ERC FUNDED PROJECTS

Aggregates of proteins such as amyloid-beta and alpha-synuclein circulate the extracellular space of the brain (ECS) and are thought to be key players in the development of neurodegenerative diseases. The clearance of these aggregates (among other toxic metabolites) is a fundamental physiological feature of the brain which is poorly understood due to the lack of techniques to study the nanoscale organisation of the ECS. Exciting advances in this field have recently shown that clearance is enhanced during sleep due to a major volume change in the ECS, facilitating the flow of the interstitial fluid. However, this process has only been characterised at a low spatial resolution while the physiological changes occur at the nanoscale. The recently proposed “glymphatic” pathway still remains controversial, as there are no techniques capable of distinguishing between diffusion and bulk flow in the ECS of living animals. Understanding these processes at a higher spatial resolution requires the development of single-molecule imaging techniques that can study the brain in living animals. Taking advantage of the strategies I have recently developed to target single-molecules in the brain in vivo with nanoparticles, we will do “nanoscopy” in living animals. Our proposal will test the glymphatic pathway at the spatial scale in which events happen, and explore how sleep and wake cycles alter the ECS and the diffusion of receptors in neuronal plasma membrane. Overall, BrainNanoFlow aims to understand how nanoscale changes in the ECS facilitate clearance of protein aggregates. We will also provide new insights to the pathological consequences of impaired clearance, focusing on the interactions between these aggregates and their putative receptors. Being able to perform single-molecule studies in vivo in the brain will be a major breakthrough in neurobiology, making possible the study of physiological and pathological processes that cannot be studied in simpler brain preparations.

1 552 948 €

Start date: 2018-12-01, End date: 2023-11-30

Protein misfolding causes devastating health conditions such as neurodegeneration. Although the disease-causing protein is widely expressed, its misfolding occurs only in certain cell-types such as neurons. What governs the susceptibility of some tissues to misfolding is a fundamental question with biomedical relevance. Molecular chaperones help cellular proteins fold into their native conformation. Despite the generality of their function, chaperones are differentially expressed across various tissues. Moreover exposure to misfolding stress changes chaperone expression in a cell-type-dependent manner. Thus cell-type-specific regulation of chaperones is a major determinant of susceptibility to misfolding. The molecular mechanisms governing chaperone levels in different cell-types are not understood, forming the basis of this proposal. We will take a multidisciplinary approach to address two key questions: (1) How are chaperone levels co-ordinated with tissue-specific demands on protein folding? (2) How do different cell-types regulate chaperone genes when exposed to the same misfolding stress? Cellular chaperone levels and their response to misfolding stress are both driven by transcriptional changes and influenced by chromatin. The proposed work will bring the conceptual, technological and computational advances of chromatin/ transcription field to understand chaperone biology and misfolding diseases. Using in vivo mouse model and in vitro differentiation model, we will investigate molecular mechanisms that control chaperone levels in relevant tissues. Our work will provide insights into functional specialization of chaperones driven by tissue-specific folding demands. We will develop a novel and ambitious approach to assess protein-folding capacity in single cells moving the chaperone field beyond state-of-the-art. Thus by implementing genetic, computational and biochemical approaches, we aim to understand cell-type-specificity of chaperone regulation.

1 992 500 €

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

Diffusive shock acceleration is widely acknowledged as the most likely source of cosmic rays and high energy particles. The basic macroscopic theory of how cosmic rays gain energy during multiple shock crossings is well known, but the microphysics of the interaction between cosmic rays (CR) and the MHD background fluid remained poorly understood before the recent discovery of a new non-resonant instability by which the CR precursor could greatly amplify the ambient magnetic field. The aims of the project are: 1) to develop the first self-consistent non-linear simulation of the CR/MHD interaction; to calculate the magnitude of the saturated magnetic field and the maximum energy to which CR are accelerated. We will characterise the structure of the amplified magnetic field and compare it with x-ray observations of the time-evolving outer shock of supernova remnants (SNR). We will investigate the effect of various orientations of the shock relative to the ambient magnetic field, the effect of non-diffusive transport on the energy spectrum and CR escape from the SNR, and how these match observation. 2) to extend the simulation to relativistic shocks as found in gamma-ray bursts (GRB) and active galactic nuclei (AGN); to establish whether the non-resonant instability operates effectively at relativistic shock velocities, whether it explains the large magnetic field found in GRB, and determine the maximum CR energy achieved by relativistic shocks. 3) to investigate high density shocks in GRB, x-ray flashes (XRF) and supernovae (SN) where radiative processes, pair production and other particle/photon and particle/particle interactions are important. We shall investigate CR acceleration on SN shock breakout and very young SNR as a possible source of very high energy CR.

900 024 €

Start date: 2010-05-01, End date: 2015-04-30

An intense debate is raging within evolutionary anthropology as to whether the evolution of human behaviour is driven by selection pressure on the individual or on the group. Until recently there was consensus amongst evolutionary biologists and evolutionary anthropologists that natural selection caused behaviours to evolve that benefit the individual or close kin. However the idea that cultural behaviours that favour the group can evolve, even at the expense of individual well-being, is now being supported by some evolutionary anthropologists and economists. Models of cultural group selection rely on patterns of cultural transmission that maintain differences between cultural groups, because either decisions are based on what most others in the group do, or non-conformists are punished in some way. If such biased transmission occurs, then humans may be following a unique evolutionary trajectory towards extreme sociality; such models potentially explain behaviours such as altruism towards non-relatives or limiting your reproductive rate. However, relevant empirical evidence from real world populations, concerning behaviour that potentially influences reproductive success, is almost entirely lacking. The projects proposed here are designed to help fill that gap. In micro-evolutionary studies we will seek evidence for the patterns cultural transmission or social learning that enable cultural group selection to act, and ask how these processes depend on properties of the community, and thus how robust are they to the demographic and societal changes that accompany modernisation. These include studies of the spread of modern contraception through communities; and studies of punishment of selfish players in economic games. In macro-evolutionary studies, we will use phylogenetic cross-cultural comparative methods to show how different cultural traits change over the long term, and ask whether social or ecological variables are driving that cultural change.

1 801 978 €

Start date: 2010-05-01, End date: 2016-04-30