TABLE 1.
Mean sessions to meet acquisition criteria (two consecutive sessions of earning ≥10 infusions and ≥80% of responses made on the active lever), number of rats meeting acquisition criteria within 10 sessions, mean number of infusions earned the last three sessions of acquisition (FR1), and mean number of infusions earned under an FR5 schedule of reinforcement
| History | Sessions to acquire mean + S.E.M. |
Rats acquired n acquired / total n (%) |
Infusions on FR1 mean + S.E.M. |
Infusions on FR5 mean + SEM |
|---|---|---|---|---|
| MDPV group | 4.5 + 0.5 | 16/16 (100) | 69.6 + 29.8 | 41.1 + 4.2 |
| MDPV high-responders | 4.6 + 0.7 | 5/5 (100) | 165.4 + 115.2 | 60.1 + 10.4 |
| MDPV low-responders | 4.5 + 0.7 | 11/11 (100) | 35.4 + 2.8 | 33.2 + 2.1 |
| Cocaine | 4.9 + 0.6 | 10/16 (62.5) | 29.8 + 6.0 | 42.7 + 2.3 |
| Fentanyl | 6.0 + 0.6 | 15/16 (93.8) | 22.7 + 4.2 | 21.1 + 3.0 |
| Nicotine | 6.7 + 0.6 | 14/16 (87.5) | 15.7 + 1.8 | 10.9 + 0.8 |
| Ketamine | 7.9 + 0.5 a,b | 14/16 (87.5) | 31.8 + 3.3 | 41.5 + 2.3 |
| Noncontingent cocaine MDPV self-administration |
2.2 + 0.1 a | 16/16 (100) | 43.9 + 2.6 | 77.0 + 23.7 |
|
Noncontingent cocaine
MDPV high-responders |
2.3 + 0.3 | 3/3 (100) | 46.8 + 9.6 | 242.7 + 73.3 |
|
Noncontingent cocaine
MDPV low-responders |
2.2 + 0.1 | 13/13 (100) | 43.4 + 2.6 | 38.8 + 7.9 |
| Noncontingent MDPV Cocaine self-administration |
2.7 + 0.3 b | 15/16 (93.8) | 48.0 + 4.9 | 44.3 + 1.9 |
a P < 0.05; significantly different from MDPV group
b P < 0.05; significantly different from cocaine