ERC FUNDED PROJECTS

Despite considerable advances in drug discovery, resistance to anticancer chemotherapy confounds the effective treatment of patients. Cancer cells can acquire broad cross-resistance to mechanistically and structurally unrelated drugs. P-glycoprotein (Pgp) actively extrudes many types of drugs from cancer cells, thereby conferring resistance to those agents. The central tenet of my work is that Pgp, a universally accepted biomarker of drug resistance, should in addition be considered as a molecular target of multidrug-resistant (MDR) cancer cells. Successful targeting of MDR cells would reduce the tumor burden and would also enable the elimination of ABC transporter-overexpressing cancer stem cells that are responsible for the replenishment of tumors. The proposed project is based on the following observations: - First, by using a pharmacogenomic approach, I have revealed the hidden vulnerability of MDRcells (Szakács et al. 2004, Cancer Cell 6, 129-37); - Second, I have identified a series of MDR-selective compounds with increased toxicity toPgp-expressing cells (Turk et al.,Cancer Res, 2009. 69(21)); - Third, I have shown that MDR-selective compounds can be used to prevent theemergence of MDR (Ludwig, Szakács et al. 2006, Cancer Res 66, 4808-15); - Fourth, we have generated initial pharmacophore models for cytotoxicity and MDR-selectivity (Hall et al. 2009, J Med Chem 52, 3191-3204). I propose a comprehensive series of studies that will address thefollowing critical questions: - First, what is the scope of MDR-selective compounds? - Second, what is their mechanism of action? - Third, what is the optimal therapeutic modality? Extensive biological, pharmacological and bioinformatic analyses will be utilized to address four major specific aims. These aims address basic questions concerning the physiology of MDR ABC transporters in determining the mechanism of action of MDR-selective compounds, setting the stage for a fresh therapeutic approach that may eventually translate into improved patient care.

1 499 640 €

Start date: 2012-01-01, End date: 2016-12-31

Understanding how and why individuals develop strikingly different life histories is a major goal in evolutionary biology. It is also a prerequisite for conserving important biodiversity within species and predicting the impacts of environmental change on populations. The aim of my study is to examine a key threshold phenotypic trait (alternative migratory tactics) in a series of large scale laboratory and field experiments, integrating several previously independent perspectives from evolutionary ecology, ecophysiology and genomics, to produce a downstream predictive model. My chosen study species, the brown trout Salmo trutta, has an extensive history of genetic and experimental work and exhibits ‘partial migration’: individuals either migrate to sea (‘sea trout’) or remain in freshwater their whole lives. Recent advances in molecular parentage assignment, quantitative genetics and genomics (next generation sequencing and bioinformatics) will allow unprecedented insight into how alternative life history phenotypes are moulded by the interaction between genes and environment. To provide additional mechanistic understanding of these processes, the balance between metabolic requirements during growth and available extrinsic resources will be investigated as the major physiological driver of migratory behaviour. Together these results will be used to develop a predictive model to explore the consequences of rapid environmental change, accounting for the effects of genetics and environment on phenotype and on population demographics. In addition to their value for conservation and management of an iconic and key species in European freshwaters and coastal seas, these results will generate novel insight into the evolution of migratory behaviour generally, providing a text book example of how alternative life histories are shaped and maintained in wild populations.

1 499 202 €

Start date: 2015-05-01, End date: 2020-04-30

With the advent of new sequencing technologies, population geneticists now have access to more data than ever before. We have access to thousands of human genomes from a diverse set of populations around the globe, and, thanks to advances in DNA extraction and library preparation, we now are beginning to have access to ancient DNA sequence data. These data have greatly improved our knowledge of human history, human adaptation to different environments and human disease. Genome-wide studies have highlighted many genes or genomic loci that may play a role in adaptive or disease related phenotypes of biological importance. With these collections of modern and ancient sequence data we want to answer a key evolutionary question: how do human adaptations arise? We strongly believe that the state-of-the-art methodologies for uncovering signatures of adaptation are blind to potential modes of adaptation because they are lacking two critical components – more complete integration of multiple population haplotype data (including archaic, ancient and modern samples), and an account of population interactions that facilitate adaptation. Therefore I plan to develop new methods to detect shared selective events across populations by creating novel statistical summaries, and to detect admixture-facilitated adaptation which we believe is likely a common mode of natural selection. We will apply these tools to new datasets to characterize the interplay of natural selection, archaic and modern admixture in populations in the Americas and make a comparative analysis of modern and ancient European samples to understand the origin and changing profile of adaptive archaic alleles. As a result our work will reveal evolutionary processes that have played an important role in human evolution and disease.

