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Search Results: 1 - 10 of 22294 matches for " Hans-Christian Pape "
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Patterns of Coupled Theta Activity in Amygdala-Hippocampal-Prefrontal Cortical Circuits during Fear Extinction
J?rg Lesting, Rajeevan T. Narayanan, Christian Kluge, Susan Sangha, Thomas Seidenbecher, Hans-Christian Pape
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021714
Abstract: Signals related to fear memory and extinction are processed within brain pathways involving the lateral amygdala (LA) for formation of aversive stimulus associations, the CA1 area of the hippocampus for context-dependent modulation of these associations, and the infralimbic region of the medial prefrontal cortex (mPFC) for extinction processes. While many studies have addressed the contribution of each of these modules individually, little is known about their interactions and how they function as an integrated system. Here we show, by combining multiple site local field potential (LFP) and unit recordings in freely behaving mice in a fear conditioning paradigm, that theta oscillations may provide a means for temporally and functionally connecting these modules. Theta oscillations occurred with high specificity in the CA1-LA-mPFC network. Theta coupling increased between all areas during retrieval of conditioned fear, and declined during extinction learning. During extinction recall, theta coupling partly rebounded in LA-mPFC and CA1-mPFC, and remained at a low level in CA1-LA. Interfering with theta coupling through local electrical microstimulation in CA1-LA affected conditioned fear and extinction recall depending on theta phase. These results support the hypothesis that theta coupling provides a means for inter-areal coordination in conditioned behavioral responsiveness. More specifically, theta oscillations seem to contribute to a population code indicating conditioned stimuli during recall of fear memory before and after extinction.
Directional Theta Coherence in Prefrontal Cortical to Amygdalo-Hippocampal Pathways Signals Fear Extinction
J?rg Lesting, Thiemo Daldrup, Venu Narayanan, Christian Himpe, Thomas Seidenbecher, Hans-Christian Pape
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0077707
Abstract: Theta oscillations are considered crucial mechanisms in neuronal communication across brain areas, required for consolidation and retrieval of fear memories. One form of inhibitory learning allowing adaptive control of fear memory is extinction, a deficit of which leads to maladaptive fear expression potentially leading to anxiety disorders. Behavioral responses after extinction training are thought to reflect a balance of recall from extinction memory and initial fear memory traces. Therefore, we hypothesized that the initial fear memory circuits impact behavioral fear after extinction, and more specifically, that the dynamics of theta synchrony in these pathways signal the individual fear response. Simultaneous multi-channel local field and unit recordings were obtained from the infralimbic prefrontal cortex, the hippocampal CA1 and the lateral amygdala in mice. Data revealed that the pattern of theta coherence and directionality within and across regions correlated with individual behavioral responses. Upon conditioned freezing, units were phase-locked to synchronized theta oscillations in these pathways, characterizing states of fear memory retrieval. When the conditioned stimulus evoked no fear during extinction recall, theta interactions were directional with prefrontal cortical spike firing leading hippocampal and amygdalar theta oscillations. These results indicate that the directional dynamics of theta-entrained activity across these areas guide changes in appraisal of threatening stimuli during fear memory and extinction retrieval. Given that exposure therapy involves procedures and pathways similar to those during extinction of conditioned fear, one therapeutical extension might be useful that imposes artificial theta activity to prefrontal cortical-amygdalo-hippocampal pathways that mimics the directionality signaling successful extinction recall.
