Our picture of the role of sex steroids in different parts of the brain is still incomplete. More recent studies using assays such as immunohistochemistry methods and in situ hybridization techniques have extended the range of brain regions, cell types, and cellular locations in which sex steroids have been found (Guerriero, 2009; Sarkey, Azcoitia, Garcia-Segura, Garcia-Ovejero, & DonCarlos, 2008). Besides questions relating to the “non-classic” functions of receptors outside of the nucleus, we are just beginning to explore how splice variations in steroid receptor transcription may impact both function and the ability of existing assays to register their presence (Weickert et al., 2008; Weiser, Foradori, & Handa, 2008). There is also limited data regarding developmental changes in sex steroid receptor expression, particularly during puberty (Sugiyama et al., 2009).
