Fig. 1.

Plasma tryptophan concentration. Relative concentration (mean±SEM) of tryptophan in plasma compared to baseline. Open triangles correspond to the TRP minus group; closed squares correspond to the control group. The vertical grey bars correspond to, respectively, first diet administration, second diet administration and novelty exposure. Asterisk indicates a significant difference between the two groups, p < 0.05; sigma indicates a significant difference compared to the baseline value, p < 0.05