Table 2.
Group means ± SEM of anxiety-like behavior and exploratory locomotion of male heterozygous (+∕−) and homozygous (−∕−) 5-HTT knockout mice and their wildtype counterparts (+∕+) that experienced either an adverse (AE) or beneficial (BE) environment during adolescence.
| Anxiety-like behavior and exploratory locomotion Parameter | AE | BE | Effect of environment (E) | Effect of genotype (G) | G × E | ||||
|---|---|---|---|---|---|---|---|---|---|
| +∕+ | +∕− | −∕− | +∕+ | +∕− | −∕− | ||||
| ELEVATED PLUS MAZE | |||||||||
| Open arm entries (relative) | 0.44 ± 0.04 | 0.42 ± 0.04 | 0.23 ± 0.04 | 0.41 ± 0.03 | 0.41 ± 0.05 | 0.35 ± 0.06 | F(1, 72) = 0.634; p = 0.429 | F(2, 72) = 6.143; p = 0.003 | F(2, 72) = 1.681; p = 0.193 |
| Time on open arms (relative) | 0.35 ± 0.05 | 0.37 ± 0.05 | 0.11 ± 0.02 | 0.29 ± 0.04 | 0.29 ± 0.06 | 0.16 ± 0.04 | F(1, 72) = 0.591; p = 0.445 | F(2, 72) = 12.805; p < 0.001 | F(2, 72) = 1.289; p = 0.282 |
| Distance on open arms (m) | 3.09 ± 0.51 | 2.79 ± 0.43 | 0.61 ± 0.19 | 2.29 ± 0.47 | 2.14 ± 0.41 | 1.23 ± 0.38 | F(1, 72) = 0.318; p = 0.575 | F(2, 72) = 16.153; p < 0.001 | F(2, 72) = 1.840; p = 0.166 |
| Total distance (m) | 11.45 ± 0.72 | 10.33 ± 0.72 | 7.99 ± 0.67 | 9.70 ± 0.72 | 8.93 ± 0.61 | 5.56 ± 0.66 | F(1, 72) = 10.966; p = 0.001 | F(2, 72) = 16.104; p < 0.001 | F(2, 72) = 0.286; p = 0.752 |
| DARK-LIGHT | |||||||||
| Entries to light compartment (#) | 11.92 ± 1.78 | 10.57 ± 1.82 | 6.46 ± 0.96 | 7.57 ± 1.11 | 6.93 ± 1.17 | 2.83 ± 0.71 | F(1, 72) = 12.824; p = 0.001 | F(2, 72) = 7.577; p = 0.001 | F(2, 72) = 0.027; p = 0.974 |
| Time in light compartment (s) | 77.18 ± 12.14 | 72.59 ± 11.56 | 32.32 ± 5.30 | 58.25 ± 14.53 | 63.62 ± 17.18 | 19.26 ± 6.34 | F(1, 72) = 2.824; p = 0.097 | F(2, 72) = 7.664; p = 0.001 | F(2, 72) = 0.031; p = 0.970 |
| Latency to enter light compartment (s) | 45.85 ± 23.59 | 42.21 ± 22.30 | 73.23 ± 16.26 | 94.34 ± 23.96 | 109.07 ± 27.13 | 202.23 ± 24.20 | F(1, 72) = 17.076; p < 0.001 | F(2, 72) = 7.156; p = 0.001 | F(2, 72) = 0.202; p = 0.818 |
| OPEN FIELD | |||||||||
| Total distance (m) | 33.63 ± 1.66 | 35.43 ± 1.90 | 24.87 ± 1.72 | 31.10 ± 2.10 | 28.92 ± 1.50 | 20.60 ± 1.38 | F(1, 72) = 9.815; p = 0.003 | F(2, 72) = 19.756; p < 0.001 | F(2, 72) = 0.677; p = 0.511 |
| Center entries (#) | 10.00 ± 1.21 | 10.00 ± 0.96 | 4.46 ± 0.87 | 7.54 ± 1.31 | 7.62 ± 1.30 | 3.33 ± 0.74 | F(1, 72) = 4.979; p = 0.029 | F(2, 72) = 13.092; p < 0.001 | F(2, 72) = 0.230; p = 0.795 |
| Time in center (s) | 16.15 ± 2.71 | 16.97 ± 2.38 | 7.39 ± 1.44 | 11.12 ± 1.85 | 13.13 ± 2.90 | 5.82 ± 1.27 | F(1, 72) = 3.856; p = 0.053 | F(2, 72) = 10.900; p < 0.001 | F(2, 72) = 0.263; p = 0.769 |
| FREE EXPLORATION | |||||||||
| Latency to enter arena (s) | 129.22 ± 51.81 | 111.06 ± 21.76 | 351.83 ± 72.06 | 161.25 ± 84.92 | 88.71 ± 21.66 | 251.31 ± 73.03 | F(1, 63) = 2.552; p = 0.115 | F(2, 63) = 12.377; p < 0.001 | F(2, 63) = 0.063; p = 0.939 |
| Entries to arena (#) | 30.00 ± 3.39 | 33.08 ± 2.55 | 19.67 ± 2.33 | 29.8 ± 4.11 | 26.00 ± 2.04 | 21.27 ± 4.84 | F(1, 63) = 0.212; p = 0.647 | F(2, 63) = 6.617; p = 0.002 | F(2, 63) = 1.454; p = 0.241 |
| Total distance (m) | 30.90 ± 4.19 | 27.74 ± 2.67 | 14.54 ± 2.90 | 27.58 ± 5.05 | 26.42 ± 3.26 | 16.72 ± 3.60 | F(1, 63) = 0.078; p = 0.781 | F(2, 63) = 8.144; p = 0.001 | F(2, 63) = 0.288; p = 0.751 |
| Time in arena (s) | 313.34 ± 44.74 | 280.59 ± 22.47 | 149.72 ± 29.16 | 277.29 ± 51.25 | 291.55 ± 37.76 | 175.89 ± 37.85 | F(1, 63) < 0.001; p = 0.990 | F(2, 63) = 7.919; p = 0.001 | F(2, 63) = 0.363; p = 0.697 |
Effects of environment, genotype and gene by environment interaction (G x E) on anxiety-like behavior and exploratory locomotion. Statistics: ANOVA, bold: p ≤ 0.05. EPM, DL, OF: AE +∕+ n = 13, AE +∕− n = 14, AE −∕− n = 13, BE +∕+ n = 13, BE +∕− n = 13, BE −∕− n = 12; FE: AE +∕+ n = 11, AE +∕− n = 13, AE −∕− n = 12, BE +∕+ n = 10, BE +∕− n = 12, BE −∕− n = 11.