Table 7. Differences in Tickling Outcomes in Bi-Directionally Selected Rats in Comparison to Randomly Bred Rats.
| Outcome Measurement | High-Line* | Low- Line* | Author Year |
|---|---|---|---|
| Approach behaviors after tickling | ↑ | - | Panksepp 2000 |
| Tickling avoidance | ↓ | - | |
| Fecal boli during tickling, open field test, & porsolt swim test | - | ↑ | Burgdorf 2009 |
| Bites towards resident animal in social defeat test | ↓ | - | |
| Contact with conspecifics in a social interaction test | - | ↓ | |
| Preference for dilute sucrose | ↑ | - | |
| Anxiety & Fear Behaviors during Open Field | ↓ | ↑ | |
| Level of metenkephalin in brain | ↑ | ↓ | |
| Level of cholecystokinin in brain | ↓ | ↑ | |
| Spontaneous locomotor activity | ↑ | - | Brudzynski 2011 |
The effects of bi-directional selection of production of high or low levels of 50-kHz 50-kHz vocalizations during tickling (high-line or low-line). *All results are in comparison to randomly bred rats. A dash indicates no significant difference compared to randomly bred rats.