Social Defeat: Impact on Fear Extinction and Amygdala-Prefrontal Cortical Theta Synchrony in 5-HTT Deficient Mice
Venu Narayanan, Rebecca S. Heiming, Friederike Jansen, J?rg Lesting, Norbert Sachser, Hans-Christian Pape, Thomas Seidenbecher
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0022600
Abstract: Emotions, such as fear and anxiety, can be modulated by both environmental and genetic factors. One genetic factor is for example the genetically encoded variation of the serotonin transporter (5-HTT) expression. In this context, the 5-HTT plays a key role in the regulation of central 5-HT neurotransmission, which is critically involved in the physiological regulation of emotions including fear and anxiety. However, a systematic study which examines the combined influence of environmental and genetic factors on fear-related behavior and the underlying neurophysiological basis is missing. Therefore, in this study we used the 5-HTT-deficient mouse model for studying emotional dysregulation to evaluate consequences of genotype specific disruption of 5-HTT function and repeated social defeat for fear-related behaviors and corresponding neurophysiological activities in the lateral amygdala (LA) and infralimbic region of the medial prefrontal cortex (mPFC) in male 5-HTT wild-type (+/+), homo- (?/?) and heterozygous (+/?) mice. Naive males and experienced losers (generated in a resident-intruder paradigm) of all three genotypes, unilaterally equipped with recording electrodes in LA and mPFC, underwent a Pavlovian fear conditioning. Fear memory and extinction of conditioned fear was examined while recording neuronal activity simultaneously with fear-related behavior. Compared to naive 5-HTT+/+ and +/? mice, 5-HTT?/? mice showed impaired recall of extinction. In addition, 5-HTT?/? and +/? experienced losers showed delayed extinction learning and impaired recall of extinction. Impaired behavioral responses were accompanied by increased theta synchronization between the LA and mPFC during extinction learning in 5-HTT-/? and +/? losers. Furthermore, impaired extinction recall was accompanied with increased theta synchronization in 5-HTT?/? naive and in 5-HTT?/? and +/? loser mice. In conclusion, extinction learning and memory of conditioned fear can be modulated by both the 5-HTT gene activity and social experiences in adulthood, accompanied by corresponding alterations of the theta activity in the amygdala-prefrontal cortex network.
Towards a new strategy to implement psychosomatic knowledge in medical practice
Hans-Christian Deter
BioPsychoSocial Medicine , 2008, DOI: 10.1186/1751-0759-2-1
Abstract: As we better understand the mechanisms of the development in these diseases. especially the psychosocial influences, each country needs to develop a strategy to implement this knowledge into its practice of medicine.The conditions of the health care system in Germany differ from those of France and Japan. Thus, it seems necessary to promote psychosomatic knowledge – conducting convincing psychosomatic studies in different medical fields – in the national health care system and in society. To implement this it is necessary to have cooperation between workers in government, in faculties/universities and in medical associations. However, the basis is holistic thinking about mind and body in the society. Japanese culture is in accord with holistic thinking in Europe and with the ideas of psychosomatic theory and practice in Germany. Victor von Weizs?cker and Thure von Uexküll in Germany and Yujiro Ikemi in Japan attempted to bring psychosomatic thinking into clinical practice as an advantage for all patients.The differences between these earlier times and today in psychosomatic research are that, (1) we need good data in all medical fields to demonstrate psychosomatic interactions in different diseases, (2) we need to show that special psychosomatic strategies of treatment are useful for special psychological, biological and social targets in these diseases, and (3) to demonstrate in randomized psychosomatic clinical trials that treatment effects are comparable to other, more usual, treatments (TAU). Only in this way is it possible to bring psychosomatic experiences and knowledge into the national and international guidelines for special diseases, as have the European guidelines for prevention of coronary heart diseases (Orth-Gomer et al. 2005) [1].This is a program in many national and international psychosomatic research centres and will be supported by the national psychosomatic societies. The communication and integration of these ongoing studies in journals such as
Psychosocial interventions for patients with chronic disease
Hans-Christian Deter
BioPsychoSocial Medicine , 2012, DOI: 10.1186/1751-0759-6-2
