Electrophysiological monitoring of hearing function during cochlear perilymphatic perfusions.
CONCLUSIONS
The cochlear perilymphatic perfusion produces, by itself, significant effects in the cochlear physiology that could be associated with the surgical procedure. These effects need to be well characterized to allow a reliable quantification of the effects of the experimental agent being tested.


OBJECTIVE
The study focused on the accurate description of the electrophysiological effects on the cochlear potential recordings of perilymphatic perfusions.


METHODS
Two successive cochlear perilymphatic perfusions were carried out. The first used artificial perilymph. The second used artificial perilymph alone or a kainic acid (KA) solution in artificial perilymph. The compound action potential of the auditory nerve (CAP-AN) was recorded: (1) before the first perfusion, (2) after the first perfusion and (3) after the second perfusion, and compared between groups.


RESULTS
The first intracochlear perfusion with artificial perilymph produced significant effects in the CAP-AN that could be related to the surgical procedure. These effects were analysed separately from the effects produced by the KA. In particular, the KA administered intracochlearly produced a significant increase in the latency and a decrease in the amplitude of the CAP-AN N1 wave compared with the controls that were perfused twice with artificial perilymph.
Otorhinolaryngology Service, Hospital Comarcal de El Bierzo Ponferrada, Spain.
Jesús
J
San Román
Francisco
F
Carricondo
Mari-Cruz
MC
Iglesias-Moreno
Cristina
C
Martín-Villares
Joaquín
J
Poch-Broto
Pablo
P
Gil-Loyzaga
D000161:Acoustic Stimulation / Q000379:methods; D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology*; D000818:Animals; D001300:Audiometry, Evoked Response; D003051:Cochlea / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology*; D003056:Cochlear Nerve / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D009925:Organ of Corti / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D010477:Perfusion / Q000379:methods*; D010498:Perilymph / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology
D018690:Excitatory Amino Acid Agonists; D007608:Kainic Acid