1 500 000 €

Start date: 2020-01-01, End date: 2024-12-31

We and others have recently delineated the molecular architecture of a new feedback pathway in brain synapses, which operates as a synaptic circuit breaker. This pathway is supposed to use a group of lipid messengers as retrograde synaptic signals, the so-called endocannabinoids. Although heterogeneous in their chemical structures, these molecules along with the psychoactive compound in cannabis are thought to target the same effector in the brain, the CB1 receptor. However, the molecular catalog of these bioactive lipids and their metabolic enzymes has been expanding rapidly by recent advances in lipidomics and proteomics raising the possibility that these lipids may also serve novel, yet unidentified physiological functions. Thus, the overall aim of our research program is to define the molecular and anatomical organization of these endocannabinoid-mediated pathways and to determine their functional significance. In the present proposal, we will focus on understanding how these novel pathways regulate synaptic and extrasynaptic signaling in hippocampal neurons. Using combination of lipidomic, genetic and high-resolution anatomical approaches, we will identify distinct chemical species of endocannabinoids and will show how their metabolic enzymes are segregated into different subcellular compartments in cell type- and synapse-specific manner. Subsequently, we will use genetically encoded gain-of-function, loss-of-function and reporter constructs in imaging experiments and electrophysiological recordings to gain insights into the diverse tasks that these new pathways serve in synaptic transmission and extrasynaptic signal processing. Our proposed experiments will reveal fundamental principles of intercellular and intracellular endocannabinoid signaling in the brain.

1 638 000 €

Start date: 2009-11-01, End date: 2014-10-31

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 Alzheimer’s. 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.

1 499 463 €

Start date: 2017-05-01, End date: 2022-04-30

The genetic code was established at a very early stage during the evolution of life on Earth and is nearly universal. In eukaryotic nuclear genes, the only known examples of a sense codon that underwent an evolutionary change of meaning, from one amino acid to another, occur in yeast species. The codon CUG is translated as Leu in the universal genetic code, but it has long been known to be translated as Ser in some Candida species. In recent work, we discovered that this switch is one of three parallel reassignments of CUG that occurred in three closely related clades of yeasts. CUG was reassigned once from Leu to Ala, and twice from Leu to Ser, in three separate events. The meaning of sense codons in the nuclear genetic code has otherwise remained completely stable during all of eukaryotic evolution, so why was CUG so unstable in yeasts? CODEKILLER will test a radical new hypothesis that the genetic code changes were caused by a killer toxin that specifically attacked the tRNA that translated CUG as Leu. The hypothesis implies that the reassignments of CUG were not driven by selection in favor of their effects on the proteome, as commonly assumed, but by selection against the existence of a particular tRNA. As well as searching for this killer toxin, we will study the detailed mechanism of genetic code change by engineering a reversal of a CUG-Ser species back to CUG-Leu translation, and investigate translation in some species that naturally contain both tRNA-Leu and tRNA-Ser molecules capable of decoding CUG.

