Table 3.
Localization of opioid receptors in related brain regions and peripheral tissues
| Brain region | Opioid receptors
|
||
|---|---|---|---|
| μ | δ | κ | |
| Cortex | |||
| Cingulate cortex | +/++++ | +/++++ | +/++ |
| Frontal parietal cortex | ++/+++ | ++/+++ | −/++ |
| Temporal cortex | ++/+++ | +/+++ | −/+ |
| Hippocampus | |||
| Pyramidal cell layers | +++ | ++ | + |
| Dentate gyrus (dorsal) | − | − | − |
| Dentate gyrus (ventral) | +++/++++ | + | + |
| Caudate putamen | ++++ | ++++ | +++ |
| Nucleus accumbens | ++++ | ++++ | +++ |
| Amygdala | |||
| Medial nucleus | +++ | ++ | ++ |
| Central nucleus | − | − | ++ |
| Lateral | ++++ | +++ | +++ |
| Basolateral | ++++ | +++ | +++ |
| Thalamus | |||
| Laterodorsal nucleus | ++ | − | − |
| Central medial nucleus | ++++ | + | ++ |
| Medial geniculate nucleus | ++++ | − | + |
| Zona incerta | − | − | ++ |
| Hypothalamus | |||
| Lateral | + | − | ++ |
| Paraventricular nucleus | − | − | ++ |
| Supraoptic nucleus | − | − | ++ |
| Median eminence | − | − | +++ |
| Arcuate nucleus | − | − | ++ |
| Ventral tegmental area | ++ | − | |
| Raphe nucleus | +++ | − | ++ |
| Pituitary (rat) | +/− | +/− | ++ |
| Pituitary (human) | +++ | +/− | ++ |