Morphological plasticity of dendritic spine-like structures of dPSNs after axotomy injury treated with or without GDNF. (A) Schematic drawings and representative images of the five different types of spine-like structures. Comparisons of the number (B), density (C), number by branch order, (D) percentage of types of spine-like structures overall and by the different types across the sham, TX, and TX + GDNF groups. * p < 0.05 compared with sham group. ** p < 0.01 compared with sham group. Bar heights represent means ± SD.