Figure 4. Monosynaptic rabies virus mediated trans-synaptic tracing of vibrissa premotor neural circuitry after the onset of active whisking.
(A) Schematic of the experimental strategy.
(B–D) Representative images of ΔG-GFP labeled vFMN premotor neurons from P8→P15 tracing in the respiration-related nuclei: preBötC (B); BötC (C) and KF (D). See Figure S5 for tracing results in other nuclei.
(E) No vFMN premotor neurons were found in LPGi following P1→P8 tracing.
(F) The new group of vFMN premotor neurons was found bilaterally in rostral LPGi following P8→P15 tracing (arrows). Stars indicate neuronal degeneration and glial infiltration (numerous DAPI-positive nuclei) in FN and LPGi.
(G) A high-magnification image of LPGi premotor neurons.
(H) 3D model showing the distribution of vFMN premotor neurons after the onset of whisking. Left: coronal view; Middle: lateral view. The dot colors denote rostrocaudal positions of premotor neurons.
(I) Cross-correlation analysis of distributions of vFMN premotor neurons from 4 animals. Color scale indicates correlation values (0.6~1).
(J–L) vFMN-ex also receive “new” premotor inputs from neurons located in LPGi. (L) is 160 µm caudal to (K).
Scale bars, 200 µm (E–F, J–L); 50 µm (G).