Project acronym ADDICTIONCIRCUITS
Project Drug addiction: molecular changes in reward and aversion circuits
Researcher (PI) Nils David Engblom
Host Institution (HI) LINKOPINGS UNIVERSITET
Call Details Starting Grant (StG), LS5, ERC-2010-StG_20091118
Summary Our affective and motivational state is important for our decisions, actions and quality of life. Many pathological conditions affect this state. For example, addictive drugs are hyperactivating the reward system and trigger a strong motivation for continued drug intake, whereas many somatic and psychiatric diseases lead to an aversive state, characterized by loss of motivation. I will study specific neural circuits and mechanisms underlying reward and aversion, and how pathological signaling in these systems can trigger relapse in drug addiction.
Given the important role of the dopaminergic neurons in the midbrain for many aspects of reward signaling, I will study how synaptic plasticity in these cells, and in their target neurons in the striatum, contribute to relapse in drug seeking. I will also study the circuits underlying aversion. Little is known about these circuits, but my hypothesis is that an important component of aversion is signaled by a specific neuronal population in the brainstem parabrachial nucleus, projecting to the central amygdala. We will test this hypothesis and also determine how this aversion circuit contributes to the persistence of addiction and to relapse.
To dissect this complicated system, I am developing new genetic methods for manipulating and visualizing specific functional circuits in the mouse brain. My unique combination of state-of-the-art competence in transgenics and cutting edge knowledge in the anatomy and functional organization of the circuits behind reward and aversion should allow me to decode these systems, linking discrete circuits to behavior.
Collectively, the results will indicate how signals encoding aversion and reward are integrated to control addictive behavior and they may identify novel avenues for treatment of drug addiction as well as aversion-related symptoms affecting patients with chronic inflammatory conditions and cancer.
Summary
Our affective and motivational state is important for our decisions, actions and quality of life. Many pathological conditions affect this state. For example, addictive drugs are hyperactivating the reward system and trigger a strong motivation for continued drug intake, whereas many somatic and psychiatric diseases lead to an aversive state, characterized by loss of motivation. I will study specific neural circuits and mechanisms underlying reward and aversion, and how pathological signaling in these systems can trigger relapse in drug addiction.
Given the important role of the dopaminergic neurons in the midbrain for many aspects of reward signaling, I will study how synaptic plasticity in these cells, and in their target neurons in the striatum, contribute to relapse in drug seeking. I will also study the circuits underlying aversion. Little is known about these circuits, but my hypothesis is that an important component of aversion is signaled by a specific neuronal population in the brainstem parabrachial nucleus, projecting to the central amygdala. We will test this hypothesis and also determine how this aversion circuit contributes to the persistence of addiction and to relapse.
To dissect this complicated system, I am developing new genetic methods for manipulating and visualizing specific functional circuits in the mouse brain. My unique combination of state-of-the-art competence in transgenics and cutting edge knowledge in the anatomy and functional organization of the circuits behind reward and aversion should allow me to decode these systems, linking discrete circuits to behavior.
Collectively, the results will indicate how signals encoding aversion and reward are integrated to control addictive behavior and they may identify novel avenues for treatment of drug addiction as well as aversion-related symptoms affecting patients with chronic inflammatory conditions and cancer.
