Fig. 5.

Postnatal development of the ventilatory response to CO₂ expressed as % increase in V̇e/V̇o₂ as a function of postnatal age and effect on this CO₂ response of exposure to a tryptophan-deficient diet. Dark bars, control diet group; light bars, tryptophan-deficient diet group. These normalized data were analyzed with a 2-way repeated-measures ANOVA with diet and age as factors. There was an overall effect of diet (P < 0.001) and age (P < 0.001). The interactive effect (age × diet) was significant in males (P < 0.001) and of borderline significance in females (P < 0.06). *Post hoc testing (Bonferroni) showed significance in males at P5, P15, and P25 (P < 0.01) and in females at P15 (P < 0.03) and P25 (P < 0.01).