Table 8.
Glucocorticoid signaling in fear extinction (preclinical studies).
| Facilitating glucocorticoid signaling | |||||
|---|---|---|---|---|---|
| Drug | Extinction training | Extinction retrieval | Long-term extinction | Route | Reference |
| Corticosterone (GR/MR ag) | ns | +1 | No effect (Re-in) | ip | (Blundell et al., 2011) |
| ns | −2 | ns | ip | (Den et al., 2014) | |
| Dexamethasone (GR ag) | ns | + | ns | ip | (Ninomiya et al., 2010); (Yang et al., 2006, 2007) |
| RU28362 (GR ag) | ns | + | ns | AMY | (Yang et al., 2006) |
| Ganoxolone (allopregnanolone analog) | +*3 | +*3 | ns | ip | (Pinna & Rasmusson, 2014) |
| Inhibiting glucocorticoid signaling | |||||
| Metyrapone (CORT/cortisol synthesis inhibitor) | No effect | − | −* | sc | (Barrett & Gonzalez-Lima, 2004); (Clay et al., 2011) |
| ns | − | ns | sc | (Blundell et al., 2011); (Yang et al., 2006, 2007) | |
| Mifepristone (GR and progesterone ant) | ns | − | ns | AMY | (Yang et al., 2006) |
1
Drug administration following extinction training;
2
in adolescent but not adult rats if exposed to CORT one week prior to (drug free) testing; adults also show impaired extinction retrieval if they were exposed to one week of CORT in their adolescence;
3
socially isolated mice, CAVE ganoxolone was administered following a reactivation session 24h prior extinction training.
+, Improved; -, impaired; ip, intraperitoneal injection; sc, subcutaneous injection; ns, not studied; AMY, intra-amygdala administration; Re-in, reinstatement; ag, agonist; ant, antagonist; GR, glucocorticoid receptor; MR, mineralocorticoid receptor; CORT, corticosteroid.