Max ERC Funding
1 500 000 €
Duration
Start date: 2010-10-01, End date: 2015-09-30
Project acronym BrainInBrain
Project Neural circuits underlying complex brain function across animals - from conserved core concepts to specializations defining a species’ identity
Researcher (PI) Stanley HEINZE
Host Institution (HI) LUNDS UNIVERSITET
Call Details Starting Grant (StG), LS5, ERC-2016-STG
Summary The core function of all brains is to compute the current state of the world, compare it to the desired state of the world and select motor programs that drive behavior minimizing any mismatch. The circuits underlying these functions are the key to understand brains in general, but so far they are completely unknown. Three problems have hindered progress: 1) The animal’s desired state of the world is rarely known. 2) Most studies in simple models have focused on sensory driven, reflex-like processes, and not considered self-initiated behavior. 3) The circuits underlying complex behaviors in vertebrates are widely distributed, containing millions of neurons. With this proposal I aim at overcoming these problems using insects, whose tiny brains solve the same basic problems as our brains but with 100,000 times fewer cells. Moreover, the central complex, a single conserved brain region consisting of only a few thousand neurons, is crucial for sensory integration, motor control and state-dependent modulation, essentially being a ‘brain in the brain’. To simplify the problem further I will focus on navigation behavior. Here, the desired and actual states of the world are equal to the desired and current headings of the animal, with mismatches resulting in compensatory steering. I have previously shown how the central complex encodes the animal’s current heading. Now I will use behavioral training to generate animals with highly defined desired headings, and correlate neural activity with the animal’s ‘intentions’ and actions - at the level of identified neurons. To establish the involved conserved core circuitry valid across insects I will compare species with distinct lifestyles. Secondly, I will reveal how these circuits have evolved to account for each species’ unique ecology. The proposed work will provide a coherent framework to study key concepts of fundamental brain functions in unprecedented detail - using a single, conserved, but flexible neural circuit.
Summary
The core function of all brains is to compute the current state of the world, compare it to the desired state of the world and select motor programs that drive behavior minimizing any mismatch. The circuits underlying these functions are the key to understand brains in general, but so far they are completely unknown. Three problems have hindered progress: 1) The animal’s desired state of the world is rarely known. 2) Most studies in simple models have focused on sensory driven, reflex-like processes, and not considered self-initiated behavior. 3) The circuits underlying complex behaviors in vertebrates are widely distributed, containing millions of neurons. With this proposal I aim at overcoming these problems using insects, whose tiny brains solve the same basic problems as our brains but with 100,000 times fewer cells. Moreover, the central complex, a single conserved brain region consisting of only a few thousand neurons, is crucial for sensory integration, motor control and state-dependent modulation, essentially being a ‘brain in the brain’. To simplify the problem further I will focus on navigation behavior. Here, the desired and actual states of the world are equal to the desired and current headings of the animal, with mismatches resulting in compensatory steering. I have previously shown how the central complex encodes the animal’s current heading. Now I will use behavioral training to generate animals with highly defined desired headings, and correlate neural activity with the animal’s ‘intentions’ and actions - at the level of identified neurons. To establish the involved conserved core circuitry valid across insects I will compare species with distinct lifestyles. Secondly, I will reveal how these circuits have evolved to account for each species’ unique ecology. The proposed work will provide a coherent framework to study key concepts of fundamental brain functions in unprecedented detail - using a single, conserved, but flexible neural circuit.
Max ERC Funding
1 500 000 €
Duration
Start date: 2017-01-01, End date: 2021-12-31
Project acronym BRAINSIGNALS
Project Optical dissection of circuits underlying fast cholinergic signalling during cognitive behaviour
Researcher (PI) Huibert Mansvelder
Host Institution (HI) STICHTING VU
Call Details Starting Grant (StG), LS5, ERC-2011-StG_20101109
Summary Our ability to think, to memorize and focus our thoughts depends on acetylcholine signaling in the brain. The loss of cholinergic signalling in for instance Alzheimer’s disease strongly compromises these cognitive abilities. The traditional view on the role of cholinergic input to the neocortex is that slowly changing levels of extracellular acetylcholine (ACh) mediate different arousal states. This view has been challenged by recent studies demonstrating that rapid phasic changes in ACh levels at the scale of seconds are correlated with focus of attention, suggesting that these signals may mediate defined cognitive operations. Despite a wealth of anatomical data on the organization of the cholinergic system, very little understanding exists on its functional organization. How the relatively sparse input of cholinergic transmission in the prefrontal cortex elicits such a profound and specific control over attention is unknown. The main objective of this proposal is to develop a causal understanding of how cellular mechanisms of fast acetylcholine signalling are orchestrated during cognitive behaviour.
