Project acronym 100 Archaic Genomes
Project Genome sequences from extinct hominins
Researcher (PI) Svante PaeaeBO
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Country Germany
Call Details Advanced Grant (AdG), LS2, ERC-2015-AdG
Summary Neandertals and Denisovans, an Asian group distantly related to Neandertals, are the closest evolutionary relatives of present-day humans. They are thus of direct relevance for understanding the origin of modern humans and how modern humans differ from their closest relatives. We will generate genome-wide data from a large number of Neandertal and Denisovan individuals from across their geographical and temporal range as well as from other extinct hominin groups which we may discover. This will be possible by automating highly sensitive approaches to ancient DNA extraction and DNA libraries construction that we have developed so that they can be applied to many specimens from many sites in order to identify those that contain retrievable DNA. Whenever possible we will sequence whole genomes and in other cases use DNA capture methods to generate high-quality data from representative parts of the genome. This will allow us to study the population history of Neandertals and Denisovans, elucidate how many times and where these extinct hominins contributed genes to present-day people, and the extent to which modern humans and archaic groups contributed genetically to Neandertals and Denisovans. By retrieving DNA from specimens that go back to the Middle Pleistocene we will furthermore shed light on the early history and origins of Neandertals and Denisovans.
Summary
Neandertals and Denisovans, an Asian group distantly related to Neandertals, are the closest evolutionary relatives of present-day humans. They are thus of direct relevance for understanding the origin of modern humans and how modern humans differ from their closest relatives. We will generate genome-wide data from a large number of Neandertal and Denisovan individuals from across their geographical and temporal range as well as from other extinct hominin groups which we may discover. This will be possible by automating highly sensitive approaches to ancient DNA extraction and DNA libraries construction that we have developed so that they can be applied to many specimens from many sites in order to identify those that contain retrievable DNA. Whenever possible we will sequence whole genomes and in other cases use DNA capture methods to generate high-quality data from representative parts of the genome. This will allow us to study the population history of Neandertals and Denisovans, elucidate how many times and where these extinct hominins contributed genes to present-day people, and the extent to which modern humans and archaic groups contributed genetically to Neandertals and Denisovans. By retrieving DNA from specimens that go back to the Middle Pleistocene we will furthermore shed light on the early history and origins of Neandertals and Denisovans.
Max ERC Funding
2 350 000 €
Duration
Start date: 2016-11-01, End date: 2021-10-31
Project acronym 3DBrainStrom
Project Brain metastases: Deciphering tumor-stroma interactions in three dimensions for the rational design of nanomedicines
Researcher (PI) Ronit Satchi Fainaro
Host Institution (HI) TEL AVIV UNIVERSITY
Country Israel
Call Details Advanced Grant (AdG), LS7, ERC-2018-ADG
Summary Brain metastases represent a major therapeutic challenge. Despite significant breakthroughs in targeted therapies, survival rates of patients with brain metastases remain poor. Nowadays, discovery, development and evaluation of new therapies are performed on human cancer cells grown in 2D on rigid plastic plates followed by in vivo testing in immunodeficient mice. These experimental settings are lacking and constitute a fundamental hurdle for the translation of preclinical discoveries into clinical practice. We propose to establish 3D-printed models of brain metastases (Aim 1), which include brain extracellular matrix, stroma and serum containing immune cells flowing in functional tumor vessels. Our unique models better capture the clinical physio-mechanical tissue properties, signaling pathways, hemodynamics and drug responsiveness. Using our 3D-printed models, we aim to develop two new fronts for identifying novel clinically-relevant molecular drivers (Aim 2) followed by the development of precision nanomedicines (Aim 3). We will exploit our vast experience in anticancer nanomedicines to design three therapeutic approaches that target various cellular compartments involved in brain metastases: 1) Prevention of brain metastatic colonization using targeted nano-vaccines, which elicit antitumor immune response; 2) Intervention of tumor-brain stroma cells crosstalk when brain micrometastases establish; 3) Regression of macrometastatic disease by selectively targeting tumor cells. These approaches will materialize using our libraries of polymeric nanocarriers that selectively accumulate in tumors.
