Fig. 9
From: Neurochemical mechanism of muscular pain: Insight from the study on delayed onset muscle soreness
Modified from Murase et al. [19]
NGF and GDNF synergistically amplifies muscular hypersensitivity. a: Dose–response relationship of the NGF-induced decrease of MMWT (mechanical hypersensitivity). n = 6 except 0.2 μM and 0.8 μM NGF (n = 8). b: Dose–response relationship of the GDNF-induced decrease in MMWT. n = 6 each. c: A mixture of NGF (0.1 μM) and GDNF (0.008 M), which alone did not induce a decrease in MMWT, induces a pronounced decrease in MMWT. n = 6. d: Sample photograph of pERK immunohistochemistry of the DRG (L5) after compression (1500 mN) of the muscle treated with PBS (left) or a mixture of low NGF (0.1 μM) and low GDNF (0.008 μM) (right). e: Percentage of pERK+ DRG neurons after each treatment. Neither low NGF nor low GDNF induced a larger percentage of pERK+ neurons compared with PBS, but a mixture of both (Low Mix) induced a significantly larger increase.