Table 5.
Fear conditioning: age sensitivity.
| Study | Species/strain | Age (months) | Age deficits | Mirror lesions in young | Confounds/strain differences | Effect of cognition-enhancing drugs | Cerebellum-sensitive | Hippocampus-sensitive |
|---|---|---|---|---|---|---|---|---|
| Cuppini et al. (2006) | Sprague-Dawley rat | 2, 5, 12 | None | No | No | |||
| Doyere et al. (2000) | Wistar rat | 7, 22 | 22 months froze more to context | No | No | |||
| Feiro and Gould (2005) | C57BL/6 | 2–3, 19–20 | 19–20 months to CS at 48+ h retention | No | Yes | |||
| Gerlai (1998) | C57BL/6, DBA/2 | 3–4 | Not rested | Lesions partially impair | DBA more sensitive to shock; C57 froze more to context and tone CS | No | ||
| Gould and Feiro (2005) | C57BL/6 | 2–3, 19–20 | 19–20 to CS at 48+ h retention | No | Galantamine-rescued deficits | No | ||
| Gould and Wehner (1999) | C57BL/6 | 2–3 | Nicotine enhances context learning | Yes | ||||
| Houston et al. (1999) | Fisher 344 rat | 3, 9, 27 | 27 months to context in 20–60 day retention | Yes | Yes | |||
| Kaczorowski and Disterhoft (2009) | C57/SJL F1 hybrid | 2–4, 8 | Subset of aged impaired on context | Yes | Yes | |||
| Liu et al. (2003) | C57BL/6 | 8, 11 | 11 months to context in 24-h retention | Yes | Yes | |||
| Mesches et al. (2004) | Fisher 344 rat | 6, 18 | 18 months to context in 48-h retention | Yes | Yes | |||
| Oler and Markus (1998) | Fisher 344 rat | 4, 10, 23 | 23 months to context in 52-day retention | Yes | Yes | |||
| Owen et al. (1997) | 12 inbred and seven hybrid strains | 2–3 | Good: C57, 129, hybrids; Poor: FVB, DBA, Bub, C3H | |||||
| Paylor et al. (1994) | C57BL/6, DBA/2 | 3–4 | C57 froze more to context | Yes | ||||
| Stoehr and Wenk (1995) | Fisher 344 rat | 3, 9, 24 | 24 months | Yes | Yes | |||
| Villarreal et al. (2004) | Fisher 344 rat | 2–4, 22–24 | 22–24 months impaired on trace cued | Yes | No age deficits in delay paradigm | Yes |
Species is mouse unless otherwise specified. C57 = C57BL/6.