This project will result in a paradigm shift by generating new preclinical cancer models that will bridge the translational gap in cancer therapeutics. The insights and tumor-stroma-targeted nanomedicines developed here will pave the way for prediction of patient outcome, revolutionizing our perception of tumor modelling and consequently the way we prevent and treat cancer.
Summary
Brain metastases represent a major therapeutic challenge. Despite significant breakthroughs in targeted therapies, survival rates of patients with brain metastases remain poor. Nowadays, discovery, development and evaluation of new therapies are performed on human cancer cells grown in 2D on rigid plastic plates followed by in vivo testing in immunodeficient mice. These experimental settings are lacking and constitute a fundamental hurdle for the translation of preclinical discoveries into clinical practice. We propose to establish 3D-printed models of brain metastases (Aim 1), which include brain extracellular matrix, stroma and serum containing immune cells flowing in functional tumor vessels. Our unique models better capture the clinical physio-mechanical tissue properties, signaling pathways, hemodynamics and drug responsiveness. Using our 3D-printed models, we aim to develop two new fronts for identifying novel clinically-relevant molecular drivers (Aim 2) followed by the development of precision nanomedicines (Aim 3). We will exploit our vast experience in anticancer nanomedicines to design three therapeutic approaches that target various cellular compartments involved in brain metastases: 1) Prevention of brain metastatic colonization using targeted nano-vaccines, which elicit antitumor immune response; 2) Intervention of tumor-brain stroma cells crosstalk when brain micrometastases establish; 3) Regression of macrometastatic disease by selectively targeting tumor cells. These approaches will materialize using our libraries of polymeric nanocarriers that selectively accumulate in tumors.
This project will result in a paradigm shift by generating new preclinical cancer models that will bridge the translational gap in cancer therapeutics. The insights and tumor-stroma-targeted nanomedicines developed here will pave the way for prediction of patient outcome, revolutionizing our perception of tumor modelling and consequently the way we prevent and treat cancer.
Max ERC Funding
2 353 125 €
Duration
Start date: 2019-04-01, End date: 2024-03-31
Project acronym 3DEpi
Project Transgenerational epigenetic inheritance of chromatin states : the role of Polycomb and 3D chromosome architecture
Researcher (PI) Giacomo CAVALLI
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Country France
Call Details Advanced Grant (AdG), LS2, ERC-2017-ADG
Summary Epigenetic inheritance entails transmission of phenotypic traits not encoded in the DNA sequence and, in the most extreme case, Transgenerational Epigenetic Inheritance (TEI) involves transmission of memory through multiple generations. Very little is known on the mechanisms governing TEI and this is the subject of the present proposal. By transiently enhancing long-range chromatin interactions, we recently established isogenic Drosophila epilines that carry stable alternative epialleles, defined by differential levels of the Polycomb-dependent H3K27me3 mark. Furthermore, we extended our paradigm to natural phenotypes. These are ideal systems to study the role of Polycomb group (PcG) proteins and other components in regulating nuclear organization and epigenetic inheritance of chromatin states. The present project conjugates genetics, epigenomics, imaging and molecular biology to reach three critical aims.
Aim 1: Analysis of the molecular mechanisms regulating Polycomb-mediated TEI. We will identify the DNA, protein and RNA components that trigger and maintain transgenerational chromatin inheritance as well as their mechanisms of action.
Aim 2: Role of 3D genome organization in the regulation of TEI. We will analyze the developmental dynamics of TEI-inducing long-range chromatin interactions, identify chromatin components mediating 3D chromatin contacts and characterize their function in the TEI process.
Aim 3: Identification of a broader role of TEI during development. TEI might reflect a normal role of PcG components in the transmission of parental chromatin onto the next embryonic generation. We will explore this possibility by establishing other TEI paradigms and by relating TEI to the normal PcG function in these systems and in normal development.
