Question

What effect does prenatal exposure to high levels of testoster one have on the development of female rats? Check all correct options for full credit.

What effect does prenatal exposure to high levels of testosterone have on the development of female rats? Check all correct options for full credit.

a. They have an SDN that is larger than that what you would find in a typical female rat.

b. They are more sexually attracted to other females that are females who experienced low levels of testosterone during early development.

c. They display male patterns of copulatory behavior in adulthood.

d. They have a smaller SDN than is typically found in female rats.

Answer 1

Answer - a and b

During early development, testosterone plays an important role in sexual differentiation of the mammalian brain and has enduring influences on behavior. Testosterone exerts these influences at times when the tests are active, as evidenced by higher concentrations of testosterone in developing male than in developing female animals. This article critically reviews the available evidence regarding the influences of testosterone on human gender-related development. In humans, testosterone is elevated in males from about weeks 8 to 24 of gestation and then again during early postnatal development.

Female animals treated with testosterone prenatally or neonatally subsequently show increased male-typical behavior and decreased female-typical behavior. Similarly, male animals that have their testes removed early in development later show increased female-typical behavior and reduced male-typical behavior. These effects have been seen for sexual behaviors and for non-reproductive behaviors that differ by sex, such as aggression and juvenile rough-and-tumble play. They also have been seen in numerous species ranging from rodents to non-human primates

Early hormone manipulations produce changes in the mammalian brain as well as in behavior. The sexually dimorphic nucleus of the preoptic area (SDN-POA) provides a prototypical example of these effects. The SDN-POA is larger in volume and contains more neurons in male than in female rats. Treating female rats with testosterone during early development increases SDN-POA volume in adulthood and castrating developing males reduces it. Testosterone and hormones produced from it have been found to influence cell survival, neurite outgrowth, and neurochemical specification during early development in rodents. The effects of early androgen exposure on both the brain and behavior are often described as organizational, and early androgen exposure is thought to produce enduring changes in behavior by altering the development and organization of underlying brain circuits.