Project acronym ABATSYNAPSE
Project Evolution of Alzheimer’s Disease: From dynamics of single synapses to memory loss
Researcher (PI) Inna Slutsky
Host Institution (HI) TEL AVIV UNIVERSITY
Call Details Starting Grant (StG), LS5, ERC-2011-StG_20101109
Summary A persistent challenge in unravelling mechanisms that regulate memory function is how to bridge the gap between inter-molecular dynamics of single proteins, activity of individual synapses and emerging properties of neuronal circuits. The prototype condition of disintegrating neuronal circuits is Alzheimer’s Disease (AD). Since the early time of Alois Alzheimer at the turn of the 20th century, scientists have been searching for a molecular entity that is in the roots of the cognitive deficits. Although diverse lines of evidence suggest that the amyloid-beta peptide (Abeta) plays a central role in synaptic dysfunctions of AD, several key questions remain unresolved. First, endogenous Abeta peptides are secreted by neurons throughout life, but their physiological functions are largely unknown. Second, experience-dependent physiological mechanisms that initiate the changes in Abeta composition in sporadic, the most frequent form of AD, are unidentified. And finally, molecular mechanisms that trigger Abeta-induced synaptic failure and memory decline remain elusive.
To target these questions, I propose to develop an integrative approach to correlate structure and function at the level of single synapses in hippocampal circuits. State-of-the-art techniques will enable the simultaneous real-time visualization of inter-molecular dynamics within signalling complexes and functional synaptic modifications. Utilizing FRET spectroscopy, high-resolution optical imaging, electrophysiology, molecular biology and biochemistry we will determine the casual relationship between ongoing neuronal activity, temporo-spatial dynamics and molecular composition of Abeta, structural rearrangements within the Abeta signalling complexes and plasticity of single synapses and whole networks. The proposed research will elucidate fundamental principles of neuronal circuits function and identify critical steps that initiate primary synaptic dysfunctions at the very early stages of sporadic AD.
Summary
A persistent challenge in unravelling mechanisms that regulate memory function is how to bridge the gap between inter-molecular dynamics of single proteins, activity of individual synapses and emerging properties of neuronal circuits. The prototype condition of disintegrating neuronal circuits is Alzheimer’s Disease (AD). Since the early time of Alois Alzheimer at the turn of the 20th century, scientists have been searching for a molecular entity that is in the roots of the cognitive deficits. Although diverse lines of evidence suggest that the amyloid-beta peptide (Abeta) plays a central role in synaptic dysfunctions of AD, several key questions remain unresolved. First, endogenous Abeta peptides are secreted by neurons throughout life, but their physiological functions are largely unknown. Second, experience-dependent physiological mechanisms that initiate the changes in Abeta composition in sporadic, the most frequent form of AD, are unidentified. And finally, molecular mechanisms that trigger Abeta-induced synaptic failure and memory decline remain elusive.
To target these questions, I propose to develop an integrative approach to correlate structure and function at the level of single synapses in hippocampal circuits. State-of-the-art techniques will enable the simultaneous real-time visualization of inter-molecular dynamics within signalling complexes and functional synaptic modifications. Utilizing FRET spectroscopy, high-resolution optical imaging, electrophysiology, molecular biology and biochemistry we will determine the casual relationship between ongoing neuronal activity, temporo-spatial dynamics and molecular composition of Abeta, structural rearrangements within the Abeta signalling complexes and plasticity of single synapses and whole networks. The proposed research will elucidate fundamental principles of neuronal circuits function and identify critical steps that initiate primary synaptic dysfunctions at the very early stages of sporadic AD.
