Direction-Selective Dendritic Action Potentials in Rabbit Retina

Dendritic spikes that propagate toward the soma are well documented, but their physiological role remains uncertain. Our in vitro patch-clamp recordings and two-photon calcium imaging show that direction-selective retinal ganglion cells (DSGCs) utilize orthograde dendritic spikes during physiologica...

Full description

Saved in:
Bibliographic Details
Published in:Neuron (Cambridge, Mass.) Mass.), 2005-09, Vol.47 (5), p.739-750
Main Authors: Oesch, Nicholas, Euler, Thomas, Taylor, W. Rowland
Format: Article
Language:English
Subjects:
Action Potentials - physiology
Anesthetics, Local - pharmacology
Animals
Calcium - metabolism
Dendrites - physiology
Diagnostic Imaging
Electrophysiology
In Vitro Techniques
Light
Motion Perception - physiology
Orientation - physiology
Patch-Clamp Techniques
Photic Stimulation
Rabbits
Retina - physiology
Retinal Ganglion Cells - physiology
Rodents
Tetrodotoxin - pharmacology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Dendritic spikes that propagate toward the soma are well documented, but their physiological role remains uncertain. Our in vitro patch-clamp recordings and two-photon calcium imaging show that direction-selective retinal ganglion cells (DSGCs) utilize orthograde dendritic spikes during physiological activity. DSGCs signal the direction of image motion. Excitatory subthreshold postsynaptic potentials are observed in DSGCs for motion in all directions and provide a weakly tuned directional signal. However, spikes are generated over only a narrow range of motion angles, indicating that spike generation greatly enhances directional tuning. Our results indicate that spikes are initiated at multiple sites within the dendritic arbors of DSGCs and that each dendritic spike initiates a somatic spike. We propose that dendritic spike failure, produced by local inhibitory inputs, might be a critical factor that enhances directional tuning of somatic spikes.
ISSN:0896-6273
1097-4199
DOI:10.1016/j.neuron.2005.06.036