Regulation of Dopamine D1 Receptors in Guinea Pig Cochlea
LI Xueshi
LI Xingqi
HAN Lin
WANG Lin
YU Lisheng
Abstract：Objective To study the regulation of dopamine D1 receptors in guinea pig cochlea, and changes of co-chlear potentials and otoacoustic emissions after dopamine D1 receptor antagonist perfusion. Methods Twenty healthy guinea pigs were randomly divided to receive left ear whole intracochlear perfusion with either artificial perilymph solu-tions, or with 20 μmol/L dopamine D1 receptor antagonist (SCH23390). Before and 5, 15, 30, 60 and 120 min after per-fusion, compound action potentials (CAP) evoked by clicks, cochlear microphnics (CM) evoked by 4 kHz tone bursts and distortion product otoacoustic emissions (DPOAE) were recorded and their input/output (I/O) functions obtained. Results There was no significant difference in CAP threshold and amplitude before and after perfusion with the artifi-cial perilymph solution (P＞0.05). Increased amplitude in CAP was noted 5 min after perfused with SCH23390 (P=0.005), which decreased as perfusion time prolonged to a level below the pre-perfusion amplitude (P=0.02). The ampli-tudes of CM and DPOAEs remained unchanged in both groups (P＞0.05). The input/output function of CAP and CM re-mained nonlinear. Conclusions Dopamine D1 receptor antagonist can block the inhibitory effect of dopamine on the af-ferent nerve without influencing outer hair cells. The effect is temporary.
Keywords：DopamineCochleaCochlear Microphonics (CM)Compound Action Potential (CAP)Distortion Product Otoacoustic Emissions (DPOAE)
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 369-374 )