectomy and posterior callosotomy. Western blot analysis showed no remarkable variations in cortical AR expression in any of the groups except in group I where a significant decrease in AR levels was found. Similarly, both immunocytochemical study and cell count estimation showed a lower AR immunoreactivity in occipital cortex of callosotomized rats than in other groups. In addition, there was no difference in serum T and LH concentration between sham-callosotomized and callosotomized rats. In conclusion, our results show that posterior callosotomy led to a reduction in AR in the right occipital cortex suggesting a putative inhibiting effect of the contralateral cortical area.

  7. The Role of the Insular Cortex in Retaliation

    Science.gov (United States)

    Lobbestael, Jill; Arntz, Arnoud; Brugman, Suzanne; Sack, Alexander Thomas

    2016-01-01

    The insular cortex has consistently been associated with various aspects of emotion regulation and social interaction, including anger processing and overt aggression. Aggression research distinguishes proactive or instrumental aggression from retaliation, i.e. aggression in response to provocation. Here, we investigated the specific role of the insular cortex during retaliation, employing a controlled behavioral aggression paradigm implementing different levels of provocation. Fifteen healthy male volunteers underwent whole brain functional magnetic resonance imaging (fMRI) to identify brain regions involved in interaction with either a provoking or a non-provoking opponent. FMRI group analyses were complemented by examining the parametric modulations of brain activity related to the individual level of displayed aggression. These analyses identified a hemispheric lateralization as well as an anatomical segregation of insular cortex with specifically the left posterior part being involved in retaliation. The left-lateralization of insular activity during retaliation is in accordance with evidence from electro-physiological studies, suggesting left-lateralized fronto-cortical dominance during anger processing and aggressive acts. The posterior localization of insular activity, on the other hand, suggests a spatial segregation within insular cortex with particularly the posterior part being involved in the processing of emotions that trigger intense bodily sensations and immediate action tendencies. PMID:27096431

  8. Functional sex differences in human primary auditory cortex

    International Nuclear Information System (INIS)

    We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Our results suggest that sex is an important factor in auditory brain studies. (orig.)

  9. Immunoprofiling of rice root cortex reveals two cortical subdomains

    Directory of Open Access Journals (Sweden)

    Sophia eHenry

    2016-01-01

    Full Text Available The formation and differentiation of aerenchyma, i.e., air-containing cavities that are critical for flooding tolerance, take place exclusively in the cortex. The understanding of development and differentiation of the cortex is thus an important issue; however, studies on this tissue are limited, partly because of the lack of available molecular tools. We screened a commercially available library of cell wall antibodies to identify markers of cortical tissue in rice roots. Out of the 174 antibodies screened, eight were cortex-specific. Our analysis revealed that two types of cortical tissues are present in rice root seedlings. We named these cell layers 'inner' and 'outer' based on their location relative to the stele. We then used the antibodies to clarify cell identity in lateral roots. Without these markers, previous studies could not distinguish between the cortex and sclerenchyma in small lateral roots. By immunostaining lateral root sections, we showed that the internal ground tissue in small lateral roots has outer cortical identity.

  10. Orientation-tuned surround suppression in mouse visual cortex

    NARCIS (Netherlands)

    Self, Matthew W; Lorteije, Jeannette A M; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N; Heimel, J.A.; Roelfsema, Pieter R

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those contai

  11. Extinction Circuits for Fear and Addiction Overlap in Prefrontal Cortex

    Science.gov (United States)

    Peters, Jamie; Kalivas, Peter W.; Quirk, Gregory J.

    2009-01-01

    Extinction is a form of inhibitory learning that suppresses a previously conditioned response. Both fear and drug seeking are conditioned responses that can lead to maladaptive behavior when expressed inappropriately, manifesting as anxiety disorders and addiction, respectively. Recent evidence indicates that the medial prefrontal cortex (mPFC) is…

  12. Perceptual Learning and Dynamic Changes in Primary Visual Cortex

    OpenAIRE

    Carmel, David; Carrasco, Marisa

    2008-01-01

    Perceptual learning is the improved performance that follows practice in a perceptual task. In this issue of Neuron, Yotsumoto et al. use fMRI to show that stimuli presented at the location used in training initially evoke greater activation in primary visual cortex than stimuli presented elsewhere, but this difference disappears once learning asymptotes.

  13. Parietal cortex mediates perceptual Gestalt grouping independent of stimulus size.

    Science.gov (United States)

    Grassi, Pablo R; Zaretskaya, Natalia; Bartels, Andreas

    2016-06-01

    The integration of local moving elements into a unified gestalt percept has previously been linked to the posterior parietal cortex. There are two possible interpretations for the lack of involvement of other occipital regions. The first is that parietal cortex is indeed uniquely functionally specialized to perform grouping. Another possibility is that other visual regions can perform grouping as well, but that the large spatial separation of the local elements used previously exceeded their neurons' receptive field (RF) sizes, preventing their involvement. In this study we distinguished between these two alternatives. We measured whole-brain activity using fMRI in response to a bistable motion illusion that induced mutually exclusive percepts of either an illusory global Gestalt or of local elements. The stimulus was presented in two sizes, a large version known to activate IPS only, and a version sufficiently small to fit into the RFs of mid-level dorsal regions such as V5/MT. We found that none of the separately localized motion regions apart from parietal cortex showed a preference for global Gestalt perception, even for the smaller version of the stimulus. This outcome suggests that grouping-by-motion is mediated by a specialized size-invariant mechanism with parietal cortex as its anatomical substrate. PMID:26975554

  14. Towards a circuit mechanism for movement tuning in motor cortex

    Directory of Open Access Journals (Sweden)

    Thomas C Harrison

    2013-01-01

    Full Text Available The firing rates of neurons in primate motor cortex have been related to multiple parameters of voluntary movement. This finding has been corroborated by stimulation-based studies that have mapped complex movements in rodent and primate motor cortex. However, it has been difficult to link the movement tuning of a neuron with its role within the cortical microcircuit. In sensory cortex, neuronal tuning is largely established by afferents delivering information from tuned receptors in the periphery. Motor cortex, which lacks the granular input layer, may be better understood by analyzing its efferent projections. As a primary source of cortical output, layer 5 neurons represent an ideal starting point for this line of experimentation. It is in these deep output layers that movements can most effectively be evoked by intracortical microstimulation and recordings can obtain the most useful signals for the control of motor prostheses. Studies focused on layer 5 output neurons have revealed that projection identity is a fundamental property related to the laminar position, receptive field and ion channel complement of these cells. Given the variety of brain areas targeted by layer 5 output neurons, knowledge of a neuron’s downstream connectivity may provide insight into its movement tuning. Future experiments that relate motor behavior to the activity of neurons with a known projection identity will yield a more detailed understanding of the function of cortical microcircuits.

  15. Role of Frontal Cortex in Attentional Capture by Singleton Distractors

    Science.gov (United States)

    de Fockert, Jan W.; Theeuwes, Jan

    2012-01-01

    The role of frontal cortex in selective attention to visual distractors was examined in an attentional capture task in which participants searched for a unique shape in the presence or absence of an additional colour singleton distractor. The presence of the additional singleton was associated with slower behavioural responses to the shape target,…

  16. Functional sex differences in human primary auditory cortex

    Energy Technology Data Exchange (ETDEWEB)

    Ruytjens, Liesbet [University Medical Center Groningen, Department of Otorhinolaryngology, Groningen (Netherlands); University Medical Center Utrecht, Department Otorhinolaryngology, P.O. Box 85500, Utrecht (Netherlands); Georgiadis, Janniko R. [University of Groningen, University Medical Center Groningen, Department of Anatomy and Embryology, Groningen (Netherlands); Holstege, Gert [University of Groningen, University Medical Center Groningen, Center for Uroneurology, Groningen (Netherlands); Wit, Hero P. [University Medical Center Groningen, Department of Otorhinolaryngology, Groningen (Netherlands); Albers, Frans W.J. [University Medical Center Utrecht, Department Otorhinolaryngology, P.O. Box 85500, Utrecht (Netherlands); Willemsen, Antoon T.M. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands)

    2007-12-15

    We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Our results suggest that sex is an important factor in auditory brain studies. (orig.)

  17. Comparison of Plasticity In Vivo and In Vitro in the Developing Visual Cortex of Normal and Protein Kinase A RIβ-Deficient Mice

    OpenAIRE

    Hensch, Takao K.; Gordon, Joshua A.; Brandon, Eugene P.; McKnight, G. Stanley; Idzerda, Rejean L.; Stryker, Michael P.

    1998-01-01

    Developing sensory systems are sculpted by an activity-dependent strengthening and weakening of connections. Long-term potentiation (LTP) and depression (LTD) in vitro have been proposed to model this experience-dependent circuit refinement. We directly compared LTP and LTD induction in vitro with plasticity in vivo in the developing visual cortex of a mouse mutant of protein kinase A (PKA), a key enzyme implicated in the plasticity of a diverse array of systems.

  18. Differential erbB signaling in astrocytes from the cerebral cortex and the hypothalamus of the human brain. : ErbB signaling in human astrocytes

    OpenAIRE

    Sharif, Ariane; Duhem-Tonnelle, Véronique; Allet, Cécile; Baroncini, Marc; Loyens, Anne; Kerr-Conte, Julie; Collier, Francis; Blond, Serge; Ojeda, Sergio; Junier, Marie-Pierre; Prévot, Vincent

    2009-01-01

    Studies in rodents have shown that astroglial erbB tyrosine kinase receptors are key regulatory elements in neuron-glia communication. Although both astrocytes and deregulation of erbB functions have been implicated in the pathogenesis of many common human brain disorders, erbB signaling in native human brain astrocytes has never been explored. Taking advantage of our ability to perform primary cultures from the cortex and the hypothalamus of human fetuses, we conducted a thorough analysis of...

  19. The role of prefrontal cortex during postural control in Parkinsonian syndromes a functional near-infrared spectroscopy study.

    Science.gov (United States)

    Mahoney, Jeannette R; Holtzer, Roee; Izzetoglu, Meltem; Zemon, Vance; Verghese, Joe; Allali, Gilles

    2016-02-15

    Postural instability represents a main source of disability in Parkinsonian syndromes and its pathophysiology is poorly understood. Indirect probes (i.e., mental imagery) of brain involvement support the role of prefrontal cortex as a key cortical region for postural control in older adults with and without Parkinsonian syndromes. Using functional near infrared spectroscopy (fNIRs) as a direct online cortical probe, this study aimed to compare neural activation patterns in prefrontal cortex, postural stability, and their respective interactions, in (1) patients with Parkinsonian syndromes; (2) those with mild parkinsonian signs; (3) and healthy older adults. Among 269 non-demented older adults (76.41 ± 6.70 years, 56% women), 26 individuals presented with Parkinsonian syndromes (Unified Parkinson's disease rating scale (UPDRS): 11.08 ± 3.60), 117 had mild parkinsonian signs (UPDRS: 3.21 ± 2.49), and 126 individuals were included as a healthy control group. Participants were asked to stand upright and count silently for ten seconds while changes in oxygenated hemoglobin levels over prefrontal cortex were measured using fNIRs. We simultaneously evaluated postural stability with center of pressure velocity data recorded on an instrumented walkway. Compared to healthy controls and patients with mild parkinsonian signs, patients with Parkinsonian syndromes demonstrated significantly higher prefrontal oxygenation levels to maintain postural stability. The pattern of brain activation and postural control of participants with mild parkinsonian signs were similar to that of normal controls. These findings highlight the online role of the prefrontal cortex in postural control in patients with Parkinsonian syndromes and afford the opportunity to improve therapeutic options for postural instability. PMID:26551767

  20. Neural Dynamics and Information Representation in Microcircuits of Motor Cortex

    Directory of Open Access Journals (Sweden)

    Yasuhiro eTsubo

    2013-05-01

    Full Text Available The brain has to analyze and respond to external events that can change rapidly from time to time, suggesting that information processing by the brain may be essentially dynamic rather than static. The dynamical features of neural computation are of significant importance in motor cortex that governs the process of movement generation and learning. In this paper, we discuss these features based primarily on our recent findings on neural dynamics and information coding in the microcircuit of rat motor cortex. In fact, cortical neurons show a variety of dynamical behavior from rhythmic activity in various frequency bands to highly irregular spike firing. Of particular interest are the similarity and dissimilarity of the neuronal response properties in different layers of motor cortex. By conducting electrophysiological recordings in slice preparation, we report the phase response curves of neurons in different cortical layers to demonstrate their layer-dependent synchronization properties. We then study how motor cortex recruits task-related neurons in different layers for voluntary arm movements by simultaneous juxtacellular and multiunit recordings from behaving rats. The results suggest an interesting difference in the spectrum of functional activity between the superficial and deep layers. Furthermore, the task-related activities recorded from various layers exhibited power law distributions of inter-spike intervals (ISIs, in contrast to a general belief that ISIs obey Poisson or Gamma distributions in cortical neurons. We present a theoretical argument that this power law of in vivo neurons may represent the maximization of the entropy of firing rate with limited energy consumption of spike generation. Though further studies are required to fully clarify the functional implications of this coding principle, it may shed new light on information representations by neurons and circuits in motor cortex.

  1. Infrared thermal imaging of rat somatosensory cortex with whisker stimulation.

    Science.gov (United States)

    Suzuki, Takashi; Ooi, Yasuhiro; Seki, Junji

    2012-04-01

    The present study aims to validate the applicability of infrared (IR) thermal imaging for the study of brain function through experiments on the rat barrel cortex. Regional changes in neural activity within the brain produce alterations in local thermal equilibrium via increases in metabolic activity and blood flow. We studied the relationship between temperature change and neural activity in anesthetized rats using IR imaging to visualize stimulus-induced changes in the somatosensory cortex of the brain. Sensory stimulation of the vibrissae (whiskers) was given for 10 s using an oscillating whisker vibrator (5-mm deflection at 10, 5, and 1 Hz). The brain temperature in the observational region continued to increase significantly with whisker stimulation. The mean peak recorded temperature changes were 0.048 ± 0.028, 0.054 ± 0.036, and 0.097 ± 0.015°C at 10, 5, and 1 Hz, respectively. We also observed that the temperature increase occurred in a focal spot, radiating to encompass a larger region within the contralateral barrel cortex region during single-whisker stimulation. Whisker stimulation also produced ipsilateral cortex temperature increases, which were localized in the same region as the pial arterioles. Temperature increase in the barrel cortex was also observed in rats treated with a calcium channel blocker (nimodipine), which acts to suppress the hemodynamic response to neural activity. Thus the location and area of temperature increase were found to change in accordance with the region of neural activation. These results indicate that IR thermal imaging is viable as a functional quantitative neuroimaging technique. PMID:22282486

  2. Music perception and cognition following bilateral lesions of auditory cortex.

    Science.gov (United States)

    Tramo, M J; Bharucha, J J; Musiek, F E

    1990-01-01

    We present experimental and anatomical data from a case study of impaired auditory perception following bilateral hemispheric strokes. To consider the cortical representation of sensory, perceptual, and cognitive functions mediating tonal information processing in music, pure tone sensation thresholds, spectral intonation judgments, and the associative priming of spectral intonation judgments by harmonic context were examined, and lesion localization was analyzed quantitatively using straight-line two-dimensional maps of the cortical surface reconstructed from magnetic resonance images. Despite normal pure tone sensation thresholds at 250-8000 Hz, the perception of tonal spectra was severely impaired, such that harmonic structures (major triads) were almost uniformly judged to sound dissonant; yet, the associative priming of spectral intonation judgments by harmonic context was preserved, indicating that cognitive representations of tonal hierarchies in music remained intact and accessible. Brainprints demonstrated complete bilateral lesions of the transverse gyri of Heschl and partial lesions of the right and left superior temporal gyri involving 98 and 20% of their surface areas, respectively. In the right hemisphere, there was partial sparing of the planum temporale, temporoparietal junction, and inferior parietal cortex. In the left hemisphere, all of the superior temporal region anterior to the transverse gyrus and parts of the planum temporale, temporoparietal junction, inferior parietal cortex, and insula were spared. These observations suggest that (1) sensory, perceptual, and cognitive functions mediating tonal information processing in music are neurologically dissociable; (2) complete bilateral lesions of primary auditory cortex combined with partial bilateral lesions of auditory association cortex chronically impair tonal consonance perception; (3) cognitive functions that hierarchically structure pitch information and generate harmonic expectancies

  3. Increased resting state connectivity between ipsilesional motor cortex and contralesional premotor cortex after transcranial direct current stimulation with physical therapy.

    Science.gov (United States)

    Chen, Joyce L; Schlaug, Gottfried

    2016-01-01

    Non-invasive stimulation of the brain using transcranial direct current stimulation (tDCS) during motor rehabilitation can improve the recovery of movements in individuals with stroke. However, the neural substrates that underlie the clinical improvements are not well understood. In this proof-of-principle open-label pilot study, five individuals with stroke received 10 sessions of tDCS while undergoing usual care physical/occupational therapy for the arm and hand. Motor impairment as indexed by the Upper Extremity Fugl Meyer assessment was significantly reduced after the intervention. Resting state fMRI connectivity increased between ipsilesional motor cortex and contralesional premotor cortex after the intervention. These findings provide preliminary evidence that the neural underpinnings of tDCS coupled with rehabilitation exercises, may be mediated by interactions between motor and premotor cortex. The latter, of which has been shown to play an important role in the recovery of movements post-stroke. Our data suggest premotor cortex could be tested as a target region for non-invasive brain-stimulation to enhance connectivity between regions that might be beneficial for stroke motor recovery. PMID:26980052

  4. Golgi Analysis of Neuron Morphology in the Presumptive Somatosensory Cortex and Visual Cortex of the Florida Manatee (Trichechus manatus latirostris).

    Science.gov (United States)

    Reyes, Laura D; Harland, Tessa; Reep, Roger L; Sherwood, Chet C; Jacobs, Bob

    2016-01-01

    The current study investigates neuron morphology in presumptive primary somatosensory (S1) and primary visual (V1) cortices of the Florida manatee (Trichechus manatus latirostris) as revealed by Golgi impregnation. Sirenians, including manatees, have an aquatic lifestyle, a large body size, and a relatively large lissencephalic brain. The present study examines neuron morphology in 3 cortical areas: in S1, dorsolateral cortex area 1 (DL1) and cluster cortex area 2 (CL2) and in V1, dorsolateral cortex area 4 (DL4). Neurons exhibited a variety of morphological types, with pyramidal neurons being the most common. The large variety of neuron types present in the manatee cortex was comparable to that seen in other eutherian mammals, except for rodents and primates, where pyramid-shaped neurons predominate. A comparison between pyramidal neurons in S1 and V1 indicated relatively greater dendritic branching in S1. Across all 3 areas, the dendritic arborization pattern of pyramidal neurons was also similar to that observed previously in the afrotherian rock hyrax, cetartiodactyls, opossums, and echidnas but did not resemble the widely bifurcated dendrites seen in the large-brained African elephant. Despite adaptations for an aquatic environment, manatees did not share specific neuron types such as tritufted and star-like neurons that have been found in cetaceans. Manatees exhibit an evolutionarily primitive pattern of cortical neuron morphology shared with most other mammals and do not appear to have neuronal specializations for an aquatic niche. PMID:27166161

  5. Human Resources Key Performance Indicators

    Directory of Open Access Journals (Sweden)

    Gabčanová Iveta

    2012-03-01

    Full Text Available The article brings out a proposed strategy map and respective key performance indicators (KPIs in human resources (HR. The article provides an overview of how HR activities are supported in order to reach the partial goals of HR as defined in the strategic map. Overall the aim of the paper is to show the possibilities of using the modern Balanced Scorecard method in human capital.

  6. Human Resources Key Performance Indicators

    OpenAIRE

    Gabčanová Iveta

    2012-01-01

    The article brings out a proposed strategy map and respective key performance indicators (KPIs) in human resources (HR). The article provides an overview of how HR activities are supported in order to reach the partial goals of HR as defined in the strategic map. Overall the aim of the paper is to show the possibilities of using the modern Balanced Scorecard method in human capital.

  7. The Body: The Key Concepts

    OpenAIRE

    Blackman, Lisa

    2008-01-01

    Questions around 'the body' are central to social theory. Our changing understanding of the body now challenges the ways we conceive power, ideology, subjectivity and social and cultural process. The Body: the key concepts highlights and analyses the debates which make the body central to current sociological, psychological, cultural and feminist thinking. Today, questions around the body are intrinsic to a wide range of debates - from technological developments in media and communications, t...

  8. Keys for rural territorial development

    OpenAIRE

    Juan Patricio Molina

    2010-01-01

    This article presents the introductory discourse of the Symposium on Rural Development with Territorial Approach organized by the Research Group on Rural Management and Development at Universidad Nacional de Colombia, held in Bogotá on march 4 and 5 2010. As the framework of the sixty papers presented at the symposium, the concepts of territory and rural development with territorial approach are introduced. Five key elements of rural territorial development are examined.

  9. Key Topics in Sports Medicine

    OpenAIRE

    Amir Ali Narvani; Panagiotis Thomas; Burce Lynn

    2006-01-01

    Key Topics in Sports Medicine is a single quick reference source for sports and exercise medicine. It presents the essential information from across relevant topic areas, and includes both the core and emerging issues in this rapidly developing field. It covers: 1) Sports injuries, rehabilitation and injury prevention, 2) Exercise physiology, fitness testing and training, 3) Drugs in sport, 4) Exercise and health promotion, 5) Sport and exercise for special and clinical populations, 6) The ps...

  10. Key issues in managed competition.

    OpenAIRE

    Shapiro, D W

    1994-01-01

    All managed competition proposals for health system reform must confront several key issues. The premiums paid to health care purchasing cooperatives will need to be subsidized for those who cannot pay full fare; the amount and sources of the subsidies are controversial political issues. The payments passed on by purchasing cooperatives to health plans must be risk adjusted to account for differences in the health care needs of their enrolled populations. This is essential to create a level p...

  11. OCDMA Network and Key Technology

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    OCDMA's network application on LAN, metro-ring and backbone networks are discussed. Its simple tell-go protocol makes it a powerful competitor with CSMA/CD in optical LANs. Its large soft capacity could erase the wavelength routing algorithm of WDM based metro-ring. And its content susceptibility could be largely used in label switching backbone network. And why should be 2D CODEC as well as interference cancellation is although mentioned as OCDMA key technology.

  12. Detector decoy quantum key distribution

    International Nuclear Information System (INIS)

    Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum key distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum key distribution protocols.

  13. Detector decoy quantum key distribution

    Energy Technology Data Exchange (ETDEWEB)

    Moroder, Tobias; Luetkenhaus, Norbert [Quantum Information Theory Group, Institute of Theoretical Physics I, University Erlangen-Nuremberg, Staudtstrasse 7/B2, 91058 Erlangen (Germany); Curty, Marcos [ETSI Telecomunicacion, Department of Signal Theory and Communications, University of Vigo, Campus Universitario, E-36310 Vigo (Spain)], E-mail: tmoroder@iqc.ca

    2009-04-15

    Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum key distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum key distribution protocols.

  14. KeySpan Energy Canada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    Operating in Alberta, KeySpan is a gas processing company with 14 gas plant facilities and pipelines in the province. Since its employees are sometimes working at remote locations, it has been difficult to use conventional classroom and seminar learning techniques to meet training needs. Cost-effective and innovative learning delivery solutions are now available from sophisticated information and communication technologies such as the Internet. In 1998, the Capability Development System (CDS) was developed by KeySpan as an on-line training system. It comprised a software assessment tool, a number of skills profiles for different occupations, and a curriculum registry providing technical information on the gas processing industry. E-learning initiatives are focused on specific projects or business units in order to better manage the training outcomes. The e-learning experience of KeySpan has resulted in benefits such as: better support to its customers and clients' needs through focused training on company-critical processes, services, products, and functions; more efficient employees; and, employees that feel part of the team.

  15. DEDD Symmetric-Key Cryptosystem

    Directory of Open Access Journals (Sweden)

    Praloy Shankar De, Prasenjit Maiti

    2013-03-01

    Full Text Available Now a days the greatest challenge to the cyber worldis security. We need more and more security for ourunsecured systems because technology is not aconstant factor. There are lots of catalysts, canbreak the securitysystem. Day by day number ofhackers is being increased.Existing old methods ofsecurity often fails to overcome it. But as an ancientquote says it’s true that “Old is Gold”, thosemethods help us to develop a new idea to sort outour problem in situ thus leads us to discover a newhorizon.In this paper an attempt has been made tofocus on an algorithmof cryptography that wasmadebyusingold methodologies.DEDDsymmetric-key cryptosystem is the new approach tosymmetric keyalgorithm. By this method we candoubly encrypt and doubly decrypt the message.Itmeans thesender will generate the cipher text fromthe plain texttwice.Thereceiverwillalsohavetodecrypt theciphers for two times and thenthecommunicationbetween themwill be completed.For generating the key,we willtake the messagelengthin first encryptionand insecond encryptionwe will apply shifting techniqueon a methodintegrate_expo which calculates the value ofe^integration (m^k dm from limit m=0 to limitm=m1(message length where e=exponential,m=variable.Double de-cryption will be done by thereverse process ofencryption techniques. There arelots of algorithms for symmetric key cryptographylike DES, AES,BLOWFISH, andHMAC-MD5etc.

  16. Subclinical delusional thinking predicts lateral temporal cortex responses during social reflection

    OpenAIRE

    Brent, Benjamin K.; Coombs, Garth; Keshavan, Matcheri S.; Seidman, Larry J.; Moran, Joseph M.; Holt, Daphne J.

    2012-01-01

    Neuroimaging studies have demonstrated associations between delusions in psychotic disorders and abnormalities of brain areas involved in social cognition, including medial prefrontal cortex (MPFC), posterior cingulate cortex, and lateral temporal cortex (LTC). General population studies have linked subclinical delusional thinking to impaired social cognition, raising the question of whether a specific pattern of brain activity during social perception is associated with delusional beliefs. H...

