Hypothalamic demyelination causing panhypopituitarism.

Science.gov (United States)

Dixon-Douglas, Julia; Burgess, John; Dreyer, Michael

2018-05-01

Hypothalamic involvement in multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) is rare and endocrinopathies involving the hypothalamic-pituitary axis in patients with demyelinating conditions have rarely been reported. We present two cases of MS/NMOSD with associated hypothalamic-pituitary involvement and subsequent hypopituitarism, including the first report of a patient with hypothalamic demyelination causing panhypopituitarism. Differential diagnoses, including alemtuzumab-related and primary pituitary pathology are discussed. © 2018 Royal Australasian College of Physicians.

Activation of hypothalamic RIP-Cre neurons promotes beiging of WAT via sympathetic nervous system.

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Wang, Baile; Li, Ang; Li, Xiaomu; Ho, Philip Wl; Wu, Donghai; Wang, Xiaoqi; Liu, Zhuohao; Wu, Kelvin Kl; Yau, Sonata Sy; Xu, Aimin; Cheng, Kenneth Ky

2018-04-01

Activation of brown adipose tissue (BAT) and beige fat by cold increases energy expenditure. Although their activation is known to be differentially regulated in part by hypothalamus, the underlying neural pathways and populations remain poorly characterized. Here, we show that activation of rat-insulin-promoter-Cre (RIP-Cre) neurons in ventromedial hypothalamus (VMH) preferentially promotes recruitment of beige fat via a selective control of sympathetic nervous system (SNS) outflow to subcutaneous white adipose tissue (sWAT), but has no effect on BAT Genetic ablation of APPL2 in RIP-Cre neurons diminishes beiging in sWAT without affecting BAT, leading to cold intolerance and obesity in mice. Such defects are reversed by activation of RIP-Cre neurons, inactivation of VMH AMPK, or treatment with a β3-adrenergic receptor agonist. Hypothalamic APPL2 enhances neuronal activation in VMH RIP-Cre neurons and raphe pallidus, thereby eliciting SNS outflow to sWAT and subsequent beiging. These data suggest that beige fat can be selectively activated by VMH RIP-Cre neurons, in which the APPL2-AMPK signaling axis is crucial for this defending mechanism to cold and obesity. © 2018 The Authors.

Hypothalamic glioma masquerading as craniopharyngioma

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Sameer Vyas

2013-01-01

Full Text Available Hypothalamic glioma account for 10-15% of supratentorial tumors in children. They usually present earlier (first 5 years of age than craniopharyngioma. Hypothalamic glioma poses a diagnostic dilemma with craniopharyngioma and other hypothalamic region tumors, when they present with atypical clinical or imaging patterns. Neuroimaging modalities especially MRI plays a very important role in scrutinizing the lesions in the hypothalamic region. We report a case of a hypothalamic glioma masquerading as a craniopharyngioma on imaging along with brief review of both the tumors.

PI3K in the ventromedial hypothalamic nucleus mediates estrogenic actions on energy expenditure in female mice

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Estrogens act in the ventromedial hypothalamic nucleus (VMH) to regulate body weight homeostasis. However, the molecular mechanisms underlying these estrogenic effects are unknown. We show that activation of estrogen receptor-a (ERa) stimulates neural firing of VMH neurons expressing ERa, and these ...

Neonatal ghrelin programs development of hypothalamic feeding circuits

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Steculorum, Sophie M.; Collden, Gustav; Coupe, Berengere; Croizier, Sophie; Lockie, Sarah; Andrews, Zane B.; Jarosch, Florian; Klussmann, Sven; Bouret, Sebastien G.

2015-01-01

A complex neural network regulates body weight and energy balance, and dysfunction in the communication between the gut and this neural network is associated with metabolic diseases, such as obesity. The stomach-derived hormone ghrelin stimulates appetite through interactions with neurons in the arcuate nucleus of the hypothalamus (ARH). Here, we evaluated the physiological and neurobiological contribution of ghrelin during development by specifically blocking ghrelin action during early postnatal development in mice. Ghrelin blockade in neonatal mice resulted in enhanced ARH neural projections and long-term metabolic effects, including increased body weight, visceral fat, and blood glucose levels and decreased leptin sensitivity. In addition, chronic administration of ghrelin during postnatal life impaired the normal development of ARH projections and caused metabolic dysfunction. Consistent with these observations, direct exposure of postnatal ARH neuronal explants to ghrelin blunted axonal growth and blocked the neurotrophic effect of the adipocyte-derived hormone leptin. Moreover, chronic ghrelin exposure in neonatal mice also attenuated leptin-induced STAT3 signaling in ARH neurons. Collectively, these data reveal that ghrelin plays an inhibitory role in the development of hypothalamic neural circuits and suggest that proper expression of ghrelin during neonatal life is pivotal for lifelong metabolic regulation. PMID:25607843

Hypothalamic 2-arachidonoylglycerol regulates multistage process of high-fat diet preferences.

Directory of Open Access Journals (Sweden)

Sei Higuchi

Full Text Available In this study, we examined alterations in the hypothalamic reward system related to high-fat diet (HFD preferences. We previously reported that hypothalamic 2-arachidonoylglycerol (2-AG and glial fibrillary acid protein (GFAP were increased after conditioning to the rewarding properties of a HFD. Here, we hypothesized that increased 2-AG influences the hypothalamic reward system.The conditioned place preference test (CPP test was used to evaluate HFD preferences. Hypothalamic 2-AG was quantified by gas chromatography-mass spectrometry. The expression of GFAP was examined by immunostaining and western blotting.Consumption of a HFD over either 3 or 7 days increased HFD preferences and transiently increased hypothalamic 2-AG levels. HFD consumption over 14 days similarly increased HFD preferences but elicited a long-lasting increase in hypothalamic 2-AG and GFAP levels. The cannabinoid 1 receptor antagonist O-2050 reduced preferences for HFDs after 3, 7, or 14 days of HFD consumption and reduced expression of GFAP after 14 days of HFD consumption. The astrocyte metabolic inhibitor Fluorocitrate blocked HFD preferences after 14 days of HFD consumption.High levels of 2-AG appear to induce HFD preferences, and activate hypothalamic astrocytes via the cannabinoid system. We propose that there may be two distinct stages in the development of HFD preferences. The induction stage involves a transient increase in 2-AG, whereas the maintenance stage involves a long lasting increase in 2-AG levels and activation of astrocytes. Accordingly, hypothalamic 2-AG may influence the development of HFD preferences.

Role of hypothalamic melanocortin system in adaptation of food intake to food protein increase in mice.

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Bruno Pillot

Full Text Available The hypothalamic melanocortin system--the melanocortin receptor of type 4 (MC4R and its ligands: α-melanin-stimulating hormone (α-MSH, agonist, inducing hypophagia, and agouti-related protein (AgRP, antagonist, inducing hyperphagia--is considered to play a central role in the control of food intake. We tested its implication in the mediation of the hunger-curbing effects of protein-enriched diets (PED in mice. Whereas there was a 20% decrease in food intake in mice fed on the PED, compared to mice fed on an isocaloric starch-enriched diet, there was a paradoxical decrease in expression of the hypothalamic proopiomelanocortin gene, precursor of α-MSH, and increase in expression of the gene encoding AgRP. The hypophagia effect of PED took place in mice with invalidation of either MC4R or POMC, and was even strengthened in mice with ablation of the AgRP-expressing neurons. These data strongly suggest that the hypothalamic melanocortin system does not mediate the hunger-curbing effects induced by changes in the macronutrient composition of food. Rather, the role of this system might be to defend the body against the variations in food intake generated by the nutritional environment.

Function of hypothalamic-hypophyseal-ovarian system in radiation treatment of patients with cervical cancer

International Nuclear Information System (INIS)

Modnikov, O.P.

1984-01-01

Radioimmunoassay of the hypothalamic-hypophyseal-ovarian interrelationships was performed in 87 patients with cervical cancer and 37 practically healthy women. The basal level of the follicle-stimulating hormone (ESH), luteinizing hormone (LH) and estradiol as well as their response to the administration of the releasing factor of the hypothalamus (luliberin) were studied. Some disorders that manifested thermselved in the decreased level of estradiol, were established in the patients with cervical cancer even before irradiation. Concomitant radiation therapy resulted in pronounced changes in the activities of the hypothalamic-hypophyseal-ovarian system that manifested themselves in the lowered rate of LH increment in response to the administration of luliberin and the absence of estradiol response to the load. These changes persisted long after the termination of concomitant radiation therapy

The role of hypothalamic inflammation, the hypothalamic-pituitary-adrenal axis and serotonin in the cancer anorexia-cachexia syndrome.

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van Norren, Klaske; Dwarkasing, Jvalini T; Witkamp, Renger F

2017-09-01

In cancer patients, the development of cachexia (muscle wasting) is frequently aggravated by anorexia (loss of appetite). Their concurrence is often referred to as anorexia-cachexia syndrome. This review focusses on the recent evidence underlining hypothalamic inflammation as key driver of these processes. Special attention is given to the involvement of hypothalamic serotonin. The anorexia-cachexia syndrome is directly associated with higher mortality in cancer patients. Recent reports confirm its severe impact on the quality of life of patients and their families.Hypothalamic inflammation has been shown to contribute to muscle and adipose tissue loss in cancer via central hypothalamic interleukine (IL)1β-induced activation of the hypothalamic-pituitary-adrenal axis. The resulting release of glucocorticoids directly stimulates catabolic processes in these tissues via activation of the ubiquitin-proteosome pathway. Next to this, hypothalamic inflammation has been shown to reduce food intake in cancer by triggering changes in orexigenic and anorexigenic responses via upregulation of serotonin availability and stimulation of its signalling pathways in hypothalamic tissues. This combination of reduced food intake and stimulation of tissue catabolism represents a dual mechanism by which hypothalamic inflammation contributes to the development and maintenance of anorexia and cachexia in cancer. Hypothalamic inflammation is a driving force in the development of the anorexia-cachexia syndrome via hypothalamic-pituitary-adrenal axis and serotonin pathway activation.

Role of Hypothalamic Melanocortin System in Adaptation of Food Intake to Food Protein Increase in Mice

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Pillot, Bruno; Duraffourd, Céline; Bégeot, Martine; Joly, Aurélie; Luquet, Serge; Houberdon, Isabelle; Naville, Danielle; Vigier, Michèle; Gautier-Stein, Amandine; Magnan, Christophe; Mithieux, Gilles

2011-01-01

The hypothalamic melanocortin system—the melanocortin receptor of type 4 (MC4R) and its ligands: α-melanin-stimulating hormone (α-MSH, agonist, inducing hypophagia), and agouti-related protein (AgRP, antagonist, inducing hyperphagia)—is considered to play a central role in the control of food intake. We tested its implication in the mediation of the hunger-curbing effects of protein-enriched diets (PED) in mice. Whereas there was a 20% decrease in food intake in mice fed on the PED, compared to mice fed on an isocaloric starch-enriched diet, there was a paradoxical decrease in expression of the hypothalamic proopiomelanocortin gene, precursor of α-MSH, and increase in expression of the gene encoding AgRP. The hypophagia effect of PED took place in mice with invalidation of either MC4R or POMC, and was even strengthened in mice with ablation of the AgRP-expressing neurons. These data strongly suggest that the hypothalamic melanocortin system does not mediate the hunger-curbing effects induced by changes in the macronutrient composition of food. Rather, the role of this system might be to defend the body against the variations in food intake generated by the nutritional environment. PMID:21544212

Alterations in the hypothalamic melanocortin pathway in amyotrophic lateral sclerosis.

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Vercruysse, Pauline; Sinniger, Jérôme; El Oussini, Hajer; Scekic-Zahirovic, Jelena; Dieterlé, Stéphane; Dengler, Reinhard; Meyer, Thomas; Zierz, Stephan; Kassubek, Jan; Fischer, Wilhelm; Dreyhaupt, Jens; Grehl, Torsten; Hermann, Andreas; Grosskreutz, Julian; Witting, Anke; Van Den Bosch, Ludo; Spreux-Varoquaux, Odile; Ludolph, Albert C; Dupuis, Luc

2016-04-01

Amyotrophic lateral sclerosis, the most common adult-onset motor neuron disease, leads to death within 3 to 5 years after onset. Beyond progressive motor impairment, patients with amyotrophic lateral sclerosis suffer from major defects in energy metabolism, such as weight loss, which are well correlated with survival. Indeed, nutritional intervention targeting weight loss might improve survival of patients. However, the neural mechanisms underlying metabolic impairment in patients with amyotrophic lateral sclerosis remain elusive, in particular due to the lack of longitudinal studies. Here we took advantage of samples collected during the clinical trial of pioglitazone (GERP-ALS), and characterized longitudinally energy metabolism of patients with amyotrophic lateral sclerosis in response to pioglitazone, a drug with well-characterized metabolic effects. As expected, pioglitazone decreased glycaemia, decreased liver enzymes and increased circulating adiponectin in patients with amyotrophic lateral sclerosis, showing its efficacy in the periphery. However, pioglitazone did not increase body weight of patients with amyotrophic lateral sclerosis independently of bulbar involvement. As pioglitazone increases body weight through a direct inhibition of the hypothalamic melanocortin system, we studied hypothalamic neurons producing proopiomelanocortin (POMC) and the endogenous melanocortin inhibitor agouti-related peptide (AGRP), in mice expressing amyotrophic lateral sclerosis-linked mutant SOD1(G86R). We observed lower Pomc but higher Agrp mRNA levels in the hypothalamus of presymptomatic SOD1(G86R) mice. Consistently, numbers of POMC-positive neurons were decreased, whereas AGRP fibre density was elevated in the hypothalamic arcuate nucleus of SOD1(G86R) mice. Consistent with a defect in the hypothalamic melanocortin system, food intake after short term fasting was increased in SOD1(G86R) mice. Importantly, these findings were replicated in two other amyotrophic

Stress, glucocorticoid hormones, and hippocampal neural progenitor cells: implications to mood disorders.

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Kino, Tomoshige

2015-01-01

The hypothalamic-pituitary-adrenal (HPA) axis and its end-effectors glucocorticoid hormones play central roles in the adaptive response to numerous stressors that can be either internal or external. Thus, this system has a strong impact on the brain hippocampus and its major functions, such as cognition, memory as well as behavior, and mood. The hippocampal area of the adult brain contains neural stem cells or more committed neural progenitor cells, which retain throughout the human life the ability of self-renewal and to differentiate into multiple neural cell lineages, such as neurons, astrocytes, and oligodendrocytes. Importantly, these characteristic cells contribute significantly to the above-indicated functions of the hippocampus, while various stressors and glucocorticoids influence proliferation, differentiation, and fate of these cells. This review offers an overview of the current understanding on the interactions between the HPA axis/glucocorticoid stress-responsive system and hippocampal neural progenitor cells by focusing on the actions of glucocorticoids. Also addressed is a further discussion on the implications of such interactions to the pathophysiology of mood disorders.

Rapid sensing of l-leucine by human and murine hypothalamic neurons: Neurochemical and mechanistic insights.

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Heeley, Nicholas; Kirwan, Peter; Darwish, Tamana; Arnaud, Marion; Evans, Mark L; Merkle, Florian T; Reimann, Frank; Gribble, Fiona M; Blouet, Clemence

2018-04-01

Dietary proteins are sensed by hypothalamic neurons and strongly influence multiple aspects of metabolic health, including appetite, weight gain, and adiposity. However, little is known about the mechanisms by which hypothalamic neural circuits controlling behavior and metabolism sense protein availability. The aim of this study is to characterize how neurons from the mediobasal hypothalamus respond to a signal of protein availability: the amino acid l-leucine. We used primary cultures of post-weaning murine mediobasal hypothalamic neurons, hypothalamic neurons derived from human induced pluripotent stem cells, and calcium imaging to characterize rapid neuronal responses to physiological changes in extracellular l-Leucine concentration. A neurochemically diverse subset of both mouse and human hypothalamic neurons responded rapidly to l-leucine. Consistent with l-leucine's anorexigenic role, we found that 25% of mouse MBH POMC neurons were activated by l-leucine. 10% of MBH NPY neurons were inhibited by l-leucine, and leucine rapidly reduced AGRP secretion, providing a mechanism for the rapid leucine-induced inhibition of foraging behavior in rodents. Surprisingly, none of the candidate mechanisms previously implicated in hypothalamic leucine sensing (K ATP channels, mTORC1 signaling, amino-acid decarboxylation) were involved in the acute activity changes produced by l-leucine. Instead, our data indicate that leucine-induced neuronal activation involves a plasma membrane Ca 2+ channel, whereas leucine-induced neuronal inhibition is mediated by inhibition of a store-operated Ca 2+ current. A subset of neurons in the mediobasal hypothalamus rapidly respond to physiological changes in extracellular leucine concentration. Leucine can produce both increases and decreases in neuronal Ca 2+ concentrations in a neurochemically-diverse group of neurons, including some POMC and NPY/AGRP neurons. Our data reveal that leucine can signal through novel mechanisms to rapidly

Exercise protects against high-fat diet-induced hypothalamic inflammation.

Science.gov (United States)

Yi, Chun-Xia; Al-Massadi, Omar; Donelan, Elizabeth; Lehti, Maarit; Weber, Jon; Ress, Chandler; Trivedi, Chitrang; Müller, Timo D; Woods, Stephen C; Hofmann, Susanna M

2012-06-25

Hypothalamic inflammation is a potentially important process in the pathogenesis of high-fat diet-induced metabolic disorders that has recently received significant attention. Microglia are macrophage-like cells of the central nervous system which are activated by pro-inflammatory signals causing local production of specific interleukins and cytokines, and these in turn may further promote systemic metabolic disease. Whether or how this microglial activation can be averted or reversed is unknown. Since running exercise improves systemic metabolic health and has been found to promote neuronal survival as well as the recovery of brain functions after injury, we hypothesized that regular treadmill running may blunt the effect of western diet on hypothalamic inflammation. Using low-density lipoprotein receptor deficient (l dlr-/-) mice to better reflect human lipid metabolism, we first confirmed that microglial activation in the hypothalamus is severely increased upon exposure to a high-fat, or "western", diet. Moderate, but regular, treadmill running exercise markedly decreased hypothalamic inflammation in these mice. Furthermore, the observed decline in microglial activation was associated with an improvement of glucose tolerance. Our findings support the hypothesis that hypothalamic inflammation can be reversed by exercise and suggest that interventions to avert or reverse neuronal damage may offer relevant potential in obesity treatment and prevention. Copyright © 2012 Elsevier Inc. All rights reserved.

Neural Systems Laboratory

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Federal Laboratory Consortium — As part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the...

MR appearance of hypothalamic hamartoma

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Hahn, F.J.; Leibrock, L.G.; Huseman, C.A.; Makos, M.M.

1988-02-01

Hypothalamic hamartoma is the most common detectable cerebral lesion causing precocious puberty. Two histologically confirmed cases were studied by computerized tomography (CT) and magnetic resonance (MR) imaging. T2 weighted, sagittal MR images were superior to CT in delineating the tumor from surrounding grey matter. The lesion was isointense to grey matter on T1 weighted images allowing exclusion of other hypothalamic tumors. MR will undoubtedly become the imaging modality of choice in the detection of hypothalamic hamartoma.

Paraneoplastic limbic encephalitis with associated hypothalamitis mimicking a hyperdense hypothalamic tumor: a case report

International Nuclear Information System (INIS)

Bataduwaarachchi, Vipula R.; Tissera, Nirmali

2016-01-01

Paraneoplastic limbic encephalitis is an uncommon association of common malignancies such as small cell lung carcinoma, testicular teratoma, and breast carcinoma. The nonspecific nature of the clinical presentation, lack of freely available diagnostic markers, and requirement for advanced imaging techniques pose a great challenge in the diagnosis of this disease in resource-poor settings. A 64-year-old previously healthy Sri Lankan man was admitted to the general medical unit with subacute memory impairment regarding recent events that had occurred during the previous 3 weeks. Initial noncontrast computed tomography of the brain revealed a hyperdensity in the hypothalamic region surrounded by hypodensities extending toward the bilateral temporal lobes; these findings were consistent with a possible hypothalamic tumor with perilesional edema. The patient later developed cranial diabetes insipidus, which was further suggestive of hypothalamic disease. Interestingly, gadolinium-enhanced magnetic resonance imaging of the brain showed no such lesions; instead, it showed prominent T2-weighted signals in the inner mesial region, characteristic of encephalitis. The possibility of tuberculosis and viral encephalitis was excluded based on cerebrospinal fluid analysis results. Limbic encephalitis with predominant hypothalamitis was suspected based on the radiological pattern. Subsequent screening for underlying malignancy revealed a mass lesion in the right hilum on chest radiographs. Histological examination of the lesion showed small cell lung cancer of the “oat cell” variety. We suggest that the initial appearance of a hyperdensity in the hypothalamus region on noncontrast computed tomography is probably due to hyperemia caused by hypothalamitis. If hypothalamitis is predominant in a patient with paraneoplastic limbic encephalitis, magnetic resonance imaging will help to differentiate it from a hypothalamic secondary deposit. Limbic encephalitis should be considered in

Computed tomography in hypothalamic hamartoma

International Nuclear Information System (INIS)

Mori, Koreaki; Takeuchi, Juji; Hanakita, Junya; Handa, Hajime; Nakano, Yoshihisa.

1981-01-01

Two cases of hypothalamic hamartoma were reported. Hypothalamic hamartoma is a rate tumor. The onset of symptoms is in infancy and early childhood. Clinical symptoms are composed of convulsive seizures, laughing spells and precocious puberty. CT finding of hypothalamic hamartoma is a mass in the suprasellar and interpeduncular cisterns which has the same density as the surrounding normal brain. The mass is not enhanced by injection of the contrast material and is easily differentiated from other masses in the suprasellar region. (author)

Delineating the regulation of energy homeostasis using hypothalamic cell models.

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Wellhauser, Leigh; Gojska, Nicole M; Belsham, Denise D

2015-01-01

Attesting to its intimate peripheral connections, hypothalamic neurons integrate nutritional and hormonal cues to effectively manage energy homeostasis according to the overall status of the system. Extensive progress in the identification of essential transcriptional and post-translational mechanisms regulating the controlled expression and actions of hypothalamic neuropeptides has been identified through the use of animal and cell models. This review will introduce the basic techniques of hypothalamic investigation both in vivo and in vitro and will briefly highlight the key advantages and challenges of their use. Further emphasis will be place on the use of immortalized models of hypothalamic neurons for in vitro study of feeding regulation, with a particular focus on cell lines proving themselves most fruitful in deciphering fundamental basics of NPY/AgRP, Proglucagon, and POMC neuropeptide function. Copyright © 2014 Elsevier Inc. All rights reserved.

Fetal alcohol programming of hypothalamic proopiomelanocortin system by epigenetic mechanisms and later life vulnerability to stress.

Science.gov (United States)

Bekdash, Rola; Zhang, Changqing; Sarkar, Dipak

2014-09-01

Hypothalamic proopiomelanocortin (POMC) neurons, one of the major regulators of the hypothalamic-pituitary-adrenal (HPA) axis, immune functions, and energy homeostasis, are vulnerable to the adverse effects of fetal alcohol exposure (FAE). These effects are manifested in POMC neurons by a decrease in Pomc gene expression, a decrement in the levels of its derived peptide β-endorphin and a dysregulation of the stress response in the adult offspring. The HPA axis is a major neuroendocrine system with pivotal physiological functions and mode of regulation. This system has been shown to be perturbed by prenatal alcohol exposure. It has been demonstrated that the perturbation of the HPA axis by FAE is long-lasting and is linked to molecular, neurophysiological, and behavioral changes in exposed individuals. Recently, we showed that the dysregulation of the POMC system function by FAE is induced by epigenetic mechanisms such as hypermethylation of Pomc gene promoter and an alteration in histone marks in POMC neurons. This developmental programming of the POMC system by FAE altered the transcriptome in POMC neurons and induced a hyperresponse to stress in adulthood. These long-lasting epigenetic changes influenced subsequent generations via the male germline. We also demonstrated that the epigenetic programming of the POMC system by FAE was reversed in adulthood with the application of the inhibitors of DNA methylation or histone modifications. Thus, prenatal environmental influences, such as alcohol exposure, could epigenetically modulate POMC neuronal circuits and function to shape adult behavioral patterns. Identifying specific epigenetic factors in hypothalamic POMC neurons that are modulated by fetal alcohol and target Pomc gene could be potentially useful for the development of new therapeutic approaches to treat stress-related diseases in patients with fetal alcohol spectrum disorders. Copyright © 2014 by the Research Society on Alcoholism.

Artificial Neural Network Analysis System

Science.gov (United States)

2001-02-27

Contract No. DASG60-00-M-0201 Purchase request no.: Foot in the Door-01 Title Name: Artificial Neural Network Analysis System Company: Atlantic... Artificial Neural Network Analysis System 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Powell, Bruce C 5d. PROJECT NUMBER 5e. TASK NUMBER...34) 27-02-2001 Report Type N/A Dates Covered (from... to) ("DD MON YYYY") 28-10-2000 27-02-2001 Title and Subtitle Artificial Neural Network Analysis

Bidirectional neural interface: Closed-loop feedback control for hybrid neural systems.

Science.gov (United States)

Chou, Zane; Lim, Jeffrey; Brown, Sophie; Keller, Melissa; Bugbee, Joseph; Broccard, Frédéric D; Khraiche, Massoud L; Silva, Gabriel A; Cauwenberghs, Gert

2015-01-01

Closed-loop neural prostheses enable bidirectional communication between the biological and artificial components of a hybrid system. However, a major challenge in this field is the limited understanding of how these components, the two separate neural networks, interact with each other. In this paper, we propose an in vitro model of a closed-loop system that allows for easy experimental testing and modification of both biological and artificial network parameters. The interface closes the system loop in real time by stimulating each network based on recorded activity of the other network, within preset parameters. As a proof of concept we demonstrate that the bidirectional interface is able to establish and control network properties, such as synchrony, in a hybrid system of two neural networks more significantly more effectively than the same system without the interface or with unidirectional alternatives. This success holds promise for the application of closed-loop systems in neural prostheses, brain-machine interfaces, and drug testing.

The hypothalamic- pituitary -adrenal -leptin axis and metabolic health: A systems approach to resilience, robustness and control

NARCIS (Netherlands)

Aschbacher, K.; Rodriguez-Fernandez, M.; Wietmarschen, H. van; Tomiyama, A.; Jain, S.; Epel, E.; Doyle III, F.J.; Greef, J. van der

2014-01-01

Glucocorticoids contribute to obesity and metabolic syndrome; however, the mechanisms are unclear, and prognostic measures are unavailable. A systems level understanding of the hypothalamic-pituitary-adrenal (HPA) -leptin axis may reveal novel insights. Eighteen obese premenopausal women provided

Medical therapy of hypothalamic diseases

International Nuclear Information System (INIS)

Werder, K. von; Mueller, O.A.

1985-01-01

Hormonal disturbances caused by hypothalamic pathology can be treated effectively by target hormone replacement in the case of failure of glandotropic hormone secretion. Hyposomatotropism in children has to be substituted by parenteral administration of growth hormone. In addition gonadotropins respectively gonadotropin releasing factor have to be given in order to restore fertility in hypothalamic hypogonadism. Posterior pituitary failure can be adequately replaced by administration of analogues of antidiuretic hormone. Hypothalamic pathology causing hypersecretion of anterior pituitary hormones may also be accessable to medical treatment. This pertains particularly to hyperprolactinemia and precocious puberty. However, there is no medical therapy so far for hypothalamic disturbances leading to veterative dysfunction like disturbances of temperature regulation and control of thirst and polyphagia. In this situation symptomatic correction of the abnormality represents the only possibility to keep these patients alive. (Author)

Sox21 deletion in mice causes postnatal growth deficiency without physiological disruption of hypothalamic-pituitary endocrine axes.

Science.gov (United States)

Cheung, Leonard Y M; Okano, Hideyuki; Camper, Sally A

2017-01-05

The hypothalamic-pituitary axes are the coordinating centers for multiple endocrine gland functions and physiological processes. Defects in the hypothalamus or pituitary gland can cause reduced growth and severe short stature, affecting approximately 1 in 4000 children, and a large percentage of cases of pituitary hormone deficiencies do not have an identified genetic cause. SOX21 is a protein that regulates hair, neural, and trophoblast stem cell differentiation. Mice lacking Sox21 have reduced growth, but the etiology of this growth defect has not been described. We studied the expression of Sox21 in hypothalamic-pituitary development and examined multiple endocrine axes in these mice. We find no evidence of reduced intrauterine growth, food intake, or physical activity, but there is evidence for increased energy expenditure in mutants. In addition, despite changes in pituitary hormone expression, hypothalamic-pituitary axes appear to be functional. Therefore, SOX21 variants may be a cause of non-endocrine short stature in humans. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Hypothalamic involvement in stress-induced hypocalcemia in rats.

Science.gov (United States)

Aou, S; Ma, J; Hori, T

1993-08-20

Although hormonal regulation of blood calcium homeostasis has been intensively investigated in the peripheral organs, the involvement of the central nervous system in calcium regulation is still poorly understood. In the present study, we found that (1) bilateral lesions of the ventromedial nucleus of the hypothalamus (VMH), but not those of the paraventricular hypothalamic nucleus or the lateral hypothalamic area, eliminated immobilization (IMB)-induced hypocalcemia, and (2) electrical stimulation of the VMH decreased the blood calcium level. The results suggest that the VMH has a hypocalcemic function and plays a role in IMB-induced hypocalcemia.

Effects of spaceflight on hypothalamic peptide systems controlling pituitary growth hormone dynamics

Science.gov (United States)

Sawchenko, P. E.; Arias, C.; Krasnov, I.; Grindeland, R. E.; Vale, W.

1992-01-01

Possible effects of reduced gravity on central hypophysiotropic systems controlling growth hormone (GH) secretion were investigated in rats flown on Cosmos 1887 and 2044 biosatellites. Immunohistochemical (IHC)staining for the growth hormone-releasing factor (GRF), somatostatin (SS), and other hypothalamic hormones was performed on hypothalami obtained from rats. IHC analysis was complemented by quantitative in situ assessments of mRNAs encoding the precursors for these hormones. Data obtained suggest that exposure to microgravity causes a preferential reduction in GRF peptide and mRNA levels in hypophysiotropic neurons, which may contribute to impared GH secretion in animals subjected to spaceflight. Effects of weightlessness are not mimicked by hindlimb suspension in this system.

Hypocretin/orexin loss changes the hypothalamic immune response.

Science.gov (United States)

Tanaka, Susumu; Takizawa, Nae; Honda, Yoshiko; Koike, Taro; Oe, Souichi; Toyoda, Hiromi; Kodama, Tohru; Yamada, Hisao

2016-10-01

Hypocretin, also known as orexin, maintains the vigilance state and regulates various physiological processes, such as arousal, sleep, food intake, energy expenditure, and reward. Previously, we found that when wild-type mice and hypocretin/ataxin-3 littermates (which are depleted of hypothalamic hypocretin-expressing neurons postnatally) were administered lipopolysaccharide (LPS), the two genotypes exhibited significant differences in their sleep/wake cycle, including differences in the degree of increase in sleep periods and in recovery from sickness behaviour. In the present study, we examined changes in the hypothalamic vigilance system and in the hypothalamic expression of inflammatory factors in response to LPS in hypocretin/ataxin-3 mice. Peripheral immune challenge with LPS affected the hypothalamic immune response and vigilance states. This response was altered by the loss of hypocretin. Hypocretin expression was inhibited after LPS injection in both hypocretin/ataxin-3 mice and their wild-type littermates, but expression was completely abolished only in hypocretin/ataxin-3 mice. Increases in the number of histidine decarboxylase (HDC)-positive cells and in Hdc mRNA expression were found in hypocretin/ataxin-3 mice, and this increase was suppressed by LPS. Hypocretin loss did not impact the change in expression of hypothalamic inflammatory factors in response to LPS, except for interferon gamma and colony stimulating factor 3. The number of c-Fos-positive/HDC-positive cells in hypocretin/ataxin-3 mice administered LPS injections was elevated, even during the rest period, in all areas, suggesting that there is an increase in the activity of histaminergic neurons in hypocretin/ataxin-3 mice following LPS injection. Taken together, our results suggest a novel role for hypocretin in the hypothalamic response to peripheral immune challenge. Our findings contribute to the understanding of the pathophysiology of narcolepsy. Copyright © 2016 Elsevier Inc. All

Zebrafish adult-derived hypothalamic neurospheres generate gonadotropin-releasing hormone (GnRH neurons

Directory of Open Access Journals (Sweden)

Christian Cortés-Campos

2015-09-01

Full Text Available Gonadotropin-releasing hormone (GnRH is a hypothalamic decapeptide essential for fertility in vertebrates. Human male patients lacking GnRH and treated with hormone therapy can remain fertile after cessation of treatment suggesting that new GnRH neurons can be generated during adult life. We used zebrafish to investigate the neurogenic potential of the adult hypothalamus. Previously we have characterized the development of GnRH cells in the zebrafish linking genetic pathways to the differentiation of neuromodulatory and endocrine GnRH cells in specific regions of the brain. Here, we developed a new method to obtain neural progenitors from the adult hypothalamus in vitro. Using this system, we show that neurospheres derived from the adult hypothalamus can be maintained in culture and subsequently differentiate glia and neurons. Importantly, the adult derived progenitors differentiate into neurons containing GnRH and the number of cells is increased through exposure to either testosterone or GnRH, hormones used in therapeutic treatment in humans. Finally, we show in vivo that a neurogenic niche in the hypothalamus contains GnRH positive neurons. Thus, we demonstrated for the first time that neurospheres can be derived from the hypothalamus of the adult zebrafish and that these neural progenitors are capable of producing GnRH containing neurons.

Intelligent neural network diagnostic system

International Nuclear Information System (INIS)

Mohamed, A.H.

2010-01-01

Recently, artificial neural network (ANN) has made a significant mark in the domain of diagnostic applications. Neural networks are used to implement complex non-linear mappings (functions) using simple elementary units interrelated through connections with adaptive weights. The performance of the ANN is mainly depending on their topology structure and weights. Some systems have been developed using genetic algorithm (GA) to optimize the topology of the ANN. But, they suffer from some limitations. They are : (1) The computation time requires for training the ANN several time reaching for the average weight required, (2) Slowness of GA for optimization process and (3) Fitness noise appeared in the optimization of ANN. This research suggests new issues to overcome these limitations for finding optimal neural network architectures to learn particular problems. This proposed methodology is used to develop a diagnostic neural network system. It has been applied for a 600 MW turbo-generator as a case of real complex systems. The proposed system has proved its significant performance compared to two common methods used in the diagnostic applications.

Reduced α-MSH Underlies Hypothalamic ER-Stress-Induced Hepatic Gluconeogenesis.

Science.gov (United States)

Schneeberger, Marc; Gómez-Valadés, Alicia G; Altirriba, Jordi; Sebastián, David; Ramírez, Sara; Garcia, Ainhoa; Esteban, Yaiza; Drougard, Anne; Ferrés-Coy, Albert; Bortolozzi, Analía; Garcia-Roves, Pablo M; Jones, John G; Manadas, Bruno; Zorzano, Antonio; Gomis, Ramon; Claret, Marc

2015-07-21

Alterations in ER homeostasis have been implicated in the pathophysiology of obesity and type-2 diabetes (T2D). Acute ER stress induction in the hypothalamus produces glucose metabolism perturbations. However, the neurobiological basis linking hypothalamic ER stress with abnormal glucose metabolism remains unknown. Here, we report that genetic and induced models of hypothalamic ER stress are associated with alterations in systemic glucose homeostasis due to increased gluconeogenesis (GNG) independent of body weight changes. Defective alpha melanocyte-stimulating hormone (α-MSH) production underlies this metabolic phenotype, as pharmacological strategies aimed at rescuing hypothalamic α-MSH content reversed this phenotype at metabolic and molecular level. Collectively, our results posit defective α-MSH processing as a fundamental mediator of enhanced GNG in the context of hypothalamic ER stress and establish α-MSH deficiency in proopiomelanocortin (POMC) neurons as a potential contributor to the pathophysiology of T2D. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Pathophysiology and clinical characteristics of hypothalamic obesity in children and adolescents

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Ja Hye Kim

2013-12-01

Full Text Available The hypothalamus plays a key role in the regulation of body weight by balancing the intake of food, energy expenditure, and body fat stores, as evidenced by the fact that most monogenic syndromes of morbid obesity result from mutations in genes expressed in the hypothalamus. Hypothalamic obesity is a result of impairment in the hypothalamic regulatory centers of body weight and energy expenditure, and is caused by structural damage to the hypothalamus, radiotherapy, Prader-Willi syndrome, and mutations in the LEP, LEPR, POMC, MC4R and CART genes. The pathophysiology includes loss of sensitivity to afferent peripheral humoral signals, such as leptin, dysregulated insulin secretion, and impaired activity of the sympathetic nervous system. Dysregulation of 11β-hydroxysteroid dehydrogenase 1 activity and melatonin may also have a role in the development of hypothalamic obesity. Intervention of this complex entity requires simultaneous targeting of several mechanisms that are deranged in patients with hypothalamic obesity. Despite a great deal of theoretical understanding, effective treatment for hypothalamic obesity has not yet been developed. Therefore, understanding the mechanisms that control food intake and energy homeostasis and pathophysiology of hypothalamic obesity can be the cornerstone of the development of new treatments options. Early identification of patients at-risk can relieve the severity of weight gain by the provision of dietary and behavioral modification, and antiobesity medication. This review summarizes recent advances of the pathophysiology, endocrine characteristics, and treatment strategies of hypothalamic obesity.

Hypothalamic glucose sensing: making ends meet

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Vanessa eRouth

2014-12-01

Full Text Available The neuroendocrine system governs essential survival and homeostatic functions. For example, growth is needed for development. Thermoregulation maintains optimal core temperature in a changing environment. Reproduction ensures species survival. Stress and immune responses enable an organism to overcome external and internal threats. The circadian system regulates arousal and sleep such that vegetative and active functions do not overlap. All of these functions require a significant portion of the body’s energy. As the integrator of the neuroendocrine system, the hypothalamus carefully assesses the energy status of the body in order to appropriately partition resources to provide for each system without compromising the others. While doing so the hypothalamus must ensure that adequate glucose levels are preserved for brain function since glucose is the primary fuel of the brain. To this end, the hypothalamus contains specialized glucose sensing neurons which are scattered throughout the nuclei controlling distinct neuroendocrine functions. We hypothesize that these neurons play a key role in enabling the hypothalamus to partition energy to meet these peripheral survival needs without endangering the brain’s glucose supply. The goal of this review is to describe the varied mechanisms underlying glucose sensing in neurons within discrete hypothalamic nuclei. We will then evaluate the way in which peripheral energy status regulates glucose sensitivity. For example, during energy deficit such as fasting specific hypothalamic glucose sensing neurons become sensitized to decreased glucose. This increases the gain of the information relay when glucose availability is a greater concern for the brain. Finally, changes in glucose sensitivity under pathological conditions (e.g., recurrent insulin-hypoglycemia, diabetes will be addressed. The overall goal of this review is to place glucose sensing neurons within the context of hypothalamic control of

Hypothalamic dysfunction following whole-brain irradiation

International Nuclear Information System (INIS)

Mechanick, J.I.; Hochberg, F.H.; LaRocque, A.

1986-01-01

The authors describe 15 cases with evidence of hypothalamic dysfunction 2 to 9 years following megavoltage whole-brain x-irradiation for primary glial neoplasm. The patients received 4000 to 5000 rads in 180- to 200-rad fractions. Dysfunction occurred in the absence of computerized tomography-delineated radiation necrosis or hypothalamic invasion by tumor, and antedated the onset of dementia. Fourteen patients displayed symptoms reflecting disturbances of personality, libido, thirst, appetite, or sleep. Hyperprolactinemia (with prolactin levels up to 70 ng/ml) was present in all of the nine patients so tested. Of seven patients tested with thyrotropin-releasing hormone, one demonstrated an abnormal pituitary gland response consistent with a hypothalamic disorder. Seven patients developed cognitive abnormalities. Computerized tomography scans performed a median of 4 years after tumor diagnosis revealed no hypothalamic tumor or diminished density of the hypothalamus. Cortical atrophy was present in 50% of cases and third ventricular dilatation in 58%. Hypothalamic dysfunction, heralded by endocrine, behavioral, and cognitive impairment, represents a common, subtle form of radiation damage

Organization of the sleep-related neural systems in the brain of the minke whale (Balaenoptera acutorostrata).

Science.gov (United States)

Dell, Leigh-Anne; Karlsson, Karl Ae; Patzke, Nina; Spocter, Muhammad A; Siegel, Jerome M; Manger, Paul R

2016-07-01

The current study analyzed the nuclear organization of the neural systems related to the control and regulation of sleep and wake in the basal forebrain, diencephalon, midbrain, and pons of the minke whale, a mysticete cetacean. While odontocete cetaceans sleep in an unusual manner, with unihemispheric slow wave sleep (USWS) and suppressed REM sleep, it is unclear whether the mysticete whales show a similar sleep pattern. Previously, we detailed a range of features in the odontocete brain that appear to be related to odontocete-type sleep, and here present our analysis of these features in the minke whale brain. All neural elements involved in sleep regulation and control found in bihemispheric sleeping mammals and the harbor porpoise were present in the minke whale, with no specific nuclei being absent, and no novel nuclei being present. This qualitative similarity relates to the cholinergic, noradrenergic, serotonergic and orexinergic systems, and the GABAergic elements of these nuclei. Quantitative analysis revealed that the numbers of pontine cholinergic (274,242) and noradrenergic (203,686) neurons, and hypothalamic orexinergic neurons (277,604), are markedly higher than other large-brained bihemispheric sleeping mammals. Small telencephalic commissures (anterior, corpus callosum, and hippocampal), an enlarged posterior commissure, supernumerary pontine cholinergic and noradrenergic cells, and an enlarged peripheral division of the dorsal raphe nuclear complex of the minke whale, all indicate that the suite of neural characteristics thought to be involved in the control of USWS and the suppression of REM in the odontocete cetaceans are present in the minke whale. J. Comp. Neurol. 524:2018-2035, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Inner capillary diameter of hypothalamic paraventricular nucleus of female rat increases during lactation

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Cortés-Sol Albertina

2013-01-01

Full Text Available Abstract Background The role of the endothelial cell (EC in blood flow regulation within the central nervous system has been little studied. Here, we explored EC participation in morphological changes of the anterior hypothalamic paraventricular nucleus (PVN microvasculature of female rats at two reproductive stages with different metabolic demand (virginity and lactation. We measured the inner capillary diameter (ICD of 800 capillaries from either the magnocellular or parvocellular regions. The space occupied by neural (somas, dendrites and axons and glial, but excluding vascular elements of the neurovascular compartment was also measured in 100-μm2 sample fields of both PVN subdivisions. Results The PVN of both groups of animals showed ICDs that ranged from 3 to 10 microns. The virgin group presented mostly capillaries with small ICD, whereas the lactating females exhibited a significant increment in the percentage of capillaries with larger ICD. The space occupied by the neural and glial elements of the neurovascular compartment did not show changes with lactation. Conclusions Our findings suggest that during lactation the microvasculature of the PVN of female rats undergoes dynamic, transitory changes in blood flow as represented by an increment in the ICD through a self-cytoplasmic volume modification reflected by EC changes. A model of this process is proposed.

Neural Control of the Immune System

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Sundman, Eva; Olofsson, Peder S.

2014-01-01

Neural reflexes support homeostasis by modulating the function of organ systems. Recent advances in neuroscience and immunology have revealed that neural reflexes also regulate the immune system. Activation of the vagus nerve modulates leukocyte cytokine production and alleviates experimental shock and autoimmune disease, and recent data have…

Increased hypothalamic serotonin turnover in inflammation-induced anorexia.

Science.gov (United States)

Dwarkasing, J T; Witkamp, R F; Boekschoten, M V; Ter Laak, M C; Heins, M S; van Norren, K

2016-05-20

Anorexia can occur as a serious complication of disease. Increasing evidence suggests that inflammation plays a major role, along with a hypothalamic dysregulation characterized by locally elevated serotonin levels. The present study was undertaken to further explore the connections between peripheral inflammation, anorexia and hypothalamic serotonin metabolism and signaling pathways. First, we investigated the response of two hypothalamic neuronal cell lines to TNFα, IL-6 and LPS. Next, we studied transcriptomic changes and serotonergic activity in the hypothalamus of mice after intraperitoneal injection with TNFα, IL-6 or a combination of TNFα and IL-6. In vitro, we showed that hypothalamic neurons responded to inflammatory mediators by releasing cytokines. This inflammatory response was associated with an increased serotonin release. Mice injected with TNFα and IL-6 showed decreased food intake, associated with altered expression of inflammation-related genes in the hypothalamus. In addition, hypothalamic serotonin turnover showed to be elevated in treated mice. Overall, our results underline that peripheral inflammation reaches the hypothalamus where it affects hypothalamic serotoninergic metabolism. These hypothalamic changes in serotonin pathways are associated with decreased food intake, providing evidence for a role of serotonin in inflammation-induced anorexia.

Neural control of magnetic suspension systems

Science.gov (United States)

Gray, W. Steven

1993-01-01

The purpose of this research program is to design, build and test (in cooperation with NASA personnel from the NASA Langley Research Center) neural controllers for two different small air-gap magnetic suspension systems. The general objective of the program is to study neural network architectures for the purpose of control in an experimental setting and to demonstrate the feasibility of the concept. The specific objectives of the research program are: (1) to demonstrate through simulation and experimentation the feasibility of using neural controllers to stabilize a nonlinear magnetic suspension system; (2) to investigate through simulation and experimentation the performance of neural controllers designs under various types of parametric and nonparametric uncertainty; (3) to investigate through simulation and experimentation various types of neural architectures for real-time control with respect to performance and complexity; and (4) to benchmark in an experimental setting the performance of neural controllers against other types of existing linear and nonlinear compensator designs. To date, the first one-dimensional, small air-gap magnetic suspension system has been built, tested and delivered to the NASA Langley Research Center. The device is currently being stabilized with a digital linear phase-lead controller. The neural controller hardware is under construction. Two different neural network paradigms are under consideration, one based on hidden layer feedforward networks trained via back propagation and one based on using Gaussian radial basis functions trained by analytical methods related to stability conditions. Some advanced nonlinear control algorithms using feedback linearization and sliding mode control are in simulation studies.

Bariatric Surgery in Hypothalamic Obesity

OpenAIRE

Bingham, Nathan C.; Rose, Susan R.; Inge, Thomas H.

2012-01-01

Craniopharyngiomas (CP) are epithelial neoplasms generally found in the area of the pituitary and hypothalamus. Despite benign histology, these tumors and/or their treatment often result in significant, debilitating disorders of endocrine, neurological, behavioral, and metabolic systems. Severe obesity is observed in a high percentage of patients with CP resulting in significant comorbidities and negatively impacting quality of life. Obesity occurs as a result of hypothalamic damage and disru...

Systemic Effects of Hypothermia due to Hypothalamic Dysfunction after Resection of a Craniopharyngioma : Case Report and Review of Literature

NARCIS (Netherlands)

de Vetten, L.; Bocca, Gianni

Objective With this case report, we aim to improve recognition of the systemic effects of hypothermia due to hypothalamic dysfunctioning. We present a patient who developed temperature dysregulation after surgery for craniopharyngioma. He suffered from several episodes of hypothermia associated with

Neural neworks in a management information systems

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Jana Weinlichová

2009-01-01

Full Text Available For having retrospection for all over the data which are used, analyzed, evaluated and for a future incident predictions are used Management Information Systems and Business Intelligence. In case of not to be able to apply standard methods of data processing there can be with benefit applied an Artificial Intelligence. In this article will be referred to proofed abilities of Neural Networks. The Neural Networks is supported by many software products related to provide effective solution of manager issues. Those products are given as primary support for manager issues solving. We were tried to find reciprocally between products using Neural Networks and between Management Information Systems for finding a real possibility of applying Neural Networks as a direct part of Management Information Systems (MIS. In the article are presented possibilities to apply Neural Networks on different types of tasks in MIS.

Collaborative Recurrent Neural Networks forDynamic Recommender Systems

Science.gov (United States)

2016-11-22

JMLR: Workshop and Conference Proceedings 63:366–381, 2016 ACML 2016 Collaborative Recurrent Neural Networks for Dynamic Recommender Systems Young...an unprece- dented scale. Although such activity logs are abundantly available, most approaches to recommender systems are based on the rating...Recurrent Neural Network, Recommender System , Neural Language Model, Collaborative Filtering 1. Introduction As ever larger parts of the population

Spiking Neural P Systems with Communication on Request.

Science.gov (United States)

Pan, Linqiang; Păun, Gheorghe; Zhang, Gexiang; Neri, Ferrante

2017-12-01

Spiking Neural [Formula: see text] Systems are Neural System models characterized by the fact that each neuron mimics a biological cell and the communication between neurons is based on spikes. In the Spiking Neural [Formula: see text] systems investigated so far, the application of evolution rules depends on the contents of a neuron (checked by means of a regular expression). In these [Formula: see text] systems, a specified number of spikes are consumed and a specified number of spikes are produced, and then sent to each of the neurons linked by a synapse to the evolving neuron. [Formula: see text]In the present work, a novel communication strategy among neurons of Spiking Neural [Formula: see text] Systems is proposed. In the resulting models, called Spiking Neural [Formula: see text] Systems with Communication on Request, the spikes are requested from neighboring neurons, depending on the contents of the neuron (still checked by means of a regular expression). Unlike the traditional Spiking Neural [Formula: see text] systems, no spikes are consumed or created: the spikes are only moved along synapses and replicated (when two or more neurons request the contents of the same neuron). [Formula: see text]The Spiking Neural [Formula: see text] Systems with Communication on Request are proved to be computationally universal, that is, equivalent with Turing machines as long as two types of spikes are used. Following this work, further research questions are listed to be open problems.

Hypothalamic-Pituitary-Adrenal Axis Modulation of Glucocorticoids in the Cardiovascular System.

Science.gov (United States)

Burford, Natalie G; Webster, Natalia A; Cruz-Topete, Diana

2017-10-16

The collective of endocrine organs acting in homeostatic regulation-known as the hypothalamic-pituitary-adrenal (HPA) axis-comprises an integration of the central nervous system as well as peripheral tissues. These organs respond to imminent or perceived threats that elicit a stress response, primarily culminating in the release of glucocorticoids into the systemic circulation by the adrenal glands. Although the secretion of glucocorticoids serves to protect and maintain homeostasis in the typical operation at baseline levels, inadequate regulation can lead to physiologic and psychologic pathologies. The cardiovascular system is especially susceptible to prolonged dysregulation of the HPA axis and glucocorticoid production. There is debate about whether cardiovascular health risks arise from the direct detrimental effects of stress axis activation or whether pathologies develop secondary to the accompanying metabolic strain of excess glucocorticoids. In this review, we will explore the emerging research that indicates stress does have direct effects on the cardiovascular system via the HPA axis activation, with emphasis on the latest research on the impact of glucocorticoids signaling in the vasculature and the heart.

Hypothalamic-Pituitary-Adrenal Axis Modulation of Glucocorticoids in the Cardiovascular System

Directory of Open Access Journals (Sweden)

Natalie G. Burford

2017-10-01

Full Text Available The collective of endocrine organs acting in homeostatic regulation—known as the hypothalamic-pituitary-adrenal (HPA axis—comprises an integration of the central nervous system as well as peripheral tissues. These organs respond to imminent or perceived threats that elicit a stress response, primarily culminating in the release of glucocorticoids into the systemic circulation by the adrenal glands. Although the secretion of glucocorticoids serves to protect and maintain homeostasis in the typical operation at baseline levels, inadequate regulation can lead to physiologic and psychologic pathologies. The cardiovascular system is especially susceptible to prolonged dysregulation of the HPA axis and glucocorticoid production. There is debate about whether cardiovascular health risks arise from the direct detrimental effects of stress axis activation or whether pathologies develop secondary to the accompanying metabolic strain of excess glucocorticoids. In this review, we will explore the emerging research that indicates stress does have direct effects on the cardiovascular system via the HPA axis activation, with emphasis on the latest research on the impact of glucocorticoids signaling in the vasculature and the heart.

Stereotaxic approach to hypothalamic nuclei of the shiba goat with radiographic monitoring

International Nuclear Information System (INIS)

Mori, Y.; Takeuchi, Y.; Shimada, M.; Hayashi, S.; Hoshino, K.

1990-01-01

Practical method was devised for precise approach to hypothalamic nuclei in the Shiba goat. A stereotaxic instrument and a brain atlas with stereotaxic coordinates were developed. For an accurate placement of probes into specific hypothalamic regions a radiographic method was employed in which radio-opaque material was injected into the lateral ventricle and the ventricular outline was depicted. A sagittal diagram showing the arrangement of hypothalamic nuclei in relation to the brain ventricular system was constructed from the transverse stereotaxic atlas. This diagram was revealed extremely useful in pinpointing the target on the radiographs of lateral view. Precision of this method was evaluated in female Shiba goats (n = 4) by comparing radiographically estimated positions of hypothalamic nuclei with those histologically determined. Despite of cranial variability among individual animals these two parameters matched well each other in all the nuclei examined. Furthermore, chronic cannulae were implanted into different hypothalamic structures of one goat and the accuracy of their placement was confirmed histologically. Thus, it was revealed that the stereotaxy by aid of radiography herein described was accurate enough to apply to various neuroendocrinological studies in the Shiba goat

Levels of human and rat hypothalamic growth hormone-releasing factor as determined by specific radioimmunoassay systems

International Nuclear Information System (INIS)

Audhya, T.; Manzione, M.M.; Nakane, T.; Kanie, N.; Passarelli, J.; Russo, M.; Hollander, C.S.

1985-01-01

Polyclonal antibodies to synthetic human pancreatic growth hormone-releasing factor [hpGRF(1-44)NH 2 ] and rat hypothalamic growth hormone-releasing factor [rhGRF(1-43)OH] were produced in rabbits. A subsequent booster injection by the conventional intramuscular route resulted in high-titer antibodies, which at a 1:20,000 dilution were used to develop highly sensitive and specific radioimmunoassays for these peptides. The antibody to hpGRF(1-44)NH 2 is directed against the COOH-terminal region of the molecule, as shown by its cross reactivity with various hpGRF analogues. Serial dilutions of human and rat hypothalamic extracts demonstrated parallelism with the corresponding species-specific standard and 125 I-labeled tracer. There was no cross reactivity with other neuropeptides, gastrointestinal peptides, or hypothalamic extracts of other species. Age-related changes in hypothalamic GRF content were present in rats, with a gradual increase from 2 to 16 weeks and a correlation between increasing body weight and GRF content. These radioimmunoassays will serve as important tools for understanding the regulation of growth hormone secretion in both human and rat

Hypothalamic lipophagy and energetic balance

OpenAIRE

Singh, Rajat

2011-01-01

Autophagy is a conserved cellular turnover process that degrades unwanted cytoplasmic material within lysosomes. Through ?in bulk? degradation of cytoplasmic proteins and organelles, including lipid droplets, autophagy helps provide an alternative fuel source, in particular, when nutrients are scarce. Recent work demonstrates a role for autophagy in hypothalamic agouti-related peptide (AgRP) neurons in regulation of food intake and energy balance. The induction of autophagy in hypothalamic ne...

Disrupted-in-Schizophrenia-1 is essential for normal hypothalamic-pituitary-interrenal (HPI) axis function.

Science.gov (United States)

Eachus, Helen; Bright, Charlotte; Cunliffe, Vincent T; Placzek, Marysia; Wood, Jonathan D; Watt, Penelope J

2017-06-01

Psychiatric disorders arise due to an interplay of genetic and environmental factors, including stress. Studies in rodents have shown that mutants for Disrupted-In-Schizophrenia-1 (DISC1), a well-accepted genetic risk factor for mental illness, display abnormal behaviours in response to stress, but the mechanisms through which DISC1 affects stress responses remain poorly understood. Using two lines of zebrafish homozygous mutant for disc1, we investigated behaviour and functioning of the hypothalamic-pituitary-interrenal (HPI) axis, the fish equivalent of the hypothalamic-pituitary-adrenal (HPA) axis. Here, we show that the role of DISC1 in stress responses is evolutionarily conserved and that DISC1 is essential for normal functioning of the HPI axis. Adult zebrafish homozygous mutant for disc1 show aberrant behavioural responses to stress. Our studies reveal that in the embryo, disc1 is expressed in neural progenitor cells of the hypothalamus, a conserved region of the vertebrate brain that centrally controls responses to environmental stressors. In disc1 mutant embryos, proliferating rx3+ hypothalamic progenitors are not maintained normally and neuronal differentiation is compromised: rx3-derived ff1b+ neurons, implicated in anxiety-related behaviours, and corticotrophin releasing hormone (crh) neurons, key regulators of the stress axis, develop abnormally, and rx3-derived pomc+ neurons are disorganised. Abnormal hypothalamic development is associated with dysfunctional behavioural and neuroendocrine stress responses. In contrast to wild type siblings, disc1 mutant larvae show altered crh levels, fail to upregulate cortisol levels when under stress and do not modulate shoal cohesion, indicative of abnormal social behaviour. These data indicate that disc1 is essential for normal development of the hypothalamus and for the correct functioning of the HPA/HPI axis. © The Author 2017. Published by Oxford University Press.

Prokineticin 2 Is a Hypothalamic Neuropeptide That Potently Inhibits Food Intake

OpenAIRE

Gardiner, JV; Bataveljic, A; Patel, NA; Bewick, GA; Roy, D; Campbell, D; Greenwood, HC; Murphy, KG; Hameed, S; Jethwa, PH; Ebling, FJP; Vickers, SP; Cheetham, S; Ghatei, MA; Bloom, SR

2009-01-01

OBJECTIVE Prokineticin 2 (PK2) is a hypothalamic neuropeptide expressed in central nervous system areas known to be involved in food intake. We therefore hypothesized that PK2 plays a role in energy homeostasis. RESEARCH DESIGN AND METHODS We investigated the effect of nutritional status on hypothalamic PK2 expression and effects of PK2 on the regulation of food intake by intracerebroventricular (ICV) injection of PK2 and anti-PK2 antibody. Subsequently, we investigated the potential mechanis...

Genetic learning in rule-based and neural systems

Science.gov (United States)

Smith, Robert E.

1993-01-01

The design of neural networks and fuzzy systems can involve complex, nonlinear, and ill-conditioned optimization problems. Often, traditional optimization schemes are inadequate or inapplicable for such tasks. Genetic Algorithms (GA's) are a class of optimization procedures whose mechanics are based on those of natural genetics. Mathematical arguments show how GAs bring substantial computational leverage to search problems, without requiring the mathematical characteristics often necessary for traditional optimization schemes (e.g., modality, continuity, availability of derivative information, etc.). GA's have proven effective in a variety of search tasks that arise in neural networks and fuzzy systems. This presentation begins by introducing the mechanism and theoretical underpinnings of GA's. GA's are then related to a class of rule-based machine learning systems called learning classifier systems (LCS's). An LCS implements a low-level production-system that uses a GA as its primary rule discovery mechanism. This presentation illustrates how, despite its rule-based framework, an LCS can be thought of as a competitive neural network. Neural network simulator code for an LCS is presented. In this context, the GA is doing more than optimizing and objective function. It is searching for an ecology of hidden nodes with limited connectivity. The GA attempts to evolve this ecology such that effective neural network performance results. The GA is particularly well adapted to this task, given its naturally-inspired basis. The LCS/neural network analogy extends itself to other, more traditional neural networks. Conclusions to the presentation discuss the implications of using GA's in ecological search problems that arise in neural and fuzzy systems.

Course and forecast of the hypothalamic pubertal syndrome

International Nuclear Information System (INIS)

Kayusheva, I.V.