Max ERC Funding
2 000 000 €
Duration
Start date: 2011-12-01, End date: 2017-09-30
Project acronym AXONGROWTH
Project Systematic analysis of the molecular mechanisms underlying axon growth during development and following injury
Researcher (PI) Oren Schuldiner
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Consolidator Grant (CoG), LS5, ERC-2013-CoG
Summary Axon growth potential declines during development, contributing to the lack of effective regeneration in the adult central nervous system. What determines the intrinsic growth potential of neurites, and how such growth is regulated during development, disease and following injury is a fundamental question in neuroscience. Although multiple lines of evidence indicate that intrinsic growth capability is genetically encoded, its nature remains poorly defined. Neuronal remodeling of the Drosophila mushroom body offers a unique opportunity to study the mechanisms of various types of axon degeneration and growth. We have recently demonstrated that regrowth of axons following developmental pruning is not only distinct from initial outgrowth but also shares molecular similarities with regeneration following injury. In this proposal we combine state of the art tools from genomics, functional genetics and microscopy to perform a comprehensive study of the mechanisms underlying axon growth during development and following injury. First, we will combine genetic, biochemical and genomic studies to gain a mechanistic understanding of the developmental regrowth program. Next, we will perform extensive transcriptomic analyses and comparisons aimed at defining the genetic programs involved in initial axon growth, developmental regrowth, and regeneration following injury. Finally, we will harness the genetic power of Drosophila to perform a comprehensive functional analysis of genes and pathways, those previously known and new ones that we will discover, in various neurite growth paradigms. Importantly, these functional assays will be performed in the same organism, allowing us to use identical genetic mutations across our analyses. To this end, our identification of a new genetic program regulating developmental axon regrowth, together with emerging tools in genomics, places us in a unique position to gain a broad understanding of axon growth during development and following injury.
Summary
Axon growth potential declines during development, contributing to the lack of effective regeneration in the adult central nervous system. What determines the intrinsic growth potential of neurites, and how such growth is regulated during development, disease and following injury is a fundamental question in neuroscience. Although multiple lines of evidence indicate that intrinsic growth capability is genetically encoded, its nature remains poorly defined. Neuronal remodeling of the Drosophila mushroom body offers a unique opportunity to study the mechanisms of various types of axon degeneration and growth. We have recently demonstrated that regrowth of axons following developmental pruning is not only distinct from initial outgrowth but also shares molecular similarities with regeneration following injury. In this proposal we combine state of the art tools from genomics, functional genetics and microscopy to perform a comprehensive study of the mechanisms underlying axon growth during development and following injury. First, we will combine genetic, biochemical and genomic studies to gain a mechanistic understanding of the developmental regrowth program. Next, we will perform extensive transcriptomic analyses and comparisons aimed at defining the genetic programs involved in initial axon growth, developmental regrowth, and regeneration following injury. Finally, we will harness the genetic power of Drosophila to perform a comprehensive functional analysis of genes and pathways, those previously known and new ones that we will discover, in various neurite growth paradigms. Importantly, these functional assays will be performed in the same organism, allowing us to use identical genetic mutations across our analyses. To this end, our identification of a new genetic program regulating developmental axon regrowth, together with emerging tools in genomics, places us in a unique position to gain a broad understanding of axon growth during development and following injury.
Max ERC Funding
2 000 000 €
Duration
Start date: 2014-03-01, End date: 2019-02-28
Project acronym BehavIndividuality
Project Uncovering the basis of behavioral individuality across developmental time-scales
Researcher (PI) Shay Stern
Host Institution (HI) TECHNION - ISRAEL INSTITUTE OF TECHNOLOGY
Call Details Starting Grant (StG), LS5, ERC-2019-STG
Summary A fundamental question in biology is why different individuals show different behaviors. While individuality in behavior is usually explained by genetic heterogeneity or differences in environmental exposures, more recent studies have shown that stable behavioral variation is also observed among isogenic individuals that were raised in the same environment. However, this important and potentially conserved epigenetic source of individual-to-individual behavioral variation remains largely unexplored. I have recently developed a novel imaging setup, using C. elegans, that allowed for the first time to study behavioral individuality across the full development time of animals, at high spatiotemporal resolution and under tightly controlled environmental conditions (Stern et al. Cell 2017). By using this unique system I found that isogenic animals show long-term behavioral individuality that persists across all developmental stages, and was dependent on specific neuromodulators. In this proposal I suggest to study how behavioral individuality emerges across development from non-genetic differences among individuals. In particular, I plan to (i) identify neuronal circuits and variations therein that lead to different behavioral states among individuals by combining my established methods for longitudinal behavioral quantifications with cutting-edge neuronal imaging and molecular techniques; (ii) study the role of conserved epigenetic mechanisms in generating stable neuronal and behavioral variations by integrating high-throughput gene-expression, neuronal, and behavioral analyses in single animals; and (iii) explore how stressful conditions affect behavioral individuality. I hypothesize that stress may enhance variation as a population-level mechanism to diversify risk in the face of complex or unpredictable conditions. The proposed research will shed light on novel processes that establish and maintain inter-individual diversity in neuronal and behavioral patterns.