  17. Increased stress vulnerability after a prefrontal cortex lesion in female rats

    NARCIS (Netherlands)

    Gerrits, M; Westenbroek, C; Fokkema, DS; Jongsma, ME; Den Boer, JA; Ter Horst, GJ

    2003-01-01

    Neuroimaging studies in patients suffering from affective disorders have shown decreased volume and reduced regional cerebral blood flow in multiple areas of the prefrontal cortex, including the medial prefrontal cortex and the orbitofrontal cortex. This aberrant brain activity is among other things

  18. Peripheral nerve injury induces glial activation in primary motor cortex

    Directory of Open Access Journals (Sweden)

    Julieta Troncoso

    2015-02-01

    Full Text Available Preliminary evidence suggests that peripheral facial nerve injuries are associated with sensorimotor cortex reorganization. We have characterized facial nerve lesion-induced structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with glial cell density using a rodent facial paralysis model. First, we used adult transgenic mice expressing green fluorescent protein in microglia and yellow fluorescent protein in pyramidal neurons which were subjected to either unilateral lesion of the facial nerve or sham surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1. It was found that facial nerve lesion induced long-lasting changes in dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Pyramidal cells’ dendritic arborization underwent overall shrinkage and transient spine pruning. Moreover, microglial cell density surrounding vM1 layer 5 pyramidal neurons was significantly increased with morphological bias towards the activated phenotype. Additionally, we induced facial nerve lesion in Wistar rats to evaluate the degree and extension of facial nerve lesion-induced reorganization processes in central nervous system using neuronal and glial markers. Immunoreactivity to NeuN (neuronal nuclei antigen, GAP-43 (growth-associated protein 43, GFAP (glial fibrillary acidic protein, and Iba 1 (Ionized calcium binding adaptor molecule 1 were evaluated 1, 3, 7, 14, 28 and 35 days after either unilateral facial nerve lesion or sham surgery. Patches of decreased NeuN immunoreactivity were found bilaterally in vM1 as well as in primary somatosensory cortex (CxS1. Significantly increased GAP-43 immunoreactivity was found bilaterally after the lesion in hippocampus, striatum, and sensorimotor cortex. One day after lesion GFAP immunoreactivity increased bilaterally in hippocampus, subcortical white

  19. Decommissioning - The keys to success

    International Nuclear Information System (INIS)

    The United Kingdom Atomic Energy Authority (UKAEA) owns and operates five sites across the United Kingdom. The Winfrith site in Dorset was established in the late 1950's as a centre for development of prototype reactors. During its history, nine research reactors have operated on the site together with: a fuel fabrication facility; a post irradiation examination facility; radiochemistry laboratories, etc. The largest reactor, a 100MWe Steam Generating Heavy Water Reactor, was closed down in 1990 and the last research reactor was closed in 1995. Since the early 1990's the site has been undergoing a programme of progressive decommissioning with a view to releasing the site for alternative use unrestricted by the site's nuclear history. Key drivers for the design of the programme were safety, minimising adverse environmental effects, minimising costs and ensuring stakeholder support. One requirement of the stakeholders was to ensure that the site continued to provide high quality employment. This was successfully achieved by developing a Science and Technology Park on the nuclear site. Over 40 companies are now located on the Park providing over 1000 jobs. This paper will focus on the lessons learnt from over a decade of experience of decommissioning at Winfrith and will attempt to identify the 'keys to successful decommissioning'. These 'keys' will include: defining the site end-point; planning the programme; defining the commercial strategy; cost estimation; evaluation and management of risks; safety and environmental management; and stakeholder engagement. In particular, the paper will explore the very close relationship between: funding profiles; cost estimation; risk management and commercial strategy. It will show that these aspects of the programme cannot be considered separately. The paper will attempt to show that, with careful planning; decommissioning can be achieved safety and give good value for money to the funding authority. (author)

  20. Fibre Optic Communication Key Devices

    CERN Document Server

    Grote, Norbert

    2012-01-01

    The book gives an in-depth description of the key devices of current and next generation fibre optic communication networks. In particular, the book covers devices such as semiconductor lasers, optical amplifiers, modulators, wavelength filters, and detectors but the relevant properties of optical fibres as well. The presentations include the physical principles underlying the various devices, the technologies used for the realization of the different devices, typical performance characteristics and limitations, and development trends towards more advanced components are also illustrated. Thus the scope of the book spans relevant principles, state-of-the-art implementations, the status of current research and expected future components.

  1. Authenticated Key Agreement in Group Settings

    Institute of Scientific and Technical Information of China (English)

    LI Ming; WANG Yong; GU Da-wu; BAI Ying-cai

    2006-01-01

    An enhanced definition of implicit key authentication and a secure group key agreement scheme from pairings are presented. This scheme combines the merits of group public key and key trees to achieve a communication-efficient and authenticated group key agreement protocol. Besides, it avoids dependence on signature or MAC by involving member's long-term keys and short-term keys in the group key. Furthermore, the idea behind this design can be employed as a general approach to extend the authenticated two-party Diffie-Hellman protocols to group settings.

  2. Sensory experience modifies feature map relationships in visual cortex.

    Science.gov (United States)

    Cloherty, Shaun L; Hughes, Nicholas J; Hietanen, Markus A; Bhagavatula, Partha S; Goodhill, Geoffrey J; Ibbotson, Michael R

    2016-01-01

    The extent to which brain structure is influenced by sensory input during development is a critical but controversial question. A paradigmatic system for studying this is the mammalian visual cortex. Maps of orientation preference (OP) and ocular dominance (OD) in the primary visual cortex of ferrets, cats and monkeys can be individually changed by altered visual input. However, the spatial relationship between OP and OD maps has appeared immutable. Using a computational model we predicted that biasing the visual input to orthogonal orientation in the two eyes should cause a shift of OP pinwheels towards the border of OD columns. We then confirmed this prediction by rearing cats wearing orthogonally oriented cylindrical lenses over each eye. Thus, the spatial relationship between OP and OD maps can be modified by visual experience, revealing a previously unknown degree of brain plasticity in response to sensory input. PMID:27310531

  3. Sensory experience modifies feature map relationships in visual cortex

    Science.gov (United States)

    Cloherty, Shaun L; Hughes, Nicholas J; Hietanen, Markus A; Bhagavatula, Partha S

    2016-01-01

    The extent to which brain structure is influenced by sensory input during development is a critical but controversial question. A paradigmatic system for studying this is the mammalian visual cortex. Maps of orientation preference (OP) and ocular dominance (OD) in the primary visual cortex of ferrets, cats and monkeys can be individually changed by altered visual input. However, the spatial relationship between OP and OD maps has appeared immutable. Using a computational model we predicted that biasing the visual input to orthogonal orientation in the two eyes should cause a shift of OP pinwheels towards the border of OD columns. We then confirmed this prediction by rearing cats wearing orthogonally oriented cylindrical lenses over each eye. Thus, the spatial relationship between OP and OD maps can be modified by visual experience, revealing a previously unknown degree of brain plasticity in response to sensory input. DOI: http://dx.doi.org/10.7554/eLife.13911.001 PMID:27310531

  4. Retrosplenial cortex maps the conjunction of internal and external spaces.

    Science.gov (United States)

    Alexander, Andrew S; Nitz, Douglas A

    2015-08-01

    Intelligent behavior demands not only multiple forms of spatial representation, but also coordination among the brain regions mediating those representations. Retrosplenial cortex is densely interconnected with the majority of cortical and subcortical brain structures that register an animal's position in multiple internal and external spatial frames of reference. This unique anatomy suggests that it functions to integrate distinct forms of spatial information and provides an interface for transformations between them. Evidence for this was found in rats traversing two different routes placed at different environmental locations. Retrosplenial ensembles robustly encoded conjunctions of progress through the current route, position in the larger environment and the left versus right turning behavior of the animal. Thus, the retrosplenial cortex has the requisite dynamics to serve as an intermediary between brain regions generating different forms of spatial mapping, a result that is consistent with navigational and episodic memory impairments following damage to this region in humans. PMID:26147532

  5. Causal evidence for frontal cortex organization for perceptual decision making.

    Science.gov (United States)

    Rahnev, Dobromir; Nee, Derek Evan; Riddle, Justin; Larson, Alina Sue; D'Esposito, Mark

    2016-05-24

    Although recent research has shown that the frontal cortex has a critical role in perceptual decision making, an overarching theory of frontal functional organization for perception has yet to emerge. Perceptual decision making is temporally organized such that it requires the processes of selection, criterion setting, and evaluation. We hypothesized that exploring this temporal structure would reveal a large-scale frontal organization for perception. A causal intervention with transcranial magnetic stimulation revealed clear specialization along the rostrocaudal axis such that the control of successive stages of perceptual decision making was selectively affected by perturbation of successively rostral areas. Simulations with a dynamic model of decision making suggested distinct computational contributions of each region. Finally, the emergent frontal gradient was further corroborated by functional MRI. These causal results provide an organizational principle for the role of frontal cortex in the control of perceptual decision making and suggest specific mechanistic contributions for its different subregions. PMID:27162349

  6. Not so "silent":The human prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Prakash Narain Tandon

    2013-01-01

    Full Text Available Little was known about the human prefrontal cortex till recently. It was thus labeled as the "silent area," "uncommitted cortex." It not only constitutes the largest component of the human brain but is the latest evolutionary addition to the mammalian brain. It endows the human beings with qualities that differentiate humans from all other animals. During the last couple of decades the advent of modern electrophysiological and imaging (functional magnetic resonance imaging, proton emission tomography, SPECT techniques have provided a wealth of insight into its role in memory, thought, emotions, moral judgment, social behavior, evaluating rewards, and assessing its fairness or otherwise and above all self-awareness. This brief review summarize the recent significant observations on its functions and connectivity which would interest the cognitive scientists and clinicians alike.

  7. What must a global theory of cortex explain?

    Science.gov (United States)

    Valiant, Leslie G

    2014-04-01

    At present there is no generally accepted theory of how cognitive phenomena arise from computations in cortex. Further, there is no consensus on how the search for one should be refocussed so as to make it more fruitful. In this short piece we observe that research in computer science over the last several decades has shown that significant computational phenomena need to circumvent significant inherent quantitative impediments, such as of computational complexity. We argue that computational neuroscience has to be informed by the same quantitative concerns for it to succeed. It is conceivable that the brain is the one computation that does not need to circumvent any such obstacles, but if that were the case then quantitatively plausible theories of cortex would now surely abound and be driving experimental investigations. PMID:24709595

  8. The hippocampus as a stable memory allocator for cortex.

    Science.gov (United States)

    Valiant, Leslie G

    2012-11-01

    It is suggested here that mammalian hippocampus serves as an allocator of neurons in cortex for memorizing new items. A construction of a shallow feedforward network with biologically plausible parameters is given that possesses the characteristics needed for such an allocator. In particular, the construction is stabilizing in that for inputs within a range of activity levels spanning more than an order of magnitude, the output will have activity levels differing as little as 1%. It is also noise tolerant in that pairs of input patterns that differ little will generate output patterns that differ little. Further, pairs of inputs that differ by much will be mapped to outputs that also differ sufficiently that they can be treated by cortex as distinct. PMID:22920849

  9. Cerebellar networks with the cerebral cortex and basal ganglia.

    Science.gov (United States)

    Bostan, Andreea C; Dum, Richard P; Strick, Peter L

    2013-05-01

    The dominant view of cerebellar function has been that it is exclusively concerned with motor control and coordination. Recent findings from neuroanatomical, behavioral, and imaging studies have profoundly changed this view. Neuroanatomical studies using virus transneuronal tracers have demonstrated that cerebellar output reaches vast areas of the neocortex, including regions of prefrontal and posterior parietal cortex. Furthermore, it has recently become clear that the cerebellum is reciprocally connected with the basal ganglia, which suggests that the two subcortical structures are part of a densely interconnected network. Taken together, these findings elucidate the neuroanatomical substrate for cerebellar involvement in non-motor functions mediated by the prefrontal and posterior parietal cortex, as well as in processes traditionally associated with the basal ganglia. PMID:23579055

  10. Neural Anatomy of Primary Visual Cortex Limits Visual Working Memory.

    Science.gov (United States)

    Bergmann, Johanna; Genç, Erhan; Kohler, Axel; Singer, Wolf; Pearson, Joel

    2016-01-01

    Despite the immense processing power of the human brain, working memory storage is severely limited, and the neuroanatomical basis of these limitations has remained elusive. Here, we show that the stable storage limits of visual working memory for over 9 s are bound by the precise gray matter volume of primary visual cortex (V1), defined by fMRI retinotopic mapping. Individuals with a bigger V1 tended to have greater visual working memory storage. This relationship was present independently for both surface size and thickness of V1 but absent in V2, V3 and for non-visual working memory measures. Additional whole-brain analyses confirmed the specificity of the relationship to V1. Our findings indicate that the size of primary visual cortex plays a critical role in limiting what we can hold in mind, acting like a gatekeeper in constraining the richness of working mental function. PMID:25100854

  11. Higher Order Spike Synchrony in Prefrontal Cortex during visual memory

    Directory of Open Access Journals (Sweden)

    Gordon ePipa

    2011-06-01

    Full Text Available Precise temporal synchrony of spike firing has been postulated as an important neuronal mechanism for signal integration and the induction of plasticity in neocortex. As prefrontal cortex plays an important role in organizing memory and executive functions, the convergence of multiple visual pathways onto PFC predicts that neurons should preferentially synchronize their spiking when stimulus information is processed. Furthermore, synchronous spike firing should intensify if memory processes require the induction of neuronal plasticity, even if this is only for short-term. Here we show with multiple simultaneously recorded units in ventral prefrontal cortex that neurons participate in 3 ms precise synchronous discharges distributed across multiple sites separated by at least 500 µm. The frequency of synchronous firing is modulated by behavioral performance and is specific for the memorized visual stimuli. In particular, during the memory period in which activity is not stimulus driven, larger groups of up to 7 sites exhibit performance dependent modulation of their spike synchronization.

  12. Insular cortex activity and the evocation of laughter.

    Science.gov (United States)

    Wattendorf, Elise; Westermann, Birgit; Lotze, Martin; Fiedler, Klaus; Celio, Marco R

    2016-06-01

    The insular cortex is fundamentally involved in the processing of interoceptive information. It has been postulated that the integrative monitoring of the bodily responses to environmental stimuli is crucial for the recognition and experience of emotions. Because emotional arousal is known to be closely coupled to functions of the anterior insula, we suspected laughter to be associated primarily with neuronal activity in this region. An anatomically constrained re-analysis of our imaging data pertaining to ticklish laughter, to inhibited ticklish laughter, and to voluntary laughter revealed regional differences in the levels of neuronal activity in the posterior and mid-/anterior portions of the insula. Ticklish laughter was associated specifically with right ventral anterior insular activity, which was not detected under the other two conditions. Hence, apparently, only laughter that is evoked as an emotional response bears the signature of autonomic arousal in the insular cortex. J. Comp. Neurol. 524:1608-1615, 2016. © 2015 Wiley Periodicals, Inc. PMID:26287648

  13. Short-term plasticity of the human auditory cortex.

    Science.gov (United States)

    Pantev, C; Wollbrink, A; Roberts, L E; Engelien, A; Lütkenhöner, B

    1999-09-18

    Magnetoencephalographic measurements (MEG) were used to examine the effect on the human auditory cortex of removing specific frequencies from the acoustic environment. Subjects listened for 3 h on three consecutive days to music "notched" by removal of a narrow frequency band centered on 1 kHz. Immediately after listening to the notched music, the neural representation for a 1-kHz test stimulus centered on the notch was found to be significantly diminished compared to the neural representation for a 0.5-kHz control stimulus centered one octave below the region of notching. The diminished neural representation for 1 kHz reversed to baseline between the successive listening sessions. These results suggest that rapid changes can occur in the tuning of neurons in the adult human auditory cortex following manipulation of the acoustic environment. A dynamic form of neural plasticity may underlie the phenomenon observed here. PMID:10526109

  14. Key energy technologies for Europe

    International Nuclear Information System (INIS)

    The report is part of the work undertaken by the High-Level Expert Group to prepare a report on emerging science and technology trends and the implications for EU and Member State research policies. The outline of the report is: 1) In the introductory section, energy technologies are defined and for analytical reasons further narrowed down; 2) The description of the socio-economic challenges facing Europe in the energy field is based on the analysis made by the International Energy Agency going back to 1970 and with forecasts to 2030. Both the world situation and the European situation are described. This section also contains an overview of the main EU policy responses to energy. Both EU energy R and D as well as Member State energy R and D resources are described in view of international efforts; 3) The description of the science and technology base is made for selected energy technologies, including energy efficiency, biomass, hydrogen, and fuel cells, photovoltaics, clean fossil fuel technologies and CO2 capture and storage, nuclear fission and fusion. When possible, a SWOT is made for each technology and finally summarised; 4) The forward look highlights some of the key problems and uncertainties related to the future energy situation. Examples of recent energy foresights are given, including national energy foresights in Sweden and the UK as well as links to a number of regional and national foresights and roadmaps; 5) Appendix 1 contains a short description of key international organisations dealing with energy technologies and energy research. (ln)

  15. Tension-related activity in the orbitofrontal cortex and amygdala: an fMRI study with music.

    Science.gov (United States)

    Lehne, Moritz; Rohrmeier, Martin; Koelsch, Stefan

    2014-10-01

    Tonal music is characterized by a continuous flow of tension and resolution. This flow of tension and resolution is closely related to processes of expectancy and prediction and is a key mediator of music-evoked emotions. However, the neural correlates of subjectively experienced tension and resolution have not yet been investigated. We acquired continuous ratings of musical tension for four piano pieces. In a subsequent functional magnetic resonance imaging experiment, we identified blood oxygen level-dependent signal increases related to musical tension in the left lateral orbitofrontal cortex (pars orbitalis of the inferior frontal gyrus). In addition, a region of interest analysis in bilateral amygdala showed activation in the right superficial amygdala during periods of increasing tension (compared with decreasing tension). This is the first neuroimaging study investigating the time-varying changes of the emotional experience of musical tension, revealing brain activity in key areas of affective processing. PMID:23974947

  16. Differential Striatal Spine Pathology in Parkinson’s disease and Cocaine Addiction: A Key Role of Dopamine?

    OpenAIRE

    Villalba, Rosa M.; Smith, Yoland

    2013-01-01

    In the striatum, the dendritic tree of the two main populations of projection neurons, called “Medium Spiny Neurons (MSNs)”, are covered with spines that receive glutamatergic inputs from the cerebral cortex and thalamus. In Parkinson’s disease (PD), striatal MSNs undergo an important loss of dendritic spines, whereas aberrant overgrowth of striatal spines occurs following chronic cocaine exposure. This review examines the possibility that opposite dopamine dysregulation is one of the key fac...

  17. Functional magnetic resonance imaging evaluation of visual cortex activation in patients with anterior visual pathway lesions

    Institute of Scientific and Technical Information of China (English)

    Xiufeng Song; Guohua Wang; Tong Zhang; Lei Feng; Peng An; Yueli Zhu

    2012-01-01

    The aim of this study was to examine the secondary visual cortex functional disorder in patients with glaucoma and large pituitary adenoma by functional magnetic resonance imaging, and to determine the correlation between visual field defect and primary visual cortex activation. Results showed that single eye stimulation resulted in bilateral visual cortex activation in patients with glaucoma or large pituitary adenoma. Compared with the normal control group, the extent and intensity of visual cortex activation was decreased after left and right eye stimulation, and functional magnetic resonance imaging revealed a correlation between visual field defects and visual cortex activation in patients with glaucoma and large pituitary adenoma. These functional magnetic resonance imaging data suggest that anterior optic pathway lesions can cause secondary functional disorder of the visual cortex, and that visual defects are correlated with visual cortex activation.

  18. Functional organization and visual representations in human ventral lateral prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Annie Wai Yiu Chan

    2013-07-01

    Full Text Available Recent neuroimaging studies in both human and non-human primates have identified face selective activation in the ventral lateral prefrontal cortex even in the absence of working memory demands. Further, research has suggested that this face-selective response is largely driven by the presence of the eyes. However, the nature and origin of visual category responses in the ventral lateral prefrontal cortex remain unclear. Further, in a broader sense, how do these findings relate to our current understandings of lateral prefrontal cortex? What do these findings tell us about the underlying function and organization principles of the ventral lateral prefrontal cortex? What is the future direction for investigating visual representations in this cortex? This review focuses on the function, topography, and circuitry of the ventral lateral prefrontal cortex to enhance our understanding of the evolution and development of this cortex.

  19. Chronic Unpredictable Stress Promotes Neuronal Apoptosis in the Cerebral Cortex

    OpenAIRE

    Bachis, Alessia; Cruz, Maria Idalia; Nosheny, Rachael L.; Mocchetti, Italo

    2008-01-01

    Stress-mediated loss of synaptogenesis in the hippocampus appears to play a role in depressive and mood disorders. However, little is known about the effect of stress/depression on the plasticity and survival of cortical neurons. In this report, we have examined whether chronic stress increases the vulnerability of neurons in the rat cortex. We have used a chronic unpredictable mild stress (CMS) as a rat model of depression. CMS (5 weeks treatment) produced anedonia and increased corticostero...

  20. Motor cortex electric stimulation for the treatment of neuropathic pain

    OpenAIRE

    Walter J. Fagundes-Pereyra; Manoel Jacobsen Teixeira; Nicolas Reyns; Gustavo Touzet; Sérgio Dantas; Emmanuelle Laureau; Serge Blond

    2010-01-01

    OBJECTIVE: Motor cortex stimulation (MCS) is considered to be an effective treatment for chronic neuropathic pain. The aim of the present study was to assess the efficacy of MCS for treating neuropathic pain. METHOD: 27 patients with chronic neuropathic pain were operated. Electrodes were implanted with the use of an stereotactic frame. Electrophysiological evaluations (motor stimulation and somatosensory evoked potentials) were performed, with guidance by means of three-dimensional reconstru...

  1. Prefrontal Cortex Motivated Cognitive Architecture for Multiple Robots

    OpenAIRE

    Mishra, Amit Kumar; Kumar, Abhishek; Deb, Dipankar

    2014-01-01

    In this paper, we introduce a cerebral cortex inspired architecture for robots in which we have mapped hierarchical cortical representation of human brain to logic flow and decision making process. Our work focuses on the two major features of human cognitive process, viz. the perception action cycle and its hierarchical organization, and the decision making process. To prove the effectiveness of our proposed method, we incorporated this architecture in our robot which we named as Cognitive I...

  2. Stereoscopic Vision in the Absence of the Lateral Occipital Cortex

    OpenAIRE

    Read, JC; Phillipson, GP; Serrano-Pedraza, I; Milner, AD; Parker, AJ

    2010-01-01

    Both dorsal and ventral cortical visual streams contain neurons sensitive to binocular disparities, but the two streams may underlie different aspects of stereoscopic vision. Here we investigate stereopsis in the neurological patient D.F., whose ventral stream, specifically lateral occipital cortex, has been damaged bilaterally, causing profound visual form agnosia. Despite her severe damage to cortical visual areas, we report that DF's stereo vision is strikingly unimpaired. She is better th...

  3. Dynamical organization of the cytoskeletal cortex probed by micropipette aspiration

    OpenAIRE

    Brugués, Jan; Maugis, Benoit; Casademunt, Jaume; Nassoy, Pierre; Amblard, François; Sens, Pierre

    2010-01-01

    Bleb-based cell motility proceeds by the successive inflation and retraction of large spherical membrane protrusions (“blebs”) coupled with substrate adhesion. In addition to their role in motility, cellular blebs constitute a remarkable illustration of the dynamical interactions between the cytoskeletal cortex and the plasma membrane. Here we study the bleb-based motions of Entamoeba histolytica in the constrained geometry of a micropipette. We construct a generic theoretical model that comb...

  4. A Neural Circuit for Spatial Summation in Visual Cortex

    OpenAIRE

    Adesnik, Hillel; Bruns, William; Taniguchi, Hiroki; Huang, Z. Josh; Scanziani, Massimo

    2012-01-01

    The response of cortical neurons to a sensory stimulus is modulated by the context. In the visual cortex, for example, stimulation of a pyramidal cell's receptive field surround can attenuate the cell’s response to a stimulus in its receptive field’s center, a phenomenon called surround suppression. Whether cortical circuits contribute to surround suppression or whether the phenomenon is entirely relayed from earlier stages of visual processing is controversial. Here we discover that, in cont...

  5. Downregulation of the posterior medial frontal cortex prevents social conformity

    OpenAIRE

    Klucharev, V.; Munneke, M.; Smidts, A.; Fernandez, G.S.E.

    2011-01-01

    We often change our behavior to conform to real or imagined group pressure. Social influence on our behavior has been extensively studied in social psychology, but its neural mechanisms have remained largely unknown. Here we demonstrate that the transient downregulation of the posterior medial frontal cortex by theta-burst transcranial magnetic stimulation reduces conformity, as indicated by reduced conformal adjustments in line with group opinion. Both the extent and probability of conformal...

  6. Intracortical inhibition of the motor cortex is normal in chorea

    OpenAIRE

    HANAJIMA, R; Ugawa, Y; Y. Terao; Furubayashi, T.; Machii, K; Shiio, Y.; H. Enomoto; Uesugi, H.; Mochizuki, H.; Kanazawa, I

    1999-01-01

    Intracortical inhibition of the motor cortex was investigated using a paired pulse magnetic stimulation method in 14 patients with chorea caused by various aetiologies (six patients with Huntington's disease, one with chorea acanthocytosis, a patient with systemic lupus erythematosus with a vascular lesion in the caudate, three with senile chorea and three with chorea of unknown aetiology). The time course and amount of inhibition was the same in the patients as in normal su...

  7. Intersection of reward and memory in monkey rhinal cortex

    OpenAIRE

    Clark, Andrew M.; Bouret, Sebastien; Young, Adrienne M.; Barry J Richmond

    2012-01-01

    In humans and other animals the vigor with which a reward is pursued depends on its desirability, that is, on the reward’s predicted value. Predicted value is generally context dependent, varying according to the value of rewards obtained in the recent and distant past. Signals related to reward prediction and valuation are believed to be encoded in a circuit centered around midbrain dopamine neurons and their targets in the prefrontal cortex and basal ganglia. Notably absent from this hypoth...

  8. Learning warps object representations in the ventral temporal cortex

    OpenAIRE

    Clarke, Alex; Pell, Philip J.; Ranganath, Charan; Tyler, Lorraine K.

    2016-01-01

    The human ventral temporal cortex (VTC) plays a critical role in object recognition. Although it is well established that visual experience shapes VTC object representations, the impact of semantic and contextual learning is unclear. In this study, we tracked changes in representations of novel visual objects that emerged after learning meaningful information about each object. Over multiple training sessions, participants learned to associate semantic features (e.g. ?made of wood?, ?floats?)...

  9. Retinotopically defined primary visual cortex in Williams syndrome

    OpenAIRE

    Olsen, Rosanna K.; Kippenhan, J. Shane; Japee, Shruti; Kohn, Philip; Mervis, Carolyn B.; Saad, Ziad S.; Morris, Colleen A.; Meyer-Lindenberg, Andreas; Berman, Karen Faith

    2009-01-01

    Williams syndrome, caused by a hemizygous microdeletion on chromosome 7q11.23, is characterized by severe impairment in visuospatial construction. To examine potential contributions of early visual processing to this cognitive problem, we functionally mapped the size and neuroanatomical variability of primary visual cortex (V1) in high-functioning adults with Williams syndrome and age- and IQ-matched control participants from the general population by using fMRI-based retinotopic mapping and ...

  10. Exercise increases mitochondrial glutamate oxidation in the mouse cerebral cortex.

    Science.gov (United States)

    Herbst, Eric A F; Holloway, Graham P

    2016-07-01

    The present study investigated the impact of acute exercise on stimulating mitochondrial respiratory function in mouse cerebral cortex. Where pyruvate-stimulated respiration was not affected by acute exercise, glutamate respiration was enhanced following the exercise bout. Additional assessment revealed that this affect was dependent on the presence of malate and did not occur when substituting glutamine for glutamate. As such, our results suggest that glutamate oxidation is enhanced with acute exercise through activation of the malate-aspartate shuttle. PMID:27184881

  11. Orosensory and Homeostatic Functions of the Insular Taste Cortex

    OpenAIRE

    de Araujo, Ivan E; Geha, Paul; Small, Dana M.

    2012-01-01

    The gustatory aspect of the insular cortex is part of the brain circuit that controls ingestive behaviors based on chemosensory inputs. However, the sensory properties of foods are not restricted to taste and should also include salient features such as odor, texture, temperature, and appearance. Therefore, it is reasonable to hypothesize that specialized circuits within the central taste pathways must be involved in representing several other oral sensory modalities in addition to taste. In ...

  12. Insular cortex activity and the evocation of laughter

    OpenAIRE

    Wattendorf, Elise; Westermann, Birgit; Lotze, Martin; Fiedler, Klaus; Celio, Marco R.

    2015-01-01

    The insular cortex is fundamentally involved in the processing of interoceptive information. It has been postulated that the integrative monitoring of the bodily responses to environmental stimuli is crucial for the recognition and experience of emotions. Because emotional arousal is known to be closely coupled to functions of the anterior insula, we suspected laughter to be associated primarily with neuronal activity in this region. An anatomically constrained re-analysis of our imaging data...

  13. The Insular Taste Cortex Contributes to Odor Quality Coding

    OpenAIRE

    Veldhuizen, Maria G; Nachtigal, Danielle; Teulings, Lynsey; Gitelman, Darren R.; Small, Dana M.

    2010-01-01

    Despite distinct peripheral and central pathways, stimulation of both the olfactory and the gustatory systems may give rise to the sensation of sweetness. Whether there is a common central mechanism producing sweet quality sensations or two discrete mechanisms associated independently with gustatory and olfactory stimuli is currently unknown. Here we used fMRI to determine whether odor sweetness is represented in the piriform olfactory cortex, which is thought to code odor quality, or in the ...

