Fig. 4

Changes in ratio of pre-inspiratory time of HG to a total length of the respiratory cycle (T pre-I/Tc) (a), and ratio of the pre-inspiratory hypoglossal nerve amplitude to the inspiratory HG peak amplitude (A pre-I/A HG) (b) in respiratory response to hypoxia after injection of vehicle (Sham) or 6-OHDA into the third brain ventricle. All values are given as mean ± SEM. N normoxia, R recovery after the hypoxic stimulus. *^#p < 0.05. *—statistical significance versus normoxia (N) value, #—significance between corresponding values in 6-OHDA and Sham group (n = 6–7)