Mechanism of High-Frequency Signaling at a Depressing Ribbon Synapse
| Autor: | Adam C. Light, Chad P. Grabner, Charles P. Ratliff, Steven H. DeVries |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Retinal Bipolar Cells AMPA receptor Neurotransmission Ribbon synapse Biology Synaptic Transmission Retinal Cone Photoreceptor Cells Exocytosis Retina Article Synapse 03 medical and health sciences 0302 clinical medicine Postsynaptic potential Animals General Neuroscience Excitatory Postsynaptic Potentials Electric Stimulation 030104 developmental biology Synapses Biophysics Excitatory postsynaptic potential Calcium sense organs Neuroscience 030217 neurology & neurosurgery Signal Transduction |
| Zdroj: | Neuron |
| ISSN: | 0896-6273 |
| DOI: | 10.1016/j.neuron.2016.05.019 |
| Popis: | Ribbon synapses mediate continuous release in neurons that have graded voltage responses. While mammalian retinas can signal visual flicker at 80-100 Hz, the time constant, tau, for the refilling of a depleted vesicle release pool at cone photoreceptor ribbons is 0.7-1.1 s. Due to this prolonged depression, the mechanism for encoding high temporal frequencies is unclear. To determine the mechanism of high-frequency signaling, we focused on an "Off" cone bipolar cell type in the ground squirrel, the cb2, whose transient postsynaptic responses recovered following presynaptic depletion with a tau of similar to 0.1 s, or 7- to 10-fold faster than the tau for presynaptic pool refilling. The difference in recovery time course is caused by AMPA receptor saturation, where partial refilling of the presynaptic pool is sufficient for a full postsynaptic response. By limiting the dynamic range of the synapse, receptor saturation counteracts ribbon depression to produce rapid recovery and facilitate high-frequency signaling. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|