  14. Auditory, Somatosensory, and Multisensory Insular Cortex in the Rat

    OpenAIRE

    Rodgers, Krista M.; Benison, Alexander M.; Klein, Andrea; Barth, Daniel S.

    2008-01-01

    Compared with other areas of the forebrain, the function of insular cortex is poorly understood. This study examined the unisensory and multisensory function of the rat insula using high-resolution, whole-hemisphere, epipial evoked potential mapping. We found the posterior insula to contain distinct auditory and somatotopically organized somatosensory fields with an interposed and overlapping region capable of integrating these sensory modalities. Unisensory and multisensory responses were un...

  15. The insular taste cortex contributes to odor quality coding

    OpenAIRE

    Gitelman, Darren R.; Small, Dana M.

    2010-01-01

    Despite distinct peripheral and central pathways, stimulation of both the olfactory and the gustatory systems may give rise to the sensation of sweetness. Whether there is a common central mechanism producing sweet quality sensations or two discrete mechanisms associated independently with gustatory and olfactory stimuli is currently unknown. Here we used fMRI to determine whether odor sweetness is represented in the piriform olfactory cortex, which is thought to code odor quality, or in the ...

  16. Coding of Vocalizations by Single Neurons in Ventrolateral Prefrontal Cortex

    OpenAIRE

    Plakke, Bethany; Diltz, Mark D.; Romanski, Lizabeth M.

    2013-01-01

    Neuronal activity in single prefrontal neurons has been correlated with behavioral responses, rules, task variables and stimulus features. In the non-human primate, neurons recorded in ventrolateral prefrontal cortex (VLPFC) have been found to respond to species-specific vocalizations. Previous studies have found multisensory neurons which respond to simultaneously presented faces and vocalizations in this region. Behavioral data suggests that face and vocal information are inextricably linke...

  17. Morphological Heterogeneity of Layer VI Neurons in Mouse Barrel Cortex

    OpenAIRE

    Chen, Chia-Chien; Abrams, Svetlana; Pinhas, Alex; Brumberg, Joshua C.

    2009-01-01

    Understanding the basic neuronal building blocks of the neocortex is a necessary first step toward comprehending the composition of cortical circuits. Neocortical layer VI is the most morphologically diverse layer and plays a pivotal role in gating information to the cortex via its feedback connection to the thalamus and other ipsilateral and callosal corticocortical connections. The heterogeneity of function within this layer is presumably linked to its varied morphological composition. Howe...

  18. Sparse representation of sounds in the unanesthetized auditory cortex.

    Directory of Open Access Journals (Sweden)

    Tomás Hromádka

    2008-01-01

    Full Text Available How do neuronal populations in the auditory cortex represent acoustic stimuli? Although sound-evoked neural responses in the anesthetized auditory cortex are mainly transient, recent experiments in the unanesthetized preparation have emphasized subpopulations with other response properties. To quantify the relative contributions of these different subpopulations in the awake preparation, we have estimated the representation of sounds across the neuronal population using a representative ensemble of stimuli. We used cell-attached recording with a glass electrode, a method for which single-unit isolation does not depend on neuronal activity, to quantify the fraction of neurons engaged by acoustic stimuli (tones, frequency modulated sweeps, white-noise bursts, and natural stimuli in the primary auditory cortex of awake head-fixed rats. We find that the population response is sparse, with stimuli typically eliciting high firing rates (>20 spikes/second in less than 5% of neurons at any instant. Some neurons had very low spontaneous firing rates (<0.01 spikes/second. At the other extreme, some neurons had driven rates in excess of 50 spikes/second. Interestingly, the overall population response was well described by a lognormal distribution, rather than the exponential distribution that is often reported. Our results represent, to our knowledge, the first quantitative evidence for sparse representations of sounds in the unanesthetized auditory cortex. Our results are compatible with a model in which most neurons are silent much of the time, and in which representations are composed of small dynamic subsets of highly active neurons.

  19. Orientation-tuned surround suppression in mouse visual cortex

    OpenAIRE

    Self, Matthew W.; Lorteije, Jeannette A. M.; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N.; Heimel, J.A.; Roelfsema, Pieter R.

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those containing orientation contrast. This effect is thought to be important for scene segmentation, but the underlying neural mechanisms are poorly understood. We asked whether it is possible to study these ...

  20. "Visual" Cortex Responds to Spoken Language in Blind Children

    OpenAIRE

    Bedny, Marina; Richardson, Hilary; Saxe, Rebecca R.

    2015-01-01

    Plasticity in the visual cortex of blind individuals provides a rare window into the mechanisms of cortical specialization. In the absence of visual input, occipital (“visual”) brain regions respond to sound and spoken language. Here, we examined the time course and developmental mechanism of this plasticity in blind children. Nineteen blind and 40 sighted children and adolescents (4–17 years old) listened to stories and two auditory control conditions (unfamiliar foreign speech, and music). ...

  1. Decoding bipedal locomotion from the rat sensorimotor cortex

    Science.gov (United States)

    Rigosa, J.; Panarese, A.; Dominici, N.; Friedli, L.; van den Brand, R.; Carpaneto, J.; DiGiovanna, J.; Courtine, G.; Micera, S.

    2015-10-01

    Objective. Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower limb movement from the motor cortex has received comparatively little attention. Here, we performed experiments to identify the type and amount of information that can be decoded from neuronal ensemble activity in the hindlimb area of the rat motor cortex during bipedal locomotor tasks. Approach. Rats were trained to stand, step on a treadmill, walk overground and climb staircases in a bipedal posture. To impose this gait, the rats were secured in a robotic interface that provided support against the direction of gravity and in the mediolateral direction, but behaved transparently in the forward direction. After completion of training, rats were chronically implanted with a micro-wire array spanning the left hindlimb motor cortex to record single and multi-unit activity, and bipolar electrodes into 10 muscles of the right hindlimb to monitor electromyographic signals. Whole-body kinematics, muscle activity, and neural signals were simultaneously recorded during execution of the trained tasks over multiple days of testing. Hindlimb kinematics, muscle activity, gait phases, and locomotor tasks were decoded using offline classification algorithms. Main results. We found that the stance and swing phases of gait and the locomotor tasks were detected with accuracies as robust as 90% in all rats. Decoded hindlimb kinematics and muscle activity exhibited a larger variability across rats and tasks. Significance. Our study shows that the rodent motor cortex contains useful information for lower limb neuroprosthetic development. However, brain-machine interfaces estimating gait phases or locomotor behaviors, instead of continuous variables such as limb joint positions or speeds

  2. Anatomical Origins of Ocular Dominance in Mouse Primary Visual Cortex

    OpenAIRE

    Coleman, Jason E.; Law, Karen; Bear, Mark F.

    2009-01-01

    Ocular dominance (OD) plasticity is a classic paradigm for studying the effect of experience and deprivation on cortical development, and is manifested as shifts in the relative strength of binocular inputs to primary visual cortex (V1). The mouse has become an increasingly popular model for mechanistic studies of OD plasticity and, consequently, it is important that we understand how binocularity is constructed in this species. One puzzling feature of the mouse visual system is the gross dis...

  3. Flexible neural mechanisms of cognitive control within human prefrontal cortex

    OpenAIRE

    Braver, Todd S.; Paxton, Jessica L.; Locke, Hannah S.; Barch, Deanna M

    2009-01-01

    A major challenge in research on executive control is to reveal its functional decomposition into underlying neural mechanisms. A typical assumption is that this decomposition occurs solely through anatomically based dissociations. Here we tested an alternative hypothesis that different cognitive control processes may be implemented within the same brain regions, with fractionation and dissociation occurring on the basis of temporal dynamics. Regions within lateral prefrontal cortex (PFC) wer...

  4. Prefrontal Cortex, Emotion, and Approach/Withdrawal Motivation

    OpenAIRE

    Spielberg, Jeffrey M; Stewart, Jennifer L.; Levin, Rebecca L.; Miller, Gregory A.; Heller, Wendy

    2008-01-01

    This article provides a selective review of the literature and current theories regarding the role of prefrontal cortex, along with some other critical brain regions, in emotion and motivation. Seemingly contradictory findings have often appeared in this literature. Research attempting to resolve these contradictions has been the basis of new areas of growth and has led to more sophisticated understandings of emotional and motivational processes as well as neural networks associated with thes...

  5. Emergence of Complex Wave Patterns in Primate Cerebral Cortex

    OpenAIRE

    Townsend, Rory G.; Solomon, Selina S.; Chen, Spencer C.; Pietersen, Alexander N.J.; Martin, Paul R.; Solomon, Samuel G.; Gong, Pulin

    2015-01-01

    Slow brain rhythms are attributed to near-simultaneous (synchronous) changes in activity in neuron populations in the brain. Because they are slow and widespread, synchronous rhythms have not been considered crucial for information processing in the waking state. Here we adapted methods from turbulence physics to analyze δ-band (1–4 Hz) rhythms in local field potential (LFP) activity, in multielectrode recordings from cerebral cortex in anesthetized marmoset monkeys. We found that synchrony c...

  6. Adaptive filtering enhances information transmission in visual cortex

    OpenAIRE

    Sharpee, Tatyana O.; Sugihara, Hiroki; Kurgansky, Andrei V.; Rebrik, Sergei P.; Stryker, Michael P.; Miller, Kenneth D.

    2006-01-01

    Sensory neuroscience seeks to understand how the brain encodes natural environments. However, neural coding has largely been studied using simplified stimuli. In order to assess whether the brain’s coding strategy depends on the stimulus ensemble, we apply a new information-theoretic method that allows unbiased calculation of neural filters (receptive fields) from responses to natural scenes or other complex signals with strong multipoint correlations. In the cat primary visual cortex we comp...

  7. Development and Plasticity of the Primary Visual Cortex

    OpenAIRE

    Espinosa, J. Sebastian; Stryker, Michael P.

    2012-01-01

    Hubel and Wiesel began the modern study of development and plasticity of primary visual cortex (V1), discovering response properties of cortical neurons that distinguished them from their inputs and that were arranged in a functional architecture. Their findings revealed an early innate period of development and a later critical period of dramatic experience-dependent plasticity. Recent studies have used rodents to benefit from biochemistry and genetics. The roles of spontaneous neural activi...

  8. Distinct mechanisms for size tuning in primate visual cortex

    OpenAIRE

    Briggs, Farran; Usrey, W. Martin

    2011-01-01

    Most neurons in primary visual cortex (V1) are selective for stimulus size, a property with important implications for salient feature detection. Size selectivity involves dynamic interactions between neuronal circuits that establish the classical (center) and extraclassical (surround) of a neuron’s receptive field. Although much is known about the tuning properties and stimulus selectivity of the center and surround subunits, relatively little is known about how these subunits interact to ac...

  9. Is the Medial Prefrontal Cortex Necessary for Theory of Mind?

    OpenAIRE

    Otti, Alexander; Wohlschläger, Afra; Noll-Hussong, Michael

    2015-01-01

    Background: Successful social interaction relies on the ability to attribute mental states to other people. Previous functional neuroimaging studies have shown that this process, described as Theory of Mind (ToM) or mentalization, is reliably associated with activation of the medial prefrontal cortex (mPFC). However, this study presents a novel and surprising finding that provides new insight into the role of the mPFC in mentalization tasks. Methodology/Principal Findings: Twenty ...

  10. Prefrontal Cortex in Learning to Overcome Generalized Fear

    OpenAIRE

    Edward Korzus

    2015-01-01

    SUMMARY Normal brain functioning relies critically on the ability to control appropriate behavioral responses to fearful stimuli. Overgeneralized fear is the major symptom of anxiety disorders including posttraumatic stress disorder. This review describes recent data demonstrating that the medial prefrontal cortex (mPFC) plays a critical role in the refining of cues that drive the acquisition of fear response. Recent studies on molecular mechanisms that underlie the role of mPFC in fear discr...

  11. Structural and Functional Dichotomy of Human Midcingulate Cortex

    OpenAIRE

    Vogt, Brent A.; Berger, Gail R.; Derbyshire, Stuart W G

    2003-01-01

    Anterior cingulate cortex is comprised of perigenual and midcingulate regions based on cytology, imaging, and connections. Its anterior (aMCC) and posterior (pMCC) parts and transition to posterior area 23 were evaluated in 6 human cingulate gyri with Nissl-staining and immunoreactions for neuron-specific nuclear binding protein and intermediate neurofilament proteins (NFP) and their pain and emotion functions evaluated in standard coordinates. Morphological differences included a poorly diff...

  12. Behavioral Effects of Congenital Ventromedial Prefrontal Cortex Malformation

    OpenAIRE

    Boes Aaron D; Grafft Amanda; Joshi Charuta; Chuang Nathaniel A; Nopoulos Peg; Anderson Steven W

    2011-01-01

    Abstract Background A detailed behavioral profile associated with focal congenital malformation of the ventromedial prefrontal cortex (vmPFC) has not been reported previously. Here we describe a 14 year-old boy, B.W., with neurological and psychiatric sequelae stemming from focal cortical malformation of the left vmPFC. Case Presentation B.W.'s behavior has been characterized through extensive review Patience of clinical and personal records along with behavioral and neuropsychological testin...

  13. Principles underlying sensory map topography in primary visual cortex.

    Science.gov (United States)

    Kremkow, Jens; Jin, Jianzhong; Wang, Yushi; Alonso, Jose M

    2016-05-01

    The primary visual cortex contains a detailed map of the visual scene, which is represented according to multiple stimulus dimensions including spatial location, ocular dominance and stimulus orientation. The maps for spatial location and ocular dominance arise from the spatial arrangement of thalamic afferent axons in the cortex. However, the origins of the other maps remain unclear. Here we show that the cortical maps for orientation, direction and retinal disparity in the cat (Felis catus) are all strongly related to the organization of the map for spatial location of light (ON) and dark (OFF) stimuli, an organization that we show is OFF-dominated, OFF-centric and runs orthogonal to ocular dominance columns. Because this ON-OFF organization originates from the clustering of ON and OFF thalamic afferents in the visual cortex, we conclude that all main features of visual cortical topography, including orientation, direction and retinal disparity, follow a common organizing principle that arranges thalamic axons with similar retinotopy and ON-OFF polarity in neighbouring cortical regions. PMID:27120164

  14. Specialized Cortex Glial Cells Accumulate Lipid Droplets in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Viktor Kis

    Full Text Available Lipid droplets (LDs are common organelles of the majority of eukaryotic cell types. Their biological significance has been extensively studied in mammalian liver cells and white adipose tissue. Although the central nervous system contains the highest relative amount and the largest number of different lipid species, neither the spatial nor the temporal distribution of LDs has been described. In this study, we used the brain of the fruitfly, Drosophila melanogaster, to investigate the neuroanatomy of LDs. We demonstrated that LDs are exclusively localised in glial cells but not in neurons in the larval nervous system. We showed that the brain's LD pool, rather than being constant, changes dynamically during development and reaches its highest value at the beginning of metamorphosis. LDs are particularly enriched in cortex glial cells located close to the brain surface. These specialized superficial cortex glial cells contain the highest amount of LDs among glial cell types and encapsulate neuroblasts and their daughter cells. Superficial cortex glial cells, combined with subperineurial glial cells, express the Drosophila fatty acid binding protein (Dfabp, as we have demonstrated through light- and electron microscopic immunocytochemistry. To the best of our best knowledge this is the first study that describes LD neuroanatomy in the Drosophila larval brain.

  15. Olfactory Predictive Codes and Stimulus Templates in Piriform Cortex

    Science.gov (United States)

    Zelano, Christina; Mohanty, Aprajita; Gottfried, Jay A.

    2011-01-01

    Summary Neuroscientific models of sensory perception suggest that the brain utilizes predictive codes in advance of a stimulus encounter, enabling organisms to infer forthcoming sensory events. However, it is poorly understood how such mechanisms are implemented in the olfactory system. Combining high-resolution functional magnetic resonance imaging with multivariate (pattern-based) analyses, we examined the spatiotemporal evolution of odor perception in the human brain during an olfactory search task. Ensemble activity patterns in anterior piriform cortex (APC) and orbitofrontal cortex (OFC) reflected the attended odor target both before and after stimulus onset. In contrast, pre-stimulus ensemble representations of the odor target in posterior piriform cortex (PPC) gave way to post-stimulus representations of the odor itself. Critically, the robustness of target-related patterns in PPC predicted subsequent behavioral performance. Our findings directly show that the brain generates predictive templates or “search images” in PPC, with physical correspondence to odor-specific pattern representations, to augment olfactory perception. PMID:21982378

  16. Brain polyphosphoinositide metabolism during focal ischemia in rat cortex

    International Nuclear Information System (INIS)

    Using a rat model of stroke, we examined the effects of focal cerebral ischemia on the metabolism of polyphosphoinositides by injecting 32Pi into both the left and right cortices. After equilibration of the label for 2-3 hours, ischemia induced a significant decrease (p less than 0.001) in the concentrations of labeled phosphatidyl 4,5-bisphosphates (66-78%) and phosphatidylinositol 4-phosphate (64-67%) in the right middle cerebral artery cortex of four rats. The phospholipid labeling pattern in the left middle cerebral artery cortex, which sustained only mild ischemia and no permanent tissue damage, was not different from that of two sham-operated controls. However, when 32Pi was injected 1 hour after the ischemic insult, there was a significant decrease (p less than 0.01) in the incorporation of label into the phospholipids in both cortices of four ischemic rats compared with four sham-operated controls. Furthermore, differences in the phospholipid labeling pattern were observed in the left cortex compared with the sham-operated controls. The change in labeling pattern was attributed to the partial reduction in blood flow following ligation of the common carotid arteries. We provide a sensitive procedure for probing the effects of focal cerebral ischemia on the polyphosphoinositide signaling pathway in the brain, which may play an important role in the pathogenesis of tissue injury

  17. Neural mechanisms of perceptual grouping in human visual cortex

    Institute of Scientific and Technical Information of China (English)

    MAO Lihua; HAN Shihui; GUO Chunyan; JIANG Yi

    2004-01-01

    The current work examined neural substrates of perceptual grouping in human visual cortex using event-related potential (ERP) recording. Stimulus arrays consisted of local elements that were either evenly spaced (uniform stimuli) or grouped into columns or rows by proximity or color similarity (grouping stimuli). High-density ERPs were recorded while subjects identified orientations of perceptual groups in stimulus arrays that were presented randomly in one of the four quadrants of the visual field. Both uniform and grouping stimulus arrays elicited an early ERP component (C1), which peaked at about 70 ms after stimulus onset and changed its polarity as a function of stimulated elevations. Dipole modeling based on realistic- head boundary-element models revealed generators of the C1 component in the calcarine cortex. The C1 was modulated by perceptual grouping of local elements based on proximity, and this grouping effect was stronger in the upper than in the lower visual field. The findings provide ERP evidence for the engagement of human primary visual cortex in the early stage of perceptual grouping.

  18. Ontogeny of somatostatin receptors in the rat somatosensory cortex

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, B.J.; Leroux, P.; Bodenant, C.; Vaudry, H. (Groupe de Recherche en Endocrinologie Moleculaire, CNRS URA 650, Unite Affiliee a l' INSERM, Mont-Saint-Aignan, (France))

    1991-03-08

    The distribution and density of SRIF receptors (SRIF-R) were studied during development in the rat somatosensory cortex by in vitro autoradiography with monoiodinated (Tyr0-DTrp8)S14. In 16-day-old fetuses (E16), intense labeling was evident in the intermediate zone of the cortex while low concentrations of SRIF-R were detected in the marginal and ventricular zones. The highest density of SRIF-R was measured in the intermediate zone at E18. At this stage, labeling was also intense in the internal part of the developing cortical plate; in contrast, the concentration of binding sites associated with the marginal and ventricular zones remained relatively low. Profound modifications in the distribution of SRIF-R appeared at birth. In particular, a transient reduction of receptor density occurred in the cortical plate. During the first postnatal week, the density of receptors measured in the intermediate zone decreased gradually; conversely, high levels of SRIF-R were observed in the developing cortical layers (II to VI). At postpartum day 13 (P13), a stage which just precedes completion of cell migration in the parietal cortex, the most intensely labeled regions were layers V-VI and future layers II-III. From P13 to adulthood, the concentrations of SRIF-R decreased in all cortical layers (I to VI) and the pattern of distribution of receptors at P21 was similar to that observed in the adults.

  19. Ontogeny of somatostatin receptors in the rat somatosensory cortex

    International Nuclear Information System (INIS)

    The distribution and density of SRIF receptors (SRIF-R) were studied during development in the rat somatosensory cortex by in vitro autoradiography with monoiodinated [Tyr0-DTrp8]S14. In 16-day-old fetuses (E16), intense labeling was evident in the intermediate zone of the cortex while low concentrations of SRIF-R were detected in the marginal and ventricular zones. The highest density of SRIF-R was measured in the intermediate zone at E18. At this stage, labeling was also intense in the internal part of the developing cortical plate; in contrast, the concentration of binding sites associated with the marginal and ventricular zones remained relatively low. Profound modifications in the distribution of SRIF-R appeared at birth. In particular, a transient reduction of receptor density occurred in the cortical plate. During the first postnatal week, the density of receptors measured in the intermediate zone decreased gradually; conversely, high levels of SRIF-R were observed in the developing cortical layers (II to VI). At postpartum day 13 (P13), a stage which just precedes completion of cell migration in the parietal cortex, the most intensely labeled regions were layers V-VI and future layers II-III. From P13 to adulthood, the concentrations of SRIF-R decreased in all cortical layers (I to VI) and the pattern of distribution of receptors at P21 was similar to that observed in the adults

  20. Remodeling of inhibitory synaptic connections in developing ferret visual cortex

    Directory of Open Access Journals (Sweden)

    Dalva Matthew B

    2010-02-01

    Full Text Available Abstract Background In the visual cortex, as in many other regions of the developing brain, excitatory synaptic connections undergo substantial remodeling during development. While evidence suggests that local inhibitory synapses may behave similarly, the extent and mechanisms that mediate remodeling of inhibitory connections are not well understood. Results Using scanning laser photostimulation in slices of developing ferret visual cortex, we assessed the overall patterns of developing inhibitory and excitatory synaptic connections converging onto individual neurons. Inhibitory synaptic inputs onto pyramidal neurons in cortical layers 2 and 3 were already present as early as postnatal day 20, well before eye opening, and originated from regions close to the recorded neurons. During the ensuing 2 weeks, the numbers of synaptic inputs increased, with the numbers of inhibitory (and excitatory synaptic inputs peaking near the time of eye opening. The pattern of inhibitory inputs refined rapidly prior to the refinement of excitatory inputs. By uncaging the neurotransmtter GABA in brain slices from animals of different ages, we find that this rapid refinement correlated with a loss of excitatory activity by GABA. Conclusion Inhibitory synapses, like excitatory synapses, undergo significant postnatal remodeling. The time course of the remodeling of inhibitory connections correlates with the emergence of orientation tuning in the visual cortex, implicating these rearrangements in the genesis of adult cortical response properties.

  1. The role of the midcingulate cortex in monitoring others’ decisions

    Directory of Open Access Journals (Sweden)

    Matthew A J Apps

    2013-12-01

    Full Text Available A plethora of research has implicated the cingulate cortex in the processing of social information (i.e. processing elicited by, about, and directed towards others and reward-related information that guides decision-making. However, it is often overlooked that there is variability in the cytoarchitectonic properties and anatomical connections across the cingulate cortex, which is indicative of functional variability. Here we review evidence from lesion, single-unit recording and functional imaging studies. Taken together, these support the claim that the processing of information that has the greatest influence on social behaviour can be localised to the gyral surface of the midcingulate cortex (MCCg. We propose that the MCCg is engaged when predicting and monitoring the outcomes of decisions during social interactions. In particular, the MCCg processes statistical information that tracks the extent to which the outcomes of decisions meet goals when interacting with others. We provide a novel framework for the computational mechanisms that underpin such social information processing in the MCCg. This framework provides testable hypotheses for the social deficits displayed in autism spectrum disorders and psychopathy.

  2. The insular taste cortex contributes to odor quality coding

    Directory of Open Access Journals (Sweden)

    Maria G Veldhuizen

    2010-07-01

    Full Text Available Despite distinct peripheral and central pathways, stimulation of both the olfactory and the gustatory systems may give rise to the sensation of sweetness. Whether there is a common central mechanism producing sweet quality sensations or two discrete mechanisms associated independently with gustatory and olfactory stimuli is currently unknown. Here we used fMRI to determine whether odor sweetness is represented in the piriform olfactory cortex, which is thought to code odor quality, or in the insular taste cortex, which is thought to code taste quality. Fifteen participants sampled two concentrations of a pure sweet taste (sucrose, two sweet food odors (chocolate and strawberry, and two sweet floral odors (lilac and rose. Replicating prior work we found that olfactory stimulation activated the piriform, orbitofrontal and insular cortices. Of these regions, only the insula also responded to sweet taste. More importantly, the magnitude of the response to the food odors, but not to the non-food odors, in this region of insula was positively correlated with odor sweetness rating. These findings demonstrate that insular taste cortex contributes to odor quality coding by representing the taste-like aspects of food odors. Since the effect was specific to the food odors, and only food odors are experienced with taste, we suggest this common central mechanism develops as a function of experiencing flavors.

  3. Engagement of right temporal cortex during processing of linguistic context.

    Science.gov (United States)

    Kircher, T T; Brammer, M; Tous Andreu, N; Williams, S C; McGuire, P K

    2001-01-01

    Language processing involves the interplay of areas in both cerebral hemispheres. Whereas the left temporal lobe is necessary for most language tasks, the right hemisphere seems to be additionally activated during processing of paragraphs and metaphors. We studied the neural correlates of word generation and selection in a sentence context, using functional magnetic resonance imaging (fMRI). Cerebral activation was measured while seven healthy, right handed volunteers read and completed sentence stems, with relatively low Cloze frequency, out loud. During a GENERATION condition, subjects were required to generate a word which completed a sentence stem appropriately. During a DECISION condition, subjects selected and articulated one of two presented terminal words. A READING condition in which subjects read an appropriate completion aloud, served as baseline. When GENERATION was compared to READING or DECISION, the left middle frontal, anterior cingulate, precuneus and right lateral temporal cortex were activated. During DECISION relative to READING, the left inferior frontal and middle/superior temporal cortex bilaterally were activated. The prominent engagement of the right lateral temporal cortex during the GENERATION conditions may reflect the processing of linguistic context, and particularly the activation of multiple meanings in the course of producing an appropriate completion. PMID:11369403

  4. On the origin of the functional architecture of the cortex.

    Directory of Open Access Journals (Sweden)

    Dario L Ringach

    Full Text Available The basic structure of receptive fields and functional maps in primary visual cortex is established without exposure to normal sensory experience and before the onset of the critical period. How the brain wires these circuits in the early stages of development remains unknown. Possible explanations include activity-dependent mechanisms driven by spontaneous activity in the retina and thalamus, and molecular guidance orchestrating thalamo-cortical connections on a fine spatial scale. Here I propose an alternative hypothesis: the blueprint for receptive fields, feature maps, and their inter-relationships may reside in the layout of the retinal ganglion cell mosaics along with a simple statistical connectivity scheme dictating the wiring between thalamus and cortex. The model is shown to account for a number of experimental findings, including the relationship between retinotopy, orientation maps, spatial frequency maps and cytochrome oxidase patches. The theory's simplicity, explanatory and predictive power makes it a serious candidate for the origin of the functional architecture of primary visual cortex.

