Project acronym 2STEPPARKIN
Project A novel two-step model for neurodegeneration in Parkinson’s disease
Researcher (PI) Emi Nagoshi
Host Institution (HI) UNIVERSITE DE GENEVE
Call Details Starting Grant (StG), LS5, ERC-2012-StG_20111109
Summary Parkinson’s disease (PD) is the second most common neurodegenerative disorder primarily caused by the progressive loss of dopaminergic (DA) neurons in the substantia nigra (SN). Despite the advances in gene discovery associated with PD, the knowledge of the PD pathogenesis is largely limited to the involvement of these genes in the generic cell death pathways, and why degeneration is specific to DA neurons and why the degeneration is progressive remain enigmatic. Broad goal of our work is therefore to elucidate the mechanisms underlying specific and progressive DA neuron degeneration in PD. Our new Drosophila model of PD ⎯Fer2 gene loss-of-function mutation⎯ is unusually well suited to address these questions. Fer2 mutants exhibit specific and progressive death of brain DA neurons as well as severe locomotor defects and short life span. Strikingly, the death of DA neuron is initiated in a small cluster of Fer2-expressing DA neurons and subsequently propagates to Fer2-negative DA neurons. We therefore propose a novel two-step model of the neurodegeneration in PD: primary cell death occurs in a specific subset of dopamindegic neurons that are genetically defined, and subsequently the failure of the neuronal connectivity triggers and propagates secondary cell death to remaining DA neurons. In this research, we will test this hypothesis and investigate the underlying molecular mechanisms. This will be the first study to examine circuit-dependency in DA neuron degeneration. Our approach will use a combination of non-biased genomic techniques and candidate-based screening, in addition to the powerful Drosophila genetic toolbox. Furthermore, to test this hypothesis beyond the Drosophila model, we will establish new mouse models of PD that exhibit progressive DA neuron degeneration. Outcome of this research will likely revolutionize the understanding of PD pathogenesis and open an avenue toward the discovery of effective therapy strategies against PD.
Summary
Parkinson’s disease (PD) is the second most common neurodegenerative disorder primarily caused by the progressive loss of dopaminergic (DA) neurons in the substantia nigra (SN). Despite the advances in gene discovery associated with PD, the knowledge of the PD pathogenesis is largely limited to the involvement of these genes in the generic cell death pathways, and why degeneration is specific to DA neurons and why the degeneration is progressive remain enigmatic. Broad goal of our work is therefore to elucidate the mechanisms underlying specific and progressive DA neuron degeneration in PD. Our new Drosophila model of PD ⎯Fer2 gene loss-of-function mutation⎯ is unusually well suited to address these questions. Fer2 mutants exhibit specific and progressive death of brain DA neurons as well as severe locomotor defects and short life span. Strikingly, the death of DA neuron is initiated in a small cluster of Fer2-expressing DA neurons and subsequently propagates to Fer2-negative DA neurons. We therefore propose a novel two-step model of the neurodegeneration in PD: primary cell death occurs in a specific subset of dopamindegic neurons that are genetically defined, and subsequently the failure of the neuronal connectivity triggers and propagates secondary cell death to remaining DA neurons. In this research, we will test this hypothesis and investigate the underlying molecular mechanisms. This will be the first study to examine circuit-dependency in DA neuron degeneration. Our approach will use a combination of non-biased genomic techniques and candidate-based screening, in addition to the powerful Drosophila genetic toolbox. Furthermore, to test this hypothesis beyond the Drosophila model, we will establish new mouse models of PD that exhibit progressive DA neuron degeneration. Outcome of this research will likely revolutionize the understanding of PD pathogenesis and open an avenue toward the discovery of effective therapy strategies against PD.
