Table 2.
Summary of effects of different adenosinergic ligands on discriminative-stimulus effects of nicotine, methamphetamine, and cocaine (present study; Munzar et al. 2002; Justinova et al. 2003).
| Adenosine agonists | Adenosine antagonists | |||||
|---|---|---|---|---|---|---|
| Discriminated Drug | Effect | A1 CPA | A2A CGS 21680 | A1 CPT | A2A MSX-3 | Non-selective Caffeine |
| No Caffeine Exposure in Drinking water | ||||||
| Nicotine | Generalization | None | None | Partial | Partial | Partial |
| Shift of DRC | No shift | No shift | Left | Left | Left | |
| Methamphetamine | Generalization | None | None | Partial | Partial | Partial |
| Shift of DRC | No shift | No shift | Left | Left | Left | |
| Cocaine | Generalization | None | Partial | Partial | Partial | Partial |
| Shift of DRC | Left | Left | Left | Left | Left* | |
| Chronic Caffeine Exposure in Drinking Water | ||||||
| Nicotine | Generalization | None | None | None | ||
| Shift of DRC | No shift | No shift | No shift | |||
| Methamphetamine | Generalization | None | Partial | None | ||
| Shift of DRC | No shift | Left | Left | |||
| Cocaine | Generalization | None | Partial | Partial | ||
| Shift of DRC | No shift | Left | Left | |||
DRC = Dose-response curve