Compounds of formula (I) wherein A and B are amine-substituted sidechains, Y1 and Y2 form various tricyclic cores, Xa and Xb are C, CH, or N, as defined herein, and Rx is an optional substituent. Compounds and compositions of formula (I) are contemplated as well as methods for treating conditions or disorders prevented by or ameliorated by α7 nAChR ligands that encompass compounds of formula (I) and other tricyclic derivatives. Methods of using amino-substituted tricyclic derivatives also are described herein.