Max ERC Funding
1 518 960 €
Duration
Start date: 2013-06-01, End date: 2018-05-31
Project acronym AMYLOID
Project Identification and modulation of pathogenic Amyloid beta-peptide species
Researcher (PI) Christian Haass
Host Institution (HI) LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN
Call Details Advanced Grant (AdG), LS5, ERC-2012-ADG_20120314
Summary The frequency of Alzheimer's disease (AD) will dramatically increase in the ageing western society during the next decades. Currently, about 18 million people suffer worldwide from AD. Since no cure is available, this devastating disorder represents one of the most challenging socio-economical problems of our future. As onset and progression of AD is triggered by the amyloid cascade, I will put particular attention on amyloid ß-peptide (Aß). The reason for this approach is, that even though 20 years ago the Aß generating processing pathway was identified (Haass et al., Nature 1992a & b), the identity of the Aß species, which initiate the deadly cascade is still unknown. I will first tackle this challenge by investigating if a novel and so far completely overlooked proteolytic processing pathway is involved in the generation of Aß species capable to initiate spreading of pathology and neurotoxicity. I will then search for modulating proteins, which could affect generation of pathological Aß species. This includes a genome-wide screen for modifiers of gamma-secretase, one of the proteases involved in Aß generation as well as a targeted search for RNA binding proteins capable to posttranscriptionally regulate beta- and alpha-secretase. In a disease-crossing approach, RNA binding proteins, which were recently found not only to be deposited in Frontotemporal Lobar Degeneration and Amyotrophic Lateral Sclerosis but also in many AD cases, will be investigated for their potential to modulate Aß aggregation and AD pathology. Modifiers and novel antibodies specifically recognizing neurotoxic Aß assemblies will be validated for their potential not only to prevent amyloid plaque formation, but also spreading of pathology as well as neurotoxicity. In vivo validations include studies in innovative zebrafish models, which allow life imaging of neuronal cell death, as well as the establishment of microPET amyloid imaging for longitudinal studies in individual animals.
Summary
The frequency of Alzheimer's disease (AD) will dramatically increase in the ageing western society during the next decades. Currently, about 18 million people suffer worldwide from AD. Since no cure is available, this devastating disorder represents one of the most challenging socio-economical problems of our future. As onset and progression of AD is triggered by the amyloid cascade, I will put particular attention on amyloid ß-peptide (Aß). The reason for this approach is, that even though 20 years ago the Aß generating processing pathway was identified (Haass et al., Nature 1992a & b), the identity of the Aß species, which initiate the deadly cascade is still unknown. I will first tackle this challenge by investigating if a novel and so far completely overlooked proteolytic processing pathway is involved in the generation of Aß species capable to initiate spreading of pathology and neurotoxicity. I will then search for modulating proteins, which could affect generation of pathological Aß species. This includes a genome-wide screen for modifiers of gamma-secretase, one of the proteases involved in Aß generation as well as a targeted search for RNA binding proteins capable to posttranscriptionally regulate beta- and alpha-secretase. In a disease-crossing approach, RNA binding proteins, which were recently found not only to be deposited in Frontotemporal Lobar Degeneration and Amyotrophic Lateral Sclerosis but also in many AD cases, will be investigated for their potential to modulate Aß aggregation and AD pathology. Modifiers and novel antibodies specifically recognizing neurotoxic Aß assemblies will be validated for their potential not only to prevent amyloid plaque formation, but also spreading of pathology as well as neurotoxicity. In vivo validations include studies in innovative zebrafish models, which allow life imaging of neuronal cell death, as well as the establishment of microPET amyloid imaging for longitudinal studies in individual animals.
Max ERC Funding
2 497 020 €
Duration
Start date: 2013-03-01, End date: 2018-02-28
Project acronym AXONSURVIVAL
Project Axon survival: the role of protein synthesis
Researcher (PI) Christine Elizabeth Holt
Host Institution (HI) THE CHANCELLOR MASTERS AND SCHOLARSOF THE UNIVERSITY OF CAMBRIDGE
Call Details Advanced Grant (AdG), LS5, ERC-2012-ADG_20120314
Summary Neurons make long-distance connections with synaptic targets via axons. These axons survive throughout the lifetime of an organism, often many years in mammals, yet how axons are maintained is not fully understood. Recently, we provided in vivo evidence that local mRNA translation in mature axons is required for their maintenance. This new finding, along with in vitro work from other groups, indicates that promoting axonal protein synthesis is a key mechanism by which trophic factors act to prevent axon degeneration. Here we propose a program of research to investigate the importance of ribosomal proteins (RPs) in axon maintenance and degeneration. The rationale for this is fourfold. First, recent genome-wide studies of axonal transcriptomes have revealed that protein synthesis (including RP mRNAs) is the highest functional category in several neuronal types. Second, some RPs have evolved extra-ribosomal functions that include signalling, such as 67LR which acts both as a cell surface receptor for laminin and as a RP. Third, mutations in different RPs in vertebrates cause unexpectedly specific defects, such as the loss of optic axons. Fourth, preliminary results show that RP mRNAs are translated in optic axons in response to trophic factors. Collectively these findings lead us to propose that locally synthesized RPs play a role in axon maintenance through either ribosomal or extra-ribosomal function. To pursue this proposal, we will perform unbiased screens and functional assays using an array of experimental approaches and animal models. By gaining an understanding of how local RP synthesis contributes to axon survival, our studies have the potential to provide novel insights into how components conventionally associated with a housekeeping role (translation) are linked to axon degeneration. Our findings could provide new directions for developing therapeutic tools for neurodegenerative disorders and may have an impact on more diverse areas of biology and disease.
