Table 2.
Treatment effects on memory and amygdala norepinephrine levels
| Treatmenta | Memory effect | Amygdala norepinephrine | Reference |
|---|---|---|---|
| Footshock (FS) | Varies with FS intensity | Varies with FS intensity | Quirarte et al. 1998 |
| Vagus Stimulation | Enhances | Increases | Hassert et al., 2004 |
| IA training | Varies with FS intensity | Increasesb | McIntyre et al. 2002 |
| Epinephrine | Enhancesc | Increases | Williams et al. 1998 |
| Corticosterone | Enhancesc | Increases | McReynolds et al., 2010 |
| Muscimol | Impairs | Decreases | Hatfield et al. 1999 |
| Picrotoxin | Enhances | Increases | Hatfield et al. 1999 |
| β-endorphin | Impairs | Decreases | Quirarte et al. 1998 |
| Naloxone | Enhances | Increases | Quirarte et al. 1998 |
All treatments given immediately posttraining.
Training-induced increase in norepinephrine correlates with retention performance tested 24 hours later.
Epinephrine and corticosterone produce inverted U dose-response effects on memory retention. Effects presented here are based on administration of memory-enhancing doses.