Testosterone Metabolites Differentially Maintain Adult Morphology in a Sexually Dimorphic Neuromuscular System

The study investigated the role of testosterone metabolites, estrogens, and nonaromatizable androgens in maintaining the morphology of the sexually dimorphic spinal nucleus of the bulbocavernosus (SNB) neuromuscular system in adult rats. It was found that castration led to reductions in SNB target muscle size, soma size, and dendritic morphology. Testosterone treatment after castration effectively maintained SNB soma size, dendritic morphology, and increased target muscle size, while dihydrotestosterone was less effective. Estradiol treatment did not prevent castration-induced atrophy, and treatments with finasteride or fadrozole did not alter SNB morphology in intact males. The results suggested that androgens were crucial for maintaining adult motoneuron and muscle morphology.