Link between functional and morphological changes in the inner ear--functional changes produced by ototoxic agents and their interactions.
Common potentials used to evaluate cochlear function are the ac cochlear potential (ACCP), N1 and the positive dc endocochlear potential (EP). The ACCP is an electrical analogue of the sound stimulus; its source is the electrical activity of the cochlear hair cells. N1 is a volume conductor recorded action potential of the auditory nerve. The EP is the positive polarization of the middle compartment of the cochlea (scala media) with respect to the other compartments (the scalae tympani and vestibuli); the stria vascularis is apparently responsible for the EP. Generally, ototoxic drugs and very intense broad-band noise affect the basal portion of the cochlea first and, because of tonotopic organization, the ACCP responses to high frequency pure tones are affected before those to the low frequencies. However, the correlation between the effect of an ototraumatic agent on the ACCP and its effect on cochlear morphology is not always reliable. The correlations between changes in N1 and EP and in cochlear morphology are even less precise. Also discussed will be the cochlear effects of noise and the ototoxic interactions between drug/drug, noise/drug, and noise/drug/otitis media.
D000111:Acetylcysteine / Q000009:adverse effects; D000328:Adult; D000617:Aminoglycosides / Q000009:adverse effects; D000625:Aminooxyacetic Acid / Q000494:pharmacology; D000777:Anesthetics / Q000009:adverse effects; D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D000970:Antineoplastic Agents / Q000009:adverse effects; D001241:Aspirin / Q000009:adverse effects / Q000633:toxicity; D002648:Child; D002701:Chloramphenicol / Q000633:toxicity; D003051:Cochlea / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D003055:Cochlear Microphonic Potentials / Q000187:drug effects; D004232:Diuretics / Q000009:adverse effects; D004357:Drug Synergism; D004917:Erythromycin / Q000009:adverse effects; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D005990:Glycerol / Q000009:adverse effects; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000473:pathology; D006319:Hearing Loss, Sensorineural / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control; D006801:Humans; D007759:Labyrinth Diseases / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D009622:Noise / Q000009:adverse effects; D010033:Otitis Media / Q000150:complications; D051381:Rats; D013316:Stria Vascularis / Q000187:drug effects / Q000473:pathology
D000617:Aminoglycosides; D000777:Anesthetics; D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D004232:Diuretics; D000625:Aminooxyacetic Acid; D004917:Erythromycin; D002701:Chloramphenicol; D005990:Glycerol; D001241:Aspirin; D000111:Acetylcysteine