Abstract: In a psychosomatic therapeutic intervention there are very different targets, such as psychological symptoms, personality traits, attitudes toward disease and life, risk behaviour, and social isolation and as biological targets the change of autonomic imbalance and of the effects of the psycho-endocrinological or psycho-immunological stress responses. And there are also different psychosomatic measures that influence the individual biological, psychological and sociological targets. There is a need to give different answer to different questions in the field of psychosomatic and behavioral medicine. Comparative effectiveness research is an important strategy for solving some methodological issues. What is the target of treatment for different diseases: Symptom reduction, healing, or limiting progression to the worst case - the death of patients. We know that, the patient-physician relationship is important for every medical/therapeutic action for patients with chronic diseases.This volume of BioPsychoSocial Medicine will present four different psychosomatic treatment studies from the clinical field in the sense of phase 2 studies: Reports of patients with obesity, anorexia nervosa, chronic somatoform pain and coronary artery disease were presentedBio psycho social medicine integrates different levels of research: The basic sciences focus on psychobiological mechanisms (e.g. psycho-neuroendocrinology, psycho-neuroimmunology, psycho-physiology) and psycho-somatic correlations. Various pathways have been formulated for different chronic diseases as have strategies for research on interactions between psychic phenomenon and biological functions found in different regions of the body, such as the brain-gut axis and the brain-heart axis. Medicine is not only a diagnostic discipline, but also a research field for medical practice - concentrating on physicians and other health care workers in action with their patients and focusing on the transfer of psychosomatic knowledge
Das preu ische Kultusministerium und die
Hans-Christian Jasch
Forum Historiae Iuris , 2005,
Abstract:
Forskning i tegneserier
Hans-Christian Christiansen
MedieKultur : Journal of Media and Communication Research , 1999,
Abstract: Der har altid eksisteret akademisk mistro over for massekultur. Som en f lge heraf har der v ret en tendens i forskningen til kun at betragte fel- tets modtagereffekt eller indskrive f nomenet i pessimistiske kulturbe- skrivelser: Den tidlige forskning i tegneserien har s ledes i h j grad v ret pr get af opremsninger af negative effekter, og indtil 60'erne var forskningsfeltet karakteriseret ved et meget begr nset analytisk per- spektiv. I slutningen af 60'erne blev tegneserien imidlertid ”opdaget” af litteraturteorien, der is r betonede tegneseriens sociologiske og ideolo- giske aspekter, og tillige blev tegneserien i 60'erne genstand for semio- tisk funderet analyse i k lvandet p en voksende interesse for masse- kultur. Med denne interesse for massekultur og en begyndende kulturel institutionalisering af tegneserien i Frankrig og Belgien tegnede der sig efterh nden konturerne af en tegneserieteori.
Solving Gauge Field Theory by Discretized Light-Cone Quantization
Hans-Christian Pauli
Physics , 1996,
Abstract: The canonical front form Hamiltonian for non-Abelian SU(N) gauge theory in 3+1 dimensions is mapped on an effective Hamiltonian which acts only in the Fock space of one quark and one antiquark. The approach is non-perturbative and exact. It is based on Discretized Light-Cone Quantization and the Method of Iterated Resolvents. The method resums the diagrams of perturbation theory to all orders in the coupling constant and is free of Tamm-Dancoff truncations in the Fock-space. Emphasis is put on dealing accurately with the many-body aspects of gauge field theory. Pending future renormalization group analysis the running coupling is derived to all orders in the bare coupling constant.~--- The derived effective interaction has an amazingly simple structure and is gauge invariant and frame independent. It is solvable on a small computer like a work station. The many-body amplitudes can be retrieved self-consistently from these solutions, by quadratures without solving another eigenvalue problem. The structures found allow also for developing simple phenomenological models consistent with non-Abelian gauge field theory.
On the effective light-cone QCD-Hamiltonian
Hans-Christian Pauli
Physics , 2000,
Abstract: Taking the effective interaction between a quark and an anti-quark from previous work, the dependendence on a regularization scale is removed in line with the renormalization group. In order to emphasize the essential point, the full spinor interaction is replaced by a model which includes only the Coulomb and the hyperfine interaction. By adjusting the effective quark masses, the only free parameters of the theory, the mass and the size of the pion are reproduced, as well as the mass of all other pseudo-scalar mesons. Estimates for the vector mesons are close to the empirical values. The model exposes screening rather than strict confinement. The ionization thresholds are in general much larger than the pion mass.
Applying the flow equations to QCD
Hans-Christian Pauli
Physics , 2001, DOI: 10.1016/S0920-5632(00)00912-9
Abstract: The effective quark-antiquark-interaction is derived from Lagrangian QCD in the front form by means of the flow equations. It coincides with previous results.
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