2 368 356 €

Start date: 2018-10-01, End date: 2023-09-30

Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. The macula, the central part of the retina, is responsible for optimal spatial vision. There is a growing body of evidence that a lack of a dietary pigment at the macula, known as macular pigment (MP), is associated with increased risk of AMD. MP contains the carotenoids lutein (L), zeaxanthin (Z) and meso-zeaxanthin (meso-Z). The typical western diet contains around 60 carotenoids, and 18 have been identified in human serum. However, only three are found at the macula, indicating the unique biological selectivity for their uptake at this location. The function of MP remains undetermined. It is likely that the accumulation of MP has evolved because of its optical and antioxidant properties; for example, MP limits retinal oxidative damage passively (through filtration of blue light) and actively (by quenching free radicals). Furthermore, its optical properties suggest a key role for MP in enhancing visual performance and supporting ‘super’ vision by reducing the effects of chromatic aberration and light scatter. Recent research has shown that MP can be augmented by dietary supplementation in most (but not all) subjects, suggesting that the macular concentrations of these carotenoids are suboptimal in many people. My laboratory has discovered that a dip in the central portion of this pigment, seen in around 12% of individuals, is an undesirable feature of its spatial profile and may be linked to an inability to generate meso-Z at the macula. However, we have identified that enrichment of MP can be achieved by inclusion of meso-Z in a dietary supplement. We propose to uniquely enrich MP and assess its impact on visual performance in normal subjects and visual function in patients with AMD. This groundbreaking study will advance our understanding of the protective and optical hypothesis of MP, and potentially improve normal vision and prevent or delay blindness due to AMD.

1 493 342 €

Start date: 2011-10-01, End date: 2016-09-30

Evolutionary change of gene copy number through gene duplication is a relatively pervasive phenomenon in eukaryotic genomes. However, for a subset of genes such changes are deleterious because they result in imbalances in the cell. Such dosage-sensitive genes have been increasingly implicated in disease, particularly through the association of copy number variants (CNVs) with pathogenicity. In my lab we have previously discovered that many genes in the human genome which were retained after whole genome duplication (WGD) are refractory to gene duplication both over evolutionary timescales and within populations. These are expected characteristics of dosage-balanced genes. Many of these genes are implicated in human disease. I now propose to take a computational (dry-lab) approach to examine the evolution of dosage-balanced genes further and to develop a sophisticated model of evolutionary constraint of copy number. These models will enable the identification of dosage-balanced genes and their consideration as novel candidate disease loci. Recognising and interpreting patterns of constraint is the cornerstone of molecular evolution. Through careful analysis of genome sequences with respect to gene duplication over evolutionary times and within populations, we will develop a formal and generalised model of copy-number evolution and constraint. We will use these models to identify candidate disease loci within pathogenic CNVs. We will also study the characteristics of known disease genes in order to identify novel candidate loci for dosage-dependent disease. This is an ambitious and high impact project that has the potential to yield major insights into gene copy-number constraint and its relationship to complex disease.

1 358 534 €

Start date: 2013-01-01, End date: 2018-12-31

"Why do individuals vary in their cognitive abilities? This proposal takes the disciplines of cognition and evolutionary biology into a natural setting to answer this question by investigating a variety of proximate causes and population-level consequences of individual variation in cognitive ability. It represents the first large-scale integrative study of cognitive ability on any wild population. State of the art observational (remote sensing and automated self-administration trials of learning in the wild), chemical (stable isotope analysis of diet), physiological (stress, energetics, immunocompetence), molecular (DNA fingerprinting and metabarcoding) and analytical (reaction norm, quantitative genetic) techniques will be used. The chosen study system, the great tit Parus major, is one of the most widely used in Europe, but uniquely here will consist of 12 subpopulations across deciduous and conifer woodland fragments. The proposal’s broad scope is captured in three objectives: 1) To characterise proximate causes of variation in cognitive (associative/reversal learning; problem solving; brain size) and other traits (the reactive-proactive personality axis; bill morphology), all of which can influence similar ecologically important behaviour. Quantitative genetic, social, parasite-mediated, and physiological causes will be explored. 2) To examine links between these traits, and key behaviours and trade-offs, e.g., space use, niche specialization, predation, parental care and promiscuity; and 3) To examine the consequences of this variation for life histories and fitness. The research team consists of the PI, five early career biologists, and three PhD students, and will collaborate with eight researchers from Europe and further afield. The project will reveal ground-breaking insight into why individuals vary in their cognitive ability. It aims to impact a wide scientific community, to raise public interest in science, and to inform EU biodiversity policy."

