Extracted neuron peristimulus calcium activity

Number sense, or the ability to perceive quantity, is fundamental for animal survival yet its neural basis remains poorly understood. Using two-photon fluorescence light sheet microscopy, we captured whole-brain neuronal activity in larval zebrafish (Danio rerio) in response to visual number stimuli. We identified neurons selective for specific quantities as early as 3 days post-fertilization, with a notable increase in neurons tuned to larger quantities over time. Machine learning analyses revealed that stimulus prediction accuracy from neuronal activity improved with age. Additionally, exposure to ethanol reduced the number of selective neurons in the forebrain, indicating possible cognitive impairment. Our findings enhance the understanding of neural circuits underlying number perception and introduce a broadly applicable approach for tracking single-neuron activity across the brain.