Tuning of synapse number, structure and function in the cochlea
Publikation: Beitrag in Fachzeitschrift › Forschungsartikel › Beigetragen › Begutachtung
Beitragende
Abstract
Cochlear inner hair cells (IHCs) transmit acoustic information to spiral ganglion neurons through ribbon synapses. Here we have used morphological and physiological techniques to ask whether synaptic mechanisms differ along the tonotopic axis and within IHCs in the mouse cochlea. We show that the number of ribbon synapses per IHC peaks where the cochlea is most sensitive to sound. Exocytosis, measured as membrane capacitance changes, scaled with synapse number when comparing apical and midcochlear IHCs. Synapses were distributed in the subnuclear portion of IHCs. High-resolution imaging of IHC synapses provided insights into presynaptic Ca(2+) channel clusters and Ca(2+) signals, synaptic ribbons and postsynaptic glutamate receptor clusters and revealed subtle differences in their average properties along the tonotopic axis. However, we observed substantial variability for presynaptic Ca(2+) signals, even within individual IHCs, providing a candidate presynaptic mechanism for the divergent dynamics of spiral ganglion neuron spiking.
Details
Originalsprache | Englisch |
---|---|
Seiten (von - bis) | 444-53 |
Seitenumfang | 10 |
Fachzeitschrift | Nature neuroscience |
Jahrgang | 12 |
Ausgabenummer | 4 |
Publikationsstatus | Veröffentlicht - Apr. 2009 |
Peer-Review-Status | Ja |
Extern publiziert | Ja |
Externe IDs
Scopus | 63649100112 |
---|
Schlagworte
Schlagwörter
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology, Acoustic Stimulation/methods, Alcohol Oxidoreductases, Animals, Animals, Newborn, Calbindins, Calcium/metabolism, Calcium Channel Agonists/pharmacology, Calcium Channels, L-Type/metabolism, Calcium Signaling/drug effects, Co-Repressor Proteins, Cochlea/cytology, DNA-Binding Proteins/metabolism, Evoked Potentials, Auditory, Brain Stem/physiology, Exocytosis/drug effects, Gerbillinae, Hair Cells, Auditory, Inner/physiology, Membrane Microdomains/drug effects, Membrane Potentials/drug effects, Mice, Mice, Inbred C57BL, Microscopy, Electron, Transmission, Patch-Clamp Techniques, Phosphoproteins/metabolism, Psychoacoustics, Receptors, AMPA/metabolism, S100 Calcium Binding Protein G/metabolism, Synapses/physiology, Time Factors