Fig. 2.

Comparison of the size distribution of TrkA, TrkB and TrkC positive cells in human versus mouse DRGs. (A) Distribution of the cell size (area in μm²) of TRKA (red), TRKB (green) and TRKC (blue) positive neurons in human DRGs. In human sensory tissue, the majority of TRKA positive cells exhibits a size around 300–700 μm², while TRKB positive cells peak around 1200–1600 μm² and TRKC positive cells around 1600 μm². (B) Sensory neuron size distribution in mouse DRGs shows that the majority of TrkA positive cells are 100–300 μm² in size, TrkB positive cells around 600 μm² and TrkC positive cells around 600–800 μm². By these measurements, human DRG neuron somata-areas are 1.5 to 3 times larger than mouse DRG somata when comparing the respective smallest and largest neurons of each TRK category.