Chronic Estradiol Impairs Performance on an Operant Delayed Spatial Alternation Task in Young, Middle-aged and Old Rats. January 21, 2013 Authors: Wang, V.C., Neese, S.L., Korol, D.L., and Schantz, S.L. Published: 2009 Source: Hormones and Behavior, 56, 382-390.