Figure 7. Loss of RL and RTN neurons does not change the phase relationship between putative respiratory oscillators.
(A) Cartoons indicating how relative phase (Φ, in degrees) between cervical burst peaks and either lumbar or VII respiratory peaks for each fictive breath are calculated (left) and possible change in phase relationships after loss of RL and RTN neurons (right). Schematics (top right) indicate targeted loss of Phox2b RTN (purple) and Atoh1 RL (orange) neurons. (B) Histogram (5° bins) showing the distributions of phase relationship (Φ) between cervical and either lumbar (magenta) or VII (dark blue) peaks indicating consistent temporal delays between outputs in WT mice. (C) Phase relationships (Φ) between cervical and either lumbar (cyan) or VII (tan) outputs indicate a maintenance in phase relationships between respiratory outputs in Atoh1LacZ/LacZ (RL−/RTN−) mice. (D) Loss of RL/RTN neurons broadens the phase relationship (Φ) of cervical-VII root activation compared to WT. (E). Loss of RL/RTN neurons does not effect phase (Φ) of most lumbar bursts but introduces a occasional Atoh1LacZ/LacZ specific burst pattern (arrow in C and E, F) with the cervical burst (green) followed by a pause then overlapping lumbar (magenta) and VII (dark blue) bursts. Scale bar = 500 ms.