Figure 3: Vocalisation spectras, spectral area and amplitude percentages of different groups were shown.

Vocalisation spectras were shown of the Sham (a), ANG (b), CS (c), CS+LN (d), CS+LN+LBD-BDNF (e), CS+LN+LBD-GDNF (f) and CS+LN+LBD-BDNF+LBD-GDNF (g) groups at 12 weeks after surgery. The Sham group exhibits a high amplitude with wide and continuous waveforms. (h) Spectral area percentages of different groups. The spectral area, calculated as a percentage of that in the Sham group increased over time. The spectral area percentages measured at 12 weeks after surgery were 100.0 ± 7.0%, 67.0 ± 8.2%, 54.4 ± 16.0%, 60.7 ± 11.3%, 65.1 ± 3.5%, 65.9 ± 4.6%, and 71.7 ± 9.0% of all the above group orders, respectively. The spectral area percentage of the CS+LN+LBD-BDNF group was much higher than that of the CS group at week 4, 8 and 12 week (P < 0.05), but much lower than that of CS+LN+LBD-BDNF+LBD-GDNF and Sham groups (P < 0.05). At week 12, there was no significant difference between the CS+LN+LBD-BDNF group and CS+LN+LBD-GDNF or ANG group (P > 0.05). The spectral area percentage of the CS+LN+LBD-BDNF+LBD-GDNF group showed no significant difference compared to that of the ANG group at 4 and 8 weeks (P > 0.05), while the ANG group showed significant lower compared to the CS+LN+LBD-BDNF+LBD-GDNF group at 12 weeks after surgery (P < 0.05). (i) The amplitude percentages of different groups were shown. The spectral amplitude, calculated as a percentage of that in the Sham group increased with time. The amplitude percentages of the ANG, CS+LN+LBD-BDNF, CS+LN+LBD-GDNF and CS+LN+LBD-BDNF+LBD-GDNF groups were not significantly different from that of the Sham group at 12 weeks after surgery (P > 0.05). From week 4 to week 12, the amplitude percentage of the CS+LN+LBD-BDNF+LBD-GDNF group was not significantly different from that of the CS+LN+LBD-BDNF or CS+LN+LBD-GDNF group (P > 0.05). n = 30. *P < 0.05.