Evidence of altered brain sexual differentiation in mice exposed perinatally to low, environmentally relevant levels of bisphenol A

Endocrinology. 2006 Aug;147(8):3681-91. doi: 10.1210/en.2006-0189. Epub 2006 May 4.


Humans are routinely exposed to bisphenol A (BPA), an estrogenic chemical present in food and beverage containers, dental composites, and many products in the home and workplace. BPA binds both classical nuclear estrogen receptors and facilitates membrane-initiated estrogenic effects. Here we explore the ability of environmentally relevant exposure to BPA to affect anatomical and functional measures of brain development and sexual differentiation. Anatomical evidence of alterations in brain sexual differentiation were examined in male and female offspring born to mouse dams exposed to 0, 25, or 250 ng BPA/kg body weight per day from the evening of d 8 of gestation through d 16 of lactation. These studies examined the sexually dimorphic population of tyrosine hydroxylase (TH) neurons in the rostral periventricular preoptic area, an important brain region for estrous cyclicity and estrogen-positive feedback. The significant sex differences in TH neuron number observed in control offspring were diminished or obliterated in offspring exposed to BPA primarily because of a decline in TH neuron number in BPA-exposed females. As a functional endpoint of BPA action on brain sexual differentiation, we examined the effects of perinatal BPA exposure on sexually dimorphic behaviors in the open field. Data from these studies revealed significant sex differences in the vehicle-exposed offspring that were not observed in the BPA-exposed offspring. These data indicate that BPA may be capable of altering important events during critical periods of brain development.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Arcuate Nucleus of Hypothalamus / drug effects
  • Arcuate Nucleus of Hypothalamus / embryology
  • Arcuate Nucleus of Hypothalamus / growth & development
  • Behavior, Animal / drug effects*
  • Benzhydryl Compounds
  • Cell Count
  • Critical Period, Psychological
  • Estrogens, Non-Steroidal / pharmacology*
  • Estrous Cycle / physiology
  • Exploratory Behavior / physiology
  • Female
  • Hypothalamus, Anterior* / drug effects
  • Hypothalamus, Anterior* / embryology
  • Hypothalamus, Anterior* / growth & development
  • Male
  • Mice
  • Mice, Inbred Strains
  • Neurons / cytology
  • Neurons / enzymology
  • Paraventricular Hypothalamic Nucleus / drug effects
  • Paraventricular Hypothalamic Nucleus / embryology
  • Paraventricular Hypothalamic Nucleus / growth & development
  • Phenols / pharmacology*
  • Pregnancy
  • Prenatal Exposure Delayed Effects
  • Preoptic Area / drug effects
  • Preoptic Area / embryology
  • Preoptic Area / growth & development
  • Septal Nuclei / drug effects
  • Septal Nuclei / embryology
  • Septal Nuclei / growth & development
  • Sex Characteristics*
  • Sexual Behavior, Animal / drug effects
  • Sexual Maturation
  • Tyrosine 3-Monooxygenase / metabolism


  • Benzhydryl Compounds
  • Estrogens, Non-Steroidal
  • Phenols
  • Tyrosine 3-Monooxygenase
  • bisphenol A