1 993 189 €

Start date: 2015-03-01, End date: 2020-12-31

A fundamental but unexplored problem in biology is whether and how enzymes use mechanical strain during their functioning. It is now evident that the knowledge of atomic structures and chemical interactions is not sufficient to understand the intricate mechanisms underlying enzyme specificity and efficiency. Several lines of evidence suggest that mechanical effects play crucial roles in enzyme activity. Therefore we aim to create detailed force maps that reveal how the intramolecular distribution of mechanical strains changes during the enzyme cycle and how these rearrangements drive the enzyme processes. The applicability of current nanotechniques for the investigation of this problem is limited because they do not allow simultaneous measurement of mechanical and enzymatic parameters. Thus we seek to open new avenues of research by developing site-specific sensors and passive or photoinducible molecular springs to measure force-dependent chemical/structural changes with high spatiotemporal resolution in myosin. Since force perturbations occur very rapidly, we are able to combine experimental studies with quasi-realistic in silico simulations to describe the physical background of enzyme function. We expect that our research will yield fundamental insights into the role of intramolecular strains in enzymes and thus greatly aid the design and control of enzyme processes (specificity, activity, regulation). Our studies may also lead to new paradigms in the understanding of motor systems.

750 000 €

Start date: 2008-09-01, End date: 2014-08-31

Our astonishing cognitive abilities are the consequence of complex connectivity within our neuronal networks and the large functional diversity of excitable nerve cells and their synapses. Investigations over the past half a century revealed dramatic diversity in shape, size and functional properties among synapses established by distinct cell types in different brain regions and demonstrated that the functional differences are partly due to different molecular mechanisms. However, synaptic diversity is also observed among synapses established by molecularly and morphologically uniform presynaptic cells on molecularly and morphologically uniform postsynaptic cells. Our hypothesis is that quantitative molecular differences underlie the functional diversity of such synapses. We will focus on hippocampal CA1 pyramidal cell (PC) to mGluR1α+ O-LM cell synapses, which show remarkable functional and molecular heterogeneity. In vitro multiple cell patch-clamp recordings followed by quantal analysis will be performed to quantify well-defined biophysical properties of these synapses. The molecular composition of the functionally characterized single synapses will be determined following the development of a novel postembedding immunolocalization method. Correlations between the molecular content and functional properties will be established and genetic up- and downregulation of individual synaptic proteins will be conducted to reveal causal relationships. Finally, correlations of the activity history and the functional properties of the synapses will be established by performing in vivo two-photon Ca2+ imaging in head-fixed behaving animals followed by in vitro functional characterization of their synapses. Our results will reveal quantitative molecular fingerprints of functional properties, allowing us to render dynamic behaviour to billions of synapses when the connectome of the hippocampal circuit is created using array tomography.

2 498 750 €

Start date: 2018-10-01, End date: 2023-09-30

How do we make reliable decisions given sensory information that is often weak or ambiguous? Current theories center on a brain mechanism whereby sensory evidence is integrated over time into a “decision variable” which triggers the appropriate action upon reaching a criterion. Neural signals fitting this role have been identified in monkey electrophysiology but efforts to study the neural dynamics underpinning human decision making have been hampered by technical challenges associated with non-invasive recording. This proposal builds on a recent paradigm breakthrough made by the applicant that enables parallel tracking of discrete neural signals that can be unambiguously linked to the three key information processing stages necessary for simple perceptual decisions: sensory encoding, decision formation and motor preparation. Chief among these is a freely-evolving decision variable signal which builds at an evidence-dependent rate up to an action-triggering threshold and precisely determines the timing and accuracy of perceptual reports at the single-trial level. This provides an unprecedented neurophysiological window onto the distinct parameters of the human decision process such that the underlying mechanisms of several major behavioral phenomena can finally be investigated. This proposal seeks to develop a systems-level understanding of perceptual decision making in the human brain by tackling three core questions: 1) what are the neural adaptations that allow us to deal with speed pressure and variations in the reliability of the physically presented evidence? 2) What neural mechanism determines our subjective confidence in a decision? and 3) How does aging impact on the distinct neural components underpinning perceptual decision making? Each of the experiments described in this proposal will definitively test key predictions from prominent theoretical models using a combination of temporally precise neurophysiological measurement and psychophysical modelling.