Summary
Neurons make long-distance connections with synaptic targets via axons. These axons survive throughout the lifetime of an organism, often many years in mammals, yet how axons are maintained is not fully understood. Recently, we provided in vivo evidence that local mRNA translation in mature axons is required for their maintenance. This new finding, along with in vitro work from other groups, indicates that promoting axonal protein synthesis is a key mechanism by which trophic factors act to prevent axon degeneration. Here we propose a program of research to investigate the importance of ribosomal proteins (RPs) in axon maintenance and degeneration. The rationale for this is fourfold. First, recent genome-wide studies of axonal transcriptomes have revealed that protein synthesis (including RP mRNAs) is the highest functional category in several neuronal types. Second, some RPs have evolved extra-ribosomal functions that include signalling, such as 67LR which acts both as a cell surface receptor for laminin and as a RP. Third, mutations in different RPs in vertebrates cause unexpectedly specific defects, such as the loss of optic axons. Fourth, preliminary results show that RP mRNAs are translated in optic axons in response to trophic factors. Collectively these findings lead us to propose that locally synthesized RPs play a role in axon maintenance through either ribosomal or extra-ribosomal function. To pursue this proposal, we will perform unbiased screens and functional assays using an array of experimental approaches and animal models. By gaining an understanding of how local RP synthesis contributes to axon survival, our studies have the potential to provide novel insights into how components conventionally associated with a housekeeping role (translation) are linked to axon degeneration. Our findings could provide new directions for developing therapeutic tools for neurodegenerative disorders and may have an impact on more diverse areas of biology and disease.
Max ERC Funding
2 426 573 €
Duration
Start date: 2013-03-01, End date: 2018-09-30
Project acronym BrainReadFBPredCode
Project Brain reading of contextual feedback and predictions
Researcher (PI) Lars Muckli
Host Institution (HI) UNIVERSITY OF GLASGOW
Call Details Starting Grant (StG), LS5, ERC-2012-StG_20111109
Summary We are currently witnessing a paradigm shift in our understanding of human brain function, moving towards a clearer description of cortical processing. Sensory systems are no longer considered as 'passively recording' but rather as dynamically anticipating and adapting to the rapidly changing environment. These new ideas are encompassed in the predictive coding framework, and indeed in a unifying theory of the brain (Friston, 2010). In terms of brain computation, a predictive model is created in higher cortical areas and communicated to lower sensory areas through feedback connections. Based on my pioneering research I propose experiments that are capable of ‘brain-reading’ cortical feedback– which would contribute invaluable data to theoretical frameworks.
The proposed research project will advance our understanding of ongoing brain activity, contextual processing, and cortical feedback - contributing to what is known about general cortical functions. By providing new insights as to the information content of cortical feedback, the proposal will fill one of the most important gaps in today’s knowledge about brain function. Friston’s unifying theory of the brain (Friston, 2010) and contemporary models of the predictive-coding framework (Hawkins and Blakeslee, 2004;Mumford, 1992;Rao and Ballard, 1999) assign feedback processing an essential role in cortical processing. Compared to feedforward information processing, our knowledge about feedback processing is in its infancy. The proposal introduces parametric and explorative brain reading designs to investigate this feedback processing. The chief goal of my proposal will be precision measures of cortical feedback, and a more ambitious objective is to read mental images and inner thoughts.
Summary
We are currently witnessing a paradigm shift in our understanding of human brain function, moving towards a clearer description of cortical processing. Sensory systems are no longer considered as 'passively recording' but rather as dynamically anticipating and adapting to the rapidly changing environment. These new ideas are encompassed in the predictive coding framework, and indeed in a unifying theory of the brain (Friston, 2010). In terms of brain computation, a predictive model is created in higher cortical areas and communicated to lower sensory areas through feedback connections. Based on my pioneering research I propose experiments that are capable of ‘brain-reading’ cortical feedback– which would contribute invaluable data to theoretical frameworks.
