Budapest, Hungary

Hungarian Academy of Sciences
Budapest, Hungary

The Hungarian Academy of science ) is the most important and prestigious learned society of Hungary. Its seat is at the bank of the Danube in Budapest. The main responsibilities are the cultivation of science, disseminate the results of science, the supporting of research and development and the representation of Hungarian science domestically and around the world. Wikipedia.

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Aggression research was for long dominated by the assumption that aggression-related psychopathologies result from the excessive activation of aggression-promoting brain mechanisms. This assumption was recently challenged by findings with models of aggression that mimic etiological factors of aggression-related psychopathologies. Subjects submitted to such procedures show abnormal attack features (mismatch between provocation and response, disregard of species-specific rules, and insensitivity toward the social signals of opponents). We review here 12 such laboratory models and the available human findings on the neural background of abnormal aggression. We focus on the hypothalamus, a region tightly involved in the execution of attacks. Data show that the hypothalamic mechanisms controlling attacks (general activation levels, local serotonin, vasopressin, substance P, glutamate, GABA, and dopamine neurotransmission) undergo etiological factor-dependent changes. Findings suggest that the emotional component of attacks differentiates two basic types of hypothalamic mechanisms. Aggression associated with increased arousal (emotional/reactive aggression) is paralleled by increased mediobasal hypothalamic activation, increased hypothalamic vasopressinergic, but diminished hypothalamic serotonergic neurotransmission. In aggression models associated with low arousal (unemotional/proactive aggression), the lateral but not the mediobasal hypothalamus is over-activated. In addition, the anti-aggressive effect of serotonergic neurotransmission is lost and paradoxical changes were noticed in vasopressinergic neurotransmission. We conclude that there is no single 'neurobiological road' to abnormal aggression: the neural background shows qualitative, etiological factor-dependent differences. Findings obtained with different models should be viewed as alternative mechanisms rather than conflicting data. The relevance of these findings for understanding and treating of aggression-related psychopathologies is discussed.This article is part of a Special Issue entitled 'Extrasynaptic ionotropic receptors'. © 2012 Elsevier Inc.

Nusser Z.,Hungarian Academy of Sciences
Current Opinion in Neurobiology | Year: 2012

Following the astonishing molecular diversity of voltage-gated ion channels that was revealed in the past few decades, the ion channel repertoire expressed by neurons has been implicated as the major factor governing their functional heterogeneity. Although the molecular structure of ion channels is a key determinant of their biophysical properties, their subcellular distribution and densities on the surface of nerve cells are just as important for fulfilling functional requirements. Recent results obtained with high resolution quantitative localization techniques revealed complex, subcellular compartment-specific distribution patterns of distinct ion channels. Here I suggest that within a given neuron type every ion channel has a unique cell surface distribution pattern, with the functional consequence that this dramatically increases the computational power of nerve cells. © 2011 Elsevier Ltd.

Makara J.,Hungarian Academy of Sciences | Magee J.,Howard Hughes Medical Institute
Neuron | Year: 2013

The hippocampal CA3 region is essential for pattern completion and generation of sharp-wave ripples. During these operations, coordinated activation of ensembles of CA3 pyramidal neurons produces spatiotemporally structured input patterns arriving onto dendrites of recurrently connected CA3 neurons. To understand how such input patterns are translated into specific output patterns, we characterized dendritic integration in CA3 pyramidal cells using two-photon imaging and glutamate uncaging. We found that thin dendrites of CA3 pyramidal neurons integrate synchronous synaptic input in a highly supralinear fashion. The amplification was primarily mediated by NMDA receptor activation and was present over a relatively broad range of spatiotemporal input patterns. The decay of voltage responses, temporal summation, and action potential output was regulated in a compartmentalized fashion mainly by a G-protein-activated inwardly rectifying K+ current. Our results suggest that plastic dendritic integrativemechanisms may support ensemble behavior in pyramidal neurons of the hippocampal circuitry. © 2013 The Authors.