1987-01-01

A total of 223 patients with the hypothalamic pubertal syndrome (HPS) were followed up for 1 to 22 years. The course of HPS was regressive, stable , recurrent or progressive and dependent on the initial depth and spread of hypothalamic lesion, repeated unfavourable hypothalamic exposures, and timely and regular treatment. HPS outcomes were followed up in 190 cases. The recovery was complete in 21.05%, obesity alone persisted in 10.53%, vegetovascular dystonia was persistent in 7.36%, and polycystic ovaries in 5.79%. Neuroendocrine hypothalamic syndrome was the most common (50.53%) HPS outcome. Hormone levels in blood were investigated using radioimmunoassay in patients with neuroendocrine form of HPS

A genetic basis for functional hypothalamic amenorrhea.

Science.gov (United States)

Caronia, Lisa M; Martin, Cecilia; Welt, Corrine K; Sykiotis, Gerasimos P; Quinton, Richard; Thambundit, Apisadaporn; Avbelj, Magdalena; Dhruvakumar, Sadhana; Plummer, Lacey; Hughes, Virginia A; Seminara, Stephanie B; Boepple, Paul A; Sidis, Yisrael; Crowley, William F; Martin, Kathryn A; Hall, Janet E; Pitteloud, Nelly

2011-01-20

Functional hypothalamic amenorrhea is a reversible form of gonadotropin-releasing hormone (GnRH) deficiency commonly triggered by stressors such as excessive exercise, nutritional deficits, or psychological distress. Women vary in their susceptibility to inhibition of the reproductive axis by such stressors, but it is unknown whether this variability reflects a genetic predisposition to hypothalamic amenorrhea. We hypothesized that mutations in genes involved in idiopathic hypogonadotropic hypogonadism, a congenital form of GnRH deficiency, are associated with hypothalamic amenorrhea. We analyzed the coding sequence of genes associated with idiopathic hypogonadotropic hypogonadism in 55 women with hypothalamic amenorrhea and performed in vitro studies of the identified mutations. Six heterozygous mutations were identified in 7 of the 55 patients with hypothalamic amenorrhea: two variants in the fibroblast growth factor receptor 1 gene FGFR1 (G260E and R756H), two in the prokineticin receptor 2 gene PROKR2 (R85H and L173R), one in the GnRH receptor gene GNRHR (R262Q), and one in the Kallmann syndrome 1 sequence gene KAL1 (V371I). No mutations were found in a cohort of 422 controls with normal menstrual cycles. In vitro studies showed that FGFR1 G260E, FGFR1 R756H, and PROKR2 R85H are loss-of-function mutations, as has been previously shown for PROKR2 L173R and GNRHR R262Q. Rare variants in genes associated with idiopathic hypogonadotropic hypogonadism are found in women with hypothalamic amenorrhea, suggesting that these mutations may contribute to the variable susceptibility of women to the functional changes in GnRH secretion that characterize hypothalamic amenorrhea. Our observations provide evidence for the role of rare variants in common multifactorial disease. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT00494169.).

Risk factors for mortality caused by hypothalamic obesity in children with hypothalamic tumours.

Science.gov (United States)

Haliloglu, B; Atay, Z; Guran, T; Abalı, S; Bas, S; Turan, S; Bereket, A

2016-10-01

Hypothalamic obesity (HyOb) is a common complication of childhood hypothalamic tumours. Patients with HyOb probably have a higher mortality rate than those with other types of obesity due in many cases to obstructive sleep apnoea/hypoventilation. To identify predictive factors for mortality caused by HyOb in children. Twenty children with HyOb secondary to hypothalamic tumours that were followed-up for ≥3 years and aged 6 years at diagnosis (3.71 ± 1.96 vs. 0.83 ± 0.73, P  1 SDS after 6 months of therapy (RR: 8.4, P obesity-related mortality rates were higher in the patients aged  0.05). The mortality rate was also 3.7-fold higher in the patients with a maximum BMI SDS ≥ 3 at any time during the first 3 years after therapy(P > 0.05). An increase in BMI SDS after 6 months of therapy was observed to be a risk factor for mortality caused by HyOb. In addition, age obesity is required. © 2015 World Obesity.

Flatfish metamorphosis: a hypothalamic independent process?

Science.gov (United States)

Campinho, Marco A; Silva, Nadia; Roman-Padilla, Javier; Ponce, Marian; Manchado, Manuel; Power, Deborah M

2015-03-15

Anuran and flatfish metamorphosis are tightly regulated by thyroid hormones that are the necessary and sufficient factors that drive this developmental event. In the present study whole mount in situ hybridization (WISH) and quantitative PCR in sole are used to explore the central regulation of flatfish metamorphosis. Central regulation of the thyroid in vertebrates is mediated by the hypothalamus-pituitary-thyroid (HPT) axis. Teleosts diverge from other vertebrates as hypothalamic regulation in the HPT axis is proposed to be through hypothalamic inhibition although the regulatory factor remains enigmatic. The dynamics of the HPT axis during sole metamorphosis revealed integration between the activity of the thyrotrophes in the pituitary and the thyroid follicles. No evidence was found supporting a role for thyroid releasing hormone (trh) or corticotrophin releasing hormone (crh) in hypothalamic control of TH production during sole metamorphosis. Intriguingly the results of the present study suggest that neither hypothalamic trh nor crh expression changes during sole metamorphosis and raises questions about the role of these factors and the hypothalamus in regulation of thyrotrophs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Lack of the central nervous system- and neural crest-expressed forkhead gene Foxs1 affects motor function and body weight.

Science.gov (United States)

Heglind, Mikael; Cederberg, Anna; Aquino, Jorge; Lucas, Guilherme; Ernfors, Patrik; Enerbäck, Sven

2005-07-01

To gain insight into the expression pattern and functional importance of the forkhead transcription factor Foxs1, we constructed a Foxs1-beta-galactosidase reporter gene "knock-in" (Foxs1beta-gal/beta-gal) mouse, in which the wild-type (wt) Foxs1 allele has been inactivated and replaced by a beta-galactosidase reporter gene. Staining for beta-galactosidase activity reveals an expression pattern encompassing neural crest-derived cells, e.g., cranial and dorsal root ganglia as well as several other cell populations in the central nervous system (CNS), most prominently the internal granule layer of cerebellum. Other sites of expression include the lachrymal gland, outer nuclear layer of retina, enteric ganglion neurons, and a subset of thalamic and hypothalamic nuclei. In the CNS, blood vessel-associated smooth muscle cells and pericytes stain positive for Foxs1. Foxs1beta-gal/beta-gal mice perform significantly better (P fat diet, and we speculate that dorsomedial hypothalamic neurons, expressing Foxs1, could play a role in regulating body weight via regulation of sympathetic outflow. In support of this, we observed increased levels of uncoupling protein 1 mRNA in Foxs1beta-gal/beta-gal mice. This points toward a role for Foxs1 in the integration and processing of neuronal signals of importance for energy turnover and motor function.

Organization of the sleep-related neural systems in the brain of the river hippopotamus (Hippopotamus amphibius): A most unusual cetartiodactyl species.

Science.gov (United States)

Dell, Leigh-Anne; Patzke, Nina; Spocter, Muhammad A; Bertelsen, Mads F; Siegel, Jerome M; Manger, Paul R

2016-07-01

This study provides the first systematic analysis of the nuclear organization of the neural systems related to sleep and wake in the basal forebrain, diencephalon, midbrain, and pons of the river hippopotamus, one of the closest extant terrestrial relatives of the cetaceans. All nuclei involved in sleep regulation and control found in other mammals, including cetaceans, were present in the river hippopotamus, with no specific nuclei being absent, but novel features of the cholinergic system, including novel nuclei, were present. This qualitative similarity relates to the cholinergic, noradrenergic, serotonergic, and orexinergic systems and is extended to the γ-aminobutyric acid (GABA)ergic elements of these nuclei. Quantitative analysis reveals that the numbers of pontine cholinergic (259,578) and noradrenergic (127,752) neurons, and hypothalamic orexinergic neurons (68,398) are markedly higher than in other large-brained mammals. These features, along with novel cholinergic nuclei in the intralaminar nuclei of the dorsal thalamus and the ventral tegmental area of the midbrain, as well as a major expansion of the hypothalamic cholinergic nuclei and a large laterodorsal tegmental nucleus of the pons that has both parvocellular and magnocellular cholinergic neurons, indicates an unusual sleep phenomenology for the hippopotamus. Our observations indicate that the hippopotamus is likely to be a bihemispheric sleeper that expresses REM sleep. The novel features of the cholinergic system suggest the presence of an undescribed sleep state in the hippopotamus, as well as the possibility that this animal could, more rapidly than other mammals, switch cortical electroencephalographic activity from one state to another. J. Comp. Neurol. 524:2036-2058, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Cocaine- and amphetamine-regulated transcript is present in hypothalamic neuroendocrine neurones and is released to the hypothalamic-pituitary portal circuit.

Science.gov (United States)

Larsen, P J; Seier, V; Fink-Jensen, A; Holst, J J; Warberg, J; Vrang, N

2003-03-01

Cocaine- and amphetamine-regulated transcript (CART) is present in a number of hypothalamic nuclei. Besides actions in circuits regulating feeding behaviour and stress responses, the hypothalamic functions of CART are largely unknown. We report that CART immunoreactivity is present in hypothalamic neuroendocrine neurones. Adult male rats received a systemic injection of the neuronal tracer Fluorogold (FG) 2 days before fixation, and subsequent double- and triple-labelling immunoflourescence analysis demonstrated that neuroendocrine CART-containing neurones were present in the anteroventral periventricular, supraoptic, paraventricular (PVN) and periventricular nuclei of the hypothalamus. In the PVN, CART-positive neuroendocrine neurones were found in all of cytoarchitectonically identified nuclei. In the periventricular nucleus, approximately one-third of somatostatin cells were also CART-immunoreactive. In the medial parvicellular subnucleus of the PVN, CART and FG coexisted with thyrotrophin-releasing hormone, whereas very few of the corticotrophin-releasing hormone containing cells were CART-immunoreactive. In the arcuate nucleus, CART was extensively colocalized with pro-opiomelanocortin in the ventrolateral part, but completely absent from neuroendocrine neurones of the dorsomedial part. To assess the possible role of CART as a hypothalamic-releasing factor, immunoreactive CART was measured in blood samples from the long portal vessels connecting the median eminence with the anterior pituitary gland. Adult male rats were anaesthetized and the infundibular stalk exposed via a transpharyngeal approach. The long portal vessels were transected and blood collected in 30-min periods (one prestimulatory and three poststimulatory periods). Compared to systemic venous plasma samples, baseline concentrations of immunoreactive CART were elevated in portal plasma. Exposure to sodium nitroprusside hypotension triggered a two-fold elevation of portal CART42

Computed tomography demonstration of a hypothalamic metastasis

International Nuclear Information System (INIS)

Chakeres, D.W.

1983-01-01

This case report describes a patient who presented with panhypopituitarism secondary to hypothalamic metastasis. A primary hypothalamic abnormality was suggested by computed tomographic (CT) demonstration of a small enhancing circular mass centered within the hypothalamus. Sellar radiographs and cerebral angiography were normal. (orig.)

Computed tomography demonstration of a hypothalamic metastasis

Energy Technology Data Exchange (ETDEWEB)

Chakeres, D.W.

1983-05-01

This case report describes a patient who presented with panhypopituitarism secondary to hypothalamic metastasis. A primary hypothalamic abnormality was suggested by computed tomographic (CT) demonstration of a small enhancing circular mass centered within the hypothalamus. Sellar radiographs and cerebral angiography were normal.

Participation of hypothalamic CB1 receptors in reproductive axis disruption during immune challenge.

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Surkin, P N; Di Rosso, M E; Correa, F; Elverdin, J C; Genaro, A M; De Laurentiis, A; Fernández-Solari, J

2017-08-01

Immune challenge inhibits reproductive function and endocannabinoids (eCB) modulate sexual hormones. However, no studies have been performed to assess whether the eCB system mediates the inhibition of hormones that control reproduction as a result of immune system activation during systemic infections. For that reason, we evaluated the participation of the hypothalamic cannabinoid receptor CB1 on the hypothalamic-pituitary-gonadal (HPG) axis activity in rats submitted to immune challenge. Male adult rats were treated i.c.v. administration with a CB1 antagonist/inverse agonist (AM251) (500 ng/5 μL), followed by an i.p. injection of lipopolysaccharide (LPS) (5 mg/kg) 15 minutes later. Plasmatic, hypothalamic and adenohypophyseal pro-inflammatory cytokines, hormones and neuropeptides were assessed 90 or 180 minutes post-LPS. The plasma concentration of tumour necrosis factor α and adenohypophyseal mRNA expression of Tnfα and Il1β increased 90 and 180 minutes post i.p. administration of LPS. However, cytokine mRNA expression in the hypothalamus increased only 180 minutes post-LPS, suggesting an inflammatory delay in this organ. CB1 receptor blockade with AM251 increased LPS inflammatory effects, particularly in the hypothalamus. LPS also inhibited the HPG axis by decreasing gonadotrophin-releasing hormone hypothalamic content and plasma levels of luteinising hormone and testosterone. These disruptor effects were accompanied by decreased hypothalamic Kiss1 mRNA expression and prostaglandin E2 content, as well as by increased gonadotrophin-inhibitory hormone (Rfrp3) mRNA expression. All these disruptive effects were prevented by the presence of AM251. In summary, our results suggest that, in male rats, eCB mediate immune challenge-inhibitory effects on reproductive axis at least partially via hypothalamic CB1 activation. In addition, this receptor also participates in homeostasis recovery by modulating the inflammatory process taking place after LPS

Regulation of hypothalamic NPY by diet and smoking.

Science.gov (United States)

Chen, Hui; Hansen, Michelle J; Jones, Jessica E; Vlahos, Ross; Bozinovski, Steve; Anderson, Gary P; Morris, Margaret J

2007-02-01

Appetite is regulated by a number of hypothalamic neuropeptides including neuropeptide Y (NPY), a powerful feeding stimulator that responds to feeding status, and drugs such as nicotine and cannabis. There is debate regarding the extent of the influence of obesity on hypothalamic NPY. We measured hypothalamic NPY in male Sprague-Dawley rats after short or long term exposure to cafeteria-style high fat diet (32% energy as fat) or laboratory chow (12% fat). Caloric intake and body weight were increased in the high fat diet group, and brown fat and white fat masses were significantly increased after 2 weeks. Hypothalamic NPY concentration was only significantly decreased after long term consumption of the high fat diet. Nicotine decreases food intake and body weight, with conflicting effects on hypothalamic NPY reported. Body weight, plasma hormones and brain NPY were investigated in male Balb/c mice exposed to cigarette smoke for 4 days, 4 and 12 weeks. Food intake was significantly decreased by smoke exposure (2.32+/-0.03g/24h versus 2.71+/-0.04g/24h in control mice (non-smoke exposed) at 12 weeks). Relative to control mice, smoke exposure led to greater weight loss, while pair-feeding the equivalent amount of chow caused an intermediate weight loss. Chronic smoke exposure, but not pair-feeding, was associated with decreased hypothalamic NPY concentration, suggesting an inhibitory effect of cigarette smoking on brain NPY levels. Thus, consumption of a high fat diet and smoke exposure reprogram hypothalamic NPY. Reduced NPY may contribute to the anorexic effect of smoke exposure.

Use of cognitive behavior therapy for functional hypothalamic amenorrhea.

Science.gov (United States)

Berga, Sarah L; Loucks, Tammy L

2006-12-01

Behaviors that chronically activate the hypothalamic-pituitary-adrenal (HPA) axis and/or suppress the hypothalamic-pituitary-thyroidal (HPT) axis disrupt the hypothalamic-pituitary-gonadal axis in women and men. Individuals with functional hypothalamic hypogonadism typically engage in a combination of behaviors that concomitantly heighten psychogenic stress and increase energy demand. Although it is not widely recognized clinically, functional forms of hypothalamic hypogonadism are more than an isolated disruption of gonadotropin-releasing hormone (GnRH) drive and reproductive compromise. Indeed, women with functional hypothalamic amenorrhea display a constellation of neuroendocrine aberrations that reflect allostatic adjustments to chronic stress. Given these considerations, we have suggested that complete neuroendocrine recovery would involve more than reproductive recovery. Hormone replacement strategies have limited benefit because they do not ameliorate allostatic endocrine adjustments, particularly the activation of the adrenal and the suppression of the thyroidal axes. Indeed, the rationale for the use of sex steroid replacement is based on the erroneous assumption that functional forms of hypothalamic hypogonadism represent only or primarily an alteration in the hypothalamic-pituitary-gonadal axis. Potential health consequences of functional hypothalamic amenorrhea, often termed stress-induced anovulation, may include an increased risk of cardiovascular disease, osteoporosis, depression, other psychiatric conditions, and dementia. Although fertility can be restored with exogenous administration of gonadotropins or pulsatile GnRH, fertility management alone will not permit recovery of the adrenal and thyroidal axes. Initiating pregnancy with exogenous means without reversing the hormonal milieu induced by chronic stress may increase the likelihood of poor obstetrical, fetal, or neonatal outcomes. In contrast, behavioral and psychological interventions that

Dietary sugars, not lipids, drive hypothalamic inflammation

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Yuanqing Gao

2017-08-01

Conclusions: Combined overconsumption of fat and sugar, but not the overconsumption of fat per se, leads to excessive CML production in hypothalamic neurons, which, in turn, stimulates hypothalamic inflammatory responses such as microgliosis and eventually leads to neuronal dysfunction in the control of energy metabolism.

Hypothalamic BOLD response to glucose intake and hypothalamic volume are similar in anorexia nervosa and healthy control subjects

Directory of Open Access Journals (Sweden)

Anna M Van Opstal

2015-05-01

Full Text Available Background. Inconsistent findings about the neurobiology of Anorexia Nervosa (AN hinder the development of effective treatments for this severe mental disorder. Therefore the need arises for elucidation of neurobiological factors involved in the pathophysiology of AN. The hypothalamus plays a key role in the neurobiological processes that govern food intake and energy homeostasis, processes that are disturbed in anorexia nervosa (AN. The present study will assess the hypothalamic response to energy intake and the hypothalamic structure in patients with AN and healthy controls. Methods. 10 women aged 18-30 years diagnosed with AN and 11 healthy, lean (BMI <23 kg/m2 women in the same age range were recruited. We used functional magnetic resonance imaging (MRI to determine function of the hypothalamus in response to glucose. Structural MRI was used to determine differences in hypothalamic volume and local grey volume using manual segmentation and voxel-based morphometry.Results. No differences were found in hypothalamic volume and neuronal activity in response to a glucose load between the patients and controls. Whole brain structural analysis showed a significant decrease in grey matter volume in the cingulate cortex in the AN patients, bilaterally.Conclusions. We argue that in spite of various known changes in the hypothalamus the direct hypothalamic response to glucose intake is similar in AN patients and healthy controls.

Approaches Mediating Oxytocin Regulation of the Immune System.

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Li, Tong; Wang, Ping; Wang, Stephani C; Wang, Yu-Feng

2016-01-01

The hypothalamic neuroendocrine system is mainly composed of the neural structures regulating hormone secretion from the pituitary gland and has been considered as the higher regulatory center of the immune system. Recently, the hypothalamo-neurohypophysial system (HNS) emerged as an important component of neuroendocrine-immune network, wherein the oxytocin (OT)-secreting system (OSS) plays an essential role. The OSS, consisting of OT neurons in the supraoptic nucleus, paraventricular nucleus, their several accessory nuclei and associated structures, can integrate neural, endocrine, metabolic, and immune information and plays a pivotal role in the development and functions of the immune system. The OSS can promote the development of thymus and bone marrow, perform immune surveillance, strengthen immune defense, and maintain immune homeostasis. Correspondingly, OT can inhibit inflammation, exert antibiotic-like effect, promote wound healing and regeneration, and suppress stress-associated immune disorders. In this process, the OSS can release OT to act on immune system directly by activating OT receptors or through modulating activities of other hypothalamic-pituitary-immune axes and autonomic nervous system indirectly. However, our understandings of the role of the OSS in neuroendocrine regulation of immune system are largely incomplete, particularly its relationship with other hypothalamic-pituitary-immune axes and the vasopressin-secreting system that coexists with the OSS in the HNS. In addition, it remains unclear about the relationship between the OSS and peripherally produced OT in immune regulation, particularly intrathymic OT that is known to elicit central immunological self-tolerance of T-cells to hypophysial hormones. In this work, we provide a brief review of current knowledge of the features of OSS regulation of the immune system and of potential approaches that mediate OSS coordination of the activities of entire neuroendocrine-immune network.

Exercise protects against high-fat diet-induced hypothalamic inflammation

NARCIS (Netherlands)

Yi, Chun-Xia; Al-Massadi, Omar; Donelan, Elizabeth; Lehti, Maarit; Weber, Jon; Ress, Chandler; Trivedi, Chitrang; Müller, Timo D.; Woods, Stephen C.; Hofmann, Susanna M.

2012-01-01

Hypothalamic inflammation is a potentially important process in the pathogenesis of high-fat diet-induced metabolic disorders that has recently received significant attention. Microglia are macrophage-like cells of the central nervous system which are activated by pro-inflammatory signals causing

System and method for determining stability of a neural system

Science.gov (United States)

Curtis, Steven A. (Inventor)

2011-01-01

Disclosed are methods, systems, and computer-readable media for determining stability of a neural system. The method includes tracking a function world line of an N element neural system within at least one behavioral space, determining whether the tracking function world line is approaching a psychological stability surface, and implementing a quantitative solution that corrects instability if the tracked function world line is approaching the psychological stability surface.

A Genetic Basis for Functional Hypothalamic Amenorrhea

Science.gov (United States)

Caronia, Lisa M.; Martin, Cecilia; Welt, Corrine K.; Sykiotis, Gerasimos P.; Quinton, Richard; Thambundit, Apisadaporn; Avbelj, Magdalena; Dhruvakumar, Sadhana; Plummer, Lacey; Hughes, Virginia A.; Seminara, Stephanie B.; Boepple, Paul A.; Sidis, Yisrael; Crowley, William F.; Martin, Kathryn A.; Hall, Janet E.; Pitteloud, Nelly

2011-01-01

BACKGROUND Functional hypothalamic amenorrhea is a reversible form of gonadotropin-releasing hormone (GnRH) deficiency commonly triggered by stressors such as excessive exercise, nutritional deficits, or psychological distress. Women vary in their susceptibility to inhibition of the reproductive axis by such stressors, but it is unknown whether this variability reflects a genetic predisposition to hypothalamic amenorrhea. We hypothesized that mutations in genes involved in idiopathic hypogonadotropic hypogonadism, a congenital form of GnRH deficiency, are associated with hypothalamic amenorrhea. METHODS We analyzed the coding sequence of genes associated with idiopathic hypogonadotropic hypogonadism in 55 women with hypothalamic amenorrhea and performed in vitro studies of the identified mutations. RESULTS Six heterozygous mutations were identified in 7 of the 55 patients with hypothalamic amenorrhea: two variants in the fibroblast growth factor receptor 1 gene FGFR1 (G260E and R756H), two in the prokineticin receptor 2 gene PROKR2 (R85H and L173R), one in the GnRH receptor gene GNRHR (R262Q), and one in the Kall-mann syndrome 1 sequence gene KAL1 (V371I). No mutations were found in a cohort of 422 controls with normal menstrual cycles. In vitro studies showed that FGFR1 G260E, FGFR1 R756H, and PROKR2 R85H are loss-of-function mutations, as has been previously shown for PROKR2 L173R and GNRHR R262Q. CONCLUSIONS Rare variants in genes associated with idiopathic hypogonadotropic hypogonadism are found in women with hypothalamic amenorrhea, suggesting that these mutations may contribute to the variable susceptibility of women to the functional changes in GnRH secretion that characterize hypothalamic amenorrhea. Our observations provide evidence for the role of rare variants in common multifactorial disease. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT00494169.) PMID:21247312

Craniopharyngioma and hypothalamic injury: latest insights into consequent eating disorders and obesity

Science.gov (United States)

Müller, Hermann L.

2016-01-01

Purpose of review Hypothalamic alterations, pathological or treatment induced, have major impact on prognosis in craniopharyngioma patients mainly because of consequent hypothalamic obesity. Recent insight in molecular genetics, treatment strategies, risk factors and outcomes associated with hypothalamic obesity provide novel therapeutic perspectives. This review includes relevant publications since 2013. Recent findings Recent findings confirm that alterations in posterior hypothalamic areas because of tumour location and/or treatment-related injuries are associated with severe hypothalamic obesity, reduced overall survival and impaired quality of life in long-term survivors of childhood-onset craniopharyngioma. However, eating disorders are observed because of hypothalamic obesity without clear disease-specific patterns. Treatment options for hypothalamic obesity are very limited. Treatment with invasive, nonreversible bariatric methods such as Roux-en-Y gastric bypass is most efficient in weight reduction, but controversial in the paediatric population because of medical, ethical, and legal considerations. Accordingly, treatment in craniopharyngioma should focus on prevention of (further) hypothalamic injury. Presurgical imaging for grading of hypothalamic involvement should be the basis for hypothalamus-sparing strategies conducted by experienced multidisciplinary teams. Summary Until a nonsurgical therapeutic option for hypothalamic obesity for paediatric patients is found, prevention of hypothalamic injury should be the preferred treatment strategy, conducted exclusively by experienced multidisciplinary teams. PMID:26574645

Efferent connections from the lateral hypothalamic region and the lateral preoptic area to the hypothalamic paraventricular nucleus of the rat

DEFF Research Database (Denmark)

Larsen, P J; Hay-Schmidt, Anders; Mikkelsen, J D

1994-01-01

, iontophoretic injections of the anterograde tracer Phaseolus vulgaris-leucoagglutinin were delivered into distinct areas of the lateral hypothalamic region. Neurons of the intermediate hypothalamic area projected mainly to the PVN subnuclei, which contained parvicellular neuroendocrine cells. In contrast...

Hypothalamic Obesity in Craniopharyngioma Patients: Disturbed Energy Homeostasis Related to Extent of Hypothalamic Damage and Its Implication for Obesity Intervention

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Christian L. Roth

2015-09-01

Full Text Available Hypothalamic obesity (HO occurs in patients with tumors and lesions in the medial hypothalamic region. Hypothalamic dysfunction can lead to hyperinsulinemia and leptin resistance. This review is focused on HO caused by craniopharyngiomas (CP, which are the most common childhood brain tumors of nonglial origin. Despite excellent overall survival rates, CP patients have substantially reduced quality of life because of significant long-term sequelae, notably severe obesity in about 50% of patients, leading to a high rate of cardiovascular mortality. Recent studies reported that both hyperphagia and decreased energy expenditure can contribute to severe obesity in HO patients. Recognized risk factors for severe obesity include large hypothalamic tumors or lesions affecting several medial and posterior hypothalamic nuclei that impact satiety signaling pathways. Structural damage in these nuclei often lead to hyperphagia, rapid weight gain, central insulin and leptin resistance, decreased sympathetic activity, low energy expenditure, and increased energy storage in adipose tissue. To date, most efforts to treat HO have shown disappointing long-term success rates. However, treatments based on the distinct pathophysiology of disturbed energy homeostasis related to CP may offer options for successful interventions in the future.

PWR system simulation and parameter estimation with neural networks

Energy Technology Data Exchange (ETDEWEB)

Akkurt, Hatice; Colak, Uener E-mail: uc@nuke.hacettepe.edu.tr

2002-11-01

A detailed nonlinear model for a typical PWR system has been considered for the development of simulation software. Each component in the system has been represented by appropriate differential equations. The SCILAB software was used for solving nonlinear equations to simulate steady-state and transient operational conditions. Overall system has been constructed by connecting individual components to each other. The validity of models for individual components and overall system has been verified. The system response against given transients have been analyzed. A neural network has been utilized to estimate system parameters during transients. Different transients have been imposed in training and prediction stages with neural networks. Reactor power and system reactivity during the transient event have been predicted by the neural network. Results show that neural networks estimations are in good agreement with the calculated response of the reactor system. The maximum errors are within {+-}0.254% for power and between -0.146 and 0.353% for reactivity prediction cases. Steam generator parameters, pressure and water level, are also successfully predicted by the neural network employed in this study. The noise imposed on the input parameters of the neural network deteriorates the power estimation capability whereas the reactivity estimation capability is not significantly affected.

PWR system simulation and parameter estimation with neural networks

International Nuclear Information System (INIS)

Akkurt, Hatice; Colak, Uener

2002-01-01

A detailed nonlinear model for a typical PWR system has been considered for the development of simulation software. Each component in the system has been represented by appropriate differential equations. The SCILAB software was used for solving nonlinear equations to simulate steady-state and transient operational conditions. Overall system has been constructed by connecting individual components to each other. The validity of models for individual components and overall system has been verified. The system response against given transients have been analyzed. A neural network has been utilized to estimate system parameters during transients. Different transients have been imposed in training and prediction stages with neural networks. Reactor power and system reactivity during the transient event have been predicted by the neural network. Results show that neural networks estimations are in good agreement with the calculated response of the reactor system. The maximum errors are within ±0.254% for power and between -0.146 and 0.353% for reactivity prediction cases. Steam generator parameters, pressure and water level, are also successfully predicted by the neural network employed in this study. The noise imposed on the input parameters of the neural network deteriorates the power estimation capability whereas the reactivity estimation capability is not significantly affected

Integrated Neural Flight and Propulsion Control System

Science.gov (United States)

Kaneshige, John; Gundy-Burlet, Karen; Norvig, Peter (Technical Monitor)

2001-01-01

This paper describes an integrated neural flight and propulsion control system. which uses a neural network based approach for applying alternate sources of control power in the presence of damage or failures. Under normal operating conditions, the system utilizes conventional flight control surfaces. Neural networks are used to provide consistent handling qualities across flight conditions and for different aircraft configurations. Under damage or failure conditions, the system may utilize unconventional flight control surface allocations, along with integrated propulsion control, when additional control power is necessary for achieving desired flight control performance. In this case, neural networks are used to adapt to changes in aircraft dynamics and control allocation schemes. Of significant importance here is the fact that this system can operate without emergency or backup flight control mode operations. An additional advantage is that this system can utilize, but does not require, fault detection and isolation information or explicit parameter identification. Piloted simulation studies were performed on a commercial transport aircraft simulator. Subjects included both NASA test pilots and commercial airline crews. Results demonstrate the potential for improving handing qualities and significantly increasing survivability rates under various simulated failure conditions.

Increasing fatty acid oxidation remodels the hypothalamic neurometabolome to mitigate stress and inflammation.

Directory of Open Access Journals (Sweden)

Joseph W McFadden

Full Text Available Modification of hypothalamic fatty acid (FA metabolism can improve energy homeostasis and prevent hyperphagia and excessive weight gain in diet-induced obesity (DIO from a diet high in saturated fatty acids. We have shown previously that C75, a stimulator of carnitine palmitoyl transferase-1 (CPT-1 and fatty acid oxidation (FAOx, exerts at least some of its hypophagic effects via neuronal mechanisms in the hypothalamus. In the present work, we characterized the effects of C75 and another anorexigenic compound, the glycerol-3-phosphate acyltransferase (GPAT inhibitor FSG67, on FA metabolism, metabolomics profiles, and metabolic stress responses in cultured hypothalamic neurons and hypothalamic neuronal cell lines during lipid excess with palmitate. Both compounds enhanced palmitate oxidation, increased ATP, and inactivated AMP-activated protein kinase (AMPK in hypothalamic neurons in vitro. Lipidomics and untargeted metabolomics revealed that enhanced catabolism of FA decreased palmitate availability and prevented the production of fatty acylglycerols, ceramides, and cholesterol esters, lipids that are associated with lipotoxicity-provoked metabolic stress. This improved metabolic signature was accompanied by increased levels of reactive oxygen species (ROS, and yet favorable changes in oxidative stress, overt ER stress, and inflammation. We propose that enhancing FAOx in hypothalamic neurons exposed to excess lipids promotes metabolic remodeling that reduces local inflammatory and cell stress responses. This shift would restore mitochondrial function such that increased FAOx can produce hypothalamic neuronal ATP and lead to decreased food intake and body weight to improve systemic metabolism.

The Effects of GABAergic Polarity Changes on Episodic Neural Network Activity in Developing Neural Systems

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Wilfredo Blanco

2017-09-01

Full Text Available Early in development, neural systems have primarily excitatory coupling, where even GABAergic synapses are excitatory. Many of these systems exhibit spontaneous episodes of activity that have been characterized through both experimental and computational studies. As development progress the neural system goes through many changes, including synaptic remodeling, intrinsic plasticity in the ion channel expression, and a transformation of GABAergic synapses from excitatory to inhibitory. What effect each of these, and other, changes have on the network behavior is hard to know from experimental studies since they all happen in parallel. One advantage of a computational approach is that one has the ability to study developmental changes in isolation. Here, we examine the effects of GABAergic synapse polarity change on the spontaneous activity of both a mean field and a neural network model that has both glutamatergic and GABAergic coupling, representative of a developing neural network. We find some intuitive behavioral changes as the GABAergic neurons go from excitatory to inhibitory, shared by both models, such as a decrease in the duration of episodes. We also find some paradoxical changes in the activity that are only present in the neural network model. In particular, we find that during early development the inter-episode durations become longer on average, while later in development they become shorter. In addressing this unexpected finding, we uncover a priming effect that is particularly important for a small subset of neurons, called the “intermediate neurons.” We characterize these neurons and demonstrate why they are crucial to episode initiation, and why the paradoxical behavioral change result from priming of these neurons. The study illustrates how even arguably the simplest of developmental changes that occurs in neural systems can present non-intuitive behaviors. It also makes predictions about neural network behavioral changes

Diagnostic Neural Network Systems for the Electronic Circuits

International Nuclear Information System (INIS)

Mohamed, A.H.

2014-01-01

Neural Networks is one of the most important artificial intelligent approaches for solving the diagnostic processes. This research concerns with uses the neural networks for diagnosis of the electronic circuits. Modern electronic systems contain both the analog and digital circuits. But, diagnosis of the analog circuits suffers from great complexity due to their nonlinearity. To overcome this problem, the proposed system introduces a diagnostic system that uses the neural network to diagnose both the digital and analog circuits. So, it can face the new requirements for the modern electronic systems. A fault dictionary method was implemented in the system. Experimental results are presented on three electronic systems. They are: artificial kidney, wireless network and personal computer systems. The proposed system has improved the performance of the diagnostic systems when applied for these practical cases

Anomalous hypothalamic responses to humor in cataplexy.

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Allan L Reiss

2008-05-01

Full Text Available Cataplexy is observed in a subset of patients with narcolepsy and affects approximately 1 in 2,000 persons. Cataplexy is most often triggered by strong emotions such as laughter, which can result in transient, yet debilitating, muscle atonia. The objective of this study was to examine the neural systems underlying humor processing in individuals with cataplexy.While undergoing functional Magnetic Resonance Imaging (fMRI, we showed ten narcolepsy-cataplexy patients and ten healthy controls humorous cartoons. In addition, we examined the brain activity of one subject while in a full-blown cataplectic attack. Behavioral results showed that participants with cataplexy rated significantly fewer humorous cartoons as funny compared to controls. Concurrent fMRI showed that patients, when compared to controls and in the absence of overt cataplexy symptoms, showed pronounced activity in the emotional network including the ventral striatum and hypothalamus while viewing humorous versus non-humorous cartoons. Increased activity was also observed in the right inferior frontal gyri--a core component of the inhibitory circuitry. In comparison, the one subject who experienced a cataplectic attack showed dramatic reductions in hypothalamic activity.These findings suggest an overdrive of the emotional circuitry and possible compensatory suppression by cortical inhibitory regions in cataplexy. Moreover, during cataplectic attacks, the hypothalamus is characterized by a marked decrease in activity similar to that observed during sleep. One possible explanation for these findings is an initial overdrive and compensatory shutdown of the hypothalamus resulting in full cataplectic symptoms.

Hypothalamic stem cells control ageing speed partly through exosomal miRNAs.

Science.gov (United States)

Zhang, Yalin; Kim, Min Soo; Jia, Baosen; Yan, Jingqi; Zuniga-Hertz, Juan Pablo; Han, Cheng; Cai, Dongsheng

2017-08-03

It has been proposed that the hypothalamus helps to control ageing, but the mechanisms responsible remain unclear. Here we develop several mouse models in which hypothalamic stem/progenitor cells that co-express Sox2 and Bmi1 are ablated, as we observed that ageing in mice started with a substantial loss of these hypothalamic cells. Each mouse model consistently displayed acceleration of ageing-like physiological changes or a shortened lifespan. Conversely, ageing retardation and lifespan extension were achieved in mid-aged mice that were locally implanted with healthy hypothalamic stem/progenitor cells that had been genetically engineered to survive in the ageing-related hypothalamic inflammatory microenvironment. Mechanistically, hypothalamic stem/progenitor cells contributed greatly to exosomal microRNAs (miRNAs) in the cerebrospinal fluid, and these exosomal miRNAs declined during ageing, whereas central treatment with healthy hypothalamic stem/progenitor cell-secreted exosomes led to the slowing of ageing. In conclusion, ageing speed is substantially controlled by hypothalamic stem cells, partially through the release of exosomal miRNAs.

Analysis of complex systems using neural networks

International Nuclear Information System (INIS)

Uhrig, R.E.

1992-01-01

The application of neural networks, alone or in conjunction with other advanced technologies (expert systems, fuzzy logic, and/or genetic algorithms), to some of the problems of complex engineering systems has the potential to enhance the safety, reliability, and operability of these systems. Typically, the measured variables from the systems are analog variables that must be sampled and normalized to expected peak values before they are introduced into neural networks. Often data must be processed to put it into a form more acceptable to the neural network (e.g., a fast Fourier transformation of the time-series data to produce a spectral plot of the data). Specific applications described include: (1) Diagnostics: State of the Plant (2) Hybrid System for Transient Identification, (3) Sensor Validation, (4) Plant-Wide Monitoring, (5) Monitoring of Performance and Efficiency, and (6) Analysis of Vibrations. Although specific examples described deal with nuclear power plants or their subsystems, the techniques described can be applied to a wide variety of complex engineering systems

Neural network-based model reference adaptive control system.

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Patino, H D; Liu, D

2000-01-01

In this paper, an approach to model reference adaptive control based on neural networks is proposed and analyzed for a class of first-order continuous-time nonlinear dynamical systems. The controller structure can employ either a radial basis function network or a feedforward neural network to compensate adaptively the nonlinearities in the plant. A stable controller-parameter adjustment mechanism, which is determined using the Lyapunov theory, is constructed using a sigma-modification-type updating law. The evaluation of control error in terms of the neural network learning error is performed. That is, the control error converges asymptotically to a neighborhood of zero, whose size is evaluated and depends on the approximation error of the neural network. In the design and analysis of neural network-based control systems, it is important to take into account the neural network learning error and its influence on the control error of the plant. Simulation results showing the feasibility and performance of the proposed approach are given.

Hypothalamic amenorrhea. The effects of environmental stresses on the reproductive system: a central effect of the central nervous system.

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Warren, M P; Fried, J L

2001-09-01

Although the treatment of anovulation has become significantly more specialized and complex in the centuries since Hippocrates, a complete understanding of the causes and mechanisms of hypothalamic amenorrhea has not been achieved. Even the best research on hypothalamic amenorrhea is plagued by the lack of longitudinal studies, the use of different exercise models, the difficulty of controlling for caloric intake, and the fact that genetics may have a role in the disorder. Continuing research on metabolic rate, leptin, and other factors will ultimately answer many of the outstanding questions and will help to create better tools for treating this disorder.

Role of developmental factors in hypothalamic function

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Jakob eBiran

2015-04-01

Full Text Available The hypothalamus is a brain region which regulates homeostasis by mediating endocrine, autonomic and behavioral functions. It is comprised of several nuclei containing distinct neuronal populations producing neuropeptides and neurotransmitters that regulate fundamental body functions including temperature and metabolic rate, thirst and hunger, sexual behavior and reproduction, circadian rhythm, and emotional responses. The identity, number and connectivity of these neuronal populations are established during the organism’s development and are of crucial importance for normal hypothalamic function. Studies have suggested that developmental abnormalities in specific hypothalamic circuits can lead to obesity, sleep disorders, anxiety, depression and autism. At the molecular level, the development of the hypothalamus is regulated by transcription factors, secreted growth factors, neuropeptides and their receptors. Recent studies in zebrafish and mouse have demonstrated that some of these molecules maintain their expression in the adult brain and subsequently play a role in the physiological functions that are regulated by hypothalamic neurons. Here, we summarize the involvement of some of the key developmental factors in hypothalamic development and function by focusing on the mouse and zebrafish genetic model organisms.

An updated view of hypothalamic-vascular-pituitary unit function and plasticity.

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Le Tissier, Paul; Campos, Pauline; Lafont, Chrystel; Romanò, Nicola; Hodson, David J; Mollard, Patrice

2017-05-01

The discoveries of novel functional adaptations of the hypothalamus and anterior pituitary gland for physiological regulation have transformed our understanding of their interaction. The activity of a small proportion of hypothalamic neurons can control complex hormonal signalling, which is disconnected from a simple stimulus and the subsequent hormone secretion relationship and is dependent on physiological status. The interrelationship of the terminals of hypothalamic neurons and pituitary cells with the vasculature has an important role in determining the pattern of neurohormone exposure. Cells in the pituitary gland form networks with distinct organizational motifs that are related to the duration and pattern of output, and modifications of these networks occur in different physiological states, can persist after cessation of demand and result in enhanced function. Consequently, the hypothalamus and pituitary can no longer be considered as having a simple stratified relationship: with the vasculature they form a tripartite system, which must function in concert for appropriate hypothalamic regulation of physiological processes, such as reproduction. An improved understanding of the mechanisms underlying these regulatory features has implications for current and future therapies that correct defects in hypothalamic-pituitary axes. In addition, recapitulating proper network organization will be an important challenge for regenerative stem cell treatment.

Bio-inspired spiking neural network for nonlinear systems control.

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Pérez, Javier; Cabrera, Juan A; Castillo, Juan J; Velasco, Juan M

2018-08-01

Spiking neural networks (SNN) are the third generation of artificial neural networks. SNN are the closest approximation to biological neural networks. SNNs make use of temporal spike trains to command inputs and outputs, allowing a faster and more complex computation. As demonstrated by biological organisms, they are a potentially good approach to designing controllers for highly nonlinear dynamic systems in which the performance of controllers developed by conventional techniques is not satisfactory or difficult to implement. SNN-based controllers exploit their ability for online learning and self-adaptation to evolve when transferred from simulations to the real world. SNN's inherent binary and temporary way of information codification facilitates their hardware implementation compared to analog neurons. Biological neural networks often require a lower number of neurons compared to other controllers based on artificial neural networks. In this work, these neuronal systems are imitated to perform the control of non-linear dynamic systems. For this purpose, a control structure based on spiking neural networks has been designed. Particular attention has been paid to optimizing the structure and size of the neural network. The proposed structure is able to control dynamic systems with a reduced number of neurons and connections. A supervised learning process using evolutionary algorithms has been carried out to perform controller training. The efficiency of the proposed network has been verified in two examples of dynamic systems control. Simulations show that the proposed control based on SNN exhibits superior performance compared to other approaches based on Neural Networks and SNNs. Copyright © 2018 Elsevier Ltd. All rights reserved.

A sexually dimorphic hypothalamic response to chronic high-fat diet consumption.

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Morselli, E; Frank, A P; Palmer, B F; Rodriguez-Navas, C; Criollo, A; Clegg, D J

2016-02-01

In this review, we discuss the observations that, following chronic high-fat diet (HFD) exposure, male mice have higher levels of saturated fatty acids (FAs) and total sphingolipids, whereas lower amounts of polyunsaturated FAs in the central nervous system (CNS) than females. Furthermore, males, when compared with female mice, have higher levels of inflammatory markers in the hypothalamus following exposure to HFD. The increase in markers of inflammation in male mice is possibly due to the reductions in proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) and estrogen receptor alpha (ERα), which is not recapitulated in female mice. Consistently, hypothalamic inflammation is induced both in male and female ERα total-body knockout mice when exposed to a HFD, thus confirming the key role of ERα in the regulation of HFD-induced hypothalamic inflammation. Finally, the HFD-induced depletion of hypothalamic ERα is associated with dysregulation in metabolic homeostasis, as evidenced by reductions in glucose tolerance and decrements in myocardial function.

Hepatic Branch Vagus Nerve Plays a Critical Role in the Recovery of Post-Ischemic Glucose Intolerance and Mediates a Neuroprotective Effect by Hypothalamic Orexin-A

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Harada, Shinichi; Yamazaki, Yui; Koda, Shuichi; Tokuyama, Shogo

2014-01-01

Orexin-A (a neuropeptide in the hypothalamus) plays an important role in many physiological functions, including the regulation of glucose metabolism. We have previously found that the development of post-ischemic glucose intolerance is one of the triggers of ischemic neuronal damage, which is suppressed by hypothalamic orexin-A. Other reports have shown that the communication system between brain and peripheral tissues through the autonomic nervous system (sympathetic, parasympathetic and vagus nerve) is important for maintaining glucose and energy metabolism. The aim of this study was to determine the involvement of the hepatic vagus nerve on hypothalamic orexin-A-mediated suppression of post-ischemic glucose intolerance development and ischemic neuronal damage. Male ddY mice were subjected to middle cerebral artery occlusion (MCAO) for 2 h. Intrahypothalamic orexin-A (5 pmol/mouse) administration significantly suppressed the development of post-ischemic glucose intolerance and neuronal damage on day 1 and 3, respectively after MCAO. MCAO-induced decrease of hepatic insulin receptors and increase of hepatic gluconeogenic enzymes on day 1 after was reversed to control levels by orexin-A. This effect was reversed by intramedullary administration of the orexin-1 receptor antagonist, SB334867, or hepatic vagotomy. In the medulla oblongata, orexin-A induced the co-localization of cholin acetyltransferase (cholinergic neuronal marker used for the vagus nerve) with orexin-1 receptor and c-Fos (activated neural cells marker). These results suggest that the hepatic branch vagus nerve projecting from the medulla oblongata plays an important role in the recovery of post-ischemic glucose intolerance and mediates a neuroprotective effect by hypothalamic orexin-A. PMID:24759941

Hepatic branch vagus nerve plays a critical role in the recovery of post-ischemic glucose intolerance and mediates a neuroprotective effect by hypothalamic orexin-A.

Directory of Open Access Journals (Sweden)

Shinichi Harada

Full Text Available Orexin-A (a neuropeptide in the hypothalamus plays an important role in many physiological functions, including the regulation of glucose metabolism. We have previously found that the development of post-ischemic glucose intolerance is one of the triggers of ischemic neuronal damage, which is suppressed by hypothalamic orexin-A. Other reports have shown that the communication system between brain and peripheral tissues through the autonomic nervous system (sympathetic, parasympathetic and vagus nerve is important for maintaining glucose and energy metabolism. The aim of this study was to determine the involvement of the hepatic vagus nerve on hypothalamic orexin-A-mediated suppression of post-ischemic glucose intolerance development and ischemic neuronal damage. Male ddY mice were subjected to middle cerebral artery occlusion (MCAO for 2 h. Intrahypothalamic orexin-A (5 pmol/mouse administration significantly suppressed the development of post-ischemic glucose intolerance and neuronal damage on day 1 and 3, respectively after MCAO. MCAO-induced decrease of hepatic insulin receptors and increase of hepatic gluconeogenic enzymes on day 1 after was reversed to control levels by orexin-A. This effect was reversed by intramedullary administration of the orexin-1 receptor antagonist, SB334867, or hepatic vagotomy. In the medulla oblongata, orexin-A induced the co-localization of cholin acetyltransferase (cholinergic neuronal marker used for the vagus nerve with orexin-1 receptor and c-Fos (activated neural cells marker. These results suggest that the hepatic branch vagus nerve projecting from the medulla oblongata plays an important role in the recovery of post-ischemic glucose intolerance and mediates a neuroprotective effect by hypothalamic orexin-A.

Hippocampal Ghrelin-positive neurons directly project to arcuate hypothalamic and medial amygdaloid nuclei. Could they modulate food-intake?

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Russo, Cristina; Russo, Antonella; Pellitteri, Rosalia; Stanzani, Stefania

2017-07-13

Feeding is a process controlled by a complex of associations between external and internal stimuli. The processes that involve learning and memory seem to exert a strong control over appetite and food intake, which is modulated by a gastrointestinal hormone, Ghrelin (Ghre). Recent studies claim that Ghre is involved in cognitive and neurobiological mechanisms that underlie the conditioning of eating behaviors. The expression of Ghre increases in anticipation of food intake based on learned behaviors. The hippocampal Ghre-containing neurons neurologically influence the orexigenic hypothalamus and consequently the learned feeding behavior. The CA1 field of Ammon's horn of the hippocampus (H-CA1) constitutes the most important neural substrate to control both appetitive and ingestive behavior. It also innervates amygdala regions that in turn innervate the hypothalamus. A recent study also implies that Ghre effects on cue-potentiated feeding behavior occur, at the least, via indirect action on the amygdala. In the present study, we investigate the neural substrates through which endogenous Ghre communicates conditioned appetite and feeding behavior within the CNS. We show the existence of a neural Ghre dependent pathway whereby peripherally-derived Ghre activates H-CA1 neurons, which in turn activate Ghre-expressing hypothalamic and amygdaloid neurons to stimulate appetite and feeding behavior. To highlight this pathway, we use two fluorescent retrograde tracers (Fluoro Gold and Dil) and immunohistochemical detection of Ghre expression in the hippocampus. Triple fluorescent-labeling has determined the presence of H-CA1 Ghre-containing collateralized neurons that project to the hypothalamus and amygdala monosynaptically. We hypothesize that H-Ghre-containing neurons in H-CA1 modulate food-intake behavior through direct pathways to the arcuate hypothalamic nucleus and medial amygdaloid nucleus. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of neural networks in CRM systems

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Bojanowska Agnieszka

2017-01-01

Full Text Available The central aim of this study is to investigate how to apply artificial neural networks in Customer Relationship Management (CRM. The paper presents several business applications of neural networks in software systems designed to aid CRM, e.g. in deciding on the profitability of building a relationship with a given customer. Furthermore, a framework for a neural-network based CRM software tool is developed. Building beneficial relationships with customers is generating considerable interest among various businesses, and is often mentioned as one of the crucial objectives of enterprises, next to their key aim: to bring satisfactory profit. There is a growing tendency among businesses to invest in CRM systems, which together with an organisational culture of a company aid managing customer relationships. It is the sheer amount of gathered data as well as the need for constant updating and analysis of this breadth of information that may imply the suitability of neural networks for the application in question. Neural networks exhibit considerably higher computational capabilities than sequential calculations because the solution to a problem is obtained without the need for developing a special algorithm. In the majority of presented CRM applications neural networks constitute and are presented as a managerial decision-taking optimisation tool.

Neural Network for Optimization of Existing Control Systems

DEFF Research Database (Denmark)

Madsen, Per Printz

1995-01-01

The purpose of this paper is to develop methods to use Neural Network based Controllers (NNC) as an optimization tool for existing control systems.......The purpose of this paper is to develop methods to use Neural Network based Controllers (NNC) as an optimization tool for existing control systems....

Short-term synaptic plasticity and heterogeneity in neural systems

Science.gov (United States)

Mejias, J. F.; Kappen, H. J.; Longtin, A.; Torres, J. J.

2013-01-01

We review some recent results on neural dynamics and information processing which arise when considering several biophysical factors of interest, in particular, short-term synaptic plasticity and neural heterogeneity. The inclusion of short-term synaptic plasticity leads to enhanced long-term memory capacities, a higher robustness of memory to noise, and irregularity in the duration of the so-called up cortical states. On the other hand, considering some level of neural heterogeneity in neuron models allows neural systems to optimize information transmission in rate coding and temporal coding, two strategies commonly used by neurons to codify information in many brain areas. In all these studies, analytical approximations can be made to explain the underlying dynamics of these neural systems.

Representation of neural networks as Lotka-Volterra systems

International Nuclear Information System (INIS)

Moreau, Yves; Vandewalle, Joos; Louies, Stephane; Brenig, Leon

1999-01-01

We study changes of coordinates that allow the representation of the ordinary differential equations describing continuous-time recurrent neural networks into differential equations describing predator-prey models--also called Lotka-Volterra systems. We transform the equations for the neural network first into quasi-monomial form, where we express the vector field of the dynamical system as a linear combination of products of powers of the variables. In practice, this transformation is possible only if the activation function is the hyperbolic tangent or the logistic sigmoied. From this quasi-monomial form, we can directly transform the system further into Lotka-Volterra equations. The resulting Lotka-Volterra system is of higher dimension than the original system, but the behavior of its first variables is equivalent to the behavior of the original neural network

Effect of cancer treatment on hypothalamic-pituitary function.

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Crowne, Elizabeth; Gleeson, Helena; Benghiat, Helen; Sanghera, Paul; Toogood, Andrew

2015-07-01

The past 30 years have seen a great improvement in survival of children and young adults treated for cancer. Cancer treatment can put patients at risk of health problems that can develop many years later, most commonly affecting the endocrine system. Patients treated with cranial radiotherapy often develop dysfunction of the hypothalamic-pituitary axis. A characteristic pattern of hormone deficiencies develops over several years. Growth hormone is disrupted most often, followed by gonadal, adrenal, and thyroid hormones, leading to abnormal growth and puberty in children, and affecting general wellbeing and fertility in adults. The severity and rate of development of hypopituitarism is determined by the dose of radiotherapy delivered to the hypothalamic-pituitary axis. Individual growth hormone deficiencies can develop after a dose as low as 10 Gy, whereas multiple hormone deficiencies are common after 60 Gy. New techniques in radiotherapy aim to reduce the effect on the hypothalamic-pituitary axis by minimising the dose received. Patients taking cytotoxic drugs do not often develop overt hypopituitarism, although the effect of radiotherapy might be enhanced. The exception is adrenal insufficiency caused by glucocorticosteroids which, although transient, can be life-threatening. New biological drugs to treat cancer can cause autoimmune hypophysitis and hypopituitarism; therefore, oncologists and endocrinologists should be vigilant and work together to optimise patient outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome may have a hypothalamus-periaqueductal gray localization.

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Chow, Cristelle; Fortier, Marielle Valerie; Das, Lena; Menon, Anuradha P; Vasanwala, Rashida; Lam, Joyce C M; Ng, Zhi Min; Ling, Simon Robert; Chan, Derrick W S; Choong, Chew Thye; Liew, Wendy K M; Thomas, Terrence

2015-05-01

Anatomical localization of the rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome has proved elusive. Most patients had neuroimaging after cardiorespiratory collapse, revealing a range of ischemic lesions. A 15-year-old obese boy with an acute febrile encephalopathy had hypoventilation, autonomic dysfunction, visual hallucinations, hyperekplexia, and disordered body temperature, and saltwater regulation. These features describe the ROHHAD syndrome. Cerebrospinal fluid analysis showed pleocytosis, elevated neopterins, and oligoclonal bands, and serology for systemic and antineuronal antibodies was negative. He improved after receiving intravenous steroids, immunoglobulins, and long-term mycophenolate. Screening for neural crest tumors was negative. Magnetic resonance imaging of the brain early in his illness showed focal inflammation in the periaqueductal gray matter and hypothalamus. This unique localization explains almost all symptoms of this rare autoimmune encephalitis. Copyright © 2015 Elsevier Inc. All rights reserved.

A genetic basis for functional hypothalamic amenorrhea.

OpenAIRE

Caronia, L.M.; Martin, C.; Welt, C.K.; Sykiotis, G.P.; Quinton, R.; Thambundit, A.; Avbelj, M.; Dhruvakumar, S.; Plummer, L.; Hughes, V.A.; Seminara, S.B.; Boepple, P.A.; Sidis, Y.; Crowley, W.F.; Martin, K.A.

2011-01-01

Background: Functional hypothalamic amenorrhea is a reversible form of gonadotropin-releasing hormone (GnRH) deficiency commonly triggered by stressors such as excessive exercise, nutritional deficits, or psychological distress. Women vary in their susceptibility to inhibition of the reproductive axis by such stressors, but it is unknown whether this variability reflects a genetic predisposition to hypothalamic amenorrhea. We hypothesized that mutations in genes involved in idiopathic hypogon...

Recent advances in understanding the role of the hypothalamic circuit during aggression

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Annegret L Falkner

2014-09-01

Full Text Available The hypothalamus was first implicated in the classic fight or flight response nearly a century ago, and since then, many important strides have been made in understanding both the circuitry and the neural dynamics underlying the generation of these behaviors. In this review, we will focus specifically on the role of the hypothalamus in aggression, paying particular attention to recent advances in the field that have allowed for functional identification of relevant hypothalamic subnuclei. Recent progress in this field has been aided by the development of new techniques for functional manipulation including optogenetics and pharmacogenetics, as well as advances in technology used for chronic in vivo recordings during complex social behaviors. We will examine the role of the hypothalamus through the complimentary lenses of 1 loss of function studies, including pharmacology and pharmacogenetics, 2 gain of function studies, including specific comparisons between results from classic electrical stimulation studies and more recent work using optogenetics, and 3 neural activity, including both immediate early gene and awake-behaving recordings. Lastly, we will outline current approaches to identifying the precise role of the hypothalamus in promoting aggressive motivation and aggressive action.

A longitudinal study of disturbances of the hypothalamic-pituitary-adrenal axis in women with progestin-negative functional hypothalamic amenorrhea.

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Kondoh, Y; Uemura, T; Murase, M; Yokoi, N; Ishikawa, M; Hirahara, F

2001-10-01

To longitudinally evaluate disturbances of the hypothalamic-pituitary-adrenal (HPA) axis in women with secondary progestin-negative hypothalamic amenorrhea. Retrospective cohort study. Yokohama City University, Yokohama, Japan. Twenty-four women with progestin-negative hypothalamic amenorrhea. Administration of human corticotropin-releasing hormone (hCRH) and treatment with a combination of estrogen and progesterone. Plasma cortisol and ACTH concentrations and period required for recovery from amenorrhea. Plasma ACTH concentrations 30 and 60 minutes after injection of hCRH and the percent maximum increment (%Cmax) of ACTH were significantly lower in the amenorrheic patients compared with the control group patients. The basal cortisol was significantly higher, and the %Cmax of cortisol was significantly lower. In the 16 patients who recovered from amenorrhea, there was a significant positive correlation (Y = 1.93X-10.8, r = 0.629) between the basal cortisol concentrations (X) and the period for recovery (Y). The serum E2 gradually increased before recovery, and this E2 increase was preceded by changes in the plasma cortisol concentration and the %Cmax values of cortisol and ACTH. The CRH test might be useful for evaluating the roles of stress and for estimating the period required for recovery in hypothalamic amenorrhea.

Ovarian steroid regulation of monoamine oxidase-A and -B mRNAs in the macaque dorsal raphe and hypothalamic nuclei.

