Table 2.
Housing and handling conditions of two outbred rat strains (Wistar and Sprague-Dawley) in breeding facilities at five different vendors (Harlan- Winkelmann, Harlan, Charles River, Janvier, and Taconic) and consequences for behavioral testing in the Loscher lab. Note that only Janvier performed daily handling habituation, while all other vendors handled the rats only shortly once to twice per week during cage cleaning. Data are from Langer et al. [19] and Honndorf et al. [40]. All data are from female rats (which were housed without males once arriving in the Loscher lab). See Theilmann et al. [217] for experiments in male rats, which resulted in similar findings. Abbreviations: n.t., not tested.
| Sprague-Dawley | Wistar | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Harlan- Winkelmann (HW) |
Harlan | Charles River (CR) |
Janvier | Taconic | Harlan- Winkelmann (HW) |
Charles River (CR) | Janvier | Taconic | |
| Housing and handling conditions at vendor | |||||||||
| Number of barriers | One | One to two | Two (closed every 5 years) | Several | One | Several | One | ||
| Type of cage | Transparent | Non transparent | Transparent | Non transparent | Transparent | Transparent | Transparent | Non-transparent | Transparent |
| Environmental enrichment in cages | Yes (tissue, PVC channels) | Yes (tissue, PVC channels) | No | No | Yes (tissue, wood, rat shelters) | Yes (tissue) | No | No | Yes (tissue, wood, rat shelters) |
| Group caged | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Transfer to new cage | 1/week | 1/week | 2/week | 1/week | 2/week | 1/week | 2/week | 1/week | 2/week |
| Estimating body weight | 3-4/week | 1-2/week | 1-2/week | 1/week | 3-4/week | 1-2/week | 1-2/week | ||
| Socialization to humans (handling to habituate rats to humans) | No | No | No | 6 times per week | No | No | No | 6 times per week | No |
| Male rats housed in the same room | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Light/dark cycle | 12 h/12 h | 12 h/12 h | 12 h/12 h | 12 h/12 h | 12 h/12 h | 12 h/12 h | 12 h/12 h | 12 h/12 h | 12 h/12 h |
| Weaning (days) | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 |
| Behavioral abnormalities during testing in Löscher lab | |||||||||
| 1. Basal (pre-SE or pre-kindling) behavior | |||||||||
| Open field | Less active than other SD substrains; increased anxiety compared to all other SD substrains | More explorative than SD rats from Taconic and CR; least level of anxiety of all SD substrains | Less active than other Wistar substrains; increased anxiety compared to all other Wistar substrains | ||||||
| Elevated plus-maze test | Less active than SD rats from Janvier and Taconic | Less active than SD rats from Janvier and Taconic | Less anxiety-related behavior than other SD substrains | Less active than other Wistar substrains | |||||
| Tests for behavioral hyperexcitability | More excitable than other SD substrains | n.t. | n.t. | n.t. | n.t. | ||||
| 2. Behavior in epileptic rats | n.t. | n.t. | n.t. | n.t. | |||||
| Open field | Increased ambulatory and rearing behavior (not observed in other SD substrains) | Increased anxiety compared to pre-SE (control) behavior (not observed in any other SD substrain) | |||||||
| Elevated plus-maze test | Only SD substrain with increased activity | ||||||||
| Tests for behavioral hyperexcitability | No increased response in pick-up test | No increased response in pick-up test | Increased response in pick-up test | Increased response in pick-up test | |||||