This research program will unravel the biological significance and the molecular underpinnings of TEI and lead the way towards establishing this area of research into a consolidated scientific discipline.
Summary
Epigenetic inheritance entails transmission of phenotypic traits not encoded in the DNA sequence and, in the most extreme case, Transgenerational Epigenetic Inheritance (TEI) involves transmission of memory through multiple generations. Very little is known on the mechanisms governing TEI and this is the subject of the present proposal. By transiently enhancing long-range chromatin interactions, we recently established isogenic Drosophila epilines that carry stable alternative epialleles, defined by differential levels of the Polycomb-dependent H3K27me3 mark. Furthermore, we extended our paradigm to natural phenotypes. These are ideal systems to study the role of Polycomb group (PcG) proteins and other components in regulating nuclear organization and epigenetic inheritance of chromatin states. The present project conjugates genetics, epigenomics, imaging and molecular biology to reach three critical aims.
Aim 1: Analysis of the molecular mechanisms regulating Polycomb-mediated TEI. We will identify the DNA, protein and RNA components that trigger and maintain transgenerational chromatin inheritance as well as their mechanisms of action.
Aim 2: Role of 3D genome organization in the regulation of TEI. We will analyze the developmental dynamics of TEI-inducing long-range chromatin interactions, identify chromatin components mediating 3D chromatin contacts and characterize their function in the TEI process.
Aim 3: Identification of a broader role of TEI during development. TEI might reflect a normal role of PcG components in the transmission of parental chromatin onto the next embryonic generation. We will explore this possibility by establishing other TEI paradigms and by relating TEI to the normal PcG function in these systems and in normal development.
This research program will unravel the biological significance and the molecular underpinnings of TEI and lead the way towards establishing this area of research into a consolidated scientific discipline.
Max ERC Funding
2 500 000 €
Duration
Start date: 2018-11-01, End date: 2023-10-31
Project acronym 4D IMAGING
Project Towards 4D Imaging of Fundamental Processes on the Atomic and Sub-Atomic Scale
Researcher (PI) Ferenc Krausz
Host Institution (HI) LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN
Country Germany
Call Details Advanced Grant (AdG), PE2, ERC-2009-AdG
Summary State-of-the-art microscopy and diffraction imaging provides insight into the atomic and sub-atomic structure of matter. They permit determination of the positions of atoms in a crystal lattice or in a molecule as well as the distribution of electrons inside atoms. State-of-the-art time-resolved spectroscopy with femtosecond and attosecond resolution provides access to dynamic changes in the atomic and electronic structure of matter. Our proposal aims at combining these two frontier techniques of XXI century science to make a long-standing dream of scientist come true: the direct observation of atoms and electrons in their natural state: in motion. Shifts in the atoms positions by tens to hundreds of picometers can make chemical bonds break apart or newly form, changing the structure and/or chemical composition of matter. Electronic motion on similar scales may result in the emission of light, or the initiation of processes that lead to a change in physical or chemical properties, or biological function. These motions happen within femtoseconds and attoseconds, respectively. To make them observable, we need a 4-dimensional (4D) imaging technique capable of recording freeze-frame snapshots of microscopic systems with picometer spatial resolution and femtosecond to attosecond exposure time. The motion can then be visualized by slow-motion replay of the freeze-frame shots. The goal of this project is to develop a 4D imaging technique that will ultimately offer picometer resolution is space and attosecond resolution in time.
