Figure 6.

Unilateral microinjection of a cre-dependent AAV expressing ChannelRhodopsin-2 (AAV-flexswitch-ChR2-eYFP) in the hypothalamic PVN. A. ChR2 expression (green) is confined to the boundaries of the PVN and expressed only in cells which co-express tdRFP (red). (A’) Higher magnification image of ChR2 expressing tdRFP positive neurons in the PVN. This study confirms the presence of active cre-recombinase in these cells and provides proof-of-principle evidence that these mice can be used to virally target GLP-1R expressing cells in discrete nuclei. B, C. ChR2-eYFP expressing axons of virally-targeted PVN neurons are distributed primarily in the caudal NTS up to the rostral end of the AP. Scale bar A = 100 μm. A’ = 10 μm. B, C = 200 μm. 3V = 3rd ventricle.