The proposed research project will advance our understanding of ongoing brain activity, contextual processing, and cortical feedback - contributing to what is known about general cortical functions. By providing new insights as to the information content of cortical feedback, the proposal will fill one of the most important gaps in today’s knowledge about brain function. Friston’s unifying theory of the brain (Friston, 2010) and contemporary models of the predictive-coding framework (Hawkins and Blakeslee, 2004;Mumford, 1992;Rao and Ballard, 1999) assign feedback processing an essential role in cortical processing. Compared to feedforward information processing, our knowledge about feedback processing is in its infancy. The proposal introduces parametric and explorative brain reading designs to investigate this feedback processing. The chief goal of my proposal will be precision measures of cortical feedback, and a more ambitious objective is to read mental images and inner thoughts.
Max ERC Funding
1 494 714 €
Duration
Start date: 2012-12-01, End date: 2017-11-30
Project acronym BRAINVISIONREHAB
Project ‘Seeing’ with the ears, hands and bionic eyes: from theories about brain organization to visual rehabilitation
Researcher (PI) Amir Amedi
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Starting Grant (StG), LS5, ERC-2012-StG_20111109
Summary My lab's work ranges from basic science, querying brain plasticity and sensory integration, to technological developments, allowing the blind to be more independent and even “see” using sounds and touch similar to bats and dolphins (a.k.a. Sensory Substitution Devices, SSDs), and back to applying these devices in research. We propose that, with proper training, any brain area or network can change the type of sensory input it uses to retrieve behaviorally task-relevant information within a matter of days. If this is true, it can have far reaching implications also for clinical rehabilitation. To achieve this, we are developing several innovative SSDs which encode the most crucial aspects of vision and increase their accessibility the blind, along with targeted, structured training protocols both in virtual environments and in real life. For instance, the “EyeMusic”, encodes colored complex images using pleasant musical scales and instruments, and the “EyeCane”, a palm-size cane, which encodes distance and depth in several directions accurately and efficiently. We provide preliminary but compelling evidence that following such training, SSDs can enable almost blind to recognize daily objects, colors, faces and facial expressions, read street signs, and aiding mobility and navigation. SSDs can also be used in conjunction with (any) invasive approach for visual rehabilitation. We are developing a novel hybrid Visual Rehabilitation Device which combines SSD and bionic eyes. In this set up, the SSDs is used in training the brain to “see” prior to surgery, in providing explanatory signal after surgery and in augmenting the capabilities of the bionic-eyes using information arriving from the same image. We will chart the dynamics of the plastic changes in the brain by performing unprecedented longitudinal Neuroimaging, Electrophysiological and Neurodisruptive approaches while individuals learn to ‘see’ using each of the visual rehabilitation approaches suggested here.
Summary
My lab's work ranges from basic science, querying brain plasticity and sensory integration, to technological developments, allowing the blind to be more independent and even “see” using sounds and touch similar to bats and dolphins (a.k.a. Sensory Substitution Devices, SSDs), and back to applying these devices in research. We propose that, with proper training, any brain area or network can change the type of sensory input it uses to retrieve behaviorally task-relevant information within a matter of days. If this is true, it can have far reaching implications also for clinical rehabilitation. To achieve this, we are developing several innovative SSDs which encode the most crucial aspects of vision and increase their accessibility the blind, along with targeted, structured training protocols both in virtual environments and in real life. For instance, the “EyeMusic”, encodes colored complex images using pleasant musical scales and instruments, and the “EyeCane”, a palm-size cane, which encodes distance and depth in several directions accurately and efficiently. We provide preliminary but compelling evidence that following such training, SSDs can enable almost blind to recognize daily objects, colors, faces and facial expressions, read street signs, and aiding mobility and navigation. SSDs can also be used in conjunction with (any) invasive approach for visual rehabilitation. We are developing a novel hybrid Visual Rehabilitation Device which combines SSD and bionic eyes. In this set up, the SSDs is used in training the brain to “see” prior to surgery, in providing explanatory signal after surgery and in augmenting the capabilities of the bionic-eyes using information arriving from the same image. We will chart the dynamics of the plastic changes in the brain by performing unprecedented longitudinal Neuroimaging, Electrophysiological and Neurodisruptive approaches while individuals learn to ‘see’ using each of the visual rehabilitation approaches suggested here.
