Fig. 5

Anterograde monosynaptic tracing of H129-dgK-G4. A. Schema of the simplified OB projection pathways. OB; olfactory bulb; Pir, piriform cortex; MeA, medial amygdaloid nucleus, anterior part; PMCo, posteromedial cortical amygdaloid nucleus; LEnt, lateral entorhinal cortex. B. The tracing timeline. Helper virus AAV2/9-mCh-gK (1.0 × 10¹² vg/ml, 150 nl) and H129-dgK-G4 (5.0 × 10⁸ pfu/ml, 150 nl) were sequentially injected into the same region of OB in wildtype C57BL/6 mice at day 1 and day 22 respectively. The brains were collected at day 27 and images were obtained after cryosection. C–G. Representative tracing results. The representative images of the injection site of OB (C) and the downstream projection target brain regions (D-G) are shown. The boxed areas are presented in the right panels with higher magnification, and the starter neurons labeled by both GFP and mCherry are indicated with white arrows. Representative images shown are of the same brain from 3 mice. The left hemisphere displays the corresponding sections from Allen Brain Reference Atlases (Image credit: Allen Institute) (D–G). H. A representative postsynaptic neuron well labeled by H129-dgK-G4. Images of a representative GFP-labeled post-synaptic neuron in LEnt are shown, and the magnified images of the dendritic segments are presented (H1-H4)