1 382 643 €

Start date: 2015-05-01, End date: 2020-04-30

This application addresses mechanisms linking the activity of single neurons with network events by defining the function of identified cell types in the cerebral cortex. The key hypotheses emerged from our experiments and propose that neurogliaform cells and axo-axonic cells achieve their function in the cortex through extreme forms of unspecificity and specificity, respectively. The project capitalizes on our discovery that neurogliaform cells reach GABAA and GABAB receptors on target cells through unitary volume transmission going beyond the classical theory which states that single cortical neurons act in or around synaptic junctions. We propose that the spatial unspecificity of neurotransmitter action leads to unprecedented functional capabilities for a single neuron simultaneously acting on neuronal, glial and vascular components of the surrounding area allowing neurogliaform cells to synchronize metabolic demand and supply in microcircuits. In contrast, axo-axonic cells represent extreme spatial specificity in the brain: terminals of axo-axonic cells exclusively target the axon initial segment of pyramidal neurons. Axo-axonic cells were considered as the most potent inhibitory neurons of the cortex. However, our experiments suggested that axo-axonic cells can be the most powerful excitatory neurons known to date by triggering complex network events. Our unprecedented recordings in the human cortex show that axo-axonic cells are crucial in activating functional assemblies which were implicated in higher order cognitive representations. We aim to define interactions between active cortical networks and axo-axonic cell triggered assemblies with an emphasis on mechanisms modulated by neurogliaform cells and commonly prescribed drugs.

2 391 695 €

Start date: 2011-06-01, End date: 2017-05-31

Microglia are the main immune cells of the brain, but their role in brain injury is highly controversial due to the difficulties in selectively manipulating and imaging microglial actions in real time. Specifically, it is unclear whether microglia control neuronal survival after injury via shaping the activity of complex neuronal networks in vivo. To this end, we have combined fast in vivo two-photon imaging of neuronal calcium responses with selective microglial manipulation for the first time. Our data suggest that microglia constantly monitor and control neuronal network activity and these actions are essential to limit excitotoxicity and neuronal death after acute brain injury. We also identify microglia as key regulators of spreading depolarization in vivo. However, the underlying mechanisms remained unexplored. Here, I propose that microglia control neuronal excitability and based on preliminary data I set out to investigate how this occurs. We will combine selective, CSF1R-mediated microglia depletion with advanced neurophysiological methods such as in vivo calcium imaging and intracranial EEG for the first time, to reveal how microglia shape activity of complex neuronal networks in the healthy and the injured brain. Then, we will study microglia-neuron interactions from the network level to nanoscale level using in vivo two-photon imaging and super-resolution microscopy. We will apply novel chemogenic and optogenetic approaches to manipulate microglia in real time, assess their role in neuronal activity changes and investigate the molecular mechanisms in vitro and in vivo. Our unpublished data also suggest that inflammation – a key contributor to brain diseases – could disrupt microglia-neuron signaling and we set out to investigate the underlying mechanisms. By using state-of the-art research tools that had not been applied previously in this context, our studies are likely to reveal novel pathophysiological mechanisms relevant for common brain diseases.

2 000 000 €

Start date: 2017-04-01, End date: 2022-03-31

Inflammatory diseases are highly prevalent, often chronic diseases that cause diminished quality of life and are connected with major causes of death in Western societies. Despite their societal impact, their pathomechanism is incompletely understood, hindering development of novel therapeutic strategies. In particular, little is known about the intracellular signal transduction processes involved in the tissue destruction phase of aggressive autoimmune diseases such as rheumatoid arthritis. The present proposal aims to clarify this issue using in vivo and in vitro studies on genetically manipulated mice. During the proposed studies, mice deficient in various signal transduction molecules such as Syk, PLCg2, Gab2 and p190 RhoGAPs will be used to test their contribution to inflammatory responses. In vitro studies will test the activation of major effector cells of inflammation (neutrophils, macrophages and osteoclasts) while in vivo studies will utilize mouse models such as autoantibody- and cytokine-induced inflammatory arthritis or autoantibody-induced glomerulonephritis. Further studies will be performed to test the contribution of the above signaling molecules to disease pathogenesis in a lineage-restricted manner, using the Cre-lox approach. Finally, wild type and mutant versions of the signaling molecules tested will be retrovirally re-expressed into the relevant knockout hematopoietic stem cells in vivo to allow structure-function studies during in vivo inflammation. Two novel transgenic strains and a knock-in (floxed) mutant will also be generated during the course of the project. Using state-of-the-art approaches and techniques, this project will provide information at unprecedented molecular detail on signal transduction mechanisms involved in inflammatory diseases, and is expected to point to possible future targets of novel anti-inflammatory therapies.

