Table 4.

Breathing frequency (f), coefficient of variation of breathing frequency (CV f), number of apneas, and percentage of time spent in apnea derived from 3–5 min plethysmographic recordings made during quiet resting ventilation in newborn (6- to 12-hr-old) wild-type (+/+) and gdnfhomozygous (−/−) mice

Genotype(n)f (breaths/min)CVf (%)No. of apneas% Apnea
+/+8120.1  ± 9.526.4  ± 1.86.8  ± 2.19.8  ± 3.9
−/−1086.9  ± 3.94-a37.7  ± 3.84-a16.5  ± 1.74-b37.7  ± 2.84-c
  • Data are shown as means ± SEM. n = sample size. Comparisons were made using Student's t test, α = 0.05.

  • F4-a Differs from wild-type;p < 0.05.

  • F4-b Differs from wild-type;p < 0.01.

  • F4-c Differs from wild-type;p < 0.001.

  • The coefficient of variation (SD/mean) was determined from cycle-by-cycle measurements of breathing frequency.