  5. Intrahemispheric cortico-cortical connections of the human auditory cortex.

    Science.gov (United States)

    Cammoun, Leila; Thiran, Jean Philippe; Griffa, Alessandra; Meuli, Reto; Hagmann, Patric; Clarke, Stephanie

    2015-11-01

    The human auditory cortex comprises the supratemporal plane and large parts of the temporal and parietal convexities. We have investigated the relevant intrahemispheric cortico-cortical connections using in vivo DSI tractography combined with landmark-based registration, automatic cortical parcellation and whole-brain structural connection matrices in 20 right-handed male subjects. On the supratemporal plane, the pattern of connectivity was related to the architectonically defined early-stage auditory areas. It revealed a three-tier architecture characterized by a cascade of connections from the primary auditory cortex to six adjacent non-primary areas and from there to the superior temporal gyrus. Graph theory-driven analysis confirmed the cascade-like connectivity pattern and demonstrated a strong degree of segregation and hierarchy within early-stage auditory areas. Putative higher-order areas on the temporal and parietal convexities had more widely spread local connectivity and long-range connections with the prefrontal cortex; analysis of optimal community structure revealed five distinct modules in each hemisphere. The pattern of temporo-parieto-frontal connectivity was partially asymmetrical. In conclusion, the human early-stage auditory cortical connectivity, as revealed by in vivo DSI tractography, has strong similarities with that of non-human primates. The modular architecture and hemispheric asymmetry in higher-order regions is compatible with segregated processing streams and lateralization of cognitive functions. PMID:25173473

  6. Learning a New Selection Rule in Visual and Frontal Cortex.

    Science.gov (United States)

    van der Togt, Chris; Stănişor, Liviu; Pooresmaeili, Arezoo; Albantakis, Larissa; Deco, Gustavo; Roelfsema, Pieter R

    2016-08-01

    How do you make a decision if you do not know the rules of the game? Models of sensory decision-making suggest that choices are slow if evidence is weak, but they may only apply if the subject knows the task rules. Here, we asked how the learning of a new rule influences neuronal activity in the visual (area V1) and frontal cortex (area FEF) of monkeys. We devised a new icon-selection task. On each day, the monkeys saw 2 new icons (small pictures) and learned which one was relevant. We rewarded eye movements to a saccade target connected to the relevant icon with a curve. Neurons in visual and frontal cortex coded the monkey's choice, because the representation of the selected curve was enhanced. Learning delayed the neuronal selection signals and we uncovered the cause of this delay in V1, where learning to select the relevant icon caused an early suppression of surrounding image elements. These results demonstrate that the learning of a new rule causes a transition from fast and random decisions to a more considerate strategy that takes additional time and they reveal the contribution of visual and frontal cortex to the learning process. PMID:27269960

  7. Motor cortex stimulation therapy for post-stroke weakness

    International Nuclear Information System (INIS)

    Motor cortex stimulation (MCS) delivered concurrently with rehabilitation therapy may enhance motor recovery following stroke. We investigated the effects of MCS on the recovery from upper extremity paresis in patients with chronic stroke. In 12 patients who had moderate arm and finger paresis at more than 4 months after stroke, an electrode was placed through a small craniotomy on the epidural space of the motor cortex that was identified using functional MRI. MCS during occupational therapy for one hour was performed 3 times a day for at least 4 weeks. The mean scores for Fugl-Meyer assessments of the arm improved, from 37 preoperatively to 46 postoperatively. The mean grip strength improved from 3.25 to 9.0 kg. All patients appeared satisfactory in their results because they recognized an improvement of arm function. Although the mechanism of the beneficial effects of MCS on recovery after stroke has not been well known, the neuroplasticity might play a important role. In a few cases of the present series, it was observed that the hand motor cortex area detected on functional MRI had been enlarged after MCS therapy. MCS could become a novel neurosurgical treatment modality for the chronic post-stroke weakness. (author)

  8. A Model of Representational Spaces in Human Cortex.

    Science.gov (United States)

    Guntupalli, J Swaroop; Hanke, Michael; Halchenko, Yaroslav O; Connolly, Andrew C; Ramadge, Peter J; Haxby, James V

    2016-06-01

    Current models of the functional architecture of human cortex emphasize areas that capture coarse-scale features of cortical topography but provide no account for population responses that encode information in fine-scale patterns of activity. Here, we present a linear model of shared representational spaces in human cortex that captures fine-scale distinctions among population responses with response-tuning basis functions that are common across brains and models cortical patterns of neural responses with individual-specific topographic basis functions. We derive a common model space for the whole cortex using a new algorithm, searchlight hyperalignment, and complex, dynamic stimuli that provide a broad sampling of visual, auditory, and social percepts. The model aligns representations across brains in occipital, temporal, parietal, and prefrontal cortices, as shown by between-subject multivariate pattern classification and intersubject correlation of representational geometry, indicating that structural principles for shared neural representations apply across widely divergent domains of information. The model provides a rigorous account for individual variability of well-known coarse-scale topographies, such as retinotopy and category selectivity, and goes further to account for fine-scale patterns that are multiplexed with coarse-scale topographies and carry finer distinctions. PMID:26980615

  9. Transitive inference: distinct contributions of rostrolateral prefrontal cortex and the hippocampus.

    Science.gov (United States)

    Wendelken, Carter; Bunge, Silvia A

    2010-05-01

    The capacity to reason about complex information is a central characteristic of human cognition. An important component of many reasoning tasks is the need to integrate multiple mental relations. Several researchers have argued that rostrolateral prefrontal cortex (RLPFC) plays a key role in relational integration. If this hypothesis is correct, then RLPFC should play a key role in transitive inference, which requires the integration of multiple relations to reach a conclusion. Thus far, however, neuroscientific research on transitive inference has focused primarily on the hippocampus. In this fMRI study, we sought to compare the roles of RLPFC and the hippocampus on a novel transitive inference paradigm. Four relations between colored balls were presented on the screen together with a target relation. Participants were asked to decide whether the target relation was correct, given the other indicated relations between balls. RLPFC, but not the hippocampus, exhibited stronger activation on trials that required relational integration as compared with trials that involved relational encoding without integration. In contrast, the hippocampus exhibited a pattern consistent with a role in relational encoding, with stronger activation on trials requiring encoding of relational predicate-argument structure as compared with trials requiring encoding of item-item associations. Functional connectivity analyses give rise to the hypothesis that RLPFC draws on hippocampal representations of mental relations during the process of relational integration. PMID:19320546

  10. Orbitofrontal cortex contribution to working memory. N-back ERP study

    International Nuclear Information System (INIS)

    Remarkable progress in cognitive neuroscience has revealed the involvement of the prefrontal cortex and the orbitofrontal cortex in human working memory, but the orbitofrontal cortex is still one of the least understood regions in the human brain. To elucidate the contribution of the orbitofrontal cortex to human working memory, we studied electroencephalography (EEG) P300 activity in n-back task. We elicited early P3 around 300 ms and late P3 around 360 ms of P300 components in n-back event related potentials (ERP). The amplitudes of the respective peaks changed depending on the working memory load (0-back, 1-back, 2-back, 3-back). We used source analysis to evaluate the orbitofrontal cortex in P3 components. A source model was constructed with the sources seeded from fMRI meta-analysis of n-back task and additional sources in the orbitofrontal cortex and the visual cortex estimated with P100 and late P3 components in the n-back ERP. This source model had more than 99% of GOF (goodness of fit) in n-back ERP. It gave us an insight of brain activity at the positions where sources existed. Early P3 was mainly produced by the dorsolateral prefrontal cortex, the ventrolateral prefrontal cortex, the inferior parietal lobule, the medial posterior parietal and the visual cortex. Late P3 was mainly produced by the medial premotor, the lateral premotor, the frontal pole and the orbitofrontal cortex. The contribution of the frontal pole and the orbitofrontal cortex had peaks around 390 ms which were later than late P3 component. In this study, the method to evaluate the orbitofrontal cortex activity in n-back ERP was provided. Our results elicited the involvement of the orbitofrontal cortex in late P3 component of n-back ERP. (author)

  11. Anhedonia and general distress show dissociable ventromedial prefrontal cortex connectivity in major depressive disorder.

    Science.gov (United States)

    Young, C B; Chen, T; Nusslock, R; Keller, J; Schatzberg, A F; Menon, V

    2016-01-01

    Anhedonia, the reduced ability to experience pleasure in response to otherwise rewarding stimuli, is a core symptom of major depressive disorder (MDD). Although the posterior ventromedial prefrontal cortex (pVMPFC) and its functional connections have been consistently implicated in MDD, their roles in anhedonia remain poorly understood. Furthermore, it is unknown whether anhedonia is primarily associated with intrinsic 'resting-state' pVMPFC functional connectivity or an inability to modulate connectivity in a context-specific manner. To address these gaps, a pVMPFC region of interest was first identified using activation likelihood estimation meta-analysis. pVMPFC connectivity was then examined in relation to anhedonia and general distress symptoms of depression, using both resting-state and task-based functional magnetic resonance imaging involving pleasant music, in current MDD and healthy control groups. In MDD, pVMPFC connectivity was negatively correlated with anhedonia but not general distress during music listening in key reward- and emotion-processing regions, including nucleus accumbens, ventral tegmental area/substantia nigra, orbitofrontal cortex and insula, as well as fronto-temporal regions involved in tracking complex sound sequences, including middle temporal gyrus and inferior frontal gyrus. No such dissociations were observed in the healthy controls, and resting-state pVMPFC connectivity did not dissociate anhedonia from general distress in either group. Our findings demonstrate that anhedonia in MDD is associated with context-specific deficits in pVMPFC connectivity with the mesolimbic reward system when encountering pleasurable stimuli, rather than a static deficit in intrinsic resting-state connectivity. Critically, identification of functional circuits associated with anhedonia better characterizes MDD heterogeneity and may help track of one of its core symptoms. PMID:27187232

  12. Consciousness without a cerebral cortex: a challenge for neuroscience and medicine.

    Science.gov (United States)

    Merker, Bjorn

    2007-02-01

    A broad range of evidence regarding the functional organization of the vertebrate brain - spanning from comparative neurology to experimental psychology and neurophysiology to clinical data - is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain - culminating in the cerebral cortex of mammals - came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. PMID:17475053

  13. Parallel Cortical Networks Formed by Modular Organization of Primary Motor Cortex Outputs.

    Science.gov (United States)

    Hamadjida, Adjia; Dea, Melvin; Deffeyes, Joan; Quessy, Stephan; Dancause, Numa

    2016-07-11

    In primates, the refinement of motor behaviors, in particular hand use, is associated with the establishment of more direct projections from primary motor cortex (M1) onto cervical motoneurons [1, 2] and the appearance of additional premotor and sensory cortical areas [3]. All of these areas have reciprocal connections with M1 [4-7]. Thus, during the evolution of the sensorimotor network, the number of interlocutors with which M1 interacts has tremendously increased. It is not clear how these additional interconnections are organized in relation to one another within the hand representation of M1. This is important because the organization of connections between M1 and phylogenetically newer and specialized cortical areas is likely to be key to the increased repertoire of hand movements in primates. In cebus monkeys, we used injections of retrograde tracers into the hand representation of different cortical areas of the sensorimotor network (ventral and dorsal premotor areas [PMv and PMd], supplementary motor area [SMA], and posterior parietal cortex [area 5]), and we analyzed the pattern of labeled neurons within the hand representation of M1. Instead of being uniformly dispersed across M1, neurons sending projections to each distant cortical area were largely segregated in different subregions of M1. These data support the view that primates split the cortical real estate of M1 into modules, each preferentially interconnected with a particular cortical area within the sensorimotor network. This modular organization could sustain parallel processing of interactions with multiple specialized cortical areas to increase the behavioral repertoire of the hand. PMID:27322001

  14. Structural basis of empathy and the domain general region in the anterior insular cortex

    Directory of Open Access Journals (Sweden)

    Isabella Mutschler

    2013-05-01

    Full Text Available Empathy is key for healthy social functioning and individual differences in empathy have strong implications for manifold domains of social behavior. Empathy comprises emotional and cognitive components, such as feeling and knowing what another person is feeling, and may also be closely linked to sensorimotor processes, which go along with the motivation and behavior to respond compassionately to another person’s feelings and to reduce another person’s pain. There is growing evidence for local plastic change in the structure of the healthy adult human brain in response to environmental demands or intrinsic factors. Here we have investigated changes in brain structure resulting from or predisposing to empathy. Structural MRI data of 101 healthy adult females was analyzed. Empathy in fictitious as well as real-life situations was assessed by using a widely used and validated self-evaluation measure. Furthermore, empathy-related structural effects were also put into the context of a functional map of the anterior insular cortex determined by activation likelihood estimate (ALE meta-analysis of previous functional imaging studies. We found that gray matter density in the left dorsal anterior insular cortex correlates with empathy and that this area overlaps with the domain general region of the anterior insula that is situated in-between functional systems involved in emotion-cognition, pain and motor tasks as determined by our meta-analysis. Thus, we propose that this insular region where we find structural differences depending on individual empathy might play a crucial role in modulating the efficiency of neural integration underlying emotional, cognitive, and sensorimotor information which is essential for global empathy.

  15. Learning to cope with stress modulates anterior cingulate cortex stargazin expression in monkeys and mice.

    Science.gov (United States)

    Lee, Alex G; Capanzana, Roxanne; Brockhurst, Jacqueline; Cheng, Michelle Y; Buckmaster, Christine L; Absher, Devin; Schatzberg, Alan F; Lyons, David M

    2016-05-01

    Intermittent mildly stressful situations provide opportunities to learn, practice, and improve coping with gains in subsequent emotion regulation. Here we investigate the effects of learning to cope with stress on anterior cingulate cortex gene expression in monkeys and mice. Anterior cingulate cortex is involved in learning, memory, cognitive control, and emotion regulation. Monkeys and mice were randomized to either stress coping or no-stress treatment conditions. Profiles of gene expression were acquired with HumanHT-12v4.0 Expression BeadChip arrays adapted for monkeys. Three genes identified in monkeys by arrays were then assessed in mice by quantitative real-time polymerase chain reaction. Expression of a key gene (PEMT) involved in acetylcholine biosynthesis was increased in monkeys by coping but this result was not verified in mice. Another gene (SPRY2) that encodes a negative regulator of neurotrophic factor signaling was decreased in monkeys by coping but this result was only partly verified in mice. The CACNG2 gene that encodes stargazin (also called TARP gamma-2) was increased by coping in monkeys as well as mice randomized to coping with or without subsequent behavioral tests of emotionality. As evidence of coping effects distinct from repeated stress exposures per se, increased stargazin expression induced by coping correlated with diminished emotionality in mice. Stargazin modulates glutamate receptor signaling and plays a role in synaptic plasticity. Molecular mechanisms of synaptic plasticity that mediate learning and memory in the context of coping with stress may provide novel targets for new treatments of disorders in human mental health. PMID:27003116

  16. Cogeneration: Key feasibility analysis parameters

    International Nuclear Information System (INIS)

    This paper first reviews the essential requirements, in terms of scope, objectives and methods, of technical/economic feasibility analyses applied to cogeneration systems proposed for industrial plants in Italy. Attention is given to the influence on overall feasibility of the following factors: electric power and fuel costs, equipment coefficients of performance, operating schedules, maintenance costs, Italian Government taxes and financial and legal incentives. Through an examination of several feasibility studies that were done on cogeneration proposals relative to different industrial sectors, a sensitivity analysis is performed on the effects of varying the weights of different cost benefit analysis parameters. With the use of statistical analyses, standard deviations are then determined for key analysis parameters, and guidelines are suggested for analysis simplifications

  17. Key Aspects of Wave Energy

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Nørgaard, Jørgen Harck

    2012-01-01

    -technical risks, it is critical to provide comprehensive and reliable information on the technologies without neglecting attractive advantages. It is possible to underline a different key of lecture of wave energy performance by considering efficiency and power production as well as device versatility......Diversification of renewable energy sources is fundamental to ensure sustainability. In this contest, wave energy can provide a substantial contribution as soon as the sector breaks into the market. In order to accelerate shift from a technology to a market focus and reduce technical and non....... By collecting the experience from mainly three different wave energy developers, the possible alternative functions (other than energy production) of the devices are describe: Wave Dragon can be effectively used to reduce coastline erosion and/or as mussel farm; the Sea wave Slot cone Generator (SSG) can...

  18. New Weak Keys in RSA

    Institute of Scientific and Technical Information of China (English)

    WANG Baocang; LIU Shuanggen; HU Yupu

    2006-01-01

    The security of the RSA system with the prime pairs of some special form is investigated. A new special-purpose algorithm for factoring RSA numbers is proposed. The basic idea of the method is to factor RSA numbers by factoring a well-chosen quadratic polynomial with integral coefficients. When viewed as a general-purpose algorithm, the new algorithm has a high computational complexity. It is shown that the RSA number n=pq can be easily factored if p and q have the special form of p=as+b, q=cs+d, where a, b, c, d are relatively small numbers. Such prime pairs (p, q) are the weak keys of RSA, so when we generate RSA modulus, we should avoid using such prime pairs (p, q).

  19. Key to Language Learning Success

    Directory of Open Access Journals (Sweden)

    Oktavian Mantiri

    2015-01-01

    Full Text Available This paper looks at the important elements of language learning and teaching i.e. the role of teachers as well as the attitude and motivation of learners. Teachers undoubtedly play crucial roles in students’ language learning outcome which could ignite or diminish students’ motivation. Positive attitudes and motivation – instrumental or integrative and intrinsic or extrinsic – are key to successful learning. Therefore it is paramount for language teachers as well as learners to know these roles and nurture the best possible ways where language teaching and learning will thrive. This paper also suggested that both stake-holders should be open to holistic approach of language learning and that other factors such as the environment could play an important part in language teaching and learning success.

  20. Medial profrontal cortex and anterior cingulate cortex in the generation of alpha activity induced by transcendental meditation: a magnetoencephalographic study.

    Directory of Open Access Journals (Sweden)

    Yamamoto,Shin

    2006-02-01

    Full Text Available

    Previous EEG studies have shown that transcendental meditation (TM increases frontal and central alpha activity. The present study was aimed at identifying the source of this alpha activity using magnetoencephalography (MEG and electroencephalography (EEG simultaneously on eight TM practitioners before, during, and after TM. The magnetic field potentials corresponding to TM-induced alpha activities on EEG recordings were extracted, and we attempted to localize the dipole sources using the multiple signal classification (MUSIC algorithm, equivalent current dipole source analysis, and the multiple spatio-temporal dipole model. Since the dipoles were mapped to both the medial prefrontal cortex (mPFC and anterior cingulate cortex (ACC, it is suggested that the mPFC and ACC play an important role in brain activity induced by TM.

  1. Key energy technologies for Europe

    Energy Technology Data Exchange (ETDEWEB)

    Holst Joergensen, Birte

    2005-09-01

    The report is part of the work undertaken by the High-Level Expert Group to prepare a report on emerging science and technology trends and the implications for EU and Member State research policies. The outline of the report is: 1) In the introductory section, energy technologies are defined and for analytical reasons further narrowed down; 2) The description of the socio-economic challenges facing Europe in the energy field is based on the analysis made by the International Energy Agency going back to 1970 and with forecasts to 2030. Both the world situation and the European situation are described. This section also contains an overview of the main EU policy responses to energy. Both EU energy R and D as well as Member State energy R and D resources are described in view of international efforts; 3) The description of the science and technology base is made for selected energy technologies, including energy efficiency, biomass, hydrogen, and fuel cells, photovoltaics, clean fossil fuel technologies and CO{sub 2} capture and storage, nuclear fission and fusion. When possible, a SWOT is made for each technology and finally summarised; 4) The forward look highlights some of the key problems and uncertainties related to the future energy situation. Examples of recent energy foresights are given, including national energy foresights in Sweden and the UK as well as links to a number of regional and national foresights and roadmaps; 5) Appendix 1 contains a short description of key international organisations dealing with energy technologies and energy research. (ln)

  2. Characterizing synaptic protein development in human visual cortex enables alignment of synaptic age with rat visual cortex

    Directory of Open Access Journals (Sweden)

    Joshua G.A Pinto

    2015-02-01

    Full Text Available Although many potential neuroplasticity based therapies have been developed in the lab, few have translated into established clinical treatments for human neurologic or neuropsychiatric diseases. Animal models, especially of the visual system, have shaped our understanding of neuroplasticity by characterizing the mechanisms that promote neural changes and defining timing of the sensitive period. The lack of knowledge about development of synaptic plasticity mechanisms in human cortex, and about alignment of synaptic age between animals and humans, has limited translation of neuroplasticity therapies. In this study, we quantified expression of a set of highly conserved pre- and post-synaptic proteins (Synapsin, Synaptophysin, PSD-95, Gephyrin and found that synaptic development in human primary visual cortex continues into late childhood. Indeed, this is many years longer than suggested by neuroanatomical studies and points to a prolonged sensitive period for plasticity in human sensory cortex. In addition, during childhood we found waves of inter-individual variability that are different for the 4 proteins and include a stage during early development (<1 year when only Gephyrin has high inter-individual variability. We also found that pre- and post-synaptic protein balances develop quickly, suggesting that maturation of certain synaptic functions happens within the first year or two of life. A multidimensional analysis (principle component analysis showed that most of the variance was captured by the sum of the 4 synaptic proteins. We used that sum to compare development of human and rat visual cortex and identified a simple linear equation that provides robust alignment of synaptic age between humans and rats. Alignment of synaptic ages is important for age-appropriate targeting and effective translation of neuroplasticity therapies from the lab to the clinic.

  3. Tools For Installing Keys On A Stud

    Science.gov (United States)

    Goodoak, Robert D.

    1995-01-01

    Two tools designed to be used together to drive long locking keys axially to install them on stud. Tools are: supporter holding keys in correct relative alignment and driver having multiple prongs, each of which fits into one of holes in supporter. Tools prevent bending and breaking of keys during installation, and make possible to install all keys simultaneously, in one motion.

  4. A change in injured corticospinal tract originating from the premotor cortex to the primary motor cortex in a patient with intracerebral hemorrhage

    Institute of Scientific and Technical Information of China (English)

    Sang Seok Yeo; Sung Ho Jang

    2012-01-01

    Many studies have attempted to elucidate the motor recovery mechanism of stroke, but the majority of these studies focus on cerebral infarct and relatively little is known about the motor recovery mechanism of intracerebral hemorrhage. In this study, we report on a patient with intracerebral hemorrhage who displayed a change in injured corticospinal tract originating from the premotor cortex to the primary motor cortex on diffusion tensor imaging. An 86-year-old woman presented with complete paralysis of the right extremities following spontaneous intracerebral hemorrhage in the left frontoparietal cortex. The patient showed motor recovery, to the extent of being able to extend affected fingers against gravity and to walk independently on even ground at 5 months after onset. Diffusion tensor imaging showed that the left corticospinal tract originated from the premotor cortex at 1 month after intracerebral hemorrhage and from the left primary motor cortex and premotor cortex at 5 months after intracerebral hemorrhage. The change of injured corticospinal tract originating from the premotor cortex to the primary motor cortex suggests motor recovery of intracerebral hemorrhage.

  5. A novel key management scheme using biometrics

    Science.gov (United States)

    Sui, Yan; Yang, Kai; Du, Yingzi; Orr, Scott; Zou, Xukai

    2010-04-01

    Key management is one of the most important issues in cryptographic systems. Several important challenges in such a context are represented by secure and efficient key generation, key distribution, as well as key revocation. Addressing such challenges requires a comprehensive solution which is robust, secure and efficient. Compared to traditional key management schemes, key management using biometrics requires the presence of the user, which can reduce fraud and protect the key better. In this paper, we propose a novel key management scheme using iris based biometrics. Our newly proposed scheme outperforms traditional key management schemes as well as some existing key-binding biometric schemes in terms of security, diversity and/or efficiency.

  6. A Cognição Social e o Córtex Cerebral Social Cognition and the Brain Cortex

    Directory of Open Access Journals (Sweden)

    Judith Butman

    2001-01-01

    Full Text Available A cognição social é o processo que orienta condutas frente a outros indivíduos da mesma espécie. Várias estruturas cerebrais têm um papel chave para controlar as condutas sociais: o córtex pré-frontal ventromedial, a amígdala, o córtex somatosensorial direito e a ínsula. O córtex pré-frontal ventromedial está comprometido com o raciocínio social e com a tomada de decisões; a amígdala com o julgamento social de faces; o córtex somatosensorial direito, com a empatia e com a simulação; enquanto que a insula, com a resposta autonômica. Estes achados estão de acordo com a hipótese do marcador somático, um mecanismo específico por meio do qual adquirimos, representamos ou memorizamos os valores de nossas ações. Estas estruturas cerebrais atuam como mediadores entre as representações perceptuais dos estímulos sensoriais e a recuperação do conhecimento que o estímulo pode ativar. O sistema límbico é a zona limítrofe; nela, a psicologia se encontra com a neurologia. A correta sincronização destas zonas e estruturas, no adulto, é a chave para uma situação livre de patologia.Social cognition refers to the processes that subserve behavior in response to other individuals of the same species. Several brain structures play a key role in guiding social behaviors: ventromedial prefrontal cortex, amygdala, right somatosensory cortex and insula. The ventromedial prefrontal cortex is most directly involved in social reasoning and decision making; the amygdala in social judgment of faces, the right somatosensory cortex in empathy and simulation and the insula in autonomic responses. These findings are corresponding to the somatic marker hypothesis, particular mechanism by which we acquire, represent and retrieve the values of our actions. These brain structures appear to mediate between perceptual representation of social stimuli and retrieval of knowledge that such stimuli can trigger. The limbic system is the border zone

  7. Altered functional connectivity of the insular cortex across prefrontal networks in cocaine addiction.

    Science.gov (United States)

    Cisler, Josh M; Elton, Amanda; Kennedy, Ashley P; Young, Jonathan; Smitherman, Sonet; Andrew James, George; Kilts, Clinton D

    2013-07-30

    Interoception is theorized to be an important process mediating substance use disorders, and the insular cortex is recognized as a core neural region supporting interoception. The purpose of this study was to compare the integration of the insular cortex into prefrontal-related resting-state networks between individuals with cocaine dependence and healthy controls. Participants comprised 41 patients with cocaine dependence and 19 controls who underwent a resting-state 3-T functional magnetic resonance imaging scan. Individuals with cocaine dependence demonstrated altered functional connectivity of the insular cortex, predominantly the right insular cortex, with all eight prefrontal-related resting-state networks identified through Independent Component Analysis (ICA). A conjunction analysis demonstrated that the right insular cortex was the neural region with the highest number of common group differences across the networks. There was no evidence that insular cortex connectivity commonly differed between groups for non-prefrontal-related networks. Further, seed-based functional connectivity analyses extended the network analyses and indicated that cocaine dependence was associated with greater connectivity of the right insula with the dorsomedial prefrontal cortex, inferior frontal gyrus, and bilateral dorsolateral prefrontal cortex. These data support the hypothesis that cocaine dependence is related to altered functional interactions of the insular cortex with prefrontal networks. The results suggest possible neural mechanisms by which the insular cortex and interoceptive information influence cognitive control and decision-making processes presumably mediated by prefrontal networks in the cocaine dependence process. PMID:23684980

  8. Quantum key distribution and cryptography

    International Nuclear Information System (INIS)

    Full text: Originally proposed by classical cryptographers, the ideas behind Quantum Key Distribution (QKD) have attracted considerable interest among the quantum optics community, which has significantly helped bring these ideas to reality. Experimental realizations have quickly evolved from early lab demonstrations to QKD systems that are now deployed in real conditions and targeting commercial applications. Although QKD can be theoretically proven to rely on 'unconditional security proofs' and should thus be able to provide security levels unachievable through computationally-based cryptographic techniques, the debate on the cryptographic applications of QKD remains somehow controversial. It seems that a consensus on that matter cannot be reached without a careful analysis of assumptions and definitions related to security models used in classical or in quantum cryptography. In this talk, we will try to present a comprehensive synthesis on this topic. We have initiated this work as a contribution to the European IP SECOQC project, confronting views and knowledge among experimental and theoretical quantum physicists, as well as classical cryptographers. (author)

  9. KEY TOPICS IN SPORTS MEDICINE

    Directory of Open Access Journals (Sweden)

