ERC FUNDED PROJECTS

Serotonin (5-HT) is a central neuromodulator and a major target of therapeutic psychoactive drugs, but relatively little is known about how it modulates information processing in neural circuits. The theory of predictive coding postulates that the brain combines raw bottom-up sensory information with top-down information from internal models to make perceptual inferences about the world. We hypothesize, based on preliminary data and prior literature, that a role of 5-HT in this process is to report prediction errors and promote the suppression and weakening of erroneous internal models. We propose that it does this by inhibiting top-down relative to bottom-up cortical information flow. To test this hypothesis, we propose a set of experiments in mice performing olfactory perceptual tasks. Our specific aims are: (1) We will test whether 5-HT neurons encode sensory prediction errors. (2) We will test their causal role in using predictive cues to guide perceptual decisions. (3) We will characterize how 5-HT influences the encoding of sensory information by neuronal populations in the olfactory cortex and identify the underlying circuitry. (4) Finally, we will map the effects of 5-HT across the whole brain and use this information to target further causal manipulations to specific 5-HT projections. We accomplish these aims using state-of-the-art optogenetic, electrophysiological and imaging techniques (including 9.4T small-animal functional magnetic resonance imaging) as well as psychophysical tasks amenable to quantitative analysis and computational theory. Together, these experiments will tackle multiple facets of an important general computational question, bringing to bear an array of cutting-edge technologies to address with unprecedented mechanistic detail how 5-HT impacts neural coding and perceptual decision-making.

2 486 074 €

Start date: 2016-01-01, End date: 2020-12-31

The brain evolves, develops, and operates in the context of animal movements. As a consequence, fundamental brain functions such as spatial perception and motor control critically depend on the precise knowledge of the ongoing body motion. An accurate internal estimate of self-movement is thought to emerge from sensorimotor integration; nonetheless, which circuits perform this internal estimation, and exactly how motor-sensory coordination is implemented within these circuits are basic questions that remain to be poorly understood. There is growing evidence suggesting that, during locomotion, motor-related and visual signals interact at early stages of visual processing. In mammals, however, it is not clear what the function of this interaction is. Recently, we have shown that a population of Drosophila optic-flow processing neurons —neurons that are sensitive to self-generated visual flow, receives convergent visual and walking-related signals to form a faithful representation of the fly’s walking movements. Leveraging from these results, and combining quantitative analysis of behavior with physiology, optogenetics, and modelling, we propose to investigate circuit mechanisms of self-movement estimation during walking. We will:1) use cell specific manipulations to identify what cells are necessary to generate the motor-related activity in the population of visual neurons, 2) record from the identified neurons and correlate their activity with specific locomotor parameters, and 3) perturb the activity of different cell-types within the identified circuits to test their role in the dynamics of the visual neurons, and on the fly’s walking behavior. These experiments will establish unprecedented causal relationships among neural activity, the formation of an internal representation, and locomotor control. The identified sensorimotor principles will establish a framework that can be tested in other scenarios or animal systems with implications both in health and disease.

1 500 000 €

Start date: 2017-11-01, End date: 2022-10-31

New generations of devices for tissue engineering (TE) should rationalize better the physical and biochemical cues operating in tandem during native regeneration, in particular at the scale/organizational-level of the stem cell niche. The understanding and the deconstruction of these factors (e.g. multiple cell types exchanging both paracrine and direct signals, structural and chemical arrangement of the extra-cellular matrix, mechanical signals…) should be then incorporated into the design of truly biomimetic biomaterials. ATLAS proposes rather unique toolboxes combining smart biomaterials and cells for the ground-breaking advances of engineering fully time-self-regulated complex 2D and 3D devices, able to adjust the cascade of processes leading to faster high-quality new tissue formation with minimum pre-processing of cells. Versatile biomaterials based on marine-origin macromolecules will be used, namely in the supramolecular assembly of instructive multilayers as nanostratified building-blocks for engineer such structures. The backbone of these biopolymers will be equipped with a variety of (bio)chemical elements permitting: post-processing chemistry and micro-patterning, specific/non-specific cell attachment, and cell-controlled degradation. Aiming at being applied in bone TE, ATLAS will integrate cells from different units of tissue physiology, namely bone and hematopoietic basic elements and consider the interactions between the immune and skeletal systems. These ingredients will permit to architect innovative films with high-level dialogue control with cells, but in particular sophisticated quasi-closed 3D capsules able to compartmentalise such components in a “globe-like” organization, providing local and long-range order for in vitro microtissue development and function. Such hybrid devices could be used in more generalised front-edge applications, including as disease models for drug discovery or test new therapies in vitro.

2 498 988 €

Start date: 2015-12-01, End date: 2020-11-30

In the last decade, solar and photovoltaic (PV) technologies have emerged as a potentially major technology for power generation in the world. So far the PV field has been dominated by silicon devices, even though this technology is still expensive.Dye-sensitized solar cells (DSC) are an important type of thin-film photovoltaics due to their potential for low-cost fabrication and versatile applications, and because their aesthetic appearance, semi-transparency and different color possibilities.This advantageous characteristic makes DSC the first choice for building integrated photovoltaics.Despite their great potential, DSCs for building applications are still not available at commercial level. However, to bring DSCs to a marketable product several developments are still needed and the present project targets to give relevant answers to three key limitations: encapsulation, glass substrate enhanced electrical conductivity and more efficient and low-cost raw-materials. Recently, the proponent successfully addressed the hermetic devices sealing by developing a laser-assisted glass sealing procedure.Thus, BI-DSC proposal envisages the development of DSC modules 30x30cm2, containing four individual cells, and their incorporation in a 1m2 double glass sheet arrangement for BIPV with an energy efficiency of at least 9% and a lifetime of 20 years. Additionally, aiming at enhanced efficiency of the final device and decreased total costs of DSCs manufacturing, new materials will be also pursued. The following inner-components were identified as critical: carbon-based counter-electrode; carbon quantum-dots and hierarchically TiO2 photoelectrode. It is then clear that this project is divided into two research though parallel directions: a fundamental research line, contributing to the development of the new generation DSC technology; while a more applied research line targets the development of a DSC functional module that can be used to pave the way for its industrialization.

1 989 300 €

Start date: 2013-03-01, End date: 2018-08-31