Figure 4

Figure 4: CTB retrograde tracing shows axon trajectories and labeling of thoracic, lumbar, and sacral DRGs. (A) Schematic of retrograde tracing injection and timeline. CTB-555 was injected into the right kidney of adult mice. Four days following the injection both kidneys were dissected as well as the ipsilateral (injected side) and contralateral (non-injected side) DRG. Schematic created with BioRender.com. (B) Sensory innervation primarily traces in the ipsilateral DRGs to the lower thoracic region (T10-T13), lumbar region (L1-L6), and sacral region (S1-S2). Tracing to the contralateral DRGs was observed in the upper lumbar region of L1 and L2. n=4 males and n=4 females, Scale bar =50μm. (C) Ipsilateral and contralateral kidney sections of a CTB-injected mouse. Immunostaining of the ipsilateral kidney section showed CTB+ (magenta) axons colocalizing with TUBB3 (green) near glomeruli and vasculature (CD31, yellow; arrowheads). CTB (magenta) colocalized with TUBB3 (green) near vasculature (CD31, yellow; arrowhead) in the contralateral kidney. (D) Schematic representation of the spinal level and DRG origin of kidney sensory afferent innervation. Schematic created with BioRender.com