Table 1.
Effect of yohimbine on object recognition memory
| Yohimbine | No prior habituation | Prior habituation |
|---|---|---|
| Saline | −1.8 ± 6.5 | 2.0 ± 3.3 |
| 0.1 mg/kg | 15.8 ± 4.2∗ | 1.5 ± 3.6 |
| 0.3 mg/kg | 35.8 ± 4.8∗ | −2.2 ± 7.3 |
| 1.0 mg/kg | 16.5 ± 5.3∗ | −2.2 ± 4.0 |
| 3.0 mg/kg | −0.01 ± 5.4 | 27.8 ± 4.0∗ |
Data represent discrimination index (%) on the 24-h retention test trial, expressed as mean ± SEM. One-way ANOVA revealed significant treatment effects in naïve rats (F4,52 = 8.88, P < 0.0001) as well as in habituated rats (F4,55 = 9.77, P < 0.0001). Yohimbine was administered subcutaneously immediately after the training trial. ∗, P < 0.05 as compared with the corresponding saline group (n = 10–17 per group).