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Gundlah, Chrisana; Lu, Nick Z; Bethea, Cynthia L

2002-03-01

The serotonin neural system plays a pivotal role in mood, affective regulation and integrative cognition, as well as numerous autonomic functions. We have shown that ovarian steroids alter the expression of several genes in the dorsal raphe of macaques, which may increase serotonin synthesis and decrease serotonin autoinhibition. Another control point in aminergic neurotransmission involves degradation by MAO. This enzyme occurs in two isoforms, A and B, which have different substrate preferences. We questioned the effect of ovarian steroid hormones on MAO-A and MAO-B mRNA expression in the dorsal raphe nucleus and hypothalamus using in situ hybridization in non-human primates. Rhesus monkeys ( Macaca mulatta; n=5/group) were spayed and either placebo treated (controls), estrogen (E) treated (28 days), progesterone (P) treated (14 days placebo+14 days P), or E+P treated (14 days E+14 days E+P). Perfusion-fixed sections (25 microm) were hybridized with a 233 bp MAO-A, or a 373 bp MAO-B, radiolabeled-antisense monkey specific probes. Autoradiographic films were analyzed by densitometry, which was performed with NIH Image Software. MAO-A and -B mRNAs were detected in the dorsal raphe nucleus (DRN) and in the hypothalamic suprachiasmatic nucleus (SCN), preoptic area (POA), paraventricular nucleus (PVN), supraoptic nucleus (SON), lateral hypothalamus (LH) and ventromedial nucleus (VMN). MAO-A mRNA optical density was significantly decreased by E, P, and E+P in the DRN and in the hypothalamic PVN, LH and VMN. Ovarian hormones had no effect on MAO-B mRNA expression in the DRN. However, there was a significant decrease in MAO-B optical density in the hypothalamic POA, LH and VMN with E, P or E+P treatment. Pixel area generally reflected optical density. Ovarian steroids decreased MAO-A, but not B, in the raphe nucleus. However, both MAO-A and B were decreased in discrete hypothalamic nuclei by hormone replacement. These data suggest that the transcriptional regulation of

Hypothalamic hamartoma associated with precocious puberty: Case report

International Nuclear Information System (INIS)

Bae, Won Kyong; Kim, Pyo Nuyn; Kim, Il Young; Lee, Byoung Ho; Lee, Kyeong Seok; Bae, Hack Gun; Yun, Il Gyu

1989-01-01

Hamartoma of the hypothalamic area is a well recognized cause of central precocious puberty. We report a case of histologically proven hypothalamic hamartoma in a 8 year old girl with precocious puberty. The CT showed an isodense, nonenhancing mass in suprasellar area, measuring 4.2 X 3.1 cm, which, to our knowledge, seems to be the largest one of the published cases. On MR imaging, the signal intensity of the mass was homogeneous and isointense relative to gray matter on T1-, and hyperintense on T2-weighted images. The clinical and radiologic findings of the published cases of hypothalamic hamartoma are reviewed

Hypothalamic hamartoma associated with precocious puberty: Case report

Energy Technology Data Exchange (ETDEWEB)

Bae, Won Kyong; Kim, Pyo Nuyn; Kim, Il Young; Lee, Byoung Ho; Lee, Kyeong Seok; Bae, Hack Gun; Yun, Il Gyu [Soonchunhyang University, Chonan Hospital, Chonan (Korea, Republic of)

1989-12-15

Hamartoma of the hypothalamic area is a well recognized cause of central precocious puberty. We report a case of histologically proven hypothalamic hamartoma in a 8 year old girl with precocious puberty. The CT showed an isodense, nonenhancing mass in suprasellar area, measuring 4.2 X 3.1 cm, which, to our knowledge, seems to be the largest one of the published cases. On MR imaging, the signal intensity of the mass was homogeneous and isointense relative to gray matter on T1-, and hyperintense on T2-weighted images. The clinical and radiologic findings of the published cases of hypothalamic hamartoma are reviewed.

Hypothalamic mTOR signaling regulates food intake.

Science.gov (United States)

Cota, Daniela; Proulx, Karine; Smith, Kathi A Blake; Kozma, Sara C; Thomas, George; Woods, Stephen C; Seeley, Randy J

2006-05-12

The mammalian Target of Rapamycin (mTOR) protein is a serine-threonine kinase that regulates cell-cycle progression and growth by sensing changes in energy status. We demonstrated that mTOR signaling plays a role in the brain mechanisms that respond to nutrient availability, regulating energy balance. In the rat, mTOR signaling is controlled by energy status in specific regions of the hypothalamus and colocalizes with neuropeptide Y and proopiomelanocortin neurons in the arcuate nucleus. Central administration of leucine increases hypothalamic mTOR signaling and decreases food intake and body weight. The hormone leptin increases hypothalamic mTOR activity, and the inhibition of mTOR signaling blunts leptin's anorectic effect. Thus, mTOR is a cellular fuel sensor whose hypothalamic activity is directly tied to the regulation of energy intake.

Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

Science.gov (United States)

Heap, Lucy A.; Vanwalleghem, Gilles C.; Thompson, Andrew W.; Favre-Bulle, Itia; Rubinsztein-Dunlop, Halina; Scott, Ethan K.

2018-01-01

The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH) to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC)/stratum griseum periventriculare (SPV), and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil. PMID:29403362

Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

Directory of Open Access Journals (Sweden)

Lucy A. Heap

2018-01-01

Full Text Available The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC/stratum griseum periventriculare (SPV, and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil.

Surgical therapy of lesions within the hypothalamic region

International Nuclear Information System (INIS)

Fahlbusch, R.; Schrell, U.

1985-01-01

On one hand pituitary microadenomas with autonomous character and those, which had been influenced by hypothalamic disorders, are summarized and discussed. On the other hand, the neurosurgical management of tumours, adjacent to our involved with the hypothalamus, are described. Endocrinologically active pituitary adenomas are characterized by their hormone excess of ACTH, GH, and prolactin. In Cushing's disease endocrine and clinical remission occurred in 74%. 3 patients out of this group showed a reincrease of ACTH after a period of remission, indicating a possible hypothalamic influence. In acromegaly the hypothalamic influence is also discussed. One patient with an ectopic GRF-producing tumour showing a reincrease of GH levels after successful transsphenoidal adenomectomy has been described. In microprolactinomas, 7 patients out of 45 showed a reincrease of prolactin-levels after a period of normalization, we also discussed hypothalamic disorders. Tumours with suprasellar extension such as macroadenomas without endocrine activity and meningiomas are removed nowadays with minimal risk for the life of the patients. In craniopharyngiomas radical excision is accompanied by a high risk of hypothalamic defects caused by mechanical lesions and possible secondary vasospasm. Finally the excision of a hamartoma growing from the floor of the third ventricle into the interpeduncular cistern is discussed. Up to now the successful excision could be documented by endocrinological data, which give no sign of further growth of the hamartoma. (Author)

Surgical therapy of lesions within the hypothalamic region

Energy Technology Data Exchange (ETDEWEB)

Fahlbusch, R.; Schrell, U. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.))

1985-01-01

On one hand pituitary microadenomas with autonomous character and those, which had been influenced by hypothalamic disorders, are summarized and discussed. On the other hand, the neurosurgical management of tumours, adjacent to or involved with the hypothalamus, are described. Endocrinologically active pituitary adenomas are characterized by their hormone excess of ACTH, GH, and prolactin. In Cushing's disease endocrine and clinical remission occurred in 74%. 3 patients out of this group showed a reincrease of ACTH after a period of remission, indicating a possible hypothalamic influence. In acromegaly the hypothalamic influence is also discussed. One patient with an ectopic GRF-producing tumour showing a reincrease of GH levels after successful transsphenoidal adenomectomy has been described. In microprolactinomas, 7 patients out of 45 showed a reincrease of prolactin-levels after a period of normalization, we also discussed hypothalamic disorders. Tumours with suprasellar extension such as macroadenomas without endocrine activity and meningiomas are removed nowadays with minimal risk for the life of the patients. In craniopharyngiomas radical excision is accompanied by a high risk of hypothalamic defects caused by mechanical lesions and possible secondary vasospasm. Finally the excision of a hamartoma growing from the floor of the third ventricle into the interpeduncular cistern is discussed. Up to now the successful excision could be documented by endocrinological data, which give no sign of further growth of the hamartoma.

Spiking neural P systems with multiple channels.

Science.gov (United States)

Peng, Hong; Yang, Jinyu; Wang, Jun; Wang, Tao; Sun, Zhang; Song, Xiaoxiao; Luo, Xiaohui; Huang, Xiangnian

2017-11-01

Spiking neural P systems (SNP systems, in short) are a class of distributed parallel computing systems inspired from the neurophysiological behavior of biological spiking neurons. In this paper, we investigate a new variant of SNP systems in which each neuron has one or more synaptic channels, called spiking neural P systems with multiple channels (SNP-MC systems, in short). The spiking rules with channel label are introduced to handle the firing mechanism of neurons, where the channel labels indicate synaptic channels of transmitting the generated spikes. The computation power of SNP-MC systems is investigated. Specifically, we prove that SNP-MC systems are Turing universal as both number generating and number accepting devices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bariatric surgery in hypothalamic obesity

Directory of Open Access Journals (Sweden)

Nathan eBingham

2012-02-01

Full Text Available Craniopharyngiomas (CP are epithelial neoplasms generally found in the area of the pituitary and hypothalamus. Despite benign histology, these tumors and/or their treatment often result in significant, debilitating disorders of endocrine, neurological, behavioral, and metabolic systems. Severe obesity is observed in a high percentage of patients with CP resulting in significant comorbidities and negatively impacting quality of life. Obesity occurs as a result of hypothalamic damage and disruption of normal homeostatic mechanisms regulating energy balance. Such pathological weight gain, termed hypothalamic obesity (HyOb, is often severe and refractory to therapy.Unfortunately, neither lifestyle intervention nor pharmacotherapy has proven truly effective in the treatment of CP-HyOb. Given the limited choices and poor results of these treatments, several groups have examined bariatric surgery as a treatment alternative for patients with CP-HyOb. While a large body of evidence exists supporting the use of bariatric surgery in the treatment of exogenous obesity and its comorbidities, its role in the treatment of HyOb has yet to be well defined. To date, the existing literature on bariatric surgery in CP-HyOb is largely limited to case reports and series with short term follow-up. Here we review the current reports on the use of bariatric surgery in the treatment of CP-HyOb. We also compare these results to those reported for other populations of HyOb, including Prader-Willi Syndrome and patients with melanocortin signaling defects. While initial reports of bariatric surgery in CP-HyOb are promising, their limited scope makes it difficult to draw any substantial conclusions as to the long term safety and efficacy of bariatric surgery in CP-HyOb. There continues to be a need for more robust, controlled, prospective trials with long term follow-up in order to better define the role of bariatric surgery in the treatment of all types of hypothalamic

Dietary sugars, not lipids, drive hypothalamic inflammation

OpenAIRE

Gao, Yuanqing; Bielohuby, Maximilian; Fleming, Thomas; Grabner, Gernot F.; Foppen, Ewout; Bernhard, Wagner; Guzm?n-Ruiz, Mara; Layritz, Clarita; Legutko, Beata; Zinser, Erwin; Garc?a-C?ceres, Cristina; Buijs, Ruud M.; Woods, Stephen C.; Kalsbeek, Andries; Seeley, Randy J.

2017-01-01

Objective: The hypothalamus of hypercaloric diet-induced obese animals is featured by a significant increase of microglial reactivity and its associated cytokine production. However, the role of dietary components, in particular fat and carbohydrate, with respect to the hypothalamic inflammatory response and the consequent impact on hypothalamic control of energy homeostasis is yet not clear. Methods: We dissected the different effects of high-carbohydrate high-fat (HCHF) diets and low-car...

Oxytocin administration suppresses hypothalamic activation in response to visual food cues.

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van der Klaauw, Agatha A; Ziauddeen, Hisham; Keogh, Julia M; Henning, Elana; Dachi, Sekesai; Fletcher, Paul C; Farooqi, I Sadaf

2017-06-27

The aim of this study was to use functional neuroimaging to investigate whether oxytocin modulates the neural response to visual food cues in brain regions involved in the control of food intake. Twenty-four normal weight volunteers received intranasal oxytocin (24 IU) or placebo in a double-blind, randomized crossover study. Measurements were made forty-five minutes after dosing. On two occasions, functional MRI (fMRI) scans were performed in the fasted state; the blood oxygen level-dependent (BOLD) response to images of high-calorie foods versus low-calorie foods was measured. Given its critical role in eating behaviour, the primary region of interest was the hypothalamus. Secondary analyses examined the parabrachial nuclei and other brain regions involved in food intake and food reward. Intranasal oxytocin administration suppressed hypothalamic activation to images of high-calorie compared to low-calorie food (P = 0.0125). There was also a trend towards suppression of activation in the parabrachial nucleus (P = 0.0683). No effects of intranasal oxytocin were seen in reward circuits or on ad libitum food intake. Further characterization of the effects of oxytocin on neural circuits in the hypothalamus is needed to establish the utility of targeting oxytocin signalling in obesity.

The nervus terminalis in amphibians: anatomy, chemistry and relationship with the hypothalamic gonadotropin-releasing hormone system.

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Muske, L E; Moore, F L

1988-01-01

The nervus terminalis (TN), a component of the olfactory system, is found in most vertebrates. The TN of some fishes and mammals contains neurons immunoreactive (ir) to gonadotropin-releasing hormone (LHRH), and to several other neuropeptides and neurotransmitter systems, but there is little information on TN chemistry in other vertebrate taxa. Using immunocytochemical techniques, we found LHRH-ir neurons in amphibian TNs. In anurans, but not in a urodele, the TN was also found to contain Phe-Met-Arg-Phe-NH2 (FMRFamide) immunoreactivity. LHRH-ir neurons of the TN and those of the septal-hypothalamic system are morphologically homogeneous and form a distinct anatomical continuum in amphibians. Based upon topographical and cytological criteria, we hypothesize that LHRH-ir systems in vertebrates might derive embryonically from the TN.

Hypothalamic pituitary dysfunction in acute nonmycobacterial infections of central nervous system

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Dinesh K Dhanwal

2011-01-01

Full Text Available Background and Objective: Acute and chronic central nervous system (CNS infections are not uncommon in tropical countries and are associated with high morbidity and mortality if specific targeted therapy is not instituted in time. Effects of tubercular meningitis, a form of chronic meningitis on hypothalamic pituitary axis, are well known both at the time of diagnosis and after few months to years of illness. However, there are few reports of pituitary dysfunction in subjects with acute CNS infections. Therefore, this study was aimed at evaluating the pituitary hormonal profile in patients with nonmycobacterial acute meningitis at the time of presentation. Materials and Methods: This prospective case series study included 30 untreated adult patients with acute meningitis, meningoencephalitis, or encephalitis, due to various nonmycobacterial agents, admitted and registered with Lok Nayak Hospital, Maulana Aazd Medical College, New Delhi, between September 2007 and March 2009. Patients with preexisting endocrine diseases, tubercular meningitis and patients on steroids were carefully excluded from the study. The basal pituitary hormonal profile was measured by the electrochemilumniscence technique for serum cortisol, luetinizing hormone (LH, follicular stimulating hormone (FSH, prolactin (PRL, thyrotropin (TSH, free tri-iodothyronine (fT3, and free thyroxine (fT4. Results: The cases (n = 30 comprised of patients with acute pyogenic meningitis (n = 23, viral meningoencephalitis (n = 4, brain abscess (n = 2, and cryptococcal meningitis (n = 1. The mean age of patients was 28.97 ± 11.306 years. Out of 30 patients, 14 (46.7% were males and 16 (58.1% were females. Adrenal insufficiency both absolute and relative was seen in seven (23.3% and hyperprolactinemia was seen in nine (30.0% of the patients. One study subject had central hypothyroidism and seven (23.3 showed low levels of LH and/or FSH. None of patients showed clinical features suggestive of

Heavy alcohol use, rather than alcohol dependence, is associated with dysregulation of the hypothalamic-pituitary-adrenal axis and the autonomic nervous system

NARCIS (Netherlands)

Boschloo, Lynn; Vogelzangs, Nicole; Licht, Carmilla M. M.; Vreeburg, Sophie A.; Smit, Johannes H.; van den Brink, Wim; Veltman, Dick J.; de Geus, Eco J. C.; Beekman, Aartjan T. F.; Penninx, Brenda W. J. H.

2011-01-01

Heavy alcohol use as well as alcohol dependence (AD) have been associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA)-axis and the autonomic nervous system (ANS). However, the relative contribution of alcohol use and AD is unclear. Baseline data were derived from 2947 persons of

Hypothalamic obesity after treatment for craniopharyngioma: the importance of the home environment

NARCIS (Netherlands)

Meijneke, Ruud W. H.; Schouten-van Meeteren, Antoinette Y. N.; de Boer, Nienke Y.; van Zundert, Suzanne; van Trotsenburg, Paul A. S.; Stoelinga, Femke; van Santen, Hanneke M.

2015-01-01

Abstract Hypothalamic obesity after treatment for craniopharyngioma is a well-recognized, severe problem. Treatment of hypothalamic obesity is difficult and often frustrating for the patient, the parents and the professional care-giver. Because hypothalamic obesity is caused by an underlying medical

Review: the role of neural crest cells in the endocrine system.

Science.gov (United States)

Adams, Meghan Sara; Bronner-Fraser, Marianne

2009-01-01

The neural crest is a pluripotent population of cells that arises at the junction of the neural tube and the dorsal ectoderm. These highly migratory cells form diverse derivatives including neurons and glia of the sensory, sympathetic, and enteric nervous systems, melanocytes, and the bones, cartilage, and connective tissues of the face. The neural crest has long been associated with the endocrine system, although not always correctly. According to current understanding, neural crest cells give rise to the chromaffin cells of the adrenal medulla, chief cells of the extra-adrenal paraganglia, and thyroid C cells. The endocrine tumors that correspond to these cell types are pheochromocytomas, extra-adrenal paragangliomas, and medullary thyroid carcinomas. Although controversies concerning embryological origin appear to have mostly been resolved, questions persist concerning the pathobiology of each tumor type and its basis in neural crest embryology. Here we present a brief history of the work on neural crest development, both in general and in application to the endocrine system. In particular, we present findings related to the plasticity and pluripotency of neural crest cells as well as a discussion of several different neural crest tumors in the endocrine system.

Integrating Artificial Immune, Neural and Endrocine Systems in Autonomous Sailing Robots

Science.gov (United States)

2010-09-24

system - Development of an adaptive hormone system capable of changing operation and control of the neural network depending on changing enviromental ...and control of the neural network depending on changing enviromental conditions • First basic design of the MOOP and a simple neural-endocrine based

Frequency-difference-dependent stochastic resonance in neural systems

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Guo, Daqing; Perc, Matjaž; Zhang, Yangsong; Xu, Peng; Yao, Dezhong

2017-08-01

Biological neurons receive multiple noisy oscillatory signals, and their dynamical response to the superposition of these signals is of fundamental importance for information processing in the brain. Here we study the response of neural systems to the weak envelope modulation signal, which is superimposed by two periodic signals with different frequencies. We show that stochastic resonance occurs at the beat frequency in neural systems at the single-neuron as well as the population level. The performance of this frequency-difference-dependent stochastic resonance is influenced by both the beat frequency and the two forcing frequencies. Compared to a single neuron, a population of neurons is more efficient in detecting the information carried by the weak envelope modulation signal at the beat frequency. Furthermore, an appropriate fine-tuning of the excitation-inhibition balance can further optimize the response of a neural ensemble to the superimposed signal. Our results thus introduce and provide insights into the generation and modulation mechanism of the frequency-difference-dependent stochastic resonance in neural systems.

Characterization of the central neural projections to brown, white, and beige adipose tissue.

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Wiedmann, Nicole M; Stefanidis, Aneta; Oldfield, Brian J

2017-11-01

The functional recruitment of classic brown adipose tissue (BAT) and inducible brown-like or beige fat is, to a large extent, dependent on intact sympathetic neural input. Whereas the central neural circuits directed specifically to BAT or white adipose tissue (WAT) are well established, there is only a developing insight into the nature of neural inputs common to both fat types. Moreover, there is no clear view of the specific central and peripheral innervation of the browned component of WAT: beige fat. The objective of the present study is to examine the neural input to both BAT and WAT in the same animal and, by exposing different cohorts of rats to either thermoneutral or cold conditions, define changes in central neural organization that will ensure that beige fat is appropriately recruited and modulated after browning of inguinal WAT (iWAT). At thermoneutrality, injection of the neurotropic (pseudorabies) viruses into BAT and WAT demonstrates that there are dedicated axonal projections, as well as collateral axonal branches of command neurons projecting to both types of fat. After cold exposure, central neural circuits directed to iWAT showed evidence of reorganization with a greater representation of command neurons projecting to both brown and beiged WAT in hypothalamic (paraventricular nucleus and lateral hypothalamus) and brainstem (raphe pallidus and locus coeruleus) sites. This shift was driven by a greater number of supraspinal neurons projecting to iWAT under cold conditions. These data provide evidence for a reorganization of the nervous system at the level of neural connectivity following browning of WAT.-Wiedmann, N. M., Stefanidis, A., Oldfield, B. J. Characterization of the central neural projections to brown, white, and beige adipose tissue. © FASEB.

Use of neural networks in the analysis of complex systems

International Nuclear Information System (INIS)

Uhrig, R.E.

1992-01-01

The application of neural networks, alone or in conjunction with other advanced technologies (expert systems, fuzzy logic, and/or genetic algorithms) to some of the problems of complex engineering systems has the potential to enhance the safety reliability and operability of these systems. The work described here deals with complex systems or parts of such systems that can be isolated from the total system. Typically, the measured variables from the systems are analog variables that must be sampled and normalized to expected peak values before they are introduced into neural networks. Often data must be processed to put it into a form more acceptable to the neural network. The neural networks are usually simulated on modern high-speed computers that carry out the calculations serially. However, it is possible to implement neural networks using specially designed microchips where the network calculations are truly carried out in parallel, thereby providing virtually instantaneous outputs for each set of inputs. Specific applications described include: Diagnostics: State of the Plant; Hybrid System for Transient Identification; Detection of Change of Mode in Complex Systems; Sensor Validation; Plant-Wide Monitoring; Monitoring of Performance and Efficiency; and Analysis of Vibrations. Although the specific examples described deal with nuclear power plants or their subsystems, the techniques described can be applied to a wide variety of complex engineering systems

Corticostriatal-hypothalamic circuitry and food motivation: integration of energy, action and reward.

Science.gov (United States)

Kelley, Ann E; Baldo, Brian A; Pratt, Wayne E; Will, Matthew J

2005-12-15

Work over the past decade has supported the idea that discrete aspects of appetitive motivation are differentially mediated by separate but interacting neurochemical systems within the nucleus accumbens (Acb). We review herein a series of studies in rats comparing the effects of manipulating Acb amino acid, opioid, acetylcholine, and dopamine systems on tests of free-feeding and food-reinforced operant responding. Results from our laboratory and in the literature support three general conclusions: (1) GABA output neurons localized exclusively within the Acb shell directly influence hypothalamic effector mechanisms for feeding motor patterns, but do not participate in the execution of more complex food-seeking strategies; (2) enkephalinergic neurons distributed throughout the Acb and caudate-putamen mediate the hedonic impact of palatable (high sugar/fat) foods, and these neurons are under modulatory control by striatal cholinergic interneurons; and (3) dopamine transmission in the Acb governs general motoric and arousal processes related to response selection and invigoration, as well as motor learning-related plasticity. These dissociations may reflect the manner in which these neurochemical systems differentially access pallido-thalamo-cortical loops reaching the voluntary motor system (in the case of opioids and dopamine), versus more restricted efferent connections to hypothalamic motor/autonomic control columns (in the case of Acb shell GABA and glutamate systems). Moreover, we hypothesize that while these systems work in tandem to coordinate the anticipatory and consummatory phases of feeding with hypothalamic energy-sensing substrates, the striatal opioid network evolved a specialized capacity to promote overeating of energy-dense foods beyond acute homeostatic needs, to ensure an energy reserve for potential future famine.

Microfluidic systems for stem cell-based neural tissue engineering.

Science.gov (United States)

Karimi, Mahdi; Bahrami, Sajad; Mirshekari, Hamed; Basri, Seyed Masoud Moosavi; Nik, Amirala Bakhshian; Aref, Amir R; Akbari, Mohsen; Hamblin, Michael R

2016-07-05

Neural tissue engineering aims at developing novel approaches for the treatment of diseases of the nervous system, by providing a permissive environment for the growth and differentiation of neural cells. Three-dimensional (3D) cell culture systems provide a closer biomimetic environment, and promote better cell differentiation and improved cell function, than could be achieved by conventional two-dimensional (2D) culture systems. With the recent advances in the discovery and introduction of different types of stem cells for tissue engineering, microfluidic platforms have provided an improved microenvironment for the 3D-culture of stem cells. Microfluidic systems can provide more precise control over the spatiotemporal distribution of chemical and physical cues at the cellular level compared to traditional systems. Various microsystems have been designed and fabricated for the purpose of neural tissue engineering. Enhanced neural migration and differentiation, and monitoring of these processes, as well as understanding the behavior of stem cells and their microenvironment have been obtained through application of different microfluidic-based stem cell culture and tissue engineering techniques. As the technology advances it may be possible to construct a "brain-on-a-chip". In this review, we describe the basics of stem cells and tissue engineering as well as microfluidics-based tissue engineering approaches. We review recent testing of various microfluidic approaches for stem cell-based neural tissue engineering.

Indirect evidence for decreased hypothalamic somatostatinergic tone in anorexia nervosa

DEFF Research Database (Denmark)

Støving, R K; Andersen, M; Flyvbjerg, A

2002-01-01

in the central feeding mechanism in anorexia nervosa (AN). Peripheral administration of pyridostigmine (PD) minimizes the release of hypothalamic SRIH. DESIGN: To study the influence of hypothalamic somatostatinergic inhibition on the exaggerated somatotroph responsiveness to GHRH in patients with severe AN, two...... indirectly to greater SRIH withdrawal and greater GHRH release in anorexia nervosa. Moreover, hypothalamic SRIH activity seems to be inversely related to cortisol levels, indirectly supporting the hypothesis that SRIH and CRH neuronal activity are inversely related in anorexia nervosa. Leptin, which...... is believed to act on hypothalamic feeding mechanisms, seems to be positively related to SRIH activity. Finally, the present data demonstrate that the potentiating effect of pyridostigmine in anorexia nervosa is related to body mass index and increases upon weight gain, suggesting that the low...

Thermal photovoltaic solar integrated system analysis using neural networks

Energy Technology Data Exchange (ETDEWEB)

Ashhab, S. [Hashemite Univ., Zarqa (Jordan). Dept. of Mechanical Engineering

2007-07-01

The energy demand in Jordan is primarily met by petroleum products. As such, the development of renewable energy systems is quite attractive. In particular, solar energy is a promising renewable energy source in Jordan and has been used for food canning, paper production, air-conditioning and sterilization. Artificial neural networks (ANNs) have received significant attention due to their capabilities in forecasting, modelling of complex nonlinear systems and control. ANNs have been used for forecasting solar energy. This paper presented a study that examined a thermal photovoltaic solar integrated system that was built in Jordan. Historical input-output system data that was collected experimentally was used to train an ANN that predicted the collector, PV module, pump and total efficiencies. The model predicted the efficiencies well and can therefore be utilized to find the operating conditions of the system that will produce the maximum system efficiencies. The paper provided a description of the photovoltaic solar system including equations for PV module efficiency; pump efficiency; and total efficiency. The paper also presented data relevant to the system performance and neural networks. The results of a neural net model were also presented based on the thermal PV solar integrated system data that was collected. It was concluded that the neural net model of the thermal photovoltaic solar integrated system set the background for achieving the best system performance. 10 refs., 6 figs.

Bilateral descending hypothalamic projections to the spinal trigeminal nucleus caudalis in rats.

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Khaled Abdallah

Full Text Available Several lines of evidence suggest that the hypothalamus is involved in trigeminal pain processing. However, the organization of descending hypothalamic projections to the spinal trigeminal nucleus caudalis (Sp5C remains poorly understood. Microinjections of the retrograde tracer, fluorogold (FG, into the Sp5C, in rats, reveal that five hypothalamic nuclei project to the Sp5C: the paraventricular nucleus, the lateral hypothalamic area, the perifornical hypothalamic area, the A11 nucleus and the retrochiasmatic area. Descending hypothalamic projections to the Sp5C are bilateral, except those from the paraventricular nucleus which exhibit a clear ipsilateral predominance. Moreover, the density of retrogradely FG-labeled neurons in the hypothalamus varies according to the dorso-ventral localization of the Sp5C injection site. There are much more labeled neurons after injections into the ventrolateral part of the Sp5C (where ophthalmic afferents project than after injections into its dorsomedial or intermediate parts (where mandibular and maxillary afferents, respectively, project. These results demonstrate that the organization of descending hypothalamic projections to the spinal dorsal horn and Sp5C are different. Whereas the former are ipsilateral, the latter are bilateral. Moreover, hypothalamic projections to the Sp5C display somatotopy, suggesting that these projections are preferentially involved in the processing of meningeal and cutaneous inputs from the ophthalmic branch of the trigeminal nerve in rats. Therefore, our results suggest that the control of trigeminal and spinal dorsal horn processing of nociceptive information by hypothalamic neurons is different and raise the question of the role of bilateral, rather than unilateral, hypothalamic control.

Evaluating neural networks and artificial intelligence systems

Science.gov (United States)

Alberts, David S.

1994-02-01

Systems have no intrinsic value in and of themselves, but rather derive value from the contributions they make to the missions, decisions, and tasks they are intended to support. The estimation of the cost-effectiveness of systems is a prerequisite for rational planning, budgeting, and investment documents. Neural network and expert system applications, although similar in their incorporation of a significant amount of decision-making capability, differ from each other in ways that affect the manner in which they can be evaluated. Both these types of systems are, by definition, evolutionary systems, which also impacts their evaluation. This paper discusses key aspects of neural network and expert system applications and their impact on the evaluation process. A practical approach or methodology for evaluating a certain class of expert systems that are particularly difficult to measure using traditional evaluation approaches is presented.

Differential sensitivity to nicotine among hypothalamic magnocellular neurons

DEFF Research Database (Denmark)

Mikkelsen, J D; Jacobsen, Julie; Kiss, Adrian Emil

2012-01-01

The magnocellular neurons in the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON) either contain vasopressin or oxytocin. Even though both hormones are released after systemic administration of nicotine, the mechanism through which the two populations of neurons are activated...... is not known. This study was carried out in the rat to investigate the effect of increasing doses of nicotine on subsets of magnocellular neurons containing either oxytocin or vasopressin....

Heightened cortisol response to exercise challenge in women with functional hypothalamic amenorrhea.

Science.gov (United States)

Sanders, Kristen M; Kawwass, Jennifer F; Loucks, Tammy; Berga, Sarah L

2018-02-01

Functional hypothalamic amenorrhea is characterized by anovulation caused by reduced gonadotropin-releasing hormone drive and is associated with hypercortisolemia that has been linked to heightened hypothalamic-pituitary-adrenal reactivity to common psychological and metabolic challenges. We hypothesized that women with functional hypothalamic amenorrhea would display greater cortisol responses to exercise challenge than ovulatory women with eumenorrhea. We completed a cross-sectional comparison of 9 women with functional hypothalamic amenorrhea and 11 women with eumenorrhea who were of reproductive age, who weighed 90-110% ideal body weight, who did not exercise excessively, and who had no formal psychiatric diagnosis. Subjects completed a 20-minute submaximal exercise challenge using a cycle ergometer in a research exercise laboratory. Heart rate and circulatory cortisol, glucose, and lactate were measured at 10-minute intervals before, during, and after the exercise challenge. Baseline (t= -10 minutes) cortisol, glucose, lactate, and heart rate were comparable between groups. Glucose levels rose modestly during exercise by 2.9% in women with eumenorrhea (P=.4) but declined by 10.6% in functional hypothalamic amenorrhea (P<.03). The nadir in glucose levels in functional hypothalamic amenorrhea occurred at the end of the 20-minute exercise challenge (t= +20 min). Lactate levels rose comparably in both groups (P<.01). Heart rate increased significantly with exercise in both groups (P<.01), but the increase was smaller in subjects with functional hypothalamic amenorrhea (P<.01). Cortisol levels increased during the exercise challenge in both groups (P<.01) and peaked 10 minutes after the exercise ended (t= +30 min). At peak, subjects with functional hypothalamic amenorrhea displayed higher cortisol levels (147±22 [standard error of the mean] ng/mL) than women with eumenorrhea (96±12 ng/mL; P=.05). The mean percent increase over baseline was 62% in women with

Developmental changes in hypothalamic oxytocin and oxytocin receptor mRNA expression and their sensitivity to fasting in male and female rats.

Science.gov (United States)

Matsuzaki, Toshiya; Iwasa, Takeshi; Munkhzaya, Munkhsaikhan; Tungalagsuvd, Altankhuu; Kawami, Takako; Murakami, Masahiro; Yamasaki, Mikio; Yamamoto, Yuri; Kato, Takeshi; Kuwahara, Akira; Yasui, Toshiyuki; Irahara, Minoru

2015-04-01

Oxytocin (OT) affects the central nervous system and is involved in a variety of social and non-social behaviors. Recently, the role played by OT in energy metabolism and its organizational effects on estrogen receptor alpha (ER-α) during the neonatal period have gained attention. In this study, the developmental changes in the hypothalamic mRNA levels of OT, the OT receptor (OTR), and ER-α were evaluated in male and female rats. In addition, the fasting-induced changes in the hypothalamic mRNA levels of OT and the OTR were evaluated. Hypothalamic explants were taken from postnatal day (PND) 10, 20, and 30 rats, and the mRNA level of each molecule was measured. Hypothalamic OT mRNA expression increased throughout the developmental period in both sexes. The rats' hypothalamic OTR mRNA levels were highest on PND 10 and decreased throughout the developmental period. In the male rats, the hypothalamic mRNA levels of ER-α were higher on PND 30 than on PND 10. On the other hand, no significant differences in hypothalamic ER-α mRNA expression were detected among the examined time points in the female rats, although hypothalamic ER-α mRNA expression tended to be higher on PND 30 than on PND 10. Significant positive correlations were detected between hypothalamic OT and ER-α mRNA expression in both the male and female rats. Hypothalamic OT mRNA expression was not affected by fasting at any of the examined time points in either sex. These results indicate that hypothalamic OT expression is not sensitive to fasting during the developmental period. In addition, as a positive correlation was detected between hypothalamic OT and ER-α mRNA expression, these two molecules might interact with each other to induce appropriate neuronal development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hypothalamic peroxisome proliferator-activated receptor gamma regulates ghrelin production and food intake.

Science.gov (United States)

Li, Qingjie; Yu, Quan; Lin, Li; Zhang, Heng; Peng, Miao; Jing, Chunxia; Xu, Geyang

2018-04-09

Peroxisome proliferator-activated receptor-γ (PPARγ) regulates fatty acid storage, glucose metabolism, and food intake. Ghrelin, a gastric hormone, provides a hunger signal to the central nervous system to stimulate appetite. However, the effects of PPARγ on ghrelin production are still unclear. In the present study, the effects of PPARγ on ghrelin production were examined in lean- or high-fat diet-induced obese (DIO) C57BL/6J mice and mHypoE-42 cells, a hypothalamic cell line. 3rd intracerebroventricular injection of adenoviral-directed overexpression of PPARγ (Ad-PPARγ) reduced hypothalamic and plasma ghrelin, food intake in both lean C57BL/6J mice and diet-induced obese mice. These changes were associated with a significant increase in mechanistic target of rapamycin complex 1 (mTORC1) activity. Overexpression of PPARγ enhanced mTORC1 signaling and suppressed ghrelin production in cultured mHypoE-42 cells. Our results suggest that hypothalamic PPARγ plays a vital role in ghrelin production and food intake in mice. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hypothalamic obesity in patients with craniopharyngioma: Profound changes of several weight regulatory circuits

Directory of Open Access Journals (Sweden)

Christian eRoth

2011-10-01

Full Text Available One of the most striking examples of dysfunctional hypothalamic signaling of energy homeostasis is observed in patients with hypothalamic lesions leading to hypothalamic obesity (HO. This drastic condition is frequently seen in patients with craniopharyngioma (CP, an embryological tumor located in the hypothalamic and/or pituitary region, frequently causing not only hypopituitarism, but also leading to damage of medial hypothalamic nuclei due to the tumor and its treatment. HO syndrome in CP patients is characterized by fatigue, decreased physical activity, uncontrolled appetite, and morbid obesity, and is associated with insulin and leptin resistance. Mechanisms leading to the profoundly disturbed energy homeostasis are complex. This review summarizes different aspects of important clinical studies as well as data obtained in rodent studies. In addition a model is provided describing how medial hypothalamic lesion can interact simultaneously with several weight regulating circuitries.

Hypothalamic hamartoma: is the epileptogenic zone always hypothalamic? Arguments for independent (third stage) secondary epileptogenesis.

Science.gov (United States)

Scholly, Julia; Valenti, Maria-Paola; Staack, Anke M; Strobl, Karl; Bast, Thomas; Kehrli, Pierre; Steinhoff, Bernhard J; Hirsch, Edouard

2013-12-01

Gelastic seizures associated with hypothalamic hamartomas (HHs) are a clinicoradiologic syndrome presenting with a variety of symptoms, including pharmacoresistant epilepsy with multiple seizure types, electroencephalography (EEG) abnormalities, precocious puberty, behavioral disturbances, and progressive cognitive deterioration. Surgery in adults provides seizure freedom in only one third of patients. The poor results of epilepsy surgery could be explained by an extrahypothalamic epileptogenic zone. The existence of an independent, secondary epileptogenic area with persistent seizures after resection of the presumably primary lesion supports the concept of a "hypothalamic plus" epilepsy. "Hypothalamic plus" epilepsy could be related to either an extrahypothalamic structural lesion (visible on magnetic resonance imaging [MRI] or on neuropathology) or if the former is absent, to a functional alteration with enhanced epileptogenic properties due to a process termed secondary epileptogenesis. We report two patients with gelastic seizures with HH (gelastic seizures isolated or associated with dyscognitive seizures of temporal origin). Both patients underwent two-step surgery: first an endoscopic resection of the HH, followed at a later time by temporal lobectomy. Both patients became seizure-free only after the temporal lobectomy. In both cases, neuropathology failed to demonstrate a significant structural lesion in the temporal lobe. To our knowledge, for the first time, these two cases suggest the existence of independent secondary epileptogenesis in humans. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

Hybrid energy system evaluation in water supply system energy production: neural network approach

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Fabio V.; Ramos, Helena M. [Civil Engineering Department, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001, Lisbon (Portugal); Reis, Luisa Fernanda R. [Universidade de Sao Paulo, EESC/USP, Departamento de Hidraulica e Saneamento., Avenida do Trabalhador Saocarlense, 400, Sao Carlos-SP (Brazil)

2010-07-01

Water supply systems are large consumers of energy and the use of hybrid systems for green energy production is this new proposal. This work presents a computational model based on neural networks to determine the best configuration of a hybrid system to generate energy in water supply systems. In this study the energy sources to make this hybrid system can be the national power grid, micro-hydro and wind turbines. The artificial neural network is composed of six layers, trained to use data generated by a model of hybrid configuration and an economic simulator - CES. The reason for the development of an advanced model of forecasting based on neural networks is to allow rapid simulation and proper interaction with hydraulic and power model simulator - HPS. The results show that this computational model is useful as advanced decision support system in the design of configurations of hybrid power systems applied to water supply systems, improving the solutions in the development of its global energy efficiency.

Anomaly detection in an automated safeguards system using neural networks

International Nuclear Information System (INIS)

Whiteson, R.; Howell, J.A.

1992-01-01

An automated safeguards system must be able to detect an anomalous event, identify the nature of the event, and recommend a corrective action. Neural networks represent a new way of thinking about basic computational mechanisms for intelligent information processing. In this paper, we discuss the issues involved in applying a neural network model to the first step of this process: anomaly detection in materials accounting systems. We extend our previous model to a 3-tank problem and compare different neural network architectures and algorithms. We evaluate the computational difficulties in training neural networks and explore how certain design principles affect the problems. The issues involved in building a neural network architecture include how the information flows, how the network is trained, how the neurons in a network are connected, how the neurons process information, and how the connections between neurons are modified. Our approach is based on the demonstrated ability of neural networks to model complex, nonlinear, real-time processes. By modeling the normal behavior of the processes, we can predict how a system should be behaving and, therefore, detect when an abnormality occurs

Changes in the responsiveness of hypothalamic PK2 and PKR1 gene expression to fasting in developing male rats.

Science.gov (United States)

Iwasa, Takeshi; Matsuzaki, Toshiya; Tungalagsuvd, Altankhuu; Munkhzaya, Munkhsaikhan; Kawami, Takako; Yamasaki, Mikio; Murakami, Masahiro; Kato, Takeshi; Kuwahara, Akira; Yasui, Toshiyuki; Irahara, Minoru

2014-11-01

Prokineticin (PK2) and its receptors (PKRs) are expressed in several regions of the central nervous system, including the hypothalamus. It has been reported that PK2 inhibits food intake via PKR1 and that the hypothalamic PK2 mRNA levels of adult rodents were reduced by food deprivation. However, some hypothalamic factors do not exhibit sensitivity to undernutrition in the early neonatal period, but subsequently become sensitive to it during the neonatal to pre-pubertal period. In this study, we investigated the changes in the sensitivity of hypothalamic PK2 and PKR1 mRNA expression to fasting during the developmental period in male rats. Under the fed conditions, the rats' hypothalamic PK2 and/or PKR1 mRNA levels were higher on postnatal day (PND) 10 than on PND20 or PND30. In addition, the hypothalamic PK2 and/or PKR1 mRNA levels of the male rats were higher than those of the females at all examined ages (PND10, 20, and 30). Hypothalamic PK2 mRNA expression was decreased by 24h fasting at PND10 and 30, but not at PND20. In addition, hypothalamic PKR1 mRNA expression was decreased by 24h fasting at PND10, but not at PND20 or 30. These results indicate that both PK2 and PKR1 are sensitive to nutritional status in male rats and that this sensitivity has already been established by the early neonatal period. It can be speculated that the PK2 system might compensate for the immaturity of other appetite regulatory factors in the early neonatal period. Copyright © 2014 ISDN. Published by Elsevier Ltd. All rights reserved.

Decoupling control of vehicle chassis system based on neural network inverse system

Science.gov (United States)

Wang, Chunyan; Zhao, Wanzhong; Luan, Zhongkai; Gao, Qi; Deng, Ke

2018-06-01

Steering and suspension are two important subsystems affecting the handling stability and riding comfort of the chassis system. In order to avoid the interference and coupling of the control channels between active front steering (AFS) and active suspension subsystems (ASS), this paper presents a composite decoupling control method, which consists of a neural network inverse system and a robust controller. The neural network inverse system is composed of a static neural network with several integrators and state feedback of the original chassis system to approach the inverse system of the nonlinear systems. The existence of the inverse system for the chassis system is proved by the reversibility derivation of Interactor algorithm. The robust controller is based on the internal model control (IMC), which is designed to improve the robustness and anti-interference of the decoupled system by adding a pre-compensation controller to the pseudo linear system. The results of the simulation and vehicle test show that the proposed decoupling controller has excellent decoupling performance, which can transform the multivariable system into a number of single input and single output systems, and eliminate the mutual influence and interference. Furthermore, it has satisfactory tracking capability and robust performance, which can improve the comprehensive performance of the chassis system.

Systemic Glucoregulation by Glucose-Sensing Neurons in the Ventromedial Hypothalamic Nucleus (VMH).

Science.gov (United States)

Shimazu, Takashi; Minokoshi, Yasuhiko

2017-05-01

The ventromedial hypothalamic nucleus (VMH) regulates glucose production in the liver as well as glucose uptake and utilization in peripheral tissues, including skeletal muscle and brown adipose tissue, via efferent sympathetic innervation and neuroendocrine mechanisms. The action of leptin on VMH neurons also increases glucose uptake in specific peripheral tissues through the sympathetic nervous system, with improved insulin sensitivity. On the other hand, subsets of VMH neurons, such as those that express steroidogenic factor 1 (SF1), sense changes in the ambient glucose concentration and are characterized as glucose-excited (GE) and glucose-inhibited (GI) neurons whose action potential frequency increases and decreases, respectively, as glucose levels rise. However, how these glucose-sensing (GE and GI) neurons in the VMH contribute to systemic glucoregulation remains poorly understood. In this review, we provide historical background and discuss recent advances related to glucoregulation by VMH neurons. In particular, the article describes the role of GE neurons in the control of peripheral glucose utilization and insulin sensitivity, which depend on mitochondrial uncoupling protein 2 of the neurons, as well as that of GI neurons in the control of hepatic glucose production through hypoglycemia-induced counterregulatory mechanisms.

Hypothalamic glucose-sensing: role of Glia-to-neuron signaling.

Science.gov (United States)

Tonon, M C; Lanfray, D; Castel, H; Vaudry, H; Morin, F

2013-12-01

The hypothalamus senses hormones and nutrients in order to regulate energy balance. In particular, detection of hypothalamic glucose levels has been shown to regulate both feeding behavior and peripheral glucose homeostasis, and impairment of this regulatory system is believed to be involved in the development of obesity and diabetes. Several data clearly demonstrate that glial cells are key elements in the perception of glucose, constituting with neurons a "glucose-sensing unit". Characterization of this interplay between glia and neurons represents an exciting challenge, and will undoubtedly contribute to identify new candidates for therapeutic intervention. The purpose of this review is to summarize the current data that stress the importance of glia in central glucose-sensing. The nature of the glia-to-neuron signaling is discussed, with a special focus on the endozepine ODN, a potent anorexigenic peptide that is highly expressed in hypothalamic glia. © Georg Thieme Verlag KG Stuttgart · New York.

Hypothalamic control of energy and glucose metabolism.

Science.gov (United States)

Sisley, Stephanie; Sandoval, Darleen

2011-09-01

The central nervous system (CNS), generally accepted to regulate energy homeostasis, has been implicated in the metabolic perturbations that either cause or are associated with obesity. Normally, the CNS receives hormonal, metabolic, and neuronal input to assure adequate energy levels and maintain stable energy homeostasis. Recent evidence also supports that the CNS uses these same inputs to regulate glucose homeostasis and this aspect of CNS regulation also becomes impaired in the face of dietary-induced obesity. This review focuses on the literature surrounding hypothalamic regulation of energy and glucose homeostasis and discusses how dysregulation of this system may contribute to obesity and T2DM.

Bone metabolism in anorexia nervosa and hypothalamic amenorrhea.

Science.gov (United States)

Chou, Sharon H; Mantzoros, Christos

2018-03-01

Anorexia nervosa (AN) and hypothalamic amenorrhea (HA) are states of chronic energy deprivation associated with severely compromised bone health. Poor bone accrual during adolescence followed by increased bone loss results in lifelong low bone density, degraded bone architecture, and higher risk of fractures, despite recovery from AN/HA. Amenorrhea is only one of several compensatory responses to the negative energy balance. Other hypothalamic-pituitary hormones are affected and contribute to bone deficits, including activation of hypothalamic-pituitary-adrenal axis and growth hormone resistance. Adipokines, particularly leptin, provide information on fat/energy stores, and gut hormones play a role in the regulation of appetite and food intake. Alterations in all these hormones influence bone metabolism. Restricted in scope, current pharmacologic approaches to improve bone health have had overall limited success. Copyright © 2017 Elsevier Inc. All rights reserved.

Hypopituitarism after external irradiation. Evidence for both hypothalamic and pituitary origin

International Nuclear Information System (INIS)

Samaan, N.A.; Bakdash, M.M.; Caderao, J.B.; Cangir, A.; Jesse, R.H. Jr.; Ballantyne, A.J.

1975-01-01

Endocrine complications after radiotherapy for tumors of the head and neck are thought to be relatively rare. The availability of synthetic hypothalamic hormones for clinical investigations and the radioimmunoassay of hormones have enabled us to study function of the hypothalamic pituitary axis in 15 patients who had radiotherapy for nasopharyngeal cancer. Fourteen had evidence of endocrine deficiency. Twelve patients had evidence of hypothalamic dysfunction, 7 developed primary pituitary hormone deficiencies, and 3 developed primary hypothyroidism. These results indicate that (1) secondary hypopituitarism due to a hypothalamic lesion after radiotherapy for nasopharyngeal cancer may be more common than suspected in the past; (2) primary hypopituitarism after irradiation of extracranial tumors can occur; and (3) primary hypothyroidism may result from irradiation of regional neck nodes

Generation of neuropeptidergic hypothalamic neurons from human pluripotent stem cells.

Science.gov (United States)

Merkle, Florian T; Maroof, Asif; Wataya, Takafumi; Sasai, Yoshiki; Studer, Lorenz; Eggan, Kevin; Schier, Alexander F

2015-02-15

Hypothalamic neurons orchestrate many essential physiological and behavioral processes via secreted neuropeptides, and are relevant to human diseases such as obesity, narcolepsy and infertility. We report the differentiation of human pluripotent stem cells into many of the major types of neuropeptidergic hypothalamic neurons, including those producing pro-opiolemelanocortin, agouti-related peptide, hypocretin/orexin, melanin-concentrating hormone, oxytocin, arginine vasopressin, corticotropin-releasing hormone (CRH) or thyrotropin-releasing hormone. Hypothalamic neurons can be generated using a 'self-patterning' strategy that yields a broad array of cell types, or via a more reproducible directed differentiation approach. Stem cell-derived human hypothalamic neurons share characteristic morphological properties and gene expression patterns with their counterparts in vivo, and are able to integrate into the mouse brain. These neurons could form the basis of cellular models, chemical screens or cellular therapies to study and treat common human diseases. © 2015. Published by The Company of Biologists Ltd.

Cerebrospinal fluid levels of corticotropin-releasing hormone in women with functional hypothalamic amenorrhea.

Science.gov (United States)

Berga, S L; Loucks-Daniels, T L; Adler, L J; Chrousos, G P; Cameron, J L; Matthews, K A; Marcus, M D

2000-04-01

Women with functional hypothalamic amenorrhea are anovulatory because of reduced gonadotropin-releasing hormone drive. Several studies have documented hypercortisolemia, which suggests that functional hypothalamic amenorrhea is stress-induced. Further, with recovery (resumption of ovulation), cortisol decreased and gonadotropin-releasing hormone drive increased. Corticotropin-releasing hormone can increase cortisol and decrease gonadotropin-releasing hormone. To determine its role in functional hypothalamic amenorrhea, we measured corticotropin-releasing hormone in cerebrospinal fluid along with arginine vasopressin, another potent adrenocorticotropic hormone secretagog, and beta-endorphin, which is released by corticotropin-releasing hormone and can inhibit gonadotropin-releasing hormone. Corticotropin-releasing hormone, vasopressin, and beta-endorphin levels were measured in cerebrospinal fluid from 14 women with eumenorrhea and 15 women with functional hypothalamic amenorrhea. Levels of corticotropin-releasing hormone in cerebrospinal fluid and of vasopressin were comparable and beta-endorphin levels were lower in women with functional hypothalamic amenorrhea. In women with established functional hypothalamic amenorrhea, increased cortisol and reduced gonadotropin-releasing hormone are not sustained by elevated cerebrospinal-fluid corticotropin-releasing hormone, vasopressin, or beta-endorphin. These data do not exclude a role for these factors in the initiation of functional hypothalamic amenorrhea.

Leptin is an effective treatment for hypothalamic amenorrhea

OpenAIRE

Chou, Sharon H.; Chamberland, John P.; Liu, Xiaowen; Matarese, Giuseppe; Gao, Chuanyun; Stefanakis, Rianna; Brinkoetter, Mary T.; Gong, Huizhi; Arampatzi, Kalliopi; Mantzoros, Christos S.

2011-01-01

Hypothalamic amenorrhea (HA) is associated with dysfunction of the hypothalamic-pituitary-peripheral endocrine axes, leading to infertility and bone loss, and usually is caused by chronic energy deficiency secondary to strenuous exercise and/or decreased food intake. Energy deficiency also leads to hypoleptinemia, which has been proposed, on the basis of observational studies as well as an open-label study, to mediate the neuroendocrine abnormalities associated with this condition. To prove d...

Identification of Complex Dynamical Systems with Neural Networks (2/2)

CERN Multimedia

CERN. Geneva

2016-01-01

The identification and analysis of high dimensional nonlinear systems is obviously a challenging task. Neural networks have been proven to be universal approximators but this still leaves the identification task a hard one. To do it efficiently, we have to violate some of the rules of classical regression theory. Furthermore we should focus on the interpretation of the resulting model to overcome its black box character. First, we will discuss function approximation with 3 layer feedforward neural networks up to new developments in deep neural networks and deep learning. These nets are not only of interest in connection with image analysis but are a center point of the current artificial intelligence developments. Second, we will focus on the analysis of complex dynamical system in the form of state space models realized as recurrent neural networks. After the introduction of small open dynamical systems we will study dynamical systems on manifolds. Here manifold and dynamics have to be identified in parall...

Identification of Complex Dynamical Systems with Neural Networks (1/2)

CERN Multimedia

CERN. Geneva

2016-01-01

The identification and analysis of high dimensional nonlinear systems is obviously a challenging task. Neural networks have been proven to be universal approximators but this still leaves the identification task a hard one. To do it efficiently, we have to violate some of the rules of classical regression theory. Furthermore we should focus on the interpretation of the resulting model to overcome its black box character. First, we will discuss function approximation with 3 layer feedforward neural networks up to new developments in deep neural networks and deep learning. These nets are not only of interest in connection with image analysis but are a center point of the current artificial intelligence developments. Second, we will focus on the analysis of complex dynamical system in the form of state space models realized as recurrent neural networks. After the introduction of small open dynamical systems we will study dynamical systems on manifolds. Here manifold and dynamics have to be identified in parall...

Neural computing thermal comfort index for HVAC systems

International Nuclear Information System (INIS)

Atthajariyakul, S.; Leephakpreeda, T.

2005-01-01

The primary purpose of a heating, ventilating and air conditioning (HVAC) system within a building is to make occupants comfortable. Without real time determination of human thermal comfort, it is not feasible for the HVAC system to yield controlled conditions of the air for human comfort all the time. This paper presents a practical approach to determine human thermal comfort quantitatively via neural computing. The neural network model allows real time determination of the thermal comfort index, where it is not practical to compute the conventional predicted mean vote (PMV) index itself in real time. The feed forward neural network model is proposed as an explicit function of the relation of the PMV index to accessible variables, i.e. the air temperature, wet bulb temperature, globe temperature, air velocity, clothing insulation and human activity. An experiment in an air conditioned office room was done to demonstrate the effectiveness of the proposed methodology. The results show good agreement between the thermal comfort index calculated from the neural network model in real time and those calculated from the conventional PMV model

Activity of the Hypothalamic-Pituitary-Adrenal System in Prenatally Stressed Male Rats on the Experimental Model of Post-Traumatic Stress Disorder.

Science.gov (United States)

Pivina, S G; Rakitskaya, V V; Akulova, V K; Ordyan, N E

2016-03-01

Using the experimental model of post-traumatic stress disorder (stress-restress paradigm), we studied the dynamics of activity of the hypothalamic-pituitary-adrenal system (HPAS) in adult male rats, whose mothers were daily subjected to restraint stress on days 15-19 of pregnancy. Prenatally stressed males that were subjected to combined stress and subsequent restress exhibited not only increased sensitivity of HPAS to negative feedback signals (manifested under restress conditions), but also enhanced stress system reactivity. These changes persisted to the 30th day after restress. Under basal conditions, the number of cells in the hypothalamic paraventricular nucleus of these animals expressing corticotropin-releasing hormone and vasopressin was shown to decrease progressively on days 1-30. By contrast, combined stress and restress in control animals were followed by an increase in the count of CRH-immunopositive cells in the magnocellular and parvocellular parts of the paraventricular nucleus and number of vasopressin-immunopositive cells in the magnocellular part of the nucleus (to the 10th day after restress). Our results indicate a peculiar level of functional activity of HPAS in prenatally stressed males in the stress-restress paradigm: decreased activity under basal conditions and enhanced reactivity during stress.

Magnetic resonance imaging of hypothalamic hamartoma

Energy Technology Data Exchange (ETDEWEB)

Kanazawa, Junichi; Uozumi, Tohru; Sakoda, Katsuaki; Yamanaka, Masami; Kihara, Mikio; Nishi, Yoshikazu; Kagawa, Yoshihiro; Kajima, Toshio.

1988-05-01

Magnetic resonance (MR) findings of two patients with a hypothalamic hamartoma are discussed. The two girls showed clinical symptoms and endocrinological signs of precocious puberty. MR imaging was of diagnostic value superior to that of CT in the demonstration of the characteristic location of this tumor and relationships to the neighboring structures because of its multi-dimensional utility. Although it has been reported that CT showed this lesion as isodense to the grey matter with and without injection of contrast medium, MR imaging depicted the lesion as a high signal intensity area on T2-weighted images in both patients. MR imaging is a useful method for the evaluation of the hypothalamic hamartoma.

Growth hormone modulates hypothalamic inflammation in long-lived pituitary dwarf mice.

Science.gov (United States)

Sadagurski, Marianna; Landeryou, Taylor; Cady, Gillian; Kopchick, John J; List, Edward O; Berryman, Darlene E; Bartke, Andrzej; Miller, Richard A

2015-12-01

Mice in which the genes for growth hormone (GH) or GH receptor (GHR(-/-) ) are disrupted from conception are dwarfs, possess low levels of IGF-1 and insulin, have low rates of cancer and diabetes, and are extremely long-lived. Median longevity is also increased in mice with deletion of hypothalamic GH-releasing hormone (GHRH), which leads to isolated GH deficiency. The remarkable extension of longevity in hypopituitary Ames dwarf mice can be reversed by a 6-week course of GH injections started at the age of 2 weeks. Here, we demonstrate that mutations that interfere with GH production or response, in the Snell dwarf, Ames dwarf, or GHR(-/-) mice lead to reduced formation of both orexigenic agouti-related peptide (AgRP) and anorexigenic proopiomelanocortin (POMC) projections to the main hypothalamic projection areas: the arcuate nucleus (ARH), paraventricular nucleus (PVH), and dorsomedial nucleus (DMH). These mutations also reduce hypothalamic inflammation in 18-month-old mice. GH injections, between 2 and 8 weeks of age, reversed both effects in Ames dwarf mice. Disruption of GHR specifically in liver (LiGHRKO), a mutation that reduces circulating IGF-1 but does not lead to lifespan extension, had no effect on hypothalamic projections or inflammation, suggesting an effect of GH, rather than peripheral IGF-1, on hypothalamic development. Hypothalamic leptin signaling, as monitored by induction of pStat3, is not impaired by GHR deficiency. Together, these results suggest that early-life disruption of GH signaling produces long-term hypothalamic changes that may contribute to the longevity of GH-deficient and GH-resistant mice. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

NNSYSID and NNCTRL Tools for system identification and control with neural networks

DEFF Research Database (Denmark)

Nørgaard, Magnus; Ravn, Ole; Poulsen, Niels Kjølstad

2001-01-01

choose among several designs such as direct inverse control, internal model control, nonlinear feedforward, feedback linearisation, optimal control, gain scheduling based on instantaneous linearisation of neural network models and nonlinear model predictive control. This article gives an overview......Two toolsets for use with MATLAB have been developed: the neural network based system identification toolbox (NNSYSID) and the neural network based control system design toolkit (NNCTRL). The NNSYSID toolbox has been designed to assist identification of nonlinear dynamic systems. It contains...... a number of nonlinear model structures based on neural networks, effective training algorithms and tools for model validation and model structure selection. The NNCTRL toolkit is an add-on to NNSYSID and provides tools for design and simulation of control systems based on neural networks. The user can...

NNSYSID and NNCTRL Tools for system identification and control with neural networks

DEFF Research Database (Denmark)

Nørgaard, Magnus; Ravn, Ole; Poulsen, Niels Kjølstad

2001-01-01

a number of nonlinear model structures based on neural networks, effective training algorithms and tools for model validation and model structure selection. The NNCTRL toolkit is an add-on to NNSYSID and provides tools for design and simulation of control systems based on neural networks. The user can...... choose among several designs such as direct inverse control, internal model control, nonlinear feedforward, feedback linearisation, optimal control, gain scheduling based on instantaneous linearisation of neural network models and nonlinear model predictive control. This article gives an overview......Two toolsets for use with MATLAB have been developed: the neural network based system identification toolbox (NNSYSID) and the neural network based control system design toolkit (NNCTRL). The NNSYSID toolbox has been designed to assist identification of nonlinear dynamic systems. It contains...

