Facilitating efferent inhibition of inner hair cells in the cochlea of the neonatal rat

JUAN D. GOUTMAN; PAUL A. FUCHS; ELISABETH GLOWATZKI

THE JOURNAL OF PHYSIOLOGY

Año: 2005 vol. 566 p. 49 - 59

0022-3751

Cholinergic brainstem neurones make inhibitory synapses on outer hair cells (OHCs) in the mature mammalian cochlea and on inner hair cells (IHCs) prior to the onset of hearing.We used electrical stimulation inanexcisedorgan ofCortipreparation toexamineevokedrelease of acetylcholine (ACh) onto neonatal IHCs fromthese efferent fibres.Whole-cell voltage-clamp recording revealed that low frequency (0.25–1 Hz) electrical stimulation produced evoked inhibitory postsynaptic currents (IPSCs) at a relatively highfraction of failures (65%) andwithmeanamplitudes of about −20 pA at −90 mV, corresponding to a quantum content of ∼1. Evoked IPSCs had biphasic waveforms at −60 mV, were blocked reversibly by α-bungarotoxin and strychnine and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. biphasic waveforms at −60 mV, were blocked reversibly by α-bungarotoxin and strychnine and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. biphasic waveforms at −60 mV, were blocked reversibly by α-bungarotoxin and strychnine and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. and are most likely mediated by the α9/α10 acetylcholine receptor, with subsequent activation of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−100 pAduetofacilitationandsummation throughout the train.Repetitive efferent stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. stimulation at 5 Hz or higher hyperpolarized IHCs by 5–10 mV and could completely prevent the generation of calcium action potentials normally evoked by depolarizing current injection. of calcium-dependent potassium (SK2) channels. Paired pulse stimulation with intervals of 10–100 mscaused facilitation of 200–300% in the mean IPSC amplitude.Atrain of 10 pulseswith an interpulse interval of 25 ms produced increasingly larger IPSCs with maximum amplitudes greater than−