ABSTRACT
Some major forces in the applications of modern molecular genetics to the understanding of brain function and behavior have led to unfortunate misunderstandings of how explorations of gene/behavior relations would evolve. This chapter provides a discussion on genetic influences on reproductive behaviors and lessons from studies of reproductive behaviors. Despite the difficulties, there has been some success with genetic analyses of the simplest forms of mammalian reproductive and aggressive behaviors. Regarding reproductive behaviors gonadectomy reduced sexual behaviors in all genotypes, but the serious deficiencies in both intromissions and ejaculations for estrogen receptor knockout males compared to wild-type controls persisted. The chapter summarizes briefly the causal routes delineated for classical estrogen receptor and thyroid hormone receptor. It concludes that the effects of classical estrogen receptor gene disruption on reproductive behaviors in females and males are not simply due to alterations in circulating gonadal hormone levels, but instead must be registered in the central nervous system.