A New Controller to Enhance PV System Performance Based on Neural Network

Directory of Open Access Journals (Sweden)

Roshdy A AbdelRassoul

2017-06-01

Full Text Available In recent years, a radical increase of photovoltaic (PV power generators installation took place because of increased efficiency of solar cells, as well as the growth of manufacturing technology of solar panels. This paper shows the operation and modeling of photovoltaic systems, particularly designing neural controller to control the system. Neural controller is optimized using particle swarm optimization (PSO   leads to getting the best performance of the designed PV system. Using neural network the maximum overshoot and rise time obtained become 0.00001% and 0.1798 seconds, respectively also this paper introduce a comparison between some kind of controller for PV system.In recent years, a radical increase of photovoltaic (PV power generators installation took place because of increased efficiency of solar cells, as well as the growth of manufacturing technology of solar panels. This paper shows the operation and modeling of photovoltaic systems, particularly designing neural controller to control the system. Neural controller is optimized using particle swarm optimization (PSO   leads to getting the best performance of the designed PV system. Using neural network the maximum overshoot and rise time obtained become 0.00001% and 0.1798 seconds, respectively also this paper introduce a comparison between some kind of controller for PV system.

Computational neural network regression model for Host based Intrusion Detection System

Directory of Open Access Journals (Sweden)

Sunil Kumar Gautam

2016-09-01

Full Text Available The current scenario of information gathering and storing in secure system is a challenging task due to increasing cyber-attacks. There exists computational neural network techniques designed for intrusion detection system, which provide security to single machine and entire network's machine. In this paper, we have used two types of computational neural network models, namely, Generalized Regression Neural Network (GRNN model and Multilayer Perceptron Neural Network (MPNN model for Host based Intrusion Detection System using log files that are generated by a single personal computer. The simulation results show correctly classified percentage of normal and abnormal (intrusion class using confusion matrix. On the basis of results and discussion, we found that the Host based Intrusion Systems Model (HISM significantly improved the detection accuracy while retaining minimum false alarm rate.

Adaptive neural network/expert system that learns fault diagnosis for different structures

Science.gov (United States)

Simon, Solomon H.

1992-08-01

Corporations need better real-time monitoring and control systems to improve productivity by watching quality and increasing production flexibility. The innovative technology to achieve this goal is evolving in the form artificial intelligence and neural networks applied to sensor processing, fusion, and interpretation. By using these advanced Al techniques, we can leverage existing systems and add value to conventional techniques. Neural networks and knowledge-based expert systems can be combined into intelligent sensor systems which provide real-time monitoring, control, evaluation, and fault diagnosis for production systems. Neural network-based intelligent sensor systems are more reliable because they can provide continuous, non-destructive monitoring and inspection. Use of neural networks can result in sensor fusion and the ability to model highly, non-linear systems. Improved models can provide a foundation for more accurate performance parameters and predictions. We discuss a research software/hardware prototype which integrates neural networks, expert systems, and sensor technologies and which can adapt across a variety of structures to perform fault diagnosis. The flexibility and adaptability of the prototype in learning two structures is presented. Potential applications are discussed.

Hypothalamic-pituitary-testicular system following testicular X-irradiation

International Nuclear Information System (INIS)

Verjans, H.L.; Eik-Nes, K.B.

1976-01-01

Testes of adult, male rats were exposed to a total dose of 1500 R of X-irradiation. Testicular weight decreased from day 8 after X-ray treatment. This decrease was, however, precded by an increment of the testis weight on day 4 following treatment. X-ray treatment of testes was associated with significant increase in serum FSH. Testicular irradiation had, however, no effect on ventral prostate and seminal vesicles weights. Serum testosterone increased only on day 1, 2 and 4 after irradiation, while serum LH levels tended to increase from day 8 post-irradiation. These changes were not significant, however, when compared with non-irradiated controls. At 7, 13 and 20 days following 1500 R of bilateral, testicular X-irradiation, the hypothalamic-pituitary unit was still capable of responding to exogenous gonadotrophin releasing factor. Serum FSH may in male rats be regulated at least partly by circulating steroids of testicular origin and partly by an unknown factor of non-interstitial cell nature. (author)

Neural neworks in a management information systems

OpenAIRE

Jana Weinlichová; Michael Štencl

2009-01-01

For having retrospection for all over the data which are used, analyzed, evaluated and for a future incident predictions are used Management Information Systems and Business Intelligence. In case of not to be able to apply standard methods of data processing there can be with benefit applied an Artificial Intelligence. In this article will be referred to proofed abilities of Neural Networks. The Neural Networks is supported by many software products related to provide effective solution of ma...

Vein matching using artificial neural network in vein authentication systems

Science.gov (United States)

Noori Hoshyar, Azadeh; Sulaiman, Riza

2011-10-01

Personal identification technology as security systems is developing rapidly. Traditional authentication modes like key; password; card are not safe enough because they could be stolen or easily forgotten. Biometric as developed technology has been applied to a wide range of systems. According to different researchers, vein biometric is a good candidate among other biometric traits such as fingerprint, hand geometry, voice, DNA and etc for authentication systems. Vein authentication systems can be designed by different methodologies. All the methodologies consist of matching stage which is too important for final verification of the system. Neural Network is an effective methodology for matching and recognizing individuals in authentication systems. Therefore, this paper explains and implements the Neural Network methodology for finger vein authentication system. Neural Network is trained in Matlab to match the vein features of authentication system. The Network simulation shows the quality of matching as 95% which is a good performance for authentication system matching.

Increased cortisol responsivity to adrenocorticotropic hormone and low plasma levels of interleukin-1 receptor antagonist in women with functional hypothalamic amenorrhea.

Science.gov (United States)

Lindahl, Magnus S; Olovsson, Matts; Nyberg, Sigrid; Thorsen, Kim; Olsson, Tommy; Sundström Poromaa, Inger

2007-01-01

To assess the hypothalamic-pituitary-adrenal (HPA) axis at all levels, to determine the origin of the previously reported hypercortisolism in patients with functional hypothalamic amenorrhea. A secondary aim was to evaluate factors outside the central nervous system which are known to affect the HPA axis, i.e., circulating levels of interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1Ra), and fat mass-adjusted leptin levels, in patients with functional hypothalamic amenorrhea and healthy controls. Cross-sectional study. Umeå University Hospital, Umeå, Sweden. Fifteen subjects with hypothalamic amenorrhea, and 14 age- and weight-matched controls. None. We collected blood samples four times during a 24-hour interval for analysis of cortisol, leptin, IL-1Ra, and IL-6 levels. We performed a low-dose oral dexamethasone test and a low-dose ACTH test. We measured body-fat percentage using a dual-energy X-ray absorptiometer. Patients with hypothalamic amenorrhea had increased diurnal cortisol levels (P<.001). The cortisol response to intravenous low-dose ACTH was increased in functional hypothalamic amenorrhea patients compared to control subjects (P<.01), but they had similar rates of dexamethasone suppression. Patients with hypothalamic amenorrhea also had decreased diurnal leptin (P<.05), and decreased diurnal IL-1Ra levels (P<.05), compared to controls. Body-fat percentage was the main predictor of leptin levels. The present study suggests novel links for the development of functional hypothalamic amenorrhea, including increased adrenal responsiveness and impairments in proinflammatory cytokine pathways.

Adaptive Synchronization of Memristor-based Chaotic Neural Systems

Directory of Open Access Journals (Sweden)

Xiaofang Hu

2014-11-01

Full Text Available Chaotic neural networks consisting of a great number of chaotic neurons are able to reproduce the rich dynamics observed in biological nervous systems. In recent years, the memristor has attracted much interest in the efficient implementation of artificial synapses and neurons. This work addresses adaptive synchronization of a class of memristor-based neural chaotic systems using a novel adaptive backstepping approach. A systematic design procedure is presented. Simulation results have demonstrated the effectiveness of the proposed adaptive synchronization method and its potential in practical application of memristive chaotic oscillators in secure communication.

Proliferative hypothalamic neurospheres express NPY, AGRP, POMC, CART and Orexin-A and differentiate to functional neurons.

Directory of Open Access Journals (Sweden)

Lígia Sousa-Ferreira

Full Text Available Some pathological conditions with feeding pattern alterations, including obesity and Huntington disease (HD are associated with hypothalamic dysfunction and neuronal cell death. Additionally, the hypothalamus is a neurogenic region with the constitutive capacity to generate new cells of neuronal lineage, in adult rodents. The aim of the present work was to evaluate the expression of feeding-related neuropeptides in hypothalamic progenitor cells and their capacity to differentiate to functional neurons which have been described to be affected by hypothalamic dysfunction. Our study shows that hypothalamic progenitor cells from rat embryos grow as floating neurospheres and express the feeding-related neuropeptides Neuropeptide Y (NPY, Agouti-related Protein (AGRP, Pro-OpioMelanocortin (POMC, Cocaine-and-Amphetamine Responsive Transcript (CART and Orexin-A/Hypocretin-1. Moreover the relative mRNA expression of NPY and POMC increases during the expansion of hypothalamic neurospheres in proliferative conditions.Mature neurons were obtained from the differentiation of hypothalamic progenitor cells including NPY, AGRP, POMC, CART and Orexin-A positive neurons. Furthermore the relative mRNA expression of NPY, CART and Orexin-A increases after the differentiation of hypothalamic neurospheres. Similarly to the adult hypothalamic neurons the neurospheres-derived neurons express the glutamate transporter EAAT3. The orexigenic and anorexigenic phenotype of these neurons was identified by functional response to ghrelin and leptin hormones, respectively. This work demonstrates the presence of appetite-related neuropeptides in hypothalamic progenitor cells and neurons obtained from the differentiation of hypothalamic neurospheres, including the neuronal phenotypes that have been described by others as being affected by hypothalamic neurodegeneration. These in vitro models can be used to study hypothalamic progenitor cells aiming a therapeutic intervention to

Radial basis function neural network for power system load-flow

International Nuclear Information System (INIS)

Karami, A.; Mohammadi, M.S.

2008-01-01

This paper presents a method for solving the load-flow problem of the electric power systems using radial basis function (RBF) neural network with a fast hybrid training method. The main idea is that some operating conditions (values) are needed to solve the set of non-linear algebraic equations of load-flow by employing an iterative numerical technique. Therefore, we may view the outputs of a load-flow program as functions of the operating conditions. Indeed, we are faced with a function approximation problem and this can be done by an RBF neural network. The proposed approach has been successfully applied to the 10-machine and 39-bus New England test system. In addition, this method has been compared with that of a multi-layer perceptron (MLP) neural network model. The simulation results show that the RBF neural network is a simpler method to implement and requires less training time to converge than the MLP neural network. (author)

An Artificial Neural Network Controller for Intelligent Transportation Systems Applications

Science.gov (United States)

1996-01-01

An Autonomous Intelligent Cruise Control (AICC) has been designed using a feedforward artificial neural network, as an example for utilizing artificial neural networks for nonlinear control problems arising in intelligent transportation systems appli...

The different effects of high-frequency stimulation of the nucleus accumbens shell and core on food consumption are possibly associated with different neural responses in the lateral hypothalamic area.

Science.gov (United States)

Wei, N; Wang, Y; Wang, X; He, Z; Zhang, M; Zhang, X; Pan, Y; Zhang, J; Qin, Z; Zhang, K

2015-08-20

Obesity may result from dysfunction of the reward system, especially in the nucleus accumbens (Acb). Based on this hypothesis, many researchers have tested the effect of high-frequency stimulation (HFS) of the Acb shell (Acb-Sh) and/or core (Acb-Co) on ingestive behaviors, but few studies have explored the possible mechanisms involved in the differences between the Acb-Sh and Acb-Co. The present study tested effects of HFS of the Acb-Sh and Acb-Co on high-fat food (HFF) consumption in rats after 24h of food deprivation. Microdialysis and electrophysiological experiments were carried out in awake rats to explore potential mechanisms. The results showed that the Acb-Sh decreased HFF consumption after food deprivation both during and post-HFS. However, HFS of the Acb-Co did not induce similar changes in food consumption. HFS of the Acb-Sh (Sh-HFS) induced an increase in GABA level in the lateral hypothalamic area (LHA) during both phases, whereas HFS of the Acb-Co (Co-HFS) did not exhibit similar effects. The electrophysiological experiment showed that nearly all the LHA neurons were inhibited by Sh-HFS, and the mean firing rate decreased significantly both during and post-HFS. In contrast, the mean firing rate of the LHA neurons did not exhibit clear changes during Co-HFS, although some individual neurons appeared to exhibit responses to Co-HFS. Considering all the data, we postulated that Sh-HFS, rather than Co-HFS, might inhibit palatable food consumption after food deprivation by decreasing the reward value of that food, which suggested that it might also disturb the process of developing obesity. The mechanisms involved in the different effects of Sh-HFS and Co-HFS on food consumption may be associated with different neural responses in the LHA. The Acb-Sh has abundant GABAergic projections to the LHA, whereas the Acb-Co has few or no GABAergic innervations to the LHA. Thus, neural activity in the LHA exhibits different responses to Sh-HFS and Co-HFS. Copyright �

High speed digital interfacing for a neural data acquisition system

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Bahr Andreas

2016-09-01

Full Text Available Diseases like schizophrenia and genetic epilepsy are supposed to be caused by disorders in the early development of the brain. For the further investigation of these relationships a custom designed application specific integrated circuit (ASIC was developed that is optimized for the recording from neonatal mice [Bahr A, Abu-Saleh L, Schroeder D, Krautschneider W. 16 Channel Neural Recording Integrated Circuit with SPI Interface and Error Correction Coding. Proc. 9th BIOSTEC 2016. Biodevices: Rome, Italy, 2016; 1: 263; Bahr A, Abu-Saleh L, Schroeder D, Krautschneider W. Development of a neural recording mixed signal integrated circuit for biomedical signal acquisition. Biomed Eng Biomed Tech Abstracts 2015; 60(S1: 298–299; Bahr A, Abu-Saleh L, Schroeder D, Krautschneider WH. 16 Channel Neural Recording Mixed Signal ASIC. CDNLive EMEA 2015 Conference Proceedings, 2015.]. To enable the live display of the neural signals a multichannel neural data acquisition system with live display functionality is presented. It implements a high speed data transmission from the ASIC to a computer with a live display functionality. The system has been successfully implemented and was used in a neural recording of a head-fixed mouse.

Parameter estimation in space systems using recurrent neural networks

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Parlos, Alexander G.; Atiya, Amir F.; Sunkel, John W.

1991-01-01

The identification of time-varying parameters encountered in space systems is addressed, using artificial neural systems. A hybrid feedforward/feedback neural network, namely a recurrent multilayer perception, is used as the model structure in the nonlinear system identification. The feedforward portion of the network architecture provides its well-known interpolation property, while through recurrency and cross-talk, the local information feedback enables representation of temporal variations in the system nonlinearities. The standard back-propagation-learning algorithm is modified and it is used for both the off-line and on-line supervised training of the proposed hybrid network. The performance of recurrent multilayer perceptron networks in identifying parameters of nonlinear dynamic systems is investigated by estimating the mass properties of a representative large spacecraft. The changes in the spacecraft inertia are predicted using a trained neural network, during two configurations corresponding to the early and late stages of the spacecraft on-orbit assembly sequence. The proposed on-line mass properties estimation capability offers encouraging results, though, further research is warranted for training and testing the predictive capabilities of these networks beyond nominal spacecraft operations.

Hypothalamic-pituitary, ovarian and adrenal contributions to polycystic ovary syndrome.

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Baskind, N Ellissa; Balen, Adam H

2016-11-01

Polycystic ovary syndrome (PCOS) is a prevalent heterogeneous disorder linked with disturbances of reproductive, endocrine and metabolic function. The definition and aetiological hypotheses of PCOS are continually developing to incorporate evolving evidence of the syndrome, which appears to be both multifactorial and polygenic. The pathophysiology of PCOS encompasses inherent ovarian dysfunction that is strongly influenced by external factors including the hypothalamic-pituitary axis and hyperinsulinaemia. Neuroendocrine abnormalities including increased gonadotrophin-releasing hormone (GnRH) pulse frequency with consequent hypersecretion of luteinising hormone (LH) affects ovarian androgen synthesis, folliculogenesis and oocyte development. Disturbed ovarian-pituitary and hypothalamic feedback accentuates the gonadotrophin abnormalities, and there is emerging evidence putatively implicating dysfunction of the Kiss 1 system. Within the follicle subunit itself, there are intra-ovarian paracrine modulators, cytokines and growth factors, which appear to play a role. Adrenally derived androgens may also contribute to the pathogenesis of PCOS, but their role is less defined. Copyright © 2016. Published by Elsevier Ltd.

Hypothalamic pituitary abnormalities in tubercular meningitis at the time of diagnosis.

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Dhanwal, Dinesh Kumar; Vyas, Anirudh; Sharma, Ashok; Saxena, Alpana

2010-12-01

Tubercular meningitis (TBM) is the most dreaded form of extra pulmonary tuberculosis associated with high morbidity and mortality. Various hypothalamic pituitary hormonal abnormalities have been reported to occur years after recovery from disease but there are no systematic studies in the literature to evaluate the pituitary hypothalamic dysfunction in patients with TBM at the time of presentation. Therefore, the present study was designed to evaluate hypothalamic pituitary abnormalities in newly diagnosed patients with TBM. Patient case series. This prospective study included 75 untreated adult patients with TBM diagnosed as "definite", "highly probable" and "probable" TBM by Ahuja's criteria and in clinical stage 1, 2 or 3 at the time of presentation to hospital. Basal hormonal profile was measured by electrochemilumniscence technique for serum cortisol, luetinizing hormone (LH), follicular stimulating hormone (FSH), prolactin (PRL), thyrotropin (TSH), free tri-iodothyronine (fT3), and free thyroxine (fT4). All patients were subjected to MRI to image brain and hypothalamic pituitary axis and CT for adrenal glands. Thirty-two (42.7%) cases showed relative or absolute cortisol insufficiency. Twenty-three (30.7%) cases showed central hypothyroidism and 37 (49.3%) cases had hyperprolactinemia. No patient had evidence of diabetes insipidus. Multiple hormone deficiency was seen in 22 (29.3%) cases. MRI of hypothalamic pituitary axis using dynamic scanning and thin cuts revealed abnormalities in 10 (13.3%) of the cases. CT adrenal gland was normal in all the patients. Tubercular meningitis is associated with both hormonal and structural abnormalities in the hypothalamic pituitary axis at the time of diagnosis.

[Functional hypothalamic amenorrhea].

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Stárka, Luboslav; Dušková, Michaela

2015-10-01

Functional hypothalamic amenorrhea (FHA) besides pregnancy and syndrome of polycystic ovary is one of the most common causes of secondary amenorrhea. FHA results from the aberrations in pulsatile gonadotropin-releasing hormone (GnRH) secretion, which in turn causes impairment of the gonadotropins (follicle-stimulating hormone and luteinizing hormone). FHA is a form of the defence of organism in situations where life functions are more important than reproductive function. FHA is reversible; it can be normalized after ceasing the stress situation. There are three types of FHA: weight loss related, stress-related, and exercise-related amenorrhea. The final consequences are complex hormonal changes manifested by profound hypoestrogenism. Additionally, these patients present mild hypercortisolemia, low serum insulin levels, low insulin-like growth factor 1 (IGF-1) and low total triiodothyronine. Women health in this disorder is disturbed in several aspects including the skeletal system, cardiovascular system, and mental problems. Patients manifest a decrease in bone mass density, which is related to an increase in fracture risk. Therefore, osteopenia and osteoporosis are the main long-term complications of FHA. Cardiovascular complications include endothelial dysfunction and abnormal changes in the lipid profile. FHA patients present significantly higher depression and anxiety and also sexual problems compared to healthy subjects.

[Patients with functional hypothalamic amenorrhea are characterized by low serum inhibin B concentrations].

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Podfigurna-Stopa, Agnieszka; Luisi, Stefano; Lazzeri, Lucia; Ciani, Valentina; Meczekalski, Błazej; Petraglia, Felice

2010-05-01

Functional hypothalamic disturbances may be the cause of secondary amenorrhea and are related to aberration in both the pattern of pulsatility and amplitude in the release of gonadotropin-releasing hormone (GnRH) in hypothalamus. Inhibin B, as an ovarian peptide plays a crucial role in reproduction function throughout regulation of folliculotropin (FSH) pituitary production and inhibiting GnRH secretion during the menstrual cycle. To measure and estimate serum inhibin B concentration in patients with functional hypothalamic amenorrhea. Material and methods. The study included 41 women suffering from functional hypothalamic amenorrhea. Secondary amenorrhea was defined as the lack of menstruation lasting at least 90 days not due to pregnancy, characterized by low serum concentrations of lutropin (LH < 5 mIU/ml)) and typical for functional hypothalamic disturbances anamnestic investigation. The control group consists of 40 healthy women with normal menstrual cycles and Body Mass Index (BMI between 18.5- 24.9 kg/m2). Medical history, examination and laboratory analysis of LH, FSH, estradiol (E), prolactin, testosterone and inhibin B were performed (ELISA--enzyme-linked immunosorbent assay). There are statistically lower serum inhibin B, FSH, LH, estradiol and prolactin concentrations in patients with functional hypothalamic amenorrhea in comparison to healthy women. Positive correlation between serum concentration of inhibin B and estradiol concentration was found in patients with functional hypothalamic amenorrhea. Patients with functional hypothalamic amenorrhea are characterized by statistical significant decrease in serum inhibin B concentration in comparison to the control group.

Desipramine inhibits histamine H1 receptor-induced Ca2+ signaling in rat hypothalamic cells.

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Ji-Ah Kang

Full Text Available The hypothalamus in the brain is the main center for appetite control and integrates signals from adipose tissue and the gastrointestinal tract. Antidepressants are known to modulate the activities of hypothalamic neurons and affect food intake, but the cellular and molecular mechanisms by which antidepressants modulate hypothalamic function remain unclear. Here we have investigated how hypothalamic neurons respond to treatment with antidepressants, including desipramine and sibutramine. In primary cultured rat hypothalamic cells, desipramine markedly suppressed the elevation of intracellular Ca(2+ evoked by histamine H1 receptor activation. Desipramine also inhibited the histamine-induced Ca(2+ increase and the expression of corticotrophin-releasing hormone in hypothalamic GT1-1 cells. The effect of desipramine was not affected by pretreatment with prazosin or propranolol, excluding catecholamine reuptake activity of desipramine as an underlying mechanism. Sibutramine which is also an antidepressant but decreases food intake, had little effect on the histamine-induced Ca(2+ increase or AMP-activated protein kinase activity. Our results reveal that desipramine and sibutramine have different effects on histamine H1 receptor signaling in hypothalamic cells and suggest that distinct regulation of hypothalamic histamine signaling might underlie the differential regulation of food intake between antidepressants.

Consumption of a high-fat diet, but not regular endurance exercise training, regulates hypothalamic lipid accumulation in mice.

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Borg, Melissa L; Omran, Simin Fallah; Weir, Jacquelyn; Meikle, Peter J; Watt, Matthew J

2012-09-01

Obesity is characterised by increased storage of fatty acids in an expanded adipose tissue mass and in peripheral tissues such as the skeletal muscle and liver, where it is associated with the development of insulin resistance. Insulin resistance also develops in the central nervous system with high-fat feeding. The capacity for hypothalamic cells to accumulate/store lipids, and the effects of obesity remain undefined. The aims of this study were (1) to examine hypothalamic lipid content in mice with increased dietary fat intake and in obese ob/ob mice fed a low-fat diet, and (2) to determine whether endurance exercise training could reduce hypothalamic lipid accumulation in high-fat fed mice. Male C57BL/6 mice were fed a low- (LFD) or high-fat diet (HFD) for 12 weeks; ob/ob mice were maintained on a chow diet. HFD-exercise (HFD-ex) mice underwent 12 weeks of high-fat feeding with 6 weeks of treadmill exercise training (increasing from 30 to 70 min day(-1)). Hypothalamic lipids were assessed by unbiased mass spectrometry. The HFD increased body mass and hepatic lipid accumulation, and induced glucose intolerance, while the HFD-ex mice had reduced body weight and improved glucose tolerance. A total of 335 lipid molecular species were identified and quantified. Lipids known to induce insulin resistance, including ceramide (22%↑), diacylglycerol (25%↑), lysophosphatidylcholine (17%↑), cholesterol esters (60%↑) and dihexosylceramide (33%↑), were increased in the hypothalamus of HFD vs. LFD mice. Hypothalamic lipids were unaltered with exercise training and in the ob/ob mice, suggesting that obesity per se does not alter hypothalamic lipids. Overall, hypothalamic lipid accumulation is regulated by dietary lipid content and is refractory to change with endurance exercise training.

Generation of neuropeptidergic hypothalamic neurons from human pluripotent stem cells

OpenAIRE

Merkle, Florian T.; Maroof, Asif; Wataya, Takafumi; Sasai, Yoshiki; Studer, Lorenz; Eggan, Kevin; Schier, Alexander F.

2015-01-01

Hypothalamic neurons orchestrate many essential physiological and behavioral processes via secreted neuropeptides, and are relevant to human diseases such as obesity, narcolepsy and infertility. We report the differentiation of human pluripotent stem cells into many of the major types of neuropeptidergic hypothalamic neurons, including those producing pro-opiolemelanocortin, agouti-related peptide, hypocretin/orexin, melanin-concentrating hormone, oxytocin, arginine vasopressin, corticotropin...

Fault diagnosis system of electromagnetic valve using neural network filter

International Nuclear Information System (INIS)

Hayashi, Shoji; Odaka, Tomohiro; Kuroiwa, Jousuke; Ogura, Hisakazu

2008-01-01

This paper is concerned with the gas leakage fault detection of electromagnetic valve using a neural network filter. In modern plants, the ability to detect and identify gas leakage faults is becoming increasingly important. The main difficulty in detecting gas leakage faults by sound signals lies in the fact that the practical plants are usually very noisy. To solve this difficulty, a neural network filter is used to eliminate background noise and raise the signal noise ratio of the sound signal. The background noise is assumed as a dynamic system, and an accurate mathematical model of the dynamic system can be established using a neural network filter. The predicted error between predicted values and practical ones constitutes the output of the filter. If the predicted error is zero, then there is no leakage. If the predicted error is greater than a certain value, then there is a leakage fault. Through application to practical pneumatic systems, it is verified that the neural network filter was effective in gas leakage detection. (author)

Effects of sugar solutions on hypothalamic appetite regulation.

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Colley, Danielle L; Castonguay, Thomas W

2015-02-01

Several hypotheses for the causes of the obesity epidemic in the US have been proposed. One such hypothesis is that dietary intake patterns have significantly shifted to include unprecedented amounts of refined sugar. We set out to determine if different sugars might promote changes in the hypothalamic mechanisms controlling food intake by measuring several hypothalamic peptides subsequent to overnight access to dilute glucose, sucrose, high fructose corn syrup, or fructose solutions. Rats were given access to food, water and a sugar solution for 24h, after which blood and tissues were collected. Fructose access (as opposed to other sugars that were tested) resulted in a doubling of circulating triglycerides. Glucose consumption resulted in upregulation of 7 satiety-related hypothalamic peptides whereas changes in gene expression were mixed for remaining sugars. Also, following multiple verification assays, 6 satiety related peptides were verified as being affected by sugar intake. These data provide evidence that not all sugars are equally effective in affecting the control of intake. Copyright © 2014. Published by Elsevier Inc.

Metabolic Impact on the Hypothalamic Kisspeptin-Kiss1r Signaling Pathway

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Fazal Wahab

2018-03-01

Full Text Available A large body of data has established the hypothalamic kisspeptin (KP and its receptor, KISS1R, as major players in the activation of the neuroendocrine reproductive axis at the time of puberty and maintenance of reproductive capacity in the adult. Due to its strategic location, this ligand-receptor pair acts as an integrator of cues from gonadal steroids as well as of circadian and seasonal variation-related information on the reproductive axis. Besides these cues, the activity of the hypothalamic KP signaling is very sensitive to the current metabolic status of the body. In conditions of energy imbalance, either positive or negative, a number of alterations in the hypothalamic KP signaling pathway have been documented in different mammalian models including nonhuman primates and human. Deficiency of metabolic fuels during fasting causes a marked reduction of Kiss1 gene transcript levels in the hypothalamus and, hence, decreases the output of KP-containing neurons. Food intake or exogenous supply of metabolic cues, such as leptin, reverses metabolic insufficiency-related changes in the hypothalamic KP signaling. Likewise, alterations in Kiss1 expression have also been reported in other situations of energy imbalance like diabetes and obesity. Information related to the body’s current metabolic status reaches to KP neurons both directly as well as indirectly via a complex network of other neurons. In this review article, we have provided an updated summary of the available literature on the regulation of the hypothalamic KP-Kiss1r signaling by metabolic cues. In particular, the potential mechanisms of metabolic impact on the hypothalamic KP-Kiss1r signaling, in light of available evidence, are discussed.

Development of an accident diagnosis system using a dynamic neural network for nuclear power plants

International Nuclear Information System (INIS)

Lee, Seung Jun; Kim, Jong Hyun; Seong, Poong Hyun

2004-01-01

In this work, an accident diagnosis system using the dynamic neural network is developed. In order to help the plant operators to quickly identify the problem, perform diagnosis and initiate recovery actions ensuring the safety of the plant, many operator support system and accident diagnosis systems have been developed. Neural networks have been recognized as a good method to implement an accident diagnosis system. However, conventional accident diagnosis systems that used neural networks did not consider a time factor sufficiently. If the neural network could be trained according to time, it is possible to perform more efficient and detailed accidents analysis. Therefore, this work suggests a dynamic neural network which has different features from existing dynamic neural networks. And a simple accident diagnosis system is implemented in order to validate the dynamic neural network. After training of the prototype, several accident diagnoses were performed. The results show that the prototype can detect the accidents correctly with good performances

Three neural network based sensor systems for environmental monitoring

International Nuclear Information System (INIS)

Keller, P.E.; Kouzes, R.T.; Kangas, L.J.

1994-05-01

Compact, portable systems capable of quickly identifying contaminants in the field are of great importance when monitoring the environment. One of the missions of the Pacific Northwest Laboratory is to examine and develop new technologies for environmental restoration and waste management at the Hanford Site. In this paper, three prototype sensing systems are discussed. These prototypes are composed of sensing elements, data acquisition system, computer, and neural network implemented in software, and are capable of automatically identifying contaminants. The first system employs an array of tin-oxide gas sensors and is used to identify chemical vapors. The second system employs an array of optical sensors and is used to identify the composition of chemical dyes in liquids. The third system contains a portable gamma-ray spectrometer and is used to identify radioactive isotopes. In these systems, the neural network is used to identify the composition of the sensed contaminant. With a neural network, the intense computation takes place during the training process. Once the network is trained, operation consists of propagating the data through the network. Since the computation involved during operation consists of vector-matrix multiplication and application of look-up tables unknown samples can be rapidly identified in the field

Peculiarities of hypothalamic-pituitary thyroid function in children born from the Chornobyl NPP accident survivors

International Nuclear Information System (INIS)

Kopylova, O.V.; Stepanenko, O.A.

2015-01-01

The 168 children born to parents exposed after the Chernobyl accident were examined to study the hypothalamic-pituitary-thyroid system function in descendants of the Chernobyl survivors. Clinical, hormonal, ultrasound examinations and challenge test with tyroliberynum were conducted. Some abnormalities that might explain the functional strain of the hypothalamic-pituitary system were identified being of a great role in origination and progress of thyroid disease. The prolonged strain leads to decreased production of thyroid hormone, which causes an increased secretion of thyroid stimulating hormone. Under the influence of TSH the thyroid gland in the first stage becomes increased in its mass, which leads to the formation of endemic goiter. Stable and permanent thyroid gland enlargement often leads to formation of the nodular goiter and other proliferative processes, namely to carcinogenesis

Fundamentals of computational intelligence neural networks, fuzzy systems, and evolutionary computation

CERN Document Server

Keller, James M; Fogel, David B

2016-01-01

This book covers the three fundamental topics that form the basis of computational intelligence: neural networks, fuzzy systems, and evolutionary computation. The text focuses on inspiration, design, theory, and practical aspects of implementing procedures to solve real-world problems. While other books in the three fields that comprise computational intelligence are written by specialists in one discipline, this book is co-written by current former Editor-in-Chief of IEEE Transactions on Neural Networks and Learning Systems, a former Editor-in-Chief of IEEE Transactions on Fuzzy Systems, and the founding Editor-in-Chief of IEEE Transactions on Evolutionary Computation. The coverage across the three topics is both uniform and consistent in style and notation. Discusses single-layer and multilayer neural networks, radial-basi function networks, and recurrent neural networks Covers fuzzy set theory, fuzzy relations, fuzzy logic interference, fuzzy clustering and classification, fuzzy measures and fuzz...

Radial basis function (RBF) neural network control for mechanical systems design, analysis and Matlab simulation

CERN Document Server

Liu, Jinkun

2013-01-01

Radial Basis Function (RBF) Neural Network Control for Mechanical Systems is motivated by the need for systematic design approaches to stable adaptive control system design using neural network approximation-based techniques. The main objectives of the book are to introduce the concrete design methods and MATLAB simulation of stable adaptive RBF neural control strategies. In this book, a broad range of implementable neural network control design methods for mechanical systems are presented, such as robot manipulators, inverted pendulums, single link flexible joint robots, motors, etc. Advanced neural network controller design methods and their stability analysis are explored. The book provides readers with the fundamentals of neural network control system design.   This book is intended for the researchers in the fields of neural adaptive control, mechanical systems, Matlab simulation, engineering design, robotics and automation. Jinkun Liu is a professor at Beijing University of Aeronautics and Astronauti...

Hypothalamic AMPK and fatty acid metabolism mediate thyroid regulation of energy balance

OpenAIRE

López, Miguel; Varela, Luis; Vázquez, María J; Rodríguez-Cuenca, Sergio; González, Carmen R; Velagapudi, Vidya R; Morgan, Donald A; Schoenmakers, Erik; Agassandian, Khristofor; Lage, Ricardo; de Morentin, Pablo Blanco Martínez; Tovar, Sulay; Nogueiras, Rubén; Carling, David; Lelliott, Christopher

2010-01-01

Thyroid hormones have widespread cellular effects; however it is unclear whether their effects on the central nervous system (CNS) contribute to global energy balance. Here, we demonstrate that either whole body hyperthyroidism or central administration of triiodothyronine (T3) decreases the activity of hypothalamic AMP-activated protein kinase (AMPK), increases sympathetic nervous system (SNS) activity and upregulates thermogenic markers in brown adipose tissue (BAT). Inhibition of the lipog...

Impact of hypothalamic reactive oxygen species in the control of energy metabolism and food intake

Directory of Open Access Journals (Sweden)

Anne eDrougard

2015-02-01

Full Text Available Hypothalamus is a key area involved in the control of metabolism and food intake via the integrations of numerous signals (hormones, neurotransmitters, metabolites from various origins. These factors modify hypothalamic neurons activity and generate adequate molecular and behavioral responses to control energy balance. In this complex integrative system, a new concept has been developed in recent years, that includes reactive oxygen species (ROS as a critical player in energy balance. ROS are known to act in many signaling pathways in different peripheral organs, but also in hypothalamus where they regulate food intake and metabolism by acting on different types of neurons, including proopiomelanocortin (POMC and agouti-related protein (AgRP/neuropeptide Y (NPY neurons. Hypothalamic ROS release is under the influence of different factors such as pancreatic and gut hormones, adipokines (leptin, apelin,..., neurotransmitters and nutrients (glucose, lipids,.... The sources of ROS production are multiple including NADPH oxidase, but also the mitochondria which is considered as the main ROS producer in the brain. ROS are considered as signaling molecules, but conversely impairment of this neuronal signaling ROS pathway contributes to alterations of autonomic nervous system and neuroendocrine function, leading to metabolic diseases such as obesity and type 2 diabetes.In this review we focus our attention on factors that are able to modulate hypothalamic ROS release in order to control food intake and energy metabolism, and whose deregulations could participate to the development of pathological conditions. This novel insight reveals an original mechanism in the hypothalamus that controls energy balance and identify hypothalamic ROS signaling as a potential therapeutic strategy to treat metabolic disorders.

Impact of hypothalamic reactive oxygen species in the regulation of energy metabolism and food intake.

Science.gov (United States)

Drougard, Anne; Fournel, Audren; Valet, Philippe; Knauf, Claude

2015-01-01

Hypothalamus is a key area involved in the control of metabolism and food intake via the integrations of numerous signals (hormones, neurotransmitters, metabolites) from various origins. These factors modify hypothalamic neurons activity and generate adequate molecular and behavioral responses to control energy balance. In this complex integrative system, a new concept has been developed in recent years, that includes reactive oxygen species (ROS) as a critical player in energy balance. ROS are known to act in many signaling pathways in different peripheral organs, but also in hypothalamus where they regulate food intake and metabolism by acting on different types of neurons, including proopiomelanocortin (POMC) and agouti-related protein (AgRP)/neuropeptide Y (NPY) neurons. Hypothalamic ROS release is under the influence of different factors such as pancreatic and gut hormones, adipokines (leptin, apelin,…), neurotransmitters and nutrients (glucose, lipids,…). The sources of ROS production are multiple including NADPH oxidase, but also the mitochondria which is considered as the main ROS producer in the brain. ROS are considered as signaling molecules, but conversely impairment of this neuronal signaling ROS pathway contributes to alterations of autonomic nervous system and neuroendocrine function, leading to metabolic diseases such as obesity and type 2 diabetes. In this review we focus our attention on factors that are able to modulate hypothalamic ROS release in order to control food intake and energy metabolism, and whose deregulations could participate to the development of pathological conditions. This novel insight reveals an original mechanism in the hypothalamus that controls energy balance and identify hypothalamic ROS signaling as a potential therapeutic strategy to treat metabolic disorders.

Cellular activation of hypothalamic hypocretin/orexin neurons facilitates short-term spatial memory in mice.

Science.gov (United States)

Aitta-Aho, Teemu; Pappa, Elpiniki; Burdakov, Denis; Apergis-Schoute, John

2016-12-01

The hypothalamic hypocretin/orexin (HO) system holds a central role in the regulation of several physiological functions critical for food-seeking behavior including mnemonic processes for effective foraging behavior. It is unclear however whether physiological increases in HO neuronal activity can support such processes. Using a designer rM3Ds receptor activation approach increasing HO neuronal activity resulted in improved short-term memory for novel locations. When tested on a non-spatial novelty object recognition task no significant difference was detected between groups indicating that hypothalamic HO neuronal activation can selectively facilitate short-term spatial memory for potentially supporting memory for locations during active exploration. Copyright © 2016 Elsevier Inc. All rights reserved.

Altered hypothalamic protein expression in a rat model of Huntington's disease.

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Wei-na Cong

Full Text Available Huntington's disease (HD is a neurodegenerative disorder, which is characterized by progressive motor impairment and cognitive alterations. Changes in energy metabolism, neuroendocrine function, body weight, euglycemia, appetite function, and circadian rhythm can also occur. It is likely that the locus of these alterations is the hypothalamus. We used the HD transgenic (tg rat model bearing 51 CAG repeats, which exhibits similar HD symptomology as HD patients to investigate hypothalamic function. We conducted detailed hypothalamic proteome analyses and also measured circulating levels of various metabolic hormones and lipids in pre-symptomatic and symptomatic animals. Our results demonstrate that there are significant alterations in HD rat hypothalamic protein expression such as glial fibrillary acidic protein (GFAP, heat shock protein-70, the oxidative damage protein glutathione peroxidase (Gpx4, glycogen synthase1 (Gys1 and the lipid synthesis enzyme acylglycerol-3-phosphate O-acyltransferase 1 (Agpat1. In addition, there are significant alterations in various circulating metabolic hormones and lipids in pre-symptomatic animals including, insulin, leptin, triglycerides and HDL, before any motor or cognitive alterations are apparent. These early metabolic and lipid alterations are likely prodromal signs of hypothalamic dysfunction. Gaining a greater understanding of the hypothalamic and metabolic alterations that occur in HD, could lead to the development of novel therapeutics for early interventional treatment of HD.

Neuromorphic neural interfaces: from neurophysiological inspiration to biohybrid coupling with nervous systems

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Broccard, Frédéric D.; Joshi, Siddharth; Wang, Jun; Cauwenberghs, Gert

2017-08-01

Objective. Computation in nervous systems operates with different computational primitives, and on different hardware, than traditional digital computation and is thus subjected to different constraints from its digital counterpart regarding the use of physical resources such as time, space and energy. In an effort to better understand neural computation on a physical medium with similar spatiotemporal and energetic constraints, the field of neuromorphic engineering aims to design and implement electronic systems that emulate in very large-scale integration (VLSI) hardware the organization and functions of neural systems at multiple levels of biological organization, from individual neurons up to large circuits and networks. Mixed analog/digital neuromorphic VLSI systems are compact, consume little power and operate in real time independently of the size and complexity of the model. Approach. This article highlights the current efforts to interface neuromorphic systems with neural systems at multiple levels of biological organization, from the synaptic to the system level, and discusses the prospects for future biohybrid systems with neuromorphic circuits of greater complexity. Main results. Single silicon neurons have been interfaced successfully with invertebrate and vertebrate neural networks. This approach allowed the investigation of neural properties that are inaccessible with traditional techniques while providing a realistic biological context not achievable with traditional numerical modeling methods. At the network level, populations of neurons are envisioned to communicate bidirectionally with neuromorphic processors of hundreds or thousands of silicon neurons. Recent work on brain-machine interfaces suggests that this is feasible with current neuromorphic technology. Significance. Biohybrid interfaces between biological neurons and VLSI neuromorphic systems of varying complexity have started to emerge in the literature. Primarily intended as a

IMPLEMENTATION OF NEURAL - CRYPTOGRAPHIC SYSTEM USING FPGA

Directory of Open Access Journals (Sweden)

KARAM M. Z. OTHMAN

2011-08-01

Full Text Available Modern cryptography techniques are virtually unbreakable. As the Internet and other forms of electronic communication become more prevalent, electronic security is becoming increasingly important. Cryptography is used to protect e-mail messages, credit card information, and corporate data. The design of the cryptography system is a conventional cryptography that uses one key for encryption and decryption process. The chosen cryptography algorithm is stream cipher algorithm that encrypt one bit at a time. The central problem in the stream-cipher cryptography is the difficulty of generating a long unpredictable sequence of binary signals from short and random key. Pseudo random number generators (PRNG have been widely used to construct this key sequence. The pseudo random number generator was designed using the Artificial Neural Networks (ANN. The Artificial Neural Networks (ANN providing the required nonlinearity properties that increases the randomness statistical properties of the pseudo random generator. The learning algorithm of this neural network is backpropagation learning algorithm. The learning process was done by software program in Matlab (software implementation to get the efficient weights. Then, the learned neural network was implemented using field programmable gate array (FPGA.

PERFORMANCE COMPARISON FOR INTRUSION DETECTION SYSTEM USING NEURAL NETWORK WITH KDD DATASET

Directory of Open Access Journals (Sweden)

S. Devaraju

2014-04-01

Full Text Available Intrusion Detection Systems are challenging task for finding the user as normal user or attack user in any organizational information systems or IT Industry. The Intrusion Detection System is an effective method to deal with the kinds of problem in networks. Different classifiers are used to detect the different kinds of attacks in networks. In this paper, the performance of intrusion detection is compared with various neural network classifiers. In the proposed research the four types of classifiers used are Feed Forward Neural Network (FFNN, Generalized Regression Neural Network (GRNN, Probabilistic Neural Network (PNN and Radial Basis Neural Network (RBNN. The performance of the full featured KDD Cup 1999 dataset is compared with that of the reduced featured KDD Cup 1999 dataset. The MATLAB software is used to train and test the dataset and the efficiency and False Alarm Rate is measured. It is proved that the reduced dataset is performing better than the full featured dataset.

Automated implementation of rule-based expert systems with neural networks for time-critical applications

Science.gov (United States)

Ramamoorthy, P. A.; Huang, Song; Govind, Girish

1991-01-01

In fault diagnosis, control and real-time monitoring, both timing and accuracy are critical for operators or machines to reach proper solutions or appropriate actions. Expert systems are becoming more popular in the manufacturing community for dealing with such problems. In recent years, neural networks have revived and their applications have spread to many areas of science and engineering. A method of using neural networks to implement rule-based expert systems for time-critical applications is discussed here. This method can convert a given rule-based system into a neural network with fixed weights and thresholds. The rules governing the translation are presented along with some examples. We also present the results of automated machine implementation of such networks from the given rule-base. This significantly simplifies the translation process to neural network expert systems from conventional rule-based systems. Results comparing the performance of the proposed approach based on neural networks vs. the classical approach are given. The possibility of very large scale integration (VLSI) realization of such neural network expert systems is also discussed.

Functional hypothalamic amenorrhea and its influence on women's health.

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Meczekalski, B; Katulski, K; Czyzyk, A; Podfigurna-Stopa, A; Maciejewska-Jeske, M

2014-11-01

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of secondary amenorrhea. There are three types of FHA: weight loss-related, stress-related, and exercise-related amenorrhea. FHA results from the aberrations in pulsatile gonadotropin-releasing hormone (GnRH) secretion, which in turn causes impairment of the gonadotropins (follicle-stimulating hormone and luteinizing hormone). The final consequences are complex hormonal changes manifested by profound hypoestrogenism. Additionally, these patients present mild hypercortisolemia, low serum insulin levels, low insulin-like growth factor 1 (IGF-1) and low total triiodothyronine. The aim of this work is to review the available data concerning the effects of FHA on different aspects of women's health. Functional hypothalamic amenorrhea is related to profound impairment of reproductive functions including anovulation and infertility. Women's health in this disorder is disturbed in several aspects including the skeletal system, cardiovascular system, and mental problems. Patients manifest a decrease in bone mass density, which is related to an increase in fracture risk. Therefore, osteopenia and osteoporosis are the main long-term complications of FHA. Cardiovascular complications include endothelial dysfunction and abnormal changes in the lipid profile. FHA patients present significantly higher depression and anxiety and also sexual problems compared to healthy subjects. FHA patients should be carefully diagnosed and properly managed to prevent both short- and long-term medical consequences.

Anatomy of melancholia: focus on hypothalamic-pituitary-adrenal axis overactivity and the role of vasopressin.

LENUS (Irish Health Repository)

Dinan, Timothy G

2012-02-03

Overactivity of the hypothalamic-pituitary-adrenal (HPA) axis characterized by hypercortisolism, adrenal hyperplasia and abnormalities in negative feedback is the most consistently described biological abnormality in melancholic depression. Corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) are the main secretagogues of the HPA\\/stress system. Produced in the parvicellular division of the hypothalamic paraventricular nucleus the release of these peptides is influenced by inputs from monoaminergic neurones. In depression, anterior pituitary CRH1 receptors are down-regulated and response to CRH infusion is blunted. By contrast, vasopressin V3 receptors on the anterior pituitary show enhanced response to AVP stimulation and this enhancement plays a key role in maintaining HPA overactivity.

Neural systems analysis of decision making during goal-directed navigation.

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Penner, Marsha R; Mizumori, Sheri J Y

2012-01-01

The ability to make adaptive decisions during goal-directed navigation is a fundamental and highly evolved behavior that requires continual coordination of perceptions, learning and memory processes, and the planning of behaviors. Here, a neurobiological account for such coordination is provided by integrating current literatures on spatial context analysis and decision-making. This integration includes discussions of our current understanding of the role of the hippocampal system in experience-dependent navigation, how hippocampal information comes to impact midbrain and striatal decision making systems, and finally the role of the striatum in the implementation of behaviors based on recent decisions. These discussions extend across cellular to neural systems levels of analysis. Not only are key findings described, but also fundamental organizing principles within and across neural systems, as well as between neural systems functions and behavior, are emphasized. It is suggested that studying decision making during goal-directed navigation is a powerful model for studying interactive brain systems and their mediation of complex behaviors. Copyright © 2011. Published by Elsevier Ltd.

Intelligent neural network and fuzzy logic control of industrial and power systems

Science.gov (United States)

Kuljaca, Ognjen

The main role played by neural network and fuzzy logic intelligent control algorithms today is to identify and compensate unknown nonlinear system dynamics. There are a number of methods developed, but often the stability analysis of neural network and fuzzy control systems was not provided. This work will meet those problems for the several algorithms. Some more complicated control algorithms included backstepping and adaptive critics will be designed. Nonlinear fuzzy control with nonadaptive fuzzy controllers is also analyzed. An experimental method for determining describing function of SISO fuzzy controller is given. The adaptive neural network tracking controller for an autonomous underwater vehicle is analyzed. A novel stability proof is provided. The implementation of the backstepping neural network controller for the coupled motor drives is described. Analysis and synthesis of adaptive critic neural network control is also provided in the work. Novel tuning laws for the system with action generating neural network and adaptive fuzzy critic are given. Stability proofs are derived for all those control methods. It is shown how these control algorithms and approaches can be used in practical engineering control. Stability proofs are given. Adaptive fuzzy logic control is analyzed. Simulation study is conducted to analyze the behavior of the adaptive fuzzy system on the different environment changes. A novel stability proof for adaptive fuzzy logic systems is given. Also, adaptive elastic fuzzy logic control architecture is described and analyzed. A novel membership function is used for elastic fuzzy logic system. The stability proof is proffered. Adaptive elastic fuzzy logic control is compared with the adaptive nonelastic fuzzy logic control. The work described in this dissertation serves as foundation on which analysis of particular representative industrial systems will be conducted. Also, it gives a good starting point for analysis of learning abilities of

Integrated evolutionary computation neural network quality controller for automated systems

Energy Technology Data Exchange (ETDEWEB)

Patro, S.; Kolarik, W.J. [Texas Tech Univ., Lubbock, TX (United States). Dept. of Industrial Engineering

1999-06-01

With increasing competition in the global market, more and more stringent quality standards and specifications are being demands at lower costs. Manufacturing applications of computing power are becoming more common. The application of neural networks to identification and control of dynamic processes has been discussed. The limitations of using neural networks for control purposes has been pointed out and a different technique, evolutionary computation, has been discussed. The results of identifying and controlling an unstable, dynamic process using evolutionary computation methods has been presented. A framework for an integrated system, using both neural networks and evolutionary computation, has been proposed to identify the process and then control the product quality, in a dynamic, multivariable system, in real-time.

Hypothalamic kappa opioid receptor mediates both diet- and MCH-induced liver damage through inflammation and ER stress

NARCIS (Netherlands)

Imbernon, Monica; Sanchez-Rebordelo, Estrella; Romero-Picó, Amparo; Kalló, Imre; Chee, Melissa J; Porteiro, Begoña; Al-Massadi, Omar; Contreras, Cristina; Fernø, Johan; Senra, Ana; Gallego, Rosalia; Folgueira, Cintia; Seoane, Luisa M; van Gestel, Margriet; Adan, Roger A; Liposits, Zsolt; Dieguez, Carlos; Lopez, Miguel; Nogueiras, Ruben

2016-01-01

The opioid system is widely known to modulate the brain reward system and thus affect human and animal behaviour, including feeding. We hypothesized that the hypothalamic opioid system might also control energy metabolism in peripheral tissues. Mice lacking the kappa opioid receptor (κOR) and

Hypothalamic PGC-1 alpha Protects Against High-Fat Diet Exposure by Regulating ER alpha

NARCIS (Netherlands)

Morselli, Eugenia; Fuente-Martin, Esther; Finan, Brian; Kim, Min; Frank, Aaron; Garcia-Caceres, Cristina; Navas, Carlos Rodriguez; Gordillo, Ruth; Neinast, Michael; Kalainayakan, Sarada P.; Li, Dan L.; Gao, Yuanqing; Yi, Chun-Xia; Hahner, Lisa; Palmer, Biff F.; Tschöp, Matthias H.; Clegg, Deborah J.

2014-01-01

High-fat diets (HFDs) lead to obesity and inflammation in the central nervous system (CNS). Estrogens and estrogen receptor alpha (ER alpha) protect premenopausal females from the metabolic complications of inflammation and obesity-related disease. Here, we demonstrate that hypothalamic PGC-1 alpha

Revealing the cerebello-ponto-hypothalamic pathway in the human brain.

Science.gov (United States)

Kamali, Arash; Karbasian, Niloofar; Rabiei, Pejman; Cano, Andres; Riascos, Roy F; Tandon, Nitin; Arevalo, Octavio; Ocasio, Laura; Younes, Kyan; Khayat-Khoei, Mahsa; Mirbagheri, Saeedeh; Hasan, Khader M

2018-04-16

The cerebellum is shown to be involved in some limbic functions of the human brain such as emotion and affect. The major connection of the cerebellum with the limbic system is known to be through the cerebello-hypothalamic pathways. The consensus is that the projections from the cerebellar nuclei to the limbic system, and particularly the hypothalamus, or from the hypothalamus to the cerebellar nuclei, are through multisynaptic pathways in the bulbar reticular formation. The detailed anatomy of the pathways responsible for mediating these responses, however, is yet to be determined. Diffusion tensor imaging may be helpful in better visualizing the surgical anatomy of the cerebello-ponto-hypothalamic (CPH) pathway. This study aimed to investigate the utility of high-spatial-resolution diffusion tensor tractography for mapping the trajectory of the CPH tract in the human brain. Fifteen healthy adults were studied. We delineated, for the first time, the detailed trajectory of the CPH tract of the human brain in fifteen normal adult subjects using high-spatial-resolution diffusion tensor tractography. We further revealed the close relationship of the CPH tract with the optic tract, temporo-pontine tract, amygdalofugal tract and the fornix in the human brain. Copyright © 2018. Published by Elsevier B.V.

Anti-aging drugs reduce hypothalamic inflammation in a sex-specific manner.

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Sadagurski, Marianna; Cady, Gillian; Miller, Richard A

2017-08-01

Aging leads to hypothalamic inflammation, but does so more slowly in mice whose lifespan has been extended by mutations that affect GH/IGF-1 signals. Early-life exposure to GH by injection, or to nutrient restriction in the first 3 weeks of life, also modulate both lifespan and the pace of hypothalamic inflammation. Three drugs extend lifespan of UM-HET3 mice in a sex-specific way: acarbose (ACA), 17-α-estradiol (17αE2), and nordihydroguaiaretic acid (NDGA), with more dramatic longevity increases in males in each case. In this study, we examined the effect of these anti-aging drugs on neuro-inflammation in hypothalamus and hippocampus. We found that age-associated hypothalamic inflammation is reduced in males but not in females at 12 months of age by ACA and 17αE2 and at 22 months of age in NDGA-treated mice. The three drugs blocked indices of hypothalamic reactive gliosis associated with aging, such as Iba-1-positive microglia and GFAP-positive astrocytes, as well as age-associated overproduction of TNF-α. This effect was not observed in drug-treated female mice or in the hippocampus of the drug-treated animals. On the other hand, caloric restriction (CR; an intervention that extends the lifespan in both sexes) significantly reduced hypothalamic microglia and TNF-α in both sexes at 12 months of age. Together, these results suggest that the extent of drug-induced changes in hypothalamic inflammatory processes is sexually dimorphic in a pattern that parallels the effects of these agents on mouse longevity and that mimics the changes seen, in both sexes, of long-lived nutrient restricted or mutant mice. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Neural Mechanisms and Information Processing in Recognition Systems

Directory of Open Access Journals (Sweden)

Mamiko Ozaki

2014-10-01

Full Text Available Nestmate recognition is a hallmark of social insects. It is based on the match/mismatch of an identity signal carried by members of the society with that of the perceiving individual. While the behavioral response, amicable or aggressive, is very clear, the neural systems underlying recognition are not fully understood. Here we contrast two alternative hypotheses for the neural mechanisms that are responsible for the perception and information processing in recognition. We focus on recognition via chemical signals, as the common modality in social insects. The first, classical, hypothesis states that upon perception of recognition cues by the sensory system the information is passed as is to the antennal lobes and to higher brain centers where the information is deciphered and compared to a neural template. Match or mismatch information is then transferred to some behavior-generating centers where the appropriate response is elicited. An alternative hypothesis, that of “pre-filter mechanism”, posits that the decision as to whether to pass on the information to the central nervous system takes place in the peripheral sensory system. We suggest that, through sensory adaptation, only alien signals are passed on to the brain, specifically to an “aggressive-behavior-switching center”, where the response is generated if the signal is above a certain threshold.

ERK1/2 mediates glucose-regulated POMC gene expression in hypothalamic neurons.

Science.gov (United States)

Zhang, Juan; Zhou, Yunting; Chen, Cheng; Yu, Feiyuan; Wang, Yun; Gu, Jiang; Ma, Lian; Ho, Guyu

2015-04-01

Hypothalamic glucose-sensing neurons regulate the expression of genes encoding feeding-related neuropetides POMC, AgRP, and NPY - the key components governing metabolic homeostasis. AMP-activated protein kinase (AMPK) is postulated to be the molecular mediator relaying glucose signals to regulate the expression of these neuropeptides. Whether other signaling mediator(s) plays a role is not clear. In this study, we investigated the role of ERK1/2 using primary hypothalamic neurons as the model system. The primary neurons were differentiated from hypothalamic progenitor cells. The differentiated neurons possessed the characteristic neuronal cell morphology and expressed neuronal post-mitotic markers as well as leptin-regulated orexigenic POMC and anorexigenic AgRP/NPY genes. Treatment of cells with glucose dose-dependently increased POMC and decreased AgRP/NPY expression with a concurrent suppression of AMPK phosphorylation. In addition, glucose treatment dose-dependently increased the ERK1/2 phosphorylation. Blockade of ERK1/2 activity with its specific inhibitor PD98059 partially (approximately 50%) abolished glucose-induced POMC expression, but had little effect on AgRP/NPY expression. Conversely, blockade of AMPK activity with its specific inhibitor produced a partial (approximately 50%) reversion of low-glucose-suppressed POMC expression, but almost completely blunted the low-glucose-induced AgRP/NPY expression. The results indicate that ERK1/2 mediated POMC but not AgRP/NPY expression. Confirming the in vitro findings, i.c.v. administration of PD98059 in rats similarly attenuated glucose-induced POMC expression in the hypothalamus, but again had little effect on AgRP/NPY expression. The results are indicative of a novel role of ERK1/2 in glucose-regulated POMC expression and offer new mechanistic insights into hypothalamic glucose sensing. © 2015 Society for Endocrinology.

Neural networks for feedback feedforward nonlinear control systems.

Science.gov (United States)

Parisini, T; Zoppoli, R

1994-01-01

This paper deals with the problem of designing feedback feedforward control strategies to drive the state of a dynamic system (in general, nonlinear) so as to track any desired trajectory joining the points of given compact sets, while minimizing a certain cost function (in general, nonquadratic). Due to the generality of the problem, conventional methods are difficult to apply. Thus, an approximate solution is sought by constraining control strategies to take on the structure of multilayer feedforward neural networks. After discussing the approximation properties of neural control strategies, a particular neural architecture is presented, which is based on what has been called the "linear-structure preserving principle". The original functional problem is then reduced to a nonlinear programming one, and backpropagation is applied to derive the optimal values of the synaptic weights. Recursive equations to compute the gradient components are presented, which generalize the classical adjoint system equations of N-stage optimal control theory. Simulation results related to nonlinear nonquadratic problems show the effectiveness of the proposed method.

