Fig. 4.

Ventilation and body temperatures were reduced in DA^Tph2−/− rats at distinct time points during development. Minute ventilation (V̇e; ml·min⁻¹·100 g⁻¹; A), breathing frequency (breaths/minute; B), tidal volume (V_T; ml/100 g; C), and rectal temperatures (body temperature; °C; D) were plotted across postnatal age in 2- or 3-day bins. Note that resting V̇e is reduced in DA^Tph2−/− rats (green; n = 7–15) compared with controls (WT and Het; blue; n = 6–15), due to a combination of reductions in frequency and V_T. Note also that body temperatures in DA^Tph2−/− rats were markedly lower compared with controls beginning on P13 despite the ambient temperature being warmed to ∼27°C. *Significant effect of genotype within age (P < 0.05, two-way ANOVA).