Efferent control of cochlear inner hair cell responses in the guinea-pig.

摘要: The efferent crossed olivocochlear bundle (c.o.c.b.) was electrically stimulated during intracellular recordings from cochlear inner hair cells in anaesthetized guinea-pigs. effect of c.o.c.b. stimulation to decrease the magnitude cell depolarizing component (d.c.) and alternating (a.c.) receptor potentials evoked by tone bursts at characteristic frequency. At low sound pressure levels, caused equivalent decreasing intensity 9-24 dB. C.o.c.b. usually had a similar on compound action potential auditory nerve. change membrane resistance moderate-level measured for alone when accompanied stimulation. Sound produced greater than with stimulation, proportion d.c. same conditions. time course slow, 50-250 ms required full recovery. effects varying frequency voltage electrical were potential. For sounds high level frequencies well below frequency, less effective reducing potentials. Frequency tuning curves taken intervals continuous showed decreases sensitivity primarily tip segment curve. When no stimulus present, resting relatively unaltered did not Since innervates mainly outer cells, these results strongly suggest that changes activity can influence thus alter transmission acoustic responses central nervous system.