Summary
A fundamental question in biology is why different individuals show different behaviors. While individuality in behavior is usually explained by genetic heterogeneity or differences in environmental exposures, more recent studies have shown that stable behavioral variation is also observed among isogenic individuals that were raised in the same environment. However, this important and potentially conserved epigenetic source of individual-to-individual behavioral variation remains largely unexplored. I have recently developed a novel imaging setup, using C. elegans, that allowed for the first time to study behavioral individuality across the full development time of animals, at high spatiotemporal resolution and under tightly controlled environmental conditions (Stern et al. Cell 2017). By using this unique system I found that isogenic animals show long-term behavioral individuality that persists across all developmental stages, and was dependent on specific neuromodulators. In this proposal I suggest to study how behavioral individuality emerges across development from non-genetic differences among individuals. In particular, I plan to (i) identify neuronal circuits and variations therein that lead to different behavioral states among individuals by combining my established methods for longitudinal behavioral quantifications with cutting-edge neuronal imaging and molecular techniques; (ii) study the role of conserved epigenetic mechanisms in generating stable neuronal and behavioral variations by integrating high-throughput gene-expression, neuronal, and behavioral analyses in single animals; and (iii) explore how stressful conditions affect behavioral individuality. I hypothesize that stress may enhance variation as a population-level mechanism to diversify risk in the face of complex or unpredictable conditions. The proposed research will shed light on novel processes that establish and maintain inter-individual diversity in neuronal and behavioral patterns.
Max ERC Funding
1 375 000 €
Duration
Start date: 2019-12-01, End date: 2024-11-30
Project acronym Brain circRNAs
Project Rounding the circle: Unravelling the biogenesis, function and mechanism of action of circRNAs in the Drosophila brain.
Researcher (PI) Sebastian Kadener
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Consolidator Grant (CoG), LS5, ERC-2014-CoG
Summary Tight regulation of RNA metabolism is essential for normal brain function. This includes co and post-transcriptional regulation, which are extremely prevalent in neurons. Recently, circular RNAs (circRNAs), a highly abundant new type of regulatory non-coding RNA have been found across the animal kingdom. Two of these RNAs have been shown to act as miRNA sponges but no function is known for the thousands of other circRNAs, indicating the existence of a widespread layer of previously unknown gene regulation.
The present proposal aims to comprehensively determine the role and mode of actions of circRNAs in gene expression and RNA metabolism in the fly brain. We will do so by studying their biogenesis, transport, and mechanism of action, as well as by determining the roles of circRNAs in neuronal function and behaviour. Briefly, we will: 1) identify factors involved in the biogenesis, localization, and stabilization of circRNAs; 2) determine neuro-developmental, molecular, neural and behavioural phenotypes associated with down or up regulation of specific circRNAs; 3) study the molecular mechanisms of action of circRNAs: identify circRNAs that work as miRNA sponges and determine whether circRNAs can encode proteins or act as signalling molecules and 4) perform mechanistic studies in order to determine cause-effect relationships between circRNA function and brain physiology and behaviour.
