Modeling normal and rebound excitation in mammalian retinal ganglion cells

2012 ◽  
Author(s):  
Tianruo Guo ◽  
D. Tsai ◽  
G. J. Suaning ◽  
N. H. Lovell ◽  
S. Dokos
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Rebound Excitation

Mechanism underlying rebound excitation in retinal ganglion cells

2007 ◽  
Vol 24 (5) ◽  
pp. 709-731 ◽  
Author(s):  
PRATIP MITRA ◽  
ROBERT F. MILLER
Keyword(s):  
Calcium Channels ◽  
Retinal Ganglion Cells ◽  
Low Voltage ◽  
Ganglion Cells ◽  
Resting Membrane Potential ◽  
Retinal Ganglion ◽  
Action Potential Firing ◽  
Potential Firing ◽  
Sufficient Magnitude ◽  
Rebound Excitation

Retinal ganglion cells (RGCs) display the phenomenon of rebound excitation, which is observed as rebound sodium action potential firing initiated at the termination of a sustained hyperpolarization below the resting membrane potential (RMP). Rebound impulse firing, in contrast to corresponding firing elicited from rest, displayed a lower net voltage threshold, shorter latency and was invariably observed as a phasic burst-like doublet of spikes. The preceding hyperpolarization leads to the recruitment of a Tetrodotoxin-insensitive depolarizing voltage overshoot, termed as the net depolarizing overshoot (NDO). Based on pharmacological sensitivities, we provide evidence that the NDO is composed of two independent but interacting components, including (1) a regenerative low threshold calcium spike (LTCS) and (2) a non-regenerative overshoot (NRO). Using voltage and current clamp recordings, we demonstrate that amphibian RGCs possess the hyperpolarization activated mixed cation channels/current,Ih, and low voltage activated (LVA) calcium channels, which underlie the generation of the NRO and LTCS respectively. At the RMP, theIhchannels are closed and the LVA calcium channels are inactivated. A hyperpolarization of sufficient magnitude and duration activatesIhand removes the inactivation of the LVA calcium channels. On termination of the hyperpolarizing influence,Ihadds an immediate depolarizing influence that boosts the generation of the LTCS. The concerted action of both conductances results in a larger amplitude and shorter latency NDO than either mechanism could achieve on its own. The NDO boosts the generation of conventional sodium spikes which are triggered on its upstroke and crest, thus eliciting rebound excitation.

scholarly journals Brightness change is optimal stimulus for parasol retinal ganglion cells

2021 ◽  
Author(s):  
Artem Pinchuk
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Smooth Transition ◽  
Linear Filter ◽  
Retinal Ganglion ◽  
Spike Response ◽  
Brightness Change ◽  
Temporal Properties ◽  
Two Sides ◽  
Rebound Excitation

Abstract Magnocellular-projecting retinal ganglion cells show spike response in two cases. Firstly, as a result of presentation of the optimal stimulus. Secondly, rebound excitation when removing the opposite stimulus. Also, there are studies suggesting that rebound excitation meets conditions to participate in visual perception at the same sensitivity and reaction speed as a response to the optimal stimulus. Thus, white noise stimulation creates possibility to catch the form of a smooth transition from one type of response to another. Using freely available data, a spike-triggered behavior map was built that does not show the area of silence between those two types of spike triggers. Moreover, linear filter with biphasic temporal properties which work as the derivative kernel demonstrate that both responses are two sides of the same coin. Thus, it is suggested to determine the optimal stimulus for magnocellular-projecting retinal ganglion cells as brightness change according to concentric center–surround receptive field structure.

Calcium Signals Induced By Tonic Firing In Rat Retinal Ganglion Cells

2012 ◽  
Vol 3 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Kyril I. Kuznetsov ◽  
Vitaliy Yu. Maslov ◽  
Svetlana A. Fedulova ◽  
Nikolai S. Veselovsky
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Calcium Signals ◽  
Tonic Firing
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