Oral glucose intake inhibits hypothalamic neuronal activity more effectively than glucose infusion

NARCIS (Netherlands)

Smeets, P.A.M.; Vidarsdottir, S.; Graaf, C. de; Stafleu, A.; Osch, M.J.P. van; Viergever, M.A.; Pijl, H.; Grond, J. van der

2007-01-01

We previously showed that hypothalamic neuronal activity, as measured by the blood oxygen level-dependent (BOLD) functional MRI signal, declines in response to oral glucose intake. To further explore the mechanism driving changes in hypothalamic neuronal activity in response to an oral glucose load,

Reliability analysis of a consecutive r-out-of-n: F system based on neural networks

International Nuclear Information System (INIS)

Habib, Aziz; Alsieidi, Ragab; Youssef, Ghada

2009-01-01

In this paper, we present a generalized Markov reliability and fault-tolerant model, which includes the effects of permanent fault and intermittent fault for reliability evaluations based on neural network techniques. The reliability of a consecutive r-out-of-n: F system was obtained with a three-layer connected neural network represents a discrete time state reliability Markov model of the system. Such that we fed the neural network with the desired reliability of the system under design. Then we extracted the parameters of the system from the neural weights at the convergence of the neural network to the desired reliability. Finally, we obtain simulation results.

Wake-promoting actions of median nerve stimulation in TBI-induced coma: An investigation of orexin-A and orexin receptor 1 in the hypothalamic region.

Science.gov (United States)

Zhong, Ying-Jun; Feng, Zhen; Wang, Liang; Wei, Tian-Qi

2015-09-01

A coma is a serious complication, which can occur following traumatic brain injury (TBI), for which no effective treatment has been established. Previous studies have suggested that neural electrical stimulation, including median nerve stimulation (MNS), may be an effective method for treating patients in a coma, and orexin‑A, an excitatory hypothalamic neuropeptide, may be involved in wakefulness. However, the exact mechanisms underlying this involvement remain to be elucidated. The present study aimed to examine the arousal‑promoting role of MNS in rats in a TBI‑induced coma and to investigate the potential mechanisms involved. A total of 90 rats were divided into three groups, comprising a control group, sham‑stimulated (TBI) group and a stimulated (TBI + MNS) group. MNS was performed on the animals, which were in a TBI‑induced comatose state. Changes in the behavior of the rats were observed following MNS. Subsequently, hypothalamic tissues were extracted from the rats 6, 12 and 24 h following TBI or MNS, respectively. The expression levels of orexin‑A and orexin receptor‑1 (OX1R) in the hypothalamus were examined using immunohistochemistry, western blotting and an enzyme‑linked immunosorbent assay. The results demonstrated that 21 rats subjected to TBI‑induced coma exhibited a restored righting reflex and response to pain stimuli following MNS. In addition, ignificant differences in the expression levels of orexin‑A and OXIR were observed among the three groups and among the time‑points. Orexin‑A and OX1R were upregulated following MNS. The rats in the stimulated group reacted to the MNS and exhibited a re‑awakening response. The results of the present study indicated that MNS may be a therapeutic option for TBI‑induced coma. The mechanism may be associated with increasing expression levels of the excitatory hypothalamic neuropeptide, orexin-A, and its receptor, OX1R, in the hypothalamic region.

An In Vitro System Comprising Immortalized Hypothalamic Neuronal Cells (GT1?7 Cells) for Evaluation of the Neuroendocrine Effects of Essential Oils

OpenAIRE

Mizuno, Dai; Konoha-Mizuno, Keiko; Mori, Miwako; Yamazaki, Kentaro; Haneda, Toshihiro; Koyama, Hironari; Kawahara, Masahiro

2015-01-01

Aromatherapy and plant-based essential oils are widely used as complementary and alternative therapies for symptoms including anxiety. Furthermore, it was reportedly effective for the care of several diseases such as Alzheimer’s disease and depressive illness. To investigate the pharmacological effects of essential oils, we developed an in vitro assay system using immortalized hypothalamic neuronal cells (GT1–7 cells). In this study, we evaluated the effects of essential oils on neuronal deat...

Dynamical systems, attractors, and neural circuits.

Science.gov (United States)

Miller, Paul

2016-01-01

Biology is the study of dynamical systems. Yet most of us working in biology have limited pedagogical training in the theory of dynamical systems, an unfortunate historical fact that can be remedied for future generations of life scientists. In my particular field of systems neuroscience, neural circuits are rife with nonlinearities at all levels of description, rendering simple methodologies and our own intuition unreliable. Therefore, our ideas are likely to be wrong unless informed by good models. These models should be based on the mathematical theories of dynamical systems since functioning neurons are dynamic-they change their membrane potential and firing rates with time. Thus, selecting the appropriate type of dynamical system upon which to base a model is an important first step in the modeling process. This step all too easily goes awry, in part because there are many frameworks to choose from, in part because the sparsely sampled data can be consistent with a variety of dynamical processes, and in part because each modeler has a preferred modeling approach that is difficult to move away from. This brief review summarizes some of the main dynamical paradigms that can arise in neural circuits, with comments on what they can achieve computationally and what signatures might reveal their presence within empirical data. I provide examples of different dynamical systems using simple circuits of two or three cells, emphasizing that any one connectivity pattern is compatible with multiple, diverse functions.

Cerebral gigantism of hypothalamic origin.

Science.gov (United States)

Ranke, M B; Bierich, J R

1983-04-01

In five cases of Sotos Syndrome serum somatomedin activities were measured. In two of these cases elevated levels and an increased secretion of growth hormone was observed. In one case (index case) a suspected hypothalamic tumor mass could be excluded, but hydrocephalus with increased intracranial pressure was present. The pathogenesis of gigantism in this syndrome is discussed.

Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation (ROHHAD syndrome): A case report and literature review.

Science.gov (United States)

Ibáñez-Micó, S; Marcos Oltra, A M; de Murcia Lemauviel, S; Ruiz Pruneda, R; Martínez Ferrández, C; Domingo Jiménez, R

ROHHAD syndrome (rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation) is a rare and complex disease, presenting in previously healthy children at the age of 2-4 years. Up to 40% of cases are associated with neural crest tumours. We present the case of a 2-year-old girl with symptoms of rapidly progressing obesity, who a few months later developed hypothalamic dysfunction with severe electrolyte imbalance, behaviour disorder, hypoventilation, and severe autonomic dysregulation, among other symptoms. Although the pathophysiology of this syndrome remains unclear, an autoimmune hypothesis has been proposed for ROHHAD. Therefore, after obtaining a limited response to intravenous immunoglobulins, we decided to test the response to a high dose cyclophosphamide (low dose was not effective either). Unfortunately our patient experienced many severe complications (among them central pontine myelinolysis, from which the patient recovered, and failure to wean from the ventilator requiring tracheostomy and long term ventilation) that required a prolonged ICU stay. Although her behaviour improved, our patient unfortunately died suddenly at home at the age of 5 due to respiratory pathology. ROHHAD syndrome is a rare and little-known disease which requires a multidisciplinary approach because it involves complex symptoms and multiple organ system involvement. Alveolar hypoventilation should be identified early and appropriate treatment should be started promptly for the best possible outcome. Immunomodulatory treatment with immunoglobulins, cyclophosphamide, or rituximab has previously resulted in symptom improvement in some cases. Because of the low incidence of the syndrome, multi-centre studies must be carried out in order to gather more accurate information about ROHHAD pathophysiology and design an appropriate therapeutic approach. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All

Relation of addiction genes to hypothalamic gene changes subserving genesis and gratification of a classic instinct, sodium appetite.

Science.gov (United States)

Liedtke, Wolfgang B; McKinley, Michael J; Walker, Lesley L; Zhang, Hao; Pfenning, Andreas R; Drago, John; Hochendoner, Sarah J; Hilton, Donald L; Lawrence, Andrew J; Denton, Derek A

2011-07-26

Sodium appetite is an instinct that involves avid specific intention. It is elicited by sodium deficiency, stress-evoked adrenocorticotropic hormone (ACTH), and reproduction. Genome-wide microarrays in sodium-deficient mice or after ACTH infusion showed up-regulation of hypothalamic genes, including dopamine- and cAMP-regulated neuronal phosphoprotein 32 kDa (DARPP-32), dopamine receptors-1 and -2, α-2C- adrenoceptor, and striatally enriched protein tyrosine phosphatase (STEP). Both DARPP-32 and neural plasticity regulator activity-regulated cytoskeleton associated protein (ARC) were up-regulated in lateral hypothalamic orexinergic neurons by sodium deficiency. Administration of dopamine D1 (SCH23390) and D2 receptor (raclopride) antagonists reduced gratification of sodium appetite triggered by sodium deficiency. SCH23390 was specific, having no effect on osmotic-induced water drinking, whereas raclopride also reduced water intake. D1 receptor KO mice had normal sodium appetite, indicating compensatory regulation. Appetite was insensitive to SCH23390, confirming the absence of off-target effects. Bilateral microinjection of SCH23390 (100 nM in 200 nL) into rats' lateral hypothalamus greatly reduced sodium appetite. Gene set enrichment analysis in hypothalami of mice with sodium appetite showed significant enrichment of gene sets previously linked to addiction (opiates and cocaine). This finding of concerted gene regulation was attenuated on gratification with perplexingly rapid kinetics of only 10 min, anteceding significant absorption of salt from the gut. Salt appetite and hedonic liking of salt taste have evolved over >100 million y (e.g., being present in Metatheria). Drugs causing pleasure and addiction are comparatively recent and likely reflect usurping of evolutionary ancient systems with high survival value by the gratification of contemporary hedonic indulgences. Our findings outline a molecular logic for instinctive behavior encoded by the brain with

A Rare Cause of Hypothalamic Obesity, Rohhad Syndrome: 2 Cases.

Science.gov (United States)

Şiraz, Ülkü Gül; Okdemir, Deniz; Direk, Gül; Akın, Leyla; Hatipoğlu, Nihal; Kendırcı, Mustafa; Kurtoğlu, Selim

2018-03-19

Rapid-onset obesity with hypoventilation, hypothalamic dysfunction and autonomic dysregulation (ROHHAD) syndrome is a rare disease that is difficult to diagnosis and distinguish from genetic obesity syndromes. The underlying causes of the disease has not been fully explained. Hypothalamic dysfunction causes endocrine problems, respiratory dysfunction and autonomic alterations. There are around 80 reported patients due to lack of recognition. We present two female patient suspected of ROHHAD due to weight gain since early childhood. The presented symptoms, respiratory and circulatory dysfunction, hypothalamic hypernatremia, hypothalamo-pituitary hormonal disorders such as santral hypothyrodism, hyperprolactinemia and santral early puberty are completely matched the criteria of ROHHAD syndrome. ROHHAD syndrome should be considered in differential diagnosis since it is difficult to distinguish from causes of monogenic obesity. Early identification of the disease reduces morbidity of the syndrome and patients require regular follow-up by a multidisciplinary approach.

Oral glucose intake inhibits hypothalamic neuronal activity more effectively than glucose infusion

NARCIS (Netherlands)

Smeets, P.A.M.; Vidarsdottir, S.; Graaf, de C.; Stafleu, A.; Osch, M.J.P.; Viergever, M.A.; Pijl, H.; Grond, van der J.

2007-01-01

Oral glucose intake inhibits hypothalamic neuronal activity more effectively than glucose infusion. Am J Physiol Endocrinol Metab 293: E754-E758, 2007. First published June 12, 2007; doi:10.1152/ajpendo.00231.2007. - We previously showed that hypothalamic neuronal activity, as measured by the blood

Fluoxetine Induces Proliferation and Inhibits Differentiation of Hypothalamic Neuroprogenitor Cells In Vitro

Science.gov (United States)

Sousa-Ferreira, Lígia; Aveleira, Célia; Botelho, Mariana; Álvaro, Ana Rita; Pereira de Almeida, Luís; Cavadas, Cláudia

2014-01-01

A significant number of children undergo maternal exposure to antidepressants and they often present low birth weight. Therefore, it is important to understand how selective serotonin reuptake inhibitors (SSRIs) affect the development of the hypothalamus, the key center for metabolism regulation. In this study we investigated the proliferative actions of fluoxetine in fetal hypothalamic neuroprogenitor cells and demonstrate that fluoxetine induces the proliferation of these cells, as shown by increased neurospheres size and number of proliferative cells (Ki-67+ cells). Moreover, fluoxetine inhibits the differentiation of hypothalamic neuroprogenitor cells, as demonstrated by decreased number of mature neurons (Neu-N+ cells) and increased number of undifferentiated cells (SOX-2+ cells). Additionally, fluoxetine-induced proliferation and maintenance of hypothalamic neuroprogenitor cells leads to changes in the mRNA levels of appetite regulator neuropeptides, including Neuropeptide Y (NPY) and Cocaine-and-Amphetamine-Regulated-Transcript (CART). This study provides the first evidence that SSRIs affect the development of hypothalamic neuroprogenitor cells in vitro with consequent alterations on appetite neuropeptides. PMID:24598761

System Identification, Prediction, Simulation and Control with Neural Networks

DEFF Research Database (Denmark)

Sørensen, O.

1997-01-01

a Gauss-Newton search direction is applied. 3) Amongst numerous model types, often met in control applications, only the Non-linear ARMAX (NARMAX) model, representing input/output description, is examined. A simulated example confirms that a neural network has the potential to perform excellent System......The intention of this paper is to make a systematic examination of the possibilities of applying neural networks in those technical areas, which are familiar to a control engineer. In other words, the potential of neural networks in control applications is given higher priority than a detailed...... study of the networks themselves. With this end in view the following restrictions have been made: 1) Amongst numerous neural network structures, only the Multi Layer Perceptron (a feed-forward network) is applied. 2) Amongst numerous training algorithms, only the Recursive Prediction Error Method using...

Cocaine- and amphetamine-regulated transcript is present in hypothalamic neuroendocrine neurones and is released to the hypothalamic-pituitary portal circuit

DEFF Research Database (Denmark)

Larsen, P J; Seier, V; Fink-Jensen, A

2003-01-01

Cocaine- and amphetamine-regulated transcript (CART) is present in a number of hypothalamic nuclei. Besides actions in circuits regulating feeding behaviour and stress responses, the hypothalamic functions of CART are largely unknown. We report that CART immunoreactivity is present in hypothalami......, supraoptic, paraventricular (PVN) and periventricular nuclei of the hypothalamus. In the PVN, CART-positive neuroendocrine neurones were found in all of cytoarchitectonically identified nuclei. In the periventricular nucleus, approximately one-third of somatostatin cells were also CART......-immunoreactive. In the medial parvicellular subnucleus of the PVN, CART and FG coexisted with thyrotrophin-releasing hormone, whereas very few of the corticotrophin-releasing hormone containing cells were CART-immunoreactive. In the arcuate nucleus, CART was extensively colocalized with pro...

Increased anti-Mullerian hormone levels and ovarian size in a subgroup of women with functional hypothalamic amenorrhea: further identification of the link between polycystic ovary syndrome and functional hypothalamic amenorrhea.

Science.gov (United States)

Carmina, Enrico; Fruzzetti, Franca; Lobo, Roger A

2016-06-01

Functional hypothalamic amenorrhea is a disorder characterized by cessation of menstrual cycles in the absence of organic disease. In most patients, it occurs in adult life after a stressful event and may be related to a condition of mild chronic energy deprivation. The endocrine pattern is characterized by low estrogen levels with an absent response to a progestogen challenge test and low-normal gonadotropin levels. A few studies have shown that some of these women may have some features of polycystic ovary syndrome; these features include an increased androgen response to gonadotropins, increased anti-Mullerian hormone levels, and altered ovarian morphology or increased ovarian size. These findings suggest a link between these 2 completely different disorders: functional hypothalamic amenorrhea and polycystic ovary syndrome. The importance of the possible coexistence of these disorders in some women is important for follow-up of these women and in their treatment if they desire to become pregnant. To determine whether a subgroup of well-characterized women with functional hypothalamic amenorrhea may have the coexistence of polycystic ovary syndrome. Retrospective analysis of women with functional hypothalamic amenorrhea. Forty consecutive patients and 28 normal age-matched control patients were studied. Blood was obtained for serum anti-Mullerian hormone, androgens, and other hormone levels and all women had ovarian ultrasonographic measurements. In the entire group of women with functional hypothalamic amenorrhea, anti-Mullerian hormone and ovarian volume were greater than in control patients. In 13 patients (32.5%), anti-Mullerian hormone was elevated (>4.7 ng/mL, levels consistent with polycystic ovary syndrome) and in this group, ovarian volume was significantly greater than in the remaining patients with functional hypothalamic amenorrhea. Four of the 13 women with functional hypothalamic amenorrhea who had elevated anti-Mullerian hormone levels (10%), also

Container-code recognition system based on computer vision and deep neural networks

Science.gov (United States)

Liu, Yi; Li, Tianjian; Jiang, Li; Liang, Xiaoyao

2018-04-01

Automatic container-code recognition system becomes a crucial requirement for ship transportation industry in recent years. In this paper, an automatic container-code recognition system based on computer vision and deep neural networks is proposed. The system consists of two modules, detection module and recognition module. The detection module applies both algorithms based on computer vision and neural networks, and generates a better detection result through combination to avoid the drawbacks of the two methods. The combined detection results are also collected for online training of the neural networks. The recognition module exploits both character segmentation and end-to-end recognition, and outputs the recognition result which passes the verification. When the recognition module generates false recognition, the result will be corrected and collected for online training of the end-to-end recognition sub-module. By combining several algorithms, the system is able to deal with more situations, and the online training mechanism can improve the performance of the neural networks at runtime. The proposed system is able to achieve 93% of overall recognition accuracy.

Evidence for a role of proline and hypothalamic astrocytes in the regulation of glucose metabolism in rats.

Science.gov (United States)

Arrieta-Cruz, Isabel; Su, Ya; Knight, Colette M; Lam, Tony K T; Gutiérrez-Juárez, Roger

2013-04-01

The metabolism of lactate to pyruvate in the mediobasal hypothalamus (MBH) regulates hepatic glucose production. Because astrocytes and neurons are functionally linked by metabolic coupling through lactate transfer via the astrocyte-neuron lactate shuttle (ANLS), we reasoned that astrocytes might be involved in the hypothalamic regulation of glucose metabolism. To examine this possibility, we used the gluconeogenic amino acid proline, which is metabolized to pyruvate in astrocytes. Our results showed that increasing the availability of proline in rats either centrally (MBH) or systemically acutely lowered blood glucose. Pancreatic clamp studies revealed that this hypoglycemic effect was due to a decrease of hepatic glucose production secondary to an inhibition of glycogenolysis, gluconeogenesis, and glucose-6-phosphatase flux. The effect of proline was mimicked by glutamate, an intermediary of proline metabolism. Interestingly, proline's action was markedly blunted by pharmacological inhibition of hypothalamic lactate dehydrogenase (LDH) suggesting that metabolic flux through LDH was required. Furthermore, short hairpin RNA-mediated knockdown of hypothalamic LDH-A, an astrocytic component of the ANLS, also blunted the glucoregulatory action of proline. Thus our studies suggest not only a new role for proline in the regulation of hepatic glucose production but also indicate that hypothalamic astrocytes are involved in the regulatory mechanism as well.

Temporal neural networks and transient analysis of complex engineering systems

Science.gov (United States)

Uluyol, Onder

A theory is introduced for a multi-layered Local Output Gamma Feedback (LOGF) neural network within the paradigm of Locally-Recurrent Globally-Feedforward neural networks. It is developed for the identification, prediction, and control tasks of spatio-temporal systems and allows for the presentation of different time scales through incorporation of a gamma memory. It is initially applied to the tasks of sunspot and Mackey-Glass series prediction as benchmarks, then it is extended to the task of power level control of a nuclear reactor at different fuel cycle conditions. The developed LOGF neuron model can also be viewed as a Transformed Input and State (TIS) Gamma memory for neural network architectures for temporal processing. The novel LOGF neuron model extends the static neuron model by incorporating into it a short-term memory structure in the form of a digital gamma filter. A feedforward neural network made up of LOGF neurons can thus be used to model dynamic systems. A learning algorithm based upon the Backpropagation-Through-Time (BTT) approach is derived. It is applicable for training a general L-layer LOGF neural network. The spatial and temporal weights and parameters of the network are iteratively optimized for a given problem using the derived learning algorithm.

Optical neural network system for pose determination of spinning satellites

Science.gov (United States)

Lee, Andrew; Casasent, David

1990-01-01

An optical neural network architecture and algorithm based on a Hopfield optimization network are presented for multitarget tracking. This tracker utilizes a neuron for every possible target track, and a quadratic energy function of neural activities which is minimized using gradient descent neural evolution. The neural net tracker is demonstrated as part of a system for determining position and orientation (pose) of spinning satellites with respect to a robotic spacecraft. The input to the system is time sequence video from a single camera. Novelty detection and filtering are utilized to locate and segment novel regions from the input images. The neural net multitarget tracker determines the correspondences (or tracks) of the novel regions as a function of time, and hence the paths of object (satellite) parts. The path traced out by a given part or region is approximately elliptical in image space, and the position, shape and orientation of the ellipse are functions of the satellite geometry and its pose. Having a geometric model of the satellite, and the elliptical path of a part in image space, the three-dimensional pose of the satellite is determined. Digital simulation results using this algorithm are presented for various satellite poses and lighting conditions.

Neural mechanisms of selective attention in the somatosensory system.

Science.gov (United States)

Gomez-Ramirez, Manuel; Hysaj, Kristjana; Niebur, Ernst

2016-09-01

Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. Copyright © 2016 the American Physiological Society.

Synthesis of recurrent neural networks for dynamical system simulation.

Science.gov (United States)

Trischler, Adam P; D'Eleuterio, Gabriele M T

2016-08-01

We review several of the most widely used techniques for training recurrent neural networks to approximate dynamical systems, then describe a novel algorithm for this task. The algorithm is based on an earlier theoretical result that guarantees the quality of the network approximation. We show that a feedforward neural network can be trained on the vector-field representation of a given dynamical system using backpropagation, then recast it as a recurrent network that replicates the original system's dynamics. After detailing this algorithm and its relation to earlier approaches, we present numerical examples that demonstrate its capabilities. One of the distinguishing features of our approach is that both the original dynamical systems and the recurrent networks that simulate them operate in continuous time. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hypothalamic food intake regulation in a cancer-cachectic mouse model

OpenAIRE

Dwarkasing, Jvalini T.; van Dijk, Miriam; Dijk, Francina J.; Boekschoten, Mark V.; Faber, Joyce; Argilès, Josep M.; Laviano, Alessandro; Müller, Michael; Witkamp, Renger F.; van Norren, Klaske

2013-01-01

Background Appetite is frequently affected in cancer patients leading to anorexia and consequently insufficient food intake. In this study, we report on hypothalamic gene expression profile of a cancer-cachectic mouse model with increased food intake. In this model, mice bearing C26 tumour have an increased food intake subsequently to the loss of body weight. We hypothesise that in this model, appetite-regulating systems in the hypothalamus, which apparently fail in anorexia, are still able t...

A modular neural network scheme applied to fault diagnosis in electric power systems.

Science.gov (United States)

Flores, Agustín; Quiles, Eduardo; García, Emilio; Morant, Francisco; Correcher, Antonio

2014-01-01

This work proposes a new method for fault diagnosis in electric power systems based on neural modules. With this method the diagnosis is performed by assigning a neural module for each type of component comprising the electric power system, whether it is a transmission line, bus or transformer. The neural modules for buses and transformers comprise two diagnostic levels which take into consideration the logic states of switches and relays, both internal and back-up, with the exception of the neural module for transmission lines which also has a third diagnostic level which takes into account the oscillograms of fault voltages and currents as well as the frequency spectrums of these oscillograms, in order to verify if the transmission line had in fact been subjected to a fault. One important advantage of the diagnostic system proposed is that its implementation does not require the use of a network configurator for the system; it does not depend on the size of the power network nor does it require retraining of the neural modules if the power network increases in size, making its application possible to only one component, a specific area, or the whole context of the power system.

Neural systems language: a formal modeling language for the systematic description, unambiguous communication, and automated digital curation of neural connectivity.

Science.gov (United States)

Brown, Ramsay A; Swanson, Larry W

2013-09-01

Systematic description and the unambiguous communication of findings and models remain among the unresolved fundamental challenges in systems neuroscience. No common descriptive frameworks exist to describe systematically the connective architecture of the nervous system, even at the grossest level of observation. Furthermore, the accelerating volume of novel data generated on neural connectivity outpaces the rate at which this data is curated into neuroinformatics databases to synthesize digitally systems-level insights from disjointed reports and observations. To help address these challenges, we propose the Neural Systems Language (NSyL). NSyL is a modeling language to be used by investigators to encode and communicate systematically reports of neural connectivity from neuroanatomy and brain imaging. NSyL engenders systematic description and communication of connectivity irrespective of the animal taxon described, experimental or observational technique implemented, or nomenclature referenced. As a language, NSyL is internally consistent, concise, and comprehensible to both humans and computers. NSyL is a promising development for systematizing the representation of neural architecture, effectively managing the increasing volume of data on neural connectivity and streamlining systems neuroscience research. Here we present similar precedent systems, how NSyL extends existing frameworks, and the reasoning behind NSyL's development. We explore NSyL's potential for balancing robustness and consistency in representation by encoding previously reported assertions of connectivity from the literature as examples. Finally, we propose and discuss the implications of a framework for how NSyL will be digitally implemented in the future to streamline curation of experimental results and bridge the gaps among anatomists, imagers, and neuroinformatics databases. Copyright © 2013 Wiley Periodicals, Inc.

Real-time cerebellar neuroprosthetic system based on a spiking neural network model of motor learning.

Science.gov (United States)

Xu, Tao; Xiao, Na; Zhai, Xiaolong; Kwan Chan, Pak; Tin, Chung

2018-02-01

Damage to the brain, as a result of various medical conditions, impacts the everyday life of patients and there is still no complete cure to neurological disorders. Neuroprostheses that can functionally replace the damaged neural circuit have recently emerged as a possible solution to these problems. Here we describe the development of a real-time cerebellar neuroprosthetic system to substitute neural function in cerebellar circuitry for learning delay eyeblink conditioning (DEC). The system was empowered by a biologically realistic spiking neural network (SNN) model of the cerebellar neural circuit, which considers the neuronal population and anatomical connectivity of the network. The model simulated synaptic plasticity critical for learning DEC. This SNN model was carefully implemented on a field programmable gate array (FPGA) platform for real-time simulation. This hardware system was interfaced in in vivo experiments with anesthetized rats and it used neural spikes recorded online from the animal to learn and trigger conditioned eyeblink in the animal during training. This rat-FPGA hybrid system was able to process neuronal spikes in real-time with an embedded cerebellum model of ~10 000 neurons and reproduce learning of DEC with different inter-stimulus intervals. Our results validated that the system performance is physiologically relevant at both the neural (firing pattern) and behavioral (eyeblink pattern) levels. This integrated system provides the sufficient computation power for mimicking the cerebellar circuit in real-time. The system interacts with the biological system naturally at the spike level and can be generalized for including other neural components (neuron types and plasticity) and neural functions for potential neuroprosthetic applications.

Radioimmunological functional examination of the adenohypophysis on pathological conditions in the hypothalamic-hypophyseal-adrenocortical system

International Nuclear Information System (INIS)

Slavnov, V.N.; Luchitskij, E.V.

1980-01-01

The corticotropic, thyrotropic and somatotropic functions of the adenohypophysis of patients with Cushing syndrome were examined radioimmunologically. Blood corticotropine and thyrotropine of these patients was characterized by a disturbed 24 hour rhythm. The release of corticotropine and somatotropine was but little increased as response to insulin hypoglycemia. The adenohypophysis responded weakly to the stimulation by thyroliberine. With the clinical remission of Cushing syndrome following treatment with chloditane or with a combined method an increased concentration of adenohypophyseal hormones in the blood could be demonstrated. The response to insulin hypoglycemic stress and to the thyroliberine stimulation was not normalized just as the 24-hour rhythm of the blood level of corticotropine and thyreotropine. Thus it can be concluded that these disturbances are caused by injuries of the central regulatory mechanisms of the hypothalamic-hypophyseal system, and pathogenetic therapeutic methods for the Cushing syndrome must be elaborated

Gonadotropin-releasing hormone for infertility in women with primary hypothalamic amenorrhea. Toward a more-interventional approach.

Science.gov (United States)

Kesrouani, A; Abdallah, M A; Attieh, E; Abboud, J; Atallah, D; Makhoul, C

2001-01-01

To assess the effectiveness of a protocol of pulsatile gonadotropin releasing-hormone (GnRH) in treating infertility in women with primary hypothalamic amenorrhea. Retrospective analysis of 44 cycles treated at an infertility center. Twenty-four patients with primary hypothalamic amenorrhea were treated intravenously with pulsatile GnRH using 5 micrograms per bolus every 90 minutes. Ultrasound monitoring and cervical assessment by Insler's scoring system allowed timed injection of human chorionic gonadotropin (hCG) and intrauterine insemination if needed. Luteal support was provided with hCG. The ovulation rate was 95% with the 5-microgram dose. A single follicle was produced in 91% of cycles. The overall pregnancy rate per ovulatory cycle was 45%, and the pregnancy rate per patient was 83%. In patients treated previously with exogenous gonadotropins, poor results were observed. Only one case of mild overstimulation was reported. Pulsatile GnRH is an effective and safe method of treating infertility in women with primary hypothalamic amenorrhea, thus simulating normal ovulation; however, more-interventional management, including the qualitative estrogenic response, may lead to optimal results and increase the pregnancy rate.

Efficient decoding with steady-state Kalman filter in neural interface systems.

Science.gov (United States)

Malik, Wasim Q; Truccolo, Wilson; Brown, Emery N; Hochberg, Leigh R

2011-02-01

The Kalman filter is commonly used in neural interface systems to decode neural activity and estimate the desired movement kinematics. We analyze a low-complexity Kalman filter implementation in which the filter gain is approximated by its steady-state form, computed offline before real-time decoding commences. We evaluate its performance using human motor cortical spike train data obtained from an intracortical recording array as part of an ongoing pilot clinical trial. We demonstrate that the standard Kalman filter gain converges to within 95% of the steady-state filter gain in 1.5±0.5 s (mean ±s.d.). The difference in the intended movement velocity decoded by the two filters vanishes within 5 s, with a correlation coefficient of 0.99 between the two decoded velocities over the session length. We also find that the steady-state Kalman filter reduces the computational load (algorithm execution time) for decoding the firing rates of 25±3 single units by a factor of 7.0±0.9. We expect that the gain in computational efficiency will be much higher in systems with larger neural ensembles. The steady-state filter can thus provide substantial runtime efficiency at little cost in terms of estimation accuracy. This far more efficient neural decoding approach will facilitate the practical implementation of future large-dimensional, multisignal neural interface systems.

Nonlinear signal processing using neural networks: Prediction and system modelling

Energy Technology Data Exchange (ETDEWEB)

Lapedes, A.; Farber, R.

1987-06-01

The backpropagation learning algorithm for neural networks is developed into a formalism for nonlinear signal processing. We illustrate the method by selecting two common topics in signal processing, prediction and system modelling, and show that nonlinear applications can be handled extremely well by using neural networks. The formalism is a natural, nonlinear extension of the linear Least Mean Squares algorithm commonly used in adaptive signal processing. Simulations are presented that document the additional performance achieved by using nonlinear neural networks. First, we demonstrate that the formalism may be used to predict points in a highly chaotic time series with orders of magnitude increase in accuracy over conventional methods including the Linear Predictive Method and the Gabor-Volterra-Weiner Polynomial Method. Deterministic chaos is thought to be involved in many physical situations including the onset of turbulence in fluids, chemical reactions and plasma physics. Secondly, we demonstrate the use of the formalism in nonlinear system modelling by providing a graphic example in which it is clear that the neural network has accurately modelled the nonlinear transfer function. It is interesting to note that the formalism provides explicit, analytic, global, approximations to the nonlinear maps underlying the various time series. Furthermore, the neural net seems to be extremely parsimonious in its requirements for data points from the time series. We show that the neural net is able to perform well because it globally approximates the relevant maps by performing a kind of generalized mode decomposition of the maps. 24 refs., 13 figs.

Distributed Adaptive Neural Control for Stochastic Nonlinear Multiagent Systems.

Science.gov (United States)

Wang, Fang; Chen, Bing; Lin, Chong; Li, Xuehua

2016-11-14

In this paper, a consensus tracking problem of nonlinear multiagent systems is investigated under a directed communication topology. All the followers are modeled by stochastic nonlinear systems in nonstrict feedback form, where nonlinearities and stochastic disturbance terms are totally unknown. Based on the structural characteristic of neural networks (in Lemma 4), a novel distributed adaptive neural control scheme is put forward. The raised control method not only effectively handles unknown nonlinearities in nonstrict feedback systems, but also copes with the interactions among agents and coupling terms. Based on the stochastic Lyapunov functional method, it is indicated that all the signals of the closed-loop system are bounded in probability and all followers' outputs are convergent to a neighborhood of the output of leader. At last, the efficiency of the control method is testified by a numerical example.

Learning in Artificial Neural Systems

Science.gov (United States)

Matheus, Christopher J.; Hohensee, William E.

1987-01-01

This paper presents an overview and analysis of learning in Artificial Neural Systems (ANS's). It begins with a general introduction to neural networks and connectionist approaches to information processing. The basis for learning in ANS's is then described, and compared with classical Machine learning. While similar in some ways, ANS learning deviates from tradition in its dependence on the modification of individual weights to bring about changes in a knowledge representation distributed across connections in a network. This unique form of learning is analyzed from two aspects: the selection of an appropriate network architecture for representing the problem, and the choice of a suitable learning rule capable of reproducing the desired function within the given network. The various network architectures are classified, and then identified with explicit restrictions on the types of functions they are capable of representing. The learning rules, i.e., algorithms that specify how the network weights are modified, are similarly taxonomized, and where possible, the limitations inherent to specific classes of rules are outlined.

Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system and proinflammatory cytokines in hypertension

International Nuclear Information System (INIS)

Su, Qing; Qin, Da-Nian; Wang, Fu-Xin; Ren, Jun; Li, Hong-Bao; Zhang, Meng; Yang, Qing; Miao, Yu-Wang; Yu, Xiao-Jing; Qi, Jie; Zhu, Zhiming; Zhu, Guo-Qing; Kang, Yu-Ming

2014-01-01

Aims: To explore whether reactive oxygen species (ROS) scavenger (tempol) in the hypothalamic paraventricular nucleus (PVN) attenuates renin–angiotensin system (RAS) and proinflammatory cytokines (PICs), and decreases the blood pressure and sympathetic activity in angiotensin II (ANG II)-induced hypertension. Methods and results: Male Sprague–Dawley rats were infused intravenously with ANG II (10 ng/kg per min) or normal saline (NS) for 4 weeks. These rats were treated with bilateral PVN infusion of oxygen free radical scavenger tempol (TEMP, 20 μg/h) or vehicle (artificial cerebrospinal fluid, aCSF) for 4 weeks. ANG II infusion resulted in increased mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA). These ANG II-infused rats also had higher levels of gp91 phox (a subunit of NAD(P)H oxidase), angiotensin-converting enzyme (ACE), and interleukin-1beta (IL-1β) in the PVN than the control animals. Treatment with PVN infusion of TEMP attenuated the overexpression of gp91 phox , ACE and IL-1β within the PVN, and decreased sympathetic activity and MAP in ANG II-infused rats. Conclusion: These findings suggest that ANG II infusion induces elevated PICs and oxidative stress in the PVN, which contribute to the sympathoexcitation in hypertension. Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system, proinflammatory cytokines and oxidative stress in ANG II-induced hypertension. - Highlights: • The effect of chronic inhibiting PVN superoxide on hypertension was investigated. • ANG II infusion induced increased proinflammatory cytokines and superoxide in PVN. • ANG II infusion resulted in oxidative stress, sympathoexcitation and hypertension. • Chronic inhibiting PVN superoxide attenuates RAS and cytokines in hypertension

Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system and proinflammatory cytokines in hypertension

Energy Technology Data Exchange (ETDEWEB)

Su, Qing [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Qin, Da-Nian, E-mail: dnqin@stu.edu.cn [Department of Physiology, Shantou University Medical College, Shantou 515041 (China); Wang, Fu-Xin [Department of Neurology, The First Affiliated Hospital of Jiamusi University, Jiamusi 154002 (China); Ren, Jun [Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY 82071 (United States); Li, Hong-Bao; Zhang, Meng; Yang, Qing; Miao, Yu-Wang; Yu, Xiao-Jing; Qi, Jie [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Zhu, Zhiming [Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, The Third Military Medical University, Chongqing Institute of Hypertension, Chongqing 400042 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China)

2014-04-15

Aims: To explore whether reactive oxygen species (ROS) scavenger (tempol) in the hypothalamic paraventricular nucleus (PVN) attenuates renin–angiotensin system (RAS) and proinflammatory cytokines (PICs), and decreases the blood pressure and sympathetic activity in angiotensin II (ANG II)-induced hypertension. Methods and results: Male Sprague–Dawley rats were infused intravenously with ANG II (10 ng/kg per min) or normal saline (NS) for 4 weeks. These rats were treated with bilateral PVN infusion of oxygen free radical scavenger tempol (TEMP, 20 μg/h) or vehicle (artificial cerebrospinal fluid, aCSF) for 4 weeks. ANG II infusion resulted in increased mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA). These ANG II-infused rats also had higher levels of gp91{sup phox} (a subunit of NAD(P)H oxidase), angiotensin-converting enzyme (ACE), and interleukin-1beta (IL-1β) in the PVN than the control animals. Treatment with PVN infusion of TEMP attenuated the overexpression of gp91{sup phox}, ACE and IL-1β within the PVN, and decreased sympathetic activity and MAP in ANG II-infused rats. Conclusion: These findings suggest that ANG II infusion induces elevated PICs and oxidative stress in the PVN, which contribute to the sympathoexcitation in hypertension. Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system, proinflammatory cytokines and oxidative stress in ANG II-induced hypertension. - Highlights: • The effect of chronic inhibiting PVN superoxide on hypertension was investigated. • ANG II infusion induced increased proinflammatory cytokines and superoxide in PVN. • ANG II infusion resulted in oxidative stress, sympathoexcitation and hypertension. • Chronic inhibiting PVN superoxide attenuates RAS and cytokines in hypertension.

Bang-bang control of feeding: role of hypothalamic and satiety signals.

Directory of Open Access Journals (Sweden)

B Silvano Zanutto

2007-05-01

Full Text Available Rats, people, and many other omnivores eat in meals rather than continuously. We show by experimental test that eating in meals is regulated by a simple bang-bang control system, an idea foreshadowed by Le Magnen and many others, shown by us to account for a wide range of behavioral data, but never explicitly tested or tied to neurophysiological facts. The hypothesis is simply that the tendency to eat rises with time at a rate determined by satiety signals. When these signals fall below a set point, eating begins, in on-off fashion. The delayed sequelae of eating increment the satiety signals, which eventually turn eating off. Thus, under free conditions, the organism eats in bouts separated by noneating activities. We report an experiment with rats to test novel predictions about meal patterns that are not explained by existing homeostatic approaches. Access to food was systematically but unpredictably interrupted just as the animal tried to start a new meal. A simple bang-bang model fits the resulting meal-pattern data well, and its elements can be identified with neurophysiological processes. Hypothalamic inputs can provide the set point for longer-term regulation carried out by a comparator in the hindbrain. Delayed gustatory and gastrointestinal aftereffects of eating act via the nucleus of the solitary tract and other hindbrain regions as neural feedback governing short-term regulation. In this way, the model forges real links between a functioning feedback mechanism, neuro-hormonal data, and both short-term (meals and long-term (eating-rate regulation behavioral data.

Neutron spectrometry and dosimetry by means of Bonner spheres system and artificial neural networks applying robust design of artificial neural networks

Energy Technology Data Exchange (ETDEWEB)

Martinez B, M.R.; Ortiz R, J.M.; Vega C, H.R. [UAZ, Av. Ramon Lopez Velarde No. 801, 98000 Zacatecas (Mexico)

2006-07-01

An Artificial Neural Network has been designed, trained and tested to unfold neutron spectra and simultaneously to calculate equivalent doses. A set of 187 neutron spectra compiled by the International Atomic Energy Agency and 13 equivalent doses were used in the artificial neural network designed, trained and tested. In order to design the neural network was used the robust design of artificial neural networks methodology, which assures that the quality of the neural networks takes into account from the design stage. Unless previous works, here, for first time a group of neural networks were designed and trained to unfold 187 neutron spectra and at the same time to calculate 13 equivalent doses, starting from the count rates coming from the Bonner spheres system by using a systematic and experimental strategy. (Author)

Neutron spectrometry and dosimetry by means of Bonner spheres system and artificial neural networks applying robust design of artificial neural networks

International Nuclear Information System (INIS)

Martinez B, M.R.; Ortiz R, J.M.; Vega C, H.R.

2006-01-01

An Artificial Neural Network has been designed, trained and tested to unfold neutron spectra and simultaneously to calculate equivalent doses. A set of 187 neutron spectra compiled by the International Atomic Energy Agency and 13 equivalent doses were used in the artificial neural network designed, trained and tested. In order to design the neural network was used the robust design of artificial neural networks methodology, which assures that the quality of the neural networks takes into account from the design stage. Unless previous works, here, for first time a group of neural networks were designed and trained to unfold 187 neutron spectra and at the same time to calculate 13 equivalent doses, starting from the count rates coming from the Bonner spheres system by using a systematic and experimental strategy. (Author)

Compact holographic optical neural network system for real-time pattern recognition

Science.gov (United States)

Lu, Taiwei; Mintzer, David T.; Kostrzewski, Andrew A.; Lin, Freddie S.

1996-08-01

One of the important characteristics of artificial neural networks is their capability for massive interconnection and parallel processing. Recently, specialized electronic neural network processors and VLSI neural chips have been introduced in the commercial market. The number of parallel channels they can handle is limited because of the limited parallel interconnections that can be implemented with 1D electronic wires. High-resolution pattern recognition problems can require a large number of neurons for parallel processing of an image. This paper describes a holographic optical neural network (HONN) that is based on high- resolution volume holographic materials and is capable of performing massive 3D parallel interconnection of tens of thousands of neurons. A HONN with more than 16,000 neurons packaged in an attache case has been developed. Rotation- shift-scale-invariant pattern recognition operations have been demonstrated with this system. System parameters such as the signal-to-noise ratio, dynamic range, and processing speed are discussed.

Real-time cerebellar neuroprosthetic system based on a spiking neural network model of motor learning

Science.gov (United States)

Xu, Tao; Xiao, Na; Zhai, Xiaolong; Chan, Pak Kwan; Tin, Chung

2018-02-01

Objective. Damage to the brain, as a result of various medical conditions, impacts the everyday life of patients and there is still no complete cure to neurological disorders. Neuroprostheses that can functionally replace the damaged neural circuit have recently emerged as a possible solution to these problems. Here we describe the development of a real-time cerebellar neuroprosthetic system to substitute neural function in cerebellar circuitry for learning delay eyeblink conditioning (DEC). Approach. The system was empowered by a biologically realistic spiking neural network (SNN) model of the cerebellar neural circuit, which considers the neuronal population and anatomical connectivity of the network. The model simulated synaptic plasticity critical for learning DEC. This SNN model was carefully implemented on a field programmable gate array (FPGA) platform for real-time simulation. This hardware system was interfaced in in vivo experiments with anesthetized rats and it used neural spikes recorded online from the animal to learn and trigger conditioned eyeblink in the animal during training. Main results. This rat-FPGA hybrid system was able to process neuronal spikes in real-time with an embedded cerebellum model of ~10 000 neurons and reproduce learning of DEC with different inter-stimulus intervals. Our results validated that the system performance is physiologically relevant at both the neural (firing pattern) and behavioral (eyeblink pattern) levels. Significance. This integrated system provides the sufficient computation power for mimicking the cerebellar circuit in real-time. The system interacts with the biological system naturally at the spike level and can be generalized for including other neural components (neuron types and plasticity) and neural functions for potential neuroprosthetic applications.

Neural network training by Kalman filtering in process system monitoring

International Nuclear Information System (INIS)

Ciftcioglu, Oe.

1996-03-01

Kalman filtering approach for neural network training is described. Its extended form is used as an adaptive filter in a nonlinear environment of the form a feedforward neural network. Kalman filtering approach generally provides fast training as well as avoiding excessive learning which results in enhanced generalization capability. The network is used in a process monitoring application where the inputs are measurement signals. Since the measurement errors are also modelled in Kalman filter the approach yields accurate training with the implication of accurate neural network model representing the input and output relationships in the application. As the process of concern is a dynamic system, the input source of information to neural network is time dependent so that the training algorithm presents an adaptive form for real-time operation for the monitoring task. (orig.)

A Modular Neural Network Scheme Applied to Fault Diagnosis in Electric Power Systems

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Agustín Flores

2014-01-01

Full Text Available This work proposes a new method for fault diagnosis in electric power systems based on neural modules. With this method the diagnosis is performed by assigning a neural module for each type of component comprising the electric power system, whether it is a transmission line, bus or transformer. The neural modules for buses and transformers comprise two diagnostic levels which take into consideration the logic states of switches and relays, both internal and back-up, with the exception of the neural module for transmission lines which also has a third diagnostic level which takes into account the oscillograms of fault voltages and currents as well as the frequency spectrums of these oscillograms, in order to verify if the transmission line had in fact been subjected to a fault. One important advantage of the diagnostic system proposed is that its implementation does not require the use of a network configurator for the system; it does not depend on the size of the power network nor does it require retraining of the neural modules if the power network increases in size, making its application possible to only one component, a specific area, or the whole context of the power system.

Inhibition of deprivation-induced food intake by GABA(A) antagonists: roles of the hypothalamic, endocrine and alimentary mechanisms.

Science.gov (United States)

Kamatchi, Ganesan L; Rathanaswami, Palaniswami

2012-07-01

The role of gamma amino butyric acid A receptors/neurons of the hypothalamic, endocrine and alimentary systems in the food intake seen in hunger was studied in 20 h food-deprived rats. Food deprivation decreased blood glucose, serum insulin and produced hyperphagia. The hyperphagia was inhibited by subcutaneous or ventromedial hypothalamic administration of gamma amino butyric acid A antagonists picrotoxin or bicuculline. Although results of blood glucose was variable, insulin level was increased by picrotoxin or bicuculline. In contrast, lateral hypothalamic administration of these agents failed to reproduce the above changes. Subcutaneous administration of picrotoxin or bicuculline increased gastric content, decreased gastric motility and small bowel transit. In contrast, ventromedial or lateral hypothalamic administration of picrotoxin or bicuculline failed to alter the gastric content but decreased the small bowel transit. The results of alimentary studies suggest that gamma amino butyric acid neurons of both ventromedial and lateral hypothalamus selectively regulate small bowel transit but not the gastric content. It may be concluded that ventromedial hypothalamus plays a dominant role in the regulation of food intake and that picrotoxin or bicuculline inhibited food intake by inhibiting gamma amino butyric acid receptors of the ventromedial hypothalamus, increasing insulin level and decreasing the gut motility.

Modulation of the mesolimbic dopamine system by leptin.

Science.gov (United States)

Opland, Darren M; Leinninger, Gina M; Myers, Martin G

2010-09-02

Nutritional status modulates many forms of reward-seeking behavior, with caloric restriction increasing the drive for drugs of abuse as well as for food. Understanding the interactions between the mesolimbic dopamine (DA) system (which mediates the incentive salience of natural and artificial rewards) and the neural and hormonal systems that sense and regulate energy balance is thus of significant importance. Leptin, which is produced by adipocytes in proportion to fat content as a hormonal signal of long-term energy stores, acts via its receptor (LepRb) on multiple populations of central nervous system neurons to modulate neural circuits in response to body energy stores. Leptin suppresses feeding and plays a central role in the control of energy balance. In addition to demonstrating that leptin modulates hypothalamic and brainstem circuits to promote satiety, recent work has begun to explore the mechanisms by which leptin influences the mesolimbic DA system and related behaviors. Indeed, leptin diminishes several measures of drug and food reward, and promotes a complex set of changes in the mesolimbic DA system. While many of the details remain to be worked out, several lines of evidence suggest that leptin regulates the mesolimbic DA system via multiple neural pathways and processes, and that distinct sets of LepRb neurons each modulate unique aspects of the mesolimbic DA system and behavior in response to leptin. 2010 Elsevier B.V. All rights reserved.

Hypoxia-inducible factor directs POMC gene to mediate hypothalamic glucose sensing and energy balance regulation.

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Hai Zhang

2011-07-01

Full Text Available Hypoxia-inducible factor (HIF is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance.

Hypoxia-Inducible Factor Directs POMC Gene to Mediate Hypothalamic Glucose Sensing and Energy Balance Regulation

Science.gov (United States)

Zhang, Hai; Zhang, Guo; Gonzalez, Frank J.; Park, Sung-min; Cai, Dongsheng

2011-01-01

Hypoxia-inducible factor (HIF) is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance. PMID:21814490

Dietary sugars, not lipids, drive hypothalamic inflammation

NARCIS (Netherlands)

Gao, Yuanqing; Bielohuby, Maximilian; Fleming, Thomas; Grabner, Gernot F; Foppen, Ewout; Bernhard, Wagner; Guzmán-Ruiz, Mara; Layritz, Clarita; Legutko, Beata; Zinser, Erwin; García-Cáceres, Cristina; Buijs, Ruud M; Woods, Stephen C; Kalsbeek, A.; Seeley, Randy J; Nawroth, Peter P; Bidlingmaier, Martin; Tschöp, Matthias H; Yi, Chun-Xia

OBJECTIVE: The hypothalamus of hypercaloric diet-induced obese animals is featured by a significant increase of microglial reactivity and its associated cytokine production. However, the role of dietary components, in particular fat and carbohydrate, with respect to the hypothalamic inflammatory

Dietary sugars, not lipids, drive hypothalamic inflammation

NARCIS (Netherlands)

Gao, Yuanqing; Bielohuby, Maximilian; Fleming, Thomas; Grabner, Gernot F.; Foppen, Ewout; Bernhard, Wagner; Guzmán-Ruiz, Mara; Layritz, Clarita; Legutko, Beata; Zinser, Erwin; García-Cáceres, Cristina; Buijs, Ruud M.; Woods, Stephen C.; Kalsbeek, Andries; Seeley, Randy J.; Nawroth, Peter P.; Bidlingmaier, Martin; Tschöp, Matthias H.; Yi, Chun-Xia

2017-01-01

Objective: The hypothalamus of hypercaloric diet-induced obese animals is featured by a significant increase of microglial reactivity and its associated cytokine production. However, the role of dietary components, in particular fat and carbohydrate, with respect to the hypothalamic inflammatory

Adaptive Neural Control for a Class of Outputs Time-Delay Nonlinear Systems

Directory of Open Access Journals (Sweden)

Ruliang Wang

2012-01-01

Full Text Available This paper considers an adaptive neural control for a class of outputs time-delay nonlinear systems with perturbed or no. Based on RBF neural networks, the radius basis function (RBF neural networks is employed to estimate the unknown continuous functions. The proposed control guarantees that all closed-loop signals remain bounded. The simulation results demonstrate the effectiveness of the proposed control scheme.

Diagnosis of mechanical pumping system using neural networks and system parameters analysis

International Nuclear Information System (INIS)

Tsai, Tai Ming; Wang, Wei Hui

2009-01-01

Normally, a mechanical pumping system is equipped to monitor some of the important input and output signals which are set to the prescribed values. This paper addressed dealing with these signals to establish the database of input- output relation by using a number of neural network models through learning algorithms. These signals encompass normal and abnormal running conditions. The abnormal running conditions were artificially generated. Meanwhile, for the purpose of setting up an on-line diagnosis network, the learning speed and accuracy of three kinds of networks, viz., the backpropagation (BPN), radial basis function (RBF) and adaptive linear (ADALINE) neural networks have been compared and assessed. The assessment criteria of the networks are compared with the correlation result matrix in terms of the neuron vectors. Both BPN and RBF are judged by the maximum vector based on the post-regression analysis, and the ADALINE is judged by the minimum vector based on the least mean square error analysis. By ignoring the neural network training time, it has been shown that if the mechanical diagnosis system is tackled off-line, the RBF method is suggested. However, for on-line diagnosis, the BPN method is recommended

Diagnosis of mechanical pumping system using neural networks and system parameters analysis

Energy Technology Data Exchange (ETDEWEB)

Tsai, Tai Ming; Wang, Wei Hui [National Taiwan Ocean University, Keelung (China)

2009-01-15

Normally, a mechanical pumping system is equipped to monitor some of the important input and output signals which are set to the prescribed values. This paper addressed dealing with these signals to establish the database of input- output relation by using a number of neural network models through learning algorithms. These signals encompass normal and abnormal running conditions. The abnormal running conditions were artificially generated. Meanwhile, for the purpose of setting up an on-line diagnosis network, the learning speed and accuracy of three kinds of networks, viz., the backpropagation (BPN), radial basis function (RBF) and adaptive linear (ADALINE) neural networks have been compared and assessed. The assessment criteria of the networks are compared with the correlation result matrix in terms of the neuron vectors. Both BPN and RBF are judged by the maximum vector based on the post-regression analysis, and the ADALINE is judged by the minimum vector based on the least mean square error analysis. By ignoring the neural network training time, it has been shown that if the mechanical diagnosis system is tackled off-line, the RBF method is suggested. However, for on-line diagnosis, the BPN method is recommended

Serotonin 5-HT2C receptor-independent expression of hypothalamic NOR1, a novel modulator of food intake and energy balance, in mice

International Nuclear Information System (INIS)

Nonogaki, Katsunori; Kaji, Takao; Ohba, Yukie; Sumii, Makiko; Wakameda, Mamoru; Tamari, Tomohiro

2009-01-01

NOR1, Nur77 and Nurr1 are orphan nuclear receptors and members of the NR4A subfamily. Here, we report that the expression of hypothalamic NOR1 was remarkably decreased in mildly obese β-endorphin-deficient mice and obese db/db mice with the leptin receptor mutation, compared with age-matched wild-type mice, whereas there were no genotypic differences in the expression of hypothalamic Nur77 or Nurr1 in these animals. The injection of NOR1 siRNA oligonucleotide into the third cerebral ventricle significantly suppressed food intake and body weight in mice. On the other hand, the decreases in hypothalamic NOR1 expression were not found in non-obese 5-HT2C receptor-deficient mice. Moreover, systemic administration of m-chlorophenylpiperazine (mCPP), a 5-HT2C/1B receptor agonist, had no effect on hypothalamic NOR1 expression, while suppressing food intake in β-endorphin-deficient mice. These findings suggest that 5-HT2C receptor-independent proopiomelanocortin-derived peptides regulate the expression of hypothalamic NOR1, which is a novel modulator of feeding behavior and energy balance.

Serotonin 5-HT2C receptor-independent expression of hypothalamic NOR1, a novel modulator of food intake and energy balance, in mice

Energy Technology Data Exchange (ETDEWEB)

Nonogaki, Katsunori, E-mail: knonogaki-tky@umin.ac.jp [Center of Excellence, Division of Molecular Metabolism and Diabetes, Tohoku University Graduate School of Medicine (Japan); Department of Lifestyle Medicine, Biomedical Engineering Center, Tohoku University (Japan); Kaji, Takao [Department of Lifestyle Medicine, Biomedical Engineering Center, Tohoku University (Japan); Ohba, Yukie; Sumii, Makiko [Center of Excellence, Division of Molecular Metabolism and Diabetes, Tohoku University Graduate School of Medicine (Japan); Wakameda, Mamoru; Tamari, Tomohiro [Charles River Laboratories Japan, Inc. (Japan)

2009-08-21

NOR1, Nur77 and Nurr1 are orphan nuclear receptors and members of the NR4A subfamily. Here, we report that the expression of hypothalamic NOR1 was remarkably decreased in mildly obese {beta}-endorphin-deficient mice and obese db/db mice with the leptin receptor mutation, compared with age-matched wild-type mice, whereas there were no genotypic differences in the expression of hypothalamic Nur77 or Nurr1 in these animals. The injection of NOR1 siRNA oligonucleotide into the third cerebral ventricle significantly suppressed food intake and body weight in mice. On the other hand, the decreases in hypothalamic NOR1 expression were not found in non-obese 5-HT2C receptor-deficient mice. Moreover, systemic administration of m-chlorophenylpiperazine (mCPP), a 5-HT2C/1B receptor agonist, had no effect on hypothalamic NOR1 expression, while suppressing food intake in {beta}-endorphin-deficient mice. These findings suggest that 5-HT2C receptor-independent proopiomelanocortin-derived peptides regulate the expression of hypothalamic NOR1, which is a novel modulator of feeding behavior and energy balance.

Fetal hypothalamic transplants into brain irradiated rats: Graft morphometry and host behavioral responses

International Nuclear Information System (INIS)

Pearlman, S.H.; Rubin, P.; White, H.C.; Wiegand, S.J.; Gash, D.M.

1990-01-01

This study was designed to test the hypothesis that neural implants can ameliorate or prevent some of the long-term changes associated with CNS irradiation. Using a rat model, the initial study focused on establishing motor, regulatory, and morphological changes associated with brain radiation treatments. Secondly, fetal hypothalamic tissue grafts were placed into the third ventricle of rats which had been previously irradiated. Adult male Long Evans rats received one of three radiation doses (15, 22.5, ampersand 30 Gy) or no radiation. Three days after irradiation, 7 animals in each dose group received an embryonic day 17 hypothalamic graft into the third ventricle while the remaining 8-9 animals in each group received injections of vehicle solution (sham). Few changes were observed in the 15 and 22.5 Gy animals, however rats in the 30 Gy treatment group showed stereotypic and ambulatory behavioral hyperactivity 32 weeks after irradiation. Regulatory changes in the high dose group included decreased growth rate and decreased urine osmolalities, but these measures were extremely variable among animals. Morphological results demonstrated that 30 Gy irradiated animals showed extensive necrosis primarily in the fimbria, which extended into the internal capsule, optic nerve, hippocampus, and thalamus. Hemorrhages were found in the hippocampus, thalamus, and fimbria. Defects in the blood-brain barrier also were evident by entry of intravascularly injected horseradish peroxidase into the parenchyma of the brain. Animals in the 30 Gy grafted group showed fewer behavioral changes and less brain damage than their sham grafted counterparts. Specifically, activity measures were comparable to normal levels, and a dilute urine was not found in the 30 Gy implanted rats. Morphological changes support these behavioral results since only two 30 Gy implanted rats showed necrosis

Neural network-based expert system for severe accident management

International Nuclear Information System (INIS)

Klopp, G.T.; Silverman, E.B.

1992-01-01

This paper presents the results of the second phase of a three-phase Severe Accident Management expert system program underway at Commonwealth Edison Company (CECo). Phase I successfully demonstrated the feasibility of Artificial Neural Networks to support several of the objectives of severe accident management. Simulated accident scenarios were generated by the Modular Accident Analysis Program (MAAP) code currently in use by CECo as part of their Individual Plant Evaluations (IPE)/Accident Management Program. The primary objectives of the second phase were to develop and demonstrate four capabilities of neural networks with respect to nuclear power plant severe accident monitoring and prediction. The results of this work would form the foundation of a demonstration system which included expert system performance features. These capabilities included the ability to: (1) Predict the time available prior to support plate (and reactor vessel) failure; (2) Calculate the time remaining until recovery actions were too late to prevent core damage; (3) Predict future parameter values of each of the MAAP parameter variables; and (4) Detect simulated sensor failure and provide best-value estimates for further processing in the presence of a sensor failure. A variety of accident scenarios for the Zion and Dresden plants were used to train and test the neural network expert system. These included large and small break LOCAs as well as a range of transient events. 3 refs., 1 fig., 1 tab

Cultured hypothalamic neurons are resistant to inflammation and insulin resistance induced by saturated fatty acids.

