SP1. Molecular control of neural tube regionalization and neuronal differentiation.


The vertebrate central nervous system (CNS) originates from the embryonic dorsal ectoderm. Differentiation of the neural epithelium from the ectoderm and the formation of the neural plate constitute the first phase of a complex process called neurulation that culminates with neural tube formation, the anlage of the future CNS. At neural plate and neural tube stages, local signalling centres in the neuroepithelium, known as secondary organizers, refine the antero-posterior specification of different neural territories. Understanding the process of patterning in the neural primordium is fundamental to identify the molecular and cellular mechanisms involved in the specification of these organizers, as well as their signalling molecules and the activated molecular pathways. This process of regional patterning in the neural tube generates the scaffold of positional information necessary to build the structural diversity that characterizes the brain, the establishment of the pioneer neuronal connections and, subsequently, permits the development of the complex neural function that underlie animal behaviour.

Much work has been devoted to the molecular processes underlying particular developmental events restricted to small areas of the brain or to a distinct feature of development (e.g. the molecular regionalization of the neuroepithelium at one precise stage of development in given vertebrate specie; the role of a group of genes in the development of a precise brain region, etc). Thus, our present view of neural regionalization appears like a puzzle of dispersed pieces that only a multidisciplinary and integrated approach might help to fully understand. This is especially relevant in the case of the isthmic organizer and its role in mesencephalic and rostral rhombencephalic development (including the cerebellum).

The analysis of genetic expressions during neural tube development is a fundamental tool to identify regional singularities in neuroepithelial domains that could be related to the specification of cellular identities. Although complementary analysis of topological relations between genetic expressions in the mesencephalic and rhombencephalic epithelium in the neural plate and tube has been fundamental to our present knowledge of brain morphogenesis, combinatory experiments with cell lineage tracing are mandatory to confirm morphogenetic relations between molecular neuroepithelial domains and brain territories. In addition, little has yet been explored on the role of neuroepithelial gene expressions in the regulation of neuronal and glial specification, cellular differentiation, migration and functional maturation (neurotransmitter production and connectivity).


The goal of this subproject is to analyze by a multidisciplinary integrated approach:
1) the role of secondary organizers in the control of neural tube molecular regionalization, and 2) the molecular pathways that regulate the processes of cellular differentiation, migration and functional maturation during brain development in vertebrates.



SP2: Neuronal migration, axon targeting and synaptogenesis


The neural assembly underlying the formation of functional networks in the mammalian cerebral cortex constitutes one of the most complex biological systems. Much of this complexity arises during development through the interaction of two distinct neuronal types, glutamatergic projection neurons and gamma-aminobutyric containing (GABAergic) interneurons. Projection neurons constitute the main substrate of cortical function, forming long-range connections between different cortical areas and with subcortical targets. Interneurons, on the other hand, are critical for cortical function because they represent the basic elements that provide inhibition, synchronize and shape several types of cortical oscillations underlying various brain functions, and prevent development of hyperexcitability and epileptiform activity. Neuronal networks in the cerebral cortex are also modulated by several inputs, among which the thalamocortical projection represents one of the most important. Thalamocortical projections convey sensory and motor inputs to the cerebral cortex, where integration of this information leads to perception and the organization of appropriate responses. In addition, thalamocortical projections participate in several parallel circuits linking the cerebral cortex, basal ganglia and thalamus. Through these pathways, thalamocortical axons contribute to many other aspects of our behavior, including movement, cognition, sleep or arousal.

The functional complexity of the cerebral cortex is the consequence of an extremely sophisticated process of assembly and remodeling, which starts at embryonic stages and continues throughout early postnatal life. During this process, projection neurons are exquisitely segregated into different layers according to their birth date, while GABAergic interneurons and thalamocortical projections navigate from long distances to reach the cortex and distribute according to highly stereotyped patterns. The integration of mouse genetics, molecular biology and novel imaging techniques has greatly accelerated our understanding of the mechanisms underlying the development of the cortex in the recent years. Moreover, we have begun to understand the functional consequences of abnormal cortical development, gaining insights into the molecular mechanisms translating form into function in the brain.


The general goal of this subproject is to obtain a comprehensive definition of the cellular and molecular mechanisms controlling the main events underlying the formation of neural networks, including neuronal migration, axon targeting and synaptogenesis. To reach this aim, we will take a multidisciplinary approach combining mouse genetics, cutting-edge imaging techniques, and conventional cellular, molecular and electrophysiological methodologies. Together with investigators in SP5, we also aim at understanding the functional consequences of perturbing cortical interneuron activity, or the impact of thalamocortical projections in the modulation of sensory information in the adult cortex.



