Fig. 4

Structural remodeling of MS-DG GABAergic projections during early-stage AD. A Injection scheme and 3D reconstruction example for anterograde tracing of MS GABAergic projections to the hilus of 6 month Vgat-WT and Vgat-AD mice. Scale bar = 100 μm. B Representative images of YFP + neurons in the MS. Scale bar = 100 μm. C Quantification of YFP-labeled cell density in the medial septum of Vgat-WT and Vgat-AD mice at 6 months of age. p = 0.90, n = 5, 3 mice. D Representative images of MS-GABA projections to the DG of 6 month Vgat-WT and Vgat-AD mice. Scale bar = 100 μm. E Quantification of YFP + GABAergic septo-DG projections in the hilus of 6 month Vgat-WT and Vgat-AD mice. n = 5, 3 mice, p = 0.06. F Quantification of % DG GABA⁺ cells contacted by YFP⁺ GABAergic septo-DG projections in the hilus of 6 month Vgat-WT and Vgat-AD mice, n = 3, 3 mice, p = 0.6325. G Representative images of mCherry⁺ input cells in MS of 5 months old Vgat-WT and Vgat-AD mice. Scale bar = 300 μm. H Quantification of mCherry⁺ input cells in highlighted regions of interest in 5 month Vgat-WT and Vgat-AD mice. n = 4, 6 mice, p = 0.463. I Representative images of retrograde tracing injection sites (DG) in 5 month Vgat-WT and Vgat-AD mice. Scale bar = 300 μm. J mCherry⁺ area within the injection site ROI (hilus) in 5 month Vgat-WT and Vgat-AD mice. p = 0.647