In a series of studies, I have identified several synaptic and cellular mechanisms by which the cholinergic system can alter neuronal circuitry function, both in cortical and subcortical areas. I have used a combination of behavioral, physiological and genetic methods in which I manipulated cholinergic receptor functionality in prefrontal cortex in a subunit specific manner and found that ACh receptors in the prefrontal cortex control attention performance. Recent advances in optogenetic and electrochemical methods now allow to rapidly manipulate and measure acetylcholine levels in freely moving, behaving animals. Using these techniques, I aim to uncover which cholinergic neurons are involved in fast cholinergic signaling during cognition and uncover the underlying neuronal mechanisms that alter prefrontal cortical network function.
Summary
Our ability to think, to memorize and focus our thoughts depends on acetylcholine signaling in the brain. The loss of cholinergic signalling in for instance Alzheimer’s disease strongly compromises these cognitive abilities. The traditional view on the role of cholinergic input to the neocortex is that slowly changing levels of extracellular acetylcholine (ACh) mediate different arousal states. This view has been challenged by recent studies demonstrating that rapid phasic changes in ACh levels at the scale of seconds are correlated with focus of attention, suggesting that these signals may mediate defined cognitive operations. Despite a wealth of anatomical data on the organization of the cholinergic system, very little understanding exists on its functional organization. How the relatively sparse input of cholinergic transmission in the prefrontal cortex elicits such a profound and specific control over attention is unknown. The main objective of this proposal is to develop a causal understanding of how cellular mechanisms of fast acetylcholine signalling are orchestrated during cognitive behaviour.
In a series of studies, I have identified several synaptic and cellular mechanisms by which the cholinergic system can alter neuronal circuitry function, both in cortical and subcortical areas. I have used a combination of behavioral, physiological and genetic methods in which I manipulated cholinergic receptor functionality in prefrontal cortex in a subunit specific manner and found that ACh receptors in the prefrontal cortex control attention performance. Recent advances in optogenetic and electrochemical methods now allow to rapidly manipulate and measure acetylcholine levels in freely moving, behaving animals. Using these techniques, I aim to uncover which cholinergic neurons are involved in fast cholinergic signaling during cognition and uncover the underlying neuronal mechanisms that alter prefrontal cortical network function.
Max ERC Funding
1 499 242 €
Duration
Start date: 2011-11-01, End date: 2016-10-31
Project acronym CCC
Project Cracking the Cerebellar Code
Researcher (PI) Christiaan Innocentius De Zeeuw
Host Institution (HI) ERASMUS UNIVERSITAIR MEDISCH CENTRUM ROTTERDAM
Call Details Advanced Grant (AdG), LS5, ERC-2011-ADG_20110310
Summary Spike trains transfer information to and from neurons. Most studies so far assume that the average firing rate or “rate coding” is the predominant way of information coding. However, spikes occur at millisecond precision, and their actual timing or “temporal coding” can in principle strongly increase the information content of spike trains. The two coding mechanisms are not mutually exclusive. Neurons may switch between rate and temporal coding, or use a combination of both coding mechanisms at the same time, which would increase the information content of spike trains even further. Here, we propose to investigate the hypothesis that temporal coding plays, next to rate coding, important and specific roles in cerebellar processing during learning. The cerebellum is ideal to study this timely topic, because it has a clear anatomy with well-organized modules and matrices, a well-described physiology of different types of neurons with distinguishable spiking activity, and a central role in various forms of tractable motor learning. Moreover, uniquely in the brain, the main types of neurons in the cerebellar system can be genetically manipulated in a cell-specific fashion, which will allow us to investigate the behavioural importance of both coding mechanisms following cell-specific interference and/or during cell-specific visual imaging. Thus, for this proposal we will create conditional mouse mutants that will be subjected to learning paradigms in which we can disentangle the contributions of rate coding and temporal coding using electrophysiological and optogenetic recordings and stimulation. Together, our experiments should elucidate how neurons in the brain communicate during natural learning behaviour and how one may be able to intervene in this process to affect or improve procedural learning skills.