1 200 000 €

Start date: 2008-10-01, End date: 2014-03-31

We will reveal the neuronal mechanisms of fundamental hippocampal and axonal functions using direct patch clamp recordings from the small axon terminals of the major glutamatergic afferent and efferent pathways of the dentate gyrus region. Specifically, we will investigate the intrinsic axonal properties and unitary synaptic functions of the axons in the dentate gyrus that originate from the entorhinal cortex, the hilar mossy cells and the hypothalamic supramammillary nucleus. The fully controlled access to the activity of individual neuronal projections allows us to address the crucial questions how upstream regions of the dentate gyrus convey physiologically relevant spike activities and how these activities are translated to unitary synaptic responses in individual dentate gyrus neurons. The successful information transfers by these mechanisms ultimately generate specific dentate gyrus cell activity that contributes to hippocampal memory functions. Comprehensive mechanistic insights are essential to understand the impacts of the activity patterns associated with fundamental physiological functions and attainable with the necessary details only with direct recordings from individual axons. For example, these knowledge are necessary to understand how single cell activities in the entorhinal cortex (carrying primary spatial information) contribute to spatial representation in the dentate (i.e. place fields). Furthermore, because the size of these recorded axon terminals matches that of the majority of cortical synapses, our discoveries will demonstrate basic biophysical and neuronal principles of axonal signaling that are relevant for universal neuronal functions throughout the CNS. Thus, an exceptional repertoire of methods, including recording from anatomically identified individual small axon terminals, voltage- and calcium imaging and computational simulations, places us in an advantaged position for revealing unprecedented information about neuronal circuits.

1 994 025 €

Start date: 2018-04-01, End date: 2023-03-31

At the onset of division the cell forms a spindle, a micro-machine made of microtubules, which divide the chromosomes by pulling on kinetochores, protein complexes on the chromosome. The central question in the field is how accurate chromosome segregation results from the interactions between kinetochores, microtubules and the associated proteins. According to the current paradigm, the forces on kinetochores are produced by k-fibers, bundles of microtubules extending between the spindle pole and the kinetochore. The proposed project is built upon a groundbreaking hypothesis that a new class of microtubules, which we term bridging microtubules, bridge sister kinetochores. Our preliminary results show that bridging microtubules are responsible for the positioning of kinetochores in HeLa and PtK1 cells. Bridging microtubules have not been studied before because this requires cutting-edge microscopy and laser microsurgery techniques. By applying these methods, with which I have extensive expertise, we will determine the organization of these microtubules, identify the proteins that link them with k-fibers, and uncover where and how the forces for kinetochore positioning and movement are generated. My strength is in taking an interdisciplinary approach, which I will use in this project by combining laser microsurgery with genetic perturbations, quantitative measurements of the responses and comparison with theoretical models. Understanding the role of bridging microtubules in force generation and chromosome movements will not only shed light on the mechanism of chromosome segregation, but may also increase the potential of mitotic anticancer strategies, as the spindle is a major target for chemotherapy. The proposed ERC funding is essential for the success of these timely and ambitious experiments, allowing me to strengthen my position as an international leader in research on cell division, thereby increasing Europe's foremost position in this field.

