Figure 1.
Respiratory rhythmic activity generated by perinatal wild-type and Lbx1 mutant mice. A, Rectified and integrated EMG recordings from the diaphragm in brainstem–spinal cord–diaphragm preparations isolated from Lbx1 mutant and wild-type mice of different perinatal stages. The frequency of rhythmic respiratory discharge increased with age in wild-type preparations but remained relatively slow and unstable in Lbx1 mutant preparations. Population data were summarized in B. Each data point was from 5, 6, 21, and 4 Lbx1 mutants, 5, 6, 16, and 4 wild-type mice for E15.5, E16.5, E18.5, and P0, respectively. *p < 0.05 between Lbx1 mutant and wild-type of the same age group. C, Plethysmographic recordings of newborn Lbx1+/+ and Lbx1GFP/+ mice.