Katona I.,Hungarian Academy of Sciences | Freund T.F.,Hungarian Academy of Sciences
Annual Review of Neuroscience | Year: 2012

Despite being regarded as a hippie science for decades, cannabinoid research has finally found its well-deserved position in mainstream neuroscience. A series of groundbreaking discoveries revealed that endocannabinoid molecules are as widespread and important as conventional neurotransmitters such as glutamate or GABA, yet they act in profoundly unconventional ways. We aim to illustrate how uncovering the molecular, anatomical, and physiological characteristics of endocannabinoid signaling has revealed new mechanistic insights into several fundamental phenomena in synaptic physiology. First, we summarize unexpected advances in the molecular complexity of biogenesis and inactivation of the two endocannabinoids, anandamide and 2-arachidonoylglycerol. Then, we show how these new metabolic routes are integrated into well-known intracellular signaling pathways. These endocannabinoid-producing signalosomes operate in phasic and tonic modes, thereby differentially governing homeostatic, short-term, and long-term synaptic plasticity throughout the brain. Finally, we discuss how cell type-and synapse-specific refinement of endocannabinoid signalingmay explain the characteristic behavioral effects of cannabinoids. © 2012 by Annual Reviews. All rights reserved.

Agency: European Commission | Branch: H2020 | Program: SGA-RIA | Phase: FETFLAGSHIP | Award Amount: 89.00M | Year: 2016

Understanding the human brain is one of the greatest scientific challenges of our time. Such an understanding can provide profound insights into our humanity, leading to fundamentally new computing technologies, and transforming the diagnosis and treatment of brain disorders. Modern ICT brings this prospect within reach. The HBP Flagship Initiative (HBP) thus proposes a unique strategy that uses ICT to integrate neuroscience data from around the world, to develop a unified multi-level understanding of the brain and diseases, and ultimately to emulate its computational capabilities. The goal is to catalyze a global collaborative effort. During the HBPs first Specific Grant Agreement (SGA1), the HBP Core Project will outline the basis for building and operating a tightly integrated Research Infrastructure, providing HBP researchers and the scientific Community with unique resources and capabilities. Partnering Projects will enable independent research groups to expand the capabilities of the HBP Platforms, in order to use them to address otherwise intractable problems in neuroscience, computing and medicine in the future. In addition, collaborations with other national, European and international initiatives will create synergies, maximizing returns on research investment. SGA1 covers the detailed steps that will be taken to move the HBP closer to achieving its ambitious Flagship Objectives.

Agency: European Commission | Branch: H2020 | Program: RIA | Phase: PHC-03-2015 | Award Amount: 6.00M | Year: 2016

We hypothesize that inappropriate thyroid hormone action in target cells is a common mechanism underlying susceptibility to age-related degenerative diseases and co-morbidities. Although regulation of systemic thyroid status is well understood and underpins treatment of common thyroid disease, it is only in the last decade that the importance of local regulation of thyroid hormone action in tissue development, homeostasis and repair has been identified. During evolution, this complex temporal and cell-specific regulation has been optimized for development and reproductive fitness but NOT for ageing. Humans with their exceptional longevity are thus exposed to a prolonged period of suboptimal local thyroid hormone action. Consistent with this, thyroid status is a continuous variable within the population that is related to fracture risk, muscle mass and cognitive decline. Moreover, in healthy longevity thyroid status is characterized by thyroid stimulating hormone in the upper half of the reference range. In these studies, we will determine how local regulation of thyroid hormone action controls tissue homeostasis and repair, whilst its dysregulation is a common mechanism underlying chronic disease development during ageing. We focus on osteoporosis, osteoarthritis, neurodegeneration and sarcopenia as paradigm age-related, degenerative disorders. Using cutting-edge technology, we will (i) identify thyroid hormone dependent biomarkers for disease susceptibility in bone, cartilage, central nervous system and skeletal muscle, (ii) manipulate cell-specific thyroid hormone action in these tissues and (iii) develop cell-type specific modulators of thyroid hormone action. THYRAGE integrates cross-disciplinary expertise from clinical and basic scientists, endocrinologists, neuroscientists, gerontologists, and industry-based peptide scientists. These studies will identify and validate novel strategies for prevention and treatment of chronic age-related degenerative disease.

Tompa P.,Vrije Universiteit Brussel | Tompa P.,Hungarian Academy of Sciences
Chemical Reviews | Year: 2014

Allostery is a classical regulatory mechanism of proteins in which a signal at 'another site' modifies the activity/function of a protein. In fact, with the recognition of the generality of the structural disorder of proteins and the landscape theory of protein structure, a 'new view' of allostery started to emerge, in which emphasis is placed on ligand-induced shifts in the conformational ensemble of the protein. The ensuing changes in ligand binding/catalytic activity might stem from coupled folding transitions of distinct binding sites or remodeling of the conformational landscape to entropically favor a particular downstream binding/catalytic event. The ensuing sigmoidal binding isotherm cannot be described by a simple saturation; rather, it shows signs of cooperation between ligands. If binding of one ligand weakens that of the others, one can also speak about negative cooperativity. To elucidate the underlying mechanistic changes, two models have been suggested, which, even today, form the basis of our textbook wisdom of this phenomenon.

