The relationship of prenatal ethanol exposure and anxiety-related behaviors and central androgen receptor and vasopressin expression in adult male mandarin voles

Abstract

Prenatal exposure to ethanol has been shown to increase the risk of anxiety in offspring. Here, we tested the effect of prenatal ethanol exposure on adult male mandarin voles (Microtus mandarinus). We examined anxiety-like behavior in the open field and elevated plus-maze tests in males exposed to ethanol prenatally. One control group was not exposed to ethanol or saline, while another control group was exposed to saline. At the age of 90days, males were tested and levels of serum testosterone, androgen receptor immunoreactive neurons (AR-IRs) and arginine vasopressin immunoreactive neurons (AVP-IRs) were measured. Animals exposed to ethanol spent less time in the center of the chamber, covered less distance and conducted fewer crossings in the open-field test. These animals also spent less time and conducted fewer crossings in the open arms. However, they spent more time and made more entries in the closed arms, and traveled less total distance during the elevated plus-maze test, compared to the control voles. Serum T was lower in the ethanol group, and the AR-IR number in the bed nucleus of the stria terminalis (BNST), medial preoptic area (mPOA) and medial amygdaloid nucleus (MeA) was significantly lower. The number of AVP-IRs in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the ethanol group was higher than that of the control groups. Our findings suggest that prenatal ethanol exposure may lead to reduced serum T levels, decreased AR and increased AVP in the CNS and result in the development of anxiety-like behaviors.