2 150 000 €

Start date: 2015-04-01, End date: 2020-03-31

A significant proportion of patients with epilepsy are refractive to pharmaceutical treatments. Recurrent, untreated epileptic seizures are associated with risk of adverse neurological, cognitive, and psychological outcomes. Despite years of study, there are still significant barriers to the management of these disorders. In my proposal I advance the hypothesis that time-targeted perturbation of neural network oscillations by transcranial electric stimulation (TES) decreases the duration of seizures. I hypothesize further that spatially focused TES and chronically applied TES intervention can also permanently reduce seizure occurrence. Our specific aims are designed to perform in vivo studies in rodent models of two seizure types (absence seizures and complex partial seizures) to evaluate the effectiveness of TES in abrogating pathologic network activity, and to use high resolution recording techniques and optogenetical methods to assess the neural mechanisms involved. Our results may help to establish general principles of the diverse epilepsy pathophysiology and introduce novel therapeutic approaches. We will establish a focal TES stimulation protocol to selectively interfere with brain regions previously identified as key structures in the pathomechanism of epilepsy. The deliverables of these experiments will make a significant advancement in the understanding of the pathomechanisms of these disorders, and will offer a new alternative treatment option as a complimentary therapeutic approach to the state of the art pharmaceutical products. The methods used in this project are unique and advanced as the first attempt to perform 512 channel extracellular recordings in the behaving animal to investigate the evolution of epileptic seizures at the neuronal network and cellular levels and by achieving spatially selective TES. The combination of these methods are deployed for both understanding the mechanisms of seizure evolution, and termination of seizures.

1 419 000 €

Start date: 2013-11-01, End date: 2018-10-31

Understanding how humans and other animals are able to learn from experience and use this information to select future behavioural strategies to obtain the reinforcers necessary for survival, is a fundamental research question in biology. Considerable progress has been made in recent years on the neural computational underpinnings of this process following the observation that the phasic activity of dopamine neurons in the midbrain resembles a prediction error from a formal computational theory known as reinforcement learning (RL). While much is known about the functions of dopamine in RL, much less is known about the computational functions of other modulatory neurotransmitter systems in the midbrain such as the cholinergic, norcpinephrine, and serotonergic systems. The goal of this research proposal to the ERC, is to begin a systematic study of the computational functions of these other neurotransmitter systems (beyond dopamine) in RL. To do this we will combine functional magnetic resonance imaging in human subjects while they perform simple decision making tasks and undergo pharmacological manipulations to modulate systemic levels of these different neurotransmitter systems. We will combine computational model-based analyses with fMRI and behavioural data in order to explore the effects that these pharmacological modulations exert on different parameters and modules within RL. Specifically, we will test the contributions that the cholinergic system makes in setting the learning rate during RL and in mediating computations of expected uncertainty in the distribution of rewards available, we will test for the role of norepinephrine in balancing the rate of exploration and exploitation during decision making, as well as in encoding the level of unexpected uncertainty, and we will explore the possible role of serotonin in setting the rate of temporal discounting for reward, or in encoding prediction errors during aversive as opposed to reward-learning.

1 841 404 €

Start date: 2010-01-01, End date: 2010-09-30

With an unprecedented increase in the human population, higher agricultural production, enhanced food safety and the protection against alarming rise of antibiotic resistant pathogenic bacteria are amongst the main challenges of this century. This proposal centered on Rhizobium-legume symbiosis aims at contributing to these tasks by i) understanding the development of symbiotic nitrogen fixing cells for improvement of the eco-friendly biological nitrogen fixation, ii) gaining a comprehensive knowledge on polyploidy having a great impact on crop yields and iii) exploiting the strategies of symbiotic plant cells for the development of novel antibiotics. Symbiotic nitrogen fixation in Rhizobium-legume interactions is a major contributor to the combined nitrogen pool in the biosphere. It takes place in root nodules where giant plant cells host the nitrogen fixing bacteria. In Medicago nodules both the plant cells and the bacteria are polyploids and incapable for cell division. These polyploid plant cells produce hundreds of symbiotic peptides (symPEPs) that provoke terminal differentiation of bacteria in symbiosis and exhibit broad range antimicrobial activities in vitro. Permanent generation of polyploid cells is essential for the nodule development. It will be studied whether the complete genome is duplicated in consecutive endocycles, how different ploidy levels affect DNA methylation and expression profile and whether polyploidy is required for the expression of symPEP genes. The activity and mode of actions of symPEPs are in the focus of the proposal; i) how symPEPs achieve bacteroid differentiation and affect nitrogen fixation and ii) whether symPEP antimicrobial activities provide novel modes of antimicrobial actions and iii) whether ¿Sym-Biotics¿ could become widely used novel antibiotics. Their applicability as plant protecting and meat decontaminating agents as well as their in vivo efficiency in mouse septicemia models will be tested.

2 320 000 €

Start date: 2011-07-01, End date: 2017-06-30