Science.gov (United States)

Choi, Sun Ju; Kim, Francis; Schwartz, Michael W; Wisse, Brent E

2010-06-01

Hypothalamic inflammation induced by high-fat feeding causes insulin and leptin resistance and contributes to the pathogenesis of obesity. Since in vitro exposure to saturated fatty acids causes inflammation and insulin resistance in many cultured cell types, we determined how cultured hypothalamic neurons respond to this stimulus. Two murine hypothalamic neuronal cell cultures, N43/5 and GT1-7, were exposed to escalating concentrations of saturated fatty acids for up to 24 h. Harvested cells were evaluated for activation of inflammation by gene expression and protein content. Insulin-treated cells were evaluated for induction of markers of insulin receptor signaling (p-IRS, p-Akt). In both hypothalamic cell lines, inflammation was induced by prototypical inflammatory mediators LPS and TNFalpha, as judged by induction of IkappaBalpha (3- to 5-fold) and IL-6 (3- to 7-fold) mRNA and p-IkappaBalpha protein, and TNFalpha pretreatment reduced insulin-mediated p-Akt activation by 30% (P fatty acid (100, 250, or 500 microM for neurons, whereas they did in control muscle and endothelial cell lines. Despite the lack of evidence of inflammatory signaling, saturated fatty acid exposure in cultured hypothalamic neurons causes endoplasmic reticulum stress, induces mitogen-activated protein kinase, and causes apoptotic cell death with prolonged exposure. We conclude that saturated fatty acid exposure does not induce inflammatory signaling or insulin resistance in cultured hypothalamic neurons. Therefore, hypothalamic neuronal inflammation in the setting of DIO may involve an indirect mechanism mediated by saturated fatty acids on nonneuronal cells.

Neural Network Target Identification System for False Alarm Reduction

Science.gov (United States)

Ye, David; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

2009-01-01

A multi-stage automated target recognition (ATR) system has been designed to perform computer vision tasks with adequate proficiency in mimicking human vision. The system is able to detect, identify, and track targets of interest. Potential regions of interest (ROIs) are first identified by the detection stage using an Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter combined with a wavelet transform. False positives are then eliminated by the verification stage using feature extraction methods in conjunction with neural networks. Feature extraction transforms the ROIs using filtering and binning algorithms to create feature vectors. A feed forward back propagation neural network (NN) is then trained to classify each feature vector and remove false positives. This paper discusses the test of the system performance and parameter optimizations process which adapts the system to various targets and datasets. The test results show that the system was successful in substantially reducing the false positive rate when tested on a sonar image dataset.

Single-session Gamma Knife radiosurgery for optic pathway/hypothalamic gliomas.

Science.gov (United States)

El-Shehaby, Amr M N; Reda, Wael A; Abdel Karim, Khaled M; Emad Eldin, Reem M; Nabeel, Ahmed M

2016-12-01

OBJECTIVE Because of their critical and central location, it is deemed necessary to fractionate when considering irradiating optic pathway/hypothalamic gliomas. Stereotactic fractionated radiotherapy is considered safer when dealing with gliomas in this location. In this study, the safety and efficacy of single-session stereotactic radiosurgery for optic pathway/hypothalamic gliomas were reviewed. METHODS Between December 2004 and June 2014, 22 patients with optic pathway/hypothalamic gliomas were treated by single-session Gamma Knife radiosurgery. Twenty patients were available for follow-up for a minimum of 1 year after treatment. The patients were 5 to 43 years (median 16 years) of age. The tumor volume was 0.15 to 18.2 cm 3 (median 3.1 cm 3 ). The prescription dose ranged from 8 to 14 Gy (median 11.5 Gy). RESULTS The mean follow-up period was 43 months. Five tumors involved the optic nerve only, and 15 tumors involved the chiasm/hypothalamus. Two patients died during the follow-up period. The tumors shrank in 12 cases, remained stable in 6 cases, and progressed in 2 cases, thereby making the tumor control rate 90%. Vision remained stable in 12 cases, improved in 6 cases, and worsened in 2 cases in which there was tumor progression. Progression-free survival was 83% at 3 years. CONCLUSIONS The initial results indicate that single-session Gamma Knife radiosurgery is a safe and effective treatment option for optic pathway/hypothalamic gliomas.

Real-time camera-based face detection using a modified LAMSTAR neural network system

Science.gov (United States)

Girado, Javier I.; Sandin, Daniel J.; DeFanti, Thomas A.; Wolf, Laura K.

2003-03-01

This paper describes a cost-effective, real-time (640x480 at 30Hz) upright frontal face detector as part of an ongoing project to develop a video-based, tetherless 3D head position and orientation tracking system. The work is specifically targeted for auto-stereoscopic displays and projection-based virtual reality systems. The proposed face detector is based on a modified LAMSTAR neural network system. At the input stage, after achieving image normalization and equalization, a sub-window analyzes facial features using a neural network. The sub-window is segmented, and each part is fed to a neural network layer consisting of a Kohonen Self-Organizing Map (SOM). The output of the SOM neural networks are interconnected and related by correlation-links, and can hence determine the presence of a face with enough redundancy to provide a high detection rate. To avoid tracking multiple faces simultaneously, the system is initially trained to track only the face centered in a box superimposed on the display. The system is also rotationally and size invariant to a certain degree.

neural control system

International Nuclear Information System (INIS)

Elshazly, A.A.E.

2002-01-01

Automatic power stabilization control is the desired objective for any reactor operation , especially, nuclear power plants. A major problem in this area is inevitable gap between a real plant ant the theory of conventional analysis and the synthesis of linear time invariant systems. in particular, the trajectory tracking control of a nonlinear plant is a class of problems in which the classical linear transfer function methods break down because no transfer function can represent the system over the entire operating region . there is a considerable amount of research on the model-inverse approach using feedback linearization technique. however, this method requires a prices plant model to implement the exact linearizing feedback, for nuclear reactor systems, this approach is not an easy task because of the uncertainty in the plant parameters and un-measurable state variables . therefore, artificial neural network (ANN) is used either in self-tuning control or in improving the conventional rule-based exper system.the main objective of this thesis is to suggest an ANN, based self-learning controller structure . this method is capable of on-line reinforcement learning and control for a nuclear reactor with a totally unknown dynamics model. previously, researches are based on back- propagation algorithm . back -propagation (BP), fast back -propagation (FBP), and levenberg-marquardt (LM), algorithms are discussed and compared for reinforcement learning. it is found that, LM algorithm is quite superior

The LILARTI neural network system

Energy Technology Data Exchange (ETDEWEB)

Allen, J.D. Jr.; Schell, F.M.; Dodd, C.V.

1992-10-01

The material of this Technical Memorandum is intended to provide the reader with conceptual and technical background information on the LILARTI neural network system of detail sufficient to confer an understanding of the LILARTI method as it is presently allied and to facilitate application of the method to problems beyond the scope of this document. Of particular importance in this regard are the descriptive sections and the Appendices which include operating instructions, partial listings of program output and data files, and network construction information.

Hypothalamic functions in patients with pituitary insufficiency

NARCIS (Netherlands)

Borgers, A.J.F.

2013-01-01

The main objective of this thesis is to increase our understanding of hypothalamic (dys)function in patients with pituitary insufficiency. This goal is driven by the clinical experience of persisting symptoms in patients adequately treated for pituitary insufficiency. We focus primarily on patients

Radiation and the hypothalamic-pituitary axis

International Nuclear Information System (INIS)

Littley, M.D.; Shalet, S.M.; Beardwell, C.G.

1991-01-01

This paper reports on radiation therapy which is an essential treatment in the management of many conditions. It is important to appreciate the high incidence of subsequent endocrine morbidity, however, if the hypothalamic pituitary region is within the radiation fields. This is very much more common with external radiation therapy than with other forms of radiation treatment. The dose and fractional of administered radiation are important determinants of the endocrine deficits, their time on onset, and severity. Irradiation of large volumes of brain and hypothalamus may increase the risk of hormonal abnormalities as may preceding surgery in the treatment of pituitary disease. The phenomena observed in children and adults illustrate that there may be damage to pituitary, hypothalamus, and higher centers. In patients who have received a significant radiation dose to the hypothalamic-pituitary region, regular follow-up is mandatory. In adults, surveillance will include pituitary function testing on an annual basis for at least 10 years. In children careful monitoring of growth and pubertal development and early treatment of radiation-induced GH deficiency are vital

Effect of treatment modality on the hypothalamic-pituitary function of patients treated with radiation therapy for pituitary adenomas: Hypothalamic dose and endocrine outcomes.

Directory of Open Access Journals (Sweden)

Andrew eElson

2014-04-01

Full Text Available Background: Both fractionated external beam radiotherapy and single fraction radiosurgery for pituitary adenomas are associated with the risk of hypothalamic-pituitary (HP axis dysfunction.Objective: To analyze the effect of treatment modality (Linac, TomoTherapy, or Gamma Knife on hypothalamic dose and correlate these with HP-Axis deficits after radiotherapy.Methods:Radiation plans of patients treated postoperatively for pituitary adenomas using Linac-based 3D Conformal Radiotherapy (CRT (n=11, TomoTherapy-based Intensity Modulated Radiation Therapy (IMRT (n=10, or Gamma Knife Stereotactic Radiosurgery (SRS(n=12 were retrospectively reviewed. Dose to the hypothalamus was analyzed and postradiotherapy hormone function including growth hormone (GH, thyroid (TSH, adrenal (ACTH, prolactin (PRL, and gonadotropins (FSH/LH were assessed. Results:Post-radiation, 13 of 27 (48% patients eligible for analysis developed at least one new hormone deficit, of which 8 of 11 (72% occurred in the Linac group, 4 of 8 (50% occurred in the TomoTherapy group, and 1 of 8 (12.5% occurred in the Gamma Knife group. Compared with fractionated techniques, Gamma Knife showed improved hypothalamic sparing for DMax Hypo, and V12Gy. For fractionated modalities, TomoTherapy showed improved dosimetric characteristics over Linac-based treatment with hypothalamic DMean (44.8 Gy vs. 26.8 Gy p=0.02, DMax (49.8 Gy vs. 39.1 Gy p=0.04, and V12Gy (100% vs. 76% p=0.004.Conclusion:Maximal dosimetric avoidance of the hypothalamus was achieved using Gamma Knife-based radiosurgery followed by TomoTherapy-based IMRT, and Linac-based 3D conformal radiation therapy, respectively.

Ecto-nucleoside triphosphate diphosphohydrolase 3 in the ventral and lateral hypothalamic area of female rats: morphological characterization and functional implications

Directory of Open Access Journals (Sweden)

Kiss David S

2009-04-01

Full Text Available Abstract Background Based on its distribution in the brain, ecto-nucleoside triphosphate diphosphohydrolase 3 (NTPDase3 may play a role in the hypothalamic regulation of homeostatic systems, including feeding, sleep-wake behavior and reproduction. To further characterize the morphological attributes of NTPDase3-immunoreactive (IR hypothalamic structures in the rat brain, here we investigated: 1. The cellular and subcellular localization of NTPDase3; 2. The effects of 17β-estradiol on the expression level of hypothalamic NTPDase3; and 3. The effects of NTPDase inhibition in hypothalamic synaptosomal preparations. Methods Combined light- and electron microscopic analyses were carried out to characterize the cellular and subcellular localization of NTPDase3-immunoreactivity. The effects of estrogen on hypothalamic NTPDase3 expression was studied by western blot technique. Finally, the effects of NTPDase inhibition on mitochondrial respiration were investigated using a Clark-type oxygen electrode. Results Combined light- and electron microscopic analysis of immunostained hypothalamic slices revealed that NTPDase3-IR is linked to ribosomes and mitochondria, is predominantly present in excitatory axon terminals and in distinct segments of the perikaryal plasma membrane. Immunohistochemical labeling of NTPDase3 and glutamic acid decarboxylase (GAD indicated that γ-amino-butyric-acid- (GABA ergic hypothalamic neurons do not express NTPDase3, further suggesting that in the hypothalamus, NTPDase3 is predominantly present in excitatory neurons. We also investigated whether estrogen influences the expression level of NTPDase3 in the ventrobasal and lateral hypothalamus. A single subcutaneous injection of estrogen differentially increased NTPDase3 expression in the medial and lateral parts of the hypothalamus, indicating that this enzyme likely plays region-specific roles in estrogen-dependent hypothalamic regulatory mechanisms. Determination of

Stochastic Oscillation in Self-Organized Critical States of Small Systems: Sensitive Resting State in Neural Systems.

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Wang, Sheng-Jun; Ouyang, Guang; Guang, Jing; Zhang, Mingsha; Wong, K Y Michael; Zhou, Changsong

2016-01-08

Self-organized critical states (SOCs) and stochastic oscillations (SOs) are simultaneously observed in neural systems, which appears to be theoretically contradictory since SOCs are characterized by scale-free avalanche sizes but oscillations indicate typical scales. Here, we show that SOs can emerge in SOCs of small size systems due to temporal correlation between large avalanches at the finite-size cutoff, resulting from the accumulation-release process in SOCs. In contrast, the critical branching process without accumulation-release dynamics cannot exhibit oscillations. The reconciliation of SOCs and SOs is demonstrated both in the sandpile model and robustly in biologically plausible neuronal networks. The oscillations can be suppressed if external inputs eliminate the prominent slow accumulation process, providing a potential explanation of the widely studied Berger effect or event-related desynchronization in neural response. The features of neural oscillations and suppression are confirmed during task processing in monkey eye-movement experiments. Our results suggest that finite-size, columnar neural circuits may play an important role in generating neural oscillations around the critical states, potentially enabling functional advantages of both SOCs and oscillations for sensitive response to transient stimuli.

A Fault Diagnosis Approach for the Hydraulic System by Artificial Neural Networks

OpenAIRE

Xiangyu He; Shanghong He

2014-01-01

Based on artificial neural networks, a fault diagnosis approach for the hydraulic system was proposed in this paper. Normal state samples were used as the training data to develop a dynamic general regression neural network (DGRNN) model. The trained DGRNN model then served as the fault determinant to diagnose test faults and the work condition of the hydraulic system was identified. Several typical faults of the hydraulic system were used to verify the fault diagnosis approach. Experiment re...

Neural System Prediction and Identification Challenge

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Ioannis eVlachos

2013-12-01

Full Text Available Can we infer the function of a biological neural network (BNN if we know the connectivity and activity of all its constituent neurons? This question is at the core of neuroscience and, accordingly, various methods have been developed to record the activity and connectivity of as many neurons as possible. Surprisingly, there is no theoretical or computational demonstration that neuronal activity and connectivity are indeed sufficient to infer the function of a BNN. Therefore, we pose the Neural Systems Identification and Prediction Challenge (nuSPIC. We provide the connectivity and activity of all neurons and invite participants (i to infer the functions implemented (hard-wired in spiking neural networks (SNNs by stimulating and recording the activity of neurons and, (ii to implement predefined mathematical/biological functions using SNNs. The nuSPICs can be accessed via a web-interface to the NEST simulator and the user is not required to know any specific programming language. Furthermore, the nuSPICs can be used as a teaching tool. Finally, nuSPICs use the crowd-sourcing model to address scientific issues. With this computational approach we aim to identify which functions can be inferred by systematic recordings of neuronal activity and connectivity. In addition, nuSPICs will help the design and application of new experimental paradigms based on the structure of the SNN and the presumed function which is to be discovered.

Neural system prediction and identification challenge.

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Vlachos, Ioannis; Zaytsev, Yury V; Spreizer, Sebastian; Aertsen, Ad; Kumar, Arvind

2013-01-01

Can we infer the function of a biological neural network (BNN) if we know the connectivity and activity of all its constituent neurons?This question is at the core of neuroscience and, accordingly, various methods have been developed to record the activity and connectivity of as many neurons as possible. Surprisingly, there is no theoretical or computational demonstration that neuronal activity and connectivity are indeed sufficient to infer the function of a BNN. Therefore, we pose the Neural Systems Identification and Prediction Challenge (nuSPIC). We provide the connectivity and activity of all neurons and invite participants (1) to infer the functions implemented (hard-wired) in spiking neural networks (SNNs) by stimulating and recording the activity of neurons and, (2) to implement predefined mathematical/biological functions using SNNs. The nuSPICs can be accessed via a web-interface to the NEST simulator and the user is not required to know any specific programming language. Furthermore, the nuSPICs can be used as a teaching tool. Finally, nuSPICs use the crowd-sourcing model to address scientific issues. With this computational approach we aim to identify which functions can be inferred by systematic recordings of neuronal activity and connectivity. In addition, nuSPICs will help the design and application of new experimental paradigms based on the structure of the SNN and the presumed function which is to be discovered.

Management of optic pathway and chiasmatic-hypothalamic gliomas in children with radiation therapy

International Nuclear Information System (INIS)

Erkal, Haldun Suekrue; Serin, Meltem; Cakmak, Ahmet

1997-01-01

Background and purpose: Optic pathway and chiasmatic-hypothalamic gliomas are rare childhood tumors. This study presents the experience in management of these tumors with radiation therapy. Materials and methods: Thirty-three children with the diagnosis of optic pathway and chiasmatic-hypothalamic gliomas were treated with radiation therapy from 1973 through 1994 in the Department of Radiation Oncology at Ankara University Faculty of Medicine. Twenty-four children had optic pathway gliomas and nine had chiasmatic-hypothalamic gliomas. Evidence of neurofibromatosis was present in six children. Subtotal resection was performed in 22 children and a biopsy in seven. The most common prescription for total tumor dose was 50 Gy, delivered in 2 Gy daily fractions. Follow-up ranged from 0.5 to 16.1 years (mean, 13.6 years). Results: Overall, progression-free and cause-specific survival probabilities for the entire group were 93%, 82% and 93%, respectively, at 5 years and 79%, 77% and 88%, respectively, at 10 years. Differences in overall, progression-free and cause-specific survival probabilities between optic pathway and chiasmatic-hypothalamic gliomas were not statistically significant. Absence of evidence of neurofibromatosis correlated with significantly better progression-free and cause-specific survival probabilities. Conclusion: Radiation therapy is effective in stabilization or improvement of vision and prevention of tumor progression in both optic pathway and chiasmatic-hypothalamic gliomas

Adaptive Control of Nonlinear Discrete-Time Systems by Using OS-ELM Neural Networks

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Xiao-Li Li

2014-01-01

Full Text Available As a kind of novel feedforward neural network with single hidden layer, ELM (extreme learning machine neural networks are studied for the identification and control of nonlinear dynamic systems. The property of simple structure and fast convergence of ELM can be shown clearly. In this paper, we are interested in adaptive control of nonlinear dynamic plants by using OS-ELM (online sequential extreme learning machine neural networks. Based on data scope division, the problem that training process of ELM neural network is sensitive to the initial training data is also solved. According to the output range of the controlled plant, the data corresponding to this range will be used to initialize ELM. Furthermore, due to the drawback of conventional adaptive control, when the OS-ELM neural network is used for adaptive control of the system with jumping parameters, the topological structure of the neural network can be adjusted dynamically by using multiple model switching strategy, and an MMAC (multiple model adaptive control will be used to improve the control performance. Simulation results are included to complement the theoretical results.

Neural networks for combined control of capacitor banks and voltage regulators in distribution systems

Energy Technology Data Exchange (ETDEWEB)

Gu, Z.; Rizy, D.T.

1996-02-01

A neural network for controlling shunt capacitor banks and feeder voltage regulators in electric distribution systems is presented. The objective of the neural controller is to minimize total I{sup 2}R losses and maintain all bus voltages within standard limits. The performance of the neural network for different input selections and training data is discussed and compared. Two different input selections are tried, one using the previous control states of the capacitors and regulator along with measured line flows and voltage which is equivalent to having feedback and the other with measured line flows and voltage without previous control settings. The results indicate that the neural net controller with feedback can outperform the one without. Also, proper selection of a training data set that adequately covers the operating space of the distribution system is important for achieving satisfactory performance with the neural controller. The neural controller is tested on a radially configured distribution system with 30 buses, 5 switchable capacitor banks an d one nine tap line regulator to demonstrate the performance characteristics associated with these principles. Monte Carlo simulations show that a carefully designed and relatively compact neural network with a small but carefully developed training set can perform quite well under slight and extreme variation of loading conditions.

Hypoglycemia: Role of Hypothalamic Glucose-Inhibited (GI) Neurons in Detection and Correction.

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Zhou, Chunxue; Teegala, Suraj B; Khan, Bilal A; Gonzalez, Christina; Routh, Vanessa H

2018-01-01

Hypoglycemia is a profound threat to the brain since glucose is its primary fuel. As a result, glucose sensors are widely located in the central nervous system and periphery. In this perspective we will focus on the role of hypothalamic glucose-inhibited (GI) neurons in sensing and correcting hypoglycemia. In particular, we will discuss GI neurons in the ventromedial hypothalamus (VMH) which express neuronal nitric oxide synthase (nNOS) and in the perifornical hypothalamus (PFH) which express orexin. The ability of VMH nNOS-GI neurons to depolarize in low glucose closely parallels the hormonal response to hypoglycemia which stimulates gluconeogenesis. We have found that nitric oxide (NO) production in low glucose is dependent on oxidative status. In this perspective we will discuss the potential relevance of our work showing that enhancing the glutathione antioxidant system prevents hypoglycemia associated autonomic failure (HAAF) in non-diabetic rats whereas VMH overexpression of the thioredoxin antioxidant system restores hypoglycemia counterregulation in rats with type 1 diabetes.We will also address the potential role of the orexin-GI neurons in the arousal response needed for hypoglycemia awareness which leads to behavioral correction (e.g., food intake, glucose administration). The potential relationship between the hypothalamic sensors and the neurocircuitry in the hindbrain and portal mesenteric vein which is critical for hypoglycemia correction will then be discussed.

Hypoglycemia: Role of Hypothalamic Glucose-Inhibited (GI Neurons in Detection and Correction

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Chunxue Zhou

2018-03-01

Full Text Available Hypoglycemia is a profound threat to the brain since glucose is its primary fuel. As a result, glucose sensors are widely located in the central nervous system and periphery. In this perspective we will focus on the role of hypothalamic glucose-inhibited (GI neurons in sensing and correcting hypoglycemia. In particular, we will discuss GI neurons in the ventromedial hypothalamus (VMH which express neuronal nitric oxide synthase (nNOS and in the perifornical hypothalamus (PFH which express orexin. The ability of VMH nNOS-GI neurons to depolarize in low glucose closely parallels the hormonal response to hypoglycemia which stimulates gluconeogenesis. We have found that nitric oxide (NO production in low glucose is dependent on oxidative status. In this perspective we will discuss the potential relevance of our work showing that enhancing the glutathione antioxidant system prevents hypoglycemia associated autonomic failure (HAAF in non-diabetic rats whereas VMH overexpression of the thioredoxin antioxidant system restores hypoglycemia counterregulation in rats with type 1 diabetes.We will also address the potential role of the orexin-GI neurons in the arousal response needed for hypoglycemia awareness which leads to behavioral correction (e.g., food intake, glucose administration. The potential relationship between the hypothalamic sensors and the neurocircuitry in the hindbrain and portal mesenteric vein which is critical for hypoglycemia correction will then be discussed.

Neuroendocrine signaling modulates specific neural networks relevant to migraine.

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Martins-Oliveira, Margarida; Akerman, Simon; Holland, Philip R; Hoffmann, Jan R; Tavares, Isaura; Goadsby, Peter J

2017-05-01

Migraine is a disabling brain disorder involving abnormal trigeminovascular activation and sensitization. Fasting or skipping meals is considered a migraine trigger and altered fasting glucose and insulin levels have been observed in migraineurs. Therefore peptides involved in appetite and glucose regulation including insulin, glucagon and leptin could potentially influence migraine neurobiology. We aimed to determine the effect of insulin (10U·kg -1 ), glucagon (100μg·200μl -1 ) and leptin (0.3, 1 and 3mg·kg -1 ) signaling on trigeminovascular nociceptive processing at the level of the trigeminocervical-complex and hypothalamus. Male rats were anesthetized and prepared for craniovascular stimulation. In vivo electrophysiology was used to determine changes in trigeminocervical neuronal responses to dural electrical stimulation, and phosphorylated extracellular signal-regulated kinases 1 and 2 (pERK1/2) immunohistochemistry to determine trigeminocervical and hypothalamic neural activity; both in response to intravenous administration of insulin, glucagon, leptin or vehicle control in combination with blood glucose analysis. Blood glucose levels were significantly decreased by insulin (pneuronal firing in the trigeminocervical-complex was significantly inhibited by insulin (pmetabolic homeostasis may occur through disturbed glucose regulation and a transient hypothalamic dysfunction. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Coupling Strength and System Size Induce Firing Activity of Globally Coupled Neural Network

International Nuclear Information System (INIS)

Wei Duqu; Luo Xiaoshu; Zou Yanli

2008-01-01

We investigate how firing activity of globally coupled neural network depends on the coupling strength C and system size N. Network elements are described by space-clamped FitzHugh-Nagumo (SCFHN) neurons with the values of parameters at which no firing activity occurs. It is found that for a given appropriate coupling strength, there is an intermediate range of system size where the firing activity of globally coupled SCFHN neural network is induced and enhanced. On the other hand, for a given intermediate system size level, there exists an optimal value of coupling strength such that the intensity of firing activity reaches its maximum. These phenomena imply that the coupling strength and system size play a vital role in firing activity of neural network

Statistical Physics of Neural Systems with Nonadditive Dendritic Coupling

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David Breuer

2014-03-01

Full Text Available How neurons process their inputs crucially determines the dynamics of biological and artificial neural networks. In such neural and neural-like systems, synaptic input is typically considered to be merely transmitted linearly or sublinearly by the dendritic compartments. Yet, single-neuron experiments report pronounced supralinear dendritic summation of sufficiently synchronous and spatially close-by inputs. Here, we provide a statistical physics approach to study the impact of such nonadditive dendritic processing on single-neuron responses and the performance of associative-memory tasks in artificial neural networks. First, we compute the effect of random input to a neuron incorporating nonlinear dendrites. This approach is independent of the details of the neuronal dynamics. Second, we use those results to study the impact of dendritic nonlinearities on the network dynamics in a paradigmatic model for associative memory, both numerically and analytically. We find that dendritic nonlinearities maintain network convergence and increase the robustness of memory performance against noise. Interestingly, an intermediate number of dendritic branches is optimal for memory functionality.

Sign Language Recognition System using Neural Network for Digital Hardware Implementation

International Nuclear Information System (INIS)

Vargas, Lorena P; Barba, Leiner; Torres, C O; Mattos, L

2011-01-01

This work presents an image pattern recognition system using neural network for the identification of sign language to deaf people. The system has several stored image that show the specific symbol in this kind of language, which is employed to teach a multilayer neural network using a back propagation algorithm. Initially, the images are processed to adapt them and to improve the performance of discriminating of the network, including in this process of filtering, reduction and elimination noise algorithms as well as edge detection. The system is evaluated using the signs without including movement in their representation.

Hypothalamic carnitine metabolism integrates nutrient and hormonal feedback to regulate energy homeostasis.

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Stark, Romana; Reichenbach, Alex; Andrews, Zane B

2015-12-15

The maintenance of energy homeostasis requires the hypothalamic integration of nutrient feedback cues, such as glucose, fatty acids, amino acids, and metabolic hormones such as insulin, leptin and ghrelin. Although hypothalamic neurons are critical to maintain energy homeostasis research efforts have focused on feedback mechanisms in isolation, such as glucose alone, fatty acids alone or single hormones. However this seems rather too simplistic considering the range of nutrient and endocrine changes associated with different metabolic states, such as starvation (negative energy balance) or diet-induced obesity (positive energy balance). In order to understand how neurons integrate multiple nutrient or hormonal signals, we need to identify and examine potential intracellular convergence points or common molecular targets that have the ability to sense glucose, fatty acids, amino acids and hormones. In this review, we focus on the role of carnitine metabolism in neurons regulating energy homeostasis. Hypothalamic carnitine metabolism represents a novel means for neurons to facilitate and control both nutrient and hormonal feedback. In terms of nutrient regulation, carnitine metabolism regulates hypothalamic fatty acid sensing through the actions of CPT1 and has an underappreciated role in glucose sensing since carnitine metabolism also buffers mitochondrial matrix levels of acetyl-CoA, an allosteric inhibitor of pyruvate dehydrogenase and hence glucose metabolism. Studies also show that hypothalamic CPT1 activity also controls hormonal feedback. We hypothesis that hypothalamic carnitine metabolism represents a key molecular target that can concurrently integrate nutrient and hormonal information, which is critical to maintain energy homeostasis. We also suggest this is relevant to broader neuroendocrine research as it predicts that hormonal signaling in the brain varies depending on current nutrient status. Indeed, the metabolic action of ghrelin, leptin or insulin

Neural signal processing and closed-loop control algorithm design for an implanted neural recording and stimulation system.

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Hamilton, Lei; McConley, Marc; Angermueller, Kai; Goldberg, David; Corba, Massimiliano; Kim, Louis; Moran, James; Parks, Philip D; Sang Chin; Widge, Alik S; Dougherty, Darin D; Eskandar, Emad N

2015-08-01

A fully autonomous intracranial device is built to continually record neural activities in different parts of the brain, process these sampled signals, decode features that correlate to behaviors and neuropsychiatric states, and use these features to deliver brain stimulation in a closed-loop fashion. In this paper, we describe the sampling and stimulation aspects of such a device. We first describe the signal processing algorithms of two unsupervised spike sorting methods. Next, we describe the LFP time-frequency analysis and feature derivation from the two spike sorting methods. Spike sorting includes a novel approach to constructing a dictionary learning algorithm in a Compressed Sensing (CS) framework. We present a joint prediction scheme to determine the class of neural spikes in the dictionary learning framework; and, the second approach is a modified OSort algorithm which is implemented in a distributed system optimized for power efficiency. Furthermore, sorted spikes and time-frequency analysis of LFP signals can be used to generate derived features (including cross-frequency coupling, spike-field coupling). We then show how these derived features can be used in the design and development of novel decode and closed-loop control algorithms that are optimized to apply deep brain stimulation based on a patient's neuropsychiatric state. For the control algorithm, we define the state vector as representative of a patient's impulsivity, avoidance, inhibition, etc. Controller parameters are optimized to apply stimulation based on the state vector's current state as well as its historical values. The overall algorithm and software design for our implantable neural recording and stimulation system uses an innovative, adaptable, and reprogrammable architecture that enables advancement of the state-of-the-art in closed-loop neural control while also meeting the challenges of system power constraints and concurrent development with ongoing scientific research designed

Neural Correlates of the Cortisol Awakening Response in Humans.

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Boehringer, Andreas; Tost, Heike; Haddad, Leila; Lederbogen, Florian; Wüst, Stefan; Schwarz, Emanuel; Meyer-Lindenberg, Andreas

2015-08-01

The cortisol rise after awakening (cortisol awakening response, CAR) is a core biomarker of hypothalamic-pituitary-adrenal (HPA) axis regulation related to psychosocial stress and stress-related psychiatric disorders. However, the neural regulation of the CAR has not been examined in humans. Here, we studied neural regulation related to the CAR in a sample of 25 healthy human participants using an established psychosocial stress paradigm together with multimodal functional and structural (voxel-based morphometry) magnetic resonance imaging. Across subjects, a smaller CAR was associated with reduced grey matter volume and increased stress-related brain activity in the perigenual ACC, a region which inhibits HPA axis activity during stress that is implicated in risk mechanisms and pathophysiology of stress-related mental diseases. Moreover, functional connectivity between the perigenual ACC and the hypothalamus, the primary controller of HPA axis activity, was associated with the CAR. Our findings provide support for a role of the perigenual ACC in regulating the CAR in humans and may aid future research on the pathophysiology of stress-related illnesses, such as depression, and environmental risk for illnesses such as schizophrenia.

Adaptive neural networks control for camera stabilization with active suspension system

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Feng Zhao

2015-08-01

Full Text Available The camera always suffers from image instability on the moving vehicle due to unintentional vibrations caused by road roughness. This article presents an adaptive neural network approach mixed with linear quadratic regulator control for a quarter-car active suspension system to stabilize the image captured area of the camera. An active suspension system provides extra force through the actuator which allows it to suppress vertical vibration of sprung mass. First, to deal with the road disturbance and the system uncertainties, radial basis function neural network is proposed to construct the map between the state error and the compensation component, which can correct the optimal state-feedback control law. The weights matrix of radial basis function neural network is adaptively tuned online. Then, the closed-loop stability and asymptotic convergence performance is guaranteed by Lyapunov analysis. Finally, the simulation results demonstrate that the proposed controller effectively suppresses the vibration of the camera and enhances the stabilization of the entire camera, where different excitations are considered to validate the system performance.

Modular Neural Networks and Type-2 Fuzzy Systems for Pattern Recognition

CERN Document Server

Melin, Patricia

2012-01-01

This book describes hybrid intelligent systems using type-2 fuzzy logic and modular neural networks for pattern recognition applications. Hybrid intelligent systems combine several intelligent computing paradigms, including fuzzy logic, neural networks, and bio-inspired optimization algorithms, which can be used to produce powerful pattern recognition systems. Type-2 fuzzy logic is an extension of traditional type-1 fuzzy logic that enables managing higher levels of uncertainty in complex real world problems, which are of particular importance in the area of pattern recognition. The book is organized in three main parts, each containing a group of chapters built around a similar subject. The first part consists of chapters with the main theme of theory and design algorithms, which are basically chapters that propose new models and concepts, which are the basis for achieving intelligent pattern recognition. The second part contains chapters with the main theme of using type-2 fuzzy models and modular neural ne...

Neural systems for preparatory control of imitation.

Science.gov (United States)

Cross, Katy A; Iacoboni, Marco

2014-01-01

Humans have an automatic tendency to imitate others. Previous studies on how we control these tendencies have focused on reactive mechanisms, where inhibition of imitation is implemented after seeing an action. This work suggests that reactive control of imitation draws on at least partially specialized mechanisms. Here, we examine preparatory imitation control, where advance information allows control processes to be employed before an action is observed. Drawing on dual route models from the spatial compatibility literature, we compare control processes using biological and non-biological stimuli to determine whether preparatory imitation control recruits specialized neural systems that are similar to those observed in reactive imitation control. Results indicate that preparatory control involves anterior prefrontal, dorsolateral prefrontal, posterior parietal and early visual cortices regardless of whether automatic responses are evoked by biological (imitative) or non-biological stimuli. These results indicate both that preparatory control of imitation uses general mechanisms, and that preparatory control of imitation draws on different neural systems from reactive imitation control. Based on the regions involved, we hypothesize that preparatory control is implemented through top-down attentional biasing of visual processing.

Effect of acute ethanol on beta-endorphin secretion from rat fetal hypothalamic neurons in primary cultures

Energy Technology Data Exchange (ETDEWEB)

Sarkar, D.K.; Minami, S. (Washington State Univ., Pullman (USA))

1990-01-01

To characterize the effect of ethanol on the hypothalamic {beta}-endorphin-containing neurons, rat fetal hypothalamic neurons were maintained in primary culture, and the secretion of {beta}-endorphin ({beta}-EP) was determined after ethanol challenges. Constant exposure to ethanol at doses of 6-50 mM produced a dose-dependent increase in basal secretion of {beta}-EP from these cultured cells. These doses of ethanol did not produce any significant effect on cell viability, DNA or protein content. The stimulated secretion of {beta}-EP following constant ethanol exposure is short-lasting. However, intermittent ethanol exposures maintained the ethanol stimulatory action on {beta}-EP secretion for a longer time. The magnitude of the {beta}-EP response to 50 mM ethanol is similar to that of the {beta}-EP response to 56 mM of potassium. Ethanol-stimulated {beta}-EP secretion required extracellular calcium and was blocked by a calcium channel blocker; a sodium channel blocker did not affect ethanol-stimulated secretion. These results suggest that the neuron culture system is a useful model for studying the cellular mechanisms involved in the ethanol-regulated hypothalamic opioid secretion.

On the Universality and Non-Universality of Spiking Neural P Systems With Rules on Synapses.

Science.gov (United States)

Song, Tao; Xu, Jinbang; Pan, Linqiang

2015-12-01

Spiking neural P systems with rules on synapses are a new variant of spiking neural P systems. In the systems, the neuron contains only spikes, while the spiking/forgetting rules are moved on the synapses. It was obtained that such system with 30 neurons (using extended spiking rules) or with 39 neurons (using standard spiking rules) is Turing universal. In this work, this number is improved to 6. Specifically, we construct a Turing universal spiking neural P system with rules on synapses having 6 neurons, which can generate any set of Turing computable natural numbers. As well, it is obtained that spiking neural P system with rules on synapses having less than two neurons are not Turing universal: i) such systems having one neuron can characterize the family of finite sets of natural numbers; ii) the family of sets of numbers generated by the systems having two neurons is included in the family of semi-linear sets of natural numbers.

A neural network approach to the study of dynamics and structure of molecular systems

International Nuclear Information System (INIS)

Getino, C.; Sumpter, B.G.; Noid, D.W.

1994-01-01

Neural networks are used to study intramolecular energy flow in molecular systems (tetratomics to macromolecules), developing new techniques for efficient analysis of data obtained from molecular-dynamics and quantum mechanics calculations. Neural networks can map phase space points to intramolecular vibrational energies along a classical trajectory (example of complicated coordinate transformation), producing reasonably accurate values for any region of the multidimensional phase space of a tetratomic molecule. Neural network energy flow predictions are found to significantly enhance the molecular-dynamics method to longer time-scales and extensive averaging of trajectories for macromolecular systems. Pattern recognition abilities of neural networks can be used to discern phase space features. Neural networks can also expand model calculations by interpolation of costly quantum mechanical ab initio data, used to develop semiempirical potential energy functions

Chronic exercise reduces hypothalamic transforming growth factor-β1 in middle-aged obese mice.

Science.gov (United States)

Silva, Vagner R R; Katashima, Carlos K; Lenhare, Luciene; Silva, Carla G B; Morari, Joseane; Camargo, Rafael L; Velloso, Licio A; Saad, Mario A; da Silva, Adelino S R; Pauli, Jose Rodrigo; Ropelle, Eduardo Rochete

2017-08-28

Obesity and aging are associated with hypothalamic inflammation, hyperphagia and abnormalities in the thermogenesis control. It has been demonstrated that the association between aging and obesity induces hypothalamic inflammation and metabolic disorders, at least in part, through the atypical hypothalamic transforming growth factor-β (TGF-β1). Physical exercise has been used to modulate several metabolic parameters. Thus, the aim of this study was to evaluate the impact of chronic exercise on TGF-β1 expression in the hypothalamus of Middle-Aged mice submitted to a one year of high-fat diet (HFD) treatment. We observed that long-term of HFD-feeding induced hypothalamic TGF-β1 accumulation, potentiated the hypothalamic inflammation, body weight gain and defective thermogenesis of Middle-Aged mice when compared to Middle-Aged animals fed on chow diet. As expected, chronic exercise induced negative energy balance, reduced food consumption and increasing the energy expenditure, which promotes body weight loss. Interestingly, exercise training reduced the TGF-β1 expression and IkB-α ser32 phosphorylation in the hypothalamus of Middle-Aged obese mice. Taken together our study demonstrated that chronic exercise suppressed the TGF-β1/IkB-α axis in the hypothalamus and improved the energy homeostasis in an animal model of obesity-associated to aging.

Evolution of Gelastic Epilepsy with Hypothalamic Hamartoma

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J Gordon Millichap

2003-11-01

Full Text Available The patterns of clinical presentation, evolution of the epilepsy, and electoclinical diagnostic features of hypothalamic hamartoma (HH in 19 patients (8 children and 11 adults, seen between 1991 and 2001, were evaluated at Kings College Hospital and the Institute of Epileptology, London, UK.

Sexual behavior reduces hypothalamic androgen receptor immunoreactivity

NARCIS (Netherlands)

Fernandez-Guasti, Alonso; Swaab, Dick; Rodríguez-Manzo, Gabriela

2003-01-01

Male sexual behavior is regulated by limbic areas like the medial preoptic nucleus (MPN), the bed nucleus of the stria terminalis (BST), the nucleus accumbens (nAcc) and the ventromedial hypothalamic nucleus (VMN). Neurons in these brain areas are rich in androgen receptors (AR) and express

Evolutionary Computation and Its Applications in Neural and Fuzzy Systems

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Biaobiao Zhang

2011-01-01

Full Text Available Neural networks and fuzzy systems are two soft-computing paradigms for system modelling. Adapting a neural or fuzzy system requires to solve two optimization problems: structural optimization and parametric optimization. Structural optimization is a discrete optimization problem which is very hard to solve using conventional optimization techniques. Parametric optimization can be solved using conventional optimization techniques, but the solution may be easily trapped at a bad local optimum. Evolutionary computation is a general-purpose stochastic global optimization approach under the universally accepted neo-Darwinian paradigm, which is a combination of the classical Darwinian evolutionary theory, the selectionism of Weismann, and the genetics of Mendel. Evolutionary algorithms are a major approach to adaptation and optimization. In this paper, we first introduce evolutionary algorithms with emphasis on genetic algorithms and evolutionary strategies. Other evolutionary algorithms such as genetic programming, evolutionary programming, particle swarm optimization, immune algorithm, and ant colony optimization are also described. Some topics pertaining to evolutionary algorithms are also discussed, and a comparison between evolutionary algorithms and simulated annealing is made. Finally, the application of EAs to the learning of neural networks as well as to the structural and parametric adaptations of fuzzy systems is also detailed.

Color Image Encryption Algorithm Based on TD-ERCS System and Wavelet Neural Network

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Kun Zhang

2015-01-01

Full Text Available In order to solve the security problem of transmission image across public networks, a new image encryption algorithm based on TD-ERCS system and wavelet neural network is proposed in this paper. According to the permutation process and the binary XOR operation from the chaotic series by producing TD-ERCS system and wavelet neural network, it can achieve image encryption. This encryption algorithm is a reversible algorithm, and it can achieve original image in the rule inverse process of encryption algorithm. Finally, through computer simulation, the experiment results show that the new chaotic encryption algorithm based on TD-ERCS system and wavelet neural network is valid and has higher security.

Hypothalamic PGC-1α Protects Against High-Fat Diet Exposure by Regulating ERα

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Eugenia Morselli

2014-10-01

Full Text Available High-fat diets (HFDs lead to obesity and inflammation in the central nervous system (CNS. Estrogens and estrogen receptor α (ERα protect premenopausal females from the metabolic complications of inflammation and obesity-related disease. Here, we demonstrate that hypothalamic PGC-1α regulates ERα and inflammation in vivo. HFD significantly increased palmitic acid (PA and sphingolipids in the CNS of male mice when compared to female mice. PA, in vitro, and HFD, in vivo, reduced PGC-1α and ERα in hypothalamic neurons and astrocytes of male mice and promoted inflammation. PGC-1α depletion with ERα overexpression significantly inhibited PA-induced inflammation, confirming that ERα is a critical determinant of the anti-inflammatory response. Physiologic relevance of ERα-regulated inflammation was demonstrated by reduced myocardial function in male, but not female, mice following chronic HFD exposure. Our findings show that HFD/PA reduces PGC-1α and ERα, promoting inflammation and decrements in myocardial function in a sex-specific way.

Hypothalamic PGC-1α protects against high-fat diet exposure by regulating ERα.

Science.gov (United States)

Morselli, Eugenia; Fuente-Martin, Esther; Finan, Brian; Kim, Min; Frank, Aaron; Garcia-Caceres, Cristina; Navas, Carlos Rodriguez; Gordillo, Ruth; Neinast, Michael; Kalainayakan, Sarada P; Li, Dan L; Gao, Yuanqing; Yi, Chun-Xia; Hahner, Lisa; Palmer, Biff F; Tschöp, Matthias H; Clegg, Deborah J

2014-10-23

High-fat diets (HFDs) lead to obesity and inflammation in the central nervous system (CNS). Estrogens and estrogen receptor α (ERα) protect premenopausal females from the metabolic complications of inflammation and obesity-related disease. Here, we demonstrate that hypothalamic PGC-1α regulates ERα and inflammation in vivo. HFD significantly increased palmitic acid (PA) and sphingolipids in the CNS of male mice when compared to female mice. PA, in vitro, and HFD, in vivo, reduced PGC-1α and ERα in hypothalamic neurons and astrocytes of male mice and promoted inflammation. PGC-1α depletion with ERα overexpression significantly inhibited PA-induced inflammation, confirming that ERα is a critical determinant of the anti-inflammatory response. Physiologic relevance of ERα-regulated inflammation was demonstrated by reduced myocardial function in male, but not female, mice following chronic HFD exposure. Our findings show that HFD/PA reduces PGC-1α and ERα, promoting inflammation and decrements in myocardial function in a sex-specific way.

Global neural dynamic surface tracking control of strict-feedback systems with application to hypersonic flight vehicle.

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Xu, Bin; Yang, Chenguang; Pan, Yongping

2015-10-01

This paper studies both indirect and direct global neural control of strict-feedback systems in the presence of unknown dynamics, using the dynamic surface control (DSC) technique in a novel manner. A new switching mechanism is designed to combine an adaptive neural controller in the neural approximation domain, together with the robust controller that pulls the transient states back into the neural approximation domain from the outside. In comparison with the conventional control techniques, which could only achieve semiglobally uniformly ultimately bounded stability, the proposed control scheme guarantees all the signals in the closed-loop system are globally uniformly ultimately bounded, such that the conventional constraints on initial conditions of the neural control system can be relaxed. The simulation studies of hypersonic flight vehicle (HFV) are performed to demonstrate the effectiveness of the proposed global neural DSC design.

Autophagy in hypothalamic AgRP neurons regulates food intake and energy balance

OpenAIRE

Kaushik, Susmita; Rodriguez-Navarro, Jose Antonio; Arias, Esperanza; Kiffin, Roberta; Sahu, Srabani; Schwartz, Gary J.; Cuervo, Ana Maria; Singh, Rajat

2011-01-01

Macroautophagy is a lysosomal degradative pathway that maintains cellular homeostasis by turning over cellular components. Here, we demonstrate a role for autophagy in hypothalamic agouti-related peptide (AgRP) neurons in the regulation of food intake and energy balance. We show that starvation-induced hypothalamic autophagy mobilizes neuron-intrinsic lipids to generate endogenous free fatty acids, which in turn regulate AgRP levels. The functional consequences of inhibiting autophagy are the...

Hypothalamic expression of KiSS-1 system and gonadotropin-releasing effects of kisspeptin in different reproductive states of the female Rat.

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Roa, J; Vigo, E; Castellano, J M; Navarro, V M; Fernández-Fernández, R; Casanueva, F F; Dieguez, C; Aguilar, E; Pinilla, L; Tena-Sempere, M

2006-06-01

Kisspeptins, products of the KiSS-1 gene with ability to bind G protein-coupled receptor 54 (GPR54), have been recently identified as major gatekeepers of reproductive function with ability to potently activate the GnRH/LH axis. Yet, despite the diversity of functional states of the female gonadotropic axis, pharmacological characterization of this effect has been mostly conducted in pubertal animals or adult male rodents, whereas similar studies have not been thoroughly conducted in the adult female. In this work, we evaluated maximal LH and FSH secretory responses to kisspeptin-10, as well as changes in sensitivity and hypothalamic expression of KiSS-1 and GPR54 genes, in different physiological and experimental models in the adult female rat. Kisspeptin-10 (1 nmol, intracerebroventricular) was able to elicit robust LH bursts at all phases of the estrous cycle, with maximal responses at estrus; yet, in diestrus LH, responses to kisspeptin were detected at doses as low as 0.1 pmol. In contrast, high doses of kisspeptin only stimulated FSH secretion at diestrus. Removal of ovarian sex steroids did not blunt the ability of kisspeptin to further elicit stimulated LH and FSH secretion, but restoration of maximal responses required replacement with estradiol and progesterone. Finally, despite suppressed basal levels, LH and FSH secretory responses to kisspeptin were preserved in pregnant and lactating females, although the magnitude of LH bursts and the sensitivity to kisspeptin were much higher in pregnant dams. Interestingly, hypothalamic KiSS-1 gene expression significantly increased during pregnancy, whereas GPR54 mRNA levels remained unaltered. In summary, our current data document for the first time the changes in hypothalamic expression of KiSS-1 system and the gonadotropic effects (maximal responses and sensitivity) of kisspeptin in different functional states of the female reproductive axis. The present data may pose interesting implications in light of the

Hypothalamic response to the chemo-signal androstadienone in gender dysphoric children and adolescents

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Sarah M Burke

2014-05-01

Full Text Available The odorous steroid androstadienone, a putative male chemo-signal, was previously reported to evoke sex differences in hypothalamic activation in adult heterosexual men and women. In order to investigate whether puberty modulated this sex difference in response to androstadienone we measured the hypothalamic responsiveness to this chemo-signal in 39 prepubertal and 41 adolescent boys and girls by means of functional magnetic resonance imaging. We then investigated whether 36 prepubertal children and 38 adolescents diagnosed with Gender Dysphoria (GD; DSM-5 exhibited sex-atypical (in accordance with their experienced gender, rather than sex-typical (in accordance with their natal sex hypothalamic activations during olfactory stimulation with androstadienone. We found that the sex difference in responsiveness to androstadienone was already present in prepubertal control children and thus likely developed during early perinatal development instead of during sexual maturation. Adolescent girls and boys with GD both responded remarkably like their experienced gender, thus sex-atypical. In contrast, prepubertal girls with GD showed neither a typically male nor female hypothalamic activation pattern and prepubertal boys with GD had hypothalamic activations in response to androstadienone that were similar to control boys, thus sex-typical. We present here a unique data set of boys and girls diagnosed with GD at two different developmental stages, showing that these children possess certain sex-atypical functional brain characteristics and may have undergone atypical sexual differentiation of the brain.

Biological neural networks as model systems for designing future parallel processing computers

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Ross, Muriel D.

1991-01-01

One of the more interesting debates of the present day centers on whether human intelligence can be simulated by computer. The author works under the premise that neurons individually are not smart at all. Rather, they are physical units which are impinged upon continuously by other matter that influences the direction of voltage shifts across the units membranes. It is only the action of a great many neurons, billions in the case of the human nervous system, that intelligent behavior emerges. What is required to understand even the simplest neural system is painstaking analysis, bit by bit, of the architecture and the physiological functioning of its various parts. The biological neural network studied, the vestibular utricular and saccular maculas of the inner ear, are among the most simple of the mammalian neural networks to understand and model. While there is still a long way to go to understand even this most simple neural network in sufficient detail for extrapolation to computers and robots, a start was made. Moreover, the insights obtained and the technologies developed help advance the understanding of the more complex neural networks that underlie human intelligence.

Gelastic seizures associated with hypothalamic hamartomas. An update in the clinical presentation, diagnosis and treatment

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José F. Tellez-Zenteno

2008-10-01

Full Text Available José F. Tellez-Zenteno1, Cesar Serrano-Almeida2, Farzad Moien-Afshari11Division of Neurology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; 2Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, CanadaAbstract: Gelastic seizures are epileptic events characterized by bouts of laughter. Laughter-like vocalization is usually combined with facial contraction in the form of a smile. Autonomic features such as flushing, tachycardia, and altered respiration are widely recognized. Conscious state may not be impaired, although this is often difficult to asses particularly in young children. Gelastic seizures have been associated classically to hypothalamic hamartomas, although different extrahypothalamic localizations have been described. Hypothalamic hamartomas are rare congenital lesions presenting with the classic triad of gelastic epilepsy, precocious puberty and developmental delay. The clinical course of patients with gelastic seizures associated with hypothalamic hamartomas is progressive, commencing with gelastic seizures in infancy, deteriorating into more complex seizure disorder resulting in intractable epilepsy. Electrophysiological, radiological, and pathophysiological studies have confirmed the intrinsic epileptogenicity of the hypothalamic hamartoma. Currently the most effective surgical approach is the trancallosal anterior interforniceal approach, however newer approaches including the endoscopic and other treatment such as radiosurgery and gamma knife have been used with success. This review focuses on the syndrome of gelastic seizures associated with hypothalamic hamartomas, but it also reviews other concepts such as status gelasticus and some aspects of gelastic seizures in other locations.Keywords: epilepsy, gelastic seizures, epilepsy surgery, hypothalamic hamartoma, intractable epilepsy

Role of Hypothalamic VGF in Energy Balance and Metabolic Adaption to Environmental Enrichment in Mice

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Foglesong, Grant D.; Huang, Wei; Liu, Xianglan; Slater, Andrew M.; Siu, Jason; Yildiz, Vedat; Salton, Stephen R. J.

2016-01-01

Environmental enrichment (EE), a housing condition providing complex physical, social, and cognitive stimulation, leads to improved metabolic health and resistance to diet-induced obesity and cancer. One underlying mechanism is the activation of the hypothalamic-sympathoneural-adipocyte axis with hypothalamic brain-derived neurotrophic factor (BDNF) as the key mediator. VGF, a peptide precursor particularly abundant in the hypothalamus, was up-regulated by EE. Overexpressing BDNF or acute injection of BDNF protein to the hypothalamus up-regulated VGF, whereas suppressing BDNF signaling down-regulated VGF expression. Moreover, hypothalamic VGF expression was regulated by leptin, melanocortin receptor agonist, and food deprivation mostly paralleled to BDNF expression. Recombinant adeno-associated virus-mediated gene transfer of Cre recombinase to floxed VGF mice specifically decreased VGF expression in the hypothalamus. In contrast to the lean and hypermetabolic phenotype of homozygous germline VGF knockout mice, specific knockdown of hypothalamic VGF in male adult mice led to increased adiposity, decreased core body temperature, reduced energy expenditure, and impaired glucose tolerance, as well as disturbance of molecular features of brown and white adipose tissues without effects on food intake. However, VGF knockdown failed to block the EE-induced BDNF up-regulation or decrease of adiposity indicating a minor role of VGF in the hypothalamic-sympathoneural-adipocyte axis. Taken together, our results suggest hypothalamic VGF responds to environmental demands and plays an important role in energy balance and glycemic control likely acting in the melanocortin pathway downstream of BDNF. PMID:26730934

Identification of complex systems by artificial neural networks. Applications to mechanical frictions

International Nuclear Information System (INIS)

Dominguez, Manuel

1998-01-01

In the frame of complex systems modelization, we describe in this report the contribution of neural networks to mechanical friction modelization. This thesis is divided in three parts, each one corresponding to every stage of the realized work. The first part takes stock of the properties of neural networks by replacing them in the statistic frame of learning theory (particularly: non-linear and non-parametric regression models) and by showing the existing links with other more 'classic' techniques from automatics. We show then how identification models can be integrated in the neural networks description as a larger nonlinear model class. A methodology of neural networks use have been developed. We focused on validation techniques using correlation functions for non-linear systems, and on the use of regularization methods. The second part deals with the problematic of friction in mechanical systems. Particularly, we present the main current identified physical phenomena, which are integrated in advanced friction modelization. Characterization of these phenomena allows us to state a priori knowledge to be used in the identification stage. We expose some of the most well-known friction models: Dahl's model, Reset Integrator and Canuda's dynamical model, which are then used in simulation studies. The last part links the former one by illustrating a real-world application: an electric jack from SFIM-Industries, used in the Very Large Telescope (VLT) control scheme. This part begins with physical system presentation. The results are compared with more 'classic' methods. We finish using neural networks compensation scheme in closed-loop control. (author) [fr

Hypothalamic kappa opioid receptor mediates both diet-induced and melanin concentrating hormone-induced liver damage through inflammation and endoplasmic reticulum stress.

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Imbernon, Monica; Sanchez-Rebordelo, Estrella; Romero-Picó, Amparo; Kalló, Imre; Chee, Melissa J; Porteiro, Begoña; Al-Massadi, Omar; Contreras, Cristina; Fernø, Johan; Senra, Ana; Gallego, Rosalia; Folgueira, Cintia; Seoane, Luisa M; van Gestel, Margriet; Adan, Roger A; Liposits, Zsolt; Dieguez, Carlos; López, Miguel; Nogueiras, Ruben

2016-10-01

The opioid system is widely known to modulate the brain reward system and thus affect the behavior of humans and other animals, including feeding. We hypothesized that the hypothalamic opioid system might also control energy metabolism in peripheral tissues. Mice lacking the kappa opioid receptor (κOR) and adenoviral vectors overexpressing or silencing κOR were stereotaxically delivered in the lateral hypothalamic area (LHA) of rats. Vagal denervation was performed to assess its effect on liver metabolism. Endoplasmic reticulum (ER) stress was inhibited by pharmacological (tauroursodeoxycholic acid) and genetic (overexpression of the chaperone glucose-regulated protein 78 kDa) approaches. The peripheral effects on lipid metabolism were assessed by histological techniques and western blot. We show that in the LHA κOR directly controls hepatic lipid metabolism through the parasympathetic nervous system, independent of changes in food intake and body weight. κOR colocalizes with melanin concentrating hormone receptor 1 (MCH-R1) in the LHA, and genetic disruption of κOR reduced melanin concentrating hormone-induced liver steatosis. The functional relevance of these findings was given by the fact that silencing of κOR in the LHA attenuated both methionine choline-deficient, diet-induced and choline-deficient, high-fat diet-induced ER stress, inflammation, steatohepatitis, and fibrosis, whereas overexpression of κOR in this area promoted liver steatosis. Overexpression of glucose-regulated protein 78 kDa in the liver abolished hypothalamic κOR-induced steatosis by reducing hepatic ER stress. This study reveals a novel hypothalamic-parasympathetic circuit modulating hepatic function through inflammation and ER stress independent of changes in food intake or body weight; these findings might have implications for the clinical use of opioid receptor antagonists. (Hepatology 2016;64:1086-1104). © 2016 The Authors. (Hepatology published by Wiley Periodicals, Inc., on

Application of neural networks to connectional expert system for identification of transients in nuclear power plants

International Nuclear Information System (INIS)

Cheon, Se Woo; Kim, Wan Joo; Chang, Soon Heung; Roh, Myung Sub

1991-01-01

The Back-propagation Neural Network (BPN) algorithm is applied to connectionist expert system for the identification of BWR transients. Several powerful features of neural network-based expert systems over traditional rule-based expert systems are described. The general mapping capability of the neural networks enables to identify transients easily. A number of case studies were performed with emphasis on the applicability of the neural networks to the diagnostic domain. It is revealed that the BPN algorithm can identify transients properly, even when incomplete or untrained symptoms are given. It is also shown that multiple transients are easily identified

The ctenophore genome and the evolutionary origins of neural systems

NARCIS (Netherlands)

Moroz, Leonid L.; Kocot, Kevin M.; Citarella, Mathew R.; Dosung, Sohn; Norekian, Tigran P.; Povolotskaya, Inna S.; Grigorenko, Anastasia P.; Dailey, Christopher; Berezikov, Eugene; Buckley, Katherine M.; Ptitsyn, Andrey; Reshetov, Denis; Mukherjee, Krishanu; Moroz, Tatiana P.; Bobkova, Yelena; Yu, Fahong; Kapitonov, Vladimir V.; Jurka, Jerzy; Bobkov, Yuri V.; Swore, Joshua J.; Girardo, David O.; Fodor, Alexander; Gusev, Fedor; Sanford, Rachel; Bruders, Rebecca; Kittler, Ellen; Mills, Claudia E.; Rast, Jonathan P.; Derelle, Romain; Solovyev, Victor V.; Kondrashov, Fyodor A.; Swalla, Billie J.; Sweedler, Jonathan V.; Rogaev, Evgeny I.; Halanych, Kenneth M.; Kohn, Andrea B.

2014-01-01

The origins of neural systems remain unresolved. In contrast to other basal metazoans, ctenophores (comb jellies) have both complex nervous and mesoderm-derived muscular systems. These holoplanktonic predators also have sophisticated ciliated locomotion, behaviour and distinct development. Here we

Dehydration-induced release of vasopressin involves activation of hypothalamic histaminergic neurons.