Summary
State-of-the-art microscopy and diffraction imaging provides insight into the atomic and sub-atomic structure of matter. They permit determination of the positions of atoms in a crystal lattice or in a molecule as well as the distribution of electrons inside atoms. State-of-the-art time-resolved spectroscopy with femtosecond and attosecond resolution provides access to dynamic changes in the atomic and electronic structure of matter. Our proposal aims at combining these two frontier techniques of XXI century science to make a long-standing dream of scientist come true: the direct observation of atoms and electrons in their natural state: in motion. Shifts in the atoms positions by tens to hundreds of picometers can make chemical bonds break apart or newly form, changing the structure and/or chemical composition of matter. Electronic motion on similar scales may result in the emission of light, or the initiation of processes that lead to a change in physical or chemical properties, or biological function. These motions happen within femtoseconds and attoseconds, respectively. To make them observable, we need a 4-dimensional (4D) imaging technique capable of recording freeze-frame snapshots of microscopic systems with picometer spatial resolution and femtosecond to attosecond exposure time. The motion can then be visualized by slow-motion replay of the freeze-frame shots. The goal of this project is to develop a 4D imaging technique that will ultimately offer picometer resolution is space and attosecond resolution in time.
Max ERC Funding
2 500 000 €
Duration
Start date: 2010-03-01, End date: 2015-02-28
Project acronym 4D-PET
Project Innovative PET scanner for dynamic imaging
Researcher (PI) Jose MarIa BENLLOCH BAVIERA
Host Institution (HI) AGENCIA ESTATAL CONSEJO SUPERIOR DEINVESTIGACIONES CIENTIFICAS
Country Spain
Call Details Advanced Grant (AdG), LS7, ERC-2015-AdG
Summary The main objective of 4D-PET is to develop an innovative whole-body PET scanner based in a new detector concept that stores 3D position and time of every single gamma interaction with unprecedented resolution. The combination of scanner geometrical design and high timing resolution will enable developing a full sequence of all gamma-ray interactions inside the scanner, including Compton interactions, like in a 3D movie. 4D-PET fully exploits Time Of Flight (TOF) information to obtain a better image quality and to increase scanner sensitivity, through the inclusion in the image formation of all Compton events occurring inside the detector, which are always rejected in state-of-the-art PET scanners. The new PET design will radically improve state-of-the-art PET performance features, overcoming limitations of current PET technology and opening up new diagnostic venues and very valuable physiological information
Summary
The main objective of 4D-PET is to develop an innovative whole-body PET scanner based in a new detector concept that stores 3D position and time of every single gamma interaction with unprecedented resolution. The combination of scanner geometrical design and high timing resolution will enable developing a full sequence of all gamma-ray interactions inside the scanner, including Compton interactions, like in a 3D movie. 4D-PET fully exploits Time Of Flight (TOF) information to obtain a better image quality and to increase scanner sensitivity, through the inclusion in the image formation of all Compton events occurring inside the detector, which are always rejected in state-of-the-art PET scanners. The new PET design will radically improve state-of-the-art PET performance features, overcoming limitations of current PET technology and opening up new diagnostic venues and very valuable physiological information
Max ERC Funding
2 048 386 €
Duration
Start date: 2017-01-01, End date: 2021-12-31
Project acronym 4PI-SKY
Project 4 pi sky: Extreme Astrophysics with Revolutionary Radio Telescopes
Researcher (PI) Robert Philip Fender
Host Institution (HI) THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD
Country United Kingdom
Call Details Advanced Grant (AdG), PE9, ERC-2010-AdG_20100224
Summary Extreme astrophysical events such as relativistic flows, cataclysmic explosions and black hole accretion are one of the key areas for astrophysics in the 21st century. The extremes of physics experienced in these environments are beyond anything achievable in any laboratory on Earth, and provide a unique glimpse at the laws of physics operating in extraordinary regimes. All of these events are associated with transient radio emission, a tracer both of the acceleration of particles to relativistic energies, and coherent emitting regions with huge effective temperatures. By studying radio bursts from these phenomena we can pinpoint the sources of explosive events, understand the budget of kinetic feedback by explosive events in the ambient medium, and probe the physical state of the universe back to the epoch of reionisation, less than a billion years after the big bang. In seeking to push back the frontiers of extreme astrophysics, I will use a trio of revolutionary new radio telescopes, LOFAR, ASKAP and MeerKAT, pathfinders for the Square Kilometre Array, and all facilities in which I have a major role in the search for transients. I will build an infrastructure which transforms their combined operations for the discovery, classification and reporting of transient astrophysical events, over the whole sky, making them much more than the sum of their parts. This will include development of environments for the coordinated handling of extreme astrophysical events, in real time, via automated systems, as well as novel techniques for the detection of these events in a sea of noise. I will furthermore augment this program by buying in as a major partner to a rapid-response robotic optical telescope, and by cementing my relationship with an orbiting X-ray facility. This multiwavelength dimension will secure the astrophysical interpretation of our observational results and help to revolutionise high-energy astrophysics via a strong scientific exploitation program.
