Send to

Choose Destination
J Neurosci. 2014 Apr 30;34(18):6233-44. doi: 10.1523/JNEUROSCI.5324-13.2014.

Global Ca2+ signaling drives ribbon-independent synaptic transmission at rod bipolar cell synapses.

Author information

Departments of Cellular and Molecular Physiology and Ophthalmology and Visual Science, Yale University, New Haven, Connecticut 06520, Department of Biology, University of Maryland, College Park, Maryland 20742, and Circuit Dynamics and Connectivity Unit, National Institutes of Health (NIH)/National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, Maryland 20892.


Ribbon-type presynaptic active zones are a hallmark of excitatory retinal synapses, and the ribbon organelle is thought to serve as the organizing point of the presynaptic active zone. Imaging of exocytosis from isolated retinal neurons, however, has revealed ectopic release (i.e., release away from ribbons) in significant quantities. Here, we demonstrate in an in vitro mouse retinal slice preparation that ribbon-independent release from rod bipolar cells activates postsynaptic AMPARs on AII amacrine cells. This form of release appears to draw on a unique, ribbon-independent, vesicle pool. Experimental, anatomical, and computational analyses indicate that it is elicited by a significant, global elevation of intraterminal [Ca(2+)] arising following local buffer saturation. Our observations support the conclusion that ribbon-independent release provides a read-out of the average behavior of all of the active zones in a rod bipolar cell's terminal.


exocytosis; retina; ribbon; vesicle

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center