The present proposal will reveal the key pathways by which circRNAs control gene expression and influence neuronal function and behaviour. Therefore it will be one of the pioneer works in the study of this new and important area of research, which we predict will fundamentally transform the study of gene expression regulation in the brain
Summary
Tight regulation of RNA metabolism is essential for normal brain function. This includes co and post-transcriptional regulation, which are extremely prevalent in neurons. Recently, circular RNAs (circRNAs), a highly abundant new type of regulatory non-coding RNA have been found across the animal kingdom. Two of these RNAs have been shown to act as miRNA sponges but no function is known for the thousands of other circRNAs, indicating the existence of a widespread layer of previously unknown gene regulation.
The present proposal aims to comprehensively determine the role and mode of actions of circRNAs in gene expression and RNA metabolism in the fly brain. We will do so by studying their biogenesis, transport, and mechanism of action, as well as by determining the roles of circRNAs in neuronal function and behaviour. Briefly, we will: 1) identify factors involved in the biogenesis, localization, and stabilization of circRNAs; 2) determine neuro-developmental, molecular, neural and behavioural phenotypes associated with down or up regulation of specific circRNAs; 3) study the molecular mechanisms of action of circRNAs: identify circRNAs that work as miRNA sponges and determine whether circRNAs can encode proteins or act as signalling molecules and 4) perform mechanistic studies in order to determine cause-effect relationships between circRNA function and brain physiology and behaviour.
The present proposal will reveal the key pathways by which circRNAs control gene expression and influence neuronal function and behaviour. Therefore it will be one of the pioneer works in the study of this new and important area of research, which we predict will fundamentally transform the study of gene expression regulation in the brain
Max ERC Funding
1 971 750 €
Duration
Start date: 2016-02-01, End date: 2021-01-31
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 CLAUSTRUM
Project The Claustrum: A Circuit Hub for Attention
Researcher (PI) Amihai CITRI
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Consolidator Grant (CoG), LS5, ERC-2017-COG
Summary Our senses face a constant barrage of information. Hence, understanding how our brain enables us to attend to relevant stimuli, while ignoring distractions, is of increasing biomedical importance. Recently, I discovered that the claustrum, a multi-sensory hub and recipient of extensive neuromodulatory input, enables resilience to distraction.
In my ERC project, I will explore the mechanisms underlying claustral mediation of resilience to distraction and develop novel approaches for assessing and modulating attention in mice, with implications for humans. Transgenic mouse models that I identified as enabling selective access to claustral neurons overcome its limiting anatomy, making the claustrum accessible to functional investigation. Using this novel genetic access, I obtained preliminary results strongly suggesting that the claustrum functions to filter distractions by adjusting cortical sensory gain.
My specific aims are: 1) To delineate the mechanisms whereby the claustrum achieves sensory gain control, by applying in-vivo cell-attached, multi-unit and fiber photometry recordings from claustral and cortical neurons during attention-demanding tasks. 2) To discriminate between the functions of the claustrum in multi-sensory integration and implementation of attention strategies, by employing multi-sensory behavioral paradigms while modulating claustral function. 3) To develop validated complementary physiological and behavioral protocols for adjusting claustral mediation of attention via neuromodulation.
This study is unique in its focus and aims: it will provide a stringent neurophysiological framework for defining a key mechanism underlying cognitive concepts of attention, and establish a novel platform for studying the function of the claustrum and manipulating its activity. The project is designed to achieve breakthroughs of fundamental nature and potentially lead to diagnostic and therapeutic advances relevant to attention disorders.
Summary
Our senses face a constant barrage of information. Hence, understanding how our brain enables us to attend to relevant stimuli, while ignoring distractions, is of increasing biomedical importance. Recently, I discovered that the claustrum, a multi-sensory hub and recipient of extensive neuromodulatory input, enables resilience to distraction.
In my ERC project, I will explore the mechanisms underlying claustral mediation of resilience to distraction and develop novel approaches for assessing and modulating attention in mice, with implications for humans. Transgenic mouse models that I identified as enabling selective access to claustral neurons overcome its limiting anatomy, making the claustrum accessible to functional investigation. Using this novel genetic access, I obtained preliminary results strongly suggesting that the claustrum functions to filter distractions by adjusting cortical sensory gain.
