Figure 6

The effects of antibiotic treatment alone or in combination with Aβ1–42 treatment on depression-related behaviours in male C57BL6 mice. To assess depression-related behaviour, animals were subjected to sucrose preference (A), social interaction (B; total interaction time) and forced swim (C; immobility time) tests. Data are expressed as mean ± SEM (n = 10). Antibiotic treatment did not change [p > 0.05] the percentage of sucrose preference, total interaction time, and immobility time in mice relative to the water + vehicle group. We also found that Aβ 1–42 administration significantly decreased the percentage of sucrose preference [p = 0.002] and the total interaction time [p = 0.002] but increased the immobility time [p = 0.025] in water-treated mice as compared to the water + vehicle animals. In addition, there were significant differences in the total interaction time [p = 0.029] and the immobility time [p = 0.01] between water + Aβ 1–42 and antibiotics + Aβ 1–42 groups. However, antibiotic treatment could not affect the sucrose preference [p > 0.05] in antibiotic-treated mice as compared to both the antibiotics + vehicle and water + vehicle groups. We also did not find any significant differences [p > 0.05] in sucrose preference, the total interaction time and the immobility time between antibiotics mice treated with Aβ 1–42 and the antibiotics + vehicle- or water + vehicle-treated animals.