SP3. The integration of Signalling Pathways during neural development


Multiples studies have shown the essential role of different signal transduction pathways during development. The last two decades have witnessed an unforeseen advance in the knowledge of the components of individual signalling pathways, but it has also become apparent that signal transduction pathways do not act individually, as linear cascades. Rather, complex signalling networks with multiple nodes of cross-communications between pathways must be established within a cell to elicit the final response in each particular scenario. However, the mechanisms by which signal transduction pathways within these networks are modulated and integrated are poorly understood, and this is particularly true for the development of the nervous system. Thus, to comprehend the acquisition of unique cell responses and cell fates during development it is crucial to further investigate how the signalling networks are built and regulated. Specifically, it is important to unravel the nodes of crosstalk between signalling cascades and the feedback loops established within those networks.


Our aim is to understand how particular cellular responses are generated after the integration of the signals that are simultaneously received by a cell during the development of the nervous system in vivo.



SP4: Molecular and cellular mechanisms for innocuous and noxious stimuli detection and their contribution to peripheral neuropathic pain.


The recent identification of molecular entities associated to the transduction of physical and chemical stimuli has provided new insights into how innocuous and noxious stimuli are detected and encoded by peripheral nerve terminals. Several members of the transient receptor potential (TRP) superfamily of ion channels are expressed by sensory neurons and gated by chemical, thermal and mechanical stimuli, thus making them strong candidates as molecular sensors for innocuous and noxious forces. Other ion channels, some having a very restricted expression pattern among peripheral sensory neurons, are also involved in the detection and encoding of somatosensory stimuli. In chronic pain states, such as those accompanying peripheral nerve injuries (i.e. diabetes, HIV/AIDS, trauma) or damage to the joints (i.e. osteoarthritis), the somatosensory system becomes maladapted resulting in exacerbated responses to innocuous stimuli. Pain resulting from an abnormal function of the nociceptive pathways and/or their relay nuclei is generically called neuropathic pain. The cellular mechanisms of chronic pain involve alterations in the properties of peripheral sensory neurons (both nociceptive and non-nociceptive) and persistent plastic changes in the connectivity and function of spinal circuitry involved in the processing of afferent signals to the brain.

Despite major advances, present knowledge about the mechanisms of activation of the different ion channels expressed by subclasses of primary sensory neurons and about the role of these channels in shaping the final nerve discharge generated at sensory terminals, or their intracellular modulation is still fragmentary. The specific alterations in the synaptic mechanisms leading to persistent activity in pain circuits are also poorly understood. An integrated view of the biological processes involved in the transduction and encoding of stimuli by intact somatic and visceral primary sensory neurons and their alteration following injury and inflammation, requires a multidimensional approach and the convergence of diverse disciplines and methodologies, including molecular biology and genetics, membrane biophysics, electrophysiology and pharmacology in vivo and in vitro as well as behavioral studies in animals and humans.


We propose to take advantage of advanced expertise at the INA in all these methodologies to address with a multidisciplinary approach the study of peripheral sensory transduction and nociceptive neurotransmission in normal and pathological conditions. Specifically, we want to dissect out the molecular and biophysical properties of transduction channels defining their role at the cellular and systems level. The ultimate aim of this effort is to obtain an integrated picture of the role of TRP channels in the normal function of the intact primary sensory neuron, the rules governing the formation of specific synapses between primary sensory neurons and dorsal horn neurons in the spinal cord and, finally, to understand the mechanisms activated by injury or inflammation to produce persistent modifications in the structure and function of sensory neurons and pain circuits.



SP5: Synaptic Plasticity and Brain Function


The term synaptic plasticity refers to a variety of activity-dependent processes that result in short-term or long-term changes in synaptic strength. These changes take place in our brain during development and every time we learn something, and consist of small physical alterations in specific synapses that lead to a modification in the performance of brain circuits. The adaptation of animals to their ever-changing environment relies on this remarkable capability. Synaptic plasticity and its relation to learning and memory have been mainly studied in two structures, the hippocampus and the neocortex. These two regions are the anatomical substrate of complex brain functions. Thus, the hippocampus is critically involved in the acquisition of explicit forms of memory. Its highly organized cellular anatomy permits the biochemical and electrophysiological analysis of circuit function both in vivo and in vitro. On the other hand, much of our understanding of how genetic factors and sensory experience shape the development of neural circuits derives from studies of plasticity in primary sensory regions of the cortex.

It has recently been possible to achieve compelling insights into the molecular mechanisms responsible for the induction and stability of synaptic changes and the acquisition and storage of new memories in the mammalian brain, thanks to the convergence of very different biological disciplines and methodologies, including molecular structure-function studies, mouse genetics, diverse electrophysiological techniques and behavioral studies.


In this subproject, we propose to apply a strongly interdisciplinary approach and state-of-the-art methodologies to decipher the molecular interactions and synaptic properties of neuronal circuits that underlie sensory transmission and plasticity and ultimately learning and memory. Together with investigators in SP1, SP2 and SP3, this SP also aims at elucidating how critical developmental events impinge on these processes.