Summary
Spike trains transfer information to and from neurons. Most studies so far assume that the average firing rate or “rate coding” is the predominant way of information coding. However, spikes occur at millisecond precision, and their actual timing or “temporal coding” can in principle strongly increase the information content of spike trains. The two coding mechanisms are not mutually exclusive. Neurons may switch between rate and temporal coding, or use a combination of both coding mechanisms at the same time, which would increase the information content of spike trains even further. Here, we propose to investigate the hypothesis that temporal coding plays, next to rate coding, important and specific roles in cerebellar processing during learning. The cerebellum is ideal to study this timely topic, because it has a clear anatomy with well-organized modules and matrices, a well-described physiology of different types of neurons with distinguishable spiking activity, and a central role in various forms of tractable motor learning. Moreover, uniquely in the brain, the main types of neurons in the cerebellar system can be genetically manipulated in a cell-specific fashion, which will allow us to investigate the behavioural importance of both coding mechanisms following cell-specific interference and/or during cell-specific visual imaging. Thus, for this proposal we will create conditional mouse mutants that will be subjected to learning paradigms in which we can disentangle the contributions of rate coding and temporal coding using electrophysiological and optogenetic recordings and stimulation. Together, our experiments should elucidate how neurons in the brain communicate during natural learning behaviour and how one may be able to intervene in this process to affect or improve procedural learning skills.
Max ERC Funding
2 499 600 €
Duration
Start date: 2012-04-01, End date: 2017-03-31
Project acronym CMTaaRS
Project Defective protein translation as a pathogenic mechanism of peripheral neuropathy
Researcher (PI) Erik Jan Marthe STORKEBAUM
Host Institution (HI) STICHTING KATHOLIEKE UNIVERSITEIT
Call Details Consolidator Grant (CoG), LS5, ERC-2017-COG
Summary Familial forms of neurodegenerative diseases are caused by mutations in a single gene. It is unknown whether distinct mutations in the same gene or in functionally related genes cause disease through similar or disparate mechanisms. Furthermore, the precise molecular mechanisms underlying virtually all neurodegenerative disorders are poorly understood, and effective treatments are typically lacking.
This is also the case for Charcot-Marie-Tooth (CMT) peripheral neuropathy caused by mutations in five distinct tRNA synthetase (aaRS) genes. We previously generated Drosophila CMT-aaRS models and used a novel method for cell-type-specific labeling of newly synthesized proteins in vivo to show that impaired protein translation may represent a common pathogenic mechanism.
In this proposal, I aim to determine whether translation is also inhibited in CMT-aaRS mouse models, and whether all mutations cause disease through gain-of-toxic-function, or alternatively, whether some mutations act through a dominant-negative mechanism. In addition, I will evaluate whether all CMT-aaRS mutant proteins inhibit translation, and I will test the hypothesis, raised by our unpublished preliminary data shown here, that a defect in the transfer of the (aminoacylated) tRNA from the mutant synthetase to elongation factor eEF1A is the molecular mechanism underlying CMT-aaRS. Finally, I will validate the identified molecular mechanism in CMT-aaRS mouse models, as the most disease-relevant mammalian model.
I expect to elucidate whether all CMT-aaRS mutations cause disease through a common molecular mechanism that involves inhibition of translation. This is of key importance from a therapeutic perspective, as a common pathogenic mechanism allows for a unified therapeutic approach. Furthermore, this proposal has the potential to unravel the detailed molecular mechanism underlying CMT-aaRS, what would constitute a breakthrough and a requirement for rational drug design for this incurable disease.
Summary
Familial forms of neurodegenerative diseases are caused by mutations in a single gene. It is unknown whether distinct mutations in the same gene or in functionally related genes cause disease through similar or disparate mechanisms. Furthermore, the precise molecular mechanisms underlying virtually all neurodegenerative disorders are poorly understood, and effective treatments are typically lacking.