Summary
Extreme astrophysical events such as relativistic flows, cataclysmic explosions and black hole accretion are one of the key areas for astrophysics in the 21st century. The extremes of physics experienced in these environments are beyond anything achievable in any laboratory on Earth, and provide a unique glimpse at the laws of physics operating in extraordinary regimes. All of these events are associated with transient radio emission, a tracer both of the acceleration of particles to relativistic energies, and coherent emitting regions with huge effective temperatures. By studying radio bursts from these phenomena we can pinpoint the sources of explosive events, understand the budget of kinetic feedback by explosive events in the ambient medium, and probe the physical state of the universe back to the epoch of reionisation, less than a billion years after the big bang. In seeking to push back the frontiers of extreme astrophysics, I will use a trio of revolutionary new radio telescopes, LOFAR, ASKAP and MeerKAT, pathfinders for the Square Kilometre Array, and all facilities in which I have a major role in the search for transients. I will build an infrastructure which transforms their combined operations for the discovery, classification and reporting of transient astrophysical events, over the whole sky, making them much more than the sum of their parts. This will include development of environments for the coordinated handling of extreme astrophysical events, in real time, via automated systems, as well as novel techniques for the detection of these events in a sea of noise. I will furthermore augment this program by buying in as a major partner to a rapid-response robotic optical telescope, and by cementing my relationship with an orbiting X-ray facility. This multiwavelength dimension will secure the astrophysical interpretation of our observational results and help to revolutionise high-energy astrophysics via a strong scientific exploitation program.
Max ERC Funding
2 999 847 €
Duration
Start date: 2011-07-01, End date: 2017-06-30
Project acronym 5D Heart Patch
Project A Functional, Mature In vivo Human Ventricular Muscle Patch for Cardiomyopathy
Researcher (PI) Kenneth Randall Chien
Host Institution (HI) KAROLINSKA INSTITUTET
Country Sweden
Call Details Advanced Grant (AdG), LS7, ERC-2016-ADG
Summary Developing new therapeutic strategies for heart regeneration is a major goal for cardiac biology and medicine. While cardiomyocytes can be generated from human pluripotent stem (hPSC) cells in vitro, it has proven difficult to use these cells to generate a large scale, mature human heart ventricular muscle graft on the injured heart in vivo. The central objective of this proposal is to optimize the generation of a large-scale pure, fully functional human ventricular muscle patch in vivo through the self-assembly of purified human ventricular progenitors and the localized expression of defined paracrine factors that drive their expansion, differentiation, vascularization, matrix formation, and maturation. Recently, we have found that purified hPSC-derived ventricular progenitors (HVPs) can self-assemble in vivo on the epicardial surface into a 3D vascularized, and functional ventricular patch with its own extracellular matrix via a cell autonomous pathway. A two-step protocol and FACS purification of HVP receptors can generate billions of pure HVPs- The current proposal will lead to the identification of defined paracrine pathways to enhance the survival, grafting/implantation, expansion, differentiation, matrix formation, vascularization and maturation of the graft in vivo. We will captalize on our unique HVP system and our novel modRNA technology to deliver therapeutic strategies by using the in vivo human ventricular muscle to model in vivo arrhythmogenic cardiomyopathy, and optimize the ability of the graft to compensate for the massive loss of functional muscle during ischemic cardiomyopathy and post-myocardial infarction. The studies will lead to new in vivo chimeric models of human cardiac disease and an experimental paradigm to optimize organ-on-organ cardiac tissue engineers of an in vivo, functional mature ventricular patch for cardiomyopathy
