Figure 10-15 Spectrum of the intrinsic activities of benzodiazepine receptor ligands, which range from agonists to inverse agonists. Structures of agonist, partial agonist, antagonist, partial inverse agonist, and inverse agonist compounds are shown. Intrinsic activity is greatest among agonists and is least among inverse agonists. Intrinsic activities are schematically indicated as positive by a plus sign and as negative by a minus sign, with 0 indicating a lack of intrinsic activity. (Redrawn with modification from Mohler H, Richards JG: The benzodiazepine receptor: A pharmacological control element of brain function. Eur J Anaesthesiol Suppl 2:15–24, 1988.)