This is also the case for Charcot-Marie-Tooth (CMT) peripheral neuropathy caused by mutations in five distinct tRNA synthetase (aaRS) genes. We previously generated Drosophila CMT-aaRS models and used a novel method for cell-type-specific labeling of newly synthesized proteins in vivo to show that impaired protein translation may represent a common pathogenic mechanism.
In this proposal, I aim to determine whether translation is also inhibited in CMT-aaRS mouse models, and whether all mutations cause disease through gain-of-toxic-function, or alternatively, whether some mutations act through a dominant-negative mechanism. In addition, I will evaluate whether all CMT-aaRS mutant proteins inhibit translation, and I will test the hypothesis, raised by our unpublished preliminary data shown here, that a defect in the transfer of the (aminoacylated) tRNA from the mutant synthetase to elongation factor eEF1A is the molecular mechanism underlying CMT-aaRS. Finally, I will validate the identified molecular mechanism in CMT-aaRS mouse models, as the most disease-relevant mammalian model.
I expect to elucidate whether all CMT-aaRS mutations cause disease through a common molecular mechanism that involves inhibition of translation. This is of key importance from a therapeutic perspective, as a common pathogenic mechanism allows for a unified therapeutic approach. Furthermore, this proposal has the potential to unravel the detailed molecular mechanism underlying CMT-aaRS, what would constitute a breakthrough and a requirement for rational drug design for this incurable disease.
Max ERC Funding
2 000 000 €
Duration
Start date: 2018-06-01, End date: 2023-05-31
Project acronym COGOPTO
Project The role of parvalbumin interneurons in cognition and behavior
Researcher (PI) Eva Marie Carlen
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Starting Grant (StG), LS5, ERC-2013-StG
Summary Cognition is a collective term for complex but sophisticated mental processes such as attention, learning, social interaction, language production, decision making and other executive functions. For normal brain function, these higher-order functions need to be aptly regulated and controlled, and the physiology and cellular substrates for cognitive functions are under intense investigation. The loss of cognitive control is intricately related to pathological states such as schizophrenia, depression, attention deficit hyperactive disorder and addiction.
Synchronized neural activity can be observed when the brain performs several important functions, including cognitive processes. As an example, gamma activity (30-80 Hz) predicts the allocation of attention and theta activity (4-12 Hz) is tightly linked to memory processes. A large body of work indicates that the integrity of local and global neural synchrony is mediated by interneuron networks and actuated by the balance of different neuromodulators.
However, much knowledge is still needed on the functional role interneurons play in cognitive processes, i.e. how the interneurons contribute to local and global network processes subserving cognition, and ultimately play a role in behavior. In addition, we need to understand how neuro-modulators, such as dopamine, regulate interneuron function.
The proposed project aims to functionally determine the specific role the parvalbumin interneurons and the neuromodulator dopamine in aspects of cognition, and in behavior. In addition, we ask the question if cognition can be enhanced.
We are employing a true multidisciplinary approach where brain activity is recorded in conjunctions with optogenetic manipulations of parvalbumin interneurons in animals performing cognitive tasks. In one set of experiments knock-down of dopamine receptors specifically in parvalbumin interneurons is employed to probe how this neuromodulator regulate network functions.
Summary
Cognition is a collective term for complex but sophisticated mental processes such as attention, learning, social interaction, language production, decision making and other executive functions. For normal brain function, these higher-order functions need to be aptly regulated and controlled, and the physiology and cellular substrates for cognitive functions are under intense investigation. The loss of cognitive control is intricately related to pathological states such as schizophrenia, depression, attention deficit hyperactive disorder and addiction.
Synchronized neural activity can be observed when the brain performs several important functions, including cognitive processes. As an example, gamma activity (30-80 Hz) predicts the allocation of attention and theta activity (4-12 Hz) is tightly linked to memory processes. A large body of work indicates that the integrity of local and global neural synchrony is mediated by interneuron networks and actuated by the balance of different neuromodulators.
