Mild carbon monoxide exposure and auditory function in the developing rat
| Autor: | Janet E. Stockard‐Sullivan, Rose A. Korsak, John Edmond, Douglas S. Webber |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
medicine.medical_specialty
Auditory Pathways Action Potentials Morris water navigation task Vestibulocochlear nerve Rats Sprague-Dawley Cellular and Molecular Neuroscience chemistry.chemical_compound Cognition Internal medicine Evoked Potentials Auditory Brain Stem medicine Animals Auditory function Maze Learning Carbon Monoxide Maternal deprivation Dose-Response Relationship Drug Maternal Deprivation Brain Vestibulocochlear Nerve Carbon monoxide exposure Rats Endocrinology Auditory brainstem response Acoustic Stimulation chemistry Anesthesia Brainstem Carbon monoxide |
| Zdroj: | Journal of Neuroscience Research. 74:644-654 |
| ISSN: | 1097-4547 0360-4012 |
| DOI: | 10.1002/jnr.10808 |
| Popis: | We have examined the influence of chronic mild exposure to carbon monoxide (CO) on cognitive (learning) and auditory function in the developing rat. We have demonstrated that the auditory pathway is compromised at exposures less than 50 ppm, whereas learning was not influenced at 100 ppm. Artificially reared rat pups were exposed to CO during the brain growth spurt and onset of myelination. Spatial learning was assessed using the Morris Water Maze and three tests of auditory function: (1) auditory brainstem conduction times; (2) the amplitude of the eighth nerve's action potential; and (3) otoacoustic emissions carried out on rat pups (age 22- 24 days). The pups were gastrostomy-reared on a rat milk substitute and chronically exposed to CO at discrete concentrations in the range of 12-100 ppm from 6 days of age to post-weaning at 21-23 days of age. We found no difference in auditory brainstem conduction times at all CO concentrations in comparison to non-exposed controls. There was a difference in otoacoustic emissions for test and controls at CO concentrations of 50 ppm but not at lower concentrations. There was a consistent attenuation of the amplitude of the eighth nerve's action potential, even at the lowest CO exposure examined. The attenuation of the amplitude of the action potential of the eighth nerve at 50 ppm carbon monoxide exposure did not completely recover by 73 days of age. We conclude that prolonged mild exposure to carbon monoxide during development causes measurable functional changes at the level of the eighth cranial nerve. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text