Tracing plasticity in the adult brain.

This application is a continuation of our previous highly successful C1 grant in which we investigated how sensory representations change by learning, with a special emphasis on neurotransmitter systems involved. We adopted a common procedure for studying adult cortical plasticity by comparing sensory representations before and after plasticity-inducing events, or by comparing trained versus untrained stimuli. Such paradigms are suited for identifying representational changes, but not for studying critical neuronal dynamics during the plasticity-inducing events themselves or during their consolidation. Therefore, the central tenet of this proposal is to follow learning-induced plasticity throughout the entire process, including the plasticity-inducing events. This requires application of emerging technologies whereby activity of (preferentially) single neurons can be tracked during extensive periods of time, which is especially challenging in primates. We will use an interdisciplinary approach involving refined correlational and genetic-based causal methods in mice and monkeys. As in the previous C1, we will focus on the dominant sensory modality (olfaction in mice and vision in monkeys) to identify mechanisms of plasticity during associative sensory learning. We will use chronically implanted Neuropixel 2.0 probes (with >1k contacts) and single-cell calcium imaging with implanted miniature microscopes. We will also take advantage of our latest developments in optogenetics and sub-mm primate fMRI to induce and measure plasticity at mesoscale resolution. Our proposed research will reveal fundamental principles underlying adult brain plasticity, which may ultimately improve rehabilitation of patients with neural impairments or enhance performance of elderly.

Keywords:plasticity, (non)- associative learning, optogenetics, long term single cell electrophysiology, chronic single cell calcium imaging, sub-mm fMRI, vision, olfaction, causality

Disciplines:Cognitive neuroscience, Behavioural neuroscience, Neurophysiology