Neonatal exposure to 17 beta-estradiol down-regulates the expression of synaptogenesis related genes in selected brain regions of adult female rats

Radhika, NS and Govindaraj, Vijayakumar and Sarangi, SK and Rao, AJ (2015) Neonatal exposure to 17 beta-estradiol down-regulates the expression of synaptogenesis related genes in selected brain regions of adult female rats. In: LIFE SCIENCES, 141 . pp. 1-7.

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Abstract

Aims: Administration of estradiol or compounds with estrogenic activity to newborn female rats results in irreversible masculinization as well as defeminization in the brain and the animals exhibit altered reproductive behavior as adults. The cellular and molecular mechanism involved in inducing the irreversible changes is largely unknown. In the present study, we have monitored the changes in the expression of selected synaptogenesis related genes in the sexually dimorphic brain regions such as POA, hypothalamus and pituitary following 17 beta-estradiol administration to neonatal female rats. Main methods: Female Wistar rats which were administered 17 beta-estradiol on day 2 and 3 after birth were sacrificed 120 days later and the expression levels of genes implicated in synaptogenesis were monitored by semi-quantitative reverse transcription PCR. Since estradiol induced up-regulation of COX-2 in POA is a marker for estradiol induced masculinization as well as defeminization, in the present study only animals in which the increase in expression of COX-2 gene was observed in POA were included in the study. Key findings: Down-regulation of genes such as NMDA-2B, NETRIN-1, BDNF, MT-5 MMP and TNF-alpha was observed in the pre-optic area of neonatally E2 treated female rat brain but not in hypothalamus and pituitary compared to the vehicle- treated controls as assessed by RT-PCR and Western blot analysis. Significance: Our results suggest a possibility that down-regulation of genes associated with synaptogenesis in POA, may be resulting in disruption of the cyclical regulation of hormone secretion by pituitary the consequence of which could be infertility and altered reproductive behavior. (C) 2015 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Publication:	LIFE SCIENCES
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copy right for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Keywords:	Neonatal 17 beta-estradiol exposure; Pre-optic area; Synaptogenesis; Hypothalamus; Pituitary
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	02 Jan 2016 09:30
Last Modified:	02 Jan 2016 09:30
URI:	http://eprints.iisc.ac.in/id/eprint/53011

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