Effect of CMS on the sucrose consumption on days 1, 7 and 14 before starting treatment with the corresponding drugs (non-stressed control, stressed control, L-tyrosine solution 10 mg/kg, L-tyrosine nanoparticles 5 mg/kg, L-tyrosine nanoparticles 10 mg/kg, fluoxetine 10 mg/kg). Sucrose consumption was measured for 1 h, half hour after treatment. Data are presented as mean ± SD with, 8 rats each group (one-way ANOVA followed by Tukey test). Total degree of freedom = 47. # The significant difference between non-stressed control and rest of groups. p < 0.05: no symbol, # p < 0.05, ## p < 0.01, ### p < 0.001.