Abstract/Details

Female rats show greater sensitivity to high-strength magnetic fields: Role of vestibular system and estrogen


2006 2006

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Abstract (summary)

This dissertation discusses the investigation of sex differences in the response to magnetic field (MF) exposure and the role of the vestibular system and estrogen in the effects of MFs. Advances in magnetic resonance imaging are driving the development of higher resolution machines equipped with high-strength static MFs. The behavioral effects of high-strength MFs are largely uncharacterized. Our laboratory has previously shown that following high-strength static magnetic field (MF) exposure, male rats suppress normal rearing behavior, walk in circles, acquire a conditioned taste aversion (CTA), and express c-Fos in vestibular and visceral relays of the brainstem. These results suggest that the MF may interact with the vestibular system producing effects similar to rotation or motion sickness.

Here, I provide evidence for sex differences in the response to MF-exposure by examining how fluctuations in endogenous estrogen across the female rat's estrous cycle and removal of the ovaries and subsequent hormone replacement influence the behavioral response to MF-exposure compared to male rats. I then provide evidence that the inner ear is required for both the behavioral and neural response to MF-exposure by showing that bilateral removal of the inner ear by chemical labyrinthectomy eliminates MF-induced CTA and MF-induced c-Fos expression in vestibular and visceral relays. I also demonstrate that estrogen influences the amount of c-Fos expression in the vestibular and visceral relays. Compared to ovariectomized rats, chronic estrogen replacement decreased c-Fos expression in the LC and SuV and reversed significant hemispheric asymmetries in other vestibular and visceral relays suggesting potential neural sites where estrogen could interact to influence the behavioral response to MF exposure. In addition, I provide evidence that the estrogen receptor subunits are present within specific areas of the vestibular and visceral relays that are responsive to MF-exposure and could potentially mediate the effects of estrogen.

Indexing (details)


Subject
Neurology;
Anatomy & physiology;
Animals
Classification
0317: Neurology
0433: Anatomy & physiology
0433: Animals
Identifier / keyword
Biological sciences; Estrogen; MRI; Magnetic fields; Vestibular
Title
Female rats show greater sensitivity to high-strength magnetic fields: Role of vestibular system and estrogen
Author
Cason, Angela Marie
Number of pages
126
Publication year
2006
Degree date
2006
School code
0071
Source
DAI-B 67/04, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
9780542659744, 0542659743
Advisor
Houpt, Thomas A.
University/institution
The Florida State University
University location
United States -- Florida
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
3216475
ProQuest document ID
305328516
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/305328516
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