Skip to main content
. Author manuscript; available in PMC: 2011 Apr 1.
Published in final edited form as: Brain Res Brain Res Rev. 2004 Oct;46(2):204–215. doi: 10.1016/j.brainresrev.2004.07.003

Fig. 4.

Fig. 4

Schematic of the hypothesis of domain type selectivity in vertebrate opioid receptors. MOR1 is the generic vertebrate mu opioid receptor, KOR1 is the kappa opioid receptor, and DOR1 is the delta opioid receptor. Type selectivity is determined by the ligand binding characteristics, or filters, by the different EL domains for each type of opioid receptor. Ovals binding to EL domains represent type-selective opioid agonists. See text for further details.