However, much knowledge is still needed on the functional role interneurons play in cognitive processes, i.e. how the interneurons contribute to local and global network processes subserving cognition, and ultimately play a role in behavior. In addition, we need to understand how neuro-modulators, such as dopamine, regulate interneuron function.
The proposed project aims to functionally determine the specific role the parvalbumin interneurons and the neuromodulator dopamine in aspects of cognition, and in behavior. In addition, we ask the question if cognition can be enhanced.
We are employing a true multidisciplinary approach where brain activity is recorded in conjunctions with optogenetic manipulations of parvalbumin interneurons in animals performing cognitive tasks. In one set of experiments knock-down of dopamine receptors specifically in parvalbumin interneurons is employed to probe how this neuromodulator regulate network functions.
Max ERC Funding
1 400 000 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
Project acronym CoordinatedDopamine
Project Coordination of regional dopamine release in the striatum during habit formation and compulsive behaviour
Researcher (PI) Ingo Willuhn
Host Institution (HI) ACADEMISCH MEDISCH CENTRUM BIJ DE UNIVERSITEIT VAN AMSTERDAM
Call Details Starting Grant (StG), LS5, ERC-2014-STG
Summary The basal ganglia consist of a set of neuroanatomical structures that participate in the representation and execution of action sequences. Dopamine neurotransmission in the striatum, the main input nucleus of the basal ganglia, is a fundamental mechanism involved in learning and regulation of such actions. The striatum has multiple functional units, where the limbic striatum is thought to mediate motivational aspects of actions (e.g., goal-directedness) and the sensorimotor striatum their automation (e.g., habit formation). A long-standing question in the field is how limbic and sensorimotor domains communicate with each other, and specifically if they do so during the automation of action sequences. It has been suggested that such coordination is implemented by reciprocal loop connections between striatal projection neurons and the dopaminergic midbrain. Although very influential in theory the effectiveness of this limbic-sensorimotor “bridging” principle has yet to be verified. I hypothesize that during the automation of behaviour regional dopamine signalling is governed by a striatal hierarchy and that dysregulation of this coordination leads to compulsive execution of automatic actions characteristic of several psychiatric disorders. To test this hypothesis, we will conduct electrochemical measurements with real-time resolution simultaneously in limbic and sensorimotor striatum to assess the regional coordination of dopamine release in behaving animals. We developed novel chronically implantable electrodes to enable monitoring of dopamine dynamics throughout the development of habitual behaviour and its compulsive execution in transgenic rats - a species suitable for our complex behavioural assays. Novel rabies virus-mediated gene delivery for in vivo optogenetics in these rats will give us the unique opportunity to test whether specific loop pathways govern striatal dopamine transmission and are causally involved in habit formation and compulsive behaviour.
Summary
The basal ganglia consist of a set of neuroanatomical structures that participate in the representation and execution of action sequences. Dopamine neurotransmission in the striatum, the main input nucleus of the basal ganglia, is a fundamental mechanism involved in learning and regulation of such actions. The striatum has multiple functional units, where the limbic striatum is thought to mediate motivational aspects of actions (e.g., goal-directedness) and the sensorimotor striatum their automation (e.g., habit formation). A long-standing question in the field is how limbic and sensorimotor domains communicate with each other, and specifically if they do so during the automation of action sequences. It has been suggested that such coordination is implemented by reciprocal loop connections between striatal projection neurons and the dopaminergic midbrain. Although very influential in theory the effectiveness of this limbic-sensorimotor “bridging” principle has yet to be verified. I hypothesize that during the automation of behaviour regional dopamine signalling is governed by a striatal hierarchy and that dysregulation of this coordination leads to compulsive execution of automatic actions characteristic of several psychiatric disorders. To test this hypothesis, we will conduct electrochemical measurements with real-time resolution simultaneously in limbic and sensorimotor striatum to assess the regional coordination of dopamine release in behaving animals. We developed novel chronically implantable electrodes to enable monitoring of dopamine dynamics throughout the development of habitual behaviour and its compulsive execution in transgenic rats - a species suitable for our complex behavioural assays. Novel rabies virus-mediated gene delivery for in vivo optogenetics in these rats will give us the unique opportunity to test whether specific loop pathways govern striatal dopamine transmission and are causally involved in habit formation and compulsive behaviour.
