Title : Calcium dependence of exocytosis and endocytosis at the cochlear inner hair cell afferent synapse - Beutner_2001_Neuron_29_681 |
Author(s) : Beutner D , Voets T , Neher E , Moser T |
Ref : Neuron , 29 :681 , 2001 |
Abstract :
Release of neurotransmitter at the inner hair cell (IHC) afferent synapse is a fundamental step in translating sound into auditory nerve excitation. To study the Ca2+ dependence of the underlying vesicle fusion and subsequent endocytosis, we combined Ca2+ uncaging with membrane capacitance measurements in mouse IHCs. Rapid elevations in [Ca2+]i above 8 microM caused a biphasic capacitance increase corresponding to the fusion of approximately 40,000 vesicles. The kinetics of exocytosis displayed a fifth-order Ca2+ dependence reaching maximal rates of >3 x 10(7) vesicle/s. Exocytosis was always followed by slow, compensatory endocytosis (tau congruent with 15 s). Higher [Ca2+]i increased the contribution of a faster mode of endocytosis with a Ca2+ independent time constant of approximately 300 ms. These properties provide for rapid and sustained transmitter release from this large presynaptic terminal. |
PubMedSearch : Beutner_2001_Neuron_29_681 |
PubMedID: 11301027 |
Beutner D, Voets T, Neher E, Moser T (2001)
Calcium dependence of exocytosis and endocytosis at the cochlear inner hair cell afferent synapse
Neuron
29 :681
Beutner D, Voets T, Neher E, Moser T (2001)
Neuron
29 :681