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Kjaer, A; Knigge, U; Rouleau, A; Garbarg, M; Warberg, J

1994-08-01

The hypothalamic neurotransmitter histamine (HA) induces arginine vasopressin (AVP) release when administered centrally. We studied and characterized this effect of HA with respect to receptor involvement. In addition, we studied the possible role of hypothalamic histaminergic neurons in the mediation of a physiological stimulus (dehydration) for AVP secretion. Intracerebroventricular administration of HA, the H1-receptor agonists 2(3-bromophenyl)HA and 2-thiazolylethylamine, or the H2-receptor agonists amthamine or 4-methyl-HA stimulated AVP secretion. The stimulatory action of HA on AVP was inhibited by pretreatment with the H1-receptor antagonist mepyramine or the H2-receptor antagonist cimetidine. Twenty-four hours of dehydration elevated the plasma osmolality from 298 +/- 3 to 310 +/- 3 mmol/liter and increased the plasma AVP concentration 4-fold. The hypothalamic content of HA and its metabolite tele-methyl-HA was elevated in response to dehydration, indicating an increased synthesis and release of hypothalamic HA. Dehydration-induced AVP secretion was lowered when neuronal HA synthesis was inhibited by the administration of (S) alpha-fluoromethylhistidine or when the animals were pretreated with the H3-receptor agonist R(alpha)methylhistamine, which inhibits the release and synthesis of HA, the H1-receptor antagonists mepyramine and cetirizine, or the H2-receptor antagonists cimetidine and ranitidine. We conclude that HA, via activation of both H1- and H2-receptors, stimulates AVP release and that HA is a physiological regulator of AVP secretion.

Loss of Magel2 impairs the development of hypothalamic Anorexigenic circuits.

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Maillard, Julien; Park, Soyoung; Croizier, Sophie; Vanacker, Charlotte; Cook, Joshua H; Prevot, Vincent; Tauber, Maithe; Bouret, Sebastien G

2016-08-01

Prader-Willi syndrome (PWS) is a genetic disorder characterized by a variety of physiological and behavioral dysregulations, including hyperphagia, a condition that can lead to life-threatening obesity. Feeding behavior is a highly complex process with multiple feedback loops that involve both peripheral and central systems. The arcuate nucleus of the hypothalamus (ARH) is critical for the regulation of homeostatic processes including feeding, and this nucleus develops during neonatal life under of the influence of both environmental and genetic factors. Although much attention has focused on the metabolic and behavioral outcomes of PWS, an understanding of its effects on the development of hypothalamic circuits remains elusive. Here, we show that mice lacking Magel2, one of the genes responsible for the etiology of PWS, display an abnormal development of ARH axonal projections. Notably, the density of anorexigenic α-melanocyte-stimulating hormone axons was reduced in adult Magel2-null mice, while the density of orexigenic agouti-related peptide fibers in the mutant mice appeared identical to that in control mice. On the basis of previous findings showing a pivotal role for metabolic hormones in hypothalamic development, we also measured leptin and ghrelin levels in Magel2-null and control neonates and found that mutant mice have normal leptin and ghrelin levels. In vitro experiments show that Magel2 directly promotes axon growth. Together, these findings suggest that a loss of Magel2 leads to the disruption of hypothalamic feeding circuits, an effect that appears to be independent of the neurodevelopmental effects of leptin and ghrelin and likely involves a direct neurotrophic effect of Magel2. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

System-Level Design of a 64-Channel Low Power Neural Spike Recording Sensor.

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Delgado-Restituto, Manuel; Rodriguez-Perez, Alberto; Darie, Angela; Soto-Sanchez, Cristina; Fernandez-Jover, Eduardo; Rodriguez-Vazquez, Angel

2017-04-01

This paper reports an integrated 64-channel neural spike recording sensor, together with all the circuitry to process and configure the channels, process the neural data, transmit via a wireless link the information and receive the required instructions. Neural signals are acquired, filtered, digitized and compressed in the channels. Additionally, each channel implements an auto-calibration algorithm which individually configures the transfer characteristics of the recording site. The system has two transmission modes; in one case the information captured by the channels is sent as uncompressed raw data; in the other, feature vectors extracted from the detected neural spikes are released. Data streams coming from the channels are serialized by the embedded digital processor. Experimental results, including in vivo measurements, show that the power consumption of the complete system is lower than 330 μW.

Increased Hypothalamic Inflammation Associated with the Susceptibility to Obesity in Rats Exposed to High-Fat Diet

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Xiaoke Wang

2012-01-01

Full Text Available Inflammation has been implicated in the hypothalamic leptin and insulin resistance resulting defective food intake during high fat diet period. To investigate hypothalamic inflammation in dietary induced obesity (DIO and obesity resistant (DIO-R rats, we established rat models of DIO and DIO-R by feeding high fat diet for 10 weeks. Then we switched half of DIO and DIO-R rats to chow food and the other half to high fat diet for the following 8 weeks to explore hypothalamic inflammation response to the low fat diet intervention. Body weight, caloric intake, HOMA-IR, as well as the mRNA expression of hypothalamic TLR4, NF-κB, TNF-α, IL-1β, and IL-6 in DIO/HF rats were significantly increased compared to DIO-R/HF and CF rats, whereas IL-10 mRNA expression was lower in both DIO/HF and DIO-R/HF rats compared with CF rats. Switching to chow food from high fat diet reduced the body weight and improved insulin sensitivity but not affecting the expressions of studied inflammatory genes in DIO rats. Take together, upregulated hypothalamic inflammation may contribute to the overeating and development of obesity susceptibility induced by high fat diet. Switching to chow food had limited role in correcting hypothalamic inflammation in DIO rats during the intervention period.

Hyperprolactinemia from radiation-induced hypothalamic hypopituitarism

International Nuclear Information System (INIS)

Corkill, G.; Hanson, F.W.; Gold, E.M.; White, V.A.

1980-01-01

In 1975 Samaan et al., described the effects of radiation damage of the hypothalamus in 15 patients with head and neck cancer. Shalet et al., in 1977 described endocrine morbidity in adults who as children had been irradiated for brain tumors. This report describes instances of hyperprolactinemia and associated hypothalamic, pituitary, and thyroid dysfunction following irradiation of a young adult female for brain neoplasia

Increased hypothalamic serotonin turnover in inflammation-induced anorexia

NARCIS (Netherlands)

Dwarkasing, J.T.; Witkamp, R.F.; Boekschoten, M.V.; Laak, ter M.C.; Heins, M.S.; Norren, van K.

2016-01-01

Background: Anorexia can occur as a serious complication of disease. Increasing evidence suggests that inflammation plays a major role, along with a hypothalamic dysregulation characterized by locally elevated serotonin levels. The present study was undertaken to further explore the connections

Pubertally born neurons and glia are functionally integrated into limbic and hypothalamic circuits of the male Syrian hamster.

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Mohr, Margaret A; Sisk, Cheryl L

2013-03-19

During puberty, the brain goes through extensive remodeling, involving the addition of new neurons and glia to brain regions beyond the canonical neurogenic regions (i.e., dentate gyrus and olfactory bulb), including limbic and hypothalamic cell groups associated with sex-typical behavior. Whether these pubertally born cells become functionally integrated into neural circuits remains unknown. To address this question, we gave male Syrian hamsters daily injections of the cell birthdate marker bromodeoxyuridine throughout puberty (postnatal day 28-49). Half of the animals were housed in enriched environments with access to a running wheel to determine whether enrichment increased the survival of pubertally born cells compared with the control environment. At 4 wk after the last BrdU injection, animals were allowed to interact with a receptive female and were then killed 1 h later. Triple-label immunofluorescence for BrdU, the mature neuron marker neuronal nuclear antigen, and the astrocytic marker glial fibrillary acidic protein revealed that a proportion of pubertally born cells in the medial preoptic area, arcuate nucleus, and medial amygdala differentiate into either mature neurons or astrocytes. Double-label immunofluorescence for BrdU and the protein Fos revealed that a subset of pubertally born cells in these regions is activated during sociosexual behavior, indicative of their functional incorporation into neural circuits. Enrichment affected the survival and activation of pubertally born cells in a brain region-specific manner. These results demonstrate that pubertally born cells located outside of the traditional neurogenic regions differentiate into neurons and glia and become functionally incorporated into neural circuits that subserve sex-typical behaviors.

Translational relevance of rodent models of hypothalamic-pituitary-adrenal function and stressors in adolescence

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Cheryl M. McCormick

2017-02-01

Full Text Available Elevations in glucocorticoids that result from environmental stressors can have programming effects on brain structure and function when the exposure occurs during sensitive periods that involve heightened neural development. In recent years, adolescence has gained increasing attention as another sensitive period of development, a period in which pubertal transitions may increase the vulnerability to stressors. There are similarities in physical and behavioural development between humans and rats, and rats have been used effectively as an animal model of adolescence and the unique plasticity of this period of ontogeny. This review focuses on benefits and challenges of rats as a model for translational research on hypothalamic-pituitary-adrenal (HPA function and stressors in adolescence, highlighting important parallels and contrasts between adolescent rats and humans, and we review the main stress procedures that are used in investigating HPA stress responses and their consequences in adolescence in rats. We conclude that a greater focus on timing of puberty as a factor in research in adolescent rats may increase the translational relevance of the findings.

Differences between otolith- and semicircular canal-activated neural circuitry in the vestibular system.

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Uchino, Yoshio; Kushiro, Keisuke

2011-12-01

In the last two decades, we have focused on establishing a reliable technique for focal stimulation of vestibular receptors to evaluate neural connectivity. Here, we summarize the vestibular-related neuronal circuits for the vestibulo-ocular reflex, vestibulocollic reflex, and vestibulospinal reflex arcs. The focal stimulating technique also uncovered some hidden neural mechanisms. In the otolith system, we identified two hidden neural mechanisms that enhance otolith receptor sensitivity. The first is commissural inhibition, which boosts sensitivity by incorporating inputs from bilateral otolith receptors, the existence of which was in contradiction to the classical understanding of the otolith system but was observed in the utricular system. The second mechanism, cross-striolar inhibition, intensifies the sensitivity of inputs from both sides of receptive cells across the striola in a single otolith sensor. This was an entirely novel finding and is typically observed in the saccular system. We discuss the possible functional meaning of commissural and cross-striolar inhibition. Finally, our focal stimulating technique was applied to elucidate the different constructions of axonal projections from each vestibular receptor to the spinal cord. We also discuss the possible function of the unique neural connectivity observed in each vestibular receptor system. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

A novel neural-wavelet approach for process diagnostics and complex system modeling

Science.gov (United States)

Gao, Rong

Neural networks have been effective in several engineering applications because of their learning abilities and robustness. However certain shortcomings, such as slow convergence and local minima, are always associated with neural networks, especially neural networks applied to highly nonlinear and non-stationary problems. These problems can be effectively alleviated by integrating a new powerful tool, wavelets, into conventional neural networks. The multi-resolution analysis and feature localization capabilities of the wavelet transform offer neural networks new possibilities for learning. A neural wavelet network approach developed in this thesis enjoys fast convergence rate with little possibility to be caught at a local minimum. It combines the localization properties of wavelets with the learning abilities of neural networks. Two different testbeds are used for testing the efficiency of the new approach. The first is magnetic flowmeter-based process diagnostics: here we extend previous work, which has demonstrated that wavelet groups contain process information, to more general process diagnostics. A loop at Applied Intelligent Systems Lab (AISL) is used for collecting and analyzing data through the neural-wavelet approach. The research is important for thermal-hydraulic processes in nuclear and other engineering fields. The neural-wavelet approach developed is also tested with data from the electric power grid. More specifically, the neural-wavelet approach is used for performing short-term and mid-term prediction of power load demand. In addition, the feasibility of determining the type of load using the proposed neural wavelet approach is also examined. The notion of cross scale product has been developed as an expedient yet reliable discriminator of loads. Theoretical issues involved in the integration of wavelets and neural networks are discussed and future work outlined.

Deficiency of leptin receptor in myeloid cells disrupts hypothalamic metabolic circuits and causes body weight increase

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Yuanqing Gao

2018-01-01

Conclusions: Myeloid cell leptin receptor deficient mice partially replicate the db/db phenotype. Leptin signaling in hypothalamic microglia is important for microglial function and a correct formation of the hypothalamic neuronal circuit regulating metabolism.

Hypothalamic neuroendocrine circuitry is programmed by maternal obesity: interaction with postnatal nutritional environment.

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Hui Chen

Full Text Available OBJECTIVE: Early life nutrition is critical for the development of hypothalamic neurons involved in energy homeostasis. We previously showed that intrauterine and early postnatal overnutrition programmed hypothalamic neurons expressing the appetite stimulator neuropeptide Y (NPY and suppressor proopiomelanocortin (POMC in offspring at weaning. However, the long-term effects of such programming and its interactions with post-weaning high-fat-diet (HFD consumption are unclear. RESEARCH DESIGN AND METHODS: Female Sprague Dawley rats were exposed to chow or HFD for 5 weeks before mating, throughout gestation and lactation. On postnatal day 1, litters were adjusted to 3/litter to induce postnatal overnutrition (vs. 12 in control. At postnatal day 20, half of the rats from each maternal group were weaned onto chow or HFD for 15 weeks. Hypothalamic appetite regulators, and fuel (glucose and lipid metabolic markers were measured. RESULTS: Offspring from obese dams gained more weight than those from lean dams independent of post-weaning diet. Maternal obesity interacted with post-weaning HFD consumption to cause greater levels of hyperphagia, adiposity, hyperlipidemia, and glucose intolerance in offspring. This was linked to increased hypothalamic NPY signaling and leptin resistance in adult offspring. Litter size reduction had a detrimental impact on insulin and adiponectin, while hypothalamic NPY and POMC mRNA expression were suppressed in the face of normal energy intake and weight gain. CONCLUSIONS: Maternal obesity, postnatal litter size reduction and post-weaning HFD consumption caused obesity via different neuroendocrine mechanism. There were strong additive effects of maternal obesity and post-weaning HFD consumption to increase the metabolic disorders in offspring.

Activation of the hypothalamic-pituitary-adrenal stress axis induces cellular oxidative stress

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Jereme G. Spiers

2015-01-01

Full Text Available Glucocorticoids released from the adrenal gland in response to stress-induced activation of the hypothalamic-pituitary-adrenal (HPA axis induce activity in the cellular reduction-oxidation (redox system. The redox system is a ubiquitous chemical mechanism allowing the transfer of electrons between donor/acceptors and target molecules during oxidative phosphorylation while simultaneously maintaining the overall cellular environment in a reduced state. The objective of this review is to present an overview of the current literature discussing the link between HPA axis-derived glucocorticoids and increased oxidative stress, particularly focussing on the redox changes observed in the hippocampus following glucocorticoid exposure.

Shades of grey; Assessing the contribution of the magno- and parvocellular systems to neural processing of the retinal input in the human visual system from the influence of neural population size and its discharge activity on the VEP.

Science.gov (United States)

Marcar, Valentine L; Baselgia, Silvana; Lüthi-Eisenegger, Barbara; Jäncke, Lutz

2018-03-01

Retinal input processing in the human visual system involves a phasic and tonic neural response. We investigated the role of the magno- and parvocellular systems by comparing the influence of the active neural population size and its discharge activity on the amplitude and latency of four VEP components. We recorded the scalp electric potential of 20 human volunteers viewing a series of dartboard images presented as a pattern reversing and pattern on-/offset stimulus. These patterns were designed to vary both neural population size coding the temporal- and spatial luminance contrast property and the discharge activity of the population involved in a systematic manner. When the VEP amplitude reflected the size of the neural population coding the temporal luminance contrast property of the image, the influence of luminance contrast followed the contrast response function of the parvocellular system. When the VEP amplitude reflected the size of the neural population responding to the spatial luminance contrast property the image, the influence of luminance contrast followed the contrast response function of the magnocellular system. The latencies of the VEP components examined exhibited the same behavior across our stimulus series. This investigation demonstrates the complex interplay of the magno- and parvocellular systems on the neural response as captured by the VEP. It also demonstrates a linear relationship between stimulus property, neural response, and the VEP and reveals the importance of feedback projections in modulating the ongoing neural response. In doing so, it corroborates the conclusions of our previous study.

Epigenetic changes in fetal hypothalamic energy regulating pathways are associated with maternal undernutrition and twinning.

Science.gov (United States)

Begum, Ghazala; Stevens, Adam; Smith, Emma Bolton; Connor, Kristin; Challis, John R G; Bloomfield, Frank; White, Anne

2012-04-01

Undernutrition during pregnancy is implicated in the programming of offspring for the development of obesity and diabetes. We hypothesized that maternal programming causes epigenetic changes in fetal hypothalamic pathways regulating metabolism. This study used sheep to examine the effect of moderate maternal undernutrition (60 d before to 30 d after mating) and twinning to investigate changes in the key metabolic regulators proopiomelanocortin (POMC) and the glucocorticoid receptor (GR) in fetal hypothalami. Methylation of the fetal hypothalamic POMC promoter was reduced in underfed singleton, fed twin, and underfed twin groups (60, 73, and 63% decrease, respectively). This was associated with reduced DNA methyltransferase activity and altered histone methylation and acetylation. Methylation of the hypothalamic GR promoter was decreased in both twin groups and in maternally underfed singleton fetuses (52, 65, and 55% decrease, respectively). This correlated with changes in histone methylation and acetylation and increased GR mRNA expression in the maternally underfed singleton group. Alterations in GR were hypothalamic specific, with no changes in hippocampi. Unaltered levels of OCT4 promoter methylation indicated gene-specific effects. In conclusion, twinning and periconceptional undernutrition are associated with epigenetic changes in fetal hypothalamic POMC and GR genes, potentially resulting in altered energy balance regulation in the offspring.

Identification and adaptive neural network control of a DC motor system with dead-zone characteristics.

Science.gov (United States)

Peng, Jinzhu; Dubay, Rickey

2011-10-01

In this paper, an adaptive control approach based on the neural networks is presented to control a DC motor system with dead-zone characteristics (DZC), where two neural networks are proposed to formulate the traditional identification and control approaches. First, a Wiener-type neural network (WNN) is proposed to identify the motor DZC, which formulates the Wiener model with a linear dynamic block in cascade with a nonlinear static gain. Second, a feedforward neural network is proposed to formulate the traditional PID controller, termed as PID-type neural network (PIDNN), which is then used to control and compensate for the DZC. In this way, the DC motor system with DZC is identified by the WNN identifier, which provides model information to the PIDNN controller in order to make it adaptive. Back-propagation algorithms are used to train both neural networks. Also, stability and convergence analysis are conducted using the Lyapunov theorem. Finally, experiments on the DC motor system demonstrated accurate identification and good compensation for dead-zone with improved control performance over the conventional PID control. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Hypothalamic control of pituitary and adrenal hormones during hypothermia.

Science.gov (United States)

Okuda, C; Miyazaki, M; Kuriyama, K

1986-01-01

In order to investigate neuroendocrinological mechanisms of hypothermia, we determined the changes in plasma concentrations of corticosterone (CS), prolactin (PRL), and thyrotropin (TSH), and their correlations with alterations in hypothalamic dopamine (DA) and thyrotropin releasing hormone (TRH), in rats restrained and immersed in a water bath at various temperatures. A graded decrease of body temperature induced a progressive increase in the plasma level of CS, whereas that of PRL showed a drastic decrease. The plasma level of TSH also showed an increase during mild hypothermia (about 35 degrees C), but this increase was not evident during profound hypothermia (below 24 degrees C). The changes in these hormones were readily reversed by rewarming animals. Although DA content in the hypothalamus was not affected, its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), showed an increase following the decrease of body temperature. Pretreatment of the animals with sulpiride, a D2-antagonist, prevented the hypothermia-induced inhibition of PRL release. Hypothalamic TRH was significantly decreased during mild hypothermia, and it returned to control levels after rewarming. These results suggest that the decrease in plasma PRL induced by hypothermia may be associated with the activation of hypothalamic DA neurons, whereas the increase in plasma TSH during mild hypothermia seems to be caused by the increased release of TRH in the hypothalamus.

Hypothalamic obesity after treatment for craniopharyngioma: the importance of the home environment.

Science.gov (United States)

Meijneke, Ruud W H; Schouten-van Meeteren, Antoinette Y N; de Boer, Nienke Y; van Zundert, Suzanne; van Trotsenburg, Paul A S; Stoelinga, Femke; van Santen, Hanneke M

2015-01-01

Hypothalamic obesity after treatment for craniopharyngioma is a well-recognized, severe problem. Treatment of hypothalamic obesity is difficult and often frustrating for the patient, the parents and the professional care-giver. Because hypothalamic obesity is caused by an underlying medical disorder, it is often assumed that regular diet and exercise are not beneficial to reduce the extraordinarily high body mass index, and in fact, lifestyle interventions have been shown to be insufficient in case of extreme hypothalamic obesity. Nevertheless, it is important to realize that also in this situation, informal care delivered by the family and appropriate parenting styles are required to minimize the obesity problem. We present a case in which weight gain in the home situation was considered unstoppable, and a very early mortality due to complications of the severe increasing obesity was considered inevitable. A permissive approach toward food intake became leading with rapid weight increase since a restrictive lifestyle was considered a senseless burden for the child. By admission to our hospital for a longer period of time, weight reduction was realized, and the merely permissive approach could be changed into active purposeful care by adequate information, instruction, guidance and encouragement of the affected child and her parents. This case illustrates that, although this type of obesity has a pathological origin, parental and environmental influences remain of extreme importance.

Neural Network Based Intrusion Detection System for Critical Infrastructures

Energy Technology Data Exchange (ETDEWEB)

Todd Vollmer; Ondrej Linda; Milos Manic

2009-07-01

Resiliency and security in control systems such as SCADA and Nuclear plant’s in today’s world of hackers and malware are a relevant concern. Computer systems used within critical infrastructures to control physical functions are not immune to the threat of cyber attacks and may be potentially vulnerable. Tailoring an intrusion detection system to the specifics of critical infrastructures can significantly improve the security of such systems. The IDS-NNM – Intrusion Detection System using Neural Network based Modeling, is presented in this paper. The main contributions of this work are: 1) the use and analyses of real network data (data recorded from an existing critical infrastructure); 2) the development of a specific window based feature extraction technique; 3) the construction of training dataset using randomly generated intrusion vectors; 4) the use of a combination of two neural network learning algorithms – the Error-Back Propagation and Levenberg-Marquardt, for normal behavior modeling. The presented algorithm was evaluated on previously unseen network data. The IDS-NNM algorithm proved to be capable of capturing all intrusion attempts presented in the network communication while not generating any false alerts.

Activation of the hypothalamic-pituitary-adrenal axis by addictive drugs: different pathways, common outcome.

Science.gov (United States)

Armario, Antonio

2010-07-01

Addictive drugs (opiates, ethanol, cannabinoids (CBs), nicotine, cocaine, amphetamines) induce activation of the hypothalamic-pituitary-adrenal (HPA) axis, with the subsequent release of adrenocorticotropic hormone and glucocorticoids. The sequence of events leading to HPA activation appears to start within the brain, suggesting that activation is not secondary to peripheral homeostatic alterations. The precise neurochemical mechanisms and brain pathways involved are markedly dependent on the particular drug, although it is assumed that information eventually converges into the hypothalamic paraventricular nucleus (PVN). Whereas some drugs may act on the hypothalamus or directly within PVN neurons (i.e. ethanol), others exert their primary action outside the PVN (i.e. CBs, nicotine, cocaine). Corticotropin-releasing hormone (CRH) has a critical role in most cases, but the changes in c-fos and CRH gene expression in the PVN also reveal differences among drugs. More studies are needed to understand how addictive drugs act on this important neuroendocrine system and their functional consequences. Copyright 2010 Elsevier Ltd. All rights reserved.

Developmental programming of hypothalamic neuronal circuits: impact on energy balance control

Directory of Open Access Journals (Sweden)

Thanuja eGali Ramamoorthy

2015-04-01

Full Text Available The prevalence of obesity in adults and children has increased globally at an alarming rate. Mounting evidence from both epidemiological studies and animal models indicates that adult obesity and associated metabolic disorders can be programmed by intrauterine and early postnatal environment- a phenomenon known as fetal programming of adult disease. Data from nutritional intervention studies in animals including maternal under- and over-nutrition support the developmental origins of obesity and metabolic syndrome. The hypothalamic neuronal circuits located in the arcuate nucleus controlling appetite and energy expenditure are set early in life and are perturbed by maternal nutritional insults. In this review, we focus on the effects of maternal nutrition in programming permanent changes in these hypothalamic circuits, with experimental evidence from animal models of maternal under- and over-nutrition. We discuss the epigenetic modifications which regulate hypothalamic gene expression as potential molecular mechanisms linking maternal diet during pregnancy to the offspring’s risk of obesity at a later age. Understanding these mechanisms in key metabolic genes may provide insights into the development of preventative intervention strategies.

Developmental programming of hypothalamic neuronal circuits: impact on energy balance control

Science.gov (United States)

Gali Ramamoorthy, Thanuja; Begum, Ghazala; Harno, Erika; White, Anne

2015-01-01

The prevalence of obesity in adults and children has increased globally at an alarming rate. Mounting evidence from both epidemiological studies and animal models indicates that adult obesity and associated metabolic disorders can be programmed by intrauterine and early postnatal environment- a phenomenon known as “fetal programming of adult disease.” Data from nutritional intervention studies in animals including maternal under- and over-nutrition support the developmental origins of obesity and metabolic syndrome. The hypothalamic neuronal circuits located in the arcuate nucleus controlling appetite and energy expenditure are set early in life and are perturbed by maternal nutritional insults. In this review, we focus on the effects of maternal nutrition in programming permanent changes in these hypothalamic circuits, with experimental evidence from animal models of maternal under- and over-nutrition. We discuss the epigenetic modifications which regulate hypothalamic gene expression as potential molecular mechanisms linking maternal diet during pregnancy to the offspring's risk of obesity at a later age. Understanding these mechanisms in key metabolic genes may provide insights into the development of preventative intervention strategies. PMID:25954145

Compensating for Channel Fading in DS-CDMA Communication Systems Employing ICA Neural Network Detectors

Directory of Open Access Journals (Sweden)

David Overbye

2005-06-01

Full Text Available In this paper we examine the impact of channel fading on the bit error rate of a DS-CDMA communication system. The system employs detectors that incorporate neural networks effecting methods of independent component analysis (ICA, subspace estimation of channel noise, and Hopfield type neural networks. The Rayleigh fading channel model is used. When employed in a Rayleigh fading environment, the ICA neural network detectors that give superior performance in a flat fading channel did not retain this superior performance. We then present a new method of compensating for channel fading based on the incorporation of priors in the ICA neural network learning algorithms. When the ICA neural network detectors were compensated using the incorporation of priors, they give significantly better performance than the traditional detectors and the uncompensated ICA detectors. Keywords: CDMA, Multi-user Detection, Rayleigh Fading, Multipath Detection, Independent Component Analysis, Prior Probability Hebbian Learning, Natural Gradient

Differential flatness properties and adaptive control of the hypothalamic-pituitary-adrenal axis model

Science.gov (United States)

Rigatos, Gerasimos

2016-12-01

It is shown that the model of the hypothalamic-pituitary-adrenal gland axis is a differentially flat one and this permits to transform it to the so-called linear canonical form. For the new description of the system's dynamics the transformed control inputs contain unknown terms which depend on the system's parameters. To identify these terms an adaptive fuzzy approximator is used in the control loop. Thus an adaptive fuzzy control scheme is implemented in which the unknown or unmodeled system dynamics is approximated by neurofuzzy networks and next this information is used by a feedback controller that makes the state variables (CRH - corticotropin releasing hormone, adenocortocotropic hormone - ACTH, cortisol) of the hypothalamic-pituitary-adrenal gland axis model converge to the desirable levels (setpoints). This adaptive control scheme is exclusively implemented with the use of output feedback, while the state vector elements which are not directly measured are estimated with the use of a state observer that operates in the control loop. The learning rate of the adaptive fuzzy system is suitably computed from Lyapunov analysis, so as to assure that both the learning procedure for the unknown system's parameters, the dynamics of the observer and the dynamics of the control loop will remain stable. The performed Lyapunov stability analysis depends on two Riccati equations, one associated with the feedback controller and one associated with the state observer. Finally, it is proven that for the control scheme that comprises the feedback controller, the state observer and the neurofuzzy approximator, an H-infinity tracking performance can be succeeded.

[Effects of hypothalamic microinjections of 6-hydroxydopamine (6-OHDA) on estral cycle and morphology of the genital tract in the female rat (author's transl)].

Science.gov (United States)

Sala, M A; Oteui, J T; Benedetti, W I

1975-01-01

To determine whether central catecholaminergic pathways are involved in the neural contral of gonadotrophin secretion, they were interrupted at the hypothalamic level by microinjections of 6-hydroxydopamine (6-OHDA). The effects on ovulation, estral cycle and ovarian and uterine histology were studied. Microinjections of 50 mug of 6-OHDA hydrobromyde were made bilaterally into the anterolateral hypothalamus in a group of rats. Another group was injected with 25 mug of 6-OHDA, while a control group recieved an equivalent volume (5 mul) of saline with ascorbic acid. Animals injected with 50 mug of 6-OHDA showed blockade of ovulation, vaginal cytology characteristics of persistent estrous, polyfollicular ovaries and enlarged uteri with hypertrophic endometrial glands. In the group injected with 25 mug, similiar effects were demonstrated, but the number of affected animals was smaller than that in the 50 mug group. Control animals dit not show modifications, either in estral cycle or in ovarian and uterine histology. These results suggest that 6-OHDA injected into the anterolateral hypothalmus interferes with catecholaminergic pathways that participate in the neural control of ovulation.

Increased hypothalamic 5-HT2A receptor gene expression and effects of pharmacologic 5-HT2A receptor inactivation in obese Ay mice

International Nuclear Information System (INIS)

Nonogaki, Katsunori; Nozue, Kana; Oka, Yoshitomo

2006-01-01

Serotonin (5-hydroxytryptamine; 5-HT) 2A receptors contribute to the effects of 5-HT on platelet aggregation and vascular smooth muscle cell proliferation, and are reportedly involved in decreases in plasma levels of adiponectin, an adipokine, in diabetic subjects. Here, we report that systemic administration of sarpogrelate, a 5-HT2A receptor antagonist, suppressed appetite and increased hypothalamic pro-opiomelanocortin and cocaine- and amphetamine-regulated transcript, corticotropin releasing hormone, 5-HT2C, and 5-HT1B receptor gene expression. A y mice, which have ectopic expression of the agouti protein, significantly increased hypothalamic 5-HT2A receptor gene expression in association with obesity compared with wild-type mice matched for age. Systemic administration of sarpogrelate suppressed overfeeding, body weight gain, and hyperglycemia in obese A y mice, whereas it did not increase plasma adiponectin levels. These results suggest that obesity increases hypothalamic 5-HT2A receptor gene expression, and pharmacologic inactivation of 5-HT2A receptors inhibits overfeeding and obesity in A y mice, but did not increase plasma adiponectin levels

Hepatic vagotomy alters limbic and hypothalamic neuropeptide responses to insulin-dependent diabetes and voluntary lard ingestion

NARCIS (Netherlands)

la Fleur, Susanne E.; Manalo, Sotara L.; Roy, Monica; Houshyar, Hani; Dallman, Mary F.

2005-01-01

Hypothalamic anorexigenic [corticotropin-releasing factor (CRF) and proopiomelanocortin] peptides decrease and the orexigen, neuropeptide Y, increases with diabetic hyperphagia. However, when diabetic rats are allowed to eat lard (saturated fat) as well as chow, both caloric intake and hypothalamic

Predictive Control of Hydronic Floor Heating Systems using Neural Networks and Genetic Algorithms

DEFF Research Database (Denmark)

Vinther, Kasper; Green, Torben; Østergaard, Søren

2017-01-01

This paper presents the use a neural network and a micro genetic algorithm to optimize future set-points in existing hydronic floor heating systems for improved energy efficiency. The neural network can be trained to predict the impact of changes in set-points on future room temperatures. Additio...... space is not guaranteed. Evaluation of the performance of multiple neural networks is performed, using different levels of information, and optimization results are presented on a detailed house simulation model....

Analysis of the DWPF glass pouring system using neural networks

International Nuclear Information System (INIS)

Calloway, T.B. Jr.; Jantzen, C.M.

1997-01-01

Neural networks were used to determine the sensitivity of 39 selected Melter/Melter Off Gas and Melter Feed System process parameters as related to the Defense Waste Processing Facility (DWPF) Melter Pour Spout Pressure during the overall analysis and resolution of the DWPF glass production and pouring issues. Two different commercial neural network software packages were used for this analysis. Models were developed and used to determine the critical parameters which accurately describe the DWPF Pour Spout Pressure. The model created using a low-end software package has a root mean square error of ± 0.35 inwc ( 2 = 0.77) with respect to the plant data used to validate and test the model. The model created using a high-end software package has a R 2 = 0.97 with respect to the plant data used to validate and test the model. The models developed for this application identified the key process parameters which contribute to the control of the DWPF Melter Pour Spout pressure during glass pouring operations. The relative contribution and ranking of the selected parameters was determined using the modeling software. Neural network computing software was determined to be a cost-effective software tool for process engineers performing troubleshooting and system performance monitoring activities. In remote high-level waste processing environments, neural network software is especially useful as a replacement for sensors which have failed and are costly to replace. The software can be used to accurately model critical remotely installed plant instrumentation. When the instrumentation fails, the software can be used to provide a soft sensor to replace the actual sensor, thereby decreasing the overall operating cost. Additionally, neural network software tools require very little training and are especially useful in mining or selecting critical variables from the vast amounts of data collected from process computers

DEVELOPMENT OF A COMPUTER SYSTEM FOR IDENTITY AUTHENTICATION USING ARTIFICIAL NEURAL NETWORKS

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Timur Kartbayev

2017-03-01

Full Text Available The aim of the study is to increase the effectiveness of automated face recognition to authenticate identity, considering features of change of the face parameters over time. The improvement of the recognition accuracy, as well as consideration of the features of temporal changes in a human face can be based on the methodology of artificial neural networks. Hybrid neural networks, combining the advantages of classical neural networks and fuzzy logic systems, allow using the network learnability along with the explanation of the findings. The structural scheme of intelligent system for identification based on artificial neural networks is proposed in this work. It realizes the principles of digital information processing and identity recognition taking into account the forecast of key characteristics’ changes over time (e.g., due to aging. The structural scheme has a three-tier architecture and implements preliminary processing, recognition and identification of images obtained as a result of monitoring. On the basis of expert knowledge, the fuzzy base of products is designed. It allows assessing possible changes in key characteristics, used to authenticate identity based on the image. To take this possibility into consideration, a neuro-fuzzy network of ANFIS type was used, which implements the algorithm of Tagaki-Sugeno. The conducted experiments showed high efficiency of the developed neural network and a low value of learning errors, which allows recommending this approach for practical implementation. Application of the developed system of fuzzy production rules that allow predicting changes in individuals over time, will improve the recognition accuracy, reduce the number of authentication failures and improve the efficiency of information processing and decision-making in applications, such as authentication of bank customers, users of mobile applications, or in video monitoring systems of sensitive sites.

Sliding mode synchronization controller design with neural network for uncertain chaotic systems

Energy Technology Data Exchange (ETDEWEB)

Mou Chen [College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)], E-mail: chenmou@nuaa.edu.cn; Jiang Changsheng; Bin Jiang; Wu Qingxian [College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

2009-02-28

A sliding mode synchronization controller is presented with RBF neural network for two chaotic systems in this paper. The compound disturbance of the synchronization error system consists of nonlinear uncertainties and exterior disturbances of chaotic systems. Based on RBF neural networks, a compound disturbance observer is proposed and the update law of parameters is given to monitor the compound disturbance. The synchronization controller is given based on the output of the compound disturbance observer. The designed controller can make the synchronization error convergent to zero and overcome the disruption of the uncertainty and the exterior disturbance of the system. Finally, an example is given to demonstrate the availability of the proposed synchronization control method.

Three-dimensional hydrogel cell culture systems for modeling neural tissue

Science.gov (United States)

Frampton, John

Two-dimensional (2-D) neural cell culture systems have served as physiological models for understanding the cellular and molecular events that underlie responses to physical and chemical stimuli, control sensory and motor function, and lead to the development of neurological diseases. However, the development of three-dimensional (3-D) cell culture systems will be essential for the advancement of experimental research in a variety of fields including tissue engineering, chemical transport and delivery, cell growth, and cell-cell communication. In 3-D cell culture, cells are provided with an environment similar to tissue, in which they are surrounded on all sides by other cells, structural molecules and adhesion ligands. Cells grown in 3-D culture systems display morphologies and functions more similar to those observed in vivo, and can be cultured in such a way as to recapitulate the structural organization and biological properties of tissue. This thesis describes a hydrogel-based culture system, capable of supporting the growth and function of several neural cell types in 3-D. Alginate hydrogels were characterized in terms of their biomechanical and biochemical properties and were functionalized by covalent attachment of whole proteins and peptide epitopes. Methods were developed for rapid cross-linking of alginate hydrogels, thus permitting the incorporation of cells into 3-D scaffolds without adversely affecting cell viability or function. A variety of neural cell types were tested including astrocytes, microglia, and neurons. Cells remained viable and functional for longer than two weeks in culture and displayed process outgrowth in 3-D. Cell constructs were created that varied in cell density, type and organization, providing experimental flexibility for studying cell interactions and behavior. In one set of experiments, 3-D glial-endothelial cell co-cultures were used to model blood-brain barrier (BBB) structure and function. This co-culture system was

ISC feedforward control of gasoline engine. Adaptive system using neural network; Jidoshayo gasoline engine no ISC feedforward seigyo. Neural network wo mochiita tekioka

Energy Technology Data Exchange (ETDEWEB)

Kinugawa, N; Morita, S; Takiyama, T [Osaka City University, Osaka (Japan)

1997-10-01

For fuel economy and a good driver`s feeling, it is necessary for idle-speed to keep at a constant low speed. But keeping low speed has danger of engine stall when the engine torque is disturbed by the alternator, and so on. In this paper, adaptive feedforward idle-speed control system against electrical loads was investigated. This system was based on the reversed tansfer functions of the object system, and a neural network was used to adapt this system for aging. Then, this neural network was also used for creating feedforward table map. Good experimental results were obtained. 2 refs., 11 figs.

Computational modeling of neural plasticity for self-organization of neural networks.

Science.gov (United States)

Chrol-Cannon, Joseph; Jin, Yaochu

2014-11-01

Self-organization in biological nervous systems during the lifetime is known to largely occur through a process of plasticity that is dependent upon the spike-timing activity in connected neurons. In the field of computational neuroscience, much effort has been dedicated to building up computational models of neural plasticity to replicate experimental data. Most recently, increasing attention has been paid to understanding the role of neural plasticity in functional and structural neural self-organization, as well as its influence on the learning performance of neural networks for accomplishing machine learning tasks such as classification and regression. Although many ideas and hypothesis have been suggested, the relationship between the structure, dynamics and learning performance of neural networks remains elusive. The purpose of this article is to review the most important computational models for neural plasticity and discuss various ideas about neural plasticity's role. Finally, we suggest a few promising research directions, in particular those along the line that combines findings in computational neuroscience and systems biology, and their synergetic roles in understanding learning, memory and cognition, thereby bridging the gap between computational neuroscience, systems biology and computational intelligence. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Development of the disable software reporting system on the basis of the neural network

Science.gov (United States)

Gavrylenko, S.; Babenko, O.; Ignatova, E.

2018-04-01

The PE structure of malicious and secure software is analyzed, features are highlighted, binary sign vectors are obtained and used as inputs for training the neural network. A software model for detecting malware based on the ART-1 neural network was developed, optimal similarity coefficients were found, and testing was performed. The obtained research results showed the possibility of using the developed system of identifying malicious software in computer systems protection systems

Hypothalamic amenorrhea in a Camurati-Engelmann disease--a case report.

Science.gov (United States)

Meczekalski, Blazej; Czyzyk, Adam; Podfigurna-Stopa, Agnieszka; Rydzewski, Bogdan; Sroczynski, Jakub; Lipinska, Małgorzata; Sokalski, Jerzy; Krawczynski, Maciej; Jamsheer, Aleksander; Katulski, Krzysztof; Genazzani, Alessandro

2013-05-01

A case report of a patient diagnosed with Camurati-Engelmann Disease (CED) in association with the functional hypothalamic amenorrhea disturbances. CED is a very rare genetically determined disorder classified as a type of bone dysplasia. Case report. Department of Gynecological Endocrinology, 3rd grade Medical University Hospital. Twenty-one years old female patient with CED admitted to the hospital because of primary amenorrhea. Her history revealed skeletal deformities and hearing impairment. Clinical examination, ultrasound, laboratory evaluations (including serum gonadotropins (FSH, LH) at basal state and after stimulation with gonadotropin-releasing hormone, serum basal estradiol) radiological studies (X-ray of the head, the lumbar spine and lower extremities; a computed tomography of the head), G-banding karyotype, polymerase chain reaction and DNA sequencing. Hormonal serum evaluations were made using an enzyme-linked immunosorbent assay. The exon 4 of the transforming growth factor beta 1 gene was amplified by a polymerase chain reaction and the product was directly sequenced. The hormonal analysis was characteristic for the hypogonadotropic hypogonadism. Radiological and molecular analyses confirmed CED diagnosis. The hypothalamic amenorrhea in a patient with CED may be explained as a consequence of fat hypotrophy and very low body mass index. Therefore, impairment within hypothalamic-pituitary axis in patients with CED should be treated with special attention.

The hypothalamic-pituitary-thyroid axis and biological rhythms: The discovery of TSH's unexpected role using animal models.

Science.gov (United States)

Ikegami, Keisuke; Yoshimura, Takashi

2017-10-01

Thyroid hormones (TH) are important for development, growth, and metabolism. It is also clear that the synthesis and secretion of TH are regulated by the hypothalamic-pituitary-thyroid (HPT) axis. Animal models have helped advance our understanding of the roles and regulatory mechanisms of TH. The animals' bodies develop through coordinated timing of cell division and differentiation. Studies of frog metamorphosis led to the discovery of TH and their role in development. However, to adapt to rhythmic environmental changes, animals also developed various endocrine rhythms. Studies of rodents clarified the neural and molecular mechanisms underlying the circadian regulation of the HPT axis. Moreover, birds have a sophisticated seasonal adaptation mechanism, and recent studies of quail revealed unexpected roles for thyroid-stimulating hormone (TSH) and TH in the seasonal regulation of reproduction. Interestingly, this mechanism is conserved in mammals. Thus, we review how animal studies have shaped our general understanding of the HPT axis in relation to biological rhythms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stochastic modeling of the hypothalamic pulse generator activity.

Science.gov (United States)

Camproux, A C; Thalabard, J C; Thomas, G

1994-11-01

Luteinizing hormone (LH) is released by the pituitary in discrete pulses. In the monkey, the appearance of LH pulses in the plasma is invariably associated with sharp increases (i.e, volleys) in the frequency of the hypothalamic pulse generator electrical activity, so that continuous monitoring of this activity by telemetry provides a unique means to study the temporal structure of the mechanism generating the pulses. To assess whether the times of occurrence and durations of previous volleys exert significant influence on the timing of the next volley, we used a class of periodic counting process models that specify the stochastic intensity of the process as the product of two factors: 1) a periodic baseline intensity and 2) a stochastic regression function with covariates representing the influence of the past. This approach allows the characterization of circadian modulation and memory range of the process underlying hypothalamic pulse generator activity, as illustrated by fitting the model to experimental data from two ovariectomized rhesus monkeys.

A Neural Networks Based Operation Guidance System for Procedure Presentation and Validation

International Nuclear Information System (INIS)

Seung, Kun Mo; Lee, Seung Jun; Seong, Poong Hyun

2006-01-01

In this paper, a neural network based operator support system is proposed to reduce operator's errors in abnormal situations in nuclear power plants (NPPs). There are many complicated situations, in which regular and suitable operations should be done by operators accordingly. In order to regulate and validate operators' operations, it is necessary to develop an operator support system which includes computer based procedures with the functions for operation validation. Many computerized procedures systems (CPS) have been recently developed. Focusing on the human machine interface (HMI) design and procedures' computerization, most of CPSs used various methodologies to enhance system's convenience, reliability and accessibility. Other than only showing procedures, the proposed system integrates a simple CPS and an operation validation system (OVS) by using artificial neural network (ANN) for operational permission and quantitative evaluation

Optogenetic Activation of a Lateral Hypothalamic-Ventral Tegmental Drive-Reward Pathway.

Science.gov (United States)

Gigante, Eduardo D; Benaliouad, Faiza; Zamora-Olivencia, Veronica; Wise, Roy A

2016-01-01

Electrical stimulation of the lateral hypothalamus can motivate feeding or can serve as a reward in its own right. It remains unclear whether the same or independent but anatomically overlapping circuitries mediate the two effects. Electrical stimulation findings implicate medial forebrain bundle (MFB) fibers of passage in both effects, and optogenetic studies confirm a contribution from fibers originating in the lateral hypothalamic area and projecting to or through the ventral tegmental area. Here we report that optogenetic activation of ventral tegmental fibers from cells of origin in more anterior or posterior portions of the MFB failed to induce either reward or feeding. The feeding and reward induced by optogenetic activation of fibers from the lateral hypothalamic cells of origin were influenced similarly by variations in stimulation pulse width and pulse frequency, consistent with the hypothesis of a common substrate for the two effects. There were, however, several cases where feeding but not self-stimulation or self-stimulation but not feeding were induced, consistent with the hypothesis that distinct but anatomically overlapping systems mediate the two effects. Thus while optogenetic stimulation provides a more selective tool for characterizing the mechanisms of stimulation-induced feeding and reward, it does not yet resolve the question of common or independent substrates.

Dynamic artificial neural networks with affective systems.

Directory of Open Access Journals (Sweden)

Catherine D Schuman

Full Text Available Artificial neural networks (ANNs are processors that are trained to perform particular tasks. We couple a computational ANN with a simulated affective system in order to explore the interaction between the two. In particular, we design a simple affective system that adjusts the threshold values in the neurons of our ANN. The aim of this paper is to demonstrate that this simple affective system can control the firing rate of the ensemble of neurons in the ANN, as well as to explore the coupling between the affective system and the processes of long term potentiation (LTP and long term depression (LTD, and the effect of the parameters of the affective system on its performance. We apply our networks with affective systems to a simple pole balancing example and briefly discuss the effect of affective systems on network performance.

[The hypothalamic syndrome in childhood (its epidemiological and clinico-electrophysiological aspects)].

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Solov'eva, A D; Vorob'eva, O V; Loseva, M M; Khaspekova, N B; Fedorova, V I; Musaeva, Z A; Filatova, E G

1994-01-01

The epidemiological survey covered 2000 city schoolchildren. They ranged in age from 7 to 15 years. Hypothalamic deficiency (HD) was detected in 5% of the examinees. Clinical and physiological findings on HD children are provided. They were found to have the history of hereditary or natal damage evidencing the acquired nature of the disease. Special emphasis is placed on HD manifestations in prepubertal and pubertal age. The authors show defective regulation of nonspecific brain systems in the form of predominant activation of the septohippocampal system and relative insufficiency of the brain stem mesencephalic reticular formation. Activation of cerebral ergotropic vegetative mechanisms combines with peripheral vegetative failure (sympathetic and parasympathetic), probably, of congenital origin.

Neuroanatomy and sex differences of the lordosis-inhibiting system in the lateral septum

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Tsukahara, Shinji; Kanaya, Moeko; Yamanouchi, Korehito

2014-01-01

Female sexual behavior in rodents, termed lordosis, is controlled by facilitatory and inhibitory systems in the brain. It has been well demonstrated that a neural pathway from the ventromedial hypothalamic nucleus (VMN) to the midbrain central gray (MCG) is essential for facilitatory regulation of lordosis. The neural pathway from the arcuate nucleus to the VMN, via the medial preoptic nucleus, in female rats mediates transient suppression of lordosis, until female sexual receptivity is induced. In addition to this pathway, other regions are involved in inhibitory regulation of lordosis in female rats. The lordosis-inhibiting systems exist not only in the female brain but also in the male brain. The systems contribute to suppression of heterotypical sexual behavior in male rats, although they have the potential ability to display lordosis. The lateral septum (LS) exerts an inhibitory influence on lordosis in both female and male rats. This review focuses on the neuroanatomy and sex differences of the lordosis-inhibiting system in the LS. The LS functionally and anatomically links to the MCG to exert suppression of lordosis. Neurons of the intermediate part of the LS (LSi) serve as lordosis-inhibiting neurons and project axons to the MCG. The LSi-MCG neural connection is sexually dimorphic, and formation of the male-like LSi-MCG neural connection is affected by aromatized testosterone originating from the testes in the postnatal period. The sexually dimorphic LSi-MCG neural connection may reflect the morphological basis of sex differences in the inhibitory regulation of lordosis in rats. PMID:25278832

Robust fault detection of wind energy conversion systems based on dynamic neural networks.

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Talebi, Nasser; Sadrnia, Mohammad Ali; Darabi, Ahmad

2014-01-01

Occurrence of faults in wind energy conversion systems (WECSs) is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS) is required. Recurrent neural networks (RNNs) have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate.

Nutrient sensing and insulin signaling in neuropeptide-expressing immortalized, hypothalamic neurons: A cellular model of insulin resistance.

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Fick, Laura J; Belsham, Denise D

2010-08-15

Obesity and type 2 diabetes mellitus represent a significant global health crisis. These two interrelated diseases are typified by perturbed insulin signaling in the hypothalamus. Using novel hypothalamic cell lines, we have begun to elucidate the molecular and intracellular mechanisms involved in the hypothalamic control of energy homeostasis and insulin resistance. In this review, we present evidence of insulin and glucose signaling pathways that lead to changes in neuropeptide gene expression. We have identified some of the molecular mechanisms involved in the control of de novo hypothalamic insulin mRNA expression. And finally, we have defined key mechanisms involved in the etiology of cellular insulin resistance in hypothalamic neurons that may play a fundamental role in cases of high levels of insulin or saturated fatty acids, often linked to the exacerbation of obesity and diabetes.

Dynamics of a neural system with a multiscale architecture

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Breakspear, Michael; Stam, Cornelis J

2005-01-01

The architecture of the brain is characterized by a modular organization repeated across a hierarchy of spatial scales—neurons, minicolumns, cortical columns, functional brain regions, and so on. It is important to consider that the processes governing neural dynamics at any given scale are not only determined by the behaviour of other neural structures at that scale, but also by the emergent behaviour of smaller scales, and the constraining influence of activity at larger scales. In this paper, we introduce a theoretical framework for neural systems in which the dynamics are nested within a multiscale architecture. In essence, the dynamics at each scale are determined by a coupled ensemble of nonlinear oscillators, which embody the principle scale-specific neurobiological processes. The dynamics at larger scales are ‘slaved’ to the emergent behaviour of smaller scales through a coupling function that depends on a multiscale wavelet decomposition. The approach is first explicated mathematically. Numerical examples are then given to illustrate phenomena such as between-scale bifurcations, and how synchronization in small-scale structures influences the dynamics in larger structures in an intuitive manner that cannot be captured by existing modelling approaches. A framework for relating the dynamical behaviour of the system to measured observables is presented and further extensions to capture wave phenomena and mode coupling are suggested. PMID:16087448

Application of hierarchical dissociated neural network in closed-loop hybrid system integrating biological and mechanical intelligence.

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Yongcheng Li

Full Text Available Neural networks are considered the origin of intelligence in organisms. In this paper, a new design of an intelligent system merging biological intelligence with artificial intelligence was created. It was based on a neural controller bidirectionally connected to an actual mobile robot to implement a novel vehicle. Two types of experimental preparations were utilized as the neural controller including 'random' and '4Q' (cultured neurons artificially divided into four interconnected parts neural network. Compared to the random cultures, the '4Q' cultures presented absolutely different activities, and the robot controlled by the '4Q' network presented better capabilities in search tasks. Our results showed that neural cultures could be successfully employed to control an artificial agent; the robot performed better and better with the stimulus because of the short-term plasticity. A new framework is provided to investigate the bidirectional biological-artificial interface and develop new strategies for a future intelligent system using these simplified model systems.

Application of Hierarchical Dissociated Neural Network in Closed-Loop Hybrid System Integrating Biological and Mechanical Intelligence

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Zhang, Bin; Wang, Yuechao; Li, Hongyi

2015-01-01

Neural networks are considered the origin of intelligence in organisms. In this paper, a new design of an intelligent system merging biological intelligence with artificial intelligence was created. It was based on a neural controller bidirectionally connected to an actual mobile robot to implement a novel vehicle. Two types of experimental preparations were utilized as the neural controller including ‘random’ and ‘4Q’ (cultured neurons artificially divided into four interconnected parts) neural network. Compared to the random cultures, the ‘4Q’ cultures presented absolutely different activities, and the robot controlled by the ‘4Q’ network presented better capabilities in search tasks. Our results showed that neural cultures could be successfully employed to control an artificial agent; the robot performed better and better with the stimulus because of the short-term plasticity. A new framework is provided to investigate the bidirectional biological-artificial interface and develop new strategies for a future intelligent system using these simplified model systems. PMID:25992579

Application of hierarchical dissociated neural network in closed-loop hybrid system integrating biological and mechanical intelligence.

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Li, Yongcheng; Sun, Rong; Zhang, Bin; Wang, Yuechao; Li, Hongyi

2015-01-01

Neural networks are considered the origin of intelligence in organisms. In this paper, a new design of an intelligent system merging biological intelligence with artificial intelligence was created. It was based on a neural controller bidirectionally connected to an actual mobile robot to implement a novel vehicle. Two types of experimental preparations were utilized as the neural controller including 'random' and '4Q' (cultured neurons artificially divided into four interconnected parts) neural network. Compared to the random cultures, the '4Q' cultures presented absolutely different activities, and the robot controlled by the '4Q' network presented better capabilities in search tasks. Our results showed that neural cultures could be successfully employed to control an artificial agent; the robot performed better and better with the stimulus because of the short-term plasticity. A new framework is provided to investigate the bidirectional biological-artificial interface and develop new strategies for a future intelligent system using these simplified model systems.

Lithofacies identification using multiple adaptive resonance theory neural networks and group decision expert system

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Chang, H.-C.; Kopaska-Merkel, D. C.; Chen, H.-C.; Rocky, Durrans S.

2000-01-01

Lithofacies identification supplies qualitative information about rocks. Lithofacies represent rock textures and are important components of hydrocarbon reservoir description. Traditional techniques of lithofacies identification from core data are costly and different geologists may provide different interpretations. In this paper, we present a low-cost intelligent system consisting of three adaptive resonance theory neural networks and a rule-based expert system to consistently and objectively identify lithofacies from well-log data. The input data are altered into different forms representing different perspectives of observation of lithofacies. Each form of input is processed by a different adaptive resonance theory neural network. Among these three adaptive resonance theory neural networks, one neural network processes the raw continuous data, another processes categorial data, and the third processes fuzzy-set data. Outputs from these three networks are then combined by the expert system using fuzzy inference to determine to which facies the input data should be assigned. Rules are prioritized to emphasize the importance of firing order. This new approach combines the learning ability of neural networks, the adaptability of fuzzy logic, and the expertise of geologists to infer facies of the rocks. This approach is applied to the Appleton Field, an oil field located in Escambia County, Alabama. The hybrid intelligence system predicts lithofacies identity from log data with 87.6% accuracy. This prediction is more accurate than those of single adaptive resonance theory networks, 79.3%, 68.0% and 66.0%, using raw, fuzzy-set, and categorical data, respectively, and by an error-backpropagation neural network, 57.3%. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.

The central role of hypothalamic inflammation in the acute illness response and cachexia.

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Burfeind, Kevin G; Michaelis, Katherine A; Marks, Daniel L

2016-06-01

When challenged with a variety of inflammatory threats, multiple systems across the body undergo physiological responses to promote defense and survival. The constellation of fever, anorexia, and fatigue is known as the acute illness response, and represents an adaptive behavioral and physiological reaction to stimuli such as infection. On the other end of the spectrum, cachexia is a deadly and clinically challenging syndrome involving anorexia, fatigue, and muscle wasting. Both of these processes are governed by inflammatory mediators including cytokines, chemokines, and immune cells. Though the effects of cachexia can be partially explained by direct effects of disease processes on wasting tissues, a growing body of evidence shows the central nervous system (CNS) also plays an essential mechanistic role in cachexia. In the context of inflammatory stress, the hypothalamus integrates signals from peripheral systems, which it translates into neuroendocrine perturbations, altered neuronal signaling, and global metabolic derangements. Therefore, we will discuss how hypothalamic inflammation is an essential driver of both the acute illness response and cachexia, and why this organ is uniquely equipped to generate and maintain chronic inflammation. First, we will focus on the role of the hypothalamus in acute responses to dietary and infectious stimuli. Next, we will discuss the role of cytokines in driving homeostatic disequilibrium, resulting in muscle wasting, anorexia, and weight loss. Finally, we will address mechanisms and mediators of chronic hypothalamic inflammation, including endothelial cells, chemokines, and peripheral leukocytes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adult exposure to tributyltin affects hypothalamic neuropeptide Y, Y1 receptor distribution, and circulating leptin in mice.

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Bo, E; Farinetti, A; Marraudino, M; Sterchele, D; Eva, C; Gotti, S; Panzica, G

2016-07-01

Tributyltin (TBT), a pesticide used in antifouling paints, is toxic for aquatic invertebrates. In vertebrates, TBT may act in obesogen- inducing adipogenetic gene transcription for adipocyte differentiation. In a previous study, we demonstrated that acute administration of TBT induces c-fos expression in the arcuate nucleus. Therefore, in this study, we tested the hypothesis that adult exposure to TBT may alter a part of the nervous pathways controlling animal food intake. In particular, we investigated the expression of neuropeptide Y (NPY) immunoreactivity. This neuropeptide forms neural circuits dedicated to food assumption and its action is mediated by Y1 receptors that are widely expressed in the hypothalamic nuclei responsible for the regulation of food intake and energy homeostasis. To this purpose, TBT was orally administered at a dose of 0.025 mg/kg/day/body weight to adult animals [male and female C57BL/6 (Y1-LacZ transgenic mice] for 4 weeks. No differences were found in body weight and fat deposition, but we observed a significant increase in feed efficiency in TBT-treated male mice and a significant decrease in circulating leptin in both sexes. Computerized quantitative analysis of NPY immunoreactivity and Y1-related β-galactosidase activity demonstrated a statistically significant reduction in NPY and Y1 transgene expression in the hypothalamic circuit controlling food intake of treated male mice in comparison with controls. In conclusion, the present results indicate that adult exposure to TBT is profoundly interfering with the nervous circuits involved in the stimulation of food intake. © 2016 American Society of Andrology and European Academy of Andrology.

Application of neural networks to software quality modeling of a very large telecommunications system.

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Khoshgoftaar, T M; Allen, E B; Hudepohl, J P; Aud, S J

1997-01-01

Society relies on telecommunications to such an extent that telecommunications software must have high reliability. Enhanced measurement for early risk assessment of latent defects (EMERALD) is a joint project of Nortel and Bell Canada for improving the reliability of telecommunications software products. This paper reports a case study of neural-network modeling techniques developed for the EMERALD system. The resulting neural network is currently in the prototype testing phase at Nortel. Neural-network models can be used to identify fault-prone modules for extra attention early in development, and thus reduce the risk of operational problems with those modules. We modeled a subset of modules representing over seven million lines of code from a very large telecommunications software system. The set consisted of those modules reused with changes from the previous release. The dependent variable was membership in the class of fault-prone modules. The independent variables were principal components of nine measures of software design attributes. We compared the neural-network model with a nonparametric discriminant model and found the neural-network model had better predictive accuracy.

