Table 2.
Effects of decreased DA transmission on impulsive action in laboratory animals.
| Drug | Dose (mg/kg) | Study | Species tested | 5-CSRT | DRL | SRT | SST | Comments |
|---|---|---|---|---|---|---|---|---|
| Haloperidol | 25, 50 µg/kg (s.c.) | Britton and Koob (1989) | Male Wistar rats | ↓ | Both doses decreased number of premature responses and increased reinforcement rate; DRL 60 | |||
| 0.05, 0.1, 0.2, 0.4 | Marrow et al. (1993) | Male Sprague Dawley rats | ↓ | Dose-dependent decrease in number of premature responses | ||||
| 0.02, 0.04, 0.08, 0.16, 0.32 | van Hest et al. (1992) | Male Wistar rats | ↓ | Decreased response rate at 0.16 and 0.32 mg/kg; DRL 72 | ||||
| Raclopride | 50, 100, 200 µg/kg (s.c.) | Amalric et al. (1993) | Male Wistar rats | ↓ | Dose-dependent decrease in number of correct trials; all doses increased number of delayed responses | |||
| 0.05 (s.c.) | Baunez et al. (1994) | Male Wistar rats | ↓ | Increased number of delayed responses | ||||
| 0.05 (s.c.) | Baunez et al. (1995) | Male Wistar rats | ↓ | Increased number of delayed responses | ||||
| 0.2, 0.5 | Cheng and Liao (2007) | Male Sprague Dawley rats | ↓ | Both doses decreased response rate, but only the highest dose decreased the number of reinforced responses; DRL 10 | ||||
| 0.2, 0.4 | Liao and Cheng (2005) | Male Wistar rats | ↓ | Both doses decreased number of premature responses and highest dose decreased reinforcement rate; DRL 10 | ||||
| 0.05, 0.1, 0.2, 0.4, 0.8 | Marrow et al. (1993) | Male Sprague Dawley rats | ↓ | Dose-dependent decrease in number of correct trials and number of premature responses, and dose-dependent increase in RT; delayed responses increased at highest dose | ||||
| Flupenthixol | 0.1, 0.2, 0.4 | Amalric and Koob (1987) | Male Wistar rats | ↓ | Reduced number of correct trials by increasing number of delayed responses at 0.2 and 0.4 mg/kg; increased RT during correct trials and decreased overall responding at highest dose | |||
| 0.01, 0.04, 0.125 | Eagle et al. (2007) | Male Lister-hooded rats | – | No effect on SSRT in either slow or fast stoppers | ||||
| 0.05, 0.1, 0.2, 0.4 | Marrow et al. (1993) | Male Sprague Dawley rats | – | Dose-dependent decrease in number of correct trials at 0.1–0.4 mg/kg | ||||
| SCH 23390 | 5, 10, 20 µg/kg (s.c.) | Amalric et al. (1993) | Male Wistar rats | – | ||||
| 0.02, 0.05 | Cheng and Liao (2007) | Male Sprague Dawley rats | ↓ | Both doses decreased number of premature responses; DRL 10 | ||||
| 0.025, 0.05, 0.075 | Harrison et al. (1997) | Male Lister-hooded rats (5-HT depleted) | ↓ | Decreased number of premature responses at 0.05 and 0.075 mg/kg | ||||
| 0.05, 0.1 | Liao and Cheng (2005) | Male Wistar rats | ↓ | Both doses decreased number of premature responses; DRL 10 | ||||
| 0.025, 0.05, 0.1, 0.2 | Marrow et al. (1993) | Male Sprague Dawley rats | ↓ | Dose-dependent decrease in number of correct trials and number of premature responses | ||||
| 5, 10, 20, 30 µg/kg | van Gaalen et al. (2006b) | Male Wistar rats | ↓ | Decreased premature responding at 10, 20 and 30 µg/kg | ||||
| Sulpiride | 20, 40, 60 | Harrison et al. (1997) | Male Lister-hooded rats | – | No effect on number of premature responses, but increased response latency at 40 and 60 mg/kg | |||
| Eticlopride | 0.01, 0.03 | Blokland et al. (2005) | Male Lewis rats | – | No effect at any dose on premature responses, but highest dose decreased food motivation on PR10 schedule; | |||
| 0.005, 0.01, 0.02 (s.c.) | Smith et al. (2000) | Male Wistar rats | ↓ | Dose-dependent decrease in number of correct trials due to increase in delayed responses at 0.01 and 0.02 mg/kg; increased RT at 0.02 mg/kg | ||||
| 0.06, 0.08, 0.1 | van Gaalen et al. (2006b) | Male Wistar rats | – | No effect on number of premature responses, but increased response latency at all doses and reduced ability of amphetamine, cocaine and nicotine to increase premature responses |
↑ = increase in impulsivity, ↓ = decrease in impulsivity, – = no effect. Doses are expressed in mg/kg, unless otherwise specified. Route of administration is i.p., unless otherwise specified.
Premature responding = Five-choice serial reaction time task (5-CSRT), Differential reinforcement of low rates of responding task (DRL); Simple reaction time task (SRT); Inability to inhibit prepotent responses = Stop-signal task (SST).