Correlation between auditory threshold and the auditory brainstem response (ABR) in rats. A possibility for the experimental study of the auditory impairments

Auditory impairments are considered to be one of the most frequent neurosensorial problems in human. The normal development and myelination of the auditory system can be impaired by certain pathological conditions such as viral infections, hyperbilirubinemia, meningitis, fetal distress and perinatal asphyxia. The early detection of this hearing loss can be diagnostic with sensitive techniques, such as the auditory brainstem response (ABR). These techniques are the relatively early component of the auditory evoked potential that reflects the electrophysiological activity of a large number of neurons in the brainstem auditory pathway after an acoustic stimulation. Normal ABR requires the integrity of the anatomical system, composed by a set of neurons, their axons, the synapses between them and the neurons on which each ABR terminate. Disruption of any portion of the system will alter the amplitude or the latency.