Progetti di ricerca

Neurobehavioral evolution has favored the exploitation of neural substrates and circuitries evolved for a main specific function to map non-primary incoming information. This phenomenon - labelled as ‘Neural Remapping’ – is particularly interesting in primary cortical areas that, though being… Leggi tutto mostly committed to a specific sensory modality, appear to play a role in the processing of inputs conveyed via non-preferred (heteromodal) channels. This heteromodal remapping (HR) is more widespread than classically assumed and encompasses early sensory (traditionally considered as sensory-specific) and motor brain areas. On a more general perspective, primary sensory and motor areas receive a variety of heteromodal inputs, but how this information is locally processed and possibly conveyed to other target areas remains largely unknown. Similarly, it is unknown the possible role of HR in physiological and pathological conditions. Actually, HR in sensory-specific areas is fostering a renewed interest because of its possible relevance in neurobehavioral recovery when a given sense, or motor function, is temporarily or permanently impaired: the brain remaps spared sensory modalities onto the deprived cortex, but its functional significance and flexibility remains unclear. Our project capitalizes on multimodal, multilevel and complementary approaches in both nonhuman primates and humans, including different clinical populations (i.e., blind people, amputees and brain-damaged patients with bodily awareness or motor disorders) and reversible experimental-deprivation models (i.e., subjects undergoing anesthetic or ischemic peripheral nerves blockage), to assess quantitatively HR processes in primary sensory and motor areas, with a particular focus on the hardly investigated responses to visual or auditory inputs in primary somatosensory and motor areas, and to tactile or auditory inputs in primary visual area. Shared tasks and synergies in the definition of methodological approaches will allow us to investigate HR from the fine-grained cellular mechanisms with multielectrode laminar recording in monkeys to the large-scale network level, with whole brain imaging and non-invasive human brain stimulation techniques. Experiments will be carried out both during complete availability of sensory information and when a given input channel is transiently or chronically disrupted (as in clinical populations). This in-depth behavioral and neurophysiological characterization at multiple resolution scales and in a variety of experimental models and clinical populations will elucidate the local- and system-level mechanisms of HR, providing a comprehensive, causal description of both the organizational features and functional architecture of these responses in primary areas and the potential mechanisms promoting neural plasticity and recovery in a variety of sensory deprivation and pathological conditions.