    Amir Ali Narvani

    2006-12-01

    Full Text Available Key Topics in Sports Medicine is a single quick reference source for sports and exercise medicine. It presents the essential information from across relevant topic areas, and includes both the core and emerging issues in this rapidly developing field. It covers: 1 Sports injuries, rehabilitation and injury prevention, 2 Exercise physiology, fitness testing and training, 3 Drugs in sport, 4 Exercise and health promotion, 5 Sport and exercise for special and clinical populations, 6 The psychology of performance and injury. PURPOSE The Key Topics format provides extensive, concise information in an accessible, easy-to-follow manner. AUDIENCE The book is targeted the students and specialists in sports medicine and rehabilitation, athletic training, physiotherapy and orthopaedic surgery. The editors are authorities in their respective fields and this handbook depends on their extensive experience and knowledge accumulated over the years. FEATURES The book contains the information for clinical guidance, rapid access to concise details and facts. It is composed of 99 topics which present the information in an order that is considered logical and progressive as in most texts. Chapter headings are: 1. Functional Anatomy, 2. Training Principles / Development of Strength and Power, 3. Biomechanical Principles, 4. Biomechanical Analysis, 5. Physiology of Training, 6. Monitoring of Training Progress, 7. Nutrition, 8. Hot and Cold Climates, 9. Altitude, 10. Sport and Travelling, 11. Principles of Sport Injury Diagnosis, 12. Principles of Sport and Soft Tissue Management, 13. Principles of Physical Therapy and Rehabilitation, 14. Principles of Sport Injury Prevention, 15. Sports Psychology, 16. Team Sports, 17. Psychological Aspects of Injury in Sport, 18. Injury Repair Process, 19. Basic Biomechanics of Tissue Injury, 20. Plain Film Radiography in Sport, 21. Nuclear Medicine, 22. Diagnostic Ultrasound, 23. MRI Scan, 24. Other Imaging, 5. Head Injury, 26. Eye

  10. Key issues in transplant tourism.

    Science.gov (United States)

    Akoh, Jacob A

    2012-02-24

    Access to organ transplantation depends on national circumstances, and is partly determined by the cost of health care, availability of transplant services, the level of technical capacity and the availability of organs. Commercial transplantation is estimated to account for 5%-10% (3500-7000) of kidney transplants performed annually throughout the world. This review is to determine the state and outcome of renal transplantation associated with transplant tourism (TT) and the key challenges with such transplantation. The stakeholders of commercial transplantation include: patients on the waiting lists in developed countries or not on any list in developing countries; dialysis funding bodies; middlemen, hosting transplant centres; organ-exporting countries; and organ vendors. TT and commercial kidney transplants are associated with a high incidence of surgical complications, acute rejection and invasive infection which cause major morbidity and mortality. There are ethical and medical concerns regarding the management of recipients of organs from vendors. The growing demand for transplantation, the perceived failure of altruistic donation in providing enough organs has led to calls for a legalised market in organ procurement or regulated trial in incentives for donation. Developing transplant services worldwide has many benefits - improving results of transplantation as they would be performed legally, increasing the donor pool and making TT unnecessary. Meanwhile there is a need to re-examine intrinsic attitudes to TT bearing in mind the cultural and economic realities of globalisation. Perhaps the World Health Organization in conjunction with The Transplantation Society would set up a working party of stakeholders to study this matter in greater detail and make recommendations. PMID:24175191

  11. Introduction strategies raise key questions.

    Science.gov (United States)

    Finger, W R; Keller, S

    1995-09-01

    Key issues that must be considered before a new contraceptive is introduced center on the need for a trained provider to begin or terminate the method, its side effects, duration of use, method's ability to meet users' needs and preferences, and extra training or staff requirements. Logistics and economic issues to consider are identifying a dependable way of effectively supplying commodities, planning extra services needed for the method, and cost of providing the method. Each contraceptive method presents a different side effect pattern and burdens the service delivery setting differently. The strategy developed to introduce or expand the 3-month injectable Depo-Provera (DMPA) can be used for any method. It includes a needs assessment and addresses regulatory issues, service delivery policies and procedures, information and training, evaluation, and other concerns. Viet Nam's needs assessment showed that Norplant should not be introduced until the service delivery system becomes stronger. Any needs assessment for expansion of contraceptive services should cover sexually transmitted disease/HIV issues. A World Health Organization strategy helps officials identify the best method mix for local situations. Introductory strategies must aim to improve the quality of family planning programs and expand choices. Many begin by examining existing data and conducting interviews with policymakers, users, providers, and women's health advocates. Introductory programs for Norplant focus on provider training, adequate counseling and informed consent for users, and ready access to removal. They need a well-prepared service delivery infrastructure. The first phase of the DMPA introductory strategy for the Philippines comprised a social marketing campaign and DMPA introduction at public clinics in 10 pilot areas with strong service delivery. Successful AIDS prevention programs show that people tend to use barrier methods when they are available. USAID is currently studying

  12. Efficient Three Party Key Exchange Protocol

    OpenAIRE

    H. K. Pathak; Manju Sanghi

    2012-01-01

    Key exchange protocols allow two or more parties communicating over a public network to establish a common secret key called a session key. In 1976, Diffie and Hellman proposed the first practical key exchange (DH key exchange) protocol.  In 2005, Abdalla and  Pointcheval suggested  a new variation  of the computational   DH assumption  called chosen based computational Diffie Hellman (CCDH)  and presented  simple password based authenticated  key exchange protocols.  Since then several three...

  13. The Case for Quantum Key Distribution

    Science.gov (United States)

    Stebila, Douglas; Mosca, Michele; Lütkenhaus, Norbert

    Quantum key distribution (QKD) promises secure key agreement by using quantum mechanical systems. We argue that QKD will be an important part of future cryptographic infrastructures. It can provide long-term confidentiality for encrypted information without reliance on computational assumptions. Although QKD still requires authentication to prevent man-in-the-middle attacks, it can make use of either information-theoretically secure symmetric key authentication or computationally secure public key authentication: even when using public key authentication, we argue that QKD still offers stronger security than classical key agreement.

  14. Quantification of the adrenal cortex hormones with radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Badillo A, V.; Carrera D, A. A.; Ibarra M, C. M., E-mail: vbadillocren@hotmail.co [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-10-15

    The pathologies of the adrenal cortex -adrenal insufficiency and Cushing syndrome- have their origin on the deficit or hypersecretion of some of the hormones that are secreted by the adrenal cortex, which is divided in three zones anatomically defined: the external zone, also called the zona glomerulosa, which is the main production site of aldosterone and mineralocorticoids; the internal zone, or zona reticularis, that produces androgens; and the external zone, or zone 1 orticotrop, which is responsible for producing glucocorticoids. In this work, a quantitative analysis of those hormones and their pathologic trigger was made; the quantification was made in the laboratory by means of highly sensitive and specific techniques, in this case, the radioimmunoassay, in which a radioisotope I-125 is used. This technique is based on the biochemical bond-type reaction, because it requires of a substance called the linker, which bonds to another called ligand. This reaction is also known as antigen-antibody (Ag-Ab), where the results of the reaction will depend on the quantity of antigen in the sample and on its affinity for the antibody. In this work, a 56 patients (of which 13 were men and 43 women) study was made. The cortisol, the ACTH, the androsterone and the DHEA values were very elevated in the majority of the cases corresponding to women, predominating cortisol; while in men, a notorious elevation of the 17 {alpha}-OH-PRG and of the DHEA-SO{sub 4} was observed. Based on that, we can conclude that 51 of them did not have mayor complications, because they just went to the laboratory once, while the remaining 5 had a medical monitoring, and they visited the laboratory more than one occasion, tell about a difficulty on their improvement. According to the results, an approximate relation of 8:2 women:men, respectively, becomes clear to the hormonal pathologies of the adrenal cortex. (Author)

  15. Sexually Monomorphic Maps and Dimorphic Responses in Rat Genital Cortex.

    Science.gov (United States)

    Lenschow, Constanze; Copley, Sean; Gardiner, Jayne M; Talbot, Zoe N; Vitenzon, Ariel; Brecht, Michael

    2016-01-11

    Mammalian external genitals show sexual dimorphism [1, 2] and can change size and shape upon sexual arousal. Genitals feature prominently in the oldest pieces of figural art [3] and phallic depictions of penises informed psychoanalytic thought about sexuality [4, 5]. Despite this longstanding interest, the neural representations of genitals are still poorly understood [6]. In somatosensory cortex specifically, many studies did not detect any cortical representation of genitals [7-9]. Studies in humans debate whether genitals are represented displaced below the foot of the cortical body map [10-12] or whether they are represented somatotopically [13-15]. We wondered what a high-resolution mapping of genital representations might tell us about the sexual differentiation of the mammalian brain. We identified genital responses in rat somatosensory cortex in a region previously assigned as arm/leg cortex. Genital responses were more common in males than in females. Despite such response dimorphism, we observed a stunning anatomical monomorphism of cortical penis and clitoris input maps revealed by cytochrome-oxidase-staining of cortical layer 4. Genital representations were somatotopic and bilaterally symmetric, and their relative size increased markedly during puberty. Size, shape, and erect posture give the cortical penis representation a phallic appearance pointing to a role in sexually aroused states. Cortical genital neurons showed unusual multi-body-part responses and sexually dimorphic receptive fields. Specifically, genital neurons were co-activated by distant body regions, which are touched during mounting in the respective sex. Genital maps indicate a deep homology of penis and clitoris representations in line with a fundamentally bi-sexual layout [16] of the vertebrate brain. PMID:26725197

  16. Circadian rhythmicity of synapses in mouse somatosensory cortex.

    Science.gov (United States)

    Jasinska, Malgorzata; Grzegorczyk, Anna; Woznicka, Olga; Jasek, Ewa; Kossut, Malgorzata; Barbacka-Surowiak, Grazyna; Litwin, Jan A; Pyza, Elzbieta

    2015-10-01

    The circadian rhythmicity displayed by motor behavior of mice: activity at night and rest during the day; and the associated changes in the sensory input are reflected by cyclic synaptic plasticity in the whisker representations located in the somatosensory (barrel) cortex. It was not clear whether diurnal rhythmic changes in synapse density previously observed in the barrel cortex resulted from changes in the activity of the animals, from daily light/dark (LD) rhythm or are driven by an endogenous clock. These changes were investigated in the barrel cortex of C57BL/6 mouse strain kept under LD 12 : 12 h conditions and in constant darkness (DD). Stereological analysis of serial electron microscopic sections was used to assess numerical density of synapses. In mice kept under LD conditions, the total density of synapses and the density of excitatory synapses located on dendritic spines was higher during the light period (rest phase). In contrast, the density of inhibitory synapses located on dendritic spines increased during the dark period (activity phase). Under DD conditions, the upregulation of the inhibitory synapses during the activity phase was retained, but the cyclic changes in the density of excitatory synapses were not observed. The results show that the circadian plasticity concerns only synapses located on spines (and not those on dendritic shafts), and that excitatory and inhibitory synapses are differently regulated during the 24 h cycle: the excitatory synapses are influenced by light, whilst the inhibitory synapses are driven by the endogenous circadian clock. PMID:26274013

  17. Gene expression in cortex and hippocampus during acute pneumococcal meningitis

    Directory of Open Access Journals (Sweden)

    Wittwer Matthias

    2006-06-01

    Full Text Available Abstract Background Pneumococcal meningitis is associated with high mortality (~30% and morbidity. Up to 50% of survivors are affected by neurological sequelae due to a wide spectrum of brain injury mainly affecting the cortex and hippocampus. Despite this significant disease burden, the genetic program that regulates the host response leading to brain damage as a consequence of bacterial meningitis is largely unknown. We used an infant rat model of pneumococcal meningitis to assess gene expression profiles in cortex and hippocampus at 22 and 44 hours after infection and in controls at 22 h after mock-infection with saline. To analyze the biological significance of the data generated by Affymetrix DNA microarrays, a bioinformatics pipeline was used combining (i a literature-profiling algorithm to cluster genes based on the vocabulary of abstracts indexed in MEDLINE (NCBI and (ii the self-organizing map (SOM, a clustering technique based on covariance in gene expression kinetics. Results Among 598 genes differentially regulated (change factor ≥ 1.5; p ≤ 0.05, 77% were automatically assigned to one of 11 functional groups with 94% accuracy. SOM disclosed six patterns of expression kinetics. Genes associated with growth control/neuroplasticity, signal transduction, cell death/survival, cytoskeleton, and immunity were generally upregulated. In contrast, genes related to neurotransmission and lipid metabolism were transiently downregulated on the whole. The majority of the genes associated with ionic homeostasis, neurotransmission, signal transduction and lipid metabolism were differentially regulated specifically in the hippocampus. Of the cell death/survival genes found to be continuously upregulated only in hippocampus, the majority are pro-apoptotic, while those continuously upregulated only in cortex are anti-apoptotic. Conclusion Temporal and spatial analysis of gene expression in experimental pneumococcal meningitis identified potential

  18. Quantification of the adrenal cortex hormones with radioimmunoassay

    International Nuclear Information System (INIS)

    The pathologies of the adrenal cortex -adrenal insufficiency and Cushing syndrome- have their origin on the deficit or hypersecretion of some of the hormones that are secreted by the adrenal cortex, which is divided in three zones anatomically defined: the external zone, also called the zona glomerulosa, which is the main production site of aldosterone and mineralocorticoids; the internal zone, or zona reticularis, that produces androgens; and the external zone, or zone 1 orticotrop, which is responsible for producing glucocorticoids. In this work, a quantitative analysis of those hormones and their pathologic trigger was made; the quantification was made in the laboratory by means of highly sensitive and specific techniques, in this case, the radioimmunoassay, in which a radioisotope I-125 is used. This technique is based on the biochemical bond-type reaction, because it requires of a substance called the linker, which bonds to another called ligand. This reaction is also known as antigen-antibody (Ag-Ab), where the results of the reaction will depend on the quantity of antigen in the sample and on its affinity for the antibody. In this work, a 56 patients (of which 13 were men and 43 women) study was made. The cortisol, the ACTH, the androsterone and the DHEA values were very elevated in the majority of the cases corresponding to women, predominating cortisol; while in men, a notorious elevation of the 17 α-OH-PRG and of the DHEA-SO4 was observed. Based on that, we can conclude that 51 of them did not have mayor complications, because they just went to the laboratory once, while the remaining 5 had a medical monitoring, and they visited the laboratory more than one occasion, tell about a difficulty on their improvement. According to the results, an approximate relation of 8:2 women:men, respectively, becomes clear to the hormonal pathologies of the adrenal cortex. (Author)

  19. The neural representation of Arabic digits in visual cortex

    Directory of Open Access Journals (Sweden)

    Lien ePeters

    2015-09-01

    Full Text Available In this study, we investigated how Arabic digits are represented in the visual cortex, and how their representation changes throughout the ventral visual processing stream, compared to the representation of letters. We probed these questions with two fMRI experiments. In Experiment 1, we explored whether we could find brain regions that were more activated for digits than for number words in a subtraction task. One such region was detected in lateral occipital cortex. However, the activity in this region might have been confounded by string length – number words contain more characters than digits. We therefore conducted a second experiment in which string length was systematically controlled. Experiment 2 revealed that the findings of the first experiment were task dependent (as it was only observed in a task in which numerosity was relevant or stimulus dependent (as it was only observed when the number of characters of a stimulus was not controlled.We further explored the characteristics of the activation patterns for digit and letter strings across the ventral visual processing stream through multi-voxel pattern analyses. We found an alteration in representations throughout the ventral processing stream from clustering based on amount of visual information in primary visual cortex towards clustering based on symbolic stimulus category higher in the visual hierarchy. The present findings converge to the conclusion that in the ventral visual system, as far as can be detected with fMRI, the distinction between Arabic digits and letter strings is represented in terms of distributed patterns rather than separate regions.

  20. TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers

    DEFF Research Database (Denmark)

    Ptito, M; Fumal, A; de Noordhout, A Martens;

    2008-01-01

    Various non-visual inputs produce cross-modal responses in the visual cortex of early blind subjects. In order to determine the qualitative experience associated with these occipital activations, we systematically stimulated the entire occipital cortex using single pulse transcranial magnetic...... stimulation (TMS) in early blind subjects and in blindfolded seeing controls. Whereas blindfolded seeing controls reported only phosphenes following occipital cortex stimulation, some of the blind subjects reported tactile sensations in the fingers that were somatotopically organized onto the visual cortex...... polysynaptic cortical pathway between the somatosensory cortex and the visual cortex in early blind subjects. These results also add new evidence that the activity of the occipital lobe in the blind takes its qualitative expression from the character of its new input source, therefore supporting the cortical...

  1. GABAergic synapses: their plasticity and role in sensory cortex

    Directory of Open Access Journals (Sweden)

    Trevor C Griffen

    2014-03-01

    Full Text Available The mammalian neocortex is composed of a variety of cell types organized in a highly interconnected circuit. GABAergic neurons account for only about 20% of cortical neurons. However, they show widespread connectivity and a high degree of diversity in morphology, location, electrophysiological properties and gene expression. In addition, distinct populations of inhibitory neurons have different sensory response properties, capacities for plasticity and sensitivities to changes in sensory experience. In this review we summarize experimental evidence regarding the properties of GABAergic neurons in primary sensory cortex. We will discuss how distinct GABAergic neurons and different forms of GABAergic inhibitory plasticity may contribute to shaping sensory cortical circuit activity and function.

  2. Images of Illusory Motion in Primary Visual Cortex

    DEFF Research Database (Denmark)

    Larsen, Axel; Madsen, Kristoffer; Ellegaard Lund, Torben;

    2006-01-01

    continuous path from one stimulus location to the other through intervening positions where no physical stimuli exist. The phenomenon has been extensively investigated for nearly a century but little is known about its neurophysiological foundation. Here we present images of activations in the primary visual...... cortex in response to real and apparent motion. The images show that during apparent motion, a path connecting the cortical representations of the stimulus locations is filled in by activation. The activation along the path of apparent motion is similar to the activation found when a stimulus is...

  3. Neural Correlates of an Auditory Afterimage in Primary Auditory Cortex

    OpenAIRE

    Noreña, A. J.; Eggermont, J. J.

    2003-01-01

    The Zwicker tone (ZT) is defined as an auditory negative afterimage, perceived after the presentation of an appropriate inducer. Typically, a notched noise (NN) with a notch width of 1/2 octave induces a ZT with a pitch falling in the frequency range of the notch. The aim of the present study was to find potential neural correlates of the ZT in the primary auditory cortex of ketamine-anesthetized cats. Responses of multiunits were recorded simultaneously with two 8-electrode arrays during 1 s...

  4. Asymmetries in the representation of space in the human auditory cortex depend on the global stimulus context.

    Science.gov (United States)

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

    2016-03-01

    Studies on humans and other mammals have provided evidence for a two-channel or three-channel representation of horizontal space in the auditory system, with one channel maximally responsive to each of the left hemispace, the right hemispace and, possibly, the midline. Mammalian studies have suggested that the contralateral channel is larger in both cortices, but human studies have found this contralateral preference in only one of the cortices. However, human studies are in conflict as to whether the contralateral preference is in the left or the right auditory cortex, and there are a number of methodological differences that this conflict could be attributed to. A key difference between studies is the duration of the silent interval preceding each stimulus and any perception of sound-source movement that the absence of a silent interval creates. We presented auditory noises that alternated between -90° (left) and +90° (right) and recorded neural responses (event-related potentials) using electroencephalography. We randomly varied the duration of the silent interval preceding each stimulus to create a condition with an immediate (local) stimulus context similar to that used in a study reporting contralateral preference in the left auditory cortex, a condition with a local context similar to that in a study reporting contralateral preference in the right auditory cortex, and an intermediate condition. Surprisingly, we found that both auditory cortices exhibited a similarly strong contralateral preference under all conditions, with responses 27% greater, on average, to the contralateral than the ipsilateral space. This suggests that both the cortices can exhibit a contralateral preference, but whether these preferences manifest depends on the global, rather than the local, stimulus context. PMID:26730514

  5. Primary motor cortex activity reduction under the regulation of SMA by real-time fMRI

    Science.gov (United States)

    Guo, Jia; Zhao, Xiaojie; Li, Yi; Yao, Li; Chen, Kewei

    2012-03-01

    Real-time fMRI (rtfMRI) is a new technology which allows human subjects to observe and control their own BOLD signal change from one or more localized brain regions during scanning. Current rtfMRI-neurofeedback studies mainly focused on the target region itself without considering other related regions influenced by the real-time feedback. However, there always exits important directional influence between many of cooperative regions. On the other hand, rtfMRI based on motor imagery mainly aimed at somatomotor cortex or primary motor area, whereas supplement motor area (SMA) was a relatively more integrated and pivotal region. In this study, we investigated whether the activities of SMA can be controlled utilizing different motor imagery strategies, and whether there exists any possible impact on an unregulated but related region, primary motor cortex (M1). SMA was first localized using overt finger tapping task, the activities of SMA were feedback to subjects visually on line during each of two subsequent imagery motor movement sessions. All thirteen healthy participants were found to be able to successfully control their SMA activities by self-fit imagery strategies which involved no actual motor movements. The activation of right M1 was also found to be significantly reduced in both intensity and extent with the neurofeedback process targeted at SMA, suggestive that not only the part of motor cortex activities were influenced under the regulation of a key region SMA, but also the increased difference between SMA and M1 might reflect the potential learning effect.

  6. Multiple subpial cortical transections for the control of intractable epilepsy in exquisite cortex.

    Science.gov (United States)

    Dogali, M; Devinsky, O; Luciano, D; Perrine, K; Beric, A

    1993-01-01

    In 5 cases suffering from intractable seizures and ictal onset in exquisite (primary somatosensory or language related) cortex, surgical therapy has been done consisting wholly or in part of multiple subpial transections. In two cases with involvement of the primary somatosensory cortex, good seizure control without detectable neurological deficit was achieved. In the other three cases with involvement of the language cortex, deficits were minimal and cleared with time. Patients became seizure-free. PMID:8109292

  7. High familial risk for mood disorder is associated with low dorsolateral prefrontal cortex serotonin transporter binding

    DEFF Research Database (Denmark)

    Frokjaer, Vibe G; Vinberg, Maj; Erritzoe, David;

    2009-01-01

    Mood disorders are elicited through a combination of genetic and environmental stress factors, and treatment with selective serotonin reuptake inhibitors ameliorates depressive symptoms. Changes in the serotonin transporter (SERT) binding may therefore occur in depressive patients and in subjects...... measured with [(11)C]DASB PET. The volumes of interest included the orbitofrontal cortex, the dorsolateral prefrontal cortex, the ventrolateral prefrontal cortex, anterior cingulate, caudate, putamen, thalamus, and midbrain. We found that individuals at high familial risk for mood disorders had a 35...

  8. Sleep-active cells in the cerebral cortex and their role in slow-wave activity

    OpenAIRE

    Gerashchenko, Dmitry; Wisor, Jonathan P.; Kilduff, Thomas S.

    2011-01-01

    We recently identified neurons in the cerebral cortex that become activated during sleep episodes with high slow-wave activity (SWA). The distinctive properties of these neurons are the ability to produce nitric oxide and their long-range projections within the cortex. In this review, we discuss how these characteristics of sleep-active cells could be relevant to SWA production in the cortex. We also discuss possible models of the role of nNOS cells in SWA production.

  9. Visual Map Shifts based on Whisker-Guided Cues in the Young Mouse Visual Cortex

    OpenAIRE

    Kohei Yoshitake; Hiroaki Tsukano; Manavu Tohmi; Seiji Komagata; Ryuichi Hishida; Takeshi Yagi; Katsuei Shibuki

    2013-01-01

    Mice navigate nearby space using their vision and whiskers, and young mice learn to integrate these heterogeneous inputs in perceptual space. We found that cortical responses were depressed in the primary visual cortex of young mice after wearing a monocular prism. This depression was uniformly observed in the primary visual cortex and was eliminated by whisker trimming or lesions in the posterior parietal cortex. Compensatory visual map shifts of responses elicited via the eye that had worn ...

  10. Differential visually-induced gamma-oscillations in human cerebral cortex

    OpenAIRE

    Asano, Eishi; Nishida, Masaaki; Fukuda, Miho; Rothermel, Robert; Juhasz, Csaba; Sood, Sandeep

    2008-01-01

    Using intracranial electrocorticography, we determined how cortical gamma-oscillations (50–150Hz) were induced by different visual tasks in nine children with focal epilepsy. In all children, full-field stroboscopic flash-stimuli induced gamma-augmentation in the anterior-medial occipital cortex (starting on average at 31-msec after stimulus presentation) and subsequently in the lateral-polar occipital cortex; minimal gamma-augmentation was noted in the inferior occipital-temporal cortex; occ...

  11. The Prelimbic Cortex and Subthalamic Nucleus Contribute to Cue-Guided Behavioral Switching

    OpenAIRE

    Baker, Phillip M.; Ragozzino, Michael E.

    2013-01-01

    Frontal cortex - basal ganglia circuitry supports behavioral switching when a change in outcome information is used to adapt response patterns. Less is known about whether specific frontal cortex-basal ganglia circuitry supports behavioral switching when cues signal that a change in response patterns should occur. The present experiments investigated whether the prelimbic cortex and subthalamic nucleus in male Long-Evans rats supports cue-guided switching in a conditional discrimination test....

  12. AUDITORY CORTICAL PLASTICITY: DOES IT PROVIDE EVIDENCE FOR COGNITIVE PROCESSING IN THE AUDITORY CORTEX?

    OpenAIRE

    Irvine, Dexter R. F.

    2007-01-01

    The past 20 years have seen substantial changes in our view of the nature of the processing carried out in auditory cortex. Some processing of a cognitive nature, previously attributed to higher order “association” areas, is now considered to take place in auditory cortex itself. One argument adduced in support of this view is the evidence indicating a remarkable degree of plasticity in the auditory cortex of adult animals. Such plasticity has been demonstrated in a wide range of paradigms, i...

  13. A Spiking Neural Network Based Cortex-Like Mechanism and Application to Facial Expression Recognition

    OpenAIRE

    Si-Yao Fu; Guo-Sheng Yang; Xin-Kai Kuai

    2012-01-01

    In this paper, we present a quantitative, highly structured cortex-simulated model, which can be simply described as feedforward, hierarchical simulation of ventral stream of visual cortex using biologically plausible, computationally convenient spiking neural network system. The motivation comes directly from recent pioneering works on detailed functional decomposition analysis of the feedforward pathway of the ventral stream of visual cortex and developments on artificial spiking neural net...

  14. Fine functional organization of auditory cortex revealed by Fourier optical imaging

    OpenAIRE

    Kalatsky, Valery A.; Polley, Daniel B.; Merzenich, Michael M.; Schreiner, Christoph E.; Stryker, Michael P.

    2005-01-01

    We provide an overall view of the functional tonotopic organization of the auditory cortex in the rat. We apply a recently developed technique for acquiring intrinsic signal optical maps, Fourier imaging, in the rat auditory cortex. These highly detailed maps, derived in a several-minute-long recording procedure, delineate multiple auditory cortical areas and demonstrate their shapes, sizes, and tonotopic order. Beyond the primary auditory cortex, there are at least three distinct areas with ...

  15. Tingzikou key water control project started construction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Tingzikou key water control project on Jialing River, one of 18 newly started key projects in 2009 for China's western part development program, formally started construction at the end of November last year.

  16. Attaching Chuck Keys to Machine Tools

    Science.gov (United States)

    Richardson, V.

    1984-01-01

    Chuck keys attached to portable machine tools by retracting lanyards. Lanyard held taut by recoil caddy attached to tool base. Chuck key available for use when needed and safely secured during operation of tool.

  17. Electronic Nicotine Delivery Systems Key Facts Infographic

    Data.gov (United States)

    U.S. Department of Health & Human Services — Explore the Electronic Nicotine Delivery Systems Key Facts Infographic which outlines key facts related to electronic nicotine delivery systems (ENDS), including...

