LAUSR

Significance Complex behavior involves the collaborative processing of multiple brain regions across 3D-space in the whole brain. Histaminergic neurons, which send its fibers to all major brain regions, is believed to regulate many physiological and pathological processes. However, the understanding of the precise 3D structural pattern of histaminergic projections is limited. Here, we reconstructed the whole-brain 3D precise structure of histaminergic projections in the mouse brain from the whole population and individual neuron perspectives, in which we quantitatively analyzed the distribution characteristics of histaminergic somata and fibers. More importantly, the direct evidence of differences between individual histaminergic neuron was provided in this work. Our findings build a solid foundation for future research studies of histaminergic neural circuits and pharmacological targets.