Max ERC Funding
1 499 900 €
Duration
Start date: 2013-09-01, End date: 2018-08-31
Project acronym CHOLINOMIRS
Project CholinomiRs: MicroRNA Regulators of Cholinergic Signalling in the Neuro-Immune Interface
Researcher (PI) Hermona Soreq
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Advanced Grant (AdG), LS5, ERC-2012-ADG_20120314
Summary "Communication between the nervous and the immune system is pivotal for maintaining homeostasis and ensuring rapid and efficient reaction to stress and infection insults. The emergence of microRNAs (miRs) as regulators of gene expression and of acetylcholine (ACh) signalling as regulator of anxiety and inflammation provides a model for studying this interaction. My hypothesis is that 1) a specific sub-group of miRs, designated ""CholinomiRs"", may silence multiple target genes in the neuro-immune interface; 2) these miRs compete with each other on the interaction with their targets, and 3) mutations interfering with miR binding lead to inherited susceptibility to anxiety and inflammation disorders by modifying these interactions. Our preliminary findings have shown that by targeting acetylcholinesterase (AChE), CholinomiR-132 can intensify acute stress, resolve intestinal inflammation and change post-ischemic stroke responses. Further, we have identified clustered single nucleotide polymorphisms (SNPs) interfering with AChE silencing by several miRs which associate with elevated trait anxiety, blood pressure and inflammation. To further study miR regulators of ACh signalling, I plan to: (1) Identify anxiety and inflammation-induced changes in CholinomiRs and their targets in challenged brain and immune cells. (2) Establish the roles of these targets for one selected CholinomiR by tissue-specific manipulations. (3) Study primate-specific CholinomiRs by continued human DNA screens to identify SNPs and in ""humanized"" mice with knocked-in human AChE and transgenic CholinomiR-608. (4) Test if therapeutic modulation of aberrant CholinomiR expression can restore homeostasis. This research will clarify how miRs interact with each other in health and disease, introduce the dimension of complexity of multi-target competition and miR interactions and make a conceptual change in miRs research while enhancing the ability to intervene with diseases involving impaired ACh signalling."
Summary
"Communication between the nervous and the immune system is pivotal for maintaining homeostasis and ensuring rapid and efficient reaction to stress and infection insults. The emergence of microRNAs (miRs) as regulators of gene expression and of acetylcholine (ACh) signalling as regulator of anxiety and inflammation provides a model for studying this interaction. My hypothesis is that 1) a specific sub-group of miRs, designated ""CholinomiRs"", may silence multiple target genes in the neuro-immune interface; 2) these miRs compete with each other on the interaction with their targets, and 3) mutations interfering with miR binding lead to inherited susceptibility to anxiety and inflammation disorders by modifying these interactions. Our preliminary findings have shown that by targeting acetylcholinesterase (AChE), CholinomiR-132 can intensify acute stress, resolve intestinal inflammation and change post-ischemic stroke responses. Further, we have identified clustered single nucleotide polymorphisms (SNPs) interfering with AChE silencing by several miRs which associate with elevated trait anxiety, blood pressure and inflammation. To further study miR regulators of ACh signalling, I plan to: (1) Identify anxiety and inflammation-induced changes in CholinomiRs and their targets in challenged brain and immune cells. (2) Establish the roles of these targets for one selected CholinomiR by tissue-specific manipulations. (3) Study primate-specific CholinomiRs by continued human DNA screens to identify SNPs and in ""humanized"" mice with knocked-in human AChE and transgenic CholinomiR-608. (4) Test if therapeutic modulation of aberrant CholinomiR expression can restore homeostasis. This research will clarify how miRs interact with each other in health and disease, introduce the dimension of complexity of multi-target competition and miR interactions and make a conceptual change in miRs research while enhancing the ability to intervene with diseases involving impaired ACh signalling."
Max ERC Funding
2 375 600 €
Duration
Start date: 2013-03-01, End date: 2018-02-28
Project acronym CLUE-BGD
Project Closing the Loop between Understanding and Effective Treatment of the Basal Ganglia and their Disorders
Researcher (PI) Hagai Bergman
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Advanced Grant (AdG), LS5, ERC-2012-ADG_20120314
Summary In this project, the basal ganglia are defined as actor-critic reinforcement learning networks that aim at an optimal tradeoff between the maximization of future cumulative rewards and the minimization of the cost (the reinforcement driven multi objective optimization RDMOO model).
