Background and purpose: The a7 nicotinic acetylcholine receptor (nAChR) has attracted considerable interest as a target for cognitive enhancement in schizophrenia and Alzheimer's Disease. However, most recently described a7 agonists are derived from the quinuclidine structural class. Alternatively, the present study identifies tilorone as a novel a7-selective agonist and characterizes analogues developed from this lead. Experimental approach: Activity and selectivity were determined from rat brain a7 and a4b2 nAChR binding, recombinant nAChR activation, and native a7 nAChR mediated stimulation of ERK1/2 phosphorylation in PC12 cells. Key results: Tilorone bound a7 nAChR (IC 50 110 nM) with high selectivity relative to a4b2 (IC 50 70 000 nM), activated human a7 nAChR with an EC 50 value of 2.5 mM and maximal response of 67% relative to acetylcholine, and showed little agonist effect at human a3b4 or a4b2 nAChRs. However, the rat a7 nAChR maximal response was only 34%. Lead optimization led to 2-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-xanthen-9-one (A-844606) with improved binding (a7 IC 50 11 nM, a4b2 IC 50 430 000 nM) and activity at both human and rat a7 nAChR (EC 50 s 1.4 and 2.2 mM and apparent efficacies 61 and 63%, respectively). These compounds also activated native a7 nAChR, stimulating ERK1/2 phosphorylation in PC12 cells. Conclusions and implications: Tilorone, known as an interferon inducer, is a selective a7 nAChR agonist, suggesting utility of the fluorenone pharmacophore for the development of a7 nAChR selective agonists. Whether a7 stimulation mediates interferon induction, or whether interferon induction may influence the potential anti-inflammatory properties of a7 nAChR agonists remains to be elucidated.