Additional studies that employed different rat or mouse SCI models and distinct 17β-estradiol treatment regimens indicated improvement of locomotor function (Cuzzocrea et al., 2008; Ritz and Hausmann, 2008; Sribnick et al., 2010). In contrast to all the reports mentioned above, Swartz et al. (2007) did not detect any alterations in BBB scores when female OVX rats ormale rats that sustained amid-thoracic contusion injury were treated with 17β-estradiol delivered in Silastic capsules (180 μg/ml or 1 mg/ml) implanted 7 days prior to injury. An interesting investigation addressed whether endogenous androgens alter the beneficial effects of 17β-estradiol on locomotor function (Kachadroka et al., 2010). These studies compared the effects of 17β- estradiol on gonadectomized and intact male rats after a mid-thoracic crush injury. The results indicated that testicular-derived endogenous androgens do not alter the beneficial effects of 17β-estradiol.