This computational model will be tested by multiple neuron recordings in the major basal ganglia structures of monkeys engaged in a similar behavioral task. We will further validate the RMDOO computational model of the basal ganglia by extending our previous studies of neural activity in the MPTP primate model of Parkinson's disease to a primate model of central serotonin depletion and emotional dysregulation disorders. The findings in the primate model of emotional dysregulation will then be compared to electrophysiological recordings carried out in human patients with treatment-resistant major depression and obsessive compulsive disorder during deep brain stimulation (DBS) procedures. I aim to find neural signatures (e.g., synchronous gamma oscillations in the actor part of the basal ganglia as predicted by the RMDOO model) characterizing these emotional disorders and to use them as triggers for closed loop adaptive DBS. Our working hypothesis holds that, as for the MPTP model of Parkinson's disease, closed loop DBS will lead to greater amelioration of the emotional deficits in serotonin depleted monkeys.
This project incorporates extensive collaborations with a team of neurosurgeons, neurologists, psychiatrists, and computer science/ neural network researchers. If successful, the findings will provide a firm understanding of the computational physiology of the basal ganglia networks and their disorders. Importantly, they will pave the way to better treatment of human patients with severe mental disorders.
Summary
In this project, the basal ganglia are defined as actor-critic reinforcement learning networks that aim at an optimal tradeoff between the maximization of future cumulative rewards and the minimization of the cost (the reinforcement driven multi objective optimization RDMOO model).
This computational model will be tested by multiple neuron recordings in the major basal ganglia structures of monkeys engaged in a similar behavioral task. We will further validate the RMDOO computational model of the basal ganglia by extending our previous studies of neural activity in the MPTP primate model of Parkinson's disease to a primate model of central serotonin depletion and emotional dysregulation disorders. The findings in the primate model of emotional dysregulation will then be compared to electrophysiological recordings carried out in human patients with treatment-resistant major depression and obsessive compulsive disorder during deep brain stimulation (DBS) procedures. I aim to find neural signatures (e.g., synchronous gamma oscillations in the actor part of the basal ganglia as predicted by the RMDOO model) characterizing these emotional disorders and to use them as triggers for closed loop adaptive DBS. Our working hypothesis holds that, as for the MPTP model of Parkinson's disease, closed loop DBS will lead to greater amelioration of the emotional deficits in serotonin depleted monkeys.
This project incorporates extensive collaborations with a team of neurosurgeons, neurologists, psychiatrists, and computer science/ neural network researchers. If successful, the findings will provide a firm understanding of the computational physiology of the basal ganglia networks and their disorders. Importantly, they will pave the way to better treatment of human patients with severe mental disorders.
Max ERC Funding
2 476 922 €
Duration
Start date: 2013-12-01, End date: 2018-11-30
Project acronym CORTEX SIMPLEX
Project Function and computation in three-layer cortex
Researcher (PI) Gilles Jean Laurent
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Call Details Advanced Grant (AdG), LS5, ERC-2012-ADG_20120314
Summary "Understanding brain function is one of the outstanding challenges of modern biology. Many studies focus on mammalian neocortex, a modular and versatile structure that operates equally well with different sensory inputs and for perception, planning as well as action. Neocortex, however, is remarkably complex. It contains many cell types, six layers, networks with local and long-range connections, and its study is technically challenging. We propose here to address central issues of cortical computation using a simpler experimental system. Neocortex evolved from a more primitive cortex, likely present in the ancestors of all amniotes. Extant reptiles are closest to this putative ancestor: their cortex contains only three layers, two of which are nearly exclusively neuropilar. Reptilian cortex is also closest to mammals’ old cortices (piriform and hippocampus). Like in mammals, reptilian cortex is modular. Its design, however, is considerably simpler and more ubiquitous than in mammals. Indeed, so far as we know, reptilian primary olfactory and visual cortices are very similar to one another. Finally, certain reptiles such as turtles have evolved biochemical and metabolic adaptations to resist long periods of anoxia. Thus, their brains can be studied ex vivo over long periods, giving experimenters access to the entire brain with an intact retina or nasal epithelium. We will use this system to study cortical computation, primarily in visual and olfactory areas. Using electrophysiological, imaging, molecular, behavioral and computational methods, we will discover the representational strategies of these two cortices in vivo, the functional architecture of their microcircuits and the computations that they carry out. This understanding of generic and ancient units of cortical computation will illuminate our studies of more complex and sophisticated cortical circuits."