Sonic hedgehog lineage in the mouse hypothalamus: from progenitor domains to hypothalamic regions

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Alvarez-Bolado Gonzalo

2012-01-01

Full Text Available Abstract Background The hypothalamus is a brain region with essential functions for homeostasis and energy metabolism, and alterations of its development can contribute to pathological conditions in the adult, like hypertension, diabetes or obesity. However, due to the anatomical complexity of the hypothalamus, its development is not well understood. Sonic hedgehog (Shh is a key developmental regulator gene expressed in a dynamic pattern in hypothalamic progenitor cells. To obtain insight into hypothalamic organization, we used genetic inducible fate mapping (GIFM to map the lineages derived from Shh-expressing progenitor domains onto the four rostrocaudally arranged hypothalamic regions: preoptic, anterior, tuberal and mammillary. Results Shh-expressing progenitors labeled at an early stage (before embryonic day (E9.5 contribute neurons and astrocytes to a large caudal area including the mammillary and posterior tuberal regions as well as tanycytes (specialized median eminence glia. Progenitors labeled at later stages (after E9.5 give rise to neurons and astrocytes of the entire tuberal region and in particular the ventromedial nucleus, but not to cells in the mammillary region and median eminence. At this stage, an additional Shh-expressing domain appears in the preoptic area and contributes mostly astrocytes to the hypothalamus. Shh-expressing progenitors do not contribute to the anterior region at any stage. Finally, we show a gradual shift from neurogenesis to gliogenesis, so that progenitors expressing Shh after E12.5 generate almost exclusively hypothalamic astrocytes. Conclusions We define a fate map of the hypothalamus, based on the dynamic expression of Shh in the hypothalamic progenitor zones. We provide evidence that the large neurogenic Shh-expressing progenitor domains of the ventral diencephalon are continuous with those of the midbrain. We demonstrate that the four classical transverse zones of the hypothalamus have clearly

Hybrid information privacy system: integration of chaotic neural network and RSA coding

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Hsu, Ming-Kai; Willey, Jeff; Lee, Ting N.; Szu, Harold H.

2005-03-01

Electronic mails are adopted worldwide; most are easily hacked by hackers. In this paper, we purposed a free, fast and convenient hybrid privacy system to protect email communication. The privacy system is implemented by combining private security RSA algorithm with specific chaos neural network encryption process. The receiver can decrypt received email as long as it can reproduce the specified chaos neural network series, so called spatial-temporal keys. The chaotic typing and initial seed value of chaos neural network series, encrypted by the RSA algorithm, can reproduce spatial-temporal keys. The encrypted chaotic typing and initial seed value are hidden in watermark mixed nonlinearly with message media, wrapped with convolution error correction codes for wireless 3rd generation cellular phones. The message media can be an arbitrary image. The pattern noise has to be considered during transmission and it could affect/change the spatial-temporal keys. Since any change/modification on chaotic typing or initial seed value of chaos neural network series is not acceptable, the RSA codec system must be robust and fault-tolerant via wireless channel. The robust and fault-tolerant properties of chaos neural networks (CNN) were proved by a field theory of Associative Memory by Szu in 1997. The 1-D chaos generating nodes from the logistic map having arbitrarily negative slope a = p/q generating the N-shaped sigmoid was given first by Szu in 1992. In this paper, we simulated the robust and fault-tolerance properties of CNN under additive noise and pattern noise. We also implement a private version of RSA coding and chaos encryption process on messages.

Hypothalamic neurogenesis persists in the aging brain and is controlled by energy-sensing IGF-I pathway.

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Chaker, Zayna; George, Caroline; Petrovska, Marija; Caron, Jean-Baptiste; Lacube, Philippe; Caillé, Isabelle; Holzenberger, Martin

2016-05-01

Hypothalamic tanycytes are specialized glial cells lining the third ventricle. They are recently identified as adult stem and/or progenitor cells, able to self-renew and give rise to new neurons postnatally. However, the long-term neurogenic potential of tanycytes and the pathways regulating lifelong cell replacement in the adult hypothalamus are largely unexplored. Using inducible nestin-CreER(T2) for conditional mutagenesis, we performed lineage tracing of adult hypothalamic stem and/or progenitor cells (HySC) and demonstrated that new neurons continue to be born throughout adult life. This neurogenesis was targeted to numerous hypothalamic nuclei and produced different types of neurons in the dorsal periventricular regions. Some adult-born neurons integrated the median eminence and arcuate nucleus during aging and produced growth hormone releasing hormone. We showed that adult hypothalamic neurogenesis was tightly controlled by insulin-like growth factors (IGF). Knockout of IGF-1 receptor from hypothalamic stem and/or progenitor cells increased neuronal production and enhanced α-tanycyte self-renewal, preserving this stem cell-like population from age-related attrition. Our data indicate that adult hypothalamus retains the capacity of cell renewal, and thus, a substantial degree of structural plasticity throughout lifespan. Copyright © 2016 Elsevier Inc. All rights reserved.

Neural systems supporting and affecting economically relevant behavior

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Braeutigam S

2012-05-01

Full Text Available Sven BraeutigamOxford Centre for Human Brain Activity, University of Oxford, Oxford, United KingdomAbstract: For about a hundred years, theorists and traders alike have tried to unravel and understand the mechanisms and hidden rules underlying and perhaps determining economically relevant behavior. This review focuses on recent developments in neuroeconomics, where the emphasis is placed on two directions of research: first, research exploiting common experiences of urban inhabitants in industrialized societies to provide experimental paradigms with a broader real-life content; second, research based on behavioral genetics, which provides an additional dimension for experimental control and manipulation. In addition, possible limitations of state-of-the-art neuroeconomics research are addressed. It is argued that observations of neuronal systems involved in economic behavior converge to some extent across the technologies and paradigms used. Conceptually, the data available as of today raise the possibility that neuroeconomic research might provide evidence at the neuronal level for the existence of multiple systems of thought and for the importance of conflict. Methodologically, Bayesian approaches in particular may play an important role in identifying mechanisms and establishing causality between patterns of neural activity and economic behavior.Keywords: neuroeconomics, behavioral genetics, decision-making, consumer behavior, neural system

Artificial frame filling using adaptive neural fuzzy inference system for particle image velocimetry dataset

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Akdemir, Bayram; Doǧan, Sercan; Aksoy, Muharrem H.; Canli, Eyüp; Özgören, Muammer

2015-03-01

Liquid behaviors are very important for many areas especially for Mechanical Engineering. Fast camera is a way to observe and search the liquid behaviors. Camera traces the dust or colored markers travelling in the liquid and takes many pictures in a second as possible as. Every image has large data structure due to resolution. For fast liquid velocity, there is not easy to evaluate or make a fluent frame after the taken images. Artificial intelligence has much popularity in science to solve the nonlinear problems. Adaptive neural fuzzy inference system is a common artificial intelligence in literature. Any particle velocity in a liquid has two dimension speed and its derivatives. Adaptive Neural Fuzzy Inference System has been used to create an artificial frame between previous and post frames as offline. Adaptive neural fuzzy inference system uses velocities and vorticities to create a crossing point vector between previous and post points. In this study, Adaptive Neural Fuzzy Inference System has been used to fill virtual frames among the real frames in order to improve image continuity. So this evaluation makes the images much understandable at chaotic or vorticity points. After executed adaptive neural fuzzy inference system, the image dataset increase two times and has a sequence as virtual and real, respectively. The obtained success is evaluated using R2 testing and mean squared error. R2 testing has a statistical importance about similarity and 0.82, 0.81, 0.85 and 0.8 were obtained for velocities and derivatives, respectively.

An Improved Recurrent Neural Network for Complex-Valued Systems of Linear Equation and Its Application to Robotic Motion Tracking.

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Ding, Lei; Xiao, Lin; Liao, Bolin; Lu, Rongbo; Peng, Hua

2017-01-01

To obtain the online solution of complex-valued systems of linear equation in complex domain with higher precision and higher convergence rate, a new neural network based on Zhang neural network (ZNN) is investigated in this paper. First, this new neural network for complex-valued systems of linear equation in complex domain is proposed and theoretically proved to be convergent within finite time. Then, the illustrative results show that the new neural network model has the higher precision and the higher convergence rate, as compared with the gradient neural network (GNN) model and the ZNN model. Finally, the application for controlling the robot using the proposed method for the complex-valued systems of linear equation is realized, and the simulation results verify the effectiveness and superiorness of the new neural network for the complex-valued systems of linear equation.

Command Filtered Adaptive Fuzzy Neural Network Backstepping Control for Marine Power System

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Xin Zhang

2014-01-01

Full Text Available In order to retrain chaotic oscillation of marine power system which is excited by periodic electromagnetism perturbation, a novel command-filtered adaptive fuzzy neural network backstepping control method is designed. First, the mathematical model of marine power system is established based on the two parallel nonlinear model. Then, main results of command-filtered adaptive fuzzy neural network backstepping control law are given. And the Lyapunov stability theory is applied to prove that the system can remain closed-loop asymptotically stable with this controller. Finally, simulation results indicate that the designed controller can suppress chaotic oscillation with fast convergence speed that makes the system return to the equilibrium point quickly; meanwhile, the parameter which induces chaotic oscillation can also be discriminated.

Silicon synaptic transistor for hardware-based spiking neural network and neuromorphic system

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Kim, Hyungjin; Hwang, Sungmin; Park, Jungjin; Park, Byung-Gook

2017-10-01

Brain-inspired neuromorphic systems have attracted much attention as new computing paradigms for power-efficient computation. Here, we report a silicon synaptic transistor with two electrically independent gates to realize a hardware-based neural network system without any switching components. The spike-timing dependent plasticity characteristics of the synaptic devices are measured and analyzed. With the help of the device model based on the measured data, the pattern recognition capability of the hardware-based spiking neural network systems is demonstrated using the modified national institute of standards and technology handwritten dataset. By comparing systems with and without inhibitory synapse part, it is confirmed that the inhibitory synapse part is an essential element in obtaining effective and high pattern classification capability.

Vertical sleeve gastrectomy reduces blood pressure and hypothalamic endoplasmic reticulum stress in mice

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Anne K. McGavigan

2017-03-01

Full Text Available Bariatric surgery, such as vertical sleeve gastrectomy (VSG, causes remarkable improvements in cardiometabolic health, including hypertension remission. However, the mechanisms responsible remain undefined and poorly studied. Therefore, we developed and validated the first murine model of VSG that recapitulates the blood pressure-lowering effect of VSG using gold-standard radiotelemetry technology. We used this model to investigate several potential mechanisms, including body mass, brain endoplasmic reticulum (ER stress signaling and brain inflammatory signaling, which are all critical contributors to the pathogenesis of obesity-associated hypertension. Mice fed on a high-fat diet underwent sham or VSG surgery and radiotelemeter implantation. Sham mice were fed ad libitum or were food restricted to match their body mass to VSG-operated mice to determine the role of body mass in the ability of VSG to lower blood pressure. Blood pressure was then measured in freely moving unstressed mice by radiotelemetry. VSG decreased energy intake, body mass and fat mass. Mean arterial blood pressure (MAP was reduced in VSG-operated mice compared with both sham-operated groups. VSG-induced reductions in MAP were accompanied by a body mass-independent decrease in hypothalamic ER stress, hypothalamic inflammation and sympathetic nervous system tone. Assessment of gut microbial populations revealed VSG-induced increases in the relative abundance of Gammaproteobacteria and Enterococcus, and decreases in Adlercreutzia. These results suggest that VSG reduces blood pressure, but this is only partly due to the reduction in body weight. VSG-induced reductions in blood pressure may be driven by a decrease in hypothalamic ER stress and inflammatory signaling, and shifts in gut microbial populations.

A neural network method for solving a system of linear variational inequalities

International Nuclear Information System (INIS)

Lan Hengyou; Cui Yishun

2009-01-01

In this paper, we transmute the solution for a new system of linear variational inequalities to an equilibrium point of neural networks, and by using analytic technique, some sufficient conditions are presented. Further, the estimation of the exponential convergence rates of the neural networks is investigated. The new and useful results obtained in this paper generalize and improve the corresponding results of recent works.

The Influence of Palatable Diets in Reward System Activation: A Mini Review

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Isabel Cristina de Macedo

2016-01-01

Full Text Available The changes in eating patterns that have occurred in recent decades are an important cause of obesity. Food intake and energy expenditure are controlled by a complex neural system involving the hypothalamic centers and peripheral satiety system (gastrointestinal and pancreatic hormones. Highly palatable and caloric food disrupts appetite regulation; however, palatable foods induce pleasure and reward. The cafeteria diet is such a palatable diet and has been shown consistently to increase body weight and induce hyperplasia in animal obesity models. Moreover, palatable high-fat foods (such as those of the cafeteria diet can induce addiction-like deficits in brain reward function and are considered to be an important source of motivation that might drive overeating and contribute to the development of obesity. The mechanism of neural adaptation triggered by palatable foods is similar to those that have been reported for nondrug addictions and long-term drug use. Thus, this review attempts to describe the potential mechanisms that might lead to highly palatable diets, such as the cafeteria diet, triggering addiction, or compulsion through the reward system.

Leptin inhibits and ghrelin augments hypothalamic noradrenaline release after stress.

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Kawakami, Akio; Okada, Nobukazu; Rokkaku, Kumiko; Honda, Kazufumi; Ishibashi, Shun; Onaka, Tatsushi

2008-09-01

Metabolic conditions affect hypothalamo-pituitary-adrenal responses to stressful stimuli. Here we examined effects of food deprivation, leptin and ghrelin upon noradrenaline release in the hypothalamic paraventricular nucleus (PVN) and plasma adrenocorticotropic hormone (ACTH) concentrations after stressful stimuli. Food deprivation augmented both noradrenaline release in the PVN and the increase in plasma ACTH concentration following electrical footshocks (FSs). An intracerebroventricular injection of leptin attenuated the increases in hypothalamic noradrenaline release and plasma ACTH concentrations after FSs, while ghrelin augmented these responses. These data suggest that leptin inhibits and ghrelin facilitates neuroendocrine stress responses via noradrenaline release and indicate that a decrease in leptin and an increase in ghrelin release after food deprivation might contribute to augmentation of stress-induced ACTH release in a fasting state.

Glucose regulates hypothalamic long-chain fatty acid metabolism via AMP-activated kinase (AMPK) in neurons and astrocytes.

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Taïb, Bouchra; Bouyakdan, Khalil; Hryhorczuk, Cécile; Rodaros, Demetra; Fulton, Stephanie; Alquier, Thierry

2013-12-27

Hypothalamic controls of energy balance rely on the detection of circulating nutrients such as glucose and long-chain fatty acids (LCFA) by the mediobasal hypothalamus (MBH). LCFA metabolism in the MBH plays a key role in the control of food intake and glucose homeostasis, yet it is not known if glucose regulates LCFA oxidation and esterification in the MBH and, if so, which hypothalamic cell type(s) and intracellular signaling mechanisms are involved. The aim of this study was to determine the impact of glucose on LCFA metabolism, assess the role of AMP-activated Kinase (AMPK), and to establish if changes in LCFA metabolism and its regulation by glucose vary as a function of the kind of LCFA, cell type, and brain region. We show that glucose inhibits palmitate oxidation via AMPK in hypothalamic neuronal cell lines, primary hypothalamic astrocyte cultures, and MBH slices ex vivo but not in cortical astrocytes and slice preparations. In contrast, oleate oxidation was not affected by glucose or AMPK inhibition in MBH slices. In addition, our results show that glucose increases palmitate, but not oleate, esterification into neutral lipids in neurons and MBH slices but not in hypothalamic astrocytes. These findings reveal for the first time the metabolic fate of different LCFA in the MBH, demonstrate AMPK-dependent glucose regulation of LCFA oxidation in both astrocytes and neurons, and establish metabolic coupling of glucose and LCFA as a distinguishing feature of hypothalamic nuclei critical for the control of energy balance.

Anomaly Detection for Resilient Control Systems Using Fuzzy-Neural Data Fusion Engine

Energy Technology Data Exchange (ETDEWEB)

Ondrej Linda; Milos Manic; Timothy R. McJunkin

2011-08-01

Resilient control systems in critical infrastructures require increased cyber-security and state-awareness. One of the necessary conditions for achieving the desired high level of resiliency is timely reporting and understanding of the status and behavioral trends of the control system. This paper describes the design and development of a neural-network based data-fusion system for increased state-awareness of resilient control systems. The proposed system consists of a dedicated data-fusion engine for each component of the control system. Each data-fusion engine implements three-layered alarm system consisting of: (1) conventional threshold-based alarms, (2) anomalous behavior detector using self-organizing maps, and (3) prediction error based alarms using neural network based signal forecasting. The proposed system was integrated with a model of the Idaho National Laboratory Hytest facility, which is a testing facility for hybrid energy systems. Experimental results demonstrate that the implemented data fusion system provides timely plant performance monitoring and cyber-state reporting.

Selected Flight Test Results for Online Learning Neural Network-Based Flight Control System

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Williams-Hayes, Peggy S.

2004-01-01

The NASA F-15 Intelligent Flight Control System project team developed a series of flight control concepts designed to demonstrate neural network-based adaptive controller benefits, with the objective to develop and flight-test control systems using neural network technology to optimize aircraft performance under nominal conditions and stabilize the aircraft under failure conditions. This report presents flight-test results for an adaptive controller using stability and control derivative values from an online learning neural network. A dynamic cell structure neural network is used in conjunction with a real-time parameter identification algorithm to estimate aerodynamic stability and control derivative increments to baseline aerodynamic derivatives in flight. This open-loop flight test set was performed in preparation for a future phase in which the learning neural network and parameter identification algorithm output would provide the flight controller with aerodynamic stability and control derivative updates in near real time. Two flight maneuvers are analyzed - pitch frequency sweep and automated flight-test maneuver designed to optimally excite the parameter identification algorithm in all axes. Frequency responses generated from flight data are compared to those obtained from nonlinear simulation runs. Flight data examination shows that addition of flight-identified aerodynamic derivative increments into the simulation improved aircraft pitch handling qualities.

The role of neural networks in nuclear power plant safety systems

International Nuclear Information System (INIS)

Boger, Z.

1993-01-01

Neural networks (NN) techniques have been applied in recent years to many systems by researchers in the nuclear power industry, mainly for modeling and sensor validation. Recent results are reviewed, including new directions in applications to control systems, safety analysis, and ''virtual'' instruments. As new fast learning algorithms become available, large systems may be learned effectively, even with few training examples. The nuclear industry hesitates to include NN in safety related systems, but it seems that the obstacles could be overcome with the demonstration of successful applications, even from other industries. Coupling of full-scale reactor simulators, as fault database generators, with neural networks learning should be explored. The integration of Expert System technology with NN should improve the Validation and Verification tasks, and also help overcome psychological barriers. It may prove that the potential of NN to help operators, compared with the existing and proposed alternatives, outweigh the risks. (author). 58 refs, 2 figs

An Implantable Wireless Neural Interface System for Simultaneous Recording and Stimulation of Peripheral Nerve with a Single Cuff Electrode.

Science.gov (United States)

Shon, Ahnsei; Chu, Jun-Uk; Jung, Jiuk; Kim, Hyungmin; Youn, Inchan

2017-12-21

Recently, implantable devices have become widely used in neural prostheses because they eliminate endemic drawbacks of conventional percutaneous neural interface systems. However, there are still several issues to be considered: low-efficiency wireless power transmission; wireless data communication over restricted operating distance with high power consumption; and limited functionality, working either as a neural signal recorder or as a stimulator. To overcome these issues, we suggest a novel implantable wireless neural interface system for simultaneous neural signal recording and stimulation using a single cuff electrode. By using widely available commercial off-the-shelf (COTS) components, an easily reconfigurable implantable wireless neural interface system was implemented into one compact module. The implantable device includes a wireless power consortium (WPC)-compliant power transmission circuit, a medical implant communication service (MICS)-band-based radio link and a cuff-electrode path controller for simultaneous neural signal recording and stimulation. During in vivo experiments with rabbit models, the implantable device successfully recorded and stimulated the tibial and peroneal nerves while communicating with the external device. The proposed system can be modified for various implantable medical devices, especially such as closed-loop control based implantable neural prostheses requiring neural signal recording and stimulation at the same time.

An Implantable Wireless Neural Interface System for Simultaneous Recording and Stimulation of Peripheral Nerve with a Single Cuff Electrode

Directory of Open Access Journals (Sweden)

Ahnsei Shon

2017-12-01

Full Text Available Recently, implantable devices have become widely used in neural prostheses because they eliminate endemic drawbacks of conventional percutaneous neural interface systems. However, there are still several issues to be considered: low-efficiency wireless power transmission; wireless data communication over restricted operating distance with high power consumption; and limited functionality, working either as a neural signal recorder or as a stimulator. To overcome these issues, we suggest a novel implantable wireless neural interface system for simultaneous neural signal recording and stimulation using a single cuff electrode. By using widely available commercial off-the-shelf (COTS components, an easily reconfigurable implantable wireless neural interface system was implemented into one compact module. The implantable device includes a wireless power consortium (WPC-compliant power transmission circuit, a medical implant communication service (MICS-band-based radio link and a cuff-electrode path controller for simultaneous neural signal recording and stimulation. During in vivo experiments with rabbit models, the implantable device successfully recorded and stimulated the tibial and peroneal nerves while communicating with the external device. The proposed system can be modified for various implantable medical devices, especially such as closed-loop control based implantable neural prostheses requiring neural signal recording and stimulation at the same time.

Stress responsiveness of the hypothalamic-pituitary-adrenal axis: age-related features of the vasopressinergic regulation

Directory of Open Access Journals (Sweden)

Nadezhda Dmitrievna Goncharova

2013-03-01

Full Text Available The hypothalamic-pituitary-adrenal (HPA axis plays a key role in adaptation to environmental stresses. Parvicellular neurons of the hypothalamic paraventricular nucleus secrete corticotrophin releasing hormone (CRH and arginine vasopressin (AVP into pituitary portal system; CRH and AVP stimulate ACTH release through specific G protein-coupled membrane receptors on pituitary corticotrophs, CRH1 for CRH and V1b for AVP; the adrenal gland cortex secretes glucocorticoids in response ACTH. The glucocorticoids activate specific receptors in brain and peripheral tissues thereby triggering the necessary metabolic, immune, neuromodulatory and behavioral changes to resist stress. While importance of CRH, as a key hypothalamic factor of HPA axis regulation in basal and stress conditions in most species, is generally recognized, role of AVP remains to be clarified. This review focuses on the role of AVP in the regulation of stress responsiveness of the HPA axis with emphasis on the effects of aging on vasopressinergic regulation of HPA axis stress responsiveness. Under most of the known stressors, AVP is necessary for acute ACTH secretion but in a context-specific manner. The current data on the AVP role in regulation of HPA responsiveness to chronic stress in adulthood are rather contradictory. The importance of the vasopressinergic regulation of the HPA stress responsiveness is greatest during fetal development, in neonatal period, and in the lactating adult. Aging associated with increased variability in several parameters of HPA function including basal state, responsiveness to stressors, and special testing. Reports on the possible role of the AVP/V1b receptor system in the increase of HPA axis hyperactivity with aging are contradictory and requires further research. Many contradictory results may be due to age and species differences in the HPA function of rodents and primates.

An artificial neural network for modeling reliability, availability and maintainability of a repairable system

International Nuclear Information System (INIS)

Rajpal, P.S.; Shishodia, K.S.; Sekhon, G.S.

2006-01-01

The paper explores the application of artificial neural networks to model the behaviour of a complex, repairable system. A composite measure of reliability, availability and maintainability parameters has been proposed for measuring the system performance. The artificial neural network has been trained using past data of a helicopter transportation facility. It is used to simulate behaviour of the facility under various constraints. The insights obtained from results of simulation are useful in formulating strategies for optimal operation of the system

Neural network application to aircraft control system design

Science.gov (United States)

Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

1991-01-01

The feasibility of using artificial neural network as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research identified to enhance the practical applicability of neural networks to flight control design.

Neural network application to aircraft control system design

Science.gov (United States)

Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

1991-01-01

The feasibility of using artificial neural networks as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research are identified to enhance the practical applicability of neural networks to flight control design.

Neural networks

International Nuclear Information System (INIS)

Denby, Bruce; Lindsey, Clark; Lyons, Louis

1992-01-01

The 1980s saw a tremendous renewal of interest in 'neural' information processing systems, or 'artificial neural networks', among computer scientists and computational biologists studying cognition. Since then, the growth of interest in neural networks in high energy physics, fueled by the need for new information processing technologies for the next generation of high energy proton colliders, can only be described as explosive

A wireless transmission neural interface system for unconstrained non-human primates.

Science.gov (United States)

Fernandez-Leon, Jose A; Parajuli, Arun; Franklin, Robert; Sorenson, Michael; Felleman, Daniel J; Hansen, Bryan J; Hu, Ming; Dragoi, Valentin

2015-10-01

Studying the brain in large animal models in a restrained laboratory rig severely limits our capacity to examine brain circuits in experimental and clinical applications. To overcome these limitations, we developed a high-fidelity 96-channel wireless system to record extracellular spikes and local field potentials from the neocortex. A removable, external case of the wireless device is attached to a titanium pedestal placed in the animal skull. Broadband neural signals are amplified, multiplexed, and continuously transmitted as TCP/IP data at a sustained rate of 24 Mbps. A Xilinx Spartan 6 FPGA assembles the digital signals into serial data frames for transmission at 20 kHz though an 802.11n wireless data link on a frequency-shift key-modulated signal at 5.7-5.8 GHz to a receiver up to 10 m away. The system is powered by two CR123A, 3 V batteries for 2 h of operation. We implanted a multi-electrode array in visual area V4 of one anesthetized monkey (Macaca fascicularis) and in the dorsolateral prefrontal cortex (dlPFC) of a freely moving monkey (Macaca mulatta). The implanted recording arrays were electrically stable and delivered broadband neural data over a year of testing. For the first time, we compared dlPFC neuronal responses to the same set of stimuli (food reward) in restrained and freely moving conditions. Although we did not find differences in neuronal responses as a function of reward type in the restrained and unrestrained conditions, there were significant differences in correlated activity. This demonstrates that measuring neural responses in freely moving animals can capture phenomena that are absent in the traditional head-fixed paradigm. We implemented a wireless neural interface for multi-electrode recordings in freely moving non-human primates, which can potentially move systems neuroscience to a new direction by allowing one to record neural signals while animals interact with their environment.

A wireless transmission neural interface system for unconstrained non-human primates

Science.gov (United States)

Fernandez-Leon, Jose A.; Parajuli, Arun; Franklin, Robert; Sorenson, Michael; Felleman, Daniel J.; Hansen, Bryan J.; Hu, Ming; Dragoi, Valentin

2015-10-01

Objective. Studying the brain in large animal models in a restrained laboratory rig severely limits our capacity to examine brain circuits in experimental and clinical applications. Approach. To overcome these limitations, we developed a high-fidelity 96-channel wireless system to record extracellular spikes and local field potentials from the neocortex. A removable, external case of the wireless device is attached to a titanium pedestal placed in the animal skull. Broadband neural signals are amplified, multiplexed, and continuously transmitted as TCP/IP data at a sustained rate of 24 Mbps. A Xilinx Spartan 6 FPGA assembles the digital signals into serial data frames for transmission at 20 kHz though an 802.11n wireless data link on a frequency-shift key-modulated signal at 5.7-5.8 GHz to a receiver up to 10 m away. The system is powered by two CR123A, 3 V batteries for 2 h of operation. Main results. We implanted a multi-electrode array in visual area V4 of one anesthetized monkey (Macaca fascicularis) and in the dorsolateral prefrontal cortex (dlPFC) of a freely moving monkey (Macaca mulatta). The implanted recording arrays were electrically stable and delivered broadband neural data over a year of testing. For the first time, we compared dlPFC neuronal responses to the same set of stimuli (food reward) in restrained and freely moving conditions. Although we did not find differences in neuronal responses as a function of reward type in the restrained and unrestrained conditions, there were significant differences in correlated activity. This demonstrates that measuring neural responses in freely moving animals can capture phenomena that are absent in the traditional head-fixed paradigm. Significance. We implemented a wireless neural interface for multi-electrode recordings in freely moving non-human primates, which can potentially move systems neuroscience to a new direction by allowing one to record neural signals while animals interact with their environment.

Efficient Embedded Decoding of Neural Network Language Models in a Machine Translation System.

Science.gov (United States)

Zamora-Martinez, Francisco; Castro-Bleda, Maria Jose

2018-02-22

Neural Network Language Models (NNLMs) are a successful approach to Natural Language Processing tasks, such as Machine Translation. We introduce in this work a Statistical Machine Translation (SMT) system which fully integrates NNLMs in the decoding stage, breaking the traditional approach based on [Formula: see text]-best list rescoring. The neural net models (both language models (LMs) and translation models) are fully coupled in the decoding stage, allowing to more strongly influence the translation quality. Computational issues were solved by using a novel idea based on memorization and smoothing of the softmax constants to avoid their computation, which introduces a trade-off between LM quality and computational cost. These ideas were studied in a machine translation task with different combinations of neural networks used both as translation models and as target LMs, comparing phrase-based and [Formula: see text]-gram-based systems, showing that the integrated approach seems more promising for [Formula: see text]-gram-based systems, even with nonfull-quality NNLMs.

Purinergic signaling pathways in endocrine system.

Science.gov (United States)

Bjelobaba, Ivana; Janjic, Marija M; Stojilkovic, Stanko S

2015-09-01

Adenosine-5'-triphosphate is released by neuroendocrine, endocrine, and other cell types and acts as an extracellular agonist for ligand-gated P2X cationic channels and G protein-coupled P2Y receptors in numerous organs and tissues, including the endocrine system. The breakdown of ATP by ectonucleotidases not only terminates its extracellular messenger functions, but also provides a pathway for the generation of two additional agonists: adenosine 5'-diphosphate, acting via some P2Y receptors, and adenosine, a native agonist for G protein-coupled adenosine receptors, also expressed in the endocrine system. This article provides a review of purinergic signaling pathways in the hypothalamic magnocellular neurosecretory cells and neurohypophysis, hypothalamic parvocellular neuroendocrine system, adenohypophysis, and effector glands organized in five axes: hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid, hypothalamic-pituitary-adrenal, hypothalamic-pituitary-growth hormone, and hypothalamic-pituitary-prolactin. We attempted to summarize current knowledge of purinergic receptor subtypes expressed in the endocrine system, including their roles in intracellular signaling, hormone secretion, and other cell functions. We also briefly review the release mechanism for adenosine-5'-triphosphate by neuroendocrine, endocrine and surrounding cells, the enzymes involved in adenosine-5'-triphosphate hydrolysis to adenosine-5'-diphosphate and adenosine, and the relevance of this pathway for sequential activation of receptors and termination of signaling. Published by Elsevier B.V.

Purinergic Signaling Pathways in Endocrine System

Science.gov (United States)

Bjelobaba, Ivana; Janjic, Marija M.; Stojilkovic, Stanko S.

2015-01-01

Adenosine-5′-triphosphate is released by neuroendocrine, endocrine, and other cell types and acts as an extracellular agonist for ligand-gated P2X cationic channels and G protein-coupled P2Y receptors in numerous organs and tissues, including the endocrine system. The breakdown of ATP by ectonucleotidases not only terminates its extracellular messenger functions, but also provides a pathway for the generation of two additional agonists: adenosine 5′-diphosphate, acting via some P2Y receptors, and adenosine, a native agonist for G protein-coupled adenosine receptors, also expressed in the endocrine system. This article provides a review of purinergic signaling pathways in the hypothalamic magnocellular neurosecretory cells and neurohypophysis, hypothalamic parvocellular neuroendocrine system, adenohypophysis, and effector glands organized in five axes: hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid, hypothalamic-pituitary-adrenal, hypothalamic-pituitary-growth hormone, and hypothalamic-pituitary-prolactin. We attempted to summarize current knowledge of purinergic receptor subtypes expressed in the endocrine system, including their roles in intracellular signaling, hormone secretion, and other cell functions. We also briefly review the release mechanism for adenosine-5′-triphosphate by neuroendocrine, endocrine and surrounding cells, the enzymes involved in adenosine-5′-triphosphate hydrolysis to adenosine-5′-diphosphate and adenosine, and the relevance of this pathway for sequential activation of receptors and termination of signaling. PMID:25960051

Anorexia and Impaired Glucose Metabolism in Mice With Hypothalamic Ablation of Glut4 Neurons

OpenAIRE

Ren, Hongxia; Lu, Taylor Y.; McGraw, Timothy E.; Accili, Domenico

2014-01-01

The central nervous system (CNS) uses glucose independent of insulin. Nonetheless, insulin receptors and insulin-responsive glucose transporters (Glut4) often colocalize in neurons (Glut4 neurons) in anatomically and functionally distinct areas of the CNS. The apparent heterogeneity of Glut4 neurons has thus far thwarted attempts to understand their function. To answer this question, we used Cre-dependent, diphtheria toxin?mediated cell ablation to selectively remove basal hypothalamic Glut4 ...

Neural-network-directed alignment of optical systems using the laser-beam spatial filter as an example

Science.gov (United States)

Decker, Arthur J.; Krasowski, Michael J.; Weiland, Kenneth E.

1993-01-01

This report describes an effort at NASA Lewis Research Center to use artificial neural networks to automate the alignment and control of optical measurement systems. Specifically, it addresses the use of commercially available neural network software and hardware to direct alignments of the common laser-beam-smoothing spatial filter. The report presents a general approach for designing alignment records and combining these into training sets to teach optical alignment functions to neural networks and discusses the use of these training sets to train several types of neural networks. Neural network configurations used include the adaptive resonance network, the back-propagation-trained network, and the counter-propagation network. This work shows that neural networks can be used to produce robust sequencers. These sequencers can learn by example to execute the step-by-step procedures of optical alignment and also can learn adaptively to correct for environmentally induced misalignment. The long-range objective is to use neural networks to automate the alignment and operation of optical measurement systems in remote, harsh, or dangerous aerospace environments. This work also shows that when neural networks are trained by a human operator, training sets should be recorded, training should be executed, and testing should be done in a manner that does not depend on intellectual judgments of the human operator.

Neural feedback linearization adaptive control for affine nonlinear systems based on neural network estimator

Directory of Open Access Journals (Sweden)

Bahita Mohamed

2011-01-01

Full Text Available In this work, we introduce an adaptive neural network controller for a class of nonlinear systems. The approach uses two Radial Basis Functions, RBF networks. The first RBF network is used to approximate the ideal control law which cannot be implemented since the dynamics of the system are unknown. The second RBF network is used for on-line estimating the control gain which is a nonlinear and unknown function of the states. The updating laws for the combined estimator and controller are derived through Lyapunov analysis. Asymptotic stability is established with the tracking errors converging to a neighborhood of the origin. Finally, the proposed method is applied to control and stabilize the inverted pendulum system.

Leptin regulates glutamate and glucose transporters in hypothalamic astrocytes

Science.gov (United States)

Fuente-Martín, Esther; García-Cáceres, Cristina; Granado, Miriam; de Ceballos, María L.; Sánchez-Garrido, Miguel Ángel; Sarman, Beatrix; Liu, Zhong-Wu; Dietrich, Marcelo O.; Tena-Sempere, Manuel; Argente-Arizón, Pilar; Díaz, Francisca; Argente, Jesús; Horvath, Tamas L.; Chowen, Julie A.

2012-01-01

Glial cells perform critical functions that alter the metabolism and activity of neurons, and there is increasing interest in their role in appetite and energy balance. Leptin, a key regulator of appetite and metabolism, has previously been reported to influence glial structural proteins and morphology. Here, we demonstrate that metabolic status and leptin also modify astrocyte-specific glutamate and glucose transporters, indicating that metabolic signals influence synaptic efficacy and glucose uptake and, ultimately, neuronal function. We found that basal and glucose-stimulated electrical activity of hypothalamic proopiomelanocortin (POMC) neurons in mice were altered in the offspring of mothers fed a high-fat diet. In adulthood, increased body weight and fasting also altered the expression of glucose and glutamate transporters. These results demonstrate that whole-organism metabolism alters hypothalamic glial cell activity and suggest that these cells play an important role in the pathology of obesity. PMID:23064363

Supraependymal cells of hypothalamic third ventricle: identification as resident phagocytes of the brain.

Science.gov (United States)

Bleier, R; Albrecht, R; Cruce, J A

1975-07-25

Cells lying on the ventricular surface of the hypothalamic ependyma of the tegu lizard exhibit the pseudopodial and flaplike processes characteristic of macrophages found elsewhere. Since they ingest latex beads, they may be considered a resident phagocytic system of the brain. The importance of ependyma and ventricular phagocytes as a first line of defense against viral invasion of the brain, as well as their role in the pathogenesis of certain virus-related diseases, is suggested by a number of experimental and clinical observations.

Neural net based determination of generator-shedding requirements in electric power systems

Energy Technology Data Exchange (ETDEWEB)

Djukanovic, M [Electrical Engineering Inst. ' Nikola Tesla' , Belgrade (Yugoslavia); Sobajic, D J; Pao, Y -H [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Electrical Engineering and Applied Physics Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Computer Engineering and Science AI WARE Inc., Cleveland, OH (United States)

1992-09-01

This paper presents an application of artificial neural networks (ANN) in support of a decision-making process by power system operators directed towards the fast stabilisation of multi-machine systems. The proposed approach considers generator shedding as the most effective discrete supplementary control for improving the dynamic performance of faulted power systems and preventing instabilities. The sensitivity of the transient energy function (TEF) with respect to changes in the amount of dropped generation is used during the training phase of ANNs to assess the critical amount of generator shedding required to prevent the loss of synchronism. The learning capabilities of neural nets are used to establish complex mappings between fault information and the amount of generation to be shed, suggesting it as the control signal to the power system operator. (author)

Towards an Irritable Bowel Syndrome Control System Based on Artificial Neural Networks

Science.gov (United States)

Podolski, Ina; Rettberg, Achim

To solve health problems with medical applications that use complex algorithms is a trend nowadays. It could also be a chance to help patients with critical problems caused from nerve irritations to overcome them and provide a better living situation. In this paper a system for monitoring and controlling the nerves from the intestine is described on a theoretical basis. The presented system could be applied to the irritable bowel syndrome. For control a neural network is used. The advantages for using a neural network for the control of irritable bowel syndrome are the adaptation and learning. These two aspects are important because the syndrome behavior varies from patient to patient and have also concerning the time a lot of variations with respect to each patient. The developed neural network is implemented and can be simulated. Therefore, it can be shown how the network monitor and control the nerves for individual input parameters.

Developing and using expert systems and neural networks in medicine: a review on benefits and challenges.

Science.gov (United States)

Sheikhtaheri, Abbas; Sadoughi, Farahnaz; Hashemi Dehaghi, Zahra

2014-09-01

Complicacy of clinical decisions justifies utilization of information systems such as artificial intelligence (e.g. expert systems and neural networks) to achieve better decisions, however, application of these systems in the medical domain faces some challenges. We aimed at to review the applications of these systems in the medical domain and discuss about such challenges. Following a brief introduction of expert systems and neural networks by representing few examples, the challenges of these systems in the medical domain are discussed. We found that the applications of expert systems and artificial neural networks have been increased in the medical domain. These systems have shown many advantages such as utilization of experts' knowledge, gaining rare knowledge, more time for assessment of the decision, more consistent decisions, and shorter decision-making process. In spite of all these advantages, there are challenges ahead of developing and using such systems including maintenance, required experts, inputting patients' data into the system, problems for knowledge acquisition, problems in modeling medical knowledge, evaluation and validation of system performance, wrong recommendations and responsibility, limited domains of such systems and necessity of integrating such systems into the routine work flows. We concluded that expert systems and neural networks can be successfully used in medicine; however, there are many concerns and questions to be answered through future studies and discussions.

Neural network based system for script identification in Indian ...

Indian Academy of Sciences (India)

2016-08-26

Aug 26, 2016 ... The paper describes a neural network-based script identification system which can be used in the machine reading of documents written in English, Hindi and Kannada language scripts. Script identification is a basic requirement in automation of document processing, in multi-script, multi-lingual ...

A neurally inspired musical instrument classification system based upon the sound onset.

Science.gov (United States)

Newton, Michael J; Smith, Leslie S

2012-06-01

Physiological evidence suggests that sound onset detection in the auditory system may be performed by specialized neurons as early as the cochlear nucleus. Psychoacoustic evidence shows that the sound onset can be important for the recognition of musical sounds. Here the sound onset is used in isolation to form tone descriptors for a musical instrument classification task. The task involves 2085 isolated musical tones from the McGill dataset across five instrument categories. A neurally inspired tone descriptor is created using a model of the auditory system's response to sound onset. A gammatone filterbank and spiking onset detectors, built from dynamic synapses and leaky integrate-and-fire neurons, create parallel spike trains that emphasize the sound onset. These are coded as a descriptor called the onset fingerprint. Classification uses a time-domain neural network, the echo state network. Reference strategies, based upon mel-frequency cepstral coefficients, evaluated either over the whole tone or only during the sound onset, provide context to the method. Classification success rates for the neurally-inspired method are around 75%. The cepstral methods perform between 73% and 76%. Further testing with tones from the Iowa MIS collection shows that the neurally inspired method is considerably more robust when tested with data from an unrelated dataset.

Glucose Regulates Hypothalamic Long-chain Fatty Acid Metabolism via AMP-activated Kinase (AMPK) in Neurons and Astrocytes*

Science.gov (United States)

Taïb, Bouchra; Bouyakdan, Khalil; Hryhorczuk, Cécile; Rodaros, Demetra; Fulton, Stephanie; Alquier, Thierry

2013-01-01

Hypothalamic controls of energy balance rely on the detection of circulating nutrients such as glucose and long-chain fatty acids (LCFA) by the mediobasal hypothalamus (MBH). LCFA metabolism in the MBH plays a key role in the control of food intake and glucose homeostasis, yet it is not known if glucose regulates LCFA oxidation and esterification in the MBH and, if so, which hypothalamic cell type(s) and intracellular signaling mechanisms are involved. The aim of this study was to determine the impact of glucose on LCFA metabolism, assess the role of AMP-activated Kinase (AMPK), and to establish if changes in LCFA metabolism and its regulation by glucose vary as a function of the kind of LCFA, cell type, and brain region. We show that glucose inhibits palmitate oxidation via AMPK in hypothalamic neuronal cell lines, primary hypothalamic astrocyte cultures, and MBH slices ex vivo but not in cortical astrocytes and slice preparations. In contrast, oleate oxidation was not affected by glucose or AMPK inhibition in MBH slices. In addition, our results show that glucose increases palmitate, but not oleate, esterification into neutral lipids in neurons and MBH slices but not in hypothalamic astrocytes. These findings reveal for the first time the metabolic fate of different LCFA in the MBH, demonstrate AMPK-dependent glucose regulation of LCFA oxidation in both astrocytes and neurons, and establish metabolic coupling of glucose and LCFA as a distinguishing feature of hypothalamic nuclei critical for the control of energy balance. PMID:24240094

[The hypothalamic-pituitary-adrenal axis and depressive disorder: recent progress].

Science.gov (United States)

Kunugi, Hiroshi; Hori, Hiroaki; Numakawa, Tadahiro; Ota, Miho

2012-08-01

Depression is a stress-induced disorder and there is compelling evidence for the involvement of hypothalamic-pituitary-adrenal (HPA) axis abnormalities in the disease. Chronic hyperactivity of the HPA axis and resultant excessive glucocorticoid (hypercortisolism) may be causal to depression. We demonstrated that the dexamethasone (DEX)/CRH test is a sensitive state-dependent marker to monitor HPA axis abnormalities. Restoration from HPA axis abnormalities occurs with clinical responses to treatment. Brain-derived neurotrophic factor (BDNF) has also been implicated in depression. We found that glucocorticoid (DEX) suppresses BDNF-induced dendrite outgrowth and synaptic formation via blocking the MAPK pathway in early-developing cultured hippocampal neurons. Furthermore, we demonstrated that glucocorticoid receptor (GR) and TrkB (a specific receptor of BDNF) interact and that DEX acutely suppresses BDNF-induced glutamate release by affecting the PLC-gamma pathway in cultured cortical neurons, indicating a mechanism underlying the effect of excessive glucocorticoid on BDNF function and resultant damage in cortical neurons. In a macroscopic view using magnetic resonance imaging (MRI), we found that individuals with hypercortisolism detected by the DEX/CRH test demonstrated volume loss in gray matter and reduced neural network assessed with diffusion tensor imaging in several brain regions. Finally, we observed that individuals with hypocortisolism detected by the DEX/CRH test tend to present more distress symptoms, maladaptive coping styles, and schizotypal personality traits than their counterparts, which points to the important role of hypocortisolism as well as hypercortisolism in depression spectrum disorders.

Stellar Image Interpretation System using Artificial Neural Networks: Unipolar Function Case

Directory of Open Access Journals (Sweden)

F. I. Younis

2001-01-01

Full Text Available An artificial neural network based system for interpreting astronomical images has been developed. The system is based on feed-forward Artificial Neural Networks (ANNs with error back-propagation learning. Knowledge about images of stars, cosmic ray events and noise found in images is used to prepare two sets of input patterns to train and test our approach. The system has been developed and implemented to scan astronomical digital images in order to segregate stellar images from other entities. It has been coded in C language for users of personal computers. An astronomical image of a star cluster from other objects is undertaken as a test case. The obtained results are found to be in very good agreement with those derived from the DAOPHOTII package, which is widely used in the astronomical community. It is proved that our system is simpler, much faster and more reliable. Moreover, no prior knowledge, or initial data from the frame to be analysed is required.

The association between the hypothalamic pituitary adrenal axis and tryptophan metabolism in persons with recurrent major depressive disorder and healthy controls

NARCIS (Netherlands)

Sorgdrager, F. J. H.; Doornbos, B.; Penninx, B. W. J. H.; de Jonge, P.; Kema, I. P.

2017-01-01

Objectives: Persistent changes in serotonergic and hypothalamic pituitary adrenal (HPA) axis functioning are implicated in recurrent types of major depressive disorder (MDD). Systemic tryptophan levels, which influence the rate of serotonin synthesis, are regulated by glucocorticoids produced along

Optimization of workflow scheduling in Utility Management System with hierarchical neural network

Directory of Open Access Journals (Sweden)

Srdjan Vukmirovic

2011-08-01

Full Text Available Grid computing could be the future computing paradigm for enterprise applications, one of its benefits being that it can be used for executing large scale applications. Utility Management Systems execute very large numbers of workflows with very high resource requirements. This paper proposes architecture for a new scheduling mechanism that dynamically executes a scheduling algorithm using feedback about the current status Grid nodes. Two Artificial Neural Networks were created in order to solve the scheduling problem. A case study is created for the Meter Data Management system with measurements from the Smart Metering system for the city of Novi Sad, Serbia. Performance tests show that significant improvement of overall execution time can be achieved by Hierarchical Artificial Neural Networks.

Neural Computations in a Dynamical System with Multiple Time Scales.

Science.gov (United States)

Mi, Yuanyuan; Lin, Xiaohan; Wu, Si

2016-01-01

Neural systems display rich short-term dynamics at various levels, e.g., spike-frequency adaptation (SFA) at the single-neuron level, and short-term facilitation (STF) and depression (STD) at the synapse level. These dynamical features typically cover a broad range of time scales and exhibit large diversity in different brain regions. It remains unclear what is the computational benefit for the brain to have such variability in short-term dynamics. In this study, we propose that the brain can exploit such dynamical features to implement multiple seemingly contradictory computations in a single neural circuit. To demonstrate this idea, we use continuous attractor neural network (CANN) as a working model and include STF, SFA and STD with increasing time constants in its dynamics. Three computational tasks are considered, which are persistent activity, adaptation, and anticipative tracking. These tasks require conflicting neural mechanisms, and hence cannot be implemented by a single dynamical feature or any combination with similar time constants. However, with properly coordinated STF, SFA and STD, we show that the network is able to implement the three computational tasks concurrently. We hope this study will shed light on the understanding of how the brain orchestrates its rich dynamics at various levels to realize diverse cognitive functions.

Neural Stem Cells: Implications for the Conventional Radiotherapy of Central Nervous System Malignancies

International Nuclear Information System (INIS)

Barani, Igor J.; Benedict, Stanley H.; Lin, Peck-Sun

2007-01-01

Advances in basic neuroscience related to neural stem cells and their malignant counterparts are challenging traditional models of central nervous system tumorigenesis and intrinsic brain repair. Neurogenesis persists into adulthood predominantly in two neurogenic centers: subventricular zone and subgranular zone. Subventricular zone is situated adjacent to lateral ventricles and subgranular zone is confined to the dentate gyrus of the hippocampus. Neural stem cells not only self-renew and differentiate along multiple lineages in these regions, but also contribute to intrinsic brain plasticity and repair. Ionizing radiation can depopulate these exquisitely sensitive regions directly or impair in situ neurogenesis by indirect, dose-dependent and inflammation-mediated mechanisms, even at doses <2 Gy. This review discusses the fundamental neural stem cell concepts within the framework of cumulative clinical experience with the treatment of central nervous system malignancies using conventional radiotherapy

Differential requirements for Gli2 and Gli3 in the regional specification of the mouse hypothalamus

Directory of Open Access Journals (Sweden)

Roberta eHaddad-Tóvolli

2015-03-01

Full Text Available Secreted protein Sonic hedgehog (Shh ventralizes the neural tube by modulating the crucial balance between activating and repressing functions (GliA, GliR of transcription factors Gli2 and Gli3. This balance—the Shh-Gli code—is species- and context-dependent and has been elucidated for the mouse spinal cord. The hypothalamus, a forebrain region regulating vital functions like homeostasis and hormone secretion, shows dynamic and intricate Shh expression as well as complex regional differentiation. Here we asked if particular combinations of Gli2 and Gli3 and of GliA and GliR functions contribute to the variety of hypothalamic regions, i.e. we wanted to clarify the hypothalamic version of the Shh-Gli code. Based on mouse mutant analysis, we show that: 1 hypothalamic regional heterogeneity is based in part on differentially stringent requirements for Gli2 or Gli3; 2 another source of diversity are differential requirements for Shh of neural vs non-neural origin; 3 Gli2 is indispensable for the specification of a medial progenitor domain generating several essential hypothalamic nuclei plus the pituitary and median eminence; 4 the suppression of Gli3R by neural and non-neural Shh is essential for hypothalamic specification. Finally, we have mapped our results on a recent model which considers the hypothalamus as a transverse region with alar and basal portions. Our data confirm the model and are explained by it.

Oxytocin and Naltrexone Successfully Treat Hypothalamic Obesity in a Boy Post-Craniopharyngioma Resection.

Science.gov (United States)

Hsu, Eugenie A; Miller, Jennifer L; Perez, Francisco A; Roth, Christian L

2018-02-01

Hypothalamic obesity, a treatment-resistant condition common to survivors of craniopharyngioma (CP), is strongly associated with a poor quality of life in this population. Oxytocin (OT), a hypothalamic neuropeptide, has been shown to play a role in the regulation of energy balance and to have anorexigenic effects in animal studies. Naltrexone (NAL), an opiate antagonist, has been shown to deter hedonic eating and to potentiate OT's effects. In this parent-observed study, we tested the administration of intranasal OT for 10 weeks (phase 1), followed by a combination of intranasal OT and NAL for 38 weeks (phase 2) in a 13-year-old male with confirmed hypothalamic obesity and hyperphagia post-CP resection. Treatment resulted in 1) reduction in body mass index (BMI) z score from 1.77 to 1.49 over 10 weeks during phase 1; 2) reduction in BMI z score from 1.49 to 0.82 over 38 weeks during phase 2; 3) reduced hyperphagia during phases 1 and 2; 4) continued hedonic high-carbohydrate food-seeking in the absence of hunger during phases 1 and 2; and 5) sustained weight reduction during decreased parental monitoring and free access to unlocked food in the home during the last 10 weeks of phase 2. This successful intervention of CP-related hypothalamic obesity and hyperphagia by OT alone and in combination with NAL is promising for conducting future studies of this treatment-recalcitrant form of obesity. Copyright © 2017 Endocrine Society

Neural networks for tracking of unknown SISO discrete-time nonlinear dynamic systems.

Science.gov (United States)

Aftab, Muhammad Saleheen; Shafiq, Muhammad

2015-11-01

This article presents a Lyapunov function based neural network tracking (LNT) strategy for single-input, single-output (SISO) discrete-time nonlinear dynamic systems. The proposed LNT architecture is composed of two feedforward neural networks operating as controller and estimator. A Lyapunov function based back propagation learning algorithm is used for online adjustment of the controller and estimator parameters. The controller and estimator error convergence and closed-loop system stability analysis is performed by Lyapunov stability theory. Moreover, two simulation examples and one real-time experiment are investigated as case studies. The achieved results successfully validate the controller performance. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Hypothalamic gene expression of appetite regulators in a cancer-cachectic mouse model [Dataset 2

OpenAIRE

Dwarkasing, Jvalini; Dijk, Francina J.; Boekschoten, Mark; Faber, Joyce; Argilès, Josep M.; Lavianio, Alessandro; Muller, Michael; Witkamp, Renger; Norren, van, Klaske

2013-01-01

Appetite is frequently affected in cancer patients, leading to anorexia and consequently insufficient food intake. In this study, we report on hypothalamic gene expression profile of a cancer cachectic mouse model with increased food intake. In this model, mice bearing C26 colon adenocarcinoma have an increased food intake subsequently to the loss of body weight. We hypothesize that in this model, appetite regulating systems in the hypothalamus, which apparently fail in anorexia, are still ab...

Hypothalamic gene expression of appetite regulators in a cancer-cachectic mouse model [Dataset 1

OpenAIRE

Dwarkasing, Jvalini; Dijk, Francina J.; Boekschoten, Mark; Faber, Joyce; Argilès, Josep M.; Lavianio, Alessandro; Muller, Michael; Witkamp, Renger; Norren, van, Klaske

2013-01-01

Appetite is frequently affected in cancer patients, leading to anorexia and consequently insufficient food intake. In this study, we report on hypothalamic gene expression profile of a cancer cachectic mouse model with increased food intake. In this model, mice bearing C26 colon adenocarcinoma have an increased food intake subsequently to the loss of body weight. We hypothesize that in this model, appetite regulating systems in the hypothalamus, which apparently fail in anorexia, are still ab...

Consensus-based distributed cooperative learning from closed-loop neural control systems.

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Chen, Weisheng; Hua, Shaoyong; Zhang, Huaguang

2015-02-01

In this paper, the neural tracking problem is addressed for a group of uncertain nonlinear systems where the system structures are identical but the reference signals are different. This paper focuses on studying the learning capability of neural networks (NNs) during the control process. First, we propose a novel control scheme called distributed cooperative learning (DCL) control scheme, by establishing the communication topology among adaptive laws of NN weights to share their learned knowledge online. It is further proved that if the communication topology is undirected and connected, all estimated weights of NNs can converge to small neighborhoods around their optimal values over a domain consisting of the union of all state orbits. Second, as a corollary it is shown that the conclusion on the deterministic learning still holds in the decentralized adaptive neural control scheme where, however, the estimated weights of NNs just converge to small neighborhoods of the optimal values along their own state orbits. Thus, the learned controllers obtained by DCL scheme have the better generalization capability than ones obtained by decentralized learning method. A simulation example is provided to verify the effectiveness and advantages of the control schemes proposed in this paper.

A novel three-dimensional system to study interactions between endothelial cells and neural cells of the developing central nervous system

Directory of Open Access Journals (Sweden)

Milner Richard

2007-01-01

Full Text Available Abstract Background During angiogenesis in the developing central nervous system (CNS, endothelial cells (EC detach from blood vessels growing on the brain surface, and migrate into the expanding brain parenchyma. Brain angiogenesis is regulated by growth factors and extracellular matrix (ECM proteins secreted by cells of the developing CNS. In addition, recent evidence suggests that EC play an important role in establishing the neural stem cell (NSC niche. Therefore, two-way communication between EC and neural cells is of fundamental importance in the developing CNS. To study the interactions between brain EC and neural cells of the developing CNS, a novel three-dimensional (3-D murine co-culture system was developed. Fluorescent-labelled brain EC were seeded onto neurospheres; floating cellular aggregates that contain NSC/neural precursor cells (NPC and smaller numbers of differentiated cells. Using this system, brain EC attachment, survival and migration into neurospheres was evaluated and the role of integrins in mediating the early adhesive events addressed. Results Brain EC attached, survived and migrated deep into neurospheres over a 5-day period. Neurospheres express the ECM proteins fibronectin and laminin, and brain EC adhesion to neurospheres was inhibited by RGD peptides and antibodies specific for the β1, but not the α6 integrin subunit. Conclusion A novel 3-D co-culture system for analysing the interactions between EC and neural cells of the developing CNS is presented. This system could be used to investigate the reciprocal influence of EC and NSC/NPC; to examine how NSC/NPC influence cerebral angiogenesis, and conversely, to examine how EC regulate the maintenance and differentiation of NSC/NPC. Using this system it is demonstrated that EC attachment to neurospheres is mediated by the fibronectin receptor, α5β1 integrin.

Neural network regulation driven by autonomous neural firings

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Cho, Myoung Won

2016-07-01

Biological neurons naturally fire spontaneously due to the existence of a noisy current. Such autonomous firings may provide a driving force for network formation because synaptic connections can be modified due to neural firings. Here, we study the effect of autonomous firings on network formation. For the temporally asymmetric Hebbian learning, bidirectional connections lose their balance easily and become unidirectional ones. Defining the difference between reciprocal connections as new variables, we could express the learning dynamics as if Ising model spins interact with each other in magnetism. We present a theoretical method to estimate the interaction between the new variables in a neural system. We apply the method to some network systems and find some tendencies of autonomous neural network regulation.

Hypothalamic CaMKKβ mediates glucagon anorectic effect and its diet-induced resistance

Science.gov (United States)

Quiñones, Mar; Al-Massadi, Omar; Gallego, Rosalía; Fernø, Johan; Diéguez, Carlos; López, Miguel; Nogueiras, Ruben

2015-01-01

Objective Glucagon receptor antagonists and humanized glucagon antibodies are currently studied as promising therapies for obesity and type II diabetes. Among its variety of actions, glucagon reduces food intake, but the molecular mechanisms mediating this effect as well as glucagon resistance are totally unknown. Methods Glucagon and adenoviral vectors were administered in specific hypothalamic nuclei of lean and diet-induced obese rats. The expression of neuropeptides controlling food intake was performed by in situ hybridization. The regulation of factors of the glucagon signaling pathway was assessed by western blot. Results The central injection of glucagon decreased feeding through a hypothalamic pathway involving protein kinase A (PKA)/Ca2+-calmodulin-dependent protein kinase kinase β (CaMKKβ)/AMP-activated protein kinase (AMPK)-dependent mechanism. More specifically, the central injection of glucagon increases PKA activity and reduces protein levels of CaMKKβ and its downstream target phosphorylated AMPK in the hypothalamic arcuate nucleus (ARC). Consistently, central glucagon significantly decreased AgRP expression. Inhibition of PKA and genetic activation of AMPK in the ARC blocked glucagon-induced anorexia in lean rats. Genetic down-regulation of glucagon receptors in the ARC stimulates fasting-induced hyperphagia. Although glucagon was unable to decrease food intake in DIO rats, glucagon sensitivity was restored after inactivation of CaMKKβ, specifically in the ARC. Thus, glucagon decreases food intake acutely via PKA/CaMKKβ/AMPK dependent pathways in the ARC, and CaMKKβ mediates its obesity-induced hypothalamic resistance. Conclusions This work reveals the molecular underpinnings by which glucagon controls feeding that may lead to a better understanding of disease states linked to anorexia and cachexia. PMID:26909312

Neural multigrid for gauge theories and other disordered systems

International Nuclear Information System (INIS)

Baeker, M.; Kalkreuter, T.; Mack, G.; Speh, M.

1992-09-01

We present evidence that multigrid works for wave equations in disordered systems, e.g. in the presence of gauge fields, no matter how strong the disorder, but one needs to introduce a 'neural computations' point of view into large scale simulations: First, the system must learn how to do the simulations efficiently, then do the simulation (fast). The method can also be used to provide smooth interpolation kernels which are needed in multigrid Monte Carlo updates. (orig.)

Role of Hypothalamic-Pituitary-Adrenal axis and corticotropin-releasing factor stress system on cue-induced relapse to alcohol seeking.