Table 4.

Coefficient of variation (SD/mean) derived from cycle-by-cycle measurements of tidal volume (V_T) and breathing frequency (f) in P4.5 wild-type, heterozygous, and homozygous knockout mice

Genotype	(n)	Coefficient of variation (VT)	Coefficient of variation (f)
+/+	10	22.7  ± 5.0%	19.4  ± 2.4%
+/−	15	28.2  ± 2.5%	18.8  ± 1.7%
−/−	6	48.6  ± 5.0%a,b	37.3  ± 3.9%a,b

BDNF-deficient mice displayed a significant increase in cycle-to-cycle variability in both V_T andf compared with wild-type and heterozygous animals. Values represent means ± SE. Mean number of measured cycles per animal: +/+ 368; +/− 406; −/− 310.

^F4_aDiffers from +/+.

^F4_bDiffers from +/−.