Summary
"Understanding brain function is one of the outstanding challenges of modern biology. Many studies focus on mammalian neocortex, a modular and versatile structure that operates equally well with different sensory inputs and for perception, planning as well as action. Neocortex, however, is remarkably complex. It contains many cell types, six layers, networks with local and long-range connections, and its study is technically challenging. We propose here to address central issues of cortical computation using a simpler experimental system. Neocortex evolved from a more primitive cortex, likely present in the ancestors of all amniotes. Extant reptiles are closest to this putative ancestor: their cortex contains only three layers, two of which are nearly exclusively neuropilar. Reptilian cortex is also closest to mammals’ old cortices (piriform and hippocampus). Like in mammals, reptilian cortex is modular. Its design, however, is considerably simpler and more ubiquitous than in mammals. Indeed, so far as we know, reptilian primary olfactory and visual cortices are very similar to one another. Finally, certain reptiles such as turtles have evolved biochemical and metabolic adaptations to resist long periods of anoxia. Thus, their brains can be studied ex vivo over long periods, giving experimenters access to the entire brain with an intact retina or nasal epithelium. We will use this system to study cortical computation, primarily in visual and olfactory areas. Using electrophysiological, imaging, molecular, behavioral and computational methods, we will discover the representational strategies of these two cortices in vivo, the functional architecture of their microcircuits and the computations that they carry out. This understanding of generic and ancient units of cortical computation will illuminate our studies of more complex and sophisticated cortical circuits."
Max ERC Funding
2 496 111 €
Duration
Start date: 2013-02-01, End date: 2018-01-31
Project acronym CORTEXFOLDING
Project Understanding the development and function of cerebral cortex folding
Researcher (PI) Victor Borrell Franco
Host Institution (HI) AGENCIA ESTATAL CONSEJO SUPERIOR DEINVESTIGACIONES CIENTIFICAS
Call Details Starting Grant (StG), LS5, ERC-2012-StG_20111109
Summary The mammalian cerebral cortex was subject to a dramatic expansion in surface area during evolution. This process is recapitulated during development and is accompanied by folding of the cortical sheet, which allows fitting a large cortical surface within a limited cranial volume. A loss of cortical folds is linked to severe intellectual impairment in humans, so cortical folding is believed to be crucial for brain function. However, developmental mechanisms responsible for cortical folding, and the influence of this on cortical function, remain largely unknown. The goal of this proposal is to understand the genetic and cellular mechanisms that control the developmental expansion and folding of the cerebral cortex, and what is the impact of these processes on its functional organization. Human studies have identified genes essential for the proper folding of the human cerebral cortex. Genetic manipulations in mice have unraveled specific functions for some of those genes in the development of the cerebral cortex. But because the mouse cerebral cortex does not fold naturally, the mechanisms of cortical expansion and folding in larger brains remain unknown. We will study these mechanisms on ferret, an ideal model with a naturally folded cerebral cortex. We will combine the advantages of ferrets with cell biology, genetics and next-generation transcriptomics, together with state-of-the-art in vivo, in vitro and in silico approaches, including in vivo imaging of functional columnar maps. The successful execution of this project will provide insights into developmental and genetic risk factors for anomalies in human cortical topology, and into mechanisms responsible for the early formation of cortical functional maps.
Summary
The mammalian cerebral cortex was subject to a dramatic expansion in surface area during evolution. This process is recapitulated during development and is accompanied by folding of the cortical sheet, which allows fitting a large cortical surface within a limited cranial volume. A loss of cortical folds is linked to severe intellectual impairment in humans, so cortical folding is believed to be crucial for brain function. However, developmental mechanisms responsible for cortical folding, and the influence of this on cortical function, remain largely unknown. The goal of this proposal is to understand the genetic and cellular mechanisms that control the developmental expansion and folding of the cerebral cortex, and what is the impact of these processes on its functional organization. Human studies have identified genes essential for the proper folding of the human cerebral cortex. Genetic manipulations in mice have unraveled specific functions for some of those genes in the development of the cerebral cortex. But because the mouse cerebral cortex does not fold naturally, the mechanisms of cortical expansion and folding in larger brains remain unknown. We will study these mechanisms on ferret, an ideal model with a naturally folded cerebral cortex. We will combine the advantages of ferrets with cell biology, genetics and next-generation transcriptomics, together with state-of-the-art in vivo, in vitro and in silico approaches, including in vivo imaging of functional columnar maps. The successful execution of this project will provide insights into developmental and genetic risk factors for anomalies in human cortical topology, and into mechanisms responsible for the early formation of cortical functional maps.
