Expected relative distributions of μ-, δ-, and κ-receptor sites in sampled tissues, compiled from in vitro autoradiographic reports, including Mansour et al. (1988) and Tohyama and Takatsuji (1998)
Tissue | μ-Site | δ-Site | κ-Site |
|---|---|---|---|
| Cervical cord | Low | Local | Local |
| Olfactory tubercles | — | Low | Low |
| Prefrontal cortex | Medium/low | High/medium | Low |
| Thalamus | High/medium | Low | Medium/low |
| Hypothalamus | Low | — | Medium/low |
| Anterior cingulate cortex | High | Low | — |
| Somatosensory cortex | Medium/low | Medium | Medium/low |
| Striata | High/medium | High | Medium |
| Amygdala with piriform cortex | High/medium | Medium/low | Medium/low |
| Hippocampus | Medium/low | Low | Low |
| Visual with temporal cortex | Medium/low | Medium/low | Low |
| Inferior colliculi | High/medium | — | Low |
| Superior colliculi | High/medium | Low | Medium/low |
| Periaqueductal gray | Low | — | Medium |
| Medulla with pons | Low | Local | Low |
| Cerebellum | — | — | Low |
—, minimal or nondetectable measurement.