An insight into the homogeneous catalytic asymmetric reactions, the organocatalytic reactions, and the heterogeneous catalytic asymmetric reactions was studied. In asymmetric reactions/syntheses of this type, chiral induction is supplied by chiral molecules of natural origin and their synthetic derivatives, or other synthetic chiral compounds. Studies on the stereochemistry of homogeneous asymmetric reactions have taken their models from the hydrogenation and transfer hydrogenation of prochiral compounds with CdC bonds and prochiral ketones in the presence of Rh and Ru complexes. Supported IL catalysts (SILC) have been developed using surface-modified silica, which show good reactivity and reversal of enantioselectivity for the case of the magnesium-based BOX complexes. Studies using Pt catalysts modified with cinchona alkaloids gave unexpected results when derivatives of the parent alkaloids were used.

Agency: European Commission | Branch: H2020 | Program: ERC-STG | Phase: ERC-2016-STG | Award Amount: 1.50M | Year: 2017

Neuromodulators such as acetylcholine and dopamine are able to rapidly reprogram neuronal information processing and dynamically change brain states. Degeneration or dysfunction of cholinergic and dopaminergic neurons can lead to neuropsychiatric conditions like schizophrenia and addiction or cognitive diseases such as Alzheimers. Neuromodulatory systems control overlapping cognitive processes and often have similar modes of action; therefore it is important to reveal cooperation and competition between different systems to understand their unique contributions to cognitive functions like learning, memory and attention. This is only possible by direct comparison, which necessitates monitoring multiple neuromodulatory systems under identical experimental conditions. Moreover, simultaneous recording of different neuromodulatory cell types goes beyond phenomenological description of similarities and differences by revealing the underlying correlation structure at the level of action potential timing. However, such data allowing direct comparison of neuromodulatory actions are still sparse. As a first step to bridge this gap, I propose to elucidate the unique versus complementary roles of two classical neuromodulatory systems, the cholinergic and dopaminergic projection system implicated in various cognitive functions including associative learning and plasticity. First, we will record optogenetically identified cholinergic and dopaminergic neurons simultaneously using chronic extracellular recording in mice undergoing classical and operant conditioning. Second, we will determine the postsynaptic impact of cholinergic and dopaminergic neurons by manipulating them both separately and simultaneously while recording consequential changes in cortical neuronal activity and learning behaviour. These experiments will reveal how major neuromodulatory systems interact to mediate similar or different aspects of the same cognitive functions.

Agency: European Commission | Branch: H2020 | Program: ERC-COG | Phase: ERC-CoG-2015 | Award Amount: 2.00M | Year: 2016

The long-term aim of the investigation is to assess the feasibility of creating an artificial sense and, thereby, a possible sensory (visual) prosthetic. While working towards this goal, we will have to address the question of how neural assembly activity relates to subjective perceptions. Finding and understanding these functional assemblies will make it possible to reactivate them in a precise, biologically relevant manner to elicit similar cortical activation as visual stimulation. Recent publications suggest that cortical connectivity can be mapped by two-photon microscopy. Here we want, therefore, to develop a novel 3D Electro-Acousto-Optical microscope for high-throughput assembly mapping. The microscope will be capable of scanning neuronal activity with one order of magnitude higher speed (300-500 kHz/ROI) and simultaneously photoactivate neurons with three order of magnitude higher efficiency (2,500 25,000 neurons/ms) than existing 3D microscopes while preserving the subcellular resolution required to simultaneously measure the somatic, the dendritic and axonal computation units in the entire V1 region of the cortex. The microscope will be based on our current 3D AO technology; on novel ultra-fast scanning technologies; new, 10-fold faster AO deflectors; and novel (multi-ROI) scanning strategies. Using our microscope in combination with novel caged neurotransmitters and optogenetic tools, we want to map cell assemblies and to understand how they form larger clusters and how they are associated with visual features. Furthermore, as a proof-of-concept of this grant, we want to restore visual perception by recreating previously mapped assembly patterns with 3D artificial photositmulation in behaving mice and see if the animal responds to the artificial stimulus in the same way as to the visual stimulus. Moreover, we want to restore visual information based spatial navigation in head restrained animals orienting and moving in a virtual labyrinth for reward.

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