Summary
Developing new therapeutic strategies for heart regeneration is a major goal for cardiac biology and medicine. While cardiomyocytes can be generated from human pluripotent stem (hPSC) cells in vitro, it has proven difficult to use these cells to generate a large scale, mature human heart ventricular muscle graft on the injured heart in vivo. The central objective of this proposal is to optimize the generation of a large-scale pure, fully functional human ventricular muscle patch in vivo through the self-assembly of purified human ventricular progenitors and the localized expression of defined paracrine factors that drive their expansion, differentiation, vascularization, matrix formation, and maturation. Recently, we have found that purified hPSC-derived ventricular progenitors (HVPs) can self-assemble in vivo on the epicardial surface into a 3D vascularized, and functional ventricular patch with its own extracellular matrix via a cell autonomous pathway. A two-step protocol and FACS purification of HVP receptors can generate billions of pure HVPs- The current proposal will lead to the identification of defined paracrine pathways to enhance the survival, grafting/implantation, expansion, differentiation, matrix formation, vascularization and maturation of the graft in vivo. We will captalize on our unique HVP system and our novel modRNA technology to deliver therapeutic strategies by using the in vivo human ventricular muscle to model in vivo arrhythmogenic cardiomyopathy, and optimize the ability of the graft to compensate for the massive loss of functional muscle during ischemic cardiomyopathy and post-myocardial infarction. The studies will lead to new in vivo chimeric models of human cardiac disease and an experimental paradigm to optimize organ-on-organ cardiac tissue engineers of an in vivo, functional mature ventricular patch for cardiomyopathy
Max ERC Funding
2 149 228 €
Duration
Start date: 2017-12-01, End date: 2022-11-30
Project acronym 5HT-OPTOGENETICS
Project Optogenetic Analysis of Serotonin Function in the Mammalian Brain
Researcher (PI) Zachary Mainen
Host Institution (HI) FUNDACAO D. ANNA SOMMER CHAMPALIMAUD E DR. CARLOS MONTEZ CHAMPALIMAUD
Country Portugal
Call Details Advanced Grant (AdG), LS5, ERC-2009-AdG
Summary Serotonin (5-HT) is implicated in a wide spectrum of brain functions and disorders. However, its functions remain controversial and enigmatic. We suggest that past work on the 5-HT system have been significantly hampered by technical limitations in the selectivity and temporal resolution of the conventional pharmacological and electrophysiological methods that have been applied. We therefore propose to apply novel optogenetic methods that will allow us to overcome these limitations and thereby gain new insight into the biological functions of this important molecule. In preliminary studies, we have demonstrated that we can deliver exogenous proteins specifically to 5-HT neurons using viral vectors. Our objectives are to (1) record, (2) stimulate and (3) silence the activity of 5-HT neurons with high molecular selectivity and temporal precision by using genetically-encoded sensors, activators and inhibitors of neural function. These tools will allow us to monitor and control the 5-HT system in real-time in freely-behaving animals and thereby to establish causal links between information processing in 5-HT neurons and specific behaviors. In combination with quantitative behavioral assays, we will use this approach to define the role of 5-HT in sensory, motor and cognitive functions. The significance of the work is three-fold. First, we will establish a new arsenal of tools for probing the physiological and behavioral functions of 5-HT neurons. Second, we will make definitive tests of major hypotheses of 5-HT function. Third, we will have possible therapeutic applications. In this way, the proposed work has the potential for a major impact in research on the role of 5-HT in brain function and dysfunction.
