Fig. 8

Tryptophan protects against cognitive declines and aberrant neurons in gp120tg mice. A–D The gp120tg mice were allowed to drink water containing 0.1% tryptophan for 1 month, then were subject to the Morris Water Maze test. A Latency to reach the hidden platform and B cumulative swim distance between the two groups during the acquisition phase (n = 9 mice per group, F_{1, 15} = 9.118, P = 0.0086; F_{1, 15} = 20.08, P = 0.0004, respectively). C Plots showing the different searching strategies of gp120tg mice and tryptophan-fed gp120tg mice in probe trials. D Percentage of time spent in the targeted quadrant in probe trials (F_{1, 15} = 1.000, P = 0.3331). E Brain sections stained with hematoxylin and eosin (scale bar: 100 μm). F Immunofluorescence showed the distribution of the NeuN and MAP-2 in the hippocampus (scale bar: 100 μm) and cortex (scale bar: 50 μm) among different groups. G The protein levels of MAP-2 and NeuN in the hippocampus (F_{3, 12} = 13.57, P = 0.0004; F_{1, 12} = 8.631, P = 0.0025, respectively). Throughout, data present mean ± SEM. In A–D, P values data are analyzed by repeated measure ANOVA with Bonferroni’s post hoc tests. In G, data are analyzed by one-way ANOVA with Tukey’s multiple comparisons. n = 5 mice per group. *P < 0.05, **P < 0.01, ***P < 0.001 compared to WT mice. ^$P < 0.05, ^$$P < 0.01, ^$$$P < 0.001 compared to 12-month-old gp120tg mice treated with PBS