Investigating neural, neurovascular, and vascular function: insights from imaging 5-HT2AR compounds, optogenetic motor mapping, and cross-modal functional mapping

Understanding how brain activity relates to behavior and cognition remains a central challenge in neuroscience. Brain function emerges from interactions between electrical, chemical, and blood dynamics across multiple spatial and temporal scales. Capturing this complexity requires methods that assess both large-scale neurophysiological activity and precise, cell-type-specific processes. Widefield optical imaging (WFOI) enables high-resolution monitoring of cortical function by simultaneously measuring hemodynamic and calcium dynamics. WFOI is particularly valuable for studying psychedelics, which show therapeutic potential but may alter neurovascular coupling, complicating the interpretation of hemodynamic signals. Using WFOI, we examined the hallucinogenic 5-HT2A receptor agonist DOI in awake mice, revealing dissociations between calcium and hemodynamic signals that were reversible with 5-HT2A receptor antagonism. Optogenetics enables precise, cell-specific neuronal activation, offering a bottom-up approach to functional mapping. We developed a system to systematically photostimulate the cortex in awake mice while tracking movement in 3D, revealing a more spatially distributed motor representation than previously recognized. Importantly, we demonstrate a strong correspondence between resting-state functional connectivity, assessed via spontaneous activity with WFOI, and action mapping via systematic whole-hemisphere photostimulation. Integrating these approaches advances our understanding of brain function and its modulation by pharmacological and behavioral interventions.