Fig. 4

A significant number of ATF3-positive dorsal root ganglion (DRG) neurons projected to the soleus. a–c Double staining for ATF3 (green) and fluorogold (FG)-labeled (blue) neurons in the L5 DRG of rats subjected to continuous stress-loading (CS). FG was injected into the soleus (a), tibialis anterior (b), or gastrocnemius (c). d The proportion of FG-labeled neurons among ATF3-positive cells after FG injection: Soleus, 57.7 ± 7.3%; tibialis anterior, 42.7 ± 14.7%; and gastrocnemius, 14.0 ± 4.1%. Soleus (n = 8), tibialis anterior (n = 4), and gastrocnemius (n = 6). *p < 0.05, **p < 0.01. One-way ANOVA with Tukey’s test. e A representative photo of the triple labeling for VGluT1 (green), ATF3 (red), and FG (blue) in the L5 DRG of CS rats. Arrowheads indicate co-expression