The differentiation of normal behavior from problem behavior is particularly challenging in young children [ 19].
The medial amygdala in particular is considered critical for sexual differentiation of play behavior because implantation of testosterone capsules into this region is sufficient to masculinize the frequency of female social play behavior [ 31].
Of particular concern, several reports have indicated that BPA exposure inhibits sexual differentiation of nonreproductive behaviors, including maze learning behavior (Carr et al. 2003; Farabollini et al. 2002), at doses as much as 1,000-fold 1,000-fold those required for stimulowern of uthanne growthoseshby 2001).
The study of mechanisms involved in the differentiation of sexual behaviors thus constitutes an invaluable tool for understanding of sex differences in general [2], [3].
In many vertebrates, the neural conversion of testosterone into estradiol by the enzyme aromatase plays a key role in the sexual differentiation of brain and behavior [4], [5], [6], [7] and in the activation of masculine sexual behaviors in adulthood [8], [9], [10].
Notably, these studies have called into question both the primacy of direct, neural mechanisms and also the linearity of the relationship between androgenic dose and sexual differentiation of brain and behavior.
Alternately, dopaminergic activation may provide a mechanism by which environmental stimuli that alter dopaminergic activity may influence protein expression and/or sexual differentiation of brain and behavior.
This suggests that ARs other than those in neurons (and presumably those outside the CNS) mediate the essential features of sexual differentiation of mouse copulatory behavior.
The specific cellular components of human stroma, in contrast to what is contained in mouse stroma, therefore provided an essential signal for growth and differentiation of normal epithelial behavior.
