Distribution of the δ-opioid receptor in the rat brain
| Highest concentrations (>500 amol/mm2) |
| External plexiform layer of the olfactory bulb |
| Nucleus accumbens |
| Olfactory tubercule |
| Intermediate concentrations (181–313 amol/mm2) |
| Layers V–VI of the cerebral cortex |
| Medial nucleus of the amygdala |
| Corpus striatum |
| Basolateral nucleus of the amygdala |
| Cortical nucleus of the amygdala |
| Layers I–II of the cerebral cortex |
| Lateral nucleus of the amygdala |
| Layers III–IV of the cerebral cortex |
| Granular layer of the olfactory bulb |
| Low concentrations (<100 amol/mm2) |
| Hippocampus pyramidal layer |
| Inferior colliculus |
| Central nucleus of the amygdala |
| Habenula |
| Globus pallidus |
| Hypothalamus |
| Glomerular layer of the olfactory bulb |
| Accessory olfactory bulb |
| Substantia gelatinosa of the spinal cord |
| Stria terminalis |
| Central gray |
| Superior collicus |
| Substantia nigra |
| Thalamus |
| Lateral geniculate bodies |
| Ventral gray of the spinal cord |
These data are taken from Mansour et al., 1988, 1995, and Sharif and Hughes, 1989. Tissues are listed in decending order of receptor density. For δ-opioid receptor density levels in the mouse brain, seeKitchen et al. (1997).