My specific aims are: 1) To delineate the mechanisms whereby the claustrum achieves sensory gain control, by applying in-vivo cell-attached, multi-unit and fiber photometry recordings from claustral and cortical neurons during attention-demanding tasks. 2) To discriminate between the functions of the claustrum in multi-sensory integration and implementation of attention strategies, by employing multi-sensory behavioral paradigms while modulating claustral function. 3) To develop validated complementary physiological and behavioral protocols for adjusting claustral mediation of attention via neuromodulation.
This study is unique in its focus and aims: it will provide a stringent neurophysiological framework for defining a key mechanism underlying cognitive concepts of attention, and establish a novel platform for studying the function of the claustrum and manipulating its activity. The project is designed to achieve breakthroughs of fundamental nature and potentially lead to diagnostic and therapeutic advances relevant to attention disorders.
Max ERC Funding
1 995 000 €
Duration
Start date: 2018-03-01, End date: 2023-02-28
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 COFBMIX
Project Cortical feedback in figure background segregation of odors.
Researcher (PI) Dan ROKNI
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Starting Grant (StG), LS5, ERC-2017-STG
Summary A key question in neuroscience is how information is processed by sensory systems to guide behavior. Most of our knowledge about sensory processing is based on presentation of simple isolated stimuli and recording corresponding neural activity in relevant brain areas. Yet sensory stimuli in real life are never isolated and typically not simple. How the brain processes complex stimuli, simultaneously arising from multiple objects is unknown. Our daily experience (as well as well-controlled experiments) shows that only parts of a complex sensory scene can be perceived - we cannot listen to more than one speaker in a party. Importantly, one can easily choose what is important and should be processed and what can be ignored as background. These observations lead to the prevalent hypothesis that feedback projections from ‘higher’ brain areas to more peripheral sensory areas are involved in processing of complex stimuli. However experimental analysis of signals conveyed by feedback projections in behaving animals is scarce. The nature of these signals and how they relate to behavior is unknown.
Here I propose a cutting edge approach to directly record feedback signals in the olfactory system of behaving mice. We will use chronically implanted electrodes to record the modulation of olfactory bulb (OB) principal neurons by task related context. Additionally, we will record from piriform cortical (PC) neurons that project back to the OB. These will be tagged with channelrhodopsin-2 and identified by light sensitivity. Finally, we will express the spectrally distinct Ca++ indicators GCaMP6 and RCaMP2 in PC neurons and in olfactory sensory neurons, respectively, and use 2-photon microscopy to analyze the spatio-temporal relationship between feedforward and feedback inputs in the OB. This comprehensive approach will provide an explanation of how feedforward and feedback inputs are integrated to process complex stimuli.
Summary
A key question in neuroscience is how information is processed by sensory systems to guide behavior. Most of our knowledge about sensory processing is based on presentation of simple isolated stimuli and recording corresponding neural activity in relevant brain areas. Yet sensory stimuli in real life are never isolated and typically not simple. How the brain processes complex stimuli, simultaneously arising from multiple objects is unknown. Our daily experience (as well as well-controlled experiments) shows that only parts of a complex sensory scene can be perceived - we cannot listen to more than one speaker in a party. Importantly, one can easily choose what is important and should be processed and what can be ignored as background. These observations lead to the prevalent hypothesis that feedback projections from ‘higher’ brain areas to more peripheral sensory areas are involved in processing of complex stimuli. However experimental analysis of signals conveyed by feedback projections in behaving animals is scarce. The nature of these signals and how they relate to behavior is unknown.
