Do J P*, Xu M*, Lee S*, et al. eLife, 2016
We performed whole-brain mapping of both inputs and outputs of four BF cell types – cholinergic, glutamatergic, and PV+ and SOM+ GABAergic neurons – in the mouse brain. Using rabies virus-mediated monosynaptic retrograde tracing to label the inputs and adeno-associated virus to trace axonal projections, we identified numerous brain areas connected to the BF. The inputs to different cell types were qualitatively similar, but the output projections showed marked differences. The connections to glutamatergic and SOM+ neurons were strongly reciprocal, while those to cholinergic and PV+ neurons were more unidirectional. These results reveal the long-range wiring diagram of the BF circuit with highly convergent inputs and divergent outputs and point to both functional commonality and specialization of different BF cell types.