This notice of funding opportunity (NOFO) aims to support research programs that adopt innovative scalable technologies to inventory, register and molecularly profile distributed cell ensembles encoding the effects of addictive substances, across various stages of exposure (acute, chronic, withdrawal, abstinence, relapse). Emphasis is on approaches capable of integrating data generated through population-scale measurements of cellular activity dynamics in behaving rodents, with other granular data modalities, collected from the same cells at single-cell resolution, such as transcriptomic class, epigenetic state, connectivity and spatial localization. The overarching goal is to deliver reference multimodal datasets thatwillinform new descriptive and predictive models of how neuronal ensembles encode addiction-associated neurobehavioral states.