Summary
Serotonin (5-HT) is implicated in a wide spectrum of brain functions and disorders. However, its functions remain controversial and enigmatic. We suggest that past work on the 5-HT system have been significantly hampered by technical limitations in the selectivity and temporal resolution of the conventional pharmacological and electrophysiological methods that have been applied. We therefore propose to apply novel optogenetic methods that will allow us to overcome these limitations and thereby gain new insight into the biological functions of this important molecule. In preliminary studies, we have demonstrated that we can deliver exogenous proteins specifically to 5-HT neurons using viral vectors. Our objectives are to (1) record, (2) stimulate and (3) silence the activity of 5-HT neurons with high molecular selectivity and temporal precision by using genetically-encoded sensors, activators and inhibitors of neural function. These tools will allow us to monitor and control the 5-HT system in real-time in freely-behaving animals and thereby to establish causal links between information processing in 5-HT neurons and specific behaviors. In combination with quantitative behavioral assays, we will use this approach to define the role of 5-HT in sensory, motor and cognitive functions. The significance of the work is three-fold. First, we will establish a new arsenal of tools for probing the physiological and behavioral functions of 5-HT neurons. Second, we will make definitive tests of major hypotheses of 5-HT function. Third, we will have possible therapeutic applications. In this way, the proposed work has the potential for a major impact in research on the role of 5-HT in brain function and dysfunction.
Max ERC Funding
2 318 636 €
Duration
Start date: 2010-07-01, End date: 2015-12-31
Project acronym 5HTCircuits
Project Modulation of cortical circuits and predictive neural coding by serotonin
Researcher (PI) Zachary Mainen
Host Institution (HI) FUNDACAO D. ANNA SOMMER CHAMPALIMAUD E DR. CARLOS MONTEZ CHAMPALIMAUD
Country Portugal
Call Details Advanced Grant (AdG), LS5, ERC-2014-ADG
Summary Serotonin (5-HT) is a central neuromodulator and a major target of therapeutic psychoactive drugs, but relatively little is known about how it modulates information processing in neural circuits. The theory of predictive coding postulates that the brain combines raw bottom-up sensory information with top-down information from internal models to make perceptual inferences about the world. We hypothesize, based on preliminary data and prior literature, that a role of 5-HT in this process is to report prediction errors and promote the suppression and weakening of erroneous internal models. We propose that it does this by inhibiting top-down relative to bottom-up cortical information flow. To test this hypothesis, we propose a set of experiments in mice performing olfactory perceptual tasks. Our specific aims are: (1) We will test whether 5-HT neurons encode sensory prediction errors. (2) We will test their causal role in using predictive cues to guide perceptual decisions. (3) We will characterize how 5-HT influences the encoding of sensory information by neuronal populations in the olfactory cortex and identify the underlying circuitry. (4) Finally, we will map the effects of 5-HT across the whole brain and use this information to target further causal manipulations to specific 5-HT projections. We accomplish these aims using state-of-the-art optogenetic, electrophysiological and imaging techniques (including 9.4T small-animal functional magnetic resonance imaging) as well as psychophysical tasks amenable to quantitative analysis and computational theory. Together, these experiments will tackle multiple facets of an important general computational question, bringing to bear an array of cutting-edge technologies to address with unprecedented mechanistic detail how 5-HT impacts neural coding and perceptual decision-making.
Summary
Serotonin (5-HT) is a central neuromodulator and a major target of therapeutic psychoactive drugs, but relatively little is known about how it modulates information processing in neural circuits. The theory of predictive coding postulates that the brain combines raw bottom-up sensory information with top-down information from internal models to make perceptual inferences about the world. We hypothesize, based on preliminary data and prior literature, that a role of 5-HT in this process is to report prediction errors and promote the suppression and weakening of erroneous internal models. We propose that it does this by inhibiting top-down relative to bottom-up cortical information flow. To test this hypothesis, we propose a set of experiments in mice performing olfactory perceptual tasks. Our specific aims are: (1) We will test whether 5-HT neurons encode sensory prediction errors. (2) We will test their causal role in using predictive cues to guide perceptual decisions. (3) We will characterize how 5-HT influences the encoding of sensory information by neuronal populations in the olfactory cortex and identify the underlying circuitry. (4) Finally, we will map the effects of 5-HT across the whole brain and use this information to target further causal manipulations to specific 5-HT projections. We accomplish these aims using state-of-the-art optogenetic, electrophysiological and imaging techniques (including 9.4T small-animal functional magnetic resonance imaging) as well as psychophysical tasks amenable to quantitative analysis and computational theory. Together, these experiments will tackle multiple facets of an important general computational question, bringing to bear an array of cutting-edge technologies to address with unprecedented mechanistic detail how 5-HT impacts neural coding and perceptual decision-making.
