EFFECTS OF PRENATAL ALCOHOL EXPOSURE AND AGING ON AUDITORY FUNCTION IN THE RAT - PRELIMINARY-RESULTS

This study investigated select aspects of peripheral and central audit ory dysfunction, as well as the pathological effects of aging, in an a nimal model of fetal alcohol syndrome (FAS). Pregnant rats consumed li quid alcohol diets containing 0, 17.5, or 35% ethanol-derived calories , from gestation day 7 to parturition. A fourth group was untreated. O ffspring of these mothers were tested for auditory and neurological fu nction, using the auditory brainstem response at 6, 12, and 18 months of age. Some animals in the alcohol-exposed groups showed a peripheral auditory disorder in the form of congenital sensorineural hearing los s. This was correlated with punctate lesions and malformed stereocilia on the auditory sensory receptor cells of the inner ear. Alcohol-expo sed animals also showed a central auditory processing disorder charact erized by prolonged transmission of neural potentials along the brains tem portion of the auditory pathway. Animals in the highest dose group also showed an augmentation in the age-related deterioration of audit ory acuity. Thus, increased peripheral and central auditory dysfunctio ns and pathological deterioration of auditory function in old age may be sequelae of FAS. Such morbidities have important implications for t he longterm clinical assessment and management of FAS patients.