Max ERC Funding
1 500 000 €
Duration
Start date: 2015-05-01, End date: 2020-04-30
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 COSI
Project Cerebellar modules and the Ontogeny of Sensorimotor Integration
Researcher (PI) Martijn Schonewille
Host Institution (HI) ERASMUS UNIVERSITAIR MEDISCH CENTRUM ROTTERDAM
Call Details Starting Grant (StG), LS5, ERC-2015-STG
Summary The perfect execution of a voluntary movement requires the appropriate integration of current bodily state, sensory input and desired outcome. To assure that this motor output becomes and remains appropriate, the brain needs to learn from the result of previous outputs. The cerebellum plays a central role in sensorimotor integration, yet -despite decades of studies- there is no generally excepted theory for cerebellar functioning. I recently demonstrated that cerebellar modules, identified based on anatomical connectivity and gene expression, differ distinctly in spike activity properties. It is my long-term goal to identify the ontogeny of anatomical and physiological differences between modules, and their functional consequences. My hypothesis is that these differences can explain existing controversies, and unify contradicting results into one central theory.
To this end, I have designed three key objectives. First, I will identify the development of connectivity and activity patterns at the input stage of the cerebellar cortex in relation to the cerebellar modules (key objective A). Next, I will relate the differences in gene expression levels between modules to differences in basal activity and strength of plasticity mechanisms in juvenile mice (key objective B). Finally, I will determine how module specific output develops in relation to behavior and what the effect of module specific mutations is on cerebellum-dependent motor tasks and higher order functions (key objective C).
Ultimately, the combined results of all key objectives will reveal how distinct difference between cerebellar modules develop, and how this ensemble ensures proper cerebellar information processing for optimal coordination of timing and force of movements. Combined with the growing body of evidence for a cerebellar role in higher order brain functions and neurodevelopmental disorders, a unifying theory would be fundamental for understanding how the juvenile brain develops.
Summary
The perfect execution of a voluntary movement requires the appropriate integration of current bodily state, sensory input and desired outcome. To assure that this motor output becomes and remains appropriate, the brain needs to learn from the result of previous outputs. The cerebellum plays a central role in sensorimotor integration, yet -despite decades of studies- there is no generally excepted theory for cerebellar functioning. I recently demonstrated that cerebellar modules, identified based on anatomical connectivity and gene expression, differ distinctly in spike activity properties. It is my long-term goal to identify the ontogeny of anatomical and physiological differences between modules, and their functional consequences. My hypothesis is that these differences can explain existing controversies, and unify contradicting results into one central theory.
To this end, I have designed three key objectives. First, I will identify the development of connectivity and activity patterns at the input stage of the cerebellar cortex in relation to the cerebellar modules (key objective A). Next, I will relate the differences in gene expression levels between modules to differences in basal activity and strength of plasticity mechanisms in juvenile mice (key objective B). Finally, I will determine how module specific output develops in relation to behavior and what the effect of module specific mutations is on cerebellum-dependent motor tasks and higher order functions (key objective C).
Ultimately, the combined results of all key objectives will reveal how distinct difference between cerebellar modules develop, and how this ensemble ensures proper cerebellar information processing for optimal coordination of timing and force of movements. Combined with the growing body of evidence for a cerebellar role in higher order brain functions and neurodevelopmental disorders, a unifying theory would be fundamental for understanding how the juvenile brain develops.
Max ERC Funding
1 500 000 €
Duration
Start date: 2016-06-01, End date: 2021-05-31
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
