Related Experiment Video
Updated: Sep 6, 2026
Postsynaptic Recordings at Afferent Dendrites Contacting Cochlear Inner Hair Cells: Monitoring Multivesicular Release at a Ribbon Synapse
Published on: February 10, 2011
Neurotrophin-3 modifies potassium currents in isolated inner hair cells from guinea-pig cochlea
Takashi Kimitsuki1, Takahiro Nakashima, Hirokazu Kawano
1Department of Otorhinolaryngology, Miyazaki Medical College, 5200 Kihara, Kiyotake-cho, Japan. kimituki@fc.miyazaki-med.ac.jp
Objective:
Neurotrophins elicited short-term glutamate release from the presynaptic locus. The aim of this study was to investigate short-term effects of neurotrophin-3 (NT-3) on the membrane current of inner hair cells (IHCs).
Methods:
IHCs were isolated from the guinea-pig cochlea. Membrane currents were measured by conventional whole-cell voltage-clamp recordings. NT-3 was dissolved in a standard external solution and applied to the IHCs under pressure using pipettes.
Results:
Six out of eight IHCs demonstrated a suppression of K currents by extracellular application of NT-3. At +60 mV, the amplitudes of the outward current in the control and NT-3 solutions were 5.6+/-1.3 and 4.2+/-1.0 nA, respectively. NT-3 suppression was voltage-independent. One cell showed an immediate suppression with NT-3 and the following potentiation during washing with standard saline.
Conclusion:
NT-3 suppressed the amplitude of K current on IHCs, suggesting that neurotrophins are capable of potentiating the hair cells' excitability. Neurotrophins may have a therapeutic value in the prevention and treatment of hearing impairment caused by inner ear damage.
