Abstract
Evidence is presented for the presence of opiate binding sites with a preference for benzomorphans in seven regions of the human brain. The highest concentration of these sites was found in the hypothalamus and the lowest level in the thalamus. By utilizing the phencyclidine derivative, 3-hydroxyphencyclidine, we have obtained data suggesting that these benzomorphan binding sites may be a mixture of κ and σ sub-types of opiate receptors.