Max ERC Funding
1 701 116 €
Duration
Start date: 2013-01-01, End date: 2018-06-30
Project acronym DCVFUSION
Project Telling the full story: how neurons send other signals than by classical synaptic transmission
Researcher (PI) Matthijs Verhage
Host Institution (HI) STICHTING VUMC
Call Details Advanced Grant (AdG), LS5, ERC-2012-ADG_20120314
Summary The regulated secretion of chemical signals in the brain occurs principally from two organelles, synaptic vesicles and dense core vesicles (DCVs). Synaptic vesicle secretion accounts for the well characterized local, fast signalling in synapses. DCVs contain a diverse collection of cargo, including many neuropeptides that trigger a multitude of modulatory effects with quite robust impact, for instance on memory, mood, pain, appetite or social behavior. Disregulation of neuropeptide secretion is firmly associated with many diseases such as cognitive and mood disorders, obesity and diabetes. In addition, many other signals depend on DCVs, for instance trophic factors and proteolytic enzymes, but also signals that typically do not diffuse like guidance cues and pre-assembled active zones. Hence, it is beyond doubt that DCV signalling is a central factor in brain communication. However, many fundamental questions remain open on DCV trafficking and secretion. Therefore, the aim of this proposal is to characterize the molecular principles that account for DCV delivery at release sites and their secretion. I will address 4 fundamental questions: What are the molecular factors that drive DCV fusion in mammalian CNS neurons? How does Ca2+ trigger DCV fusion? What are the requirements of DCV release sites and where do they occur? Can DCV fusion be targeted to synthetic release sites in vivo? I will exploit >30 mutant mouse lines and new cell biological and photonic approaches that allow for the first time a quantitative assessment of DCV-trafficking and fusion of many cargo types, in living neurons with a single vesicle resolution. Preliminary data suggest that DCV secretion is quite different from synaptic vesicle and chromaffin granule secretion. Together, these studies will produce the first systematic evaluation of the molecular identity of the core machinery that drives DCV fusion in neurons, the Ca2+-affinity of DCV fusion and the characteristics of DCV release sites.
Summary
The regulated secretion of chemical signals in the brain occurs principally from two organelles, synaptic vesicles and dense core vesicles (DCVs). Synaptic vesicle secretion accounts for the well characterized local, fast signalling in synapses. DCVs contain a diverse collection of cargo, including many neuropeptides that trigger a multitude of modulatory effects with quite robust impact, for instance on memory, mood, pain, appetite or social behavior. Disregulation of neuropeptide secretion is firmly associated with many diseases such as cognitive and mood disorders, obesity and diabetes. In addition, many other signals depend on DCVs, for instance trophic factors and proteolytic enzymes, but also signals that typically do not diffuse like guidance cues and pre-assembled active zones. Hence, it is beyond doubt that DCV signalling is a central factor in brain communication. However, many fundamental questions remain open on DCV trafficking and secretion. Therefore, the aim of this proposal is to characterize the molecular principles that account for DCV delivery at release sites and their secretion. I will address 4 fundamental questions: What are the molecular factors that drive DCV fusion in mammalian CNS neurons? How does Ca2+ trigger DCV fusion? What are the requirements of DCV release sites and where do they occur? Can DCV fusion be targeted to synthetic release sites in vivo? I will exploit >30 mutant mouse lines and new cell biological and photonic approaches that allow for the first time a quantitative assessment of DCV-trafficking and fusion of many cargo types, in living neurons with a single vesicle resolution. Preliminary data suggest that DCV secretion is quite different from synaptic vesicle and chromaffin granule secretion. Together, these studies will produce the first systematic evaluation of the molecular identity of the core machinery that drives DCV fusion in neurons, the Ca2+-affinity of DCV fusion and the characteristics of DCV release sites.
Max ERC Funding
2 439 315 €
Duration
Start date: 2013-05-01, End date: 2019-04-30
