Figure 1

Identification of whisker-innervating region in intact TG ex vivo. (a) Illustration of the mouse whisker-barrel system. (b) Representative image along the dorsal surface of an intact TG from Avil-Cre:RNZ mouse at P6. The spatial distribution of peripheral sensory neurons is visualized by X-Gal staining of the whole TG (P6; N = 4 mice). TG outline is shown. M: medial, A: anterior. (c) Representative image of an intact TG from Avil-nlsRFP mouse at P5. Brightfield (Left), RFP (Middle), Merged (Right) images. (P4–P6; N = 4). (d–f) Labeled neuron localization in the P5 TG 5 days after placing DiI crystals around A3 whisker (N = 3) (d), around E3 whisker (N = 3) (e) and lower jaw (N = 3) (f). Brightfield image (Left) and RFP filter image (Right) are shown. Green circles enclose the region of labeled neuron localization. (g) Schematic showing the whisker-row-dependent topography along the dorsal surface of the intact TG. (h) Representative image of the intact TG from the Avil-Cre:R26-GCaMP6s mouse at P5. Brightfield image (Left), GCaMP6s image (Middle), Merged image (Right). (i) (Left) Dashed lines indicates where the TG is transected from its peripheral and central connections. (Middle) Schematic of the imaging chamber used for ex vivo imaging. An intact TG attached to the cranial base is glued to the base of the chamber. (Right) Schematic of the ex vivo imaging setup. The imaging chamber is fixed to the bottom of a 10 cm-diameter petri-dish. The chamber is constantly perfused with buffers and a 20X water immersion lens is used for imaging. Scale bars: 1 mm.