Max ERC Funding
2 486 074 €
Duration
Start date: 2016-01-01, End date: 2020-12-31
Project acronym AAA
Project Adaptive Actin Architectures
Researcher (PI) Laurent Blanchoin
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Country France
Call Details Advanced Grant (AdG), LS3, ERC-2016-ADG
Summary Although we have extensive knowledge of many important processes in cell biology, including information on many of the molecules involved and the physical interactions among them, we still do not understand most of the dynamical features that are the essence of living systems. This is particularly true for the actin cytoskeleton, a major component of the internal architecture of eukaryotic cells. In living cells, actin networks constantly assemble and disassemble filaments while maintaining an apparent stable structure, suggesting a perfect balance between the two processes. Such behaviors are called “dynamic steady states”. They confer upon actin networks a high degree of plasticity allowing them to adapt in response to external changes and enable cells to adjust to their environments. Despite their fundamental importance in the regulation of cell physiology, the basic mechanisms that control the coordinated dynamics of co-existing actin networks are poorly understood. In the AAA project, first, we will characterize the parameters that allow the coupling among co-existing actin networks at steady state. In vitro reconstituted systems will be used to control the actin nucleation patterns, the closed volume of the reaction chamber and the physical interaction of the networks. We hope to unravel the mechanism allowing the global coherence of a dynamic actin cytoskeleton. Second, we will use our unique capacity to perform dynamic micropatterning, to add or remove actin nucleation sites in real time, in order to investigate the ability of dynamic networks to adapt to changes and the role of coupled network dynamics in this emergent property. In this part, in vitro experiments will be complemented by the analysis of actin network remodeling in living cells. In the end, our project will provide a comprehensive understanding of how the adaptive response of the cytoskeleton derives from the complex interplay between its biochemical, structural and mechanical properties.
Summary
Although we have extensive knowledge of many important processes in cell biology, including information on many of the molecules involved and the physical interactions among them, we still do not understand most of the dynamical features that are the essence of living systems. This is particularly true for the actin cytoskeleton, a major component of the internal architecture of eukaryotic cells. In living cells, actin networks constantly assemble and disassemble filaments while maintaining an apparent stable structure, suggesting a perfect balance between the two processes. Such behaviors are called “dynamic steady states”. They confer upon actin networks a high degree of plasticity allowing them to adapt in response to external changes and enable cells to adjust to their environments. Despite their fundamental importance in the regulation of cell physiology, the basic mechanisms that control the coordinated dynamics of co-existing actin networks are poorly understood. In the AAA project, first, we will characterize the parameters that allow the coupling among co-existing actin networks at steady state. In vitro reconstituted systems will be used to control the actin nucleation patterns, the closed volume of the reaction chamber and the physical interaction of the networks. We hope to unravel the mechanism allowing the global coherence of a dynamic actin cytoskeleton. Second, we will use our unique capacity to perform dynamic micropatterning, to add or remove actin nucleation sites in real time, in order to investigate the ability of dynamic networks to adapt to changes and the role of coupled network dynamics in this emergent property. In this part, in vitro experiments will be complemented by the analysis of actin network remodeling in living cells. In the end, our project will provide a comprehensive understanding of how the adaptive response of the cytoskeleton derives from the complex interplay between its biochemical, structural and mechanical properties.
Max ERC Funding
2 349 898 €
Duration
Start date: 2017-09-01, End date: 2022-08-31