Effects of prenatal ethanol exposure on regulation of basal hypothalamic-pituitary-adrenal activity and hippocampal 5-HT1A receptor mRNA levels in female rats across the estrous cycle

Psychoneuroendocrinology. 2008 Sep;33(8):1111-23. doi: 10.1016/j.psyneuen.2008.05.001. Epub 2008 Jul 30.

Abstract

Prenatal ethanol exposure, like other early adverse experiences, is known to alter hypothalamic-pituitary-adrenal (HPA) activity in adulthood. The present study examined the modulatory effects of the gonadal hormones on basal HPA regulation and serotonin Type 1A receptor (5-HT(1A)) mRNA levels in adult female rats prenatally exposed to ethanol (E) compared to that in females from pair-fed (PF) and ad libitum-fed control (C) conditions. We demonstrate, for the first time, long-lasting consequences of prenatal ethanol exposure for basal corticosterone (CORT) regulation and basal levels of hippocampal mineralocorticoid (MR), glucocorticoid (GR) and serotonin Type 1A (5-HT(1A)) receptor mRNA, as a function of estrous cycle stage: (1) basal CORT levels were higher in E compared to C females in proestrus but lower in E and PF compared to C females in estrus; (2) there were no differences among groups in basal levels of adrenocorticotropin (ACTH), estradiol or progesterone; (3) hippocampal MR mRNA levels were decreased in E compared to PF and C females across the estrus cycle, with the greatest effects in proestrus, whereas E (but not PF or C) females had higher hippocampal GR mRNA levels in proestrus than in estrous and diestrus; (4) 5-HT(1A) mRNA levels were increased in E compared to PF and C females in diestrus. That alterations were revealed as a function of estrous cycle stage suggests a role for the ovarian steroids in mediating the adverse effects of ethanol. Furthermore, it appears that ethanol-induced nutritional effects may play a role in mediating at least some of the effects observed. The resetting of HPA activity by early environmental events could be one mechanism linking early life experiences with long-term health consequences. Thus, changes in basal CORT levels, a shift in the MR/GR balance and alterations in 5-HT(1A) receptor mRNA could have important clinical implications for understanding the secondary disabilities, such as an increased incidence of depression, in children with FASD.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenocorticotropic Hormone / blood
  • Animals
  • Basal Metabolism / drug effects
  • Estrous Cycle / blood
  • Estrous Cycle / drug effects*
  • Estrous Cycle / genetics
  • Estrous Cycle / metabolism
  • Ethanol / adverse effects
  • Ethanol / blood
  • Ethanol / pharmacology*
  • Female
  • Hippocampus / metabolism*
  • Hydrocortisone / blood
  • Hypothalamo-Hypophyseal System / drug effects*
  • Hypothalamo-Hypophyseal System / metabolism
  • Hypothalamo-Hypophyseal System / physiopathology
  • Male
  • Pituitary-Adrenal System / drug effects*
  • Pituitary-Adrenal System / metabolism
  • Pituitary-Adrenal System / physiopathology
  • Pregnancy
  • Prenatal Exposure Delayed Effects / genetics*
  • Prenatal Exposure Delayed Effects / metabolism
  • Prenatal Exposure Delayed Effects / physiopathology
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Serotonin, 5-HT1A / genetics*
  • Receptor, Serotonin, 5-HT1A / metabolism
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism

Substances

  • Receptors, Cytoplasmic and Nuclear
  • Receptor, Serotonin, 5-HT1A
  • Ethanol
  • Adrenocorticotropic Hormone
  • Hydrocortisone