Here I propose a cutting edge approach to directly record feedback signals in the olfactory system of behaving mice. We will use chronically implanted electrodes to record the modulation of olfactory bulb (OB) principal neurons by task related context. Additionally, we will record from piriform cortical (PC) neurons that project back to the OB. These will be tagged with channelrhodopsin-2 and identified by light sensitivity. Finally, we will express the spectrally distinct Ca++ indicators GCaMP6 and RCaMP2 in PC neurons and in olfactory sensory neurons, respectively, and use 2-photon microscopy to analyze the spatio-temporal relationship between feedforward and feedback inputs in the OB. This comprehensive approach will provide an explanation of how feedforward and feedback inputs are integrated to process complex stimuli.
Max ERC Funding
1 500 000 €
Duration
Start date: 2018-04-01, End date: 2023-03-31
Project acronym DimorphicCircuits
Project Elucidating the development of sexually-dimorphic circuits: from molecular mechanisms to synapses and behavior
Researcher (PI) Meital Oren-Suissa
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS5, ERC-2019-STG
Summary In sexually reproducing species, males and females respond to environmental sensory cues and transform the input into sexually dimorphic traits. These dimorphisms are the basis for sex-biased phenotypes in many neurological diseases. Yet, complete understanding of the underlying mechanism is still missing. How does the sexual identity impose molecular changes to individual neurons and circuits? What are the sex-specific synaptic changes that occur during development in these circuits? We recently demonstrated a sexually dimorphic dimension of neuronal connectivity: neurons belonging to a shared nervous system rewire in a sex-specific manner to generate sexually dimorphic behaviors. New findings from our lab further reveal a significant difference in the way the two sexes in the nematode C. elegans respond to aversive stimuli. These dimorphic responses are mediated via sex-shared circuits that receive similar environmental input, yet respond differently.
Building on our exciting preliminary results, we seek to elucidate how genetic sex modulates neuronal function, neural circuit dynamics and behavior during development. This proposal will pursue three complementary objectives: (i) Map the repertoire of sexually dimorphic avoidance behaviors; (ii) Study the synaptic basis for the development of sexually dimorphic circuits; and (iii) Elucidate the molecular basis of sexually dimorphic neuronal circuits. These mechanisms can only be currently resolved in C. elegans, where the entire connectome of the nervous system for both sexes has been mapped. Using cutting-edge optogenetics, calcium imaging, activity-dependent trans-synaptic labeling, genetic screens and single-cell transcriptome analysis we will shed light on the elusive connection between genes, circuits and behavior. Understanding how genetic sex modulates neuronal circuits will aid in the development of novel gender-specific therapies.
Summary
In sexually reproducing species, males and females respond to environmental sensory cues and transform the input into sexually dimorphic traits. These dimorphisms are the basis for sex-biased phenotypes in many neurological diseases. Yet, complete understanding of the underlying mechanism is still missing. How does the sexual identity impose molecular changes to individual neurons and circuits? What are the sex-specific synaptic changes that occur during development in these circuits? We recently demonstrated a sexually dimorphic dimension of neuronal connectivity: neurons belonging to a shared nervous system rewire in a sex-specific manner to generate sexually dimorphic behaviors. New findings from our lab further reveal a significant difference in the way the two sexes in the nematode C. elegans respond to aversive stimuli. These dimorphic responses are mediated via sex-shared circuits that receive similar environmental input, yet respond differently.
Building on our exciting preliminary results, we seek to elucidate how genetic sex modulates neuronal function, neural circuit dynamics and behavior during development. This proposal will pursue three complementary objectives: (i) Map the repertoire of sexually dimorphic avoidance behaviors; (ii) Study the synaptic basis for the development of sexually dimorphic circuits; and (iii) Elucidate the molecular basis of sexually dimorphic neuronal circuits. These mechanisms can only be currently resolved in C. elegans, where the entire connectome of the nervous system for both sexes has been mapped. Using cutting-edge optogenetics, calcium imaging, activity-dependent trans-synaptic labeling, genetic screens and single-cell transcriptome analysis we will shed light on the elusive connection between genes, circuits and behavior. Understanding how genetic sex modulates neuronal circuits will aid in the development of novel gender-specific therapies.
Max ERC Funding
1 500 000 €
Duration
Start date: 2019-10-01, End date: 2024-09-30