  18. KEY MANAGEMENT TECHNIQUES IN WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    Khawla Naji Shnaikat

    2014-12-01

    Full Text Available The way that is used to achieve most important security requirements is the cryptography. Cryptography mainly depends on what is called cryptography keys; the cryptographic keys required to be managed by using a robustness technique that guarantees the needed security requirements. So first of all, the necessary keys need to be distributed to the nodes before they are disseminated in the target area, and then let the sensors that need to communicate establish its secure communication by having a deal on what is called pair-wise key, and allow the refreshment process for those keys to be occurred successfully when it is needed, and finally, having the ability to revoke the keys that related to compromised nodes. These phases are performing the process that is called Key Management. In this paper we will explain different key management schemes, critique them theoretically, and propose an idea as a way out for the expected problems in one of these schemes.

  19. Small scale module of the rat granular retrosplenial cortex: an example of minicolumn-like structure of the cerebral cortex

    Directory of Open Access Journals (Sweden)

    Noritaka eIchinohe

    2012-01-01

    Full Text Available Structures associated with the small scale module called minicolumn can be observed frequently in the cerebral cortex. However, the description of functional characteristics remains obscure. A significant confounding factor is the marked variability both in the definition of a minicolumn and in the diagnostic markers for identifying a minicolumn (see for review, Jones, 2000, DeFelipe et al., 2003; Rockland and Ichinohe, 2004. Within a minicolumn, cell columns are easily visualized by conventional Nissl staining. Dendritic bundles were first discovered with Golgi methods, but are more easily seen with MAP2-immunohistochemisty. Myelinated axon bundles can be seen by Tau-immunohistochemistry or myelin staining. Axon bundles of double bouquet cell can be seen by calbindin-immunohistochemistry. The spatial interrelationship among these morphological elements is more complex than expected and is neither clear nor unanimously agreed upon. In this review, I would like to focus first on the minicolumnar structure found in layers 1 and 2 of the rat granular retrosplenial cortex (GRS. This modular structure was first discovered as a combination of prominent apical dendritic bundles from layer 2 pyramidal neurons and spatially-matched thalamocortical patchy inputs (Wyss et al., 2000. Further examination showed more intricate components of this modular structure, which will be reviewed in this paper. Second, the postnatal development of this structure and potential molecular players for its formation will be reviewed. Thirdly, I will discuss how this modular organization is transformed in mutant rodents with a disorganized layer structure in the cerebral cortex (i.e., reeler mouse and Shaking Rat Kawasaki. Lastly, the potential significance of this type of module will be discussed.

  20. A Formal Theory of Key Conjuring

    OpenAIRE

    Cortier, Véronique; Delaune, Stéphanie; Steel, Graham

    2007-01-01

    We describe a formalism for key conjuring, the process by which an attacker obtains an unknown, encrypted key by repeatedly calling a cryptographic API function with random values in place of keys. This technique has been used to attack the security APIs of several Hardware Security Modules (HSMs), which are widely deployed in the ATM (cash machine) network. We propose a formalism for detecting computationally feasible key conjuring operations, incorporated into a Dolev-Yao style model of the...

  1. A String-Based Public Key Cryptosystem

    OpenAIRE

    M. Andrecut

    2014-01-01

    Traditional methods in public key cryptography are based on number theory, and suffer from problems such as dealing with very large numbers, making key creation cumbersome. Here, we propose a new public key cryptosystem based on strings only, which avoids the difficulties of the traditional number theory approach. The security mechanism for public and secret keys generation is ensured by a recursive encoding mechanism embedded in a quasi-commutative-random function, resulted from the composit...

  2. SUPPLY CHAIN MANAGEMENT – KEY FACTORS

    OpenAIRE

    Magdalena Daniela DINU

    2014-01-01

    This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of bot...

  3. Microwave Photonics Parallel Quantum Key Distribution

    OpenAIRE

    Ruiz Alba Gaya, Antonio; Mora Almerich, José; Amaya Ocampo, Waldimar Alexander; Martínez García,Alfonso; García Muñoz, Víctor; Calvo Díaz-Aldagalán, David; Capmany Francoy, José

    2011-01-01

    The incorporation of multiplexing techniques used in Microwave Photonics to Quantum Key Distribution (QKD) systems bring important advantages enabling the simultaneous and parallel delivery of multiple keys between a central station and different end-users in the context of multipoint access and metropolitan networks, or by providing higher key distribution rates in point to point links by suitably linking the parallel distributed keys. It also allows the coexistence of classical information ...

  4. Information reconciliation for Quantum Key Distribution

    OpenAIRE

    Elkouss Coronas, David; Martinez Mateo, Jesus; Martín Ayuso, Vicente; Lancho Lancho, Daniel

    2010-01-01

    Secret-key agreement, a well-known problem in cryptography, allows two parties holding correlated sequences to agree on a secret key communicating over a public channel. It is usually divided into three different procedures: advantage distillation, information reconciliation and privacy amplification. The efficiency of each one of these procedures is needed if a positive key rate is to be attained from the legitimate parties? correlated sequences. Quantum key distribution (QKD) allows the two...

  5. Quantum Key Distribution with Screening and Analyzing

    OpenAIRE

    Kye, Won-Ho

    2006-01-01

    We propose a quantum key distribution scheme by using screening angles and analyzing detectors which enable to notice the presence of Eve who eavesdrops the quantum channel, as the revised protocol of the recent quantum key distribution [Phys. Rev. Lett. 95, 040501 (2005)]. We discuss the security of the proposed quantum key distribution against various attacks including impersonation attack and Trojan Horse attack.

  6. Lightweight Key Renewals for Clustered Sensor Networks

    Directory of Open Access Journals (Sweden)

    Gicheol Wang

    2010-03-01

    Full Text Available In sensor networks, sensors are likely to be captured by attackers because they are usually deployed in an unprotected or even a hostile environment. If an adversarial compromises a sensor, he/she uses the keys from the compromised sensor to uncover the keys of others sensors. Therefore, it is very important to renew the keys of sensors in a proactive or reactive manner. Even though many group key renewal schemes have been proposed, they have some security flaws. First, they employ a single group key in a cluster so that the compromise of one sensor discloses the group key. Second, they evict the compromised nodes by updating the compromised keys with non-compromised keys. This eviction scheme is useless when the non-compromised keys are exhausted due to the increase of compromised nodes. In this paper, we propose a lightweight key renewal scheme, which evicts the compromised nodes clearly by reforming clusters excluding compromised nodes. Besides, in a cluster, each member employs a pairwise key for communication with its CH (Cluster Head so that our scheme is tolerable against sensor compromise. Our simulation results prove that the proposed scheme is more tolerable against the compromise of sensors and it is more energy-saving than the group key renewal schemes.

  7. Harry Potter and the Dichotomous Key

    Science.gov (United States)

    Crowther, David T.

    2003-01-01

    In this lesson, students use Bertie Bott's Every Flavor Beans--a "wild" candy written about in the Harry Potter books and now available in stores--to learn about classification and dichotomous keys. In these activities, students sort jelly beans according to a key and then construct a key for a "new" flavor of beans. Students then build on their…

  8. Dopaminergic Modulation of Medial Prefrontal Cortex Deactivation in Parkinson Depression

    Directory of Open Access Journals (Sweden)

    Anders H. Andersen

    2015-01-01

    Full Text Available Parkinson’s disease (PD is associated with emotional abnormalities. Dopaminergic medications ameliorate Parkinsonian motor symptoms, but less is known regarding the impact of dopaminergic agents on affective processing, particularly in depressed PD (dPD patients. The aim of this study was to examine the effects of dopaminergic pharmacotherapy on brain activation to emotional stimuli in depressed versus nondepressed Parkinson disease (ndPD patients. Participants included 18 ndPD patients (11 men, 7 women and 10 dPD patients (7 men, 3 women. Patients viewed photographs of emotional faces during functional MRI. Scans were performed while the patient was taking anti-Parkinson medication and the day after medication had been temporarily discontinued. Results indicate that dopaminergic medications have opposite effects in the prefrontal cortex depending upon depression status. DPD patients show greater deactivation in the ventromedial prefrontal cortex (VMPFC on dopaminergic medications than off, while ndPD patients show greater deactivation in this region off drugs. The VMPFC is in the default-mode network (DMN. DMN activity is negatively correlated with activity in brain systems used for external visual attention. Thus dopaminergic medications may promote increased attention to external visual stimuli among dPD patients but impede normal suppression of DMN activity during external stimulation among ndPD patients.

  9. Dopaminergic Modulation of Medial Prefrontal Cortex Deactivation in Parkinson Depression.

    Science.gov (United States)

    Andersen, Anders H; Smith, Charles D; Slevin, John T; Kryscio, Richard J; Martin, Catherine A; Schmitt, Frederick A; Blonder, Lee X

    2015-01-01

    Parkinson's disease (PD) is associated with emotional abnormalities. Dopaminergic medications ameliorate Parkinsonian motor symptoms, but less is known regarding the impact of dopaminergic agents on affective processing, particularly in depressed PD (dPD) patients. The aim of this study was to examine the effects of dopaminergic pharmacotherapy on brain activation to emotional stimuli in depressed versus nondepressed Parkinson disease (ndPD) patients. Participants included 18 ndPD patients (11 men, 7 women) and 10 dPD patients (7 men, 3 women). Patients viewed photographs of emotional faces during functional MRI. Scans were performed while the patient was taking anti-Parkinson medication and the day after medication had been temporarily discontinued. Results indicate that dopaminergic medications have opposite effects in the prefrontal cortex depending upon depression status. DPD patients show greater deactivation in the ventromedial prefrontal cortex (VMPFC) on dopaminergic medications than off, while ndPD patients show greater deactivation in this region off drugs. The VMPFC is in the default-mode network (DMN). DMN activity is negatively correlated with activity in brain systems used for external visual attention. Thus dopaminergic medications may promote increased attention to external visual stimuli among dPD patients but impede normal suppression of DMN activity during external stimulation among ndPD patients. PMID:26793404

  10. The ventral pallidum and orbitofrontal cortex support food pleasantness inferences.

    Science.gov (United States)

    Simmons, W Kyle; Rapuano, Kristina M; Ingeholm, John E; Avery, Jason; Kallman, Seth; Hall, Kevin D; Martin, Alex

    2014-03-01

    Food advertisements often promote choices that are driven by inferences about the hedonic pleasures of eating a particular food. Given the individual and public health consequences of obesity, it is critical to address unanswered questions about the specific neural systems underlying these hedonic inferences. For example, although regions such as the orbitofrontal cortex (OFC) are frequently observed to respond more to pleasant food images than less hedonically pleasing stimuli, one important hedonic brain region in particular has largely remained conspicuously absent among human studies of hedonic response to food images. Based on rodent research demonstrating that activity in the ventral pallidum underlies the hedonic pleasures experienced upon eating food rewards, one might expect that activity in this important 'hedonic hotspot' might also track inferred food pleasantness. To date, however, no human studies have assessed this question. We thus asked human subjects to undergo fMRI and make item-by-item ratings of how pleasant it would be to eat particular visually perceived foods. Activity in the ventral pallidum was strongly modulated with pleasantness inferences. Additionally, activity within a region of the orbitofrontal cortex that tracks the pleasantness of tastes was also modulated with inferred pleasantness. Importantly, the reliability of these findings is demonstrated by their replication when we repeated the experiment at a new site with new subjects. These two experiments demonstrate that the ventral pallidum, in addition to the OFC, plays a central role in the moment-to-moment hedonic inferences that influence food-related decision-making. PMID:23397317

  11. Characterization of Face-Selective Patches in Orbitofrontal Cortex

    Science.gov (United States)

    Troiani, Vanessa; Dougherty, Chase C.; Michael, Andrew M.; Olson, Ingrid R.

    2016-01-01

    Face processing involves a complex, multimodal brain network. While visual-perceptual face patches in posterior parts of the brain have been studied for over a decade, the existence and properties of face-selective regions in orbitofrontal cortex (OFC) is a relatively new area of research. While regions of OFC are implicated in the emotional processing of faces, this is typically interpreted as a domain-general response to affective value rather than a face- or socially-specific response. However, electrophysiology studies in monkeys have identified neurons in OFC that respond more to faces than any other stimuli. Here, we characterize the prevalence and location of OFC face-selective regions in 20 healthy college students. We did this by including another biologically motivating category (appetizing foods) in a variant of the standard face localizer. Results show that face-selective patches can be identified at the individual level. Furthermore, in both a region of interest (ROI) and a whole brain analysis, medial regions of the OFC were face-selective, while lateral regions were responsive to faces and foods, indicating a domain-general response in lateral OFC. Medial OFC (mOFC) response to faces scales in relationship to a measure of social motivation that is distinct from face processing abilities associated with fusiform cortex. PMID:27378880

  12. Triglycerides in the human kidney cortex: relationship with body size.

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    Ion Alexandru Bobulescu

    Full Text Available Obesity is associated with increased risk for kidney disease and uric acid nephrolithiasis, but the pathophysiological mechanisms underpinning these associations are incompletely understood. Animal experiments have suggested that renal lipid accumulation and lipotoxicity may play a role, but whether lipid accumulation occurs in humans with increasing body mass index (BMI is unknown. The association between obesity and abnormal triglyceride accumulation in non-adipose tissues (steatosis has been described in the liver, heart, skeletal muscle and pancreas, but not in the human kidney. We used a quantitative biochemical assay to quantify triglyceride in normal kidney cortex samples from 54 patients undergoing nephrectomy for localized renal cell carcinoma. In subsets of the study population we evaluated the localization of lipid droplets by Oil Red O staining and measured 16 common ceramide species by mass spectrometry. There was a positive correlation between kidney cortex trigyceride content and BMI (Spearman R = 0.27, P = 0.04. Lipid droplets detectable by optical microscopy had a sporadic distribution but were generally more prevalent in individuals with higher BMI, with predominant localization in proximal tubule cells and to a lesser extent in glomeruli. Total ceramide content was inversely correlated with triglycerides. We postulate that obesity is associated with abnormal triglyceride accumulation (steatosis in the human kidney. In turn, steatosis and lipotoxicity may contribute to the pathogenesis of obesity-associated kidney disease and nephrolithiasis.

  13. Cochlear injury and adaptive plasticity of the auditory cortex

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    ANNA R. eFETONI

    2015-02-01

    Full Text Available Growing evidence suggests that cochlear stressors as noise exposure and aging can induce homeostatic/maladaptive changes in the central auditory system from the brainstem to the cortex. Studies centered on such changes have revealed several mechanisms that operate in the context of sensory disruption after insult (noise trauma, drug- or age-related injury. The oxidative stress is central to current theories of induced sensory neural hearing loss and aging, and interventions to attenuate the hearing loss are based on antioxidant agent. The present review addresses the recent literature on the alterations in hair cells and spiral ganglion neurons due to noise-induced oxidative stress in the cochlea, as well on the impact of cochlear damage on the auditory cortex neurons. The emerging image emphasizes that noise-induced deafferentation and upward spread of cochlear damage is associated with the altered dendritic architecture of auditory pyramidal neurons. The cortical modifications may be reversed by treatment with antioxidants counteracting the cochlear redox imbalance. These findings open new therapeutic approaches to treat the functional consequences of the cortical reorganization following cochlear damage.

  14. Ventromedial prefrontal cortex, adding value to autobiographical memories.

    Science.gov (United States)

    Lin, Wen-Jing; Horner, Aidan J; Burgess, Neil

    2016-01-01

    The medial prefrontal cortex (mPFC) has been consistently implicated in autobiographical memory recall and decision making. Its function in decision making tasks is believed to relate to value representation, but its function in autobiographical memory recall is not yet clear. We hypothesised that the mPFC represents the subjective value of elements during autobiographical memory retrieval. Using functional magnetic resonance imaging during an autobiographical memory recall task, we found that the blood oxygen level dependent (BOLD) signal in ventromedial prefrontal cortex (vmPFC) was parametrically modulated by the affective values of items in participants' memories when they were recalling and evaluating these items. An unrelated modulation by the participant's familiarity with the items was also observed. During retrieval of the event, the BOLD signal in the same region was modulated by the personal significance and emotional intensity of the memory, which was correlated with the values of the items within them. These results support the idea that vmPFC processes self-relevant information, and suggest that it is involved in representing the personal emotional values of the elements comprising autobiographical memories. PMID:27338616

  15. Frontal cortex functioning in the infant broader autism phenotype.

    Science.gov (United States)

    Holmboe, Karla; Elsabbagh, Mayada; Volein, Agnes; Tucker, Leslie A; Baron-Cohen, Simon; Bolton, Patrick; Charman, Tony; Johnson, Mark H

    2010-12-01

    Atypical attention has been proposed as a marker of the broader autism phenotype. In the present study we investigated this and the related process of inhibitory control at the youngest possible age through the study of infant siblings of children with an autism spectrum disorder (Sibs-ASD). Both attention and inhibition have been related to the frontal cortex of the brain. Nine- to ten-month-old Sibs-ASD and low-risk control infants completed the Freeze-Frame task, in which infants are encouraged to inhibit looks to peripherally presented distractors whilst looking at a central animation. The attractiveness of the central stimulus is varied in order to investigate the selectivity of infants' responses. In line with previous studies, it was found that a subset of Sibs-ASD infants had difficulty disengaging attention from a central stimulus in order to orient to a peripheral stimulus. The Sibs-ASD group also showed less Selective Inhibition than controls. However, Sibs-ASD infants did demonstrate Selective Inhibitory Learning. These results provide preliminary evidence for atypical frontal cortex functioning in the infant broader autism phenotype. PMID:20609478

  16. Expectation Suppression in Early Visual Cortex Depends on Task Set

    Science.gov (United States)

    St. John-Saaltink, Elexa; Utzerath, Christian; Kok, Peter; Lau, Hakwan C.; de Lange, Floris P.

    2015-01-01

    Stimulus expectation can modulate neural responses in early sensory cortical regions, with expected stimuli often leading to a reduced neural response. However, it is unclear whether this expectation suppression is an automatic phenomenon or is instead dependent on the type of task a subject is engaged in. To investigate this, human subjects were presented with visual grating stimuli in the periphery that were either predictable or non-predictable while they performed three tasks that differently engaged cognitive resources. In two of the tasks, the predictable stimulus was task-irrelevant and spatial attention was engaged at fixation, with a high load on either perceptual or working memory resources. In the third task, the predictable stimulus was task-relevant, and therefore spatially attended. We observed that expectation suppression is dependent on the cognitive resources engaged by a subjects’ current task. When the grating was task-irrelevant, expectation suppression for predictable items was visible in retinotopically specific areas of early visual cortex (V1-V3) during the perceptual task, but it was abolished when working memory was loaded. When the grating was task-relevant and spatially attended, there was no significant effect of expectation in early visual cortex. These results suggest that expectation suppression is not an automatic phenomenon, but dependent on attentional state and type of available cognitive resources. PMID:26098331

  17. Higher Order Spike Synchrony in Prefrontal Cortex during Visual Memory.

    Science.gov (United States)

    Pipa, Gordon; Munk, Matthias H J

    2011-01-01

    Precise temporal synchrony of spike firing has been postulated as an important neuronal mechanism for signal integration and the induction of plasticity in neocortex. As prefrontal cortex plays an important role in organizing memory and executive functions, the convergence of multiple visual pathways onto PFC predicts that neurons should preferentially synchronize their spiking when stimulus information is processed. Furthermore, synchronous spike firing should intensify if memory processes require the induction of neuronal plasticity, even if this is only for short-term. Here we show with multiple simultaneously recorded units in ventral prefrontal cortex that neurons participate in 3 ms precise synchronous discharges distributed across multiple sites separated by at least 500 μm. The frequency of synchronous firing is modulated by behavioral performance and is specific for the memorized visual stimuli. In particular, during the memory period in which activity is not stimulus driven, larger groups of up to seven sites exhibit performance dependent modulation of their spike synchronization. PMID:21713065

  18. Cochlear injury and adaptive plasticity of the auditory cortex.

    Science.gov (United States)

    Fetoni, Anna Rita; Troiani, Diana; Petrosini, Laura; Paludetti, Gaetano

    2015-01-01

    Growing evidence suggests that cochlear stressors as noise exposure and aging can induce homeostatic/maladaptive changes in the central auditory system from the brainstem to the cortex. Studies centered on such changes have revealed several mechanisms that operate in the context of sensory disruption after insult (noise trauma, drug-, or age-related injury). The oxidative stress is central to current theories of induced sensory-neural hearing loss and aging, and interventions to attenuate the hearing loss are based on antioxidant agent. The present review addresses the recent literature on the alterations in hair cells and spiral ganglion neurons due to noise-induced oxidative stress in the cochlea, as well on the impact of cochlear damage on the auditory cortex neurons. The emerging image emphasizes that noise-induced deafferentation and upward spread of cochlear damage is associated with the altered dendritic architecture of auditory pyramidal neurons. The cortical modifications may be reversed by treatment with antioxidants counteracting the cochlear redox imbalance. These findings open new therapeutic approaches to treat the functional consequences of the cortical reorganization following cochlear damage. PMID:25698966

  19. Cadmium and zinc relationships in kidney cortex, liver, and pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.G.; Piscator, M.; Linnman, L.

    1977-06-01

    Zinc and cadmium have been determined in kidney cortex, liver, and pancreas from 292 subjects autopsied in Stockholm, Sweden. In the liver and pancreas zinc was found to have a normal frequency distribution, average 45.3 ..mu..g/g and 26.9 ..mu..g/g wet wt, respectively. The concentrations of zinc in these two organs were constant regardless of age at death. Zinc was shown to accumulate with age in the kidney cortex in a way similar to cadmium, and had a log-normal distribution. The calculation of the regression line between individual cadmium concentrations below 60 ..mu..g/g and zinc concentrations gave a slope constant of 0.61 (Y/sub Zn/ = 0.61 X/sub Cd/ + 24.4), which corresponds to a nearly equimolar increase of zinc. The concentrations of ''physiological zinc,'' i.e., total zinc minus the zinc related to cadmium, were normally distributed (anti x = 24.6 ..mu..g Zn/g) and did not change with age. Furthermore, data on dry weight/wet weight ratios and ash weight/dry weight ratios in relation to age are presented.

  20. Medial prefrontal cortex role in recognition memory in rodents.

    Science.gov (United States)

    Morici, Juan Facundo; Bekinschtein, Pedro; Weisstaub, Noelia V

    2015-10-01

    The study of the neurobiology of recognition memory, defined by the integration of the different components of experiences that support recollection of past experiences have been a challenge for memory researches for many years. In the last twenty years, with the development of the spontaneous novel object recognition task and all its variants this has started to change. The features of recognition memory include a particular object or person ("what"), the context in which the experience took place, which can be the arena itself or the location within a particular arena ("where") and the particular time at which the event occurred ("when"). This definition instead of the historical anthropocentric one allows the study of this type of episodic memory in animal models. Some forms of recognition memory that require integration of different features recruit the medial prefrontal cortex. Focusing on findings from spontaneous recognition memory tasks performed by rodents, this review concentrates on the description of previous works that have examined the role that the medial prefrontal cortex has on the different steps of recognition memory. We conclude that this structure, independently of the task used, is required at different memory stages when the task cannot be solved by a single item strategy. PMID:26115848

  1. A multi-modal parcellation of human cerebral cortex.

    Science.gov (United States)

    Glasser, Matthew F; Coalson, Timothy S; Robinson, Emma C; Hacker, Carl D; Harwell, John; Yacoub, Essa; Ugurbil, Kamil; Andersson, Jesper; Beckmann, Christian F; Jenkinson, Mark; Smith, Stephen M; Van Essen, David C

    2016-08-11

    Understanding the amazingly complex human cerebral cortex requires a map (or parcellation) of its major subdivisions, known as cortical areas. Making an accurate areal map has been a century-old objective in neuroscience. Using multi-modal magnetic resonance images from the Human Connectome Project (HCP) and an objective semi-automated neuroanatomical approach, we delineated 180 areas per hemisphere bounded by sharp changes in cortical architecture, function, connectivity, and/or topography in a precisely aligned group average of 210 healthy young adults. We characterized 97 new areas and 83 areas previously reported using post-mortem microscopy or other specialized study-specific approaches. To enable automated delineation and identification of these areas in new HCP subjects and in future studies, we trained a machine-learning classifier to recognize the multi-modal 'fingerprint' of each cortical area. This classifier detected the presence of 96.6% of the cortical areas in new subjects, replicated the group parcellation, and could correctly locate areas in individuals with atypical parcellations. The freely available parcellation and classifier will enable substantially improved neuroanatomical precision for studies of the structural and functional organization of human cerebral cortex and its variation across individuals and in development, aging, and disease. PMID:27437579

  2. Sharing social touch in the primary somatosensory cortex.

    Science.gov (United States)

    Bolognini, Nadia; Rossetti, Angela; Fusaro, Martina; Vallar, Giuseppe; Miniussi, Carlo

    2014-07-01

    Touch has an emotional and communicative meaning, and it plays a crucial role in social perception and empathy. The intuitive link between others' somatosensations and our sense of touch becomes ostensible in mirror-touch synesthesia, a condition in which the view of a touch on another person's body elicits conscious tactile sensations on the observer's own body [1]. This peculiar phenomenon may implicate normal social mirror mechanisms [2]. Here, we show that mirror-touch interference effects, synesthesia-like sensations, and even phantom touches can be induced in nonsynesthetes by priming the primary somatosensory cortex (SI) directly or indirectly via the posterior parietal cortex. These results were obtained by means of facilitatory paired-pulse transcranial magnetic stimulation (ppTMS) contingent upon the observation of touch. For these vicarious effects, the SI is engaged at 150 ms from the onset of the visual touch. Intriguingly, individual differences in empathic abilities, assessed with the Interpersonal Reactivity Index [3], drive the activity of the SI when nonsynesthetes witness others' tactile sensations. This evidence implies that, under normal conditions, touch observation activates the SI below the threshold for perceptual awareness [4]; through the visual-dependent tuning of SI activity by ppTMS, what is seen becomes felt, namely, mirror-touch synesthesia. On a broader perspective, the visual responsivity of the SI may allow an automatic and unconscious transference of the sensation that another person is experiencing onto oneself, and, in turn, the empathic sharing of somatosensations [2]. PMID:24954046

  3. Semantics of the Visual Environment Encoded in Parahippocampal Cortex.

    Science.gov (United States)

    Bonner, Michael F; Price, Amy Rose; Peelle, Jonathan E; Grossman, Murray

    2016-03-01

    Semantic representations capture the statistics of experience and store this information in memory. A fundamental component of this memory system is knowledge of the visual environment, including knowledge of objects and their associations. Visual semantic information underlies a range of behaviors, from perceptual categorization to cognitive processes such as language and reasoning. Here we examine the neuroanatomic system that encodes visual semantics. Across three experiments, we found converging evidence indicating that knowledge of verbally mediated visual concepts relies on information encoded in a region of the ventral-medial temporal lobe centered on parahippocampal cortex. In an fMRI study, this region was strongly engaged by the processing of concepts relying on visual knowledge but not by concepts relying on other sensory modalities. In a study of patients with the semantic variant of primary progressive aphasia (semantic dementia), atrophy that encompassed this region was associated with a specific impairment in verbally mediated visual semantic knowledge. Finally, in a structural study of healthy adults from the fMRI experiment, gray matter density in this region related to individual variability in the processing of visual concepts. The anatomic location of these findings aligns with recent work linking the ventral-medial temporal lobe with high-level visual representation, contextual associations, and reasoning through imagination. Together, this work suggests a critical role for parahippocampal cortex in linking the visual environment with knowledge systems in the human brain. PMID:26679216

  4. The Representation of Prediction Error in Auditory Cortex

    Science.gov (United States)

    Rubin, Jonathan; Ulanovsky, Nachum; Tishby, Naftali

    2016-01-01

    To survive, organisms must extract information from the past that is relevant for their future. How this process is expressed at the neural level remains unclear. We address this problem by developing a novel approach from first principles. We show here how to generate low-complexity representations of the past that produce optimal predictions of future events. We then illustrate this framework by studying the coding of ‘oddball’ sequences in auditory cortex. We find that for many neurons in primary auditory cortex, trial-by-trial fluctuations of neuronal responses correlate with the theoretical prediction error calculated from the short-term past of the stimulation sequence, under constraints on the complexity of the representation of this past sequence. In some neurons, the effect of prediction error accounted for more than 50% of response variability. Reliable predictions often depended on a representation of the sequence of the last ten or more stimuli, although the representation kept only few details of that sequence. PMID:27490251

  5. Early network activity propagates bidirectionally between hippocampus and cortex.

    Science.gov (United States)

    Barger, Zeke; Easton, Curtis R; Neuzil, Kevin E; Moody, William J

    2016-06-01

    Spontaneous activity in the developing brain helps refine neuronal connections before the arrival of sensory-driven neuronal activity. In mouse neocortex during the first postnatal week, waves of spontaneous activity originating from pacemaker regions in the septal nucleus and piriform cortex propagate through the neocortex. Using high-speed Ca(2+) imaging to resolve the spatiotemporal dynamics of wave propagation in parasagittal mouse brain slices, we show that the hippocampus can act as an additional source of neocortical waves. Some waves that originate in the hippocampus remain restricted to that structure, while others pause at the hippocampus-neocortex boundary and then propagate into the neocortex. Blocking GABAergic neurotransmission decreases the likelihood of wave propagation into neocortex, whereas blocking glutamatergic neurotransmission eliminates spontaneous and evoked hippocampal waves. A subset of hippocampal and cortical waves trigger Ca(2+) waves in astrocytic networks after a brief delay. Hippocampal waves accompanied by Ca(2+) elevation in astrocytes are more likely to propagate into the neocortex. Finally, we show that two structures in our preparation that initiate waves-the hippocampus and the piriform cortex-can be electrically stimulated to initiate propagating waves at lower thresholds than the neocortex, indicating that the intrinsic circuit properties of those regions are responsible for their pacemaker function. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 661-672, 2016. PMID:26385616

  6. pH regulation of an egg cortex tyrosine kinase.

