Effects of crossed olivocochlear bundle stimulation on the intracellular dc receptor potential from cochlear inner hair cells

Abstract

The efferent crossed olivocochlear bundle (COCB) was electrically stimulated during recordings of acoustically evoked potentials from the guinea pig cochlea. Round window recordings of the click-evoked whole nerve action potential were decreased during COCB stimulation by the equivalent of 10–20 dB SPL. Recovery was complete about 400 ms after the stimulation ended. COCB stimulation increased by 0–3 equivalent dB the round window cochlear microphonics in response to a 1-kHz continuous tone, similar to earlier investigations [T. Konishi and J. Z. Slepian, J. Acoust. Soc. Am. 49, 1762–1769 (1971)]. The inner hair cell intracellular dc receptor potential, in response to tone bursts near the characteristic frequency, was decreased during COCB stimulation and recovered during a time period similar to that followed by the whole nerve-action potential. The reductions ranged from 3–14 equivalent dB and were greatest for lower SPLs. The resting membrane potential was unchanged. Since the COCB is thought to primarily innervate the outer hair cells, these results may be a conclusive demonstration of hair cell interaction. [Supported by NIH Grants NS-05785, NS-15107, NS-07106.]

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

“…Preliminary reports of this research have been presented elsewhere (Brown, Nuttall & Masta, 1981, 1983aBrown, 1983).…”