Cortical Organization of Centrifugal Afferents to the Olfactory Bulb: Mono- and Trans-synaptic Tracing with Recombinant Neurotropic Viral Tracers

摘要

Organization of retrogradely-labeled neurons in the OB. A Schematic outlining the experimental design for RV-mediated retrograde labeling in the GL and GCL of the OB. B Injection sites of RV-ΔG-dsRed (red) and RV-ΔG-eGFP (green), each simultaneously injected into the GCL and GL of the OB along with dye (CTB647, pink) (scale bar, 100 µm). C Enlargements of B, arrowheads indicate sites of injection. D Only the ipsilateral OB had areas of retrogradely-labeled neurons (red and green) in the GL, EPL, MCL, IPL and GCL. E Ratios of RV-mediated infected neurons in each layer of the ipsilateral OB. F Schematic outlining the experimental design for PRV-mediated retrograde labeling in the GL. G, I Injection sites (arrowheads) of PRV531 (green) and dye (CTB647, pink). H, J Patterns of PRV-mediated trans-synaptic labeling of neurons in the bilateral OB at 48 h (H) and 72 h (J) after injection into the GL. Arrows indicate contralateral M/TCs infected by PRV 72 h after injection. Contra, contralateral; D, Dorsal; EPL, external plexiform layer; IPL, internal plexiform layer; MCL, mitral cell layer; GCL, granule cell layer; GL, glomerular layer; M, medial; Ipsi, ipsilateral; ONL, olfactory nerve layer. Scale bar, 500 µm; C, G, I insets 250 µm, n = 5.