    Science.gov (United States)

    Jiang, W P; Veno, P A; Wood, R W; Peaucellier, G; Kinsey, W H

    1991-07-01

    Fertilization of the echinoderm egg is known to result in the phosphorylation, on tyrosine, of a high-molecular-weight cortical protein (HMWCP) localized in the egg cortex. Studies using various parthenogenic agents indicate that this phosphorylation event occurs in response to the alkaline shift in cytoplasmic pHi which normally occurs 1 to 2 min after fertilization. In the present study, the purified egg cell surface complex was used as in vitro system to determine whether a small alkaline shift in pH, such as occurs upon fertilization, could stimulate the activity of the egg cortex-associated tyrosine kinase toward endogenous protein substrates. The results demonstrated that the cell surface complex is highly enriched in a tyrosine kinase activity which accounts for the majority of the protein kinase activity in this preparation. The activity of this tyrosine kinase toward the HMWCP and other cortical proteins was highly dependent on pH over the range pH 6.8 to 7.3. This indicates that the fertilization-associated change in cytoplasmic pH would be sufficient to trigger increased tyrosine phosphorylation of the high-molecular-weight cortical protein in vivo. The regulation of tyrosine phosphorylation by small changes in pH represents a novel control mechanism in which a tyrosine protein kinase may act as a pH-sensitive transducer. PMID:2060713

  7. Balanced feedforward inhibition and dominant recurrent inhibition in olfactory cortex.

    Science.gov (United States)

    Large, Adam M; Vogler, Nathan W; Mielo, Samantha; Oswald, Anne-Marie M

    2016-02-23

    Throughout the brain, the recruitment of feedforward and recurrent inhibition shapes neural responses. However, disentangling the relative contributions of these often-overlapping cortical circuits is challenging. The piriform cortex provides an ideal system to address this issue because the interneurons responsible for feedforward and recurrent inhibition are anatomically segregated in layer (L) 1 and L2/3 respectively. Here we use a combination of optical and electrical activation of interneurons to profile the inhibitory input received by three classes of principal excitatory neuron in the anterior piriform cortex. In all classes, we find that L1 interneurons provide weaker inhibition than L2/3 interneurons. Nonetheless, feedforward inhibitory strength covaries with the amount of afferent excitation received by each class of principal neuron. In contrast, intracortical stimulation of L2/3 evokes strong inhibition that dominates recurrent excitation in all classes. Finally, we find that the relative contributions of feedforward and recurrent pathways differ between principal neuron classes. Specifically, L2 neurons receive more reliable afferent drive and less overall inhibition than L3 neurons. Alternatively, L3 neurons receive substantially more intracortical inhibition. These three features--balanced afferent drive, dominant recurrent inhibition, and differential recruitment by afferent vs. intracortical circuits, dependent on cell class--suggest mechanisms for olfactory processing that may extend to other sensory cortices. PMID:26858458

  8. Increased Visual Stimulation Systematically Decreases Activity in Lateral Intermediate Cortex.

    Science.gov (United States)

    Nasr, Shahin; Stemmann, Heiko; Vanduffel, Wim; Tootell, Roger B H

    2015-10-01

    Previous studies have attributed multiple diverse roles to the posterior superior temporal cortex (STC), both visually driven and cognitive, including part of the default mode network (DMN). Here, we demonstrate a unifying property across this multimodal region. Specifically, the lateral intermediate (LIM) portion of STC showed an unexpected feature: a progressively decreasing fMRI response to increases in visual stimulus size (or number). Such responses are reversed in sign, relative to well-known responses in classic occipital temporal visual cortex. In LIM, this "reversed" size function was present across multiple object categories and retinotopic eccentricities. Moreover, we found a significant interaction between the LIM size function and the distribution of subjects' attention. These findings suggest that LIM serves as a part of the DMN. Further analysis of functional connectivity, plus a meta-analysis of previous fMRI results, suggests that LIM is a heterogeneous area including different subdivisions. Surprisingly, analogous fMRI tests in macaque monkeys did not reveal a clear homolog of LIM. This interspecies discrepancy supports the idea that self-referential thinking and theory of mind are more prominent in humans, compared with monkeys. PMID:25480358

  9. Morphological and functional correlates of VIP neurons in cerebral cortex

    International Nuclear Information System (INIS)

    Vasoactive Intestinal Polypeptide (VIP) promotes the hydrolysis of 3H-glycogen newly synthesized from 3H-glucose by mouse cortical slices. This effect occurs rapidly, approximately 50% of the maximal effect being reached within one minute. The maximal effect is achieved after 5 minutes and maintained for at least 25 minutes. Furthermore the glycogenolytic effect of VIP is reversible, and pharmacologically specific. Thus several neuropeptides present in cerebral cortex such as cholecystokinin-8, somatostatin-28, somatostatin-14, met-enkephalin, leu-enkephalin, do not affect 3H-glycogen levels. VIP fragments 6-28, 16-28 and 21-28 are similarly inactive. Furthermore, among the peptides which share structural homologies with VIP, such as glucagon, secretin, PHI-27 and Gastric Inhibitory Peptide, only secretin and PHI-27 promote 3H-glycogen hydrolysis, with EC50 of 500 and 300 nM respectively, compared to an EC50 of 25 nM for VIP. Immunohistochemical observations indicate that each VIP-containing bipolar cell is identified with a unique radical cortical volume, which is generally between 15-60 micrograms in diameter and overlaps with the contiguous domains of neighbouring VIP-containing bipolar cells. Thus this set of biochemical and morphological observations support the notion that VIP neurons have the capacity to regulate the availability of energy substrates in cerebral cortex locally, within circumscribed, contiguous, radial domains

  10. Porcine brain natriuretic peptide receptor in bovine adrenal cortex

    International Nuclear Information System (INIS)

    The action of porcine brain natriuretic peptide (pBNP) on the steroidogenesis was investigated in cultured bovine adrenocortical cells. Porcine BNP induced a significant dose-dependent inhibition of both ACTH- and A II-stimulated aldosterone secretion. 10/sup /minus/8/M and 10/sup /minus/7/M pBNP also significantly inhibited ACTH-stimulated cortisol and dehydroepiandrosterone (DHEA) secretions. Binding studies of [125I]-pBNP to bovine adrenocortical membrane fractions showed that adrenal cortex had high-affinity and low-capacity pBNP binding sites, with a dissociation constant (Kd) of 1.70 x 10/sup /minus/10/M and a maximal binding capacity (Bmax) of 19.9 fmol/mg protein. Finally, the 135 Kd radioactive band was specially visualized in the affinity labeling of bovine adrenal cortex with disuccinimidyl suberate (DSS). These results suggest that pBNP may have receptor-mediated suppressive actions on bovine adrenal steroidogenesis, similar to that in atrial natriuretic peptide

  11. Porcine brain natriuretic peptide receptor in bovine adrenal cortex

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, K.; Hashiguchi, T.; Ohashi, M.; Takayanagi, R.; Haji, M.; Matsuo, H.; Nawata, H.

    1989-01-01

    The action of porcine brain natriuretic peptide (pBNP) on the steroidogenesis was investigated in cultured bovine adrenocortical cells. Porcine BNP induced a significant dose-dependent inhibition of both ACTH- and A II-stimulated aldosterone secretion. 10/sup /minus/8/M and 10/sup /minus/7/M pBNP also significantly inhibited ACTH-stimulated cortisol and dehydroepiandrosterone (DHEA) secretions. Binding studies of (/sup 125/I)-pBNP to bovine adrenocortical membrane fractions showed that adrenal cortex had high-affinity and low-capacity pBNP binding sites, with a dissociation constant (Kd) of 1.70 x 10/sup /minus/10/M and a maximal binding capacity (Bmax) of 19.9 fmol/mg protein. Finally, the 135 Kd radioactive band was specially visualized in the affinity labeling of bovine adrenal cortex with disuccinimidyl suberate (DSS). These results suggest that pBNP may have receptor-mediated suppressive actions on bovine adrenal steroidogenesis, similar to that in atrial natriuretic peptide (ANP).

  12. Spatial diversity of spontaneous activity in the cortex

    Directory of Open Access Journals (Sweden)

    Andrew Yong-Yi Tan

    2015-09-01

    Full Text Available The neocortex is a layered sheet across which a basic organization is thought to widely apply. The variety of spontaneous activity patterns is similar throughout the cortex, consistent with the notion of a basic cortical organization. However, the basic organization is only an outline which needs adjustments and additions to account for the structural and functional diversity across cortical layers and areas. Such diversity suggests that spontaneous activity is spatially diverse in any particular behavioral state. Accordingly, this review summarizes the laminar and areal diversity in cortical activity during fixation and slow oscillations, and the effects of attention, anesthesia and plasticity on the cortical distribution of spontaneous activity. Among questions that remain open, characterizing the spatial diversity in spontaneous membrane potential may help elucidate how differences in circuitry among cortical regions supports their varied functions. More work is also needed to understand whether cortical spontaneous activity not only reflects cortical circuitry, but also contributes to determining the outcome of plasticity, so that it is itself a factor shaping the functional diversity of the cortex.

  13. Activity in inferior parietal and medial prefrontal cortex signals the accumulation of evidence in a probability learning task.

    Directory of Open Access Journals (Sweden)

    Mathieu d'Acremont

    Full Text Available In an uncertain environment, probabilities are key to predicting future events and making adaptive choices. However, little is known about how humans learn such probabilities and where and how they are encoded in the brain, especially when they concern more than two outcomes. During functional magnetic resonance imaging (fMRI, young adults learned the probabilities of uncertain stimuli through repetitive sampling. Stimuli represented payoffs and participants had to predict their occurrence to maximize their earnings. Choices indicated loss and risk aversion but unbiased estimation of probabilities. BOLD response in medial prefrontal cortex and angular gyri increased linearly with the probability of the currently observed stimulus, untainted by its value. Connectivity analyses during rest and task revealed that these regions belonged to the default mode network. The activation of past outcomes in memory is evoked as a possible mechanism to explain the engagement of the default mode network in probability learning. A BOLD response relating to value was detected only at decision time, mainly in striatum. It is concluded that activity in inferior parietal and medial prefrontal cortex reflects the amount of evidence accumulated in favor of competing and uncertain outcomes.

  14. Parasol cell mosaics are unlikely to drive the formation of structured orientation maps in primary visual cortex.

    Science.gov (United States)

    Hore, Victoria R A; Troy, John B; Eglen, Stephen J

    2012-11-01

    The receptive fields of on- and off-center parasol cell mosaics independently tile the retina to ensure efficient sampling of visual space. A recent theoretical model represented the on- and off-center mosaics by noisy hexagonal lattices of slightly different density. When the two lattices are overlaid, long-range Moiré interference patterns are generated. These Moiré interference patterns have been suggested to drive the formation of highly structured orientation maps in visual cortex. Here, we show that noisy hexagonal lattices do not capture the spatial statistics of parasol cell mosaics. An alternative model based upon local exclusion zones, termed as the pairwise interaction point process (PIPP) model, generates patterns that are statistically indistinguishable from parasol cell mosaics. A key difference between the PIPP model and the hexagonal lattice model is that the PIPP model does not generate Moiré interference patterns, and hence stimulated orientation maps do not show any hexagonal structure. Finally, we estimate the spatial extent of spatial correlations in parasol cell mosaics to be only 200-350 μm, far less than that required to generate Moiré interference. We conclude that parasol cell mosaics are too disordered to drive the formation of highly structured orientation maps in visual cortex. PMID:23110776

  15. Plasticity in the rat prefrontal cortex: linking gene expression and an operant learning with a computational theory.

    Directory of Open Access Journals (Sweden)

    Maximiliano Rapanelli

    Full Text Available The plasticity in the medial Prefrontal Cortex (mPFC of rodents or lateral prefrontal cortex in non human primates (lPFC, plays a key role neural circuits involved in learning and memory. Several genes, like brain-derived neurotrophic factor (BDNF, cAMP response element binding (CREB, Synapsin I, Calcium/calmodulin-dependent protein kinase II (CamKII, activity-regulated cytoskeleton-associated protein (Arc, c-jun and c-fos have been related to plasticity processes. We analysed differential expression of related plasticity genes and immediate early genes in the mPFC of rats during learning an operant conditioning task. Incompletely and completely trained animals were studied because of the distinct events predicted by our computational model at different learning stages. During learning an operant conditioning task, we measured changes in the mRNA levels by Real-Time RT-PCR during learning; expression of these markers associated to plasticity was incremented while learning and such increments began to decline when the task was learned. The plasticity changes in the lPFC during learning predicted by the model matched up with those of the representative gene BDNF. Herein, we showed for the first time that plasticity in the mPFC in rats during learning of an operant conditioning is higher while learning than when the task is learned, using an integrative approach of a computational model and gene expression.

  16. Is dorsal anterior cingulate cortex activation in response to social exclusion due to expectancy violation?: An fMRI study

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    Taishi Kawamoto

    2012-07-01

    Full Text Available People are typically quite sensitive about being accepted or excluded by others. Previous studies have suggested that the dorsal anterior cingulate cortex (dACC is a key brain region involved in the detection of social exclusion. However, this region has also been shown to be sensitive to non-social expectancy violations. We often expect other people to follow an unwritten rule in which they include us as they would expect to be included, such that social exclusion likely involves some degree of expectancy violation. The present event-related functional magnetic resonance imaging (fMRI study sought to separate the effects of expectancy violation from those of social exclusion, such that we employed an “overinclusion” condition in which a player was unexpectedly overincluded in the game by the other players. With this modification, we found that the dACC and right ventrolateral prefrontal cortex (rVLPFC were activated by exclusion, relative to overinclusion. In addition, we identified a negative correlation between exclusion-evoked brain activity and self-rated social pain in the rVLPFC, but not in the dACC. These findings suggest that the rVLPFC is critical for regulating social pain, whereas the dACC plays an important role in the detection of exclusion. The neurobiological basis of social exclusion is different from that of mere expectancy violation.

  17. Weak-Keys in Public Key Cryptosystems Based on Discrete Logarithms

    Institute of Scientific and Technical Information of China (English)

    TAI Suiyan; LUO Ping; PENG Xiaoning; WANG Daoshun

    2005-01-01

    The discrete logarithm method is the foundation of many public key algorithms. However, one type of key, defined as a weak-key, reduces the security of public key cryptosystems based on the discrete logarithm method. The weak-key occurs if the public key is a factor or multiple of the primitive element, in which case the user's private key is not needed but can be obtained based on the character of the public key. An algorithm is presented that can easily test whether there is a weak-key in the cryptosystem. An example is given to show that an attack can be completed for the Elgamal digital signature if a weak-key exists, therefore validating the danger of weak-keys. Methods are given to prevent the generation of these weak-keys.

  18. Early stress evokes dysregulation of histone modifiers in the medial prefrontal cortex across the life span.

    Science.gov (United States)

    Pusalkar, Madhavi; Suri, Deepika; Kelkar, Ashwin; Bhattacharya, Amrita; Galande, Sanjeev; Vaidya, Vidita A

    2016-03-01

    Early stress has been hypothesized to recruit epigenetic mechanisms to mediate persistent molecular, cellular, and behavioral changes. Here, we have examined the consequence of the early life stress of maternal separation (ES) on the gene expression of several histone modifiers that regulate histone acetylation and methylation within the medial prefrontal cortex (mPFC), a key limbic brain region that regulates stress responses and mood-related behavior. ES animals exhibit gene regulation of both writer (histone acetyltransferases and histone methyltransferases) and eraser (histone deacetylases and histone lysine demethylases) classes of histone modifiers. While specific histone modifiers (Kat2a, Smyd3, and Suv420h1) and the sirtuin, Sirt4 were downregulated across life within the mPFC of ES animals, namely at postnatal Day 21, 2 months, and 15 months of age, we also observed gene regulation restricted to these specific time points. Despite the decline noted in expression of several histone modifiers within the mPFC following ES, this was not accompanied by any change in global or residue-specific H3 acetylation and methylation. Our findings indicate that ES results in the regulation of several histone modifiers within the mPFC across life, and suggest that such perturbations may contribute to the altered prefrontal structural and functional plasticity observed following early adversity. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 198-210, 2016. PMID:26395029

  19. A central role for the retrosplenial cortex in de novo environmental learning

    Science.gov (United States)

    Auger, Stephen D; Zeidman, Peter; Maguire, Eleanor A

    2015-01-01

    With experience we become accustomed to the types of environments that we normally encounter as we navigate in the world. But how does this fundamental knowledge develop in the first place and what brain regions are involved? To examine de novo environmental learning, we created an ‘alien’ virtual reality world populated with landmarks of which participants had no prior experience. They learned about this environment by moving within it during functional MRI (fMRI) scanning while we tracked their evolving knowledge. Retrosplenial cortex (RSC) played a central and highly selective role by representing only the most stable, permanent features in this world. Subsequently, increased coupling was noted between RSC and hippocampus, with hippocampus then expressing knowledge of permanent landmark locations and overall environmental layout. Studying how environmental representations emerge from scratch provided a new window into the information processing underpinning the brain's navigation system, highlighting the key influence of the RSC. DOI: http://dx.doi.org/10.7554/eLife.09031.001 PMID:26284602

  20. RP58 Regulates the Multipolar-Bipolar Transition of Newborn Neurons in the Developing Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Chiaki Ohtaka-Maruyama

    2013-02-01

    Full Text Available Accumulating evidence suggests that many brain diseases are associated with defects in neuronal migration, suggesting that this step of neurogenesis is critical for brain organization. However, the molecular mechanisms underlying neuronal migration remain largely unknown. Here, we identified the zinc-finger transcriptional repressor RP58 as a key regulator of neuronal migration via multipolar-to-bipolar transition. RP58−/− neurons exhibited severe defects in the formation of leading processes and never shifted to the locomotion mode. Cre-mediated deletion of RP58 using in utero electroporation in RP58flox/flox mice revealed that RP58 functions in cell-autonomous multipolar-to-bipolar transition, independent of cell-cycle exit. Finally, we found that RP58 represses Ngn2 transcription to regulate the Ngn2-Rnd2 pathway; Ngn2 knockdown rescued migration defects of the RP58−/− neurons. Our findings highlight the critical role of RP58 in multipolar-to-bipolar transition via suppression of the Ngn2-Rnd2 pathway in the developing cerebral cortex.

  1. Tactile texture signals in primate primary somatosensory cortex and their relation to subjective roughness intensity.

    Science.gov (United States)

    Bourgeon, Stéphanie; Dépeault, Alexandra; Meftah, El-Mehdi; Chapman, C Elaine

    2016-04-01

    This study investigated the hypothesis that a simple intensive code, based on mean firing rate, could explain the cortical representation of subjective roughness intensity and its invariance with scanning speed. We examined the sensitivity of neurons in the cutaneous, finger representation of primary somatosensory cortex (S1) to a wide range of textures [1 mm high, raised-dot surfaces; spatial periods (SPs), 1.5-8.5 mm], scanned under the digit tips at different speeds (40-115 mm/s). Since subjective roughness estimates show a monotonic increase over this range and are independent of speed, we predicted that the mean firing rate of a subgroup of S1 neurons would share these properties. Single-unit recordings were made in four alert macaques (areas 3b, 1 and 2). Cells whose discharge rate showed a monotonic increase with SP, independent of speed, were particularly concentrated in area 3b. Area 2 was characterized by a high proportion of cells sensitive to speed, with or without texture sensitivity. Area 1 had intermediate properties. We suggest that area 3b and most likely area 1 play a key role in signaling roughness intensity, and that a mean rate code, signaled by both slowly and rapidly adapting neurons, is present at the level of area 3b. Finally, the substantial proportion of neurons that showed a monotonic change in discharge limited to a small range of SPs (often independent of response saturation) could play a role in discriminating smaller changes in SP. PMID:26763776

  2. BACE1 Is Necessary for Experience-Dependent Homeostatic Synaptic Plasticity in Visual Cortex

    Directory of Open Access Journals (Sweden)

    Emily Petrus

    2014-01-01

    Full Text Available Alzheimer’s disease (AD is the most common form of age-related dementia, which is thought to result from overproduction and/or reduced clearance of amyloid-beta (Aβ peptides. Studies over the past few decades suggest that Aβ is produced in an activity-dependent manner and has physiological relevance to normal brain functions. Similarly, physiological functions for β- and γ-secretases, the two key enzymes that produce Aβ by sequentially processing the amyloid precursor protein (APP, have been discovered over recent years. In particular, activity-dependent production of Aβ has been suggested to play a role in homeostatic regulation of excitatory synaptic function. There is accumulating evidence that activity-dependent immediate early gene Arc is an activity “sensor,” which acts upstream of Aβ production and triggers AMPA receptor endocytosis to homeostatically downregulate the strength of excitatory synaptic transmission. We previously reported that Arc is critical for sensory experience-dependent homeostatic reduction of excitatory synaptic transmission in the superficial layers of visual cortex. Here we demonstrate that mice lacking the major neuronal β-secretase, BACE1, exhibit a similar phenotype: stronger basal excitatory synaptic transmission and failure to adapt to changes in visual experience. Our results indicate that BACE1 plays an essential role in sensory experience-dependent homeostatic synaptic plasticity in the neocortex.

  3. Static and dynamic posterior cingulate cortex nodal topology of default mode network predicts attention task performance.

    Science.gov (United States)

    Lin, Pan; Yang, Yong; Jovicich, Jorge; De Pisapia, Nicola; Wang, Xiang; Zuo, Chun S; Levitt, James Jonathan

    2016-03-01

    Characterization of the default mode network (DMN) as a complex network of functionally interacting dynamic systems has received great interest for the study of DMN neural mechanisms. In particular, understanding the relationship of intrinsic resting-state DMN brain network with cognitive behaviors is an important issue in healthy cognition and mental disorders. However, it is still unclear how DMN functional connectivity links to cognitive behaviors during resting-state. In this study, we hypothesize that static and dynamic DMN nodal topology is associated with upcoming cognitive task performance. We used graph theory analysis in order to understand better the relationship between the DMN functional connectivity and cognitive behavior during resting-state and task performance. Nodal degree of the DMN was calculated as a metric of network topology. We found that the static and dynamic posterior cingulate cortex (PCC) nodal degree within the DMN was associated with task performance (Reaction Time). Our results show that the core node PCC nodal degree within the DMN was significantly correlated with reaction time, which suggests that the PCC plays a key role in supporting cognitive function. PMID:25904156

  4. Perceived stress predicts altered reward and loss feedback processing in medial prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Michael T Treadway

    2013-05-01

    Full Text Available Stress is significant risk factor for the development of psychopathology, particularly symptoms related to reward processing. Importantly, individuals display marked variation in how they perceive and cope with stressful events, and such differences are strongly linked to risk for developing psychiatric symptoms following stress exposure. However, many questions remain regarding the neural architecture that underlies inter-subject variability in perceptions of stressors. Using functional magnetic resonance imaging (fMRI during a monetary incentive delay paradigm, we examined the effects of self-reported perceived stress levels on neural activity during reward anticipation and feedback in a sample of healthy individuals. We found that subjects reporting more uncontrollable and overwhelming stressors displayed blunted neural responses in medial prefrontal cortex (mPFC following feedback related to monetary gains as well monetary losses. This is consistent with preclinical models that implicate the mPFC as a key site of vulnerability to the noxious effects of uncontrollable stressors. Our data help translate these findings to humans, and elucidate some of the neural mechanisms that may underlie stress-linked risk for developing reward-related psychiatric symptoms.

  5. Changes in tau phosphorylation levels in the hippocampus and frontal cortex following chronic stress

    International Nuclear Information System (INIS)

    Studies have indicated that early-life or early-onset depression is associated with a 2- to 4-fold increased risk of developing Alzheimers disease (AD). In AD, aggregation of an abnormally phosphorylated form of the tau protein may be a key pathological event. Tau is known to play a major role in promoting microtubule assembly and stabilization, and in maintaining the normal morphology of neurons. Several studies have reported that stress may induce tau phosphorylation. The main aim of the present study was to investigate possible alterations in the tau protein in the hippocampus and frontal cortex of 32 male Sprague-Dawley rats exposed to chronic unpredictable mild stress (CUMS) and then re-exposed to CUMS to mimic depression and the recurrence of depression, respectively, in humans. We evaluated the effects of CUMS, fluoxetine, and CUMS re-exposure on tau and phospho-tau. Our results showed that a single exposure to CUMS caused a significant reduction in sucrose preference, indicating a state of anhedonia. The change in behavior was accompanied by specific alterations in phospho-tau protein levels, but fluoxetine treatment reversed the CUMS-induced impairments. Moreover, changes in sucrose preference and phospho-tau were more pronounced in rats re-exposed to CUMS than in those subjected to a single exposure. Our results suggest that changes in tau phosphorylation may contribute to the link between depression and AD

  6. Changes in tau phosphorylation levels in the hippocampus and frontal cortex following chronic stress

    Directory of Open Access Journals (Sweden)

    C. Yang

    2014-03-01

    Full Text Available Studies have indicated that early-life or early-onset depression is associated with a 2- to 4-fold increased risk of developing Alzheimers disease (AD. In AD, aggregation of an abnormally phosphorylated form of the tau protein may be a key pathological event. Tau is known to play a major role in promoting microtubule assembly and stabilization, and in maintaining the normal morphology of neurons. Several studies have reported that stress may induce tau phosphorylation. The main aim of the present study was to investigate possible alterations in the tau protein in the hippocampus and frontal cortex of 32 male Sprague-Dawley rats exposed to chronic unpredictable mild stress (CUMS and then re-exposed to CUMS to mimic depression and the recurrence of depression, respectively, in humans. We evaluated the effects of CUMS, fluoxetine, and CUMS re-exposure on tau and phospho-tau. Our results showed that a single exposure to CUMS caused a significant reduction in sucrose preference, indicating a state of anhedonia. The change in behavior was accompanied by specific alterations in phospho-tau protein levels, but fluoxetine treatment reversed the CUMS-induced impairments. Moreover, changes in sucrose preference and phospho-tau were more pronounced in rats re-exposed to CUMS than in those subjected to a single exposure. Our results suggest that changes in tau phosphorylation may contribute to the link between depression and AD.

