Retrograde labelling demonstrates that the nestin+ and nestin- cholinergic neurons projected to hippocampus. (A) Photomicrograph demonstrating the deposition of fast blue dye throughout the entire MS/DBB area and the location of ChAT+ and nestin+ neurons. (B) The ChAT+ neurons in MS/DBB area. (C) The nestin+ neurons in the MS/DBB area. (D) The fast blue transported from the hippocampus was localized in the neurons of the MS/DBB area. (E) The double immunostaining of ChAT+ neurons and nestin+ neurons, arrows point to the double labelling neurons (nestin+ cholinergic neurons). (F) Photomicrograph of neurons labelled by retrograde tracing of fast blue from the hippocampus and nestin+/nestin- cholinergic neurons. Arrows and arrowheads point to the nestin+ and nestin- cholinergic neurons labelled with fast blue. Scale bar: 50 μm in A; 50 μm in B-F.