Synaptic plasticity can produce and enhance direction selectivity (Carver et al, 2008)

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Accession:116901
" ... We propose a parsimonious model of motion processing that generates direction selective responses using short-term synaptic depression and can reproduce salient features of direction selectivity found in a population of neurons in the midbrain of the weakly electric fish Eigenmannia virescens. The model achieves direction selectivity with an elementary Reichardt motion detector: information from spatially separated receptive fields converges onto a neuron via dynamically different pathways. In the model, these differences arise from convergence of information through distinct synapses that either exhibit or do not exhibit short-term synaptic depression—short-term depression produces phase-advances relative to nondepressing synapses. ..."
Reference:
1 . Carver S, Roth E, Cowan NJ, Fortune ES (2008) Synaptic plasticity can produce and enhance direction selectivity. PLoS Comput Biol 4:e32 [PubMed]
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Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism:
Cell Type(s): Electric fish midbrain torus semicircularis neuron;
Channel(s):
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: MATLAB;
Model Concept(s): Oscillations; Depression; Direction Selectivity; Synaptic Convergence;
Implementer(s): Carver, Sean [sean.carver at jhu.edu];
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carver
stimuli
Igamma.m
Igrey.m
Ipreinitseq.m
Isequence.m
Isine.m
                            
function I = Igrey(varargin) 
% IGREY Returns a constant intensity as a function of time and space 
%
% I = IGREY(x,t,greyvalue) returns intensity I(x,t) = greyvalue
%     More precisely, returns I = greyvalue*ones(length(x),length(t)) 
%     By convention, greyvalue = 0 is 50% grey.
%
% PERIOD = IGREY() returns 0, the period of the stimulus (i.e. constant)
%          The PERIOD function was used in our implementation of 
%          the original Chance model to save memory (so that the intensity 
%          of only one cycle of the need be handled). 
%          It is not used for the present model.
%
% STRING = IGREY() returns string '{''greyvalue''}';
%
% Code written by SEAN CARVER, last modified 12-5-2007

if nargin==0
  I = '{greyvalue}';
elseif nargin < 2 
  I = 0; 
else
  x = varargin{1};
  t = varargin{2};
  greyvalue = varargin{3};
  I = greyvalue*ones(length(x),length(t)); 
end