  7. Changes in tau phosphorylation levels in the hippocampus and frontal cortex following chronic stress

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.; Guo, X. [Wuhan University, Renmin Hospital, Department of Psychiatry, Wuhan, China, Department of Psychiatry, Renmin Hospital, Wuhan University, Wuhan (China); Wang, G.H. [Wuhan University, Renmin Hospital, Department of Psychiatry, Wuhan, China, Department of Psychiatry, Renmin Hospital, Wuhan University, Wuhan (China); Wuhan University, Institute of Neuropsychiatry, Wuhan, China, Institute of Neuropsychiatry, Wuhan University, Wuhan (China); Wang, H.L.; Liu, Z.C.; Liu, H.; Zhu, Z.X.; Li, Y. [Wuhan University, Renmin Hospital, Department of Psychiatry, Wuhan, China, Department of Psychiatry, Renmin Hospital, Wuhan University, Wuhan (China)

    2014-03-03

    Studies have indicated that early-life or early-onset depression is associated with a 2- to 4-fold increased risk of developing Alzheimers disease (AD). In AD, aggregation of an abnormally phosphorylated form of the tau protein may be a key pathological event. Tau is known to play a major role in promoting microtubule assembly and stabilization, and in maintaining the normal morphology of neurons. Several studies have reported that stress may induce tau phosphorylation. The main aim of the present study was to investigate possible alterations in the tau protein in the hippocampus and frontal cortex of 32 male Sprague-Dawley rats exposed to chronic unpredictable mild stress (CUMS) and then re-exposed to CUMS to mimic depression and the recurrence of depression, respectively, in humans. We evaluated the effects of CUMS, fluoxetine, and CUMS re-exposure on tau and phospho-tau. Our results showed that a single exposure to CUMS caused a significant reduction in sucrose preference, indicating a state of anhedonia. The change in behavior was accompanied by specific alterations in phospho-tau protein levels, but fluoxetine treatment reversed the CUMS-induced impairments. Moreover, changes in sucrose preference and phospho-tau were more pronounced in rats re-exposed to CUMS than in those subjected to a single exposure. Our results suggest that changes in tau phosphorylation may contribute to the link between depression and AD.

  8. Lateral frontal cortex volume reduction in Tourette syndrome revealed by VBM

    Directory of Open Access Journals (Sweden)

    Wittfoth Matthias

    2012-02-01

    Full Text Available Abstract Background Structural changes have been found predominantly in the frontal cortex and in the striatum in children and adolescents with Gilles de la Tourette syndrome (GTS. The influence of comorbid symptomatology is unclear. Here we sought to address the question of gray matter abnormalities in GTS patients with co-morbid obsessive-compulsive disorder (OCD and/or attention deficit hyperactivity disorder (ADHD using voxel-based morphometry (VBM in twenty-nine adult actually unmedicated GTS patients and twenty-five healthy control subjects. Results In GTS we detected a cluster of decreased gray matter volume in the left inferior frontal gyrus (IFG, but no regions demonstrating volume increases. By comparing subgroups of GTS with comorbid ADHD to the subgroup with comorbid OCD, we found a left-sided amygdalar volume increase. Conclusions From our results it is suggested that the left IFG may constitute a common underlying structural correlate of GTS with co-morbid OCD/ADHD. A volume reduction in this brain region that has been previously identified as a key region in OCD and was associated with the active inhibition of attentional processes may reflect the failure to control behavior. Amygdala volume increase is discussed on the background of a linkage of this structure with ADHD symptomatology. Correlations with clinical data revealed gray matter volume changes in specific brain areas that have been described in these conditions each.

  9. GABA concentration in posterior cingulate cortex predicts putamen response during resting state fMRI.

    Directory of Open Access Journals (Sweden)

    Jorge Arrubla

    Full Text Available The role of neurotransmitters in the activity of resting state networks has been gaining attention and has become a field of research with magnetic resonance spectroscopy (MRS being one of the key techniques. MRS permits the measurement of γ-aminobutyric acid (GABA and glutamate levels, the central biochemical constituents of the excitation-inhibition balance in vivo. The inhibitory effects of GABA in the brain have been largely investigated in relation to the activity of resting state networks in functional magnetic resonance imaging (fMRI. In this study GABA concentration in the posterior cingulate cortex (PCC was measured using single voxel spectra acquired with standard point resolved spectroscopy (PRESS from 20 healthy male volunteers at 3 T. Resting state fMRI was consecutively measured and the values of GABA/Creatine+Phosphocreatine ratio (GABA ratio were included in a general linear model matrix as a step of dual regression analysis in order to identify voxels whose neuroimaging metrics during rest were related to individual levels of the GABA ratio. Our data show that the connection strength of putamen to the default-mode network during resting state has a negative linear relationship with the GABA ratio measured in the PCC. These findings highlight the role of PCC and GABA in segregation of the motor input, which is an inherent condition that characterises resting state.

  10. A causal role for posterior medial frontal cortex in choice-induced preference change.

    Science.gov (United States)

    Izuma, Keise; Akula, Shyam; Murayama, Kou; Wu, Daw-An; Iacoboni, Marco; Adolphs, Ralph

    2015-02-25

    After a person chooses between two items, preference for the chosen item will increase and preference for the unchosen item will decrease because of the choice made. In other words, we tend to justify or rationalize our past behavior by changing our attitude. This phenomenon of choice-induced preference change has been traditionally explained by cognitive dissonance theory. Choosing something that is disliked or not choosing something that is liked are both cognitively inconsistent and, to reduce this inconsistency, people tend to change their subsequently stated preference in accordance with their past choices. Previously, human neuroimaging studies identified posterior medial frontal cortex (pMFC) as a key brain region involved in cognitive dissonance. However, it remains unknown whether the pMFC plays a causal role in inducing preference change after cognitive dissonance. Here, we demonstrate that 25 min, 1 Hz repetitive transcranial magnetic stimulation applied over the pMFC significantly reduces choice-induced preference change compared with sham stimulation or control stimulation over a different brain region, demonstrating a causal role for the pMFC. PMID:25716858

  11. Brain-computer interfaces: an overview of the hardware to record neural signals from the cortex.

    Science.gov (United States)

    Stieglitz, Thomas; Rubehn, Birthe; Henle, Christian; Kisban, Sebastian; Herwik, Stanislav; Ruther, Patrick; Schuettler, Martin

    2009-01-01

    Brain-computer interfaces (BCIs) record neural signals from cortical origin with the objective to control a user interface for communication purposes, a robotic artifact or artificial limb as actuator. One of the key components of such a neuroprosthetic system is the neuro-technical interface itself, the electrode array. In this chapter, different designs and manufacturing techniques will be compared and assessed with respect to scaling and assembling limitations. The overview includes electroencephalogram (EEG) electrodes and epicortical brain-machine interfaces to record local field potentials (LFPs) from the surface of the cortex as well as intracortical needle electrodes that are intended to record single-unit activity. Two exemplary complementary technologies for micromachining of polyimide-based arrays and laser manufacturing of silicone rubber are presented and discussed with respect to spatial resolution, scaling limitations, and system properties. Advanced silicon micromachining technologies have led to highly sophisticated intracortical electrode arrays for fundamental neuroscientific applications. In this chapter, major approaches from the USA and Europe will be introduced and compared concerning complexity, modularity, and reliability. An assessment of the different technological solutions comparable to a strength weaknesses opportunities, and threats (SWOT) analysis might serve as guidance to select the adequate electrode array configuration for each control paradigm and strategy to realize robust, fast, and reliable BCIs. PMID:19660664

  12. The roles of the medial prefrontal cortex and striatum in reputation processing.

    Science.gov (United States)

    Izuma, Keise; Saito, Daisuke N; Sadato, Norihiro

    2010-01-01

    How we are viewed by other individuals-our reputation-has a considerable influence on our everyday behaviors and is considered an important concept in explaining altruism, a uniquely human trait. Previously it has been proposed that processing one's own reputation requires a reputation representation in the medial prefrontal cortex (mPFC) and a value representation in the striatum. Here, we directly tested this idea using functional magnetic resonance imaging (fMRI). Subjects disclosed their behavioral tendencies with reference to social norms in the presence or absence of other people, a manipulation that is known to greatly affect an individual's concern for their reputation. The mPFC showed strong activation during self-referential processing, and this activity was enhanced by the mere presence of observers. Moreover, the striatum was also strongly activated when subjects responded in front of observers. Thus, the present study demonstrated that the mPFC and striatum were automatically recruited when the task placed a high demand on processing how one is viewed by others. Taken together, our findings suggest that the mPFC and the striatum play a key role in regulating human social behaviors, and these results provide valuable insight into the neural basis of human altruism. PMID:19705330

  13. Dopaminergic Modulation of Excitatory Transmission in the Anterior Cingulate Cortex of Adult Mice.

    Science.gov (United States)

    Darvish-Ghane, Soroush; Yamanaka, Manabu; Zhuo, Min

    2016-01-01

    Dopamine (DA) possesses potent neuromodulatory properties in the central nervous system. In the anterior cingulate cortex, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPAR) are key ion channels in mediating nerve injury induced long-term potentiation (LTP) and chronic pain phenotype. In the present study, we reported the effects of DA on glutamate mediated excitatory post-synaptic currents (EPSCs) in pyramidal neurons of layer II/III of the ACC in adult mice. Bath application of DA (50 μM) caused a significant, rapid and reversible inhibition of evoked EPSCs (eEPSC). This inhibitory effect is dose-related and was absent in lower concentration of DA (5 μM). Furthermore, selective postsynaptic application of GDP-β-S (1.6 mM) in the internal solution completely abolished the inhibitory effects of DA (50 μM). We also investigated modulation of spontaneous EPSCs (sEPSCs) and TTX sensitive, miniature EPSCs (mEPSCs) by DA. Our results indicated mixed effects of potentiation and inhibition of frequency and amplitude for sEPSCs and mEPSCs. Furthermore, high doses of SCH23390 (100 μM) and sulpiride (100 μM) revealed that, inhibition of eEPSCs is mediated by postsynaptic D2-receptors (D2R). Our finding posits a pre- and postsynaptic mode of pyramidal neuron EPSC modulation in mice ACC by DA. PMID:27317578

  14. Medial prefrontal cortex-dorsal anterior cingulate cortex connectivity during behavior selection without an objective correct answer.

    Science.gov (United States)

    Nakao, Takashi; Osumi, Takahiro; Ohira, Hideki; Kasuya, Yukinori; Shinoda, Jun; Yamada, Jitsuhiro; Northoff, Georg

    2010-10-01

    Life choices (e.g., occupational choice) often include situations with two or more possible correct answers, thereby putting us in a situation of conflict. Recent reports have described that the evaluation of conflict might be crucially mediated by neural activity in the dorsal anterior cingulate cortex (dACC), although the reduction of conflict might rather be associated with neural activity in the medial prefrontal cortex (MPFC). What remains unclear is whether these regions mutually interact, thereby raising the question of their functional connectivity during conflict situations. Using psychophysiological interaction (PPI) analyses of functional magnetic resonance imaging (fMRI) data, this study shows that the dACC co-varied significantly higher with the MPFC during an occupational choice task with two possible correct answers when compared to the control task: a word-length task with one possible correct answer. These results suggest that the MPFC has a functional relation with dACC, especially in conflict situations where there is no objective correct answer. Taken together, this lends support to the assumption that the MPFC might be crucial in biasing the decision, thereby reducing conflict. PMID:20655361

  15. Efficient Authenticated Key Agreement Protocol Using Self-Certified Public Keys from Pairings

    Institute of Scientific and Technical Information of China (English)

    SHAO Zu-hua

    2005-01-01

    An efficient authenticated key agreement protocol is proposed, which makes use of bilinear pairings and selfcertified public keys. Its security is based on the security assumptions of the bilinear Diffie-Hellman problem and the computational Diffie-Hellman problem. Users can choose their private keys independently. The public keys and identities of users can be verified implicitly when the session key being generating in a logically single step. A trusted Key Generation Center is no longer required as in the ID-based authenticated key agreement protocols. Compared with existing authenticated key agreement protocols from pairings, the new proposed protocol is more efficient and secure.

  16. Midcingulate cortex: Structure, connections, homologies, functions and diseases.

    Science.gov (United States)

    Vogt, Brent A

    2016-07-01

    Midcingulate cortex (MCC) has risen in prominence as human imaging identifies unique structural and functional activity therein and this is the first review of its structure, connections, functions and disease vulnerabilities. The MCC has two divisions (anterior, aMCC and posterior, pMCC) that represent functional units and the cytoarchitecture, connections and neurocytology of each is shown with immunohistochemistry and receptor binding. The MCC is not a division of anterior cingulate cortex (ACC) and the "dorsal ACC" designation is a misnomer as it incorrectly implies that MCC is a division of ACC. Interpretation of findings among species and developing models of human diseases requires detailed comparative studies which is shown here for five species with flat maps and immunohistochemistry (human, monkey, rabbit, rat, mouse). The largest neurons in human cingulate cortex are in layer Vb of area 24 d in pMCC which project to the spinal cord. This area is part of the caudal cingulate premotor area which is involved in multisensory orientation of the head and body in space and neuron responses are tuned for the force and direction of movement. In contrast, the rostral cingulate premotor area in aMCC is involved in action-reinforcement associations and selection based on the amount of reward or aversive properties of a potential movement. The aMCC is activated by nociceptive information from the midline, mediodorsal and intralaminar thalamic nuclei which evoke fear and mediates nocifensive behaviors. This subregion also has high dopaminergic afferents and high dopamine-1 receptor binding and is engaged in reward processes. Opposing pain/avoidance and reward/approach functions are selected by assessment of potential outcomes and error detection according to feedback-mediated, decision making. Parietal afferents differentially terminate in MCC and provide for multisensory control in an eye- and head-centric manner. Finally, MCC vulnerability in human disease confirms

  17. Simple Web-based interactive key development software (WEBiKEY) and an example key for Kuruna (Poaceae: Bambusoideae)1

    Science.gov (United States)

    Attigala, Lakshmi; De Silva, Nuwan I.; Clark, Lynn G.

    2016-01-01

    Premise of the study: Programs that are user-friendly and freely available for developing Web-based interactive keys are scarce and most of the well-structured applications are relatively expensive. WEBiKEY was developed to enable researchers to easily develop their own Web-based interactive keys with fewer resources. Methods and Results: A Web-based multiaccess identification tool (WEBiKEY) was developed that uses freely available Microsoft ASP.NET technologies and an SQL Server database for Windows-based hosting environments. WEBiKEY was tested for its usability with a sample data set, the temperate woody bamboo genus Kuruna (Poaceae). Conclusions: WEBiKEY is freely available to the public and can be used to develop Web-based interactive keys for any group of species. The interactive key we developed for Kuruna using WEBiKEY enables users to visually inspect characteristics of Kuruna and identify an unknown specimen as one of seven possible species in the genus. PMID:27144109

  18. Simple Web-based interactive key development software (WEBiKEY) and an example key for Kuruna (Poaceae: Bambusoideae) 1

    OpenAIRE

    Attigala, Lakshmi; De Silva, Nuwan I.; Clark, Lynn G.

    2016-01-01

    Premise of the study: Programs that are user-friendly and freely available for developing Web-based interactive keys are scarce and most of the well-structured applications are relatively expensive. WEBiKEY was developed to enable researchers to easily develop their own Web-based interactive keys with fewer resources. Methods and Results: A Web-based multiaccess identification tool (WEBiKEY) was developed that uses freely available Microsoft ASP.NET technologies and an SQL Server database for...

  19. Multilayer multicast key management with threshold cryptography

    Science.gov (United States)

    Dexter, Scott D.; Belostotskiy, Roman; Eskicioglu, Ahmet M.

    2004-06-01

    The problem of distributing multimedia securely over the Internet is often viewed as an instance of secure multicast communication, in which multicast messages are protected by a group key shared among the group of clients. One important class of key management schemes makes use of a hierarchical key distribution tree. Constructing a hierarchical tree based on secret shares rather than keys yields a scheme that is both more flexible and provably secure. Both the key-based and share-based hierarchical key distribution tree techniques are designed for managing keys for a single data stream. Recent work shows how redundancies that arise when this scheme is extended to multi-stream (e.g. scalable video) applications may be exploited in the key-based system by viewing the set of clients as a "multi-group". In this paper, we present results from an adaptation of a multi-group key management scheme using threshold cryptography. We describe how the multi-group scheme is adapted to work with secret shares, and compare this scheme with a naíve multi-stream key-management solution by measuring performance across several critical parameters, including tree degree, multi-group size, and number of shares stored at each node.

  20. Induction of motor associative plasticity in the posterior parietal cortex-primary motor network

    DEFF Research Database (Denmark)

    Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer;

    2015-01-01

    There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right...

  1. Williams Syndrome Hypersociability: A Neuropsychological Study of the Amygdala and Prefrontal Cortex Hypotheses

    Science.gov (United States)

    Capitao, Liliana; Sampaio, Adriana; Fernandez, Montse; Sousa, Nuno; Pinheiro, Ana; Goncalves, Oscar F.

    2011-01-01

    Individuals with Williams syndrome display indiscriminate approach towards strangers. Neuroimaging studies conducted so far have linked this social profile to structural and/or functional abnormalities in WS amygdala and prefrontal cortex. In this study, the neuropsychological hypotheses of amygdala and prefrontal cortex involvement in WS…

  2. Functional connectivity within the visual cortex of the rat shows state changes.

    NARCIS (Netherlands)

    C. van der Togt; V.A.F. Lamme; H. Spekreijse

    1998-01-01

    The aim of this study was to investigate the dynamics of the horizontal functional connectivity within the visual cortex during spontaneous activity or during visual stimulation. Two arrays of 16 electrodes were inserted in the visual cortex of a rat. From these electrodes a depth profile was Obtain

  3. Modality-specific involvement of occipital cortex in the early blind

    NARCIS (Netherlands)

    Lubbe, van der R.H.J.; Mierlo, van C.M.; Postma, A.

    2008-01-01

    What happens in occipital cortex when neuronal activity is no longer evoked by regular visual stimulation? Studying brain activity induced by tactile and auditory stimuli in the blind may provide an answer. Several studies indicate that occipital cortex in the blind is recruited in simple tasks, lik

  4. A Semi-Persistent Adult Ocular Dominance Plasticity in Visual Cortex Is Stabilized by Activated CREB

    Science.gov (United States)

    Barco, Angel; Kandel, Eric R.; Gordon, Barbara; Lickey, Marvin E.; Suzuki, Seigo; Pham, Tony A.; Graham, Sarah J.

    2004-01-01

    The adult cerebral cortex can adapt to environmental change. Using monocular deprivation as a paradigm, we find that rapid experience-dependent plasticity exists even in the mature primary visual cortex. However, adult cortical plasticity differs from developmental plasticity in two important ways. First, the effect of adult, but not juvenile…

  5. Revisiting the Role of the Prefrontal Cortex in the Pathophysiology of Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Halperin, Jeffrey M.; Schulz, Kurt P.

    2006-01-01

    Most neural models for the pathophysiology of attention-deficit/hyperactivity disorder (ADHD) have centered on the prefrontal cortex and its interconnections with the striatum and other subcortical structures. However, research only partially supports these models, and they do not correspond with the development of the prefrontal cortex and its…

  6. Predicting the location of human perirhinal cortex, Brodmann's area 35, from MRI

    DEFF Research Database (Denmark)

    Augustinack, Jean C.; Huber, Kristen E.; Stevens, Allison A.;

    2013-01-01

    The perirhinal cortex (Brodmann's area 35) is a multimodal area that is important for normal memory function. Specifically, perirhinal cortex is involved in the detection of novel objects and manifests neurofibrillary tangles in Alzheimer's disease very early in disease progression. We scanned ex...

  7. Cryopreserved ovarian cortex from patients with leukemia in complete remission contains no apparent viable malignant cells

    DEFF Research Database (Denmark)

    Greve, Tine; Clasen-Linde, Erik; Andersen, Morten T; Andersen, Mette K; Sørensen, Stine D; Rosendahl, Mikkel; Ralfkiær, Elisabeth; Yding Andersen, Claus

    2012-01-01

    Some women suffering from leukemia require bone marrow transplantation to be cured. Bone marrow transplantation is associated with a high risk of sterility and some patients are offered fertility preservation by cryopreservation of ovarian cortex. Transplantation of ovarian cortex to women cured of...

  8. Continuous theta-burst stimulation of the primary motor cortex in essential tremor

    DEFF Research Database (Denmark)

    Hellriegel, Helge; Schulz, Eva M; Siebner, Hartwig R; Deuschl, Günther; Raethjen, Jan H

    2012-01-01

    We investigated whether essential tremor (ET) can be altered by suppressing the corticospinal excitability in the primary motor cortex (M1) with transcranial magnetic stimulation.......We investigated whether essential tremor (ET) can be altered by suppressing the corticospinal excitability in the primary motor cortex (M1) with transcranial magnetic stimulation....

  9. 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…

  10. Separating the influence of the cortex and foam on the mechanical properties of porcupine quills.

    Science.gov (United States)

    Yang, Wen; McKittrick, Joanna

    2013-11-01

    Lightweight thin cylinders filled with a foam have applications as collapsible energy absorbers for crashworthy and flotation applications. The local buckling compressive strength and Young's modulus are dependent on material and geometrical properties. Porcupine quills have a thin cortex filled with closed-cell foam, and are entirely composed of α-keratin. The cortex carries the majority of the compressive load, but the foam is able to accommodate and release some of the deformation of the cortex during buckling. The presence of the foam increases the critical buckling strength, buckling strain and elastic strain energy absorption over that of the cortex. Good agreement is found between experimental results and modeled predictions. A strain distribution map of the foam close to the buckled cortex demonstrates that the deformation of the cells plays an important role in accommodating local buckling of the cortex. The robust connection between the foam and cortex results in superior crushing properties compared to synthetic sandwich structure where the foam normally separates from the shell. The foam/cortex construction of the quill can guide future biomimetic fabrications of light weight buckle-resistant columns. PMID:23872514

  11. Inactivation of the Infralimbic but Not the Prelimbic Cortex Impairs Consolidation and Retrieval of Fear Extinction

    Science.gov (United States)

    Laurent, Vincent; Westbrook, R. Frederick

    2009-01-01

    Rats were subjected to one or two cycles of context fear conditioning and extinction to study the roles of the prelimbic cortex (PL) and infralimbic cortex (IL) in learning and relearning to inhibit fear responses. Inactivation of the PL depressed fear responses across the first or second extinction but did not impair learning or relearning fear…

  12. High-intensity Erotic Visual Stimuli De-activate the Primary Visual Cortex in Women

    NARCIS (Netherlands)

    Huynh, Hieu K.; Beers, Caroline; Willemsen, Antoon; Lont, Erna; Laan, Ellen; Dierckx, Rudi; Jansen, Monique; Sand, Michael; Schultz, Willibrord Weijmar; Holstege, Gert

    2012-01-01

    Introduction. The primary visual cortex, Brodmann's area (BA 17), plays a vital role in basic survival mechanisms in humans. In most neuro-imaging studies in which the volunteers have to watch pictures or movies, the primary visual cortex is similarly activated independent of the content of the pict

  13. Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

    Science.gov (United States)

    Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

    2011-01-01

    Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

  14. A radial glia-specific role of RhoA in double cortex formation

    DEFF Research Database (Denmark)

    Cappello, Silvia; Böhringer, Christian R J; Bergami, Matteo;

    2012-01-01

    The positioning of neurons in the cerebral cortex is of crucial importance for its function as highlighted by the severe consequences of migrational disorders in patients. Here we show that genetic deletion of the small GTPase RhoA in the developing cerebral cortex results in two migrational diso...

  15. Sexual attraction enhances glutamate transmission in mammalian anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Wu Long-Jun

    2009-05-01

    Full Text Available Abstract Functional human brain imaging studies have indicated the essential role of cortical regions, such as the anterior cingulate cortex (ACC, in romantic love and sex. However, the neurobiological basis of how the ACC neurons are activated and engaged in sexual attraction remains unknown. Using transgenic mice in which the expression of green fluorescent protein (GFP is controlled by the promoter of the activity-dependent gene c-fos, we found that ACC pyramidal neurons are activated by sexual attraction. The presynaptic glutamate release to the activated neurons is increased and pharmacological inhibition of neuronal activities in the ACC reduced the interest of male mice to female mice. Our results present direct evidence of the critical role of the ACC in sexual attraction, and long-term increases in glutamate mediated excitatory transmission may contribute to sexual attraction between male and female mice.

  16. Watching cartoons activates the medial prefrontal cortex in children

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The medial prefrontal cortex (MPFC) of human adults is involved in attributing mental states to real human agents but not to virtual artificial characters. This study examined whether such differential MPFC activity can be observed in children who are more fascinated by cartoons than adults. We measured brain activity using functional magnetic resonance imaging (fMRI) while 10-year-old children watched movie and cartoon clips, simulating real and virtual visual worlds, respectively. We showed neuroimaging evidence that, in contrast to adults, the MPFC of children was activated when perceiving both human agents and artificial characters in coherent visual events. Our findings suggest that, around the age of 10 years, the MPFC activity in children is different from that in adults in that it can be spontaneously activated by non-human agents in a virtual visual world.

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

    Science.gov (United States)

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

    2009-12-11

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

  18. Organization of texture segregation processing in primate visual cortex.

    Science.gov (United States)

    Lamme, V A; van Dijk, B W; Spekereijse, H

    1993-01-01

    We investigated the intracortical organization of neuronal mass activity that is related to texture segregation on the basis of orientation contrast. Evoked potentials were recorded to a stimulus, signalling a contribution from texture segregation-sensitive mechanisms by means of specific response components. The specific components could only be recorded when textons had a spatial organization that leads to the percept of image segmentation. Equivalent dipole estimations of the specific response components suggested the presence of texture segregation-related activity in the primary visual cortex. These results were corroborated by current-source-density analysis of intracortical recordings in the awake monkey. A specific involvement of layers 2/3 and 5 of area 17 in the global process of image segmentation could be demonstrated. PMID:8217932

  19. Behavioral effects of congenital ventromedial prefrontal cortex malformation

    Directory of Open Access Journals (Sweden)

    Boes Aaron D

    2011-12-01

    Full Text Available Abstract Background A detailed behavioral profile associated with focal congenital malformation of the ventromedial prefrontal cortex (vmPFC has not been reported previously. Here we describe a 14 year-old boy, B.W., with neurological and psychiatric sequelae stemming from focal cortical malformation of the left vmPFC. Case Presentation B.W.'s behavior has been characterized through extensive review Patience of clinical and personal records along with behavioral and neuropsychological testing. A central feature of the behavioral profile is severe antisocial behavior. He is aggressive, manipulative, and callous; features consistent with psychopathy. Other problems include: egocentricity, impulsivity, hyperactivity, lack of empathy, lack of respect for authority, impaired moral judgment, an inability to plan ahead, and poor frustration tolerance. Conclusions The vmPFC has a profound contribution to the development of human prosocial behavior. B.W. demonstrates how a congenital lesion to this cortical region severely disrupts this process.

  20. Metabifurcation analysis of a mean field model of the cortex

    CERN Document Server

    Frascoli, Federico; Bojak, Ingo; Liley, David T J

    2010-01-01

    Mean field models (MFMs) of cortical tissue incorporate salient features of neural masses to model activity at the population level. One of the common aspects of MFM descriptions is the presence of a high dimensional parameter space capturing neurobiological attributes relevant to brain dynamics. We study the physiological parameter space of a MFM of electrocortical activity and discover robust correlations between physiological attributes of the model cortex and its dynamical features. These correlations are revealed by the study of bifurcation plots, which show that the model responses to changes in inhibition belong to two families. After investigating and characterizing these, we discuss their essential differences in terms of four important aspects: power responses with respect to the modeled action of anesthetics, reaction to exogenous stimuli, distribution of model parameters and oscillatory repertoires when inhibition is enhanced. Furthermore, while the complexity of sustained periodic orbits differs ...