SP6. Excellence Training Program in Interdisciplinary Neurosciences: Harbouring to Interdisciplinary Neuroscience a new Generation of European Scientists (HINGES)

With this Consolider action, we propose an ambitious and innovative training program in interdisciplinary and emerging fields of Neurosciences for European Ph.D. students of excellence, that could be extended to young postdoctoral researchers originally trained in other disciplines and interested in moving to these exciting fields. This endeavour will be fostered by the research groups in this consortium, belonging to the INA and working in different fields of modern Neurosciences with high qualification and proven research experience. We believe that the integration in joint, frontier projects will further facilitate cross-fertilization among the various researchers that may be using different experimental approaches but share common intellectual interests, increasing the profile of the host institution and the integration of other research groups.

The scientific programme aims at stimulating and developing high quality integrated research on competitive and interdisciplinary aspects of Neurosciences. In particular, we propose the following objectives:

1. To establish a training programme of excellence in Interdisciplinary Neurosciences at INA for a total of 10 selected European students, who are expected to play an important role in generating and pursuing original research. These students will be fully supported for a 4 years training period. Training in more than one Neuroscience discipline will enable outstanding young researchers to make significant contributions to advance our understanding of complex functions.

2. To facilitate the access and training of young postdoctoral fellows who obtained their Ph.D. in other disciplines and are interested in moving to the exciting field of Neurosciences. In particular, researchers with a Ph.D. degree in physics, chemistry, mathematics or computer sciences that wish to gain research experience in the life sciences will be specially considered. The previous experience and knowledge in other disciplines of these fellows would be a valuable addition to the host laboratories and may represent the stepping stone to launch new and innovative projects.

3. To reinforce networking, both with other European institutions working in Neurosciences and with MSEs developing their activities in this field.

In summary, the final purpose of the HINGES programme is to provide a world-class multidisciplinary research environment to a new generation of European Neuroscientists .

The Research Team engages a substantial proportion of the INA members. For that reason, high performance and state-of-the-art techniques as well as several experimental models (flies, fish, chicken and mice) could be used in a cooperative manner to explore problems from molecular to integrative levels. The research groups involved in HINGES activities may be grouped in 3 general subprograms pertaining to formative activities: "DEVELOPMENT", "MECHANISMS" and "SYSTEMS"

1. Subprogram "DEVELOPMENT": This subprogram will be implemented by research groups dedicated to the study of pattern formation, growth control mechanisms, neurogenesis, migration and axonal guidance, and synaptogenesis (Subprojects 1, 2 and 3) Research involves a multidisciplinary integrated approach directed towards analysing the development of the nervous system and the formation of neural networks.

2. Subprogram "MECHANISMS": This subprogram will be handle by research groups that carry out basic research related to biochemistry, biophysics, pharmacology and molecular biology of neuroreceptors, ionic channels and proteins involved in neurotransmission. Its goal is to better understand the essential processes underlying the function of neuronal cells at the molecular and cellular level, such as synaptic transmission and plasticity, signal transduction, etc. (Subprojects 2, 4, and 5).

3. Subprogram "SYSTEMS": This subprogram will be organized by groups whose research focuses on how the cerebral cortex and various sensory systems function, primarily through the use of electrophysiological, computational and imaging techniques (Subprojects 4 and 5). It has the ambitious goal of understanding how the activity of individual neurons integrated in complex circuits underlies complex brain function, such as memory or perception.


Thus, the scope of research ranges from biological functions at the molecular and cellular level up to biological systems including cognitive functions. Within this broad area, all levels of analysis are supported from studies on genes and individual molecules, intracellular networks, intercellular associations in tissues and organs, to networks underlying complex brain functions. Research by recruited early-state researchers in the HINGES programme will be carried out exclusively in the interphases of at least two of these subprograms. Their activities have the potential to become an essential addition to our institution, since they can have a major impact to hinge and articulate the current backbone of research at INA.

The specific PhD Training Programme in Neurosciences will provide courses and research training to 10 European graduate students in several areas of basic neurosciences. The programme leads to a degree of Doctor in Philosophy (PhD). All courses of the programme will be held in English and will have assigned an appropriate number of ECTS (European Credit Transfer System) credits to facilitate the recognition of completed courses at other institutions.

Overview of Program.

Students will complete one year of theoretical and practical studies in areas related to the development and function of the nervous system. This first period will include lectures, tutorials, seminars, methods courses, and laboratory rotations. The student can accumulate 60 credits (ECTS) in one year, allowing admission to the Master's exams at the end of the academic year. After this period the student can either complete the master's degree by writing a thesis during a subsequent 6 month time period, or begin the 3 year doctoral period of the program. To be admitted to the Ph.D. Programme a candidate must receive a total grade of C (Good) or better in the theoretical part of the master's examination.