Abstract

Ultrasound (US) has become a standard procedure used during pregnancy to document the health and development of a fetus. When ultrasound was first developed, some researchers urged caution, suggesting that the possibility of hazard should be kept under constant review. Given the routine application of fetal ultrasound imaging, any possibility of deleterious developmental effects resulting from its use is an important public health issue. Rats have a well characterized central nervous system whose neurochemical pathways and neuronal electrophysiology qualitatively correspond to those of humans. Because of this, we opted to use Wistar rats as an animal model to document effects from ultrasound exposure. We exposed one group of rats on prenatal days 15 and 20 for fifteen minutes. A control group was exposed subjected to similar conditions, however no ultrasound exposure was given. A third group was exposed for ten minutes each on post natal days (PND) 2 and 3 while a fourth control group was exposed to the same conditions as group three with no ultrasound exposure. The rats were then watched for developmental delays. When the rats reached the appropriate age, they were given a locomotor task to test for appropriate motor responses. Acoustic startle and prepulse inhibition tests were administered to test for sensorimotor gating, hearing, and motor response. Finally, a brainstem auditory evoke potential test was given to track auditory threshold and appropriate neural firing at various auditory nuclei. Postnatally US exposed rats showed a decreased acoustic startle response and prenatally exposed rats exhibited a speeding up in components of the brainstem auditory evoked potential test.

Degree

MS

College and Department

Life Sciences; Neuroscience

Rights

http://lib.byu.edu/about/copyright/

Date Submitted

2007-04-27

Document Type

Thesis

Handle

http://hdl.lib.byu.edu/1877/etd1830

Keywords

ultrasound, auditory system

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