Key to treatment groups
| Treatment | Peripheral injection | PVN injection | Food available? |
|---|---|---|---|
| sal/sal | Saline (0.9%) | Saline (0.9%) | Yes |
| nlx/sal | Naloxone (1 mg/kg) | Saline (0.9%) | Yes |
| sal/NPY | Saline (0.9%) | NPY (1 μg) | Yes |
| sal/NPY(D) | Saline (0.9%) | NPY (1 μg) | No |
| nlx/NPY | Naloxone (1 mg/kg) | NPY (1 μg) | Yes |