Bilateral resting-state functional connectivity reflects spontaneous neural interactions measured by mouse fMRI with optogenetic silencing

Motivation: Despite the widespread use of resting-state fMRI in the neuroscience field, the relationship between functional connectivity and neural interactions is not fully understood. Goal(s): We aimed to explore whether resting-state functional connectivity arises from spontaneous neural interactions among brain regions. Approach: We conducted resting-state and multi-site optogenetic fMRI in excitatory or inhibitory neuron-specific optogenetic mouse models and examined their relationship. Results: Resting-state functional connectivity patterns were strongly correlated with optogenetic silencing-induced connectivity which revealed extensive intrahemispheric and interhemispheric neural interactions during rest. This result suggests that functional connectivity arises from neural interactions via polysynaptic structural connectivity. Impact: The results support the notion that functional connectivity stems from spontaneous neural interactions between regions. Our next goal is to investigate whether brain state-dependent functional connectivity alterations stem from enhanced or weakened neural interactions, using multi-site optogenetic silencing fMRI.